Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
hepatomegaly and elevated liver enzyme levels in type 1 diabetes mellitus ( dm ) patients can be caused by hepatic glycogenosis , viral hepatitis , autoimmune hepatitis , or metabolic liver diseases .
mauriac syndrome is a rare complication of type 1 dm that is characterized by hepatomegaly due to hepatic glycogenosis , growth retardation , delayed development of puberty , and cushingoid features .
it is caused by abnormal hormone secretion and metabolic abnormalities because of inappropriate glycemic control1 ) .
if the insulin dosage is insufficient to control hyperglycemia , it can stimulate hepatic glycogenosis and fatty acid synthesis , resulting in inhibition of glycogenolysis and hepatomegaly .
hepatic glycogenosis in type 1 dm patients is a reversible complication by strict blood glucose level control , which is different from nonalcoholic steatohepatitis ( nash ) in obese type 2 dm .
thus far , eight cases of type 1 dm accompanied by hepatic glycogenosis and three cases of mauriac syndrome have been reported in korea234 ) .
we report a case of hepatic glycogenosis mimicking mauriac syndrome in a patient with poorly controlled type 1 dm who showed hepatomegaly , cushingoid face , mild growth retardation , and delayed menarche .
a 14-year - old girl was admitted to the catholic university of korea , seoul st .
total daily insulin dosage was 12 iu ( 0.26 iu / kg / day ) .
she had previously been admitted seven times because of diabetic ketoacidosis in the previous 2 years . at the time of admission , the patient had clear consciousness , with the following vital signs : blood pressure , 90/60 mmhg ; pulse , 118/min ; and body temperature , 36.5. the height of the patient was 155 cm , and her weight was 46 kg , which were in the 25th and 50th percentiles , respectively .
growth velocity decreased to 3.3 cm / yr in the past 2 years ( fig .
the patient presented with tanner stage iv breast and tanner stage iii pubic hair ; however , the patient did not experienced menarche .
bone age was delayed by 2 years compared to her chronological age . upon physical examination
blood test results revealed the following values : white blood cells , 4,840/mm ( 47.5% neutrophils and 42.6% lymphocytes ) ; hemoglobin , 13.4 g / dl ; platelets , 218,000/mm ; aspartate aminotransferase ( ast ) , 1,408 iu / l ; and alanine aminotransferase ( alt ) , 459 iu / l ; gamma glutamyltransferase , 430 iu / l ; and amylase , 115 iu / l . the glycosylated hemoglobin ( hba1c ) level was 14.3% , and ketone was not detected in urine . to rule out viral hepatitis ,
we performed serologic tests for hepatitis a , b , and c ; epstein - barr virus ; and cytomegalovirus infections , and obtained negative results .
furthermore , the results of autoimmune hepatitis , including antinuclear antibody , antismooth muscle antibody , and antiliver kidney microsome antibody , were all negative .
thyroid function was normal and the following hormone levels were presented : insulin - like growth factor-1 ( igf-1 ) , 203 ng / ml ; luteinizing hormone ( lh ) , 4.47 miu / ml ; follicle - stimulating hormone ( fsh ) , 4.77 miu / ml ; and estradiol ( e2 ) , 35.44 pg / ml . the plasma cortisol level was 5.73 g / dl and the adrenocorticotropic hormone level was 17.14 pg / ml at 8:00 am .
3 ) . through a liver biopsy , we found ballooning degeneration with nuclear vacuolization of hepatocytes ( fig .
hepatocytes were strongly positive in a periodic acid - schiff ( pas ) stain ( fig .
4b ) , and such positive finding disappeared with diastase ( d - pas ) ( fig .
the insulin dosage was gradually increased over 3 months ; thus , the total daily insulin dosage became 36 iu ( 0.65 iu / kg / day ) .
to prevent hypoglycemia , we prescribed 60 g ( 1.3 g / kg ) of uncooked cornstarch between meals and bedtime . after implementing strict glycemic control , hepatomegaly was improved and elevated transaminase levels returned to normal ranges .
moreover , the patient manifested menarche at the age of 15.3 years and a regular menstruation cycle thereafter .
hepatic glycogenosis in type 1 dm is a key mechanism of mauriac syndrome and is a rare diabetic complication first reported by mauriac in 19305 ) .
hepatic glycogenosis can be caused by either a persistent hyperglycemia due to insulin deficiency or conversion of excess glucose administered to control hypoglycemia due to excessive insulin administration . with regard to the latter mechanism ,
furthermore , the secretion of the antagonistic hormone cortisol increases in type 1 dm patients with poor glycemic control . such excess cortisol inhibits hepatic glycogenolysis and increases fatty acid synthesis in the liver , causing hepatomegaly .
moreover , hypercortisolism can result in cushingoid features and delay in bone maturation , which in turn leads to delayed growth and puberty1 ) .
growth retardation and delayed puberty with hepatic glycogenosis in uncontrolled type 1 dm patients are distinct characteristics of mauriac syndrome . in patients with mauriac syndrome , circulating igf-1 levels are normal or reduced despite normal hypothalamic - pituitary functions .
patients with mauriac syndrome also exhibit resistance to growth hormones , which is caused by a decrease in igf-1 bioactivity , igf-1 receptor defects , and circulating igf-1 inhibitors9101112 ) .
delayed puberty can manifest as a result of insulin deficiency , hyperglycemia itself , or decreased lh and fsh secretion caused by the gonadotropin - releasing hormone due to stress hormone secretion after poor glycemic control .
insulin administered to the subcutaneous tissue bypasses the hepatic first - pass metabolism and is absorbed directly via systemic circulation .
then , the insulin binds with the receptor at the ovary to excessively stimulate the ovary , thereby increasing androgen secretion .
if peripheral insulin resistance increases because of hyperglycemia , polycystic ovary syndrome can occur , causing ovarian failure and amenorrhea1314 ) .
although growth retardation and delayed puberty were not prominent in our patient , the patient exhibited very similar clinical manifestations of mauriac syndrome .
the reason that the signs of growth retardation and delayed puberty were mild in our patient was probably because hepatic glycogenosis occurred in the late stage of pubertal development , thereby only minimally affecting the patient 's growth and puberty . as we did not measure 24-hour urinary free cortisol levels and the 8:00 am .
if the symptoms of mauriac syndrome recur , a detailed evaluation of hypercortisolism will be necessary
. treatments of hepatic glycogenosis in type 1 dm include strict glycemic control through appropriate diet and insulin dosage .
although regular diet and sufficient insulin dosage are important in controlling hyperglycemia , determining the appropriate insulin dosage is difficult when hyperglycemia is accompanied by frequent hypoglycemia , as in the case of our patient .
as glycogenolysis does not properly occur even with hypoglycemia in the patient with hepatic glycogenosis , additional glucose supply is necessary .
however , the glycemic effects of conventional snacks only manifest 2 hours after consumption . moreover , as the glycemic effect inevitably decreases with time , hypoglycemia can recur .
consequently , consuming uncooked cornstarch to induce delayed glycemic effects facilitates the prevention of hypoglycemia15 ) .
hepatic glycogenosis does not occur in all patients with type 1 dm who have poor glycemic control .
although the risk factors of hepatic glycogenosis are not yet known , we postulate that wide fluctuations of blood glucose levels and a long period of poor glycemic control increase the risk of hepatic glycogenosis .
however , hepatic glycogenosis in type 1 dm is a reversible complication that is different from nash , which is often presented in obese type 2 dm patients .
therefore , appropriate glycemic control is important to the treatment and prevention of hepatic glycogenosis in type 1 dm .

