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:
falls of the elderly always lead to serious health issues as the decline of their physical fitness .
fracture is the most common injury in fall of an elderly and there is also a certain possibility to get coma , brain trauma , and paralysis . at most fall situations , the fall process is the main source of injury because of the high impact . but sometimes the late medical salvage may worsen the situation .
that means the faster the salvage comes , the less risk the elderly will face .
mems ( microelectro mechanical systems ) sensors have simplified the design and implementation of sensor system .
location based service ( lbs ) makes it more convenient to locate the elderly in health monitoring . beside these
cameras are distributed at limited space to offer pictures or videos of human activities to implement fall detection algorithm .
external supports such as motion sensors could be used to enhance computer vision based fall detection method , and a data fusion algorithm can operate the validation and correlation among the two subsystems to raise robust performance of fall detection .
these computer based methods work effectively in indoor environment , but they are hard to realize in outdoor environment as the deployment of cameras is always limited .
there are several kinds of detection methods which differ in constitution of motion sensors and detection algorithms .
a single triaxial accelerometer can provide object 's accelerations in three directions which include the influence of gravity .
the influence of gravity or dynamic acceleration is available by using a low pass filter or a high pass filter .
some kinds of angular movement information can also be calculated based on the relationship between acceleration components and their vector sum .
a triaxial magnetometer can detect magnetic strength in three directions , and it can also provide angular motion information in the horizontal plane .
but the environment magnetic field may disturb the geomagnetic field which reduces the reliability of the magnetometer outputs , for instance , in some steel structure architecture or near some objects with strong electromagnetism . as angular information
can also be extracted from accelerometer measurements , a state space filter such as the kalman filter is a commonly used technique to combine angular motion information . beside these , sensors such as barometer can also assist pure motion sensors at human gait recognition .
but , in fact , using more sensors means more power consumption , and it is a challenge to design a proper algorithm to fuse different kinds of sensors .
a single triaxial accelerometer is quite enough for human fall detection as sufficient information could be extracted from its measurements .
besides this , the accelerometer coordinate does not have to be fixed if only the magnitude of sum vector is needed , and that is quite convenient for wearable application . in this paper , a fall detection system based on a wearable device is developed .
the hardware and software realization of the device is mainly based on a single triaxial accelerometer and gps / gsm module .
the device uses an efficient fall detection algorithm with less resource and power consumption , which means that it is a proper design for outdoor application .
then it will get the elderly 's geographic position and send fall alarm short message to caregivers .
so the elderly who has fallen can get timely help to minimize the negative influence .
information like linear movements ( e.g. , displacement , velocity , and acceleration ) and angular movements ( e.g. , angle , angular velocity , and angular acceleration ) could be obtained directly or indirectly . beside these
, frequency domain parameters could be extracted from basic sensor measurements by techniques such as fft and wavelet [ 11 , 12 ] .
for single triaxial accelerometer application , accelerations and derived angular parameters could be used as recognition features . fall detection algorithm design
according to the recognition feature , fall detection algorithms are classified as threshold based and machine learning based . for threshold
based method , threshold of recognition feature is set by the designer before application which makes the algorithm have rapid response and less resource consumption .
but the choice of threshold needs both rigorous schemes and adequate experiments . for machine learning based design
, the classification of fall and normal activities is available with the assistance of technologies such as support vector machine ( svm ) and neural network [ 14 , 15 ] .
machine learning assistance may enhance system robustness to some extent , but its algorithm design is always high computing resource consumed which limits its application in wearable device . as the compact wearable device requires low power consumption and a single triaxial accelerometer could provide effective information , threshold based fall detection algorithm will be used in this system . algorithm used in this fall alarm system
when a real fall happens , collision between human 's body and ground will produce obvious peak value at the sum acceleration a which has magnitude as
 ( 1)a = ax2+ay2+az2 ,
 where ax , ay , and az present accelerometer measurements of three axes .
the system uses the sum acceleration as the first step to distinguish high intensity movements from others .
but normal motions such as jumping or sitting also produce peak values , which mean that additional detection features are required .
as human 's motion has low acceleration , it is feasible to get gravity component in each axis by using a low pass filter . if gravity components could be separated before and after human 's fall , then it is possible to calculate the rotation angle of accelerometer coordinate in 3d space , which is also equivalent to the rotation angle of gravity vector relative to fixed coordinate .
quaternion is an effective tool to describe rotation movement in human 's gait change which also includes falling .
a quaternion could be described as
 ( 2)q = q0+q1i+q2j+q3k
 which has magnitude as
 ( 3)q = q02+q12+q22+q32 .
unit quaternion which has magnitude q = 1 can be described as
 ( 4)q = cos2+sin2qxi+sin2qyj+sin2qzk. as shown in figure 3 , rotation angle of q equals . the rotation axis is orthogonal to the rotation plane and its direction is in accordance with right hand screw rule .
qx , qy , and qz are three components of the unit vector which describes the orientation of the quaternion at the fixed coordinate .
besides rotation movement , quaternion can also describe a vector in 3d space , such as the gravity vector g which could be described as a quaternion
 ( 5)g=0+gxi+gyj+gzk.gx , gy , and gz are three components of g which has quaternion magnitude as
 ( 6)g = gx2+gy2+gz2=g . a unit quaternion q is used to describe human 's falling movement , which can also be divided into three rotation quaternions q1
, q2 , and q3 to simplify the calculation as shown in figure 4 . with the help of gravity vector information before and after human 's falling movement as shown in figure 3 , these three separated quaternions are all available .

q
 1 could be expressed as
 ( 7)q1=cos12+sin12sini+sin12cosj
 which has rotation angle and rotation axis information as
 ( 8)1=arctangbefore , zgbefore , x2+gbefore , y2,sin=gbefore , ygbefore , x2+gbefore , y2,cos=gbefore , xgbefore , x2+gbefore , y2 .
quaternion q2 can be calculated as
 ( 9)q2=cos22+sin22k
 which has rotation angle as
 ( 10)2=arctan2gafter , ygafter , xarctan2gbefore , ygbefore , x .
quaternion q3 is
 ( 11)q3=cos32+sin32sini+sin32cosj
 with rotation angle and rotation axis information as
 ( 12)3=arctangafter , zgafter , x2+gafter , y2,sin=gafter , ygafter , x2+gafter , y2,cos=gafter , xgafter , x2+gafter , y2 .
then the rotation of the fall movement can be expressed by quaternion multiplication as
 ( 13)gafter = qgbeforeq=q3q2q1gbeforeq1q2q3 ,
 where q=q0-q1i -- q2j -- q3k- is the conjugate quaternion of q. quaternion algebra is normally implemented based on basic matrix algebra .
quaternion multiplication used above could be realized by matrix multiplication as
 ( 14)qgbefore = mq0gbefore , xgbefore , ygbefore , z = q0q1q2q3q1q0q3q2q2q3q0q1q3q2q1q00gbefore , xgbefore , ygbefore , z .
the whole rotation quaternion can also be decomposed as
 ( 15)q = q3q2q1=mq3mq2q1.q1 , q2 , and q3 are all available based on gravity information before and after the falling movement . at last , it is possible to get four elements of quaternion q by the equation above and the rotation angle  could be calculated as
 ( 16)=2arctanq12+q22+q32q0 .
when an object is falling , magnitude of  will approach 90 which is also a character different from most normal activities .
the wearable device will be mounted on human 's waist at first to reflect the motion of human body closely , and the device will record gbefore while the elderly is standing still .
there is no special requirement of the device orientation but only keep stationary during the wear .
athreshold means the threshold of sum acceleration magnitude and tthreshold means the threshold of oscillation time duration after the break of athreshold . when measurements in three different axes have been acquired , the sum acceleration |a| will be calculated .
when a real fall happens , sum acceleration will reach peak value of |a|  athreshold . in a real falling
, the fluctuation of acceleration will stop in time duration tthreshold and then the sum acceleration is |a|  g as the elderly will lie on the ground . then the acceleration a is recorded as gafter .
, the system will consider it as a fall if the rotation angle ||  90.
ti 's 16 bits mcu msp430f1611 is used to control the whole system and imply the detection algorithm .
the measurement range of accelerometer could be set at 2  g , 4  g , 8  g , or 16
g , and the maximal sampling rate is 3.2  khz . as human 's activities are normally at low frequency bands , 100  hz is a proper sampling rate for human fall detection .
there is an inner digital filter in adxl345 which could weaken noise and reduce the burden of digital signal processing in mcu to some extent .
the measurements will be sent through iic ( interintegrated circuit ) bus communication between the sensor and the mcu .
sim908 can offer gps and gsm service on serial port communication with mcu , and it can also work in low power mode .
each hardware component of the wearable device is working under low voltage and the detection algorithm does not need complex calculation resource , so the power consumption of the whole device is quite low .
a 1200  mah , 3.7  v polymer lithium battery is quite enough to provide the need of the wearable device for a couple of days .
hardware structure of the detection device is shown in figure 6 , and the pcb board prototype is shown in figure 7 .
one of them is the software design in wearable device , and the other is in the caregiver 's handset .
after initialization of the system , gbefore would be extracted from acceleration measurements by using a low pass filter when the elderly is standing .
if a fall has been detected , the wearable device will locate the user and send alarm short message to caregivers immediately .
if the user withdraws the alarm by pressing a button manually , the device will get back to fall detection state and a short message will be sent to inform the caregivers .
there is a url ( universal resource locator ) which links to a web map in the alarm short message .
the fall location information will be highlighted on a web map when the caregiver opens this link .
system test of the fall detection system has been conducted based on the system design described above . the sampling rate of accelerometer is set at 100  hz and the measurement range is 16  g with a maximum precision of 4  mg .
mcu will read raw measurements from sensor 's inner fifo and apply the detection algorithm .
the test objects are three different volunteers at the ages of 23 , 42 , and 60 , respectively . based on analysis of these volunteers ' experiment data , athreshold and tthreshold
are set as 2  g and 2  s , respectively . in order to get g
when standing and lying after the fall , sum acceleration a which has magnitude between ( 1  0.3 )  g and ( 1 + 0.3 )  g will be considered as gbefore and gafter .
considering that the tilt of the ground or the lying posture of the elderly may affect the rotation angle , rotation angle  between ( 90  30) and ( 90 + 30) will infer that the elderly has fallen .
system test contains five kinds of activities of daily living ( i.e. , walking , jumping , squatting , sitting , and resting ) and four kinds of fallings ( i.e. , forward , backward , leftward , and rightward ) .
each kind of motion has been repeated 20 times on each volunteer , and the detection results of the proposed algorithm and an acceleration threshold based algorithm   are listed in table 1 . the sensitivity and specificity [ 21 , 22 ] of the proposed system can be got from the test data in table 1 .
test results of acceleration threshold based algorithm show lower sensitivity and specificity at 91.6% and 88.7% , respectively .

