An alternative method for determining the coefficient of thermal expansion of composite material of spherical particles

Composite material is widely used in modern structures. Many researchers have been involved in studying, developing and applying this kind of material. The composite material of spherical particles is a material composed of continuous matrix phase and spherical particles. In modern technique, it is very necessary to consider the influence of temperature on toughness and stability of structures. Therefore, determining the coefficient of thermal expansion of composite as a function of the coefficients and volume fractions of matrix and particle phases is a practical requirement. In this paper. we would like to introduce an alternative derivation method in order to obtain the thermal expansion coefficient of two-phase composite of spherical particles. Our results are the same as Vanin's and other authors'

Application of directional derivative method to determine boundary of magnetic sources by total magnetic anomalies

This paper presents the Directional Derivative method to determine location and boundaries of the magnetic directional structure sources through a new function DG (Directional Gradient - DG). Algorithm and computer program are made a code by Matlab language to attempt to calculate on 3D models in the compare with Horizontal derivative method (HG). A new function DG also applied to determine the boundary of magnetic sources by the total magnetic anomalies of Tuan Giao region. The result shows that with the application of new function DG, the boundaries of magnetic sources are exactly defined although they have a directional structure and small horizontal size. Moreover, because it does not depend on directions of magnetization, so in the computation, the transformation of the magnetic field to the pole can ignore, thus, reduce transient error. Alternatively, with the application of new function DG, the interferences in case the sources distributed close together are overcome. This usefulness affirms the possibility of application of the this method in the analysis and interpretation of magnetic data in Vietnam.ReferencesBhaskara Rao D. and N. Ramesh Babu, 1993. A fortran 77 computer program for tree dimensional inversion of magnetic anomalies resulting from multiple prismatic bodies, Computer Geosciences, 19(8), 781-801.Beiki M., David A. Clark, James R. Austin, and Clive A. Foss, 2012. Estimating source location using normalized magnetic source strength calculated from magnetic gradient tensor data. Geophysics, 77(6), J23-J37. Blakely R.J., and R. W. Simpson, 1986. Approximating edges of source bodies from magnetic or gravity anomalies: Geophysics, 51, 1494 -1498. Blakely R.J., 1995. Potential theory in gravity and magnetic applications, Cambridge University Press. Cao Dinh Trieu, Pham Huy Long, 2002. Tectonic fault in Vietnam. Publisher of Science and Engineering. Debeglia N. and J. Corpel, 1997. Automatic 3-D interpretation of potential field data using analytic signal derivatives. Geophysics, 62, 87-96.Geological and Mineral resources map on 1:200,000. Seriesof Tay Bac, sheets of Muong Kha - Son La (F-48-XXV-F-48-XXVI), Phong Sa Ly - Dien Bien Phu (F-48-XIX-F-48-XX), Kim Binh - Lao Cai (F-48-VIII-F-48-XIV), 2005. Published and copyringt by Department of Geology and Minerals of Vietnam, Hanoi. Le Huy Minh, Luu Viet Hung, Cao Dinh Trieu, 2001. Some modern methods of the interpretation aeromagnetic data applied for Tuan Giao region. Vietnam Journal of Earth Sciences, 22(3), 207-216. Le Huy Minh, Luu Viet Hung, Cao Dinh Trieu, 2002. Using the maximum horizontal gradient vector to interpret magnetic and gravity data in Vietnam. Vietnam Journal of Earth Sciences, 24(1), 67-80. Nabighian M.N., 1972. The analytic signal of two-dimensional magnetic bodies with polygonal cross-section: Its properties and use of automated anomaly interpretation: Geophysics, 37, 507-517. Nabighian M.N., 1974. Additional comments on the analytic signal of two-dimensionalmagnetic bodies with polygonal cross-section. Geophysics, 39, 85-92. Roest W. R., J. Verhoef and  M. Pilkington, 1992. Magnetic interpretation using the 3-D analytic signal: Geophysics, 57, 116-125. Vo Thanh Son, Le Huy Minh, Luu Viet Hung, 2005. Three-dimensional analytic signal method and its application in interpretation of aeromagnetic anomaly maps in the Tuan Giao region. Proceedings of the 4th geophysical scientific and technical conference of Vietnam, Publisher of Science and Engineering 2005. Vo Thanh Son, Le Huy Minh, Luu Viet Hung, 2005. Determining the horizontal position and depth of the density discontinuties in Red River Delta by using the vertical derivative and Euler deconvolution for the gravity anomaly data, Journal of Geology, Series A, 287(3-4), 39-52.Vo Thanh Son, et al., 2007. Determining the location and depth of contrast magnetic boundaries by using 3D analytics signal method and higher derivatives. Proceeding of the 5th geophysical scientific and technical conference of Vietnam.

