Solving Integer Programming Problems Using Genetic Algorithms

Pham Nguyen Anh Huy,Chu Tat Bich San,E. Triantaphyllou 대한전자공학회 2004 International Conference on Electronics, Informati Vol.2004 No.8

Some Results of Recent Investigation and Application of Rubber Blends in Vietnam

Bui Chuong,Nguyen Thanh Liem,Dang Viet Hung,Nguyen Huy Tung,Nguyen Pham Duy Linh,Nguyen Thanh Nhan,Pham Ngoc Linh,Le Anh Kien,Chu Chien Huu 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

We have investigated the change of tensile strength (TS) of Natural rubber/chloroprene rubber (NR/CR) blends during combination ageing, including heating and dynamic mechanical loading. Using model of statistical experiment, we built the equation describing the dependence of TS on four factors: temperature T, number of cyclic loadings N, contents of NR (C_NR) and chloroprene (CCR). This equation allows predict the TS change of NR/CR blends after combination ageing with accepted inaccuracy – less than 10%. We also investigated the effect of nanofillers, such as nanoclay, SiO2, Fe₃O4, on adhesion of some rubber blends to polyester and steel cords. It was found, in the case of EPDM/CIIR rubber blends, both nanoclay and SiO2 have no effect on adhesion to steel cords, while nano SiO2 may enhance adhesion to polyester cords. On other side, Fe₃O4 may remarkably enhance adhesion of NR/CR blends to steel. Mentioned results are successfully applied in some practical rubber products working under fatigue conditions, such as rubber/steel antivibration pad for locomotive, heat resistant conveyor, water dam, underwater lift bag.

A Vapor Sensor Based on a Porous Silicon Microcavity for the Determination of Solvent Solutions

Huy Bui,Thuy Van Nguyen,The Anh Nguyen,Thanh Binh Pham,Quoc Trung Dang,Thuy Chi Do,Quang Minh Ngo,Roberto Coisson,Van Hoi Pham 한국광학회 2014 Current Optics and Photonics Vol.18 No.4

A porous silicon microcavity (PSMC) sensor has been made for vapors of solvent solutions, and a method has been developed in order to obtain simultaneous determination of two volatile substances with different concentrations. In our work, the temperature of the solution and the velocity of the air stream flowing through the solution have been used to control the response of the sensor for ethanol and acetone solutions. We study the dependence of the cavity-resonant wavelength shift on solvent concentration, velocity of the airflow and solution temperature. The wavelength shift depends linearly on concentration and increases with solution temperature and velocity of the airflow. The dependence of the wavelength shift on the solution temperature in the measurement contains properties of the temperature dependence of the solvent vapor pressure, which characterizes each solvent. As a result, the dependence of the wavelength shift on the solution temperature discriminates between solutions of ethanol and acetone with different concentrations. This suggests a possibility for the simultaneous determination of the volatile substances and their concentrations.

Homogeneous Disturbance Observer Based on Sliding Mode Observer and Controller for T-Type Inverter

Do Tuan Anh,Pham Quoc Huy,Giap Van Nam,Nguyen Quang Dich,Vu Phuong 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

This paper proposes a novel sliding mode control (SMC) for the T-Type inverter in the standalone mode. Firstly, the accuracy of the estimated states used to construct the fxed-time SMC and the disturbance observer (DOB) is improved by a proposed sliding mode observer (SMO). Secondly, a DOB is designed without the requirement of the frst derivative or the format of the disturbance. Thirdly, an advanced reaching law is utilized for both the SMO, the DOB, and the SMC controller for the chattering elimination. Fourth, the stability of the proposed controller is confrmed by the Lyapunov condition. The performance of the proposed control strategy is validated by simulations and experiments with the same scenarios of nonlinear load and parameter variations. The results prove that the output voltage of the proposed control method meets the standard EN 62040 with the total harmonic distortion being lower than 5% in all cases, which is superior to the performance of the traditional controller.

Nano-porous Silicon Microcavity Sensors for Determination of Organic Fuel Mixtures

Van Hoi Pham,Huy Bui,Le Ha Hoang,Thuy Van Nguyen,The Anh Nguyen,Thanh Son Pham,Quang Minh Ngo 한국광학회 2013 Current Optics and Photonics Vol.17 No.5

We present the preparation and characteristics of liquid-phase sensors based on nano-porous silicon multilayer structures for determination of organic content in gasoline. The principle of the sensor is a determination of the cavity-resonant wavelength shift caused by refractive index change of the nano-porous silicon multilayer cavity due to the interaction with liquids. We use the transfer matrix method (TMM)for the design and prediction of characteristics of microcavity sensors based on nano-porous silicon multilayer structures. The preparation process of the nano-porous silicon microcavity is based on electrochemical etching of single-crystal silicon substrates, which can exactly control the porosity and thickness of the porous silicon layers. The basic characteristics of sensors obtained by experimental measurements of the different liquids with known refractive indices are in good agreement with simulation calculations. The reversibility of liquid-phase sensors is confirmed by fast complete evaporation of organic solvents using a low vacuum pump. The nano-porous silicon microcavity sensors can be used to determine different kinds of organic fuel mixtures such as bio-fuel (E5), A92 added ethanol and methanol of different concentrations up to 15%.