figure 9 shows the accelerations in different kinds of fallings which all trigger the fall alarm correctly and the corresponding rotation angles are 91.9 , 100.5 , 104.7 , and 114.1.
 figure 10 shows acceleration during activity of lying down and resting which has rotation angle of 117.0 and similar waveform to falling , but the peak acceleration is much lower .
they all do not have rotation about 90 ; even some of the peak values are quite high , so the fall alarm has not been triggered .
an alarm sms ( short message service ) containing a map url has been received by the handset as shown in figure 12 when a fall has been detected . clicking
the url will open a map in web browser on which the fall location will be displayed accurately as shown in figure 13 .
this paper developed a fall detection system based on a single triaxial accelerometer based wearable device .
there is no special requirement of the device 's mounting orientation because the algorithm does not claim the axes of accelerometer to be fixed strictly .
the system has low power consumed hardware design and highly efficient algorithm which could extend the service time of the wearable device .
as normal activity of resting also has similar rotation as falling , it may trigger fall alarm when the body hits ground heavily .
so the choice of athreshold is quite important to distinguish falling from heavily lying activity .
sufficient sample number collected from subjects with different age and gender will improve the reliability and robustness of the threshold . beside these , technologies such as svm and neural network are considerable to seek out a proper classification method based on the features used in this system .

Answer:
fall detection is a major challenge in the public healthcare domain , especially for the elderly as the decline of their physical fitness , and timely and reliable surveillance is necessary to mitigate the negative effects of falls .
 this paper develops a novel fall detection system based on a wearable device .
 the system monitors the movements of human body , recognizes a fall from normal daily activities by an effective quaternion algorithm , and automatically sends request for help to the caregivers with the patient 's location .


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:
when they look at the smartphone screen in this posture for a long time , they experience
 shoulder and neck pain , and occasionally complain of headaches1 .
when continuous loads are applied in a static posture with the head
 kept lowered , musculoskeletal diseases may develop2 .
this may lead to myofascial pain syndrome by causing stress and excessive tension in the
 muscles around the neck and shoulders3 .

myofascial pain syndrome may develop along with tissue damage , or abnormal conditions may
 occur as a result of abrupt stress or excessive tension on the muscles4 .
jobs that require sitting at a desk for long hours , such as computer and office work ,
 negatively influence the neck and shoulder muscles5 .
in addition , changes in the strength of the deep cervical flexors ,
 endurance , and the location of the lower jaw have been shown in individuals with neck pain ,
 compared with individuals without neck pain6 .
kieine and schumman studied the activity of the upper trapezius associated with changes in
 shoulder postures , and tepper studied the effects of computer work on the activity of the
 upper trapezius7 , 8 .
these studies found that incorrect postures cause excessive tension
 in the upper trapezius and the surrounding muscles .
such excessive tension is known to cause
 pain by developing abnormal forces in the skeletal system9 , 10 .
the measurement of cervical - bent postures of women using computers showed increases in the
 head tilting of women complaining of pain11 .
a large proportion of the existing studies have focused on the
 visual display terminal ( vdt ) that is commonly seen with office computers .
in addition , some
 studies have examined the fatigue and activity of cervical muscles under the postures
 adopted while using a microscope in the workplace as well as the activity of cervical
 muscles while individuals were watching a digital multimedia broadcasting ( dmb ) phone12,13,14 .
smartphones and tablets have recently
 drawn a great amount of attention and have become almost daily necessities ; however , these
 devices and other similar new devices may cause cervical deformities when used for extended
 hours . therefore
, multiple studies on changes in the activity and fatigue of cervical
 erectors in the postures of smartphone users should be conducted in various environments to
 prevent skeletal diseases .
therefore , this study was conducted to investigate the changes in
 the activity and fatigue of the splenius capitis and upper trapezius agonistic muscles , the
 muscles that support the head , under the three postures adopted most frequently while using
 a smartphone .
in this study , the three common postures while using a smartphone were considered as
 independent variables , and the corresponding muscle activity and fatigue as dependent
 variables .
the experiment was based on a within - group design in which tests were performed
 on a single group under three different conditions .
the subjects were 15 college students in
 their 20s who were given complete explanations about the experiment in advance .
the subjects
 were required to be healthy individuals with no history of spinal damage or undergoing any
 surgery , and no hand or wrist injuries or other surgeries during the preceding six months .

all participants were instructed about potential risks and experimental design , and were
 provided with an informed consent form to sign prior to participation , with the knowledge
 that they could withdraw at any time .
general
 characteristics of the subjects are shown in table
 1table 1.general characteristics of the subjectsmeanectage ( yrs)23.6  2.4height ( cm)174.7  7.6weight ( kg)69.2  11.9gender ( men / women)8/7 .
the muscles targeted for measuring muscle activity were the splenius capitis and upper
 trapezius , which are the agonistic muscles for cervical extension and are known to cause
 neck pain11 , 15 .
the researcher identified the location of these muscles by
 activating the areas around the subjects relevant muscles , and then attached electrodes , as
 shown in table 2table 2.locations for attachment of electrodesmusclelocationsplenius capitismidpoint between the spinous process of c7 and the
 peak of the shoulder bladeupper trapeziusthe point 2 cm away from the lateral side of t4 , by referring to previous studies15 .
the electrodes were attached after sterilization with alcohol
 would be adequate , and the electrodes were attached after sterilization with alcohol using
 cotton balls .
the markers of a three - dimensional motion analyzer were attached to
 objectively determine the maximum cervical bending posture , middle cervical bending posture ,
 and neutral posture .
the markers were attached to the center of the forehead , the seventh
 cervical vertebra ( c7 ) , and the seventh thoracic vertebra ( t7 ) .
a chair of the same height as that in a subway train was prepared , and each subject was
 instructed to sit in the chair with his or her hips touching the back of the chair and the
 pelvis fixed . in the maximum bending posture ,
the subject was instructed to place a
 smartphone as high as the subject s elbow and grab it with both hands 5  cm away from the
 trunk ( fig .
maximum bending posture in the middle bending posture , the subject s her upper arms were close to the trunk and the
 neck was bent slightly in a comfortable manner ( fig .
 2fig .
the edge of the upper part of the smartphone s screen and
 the subject s eye level were kept horizontal ( fig .

the average degree of neck - bending during each of the three postures was obtained
 by measuring and averaging the degrees of the three motion markers for each posture during
 preliminary tests on five subjects .
the average degree of neck - bending was 100 for the
 maximum bending posture , 122 for the middle bending posture , and 131 for the neutral
 posture .
a height - adjustable table was prepared to support the subjects arms during the
 postures to avoid fatigue in the arms16 .

surface electromyography ( semg ) was used to measure the 15 subjects while they remained in
 the three postures , and measurements were performed randomly to reduce errors caused by
 measuring in the sequence of the postures .
while each subject was adopting each posture for
 five minutes , he or she was instructed to continuously type the sentences  the blue house is
 not seen from the outside .  and
after five
 minutes , the subject s muscle activity and fatigue were measured . after being measured under
 one condition ,
each subject was provided with a 24-hour break to recover from fatigue , and
 then was tested under the next condition17 . in this study , a chair having the same height as that of a seat in
 a subway train and a height - adjustable vibrating table was used .
the smartphone used during
 the experiment was one that is commonly used by koreans , and a three - dimensional motion
 analyzer ( smart e , italy ) was employed to measure the degree of bending during each posture .

