Electronic word-of-mouth (eWOM) on social networking sites (SNS): Roles of information credibility in shaping online purchase intention.

Electronic word of mouth (eWOM) on social networking sites (SNS) has become crucial in shaping online consumers' purchase intentions, reflecting the growing reliance on rich nature of user-generated content and recommendations shared on these platforms. This study aims to investigate the intricate relationships among different factors of eWOM information, including information credibility, information usefulness, information adoption, attitude towards information, and their impacts on online purchase intention. This study draws upon the Information Adoption Model (IAM) and the Information Acceptance Model (IACM) foundation theory which reveal the steps individuals take in adopting new information, and focuses on how perceptions and attitudes towards information shape acceptance. The study used a quantitative approach, utilizing a structured questionnaire to collect data from 337 Vietnamese individuals actively engaged in eWOM activities on various SNS platforms. Statistical analysis was conducted using partial least squares structural equation modeling (PLS-SEM). The findings show that information credibility significantly influences both information usefulness and adoption. Interestingly, while information usefulness shapes user attitudes, it does not directly impact online purchase intention. Similarly, a positive attitude toward eWOM does not necessarily lead to information adoption. This suggests that consumers may hold favorable views of eWOM content without actively adopting it. Information adoption emerges as a critical determinant of online purchase intention, emphasizing the importance of promoting user engagement and trust in eWOM information. These findings contribute to a deeper understanding of online consumer behavior and provide valuable guidance for stakeholders seeking to leverage eWOM effectively in digital marketing.

Low HBV knowledge is associated with low HBV vaccination uptake in general adult population despite incentivization of HBV vaccination.

BACKGROUND: Hepatitis B virus (HBV) vaccination in Vietnamese adults remains low and unequally distributed. We conducted a study on HBV-naïve adults living in Ho Chi Minh City, Viet Nam, to determine barriers associated with HBV vaccination uptake after removing the financial barrier by providing free coupons for HBV vaccination. METHODS: After being screened for HBsAg, anti-HBs, and anti-HBc, 284 HBV-naïve study participants aged 18 and over (i.e., negative for HBsAg, anti-HBs, and anti-HBc total) were provided free 3-dose HBV vaccine coupons. Next, study participants' receipt of 1st, 2nd, and 3rd doses of HBV vaccine was documented at a pre-specified study healthcare facility, where HBV vaccines were distributed at no cost to the participants. Upon study entry, participants answered questionnaires on sociodemographics, knowledge of HBV and HBV vaccination, and related social and behavioral factors. The proportions of three doses of HBV vaccine uptake and their confidence intervals were analyzed. Associations of HBV vaccine initiation with exposures at study entry were evaluated using modified Poisson regression. RESULTS: 98.9% (281 of 284) of study participants had complete data and were included in the analysis. The proportion of participants obtaining the 1st, 2nd, and 3rd doses of HBV vaccine was 11.7% (95% Confidence Interval [95% CI] 8.0-15.5%), 10.7% (95%CI 7.1-14.3%), and 8.9% (95%CI 5.6-12.2%), respectively. On the other hand, participants were more likely to initiate the 1st dose if they had adequate knowledge of transmission (adjusted relative risk [aRR] = 2.58, 95% CI 1.12-5.92), adequate knowledge of severity (aRR = 6.75, 95%CI 3.38-13.48), and annual health-checking seeking behavior (aRR = 2.04, 95%CI 1.07-3.87). CONCLUSION: We documented a low HBV vaccination uptake despite incentivization. However, increased vaccine initiation was associated with better HBV knowledge and annual health check-up adherence. When considering expanding HBV vaccination to the general adult population, we should appreciate that HBV knowledge is an independent predictor of vaccine uptake.

Miliutine C methyl ester, a new drimane sesquiterpene and bioactive alkaloids from the stems of Miliusa velutina.

