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The angiotensin-converting enzyme 2 (ACE2) and main protease (MPro), are the putative drug candidates for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we performed 3D-QSAR pharmacophore modeling and screened 1,264,479 ligands gathered from Pubchem and Zinc databases. Following the calculation of the ADMET properties, molecular docking was carried out. Moreover, the de novo ligand design was performed. MD simulation was then applied to survey the behavior of the ligand-protein complexes. Furthermore, MMPBSA has utilized to re-estimate the binding affinities. Then, a free energy landscape was used to find the most stable conformation of the complexes. Finally, the hybrid QM-MM method was carried out for the precise calculation of the energies. The Hypo1 pharmacophore model was selected as the best model. Our docking results indicate that the compounds ZINC12562757 and 112,260,215 were the best potential inhibitors of the ACE2 and MPro, respectively. Furthermore, the Evo_1 compound enjoys the highest docking energy among the designed de novo ligands. Results of RMSD, RMSF, H-bond, and DSSP analyses have demonstrated that the lead compounds preserve the stability of the complexes’ conformation during the MD simulation. MMPBSA data confirmed the molecular docking results. The results of QM-MM showed that Evo_1 has a stronger potential for specific inhibition of MPro, as compared to the 112,260,215 compound.

The rapid spread and high mortality rate of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) have recently received worldwide attention. Understanding the pathologic features and behavior of this new virus can help control its spread. The present study aimed to compare SARS-CoV-2 with other similar viruses. This study is a systematic review of current evidence conducted in September 2020. A search was carried out utilizing the keywords in the online databases, including Google Scholar, PubMed, Scopus, Science Direct, and Web of Science. The original peer-reviewed papers written in English that met the eligibility criteria were included in the final report. In this study, we compared SARS-CoV-2 with similar viruses such as influenza, Zika, Ebola, HIV, SARS-COV, and Middle East Respiratory Syndrome Coronaviruses (MERS-COV) in the features such as envelope structure, risk factors, duration of the disease, common symptoms, and treatments. Moreover, Coronavirus Disease 2019 (COVID-19) has many similarities with the other viruses explained in the present study. However, there are still controversies about the virus’s behavior. Although there are similarities between the abovementioned viruses, the scientific community should also pay special attention to distinct features of SARS-CoV-2, particularly the high probability of transmission in the human population, which causes substantial morbidity and mortality worldwide. Future studies are needed further to explore the biological and epidemiological behavior of this virus.

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Background: The natural childbirth instruction program, which aims to reduce the cesarean section (C-section) rates in the country and pay attention to demographic policies, has achieved significant accomplishments in the short time span since it was implemented throughout the country. In the present study, the advantages and challenges of the implementation of this program have been analyzed. Materials and Methods: This qualitative study carried out with the participation of 32 knowledgeable individuals who were selected using purposeful sampling and snowball sampling methods among the personnel of Kerman University of Medical Sciences, and it's affiliated educational (university) hospital. The data were collected through semi-structured interviews based on the research objectives, review of texts, and experts' experiences. Data analysis was performed using content analysis method in MaxQDA software. Results: Data analysis provided the 5 main categories of implementation instructions' strengths, implementation instructions' defects, implementation instructions' achievements, implementation instructions' challenges and threats, and suggestions. Conclusions: Accountability in the system that provides health care services for pregnant mothers in public hospitals has been created through the implementation of the natural childbirth promotion package. If managerial barriers and executive and legal inefficiencies are followed up and suitable measures are taken for solving the intra-system conflicts, we can hope that the package, which has been one of the most serious efforts made by the Ministry of Health over the past decades to reduce cesarean delivery, will achieve significant accomplishments.