Answer:
hepatic glycogenosis in type 1 diabetes mellitus ( dm ) can be caused by poor glycemic control due to insulin deficiency , excessive insulin treatment for diabetic ketoacidosis , or excessive glucose administration to control hypoglycemia .
 mauriac syndrome , which is characterized by hepatomegaly due to hepatic glycogenosis , growth retardation , delayed puberty , and cushingoid features , is a rare diabetic complication .
 we report a case of hepatic glycogenosis mimicking mauriac syndrome . a 14-year - old girl with poorly controlled type 1 dm
 was admitted to the catholic university of korea , seoul st .
 mary 's hospital for abdominal pain and distension .
 physical examination revealed hepatomegaly and a cushingoid face .
 the growth rate of the patient had decreased , and she had not yet experienced menarche .
 laboratory findings revealed elevated liver enzyme levels .
 a liver biopsy confirmed hepatic glycogenosis .
 continuous glucose monitoring showed hyperglycemia after meals and frequent hypoglycemia before meals . to control hyperglycemia , we increased insulin dosage by using an insulin pump .
 in addition , we prescribed uncooked cornstarch to prevent hypoglycemia .
 after strict blood glucose control , the patient 's liver functions and size normalized .
 the patient subsequently underwent menarche .
 hepatic glycogenosis is a complication of type 1 dm that is reversible with appropriate glycemic control .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
the anterior cruciate ligament ( acl ) is the most frequently injured knee ligament , and
 accounts for about 50% of all ligament injuries1 .
acl injury is a common cause of knee instability and alters the
 kinematics of the knee2 .
most are caused by non - contact injury
 mechanisms , such as landing from a jump , or rapid deceleration3 .
an acl injury typically occurs during the landing portion of a jump
 in ordinary sports activities and has a greater incidence among women than among men4 .
patients with acl injury often have symptoms of knee
 instability , which may lead to functional change in and damage to other joint structures ,
 and interfere with activities of daily living5 .
patients with acl injuries have difficulty recovering normal
 walking ability and full function of the lower limbs6 .
knee instability following acl injury results in various negative factors , which can be
 circumvented using acl reconstruction .
reconstructive techniques have been refined to
 achieve better stabilization of the knee and other joints in order to improve functional
 recovery7 .
it has been suggested that
 the lack of full recovery of knee function after acl reconstruction is due to sensory and
 motor behavior deficits .
muscle strength , endurance , flexibility and balance training are
 used as therapeutic exercises in rehabilitation settings .
proprioceptive afferent neural
 input is also important in functional control during sports activities8 . in the clinic ,
patients are always asked to walk normally ,
 but few exercise methods provide normal proprioceptive input during walking training . in recent years ,
robot - assisted therapy ( rat ) rehabilitation , which simulates normal
 walking , has also been used to help patients with spinal cord injury or stroke9 .
the major difference between robot - assisted weight - supported treadmill training and
 existing supported ambulation training is the addition of a mechanical assistant in the rat ,
 so that alternative steps with both feet can be achieved by patients10 .
moreover , simulation of a normal walking pattern
 facilitates input from the peripheral nerves . in this manner ,
the remaining central nervous
 system can be stimulated so that regeneration of the nerves involved in traumatic spinal
 cord injury can be completed .
recent studies have shown that this method is associated with
 significant improvements in reaction time and bowel function11 , 12 .
the aim of this study was to examine the long - term interventions effects of rat
 rehabilitation on functional activity levels after acl reconstruction .
this study recruited 8 patients who underwent arthroscopic acl reconstruction in boai
 hospitals in beijing , china , between september and december 2015 .
patients performed
 rehabilitation exercises for at least 2 months at the department of physical therapy .
the
 subjects were limited to patients who had undergone acl reconstruction with autografts ,
 performed by the same surgeon , and showed no differences in anatomical stability based on
 radiographic and magnetic resonance imaging .
the characteristics of the 8 subjects ( 6 males and 2 females ) are shown in table 1table 1.subject characteristicsmean  sd ( n=8)age ( yrs)35.2  3.2height ( cm)173.4  8.6weight ( kg)79.5  16.8 . the subjects participated in rat for one month .
the purpose and content of
 this research were explained to the subjects , who gave their informed consent to
 participation in this study .
the study was approved by the research ethics committee of
 china rehabilitation research center ( irb no .
was carried out as traditional
 physiotherapy , which included the muscle strength training , joint mobilization , balance
 training , and endurance training .
the walking training used a rehabilitation training robot
 ( mbz - cpm1 , manbuzhe [ tian jin ] rehabilitation equipment co. , ltd . , china ) . in the treadmill
 and rat training ,
the initial training speed was 1.5  km / h , which was progressively increased
 to 1.8  km / h as quickly as possible while maintaining gait quality13 .
the body weight system was initiated at 35% , and 70%
 guidance force was provided for the participants14 .
the walking training lasted for 20  min a day , and was performed 5
 times a week .
the extension strength of the knee joint , and walking and balance abilities
 were measured before and after the one - month intervention .
walking ability was evaluated using the 10-meter walk test ( 10mwt ) and the timed up - and - go
 ( tug ) test .
balance ability was assessed using the functional reach test ( frt ) . for the
 assessment of knee extension strength , surface electromyography
( semg ) and the maximal
 extensor strength of the knee joint were measured with the subjects seated and the knee
 flexed at 45. in the semg evaluation of the vastus lateralis ( vl ) and vastus medialis ( vm ) muscles ,
 maximum isometric contraction in the start position was maintained for 5  s , during which the
 maximum and average semg values of the muscle were measured by an semg system ( telemyo
 2400 t ; noraxon , scottsdale , az , usa ) .
the maximum and average extensor strengths of
 isokinetic movement of the knee joint were measured using an isokinetic dynamometer ( prima
 plus , easytech , italy ) .
the
 wilcoxon test was used to compare the 10 mwt , tug , frt , the maximum and average semg values
 of vl and vm , and the maximum and average extensor strengths of the knee joint isokinetic
 movement before and after the one - month intervention .
all the subjects in this study received rat training 20 times over one month . the results
 of the 8 subjects
are shown in table
 2table 2.the long - term interventions effects of rat10mwt ( s)tug test ( s)frt ( cm)maximum semg value of lateralis(v)average semg value of lateralis(v)maximum semg value of medialis ( v)average semg value of medialis ( v)maximum extensor strength ( nm)average extensor strength ( nm)before one month rat intervention8.8  1.1 * 10.0  0.819.3  5.1**1,872.2  966.0280.3  131.11,405  676.5189.5  60.3 * 41.0  22.3 * 37.0  21.7**after one month rat intervention7.3  0.3 * 9.5
1.626.5  4.8**1,915.7  827.4315.0  113.51,590  261.7230.3  67.2 * 52.3  24.1 * 47.7  22.5***p<0.05 ; * * p<0.01 .
10mwt : 10-meter walk test ; tug : timed up - and - go ; frt : functional reach test ; rat :
 robot - assisted therapy .
10mwt : 10-meter walk test ; tug : timed up - and - go ; frt : functional reach test ; rat :
 robot - assisted therapy the average semg value of vm , frt , and the maximum and average extensor strengths of the
 knee joint isokinetic movement increased significantly .
however , the changes the maximum and average semg values of vl , the maximum
 semg values of vm and tug were not significant .
according to the results , the walking ability , balance ability and the extensor strength of
 the knee joint were improved by the rat treatment , and the average semg value of the vastus
 medialis muscle significantly increased .
the reason for these results is that robotic walking training enabled the bilateral lower
 limbs to perform alternative and circulatory movements , which can effectively adjust lower
 limb movement after acl reconstruction . in this manner , walking ability can also be
 improved .
there was no significant change in the semg value of the vastus lateralis , presumably
 because weakness of knee joint muscle is often observed in the vastus medialis , which is the
 first muscle to show weakness among the quadriceps muscles15 .
many studies have attempted to suggest the best angular velocity
 during isokinetic exercise to selectively strengthen the vastus medialis16 .
however , compared to the vastus
 lateralis , the vastus medialis was clearly enhanced by rat training .
these results suggest that walking ability and muscle strength can be improved by robotic
 walking training as a long - term intervention .
future studies with a control group and more
 subjects are needed to investigate the effects of different walking models using rat after
 long - term intervention for patients with acl reconstruction .

Answer:
[ purpose ] the aim of this study was to examine the long - term interventions effects of
 robot - assisted therapy rehabilitation on functional activity levels after anterior
 cruciate ligament reconstruction . [ subjects and methods ] the subjects were 8 patients ( 6
 males and 2 females ) who received anterior cruciate ligament reconstruction . the subjects
 participated in robot - assisted therapy lasting for one month .
 the timed up - and - go test ,
 10-meter walk test , functional reach test , surface electromyography of the vastus
 lateralis and vastus medialis , and extensor strength of isokinetic movement of the knee
 joint were evaluated before and after the intervention .
 [ results ] the average value of the
 of vastus medialis emg , functional reach test , and the maximum and average extensor
 strength of the knee joint isokinetic movement increased significantly , and the time of
 the 10-meter walk test decreased significantly .
 [ conclusion ] these results suggest that
 walking ability and muscle strength can be improved by robotic walking training as a
 long - term intervention .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
computers now play an increasingly important role in our daily lives , and their use is
 associated with lower back pain .
the sacroiliac joint ( sij ) is a widely described source of
 low back pain .
therapeutic approaches to relieve this pain include the application of a
 pelvic compression belt ( pcb)1 .

researchers have suggested that functional exercises conducted using a pcb have a beneficial
 effect associated with muscle strengthening2 .
pcb are effective for stabilizing pelvic articulation and enable
 exercises that address coordination and stabilization3 .
furthermore , evidence shows that application of a pcb can relieve
 pain and facilitate neuromuscular performance during rehabilitation exercises in patients
 with lumbopelvic problems4 .
in particular ,
 pcbs effectively alter the activation patterns of hip extensor muscles in females with
 chronic low back pain during prone hip extension5 .
moreover , pcbs offer a conservative measure for the treatment of
 sacroiliac joint pain and are cheap and considered to be without any adverse side
 effects6 .
in addition , it has been shown
 that use of a pcb significantly improves health - related quality of life and possibly
 decreases sacroiliac joint - related pain6 .

hammer et al.7 suggested that pcb
 application is accompanied by altered rectus femoris activity when walking .
furthermore , pcb
 improve postural steadiness7 . however , it
 is unknown whether pcb alter trunk and lower - extremity muscle activities in healthy adults .

therefore , the purpose of this study was to investigate the effects of a pcb on these muscle
 activities in normal healthy adults .
all
 were given comprehensive information on the study , and all provided written informed consent
 according to the ethical standards of the declaration of helsinki prior to participation and
 agreed to participate in the study ( table
 1table 1.pre- and post - intervention electromyography values of subjects wearing or not
 wearing a pelvic compression belt ( units : % mvic)without pelvic compression beltwith pelvic compression beltchange valueerector spinae*101.7  8.8 80.9  5.6 20.8  10.9oblique internus abdominis*107.8  20.4 87.0  12.420.8
11.7rectus femoris*93.7  15.977.8  8.0 15.8  17.7long head of the biceps femoris*94.7  17.383.6  11.0 11.1  13.2mean  sd .
their average ages , heights , and weights were 21.60  1.08  years , 171.20
 6.23  cm , and 71.23  8.64  kg , respectively .
significant intergroup difference between the gains achieved
 ( p<0.05 ) the pelvic compression belt ( the com - pressor , optp , minneapolis , mn , usa ) used was an
 adjustable body belt with four elastic compression bands that provide stabilizing pressure
 and was designed to allow the amount of compression to be adjusted at targeted compression
 sites . the pcb was placed below the anterior superior iliac spine ( asis)8 , and stabilizing pressure was applied using
 the elastic compression bands after confirming the location of the compression site .
four surface electromyography signals were processed
 through the mp150 system when subjects were in the bridge position and transformed into
 digital signals , which were filtered and processed using acqknowledge software ver .
3.7.3
 ( biopac systems inc . , goleta , ca , usa ) on a personal computer .
a 1,000  hz sampling rate was
 used for electromyography signals , and their amplified waveform was filtered using a
 60500  hz band - pass filter and a 60  hz of notch filter . for quantifying collected signals ,
 we used root mean square values9 . in
 addition , the signals collected from each muscle were normalized versus the maximal
 voluntary isometric contraction ( % mvic ) . to measure muscle activation at maximal voluntary isometric contraction ,
after collection of
 the data for 5 seconds at maximal voluntary isometric contraction for each muscle , the
 average electromyographic signals as a percentage of mvic for 3 of the 5 seconds , excluding
 the data for 1 second each from the beginning and end , were used .
muscle activation was measured using electromyogram electrodes fixed to areas of muscle
 fibers and by pressing on muscle parts and following the direction of muscle texture to find
 the appropriate positions .
the locations of the surface electrodes were as follows : ( 1 ) for the elector spinae , 2  cm
 lateral to the spinous process at the l45 interspace10 ; ( 2 ) for the oblique internus abdominis ( oi ) , in the center of the
 triangle formed by a horizontal line between the anterior superior iliac spine of the
 innominate and the umbilicus , midline , and the inguinal ligament11 ; ( 3 ) for the rectus femoris , the midpoint between the
 upper margin of the patella and asis12 ;
 and ( 4 ) for the long head of the biceps femoris , the midpoint between the gluteal fold and
 the knee joint13 .
intragroup comparisons of variables before and after the intervention were performed using
 the paired samples t - test .
ibm spss statistics ver . 20.0 ( ibm corp , armonk , ny , usa )
the subjects showed a significant decrease in muscle activation in the erector spinae ,
 oblique internus abdominis , rectus femoris , and biceps femoris while wearing the pcb
 ( p<0.05 ) ( table 1 ) .
this study was undertaken to determine how a pcb affects erector spinae ( es ) , oblique
 internus abdominis ( oi ) , rectus femoris ( rf ) , and long head of the biceps femoris ( bf )
 muscle activation in healthy adults . we observed reduced es , oi , rf , and bf activity with a
 pcb compared with without a pcb in the bridge position .
several possible explanations exist
 for less muscle activity in abdominal muscles than in core muscles while wearing the pcb .
 stabilizing the core is a dynamic process of maintaining balance .
kaushik et al.14 suggested that the transverse abdominis is
 the first muscle activated during lower extremity movements , indicating that it is a primary
 muscle linked to core stability during lower limb movements . in the present study ,
the
 decreased oi activity indicated that subjects required less effort to maintain stability
 when wearing the pcb .
nevertheless , kim et al.15 suggested that decreasing the activation of abdominal muscles on an
 unstable surface using an external support , such as a pcb , is suitable for improving
 abdominal muscle control and lumbopelvic stability . in a recent study by hu et al.16
, it was found that transverse and oblique
 abdominal muscles were less active with a pcb in normal subjects because these coordinated
 muscles are activated to press the ilia against the sacrum , creating a forced closure , and
 the pelvic belt may have substituted for this stabilizing activity .
therefore , it is thought
 that the use of a pcb with external pelvic compression might have improved pelvic joint
 stability and altered neuromotor control of the lumbopelvic and thigh muscles .
first , the small sample size may have adversely
 influenced certain variables and impacted results .
second , the compression force of the
 pelvic belt was not controlled , although the belt was adjusted by a skilled physical
 therapist .
furthermore , we recruited healthy adults without a history of low back pain or
 sacroiliac joint pain , and thus , our findings can not be generalized to other populations .
 finally , we measured emg activity of the trunk and lower extremity , but this is insufficient
 to represent muscle force directly .
further studies are needed to investigate a more diverse
 sample of normal healthy subjects .