Previous results from the our research group have isolated numerous compounds, including novel ones, but the anticancer activity of Miliusa velutina has not been demonstrated. In this study, from the most active ethyl acetate extract of the stems of Miliusa velutina, seven compounds were isolated and determined structures, including a new drimane sesquiterpenoid compound named miliutine C methyl ester (1) and three bioactive alkaloids (5-7). These three alkaloids (5-7) exhibited strong anticancer activities against various cancer cell lines such as MCF-7, HepG2, HeLa, NCI H460 and normal fibroblasts. Especially, on MCF-7 and normal fibroblasts with values of IC50 (µM) in order for compounds 5 (3.38, 31.15), 6 (21.96, 102.00), 7 (7.90, greater than 300), to compare with positive control camptothecin (0.020, 4.51); which is highly noteworthy. These results contribute to elucidating and confirming the value of Miliusa velutina, similar to other published and folkloric findings.

Nanoscale friction behavior and deformation during copper chemical mechanical polishing process.

CONTEXT: The mechanical characteristics and deformation behavior of Cu material under the nanoscratching through a diamond tooltip on the workpiece are studied using molecular dynamics (MD) simulation. Effects of scratching velocity, scratching depth, workpiece temperature, and grain size on the total force, shear strain, pile-up, shear stress, workpiece temperature, and phase transformation are investigated. The results reveal that increasing the scratching velocity leads to higher oscillation in total force, greater shear strain and shear stress, higher pile-up on the workpiece surface, and higher workpiece temperatures. The effect of the scratching velocity on phase transformation shows that most of the dislocation is a transformation structure from the FCC structure to the HCP, BCC, and other structures in all workpieces during the nanoscratching process. In addition, with increasing the scratching depth, material pile-up becomes more prominent, consequently elevating the contact area between the diamond tooltip and the workpiece, which simultaneously leads to an increase in total force, shear strain, pile-up, shear stress, and workpiece temperature. The MD simulation results revealed that the subsurface region of nanoscratched Cu single-crystal experiences the formation of stacking faults, vacancy defects, and cluster vacancies. In studying the effect of workpiece temperature, the results show that higher temperatures lead to the decline of scratching force, high plastic deformation, increased shear strain and stress, lower pile-up height, and high transition from the FCC structure to both other and BCC structures. For polycrystalline structures, the force curves occur in the oscillation state in all cases of different grain sizes because of the dislocation deformation during the cutting process. The maximum force decreases with diminishing grain size, attributed to the inverse Hall-Petch relation. As the grain size increases, leading to a decrease in the shear strain, stress, and an uneven pile up; also, the HCP structure rises with decreasing grain boundary and the partial dislocation and stacking fault mobilize inside grains. METHODS: By using molecular dynamics (MD) simulation based on the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) software, all molecular interactions were described by the Lennard-Jones (LJ) and embedded atom method (EAM) potentials. In order to mitigate the effects of temperature fluctuations, the system employs an isothermal and isobaric (NPT) ensemble for precise temperature control. The temperature was set as 300 K and the time step was 1 fs (femtosecond).

Miliutine A acid, a new cyclofarnesane sesquiterpene from the stems of Miliusa velutina.

Six compounds were isolated from the ethyl acetate extract of the stems of Miliusa velutina, including miliutine A acid (1), a new cyclofarnesane sesquiterpenoid; miliutine B methyl ester (2), a cyclofarnesane sesquiterpenoid which was determined the absolute configuration for the first time and four known phenol derivatives (3-6). NMR spectroscopic and mass spectrometry were used for identifying relative configurations. The assignments of the absolute configurations were determined based on Electronic Circular Dichroism (ECD) and NOESY spectra analysis. All six compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay and they showed weak or none activities.

Two new halogenated sesquiterpene lactones from Palisada intermedia.

Two new sesquiterpene lactones, laurenolide A (1) and laurenolide B (2), along with six known compounds, palmitic acid (3), (R,R)-hexahydrofarnesyl acetone (4), trans-phytol acetate (5), cholesterol (6), cholesteryl acetate (7), cholesteryl heptadecanoate (8) were isolated from Palisada intermedia. The chemical structures of all compounds were elucidated by 1D and 2D-NMR spectroscopy and HR-ESI-MS analysis as well as compared with data in the literature. The petroleum ether, chloroform, ethyl acetate, methanol extracts and compounds 1, 2 were tested for the inhibition of two cancer cell lines MCF-7, NCI-H460 and they showed weak or none activities.

