http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/issue/feed Science and Technology Development Journal - Natural Sciences 2019-09-18T14:38:53+00:00 Phuc Van Pham pvphuc@vnuhcm.edu.vn Open Journal Systems http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/801 Effects of the electrosprayed polycaprolactone microparticles morphology on the polycaprolactone degradation 2019-09-18T14:38:53+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_801_cover_en_US.png Nguyen-Vu Viet Linh nguyenvuvietlinh@hcmut.edu.vn Nguyen Quoc Viet phamvanphuc2308@gmail.com Huynh Dai Phu phamvanphuc2308@gmail.com <p>The polycaprolactone (PCL) microparticles fabricated by electrospray technique have been studied and applied in drug and protein delivery system. The degradation of PCL and the release of drug/protein from the polymeric microparticles (MPs) were desired to happen simultaneously. When the new dosage was administrated, the PCL MPs were degraded and eliminated out of the body. This research indicated that the degradation of PCL was influenced by the various morphology of electrosprayed microparticles. The different sizes of 11.8 μm and 5.17 μm and the various shapes of the PCL MPs such as hollow, porous and wrinkle particles and spheres were investigated the PCL degradation in the PBS solution, at pH 7.4. The morphology of PCL MPs was designed by controlling the polymer solution and the electrosprayed processing parameters such as the flow rate and collecting distance. Scanning electron microscopy and gel permeation chromatography were order to determine the change of the morphology and number molecule weight (Mn) of PCL MPs. The porous, distorted and smaller particles reduced the Mn faster than the microspheres because of the larger surface area of MPs contacted with PBS solution. After 77 days, PCL MPs which were fabricated by the processing parameter, including 2.5% PCL in DCM, flow rate of 0.8 mL/h, voltage of 18 kV, collecting distance of 25 cm, reduced 49.96% molecular weight (decreasing from Mn= 80,438 g/mol to 40,225 g/mol).</p> <p>&nbsp;</p> 2019-08-04T00:00:00+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/802 Genaration and assessment of immunomagnetic nanoparticles capable of T-cell removal 2019-09-18T14:38:51+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_802_cover_en_US.png Kien-Quang Huynh phamvanphuc2308@gmail.com Thuan Van Tran phamvanphuc2308@gmail.com Thao-Suong Tran-Nguyen phamvanphuc2308@gmail.com Kieu-Hanh Thi Ta phamvanphuc2308@gmail.com Hieu Tran-Van tvhieu@hcmus.edu.vn <p>Hematopoietic stem cells (HSCs) transplantation has been the potential treatment for hematopoietic disorder patients. However, once they were prescribed HSCs transplantation as the therapy, especially allogeneic transplantation, they would face Graft versus Host disease (GvHD), which causes by the presence of T cells in donor tissue. To deal with the risk of GvHD, removal T cells in donor tissue prior to transplant to recipient is extremely indispensable. Nowadays, MACS technique using immuno-magnetic nanoparticles in order to deplete T cells shows potential solution in the transplantation. In this study, we prepared immuno-magnetic nanoparticles for separation of Jurkat T cells from cell culture. Anti-Jurkat T antibodies were conjugated onto magnetic nanoparticles via recombinant protein A/G, an antibody’s Fc specific binding protein. The bonds between protein A/G and immuno-magnetic nanoparticles were covalently linked by amine groups on the surface of magnetic nanoparticles and the protein through 3-(2 pyridyldithio) propionic acid N hydroxysuccinimide ester (SPDP). Approximately 85 μg of protein A/G and 21 μg of antibody were bound to one mg of magnetic beads. The immuno-magnetic nanoparticles were capable of isolating up to 53.3% of Jurkat T cells from culture medium.</p> 2019-08-06T23:17:19+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/803 Effect of gibberellic acid and urea on the growth of pineapple fruit (Ananas comosus (L.) Merr.) 2019-09-18T14:38:49+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_803_cover_en_US.png Le Van Ut levanut.edu@gmail.com Vo Thi Bach Mai phamvanphuc2308@gmail.com <p>Effects of gibberellic acid (GA3) and urea on Queen pineapples (<em>Ananas comosus</em> (L.) Merr.) growth in the field were discussed in this study. Pineapples were sprayed with GA3 (at the concentration of 1, 5, 10, 20, 40, 60, 80 and 100 mg.L<sup>-1</sup>) or urea (at the concentration of 1, 5, 10, 15, 20, 25 and 30 g.L<sup>-1</sup>) on day 0 and day 3 at the beginning of growth period (50% dried flowers). Fruits