103 research outputs found

    Enforcement of Contracts in Vietnam and the Risks of Bilateral Investment Treaty (BIT) Disputes

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    The Constitution in force (1992) consists of 147 articles divided into twelve chapters after a preamble, embodying the policy and legislation of Doi Moi. As for the political system, it is stipulated that: “The State promotes a multi-component commodity economy functioning in accordance with market mechanisms under the management of the State and following a socialist orientation. The multi-component economic structure with various forms of organization of production and trading is based on a system of ownership by the entire people, by collectives, and by private individuals, of which ownership by the entire people and by collectives constitutes the foundation.” This article provides an acute analysis of the structural and procedural provisions of the frameworks for contract enforcement in Vietnam, addressing both domestic and foreign transactional disputes and the key issues associated with these. The link between Doi Moi, and consequential integration with the international economy and the influence of collective interests stipulated in the Constitution are discussed in this article, and we also consider examples from other jurisdictions to provide both insight and an understanding into this relationship that defines contract enforcement in Vietnam

    Bismuth Oxychloride as an Efficient Heterogeneous Catalyst for Aldol Condensation Reaction between Aldehydes and Ketones

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    The aldol reaction is a cornerstone of modern synthetic organic chemistry in which the β-hydroxyketone was formed by the reaction of an enol or an enolate and a carbonyl compound. Benzalacetone is one of the fundamental building blocks of benzalacetone synthase structure that play an important role for construction of a variety of medicinally crucial phenylbutanoids, such as anti-inflammatory glucoside lindleyin in rhubarb and gingerol. The non-transition metal material attracted much attention from research groups on the world, such a potential catalyst as BiOCl for organic reaction due to its remarkably chemical and physical properties as relative stability, resistance of air and moisture, low toxicity. The BiOCl material was synthesized by the solvothermal method. The structure features of material were defined by modern analytic methods such as X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FT-IR), Scaning Electron Microscope (SEM), and Nitrogen Adsorption-Desorption Isotherms. The BiOCl material was successfully utilized as a catalyst for the aldol condensation reaction of benzaldehyde and acetone. The reaction was performed in the mild condition with the presence of 10 mol% catalyst and 2 equivalent of Cs2CO3 as base without by-product in very short reaction times and good yields. The benzalacetone product obtained around 85% yield at 120 °C for 24 h. The BiOCl material after reaction was recovered and reused many times without significant reducing of catalytic activity. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

    NHÂN GIỐNG LAN GIẢ HẠC (Dendrobium anosmum) ĐỘT BIẾN BẰNG PHƯƠNG PHÁP NUÔI CẤY IN VITRO

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    Currently, mutant orchids are very interested in orchid lovers who want to collect, but the price of mutant orchids is costly leading to many orchid lovers are unable to own it. This study aims to create mutant orchid plantlets with high quantity and low cost via in vitro propagation method. From the self-pollinated six months old seedpods, we have successfully propagated the orchid mutant seedlings. The results showed that the suitable medium for mutant orchid seed germination and creating protocorm was the basic MS medium supplemented with 0.5 mg/L BA with a rate of up to 93%. The medium for shoot formation and shoot development from protocorm was the best on MS medium added with 1.0 mg/L BA and 0.5 mg/L IBA with a rate of 88%. The rooting induction was 99.06% and the root length reached 5.34 cm with an average of 8.53 roots/shoot when shoots cultured on MS medium supplemented with 1.0 mg/L NAA. The survival rate of in vitro Dendrobium anosmum mutant seedlings after 60 days in the nursery stage was 84.9% on coir and rice husks substrates (1:1).Hiện nay, hoa lan đột biến đang trở thành tâm điểm được nhiều người quan tâm sưu tầm, nhưng do giá thành cây giống quá cao nên rất ít người có thể sở hữu. Để tạo ra giống với số lượng lớn, rẻ thì việc nhân giống in vitro những giống lan này là cần thiết. Vì vậy, từ vật liệu khởi đầu là quả lan sáu tháng tuổi tự thụ phấn từ cây mẹ đột biến, chúng tôi đã xây dựng thành công quy trình nhân giống lan Giả hạc đột biến bằng phương pháp nuôi cấy in vitro. Kết quả cho thấy môi trường thích hợp cho hạt lan đột biến nảy mầm tạo protocorm là môi trường MS cơ bản, bổ sung 0,5 mg/L N6-benzyladenine (BA) với tỷ lệ 93%. Môi trường thích hợp để protocorm tạo chồi là MS cơ bản, bổ sung 1,0 mg/L BA và 0,5 mg/L indole 3-butyric acid (IBA) với tỷ lệ tạo chồi 88%, chiều cao và số lá trên chồi trung bình 1,42 cm và 2,4 lá. Môi trường tối ưu để chồi tạo cây hoàn chỉnh là môi trường MS cơ bản, bổ sung 1,0 mg/L naphthaleneacetic acid (NAA) với tỷ lệ 99,06% chồi ra rễ; chiều dài rễ đạt 5,34 cm với trung bình 8,53 rễ/chồi. Tỷ lệ sống của cây con in vitro đột biến sau 60 ngày ra vườn ươm là 84,9% trên giá thể xơ dừa và trấu hun (1:1)