Nepetifoliol - a new glutinane-triterpenoid from Leonotis nepetifolia.

A new glutinane-triterpenoid, nepetifoliol (1), together with two known compounds, dymacrin D (2), and (+)-ar-tumerone (3) were isolated from the n-hexane extract of the aerial parts of Leonotis nepetifolia. Their chemical structures were elucidated by spectroscopic data analysis as well as the comparison of their NMR data with the ones published in the literatures. A putative biosynthetic pathway for the formation of the new compound (anti-diaxial-5,6-diol) (1) from the precursor triterpene glutinol was proposed. Compounds (2), (3) and some previously reported ones, isolated from this extract, including 5α-stigmasta-22-ene-3-one (4), friedelin (5), chrysophanol (6), physcion (7), and 4'-O-methylalpinumisoflavone (8) were evaluated for their α-glucosidase inhibition. Among tested compounds, 3 and 6 showed good activities with their IC50 values of 5.3 ± 0.2 and 4.9 ± 0.3 µg/mL, respectively, comparing to the positive control, acarbose (IC50 127.7 ± 0.2 µg/mL).

Mediation effects of post-series depression on the relationship between life satisfaction and positive mental health of Vietnamese: A cross-sectional study in COVID-19 pandemic context.

Vietnam, a middle-income country, has been suffering four waves of the Coronavirus disease 2019 (COVID-19) pandemic and a massive lockdown to suppress the spread of this infectious disease. Consequently, COVID-19 has caused psychological ramifications and affected humankind's life satisfaction. Because of the lockdown period, numerous people had plentiful time. Hence, they found solace in excessive watching of television and movies, which could lead to post-series depression. The purpose of this study is to investigate the relationship between life satisfaction (LS), post-series depression (PSD), and positive mental health (PMH) and inquire about the mediation effect of satisfaction of life and PSD. A total of 2,572 participants who were voluntarily recruited from various media platforms completed self-report questionnaires, including the Satisfaction with life scale, Post-series depression scale, and Positive Mental Health Scale. This study was assessed using the PLS-SEM approach. The findings of this research discovered (i) a significantly positive effect of LS on PMH; (ii) a significantly negative effect of PSD on PMH; (iii) a significantly negative effect of LS on PSD, and (iv) a significant indirect effect of LS on PMH through PSD. The study provided additional evidence to the relationship between life satisfaction and PMH of individuals. Besides, the negative effects of PSD, which is a non-clinical term for feeling down that frequently appears after individuals finish their much-loved film and TV series, on individuals' PMH is proved, especially in the COVID-19 pandemic context in which Vietnamese people must remain in their current location.

Mediation Effects of Premarital Sexual Permissiveness on the Relationship Between Expectations for Marriage and Marital Intention of Vietnamese Undergraduate Students.

Purpose: The purpose of this study was to investigate the direct and indirect effects of expectations for marital relationships and premarital sexual permissiveness on intent to marry of Vietnamese emerging adults. Patients and Methods: Our cross-sectional study was focused on emerging adults including 344 participants, undergraduate students from universities in Viet Nam. This study was assessed by using the PLS-SEM approach. Results: The main findings demonstrated that (i) sexual orientation have a significant effect on marital intention; (ii) individuals' expectations for marital relationship have a direct effect on marital intention; and (iii) premarital sexuality permissiveness mediates the relationship between expectations for marital relationship and marital intention. Conclusion: Our results contribute important documents and clearer understanding of emerging adults' expectations and requirements in a relationship for the marriage decision-making process.

Demonstration of a population-based HCV serosurvey in Ho Chi Minh City, Viet Nam: Establishing baseline prevalence of and continuum of care for HCV micro-elimination by 2030.