were sampled every 15 days from day 0 to day 75 for assessment on fruit weight, fruit size, and fruit quality. Besides, fruits (which were sprayed with GA3 at the concentration of 40 mg.L<sup>-1</sup> or urea at the concentration of 15 g.L<sup>-1</sup>) were sampled on the 15th day from the day which processed to determine the size of cells. The results showed that the treatments with four highest concentration of GA3 (40, 60, 80 and 100 mg.L<sup>-1</sup>) or urea (15, 20, 25 and 30 g.L<sup>-1</sup>) significantly increased fruit weights and fruit sizes. In addition, the treatments of GA3 in high concentration (40 - 100 mg.L<sup>-1</sup>) stimulated the increase of sugar content and vitamin C content in the fruit flesh compared to the control. The treatments of urea at different concentrations did not alter the fruit quality index. Exogenous GA3 at the concentration of 40 mg.L<sup>-1</sup> or urea at the concentration of 15 g.L<sup>-1</sup> stimulated the increase of fruit weight without decreasing the fruit quality. In which, exogenous GA3 at concentration 40 mg.L<sup>-1</sup> increased the fruit weight by enlarging flesh cell.</p> <p>&nbsp;</p> 2019-08-07T00:00:00+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/518 Verifying the accuracy of 3D-CRT dose distributions calculated by the Prowess Panther treatment planning system (TPS) with Monte Carlo (MC) simulation for head-and-neck (H&N) patients 2019-09-18T14:38:44+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_518_cover_en_US.png Luong Thi Oanh oanhluong220995@gmail.com Duong Thanh Tai thanhtai_phys@yahoo.com Hoang Duc Tuan hoangtuan714@gmail.com Truong Thi Hong Loan tthloan@hcmus.edu.vn <p>The purpose of this study is to verify and compare the three Dimensional Conformal Radiation Therapy (3D-CRT) dose distributions calculated by the Prowess Panther treatment planning system (TPS) with Monte Carlo (MC) simulation for head-and-neck (H&amp;N) patients. In this study, we used the EGSnrc Monte Carlo code which includes BEAMnrc and DOSXYZnrc programs. Firstly, the clinical 6 MV photon beams form Siemens Primus linear accelerator at Dong Nai General Hospital were simulated using the BEAMnrc. Secondly, the absorbed dose to patients treated by 3D-CRT was computed using the DOSXYZnrc. Finally, the simulated dose distributions were then compared with the ones calculated by the Fast Photon Effective algorithm on the TPS, using the relative dose error comparison and the gamma index using global methods implemented in PTW-VeriSoft with 3%/3 mm. There is a good agreement between the MC and TPS dose. The average gamma passing rates were 92.8% based on the 3%/3 mm. The average dose in the PTV agreed well between the TPS with 0.97% error. MC predict dose was higher than the mean dose to the parotid glands and spinal cord compared to TPS. We have implemented the EGSnrc-based Monte Carlo simulation to verify the 3D-CRT plans generated by Prowess Panther TPS. Our results showed that the TPS agreed with the one of MC.</p> <p>&nbsp;</p> 2019-08-09T01:26:52+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/687 Inventory and mapping the air emissions from transportation activities in Ho Chi Minh city 2019-09-18T14:38:46+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_687_cover_en_US.png VU HOANG NGOC KHUE vhnk1304@gmail.com HO MINH DUNG h_minhdung@yahoo.com NGUYEN THOAI TAM thoaitam1986@gmail.com NGUYEN THI THUY HANG hangnguyen6769@gmail.com HO QUOC BANG bangquoc@yahoo.com <p>Ho Chi Minh City plays a role as a leading economic and social center in the South of Vietnam, together with the urbanization, transportation system is being rapidly developing, resulting in an increase in emissions from these activities, and worsen the quality of the city. Therefore in this study, emission inventory for transportation has been conducted using the EMISENS model and then using GIS solfware to distribute the emissions in space in order to have the overall picture of air emissions of this city. The results showed that on-road activites especially from using motorcycles are the major contributer to air emissions in the city. On-road source in general accounting for 88% of NOx, 99% of CO, 79% of SO2, 99% of NMVOC, 88% of PM in total emissions from transportation activities. Key finding in this study is that hahour activities contribute up to 20% of total SOx and 10% of total PM. Other sources of transportation (airport, habour, bus station, rail way) only accounting for negligible amount of emissions Emission maps of transportation showed that central areas (District 1, District 10, District 3 and District 5) reached higer level of emissions than others. In additions, harbours areas as District 2, District 4 and District 7 where Saigon Port and Cat Lat Port are located in suffer the highest emissions of SO2, NOx and Dust.