Science and Technology Development Journal http://stdj.scienceandtechnology.com.vn/index.php/stdj <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="học phía Nam nói chung. "><br></span><span title="Tính đến hết năm 2016 Tạp chí đã xuất bản được 276 số với 2714 bài nghiên cứu của các nhà khoa học, cán bộ trong và ngoài ĐHQG-HCM trong 5 lĩnh vực nghiên cứu: Kỹ thuật và Công nghệ, Khoa học Tự nhiên,">By the end of 2016, the journal has published 276 issues with 2714 research articles in five areas of research: Engineering and Technology, Natural Sciences, </span><span title="Khoa học Xã hội và Nhân văn, Kinh tế luật và Khoa học Quản lý, Khoa học Trái đất và Môi trường tương ứng với 5 chuyên san chuyên ngành của Tạp chí.">Social Sciences and Humanities, Economics of Law and Management Sciences, Earth Sciences and Environment corresponding to 5 specialized journals of the Journal. </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.">The magazine has been widely indexed in the various libraries at Vietnam. </span></span></p> <p><span id="result_box" class="" lang="en"><span title="Từ tháng 12/2006 Tạp chí đã nhận được sự giúp đỡ của tổ chức mạng quốc tế về các xuất bản phẩm khoa học thuộc Hội đồng khoa học quốc tế để tham gia vào mạng lưới các Tạp chí Khoa học quốc tế. "><br></span><span title="Hiện nay tạp chí bao gồm 5 chuyên san sau đây: ">The journal currently consists of the following five sections:<br></span><span title="• Kỹ thuật và Công nghệ, ">• Engineering and Technology</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Tự nhiên, ">• Natural Sciences</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Xã hội và Nhân văn, ">• Social Sciences and Humanities</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Kinh tế luật và Khoa học Quản lý, ">• Economics, Law and Management</span></span></p> <p><span id="result_box" class="" lang="en"><span title="• Khoa học Trái đất và Môi trường">• Sciences of Earth and Environment</span></span></p> <p><span class="" lang="en"><span title="• Khoa học Trái đất và Môi trường"><span id="result_box" class="" lang="en">• Health Sciences : It includes work from basic science, clinical science, dental, nursing and other related medical fields. <br></span></span></span></p> Viet Nam National University Ho Chi Minh City en-US Science and Technology Development Journal 1859-0128 <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> Fractionation of lignin produced from the Earleaf Acacia tree by sequential industrial organic solvents http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2509 <p><strong>Introduction: </strong>Understanding the fractions of lignin is important for further conversion of lignin into valuable products. Herein, the “home-made” lignin from Earleaf Acacia tree was extracted by sequential industrial organic solvent and characterized each fraction to reveal its properties for further catalytic applications.</p> <p><strong>Methods: </strong>In this work, lignin was prepared from the Earleaf Acacia tree using the soda method. Then, the prepared lignin was fractionated by sequential solvents of ethyl acetate, ethanol, methanol, and acetone. Each lignin fractions were characterized by FT-IR and GPC.</p> <p><strong>Results: </strong>The FT-IR results confirmed the soda method can produce lignin from woodchips. The fractionation of lignin separated the lignin mixture into different molecular weight fraction from light – medium into heavy compounds.</p> <p><strong>Conclusion: </strong>Lignin was produced from woodchips using the soda method successfully. The fractionation using the sequential organic solvents showed the separation of different molecular weight of lignin, which allow to apply for the further conversion into useful products.</p> Thong Hoang Le Khanh B. Vu Quynh-Thy Song Nguyen Phat Van Huynh Khanh-Ly T. Huynh Khoa Dang Tong Thong Le Minh Pham An Tran Nguyen Minh Van Cuong Nguyen Thanh Khoa Phung ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-02-22 2021-02-22 24 1 1835 1841 10.32508/stdj.v24i1.2509 title description none g Density functional theory insights into the bonding of CH3OH and CH3O with Ir(111) surface http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2485 <p><strong>Introduction</strong>: Understanding the adsorption characteristics of CH3OH and CH3O on the noble metal surfaces is essential for designing better catalysts for the on-board production of hydrogen from CH3OH. This study aims to provide insights into the adsorption behavior of these molecules on Ir(111) surface.