检索结果-南通市图书馆

Electrochemical Immunosensor for Detection of Atrazine Based on Polyaniline/Graphene

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2016年第6期32卷 539-544页

作者： Nguyen Van Chu Nguyen Hai Binh Cao Thi Thanh Nguyen Van Tu Nguyen Le Huy Nguyen Tuan Dzung Phan Ngoc Minh Vu Thi Thu Tran Dai Lam Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau Giay.HanoiViet Nam School of Chemical Engineering.hanoi University of Science and Technology 1 Dai Co VietHanoiViet Ham Institute for Tropical Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc VietHanoiViet Nam Center for High Technology Development Vietnam Academy of Science and Technology18 Hoang Quoc VietHanoiViet Nam University of Science and Technology of hanoi.18 Hoang Quoc Viet HanoiViet Ham Graduate University of Science and Technology.Vietnam Academy of Science and Technology 18 Hoang Quoc Viet.HanoiViet Nam

In this study, a novel layer-by-layer polyaniline/graphene （PANi/Gr） structure for electrochemical detec- tion of atrazine was developed. Gr film was synthesized by thermal chemical vapor deposition （CVD） method and transferred onto the PANi-predeposited microelectrode. The properties of PANi/Gr film were thoroughly investigated by high-resolution transmission electron microscopy and Raman techniques. The most attractive feature of this system is a suitable microenvironment, which could provide an amplifi- cation of the conductive signal, thus may contribute to enhancing electron transfer and subsequently improve the sensitivity in electrochemical measurements. With low detection limit （- 43 × 10 -12 g/L）, ac-ceptable stability and good reproducibility, the proposed electrochemical immunosensor could be advantageously extended for multiplexed detection of other agents of environmental pollution.

关键词： Electrochemical immunosensor Polyaniline Graphene Atrazine

Properties of poly（1-naphthylamine）/Fe3O4 composites and arsenic adsorption capacity in wastewater

在线全文

学校读者我要写书评

暂无评论

Frontiers of Materials Science 2016年第1期10卷 56-65页

作者： Minh Thi TRAN Thi Huyen Trang NGUYEN Quoc Trung VU Minh Vuong NGUYEN Faculty of Physics Hanoi National University of Education 136-Xuanthuy Street Caugiay District Hanoi Vietnam Faculty of Chemistry Hanoi National University of Education 136-Xuanthuy Street Caugiay District Hanoi Vietnam Department of Physics Quynhon University 170 An Duong Vuong Quynhon Vietnam

The research results of poly（1-naphthylamine）lFe3O4 （PNA/Fe3O4） nanocomposites synthesized by a chemical method for As（Ⅲ） wastewater treatment are presented in this paper. XRD patterns and TEM images showed that the Fe3O4 grain size varied from 13 to 20 nm. The results of Raman spectral analysis showed that PNA participated in part of the PNA/Fe3O4 composite samples. The grain size of PNA/Fe3O4 composite samples is about 25-30 nm measured by SEM. The results of vibrating sample magnetometer measurements at room temperature showed that the saturation magnetic moment of PNA/Fe3O4 samples decreased from 63.13 to 43.43 emu/g, while the PNA concentration increased from 5% to 15%. The nitrogen adsorption-desorption isotherm of samples at 77 K at a relative pressure PIPo of about 1 was studied in order to investigate the surface and porous structure of nanoparticles by the BET method. Although the saturation magnetic moments of samples decreased with the polymer concentration increase, the arsenic adsorption capacity of the PNA/Fe3O4 sample with the PNA concentration of 5% is better than that of Fe3O4 in a solution with pH = 7. In the solution with pH 〉 14, the arsenic adsorption of magnetic nanoparticles is insignificant.

关键词： poly(1-naphthylamin)/Fe3O4 nanocomposite magnetization arsenic adsorption

Detecting Tuberculosis from Vietnamese X-Ray Imaging Using Transfer Learning Approach

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第3期74卷 5001-5016页

作者： Ha Manh Toan Lam Thanh Hien Ngo Duc Vinh Do Nang Toan Institute of Information Technology–Vietnam Academy of Science and Technology Hanoi10072Vietnam Lac Hong University Bien HoaDong Nai76120Vietnam hanoi University of Industry Hanoi11915Vietnam

Deep learning created a sharp rise in the development of autonomous image recognition systems,especially in the case of the medical *** lung problems,tuberculosis,caused by a bacterium called Mycobacterium tuberculosis,is a dangerous disease because of its infection and *** an infected person coughs or sneezes,tiny droplets can bring pathogens to others through *** mainly damages the lungs,but it also affects any part of the ***,during the period of the COVID-19(coronavirus disease 2019)pandemic,the access to tuberculosis diagnosis and treatment has become more difficult,so early and simple detection of tuberculosis has been more and more *** our study,we focused on tuberculosis diagnosis by using the chestX-ray image,the essential input for the radiologist’s profession,and researched the effectiveness of the transfer learning approach in the case study of Vietnamese chest X-ray *** proposed four strategies to clarify our hypothesis in different ways of applying transfer learning and different training set *** also prepared a Vietnamese X-ray image dataset with the support of the VRPACS team to provide the basis for training and testing deep learning *** experiments were carried out by applying three different architectures,Alexnet,Resnet,and Densenet,on international,Vietnamese,and combined X-ray image *** training,all models were verified on a pure Vietnamese X-rays *** results show that transfer learning is suitable in the case study of Vietnamese chest X-ray images with high evaluating metrics in terms of AUC(Area under the Receiver Operating Characteristic Curve),sensitivity,specificity,and *** the best strategy,most of the scores were more than 0.93,and all AUCs were more than 0.98.

