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[Display omitted] • This study proposes novel auxetic medical stents. • Two-dimensional metamaterials were fabricated through additive manufacturing technique. • Finite element analysis was employed to investigate the mechanical behaviour. • An excellent correlation was observed between the FEA and experimental results. • The modifications made to the rib-unit cells had a significant effect on the stent's recoil behaviour. Due to the significant mortality rate associated with atherosclerosis-induced cardiovascular disease, the utilization of advanced intravascular stents with superior mechanical performance is imperative for the restoration of obstructed arteries. This study proposes novel auxetic medical stents that aim to enhance critical parameters of biomedical stents. This includes load-bearing capacity, expanded opening percentage, and reduced recoil percentage. On this matter, the missing rib auxetic unit cell has been considered and geometrically modified to achieve these objectives. Two-dimensional (2D) metamaterials were fabricated through additive manufacturing technique and subjected to experimental testing. Then, finite element analysis (FEA) was employed to gain comprehensive insights into the mechanical behaviour of the proposed medical stents. Remarkably, an excellent correlation was observed between the FEA and experimental results, validating the high precision of the analysis. The findings reveal that the stents classified as "E-category" exhibit the highest final opening percentage while concurrently demonstrating the lowest recoil percentage. The base stent exhibited a relatively high recoil percentage of 15.56%, indicating a significant amount of recoil or spring-back after deformation. In contrast, the modified "E-category" stent displayed a substantially lower recoil percentage of 1.62%. This notable reduction in recoil percentage indicates that the modifications made to the rib-unit cells had a significant and beneficial effect on the stent's recoil behaviour and minimizing potential damage to arterial tissue during stent deployment (angioplasty) and balloon pressure. The modified design likely enhances the stent's ability to maintain its shape and resist recoil, making it more effective and reliable in its intended application. Additionally, more aspects of biomedical stents such as foreshortening, and dog-boning of the modified missing rib stents were meticulously examined through FEA. [ABSTRACT FROM AUTHOR]

One of the most important dimensions of cooperative systems, which have existed in Iran since 1974, is cooperative rural production enterprises. In this study, the performance of rural production cooperatives in Iran is examined in relation to the social capital components of the members. This study's statistical population consisted of 16,870 members from 41 cooperatives. 217 samples of cooperative members and 98 samples of the cooperative's management and board of directors were selected using the Cochran formula, and questionnaires were filled out for each group. The results showed that from the viewpoint of the members of rural cooperatives, the most important factor in improving the performance of cooperatives was the use of effective extension training (model-extension sites). The results also showed that members' satisfaction and training members of cooperatives can play an important role in improving the performance of cooperatives. The results of this research, while emphasizing the role of education (especially extension activities), can help rural development planners in improving the performance of rural cooperatives in their regions. [Display omitted] • The study identified the impacts of social capitals on the performance of rural production cooperatives. • The most important factor in improving the performance was the use the extension trainings. • Members' satisfaction and training play an important role in improving the performance. • The level of education in production cooperatives has a direct relationship with trust and satisfaction. • Cooperatives do not perform well in the fields of sales, marketing and insurance. [ABSTRACT FROM AUTHOR]

Background Pterygium is the human eye lesion whose prevalence in the general population is estimated about 2%. The disease, in extreme phase, can lead to visual disturbance and eventually causes complete loss of vision due to the lesion growth over the papillary axis. Pterygium invasive tissue is a tumor-like tissue that is initially identified and then is attacked by cytotoxic T cells. Cytotoxic T lymphocyte associated antigen 4 (CTLA4), as a modulator molecule of the adaptive immune system, plays a critical role in maintaining peripheral T cell tolerance by diminishing its responsiveness and increasing its activation threshold. The aim of this study is to investigate the association between some epigenetic changes of the CTLA4 gene, such as promoter methylation and gene expression, and pathogenesis of pterygia. Materials and methods Genomic DNA was extracted from 75 formalin-fixed, paraffin-embedded tissues of pterygia and 70 specimens of normal conjunctiva from eyes without pterygium as the control group, collected from Sistan and Baluchestan population. CTLA4 gene promoter methylation was carried out by methylation-specific PCR technique. The gene expression analysis was done on extracted total RNA from 20 healthy and 23 pterygium tissue samples using Real-Time PCR technique. Results Promoter methylation changes of CTLA4 gene were not statistically different in patients with pterygium in comparison with healthy controls (OR = 1.614; 95% CI = 0.57–4.75; P value = 0.37). However, gene expression level of CTLA4 was remarkably different in patients and healthy controls (Mean ± SD: 1.343 ± 0.133 and 2.027 ± 0.219, respectively; P value = 0.009). Conclusion This is a credible evidence of CTLA4 gene expression in human eye tissue. This first hand attempt of investigating the association of epigenetic changes of the CTLA4 gene and pathogenesis of pterygia, indicated a significant intensification of the gene expression of CTLA4 in patients with pterygia. We suggest that increasing CTLA4 gene expression can be a trigger which promotes pterygium enlargement. However, further studies on more populations with larger sample sizes need to be done to verify this hypothesis in the future. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this paper is to propose a new method for the detection of inter-turn short circuits in the stator windings of induction motors. In the previous reported methods, the supply voltage unbalance was the major difficulty, and this was solved mostly based on the sequence component impedance or current which are difficult to implement. Some other methods essentially are included in the offline methods. The proposed method is based on the motor current signature analysis and utilizes three phase current spectra to overcome the mentioned problem. Simulation results indicate that under healthy conditions, the rotor slot harmonics have the same magnitude in three phase currents, while under even 1 turn (0.3%) short circuit condition they differ from each other. Although the magnitude of these harmonics depends on the level of unbalanced voltage, they have the same magnitude in three phases in these conditions. Experiments performed under various load, fault, and supply voltage conditions validate the simulation results and demonstrate the effectiveness of the proposed technique. It is shown that the detection of resistive slight short circuits, without sensitivity to supply voltage unbalance is possible. [ABSTRACT FROM AUTHOR]

