Creep resistance and fracture tolerance are considered two essential aspects to look at for material selection and optimization in high-temperature applications. Materials with extensive industrial ...applications must inherit adequate immune against creep such that operating temperatures can be raised to maximize performance ensuring a long service life of the equipment. The creep study of cupronickel (CuNi) alloy has become crucial because cupronickel alloys are enticing candidates for high-temperature applications. Nevertheless, the fundamental understanding of creep deformation in cupronickel alloys is still obscure. Herein, we executed classical Molecular Dynamics (MD) simulations to reveal the nature of creep characteristics of cupronickel alloy at a molecular level. In particular, we investigated the thermal and mechanical properties of nanocrystalline (NC) Cu, Ni, and Cu0.5Ni0.5 alloy. As the Cu content in the alloy is raised from 0 to 100%, the steady-state creep rate (SSCR) exhibits a ∼12% increment. Based on our MD simulations, we found that the SSCR of Cu0.5Ni0.5 alloy speeds up dramatically under elevated stress, temperature, and decreasing grain size. Our MD results also reveal that at low stress, the governing creep process is the confluence of lattice diffusion, grain boundary diffusion, and grain boundary sliding, while at high stress, the governing creep mechanism turns into dislocation dominated. Admittedly, our computational analysis will help acquire fundamental insights into the creep mechanism of NC cupronickel alloy, which is crucial for the successful usage of this alloy in corrosive, high stress, and high-temperature applications.
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•MD is used to study the tensile, thermodynamic, and creep resistance of NC cupronickel alloy.•Increasing Cu content significantly reduces the tensile strength, melting point, and creep resistance of the alloy.•NC Ni demonstrates the largest tensile strength, melting point, and creep resistance followed by NC CuxNi1-x, and Cu.•SSCR of NC Cu0.5Ni0.5 alloy speeds up dramatically under elevated stress, temperature, and decreasing grain size.•At low stress, the governing creep process is the confluence of diffusions and grain boundary sliding.
Wild waterfowl are considered as the natural reservoir for avian influenza (AI) viruses. Bangladesh has been experiencing highly pathogenic avian influenza (HPAI) outbreaks since 2007, mostly in ...chickens and occasionally in ducks. Ducks play an important role in the persistence and genetic recombination of AI viruses. This paper presents the results of serological and virological monitoring of AI in domestic ducks in 2013 in the north-east region of Bangladesh.
A total of 871 and 662 serum samples and 909 and 302 pairs of cloacal and oropharyngeal swabs from domestic ducks of Mymensingh and Sylhet division, respectively, were analysed. Antibodies to type A influenza virus were detected by blocking ELISA in 60.73 and 47.73% serum samples of Mymensingh and Sylhet division, respectively. On haemagglutination-inhibition (HI) test 17.5% of ELISA positive serum samples were found to be seropositive to H5 avian influenza virus. Five cloacal swabs and one oropharyngeal swab were positive for M gene of type A influenza virus by real time RT-PCR (rRT-PCR), but all of them were negative for H5 influenza virus. Three of the six viruses were successfully characterized as H1N5, H2N5 and H7N5 subtype of AI virus, the other three remained uncharacterized. On sequencing and phylogenetic analysis the HA and NA genes were found to be of Eurasian avian lineage. The H7 virus had cleavage site motif of low pathogenic virus.
Low pathogenic avian influenza viruses were detected from apparently healthy domestic ducks. A small proportion of domestic ducks were found seropositive to H5 AI virus.
