Aiming to design a catalyst for stable electrooxidation of water at low pH, the present work explores the properties and structural features of electrodeposited composite oxides based on Bi and Co, ...which were anticipated to provide stability and catalytical activity, respectively. Materials deposited as very thin (ca 50 nm) films on F‐doped SnO2 (FTO) substrate do not initially exhibit high activity in 0.1 M H2SO4, but are activated during operation through the electrooxidatively‐induced enrichment of the catalytic surface with Co and Sn oxides. The latter originate from the FTO support and are identified as an important component of the catalyst through control experiments with a Sn‐free substrate and with Sn2+ intentionally added at the electrodeposition stage. A distinctive feature of the Co−Bi−Sn‐based electrocatalyst is the slow but persistent improvement in the activity during operation in 0.1 M H2SO4 at both ambient and elevated (60 °C) temperatures, which contrasts with the continuously degrading behaviour of state‐of‐the‐art oxygen evolution catalysts at low pH. This is demonstrated by 9‐day‐long galvanostatic tests at 10 mA cm−2, during which the Co−Bi−Sn‐based thin film catalyst shows no degradation and sustains stable water oxidation at ca 1.9 V vs. reversible hydrogen electrode. The effects of tin leaching from the support detected herein might have implications to other acidic water oxidation catalysts supported on high‐surface area doped SnO2 materials.
SYNOPSIS. Stable oxygen evolution reaction at low pH catalysed by cobalt‐bismuth oxides is promoted by small amounts of tin leaching from the F‐doped SnO2 support.
Abstract
The envelope protein VP28 of white spot syndrome virus (WSSV) is considered a candidate antigen for use in a potential vaccine to this important shrimp pathogen (the cause of white spot ...syndrome, WSS). Here, we used spores of Bacillus subtilis to display VP28 on the spore surface. Trials were conducted to evaluate their ability to protect shrimps against WSSV infection. The gene cotB-vp28 was integrated into the chromosome of the laboratory strain B. subtilisPY79, and expression of CotB-VP28 was detected by Western blotting and immunofluorescence. Expression of CotB-VP28 was equivalent to 1000 molecules per spore. PY79 and CotB-VP28 spores were mixed with pellets for feeding of whiteleg shrimps (Litopenaeus vannamei), followed by WSSV challenge. Superoxidase dismutase (SOD), phenoloxidase activities and mortality rates of the two shrimp groups were evaluated. Groups fed with PY79 and CotB-VP28 spores at day 7 had increased SOD activities of 29% and increased phenoloxidase activities of 15% and 33%, respectively, compared to those of the control group. Fourteen days postchallenge, 35% of vaccinated shrimps had died compared to 49% of those fed naked spores (PY79) and 66% untreated, unchallenged animals. These data suggest that spores expressing VP28 have potential as a prophylactic treatment of WSS.
Recombinant Bacillus subtilis spores with VP28 antigen expressed on the surface have been proven to be a potential oral treatment to protect Litopenaeus vannamei shrimp against white spot syndrome.
Graphical Abstract Figure.
Recombinant Bacillus subtilis spores with VP28 antigen expressed on the surface have been proven to be a potential oral treatment to protect Litopenaeus vannamei shrimp against white spot syndrome.
Vietnam is experiencing an epidemiologic transition with an increased prevalence of non-communicable diseases. Novel, large-scale, effective, and sustainable interventions to control hypertension in ...Vietnam are needed. We report the results of a cluster-randomized feasibility trial at 3 months follow-up conducted in Hung Yen province, Vietnam, designed to evaluate the feasibility and acceptability of two community-based interventions to improve hypertension control: a "storytelling" intervention, "We Talk about Our Hypertension," and a didactic intervention.
The storytelling intervention included stories about strategies for coping with hypertension, with patients speaking in their own words, and didactic content about the importance of healthy lifestyle behaviors including salt reduction and exercise. The didactic intervention included only didactic content. The storytelling intervention was delivered by two DVDs at 3-month intervals; the didactic intervention included only one installment. The trial was conducted in four communes, equally randomized to the two interventions.