Answer:
[ purpose ] the purpose of this study was to investigate the effects of a pelvic belt on
 the activities of trunk and lower extremity muscles in normal adults .
 [ subjects and
 methods ] the subjects were 20 normal individuals without a history of orthopedic problems .
 the pelvic compression belt ( the com - pressor , optp , minneapolis , mn , usa ) was an
 adjustable body belt with four elastic compression bands that provide stabilizing pressure
 and was designed to adjust the amount of force applied and to alter sites of compression .

 the body belt was placed below the anterior superior iliac spine , and stabilizing pressure
 was applied to the belt using the elastic compression bands in the bridge position after
 confirming the site of compression .
 [ results ] the subjects showed a significant decrease
 in muscle activation in the erector spinae , oblique internus abdominis , rectus femoris ,
 and biceps femoris while wearing the pelvic belt .
 [ conclusion ] the use of a pelvic
 compression belt with external pelvic compression might improve pelvic joint stability and
 alter neuromotor control of the lumbopelvic and thigh muscles .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
a young man was referred with a chief complaint of blurred vision and pain of the left eye 1 month after herpetic encephalitis in the left frontotemporal lobe .
the patient had multiple foci of retinitis in the retinal periphery associated with vitritis , blot retinal hemorrhage and retinal arteriolitis .
the impression of acute retinal necrosis was confirmed by polymerase chain reaction of aqueous humor by detecting herpes simplex virus type 2 ; therefore , the patient received intravenous acyclovir .
herpetic encephalitis may be a risk factor for acute retinal necrosis . the virus may reach the eye by the trans - axonal route .
acute retinal necrosis ( arn ) is one of the clinical presentations of herpes simplex virus ( hsv ) .
this disease may present several years after a primary infection , or it may occur following systemic herpetic infection such as herpetic dermatitis . the prevalence of the disease is equal in both sexes and it occurs in the 5th-7th decade of life .
american uveitis society criteria for the diagnosis of arn syndrome are : one or more foci of retinal necrosis with discrete borders located in the peripheral retina , rapid progression in the absence of antiviral therapy , circumferential spread , occlusive vasculopathy with arteriolar involvement , prominent vitritis , and anterior chamber inflammation .
optic neuropathy , scleritis , and pain are supportive but not required . in most patients , the diagnosis is made clinically .
polymerase chain reaction ( pcr ) analysis of the aqueous humor can detect the cause of arn specifically .
pcr is very helpful in the detection of the varicella zoster , hsv type 1 and 2 .
patients with arn due to hsv-1 and varicella zoster virus tend to be older , whereas those with arn due to hsv-2 tend to be younger [ 3 , 4 ] . in this article , we report one case of unilateral arn 1 month after the herpetic encephalitis .
the patient is a 25-year - old man who was admitted with a chief complaint of decreased vision and pain in left eye for the previous 4 days .
the patient also complained of perception of floating objects in the visual field of the left eye .
the patient had no past medical history indicating an immunocompromised state ; he had been admitted to the neurology ward due to herpetic encephalitis 1 month previous to the occurrence of visual symptoms .
herpetic encephalitis diagnosis was made by brain mri ( fig . 1 ) and pcr analysis of the cerebrospinal fluid .
he did not report any underlying disease or drug consumption except oral acyclovir 800 mg every 8 h. at physical examination , the right eye was normal . in the left eye ,
visual acuity was 0.1 , papillary reflex was normal and marcus gunn sign was negative .
slit lamp examination of the left eye revealed conjunctival hyperemia and ciliary injection , diffuse fine keratic precipitates in the corneal endothelium , 3 + cellular reaction in the anterior chamber , 3 + cellular reaction in the vitreous without snowball or snowbank opacities , or vitreous hemorrhage . in fundoscopic examination , multiple foci of retinitis and retinal necrosis
2 ) associated with arteriolar involvement ( arteriolitis ) , blot retinal hemorrhage and optic disc hyperemia .
pcr analysis of aqueous humor revealed hsv-2 , so the patient was admitted with the diagnosis of arn and received intravenous acyclovir for 10 days ( 10 mg / kg / day ) .
after 48 h of antiviral therapy , a systemic corticosteroid ( prednisolone 1 mg / kg / day ) was introduced and subsequently tapered over several weeks to treat active inflammation .
the patient also received aspirin to treat an associated hypercoagulable state . with this treatment , no new lesion developed and opacity of the media decreased ; so prophylactic barrier laser photocoagulation in the areas of healthy retina at the posterior borders of the necrotic lesion prevented retinal detachment .
intravitreal antiviral agents such as ganciclovir and foscarnet were not used in this patient because the disease was controlled by intravenous acyclovir .
after discharge from hospital , oral acyclovir 400 mg every 5 h was started . during follow - up ,
the inflammation decreased and the patient had no vitreous traction or retinal detachment or other eye involvement .
the brain and retinal involvement were on one side ; after 1 month of left frontotemporal lobe involvement of the brain , the retina was involved on the left side .
some of the studies report arn several years after neonatal and infantile herpetic encephalitis [ 5 , 6 ] ; therefore , herpetic encephalitis may be a risk factor for arn development .
other articles report that the virus accesses the retina from the brain by the trans - axonal route ; consequently , this virus can cause recurrent episodes of arn [ 8 , 9 ] . these reports may necessitate a prophylaxis with antiviral agents after herpetic encephalitis to prevent arn . in a study by pavsio et al . , the role of long - term prophylaxis with acyclovir in children who had herpetic encephalitis is an important issue .
prophylaxis could be considered after hsv encephalitis to prevent arn or after arn to prevent second eye involvement .
acyclovir used as prophylaxis for recurrent genital hsv infection in adults for 5 or more years has been associated with minimal toxicity and the selection of resistant strains has not been demonstrated , but there is little experience with the duration of prophylaxis that would have been necessary to prevent arn in our patient . with this report
we reemphasize the correlation between these two diseases . on the other hand , arn may be an indication of possible central nervous system involvement and neuroimaging may be necessary in all cases of arn to rule out herpetic encephalitis .

