http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/issue/feed Science and Technology Development Journal - Natural Sciences 2020-07-07T12:35:15+00:00 Phuc Van Pham pvphuc@vnuhcm.edu.vn Open Journal Systems http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/907 A review of COVID-19: Molecular basis, diagnosis, therapeutics and prevention 2020-07-07T12:35:13+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_907_cover_en_US.png Mai T. N. HUYNH nmaihuynh0603@gmail.com Phuc H. T. NGUYEN nhtphuc@hcmus.edu.vn Hieu H. C. PHAN prokaryote98@gmail.com Nghia T. H. PHAN phtnghia@hcmus.edu.vn Kong H. LE lehongkonga2@gmail.com Nhu T. H. TRUONG nhunhutruong1210@gmail.com Khanh LE khanhle@cisbay.com Dung V. HO hodungbyt@gmail.com Vy T. NGUYEN ntvy@hcmus.edu.vn Ha L. B TRAN tlbha@hcmus.edu.vn Hieu V. TRAN tvhieu@hcmus.edu.vn Hoang H. NGUYEN nhhoang@hcmus.edu.vn Nhan T. NGUYEN ntrnhan@hcmus.edu.vn Thuoc L. TRAN tlthuoc@hcmus.edu.vn <p>Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the confirmed viral pathogen of COVID-19, a pandemic originated from Wuhan, China at the end of 2019. Since then, SARS-CoV-2 has rapidly spread across the globe with over 8 million confirmed cases and more than 430.000 deaths worldwide as of mid-June 2020. Similar to other strains of coronavirus, the envelope of SARS-CoV-2 comprises of three structural proteins: S protein (spike), E protein (envelope) and M glycoprotein (membrane). SARS-CoV-2 capsids are spherical or pleomorphic. Each capsid contains a positive-sense single-stranded RNA (+ssRNA-Class IV-Baltimore) associated with nucleoprotein N. The viral RNA genome is approximately 30 kb in length and contains 14 open reading frames (ORFs). The binding affinity of the viral S protein to the ACE2 (angiotensin-converting enzyme 2) receptor facilitates the attachment of SARS-CoV-2 to human epithelial cells. Upon binding, SARS-CoV-2 spike protein is cleaved and activated by TMPRSS2 (transmembrane protease, serine 2) or by cathepsin L at the cleavage site S2', and also by furin at the cleavage site S1/S2. The furin cleavage motif RR_R is a notable feature, firstly found in SARS-CoV-2 S protein, which may increase virus transmission rate. This feature and many others might result from several evolution events in SARS-CoV-2 genome. These events could occur when coronaviruses, including SARS-CoV-2, spread from one host to another. They can be causative to high virulence and transmission rate of future coronavirus strains, which may require the development of newer vaccine generations. To understand of SARS-CoV-2’s structure, infection mechanism, diagnosis, treatment, and vaccine development strategies, a review of current literature is of highly importance to disease control in Vietnam.</p> 2020-07-01T00:00:00+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/838 The second-order composed radial derivatives of perturbation mappings of parametric set-valued optimization problems 2020-07-07T12:35:15+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_838_cover_en_US.png Phạm Lê Bạch Ngọc plbngoc0611@gmail.com Nguyen Thanh Tung nttung@vnkgu.edu.vn Nguyen Huynh Nghia nghia1703208033@vnkgu.edu.vn <p>In the paper, we study the generalized differentiability in set-valued optimization, namely stydying the second-order composed radial derivative of a given set-valued mapping. Inspired by the adjacent cone and the higher-order radial con in Anh NLH et al. (2011), we introduce the second-order composed radial derivative.&nbsp; Then, its basic properties are investigated and relationships between the second-order compsoed radial derivative of a given set-valued mapping and that of its profile are obtained. Finally, applications of this derivative to sensitivity analysis are studied. In detail, we work on a parametrized set-valued optimization problem concerning Pareto solutions.&nbsp; Based on the above-mentioned results, we find out sensitivity analysis for Pareto solution mapping of the problem. More precisely, we establish the second-order composed radial derivative for the perturbation mapping (here, the perturbation means the Pareto solution mapping concerning some parameter). Some examples are given to illustrate our results. The obtained results are new and improve the existing ones in the literature.</p> 2020-07-01T00:00:00+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/900 Heterologous expression of human KGF/FGF7 (Keratinocyte growth factor) in Pichia pastoris 2020-07-07T12:35:11+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_900_cover_en_US.png Thư Anh Nguyễn Phạm npathu@hcmus.edu.vn Trang Thị Thuỳ Nguyễn ptd0678@gmail.com Nghĩa Hiếu Nguyễn nghnghia@hcmus.edu.vn Thao Thi Phuong Dang thaodp@hcmus.edu.vn <p>Keratinocyte Growth Factor (KGF) is a paracrine-acting and epithelium-specific growth factor produced by cells of mesenchymal origin, play an important role in promoting proliferation, differentiation, motility of epithelial cells and stimulating regeneration of damaged epithelial tissues. Recent studies indicated that recombinant KGF is produced in many different expression systems such as bacteria, insect cells, plant and mammalian cells. However, KGF’s yields obtained from these systems is low and production’s cost is high especially in mammalian cells. In this study, the yeast <em>Pichia pastoris</em> was chosen as a host for KGF expression through induction of methanol by promoter AOX on pPICzαA vector system. The results demonstrated that the <em>Pichia pastoris</em> X33:<em>kgf</em>&nbsp; transformants secreted KGF directly into BMMY medium after inducing by 0.5% methanol. The recombinant protein was purified by heparin affinity chromatography with the yield of 1.35 mg/l and the purity of 99.89% showed by SDS-PAGE. In addition, MTT assay showed the purified recombinant KGF had a proliferation effect on A549 cell line since A549 known as a cell has KGF’s receptor.</p> 2020-07-01T22:36:28+00:00 ##submission.copyrightStatement##