Estrogens are a group of hormones that have diverse effects on both reproductive and non-reproductive organs. Conjugated estrogens are medicine that contains a mixture of estrogen hormones. The study ...was conducted to observe the effects of varying doses of conjugated estrogen on body weight, hormonal and histological alterations of reproductive organs in adult swiss albino female mice. In this study, 60 female swiss albino mice (Mus musculus) aged 28–30 days with an average body weight of 28.2 ± 1 g were used. At first, the mice were randomly divided into 4 groups each containing 15 mice. Group A was served as vehicle control and fed on standard mice pellet and fresh drinking water. While, groups B, C and D were administered with conjugated estrogen orally at the daily dose rate of 125 μg, 250 μg and 500 μg/kg body weight respectively with 1 mL sesame oil as a vehicle by mixing with feed. The experiment was carried out for 90 days. After humanly euthanized, blood was collected and serum was prepared and organs were collected for histopathology. The results revealed that higher doses of conjugated estrogen resulted in weight loss in premenopausal female mice compared to lower doses. Serum estrogen and thyroxine concentration was increased significantly following the doses of conjugated estrogen. Ovarian histotexture showed congested blood vessels and cystic space with degeneration of follicles and corpus luteum. Uterine lesions included massive macrophage infiltration in endometrium and hyperplasia of glandular epithelium at a lower dose; hyperplasia and hypertrophy of glandular epithelium (pleomorphism) with normal macrophage infiltration in endometrium at a higher dose. Therefore, it can be concluded that oral conjugated estrogen therapy at high dose has more detrimental impacts on body weight and reproductive function compared to lower dose in female adult mice.
Bisphenol-A (BPA) is a potentially hazardous substance and is extensively used in manufacturing industries as a plasticizing agent. The current research intended to determine the revival actions of ...zinc (Zn) and folic acid (FA) on hematological parameters and hepatorenal function in BPA-exposed male albino mice. A total of 75 adult male mice, aged 25 to 28 days, were split into five groups. Group A (the control group) received a normal diet, while a daily dosage of 50 mg BPA/kg body weight (BW) in the diet was provided to groups B–E. Groups C, D, and E received daily supplements of 10 mg Zn/kg BW, 3 mg FA/kg BW, or both in the feed. After 12 weeks of treatment, serum was prepared by collecting blood, and the kidney and liver were taken for a histotexture study. The results demonstrate that hematological values dropped significantly (p< 0.05) in the BPA-treated group and increased following Zn and FA supplementations, while no significant alterations in erythrocyte indices were observed among control and treated groups. The BPA group used to have significantly (p< 0.05) higher liver and kidney biomarkers levels, which were restored by Zn and FA. The effects of BPA administration included severe hepatocyte degeneration and necrosis, as well as renal tubule epithelium loss, all of which were improved by Zn and FA. Hence, the findings suggest Zn and FA could be potential preventative agents against BPA-induced toxicity.
Escherichia coli is known as one of the most important foodborne pathogens in humans, and contaminated chicken meat is an important source of foodborne infection with this bacterium. The occurrence ...of extended-spectrum β-lactamase (ESBL)-producing E. coli (ESBL-Ec), in particular, in chicken meat is considered a global health problem. This study aimed to determine the magnitude of E. coli, with special emphasis on ESBL-Ec, along with their phenotypic antimicrobial resistance pattern in frozen chicken meat. The study also focused on the determination of ESBL-encoding genes in E. coli. A total of 113 frozen chicken meat samples were purchased from 40 outlets of nine branded supershops in five megacities in Bangladesh. Isolation and identification of E. coli were done based on cultural and biochemical properties, as well as PCR assay. The resistance pattern was determined by the disc diffusion method. ESBL-encoding genes were determined by multiplex PCR. The results showed that 76.1% of samples were positive for E. coli, of which 86% were ESBL producers. All the isolates were multidrug-resistant (MDR). Resistance to 9–11 and 12–13 antimicrobial classes was observed in 38.4% and 17.4% isolates, respectively, while only 11.6% were resistant to 3–5 classes. Possible extensive drug resistance (pXDR) was found in 2.3% of isolates. High single resistance was observed for oxytetracycline (93%) and amoxicillin (91.9%), followed by ampicillin (89.5%), trimethoprim–sulfamethoxazole, and pefloxacin (88.4%), and tetracycline (84.9%). Most importantly, 89.6% of isolates were resistant to carbapenems. All the isolates were positive for the blaTEM gene. However, the blaSHV and blaCTX-M-2 genes were identified in two ESBL-non producer isolates. None of the isolates carried the blaCTX-M-1 gene. This study provided evidence of the existence of MDR and pXDR ESBL-Ec in frozen chicken meat in Bangladesh, which may pose a risk to human health if the meat is not properly cooked or pickled raw only. This emphasizes the importance of the implementation of good slaughtering and processing practices by the processors.
