15 research outputs found

    Impact of HIV infection and anti-retroviral therapy on the immune profile of and microbial translocation in HIV-infected children in Vietnam

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    CD4+ T-lymphocyte destruction, microbial translocation, and systemic immune activation are the main mechanisms of the pathogenesis of human immunodeficiency virus type 1 (HIV) infection. To investigate the impact of HIV infection and antiretroviral therapy (ART) on the immune profile of and microbial translocation in HIV-infected children, 60 HIV vertically infected children (31 without ART: HIV(+) and 29 with ART: ART(+)) and 20 HIV-uninfected children (HIV(–)) aged 2–12 years were recruited in Vietnam, and their blood samples were immunologically and bacteriologically analyzed. Among the HIV(+) children, the total CD4+-cell and their subset (type 1 helper T-cell (Th1)/Th2/Th17) counts were inversely correlated with age (all p < 0.05), whereas regulatory T-cell (Treg) counts and CD4/CD8 ratios had become lower, and the CD38+HLA (human leukocyte antigen)-DR+CD8+- (activated CD8+) cell percentage and plasma soluble CD14 (sCD14, a monocyte activation marker) levels had become higher than those of HIV(–) children by the age of 2 years; the CD4/CD8 ratio was inversely correlated with the plasma HIV RNA load and CD8+-cell activation status. Among the ART(+) children, the total CD4+-cell and Th2/Th17/Treg-subset counts and the CD4/CD8 ratio gradually increased, with estimated ART periods of normalization being 4.8–8.3 years, whereas Th1 counts and the CD8+-cell activation status normalized within 1 year of ART initiation. sCD14 levels remained high even after ART initiation. The detection frequency of bacterial 16S/23S ribosomal DNA/RNA in blood did not differ between HIV-infected and -uninfected children. Thus, in children, HIV infection caused a rapid decrease in Treg counts and the early activation of CD8+ cells and monocytes, and ART induced rapid Th1 recovery and early CD8+-cell activation normalization but had little effect on monocyte activation. The CD4/CD8 ratio could therefore be an additional marker for ART monitoring. © 2016 by the authors; licensee MDPI, Basel, Switzerland

    Na2Fe3(SO4)4 là vật liệu cathode mới với điện thế cao dùng cho pin sodium-ion

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    Based on the density functional theory, we propose a promising cathode material, Na2Fe3(SO4)4, applicable for sodium-ion batteries. The crystal structure, stability, average voltage, and diffusion mechanism are carefully investigated to evaluate the electrochemical properties. The proposed material exhibits a high voltage of 4.0 V during the Na extraction. A small polaron is proved to be formed preferably at the first nearest Fe sites to Na vacancy and simultaneously accompanies the Na vacancy during its migration. Four elementary diffusion processes of the polaron–Na vacancy complexes, namely two parallel and two crossing processes, have been explored. The significant difference of activation energies between parallel and crossing processes suggests the substantial effect of the small polaron migration on the Na vacancy diffusion. We found that the parallel process along the [001] direction has the lowest activation energy of 808 meV, implying that the Na vacancy preferably diffuses in a zigzag pathway along the [001] direction.Chúng tôi đề xuất một vật liệu cathode mới Na2Fe3(SO4)4 có thể dùng cho pin sodium-ion dựa theo lý thuyết phiếm hàm mật độ. Cấu trúc tinh thể, tính bền, điện thế trung bình và cơ chế khuếch tán được khảo sát cẩn thận để đánh giá các tính chất điện hóa. Vật liệu đề xuất có thể đạt điện thế cao 4.0 V trong quá trình giải phóng ion Na. Chuẩn hạt polaron nhỏ ưu tiên hình thành tại vị trí Fe gần nhất với vị trí khuyết ion Na và chuyển động đồng thời với vị khuyết ion Na trong suốt quá trình chuyển động của nó. Bốn quá trình khuếch tán của tổ hợp vị trí khuyết ion Na và polaron được khảo sát gồm có 2 quá trình song song và 2 quá trình chéo. Sự khác biệt về năng lượng kích hoạt giữa các quá trình song song và chéo cho thấy hiệu ứng đáng kể của các polaron nhỏ đến quá trình khuếch tán của vị trí khuyết ion Na. Chúng tôi nhận thấy quá trình song song dọc theo hướng [001] có năng lượng kích hoạt thấp nhất là 808 meV, điều này gợi ý rằng vị trí khuyết ion Na ưu tiên khuếch tán theo một đường zigzag dọc theo hướng [001]

    Characterisation of morphology and anatomy of the main cocoa varieties in the Southern Vietnam

