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Dy and Ho iron garnets in form of nanoparticles were synthesized by citrate sol-gel method. Phase formation, lattice constant and average crystallite sizes of the samples were determined via XRD measurements. Morphology and particle size distribution were studied by TEM and chemical composition was checked by EDX. Magnetic measurements in temperature range 5–600 K and in the maximum applied field of 50 kOe were carried out by using SQUID and VSM. Their magnetic parameters, including Curie temperature, magnetization compensation temperature, spontaneous magnetization, high-field susceptibility, magnetic coercivity were discussed in the framework of three interacting magnetic sublattices, magnetocrystalline anisotropy, core-shell model and compared to those of the bulk materials. Based on these analyses further evaluation on the crystallinity and homogeneity of the samples has been made.

This study aims to determine the prevalence of Campylobacter and its antibiotic susceptibility at slaughterhouses and live poultry markets in the Mekong Delta, Vietnam. A total of 177 samples, including 112 fecal samples, 28 cecal samples, and 37 rectal swab samples were collected. Thirty-nine samples tested positive for Campylobacter spp. by culture method, accounting for 22%. Isolation rates of Campylobacter in rectal swab samples were highest at 29.7% (11/37), followed by cecal samples at 25% (7/28) and fecal dropping samples at 18.8% (21/112). Species identification was performed by multiplex PCR and the result showed that the prevalence of Campylobacter coli (12.4%) was higher than Campylobacter jejuni (3.4%). Antibiotic susceptibility test showed that all isolated Campylobacter were susceptible to imipenem and meropenem (100%). Most Campylobacter were resistant to tetracycline (96.4%), ciprofloxacin (92.9%), nalidixic acid (89.3%), and ampicillin (67.9%). This study highlights the high contamination of Campylobacter and its antibiotic resistance in poultry in the Mekong Delta, Vietnam.

African swine fever (ASF) is a highly infectious disease in pigs caused by the African swine fever virus (ASFV), which might result in 100% mortality. Pigs infected with ASFV might display different clinical and pathological features depending on virulence and host factors. This study aimed to determine features of clinical symptoms, macroscopic, and microscopic lesions of ASF in the Mekong Delta (MD), Vietnam during 2021–2022. The investigation was conducted following three fatal outbreaks of ASF in Hau Giang, Vinh Long, and Can Tho provinces, which are three central provinces out of thirteen in the MD. The spleen, lymph nodes, liver, kidney, and heart were collected from three infected pigs that displayed clinical symptoms of ASFV infection and confirmed the presence of ASFV by conventional PCR. The results indicated that infected pigs showed common clinical symptoms including high fever, anorexia, and moderate petechiae on the skin. Severe hemorrhage was observed in lymph nodes, spleen, kidneys, intestines, and gallbladders which were the main lesions during post-mortem examination. Microscopic lesions were characterized by lymphocytopenia, atrophy of lymphoid follicles in the immune system. However, distinct variations in clinical symptoms, macroscopic, and microscopic features among ASFV infection cases were not documented. This study provides a further understanding of the clinical presentation and pathological lesions caused by the ASFV strain circulating in the MD.

Background: Chicken infectious anemia (CIA) caused by chicken infectious anemia virus (CIAV) is considered one of the most important immunosuppressive diseases affecting chicken and recently poses a great economic burden to the poultry industry worldwide. Aim: This study aims to identify the presence of CIAV in the Mekong delta (MD), Vietnam and to determine genotypes of CIAVs that are currently circulating in this area. Methods: Organ samples (spleen, liver, and thymus) of 144 chickens suspected with CIA from 47 poultry farms were collected. A total of 47 pooled samples, each containing two to four chickens of each farm, were tested for the presence of CIAV. Results: Twenty out of 47 pooled organ samples (pool of two to four chickens per farm) were positive for CIAV using PCR targeting the viral VP1 gene. The VP1 amplicons of eight representative CIAVs were subjected for sequencing and genetic characterization. Phylogenetic analysis based on partial VP1 gene sequence revealed that the CIAVs detected in the MD grouped into different genotypes of II, IIIa, and IIIc together with CIAVs previously detected in the northern Vietnam and other Asian countries. The phylogenetic analysis also confirmed that detected CIAVs genetically differed from vaccine strains. In addition, deduced amino acids of the VP1 identified several critical amino acid substitutions in the VP1 protein that are likely associated with the virulence of CIAV. Conclusion: This is the first report to detect and determine genetic characterization of the circulating CIAVs in the MD. Therefore, this study provides important understanding on the evolution of CIAVs and highlights the importance of implementing prompt control measures against CIAVs in the MD and Vietnam. [Open Vet J 2023; 13(6.000): 690-696]