关键词： Tuberculosis diagnosis transfer learning Vietnamese chest X-ray

Nonlinear thermo-mechanical stability of eccentrically stiffened functionally graded material sandwich doubly curved shallow shells with general sigmoid law and power law according to third-order shear deformation theory

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第2期38卷 191-216页

作者： D.V.DUNG D.T.DONG Faculty of Mathematics Mechanics and Informatics Vietnam National University Hanoi 100000 Vietnam Faculty of Civil Engineering University of Transport Technology Hanoi 100000 Vietnam

In this paper, the nonlinear analysis of stability of functionally graded ma- terial （FGM） sandwich doubly curved shallow shells is studied under thermo-mechanical loads with material properties obeying the general sigmoid law and power law of four ma- terial models. Shells are reinforced by the FGM stiffeners and rest on elastic foundations. Theoretical formulations are derived by the third-order shear deformation theory （TSDT） with the von Karman-type nonlinearity taking into account the initial geometrical im- perfection and smeared stiffener technique. The explicit expressions for determining the critical buckling load and the post-buckling mechanical and thermal load-deflection curves are obtained by the Galerkin method. Two iterative algorithms are presented. The effects of the stiffeners, the thermal element, the distribution law of material, the initial imper- fection, the foundation, and the geometrical parameters on buckling and post-buckling of shells are investigated.

关键词： functionally graded material (FGM) sandwich double curved shallow shell,thermo-mechanical stability FGM stiffener elastic foundation

DENSITY ESTIMATES FOR SOLUTIONS OF STOCHASTIC FUNCTIONAL DIFFERENTIAL EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2019年第4期39卷 955-970页

作者： Nguyen Tien DUNG Ta Cong SON Tran Manh CUONG Nguyen Van TAN Trinh Nhu QUYNH Department of Mathematics FPT University Hoa Lac High Tech Park Hanoi Vietnam Department of Mathematics VNU Hanoi University of Science 334 Nguyen Trai Thanh Xuan Hanoi Vietnam Department of Foundation Academy of Cryptography Techniques Hl Chien Thang Thanh Tri Hanoi Vietnam Military Information Technology Institute 17 Hoang Sam Cau Giay Hanoi Vietnam

In this article, we investigate the density of the solution to a class of stochastic functional differential equations by means of Malliavin calculus. Our aim is to provide upper and lower Gaussian estimates for the d... 详细信息

关键词： Stochastic functional differential equations density estimates Malliavin calculus

Nonlinear stability of functionally graded material(FGM)sandwich cylindrical shells reinforced by FGM stiffeners in thermal environment

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第5期38卷 647-670页

作者： D.V.DUNG N.T.NGA L.K.HOA Faculty of Mathematics Mechanics and InformaticsVietnam National UniversityHanoi 100000Vietnam Faculty of Basic Science Military Logistic AcademyHanoi 100000Vietnam

In this paper, Donnell＇s shell theory and smeared stiffeners technique are improved to analyze the postbuckling and buckling behaviors of circular cylindrical shells of stiffened thin functionally graded material （FGM） sandwich under an axial loading on elastic foundations, and the shells are considered in a thermal environment. The shells are stiffened by FGM rings and stringers. A general sigmoid law and a general power law are proposed. Thermal elements of the shells and reinforcement stiffeners are considered. Explicit expressions to find critical loads and postbuckling load-deflection curves are obtained by applying the Galerkin method and choosing the three-term approximate solution of deflection. Numerical results show various effects of temperature, elastic foundation, stiffeners, material and geometrical properties, and the ratio between face sheet thickness and total thickness on the nonlinear behavior of shells.

关键词： functionally graded material (FGM) stiffened cylindrical shell sandwich,thermal environment

Buckling analysis of functionally graded material(FGM) sandwich truncated conical shells reinforced by FGM stiffeners filled inside by elastic foundations

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2016年第7期37卷 879-902页

作者： D.V.DUNG L.K.HOA B.T.THUYET N.T.NGA Faculty of Mathematics Mechanics and Informatics Vietnam National University Faculty of Basic Science Military Logistic AcademyHanoi Faculty of Mining Hanoi University of Mining and Geology

An analytical solution for buckling of an eccentrically stiffened sandwich truncated conical shell is investigated. The shell consists of two functionally graded material （FGM） coating layers and a core layer which are metal or ceramic subjected to an axial compressive load and an external uniform pressure. Shells are reinforced by stringers and rings, in which the material properties of shells and stiffeners are graded in the thickness direction following a general sigmoid law distribution. Two models of coated shell-stiffener arrangements are investigated. The change of the spacing between stringers in the meridional direction is taken into account. A couple set of three-variable- coefficient partial differential equations in terms of displacement components are solved by the Galerkin method. A closed-form expression for determining the buckling load is obtained. The numerical examples are presented and compared with previous works.