Antibacterial activity of Piper betle extracts on Helicobacter pylori and identification of potential compounds

Helicobacter pylori is one of the most common infectious bacteria in the world that causes gastric diseases leading to cancer. The increase of multiple antibiotic resistance rates of H. pylori have been reported worldwide. Thus, development of novel drugs is urgently required. Piper betle has many therapeutic values in traditional medicine. In this study, therefore, we investigated antibacterial activity of P. betle extracts and their fractions against a H. pylori strain isolated in Vietnam. The agar disk diffusion assay showed inhibition zone of ethyl acetate extract and methanol extract from P. betle leaf that of were 46 mm and 32 mm in diameter, respectively. After fractionation of the ethyl acetate extract through silica gel column chromatography, two peaks, PD2 and PD3, out of 12 fractions showed the strongest antibacterial activity. PD2 was sub-fractionated further by re-chromatography on the silica gel column, and subfraction TK12 gave best resolution on LC-MS analysis. Finally, 4 potential compounds, quercetrin, calodenin B, vitexin and plicatipyrone, were identified in TK12 fraction.

Effects of guava (Psidium guajava L.) and bhumi amla (Phyllanthus amarus Chum et Thonn) extracts on haematological parameters and oxidative stress of striped catfish (Pangasianodon hypophthalmus) fingerlings exposed to high-temperature stress

Effects of guava (Psidium guajava L.) and bhumi amla (Phyllanthus amarus Chum et Thonn) on haematology and thermal stress mitigation of striped catfish (Pangasianodon hypophthalmus) were investigated. In a 42-day trial, fish were administered 4 diets as control (without extract), 0.2% P. guajava (Pg0.2), 0.5% P. amarus (Pa0.5), and a mixture of Pg0.2 and Pa0.5 (Mix). Fish were then subjected to temperatures of 27°C, 31°C, and 35°C for another 42 days. Haematological parameters were highest at 35°C, but these parameters were not significantly different from values recorded at 31°C on day 14 post-temperature challenge. The Pg0.2 diet modified red blood cells, haematocrit, and haemoglobin (p<0.05). The lowest glucose concentration was recorded in Pg0.2 (57.4±1.34 mg/100 mL) and Mix (58.9±1.87 mg/100 mL) groups after 14 days of thermal exposure. Glucose concentration surged on the third-day post-temperature challenge, then declined, and was maintained at 35°C until the end of the experiment which was not significant if compared to those at 27°C. Pg0.2 and Mix diets significantly reduced lipid peroxidation and enhanced catalase in gill and liver after 42 days. In the case average water temperature in the Mekong Delta remains below 35°C, the feeding diets for P. hypophthalmus administered Pg0.2 or..

IDENTIFICATION AND CHARACTERIZATION OF A PURPLE NONSULFUR BACTERIUM ISOLATED FROM COASTAL AREA OF HAI PHONG FOR USING IN PRODUCTION OF UNSATURATED FATTY ACID (OMEGA 6, 7, 9)

Purple nonsulfur bacteria are a group that has so much biotechnological applications, particularly in producing of functional food rich with unsaturated fatty acids. A purple nonsulfur bacterium (named HPB.6) was chosen based on its strong growth, high lipid and synthesis of unsaturated fatty acid (omega 6,7,9). Studying on basic biological characteristics showed that the cells of HPB.6 were observed as ovoid-rod shape, none motility, Gram negative staining. The diameter of single bacterium was about 0.8-1.0 µm. The cells divide by binary fission and had bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0% (optimum 3%), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 4.0 - 5.2 mM. Based on morphological, physiological properties and 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum

A High-Quality Genome Assembly of Striped Catfish (Pangasianodon hypophthalmus) Based on Highly Accurate Long-Read HiFi Sequencing Data

The HiFi sequencing technology yields highly accurate long-read data with accuracies greater than 99.9% that can be used to improve results for complex applications such as genome assembly. Our study presents a high-quality chromosome-scale genome assembly of striped catfish (Pangasianodon hypophthalmus), a commercially important species cultured mainly in Vietnam, integrating HiFi reads and Hi-C data. A 788.4 Mb genome containing 381 scaffolds with an N50 length of 21.8 Mb has been obtained from HiFi reads. These scaffolds have been further ordered and clustered into 30 chromosome groups, ranging from 1.4 to 57.6 Mb, based on Hi-C data. The present updated assembly has a contig N50 of 14.7 Mb, representing a 245-fold and 4.2-fold improvement over the previous Illumina and Illumina-Nanopore-Hi-C based version, respectively. In addition, the proportion of repeat elements and BUSCO genes identified in our genome is remarkably higher than in the two previously released striped catfish genomes. These results highlight the power of using HiFi reads to assemble the highly repetitive regions and to improve the quality of genome assembly. The updated, high-quality genome assembled in this work will provide a valuable genomic resource for future population genetics, conservation biology and selective breeding studies of striped catfish