Answer:
purposeto report a case of unilateral acute retinal necrosis after herpetic encephalitiscase reporta young man was referred with a chief complaint of blurred vision and pain of the left eye 1 month after herpetic encephalitis in the left frontotemporal lobe .
 the patient had multiple foci of retinitis in the retinal periphery associated with vitritis , blot retinal hemorrhage and retinal arteriolitis .
 the impression of acute retinal necrosis was confirmed by polymerase chain reaction of aqueous humor by detecting herpes simplex virus type 2 ; therefore , the patient received intravenous acyclovir.conclusionherpetic encephalitis may be a risk factor for acute retinal necrosis .
 the virus may reach the eye by the trans - axonal route .
 prophylaxis with acyclovir may be necessary after herpetic encephalitis to prevent acute retinal necrosis .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
the treatment of patients with multiple trauma requires a different approach to that of patients with regular trauma because they are threatened not only by the injuries themselves , but also by the metabolic disruptions that follow.1 delay in surgery , blunt trauma , extensive soft tissue damage , and combined orthopedic and vascular injuries have been associated with an increased risk of amputation , while associated nerve and bone injuries with extensive soft tissue damage are risk factors for a poor outcome.2 acute renal failure is the main cause of death in patients with war wounds and trauma of the extremities
. it would be helpful to minimize mortality in these patients by managing shock in a timely manner and taking the decision to amputate appropriately and promptly.3 severe head injury is known to be a major determinant of mortality in patients with multiple injuries , but other injuries also contribute to the clinical outcome.4,5 different mechanisms of injury , such as motor vehicle crashes , falls , or pedestrians being struck by a motor vehicle , impart varying degrees of force and energy transfer that may impact outcomes ; this was found to predict mortality and functional impairment independently at hospital discharge.6 acute lower extremity compartment syndrome is a devastating complication that often presents silently in critically injured patients.7 patients who underwent delayed fasciotomy had twice the rate of major amputation and a three - fold higher mortality rate.8 the aim of this study was to evaluate if injuries of the extremities are associated with a higher one - month mortality rate than other types of associated trauma .
this prospective , observational , cohort study was carried out in the regional emergency center of hospital de base after prior approval by the ethics research committee of the so jos do rio preto medical school .
the emergency department follows a systematic pathway to provide initial assistance to accident victims using the atls ( advanced trauma life support ) protocol .
all live accident victims treated in the emergency department from july 2004 to june 2005 were included .
patients who were dead on arrival and not submitted to any type of inhospital resuscitation procedure were not included in the study .
accident victims were allocated to two groups , ie , those with severe injuries to the extremities or pelvis ( abbreviated injury scale [ ais ] 34 ) and those without injuries or with minor injuries to the extremities ( ais 02 ) .
the fisher s exact test and relative risk were used for statistical analysis , and an alpha error of 5% ( p  0.05 ) was considered statistically significant .
a total of 3489 patients were evaluated in this study ; 3244 ( 92.98% ) did not have severe trauma of the extremities ( ais 02 ) , 34 ( 1.05% ) of whom died .
severe injuries of the extremities ( ais 34 ) occurred in 245 ( 7.02% ) of the patients , with 13 ( 5.31% ) dying ( fisher s exact test : p = 0.001 , relative risk 5.063 , 95% confidence interval [ ci ] : 2.7079.467 , table 1 ) .
table 2 shows the age , type of injury sustained , and time until death after trauma for the patients who died .
of the 245 patients with ais 34 , 71 ( 28.98% ) were women and 174 ( 71.02% ) were men , with the mean age of the men being 40.1  20.5 years and of the women 60.2  23.6 years .
this study assessed whether severe injuries of the extremities affect the overall mortality rate in accident victims .
the death rate was found to be higher for patients with ais 34 than in those without injuries or with minor injuries to the limbs .
thus , these data serve as a warning in respect to increased risk of death in orthopedic patients compared with general trauma patients . when the severity of specific injuries in accident victims is reported in the literature ,
head trauma is cited as one of the main causes of death.5,6 however , there are few data in the literature about the association between death and injuries to the extremities .
one study reported that the mortality rate in accident victims with extremity injuries was higher in pedestrians struck by motor vehicles ( 20% ) , and for those with head injuries , it was higher for motor cycle crash victims ( 16%).6 the first phase of management for these patients aims to control bleeding , by surgical intervention if necessary , and to prevent further wound contamination .
the second phase consists of resuscitation in the intensive care unit , and the third phase aims at definitive repair of the injuries sustained.9 pelvic injuries represent a thorny and stubborn therapeutic challenge .
rapid diagnosis and effective treatment (  damage control  ) of these injuries play a key role in the patient s survival , inasmuch as the mortality of multiply injured patients with pelvic ring disruption remains high ( 20%35%).10 the preclinical management of patients with multiple trauma influences the prognosis regarding mortality and morbidity .
diagnostic overview , protection of vital functions in the special circumstance of shock , immobilization of the spine , and treatment of isolated injuries are an essential part of preclinical management.11 the type of trauma is known to influence the mortality rate.12 in this study , all the patients received specialized pre - hospital assistance , and were treated in a regional trauma reference center . in spite of all the care given at the scene of the accident through to discharge from hospital , trauma of the extremities was a significant cause of death .
accident victims with injuries of the extremities are at higher risk for death than those with other types of trauma .

Answer:
background : the aim of this study was to evaluate one - month hospital mortality in victims with injuries of the extremities.methods:all accident victims admitted to the hospital de base in so jos do rio preto , brazil , during the period from july 2004 to june 2005 , were evaluated in an observational study .
 patients were classified using the abbreviated injury scale ( ais ) .
 patients with severe injuries of the extremities ( ais 34 ) were compared with those without injuries or with minor extremity injuries ( ais 02).results : a total of 3489 accident victims were evaluated ; 3244 ( 92.98% ) did not suffer injuries or had minor injuries of the extremities ( ais 02 ) and 245 ( 7.02% ) had severe injuries ( ais 34 ) .
 of the 245 patients with ais 34 extremity injuries , 13 ( 5.31% ) patients died , and of those without severe injuries to the extremities , 34 ( 1.05% ) died ( fisher s exact test p = 0.0000 , relative risk 5.063 , 95% confidence interval [ ci ] : 2.7079.467).conclusion : patients with injuries of the extremities are at greater risk of death than accident victims with other types of trauma .


Question:
You will be shown the title of a chemistry paper, together with sections excerpted from the body of the paper. The paper sections may include HTML tags like `<p>` and `</p>`; please ignore these. Your task is to write an abstract for the paper. Your response should include the abstract and no other text.

Title:
Preparation of Zr(Mo,W)2O8 with a larger negative thermal expansion by controlling the thermal decomposition of Zr(Mo,W)2(OH,Cl)2∙2H2O

Paper sections:

The DTA curve for ZrMo x W 2−x O 7 (OH,Cl) 2 •2H 2 O showed the expected endothermic peak, corresponding to the weight loss and formation of the orthorhombic phase of β-ZrMo 2 O 8 , while the two exothermic peaks at 700 and 800 K can be assigned to the crystallization of the cubic γ-ZrMo 2 O 8 and trigonal α−ZrMo 2 O 8 phases, respectively 10 .

The solid solutions of ZrW 2−x Mo x O 8 (with different values of "x") have been prepared by a number of scientific groups 7,8,[11][12][13][14] . A significant number of solid solutions of the precursor ZrMo x W 2−x O 7 (OH) 2 •2H 2 O was prepared by Ling Huang and co-authors 12 . Cubic phases were obtained for x = 0.2, 0.4, 0.6, 0.7 and 0.8, but the NTE coefficients were not measured. Accurate measurement of the NTE coefficient for ZrMo x W 2−x O 8 (x = 1.0) was reported in work 6 . For the cubic, ordered phase, the NTE was −9.0•10 −6 K −1 from 2 to 200 K, and −5. We assumed that one of the cubic-ZrMo x W 2−x O 8 solutions may have a larger coefficient than that previously determined. We carefully investigated the conditions for obtaining cubic-ZrMo x W 2−x O 8 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, and 2.0) from precursors and measured their NTE coefficients.

Results and Discussion

Synthesis of the precursors and their characterization.     The powders of ZrMo x W 2−x O 7 (OH,Cl) 2 •2H 2 O were examined by powder X-ray diffraction (Fig. 1) on a DRON-RM4 diffractometer (CuK α source, graphite monochromator at the diffracted beam, room temperature, 2θ range 5-60°). The experimental data were processed with the PowderCell program v.2.4 15 , and the data from the powder structural database powder diffraction file (PDF) were used as the reference 16 . The EDX spectral analysis was performed using a Hitachi TM3030 desktop scanning electron microscope and the Quantax70 microanalysis system.

The PXRD data showed that all the samples were single phase. We performed an EDX investigation for all the prepared samples and found that the preset stoichiometry was retained in the products of the reaction within the experimental uncertainty. Determining the content of molybdenum and tungsten in ZrMo x W 2−x O 7 (OH,-Cl) 2 •2H 2 O by the Zen-Retgers rule is extremely difficult because of the extreme similarity of the unit cell volumes (Table 1).  High-temperature experiments were carried with time-resolved diffractometry at channel 5b of the Siberian Synchrotron and Therahertz Radiation Centre 17,18 . The wavelength used was 1.516 A. The diffraction patterns were recorded by a one-coordinate detector (OD-3) developed in Budker Institute of Nuclear Physics of Siberian Branch Russian Academy of Sciences 19 . The exposure time for a frame was set to 1 minute. The samples were heated in air up to 1123 K at a rate of 10 K/min.

DTA and high-temperature PXRD of

The behaviours of the ZrMo x W 2−x O 7 (OH,Cl) 2 •2H 2 O samples upon thermal decomposition are similar (Fig. 2a), but some features depend on the value of "x". The decomposition of ZrMo x W 2−x O 7 (OH,Cl) 2 •2H 2 O begins at 450 K for x = 2 and increases linearly up to 500 K for x = 0. The first stage is accompanied by an endothermic effect and a weight loss (Fig. 3). The data from the high-temperature PXRD confirmed the following reaction: We calculated the molar ratio of the chloride ion to the hydroxide ion (In all the samples, the ratio was approximately 1:3.) based on the loss of the mass, which was measured by DTA, as described in article 9 .  The crystallite sizes did not increase with the temperature in our experiments. Allen 20 used a long heat treatment (8 hours at 573 K) to prepare good crystalline samples of orthorhombic-ZrMo x W 2−x O 8 .

The second transformation did not have a weight loss and was accompanied by an exothermal effect. The temperatures of the transformation (650-800 K) had a complex dependence on the parameter "x" (Fig. 2a). We observed the appearance of the peaks of a nicely crystalline cubic-phase ZrMo x W 2−x O 8 in the powder pattern. The width of the synthetic "window" for single-phase, cubic ZrMo x W 2−x O 8 was not large: 70-200 K (x = 0-1.4) and 30-50 K (x = 1.4-2.0). Preparation of pure cubic, single-phase samples required accurate work. The precursor had to be heated to the minimal possible temperature (blue line on Fig. 2b) and held for 10-60 minutes (60 minutes for x = 0 and 10 minutes for x = 2).

Further heating led to the formation of trigonal ZrMo x W 2−x O 8 at 500-700 K (x = 1.2-2.0) or decomposition of the material into constituent oxides at 1050 K (x = 0-1.0) (Fig. 2b). In study 14 , it was found that the resulting products with x ≤ 0.5 would decompose to WO 3 /MoO 3 and ZrO 2 upon a temperature increase, while for x > 0.5, the cubic phase would transform into the trigonal phase. Shi Yongfang 11 noted that the appearance of the trigonal phase occurs at relatively low temperatures, i.e., 861 K (x = 0.73) and 889 K (x = 0.53). This fact was confirmed in our work. Trace amounts of the trigonal phase were often present in all the PXRD patterns, while the cubic compound was the main phase. However, we did not observe the exothermal effect for the cubic-to-trigonal transformation for x = 0.2-0.8, 1.6, and 1.8 in the DTA experiments.