</p> <p><strong>Methods</strong>: The adsorption structure, the adsorption energy, and the bonding mechanism of CH3OH and CH3O with Ir(111) surface were investigated by means of the density functional theory (DFT) calculations and the Bader charge analysis.</p> <p><strong>Results</strong>: The DFT results show that the adsorption of CH3OH and CH3O is driven by the formation of Ir–O bond at the top site of the surface by the overlap of O-2p and Ir-5d orbitals. The overlap of these orbitals is greater in the absorption of CH3O, resulting in stronger adsorption energy of CH3O (2.23 eV vs. 0.32 eV). In agreement with the adsorption strength, the charge transfer from CH3O to the surface is significantly larger than from CH3OH (0.386 e vs. 0.073 e).</p> <p><strong>Conclusion</strong>: Although driven by the same adsorption bond, the difference in the molecular characteristics leads to a marked difference in the absorption strength of CH3OH and CH3O on Ir(111) surface.</p> Thong Le Minh Pham Khoa Thanh Phung Thang Viet Ho Thi Anh Le An Thai Thi Nguyen ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-02-02 2021-02-02 24 1 1828 1834 10.32508/stdj.v24i1.2485 title description none g Phenolic compounds from the lichen Parmotrema tinctorum http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2490 <p><strong>Introduction</strong>: The metabolites of lichens concentrated depsidones, depsides, and diphenyl ethers were possessed antibiotic, antifungal, antiviral, antitumor, and anticancer activities. Parmotrema tinctorum (Despr. ex Nyl.) Hale, a species of foliose lichen, is widely distributed in Lam Dong province, Vietnam. Herein, this paper describes the isolation and structure elucidation of seven compounds isolated from this lichen. <strong>Methods</strong>: Phytochemical investigations of the ethyl acetate extract of the lichen P. tinctorum led to the isolation of seven pure compounds. Their chemical structures were elucidated by extensive HR-ESI-MS and NMR spectroscopic analysis and comparison with previously published data. <strong>Results</strong>: Seven compounds, namely orcinol (1), orsellinic acid (2), methyl orsellinate (3), methyl heamatomate (4), lecanorin (5), lecanoric acid (6), and gyrophoric acid (7). These compounds were determined the α-glucosidase inhibitory activity. <strong>Conclusions</strong>: Compound 7 was determined for the first time in P. tinctorum, and this was also the first time these compounds were determined the α-glucosidase inhibitory activity.</p> Huynh Bui Linh Chi Van Muoi Bui Thi Quynh Nhu Phan Kim Phi Phung Nguyen ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-02-25 2021-02-25 24 1 1842 1846 10.32508/stdj.v24i1.2490 title description none g Transfer hydrogenation of benzaldehyde over embedded copper nanoparticles http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2507 <p>Transfer hydrogenation is one of the reactions of high industrial application and copper catalyst is widely used in variety of hydrgenated substrates. Unfortunately, these hydrogenated processes were usually performed at high temperature and pressure as well as high concentration of catalyst. In this study, we have tried to reduce the dangerous condition by using copper nanoparticles as catalyst and the catalytic activity will be evaluated via the transfer hydrogenation of benzaldehyde. Besides, copper nanoparticles were successful prepared by the reduction between CuSO<sub>4</sub>.5H<sub>2</sub>O and NaBH<sub>4</sub> in the presence of PVP. All catalysts were fully characterized.</p> Thanh Thien Co ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-02-28 2021-02-28 24 1 1847 1853 10.32508/stdj.v24i1.2507 title description none g Improvement of antibacterial efficacy using antibiotic encapsulated silica-containing redox nanoparticles http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2495 <p><strong>Purpose</strong>: Improving solubility and antibacterial efficiency of cephalothin by using silica-containing redox nanoparticle (siRNP) as a system to encapsulate and deliver this hydrophobic antibiotic.