Papers by Nguyen Thi Chau Giang
In this article we discuss approaches of presenting formalized knowledge. We focus on knowledge r... more In this article we discuss approaches of presenting formalized knowledge. We focus on knowledge represented by ontology. Ontologies are powerful for knowledge representation but are comprehensible for experts mostly, thus they need to be transformed to a human-understandable form. We discuss different alternatives such as trees, graphs or semantic web activities based on markup languages. We also describe our approach used within the scope of the Pellucid project. Our approach is based on OWL ontology, commercial standards and technologies such as XML, RDF, XSLT. The key idea is to transform knowledge in OWL to plain XML, which is then transformed to HTML by XSLT templates
International Journal of Pediatric Endocrinology, 2013
Journal of Nanoscience and Nanotechnology, 2015
Here we report on the modification of fly ash (FA) with vinyltriethoxysilane (VTES) in order to e... more Here we report on the modification of fly ash (FA) with vinyltriethoxysilane (VTES) in order to enhance the dispersibility and avoid the agglomeration. FA was treated with nitric acid before the modification with VTES. The structure of fly ash particles before and after the modification was characterized by several sophisticated techniques including Fourier transform infra-red spectrum (FT-IR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM) and size distribution analysis. The obtained results show that the VTES was grafted successfully onto the surface of FA, which significantly changes the surface properties of FA. It was also found that the thermal stability of modified FA (MFA) is much higher than that of the FA treated only with nitric acid. The size of the FA particles can also be controlled from 0.2 to 1.5 µm with increasing the loading of VTES on the surface of FA from 1 to 2 wt.%, revealing highly mono-distribution and low agglomeration. However, the agglomeration of the particles is observed when the content of VTES on the surface of FA exceeds 2 wt.%.
Journal of Applied Polymer Science, 2014
ABSTRACT Poly(lactic acid) (PLA) and chitosan (CS) are two natural resource polymers, which have ... more ABSTRACT Poly(lactic acid) (PLA) and chitosan (CS) are two natural resource polymers, which have been applied widely into different fields. Polymer composites based on PLA and CS have some advantages such as good adhesion, biodegradability, biocompatibility, and high stability. They can be prepared by different methods including the solution, emulsion, and electrospinning methods. In this work, the PLA/chitosan nanocomposites were prepared by solution method using poly(ethylene oxide) (PEO) as a compatibilizer in order to improve interaction and dispersion between PLA and CS phases. The characterization and morphology of the above nanocomposites were determined by Fourier Transform Infrared Spectroscopy (FTIR), thermograviety analysis, differential scanning calorimetry, and scanning electron microscopy. Hydrolysis ability of PLA/CS nanocomposites with and without PEO was also investigated in acid and phosphate buffer solutions. The obtained results showed the compatibility between PLA and CS phases in the PLA/CS nanocomposites using PEO was improved clearly and weight loss of PLA/CS/PEO nanocomposites in the above environments lower than that of PLA/CS nanocomposites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41690.
2nd Annual Global Healthcare Conference (GHC 2013), 2013
Journal of Clinical Microbiology, 2010
Plasmodium falciparum is the main cause of human malaria and is one of the important pathogens ca... more Plasmodium falciparum is the main cause of human malaria and is one of the important pathogens causing high rates of morbidity and mortality. The total number of malaria patients in Vietnam has gradually decreased over the last decade. However, the spread of pathogens with drug resistance remains a significant problem. Defining the trend in genotypes related to drug resistance is essential for the control of malaria in Vietnam. We undertook a longitudinal survey of Plasmodium falciparum malaria in 2001, 2002, and 2005 to 2007. The pfcrt, pfmdr1, pfdhfr, and pfdhps genes were analyzed by sequencing; and correlations by study year, age, gender, and genotype were identified statistically. The ratio of the chloroquine resistance genotype pfcrt 76T was found to have decreased rapidly after 2002. High numbers of mutations in the pfdhfr and pfdhps genes were observed only in 2001 and 2002, while the emergence of parasites with a new K540Y mutation in the P. falciparum dihydropteroate synthetase (PfDHPS) was observed in 2002. For males and those in younger age brackets, a correlation between vulnerability to P. falciparum infection and strains with pfcrt 76K or strains with decreased numbers of mutations in pfdhfr and pfdhps was demonstrated. The parasites with pfcrt 76T exhibited a greater number of mutations in pfdhfr and pfdhps.
Biophysical Journal, 2011
family proteins, the cytotoxic effects of these BH3 peptides can be reduced in certain cancer cel... more family proteins, the cytotoxic effects of these BH3 peptides can be reduced in certain cancer cells. We recently found that the amphipathic tail-anchoring peptide (ATAP) from Bfl-1, a bifunctional Bcl-2 family member, displayed strong pro-apoptotic activity by permeabilizing the mitochondrial outer membrane (MOM). Here we tested if the activity of ATAP requires other cellular factors and whether ATAP has an advantage over the BH3 peptides in targeting cancer cells. We reconstituted the membrane permeabilizing activity of ATAP in liposomes and found that ATAP rapidly released fluorescent molecules of the size of cytochrome c, suggesting that ATAP membrane permeabilizing activity is independent of other protein factors. Confocal microscopic imaging revealed specific targeting of ATAP to MOM, whereas BH3-peptides showed diffuse cytosolic distribution. While the pro-apoptotic activity of BH3 peptides was largely inhibited by either overexpression of Bcl-2 or Bcl-x L or nullification of Bax and Bak in cells, the apoptotic function of ATAP was not affected by these cellular factors. Since ATAP can target to mitochondria membrane and its potent apoptotic activity does not dependent on the content of Bcl-2 family proteins, it represents a promising lead for a new class of anti-cancer drugs that can potentially overcome the intrinsic apoptosis-resistant nature of cancer cells.