关键词： functionally graded material (FGM) sandwich truncated conical shell,stiffener elastic foundation buckling analysis

Effectiveness of bee venom acupuncture for patients suffering from periarthritis humeroscapularis

在线全文

学校读者我要写书评

暂无评论

中医杂志:英文版 2023年第4期43卷 795-800页

作者： Minh Duc Nguyen Thanh Van Tran Quoc Vinh Nguyen Cay Doan Ha Linh Vu Phuong Dang Senior Specialist Clinic National Hospital of AcupunctureHanoi 1000Vietnam Department of Senior Specialist National Hospital of Acupuncture Hanoi 1000Vietnam Department of Senior Specialist Military Institute of Traditional MedicineHanoi 1000Vietnam Department of minimally invasive spine National Hospital of AcupunctureHanoi 1000Vietnam Department of Medicine Dai Nam UniversityHanoi 1000Vietnam

OBJECTIVE:To evaluate the efficacy of bee venom acupuncture in humeroscapularis(PHS)***:One hundred and twenty patients diagnosed with PHS were assigned into four groups:BV1(0.01 mg/kg),BV2(0.005 mg/kg),BV3(0.0025 mg/kg),and control group(vitamin B1 plus novocain 3%injection)with 15 d of *** outcomes of the study including visual analogue scale(VAS)score andβ-endorphin,inflammatory cytokines including interleukin-10(IL-10),IL-1βand tumor necrosis factorα(TNF-α)and shoulder function score were assessed at baseline,after 10 and 15 d of ***:All four groups reported statistically significant improvement in VAS score,motion range,and shoulder function score(P<0.01),only the BV3 group showed significant increase of anti-inflammatory(IL-10)and decrease of pro-inflammatory(IL-1β,TNF-α)cytokines after treatment(P<0.05).The BV3 group presented a significant difference between all outcomes compared to the control and other ***:BV3 groups showed better recovery including reduced pain,improved motor function and normalized inflammatory cytokines than current therapy used in Vietnam and other groups.

关键词： periarthritis humeroscapularis bee venom acupuncture visual analogue scale range of motion articular shoulder function score inflammatory cytokines

Ethyl acetate extract of Smilax glabra Roxb roots and its major active compound astilbin promote osteoblastogenesis in vitro by upregulating bone cell differentiation-associated genes

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2021年第12期11卷 553-560页

作者： Huyen T.T.Nguyen Minh T.H.Nguyen Thu X.Nguyen Quan M.Pham Ha X.Nguyen Phuong T.M.Nguyen University of Science and Technology of hanoi Vietnam Academy of Science and TechnologyHanoiVietnam Institute of Biotechnology Vietnam Academy of Science and TechnologyHanoiVietnam Institute of Natural Products Chemistry Vietnam Academy of Science and TechnologyHanoiVietnam Graduate University of Science and Technology Vietnam Academy of Science and TechnologyHanoiVietnam

Objective:To investigate the osteoblastogenic activity of the ethyl acetate(EtOAc)extract of Smilax glabra Roxb roots and its major active compound ***:Astilbin was isolated from EtOAc extract using silica gel chromatography combined with fraction *** structure of astilbin was determined by analysis of the spectroscopic data in comparison with the *** method was used to detect the *** phosphatase(ALP)activity was determined by the spectrophotometric method at 405 nm using p-nitrophenyl phosphate as a *** deposition was stained with alizarin red-S,distained with cetylpyridium chloride,and quantified at 562 *** silico model for astilbin-ALP interaction was analyzed using AutoDock *** changes in expression of osteoblast differentiation related genes were determined using quantitative real-time ***:Both the EtOAc extract and astilbin had no toxicity toward osteoblast MC3T3-E1 cells at 5.0,10,25,and 50μg/*** 25μg/mL,they enhanced ALP activity and mineralization of osteoblasts up to 30%and 55%for the EtOAc extract and 22%and 41%for astilbin,*** docking analysis of astilbin-ALP interaction revealed Arg167,Asp320,His324,and His437 were key residues participating in hydrophobic interaction;meanwhile,His434 and Thr436 residues were involved in hydrogen bond formation in the active site of human tissue-nonspecific ***,the expression level of genes opn,col1,osx,and runx2 were up-regulated in astilbin treated samples with the fold changes as 2.2;3.7;4.1;2.3,respectively at 10μg/mL(P<0.05).Conclusions:The EtOAc extract and its major compound astilbin exhibit osteoblastogenic activity by up-regulating important markers for bone cell *** could be a new and promising osteogenic agent with dual actions for therapeutic applications.

关键词： Smilax glabra Roxb Astilbin Cytotoxicity Osteogenesis Osteoblast Ethyl acetate extract