Trigonal ZrMo x W 2−x O 8 (x = 1.2-1.8) had a good thermal stability, and we found no evidence of its decomposition for x = 1.4, 1.6 and 1.8 under the conditions in our experiment. Trigonal ZrMo x W 2−x O 8 (x = 1.2) decomposed at 1150 K. However, trigonal ZrMo 2 O 8 decayed into oxides with an exo-effect at 925 K.

We should note that all the transformations of orthorhombic-cubic-trigonal-oxides are exothermic. This can be explained if all those phases (with the exception of the oxides) are metastable in our experimental temperature ranges. The transformations were accompanied by a decrease in the volume of the formula unit (V/Z), e.g., for x = 1.2 (Fig. 4):

x 2 x 8 x 2 x 8

Our data directly indicated the formation of a poorly crystalline orthorhombic phase (Pmn2 1 ) of zirconium tungstate (ZrW 2 O 8 ) in the temperature range 550-825 K (Fig. 2).

NTE coefficient of cubic-ZrMo

The thermal expansion of cubic-ZrMo x W 2−x O 8 was investigated using variable temperature PXRD. Diffraction data were measured using a Bruker D8 Advance diffractometer (CuKα radiation) with a parallel-beam geometry with Göbel Mirrors. In situ experiments were carried out using an Anton Paar XRK900 reaction chamber. The patterns were measured in the 2θ range from 10 to 70° with a step of 0.05° and a collection time of 3 s per point. The heating rate was 12 K/min. The acquisition of the X-ray patterns was started when the given temperature was reached. Sample cooling was immediately performed. The profile analysis and structural refinement by the LeBail method were performed using the TOPAS v.4.3 program 21 , and the data from the powder structural database PDF were used as the standards 16 . The lengths of the coherent scattering domain were calculated using LVol-IB values (i.e., volume weighted mean column height based on the integral breadth).

When measuring the NTE coefficient, it is important to realize which form of cubic ZrMo x W 2−x O 8 is being measured, i.e., ordered or disordered. For ZrW 2 O 8, this transition is called α → β. In article 13 , the thermal effects for the transition (ordered → disordered) were measured, and a formula describing the temperature of the α → β transitions for cubic-ZrMo x W 2−x O 8 was proposed: T (K) = 432-168.45•x. We used it in our work to estimate whether the NTE coefficient belongs to the corresponding ordered or disordered form (Table 2). Of course, the dependence is not linear for x > 1; this is clearly visible when comparing the calculated and experimental values for x = 1.8 and 2.0 (Table 2).

We were able to obtain reliable data for the NTE coefficients for only the disordered phase, except for x = 1.8. The calculated coefficients have similar values (from −3.5•10 −6 K −1 to −4.5•10 −6 K −1 ) and almost did not differ from those of the "pure components". Our value of the NTE coefficient, 3.5•10 −6 K −1 , for x = 0.4 did not coincide with the value 8    Heating of the precursors up to T = 525-50•x K affords crystals of orthorhombic ZrMo x W 2−x O 8 (10-15 nm). Cubic ZrMo x W 2−x O 8 solid solutions with a small crystal grain size (30-100 nm) can be obtained by thermal decomposition of the corresponding precursor or orthorhombic ZrMo x W 2−x O 8 at a temperature up to 850-900 K at x ≤ 1.8 and T = 2200-750•x K at x > 1.8.

Trigonal ZrMo x W 2−x O 8 (only for x > 1) can be prepared by heating the precursor or cubic ZrMo x W 2−x O 8 or orthorhombic ZrMo x W 2−x O 8 up to 850-1050 K, depending on the exact composition.

Solid solutions of cubic ZrMo x W 2−x O 8 in the ordered form have a higher coefficient of thermal expansion (CTE) in comparison to that of other materials, but they exist in a very limited and relatively low-temperature range, which limits their possible applications.

The disordered form of cubic ZrMo x W 2−x O 8 solid solutions does not have an advantage over that of the "pure components" in the value of CTE. The use of solid solutions is justified in the case when it is necessary to have a uniform CTE material for a certain temperature range (e.g., 250-800 K for x = 1.0).

Answer: Solid solutions of Zr(Mo,W) 2 O 7 (OH,Cl) 2 •2H 2 O with a preset ratio of components were prepared by a hydrothermal method. The chemical composition of the solutions was determined by energy dispersive X-ray spectroscopy (EDX). For all the samples of ZrMo x W 2−x O 7 (OH,Cl) 2 •2H 2 O (x = 0.0, 0.2,


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
osteosarcoma ( os ) develops most frequently in the extremities , and it is the most common histologic form of the primary bone cancers.1
 2 head and neck oss are rare , comprising only 6 to 10% of all oss.3

4 they typically present in the third or fourth decade of life and comprise only 1% of all pediatric head and neck malignancies .
the most common craniofacial sites affected by oss are the mandible and maxilla , followed by the calvaria and then the skull base.4
 5
 6 on cytology , os can be divided into several pathologic types , including the pleomorphic , epithelioid , chondroblastic , small cell , mixed , and osteoclast - like giant cell types.6 in head and neck oss , the chondroblastic type occurs most frequently.7
  skull base oss can be challenging to resect and an aggressive surgical approach can result in poor cosmetic outcome.8 imaging plays a crucial role in the diagnosis of each subtype of os and ultimately in patients ' survival because the diagnosis is based on a combination of histopathologic and imaging features .
the therapeutic options and prognoses for different types of os differ from each other , so correct diagnosis is essential.9
 10 magnetic resonance imaging ( mri ) or computed tomographic ( ct ) scan should be used to assess the extent of the primary tumor.11
  in this case report , we describe a pediatric patient of occipital os of the chondroblastic type .
the chondroblastic type of os has an exceedingly poor outcome.12 however , the detailed imaging description of such cases have not been reported in the previous literatures .
we present the ct , mri , and enhanced mri features of this case , followed by a brief review of the related cases reported in the previous literatures
a 9-year - old boy was admitted to our hospital with a major complaint of a growing mass on his head .
physical examination found a firm and tough mass on the right occipital that showed no tenderness upon palpation .
ct scan showed the right occipital bone to be irregularly thickened with fluffy and cloudy calcification , with a mass deriving from the internal occipital protuberance extending toward the basilar part of the occipital bone , invading the neighboring jugular foramen , the sublingual neural tube , and the mamillary process . on mri ,
the lesion was 4.5-  5.5-  6.5-cm in size with calcifications areas of hypointensity in t1- and heterogeneous in t2-weighted series .
contrast mri showed peripheral and septal enhancement in the interior side of the tumor ( fig .
significant mass effect was present , distorting the cerebellar hemisphere , pons , and the forth ventricle , which led to hydrocephalus , and the oppression of the sigmoid sinus and the transverse sinus .
2 ) , corresponding to the features of chondroblastic os , and occipital bone chondroblastic os was the final definitive diagnosis .
( b ) t1-weighted image shows a 4-  8-  10-cm mass lesion , isointense to the skull .
( c , d ) the mass is hypointense in most areas in the t2-weighted series , with focal high signals in the t2-weighted series and reduced signal in flair series.(e ) in gd - enhanced mri , most areas show no enhancement or heterogeneous enhancement , with peripheral and atypical septal enhancement on the coronal plane ( white arrows ) .
( f ) no hyperintensity was observed in both intra- and peritumoral areas in the dwi series .

histopathologic examination ( hematoxylin and eosin , 200 ) shows lace - like osteoid material abutting the neoplastic cells .
they typically present in the third or fourth decade of life , account for fewer than 5% of oss in children , and comprise only 1% of all pediatric head and neck malignancies .
the most common craniofacial sites are the mandible and maxilla , followed by the calvaria and then the skull base.13
 14
 15 our case in the right occipital bone of skull base is a very rare location . a search of the english language literature revealed 22 cranial oss previously reported in children ( table 1 ) : 12 calvarial tumors and 10 tumors of the skull base .
the mean age of the pediatric patients with cranial os was 12.2 years old in this table .
can be divided into pleomorphic , epithelioid , chondroblastic , small cell , mixed , and osteoclast - like giant cell types.6 our case is a chondroblastic subtype , which occurs most frequently in head and neck oss .
abbreviations : gtr , gross total resection ; nr , not reported ; rt , radiation therapy ; str , subtotal resection .
the etiology of os is unknown , but the major risk factors for development of os in craniofacial bones may be similar to those of the long skeletal bones , consisting of exposure to radiation , retinoblastoma , li - fraumeni syndrome , and paget 's disease .
other bone abnormalities , such as fibrous dysplasia , multiple osteochondromatosis , chronic osteomyelitis , myositis ossificans , and trauma , have also been proposed as risk factors.7
 15
 16 the presenting symptoms varied with the location of the tumors .
the maxillary or cranial lesions usually produced no pain , which was in accordance with our case ; however , mandibular tumors frequently presented with focal painful swelling.17
 18 other common presenting symptoms include headache , cranial nerve palsies , exophthalmos , and visual impairment due to different location of the tumor.5
 13
  ct best demonstrates tumor mineralization , especially when minimal , and it is usually able to demonstrate tumor extension into the soft tissues . hemorrhage , necrosis , and unmineralized , chondroblastic , or fibroblastic components of the tumor will appear as areas of low attenuation on ct if present . unlike any other conventional oss , we see fluffy calcification in our case , and we believe it is a characteristic of os . the osteoblastic subtype is most common with nearly 90% containing variable amounts of cloudlike opacities.19 bose20 reported an osteoblastic os that appears as a large soft tissue density mass with a few bony densities .
compared with our case , the soft tissue mass is prominent and the calcification is less and diffuse .
mri is the preferred modality for locally staging os , and it should be performed before percutaneous biopsy because it can help identify areas of viable tumor and mineralized matrix . in our case of gadolinium ( gd)enhanced mri
, we found no enhancement or heterogeneous enhancement in most areas of the tumor , with septonodular and rim enhancement , which is in in accordance with the current literature .
areas that demonstrate either a heterogeneous enhancement pattern or lack enhancement are the preferred sites for biopsy because they are more likely to contain both chondroid and osteoid elements that are necessary for the correct diagnosis.21
 22 chondrosarcomas shows similar image characteristic , but they occur in an older age with a mean age of 57 years old .
chondroblastic oss also have significantly higher minimum and maximum apparent diffusion coefficient ( adc ) values compared with other conventional os subtypes , but they have a lower minimum adc and similar maximum adc value compared with chondrosarcoma.23
  skull base oss can be challenging to resect , and an aggressive surgical approach can result in poor cosmetic outcome .
thus , skull base tumors have a poorer prognosis than mandibular or maxillary tumors.3 complete surgical excision is the mainstay of treatment of the primary tumor .
local recurrence is the main reason of treatment failure and mortality in head and neck oss .
positive margins and a high tumor grade correlate with a statistically significant decrease in survival.11 in our case , the tumor could not be completely removed because it invades significant neighboring bone structures , including the jugular foreman and the sublingual neural tube .
the patient died after 6 months as a result of local recurrence . in summary ,
chondroblastic os has been shown to be associated with a poor preoperative chemotherapy response and has a worse prognosis than other variants.24 however , this subtype has some particular image characteristic , which helps surgeons identify before surgery and set early therapeutic regimens .