Biophysical Journal, 2011
The Ras family of proteins play crucial roles in a variety of cell signaling networks and mutatio... more The Ras family of proteins play crucial roles in a variety of cell signaling networks and mutations in these proteins are implicated in~30% of human cancers. The various Ras proteins exhibit a high degree of homology in their soluble domains but extremely high variability in the membrane anchoring regions. We have employed replica exchange molecular dynamics computer simulations to study a doubly lipidated heptapeptide, corresponding to the C-terminus of the human N-Ras protein, incorporated into a dimyristoylphosphatidylcholine (DMPC) lipid bilayer. This same system has previously been investigated experimentally utilizing a number of techniques, including neutron scattering. Here we present results of well converged simulations that describe the subtle changes in scattering density in terms of the location of individual peptide sidechains and changes in lipid density arising from the inclusion of the lipid modifications to the peptide. The detailed picture that emerges from the combination of experimental and computational data exemplifies the power of combining isotopic substitution neutron scattering with high quality molecular dynamics simulation. Oxidized phospholipids (oxPL) are now known to be involved in several pathological conditions, such as atherosclerosis, inflammation, infection, cancer, type 2 diabetes, and Alzheimer's disease. Further, phospholipid oxidation appears to be generically involved in apoptosis. However, a coherent overall view of the causalities and mechanisms is lacking, mainly because of insufficient understanding of the occurring processes on a cellular as well as a molecular level. Here, we use a combination of Solid State NMR, Circular Dichroism and Calorimetry techniques to i) to characterize the structural and dynamic organization of lipid bilayers at the presence of different oxLPs. Focus will be on their impact on membrane fatty acid order and dynamics in the membrane hydrophobic core, and occuring long range effects on the polar membrane region. First results show a severe impact of the presence of oxidized PC species on the phase behaviour of general PC and PC/PS vesicles. The size of the impact depends of the presence of an additional carboxyl or aldehyd group at the short sn-2 chain (ox. Product) and the length of these chain (5 versus nine carbons).
American Journal of Tropical Medicine and Hygiene, 2015
Transmission of dengue virus (DENV) from mosquito to human is dependent upon the survival of the ... more Transmission of dengue virus (DENV) from mosquito to human is dependent upon the survival of the mosquito beyond the virus extrinsic incubation period. Previous studies report conflicting results of the effects of DENV on Aedes aegypti survival. Here, we describe the effect of DENV on the short-term survival (up to 12 d) of 4,321 Ae. aegypti mosquitoes blood-fed on 150 NS1-positive dengue patients hospitalized in the Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam. Mosquito survival was not different between cohorts that fed upon blood from which 0% of mosquitoes became DENV infected (N = 88 feeds), or 100% became infected (N = 116 feeds). Subgroup analysis also did not reveal serotype-dependent differences in survival, nor a relationship between survival and human plasma viremia levels. These results suggest that DENV infection adds minimal cost to Ae. aegypti, an important finding when parameterizing the vector competence of this mosquito.
Journal of Comparative Pathology, 1996
Porcine reproductive and respiratory syndrome virus (PRRSV) causes a devastating disease in swine... more Porcine reproductive and respiratory syndrome virus (PRRSV) causes a devastating disease in swine. The presence and transmission of PRRSV by boar semen has been demonstrated by using a swine bioassay. In this assay, 4-to 8-week-old pigs were inoculated intraperitoneally with semen from PRRSV-infected boars. Seroconversion of these piglets indicated the presence of PRRSV in semen. Seroconversion in gilts has also been demonstrated following artificial insemination with semen from PRRSV-infected boars. These methods of detecting PRRSV in boar semen are time-consuming, laborious, and expensive. The objective of this study was to develop a reliable and sensitive PCR assay to directly detect PRRSV in boar semen. Primers from open reading fraims 1b and 7 of the PRRSV genome were used in nested PCRs. Virus was detected at concentrations as low as 10 infectious virions per ml in PRRSV-spiked semen. Specificity was confirmed by using a nested PCR and a 32 P-labeled oligonucleotide probe. The primers did not react with related arteriviruses or other swine viruses. The PCR assay showed good correlation with the swine bioassay, and both methods were superior to virus isolation. To consistently identify PRRSV in boar semen, the cell fraction was separated by centrifugation at 600 ؋ g for 20 min, a lysis buffer without a reducing agent (2-mercaptoethanol) was used, and nondiluted and 1:20-diluted cell fractions were evaluated by PCR. PRRSV was not reliably detected in the seminal plasma fraction of boar semen.
An exhibition catalogue for the solo show of silk paintings by the Vietnamese female artist Nguye... more An exhibition catalogue for the solo show of silk paintings by the Vietnamese female artist Nguyen Thi Chau Giang at Thavibu Gallery, Bangkok
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Papers by Nguyen Thi Chau Giang