Appropriation of Protocol for Laparoscopic Pancreaticoduodenectomy in Treatment of Periampullary Cancer

( Minh Hai Pham ),( Quan Anh Tuan Le ),( Hoang Bac Nguyen ),( Quang Hung Vu ),( Thai Ngoc Huy Tran ),( Hang Dang Khoa N Guyen ),( Thi Ngoc Sang Duong ),( Van Toan Tran ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Laparoscopic pancreaticoduodenectomy (LPD) is considered as a safe and effective procedure in well - selected patients and appropriate surgical technique. Our aim is to evaluate suitability of using protocol for LPD in treatment of periampullary cancer at a single team. Methods: case series Results: Indication for LPD included 37 cases with resectable tumors which were classified basing on NCCN. All witness evaluation risk of complications with PREPARE score, ASA and evaluation risk of postoperative pancreatic fistula (POPF) with FRS classification. There were 2 open conversions because of vein resections, accounting for 5.4%. Standard lymphadenectomy was performed in all of 37 cases. In term of PREPARE score, major complications (Clavien - Dindo >= III) were 17.8%, 0% and 0% (5/28, 0/5 and 0/2 cases) in low risk, intermediate risk and high risk group, respectively. All of cases had ASA I or II. POPF happened 11.1% (1/9), 4.1% (1/24) and 50% (1/2) in low risk, intermediate risk and high risk group, respectively. Frozen section was needed for R0 margin. Retrieved lymph nodes was 8 - 18 with 12 lymph nodes in average. Conclusions: Indication for LPD with resectable tumors is acceptable. ASA I or II is a safe measure to select patient for LPD. FRS classification shows appropriation to evaluate risk of POPF.

Efficacy of electrochemically activated water solution in gingivitis treatment

Dinh‑Toi Chu,Van‑Huy Pham,Thien Chu‑Dinh,Truong Nhu Ngoc Vo,Duc Long Duong,Van Nhon Bui,Minh Son Tong,Thi Thu Phuong Nguyen,Quynh Anh Le,Khanh‑Hoang Nguyen 한국약제학회 2019 Journal of Pharmaceutical Investigation Vol.49 No.3

Mouthwash is one of the most commonly oral healthcare products for prevention and treatment of gum diseases. Dr. ECA is a disinfectant solution manufactured by a Vietnamese company and has been licensed for oral healthcare, but its effect on gingivitis is still unclear. To evaluate the effectiveness of this product in the treatment of gingivitis, we conducted a clinical study in 60 students diagnosed with gingivitis to compare the results of gingivitis treatment using Dr. ECA and a control mouthwash (a demonstrated anti-gingivitis product). The data showed that in the treated group, the rate of good Gingivitis Index (GI) before treatment was 46.67%, but after 2 and 4 weeks of using Dr. ECA that rate was increased to 96.67% and 100%, respectively. The percentage of patients with bleeding on probing was 63.33% but declined sharply after 2 weeks of treatment to 6.67%, and further reduced to 3.33% after 4 weeks of treatment. The treatment outcomes in were similar in the Dr. ECA treated group and control one with no statistically significant difference. Our results suggest that the electrolyte saline solution Dr. ECA is effective in treating gingivitis. Its effects are similar to other mouthwash products that had been approved and marketed.

Detection of Vibrio cholerae O1 by Using Cerium Oxide Nanowires - Based Immunosensor with Different Antibody Immobilization Methods

Phuong Dinh Tam,Nguyen Luong Hoang,Hoang Lan,Pham Hung Vuong,Ta Thi Nhat Anh,Tran Quang Huy,Nguyen Thanh Thuy 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.10

In this work, we evaluated the effects of different antibody immobilization strategies on the response of a CeO2-nanowires (NWs)-based immunosensor for V ibrio cholerae O1 detection. Accordingly, the changes in the electron-transfer resistance (Ret) from before to after cells bind to an antibody-modified electrode prepared by using three different methods of antibody immobilization were determined. The values were 16.2%, 8.3%, and 6.65% for the method that utilized protein A, antibodies activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC)/Nhydroxysuccinimide (NHS), and absorption, respectively. Cyclic voltammetry confirmed that the change in the current was highest for the immunosensors prepared using protein A (11%), followed by those prepared with EDC/NHS-activated antibodies (9%), and finally, those prepared through absorption (7.5%). The order of the antibody immobilization strategies in terms of resulting immunosensor detection limit and sensitivity was as follows order: absorption (3.2 × 103 CFU/mL; 45.1 /CFU·mL−1) < EDC/NHS-activated antibody (1.0 × 103 CFU/mL; 50.6 /CFU·mL−1) < protein A (1.0 × 102 CFU/mL; 65.8 /CFU·mL−1). Thus, we confirmed that the protein A - mediated method showed significantly high cell binding efficiencies compared to the random immobilization method.