Answer:
primary osteosarcomas of the skull and skull base are rare and comprise  <  2% of all skull tumors . in head and neck osteosarcomas ,
 the chondroblastic subtype occurs most frequently , which has an exceedingly poor outcome , but its image characteristic remains unknown .
 herein , we report a case in the right occipital bone of the skull base and the unique characteristics of image . pathologic examination of the surgical specimens led to the diagnosis of chondroblastic osteosarcomas .
 we believe those image characteristics can improve the understanding of skull chondroblastic osteosarcoma and the preoperative diagnosis .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
recent results from the national institutes of health ( nih ) frequent hemodialysis network ( fhn ) daily trial and the following rehabilitation , economics and everyday - dialysis outcome measurements ( freedom ) study have provided confirmation of the clinical and quality of life ( qol ) benefits of short daily hemodialysis ( sdhd ) when compared to conventional thrice weekly in - center hemodialysis ( chd ) .
the fhn study was conducted in - center ; however , sdhd in the usa is more commonly performed as a home therapy and is not offered as a standard treatment modality in most dialysis clinics .
although it has been nearly 50 years since the early pioneers such as belding scribner and stanley shaldon began dialyzing patients in their homes , peaking at 40% of all us dialysis patients in 1973 , the popularity of home hemodialysis ( hd ) has been limited in the usa for a number of reasons , including lack of suitable equipment and increased cost .
the last few years , however , have seen a revival in home hd , resulting in renewed interest in the various forms of more frequent therapy , including sdhd .
the revival of home dialysis was led in the mid 1990s by robert uldall , andreas pierratos and others in canada , gradually spreading throughout the usa .
this re - emergence has been made possible by recent advances in technology , including portable and more user - friendly machines designed specifically for use in the home environment . in 2005 , the fda cleared the first hd machine for home use in the usa , the nxstage system one. fda clearance was based on an open - label , prospective , two - treatment two - period crossover study on 32 patients to compare sdhd performed in - center ( prescribed six times / week ) versus sdhd performed at home .
the study was conducted at six centers in the usa under an investigational device exemption .
this study showed sdhd was delivered as efficiently in the home environment as in - center , with 98.5% of treatments performed successfully in - center versus 97.3% at home .
notably , the composite rate of intra - dialytic and inter - dialytic adverse events was significantly higher during the in - center phase when compared with the home phase ( 5.3 versus 2.1 adverse events/100 treatments ; p = 0.007 ) , suggesting hd therapy is at least as safe at home as in - center .
when comparing clinical parameters from the period immediately preceding the study when patients were treated with conventional thrice weekly center hd , home sdhd was associated with reductions in blood pressure , antihypertensive medications and interdialytic weight gain . since the clearance of the nxstage system one in the usa , the number of patients now performing home dialysis is estimated to be 5000 , with the majority of these patients performing sdhd .
although this represents a considerable increase over the past 5 years , it is still only 1% of the total end - stage renal disease ( esrd ) population .
sdhd offers the promise of improved clinical outcomes in patients with kidney failure , and given the positive results recently released from both the fhn and freedom studies outlined below , sdhd has the potential to become a more viable and popular choice amongst many esrd patients .
results recently published from the fhn daily trial , funded by the nih , showed that in - center sdhd ( prescribed six times / week ) , provided significant benefits in both composite co - primary outcomes of death or 12-month change in left ventricular mass ( lvm ) and death or 12-month change in the rand-36 physical health composite ( phc ) score .
specifically , the fhn daily trial showed patients randomized to sdhd reduced their lvm by 16.3  35.3 g ( p < 0.001 ) and improved their phc score by 3.3  8.9 points ( p = 0.004 ) , after 12 months .
however , patients on sdhd were more likely to undergo interventions related to vascular access , a result which will require further elucidation with the ongoing analysis of the trial
. the fhn trial will be a tremendous source of data to further dissect the advantages seen with daily therapy in the coming years .
the freedom study is an ongoing prospective cohort study investigating the clinical and economic benefits of sdhd .
the objectives of the freedom study are to compare a cohort of patients starting sdhd using the nxstage system one to a matched cohort of patients receiving chd for all - cause hospitalizations and non - treatment - related medical expenditures .
using a 10-to-1 ratio , totaling 5000 patients , the matched thrice weekly in - center hd cohort will be obtained from the us renal data system ( usrds ) database .
in addition , changes in qol measures , urea kinetics , management of anemia , bone and mineral metabolism , nutrition , vascular access interventions and use of medications will be examined .
the freedom study will involve up to 70 clinical sites and 500 participants , with a minimum 1-year follow - up .
study participants complete qol surveys at the time of study enrollment , at 4 and 12 months and every 6 months thereafter .
interim data recently released from the freedom study has shown that sdhd , performed in the home environment , is associated with significant improvements in several important clinical and qol measures when compared to conventional thrice weekly in - center hd .
interim results from the freedom study investigating the effect of sdhd on depressive symptoms were recently published .
depressive symptoms were examined in 248 participants at enrollment and at 4 and 12 months by administering the validated beck depression inventory ( bdi)-ii survey .
the study protocol requires that the site investigator be notified immediately of a bdi score > 10 , with mild and moderate to severe depressive symptoms defined as bdi scores of 1115 and > 15 , respectively . in summary ,
sdhd was associated with a significant improvement in mean bdi score over 12 months [ 11.2 , 95% confidence interval ( ci ) 9.612.9 , versus 7.8 ( 95% ci 6.59.1 ) ; p < 0.001 ] , in the per - protocol ( pp ) cohort .
similar results were found in the intent - to - treat ( itt ) cohort . for participants with moderate to severe depressive symptoms , the bdi scores almost halved over 12 months [ 24.4 ( 95% ci 19.429.4 ) versus 12.6 ( 95% ci 8.017.2 ) ; p < 0.001 ] .
it should be noted that a bdi score > 15 previously has been shown to be highly predictive of a diagnosis of clinical depression .
the percentage of participants with depressive symptoms ( bdi score > 10 ) significantly decreased during 12 months ( 41 versus 27% ; p < 0.03 ) . similarly in the fhn study , patients participating in the daily arm did show a trend toward improvement after 12 months when compared to baseline ( 12.6  8.7 versus 10.4  8.5 , p = 0.1 ) .
although this trend was not statistically significant , one might speculate that undergoing daily dialysis therapy at home may contribute to this improvement .
considering the practical feasibility of daily dialysis both from a logistical and a patient comfort perspective , one might hypothesize that the home setting may further enhance the benefits of sdhd experienced in - center .
the long - term effect of sdhd on post - dialysis recovery time was also assessed in the freedom study by administering the following previously validated question :  how long does it take you to recover from a dialysis session and resume your normal , usual activities?   interim results were recently published   and confirmed that sdhd is associated with a significant decrease in post - dialysis recovery time [ 476 min ( 95% ci 359594 ) versus 63 min ( 95% ci 3295 ) ; p < 0.001 ] .
the percentage of participants experiencing prolonged post - dialysis recovery time ( > 60 min ) also significantly decreased over the 12-month period ( 81 versus 35% ; p < 0.001 ) .
the fhn daily trial showed significant improvements in control of hyperphosphatemia for patients on sdhd .
a significant reduction in mean serum phosphate was also reported in an interim report from the freedom study , along with significant reductions in the calcium  phosphate product , serum creatinine , serum potassium and a trend toward a reduction in blood urea nitrogen .
both the fhn daily trial and an interim analysis from the freedom study showed no change in serum albumin levels .
well - known uremic symptoms , including restless legs symptoms ( rls ) and poor sleep quality are common in the hd population .
poor sleep quality and rls have both been linked to increased risk of death for these patients [ 9 , 10 ] .
a recent interim report from the freedom study demonstrated initiation of sdhd at home is associated with significant improvement in rls and sleep disturbances .
results from 235 patients found 40% suffered from rls at baseline , which was associated with poorer sleep quality and respiratory disturbances . among patients with rls , the mean irls ( international restless legs severity scale ) score improved significantly at month 12 , after adjustment for use of rls - related medications ( 18 versus 11 , p < 0.0001 ) . among patients with moderate - to - severe rls ( irls score 15 )
, there was an even greater improvement in the irls score ( 23 versus 13 , p < 0.001 ) . over the 12-month period , there was decline in the percentage of patients reporting rls ( 35 versus 26% , p = 0.05 ) and those reporting moderate - to - severe restless legs symptoms ( 59 versus 43% , p = 0.06 ) .
there was a similar and sustained improvement in several scales of the medical outcomes study sleep survey over 12 months , after adjustment for presence of rls and use of anxiolytics and hypnotics .
recent results from both the fhn daily trial and freedom study have shown that sdhd , performed either in - center or at home , is associated with several important clinical and qol benefits when compared to conventional thrice weekly hd .
the improvements in left ventricular mass , control of hypertension and improvement in hyperphosphatemia demonstrated in the fhn trial , in conjunction with the positive interim findings from the freedom study , including improvements in depressive symptoms , post - dialysis fatigue , various laboratory parameters , restless leg syndrome and sleep disorders , confirm the anecdotal benefits of sdhd seen and reported by many practicing nephrologists and their patients . until now
, a complex variety of reasons has hindered the more widespread use of sdhd in the usa and globally .
however , the results of these studies may provide a new impetus for esrd patients and nephrologists to reconsider the paradigm of thrice weekly center hd as the  default therapy. such a paradigm shift will likely increase the possibility for improved clinical outcomes and overall patient care for those affected by esrd .

