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Rapid expansion of biopharmaceutical market calls for more efficient and reliable platforms to culture mammalian cells on a large scale. Stirred-tank bioreactors have been widely used for large-scale cell culture. However, it requires months of trials and errors to optimize culture conditions for each cell line. In this article, we extend our earlier studies on rolled scaffold (RS) bioreactors for high-density adherent cell culture and report two new implementations of RSs with greatly enhanced mass-manufacturability, termed as Mesh-RS and Fiber-RS. CHO-K1 cells were successfully expanded in Mesh-RS and Fiber-RS bioreactors with an average growth rate of 1.09 ± 0.04 1/day and 0.95 ± 0.07 1/day, which were higher than those reported in similar studies. Fiber-RS bioreactor exhibited a very high cell density of 72.8 × 10

Polymorphic Ga2S3 nanowires grown via chemical vapor deposition exhibit distinctive evolution of various crystal structures.

Exosomes from Nischarin Tumors Reduce Focal Adhesions and Cell Spreading

Characterization of Exosomes in Human Cell Lines

Supplementary Figure legends

Caspase 3 Staining of Mouse Tumors From Exosome Studies

Nischarin Decreases the Attachment of Breast Cancer Cells

Schematic Representation of the Effects of Nischarin on Breast Cancer Cell Motility through Exosomes

Exosomes are small extracellular microvesicles that are secreted by cells when intracellular multivesicular bodies fuse with the plasma membrane. We have previously demonstrated that Nischarin inhibits focal adhesion formation, cell migration, and invasion, leading to reduced activation of focal adhesion kinase. In this study, we propose that the tumor suppressor Nischarin regulates the release of exosomes. When cocultured on exosomes from Nischarin-positive cells, breast cancer cells exhibited reduced survival, migration, adhesion, and spreading. The same cocultures formed xenograft tumors of significantly reduced volume following injection into mice. Exosomes secreted by Nischarin-expressing tumors inhibited tumor growth. Expression of only one allele of Nischarin increased secretion of exosomes, and Rab14 activity modulated exosome secretions and cell growth. Taken together, this study reveals a novel role for Nischarin in preventing cancer cell motility, which contributes to our understanding of exosome biology.Significance:Regulation of Nischarin-mediated exosome secretion by Rab14 seems to play an important role in controlling tumor growth and migration.See related commentary by McAndrews and Kalluri, p. 2099

BackgroundSchool violence and injury are major public health problems worldwide; however, current information on these issues in Vietnam is lacking. We aim to investigate the prevalence of violence and non-fatal injury and associated factors among Vietnamese adolescents aged 13-17 years old.MethodsWe used data from the 2019 Vietnam Global School-based Student Health Survey (GSHS), which is a nationally representative survey developed by the World Health Organization to monitor behavioral risk factors among school-aged students. The Vietnam GSHS 2019 was conducted in 20 provinces and cities, with a sample size of 7,690 male and female students aged 13-17 years old.ResultsWe found the prevalence of violence and non-fatal injury was 14.5% and 21.4%, respectively. Common risk factors for both violence and non-fatal injuries included cigarette smoking, alcohol use, mental health problems, and living with neither parent; violence was also a risk factor for non-fatal injuries. Student older age was associated with lower odds of school violence. Parents played an important role in preventing violence among female students and non-fatal injuries in both genders.ConclusionsFuture policies should consider individual factors as well as adolescent-parent bonding, to mitigate the burden of violence and injury among in-school adolescents in Vietnam.

The polymorphism of nanostructures is of paramount importance for many promising applications in high-performance nanodevices. We report the chemical vapor deposition synthesis of Ga

BackgroundVietnam’s national tobacco control strategy aims to reduce the rate of smoking among male adults from 45% in 2015 to 39% by 2020. The aim of this paper is to assess what contribution cigarette tax increases under Vietnam’s current excise tax plan can be expected to make to this target, and to discuss what additional measures might be implemented accordingly.MethodsThis study uses a mix of administrative datasets and predictive modelling techniques to assess the expected impact of tax and price increases on cigarette consumption, tobacco tax revenues and the rate of smoking between 2015 and 2020.FindingsThe average retail price of cigarettes is estimated to have increased by 16% (sensitivity analysis: 14%–18%) in inflation-adjusted terms between 2015 and 2020, while cigarette consumption is projected to decrease by 5.1% (4.5%–5.5%). The rate of smoking among males is projected to decrease to 42.8% (42.1%–43.6%) compared with the target of 39%. Total tax revenues from cigarettes are projected to increase by 21% (19%–23%), reflecting an extra ₫3300 billion in inflation-adjusted revenues for the government.ConclusionThe current excise tax law is expected to have only a modest impact on the rate of smoking in Vietnam, though it has generated tax revenues. If Vietnam is to achieve its tobacco control targets, the government should implement a mixed excise system with a high-specific component to promote public health by raising the price of cigarettes more significantly.

