Estimating the deflection of weft yarn in plain woven fabric using yarn pull out test

A simple and practical model has been proposed to calculate the deflection of weft in a plain woven fabric using yarn pull out test. In this modeling, the weft yarn is considered as an elastic beam, which is fixed supported at ends, and deflected at the middle by the normal load applied by the warp. The case of small deflection is adopted to calculate the maximum deflection of weft yarn and to study the shape and geometry of the bent weft. The normal load is estimated from pullout test. Bending rigidity of the weft yarn is calculated from the relation between the bending rigidities of fabric and thread. Five different weft densities have been studied. The shape of actual weft has been studied by microscopic photography from the lateral section of the fabric, and compared to the theoretical deflection curve of weft based on small deflection modeling. The results show that the actual and theoretical curves are reasonably close to each other. The maximum deflection of the weft yarn increases as the weft density (picks/cm) increases. This may be due to the increase in normal load in higher densities of the weft yarns. The results also show that the deviation of theoretical curve from the actual curve increases with the decrease in weft density

The influence of study guide on clinical education of nursery students

Introduction: Presence of up-to-date knowledge, sufficient incentive and knowing the methods for clinical skills performance are the most crucial basics for patient care. In this study, influence of instruction based on the study guide will be investigated on the clinical competence and satisfaction of students. Methods: This study is a quasi-experimental research. 37 nursing students participates in this study. The study conducted in CCU ward. First, study guide for CCU ward prepared. Then, participants divided into two groups: control and experimental group. Control group take the course as a formal course and then experimental group take the course by the use of study guide. At the end of each course an OSCE devised for measurement of clinical skills competencies. SPSS software (version 11.5) used for data analysis and means compared by the use of student “t” test and Leven test.. Results: The clinical competencies of experimental group improved ahead of control group. (P value=0.002). 88.3% of students satisfied because of study guide usage for learning clinical competencies. Conclusion: The findings of study shows that use of study guide can be helpful for improving quality of education and students’ satisfaction. It is congruent with other studie

Reply to "Double-counting of effect sizes and inappropriate exclusion of studies in "The influence of vitamin D supplementation on IGF-1 levels in humans: A systematic review and meta_analysis"

Dear Editor, We appreciate the comments provided to us in the letter from Amiri et al. We would like to offer some clarifications in response to the comments. Firstly, the authors claimed that we included the control group more than once from the same publication including different arms. The authors also identified mistakes made during data screening and expressed concerns that the mistakes would lead to errors within our analysis (Kord-Varkaneh et al., 2020). We sincerely thank the authors for pointing out these mistakes. In response, based on The Cochrane Handbook for Systematic Reviews, we have now reanalyzed the results by combining the intervention groups to create a single pair-wise comparison and updated our meta-analysis as displayed below. We initially excluded Sorva, Antti et al. from our study because based on our inclusion criteria we only included studies that had more than 10 participants in each group (Sorva et al., 1994), although we did not originally include this criterion in our publication (Kord-Varkaneh et al., 2020). However, after including Norenstedt, S. et al. and Sinha-Hikim, I. et al. (Sinha-Hikim et al., 2015; Norenstedt et al., 2013) our overall effect size changed from (WMD: 4 ng/ml, 95 % CI: -4 to 11, p = 0.35) to (WMD: 1.01 ng/ml, 95 % CI: --6.78 to 8.81, p = 0.799) without a change in overall significance (Fig. 1). In addtion, subgroup analyses showed that vitamin D dosage ≤1000 IU/day (WMD: 11.36 ng/ml, 95 % CI: 1.57–21.16, I2 = 79 %) significantly increased IGF-1 than vitamin D dosage <1000 IU/day (WMD: -2.8 ng/ml, 95 % CI: -7.02 to 1.6, I2 = 51 %). Moreover, an intervention duration of ≤12 weeks (WMD: 9.92 ng/ml, 95 % CI: 3–16.83, I2 = 77 %) significantly increased IGF-1 compared to a duration of <12 weeks (WMD: -5.43 ng/ml, 95 % CI: -10.25 to -0.61, I2 = 0.0 %). In addition, baseline serum vitamin D (<20 ng/mL vas ≥20 ng/mL) we did not observe significantly.The authors sincerely thank Shahid Beheshti University of Medical Sciences for all moral and material supports. This study was supported by grants from the S tudent Research Committee, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran (Grant's ID: 1398/3995).Scopu

The influence of vitamin D supplementation on IGF-1 levels in humans: A systematic review and meta-analysis

© 2019 Elsevier B.V. Background: Inconsistencies exist with regard to influence of vitamin D supplementation on IGF-1 levels. The inconsistencies could be attributed to several factors, such as dosage and duration of intervention, among others. To address these inconsistencies, this study was conducted to determine the impact of vitamin D supplementation on IGF-1 levels through a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods: A comprehensive systematic search was carried out in PubMed/MEDLINE, Web of Science, SCOPUS and Embase for RCTs that investigated the impact of vitamin D intake on circulating IGF-1 levels from inception until June 2019. Weighted mean difference (WMD) with the 95 % CI were applied for estimating combined effect size. Subgroup analysis was performed to specify the source of heterogeneity among studies. Results: Pooled results from eight studies demonstrated an overall non-significant increase in IGF-1 following vitamin D supplementation (WMD: 4 ng/ml, 95 % CI: −4 to 11). However, a significant degree of heterogeneity among studies was observed (I2 = 66 %). The subgroup analyses showed that vitamin D dosage of ≤1000 IU/day (WMD: 10 ng/ml) significantly increased IGF-1 compared to the vitamin D dosage of <1000 IU/day (WMD: −1 ng/ml). Moreover, intervention duration ≤12 weeks (WMD: 11 ng/ml) significantly increased IGF-1 compared to intervention duration <12 weeks (WMD: −3 ng/ml). In the epidemiological cohort study, participants under 60 years of age with a higher dietary vitamin D intake had significantly higher IGF-1 levels when compared to those with lower dietary vitamin D intake in second categories. Conclusion: The main results indicate a non-significant increase in IGF-1 following vitamin D supplementation. Additionally, vitamin D dosages of <1000 IU/day and intervention durations of <12 weeks significantly raised IGF-1 levels.The authors sincerely thank Shahid Beheshti University of Medical Sciences for all moral and material supports. This study was supported by grants from the Student Research Committee, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran (Grant’s ID: 1398/3995)