Analysis of the Transformerless Boost dc-dc Converter with High Voltage Gain in Different Operating Modes and Critical Inductance Calculations

In the high voltage dc-dc boost converters, the energy transmission modes are divided into continuous conduction mode (CCM) and discontinuous conduction mode (DCM). In addition, these modes are also divided into two different modes: complete inductor supply mode (CISM) and incomplete inductor supply mode (IISM). In this paper, the operation of the boost dc-dc converter with high voltage gain is analyzed. Firstly, the energy transmission process between CCM and DCM is analyzed. Then, this process is investigated between IISM and CISM. Moreover, the critical inductance between CCM and DCM in addition to CISM and IISM is calculated. Finally, in order to verify the presented theoretical issues, the simulation results in EMTDC/PSCAD software program are used

Global Quality of Life in HIV/AIDS Patients: A Systematic Review and Meta-Analysis

Background: Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) is known as one of the most chronic conditions, having significant effects on physical and mental health status in infected individuals, and thus reducing their quality of life (QoL).Methods: I n t his s ystematic r eview, t he d ata w ere i nitially collected from the databases of Scopus, PubMed, Embase, Web of Science, and Google Scholar from January 2000 to September 2020 based on the inclusion and exclusion criteria of the study. The data were then analyzed by using the R software.Results: A total number of 25 research articles addressing the QoL in 5,952 HIV/AIDS patients were evaluated using three valid questionnaires, including the Medical Outcomes Study HIV Health Survey (MOS-HIV), the 36-Item Short Form Health Survey (SF-36), and the World Health Organization Quality of Life in HIV-Infected Persons (WHOQoL-HIV). Based on the MOS-HIV, the SF-36, and the WHOQoL-HIV questionnaires, the QoL mean scores in HIV/AIDS patients were 51.80 (49.4- 54.57), 54.81 (52.68-56.93), and 13.62 (11.97-15.26), respectively. In addition, the physical items gained a higher mean score than the mental ones in all the questionnaires. The QoL showed higher mean scores in the SF-36 and the WHOQoL-HIV questionnaires in Africa, except for the MOS-HIV questionnaire, which had the highest mean score in North America.Conclusion: Overall, the QoL in HIV/AIDS patients in this study was acceptable, even though further changes and studies are still required to support the findings

SARS-CoV-2 molecular and phylogenetic analysis in COVID-19 patients : a preliminary report from Iran

Background: The aim of the current study was to investigate and track the SARS-CoV-2 in Iranian Coronavirus Disease 2019 (COVID-19) patients using molecular and phylogenetic methods. Methods: We enrolled seven confirmed cases of COVID-19 patients for the phylogenetic assessment of the SARS-CoV-2 in Iran. The nsp-2, nsp-12, and S genes were amplified using one-step RT-PCR and sequenced using Sanger sequencing method. Popular bioinformatics software were used for sequences alignment and analysis as well as phylogenetic construction. Results: The mean age of the patients in the present study was 60.42 ± 9.94 years and 57.1 (4/7) were male. The results indicated high similarity between Iranian and Chinese strains. We could not find any particular polymorphisms in the assessed regions of the three genes. Phylogenetic trees by neighbor-joining and maximum likelihood method of nsp-2, nsp-12, and S genes showed that there are not any differences between Iranian isolates and those of other countries. Conclusion: As a preliminary phylogenetic study in Iranian SARS-CoV-2 isolates, we found that these isolates are closely related to the Chinese and reference sequences. Also, no sensible differences were observed between Iranian isolates and those of other countries. Further investigations are recommended using more comprehensive methods and larger sample sizes. © 202