Background: A baseline of hepatitis C virus (HCV) burden and other HCV epidemiological profiles is necessary for HCV micro-elimination in Ho Chi Minh City (HCMC), Viet Nam. This study aimed to determine HCV exposure and prevalence of HCV viremia as well as the proportion of HCV testing and treatment uptake among participants. Methods: From 2019 to 2020, the probability proportionate to size sampling method was deployed to representatively invite approximately 20,000 adults (18 or older) throughout HCMC to free screening and linkage to care for HCV. Findings: In HCMC, the weighted prevalence of anti-HCV was 1·3% (95% CI, 1·1%-1·6%). Individuals born from 1945 to 1964 had the anti-HCV prevalence of 3·6% (95% CI, 3·0%-4·2%) and represented 40·4% of all HCV cases. There were wide variations in anti-HCV prevalence in HCMC, including variations between districts, risk factors, and socioeconomic statuses. A baseline HCV continuum of care for the city demonstrated that only 28·5% (85/298, 95%CI 23·4-33·7%) of persons with anti-HCV (+) were aware of their HCV status, with 77.6% (66/85, 95%CI 68·8-86·5%) diagnosing HCV incidentally, 82·7% (62/75, 95%CI 74·1-91·2%) initiating anti-HCV therapy, and 53.6% (30/56, 95%CI 40·5-66·6%) achieving HCV cures. Interpretation: There remains a considerable disease burden of HCV in HCMC of which a significant proportion was in the age group born between 1945 to 1964. Additionally, there were significant gaps in HCV awareness, screening, and access to care in the community in Viet Nam. Thus, future interventions must have pragmatic targets, be tailored to the local needs, and emphasise screening. Funding: This work was supported by investigator-sponsored research grants from Gilead Sciences Inc. (Grant No: IN-US-987-5382); Roche Diagnostic International Ltd. (Grant No. SUB-000196); and in-kind donations from Abbott Diagnostic Viet Nam; Hepatitis B Foundation; Medic Medical Center, Viet Nam; Johns Hopkins University School of Medicine's Center of Excellence for Liver Disease in Viet Nam; and the Board of Directors, Viet Nam Viral Hepatitis Alliance (V-VHA).

Two new sesquiterpenes from the stems of Miliusa velutina.

From the ethyl acetate extract of the stems of Miliusa velutina, seven compounds (1-7) were isolated, including two new compounds such as mivelutina A acid (1), mivelutina B acid (2) and one known compound mivelutina B methyl ester (3). For this NMR data were not known previously. Their relative structures were elucidated based on NMR spectroscopic analysis. The absolute configuartions were determined based on DFT calculations of 13C chemical shifts. All of the seven compounds were screened for their in vitro cytotoxic activities against HepG2 cell line using the SRB assay. Epoxyconiferyl alcohol (7) showed the highest potential for the cytotoxicity of cancer cell lines HepG2 with the IC50 values of 95.94 µg/mL (527 µM).

Pellets Inoculated with Bacillus amyloliquefaciens H57 Modulates Diet Preference and Rumen Factors Associated with Appetite Regulation in Steers.

This study examined whether the probiotic Bacillus amyloliquefaciens strain H57 (H57) affects ruminal fermentation parameters that exercise post-ingestive feedback appetite control mechanisms. A 4 × 4 Latin square design was used to separate pre- and post-ingestive effects of H57 in four rumen-fistulated steers. The steers were offered a set amount of feedlot pellets, inoculated with H57 or without H57 (control, C). Half of the total amount of pellets fed were introduced intra-ruminally (r), and then the remaining pellets were orally consumed (o) to make four feeding treatments: H57r/H57o, H57r/Co, Cr/H57o and Cr/Co. Rumen fluid was sampled at 2, 4 and 6 h after feeding. Preference behaviour was tested immediately after the 6 h rumen fluid sampling by simultaneously offering the steers 4 kg of each of H57 and C pellets in adjacent troughs for 5 min. Steers preferred the pellets with added H57 over the C pellets (56:44; p < 0.001) and their preferences were not affected by the treatment protocol imposed to separate post- from pre-ingestive effects (p > 0.05). Steers fed H57 pellets had higher ruminal pH, molar proportions of iso-butyrate and iso-valerate (p < 0.05) and tended to have greater ruminal ammonia concentrations compared to those fed C pellets (p < 0.1). However, post-ingestive signals did not affect diet preference more than pre-ingestive signals.