    Chemical composition and cytotoxic activity of the essential oils of Cymbopogon citratus L. Grown in phu tho province

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    Culms and leaves of Cymbopogon citratus L. were collected from two regions of Phu Tho province (Thanh Son and Phu Ninh) and used as materials for essential oil extraction. Oils obtained were steam-distilled, analyzed for chemical composition and evaluated for cytotoxic activity against three different cancer cell lines. The GC/MS analysis showed that citral is the major content of the steam-distilled essential oils which was found in the range of 64.15-76.22%. Camphene was found only in culm oils of both regions but it was not detected in the leaf oils. Interestingly, the isomer forms of ocimene present at higher content in the culm oils than in the leaf oils whereas myrcene content in the leaf oils is higher than that in the culm oils. In a cytotoxicity test, four essential oils of culms and leaves of C. citratus from Thanh Son and Phu Ninh showed potent activity against A549 (human lung carcinoma) cell line with the IC50 values ranging from 4.01±0.39 to 6.3±0.54 µg/ml. The essential oils (culms and leaves) from Phu Ninh exhibited moderate effects on the Hela (human cervical adenocarcinoma) cells with the IC50 values of 19.43±1.16 and 42±2.41 µg/ml, respectively. However, they were inactive against the human hepatocellular carcinoma Hep3B cell line. The essential oils from Thanh Son exhibited potent cytotoxic activity against Hela and Hep3B cell lines with the IC50 values ranging from 1.18±0.26 to 8.91±0.32 µg/ml. The results indicated that the essential oils of C. citratus from Thanh Son, Phu Tho could be considered as a promising candidate for the natural sources of anticancer agents

    MÔ PHỎNG ẢNH HƯỞNG CỦA MỰC NƯỚC BIỂN DÂNG ĐẾN BIẾN ĐỘNG ĐỊA HÌNH ĐÁY VÙNG VEN BỜ CỬA SÔNG MÊ KÔNG

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    This paper presents some study results on morphological change in the coastal region of Mekong River under the influences of sea level rise. In order to set up the models, measured data were collected, systematically and homogeneously processed to create open boundary conditions (time-serial data) for the model. Open sea boundary conditions of the model were created by NESTING method. The model (Delft3D model) was set up with 4 layers in Sigma coordinate. The results of model were validated, showing a fairly good agreement with measured data (water elevation, currents, and suspended sediment concentration) at some places in the study area. Results of some scenarios of simulation (dry and flood season) show the sea level rise due to climate change could make a reduction in the seaward sediment transport and increase its settling around estuaries. As a result, sea level rise causes an increase in the accreted rate of sandbars in southern estuary of Mekong river coastal area. The influences of sea level rise on Mekong river coastal bed topography are prevailing in the region of about 7 - 10 km seawards. Further 10 km from the coast, influences of sea level rise on coastal morphology are not significant.Bài báo trình bày các kết quả nghiên cứu dự báo biến động địa hình ở vùng ven bờ châu thổ sông Mê Kông dưới ảnh hưởng của nước biển dâng. Để thiết lập mô hình tính, các chuỗi số liệu quan trắc đã được thu thập, xử lý hệ thống và đồng bộ cho các điều kiện biên (sông, biển) của mô hình dạng chuỗi số liệu (time serial data). Các biên mở phía biển của mô hình được tạo ra bằng phương pháp lưới lồng (NESTING) từ mô hình có miền tính rộng hơn ở phía ngoài. Mô hình Delft3D với 4 lớp độ sâu theo hệ tọa độ Sigma đã được thiết lập và kiểm chứng cho thấy có sự phù hợp với số liệu đo đạc. Kết quả dự báo trong mùa cạn và mùa lũ đã cho thấy sự dâng cao mực nước biển do biến đổi khí hậu làm hạn chế sự phát tán của dòng trầm tích về phía biển và tập trung di chuyển quanh các cửa sông. Qua đó làm tăng tốc độ bồi tại các bãi bồi khu vực phía ngoài các cửa sông phía nam của vùng ven bờ châu thổ sông Mê Kông. Những ảnh hưởng do dâng cao mực nước biển đến địa hình đáy ven bờ châu thổ sông Mê Kông phổ biến diễn ra trong phạm vi khoảng 7 -       10 km từ cửa sông ra phía ngoài. Ở phía ngoài 10 km từ bờ ra, ảnh hưởng do dâng cao mực nước đến địa hình đáy hầu như không đáng kể