a wireless electrode emg system ( free emg , bte , italy ) was used as an emg device to identify
 the muscle activity and fatigue of the splenius capitis and upper trapezius .
emg data from
 the maximum cervical bending postures , middle cervical bending postures , and neutral
 postures were applied into root mean square ( rms ) for five minutes , and mean values were
 also calculated for one  min and were normalized by % rvc18 .
middle bending posture the study data were analyzed statistically , using spss version 18.0 for windows .
the
 kolmogorov - smirnov test was used to confirm that the characteristics of the data used in
 this study represented normal distribution .
an analysis of variance ( anova ) test was
 conducted to compare the activity and fatigue of the cervical erector during the three
 different postures while using the smartphone .
scheffe s test was employed as a post - hoc
 test on the statistically significant differences between the muscle groups , and the
 statistical significance level for all data was set at =0.05 .
in terms of the differences in the muscle activity for each posture , the four muscles
 measured ( right splenius capitis , right upper trapezius , left splenius capitis , left upper
 trapezius ) did not show any statistically significant differences ( table 3table 3.comparison of the muscle activity under the posturesmuscleposturemeanstandard deviationright splenius capitisneutral posture14.27.4middle bending posture13.48.2maximum bending posture 18.825.9right upper trapeziusneutral posture8.95.8middle bending posture5.53.9maximum bending posture 7.15.7left splenius capitisneutral posture14.29.9middle bending posture13.111.0maximum bending posture 13.711.0left upper trapeziusneutral posture7.74.4middle bending posture5.63.9maximum bending posture7.91.2 ) .
the comparison of muscle fatigue among the postures showed statistically significant
 differences for the right splenius capitis , left splenius capitis , and left upper trapezius
 ( table 4table 4.comparison of the muscle activity under the posturesmuscleposturemeanstandard deviationright splenius capitisneutral posture0.20.0middle bending posture0.20.0maximum bending posture0.20.0right upper trapeziusneutral posture0.20.0middle bending posture0.20.0maximum bending posture0.20.0left splenius capitisneutral posture0.20.0middle bending posture0.20.0maximum bending posture0.20.0left upper trapeziusneutral posture0.20.0middle bending posture0.20.0maximum bending posture0.20.0values are shown as mean  sd , * p<0.05 . significant difference in
 three postures . : significantly different compared with middle bending
 posture . : significantly different compared with maximum bending
 posture . ) .
values are shown as mean  sd , * p<0.05 . significant difference in
 three postures .
the purpose of this study was to examine changes in muscle activity and fatigue under
 different postures while using a smartphone , because of their rapidly increasing use . in
 particular , polakowska reported that cervical degenerative changes appear due to working
 postures , types of motions during work , and amplitude of vibration ; paccinni et al . reported
 that improper postures are associated with abnormal cervical curvatures19 , 20 .
therefore , one
 aim of this study was to provide basic data on correct postures while using a smartphone to
 prevent neck pain and deformation that can occur due to their extended use in undesirable
 postures . in terms of changes in muscle fatigue associated with postural changes during
 smartphone use , this study showed that the maximum bending posture resulted in significantly
 higher levels of muscle fatigue in the right splenius capitis , left splenius capitis , and
 left upper trapezius , compared with middle bending posture .
there were no significant differences in muscle activity in the right splenius capitis ,
 left splenius capitis , and left upper trapezius among the three postures .
however , there
 was no change in muscle activity because of the experimenter s tension by the awareness of
 experiments was not controlled and the realization of real long - time smart phone use was
 limited by measuring emg signal for short smart phone using time of five minutes21,22,23.this result is consistent with that of
 jung s study , in which during the head - neck bending exercise of the cervical lordosis group ,
 kyphosis group , and hyperlordosis group , a comparative analysis was performed on the
 activity of the deep flexor and the sternocleidomastoid using pressure and ultrasonic
 images , and a higher level of pressure led to a corresponding increase in the activity of
 the deep cervical flexor24 .
, these results may be because muscles exercise their forces in the
 opposite direction to fight opposite movements25 .
however , the results of this study differ from those of some
 previous studies .
for example , thuresson compared muscle activity during the cervical
 neutral posture and cervical 20 forward bending posture on the axis of c7t1 , and found a
 higher level of muscle activity during the 20 forward bending . in addition , yoo compared
 muscle activity during the neutral posture and bending posture , and reported a statistically
 significant higher level of muscle activity during the bending posture17 , 26 . according to
 the results of villanueva s study , in which the trunk s movements affected the activity of
 the muscles that surround it , continuous use of smartphone in the present study may have
 caused contractions of muscles in the hands , wrists , and arms .
thus , muscle activation in
 the cervical erector was not only confined to the cervical area but also spread into the
 hands , wrists , and arms , thereby resulting in no statistically significant changes in muscle
 activity27 . in this study ,
the muscle fatigue under the maximum bending posture and neutral posture
 showed similar levels of increases , although this result was not statistically significant .

some studies have reported that a smaller degree of joint flexion led to a statistically
 significant higher level of muscle fatigue , which may also support the present study
 result28 , 29 .
in addition , a smaller degree of cervical flexion increases the
 level of head - lowering , and the head is then influenced by gravity to a larger extent30 . here , a larger load is applied to the
 cervical erector to support the relevant position , which may cause increased levels of
 fatigue .
first , the subjects were measured while they were
 using a smartphone for a short time of five minutes ; therefore , the study did not fully
 reproduce the situation of individuals using their smartphones in the subway , which is
 typically for longer periods .
in addition , the subjects were 15 college students in their
 20s , and thus , the results derived can not be generalized for various age groups .
moreover ,
 it was difficult to control the subjects daily activities during the 24-hour break provided
 after each measurement . consequently , a follow - up study should fully reproduce the
 conditions in which individuals use their smartphones on public transportation , and test
 subjects from various age groups for longer durations of smartphone use .

Answer:
[ purpose ] the purpose of this study was to identify changes in the activity and fatigue
 of the splenius capitis and upper trapezius muscles , which are agonists to the muscles
 supporting the head , under the three postures most frequently adopted while using a
 smartphone . [ subjects and methods ] the subjects were 15 college students in their 20s .

 they formed a single group and had to adopt three different postures ( maximum bending ,
 middle bending , and neutral ) . while the 15 subjects maintained the postures , muscle
 activity and fatigue
 were measured using surface electromyography .
 [ results ] comparison of
 the muscle fatigue caused by each posture showed statistically significant differences for
 the right splenius capitis , left splenius capitis , and left upper trapezius muscles . in
 addition , maintaining the maximum bending posture while using a smartphone resulted in
 higher levels of fatigue in the right splenius capitis , left splenius capitis , and left
 upper trapezius muscles compared with those for the middle bending posture .
 [ conclusion ]
 therefore , this study suggests that individuals should bend their neck slightly when using
 a smartphone , rather than bending it too much , or keep their neck straight to reduce
 fatigue of the cervical erector 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:
ameloblastomas are rare benign odontogenic tumours , most commonly found in a patient s lower jaw .
although rarely metastatic , the growth of these lesions can result in defects in the jaw easily destroying surrounding bony tissues .
for this reason , the treatment is often excision of the lesion , with wide excision margins , resulting in the absence of a part , or all , of the mandible .
the surgical approach for correction of this mandibular defect is often reconstruction of the mandible in view of inserting dental implants at a later date . despite surgical advancements ,
, bone grafting with non - vascularized bone remains a good option where facilities for soft tissue flaps are not readily accessible .
creating an effective wound closure and reducing the incidence of infection is an important stage in the success of the operation , and has been combated here by tissue expanding the submucosa , using osmed pellets , prior to surgery .
this is a relatively new technique to the mandibular region and has the potential to revolutionize the success of microsurgeries in this area . in this report
, i describe a woman who underwent a repair of her mandibular defect by a combination of innovative techniques , in order to reduce the risk of complications and get her back to an aesthetically pleasing level .
a 35-year - old lady presented to the craniofacial surgeons looking for a permanent fixture to the bony defect in her lower - right mandible . in 1991
she had her first operation to remove the ameloblastoma and then had it further excised 6 years later due to a reoccurrence .
this resulted in an absence of teeth from the canines back and removal of bone down to the inferior alveolar nerve .
the patient has since been clear of any further reoccurrences and wears lower dentures for aesthetic reasons .
she has no significant past medical history nor family history , nor does she have any known drug allergies .
she does not smoke or drink alcohol . on clinical examination , the patient experiences mild parasthesia in the distribution of her right inferior dental nerve , particularly the lateral aspect of the lower lip . on examination ,
there is clear absence of teeth on the lower - right side from the canines back ( to include the premolar , molar and wisdom teeth ) and presence of healthy oral mucosa with laxity to move the submucosa medially .
there is a loss of the vertical height of the posterior body of the mandible of about 50% and the vestigial remnants of the lingual plate are just palpable and visible on plain radiograph and ct .
scans show that the superior margin of the resection is well corticated under the inferior dental nerve ( fig .
, the patient wishes to get dental implants . the surgical approach taken , prior to the implants ,
( b ) ct scan of head imaging of the patient 's mandibular defect pre - surgically .
( a ) radiolocal image of patient 's jaw . ( b ) ct scan of head the patient was initially given the option between a bone graft or vascularized tissue ( free fibular flap ) and informed of the complications  a bone graft carries a risk of rejection and vascularized tissue needs an increased amount of post - operative care to ensure that the tissue remains vascularized .
the patient was not keen on a free flap and given the fact that the bony deformity was < 5 cm , non - vascularized iliac bone graft was deemed to be sufficient to carry out this operation .
the first step was achieving significant tissue expansion ( > 2 cm ) using osmed pellets , guided into the submucosa and kept over the alveolar ridge for several months ( fig .
( c ) osmed pellets before insertion into the submucosa image of patient 's oral cavity during insertion of osmed pellets . ( a ) incisions made in the submucosa .
( c ) osmed pellets before insertion into the submucosa two months later , the patient underwent the main bulk of her operation .
the osmed pellets were removed from the subperiosteum ( fig .  3a and b ) and the iliac bone graft
was taken , made up of cortical and cancellous bone and placed to one side ( fig .
an epidural catheter was placed inside the soft tissue of the graft site and left overnight .
it had a continuous fusion of a local anaesthetic to improve post - operative pain and encourage early mobilization .

