Impaired local dynamic stability during treadmill walking predicts future falls in patients with multiple sclerosis:A prospective cohort study

Background: Falling is a significant problem in patients with multiple sclerosis (MS) and the majority of falls occur during dynamic activities. Recently, there have been evidences focusing on falls and local stability of walking based on dynamic system theory in the elderly as well as patients with cerebral concussion. However, in patient with MS, this relationship has not been fully investigated. The aim of this study was to investigate local stability of walking as a risk factor for falling in patients with MS. Methods: Seventy patients were assessed while walking at their preferred speed on a treadmill under single and dual task conditions. A cognitive task (backward counting) was used to assess the importance of dual tasking to fall risk. Trunk kinematics were collected using a cluster marker over the level of T7 and a 7-camera motion capture system. To quantify local stability of walking, maximal finite-time Lyapunov exponent was calculated from a 12-dimensional state space reconstruction based on 3-dimensional trunk linear and angular velocity time series. Participants were classified as fallers (≥1) and non-fallers based on their prospective fall occurrence. Findings: 30 (43%) participants recorded ≥1 falls and were classified as fallers. The results of multiple logistic regression analysis revealed that short-term local dynamic stability in the single task condition (P < 0.05, odds ratio = 2.214 (1.037–4.726)) was the significant fall predictor. Interpretation: The results may indicate that the assessment of local stability of walking can identify patients who would benefit from gait retraining and fall prevention programs

Problem of Foreign Body in GI Tract

Most foreign bodies pass through the gastrointestinal tract uneventful. We report of a case of inadvertently ingested foreign body, which by endoscopy simulated a polyp and on biopsy reported as cancer, so the patient underwent an unnecessary major operation. This report emphasizes the importance of resemblance of foreign bodies with gastrointestinal neoplasm, and endoscopists, surgeons and pathologists should consider this entity in their daily practice

Protective effect of hydro alcoholic extract of Teucrium polium on Mercuric chloride-induced nephrotoxicity

زمینه و هدف: ترکیبات آنتی اکسیدانی موجود در گیاهان دارویی نماینده های مناسبی برای حفاظت در برابر مسمومیت ناشی از آلاینده های صنعتی هستند. در تحقیق حاضر اثر حفاظتی عصاره آبی الکلی برگ گیاه کلپوره (Teucrium polium) بر مسمومیت کلیوی ناشی از کلرید جیوه ارزیابی گردید. روش بررسی: در این مطالعه تجربی از 28 سر موش سوری نر استفاده شد. حیوانات به طور تصادفی در 4 گروه شاهد، گروه دریافت کننده کلرید جیوه، گروه دریافت کننده کلرید جیوه همراه با عصاره کلپوره و گروه دریافت کننده عصاره کلپوره تقسیم شدند. دوزهای کلرید جیوه و عصاره کلپوره به ترتیب mg/kg 5/1 و mg/kg 200 روزانه به مدت 8 روز به صورت داخل صفاقی تزریق شدند. در پایان، نمونه‌های خونی تهیه و مسمومیت کلیوی توسط اندازه‌گیری غلظت سرمی اوره و کراتینین با استفاده از روش اسپکتروفتومتری و کیت‌های اختصاصی بطور غیر مستقیم اندازه‌گیری شد. برای تجزیه و تحلیل داده ها از آزمون آنالیز واریانس یک طرفه و متعاقب آن تست Tukey در نرم افزار SPSS استفاده شد. یافته ها: کلرید جیوه سبب افزایش معنی داری در غلظت سرمی اوره و کراتینین در مقایسه با گروه شاهد شد (05/0

The effect of dual-task conditions on postural control in adults with low back pain:a systematic review and meta-analysis