Volatile Organic Compound Profiles Associated with Microbial Development in Feedlot Pellets Inoculated with Bacillus amyloliquefaciens H57 Probiotic.

Mould and bacterial contamination releases microbial volatile organic compounds (mVOCs), causing changes in the odour profile of a feed. Bacillus amyloliquefaciens strain H57 (H57) has the potential ability to inhibit microbial growth in animal feeds. This study tested the hypothesis that H57 influences the odour profile of stored feedlot pellets by impeding the production of mVOCs. The emission of volatile organic compounds (VOCs) of un-inoculated pellets and those inoculated with H57, stored either at ambient temperature (mean 22 °C) or at 5 °C, was monitored at 0, 1, 2, and 3 months by gas chromatography-mass spectrometry. Forty VOCs were identified in all the pellet samples analysed, 24 of which were potentially of microbial and 16 of non-microbial origin. A score plot of the principal component analysis (PCA) showed that the VOC profiles of the pellets stored at ambient temperature changed more rapidly over the 3 months than those stored at 5 °C, and that change was greater in the un-inoculated pellets when compared to the inoculated ones. The bi-plot and correlation loading plots of the PCA indicated that the separation of the un-inoculated pellets from the other treatments over the 3 months was primarily due to nine mVOCs. These mVOCs have been previously identified in grains spoiled by fungi, and could be considered potential markers of the types of fungi that H57 can protect pellets against. These data indicate the ability of H57 to maintain the odour profile and freshness of concentrated feed pellets. This protective influence can be detected as early as 3 months into ambient temperature storage.

Utilization of Response Surface Methodology in Optimization of Polysaccharides Extraction from Vietnamese Red Ganoderma lucidum by Ultrasound-Assisted Enzymatic Method and Examination of Bioactivities of the Extract.

Red Ganoderma lucidum (G. lucidum) is a popular medicinal herb commonly used in Vietnamese traditional remedies due to its potential value for health. In this study, polysaccharides were extracted from G. lucidum using ultrasound-assisted enzymatic extraction method. The response surface methodology and Box-Behnken design were employed to investigate the effects of pH, extraction temperature, extraction time, and ultrasonic power on the content of polysaccharides. Based on ultraviolet-visible spectroscopy analysis, the highest content of polysaccharides in the extract was 32.08 mg/g under optimum experimental parameters including enzyme concentration of 3%, pH of 5.5, extraction temperature of 45°C, extraction time of 30 min, and ultrasonic power of 480 W. The Fourier-transform infrared spectroscopy was also used to identify the functional groups in the extracts. The molecular weights of polysaccharides were determined by gel permeation chromatography. The obtained extract was then evaluated for anticancer activities by using (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, showing the anticancer activities with the half-maximal inhibitory concentration value of more than 512 µg/mL. This result suggested that UAEE could be considered as an appropriate and effective extraction method for bioactive crude polysaccharides from G. lucidum.

Feed Preference Response of Weaner Bull Calves to Bacillus amyloliquefaciens H57 Probiotic and Associated Volatile Organic Compounds in High Concentrate Feed Pellets.

This study tested the hypothesis that Bacillus amyloliquefaciens strain H57 (H57) improves preference by reducing the development of microbial volatile organic compounds (mVOCs) in feed pellets. Sixteen bull calves were, for 4 weeks, provided equal access to a panel of 8 automated feed bunks in a single paddock with some hay. Each bunk contained pellets with (H57) or without (Control) the H57, each aged for 4 months at either ambient or chiller temperature. Each treatment was changed to a new bunk pair position weekly. Relative preference was determined according to weight of pellets remaining per hour per treatment bunk pair per 24 h. Pellets were analysed for volatile organic compounds (VOCs) and the concentrations tested for correlation with relative preference. Calves showed the lowest preference (p < 0.0001) for the Control/Ambient treatment whereas preference for all other treatments (H57/Ambient; H57/Chiller; Control/Chiller) was similar. The Control/Ambient treatment odour profile grouped differently to the other 3 treatments which grouped similarly to each other. Up to 16 mVOCs were determined to have potential as pre-ingestive signals for the extent of microbial spoilage. Further studies are required to find which combination of these mVOCs, when added to pellets, results in feed aversion.