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    This study was completed to enhance the morphology and anatomy data of twenty cocoa cultivars (Theobroma cacao L.) which widely grow in the Southern Vietnam. Reproductive organs and plant organs were analyzed and compared based on both the morphological characteristics and anatomical tissue. These cocoa clones analysis were selected from established procedures by various researchers. Two groups of hybrid were known for having Criollo characteristic and Forastero features. Further, the Forastero hybrid group could strongly be identified on samples: TD 5, TD 6, TD 7, TD 9, TD 11, TD 13, CT 5, CT 6 and CT 21. They have Amelonado pod set and yellow/orange yellow peel. Meanwhile, the Criollo hybrid could be described on samples: CT 7, CT 8, CT 9, TD 1, TD 2, TD 8, TD 12, TD 14,TD 3, TD 6, TD 10 (with Cundeamore/Angoleta pod set) and TD 3, TD 6, TD (with red/orange-red peel). The tissue anatomy and floral description were not differ among samples. This work showed significant results for further biomolecular researches and contributed in breeding programs, conservation and variety selection activities

    Apply Optimarin Ballast System for Vietnam’s Fleet to Prevent Sea Pollution from Non-Indigenous Aquatic Species

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    Marine species are usually transported from one area to another by the ballast water used to provide safe operation for vessels. After entering a new environment, they may cause damage to the local ecosystem, leading to the disruptions of the entire marine ecosystem, and seriously affecting not only biodiversity but also several industries such as fishing and aquaculture. Therefore, the United Nations (UN) considers the presence of non-indigenous oceanic species to be one of the top four serious threats to the global environment; and, how to effectively control the non-indigenous aquatic species has captivated the special attentions of several scientists worldwide. With the significant development in the maritime industry, strict requirements the control and management of ships’ ballast water and sediments set by The UN's International Maritime Organization (IMO) have well shaped the trend in installing ballast water treatment systems. Among them, Optimarin Ballast System is preferably used in practice. However, currently, Vietnam’s fleets use a different chemical method which is not utilized elsewhere in the world. Because it is not environmentally friendly and its effectiveness hasn’t been validated yet, this paper suggests the application of OBS in the Vietnam’s fleet in order to prevent sea pollution from non-indigenous aquatic species and minimize its associated negative impacts as well as make the Vietnam’s fleet comply with IMO requirements in protecting the global environment for sustainable development

    Pharmacological Properties, Volatile Organic Compounds, and Genome Sequences of Bacterial Endophytes from the Mangrove Plant Rhizophora apiculata Blume

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    Mangrove plant endophytic bacteria are prolific sources of bioactive secondary metabolites. In the present study, twenty-three endophytic bacteria were isolated from the fresh roots of the mangrove plant Rhizophora apiculata. The identification of isolates by 16S rRNA gene sequences revealed that the isolated endophytic bacteria belonged to nine genera, including Streptomyces, Bacillus, Pseudovibrio, Microbacterium, Brevibacterium, Microbulbifer, Micrococcus, Rossellomorea, and Paracoccus. The ethyl acetate extracts of the endophytic bacteria&rsquo;s pharmacological properties were evaluated in vitro, including antimicrobial, antioxidant, &alpha;-amylase and &alpha;-glucosidase inhibitory, xanthine oxidase inhibitory, and cytotoxic activities. Gas chromatography&ndash;mass spectrometry (GC-MS) analyses of three high bioactive strains Bacillus sp. RAR_GA_16, Rossellomorea vietnamensis RAR_WA_32, and Bacillus sp. RAR_M1_44 identified major volatile organic compounds (VOCs) in their ethyl acetate extracts. Genome analyses identified biosynthesis gene clusters (BGCs) of secondary metabolites of the bacterial endophytes. The obtained results reveal that the endophytic bacteria from R. apiculata may be a potential source of pharmacological secondary metabolites, and further investigations of the high bioactive strains&mdash;such as fermentation and isolation of pure bioactive compounds, and heterologous expression of novel BGCs in appropriate expression hosts&mdash;may allow exploring and exploiting the promising bioactive compounds for future drug development

    Characterization of leaf, flower, and pod morphology among Vietnamese cocoa varieties (Theobroma cacao L.)

