X-ray diffraction study of cadmium hydroxyapatite

Solid solutions of cadmium and calcium hydroxyapatite [Ca10−x Cdx (PO4)6 (OH)2 (0 ≤ x ≤ 10)] were synthesized by a wet process in a basic medium. The lattice dimensions of these compounds vary linearly with the atom percent cadmium. The distribution of the calcium and cadmium ions between two non- equivalent crystallographic sites, (1) and (2), were determined by the Rietveld method. The site-occupancy factors of atoms indicate a slight preference of cadmium for site (2) in the apatite structure

Changes in postural and trunk muscles responses in patients with chronic nonspecific low back pain during sudden upper limb loading

Background: Alterations in the neuromuscular control of the spine were found in patients with chronic low back pain (CLBP). Sudden loading of the spine is assumed to be the cause of approximately 12 of lower back injuries. However, some aspects of this problem, such as alterations in the sensory-motor control of the spine, remain questionable. This study investigated postural and neuro- motor changes in trunk muscles during sudden upper limb loading in patients with CLBP. Methods: Electromyography of the erector spinae (ES) and transverses abdominis/internal oblique (TrA/IO) and external oblique (EOA) muscles were recorded in 20 patients with CLBP and 20 asymptomatic individuals with eyes open (EO) and eyes closed (EC) conditions. Moreover, measurements of the center of pressure (COP) and vertical ground reaction force (GRF) or Fz were recorded using a force plate. Data were analyzed using paired t-test and independent t-test at the significance level of 0.05. Results: In patients with CLBP, decreased electrical activity of the ES muscle was observed under both the EO and EC conditions and that of the TrA/IO muscle was observed under the EO condition (p < 0.05). Other findings included a shorter peak latency of the ES muscle in the EO condition and a greater increase in the peak latency of the ES muscle following the EC condition (p < 0.05). No significant differences were observed in COP and GRF measurements between the groups. Conclusion: Electrical muscle activity may indicate less stiffening or preparatory muscle activity in the trunk muscle of patients with CLBP. Altered latency of the muscle may lead to microtrauma of lumbar structures and CLBP

Comparison of cervical repositioning error in individuals with forward head posture with and without neck pain

Background and purpose: Proprioception is one of the somatic senses which is used by the nervous system for muscular control. Inappropriate posture or pain could result in impaired proprioception. One of these poor postures is forward head posture (FHP). The aim of this study was to investigate cervical repositioning error in FHP subjects with and without neck pain and normal individuals. Materials and methods: A case-control study was conducted consisting of people who had FHP without neck pain (n=31), individuals with FHP and neck pain (n=31), and healthy subjects (n=31). Cervical total range of motion (ROM) and then repositioning error in target angle (50 of full ROM in each movement(of flexion, extension, right and left lateral flexion, and right and left rotation were measured by cervical range of motion (CROM) device. Pain intensity was measured using the visual analog scale (VAS). Results: Cervical ROM in FHP subjects was significantly less than that of healthy subjects in most movement directions. The absolute repositioning error of the target angle in FHP subjects was found to be significantly more than that of healthy subjects in most movement directions (p<0.05). The mean VAS score in patients with neck pain was 4±0.68. Conclusion: FHP whether with or without pain may increase the cervical repositioning error. But presence of pain do not leads to higher rates of error. © 2016, Mazandaran University of Medical Sciences. All rights reserved

MR defecography: A diagnostic test for the evaluation of pelvic floor motion in patients with dyssynergic defecation after biofeedback therapy

Background: Dyssynergic defecation is a major cause of chronic functional constipation as a common digestive complaint. We clinically evaluated the effects of biofeedback therapy on the pelvic floor motion indices through magnetic resonance (MR) defecography, quality of life and depression in patients with dyssynergic defecation. Methods: In this clinical trial study, among patients referring to the Colorectal Clinic of Hazrat Rasoul Hospital, 22 subjects were randomly assigned into two equal groups (n= 11) to receive either standard only or biofeedback and standard therapy. Dynamic changes of the pelvic floor were measured by MR defecography. During the simulated defecation, two MR defecography dynamic indices including abnormal anorectal angle change and perineal descent were measured before and after treatment. The effects of biofeedback therapy on patients' symptoms, quality of life and severity of depression were assessed and compared with the standard therapy. Statistical analysis was carried out using independent t-test and Mann-Whitney test. Results: Paradox index (p< 0.001), perineal descent index (p< 0.001), depression (p< 0.1), physical function (p< 0.001), vitality (p< 0.001) and role emotion (p< 0.001) significantly improved in the biofeedback therapy group in contrast to the standard therapy SDT group. Conclusion: Biofeedback therapy appears to be effective in improving symptoms of functional constipation and dysfunction of pelvic floor motion as well as patient's quality of life and depression state. MR defecography is able to show the changes in dynamic indices of the pelvic floor through biofeedback therapy

The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point

Background: Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point. Methods: In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test. Results: There was significant differences in motor time and reaction time between active and control groups (p<0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p<0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups. Conclusion: The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG)

Comparison of invertor and evertor muscle strength in patients with chronic functional ankle instability

In this study we tried to measure Invertor and Evertor muscles strength with Isokinetic dynamometer to distinguish, if these muscles activate properly or not. Thirty subjects (15 healthy and 15 patients with chronic functional ankle Instability (CFAI) aged 18-30 years) participated in this study. Maximum eccentric and concentric peak Torque of invertor and evertor muscles measured with Biodex system in 2 different speeds, 60 and 120 degree per second. Statistical analysis showed that maximum eccentric peak torque of invertor muscles in both 60 and 120 degree per second differed statistical significance between two groups, as in the patients group was less than normal subjects (p<0.05). It means that eccentric weakness of invertor muscles will lead to CFAI

On the Fairlie's Moyal formulation of M(atrix)- theory

Starting from the Moyal formulation of M-theory in the large N-limit, we propose to reexamine the associated membrane equations of motion in 10 dimensions formulated in terms of Poisson bracket. Among the results obtained, we rewrite the coupled first order Nahm's equations into a simple form leading in turn to their systematic relation with $SU(\infty)$ Yang Mills equations of motion. The former are interpreted as the vanishing condition of some conserved currents which we propose. We develop also an algebraic analysis in which an ansatz is considered and find an explicit form for the membrane solution of our problem. Typical solutions known in literature can also emerge as special cases of the proposed solutionComment: 16 page

On the harmonic superspace language adapted to the Gelfand-Dickey algebra of differential operators

Methods developed for the analysis of non-linear integrable models are used in the harmonic superspace (HS) framework. These methods, when applied to the HS, can lead to extract more information about the meaning of integrability in non-linear physical problems. Among the results obtained, we give the basic ingredients towards building in the HS language the analogue of the G.D. algebra of pseudo-differential operators. Some useful convention notations and algebraic structures are also introduced to make the use of the harmonic superspace techniques more accessible.Comment: 14 page