    Synthesis of Gold Nanobipyramids by Seed-mediated Method and Santibacterial Activities

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    Metallic nanoparticles as antibacterial agents have been studied for several years. The most used antibacterial nanoparticles are silver nanoparticles. The mechanisms and  antibacterial properties of silver nanoparticles are well known, but the effects of gold nanoparticles, especially gold Nano bipyramids, are not considered. In this research, we synthesized gold nanobipyramids (NBPs) by seed mediated method using surfactant cetyltrimethylammonium bromide (CTAB). After preparing, gold nanobipyramids is removed CTAB and modified the surface using polyethylene glycol, polyvinyl alcohol and chitosan as the stabilizers. Besides, antibacterial effects of gold nanobipyramids on both Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) are investigated in this paper. The results show that gold nanobipyramids have good antibacterial activities even at low concentration. The optimal concentration of stabilizers and gold nanobipyramids in antibacterial activities are also studied in this paper

    Genome-wide association study of a panel of vietnamese rice landraces reveals new QTLs for tolerance to water deficit during the vegetative phase

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    Background: Drought tolerance is a major challenge in breeding rice for unfavorable environments. In this study, we used a panel of 180 Vietnamese rice landraces genotyped with 21,623 single-nucleotide polymorphism markers to perform a genome-wide association study (GWAS) for different drought response and recovery traits during the vegetative stage. These landraces originate from different geographical locations and are adapted to different agrosystems characterized by contrasted water regimes. Vietnamese landraces are often underrepresented in international panels used for GWAS, but they can contain original genetic determinants related to drought resistance. Results: The panel of 180 rice varieties was phenotyped under greenhouse conditions for several drought-related traits in an experimental design with 3 replicates. Plants were grown in pots for 4 weeks and drought-stressed by stopping irrigation for an additional 4 weeks. Drought sensitivity scores and leaf relative water content were measured throughout the drought stress. The recovery capacity was measured 2 weeks after plant rewatering. Several QTLs associated with these drought tolerance traits were identified by GWAS using a mixed model with control of structure and kinship. The number of detected QTLs consisted of 14 for leaf relative water content, 9 for slope of relative water content, 12 for drought sensitivity score, 3 for recovery ability and 1 for relative crop growth rate. This set of 39 QTLs actually corresponded to a total of 17 different QTLs because 9 were simultaneously associated with two or more traits, which indicates that these common loci may have pleiotropic effects on drought-related traits. No QTL was found in association with the same traits in both the indica and japonica subpanels. The possible candidate genes underlying the quantitative trait loci are reviewed. Conclusions: Some of the identified QTLs contain promising candidate genes with a function related to drought tolerance by osmotic stress adjustment

    Structure of general-population antibody titer distributions to influenza A virus.

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    Seroepidemiological studies aim to understand population-level exposure and immunity to infectious diseases. Their results are normally presented as binary outcomes describing the presence or absence of pathogen-specific antibody, despite the fact that many assays measure continuous quantities. A population's natural distribution of antibody titers to an endemic infectious disease may include information on multiple serological states - naiveté, recent infection, non-recent infection, childhood infection - depending on the disease in question and the acquisition and waning patterns of immunity. In this study, we investigate 20,152 general-population serum samples from southern Vietnam collected between 2009 and 2013 from which we report antibody titers to the influenza virus HA1 protein using a continuous titer measurement from a protein microarray assay. We describe the distributions of antibody titers to subtypes 2009 H1N1 and H3N2. Using a model selection approach to fit mixture distributions, we show that 2009 H1N1 antibody titers fall into four titer subgroups and that H3N2 titers fall into three subgroups. For H1N1, our interpretation is that the two highest-titer subgroups correspond to recent and historical infection, which is consistent with 2009 pandemic attack rates. Similar interpretations are available for H3N2, but right-censoring of titers makes these interpretations difficult to validate
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