Selective breeding of saline-tolerant striped catfish (Pangasianodon hypophthalmus) for sustainable catfish farming in climate vulnerable Mekong Delta, Vietnam

peer reviewedStriped catfish (Pangasianodon hypophthalmus), a freshwater species cultured mainly in the Mekong Delta region in Southern Vietnam, is facing a significant challenge due to salinity intrusion as a result of climatic changes. Given these evolving environmental conditions, selecting new strains with a higher salinity tolerance could make production of striped catfish economically feasible in brackish environments. In this study, we carried out a selection program aimed at developing a striped catfish strain able to survive and grow fast in a saline environment. To implement the selection program, we first collected males and females from different provinces in the Mekong delta. We next performed a factorial cross of these breeders to produce half- and full-sib families. When fish reached fry stage (47 dph), we put them in a saline environment (10 ppt) and subsequently kept 50 % of the fastest-growing fish after 143 days post hatching (dph). We repeated this mass selection procedure after 237 dph and 340 dph. We maintained in parallel a randomly selected group in saline conditions and a group of fish reared in freshwater to serve as controls. After crossing the selected individuals, we performed several tests on the next generation of fish to evaluate the effectiveness of selection after one generation in saline conditions. Average direct responses to selection were 18.0 % for growth and 11.4 % for survival rate after one generation of selection. We estimated a moderate realized heritability (0.29) for body weight. The genetic gains obtained in our study for body weight and survival rate after one generation of selection under saline conditions suggest that selection can be effective to improve ability of striped catfish to cope with saline stress. We conclude that our selection program has succeeded in developing a productive strain of striped catfish with better tolerance to salinity. © 2022 The Author

Between Communitarianism and Confucianism: Charles Taylor and the Confucian Concept of Self in Comparative Perspective

In a world increasingly marked by ideological and theological divisions, this paper aims to foster intercultural and interfaith dialogue by examining the resonances and dissonances between Charles Taylor’s communitarianism and Confucian philosophy. Focusing particularly on their theological and spiritual dimensions, the paper explores how both traditions conceptualize selfhood in terms of authenticity, community, and transcendence. Employing a multi-disciplinary approach, the study incorporates Warren G. Frisina’s critique of Taylor, shedding light on the interconnections among value, identity, and theological beliefs. Ultimately, this paper contributes to a more nuanced understanding of selfhood across different cultural and theological contexts and offers constructive insights for bridging the existing epistemological and ethical divides that separate Eastern and Western religious and philosophical thought

Synthesis and biological evaluation of shikimic acid derivatives

From shikimic acid, new series of oseltamivir analogues containing either ether sulfur or ether oxygen at C-3 position were prepared and evaluated for their biological activities. This is the first report on synthesis of oseltamivir analogues with ether sulfur at C-3. Except for compounds 4d, 4f, 7c and 7d, the remaining compounds were found to be active against MCF-7, LU-1 and KB cell lines. As oseltamivir had no cytotoxicity against different cell lines such as MCF-7, LU-1, KB, MDCK, MRC-5, VERO, MK and 293, the modification of alkyl groups at C-3 of the oseltamivir ring framework could significantly increase the cytotoxicity for this class of compounds. Loss of neuraminidase inhibition activity of these synthetic oseltamivir analogues suggested that the alkyl ether groups at C-3 should be critical for their anti-neuraminidase activity

Tryptophan and Kynurenine Enhances the Stemness and Osteogenic Differentiation of Bone Marrow-Derived Mesenchymal Stromal Cells In Vitro and In Vivo

Aging tissues present a progressive decline in homeostasis and regenerative capacities, which has been associated with degenerative changes in tissue-specific stem cells and stem cell niches. We hypothesized that amino acids could regulate the stem cell phenotype and differentiation ability of human bone marrow-derived mesenchymal stromal cells (hBMSCs). Thus, we performed a screening of 22 standard amino acids and found that D-tryptophan (10 mu M) increased the number of cells positive for the early stem cell marker SSEA-4, and the gene expression levels of OCT-4, NANOG, and SOX-2 in hBMSCs. Comparison between D- and L-tryptophan isomers showed that the latter presents a stronger effect in inducing the mRNA levels of Oct-4 and Nanog, and in increasing the osteogenic differentiation of hBMSCs. On the other hand, L-tryptophan suppressed adipogenesis. The migration and colony-forming ability of hBMSCs were also enhanced by L-tryptophan treatment. In vivo experiments delivering L-tryptophan (50 mg/kg/day) by intraperitoneal injections for three weeks confirmed that L-tryptophan significantly increased the percentage of cells positive for SSEA-4, mRNA levels of Nanog and Oct-4, and the migration and colony-forming ability of mouse BMSCs. L-kynurenine, a major metabolite of L-tryptophan, also induced similar effects of L-tryptophan in enhancing stemness and osteogenic differentiation of BMSCs in vitro and in vivo, possibly indicating the involvement of the kynurenine pathway as the downstream signaling of L-tryptophan. Finally, since BMSCs migrate to the wound healing site to promote bone healing, surgical defects of 1 mm in diameter were created in mouse femur to evaluate bone formation after two weeks of L-tryptophan or L-kynurenine injection. Both L-tryptophan and L-kynurenine accelerated bone healing compared to the PBS-injected control group. In summary, L-tryptophan enhanced the stemness and osteoblastic differentiation of BMSCs and may be used as an essential factor to maintain the stem cell properties and accelerate bone healing and/or prevent bone loss