Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh

We consider various kinds of solutions to nonsmooth vector equilibrium problems with functional constraints. By using first and second-order approximations as generalise derivatives we establish both necessary and sufficient optimality conditions. Our first-order conditions are shown to be applicable in many cases, where existing ones cannot be applied. The second-order conditions are new.

Burns is one of the popular accidents today and usually leaves serious physical and mental damage. For long time represent acute wounds, burns are evolution into chronic wounds, if inadequately managed. Up to now, there have been abundancy of natural and synthetic products for burn healing. In the study, we fabricated a thermosensitive nanocomposite hydrogel in which incorporated dual active curcumin and chitosan. Beside of a well-known characteristic of chitosan for wound healing, curcumin has been a lot of interest in burn wound healing application due to ability in depleting the action of oxidative radicals and stimulation of fibroblast cells. In order to enhance the therapeutic efficacy of curcumin, we introduced the new method to synthesize nanocurcumin in the a thermosensitive chitosan-g-Pluronic F127 copolymer solution under ultrasonication. The rheology of aqueous solutions of this material is studied as a function of temperature. The solutions of this material undergo a transition to a gel at higher temperature, above which a complex rheological behavior is observed. In addition, a minimum inhibitory concentration of this material was determined for a variety of bacterial and was compared to that of curcumin. It was found that the aqueous dispersion of this material was much more effective than curcumin against both positive and negative gram bacterial. In the third degree burn models, the nCur-CP hydrogel performed a higher burn healing rate as compared to Silvirin-treated burn. These data suggest that the nanocomposite hydrogel may be great potential for burn treatment.

The main purpose of this study is to identify the relationships between learning approach and various demographic factors. With these relationships identified, students’ learning approach can be predicted, and even in some case if we can change the factors students can adapt their learning approach toward deeper-oriented. The ASSIST questionnaire and a demographic factor one developed in house were used in this study. The survey was conducted on two Vietnam universities with a sample of 882 students, who were studying maths or math-related subjects. T-tests and ANOVA were applied in the analysis process. Many relationships between learning approaches of “deep”, “surface”, “strategic” and various demographic factors were disclosed; then solutions to encourage students to use less surface approach, and more deep approach in learning were discussed.Keywords: Learning approach; demographic factor; education; student; ASSIST.

Lưới tính toán (Computational Grid-CG) là bài toán mới xuất hiện gần đây. Việc lập lịch (scheduling) với các công việc độc lập (independent jobs) trên CG với mục tiêu cực tiểu makespan là bài toán khó nhưng hấp dẫn. Đóng góp mới nhất vào nhóm các giải thuật tiến hóa nổi tiếng như giải thuật di truyền (Genetic Algorithm-GA), tối ưu bầy đàn (Particle Swarm Optimization-PSO), giải thuật tối ưu hóa đàn kiến (Ant Colony Optimization-ACO)… để giải quyết bài toán này cũng như các bài toán trong lĩnh vực tối ưu hóa là tối ưu hóa rừng cây (Forest Optimization Algorithm-FOA) [1]. Đề tài này giới thiệu thuật toán FOA có hiệu chỉnh và áp dụng để giải quyết bài toán lập lịch các công việc độc lập trên lưới tính toán với mục tiêu cực tiểu hóa makespan. Kết quả cho thấy FOA có thể áp dụng tốt cho việc giải bài toán tối ưu hóa trên.

In this paper, we apply the bootstrap method to study the standard deviation for bone mineral density of Vietnameses women. This result is important in recognizing seriousness of the osteoporosis.

In vitro leaves of carnation (cut-off flower) variety CCF cut into small pieces about 1x1cm in size were precultured for 5 days and were co-cultivated with the Agrobacterium tumefaciens strain LBA 4404 harbouring the plasmid pVDH1396 contained the β-glucuronida gene (gusA), hygromycin phosphotransferase gene (hpt) under the control of cauliflower Mosaic virus 35S promoters, terminators, and an isopentenyl transferase (ipt) gene from Agrobacterium tumefaciens, driven by the SAG12 promoter from senescence associated gene 12 of Arabidopsis thaliana and its terminator. After 5 days of co-cultivation, explants were transferred onto the MS selection medium containing 1.0mg/l TDZ and 0.1mg/l NAA, 5mg/l hygromycin, 500 mg/l cefotaxime. Some putative shoots were tested for GUS assay. Putative shoots were transferred on MS medium 3 containing 0.5 mg/l IBA and 10 mg/l hygromycin. PCR analyses on hygromycin resistant shoots generated via Agrobacterium tumefaciens transformation to confirm the presence of the, ipt, hpt and gusA genes with expected bands 615bp, 508bp and 365bp. Analysis of putative carnation transformants to confirm that the foreign genes are inserted into the carnation genome by Southern blot analyses will be done in the future.