The mean age of the 160 study patients was 66 years, and 54% were men. Most participants described both interventions as understandable, informative, and motivational. Between baseline and 3 months, mean systolic blood pressure declined by 8.2 mmHg (95% CI 4.1-12.2) in the storytelling group and by 5.5 mmHg (95% CI 1.4-9.5) in the didactic group. The storytelling group also reported a significant increase in hypertension medication adherence.
Both interventions were well accepted in several rural communities and were shown to be potentially effective in lowering blood pressure. A large-scale randomized trial is needed to compare the effectiveness of the two interventions in controlling hypertension.
ClinicalTrials.gov, NCT02483780.
Medical surveillance data from all government health clinics in Vietnam are currently collected through a slow, paper-driven process. Short message service (SMS) technology delivered through mobile ...phones offers a simple solution to improving the speed through which disease surveillance information can be collected. Identifying health concerns earlier with this mobile-based disease surveillance system has the potential to improve the care for patients seen at community health clinics as well as predict more quickly that a medical emergency, such as a pandemic, will occur. Thus, we piloted the feasibility of an SMS-based disease surveillance system designed for healthcare workers in Vietnam to directly report disease information on diarrhea and influenza-like illness to a central data repository using their mobile phones and an intuitive, user-friendly platform. This article reports data from 1,579 patient data entries in 20 Vietnamese health clinics during a 6-month period.
Having mobile devices that provide patients with the ability to record and monitor the electrical activity of their heart enhances patient self-care and the early detection of irregular heartbeat ...(cardiac arrhythmia), yet few such devices exist in Vietnam. Challenges exist for introducing mobile electrocardiography (ECG) monitoring devices in Vietnam, including patient accessibility and affordability. A low-cost mobile ECG monitoring device designed and developed in Vietnam, which allows patients to easily measure their heart's electrical activity and navigate recordings, may be a solution.
The aim of this project is to assess the usability of the MD-Link system, a newly developed mobile handheld 1-lead ECG device, in detecting patients with irregular heartbeat. We will compare its outputs to the standard printed outputs of a 12-lead electrocardiogram generated by the Nihon Kohden Cardiofax S Electrocardiograph Model ECG-1250K.
We will conduct a cross-sectional study in two stages, including the measurement of ECG signals of patients using the MD-Link and the Nihon Kohden Cardiofax S and analysis of the selected standard outputs collected from the ECG recordings of the MD-Link and the Nihon Kohden Cardiofax S. The MD-Link consists of (1) a mobile device (eg, a smartphone); (2) a lead wire with 2 disposable electrodes; and (3) an easy-to-use mobile app interface enabling the upload and accurate display of ECG recordings to patients and their clinicians. Our research team, consisting of members from Dartmouth College; the Institute of Health, Population and Development; Hanoi University of Science and Technology; and physicians and nurses from Thanh Chan Clinic, will assist in carrying out this project.
We will proceed with a publication plan that includes a project report and, ultimately, articles for peer-reviewed journals. We also hope to disseminate our work at relevant conferences to provide more coverage and exposure to the MD-Link mobile device. Recruitment and data collection were completed in January 2018. Data analysis started in February 2018 and is ongoing. Results are expected mid-2019.
At the end of this project, we will have developed and tested the MD-Link, a low-cost mobile ECG monitoring device, with some supportive comparisons to standard ECG devices commonly used in heart clinics or hospitals in Vietnam. Our long-term goal is for the MD-Link to be easily accessible, affordable, and to fit into a patient's daily routine, thus improving the care and treatment of patients with cardiovascular diseases (CVDs).
RR1-10.2196/8762.