( b ) open site where iliac bone graft is harvested from ( c ) cortical and cancellous iliac bone submucosa after adequate tissue expansion .
( b ) open site where iliac bone graft is harvested from ( c ) cortical and cancellous iliac bone previously , using ct scans , a titanium construct was made to guide the outline of the bone graft and complete the missing height and width of the mandible .
once fitted to the patients jaw , it was packed with the bone graft and screwed down into position ( fig .
a slight groove was made on the mandible to allow space for the inferior dental nerve to lay , so that the construct did not compact the nerve and cause functional problems .

figure  5:titanium construct packed with iliac bone graft and screwed into position on the lower mandible titanium construct packed with iliac bone graft and screwed into position on the lower mandible to complete the surgery , the periosteum was sutured over the construct and then the buccal muscosa was sutured over again to form a double - layered closure ( fig .
6a  c).the purpose of this was to prevent infection and rejection , by ensuring that there was an increased distance between the foreign object ( titanium construct ) and the outside environment .
the dental implants are scheduled to be inserted several months after this operation .
 figure  6:image of patient 's surgical site .
( c ) image of post - surgical site image of patient 's surgical site .
bony defects in the maxillofacial area are a huge problem in clinical orthodontics , caused by a wide range of injuries and diseases presenting as either cosmetic or functional defects and in some instances both .
it is the importance of accounting for the anatomical , functional and aesthetic aspects that make the reconstruction so challenging .
often patients suffering from ameloblastomas undergo resection as treatment and are left with bony defects that require reconstruction . in this case , the intention was to realize an aesthetically pleasing appearance for the patient and it has been shown that bone grafting with subsequent dental implants is a successful method . as in this case , it is recommended that non - vascularized autogenous bone grafting can be used when a two - layer watertight closure is attainable .
sources of bone could have been harvested from either local or distant sites but in this case , an extra - oral site ( iliac bone ) was used as a moderate amount of bone was needed .
the surgery lasted 5 h and incorporated several novel techniques to improve the outcome of the operation .
the use of osmed pellets was innovative , as pellets of this size have only recently been experimented on goats maxilla .
as well as allowing for space to put the construct , the pellets allowed for a tension - free closure .
otherwise , the result would have been a high - tension closure , leading to rapid breakdown of the graft providing an entrance for infection , a common complication occurring when titanium plates are exposed .
advantages of the osmed tissue expanders are that the material is safe with a low complication rate and low risk of infection due to small incision site and minimal trauma .
the titanium construct is another relatively novel approach and was invaluable in the success of this surgery , as it guided reconstruction of the mandible , allowing for dental implants to be put in at a later date . at present , an alloplastic material such as titanium is often used for mandibular reconstruction as it is resistant to corrosion , adaptable and biocompatible .
although the insertion of dental implants is the end goal for this surgery , the importance of this case report is to highlight the novel techniques involved in making this surgery a success . the use of small osmed pellets in the submucosa of the mouth to cause sufficient tissue expansion and create a tension - free closure , combined with the titanium construct packed with grafted iliac bone to rebuild the jaw was an approach recommended by the doctors for the repair of bony defects of < 5 cm .
i suggest prudent management of future cases post - operatively to ensure a continued success of the graft .

Answer:
this case report describes a 35-year - old caucasian radiographer who presented with a significant mandibular bony defect following multiple excisions of an ameloblastoma . as a result , there was an absence of teeth on the lower - right mandible and a clear defect in the mandible .
 the treatment objectives were to rebuild the mandibular defect , with a long - term view of inserting dental implants . in a novel approach outlined in this presentation , tissue expansion of the submucosa , a titanium construct and an iliac bone graft
 were used to rebuild the patient s jaw .
 this surgical technique is recommended for the reconstruction of bony defects .


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:
simultaneous occurrence of hashimoto 's thyroiditis ( ht ) , and graves disease ( gd ) is rare .
a 60-year - old lady presented with tremulousness of hands , palpitation , and excessive sweating .
her weight was 46 kg , bmi 17 , afebrile , regular pulse rate of 110/min with fine tremor in hands .
thyroid gland was symmetrically enlarged , firm , without any bruit , but mildly tender with lobular surface .
initial thyroid function tests ( tft ) revealed : t3 : 3.80 ng / ml ( 0.80 - 2.10 ) , t4 : 12.40 ug / dl ( 5.10 - 12 ) , thyroid stimulating hormone ( tsh ) : 0.20 u / l ( 0.70 - 5 ) .
her anti thyroperoxidase ( tpo ) antibody : 374 iu / ml ( normal [ nl . ]
< 35 ) and tsh receptor antibody : 15 u / l ( nl . < 1 ) were both strongly positive .
99mtc pertechnetate scan showed an enlarged gland with increased uptake of radiocontrast : 17% ( nl .
thyroid fine needle aspiration cytology ( fnac ) showed sheets of hurthle cells with abdunce of lymphocytes indicating ht .
repeat tft , 3 months later showed : t3 : 4.20 ng / ml , t4 : 14.40 ug / dl , tsh : 0.001 u / l , with increased uptake on repeat scan .
our case of an elderly lady with no eye signs , lobular , firm tender goiter with patchy uptake in both lower poles on tc99 m scan were odd points in diagnosing isolated gd .
hashimoto 's thyroiditis ( ht ) and graves disease ( gd ) are the two main types of autoimmune thyroid disease .
ht rarely occurs following gd . but combined occurrence of gd and ht are rare .
a 60-year - old lady , presented with tremulousness of hands for 1 month and palpitation with excessive sweating for 3 months .
she had a history of weight loss for 6 months , and gradually enlarging neck swelling for 3 years .
her weight was 46 kg , bmi 17 , afebrile , pulse rate : 110/min / regular , blood pressure : 140/56 mm of hg .
her thyroid gland was symmetrically enlarged , firm in consistency , nodular / lobular surface and mildly tender without any bruit .
initial thyroid function tests ( tft ) revealed high t3 : 3.80 ng / ml ( 0.80 - 2.10 ) , t4 : 12.40 ug / dl ( 5.10 - 12 ) with a low tsh : 0.20
mu / l ( 0.70 - 5 ) . her tsh receptor antibody ( tsab ) : 25 u / l ( normal [ nl .
] < 1 ) , anti tpo antibody : 374 iu / ml ( nl . < 35 ) and thyroglobulin antibody : 268 iu / ml ( nl . < 65 ) were all strongly positive .
ultrasonogram of thyroid revealed an enlarged gland with hypoechoic parenchyma with fibrous septa.tc pertechnetate scan ( tc99 m scan ) revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast : 17% ( nl .
thyroid fnac showed sheets of hurthle cells with abdunce of lymphocytes and sheets of regular follicular cells , indicating ht .
repeat tft , 3 months later showed : t3 : 4.20 ng / ml , t4 : 14.40 ug / dl , tsh : 0.001 u .
repeat tc pertechnetate scan was done , which again revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast : 21% ( nl .
our patient presented with clinical symptoms and signs of thyrotoxicosis along with slightly raised t4 , t3 and low tsh with positive tsab , and diffusely increased uptake on tc99 m scan , all in favor of a diagnosis of gd .
however , there were some odd features such as elderly age , absence of eye signs , nodular , firm mildly tender goiter , hypoechoic parenchyma in ultrasonography ( usg ) , and patchy uptake in both lower poles on tc99 m scan .
fnac of the thyroid gland was suggestive of ut fnac of thyroid gland suggested ht .
so we adopted a wait and watch policy , and put the patient on beta blockers .
repeat tft , 3 months later showed persistent thyrotoxicosis and repeat tc99 m scans revealed an enlarged thyroid gland with diffusely increased uptake of radiocontrast .
diffusely increased uptake on tc99 m scan rules out hashitoxicosis , which mostly resolves within 3-months time - frame .
a diagnosis of combined occurrence of hyperthyroid gd and hd was established and anti - thyroid medication started .
reported four cases of ht in previously diagnosed patients with gd hyperthyroidism . in three cases ,
ht occured 7 - 25 years after gd treatment ; in one , it developed in a few months of gd treatment .
the diagnosis of ht was based on clinical manifestation , positive tpo and thyroglobulin antibody , and fnac .
all were middle - aged women , who had high titers of anti - thyroid antibodies and thyrotoxicosis at the onset of painful ht .
reported seven patients with hypothyroidism due to hashimoto 's disease , who developed hyperthyroid gd .
some had transient , some persisistent hyperthyroidism due to gd following hypothyroidism due to ht .
ht and gd represent the main two types of autoimmune thyroid disease . gd is caused due to hyperplasia and hyperfunction of the thyroid gland by stimulating tsab .
on the contrary , ht is thought to be due to a tsh stimulation - blocking antibody ( tsbab ) which blocks the action of tsh hormone and subsequently brings damage and atrophy to the thyroid gland .
alterations in the thyroid state related to the balance between the activities of tsab and tsbab .
moreover , approximately 15 - 20% of patients with gd have been reported to have spontaneous hypothyroidism resulting from the chronic ht .
patients with gd who have achieved remission on anti - thyroid drugs may also experience ht or hashitoxicosis or intermittent transient hyperthyrodism .
they may have both ht and gd since antibodies associated with both diseases may be present . to distinguish from relapsed gd a wait and see approach is beneficial .
a definitive diagnosis can be made by fnac biopsy , that is , fine - needle aspiration .
hashimoto 's disease , which occurs following gd may be due to extended immune response to endogenous thyroid antigens , i.e. thyroid peroxidase and thyroglobulin , which may enhance lymphocyte infiltration and finally cause ht . in conclusion , ht rarely occurs following gd . in our case of an elderly lady ,
absence of eye signs , lobular - firm tender goiter with patchy uptake in both lower poles on tc99 m scan were odd points in diagnosing isolated gd .