BACKGROUND: Dual-task conditions, which involve performing two tasks simultaneously, may exacerbate pain and further impair daily functioning in individuals with low back pain (LBP). Understanding the effects of dual-task conditions on postural control in patients with LBP is crucial for the development of effective rehabilitation programs. Our objective was to investigate the impact of dual-task conditions on postural control in individuals with LBP compared to those without LBP. METHODS: We conducted a comprehensive search of Medline via PubMed, Scopus, the Cochrane Central Register of Controlled Trials, Web of Science, and EMBASE databases, with no language restrictions, from inception to January 1, 2023. The primary outcome measures of the study were velocity, area, amplitude, phase plane portrait, and path/sway length of the center of pressure (CoP). Standardized mean difference (SMD) effect sizes were calculated, and the quality of the studies was assessed using the Newcastle-Ottawa Scale (NOS). RESULTS: From 196 studies, five involving 242 adults (≥ 18 years) met the inclusion criteria. Three studies were rated as high quality, while two were deemed moderate. In the included studies, 140 participants had non-specific LBP, while 102 participants did not report any symptoms, with mean ages of 36.68 (± 14.21) and 36.35 (± 15.39) years, respectively. Three studies had both genders, one exclusively included females, and one did not specify gender. Meta-analyses of primary outcomes revealed no significant differences in postural control between patients with LBP and pain-free controls during both easy and difficult postural tasks and cognitive load for velocity (easy: SMD - 0.09, 95% CI - 0.91 to 0.74; difficult: SMD 0.12, 95% CI - 0.67 to 0.91), area (easy: SMD 0.82, 95% CI - 2.99 to 4.62; difficult: SMD 0.14, 95% CI - 2.62 to 2.89), phase plane (easy: SMD - 0.59, 95% CI - 1.19 to 0.02; difficult: SMD - 0.18, 95% CI - 0.77 to 0.42), path/sway length (easy: SMD - 0.18, 95% CI - 0.77 to 0.42; difficult: SMD - 0.14, 95% CI - 0.84 to 0.55), and amplitude (easy: SMD 0.89, 95% CI - 1.62 to 3.39; difficult: SMD 1.31, 95% CI - 1.48 to 4.10). CONCLUSIONS: The current evidence suggests that there are no significant differences in postural control parameters during dual-task conditions between individuals with non-specific LBP and pain-free subjects. However, due to the limited number of available studies, significant publication bias, and considerable statistical heterogeneity, definitive conclusions cannot be drawn. Therefore, further research comprising high-quality studies with larger sample sizes is necessary to obtain conclusive results. Trial registration PROSPERO CRD42022359263.</p

Predicting falls among patients with multiple sclerosis:Comparison of patient-reported outcomes and performance-based measures of lower extremity functions

Background Accurate fall screening tools are needed to identify those multiple sclerosis (MS) patients at high risk of falling. The present study aimed at determining the validity of a series of performance-based measures (PBMs) of lower extremity functions and patient-reported outcomes (PROs) in predicting falls in a sample of MS patients (n = 84), who were ambulatory independent. Methods Patients were assessed using the following PBMs: timed up and go (TUG), timed 25-foot walk (T25FW), cognitive T25FW, 2-min walk (2MW), and cognitive 2MW. Moreover, a series of valid and reliable PROs were filled in by participants including the activities-specific balance confidence (ABC), 12-item multiple sclerosis walking scale (MSWS-12), fall efficacy scale international (FES-I), and modified fatigue impact scale (MFIS). The dual task cost (DTC) of 2MW and T25FW tests were calculated as a percentage of change in parameters from single to dual task conditions. Participants were classified as none-fallers and fallers (⩾1) based on their prospective fall occurrence. Results In the present study, 41(49%) participants recorded ≥ 1 fall and were classified as fallers. The results of logistic regression analysis revealed that each individual test, except DTC of 2MW and T25FW, significantly predicted future falls. However, considering the area under the curves (AUCs), PROs were more accurate compared to PBMs. In addition, the results of multiple logistic regression with the first two factors extracted from principal component analysis revealed that both factor 1 (PROs) and factor 2 (PBMs) significantly predicted falls with a greater odds ratio (OR) for factor 1 (factor 1: P = <0.0001, OR = 63.41 (6.72–597.90)) than factor 2 (P <0.05, OR = 5.03 (1.33–18.99)). Conclusions The results of this study can be used by clinicians to identify and monitor potential fallers in MS patients