Các yếu tố phiên mã NAC là tác nhân điều hòa quan trọng trong phản ứng của thực vật để đáp ứng với hạn hán và mặn, hai yếu tố stress thẩm thấu ảnh hưởng nhiều nhất tới năng suất cây đậu tương. Trong nghiên cứu trước của chúng tôi, GmNAC085 đã được xác định là gen điều hòa tiềm năng liên quan đến tính chịu hạn ở cả mô rễ và chồi của đậu tương. Trong nghiên cứu này, sự biểu hiện của gen GmNAC085 được tiếp tục đánh giá ở giống đậu tương chịu hạn tốt DT51 và chịu hạn kém MTD720 dưới các điều kiện xử lý stress thẩm thấu khác biệt. Cây 12 ngày tuổi được xử lý mất nước và mặn ở 0 giờ, 2 giờ và 10 giờ. Kết quả cho thấy, khi mất nước, sự biểu hiện của gen tăng rất nhiều lần ở cả chồi và rễ, đặc biệt là ở chồi. Cụ thể, đối với giống DT51, gen có biểu hiện tăng 30 lần ở chồi và 5 lần ở rễ tại 2 giờ; tương tự tăng 260 lần ở chồi và 8 lần ở rễ khi xử lý 10 giờ; ở giống MTD720 là 15 lần và 28 lần ở rễ, 499 lần và 494 lần ở chồi lần lượt tại 2 giờ và 10 giờ. Tương tự, khi xử lý mặn lần lượt tại 2 giờ và 10 giờ, GmNAC085 biểu hiện tăng cường ở cả mô chồi và rễ. Gen biểu hiện tăng 35 lần và 656 lần ở chồi, 2 lần và 14 lần ở rễ của DT51 sau xử lý 2 giờ và 10 giờ. Trong khi đó, ở MTD720 là 10 lần và 377 lần ở chồi, 5 lần và 26 lần ở rễ. Kết quả này cho thấy GmNAC085 không chỉ liên quan đến đáp ứng hạn ở cây đậu tương mà còn liên quan đến một số phản ứng đáp ứng tác nhân vô sinh khác. Vì vậy, GmNAC085 là gen tiềm năng cho phương pháp chuyển gen nhằm tăng tính chống chịu ở đậu tương nói riêng và cây nông nghiệp nói chung.

The immobilisation of DNA probe on gold electrode surface with the optimal concentration is very important to develop of the DNA biosensors. In this study, we conducted an experiment that determined the optimal concentration of the probe attached the electrodes for the maximum hybridization efficiency. We have used a method that control the surface density of DNA probe by annealing probe modified by thiol and mercaptohexanol. Based on the linear relationship between the mol ratio and density probe, we control probe concentration in the sensor fabricating process as well as the molecular density of DNA probes on the electrode surface. The result of probe concentration 500 nM is optimal for hybidization with DNA target.

High antigenic variability in the envelope (E) protein of different virus strains has been a major obstacle in designing effective vaccines for Dengue virus (DENV). To maintain their biological function, some parts of viral proteins remain stable during evolution thus one possible approach to solve this problem is to recognize specific regions within different protein sequences of E that have the tendency to stay constant through evolution. These regions may possess some special attributes to become a vaccine candidate against dengue virus. In this study, a computational approach was utilized to identify and analyze highly conserved amino acid sequences of the DENV E protein. Sequences of 9 amino acids or more were specifically focused due to their immune-relevant as T-cell determinants. Different bioinformatics tools were responsible for revealing conserved regions in the DENV E protein and constructing the phylogenetic tree from the sequence database. The tools also predicted immunogenicity of the identified vaccine targets. Ultimately, two peptide regions of at least 9 amino acids were chosen due to their high conserved attribute in more than 95% of all collected DENV sequences. Moreover, both of them was found to be immune-relevant by their correspondence to known or putative HLA-restricted T cell determinants. The conserved attribute of these sequences through the entire analysis of this study supports their potential as candidates for further in vitro experiments for rational design a universal vaccine which has longer and broader impact.

Breast cancer, affecting women mostly, is the second common cancer in the world. Previous studies showed that miRNAs played a role in the regulation of signal transduction pathways in many different stages of cancer. The SNPs that occur on miRNA can have broad impact in cancer by many different ways. It was found that SNP rs11614913 C>T in miR-196a2 related to breast cancer risk in Asia. In addition, the association between SNP rs6977848 T> G in miR-148a and breast cancer have early proven on the Australian. In this study, a combination of Tetra-Arms-PCR and PCR product melting analysis,was used to screen for the presence of the allele of rs11614913 and rs6977848 in Vietnamese breast cancer patients. The results showed that the frequency of C and T allele ofrs11614913 were 58.96 % and 41.04 % respectively; the frequency of T and G allele of rs6977848 were 99 % and 1 %, respectively. Based on the genotype frequencies in the HapMap, rs11614913 is predicted to be associated with breast cancer while rs6977848 is probably not related to breast cancer in Vietnam due to a highly dominant frequency of only one type allele. However, there is still need for further research on a larger sample size to confirm the association between the two SNPs with breast cancer in Vietnam.