Answer:
introduction : simultaneous occurrence of hashimoto 's thyroiditis ( ht ) , and graves disease ( gd ) is rare.aims and objectives : we report a case of simultaneous occurrence of gd and hd , at presentation.case report : a 60-year - old lady presented with tremulousness of hands , palpitation , and excessive sweating .
 she had a history of weight loss and neck - swelling .
 her weight was 46 kg , bmi 17 , afebrile , regular pulse rate of 110/min with fine tremor in hands .
 thyroid gland was symmetrically enlarged , firm , without any bruit , but mildly tender with lobular surface .
 there were no occular manifestations .
 initial thyroid function tests ( tft ) revealed : t3 : 3.80 ng / ml ( 0.80 - 2.10 ) , t4 : 12.40 ug / dl ( 5.10 - 12 ) , thyroid stimulating hormone ( tsh ) : 0.20 u / l ( 0.70 - 5 ) . her anti thyroperoxidase ( tpo ) antibody : 374 iu / ml ( normal [ nl . ]
 < 35 ) and tsh receptor antibody : 15 u / l ( nl .
 < 1 ) were both strongly positive .
 ultrasonogram of thyroid revealed a hypoechoic enlarged gland .
 99mtc pertechnetate scan showed an enlarged gland with increased uptake of radiocontrast : 17% ( nl .
 0.4 - 4% ) with some patchy defects in both lower poles .
 thyroid fine needle aspiration cytology ( fnac ) showed sheets of hurthle cells with abdunce of lymphocytes indicating ht .
 she was observed on beta blockers .
 repeat tft , 3 months later showed : t3 : 4.20 ng / ml , t4 : 14.40 ug / dl , tsh : 0.001 u / l , with increased uptake on repeat scan.conclusion:ht rarely occurs following gd .
 our case of an elderly lady with no eye signs , lobular , firm tender goiter with patchy uptake in both lower poles on tc99 m scan were odd points in diagnosing isolated gd .
 fnac confirmed simultaneous hd with gd .


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 52-year - old female patient visited the hospital complaining of pain in both breasts .
the pain started immediately after breast reduction surgery she underwent 3 years previously at a private plastic surgery hospital , and it had continued despite a subsequent surgery .
the pattern of the pain included burning , shooting and itching sensations at the operation site as well as unbearable burning sensations when the patient was in the places where the temperature was higher than normal .
the pain as measured by the visual analogue scale ( vas ) was approximately 70/100 mm .
in particular , the degree of pain was dependent on the season , and it was unbearable under hot weather , with the patient complaining of pain at vas 80 - 90/100 mm . before coming to the hospital , the patient had taken aceclofenac ( airtal , daewoong pharmaceutical ) 200 mg , pregabalin ( lyrica , pfizer ) 300 mg , acetaminophen 1,300 mg and tramadol hcl 150 mg ( ultracet , janssen korea ) per day , but the pain was not relieved .
thus , the patient tried pregabalin 600 mg , acetaminophen 1,300 mg and tramadol hcl 150 mg per day , but there was no effect .
complaining of dizziness due to ultracet , the patient started to take 20 mg of oxycodone hcl ( oxycontin , mundipharma korea ) each day , but she eventually stopped taking it because of dizziness , nausea , and vomiting .
subsequently , the patient underwent drug treatment with pregabalin 300 mg a day , but she visited the hospital because the pain did not subside .
there was no specific finding in a simple plane chest x - ray spectrograph , while digital infrared thermographic imaging ( diti ) showed a slight temperature drop in both breasts .
because the previous treatments were not effective in improving the symptoms and because the patient wanted another method of treatment due to the continued pain , it was decided that a thoracic epidural block would be performed , and informed consent was obtained from the patient .
the patient was laid on her side and the epidural space was checked using the loss - of - resistance method with a 22-gauge epidural needle ( hakko , japan ) in between the t4 and t5 , applying an aseptic technique in the interlaminar approach .
0.5% mepivacaine hcl ( emcaine 2% inj. reyon pharm ) 6 ml was then injected .
the pain was relieved into the vas range of 40 - 50/100 mm after the procedure , and the patient was discharged .
the vas was decreased to 40 - 50/100 mm after an additional procedure a week later , but the patient complained of continued pain .
a decision was made to carry out prf to the spinal nerve and its root and . to measure the level and determine the effect
, informed consent was received from the patient after she was provided with an explanation of the procedure and the side effects that may occur after the procedure . for the diagnosis ,
selective nerve root block ( snb ) was performed at t3 , t4 and t5 , one level each time in order with an interval of 2 days , by injecting 1% lidocaine 0.5 ml with a 25-gauge quincke needle ( spinocan , bbraun ) .
prf was carried out at the fourth thoracic spinal nerve and its root after giving an explanation to the patient about the procedure and the side effects that may occur after the procedure and receiving informed consent once again . after supporting the patient 's lower abdomen with a pillow and placing her in a prone position ,
the site of the procedure was disinfected by a common sterilizing method and a standard monitor was attached .
the area between t4 and t5 was identified in the anteroposterior view using a c - arm device and the 4 cm point right lateral from the t4 spinous process was chosen as the needle implantation point .
local anesthesia was carried out with 1% lidocaine , and a 20-gauge 10 cm long rf cannula ( owl sharp curved rf insulated cannula , diros technology inc . ,
usa ) with a 10 mm - active tip was then introduced into the anesthetized part . by continuously monitoring the position of the cannula with the c - arm
, it continued to the inferior of end plate of fourth thoracic vertebral body ( fig .
1 ) , and the tip of the cannula was located at the posterior border of the vertebral space in the lateral view ( fig .
3 ) , and an rf generator ( rfg-3c plus , radionics , usa ) was then connected and an electric stimulus of 50 hz at 0.1 volt was applied .
electric stimulus of 2 hz at 0.1 volt was applied , and it was verified that the muscle did not contract up to 0.8 volt .
one minute after injecting 1% mepivacaine 1 ml , prf was performed two times for 120 seconds at 42. the same procedure was performed on the opposite side after one week . during the procedure , the vital signs of the patient were normal and no side effect took place . after the procedure , the pain was reduced to vas 20 - 30/100 mm .
the patient currently undergoes oral administration of pregabalin 300 mg / day and nortriptyline ( sensival , ilsung pharm ) 10 mg / day and this was followed up at the hospital for 9 months without particular exacerbation of the pain or any other inconvenience in her daily tasks .
pain after breast surgery , which is commonly complaint by patients , is known to be related with the injury , ischemia and inflammation of the soft tissue .
if the pain in the affected part and arm continues for one year after the surgery , it is considered as chronic pain in general .
the mechanism is not yet accurately known , but the chronic pain may be caused by injuries in various peripheral nerves that arise during the surgery and can develop into neuropathic pain such as stabbing , pricking , burning , shooting and sharp pains .
wallace et al .   investigated 282 women who underwent different types of breast surgery , and their result showed that 31% of women who underwent mastectomy , 49% of those who underwent mastectomy with reconstruction , 38% of those who underwent cosmetic augmentation and 22% of those who underwent breast reduction complained of pain up to one year after the surgery .
particularly , as the survival rate of breast cancer patients has increased , the number of patients who complain of chronic pain after breast cancer survey has also increased .
the patient in this case study was also a chronic neuropathic pain patient whose pain had continued for 3 years following breast reduction surgery .
she complained of pricking , shooting and burning sensations at the site of the operation .
although the patient complained of pain immediately after the surgery , she continued to suffer neuropathic pain for 3 years without being given appropriate pain treatment because she was not able to take medicine due to the side effects of the drugs .
macrae   stated that severe acute pain after the surgery may be a risk factor for chronic pain .
this can be one possible cause of the chronic pain of the patient in this case report , because she complained severe pain at vas 70 - 80/100 mm immediately after the surgery but the pain was not properly controlled .
in general , it is thought that the intercostal nerve ( icn ) from t1 to t6 and the nerves that originate from those braches can be damaged by breast surgery . for the patient in this case report , because she complained of the pain at the dermatome of the t4 spinal nerve , neuropathic pain caused by damage at the 4th icn and at the branch was suspected .
the effect of a nerve block in controlling pain after breast surgery is well known . in particular , it was reported that a paravertebral block ( pvb ) reduced pain , nausea and vomiting after breast surgery .
in addition , kairaluoma et al .   reported that preoperative pvb reduced chronic pain after breast surgery .
these results show that a nerve block can be used in controlling pain following breast surgery effectively , preventing it from becoming chronic .
a nerve block using a local anesthetic is easy to perform in the treatment of pain and is effective in reducing pain .
however , because the duration of desensibilization may not be sufficient depending on the disease causing the pain and because many repeated procedures may be required , radiofrequency thermocoagulation is sometimes employed to maintain the effect of the nerve block .
radiofrequency thermocoagulation was first introduced in 1930 's by kirschner , who applied it treating trigeminal neuralgia at the gasserian ganglion .
recently , the application of radiofrequency thermocoagulation in the case of various diseases has gradually increased as quality of the radiofrequency generator , the associated equipment , and the catheter needle has been improved .
this treatment is highly advantageous , in that a more accurate lesion can be generated compared to other nerve - destructive procedures . moreover ,
the mechanism of radiofrequency thermocoagulation is known to change the nerve tissue due to the heat around the electrode , blocking and the inflow of the nerve stimulus . on the other hand ,
prf was introduced as a new method because another mechanism of radiofrequency - aided treatment arises in that a clinical effect is noted by the heat applied to the nerve and the electromagnetic field that forms around the electrode .
prf is a radiofrequency - aided treatment in which pulsed radiofrequency stimulus of 20 msec is generated two times every 0.5 second at a temperature of 42 , which is low enough for the nerve tissue to remain undamaged .
prf is a novel treatment method that has corrected the problems of previous radiofrequency - aided treatments based on heat .
it does not cause nerve destruction , side effects such as neuritis , or the complications of other types of radiofrequency - aided treatments based on heat .
it can be performed to treat neuropathic pain even for body parts where side effects take place frequently due to radiofrequency thermocoagulation .
it can be also performed on parts near bone or scar tissue , where the risk of complications is high when radiofrequency thermocoagulation is performed .
rohof   applied prf to the suprascapular nerve in the treatment of chronic shoulder pain and reported it to be a novel treatment method that is free from side effects or complications , in contrast to the conventional thermocoagulation .
moreover , positive effects were reported when prf was applied to peripheral nerves such as the facial nerve , superior laryngeal nerve , suprascapular nerve , intercostals nerve , obturator nerve and the joint - dominating peripheral nerve articular branch , whose main nerve is sensory . in this case report as well , although the pain was controlled by an epidural block with a local anesthetic , repeated procedures were required due to the short duration of the first treatment .
long - lasting pain reduction was achieved without any specific side effect , as the prf was carried out on the spinal nerve and its root under monitoring by a c - arm device . in this article
, we report a case in which prf was applied to control the pain of a patient who came to the hospital complaining of chronic severe neuropathic pain at the operation site that arose after breast reduction surgery .
appropriate pain control after breast surgery can reduce the suffering of the patient due to early pain and greatly affect the quality of life of the patient by preventing the pain from being chronic .
if an appropriate pain treatment had been given after breast surgery to the patient in this case report , she would have not suffered from chronic pain . in the case of breast surgery , considerable attention should be paid to postoperative pain as well as surgical pain , and pain treatment should be carried out positively .
it is thought that a nerve block as well as general analgesics can be helpful as a pain control strategy .
in addition , prf may be helpful in reducing the pain of the patients who are not responsive to a nerve block using analgesics or local anesthetics .
furthermore , additional studies are needed regarding the reduction of chronic neuropathic pain by prf after breast surgery .