The exploration of social media among Gen Z has promoted the development of influencer marketing in emerging markets. This study aims to determine how influencer marketing would impact Vietnamese Gen ...Z consumer’s purchase intention. This study employed quantitative research and used Exploratory Factor Analysis (EFA) to analyze the data. The data collection process is conducted online with a sample size of 250 Gen Z respondents. The respondents are aware of the impacts of influencer marketing on their purchase intention. The respondents are exposed to influencer marketing on social media and had experiences with online shopping. The study analyzes five factors that would influence Gen Z’s consumer purchase intention: perceived influencers’' credibility (CRE), the relevance between products and customers (RE), the entertainment value of influencers' content (ENT), perceived expertise of influencers (EXP) and peer’s review and recommendation (PEER). This study's findings concluded that 4 out of 5 factors had influenced Gen Z purchase intention: perceived influencers' credibility, the entertainment value of influencers' content, perceived expertise of influencers, and peer's review and recommendation. There is no statistical evidence to conclude that the relevance between products and customers (RE) impacts Vietnamese Gen Z’s consumer purchase intention. Remarkably, peer’s review and recommendation (PEER) is the most vital factor impacting Vietnamese Gen Z's consumer purchase intention. Managerial recommendations are provided to improve influencer marketing's effectiveness on purchase intention among Vietnamese Gen Z consumers.
Inspired by the previously published theoretical findings, the present work aims to assess the electrocatalytic activity of molybdenum(IV) sulfide modified with metallic molybdenum for the nitrogen ...reduction reaction in aqueous electrolyte solution (0.1 M Li2SO4; pH 3) and in aprotic C4mpyreFAP ionic liquid electrolyte at ambient temperature. The material of interest was synthesized via a high-temperature partial reduction of MoS2, while electrocatalytic tests followed a previously established robust protocol, which in particular involves strict control over any NH3 and NO3−/NO2− contamination at every key step. As expected, no activity was found in aqueous solutions. In aprotic medium, the formation of small amounts of ammonia at low rates was observed and was found to strongly depend on the water concentration and applied potential. However, the amount of electrochemically generated NH3 always reached a particular limit and did not increase further, even when the N2 pressure was increased from 1 to 16 bar. The results suggest rapid blockage of the surface of the investigated electromaterial with NH3, which prevents its operation as a catalyst for the ammonia electrosynthesis.
Aspergillus fumigatus is a ubiquitous fungus that is a frequent opportunistic pathogen in immunosuppressed patients. Because of its role as a pathogen, it is of considerable experimental interest. A ...set of auxotrophic isogenic strains in the A. fumigatus genome reference strain AF293 has been developed. Using molecular genetic methods, arginine and lysine auxotrophs were made by deletion of argB and lysB, respectively. Transformation of these auxotrophic strains with plasmids carrying argB or lysB, respectively, results in efficient integration at these loci. Finally, these strains are able to form stable diploids, which should further facilitate analysis of gene functions in this fungus. Furthermore, the development of this isogenic set of auxotrophic strains in the AF293 background will enable investigators to study this important opportunistic human pathogen with greater facility.
Abstract
Aiming to design a catalyst for stable electrooxidation of water at low pH, the present work explores the properties and structural features of electrodeposited composite oxides based on Bi ...and Co, which were anticipated to provide stability and catalytical activity, respectively. Materials deposited as very thin (
ca
50 nm) films on F‐doped SnO
2
(FTO) substrate do not initially exhibit high activity in 0.1 M H
2
SO
4
, but are activated during operation through the electrooxidatively‐induced enrichment of the catalytic surface with Co and Sn oxides. The latter originate from the FTO support and are identified as an important component of the catalyst through control experiments with a Sn‐free substrate and with Sn
2+
intentionally added at the electrodeposition stage. A distinctive feature of the Co−Bi−Sn‐based electrocatalyst is the slow but persistent improvement in the activity during operation in 0.1 M H
2
SO
4
at both ambient and elevated (60 °C) temperatures, which contrasts with the continuously degrading behaviour of state‐of‐the‐art oxygen evolution catalysts at low pH. This is demonstrated by 9‐day‐long galvanostatic tests at 10 mA cm
−2
, during which the Co−Bi−Sn‐based thin film catalyst shows no degradation and sustains stable water oxidation at
ca
1.9 V
vs
. reversible hydrogen electrode. The effects of tin leaching from the support detected herein might have implications to other acidic water oxidation catalysts supported on high‐surface area doped SnO
2
materials.
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