The heart has a dynamic mechanical environment contributed by its unique cellular composition and the resultant complex tissue structure. In pathological heart tissue, both the mechanics and cell composition can change and influence each other. As a result, the interplay between the cell phenotype and mechanical stimulation needs to be considered to understand the biophysical cell interactions and organization in healthy and diseased myocardium. In this work, we hypothesized that the overall tissue organization is controlled by varying densities of cardiomyocytes and fibroblasts in the heart. In order to test this hypothesis, we utilized a combination of mechanical strain, co-cultures of different cell types, and inhibitory drugs that block intercellular junction formation. To accomplish this, an image analysis pipeline was developed to automatically measure cell type-specific organization relative to the stretch direction. The results indicated that cardiac cell type-specific densities influence the overall organization of heart tissue such that it is possible to model healthy and fibrotic heart tissue in vitro. This study provides insight into how to mimic the dynamic mechanical environment of the heart in engineered tissue as well as providing valuable information about the process of cardiac remodeling and repair in diseased hearts.

We build the melting theory and the theory of the Debye temperature for defective and perfect cubic metals mainly based on the statistical moment method. Our theoretical results are applied to metals Ni, Pd and Pt. Our calculations of melting temperatures agree well with experiments and other calculations. Our other calculations are highly reliable.

Background: One of the most common diseases in free-range ducks in the Mekong Delta is "botulism". Botulism is a poultry disease caused by botulinum exotoxin of Clostridium botulinum. Aim: The purpose of the investigation was to evaluate the prevalence of botulism in free-range ducks in the Mekong Delta and the risk of infection by determining the presence of Clostridium botulinum in the farming environment. Methods: Research on 200 duck flocks with 187050 individuals raised freely in the fields in the provinces of the Mekong Delta including An Giang, Can Tho, Hau Giang, and Kien Giang. The ducks were diagnosed with botulism based on clinical symptoms. To demonstrate the presence of botulinum neurotoxins and identify serotype, samples of serum and/or gut were analyzed by mouse bioassay. Samples of soil (n=600), water (n=600), crabs (n=216), and snails (n=400) were taken from the grazing regions for Clostridium botulinum analysis by PCR assay. Results: There were 1.19% (2235/187050) free-range ducks in the Mekong Delta positive for botulism. Clinical symptoms of botulism including limberneck, drooping eyelids - enlarged pupils, and leg paralysis were prevalent across free-range ducks, with the frequency of 87.92% (1965/2235), 90.07% (2013/2235), and 79.78% (1783/2235), respectively. The lesions of pulmonary edema – hemorrhage, hemorrhagic liver, and gas-producing intestines were common, accounting for 86.19% (362/420), 95.48% (401/420), and 92.14% (387/420), respectively. Botulin toxin type C was found in a considerable number of serum samples, accounting for 40.48% (51/126). Meanwhile, the percentage of serum samples containing botulin toxin types E and D was 28.57% (36/126) and 25.40% (32/126), respectively. Clostridium botulinum was detected in the farming environment specifically 17.5% (105/600) in soil, 19.67% (118/600) in water, 8.33% (18/216) in crabs, and 3.00% (12/400) in snails. Conclusion: The free-range ducks in the Mekong Delta were at high risk of botulism because of the latent presence of Clostridium botulinum in the farming environment. [Open Vet J 2022; 12(5.000): 632-638]

Japanese encephalitis is considered an essential disease-causing swine reproductive failure in Asian countries; however, significant knowledge gaps remain about this problem in actual cases. This study examined 55 cases of reproductive failure in sows, including one abortion and 54 full-term farrowing litters, to find the Japanese encephalitis virus (JEV) and specific antibodies against JEV. Haemagglutination test was used to detect specific antibodies against JEV from 63 samples of fetal thoracic fluids and newborn un-suckling piglet sera (54 thoracic fluid samples of dead fetuses, two thoracic fluid samples of abortion fetuses, seven sera samples of weakly newborn un-suckling piglets), viral isolation and RT- PCR technique was attempted from 60 brains of fetuses and newborn un-suckling piglets, histopathology sections of fetal brains which were positive with JEV confirmed by HI test and RT-PCR were also made. The results showed that 17.46% (11/63) of thoracic fluids and sera were positive for JEV. No JEV isolation was found from 60 brain samples of dead fetuses and piglets, but RNA of JEV were detected from 5 of them (8.33%). Our results suggest that JEV should be considered the important cause of swine reproductive failure in Viet Nam.

