Science and Technology Development Journal - Natural Sciences http://stdjns.scienceandtechnology.com.vn/index.php/stdjns <p><span id="result_box" class="" lang="en"><span title="Tạp chí đã được phát hành tại các thư viện của các đơn vị thành viên của ĐHQG-HCM, các Sở Khoa học Công nghệ của các tỉnh thành trên cả nước và được Hội đồng học hàm Giáo sư Nhà nước đánh giá cao."><strong>Science and Technology Development Journal</strong> - <strong>Natural Science</strong> <strong>(STDJNS)</strong> (<strong>2588-106X</strong>) is the official journal of Viet Nam National University Ho Chi Minh City, Viet Nam, published by Viet Nam National University Ho Chi Minh City, Viet Nam. STDNS has been developed and separated from section of <strong>Nature Sciences</strong> of <strong>Science &amp; Technology Development Journal</strong> (<strong>STDJ</strong>) (<strong>1859-0128</strong>). From 2017, this section became a dependent journal with title <strong>Science and Technology Development Journal</strong> - <strong>Natural Science.&nbsp;</strong>STDJNS is a multiple discipline science journal covering from all fields of natural sciences included mathematics., computer science, chemistry science, physic, biology, environment, information technology...</span></span></p> <p><span id="result_box" class="" lang="en"><span title="Tạp chí Phát triển Khoa học và Công nghệ (PTKH&amp;CN) của Đại học Quốc gia thành phố Hồ Chí Minh (ĐHQG-HCM) được thành lập từ năm 1997, ra số đầu tiên vào tháng 1 năm 1998. Từ năm 2006 Tạp chí đã"><strong>Science and Technology Development Journal</strong> (STDJ), Vietnam National University - Ho Chi Minh City (VNU-HCM) was established in 1997. And the first issue was published in January 1998 with </span><span title="đăng ký mã số chuẩn quốc tế ISSN 1859-0128.">ISSN 1859-0128. </span><span title="Từ đó cho đến nay, Tạp chí PTKH&amp;CN đã trở thành diễn đàn khoa học quan trọng nhất của đội ngũ cán bộ nghiên cứu, giảng viên, nghiên cứu sinh của ĐHQG-HCM và cũng là diễn đàn khoa học công nghệ đáng tin cậy của">Since then, STDJ has become the most important scientific forum of scientists from VNU-HCM as well as</span><span title="nhiều nhà nghiên cứu, giảng viên các trường đại học khác tại Việt Nam."> other universities. </span><span title="Tạp chí đã trải qua 20 năm phát triển và đã trở thành nhịp cầu giao lưu khoa học, cũng như làm phong phú tài liệu tham khảo cho đội ngũ giảng viên, nghiên cứu sinh, sinh viên ĐHQG-HCM nói riêng và các Trường đại">The magazine has undergone 20 years of development and has become a bridge for scientific exchanges, as well as enriching reference materials for the faculty, doctoral students, students of VNU-HCM in particular and other universities, institutes...</span></span></p> <p><span id="result_box" class="" lang="en"><span title="Tạp chí đã được phát hành tại các thư viện của các đơn vị thành viên của ĐHQG-HCM, các Sở Khoa học Công nghệ của các tỉnh thành trên cả nước và được Hội đồng học hàm Giáo sư Nhà nước đánh giá cao.">STDJNS is a multiple discipline science journal covering from all fields of natural sciences included mathematics., computer science, chemistry science, physic, biology, environment, information technology... </span><br></span></p> <p><span class="" lang="en"><span title="• Khoa học Trái đất và Môi trường"><span id="result_box" class="" lang="en">&nbsp;</span></span></span></p> Viet Nam National University Ho Chi Minh City en-US Science and Technology Development Journal - Natural Sciences 2588-106X <p>Copyright The Author(s) 2018. This article is published with open access by Vietnam National University, Ho Chi Minh city, Vietnam. This article is distributed under the terms of the&nbsp;<a href="https://creativecommons.org/licenses/by/4.0/" target="_blank" rel="noopener">Creative Commons Attribution License (CC-BY 4.0)</a> which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.&nbsp;</p> A review of COVID-19: Molecular basis, diagnosis, therapeutics and prevention http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/907 <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> Mai T. N. HUYNH Phuc H. T. NGUYEN Hieu H. C. PHAN Nghia T. H. PHAN Kong H. LE Nhu T. H. TRUONG Khanh LE Dung V. HO Vy T. NGUYEN Ha L. B TRAN Hieu V. TRAN Hoang H. NGUYEN Nhan T. NGUYEN Thuoc L. TRAN ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2020-07-01 2020-07-01 4 3 First First 10.32508/stdjns.v4i3.907 title description none g The second-order composed radial derivatives of perturbation mappings of parametric set-valued optimization problems http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/838 <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> Phạm Lê Bạch Ngọc Nguyen Thanh Tung Nguyen Huynh Nghia ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2020-07-01 2020-07-01 4 3 First First 10.32508/stdjns.v4i3.838 title description none g Heterologous expression of human KGF/FGF7 (Keratinocyte growth factor) in Pichia pastoris http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/900 <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> Thư Anh Nguyễn Phạm Trang Thị Thuỳ Nguyễn Nghĩa Hiếu Nguyễn Thao Thi Phuong Dang ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2020-07-01 2020-07-01 4 3 First First 10.32508/stdjns.v4i3.900 title description none g