</p> <p><strong>Methods</strong>: siRNP was synthesized by assembling amphiphilic block copolymers possessing a reactive oxygen species scavenging nitroxide radical and drug absorptive silica moieties in a hydrophobic side chain. Cephalothin, a hydrophobic antibiotic, was encapsulated into siRNP (cephalothin@siRNP) by mixing and dialysis methods. Antibacterial activity of cephalothin@siRNP against <em>Staphylococcus aureus</em> (<em>S. aureus</em>) và <em>Escherichia coli</em> (<em>E. coli</em>) was evaluated by the agar diffusion method.</p> <p><strong>Results</strong>: The average size of siRNP and cephalothin@siRNP was 43.83 nm and 50.15 nm, respectively. After encapsulation in siRNP, the solubility of cephalothin was improved compared to cephalothin in an aqueous solution. The result showed that in vitro antibacterial activities of cephalothin and cephalothin@siRNP had no statistical difference after 24 h incubation on agar plates on both <em>S. aureus</em> and <em>E. coli</em>. However, after an extended incubation time, regrowth of <em>E. coli</em> colonies in the inhibitory zone was found in cephalothin treated plate. Interestingly, <em>E. coli</em> regrowth was significantly reduced in plates treated with cephalothin@siRNP.</p> <p><strong>Conclusion</strong>: In this study, siRNP successfully encapsulated cephalothin and enhanced the solubility of this drug. The antibacterial activity of cephalothin is prolonged when encapsulated in siRNP, which suppressed the reccurrence of <em>E. coli</em> colonies. Cephalothin@siRNP has the potential to inhibit antibiotic resistance.</p> Han Ngoc Tran Nhu-Thuy Trinh Hoai-Ngan Thien Pham Hanh Thi Ngoc Nguyen Vong Binh Long ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-03-11 2021-03-11 24 1 1854 1861 10.32508/stdj.v24i1.2495 title description none g Gold nanoparticles enhanced fluorescence for highly sensitive biosensors based on localized surface plasmon resonance applied in determination C-reactive protein http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/2489 <p><strong>Introduction: </strong>C-reactive protein (CPR) is known as an inflammation marker related to numerous pathology. Optical biosensor based on the fluorescence dyed is widely used in diagnosis. There are still limitations on the fluorescence signal detection due to the photobleaching effect. The localized surface plasmon resonance (LSPR) performed by gold nanoparticles (Au NPs) is testified for the enhancement of photo-signal gathered from the dye molecules.</p> <p><strong>Methods: </strong>In this study, Au NPs were used for their significant optical properties and biocompatibility additionally. The seed-mediated synthesis method provided stable NPs with all the essential qualities. A series of modification steps were done on a glass substrate before the bio-bonding for fluorescence-based sensing by a transmission mode (T-mode) detection system which is introduced for the first time in Viet Nam.</p> <p><strong>Results: </strong>The synthetic Au NPs in nanosphere structure evinced the absorbance at a maximum wavelength is 521 nm. All the followed alterations showed the accomplishment in forming the in need linking proved through the basic analysis methods. Finally, CRP with the Alexa 488 dye was observed for average at 4.8 folds of enhancement factor compared between the Au NPs coating and non-coating substrate detected by the T-mode system. The low coefficient of variation at under 0.7% appeared for the repeatability and stability of this sensor.</p> <p><strong>Conclusion: </strong>The completely modern approach of the T-mode system combined with the LSPR applied in fluorescence sensors enhanced is developed successfully. Also, the future prospect of this designed sensing method is promising by changing the materials' structures and ingredients.</p> <p><strong>Keywords:</strong> LSPR, gold nanoparticles, fluorescence enhancement, C-reaction protein, optical biosensors</p> Nhu Hoa Thi Tran Phuong Que Do Tran Bach Thang Phan Hanh Kieu Thi Ta Ngoc Xuan Dat Mai Lai Thi Hoa Thanh Van Thi Tran Dung Van Hoang ##submission.copyrightStatement## http://creativecommons.org/licenses/by/4.0 2021-03-17 2021-03-17 24 1 1862 1869 10.32508/stdj.v24i1.2489 title description none g