The peste des petit ruminants (PPR) is a disaster-class virus that causes catastrophic drawbacks to small ruminant industries in affected countries. As PPR disease has been reported in neighboring ...countries, Indonesia, which has a large population of sheep and goats, has become prone to the emerging threat of infection. Because the virus can also infect other animals with subclinical manifestations, large ruminants, such as buffaloes, may play an important role in spreading the virus in the environment. Therefore, the main objective of this study was to identify PPR seroprevalence in the buffalo population of Indonesia.
A competitive enzyme-linked immunosorbent assay was performed to identify the specific antibody for PPR viruses in the buffalo population using serum bank collection from the National Research and Innovation Agency, Indonesia.
PPR virus seroprevalence was detected in buffalo from Central Java, East Java, and East Nusa Tenggara Province in Indonesia. Although seroprevalence was low in the population, the antibody titer was relatively high in the positive samples. Sex and age were identified as determinant factors in the seroprevalence distribution of the buffalo population.
The presence of antibodies against the PPR virus in buffaloes may indicate that PPR virus is circulating in the buffalo population of Indonesia.
A total of 15 dead or sick birds from 13 clinical outbreaks of avian influenza in ducks, geese, chickens and turkeys in 2017 in Bangladesh were examined. The presence of H5N1 influenza A virus in the ...affected birds was detected by RT‐PCR. Phylogenetic analysis based on full‐length gene sequences of all eight gene segments revealed that these recent outbreaks were caused by a new reassortant of clade 2.3.2.1a H5N1 virus, which had been detected earlier in 2015 during surveillance in live bird markets (LBMs) and wet lands. This reassortant virus acquired PB2, PB1, PA, NP and NS genes from low pathogenic avian influenza viruses mostly of non‐H9N2 subtypes but retained HA, NA and M genes of the old clade 2.3.2.1a viruses. Nevertheless, the HA gene of these new viruses was 2.7% divergent from that of the old clade 2.3.2.1a viruses circulated in Bangladesh. Interestingly, similar reassortment events could be traced back in four 2.3.2.1a virus isolates of 2013 from backyard ducks. It suggests that this reassortant virus emerged in 2013, which took two years to be detected at a broader scale (i.e. in LBMs), another two years until it became widely spread in poultry and fully replaced the old viruses. Several mutations were detected in the recent Bangladeshi isolates, which are likely to influence possible phenotypic alterations such as increased mammalian adaptation, reduced susceptibility to antiviral agents and reduced host antiviral response.
Objective: To study the impact of early metabolic profiling and intervention measures in the peri¬parturient period on the occurrence of postparturient metabolic diseases in cows.
Materials and ...Methods: Using a cohort of dairy cows from two selected areas of Bangladesh, we routinely tested the serum calcium level and ketone bodies in the urine at periparturient periods. In addition, milk samples were tested for the presence of mastitis at different stages of lactation. Animals showing reduced serum calcium levels, high ketone bodies in the urine or the presence of clinical and subclinical mastitis received appropriate therapeutic intervention immediately after detection. After the intervention, the number of animals that got sick with diseases or conditions like milk fever, ketosis, mastitis, and dystocia, which are caused by metabolic problems, was recorded.
Results: In the periparturient period, most of the animals had lower serum calcium levels (8.13 ± 1.2 mg/dl), which were significantly increased by the following intervention (10.05 ± 1.4 mg/dl). On the other hand, there was a higher number of ketosis-affected animals (33.9%, 20/59) during the periparturient period, which decreased (18.6%, 11/59) during the postparturient period. Similarly, the number of mastitis-affected cows was also decreased in postparturient cows (30.9%, 13/42) than in periparturient cows (59.5%, 25/42), following improved hygienic measures. After early intervention, the number of study animals with metabolic diseases decreased from 51.7% before intervention to 15.3% after intervention.
Conclusions: Early metabolic profiling significantly reduced the occurrence of metabolic diseases in cows. Therefore, we recommend regular metabolic profiling of dairy cows and receiving early intervention measures to reduce the occurrence of metabolic diseases on the farm.