Risk factors for cannula-associated arterial thrombosis following extracorporeal membrane oxygenation support: a retrospective study

Trieu Ngan Hoang Kim,Phan Xuan Thi,Tran Linh Thanh,Pham Huy Minh,Huynh Dai Quang,Nguyen Tuan Manh,Mai Anh Tuan,Du Quan Quoc Minh,Nguyen Bach Xuan,Pham Thao Thi Ngoc 대한중환자의학회 2023 Acute and Critical Care Vol.38 No.3

Background: Hemostatic dysfunction during extracorporeal membrane oxygenation (ECMO) due to blood-circuit interaction and the consequences of shear stress imposed by flow rates lead to rapid coagulation cascade and thrombus formation in the ECMO system and blood vessels. We aimed to identify the incidence and risk factors for cannula-associated arterial thrombosis (CaAT) post-decannulation. Methods: A retrospective study of patients undergoing arterial cannula removal following ECMO was performed. We evaluated the incidence of CaAT and compared the characteristics, ECMO machine parameters, cannula sizes, number of blood products transfused during ECMO, and daily hemostasis parameters in patients with and without CaAT. Multivariate analysis identified the risk factors for CaAT. Results: Forty-seven patients requiring venoarterial ECMO (VA-ECMO) or hybrid methods were recruited for thrombosis screening. The median Sequential Organ Failure Assessment score was 11 (interquartile range, 8–13). CaAT occurred in 29 patients (61.7%), with thrombosis in the superficial femoral artery accounting for 51.7% of cases. The rate of limb ischemia complications in the CaAT group was 17.2%. Multivariate analysis determined that the ECMO flow rate–body surface area (BSA) ratio (100 ml/min/m2) was an independent factor for CaAT, with an odds ratio of 0.79 (95% confidence interval, 0.66–0.95, P=0.014). Conclusions: We found that the incidence of CaAT was 61.7% following successful decannulation from VA-ECMO or hybrid modes, and the ECMO flow rate–BSA ratio was an independent risk factor for CaAT. We suggest screening for arterial thrombosis following VA-ECMO, and further research is needed to determine the risks and benefits of such screening.

Novel 3,4-dihydro-4-oxoquinazoline-based acetohydrazides: Design, synthesis and evaluation of antitumor cytotoxicity and caspase activation activity

Huan, Le Cong,Tran, Phuong-Thao,Phuong, Cao Viet,Duc, Phan Huy,Anh, Duong Tien,Hai, Pham The,Huong, Le Thi Thu,Thuan, Nguyen Thi,Lee, Hye Jin,Park, Eun Jae,Kang, Jong Soon,Linh, Nguyen Phuong,Hieu, Tr Elsevier 2019 Bioorganic chemistry Vol.92 No.-

<P><B>Abstract</B></P> <P>In search for novel small molecules with antitumor cytotoxicity via activating procaspase-3, we have designed and synthesized three series of novel (E)-<I>N</I>′-benzylidene-4-oxoquinazolin-3(4<I>H</I>)-yl)acetohydrazides (<B>5a-j, 6a-h,</B> and <B>7a-h)</B>. On the phenyl ring ò the benzylidene part, three different substituents, including 2-OH-4-OCH<SUB>3</SUB>, 4-OCH<SUB>3</SUB>, and 4-N(CH<SUB>3</SUB>)<SUB>2</SUB>, were introduced, respectively. Biological evaluation showed that the acetohydrazides in series <B>5a-j</B>, in which the phenyl ring of the benzylidene part was substituted by 2-OH-4-OCH<SUB>3</SUB> substituent, exhibited potent cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most of the compounds, in this series, especially compounds <B>5c, 5b</B> and <B>5h,</B> also significantly activated caspase-3 activity. Among these, compound <B>5c</B> displayed 1.61-fold more potent than PAC-1 as caspase-3 activator. Cell cycle analysis showed that compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> significantly arrested the cell cycle in G1 phase. Further apoptotic studies also demonstrated compounds <B>5b</B>, <B>5c</B>, and <B>5h</B> as strong apoptotic cell death inducers. The docking simulation studies showed that these compounds could activate procaspase <I>via</I> chelating Zn<SUP>2+</SUP> ion bound to the allosteric site of the zymogen.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel (<I>E</I>)-<I>N</I>′-benzylidene-2-(4-oxoquinazolin-<I>3(4H)-yl</I>)acetohydrazides were synthesized. </LI> <LI> The acetohydrazides <B>5a-i</B> exhibited potent cytotoxicity against three human cancer cell lines. </LI> <LI> A number of cytotoxic compounds exhibited good caspase activation activity. </LI> <LI> The cytotoxic compounds were shown to arrest cells at G1 phase. </LI> <LI> The cytotoxic compounds were shown as strong apoptotic inducers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>