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Background: To resolve the impairments associated with spinal cord injury (SCI), such as decreased balance, patients have been recommended to undergo various therapeutic strategies, including the use of different physical exercise methods. The aim of this study was to evaluate the efficiency of using rebound therapy (exercise on a trampoline) on SCI individuals' static stability. Methods: Sixteen people with SCI (American Spinal Cord Association classification: A = 6, B = 6, C = 2, and D = 2) were randomly assigned to an experimental (rebound exercise) group or a control group. The rebound therapy exercise program, lasting 12 weeks, was performed by means of a modified trampoline. During the said period, the experimental group received rebound therapy exercise for 10 to 30 minutes 3 sessions a week. Standing stability parameters (ie, excursion, velocity, and path length of the center of pressure in mediolateral and anteroposterior plane) were assessed before and after the exercise intervention by Kistler force plate (50 × 60 cm). Data were analyzed by repeated measures analysis of variance. Results: Significant interactions were observed for all 6 dependent variables except excursion of the center of pressure in mediolateral and the path length of center of pressure in anteroposterior plane (P <.01). This means that the control group had no progress, whereas the experimental group made a significant improvement in terms of static stability. Conclusion: The results of this study confirmed that rebound therapy could reinforce the static stability of individuals with SCI during motionless standing. It suggests that rebound exercise is a useful sports rehabilitation method for patients with SCI and other wheelchair-bound individuals. [ABSTRACT FROM AUTHOR]

The presence of faults in a system leads to a lower value for efficiency, accuracy and speed, and, in some cases, even a complete breakdown. Thus, early fault detection is a major factor in efficiency and productivity of the procedure. In recent decades, many research studies have been conducted on troubleshooting and secondary fault detection. The current work presents an efficient and novel observer design capable of stabilizing the residue and dynamic error for the nonlinear Lipschitz systems with faults as well as a troubleshooting analysis and determining the formation of secondary faults in defective systems. The observer is designed based on linearizing dynamic error considering uncertainty, disturbance, and defects by employing non-linear gain factors instead of using state transformation. The dynamic error and residue stabilization of a non-linear faulty system have been discussed as well as the likelihood of secondary fault generation. The results indicate that the observer is able to determine fault-emergence, fault-disappearance and secondary fault formation well and quite fast. [ABSTRACT FROM AUTHOR]

In energy harvesting systems, specifications of the generated electrical energy depend on the structure's dynamics. This dependence can be used to identify the system's joint characteristics. To this end, an innovative frequency-response-function (FRF) based identification method is presented. The investigated system is a cantilever beam shaped structure with an embedded bimorph piezoelectric bender, connected to a base via bolted joint as a depiction for wing of a UAV connected to fuselage. The implemented FRF is ratio of the piezoelectric output voltage to the base input displacement. The joint identification procedure consists of analytical modeling of the system with joint, experimental testing of the system and a real-coded Genetic Algorithm (GA) method. The joint is modeled as a combination of longitudinal and torsional springs, whose stiffnesses are obtained using the GA method. The obtained results indicate that the analytical model has good correlation with the experimental data. Then, effects of the joint characteristics on the energy harvester's performance are investigated by comparison of the system with two different joint assumptions, namely, rigid and realistic joint. Finally, the effects of various joint characteristics on the energy harvester's performance are presented and approaches to achieve the maximum performance of the system are suggested. [ABSTRACT FROM AUTHOR]

Purpose: This updated meta‐analysis aimed to assess the diagnostic performance of circulating cell‐free DNA (cf‐DNA) for prostate cancer (PCa). Methods: A systematic search was conducted in PubMed, Scopus, Web of Science, and Embase databases to retrieve related studies. Several diagnostic estimates, including sensitivity (SE), specificity (SP), likelihood ratios (LRs), and diagnostic odds ratio (DOR) were also used to perform the meta‐synthesis. Additionally, the area under hierarchical summary receiver operating characteristic curves (AU‐HSROC) was used as a global measure of test accuracy. Results: Twenty‐nine unique articles were enrolled in the meta‐analysis. Pooled SE and SP for overall accuracy of cf‐DNA in PCa were obtained as 0.54 (95% CI: 0.47–0.61) and 0.92 (95% CI: 0.88–0.95), respectively. Positive LR (PLR) was 6.8 (95% CI: 4.9–9.5, I2: 92.98%) and negative LR (NLR) was 0.5 (95% CI: 0.43–0.58). Pooled DOR was 13.56 (95% CI: 9.49–19.37) and the AU‐HSROC was 0.83 (95% CI: 0.79–0.86). Conclusion: The present study suggested that cf‐DNA assays have comparable SE as well as remarkably higher SP (qualitative assays) than common biomarkers in the detection of PCa like prostate‐specific antigen (PSA). In addition, cf‐DNA assays have better performance in PCa confirmation and almost similar performance to PSA in excluding PCa patients. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global threat. Despite the production of various vaccines and different treatments, finding natural compounds to control COVID-19 is still a challenging task. Isoquinoline alkaloids are naturally occurring compounds known to have some potential antiviral activity. In this study, ten abundant isoquinoline alkaloids with antiviral activity were selected to analyze the preventive effect on COVID-19. A scrutinized evaluation based on Lipinski's rule showed that one out of ten compounds was toxic. Based on molecular docking analysis using Autodock software one of the best molecules with maximum negative binding energy was selected for further analysis. The Gromacs simulation analysis revealed that Coptisine has more action against active site Mpro of COVID-19. Overall, to make a rational design of various preventive analogues that inhibit the COVID-19, associated in vitro and in vivo analyses are needed to confirm this claim. [ABSTRACT FROM AUTHOR]

The compatibility between polymer matrix and filler is a vital issue in the fabrication of composites with desirable properties. To enhance the interfacial adhesion between matrix and filler, various surface modification treatments are applied. The objective of this study was to increase the affinity of silica and poly(urethane‐urea)s (PUUs), thereby improving the mechanical properties of the resulting composites. Stepwise surface modification of mesoporous silica with amine‐containing dendrimers was done. Various techniques were used to confirm the surface‐modified structure during the stepwise reaction. Additionally, the N2 adsorption–desorption method indicated a gradual reduction in surface area, pore diameter and pore volume of the particles, which warrants the gradual propagation of the dendrimers on the surface and also inside the pores. A type IV isotherm was obtained in this analysis. Two types of pre‐synthesized PUUs were chosen for composite preparation containing the surface‐modified silica with 0.5, 1, 2.5 and 5 wt% concentrations. Due to the high affinity of the dendrimers containing amine moieties on the particles with polyurethane, a proper dispersion of particles in the matrix was achieved based on scanning electron micrographs. Tensile measurements showed an increased Young's modulus and strength of polyurethane films as a result of addition of the particles. However, no significant improvement in the tensile performance of the composites was seen above 2.5 wt% particle loading due to some particle aggregations. © 2021 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]