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    This study examined the morphological traits of sixty three (63) cocoa varieties that have been imported and cultivated in Vietnam. These cocoa varieties were collected from five regions in Southern Vietnam and were classified into three groups based on their phylogenetic relationships. Their morphological features were individually evaluated and analysed. This included leaf characteristics (leaf and stem anatomy) and flower features (ligule shape, anther number, pollen, stamen and ovule, fruit, seed). The results of this study showed a large variation across all morphological characteristics of the evaluated cocoa varieties. The Vietnamese cocoa flower showed a diversity of morphological characteristics including five shapes of ligule (oval, broad, deltoid, elliptic and sub-lanceolate) and each stamen also has a bilobed anther with the exception of trilobed anther for TD11. Furthermore, the shape of pollen grains was found homogeneous in all 63 varieties. The colour of the stamens and ovules was purple and white respectively for all examined samples. Three kinds of fruit shapes were identified, namely Angoleta, Amelonado and Cundeamor, and these were of various colours. Additionally, an anatomical analysis on the midrib structure of the leaves from the 63 varieties showed the highest similarity, likewise the stem structure. The colour of young leaves was observed as being green and red. This is the primary research that scrutinizes the morphological biodiversity of Vietnamese cocoa varieties during the three-decade development of the Vietnam cocoa project. The results have a practical applications for cocoa cross-breeding and botanical taxonomy

    Metagenomic analysis of bacterial community structure and diversity of lignocellulolytic bacteria in Vietnamese native goat rumen

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    Objective In a previous study, analysis of Illumina sequenced metagenomic DNA data of bacteria in Vietnamese goats’ rumen showed a high diversity of putative lignocellulolytic genes. In this study, taxonomy speculation of microbial community and lignocellulolytic bacteria population in the rumen was conducted to elucidate a role of bacterial structure for effective degradation of plant materials. Methods The metagenomic data had been subjected into Basic Local Alignment Search Tool (BLASTX) algorithm and the National Center for Biotechnology Information non-redundant sequence database. Here the BLASTX hits were further processed by the Metagenome Analyzer program to statistically analyze the abundance of taxa. Results Microbial community in the rumen is defined by dominance of Bacteroidetes compared to Firmicutes. The ratio of Firmicutes versus Bacteroidetes was 0.36:1. An abundance of Synergistetes was uniquely identified in the goat microbiome may be formed by host genotype. With regard to bacterial lignocellulose degraders, the ratio of lignocellulolytic genes affiliated with Firmicutes compared to the genes linked to Bacteroidetes was 0.11:1, in which the genes encoding putative hemicellulases, carbohydrate esterases, polysaccharide lyases originated from Bacteroidetes were 14 to 20 times higher than from Firmicutes. Firmicutes seem to possess more cellulose hydrolysis capacity showing a Firmicutes/Bacteroidetes ratio of 0.35:1. Analysis of lignocellulolytic potential degraders shows that four species belonged to Bacteroidetes phylum, while two species belonged to Firmicutes phylum harbouring at least 12 different catalytic domains for all lignocellulose pretreatment, cellulose, as well as hemicellulose saccharification. Conclusion Based on these findings, we speculate that increasing the members of Bacteroidetes to keep a low ratio of Firmicutes versus Bacteroidetes in goat rumen has resulted most likely in an increased lignocellulose digestion

    Metagenomic insights into lignocellulose-degrading genes through Illuminabased de novo sequencing of the microbiome in vietnamese native goats’ rumen

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    The scarcity of enzymes having an optimal activity in lignocellulose deconstruction is an obstacle for industrial-scale conversion of cellulosic biomass into biofuels. With the aim of mining novel lignocellulolytic enzymes, a ~9 Gb metagenome of bacteria in Vietnamese native goats’ rumen was sequenced by Illumina platform. From the data, 821 ORFs encoding carbohydrate esterases (CEs) and polysaccharide lyases (PLs) serving for lignocellulose pre-treatment, 816 ORFs encoding 11 glycoside hydrolase families (GHs) of cellulases, and 2252 ORFs encoding 22 GHs of hemicellulases, were mined. The carbohydrate binding module (CBM) was also abundant with 763 ORFs, of which 480 ORFs are located with lignocellulolytic enzymes. The enzyme modularity analysis showed that CBMs are usually present in endoglucanase, endo 1,3-beta-D-glucosidase, and endoxylanase, whereas fibronectin 3-like module (FN3) mainly represents in GH3 and immunoglobulin-like domain (Ig) was located in GH9 only. Every domain located in each ORF was analyzed in detail to contribute enzymes’ modularity which is valuable for modelling, to study the structure, and for recombinant production. With the aim of confirming the annotated results, a mined ORF encoding CBM63 was highly expressed in E. coli in soluble form. The purified recombinant CBM63 exhibited no cellulase activity, but enhanced a commercial cellulase activity in the destruction of a paper filter
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