African swine fever (ASF) is a highly contagious and deadly viral disease in domestic and feral pigs. Since 2018, the disease has spread and caused large socioeconomic consequences to the pig industry in several Asian countries including China, Vietnam, and South Korea. This study aims to determine the genotype, serotype, and genetic variation of representative ASF viruses (ASFV) responsible for the outbreaks in 2019–2022 in Can Tho city, a central administrative province in the Mekong delta, Vietnam. For outbreak investigation, the presence of causative ASFVs was tested using conventional PCR targeting the B646L gene. Subsequently, the amplification and sequencing of the DNA fragments of the putative B646L gene encoding the major capsid protein p72, EP402R gene encoding the viral hemagglutinin CD2-like protein (CD2v), and intergenic region (IGR) between the l73R and I329L genes were performed for molecular characterization. Phylogenetic analyses based on B646L and EP402R genes confirmed that all ASFVs detected in Can Tho city belonged to genotype 2 and serotype 8. In addition, this study revealed that at least two variants of ASFVs, namely, IGR II and IGR III, based on the nucleotide variation of the IGR sequence, cocirculated, and caused outbreaks in Can Tho city. The molecular characterization study provides great significance for understanding the evolution of ASFVs and tracing possible sources of infection in Can Tho and Mekong delta.

Structures made from recycled aggregate concrete are exposed to high temperatures during fire scenarios which degrade their mechanical properties. Hence, this study investigated the residual mechanical properties of recycled aggregate concrete (RAC) containing ground granulated blast furnace slag (GGBS) after exposure to elevated temperatures. 21 experimental runs for design mix of RAC considering recycled coarse aggregate (RCA) replacement of natural coarse aggregate at 50, 75, and 100%, GGBS replacement of cement at 0, 20, 40, and 60% and water to binder ratio at 0.4 and 0.5 levels were used. The residual mechanical properties of RAC including compressive strength, splitting tensile strength, and elastic modulus were determined through laboratory experimental tests at room temperature (about 25°C) and after exposure to elevated temperatures of 200, 400, 600, and 800°C. Experimental results showed that residual mechanical properties of RAC decreased with increasing temperatures but their resistance to degradation was significantly enhanced with the addition of GGBS at 40% GGBS content. The novel model developed for the prediction of residual compressive strength of RAC has high prediction accuracy based on the performance metrics used to evaluate the model performance. The model has p-values less than 0.0001, a high R² value of 0.9781, a low root mean square error (RMSE) of 1.456 and mean absolute percentage error (MAPE) of 0.2287. Overall, the study contributed immensely to the knowledge of RAC as a sustainable alternative to normal concrete in areas prone to exposure to high temperatures which will significantly aid the effective fire safety design of structural members produced with recycled aggregate concrete.

The objective of this study is to report the complete-genome sequence of a field African swine fever (ASF) virus (ASFV), namely ASF/VN/CanTho-OM/2021, which caused a fatal outbreak in domestic pigs in the Mekong Delta. Complete-genome sequencing detected an 18 bp nucleotide deletion in the EP402R gene (encoding for serotype-specific proteins CD2v) of ASF/VN/CanTho-OM/2021, which was determined to belong to genotype 2 and serotype 8. This mutation pattern was confirmed as unique in GenBank; thus, ASF/VN/CanTho-OM/2021 can be considered a novel variant, with a potential change of sero-characteristics within genotype 2. An additional unique mutation of 78 bp nucleotide insertion was also observed in the B475L gene. Additionally, four copies of tandem repeat sequences were found in the intergenic region (IGR) located between I73R and I329L, previously assigned as the IGR III variant. This study is the first to report the complete genome of ASFV in the Mekong Delta, and it highlights the necessity of strengthening molecular surveillance to provide further knowledge on the evolution and incursion of ASFV in the Mekong Delta and Vietnam.

In this work, we build the model and derive the theory of nonlinear deformation for substitutional alloy AB with interstitial atom C and face-centered cubic structure under pressure from the statistical moment method. The calculation results for FCC-AuCuSi are presented. We obtain the values of density of deformation energy, maximum real stress, limit of elastic deformation, and the stress-strain curve and compare the calculated results with experiments and other calculations.

The heart has a dynamic mechanical environment contributed by its unique cellular composition and the resultant complex tissue structure. In pathological heart tissue, both the mechanics and cell composition can change and influence each other. As a result, the interplay between the cell phenotype and mechanical stimulation needs to be considered to understand the biophysical cell interactions and organization in healthy and diseased myocardium. In this work, we hypothesized that the overall tissue organization is controlled by varying densities of cardiomyocytes and fibroblasts in the heart. In order to test this hypothesis, we utilized a combination of mechanical strain, co-cultures of different cell types, and inhibitory drugs that block intercellular junction formation. To accomplish this, an image analysis pipeline was developed to automatically measure cell type-specific organization relative to the stretch direction. The results indicated that cardiac cell type-specific densities influence the overall organization of heart tissue such that it is possible to model healthy and fibrotic heart tissue in vitro. This study provides insight into how to mimic the dynamic mechanical environment of the heart in engineered tissue as well as providing valuable information about the process of cardiac remodeling and repair in diseased hearts.