Answer:
breast surgery is a common procedure performed in women .
 many women who undergo breast surgery suffer from ill - defined pain syndromes .
 a nerve block is used in the treatment of the acute and chronic pain , but the effectiveness of the treatment has been limited because of its short duration .
 recently , the advent of pulsed radiofrequency lesioning ( prf ) has proved a successful treatment for chronic refractory pain involving the peripheral nerves .
 we experienced a case of a 52-year - old female patient complaining of chronic breast neuropathic pain after breast reduction , which was relieved after prf lesioning of the 4th thoracic spinal nerve and its root .


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:
udp - glcua ( ammonium salt ; > 98% purity ) , and nad ( sodium salt ; 98% purity ) were obtained from sigma  aldrich .
purified preparations of wild - type hugdh and e161q mutant were obtained using reported procedures .
both enzymes were produced as fusion proteins containing an n - terminal extension , which comprised a solubility enhancement tag , a streptavidin tag , and a tobacco etch virus protease cleavage site .
the n - terminal extension was then removed , and the enzymes were further purified by gel filtration and anion - exchange chromatography .
a 50  mm potassium phosphate buffer at pd 5.9 , 7.0 , 7.9 or 8.8 was used .
starting concentrations were 15  mm nad , 2  mm udp - glc and 0.38  m wild - type hugdh or 15  m e161q .
after addition of all components , the reactions were incubated at 25  c for 16  h. for determination of the solvent isotope effect , enzymatic conversions in h2o or d2o were performed in a beckman coulter du800 spectrophotometer using a 50  mm potassium phosphate buffer with ph / pd 7.5 .
reaction velocity was measured by nadh absorption (   =  340  nm ) .
all spectra were recorded on a bruker drx-600 avance spectrometer ( bruker , rheinstetten , germany ) at 600.13  mhz ( h ) .
the h nmr spectra were measured at 298.2  k with presaturation ( 1.0  s ) and acquisition of 32k data points .
after zero filling to 64k data points , spectra were performed with a range of 7200  hz .
chemical shifts were referenced to external acetone ( h  =  2.225  ppm ) .
the reactions were directly made in a 5  mm high precision nmr sample tube ( promochem , wesel , germany ) to measure in situ h nmr spectra .
samples contained 2  mm udp - glc , 15  mm nad , and 0.084  m wild - type hugdh or 33  m e161q , as well as 50  mm potassium phosphate buffer in d2o ( 0.70  ml , 99.9% d , pd 7.5 or 8.3 ) .
12  h in the magnet by recording up to 64 h nmr spectra in regular intervals .
the topspin 3.0 software from bruker was used for processing the nmr spectra after data acquisition . for quantitative analysis of the nmr data ,
a correction value was subtracted from the integral values of each proton to account for background noise .
udp - glcua ( ammonium salt ; > 98% purity ) , and nad ( sodium salt ; 98% purity ) were obtained from sigma  aldrich .
purified preparations of wild - type hugdh and e161q mutant were obtained using reported procedures .
both enzymes were produced as fusion proteins containing an n - terminal extension , which comprised a solubility enhancement tag , a streptavidin tag , and a tobacco etch virus protease cleavage site .
the n - terminal extension was then removed , and the enzymes were further purified by gel filtration and anion - exchange chromatography . full details of the purification protocol are given elsewhere .
enzymatic assays were performed in 1  ml of d2o . a 50  mm potassium phosphate buffer at pd 5.9 , 7.0 , 7.9 or 8.8 was used .
starting concentrations were 15  mm nad , 2  mm udp - glc and 0.38  m wild - type hugdh or 15  m e161q .
after addition of all components , the reactions were incubated at 25  c for 16  h. for determination of the solvent isotope effect , enzymatic conversions in h2o or d2o were performed in a beckman coulter du800 spectrophotometer using a 50  mm potassium phosphate buffer with ph / pd 7.5 .
reaction velocity was measured by nadh absorption (   =  340  nm ) .
all spectra were recorded on a bruker drx-600 avance spectrometer ( bruker , rheinstetten , germany ) at 600.13  mhz ( h ) .
the h nmr spectra were measured at 298.2  k with presaturation ( 1.0  s ) and acquisition of 32k data points . after zero filling to 64k data points ,
chemical shifts were referenced to external acetone ( h  =  2.225  ppm ) .
the reactions were directly made in a 5  mm high precision nmr sample tube ( promochem , wesel , germany ) to measure in situ h nmr spectra .
samples contained 2  mm udp - glc , 15  mm nad , and 0.084  m wild - type hugdh or 33  m e161q , as well as 50  mm potassium phosphate buffer in d2o ( 0.70  ml , 99.9% d , pd 7.5 or 8.3 ) .
12  h in the magnet by recording up to 64 h nmr spectra in regular intervals .
the topspin 3.0 software from bruker was used for processing the nmr spectra after data acquisition . for quantitative analysis of the nmr data ,
a correction value was subtracted from the integral values of each proton to account for background noise .