Answer:
thrice weekly in - center hemodialysis is the standard of care for dialysis patients with end - stage renal disease ( esrd ) . however , there is ongoing debate as to whether more frequent hemodialysis , with its readier management of both toxin and fluid removal , benefits patients .
 new evidence from recent studies , both in center dialysis and in home haemodialysis patients , adds further confirmation of improved cardiovascular outcome and quality of life in patients undergoing short daily hemodialysis .
 a paradigm shift in esrd care delivery may be facilitated due to new technology enabling daily therapy at home .


Question:
You will be shown the title of a chemistry paper, together with sections excerpted from the body of the paper. The paper sections may include HTML tags like `<p>` and `</p>`; please ignore these. Your task is to write an abstract for the paper. Your response should include the abstract and no other text.

Title:
Nickel(II) Dithiocarbamate Complexes Containing Sulforhodamine B as Fluorescent Probes for Selective Detection of Nitrogen Dioxide

Paper sections:

As a dominant component in the NOx (x = 1 or 2) family, nitrogen dioxide (NO2) is a major air pollutant generated from high temperature oxidation of molecular nitrogen by oxygen in combustion.1 Whereas biologically, nitrogen dioxide is implicated as the root cause of toxic effects of reactive nitrogen species derived from nitric oxide oxidation by oxygen in the cellular system2 and from one-electron reduction of nitrite by metalloenzymes.3 As an air stable and strong lipophilic oxidant, nitrogen dioxide can trigger lipid auto-oxidation4 and oxidative nitration of aromatic amino acids, particularly tyrosine.5 However, there is a lack of selective fluorescent probes for convenient detection of nitrogen dioxide. Most fluorescent probes reported are for nitric oxide (NO) detection. While transition metal complex based probes contain the nitric oxide reactive metal as fluorescence quencher,6-10 the organic dye based probes detect nitric oxide indirectly through oxidation of aromatic amines by N2O3,11-12, which is produced via oxidation of NO by O2.13-14 We herein report the first fluorescent probe for selective detection of nitrogen dioxide, containing Ni(II) as a fluorescence quencher and NO2 reaction center.

Reaction of sulforhodamine with oxalyl chloride yielded a mixture of two isomeric compounds with -SO2Cl group in para or ortho position of the phenyl ring.15 The mixture was treated directly with piperazine and two isomers produced were separated readily by column chromatography to give para isomer, 1 and ortho isomer, 2 (Scheme 1). Due to their similarity, it was difficult to unambiguously distinguish their structures based on NMR and MS spectra alone. Hence the structures of the isomers were determined by single crystal X-ray diffractions (Figure S1) and, accordingly, the 1H NMR spectral data was assigned with certainty. In the presence of sodium hydroxide, the two isomers reacted readily with carbon disulfide to produce dithiocarbamate sodium salts 3 and 4, respectively. Dithiocarbamate is a bidentate ligand that promptly forms complexes with many transition metals, leading to quenching of the ligand fluorescence. It is reported that Ni(II) bisdithiocarbamate complexes, Ni(II)(RNCS2)2, reacts immediately with nitrogen dioxide to yield the oxidative dimerized ligand, (RNCS2)2,16 which could be fluorescent if R is a fluorophore. Hence, in order to prepare a Ni(II) based turn-on fluorescent probe for nitrogen dioxide, we mixed nickel(II) nitrate with 3 and 4 at 1 to 2 ratio and prepared 5 and 6 (Scheme 1). The structures of 5 and 6 were characterized by 1H NMR and the results were in agreement with a diamagnetic nickel complex with square-planar configuration. Additionally, their MALDI-TOF mass spectra showed isotope distribution pattern matching the expected molecular formula (Figure S2).

To illustrate the effect of two isomers on fluorescence quenching, the fluorescence quantum yields of compounds shown in Scheme 1 were measured (Table S1). The presence of piperazine group at ortho position (2, QY = 0.21) has reduced the quantum yield of the parent compound (sulforhodamine B, QY = 0.34) more significantly than the para isomer (1, QY = 0.28). Dithiocarbamate groups further reduced the quantum yield a little bit. The ortho isomer of the Ni(II) complex has the lowest quantum yield, and is 70 times lower than the ligand itself, while the para isomer 5 has only five times lower quantum yield comparing to 3. Energy transfer is not likely due to the small absorbance bands overlap between fluorophore emission and quencher absorption (Figure S3).

The mechanism behind fluorescence quenching is probably attributed to photo-induced electron transfer (PeT) from electron donor Ni(II) to sulforhodamine B excited state. The HOMO and LUMO energies of Ni(Me2NCS2)2 was calculated to be −4.09 and −1.03 eV respectively and dithiocarbamate ligand is known to stabilize Ni(III).17 Whereas the HOMO and LUMO of rhodamine B was −8.058 and −5.266 eV respectively.18 Therefore, PeT from Ni to rhoamdine B chromophore is energetically favored. PeT is highly sensitive to the distance between the fluorophore and the quencher; therefore, the shorter distance of Ni to the center of the fluorophore in 6 is likely to cause a much higher quenching efficiency than 5. From the crystal structures of 1 and 2, the distances of nitrogen (NH) in piperazine group to the centers of the fluorophore were calculated to be 9.4 and 7.4 Å, respectively. Although we failed to obtain single crystal structures of the Ni complexes, it is reasonable to assume that the distance of the Ni to the rhodamine B chromophore would be shorter in 6 in comparison to that in 5. It should be born in mind that in solution, molecular motions will have significant effect on the distances.

We evaluated the selectivity of the ortho isomer 6 towards common reactive oxygen species (ROS) in methanol (Figure S5). Only NO2 could increase the fluorescence intensity by more than 12 times, whereas other biological relevant ROS could not do so. Neither nitrite nor nitrate could switch on the fluorescence. Moreover, addition of nitric oxide donor diethylamine NONOate (DEANO) rapidly turned on the fluorescence by 12 fold within minutes and there was excellent dose response between the fluorescence intensity and the DEANO concentrations (Figure S7). In comparison, when para isomer 5 is used, the magnitude of fluorescence increase is only 1.9 times (Figure S6). Although there is a sulfonate group on the fluorophore of probe 6, its water solubility is extremely poor. In aqueous media (water and buffer), there was no fluorescence intensity gain after addition of NO2. It turned out that the reaction products precipitated out even at micromolar concentration level used in the experiment. Addition of surfactant (Tween 20) to the reaction mixture before adding NO2 led to fluorescence turning on. Therefore, to introduce the probe into physiological condition, we applied DOTAP (1,2-dioleoyl-3-trimethylammonium-propane chloride salt) liposome as a delivery vehicle for our probe. It is found that probe 6 delivered by DOTAP demonstrated excellent selectivity to NO2 (Figure 1) and good dose-response to DEANO (Figure 2) in buffered aqueous media to simulate the physiological conditions.

To further test whether the probe is sensitive to nitric oxide or nitrogen dioxide, we carried out the reaction in the absence of oxygen by degassing the probe solutions and DEANO solutions before mixing them under nitrogen, and we failed to observe any fluorescence turning-on event. This observation showed that the fluorescence turning-on by DEANO required oxygen, suggesting that it is NO2 that reacts with the probe as NO generated from DEANO is rapidly oxidized to NO2 by oxygen present in the solution.19 This was confirmed by a separate test in which the response of the probe to NO2 gas formed by mixing NO and air or commercial NO2 gas was examined. Indeed, fluorescence was turned on. To further verify if the reaction products of 6 with DEANO in the presence of air and with NO2 gas are identical, the reaction products were analyzed using HPLC and LC-MS. The results suggested that the same major products with fluorescence were generated by the probe reacted with DEANO in the presence of air and with NO2 gas in methanol. These results clearly show that NO2 can turn on the fluorescence of the probe. Moreover, the para isomer 5 also reacted with NO2 in the same way as the ortho isomer 6, as characterized by HPLC chromatograms (Figure 3).

The structures of the reaction products were then deduced on the basis of LC-MSn spectra and shown in Scheme 2. Apparently, NO2 brought forth the oxidation of dithiocarbamate ligand and generated Ni(II) free compounds with high fluorescence. We proposed that the reaction is initiated by NO2 adduct with 5/6, forming Ni(III)(R2NCS2)2(NO2). Subsequent intramolecular electron transfer reaction forms Ni(II) complex and R2NCS2• radical, which couples to give ligand dimer shown in peak B/B' (Scheme 2). The compound shown in peak A/A' is generated due to secondary oxidation reaction of (R2NCS2)2 followed by methanolysis. Consistent with the two proposed compounds, ESI-MS results of the compound shown in peak A/A' gave [M+H]+ peak at m/z = 749.2 and [M+Na]+ peak at m/z = 771.2, while ESI-MS results of compound for B/B' demonstrated two dications, [M+2H]2+ at m/z = 702.2 and [M+2Na]2+ at m/z = 724.2, respectively. Our assignments are supported by ESI-MS2 fragmentation patterns of Aˊ/Bˊ. MS2 spectrum of peak A' shown three fragments at 717.1 ((M + H)+ – CH3OH), 669.2 ((M + H)+ – SO3), and 637.0 ((M + H)+ – CH3OH – SO3), respectively. MS2 spectrum of B' gave a peak at m/z = 627.2 formed from the molecular cation through homolytic cleavage of the S-S bond followed by losing a CS2 (Figure S4).