Air pollution in metropolises is one of the serious problems of human life. Tehran is one of the cities facing air pollution problem. Urban managers concern about choosing different management methods to control air pollution. In this study, a combination of fuzzy systems and neural networks has been used to select the most suitable scenario for controlling SO 2 pollution. According to the method presented in this paper, 8 input data categories such as wind speed, precipitation, temperature, pressure, humidity, gas oil consumption, gasoline consumption and urban green space levels have been used as independent parameters and SO 2 pollutant concentration has been considered as the dependent parameter. The contribution of each meteorological station to the meteorological data was determined by Thiessen Polygon Method. Then, using adaptive neural fuzzy inference systems, modeling was done in Sugeno Method and the least root mean square error (3.19) was determined for the model. Then, by changing each of the independent parameters, the effect of each of these independent parameters on SO 2 pollutant was measured. The results showed that the parameters of pressure, urban green space, gasoline consumption, gas oil consumption, temperature, wind speed and humidity, respectively, had the greatest effect on reducing the SO 2 concentration. Since the parameters of gasoline and gas oil consumption as well as the area of green space are changeable by different policies and by human decisions, the concentration of SO 2 pollutant can be controlled by reducing the consumption of gasoline and gas oil and increasing the green space in Tehran. • Finding the lowest error rate in any of the models predicting sulfur dioxide concentration. • Determine the effect of each of the independent parameters on the concentration of SO 2. • Determination of the best predictive model for sulfur dioxide emissions based on ANFIS model. • Providing solutions to improve air pollution. [ABSTRACT FROM AUTHOR]

The main goal of this study is to assess the application of high-order compact finite-difference schemes for the solution of the Euler equations in conjunction with the compressible vorticity confinement method on both uniform Cartesian and curvilinear grids. Here, the spatial discretization of the governing equations is performed by the fourth-order compact finite-difference scheme and the temporal term is discretized by the fourth-order Runge–Kutta method. To stabilize the numerical solution, appropriate dissipation terms are applied and a detail assessment is performed to study the effects of the values of confinement and dissipation coefficients on the solution to reasonably preserve the structure of vortical flows. The accuracy and performance of the proposed solution procedure by applying the fourth-order compact finite-difference scheme are also examined by comparison with the solution obtained by the second-order central finite-difference scheme. Low-pass high-order filters are also applied to the fourth-order compact finite-difference scheme to investigate the performance of the vorticity confinement with the filtering scheme. The advection of a 2D isentropic vortex and a shock–vortex interaction problem are two test cases simulated for the assessment of the present solution methodology. The study shows that the high-order compact finite-difference schemes in conjunction with the vorticity confinement method can reasonably preserve the structure of vortical flows in coarse uniform Cartesian and curvilinear grids. Indications are that the present solution methodology is accurate and effective for solving compressible flow problems with vortical structures when coarse grids are used. [ABSTRACT FROM AUTHOR]

Summary: In spite of reports on cytokines induction by the Brucella DNA in murine model, there is no comparison between pathogenic and appropriate vaccine strains in human. We investigated the cytokines profile of human peripheral blood mononuclear cells (PBMCs) induced by DNA extracted from pathogenic isolates of Brucella melitensis and B. abortus as well as Rev1 and S19; the appropriate vaccine strains. It was observed that despite differential induction of Interleukin(IL)-12 and IL-10 production, identical IL-12/IL-10 concentration ratio was obtained by all Brucella strains DNAs that was 2 after 24h and 4 after 5 days of incubation. In addition, IL-2 and Interferon(IFN)-γ production were profoundly increased compared to the medium at day 3 and 5 respectively but IFN-α was not induced. Therefore, Brucella strains DNAs are Th1 inducing component with similar pattern in human PBMCs. [Copyright &y& Elsevier]