</p> 2019-08-09T00:00:00+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/663 Solutions to the jump-diffusion linear stochastic differential equations 2019-09-18T14:37:58+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_663_cover_en_US.png Dang Kien Cuong dkcuong@hcmuaf.edu.vn Duong Ton Dam damdt@uit.edu.vn Duong Ton Thai Duong dttduong@vnuhcm.edu.vn Du Thuan Ngo ngothuandu123@gmail.com <p>The jump-diffusion stochastic process is one of the most common forms in reality (such as wave propagation, noise propagation, turbulent flow, etc.), and researchers often refer to them in models of random processes such as Wiener process, Levy process, Ito-Hermite process, in research of G. D. Nunno, B. Oksendal, F. B. Hanson, etc. In our research, we have reviewed and solved three problems: (1) Jump-diffusion process (also known as the Ito-Levy process); (2) Solve the differential equation jump-diffusion random linear, in the case of one-dimensional; (3) Calculate the Wiener-Ito integral to the random Ito-Hermite process. The main method for dealing with the problems in our presentation is the Ito random-integrable mathematical operations for the continuous random process associated with the arbitrary differential jump by the Poisson random measure. This study aims to analyse the basic properties of jump-diffusion process that are solutions to the jump-diffusion linear stochastic differential equations: dX(t) = [a (t)X (t􀀀)+A(t)]dt + [b (t)X (t􀀀 ∫ )+B(t)]dW (t) + R0 [g (t; z)X (t􀀀)+G(t; z)] ¯N (dt;dz) with a set of stochastic continuous functions fa;b ;g ;A;B;Gg and assuming that the compensated Poisson process ¯N (t; z) is independent of the Wiener process W(t). Derived from the Ito-Hermite formulas for the Ito-Hermite process and for the Ito-Levy process class we presented the results for the differential and multiple stochastic integration for the Ito- Hermite process. We also provided a separation method to solve jump-diffusion linear differential equations.</p> <p>&nbsp;</p> 2019-09-06T12:25:39+00:00 ##submission.copyrightStatement## http://stdjns.scienceandtechnology.com.vn/index.php/stdjns/article/view/519 Down-regulation of hepatic PPARg and C/EBPa genes in Juvenile-stage zebrafish exposured chronically to bisphenol A 2019-09-18T14:37:53+00:00 http://stdjns.scienceandtechnology.com.vn/public/journals/2/article_519_cover_en_US.png Cong Thanh Nguyen thanhcong045@gmail.com Mai Thi Ngo maingo25.7@gmail.com Nga Phi Le lephinga@hcmut.edu.vn <p><strong>Introduction</strong>: Bisphenol A (BPA) is used in synthesis of plastics. It is known as a potential chemical that causes hormonal changes in human and animals. Many previously studies showed that the activity of BPA was similar to estrogen and it could affect on embryonic and newborn stages. From a different approach, a research by these authors published in 2017 suggested that BPA could effect to the fast- growing stage of an animal based on proteomic profiles of Juvenile-stage zebrafish livers long term exposured to mg/L range of the chemical. This study was the extent of that research to further investigate which metabolic receptors in liver effected by BPA exposure. Among suggestedhepatic receptors, PPARg and C/EBPa genes may be targeted by BPA under such exposure condition.</p> <p><strong>Methods</strong>: In this study, zebrafish at 30th day of age were exposed to 0, 10 and 100 mg /L BPA, respectively, and continuously for 60 days under a standar condition for testing chronic toxicity of a chemical on fish. At the end of the testing, mRNA levels of PPARg and C/EBPa genes in zebrafish livers of BPA-exposed groups were compared to that of BPA-unexposed group using Real-Time PCR method with b -actin gene as the reference gene.</p> <p><strong>Results</strong>: BPA affected transcription level of both genes depending on the concentration of the chemical. Reduction of 67% and 70% on mRNA level for PPARg and C/EBPa, respectively, was only observed on 100 mg/L BPA-exposed group. No significant change on such regulation was found in 10 mg/L BPA-exposed group.</p> <p><strong>Conclusion</strong>: Thus, the effect of BPA exposure on liver functions of zebrafish at juvenile stage may associate with hepatic PPARg and C/EBPa receptors and it depends on the chemical concentration.</p> <p>&nbsp;</p> 2019-09-13T00:00:00+00:00 ##submission.copyrightStatement##