In addition, the formula of A' and B' were confirmed by high resolution MS spectra (Table S2). Our results are in agreement with literature work, which showed that bis(diethyldithiocarbamatonickel(II)) (Ni(dtc)2) reacted with NO2, but not with NO, to give corresponding paramagnetic Ni(III)(dtc)3 as an intermediate, which decomposed to oxidized dithiocarbamate ligand, i.e. thiuram disulfide ((R2NCS2)2).16

Considering the high toxicity of NO2 in atmosphere, Health and Safety Commission (HSC) of USA has approved Occupational Exposure Standards (OESs) of 1 ppm (8-hour time weighted average) and 5 ppm (short-term exposure limit) for NO2.20 Convenient detection of gaseous NO2 would be ideal for monitoring air pollution due to NOx (x = 1 or 2, with NO2 being dominant species). For this purpose, probe 6 was successfully applied in visual detection of gaseous NO2 with the detection limit reaching 1.0 ppm using NO2 indicator strips prepared by dropping methanol/chloroform (1:1) solution of 6 (800 nM) on filter paper to give round stains of ca. 5 mm in diameter after solvent evaporation. The NO2 indicator strips were exposed to different concentrations of NO2 gas for 10 minutes. Under regular laboratory lighting conditions, there was no apparent spot detected for all indicator strips (Figure 4 right). When the strips were exposed to UV lamp (352 nm), red fluorescence spots could be observed visually for strips exposed to NO2 gas at concentration as low as 1.0 ppm and the fluorescence intensity increased in a dose dependent manner at 10 and 100 ppm NO2 (Figure 4 left). The results demonstrated that this NO2 indicator strips immobilized with probe 6 is a simple, direct and economical tool for rapid detection of gaseous NO2 at low concentrations.

To introduce the probe into biological system, liposomal carrier was applied. Cationic liposomes have been studied extensively in gene therapy applications and also cationic lipids are effective in vaccine formulations to treat cancers.21-22 Therefore, we applied DOTAP liposome as a delivery vehicle for our probe. Although it is known that DOTAP liposome at high concentration is toxic to cells, our observation showed that RAW 264.7 cells can withstand up to 100 μM DOTAP (Figure S8). To illustrate that the probe 6 uptaken by cells can be turned on by adding NO2, the RAW 264.7 cells treated with DOTAP liposome containing 6 (5 μM) were further treated with DEANO as a NO2 donor.19 The fluorescence images of the cells (Figure 5B, D) clearly illustrate that fluorescence intensity could be efficiently enhanced by adding DEANO (for intensity plot please refer to Figure S9). Moreover, the Z-stack gallery image (Figure S10) clearly shows that RAW 264.7 cells were able to efficiently uptake the probe 6 dispersed in DOTAP. A 3D image (Figure 5A, B, C, D) was also given to demonstrate the depth distribution of probe 6 inside cells, both treated and not treated with DEANO.

In conclusion, we have demonstrated that dithiocarbamate Ni(II) complexes containing sulforhodamine B fluorophore is a highly selective probe for detection of nitrogen dioxide. To the best of our knowledge, this is the first example of live cell fluorescence imaging of NO2 activity and visual detection of gaseous NO2 at low concentrations. Many third row transition metals are good fluorescence quenchers because their complexes with fluorescent ligands are paramagnetic due to the unpaired metal d electrons. In contrast, Ni(II) coordination sphere in complex 5 and 6 adopt square planar geometry and are diamagnetic. It warrants further research on understanding the quenching mechanisms of Ni(II) and developing even more sensitive probes with rationale combination of fluorophore and nickel complex.

Answer: We synthesized the Ni(II) complexes with dithiocarbamate ligand derived from ortho and para isomers sulforhodamine B fluorophores and demonstrated they are highly selective in reaction with nitrogen dioxide (NO2). Comparing to the para isomer, the ortho isomer showed much greater fluorescence increase upon reaction with nitrogen dioxide, which led to oxidation and de-complexation of dithiocarbamate ligand from Ni(II). We applied this probe for visual detection of 1 ppm nitrogen dioxide in gas phase and fluorescence imaging of NO2 in macrophage cells treated with nitrogen oxide donor.


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
numerous causes have been attributed to low back pain ( lbp ) . a long list exists , but the enlistment of sacralization as one of the causes has resulted in a lot of controversy .
sacralization is a congenital vertebral anomaly of the lumbosacral spine ( fusion between l5 and the first sacral segment ) .
several studies have described the occurrence of this anomaly in a back pain population [ 27 ] .
some authors have stated that sacralization is incidentally diagnosed and has no clinical impact [ 7 , 8 ] , whereas others claim that this anomaly may predispose patients to certain clinical disorders [ 911 ] .
this controversy has been quite intriguing and has been the stimulus for carrying out this present study .
the intention was to examine in detail the incidence of this anomaly in the lbp population .
our study aimed to use the incidence of this congenital anomaly to establish a relationship between it and lbp .
after institution review board approval for this prospective study , 500 lumbosacral radiographs of lbp patients and 500 radiographs of control group were collected over a one - year period .
the ages ranged between 16 years and 73 years , and both sexes were involved .
exclusion criteria consisted of any radiologic evidence of previous lumbosacral surgery that would obstruct our measurements . a total of 1000 lumbosacral films were examined and identified as being adequate for measurement of the desired parameters .
data collection consisted of the subject 's age at the time of imaging , gender , number of lumbar vertebral bodies , and bilateral height measurement of the lowest lumbar transverse process .
three orthopedic spine fellows performed all the measurements , using a systemized approach to decrease variability ; in addition , consultations between reviewers took place .
subjects without transverse process dysplasia were classified as normal ( type 0 ) , and those with dysplastic transverse process were classified according to the castellvi radiographic classification system   ( table 1 ) .
the incidence of sacralizations in the two groups was reported , and the anomaly was compared according to the groups .
statistically significant differences were evaluated by using contingency tables with fisher 's exact test for categorical variables .
this test was used to compare statistically the differences between the two groups according to having sacralization .
in g1 , the average age was 39.03  15.9 years ( 1673 years ) .
of these patients ( 281 women , 219 men ) , 106 were classified as positive for sacralization , with a gender distribution of 54 ( 19.22% ) women and 52 ( 23.74% ) men .
of the total number of patients ( 500 ) seen , 12 ( 2.4% ) had lumbarization . according to sacralization classification ,
the most common anatomical variant was castellvi type ia ( 6.8% ) , followed by type ib ( 5.4% ) , type iia ( 1.6% ) , type iib ( 1.8% ) , type iiia ( 1.4% ) , type iiib ( 3.4% ) , and type iv ( 0.8% ) . in g2 ,
of these cases ( 297 women , 203 men ) , 84 were classified as positive for sacralization , with a gender distribution of 39 ( 13.13% ) women and 45 ( 28.48% ) men .
of the total number of cases ( 500 ) seen , 13 ( 2.6% ) had lumbarization . according to sacralization classification ,
the most common anatomical variant was castellvi type ia ( 6% ) , followed by type ib ( 4.2% ) , type iia ( 2% ) , type iib ( 1% ) , type iiia ( 0.8% ) , type iiib ( 1.6% ) , and type iv ( 0.8% ) .
no statistically significant difference was found between the groups according to the presence of sacralization ( p = 0.09 ) ( table 4 ) .
the incidence of sacralization has been reported as 4% to 36% in the general population [ 1 , 6 , 9 , 1317 ] .
its frequency in the low back pain population ranges from 6% to 37% [ 4 , 5 , 10 , 12 , 1821 ] .
numerous studies have found no significant correlation between sacralization and low back pain [ 3 , 5 , 7 , 13 , 22 ] , while others have [ 912 , 21 , 23 ] .
authors who found no significant correlation [ 7 , 8 , 16 ] have concluded that the incidence of transitional vertebra is equal in those with and without back pain , rendering it only an incidental finding on imaging .
frymoyer et al . have determined similar rates of radiological abnormalities in three groups of patients : no lbp , moderate lbp , and severe lbp .
have reported the incidence of sacralization to be 13% in patients with lbp and 11% in their control group .
our study found an incidence rate of 21.2% for sacralization in patients , 16.8% in control group .
demonstrated that the abnormal vertebra does not constitute a risk factor for spine degenerative changes but , when degeneration occurs , it focused on the suprajacent level of the transitional vertebra .
many of the authors with lower estimations used more stringent criteria to count a vertebra as transitional , while other authors did not clearly state all of the inclusion criteria . while elster   and hsieh et al .   reported prevalence as low as 7% and 5.9% , respectively , and delport et al .   observed a rate of 30% , they were based on articulation or fusion of at least one transverse process and presence of an intervertebral disc caudal to the transitional segment , ultimately failing to recognize our most common subtype
type i. this leaves the current estimates of those with a transitional vertebra in the range of 6%37% in those seeking healthcare for low back pain , either slightly or significantly higher than the range of 4%36% commonly reported as the number with sacralization in the general population .
this large fluctuation in estimates for the general population amplifies the difficulties in determining the significance of the percentage that we found in our patients .
castellvi et al .   reported a 30% prevalence on his low back pain population .
apazidis et al .   found 35.6% prevalence of sacralization in their studies of 211 lumbar spine subjects who had no pain .
their most commonly found pathology was type ia ( 14.7% ) , as in our study .
a great deal of the controversy surrounding the association of sacralization and lbp is the result of an incomplete understanding of the variation present at the lumbosacral junction , as well as the lack of a comprehensive classification scheme that can be used to differentiate lumbosacral variation according to morphological , developmental , and clinical variants .
therefore , a comprehensive understanding of normal and abnormal variations at the lumbosacral junction and a precise classification system are needed to investigate more thoroughly the association between sacralization and lbp .
differences between the classification systems are likely the cause of much of the disagreement ; small sample size may also contribute .
the controversy in the literature centers on the issue of whether or not sacralization cause low back pain .
first , an understanding of the variation present must be achieved , complete with a standard , convenient way to categorize that variation .
second , the possible connections among the categories and both frequencies and intensities of low back pain must be investigated as thoroughly as possible .

Answer:
objective .
 the aim of this study was to determine , by plain radiography , if there is a relationship between sacralization and low back pain . methods .
 five hundred lumbosacral radiographs of low back pain patients and 500 control groups were examined .
 data collection consisted of the subject 's age at the time of imaging , gender , number of lumbar vertebral bodies , and bilateral height measurement of the lowest lumbar transverse process .
 dysplastic transverse processes were classified according to the castellvi radiographic classification system .
 the incidence of sacralization in patients and the control groups was reported , and the anomaly was compared according to the groups . results . of these patients groups ,
 106 were classified as positive for sacralization , which resulted in an incidence of 21.2% .
 the most common anatomical variant was castellvi type ia ( 6.8% ) . in the control group ,
 84 were classified as positive for sacralization , which resulted in an incidence of 16.8% .
 no statistically significant difference was found between the groups for having sacralization ( p = 0.09 ) .
 discussion .
 the relationship between sacralization and low back pain is not clear . because of this controversial future studies need to focus on identifying other parameters that are relevant to distinguishing lumbosacral variation , as well as corroborating the results obtained here with data from other samples .