Answer: graphical abstract


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 main goal of endodontic treatment is the complete apical and coronal seal of root canal system to prevent the bacterial leakage and percolation many studies have confirmed the importance of coronal leakage as a possible cause of failure of root canal treatment ( rct ) .
malone and donelly considered coronal restoration as it replaces missing tooth structure , protects remaining tooth from fracture , and prevents canals recontamination as the first protective barrier for the periapical tissues after rct .
torabinejad et al . , confirmed the results of swanson and madison 1978 that root canal treatment failure could be assumed to the delayed final restoration placement or when the temporary filling partially or completely lost .
hence , a great attention should be paid for the immediate placement of coronal restoration .
some studies suggested the placement of a barrier made of different materials on the root canal orifices for complete coronal seal .
this barrier is indicated even in cases with post retained restorations . in 1995 , ray & trope published a radiographic study about the correlation between the periapical pathosis and endodontically treated teeth .
their results indicated that the adequacy of the coronal restoration is more important than the quality of the root canal filling .
they also showed that the periapical pathosis related clearly to the quality of coronal restoration and not to the root canal filling .
kirkevang et al . gained similar results . on the contrary , many studies , showed the adequacy of root canal filling is the most important preventive measure for the periapical tissues ( although there was no negligence on the coronal restoration importance ) .
moreover , ricucci and bergenholtz reported that exposure of root canal fillings to the saliva ( teeth with missing coronal restorations ) was not necessarily associated with apical pathosis in cases with adequate endodontic treatment .
many epidemiological studies from different countries : brazil , france , turkey , belgium and australia gave conflicting results about the impact of the final coronal restoration on the status of periapical tissues .
2012 made a comprehensive review to studies related to this subject and could nt resolve this controversy .
the aim of this study was to assess the influence of the quality of coronal restorations and root canal treatment ( separately and in concomitant ) on the periapical status of endodontically treated teeth from an adult syrian subpopulation .
we randomly selected panoramic x - rays for patients attended dental school of damascus university who fulfill the selection criteria : patient 's age was set to be minimum of 19 years old , they had neither received any dental treatment for more than one year , nor had previously visited dental school clinics ( selected patients are private clinic patients ) .
our sample contained 200 high qualities panoramic x - rays which had been examined under good illumination and magnification by two endodontists with minimum 5 years experience individually . in cases when disagreement occurred ,
the number of examines teeth in panoramic x - rays ( except third molars ) were 5331 teeth , 784 teeth ( 361 teeth for males and 423 teeth for females ) received endodontic treatments ( there was a radioopaque material in the root canals or pulp chambers ) .
we recorded the type of the final fillings as following : type of coronal restoration
 no filling in 39 teeth ( 5%)filling in 320 teeth ( 42.1%)prefabricated post & filling in 26 teeth ( 3.3%)crown in 304 teeth ( 38.8%)post & crown in 85 teeth ( 10.8% ) .
  no filling in 39 teeth ( 5% ) filling in 320 teeth ( 42.1% ) prefabricated post & filling in 26 teeth ( 3.3% ) crown in 304 teeth ( 38.8% ) post & crown in 85 teeth ( 10.8% ) .
the quality of the final restorations and root canal fillings had been classified as : adequate or inadequate according to tronstad et al .
inadequate coronal restoration : final restoration appears radiographically with overhang , open margin , recurrent caries , temporary filling or no filling .
adequate root canal filling : all canals obturated with dense fillings ending about 2 mm shorter than the radiographic apex .
inadequate root canal filling : root canal fillings end more than 2 mm shorter than the radiographic apex or grossly overfilled .
periapical status was assessed by periapical index ( pai ) proposed by rstavik et al .
1986 , who scored the periapical area of the radiographic images as follows :
 normal periapical structures.small changes in bone structure.changes in the bone structure with little mineral loss.periodontitis with well - defined radiolucent area.severe periodontitis with exacerbating features .
  normal periapical structures .
according to this index we classified periapical tissue as : normal or healthy periapex : absence of radiographic evidence of diseased periapical tissues .
the worst score of all canals was taken to represent the pai score for multicanal teeth .
spss software was used for statistical analysis ( spss inc , chicago , il ) .
out of 784 endodontically treated teeth , the mandibular molars were the most frequent treated teeth .
459 cases ( 58.54% ) had been classified as having adequate coronal restoration , and 325 ( 41.46% ) cases as having inadequate one [ table 1 ] .
illustrate the type of the teeth in the study and the adequacy of the final coronal restoration in the 459 teeth with adequate final restoration , the status of periapical tissues was healthy in 353 teeth ( 76.9% ) and diseased in 106 teeth ( 23.1% ) . in the 325 teeth with inadequate coronal restoration , the status of periapical tissues was healthy in 169 teeth ( 52% ) and diseased in 156 teeth ( 48% ) [ table 2 ] .
illustrate the status of periapical tissues according to the adequacy of final coronal restoration chi - squared test was used to evaluate the major differences in the status of periapical tissues according to the adequacy of final coronal restoration as illustrated in table 3 .
evaluation of the major differences between studied groups statistical analysis revealed that the healthiness of periapical tissues affected by quality of coronal p < 0.01 [ table 4 ] .
the effect of coronal restoration type on the status of periapical tissues the study showed that 72% of the cases with final restoration absence accompanied with a clear radiographic radiolucency .
teeth with prefabricated post and filling or cast post and crown accompanied with periapical pathosis ( 38.5% and 31.8% ) respectively .
overall , the post presented in 111 cases ( 14.1% ) , 74 cases accompanied with healthy periapical tissues and 37 cases with diseased tissues .
endodontic treatments had been evaluated as adequate in 145 teeth ( 18.5% ) , and inadequate in 639 teeth ( 81.5% ) . when we compared the status of periapical tissues according to the adequacy of root canals fillings we noticed that 95.2% of the teeth were with adequate root canal fillings , and about 60.1% of the inadequate endodontically treated teeth were with healthy periapical tissues ( score one and two rstavik et al .
periradicualr disease ( pai > 2 ) had been found in 262 teeth ( 33.4% ) . 7 cases of there were with adequate treatment and 255 cases were inadequate [ table 5 ] .
the status of periapical tissues according to the adequacy of the root canal filling the difference in the number of teeth with healthy periapical tissues and adequate root canal filling were significant when compared to teeth with inadequate root canal filling .
( p < 0.001 ) . the impact of the adequacy of the coronal restoration and root canal filling on the status of periapical tissues had been studied ( separately and in concomitant ) .
classification of teeth according to the adequacy of the final restoration and root canal filling in this study the status of periapical tissue were healthy in 96.6% of cases when both final coronal restoration and root canal filling were adequate .
but the status of periapical tissues was healthy in 88.5% when only the root canal fillings were adequate and 70% when only the coronal restoration was adequate .
the status of periapical tissue was healthy in only 48.8% of cases when both the endodontic treatment and the final restoration were inadequate [ table 7 ] .
the effect of endodontic treatment and the final coronal restoration on the status of periapex for cases with both adequate restorations and adequate root canal filling , the success rate was 96.6% .
healthy periapex was observed in 88.5% of the teeth with adequate root canal filling and inadequate restoration .
when only the final restoration was adequate ( root canal treatment inadequate ) the success rate was 70% ( p = 0.04 ) .
the difference when both the final restoration and the root canal filling were inadequate was significant when compared to the other three groups .
this epidemiological study used x - rays to evaluate the presence of periapical radiolucencies , the quality of the root canal fillings and restorations with all limits of the 2 dimensional images .
one of this study disadvantages is the inability to collect detailed information about the endodontic treatment : when it was done ? if the periapical pathosis is pre or post treatment disease ? whether the periapical periodontitis is healing or expanding ?
in fact , radiographic image represents a snapshot of a continuous process of a dynamic disease . according to the study of petersson et al .
the number of healed lesions equals the number of developed ones after 10 years of follow up , indicating the reliability of epidemological studies for recording the long - term success of endodontic treatments .
this type of studies gave us valuable information about the level and development of dental practice in different periods , the common endodontic errors and the prevalence of periapical pathosis in subpopulations .
to overcome the disadvantages of this type of studies , the sample was expanded and radiographs had been evaluated by using good illumination and magnification . all panoramic x - rays in this study were taken in dental school clinics of damascus university .
many studies did not find significant differences between periapical and panoramic x - rays in evaluation of periapical pathosis .
one of the most important questions is whether the study represents the syrian subpopulation ? to come up to an answer we should mention that dental school clinics of damascus university is one of the biggest dental clinics in damascus that offers consultations and treatments to so many people from damascus and its province
. the criteria of sample selection was : the patient should have received his previous treatment outside dental school clinics ( by general practice dentists ) , did not receive any dental treatment for at least one year of attendance to give a chance for any radiographic radiolucency to be healed by that time . according to rstavik d ( 1996 ) 89% of lesions would heal after one year of endodontic therapy .
the number of endodontically treated teeth was 784 teeth ( half of them were upper and lower molars ) .
the prevalence of periapical lesions was about 33.42% , 58.5% of the coronal restorations were evaluated as adequate with different type of restorations , while 5% of the sample lost its restorations .
the incidence of apical periodontitis associated with adequate coronal restorations was lower with significant difference than inadequate ones .
the effect of the type of the coronal restorations on the status of periapical tissues was not crucial . in 111 cases out of 784 cases ,
some studies indicated that the presence of canal posts accompanied with higher percentage of periapical pathosis due to leakage during post space preparation or infrequent irrigation or weakening the remaining gutta percha .
root canal filling was adequate in 18.5% of cases which is so low when compared to other studies that consider root canal therapy as predictable treatment . in this study ,
the correlation between periapical pathosis and inadequate root canal treatment was highly significant , other studies confirmed these results . when each factor ( root canal filling or coronal restoration ) was evaluated separately , it had a significant influence on periapical health ; in fact , these two factors are un separated . to evaluate which factor
had the greater impact on outcome , we statistically analyzed the results of combination of these two factors .
success rate ( the presence of healthy periapex ) scored in 96.6% of cases with adequacy of both factors and decreased to 88.5% in cases with adequate root canal fillings and inadequate coronal restorations but with non - significant difference ( it means that root canal treatment exert greater impact on outcome ) . in cases with adequate coronal restorations and inadequate root canal fillings success rate
was recorded in 70% , which again indicates the importance of root canal filling in the success of the endodontic treatment .
the worst results were obtained when both factors are inadequate which accompanied with lower successful results and high significant difference compared to all studied groups .
that indicates the importance of a complete treatment ( adequate root canal filling and placement of adequate final coronal restoration ) .
overall results indicate that the factor that plays the key role in the success of a treatment is the quality of root canal filling without neglecting the effect of the coronal restoration .
the prevalence of periapical lesion in syrian subpopulation is high which indicate poor dental practice .
thus , considerable efforts should be spent to improve the level of endodontic treatment and promote periradicular health .

