Global prevalence of hepatitis C in general population: a systematic review and meta-analysis

Background: According to published reports from the World Health Organization, it is estimated that more than 3% of the world's population is infected with HCV. Given the impact of various factors on the prevalence of HCV in the world's population and the lack of general statistics around the world, this study aims to review the studies conducted in this field and statistical analysis of the results of general statistical studies on the prevalence of HCV in the world population. Methods: In this study, systematic review and meta-analysis of information of the studies related to the prevalence of HCV in the world using keywords including: Prevalence, HCV, Hepatitis C, Healthy Population, Healthy subjects, and General Population in SID, MagIran, IranMedex, IranDoc, ScienceDirect, Embase, Scopus, PubMed, Web of Science (WoS) databases and Google Scholar search engine were extracted without time limit until April 2020. In order to perform the analysis of qualified studies, the model of random effects was used, and the inconsistency of studies with I2 index was investigated. Data analysis was performed with Comprehensive Meta-Analysis (Version 2). Results: In a study of 98 studies with a total sample size of 236,964 people in the world, the overall prevalence of HCV was 1.8% (95% CI: 1.4%–2.3%). Also, according to the subgroup analysis in different continents; the highest prevalence of HCV in the African continent was 7.1% (95% CI: 4.4–11.5%). Conclusion: The results of this study show that the prevalence of hepatitis C in the world's population, especially in Africa, is almost high. Therefore, the officials of the World Health Organization should design measures to prevent the spread of this infection

Validation of the Persian version of the Pittsburgh Sleep Quality Index in elderly population

Objective: The purpose of this study is to determine the validity and reliability of the Persian version of the Pittsburgh Sleep Quality Index in the elderly population. Material and Methods: A methodological study was conducted as a confirmatory factor analysis. Totally, 598 elderly people were selected through cluster sampling. In addition to analyzing the three-factor structure of PSQI, internal consistency reliability, structural validity, and its concurrent validity were examined. The structural credibility of PSQI was examined using other similar tools such as Sleep Health, Epworth Sleepiness, Insomnia Severity, Global Sleep Assessment, and Berlin indices. Finally, the concurrent criterion validity of PSQI was evaluated through multivariable regression analysis and all statistical analyzes were performed using SPSS and AMOS software. Results: The reliability of the test according to Cronbach’s alpha was 0.81. Confirmatory factor analysis indicators supported goodness of fit of the structural equation model. The confirmatory factor analysis showed that the ratio of χ2 / DF was 2.66 for the three-factor structure of PSQI and the goodness of fit indices of model were acceptable for this structural model (RMSEA=0.053, CFI=0.98, TLI=0.96, NFI=0.97, GFI=0.99). In addition, the internal consistency of the PSQI was 0.81 and the scales correlation score ranged from 0.48 to 0.71. Conclusion: The results indicated that Persian version of Pittsburgh Sleep Quality Index had the required validity and reliability for the elderly population of Iran and it can be used as a useful tool by other studies

Electrospun Polymeric Substrates for Tissue Engineering: Viewpoints on Fabrication, Application, and Challenges

Electrospinning is the technique for producing nonwoven fibrous structures, to mimic the fabrication and function of the native extracellular matrix (ECM) in tissue. Prepared fibrous with this method can act as potential polymeric substrates for proliferation and differentiation of stem cells (with the cellular growth pattern similar to damaged tissue cells) and facilitation of artificial tissue remodeling. Moreover, such substrates can improve biological functions, and lead to a decrease in organ transplantation. In this chapter, we focus on the fundamental parameters and principles of the electrospinning technique to generate natural ECM-like substrates, in terms of structural and functional complexity. In the following, the application of these substrates in regenerating various tissues and the role of polymers (synthetic/natural) in the formation of such substrates is evaluated. Finally, challenges of this technique (such as cellular infiltration and inadequate mechanical strength) and solutions to overcome these limitations are studied