Misuse of antenatal care and its association with adverse outcomes of pregnancy in a Southern rural area of Vietnam.

Researchers in Vietnam reported a high percentage of pregnant women attending ANC at least once, but an insufficient utilization of ANC services remains. The evidence demonstrating how the utilization of these services affect pregnancy outcome is not documented in Vietnam. We investigated the association between the misuse of ANC services and pregnancy outcome, and assessed other determinants associated with ANC services utilization. We conducted a prospective community-based study in Trang Bom district, Dong Nai, during 12 consecutive months. Data were collected using a structured questionnaire and medical records. Women were followed up to delivery. Misuse of ANC services, related factors and its association with adverse events were assessed using logistic regression. Out of 3301 pregnant women, 91% initiated an ANC visit within first trimester, 95% attended at least three ANC visits, but a low percentage of pregnant women underwent blood and urine tests at least once (20% and 39%, respectively). Factors significantly associated with a higher risk of adverse outcomes were lack of blood test and urine test, parity ≥ 3, ANC visits < 3, history of an adverse outcome, and having a clinical condition. Blood and urine tests were less frequently used by young women, women from ethnic minorities, women using only private facilities for ANC attendance, and women with a low number of ANC visits. Despite a high percentage of early entry into ANC and of at least three ANC visits, misuse of ANC services still exists and contributes to adverse outcomes. There is a need to increase the awareness of women on the benefits of ANC services by educating young women as well as women with several children. Health workers should be encouraged to propose suitable ANC services to pregnant women.

Differential metallothionein induction patterns in three freshwater fish during sublethal copper exposure.

We assessed whether fish that tolerate higher levels of Cu exposure have a higher capacity to induce metallothionein (MT) synthesis than other, more sensitive, fish species. Furthermore, we examined if a correlation could be found between tissue Cu accumulation and MT levels. Cu accumulation and MT concentrations in gill, liver, kidney and muscle of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio) were measured during a 1 week exposure to a sublethal Cu (1 microM). Different patterns were observed for the three species regarding Cu accumulation as well as MT induction. Virtually no Cu accumulation was seen in rainbow trout gill, while in both cyprinid species gill Cu levels increased three- to four-fold. Cu accumulated fast in common carp (within the first day), but slow in gibel carp (1 week). Gill MT induction was obvious in gibel carp only, with an increase of 156% after 1 week of exposure. Liver accumulated most Cu in rainbow trout (235% increase) and common carp (144% increase), with Cu levels in liver being significantly higher in rainbow trout compared to the carp species from the start. MT induction was pronounced in common carp liver only (138% increase). In gibel carp liver, there was no clear Cu accumulation or MT induction. In contrast, gibel carp was the only species to show Cu accumulation in kidney after 3 days of exposure (83% increase), after which levels returned to normal. Concomitantly, gibel carp kidney was also the only kidney tissue to show MT induction (192-195% increase after 3 and 7 days). In common carp, a significant decrease of kidney MT levels was observed from day 1 onwards. In muscle, Cu accumulation was clear for the two cyprinid species (three- to four-fold increase) but not for rainbow trout. Of the species studied, gibel carp is the most resistant to copper polluted environments, and showed a positive significant relationship between tissue copper concentrations and MT levels in gill, liver and muscle tissues. Common carp showed an intermediate response, with significant correlations in liver and muscle tissue. In contrast, we found low MT induction in rainbow trout, the most sensitive species, and no correlation at all between MT concentrations and tissue copper contents. Possibly, the regulatory capacity for copper homeostasis was exceeded in rainbow trout, and MT synthesis inhibited.