The bottom-up synthesis process often allows the growth of metastable phase nanowires instead of the thermodynamically stable phase. Herein, we synthesized Cd3As2 nanowires with a controlled three-...

Photoelectrochemical water splitting has been considered as the most promising technology for generating hydrogen energy. Herein, we report nickel sulfide nanocrystals (NCs) as excellent catalysts for electrochemical and solar-driven photoelectrochemical (PEC) hydrogen evolution. Two polymorphic NiS and NiS1.97 NCs were synthesized with a controlled composition, and the NiS NCs showed higher electrocatalytic activity than the NiS1.97 NCs toward the hydrogen/oxygen evolution reactions in 0.5 M H2SO4 and 1 M KOH. Photocathodes were fabricated by growing the NiS and NiS1.97 NCs directly onto Si nanowire (NW) arrays. The deposition of NiS NCs results in excellent PEC performance in both acid and alkaline electroytes; the photocurrent is 10 mA cm−2 (at 0 V vs. RHE) and the onset potential is 0.2 V. In contrast, the Si-NiS1.97 photocathode exhibits much lower photocurrent and less stability. Detailed structure analysis using X-ray photoelectron spectroscopy reveals that the NiS is more metallic than the NiS1.97 and retains the same electronic structures during the catalytic reaction. The high catalytic activity of metallic NiS NCs should be the main cause of this enhanced PEC performance, promising efficient water-splitting Si-based PEC cells.

BackgroundAdolescence is a vulnerable period for many lifestyle risk behaviors. In this study, we investigated the clustering of risk behaviors and role of the school health promotion programs among adolescents in Vietnam. MethodsWe analyzed data of 7,541 adolescents aged 13-17y from the 2019 nationally representative Global School-based Student Health Survey, conducted in 20 provinces and cities in Vietnam. We applied the latent class analysis to identify groups of clustering and used Bayesian 2-level logistic regressions to evaluate the effects of school health promotion programs on these clusters. We reassessed the school effect size by incorporating different informative priors to the Bayesian models. FindingsThe most frequent lifestyle risk behavior among Vietnamese adolescents was unhealthy diet ([~]67%), followed by sedentary behavior (37% in boys and 48% in girls) and low fruit/vegetable intake ([~]31%). More than half of students had a cluster of at least two risk factors and a quarter with three risk factors. Latent class analysis detected 18% boys and 15% girls being at high-risk of lifestyle behaviors. Consistent through different priors, high quality of health promotion programs associated with lower the odds of lifestyle risk behaviors (highest quality schools vs. lowest quality schools; boys: Odds ratio (OR) = 0{middle dot}69, 95% Highest Density Interval (HDI): 0{middle dot}49 - 0{middle dot}99; girls: OR = 0{middle dot}62, 95% HDI: 0{middle dot}42 - 0{middle dot}92). InterpretationOur findings demonstrated the clustering of specific lifestyle risk behaviors among Vietnamese adolescents, suggesting a special need for required courses in schools and join interventions that target sex-specific multiple risk behaviors. FundingThe 2019 Global School-based Student Health Survey was conducted with financial support from the World Health Organization. The authors received no funding for the data analysis, data interpretation, manuscript writing, authorship, and/or publication of this article. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSAdolescence is a vulnerable period for many lifestyle risk behaviors which normally cluster and interact to exponentially elevate the risks of non-communicable diseases (NCDs). The school might play an essential role in preventing risk behaviors and motivating healthy lifestyle behaviors for in-school adolescents. We searched on PubMed and Google Scholar to identify peer-reviewed articles published in English between Jan 1, 2000 and November 25, 2020; using keywords ("health behaviors" OR "lifestyle risk behaviors "OR "health risk behaviors" OR "tobacco" OR smok* OR "alcohol" OR "physical activity" OR "physical inactivity" OR "fruit intake" OR "vegetable intake" OR "diet") AND (cluster* OR "co-occurrence") AND ("adolescent" OR "teenager" OR "youth" OR "student"). We complemented the searching database with a manual search on reference lists. We identified 39 studies that evaluated the clustering of risk behaviors among adolescents (Supplemental materials S1). Two-thirds of the studies were conducted in high-income countries. The evidence from low- and middle-income countries is currently limited in some countries; however, most of these studies used descriptive techniques to analyze the co-occurring behaviors, i.e., treating the effects of risk behaviors equally or computing the observed prevalence-to-expected prevalence ratio, which hardly evaluates the underlying association among these co-occurrences. Furthermore, no studies have focused on the role of school health promotion programs in preventing the high-risk cluster of these behaviors. Added value of this studyOur study is a pioneer in using analytical technique to investigate the clustering pattern of six major lifestyle risk behaviors of NCDs (smoking, drinking, physical inactivity, sedentary behavior, low fruit/vegetable intake, and unhealthy diet) among school-going adolescents in Vietnam. We found more than half of adolescents had a cluster of at least two factors and a quarter had three factors, with the common clusters being unhealthy diet, sedentary behaviors, low fruit/vegetable intake (in girls), and drinking (in boys). Using latent class analysis, we identified 18{middle dot}1% of boys and 14{middle dot}7% of girls were at high-risk pattern of lifestyle behaviors. Consistent across scenarios, Bayesian multilevel models showed that the quality of school health promotion programs was associated with minimizing the high-risk cluster of lifestyle behaviors. Implications of all available evidenceOur findings highlight the need for required courses in school with high-quality content for essential joint knowledge and skills to prevent multiple lifestyle risk behaviors. This becomes urgent as the current curriculum is not required in Vietnam, therefore, although the high prevalence of students completed a module for preventing an individual risk behavior; a limited number of them achieved three such modules. We also emphasize separated intervention for boys and girls since the patterns of lifestyle risk behaviors combination are different by sexes.