Presenting a model for assessing general medical students: a brief report

Background: By examining the comprehensive system for evaluating the academic progress of general medical students, often the objectives of the cognitive domain and the form of cumulative evaluation were used, and the tests were not used much for feedback to the students. The aim of the study is to develop a model that fits the levels of Miller's evaluation pyramid in formative-cumulative forms. Methods: The search was started in Iranian and international databases, magazines, curriculum of prestigious universities in the world. To find out about the latest events in the field of assessment, AMEE international virtual conferences in August 2021 and the summary booklet of medical education articles of Shahid Motahari 1400 (the 22nd national conference of medical education) were reviewed. Data analysis was done by Beredy's adaptive model. The search and analysis lasted for 11 months. Finally, a model was developed according to Miller's evaluation pyramid. Its validation was done in the focus group meeting in two ways, in person at Mashhad Medical School and virtual. Results: According to the extracted data, the approach of assessment is towards formative assessment format and improvement of traditional methods along with modern methods, which was clearly observed in the study of the curriculum of Harvard-Stanford University in America and Oxford University in England. Integrating the results with Miller's evaluation levels, and the formative and cumulative evaluation format, led to the formulation of a model with the most favorable opinions of experts. In addition, the majority of opinions and suggestions of experts were related to the change in the way of executive policies of universities and providing a context for the emergence of new idea. Conclusion: A model including measurement methods according to the levels of Miller's evaluation pyramid was developed in formative-cumulative. It is suggested that the model be reviewed by the relevant experts and notified by taking into account the implementation conditions for the correct evaluation process

Numerical Simulation of the Transient Flow around the Combined Morphing Leading-Edge and Trailing-Edge Airfoil

An integrated approach to active flow control is proposed by finding both the drooping leading edge and the morphing trailing edge for flow management. This strategy aims to manage flow separation control by utilizing the synergistic effects of both control mechanisms, which we call the combined morphing leading edge and trailing edge (CoMpLETE) technique. This design is inspired by a bionic porpoise nose and the flap movements of the cetacean species. The motion of this mechanism achieves a continuous, wave-like, variable airfoil camber. The dynamic motion of the airfoil’s upper and lower surface coordinates in response to unsteady conditions is achieved by combining the thickness-to-chord (t/c) distribution with the time-dependent camber line equation. A parameterization model was constructed to mimic the motion around the morphing airfoil at various deflection amplitudes at the stall angle of attack and morphing actuation start times. The mean properties and qualitative trends of the flow phenomena are captured by the transition SST (shear stress transport) model. The effectiveness of the dynamically morphing airfoil as a flow control approach is evaluated by obtaining flow field data, such as velocity streamlines, vorticity contours, and aerodynamic forces. Different cases are investigated for the CoMpLETE morphing airfoil, which evaluates the airfoil’s parameters, such as its morphing location, deflection amplitude, and morphing starting time. The morphing airfoil’s performance is analyzed to provide further insights into the dynamic lift and drag force variations at pre-defined deflection frequencies of 0.5 Hz, 1 Hz, and 2 Hz. The findings demonstrate that adjusting the airfoil camber reduces streamwise adverse pressure gradients, thus preventing significant flow separation. Although the trailing-edge deflection and its location along the chord influence the generation and separation of the leading-edge vortex (LEV), these results show that the combined effect of the morphing leading edge and trailing edge has the potential to mitigate flow separation. The morphing airfoil successfully contributes to the flow reattachment and significantly increases the maximum lift coefficient (cl,max)). This work also broadens its focus to investigate the aerodynamic effects of a dynamically morphing leading and trailing edge, which seamlessly transitions along the side edges. The aerodynamic performance analysis is investigated across varying morphing frequencies, amplitudes, and actuation times