Answer:
background : the purpose of this study was to determine the status of periapical tissues of endodontically treated teeth according to coronal restorations and root canal fillings separately and in concomitant in adult syrian subpopulation.methods:784 endodontically treated teeth from two hundred randomly selected syrian adult patients were radiographically evaluated . according to predetermined criteria , the quality of coronal restorations and root canal filling of each tooth
 was scored as adequate or inadequate .
 the status of periapical tissues was also classified as healthy or diseased .
 results were analyzed using chi - squared test.results:adequate coronal restorations were determined in 58.54% of cases which was accompanied with less periapical pathosis than that in teeth with inadequate restorations ( p < 0.01 ) .
 14% of teeth were restored by posts which showed no significant impact on the periapical tissues health .
 18.5% of endodontic treatments were evaluated as adequate with less number of periapical radiolucencies than that of inadequate root canal fillings ( p < 0.01 ) .
 absence of periapical pathosis was 96.6% in cases with both adequate coronal restorations and root canals fillings .
 the rate was 88.5% in cases with only adequate root canals fillings , and about 70% in cases with only adequate coronal restorations .
 when the treatment was inadequate in both coronal and root canals fillings , success rate was only observed in 48.8%.conclusion : the most important factor with regard to the periradicular tissue health is the quality of root canal filling without neglecting the influence of coronal restoration ( regardless of its type ) .
 there is a high prevalence rate of periapical pathosis in syrian subpopulation due to poor dental practice .


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:
according to numerous estimations , 15% to 29% of patients with cataract have 1.5 diopters ( d ) of refractive astigmatism.1,2 cataract surgeons usually prefer to treat cataract and correct refractive ( spherical and astigmatic ) disorders at the time of the surgery .
corneal incision ( astigmatic keratotomy ) and peripheral corneal relaxing incisions ( pcris ) were performed to treat these disorders.3,4 the main drawbacks of these approaches are that the outcome depends on multiple factors as the patient s age , the depth and length of the incision , complications related to wound healing , epithelial defects , or induction of dry - eye symptoms .
these parameters affect the visual outcome in a unpredictable way so the corneal incisions are not considered a reliable method for astigmatism correction .
toric intraocular lens ( iols ) implantation was introduced in the 1990 s as an option for astigmatism correction in cataract patients .
initially they presented the disadvantage of postoperative rotation that decreased the visual outcome.58 new toric iol designs ( acrysof   toric iol ; alcon , fort worth , tx ) , approved by the us food and drug administration ( fda ) at the end of 2005 , have been found to be more stable and appear to be the preferred iol for correcting preexisting astigmatism in conjunction with cataract surgery.9,10 the acrysof   iols are available in three options : t3 , t4 , and t5 of astigmatic correction 1.5 , 2.25 , 3.00 d , respectively ( at the iol plane ) .
the aim of this study is to report the clinical results of acrysof   toric iols implantation for preexisting astigmatism correction and compare the postoperative rotation of the iols one and six months postoperatively .
this prospective study included eyes that had cataract surgery at the papageorgiou general hospital , thessaloniki , greece , between may 2008 and december 2008 .
the study was conducted according to the tenets of the declaration of helsinki and patients gave informed consent after the nature and intent of the study had been fully explained to them .
inclusion criteria were : cataract , age 70 years or younger , and preoperative regular corneal astigmatism greater than 1.00 d. exclusion criteria were : glaucoma , corneal disease , previous corneal or intraocular surgery , macular degeneration or retinopathy , and history of ocular inflammation .
each patient had a complete ophthalmologic examination , including visual acuity ( va ) , slit - lamp examination , intraocular pressure ( iop ) measurement , and dilated fundus examination .
topography ( magellan mapper ; nidek technologies , padova , italy ) , automated refractometry ( rk600 ; reichert , inc .
, depew , ny ) , and ultrasonic immersion biometry ( ocuscan rxp ; alcon ) were performed to determine the appropriate iol spherical power .
cylindrical power and axis placement to achieve emmetropia were calculated using an online toric iol calculator program ( available from http://www.acrysoforiccalculator.com/ ) .
the 0180 axis was marked with the patient in a sitting position to avoid cyclotorsion using the nuijts / lane preoperative toric reference corneal marker ( ae-2791tbl ; asico , westmont , il ) ( figure 1 ) .
intraoperatively , the desired implantation axis was marked using an intra - op toric axis marker ii ( ae-2794 ; asico ) ( figure 2 ) .
a foldable iol was implanted in the capsular bag through a 2.75 mm limbal incision on 110. the toric iol was injected with a monarch - ii injector ( alcon ) and placed around 1015 off axis before the ophthalmic viscosurgical device ( sodium hyaluronate 1% ) was removed .
after ophthalmic viscosurgical device removal , the iol was rotated to its final position by exactly aligning the toric reference marks with the limbal implantation axis marks .
all surgeries were performed by the same experienced surgeon ( it ) using topical anesthesia and a standard divide - and - conquer phacoemulsification technique . because of the intraoperative marker design and the pen mark fading during the operation in several cases , it was difficult to assess the proper alignment of the iol after its placement . because of this difficulty , an image was captured from the real - time streaming recording of the surgery and was assessed blindly by a second operator using a commercially available software ( screen protractor ; iconico , ny , usa ) ( unpublished data ) . to overcome this difficulty we consider that the use of the marker set consisting of beveled degree gauge ( ae-1590 ; asico ) and maloney astigmatism axis marker ( ae-2741 ; asico ) is more appropriate for the whole procedure because it allows maximum visibility .
the on - screen assessment of the axis remains a useful tool for postoperative evaluation of the iol location ( figure 3 ) .
measurements of visual acuity ( using the snellen opto - type at a six - meter distance ) , iop , and comprehensive slit lamp examination were performed at one - day and one- and six - month postoperative visits . at the one- and six - month follow - up
, a digital photograph and corneal topography ( only at the one - month visit ) were obtained to estimate the postoperative rotation of the iol using the software tools mentioned above ( figure 1 ) .
outcomes of interest included uncorrected va , cylindrical astigmatism power before and after iol implantation , and the possible rotation of the iol one and six months after the operation ( when the initial desired place was at 0 ) .
absolute values of the rotation used for the analysis after detecting rotation was not under investigation .
completed data forms were analyzed with microsoft excel 2007 ( microsoft corporation , redmond , wa ) and spss software ( version 16.0 ; spss inc . , chicago , il ) .
twenty - nine eyes of 19 patients ( mean age 63.03  5.42 years ) were enrolled in this study .
uncorrected va was found to be 5/10 or more in 26 of 29 eyes ( 89.7% ) and 8/10 or more in 19 of 29 patients ( 65.5% ) .
preoperative and postoperative corneal topography showed significant reduction of refractive astigmatism in all eyes after the surgery .
mean power of the astigmatism was 2.38  0.91 d ( range 1.55 d ) preoperatively and 0.64  0.61 d ( range 02.5 d ) postoperatively ( figure 4 ) .
one month postoperation , the mean toric iol axis rotation was 2.2  1.5 ( range 0.67.8 ) .
six months postoperation , the mean toric iol axis rotation was 2.7  1.5 ( range 0.98.4 ) .
the later rotation occurred between one and six months , and was found to be more than one degree ( 1.1 ) only in one eye ( 3% ) and in all other cases was less than this value ( figure 5 ) .
it is known that one degree of deviation causes 3.3% reduction of the iol cylindrical power .
calculated reduction of the desired correction ( in diopters ) because of the observed rotation ( mean value , one and two standard deviations ) for the three iol models is shown in table 1 .
no eye had secondary surgery to reposition the iol axis within the six - month postoperative period .
the results of our study corroborate previous studies,11 which demonstrates that proper selection and preoperative examination of patients followed by uncomplicated iol implantation of one - piece hydrophobic acrylic toric iols results in acceptable stability and visual outcome .
in particular , the postoperative rotation of toric iols appears to occur in the early postoperative period ( 1 month ) and remains constant later than six months .
the lens rotates until a fibronectin and collagen adhesion develops between the iol and the posterior capsule , which prevents any further rotary motion.12 the amount of cylindrical correction reduction due to postoperative rotation was not large enough13 to affect the expected end result in final uncorrected distance va .
acrysof   one - piece hydrophobic acrylic toric iols implantation shows satisfactory stability , acceptable clinical results , and is an exceptional option for correction of refractive astigmatism .

Answer:
purpose : to present clinical results of toric intraocular lens ( iol ) implantation for preexisting astigmatism correction and determine the time of any postoperative rotation.patients and methods : twenty - nine eyes of 19 patients underwent uncomplicated phacoemulsification and were implanted with an acrysof  toric iol . uncorrected visual acuity , residual astigmatism , and postoperative rotation of the iol were estimated one and six months after the operation.results:uncorrected visual acuity was 0.5 in 26 of 29 eyes ( 89.7% ) and 0.8 in 19 of 29 patients ( 65.5% ) .
 the mean toric iol axis rotation was 2.2  1.5 ( range 0.67.8 ) one month postoperation and 2.7  1.5 ( range 0.98.4 ) six months postoperation.conclusion:implantation of one - piece hydrophobic acrylic toric iols appears to have acceptable stability , which encourages visual outcome and emerges as an attractive alternative for correction of refractive astigmatism .