Fascioliasis causes high economic losses in livestock and underlies public health problems in rural areas, mainly of low-income countries. The increasing animal infection rates in Bangladesh were ...assessed, by focusing on host species, different parts of the country, and rDNA sequences. Fasciolid flukes were collected from buffaloes, cattle, goats and sheep from many localities to assess prevalences and intensities of infection. The nuclear rDNA internal transcribed spacer (ITS) region including ITS-1 and ITS-2 spacers was analyzed by direct sequencing and cloning, given the detection of intermediate phenotypic forms in Bangladesh. The 35.4% prevalence in goats and 55.5% in buffaloes are the highest recorded in these animals in Bangladesh. In cattle (29.3%) and sheep (26.8%) prevalences are also high for these species. These prevalences are very high when compared to lowlands at similar latitudes in neighboring India. The high prevalences and intensities appear in western Bangladesh where cross-border importation of animals from India occur. The combined haplotype CH3A of Fasciola gigantica widely found in all livestock species throughout Bangladesh fits its historical connections with the western Grand Trunk Road and the eastern Tea-Horse Road. The “pure” F. hepatica sequences only in clones from specimens showing heterozygotic positions indicate recent hybridization events with local “pure” F. gigantica, since concerted evolution did not yet have sufficient time to homogenize the rDNA operon. The detection of up to six different sequences coexisting in the cloned specimens evidences crossbreeding between hybrid parents, indicating repeated, superimposed and rapidly evolving hybridization events. The high proportion of hybrids highlights an increasing animal infection trend and human infection risk, and the need for control measures, mainly concerning goats in household farming management. ITS-1 and ITS-2 markers prove to be useful for detecting recent hybrid fasciolids. The introduction of a Fasciola species with imported livestock into a highly prevalent area of the other Fasciola species may lead to a high nucleotide variation in the species-differing positions in the extremely conserved fasciolid spacers. Results suggest that, in ancient times, frequent crossbreeding inside the same Fasciola species gave rise to the very peculiar characteristics of the present-day nuclear genome of both fasciolids.
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•Assessment of the increasing fascioliasis infection rates in livestock in Bangladesh.•Complete sequencing and cloning of the nuclear rDNA ITS-1 and ITS-2 spacers.•F. hepatica sequences in clones indicate recent hybridization with local F. gigantica.•Hybrid proportion highlights an increasing animal infection trend and human risk.•Consequences of livestock importation on the conserved fasciolid rDNA spacers.
Background
Knowledge of sequential changes in haematobiochemical parameters of infected animals helps in the formulation of appropriate supportive therapy.
Objective
We investigated the sequential ...haematological and biochemical changes in peste des petits ruminants (PPR)‐infected Black Bengal goats.
Methods
Goats were either infected with PPR virus (PPRV; n = 8) or sham infected with sterile phosphate‐buffered saline (n = 4) via the intranasal route. Blood and sera were collected from both groups at different days post‐infection (dpi) and analysed. Goats were sacrificed at different dpi and the amount of PPRV RNA in different tissues was quantified by real‐time RT‐PCR.
Results
The PPRV‐infected goats showed mild depression and scanty nasal secretions starting at 4 dpi which became severe with high fever (106°F), dyspnoea, stomatitis, profuse orinasal discharge and diarrhoea at 9–13 dpi. PPRV RNA was detected in different tissues of infected goats. Severe lymphocytic leukopenia (at 18 dpi) was observed in infected goats. Total protein and albumin decreased in infected goats starting at 10 dpi. An elevated level of enzymes (alkaline phosphatase, creatine kinase, aspartate transaminase and alanine transaminase) and metabolites (blood urea nitrogen and urea B) were found in infected goats starting at 7–10 dpi, suggesting damages in the liver and kidneys. PPR‐infected goats showed elevated sodium and chloride ions starting at 7 dpi. The majority of infected goats were seroconverted by 14 dpi.
Conclusions
Anti‐diarrheal agents, aqua solutions and other medicine to support liver and kidney functions could be considered as supportive therapy against PPRV infection.
The sequential haematobiochemical changes in a Bangladeshi PPR virus strain was studied in Black Bengal goats upon experimental infection. The PPRV RNA was detected in different tissues of the infected goats. Infected goats showed high fever, nasal discharges, stomatitis and diarrhoea at 9–13 dpi. Leukopenia, hypoproteinemia, elevated serum enzymes and metabolites and electrolyte imbalance were found in the infected goats. The findings would guide in preparing appropriate supportive therapy against PPRV infection.