Exosomes are small extracellular microvesicles that are secreted by cells when intracellular multivesicular bodies fuse with the plasma membrane. We have previously demonstrated that Nischarin inhibits focal adhesion formation, cell migration, and invasion, leading to reduced activation of focal adhesion kinase. In this study, we propose that the tumor suppressor Nischarin regulates the release of exosomes. When cocultured on exosomes from Nischarin-positive cells, breast cancer cells exhibited reduced survival, migration, adhesion, and spreading. The same cocultures formed xenograft tumors of significantly reduced volume following injection into mice. Exosomes secreted by Nischarin-expressing tumors inhibited tumor growth. Expression of only one allele of Nischarin increased secretion of exosomes, and Rab14 activity modulated exosome secretions and cell growth. Taken together, this study reveals a novel role for Nischarin in preventing cancer cell motility, which contributes to our understanding of exosome biology. Significance: Regulation of Nischarin-mediated exosome secretion by Rab14 seems to play an important role in controlling tumor growth and migration. See related commentary by McAndrews and Kalluri, p. 2099

One-dimensional semiconductor nanowires often contain polytypic structures, owing to the co-existence of different crystal phases. Therefore, understanding the properties of polytypic structures is of paramount importance for many promising applications in high-performance nanodevices. Herein, we synthesized nanowires of typical III–V semiconductors, namely, gallium phosphide and gallium arsenide by using the chemical vapor transport method. The growth directions ([111] and [211]) could be switched by changing the experimental conditions, such as H2 gas flow; thus, various polytypic structures were produced simultaneously in a controlled manner. The nanobeam electron diffraction technique was employed to obtain strain mapping of the nanowires by visualizing the polytypic structures along the [111] direction. Micro-Raman spectra for individual nanowires were collected, confirming the presence of wurtzite phase in the polytypic nanowires. Further, we fabricated the photodetectors using the single nanowires, and the polytypic structures are shown to decrease the photosensitivity. Our systematic analysis provides important insight into the polytypic structures of nanowires.

Alloyed semiconductor nanowires (NWs) are of great interest for next-generation integrated optoelectronic nanodevices owing to their tunable band gap and emission wavelength. In this study, we synthesized the GaAsSe ternary alloy nanowires (NWs) with various compositions between GaAs and Ga2Se3 using chemical vapor transport method. The band gap was continuously tuned in the range of 1.5–2.1 eV because of the completely miscible solid solution at all compositions. The alloy NWs (including Ga2Se3) consisted of a cubic phase with the [011] growth direction, in contrast with the GaAs NWs grown along the [111] direction. In particular, the GaAs1–xSex (x = 0.3) alloy NWs were grown from Ga-rich Au nanoparticles such as cubic-phase AuGa2 and had a defect-free single-crystalline nature. X-ray photoelectron spectroscopy analysis reveals much less surface oxide layers for x = 0.3, suggesting that Se incorporation at this composition effectively diminishes the surface defects. We fabricated photodetectors using the...

Droplet microfluidics have a great potential in chemical and biomedical applications, due to their high throughput, versatility, and massive parallelism. To enhance their throughput, many devices based on the droplet microfluidics are using a flow-through configuration, in which the droplets are generated, transported, and analyzed in a continuous stream with a high velocity. Direct imaging of moving droplets is often necessary to characterize the spatiotemporal dynamics of the chemical reaction and physical process in the droplets. However, due to the motion blur caused by the movement of the droplets during exposure, an expensive high-speed camera is required for clear imaging, which is cost prohibitive in many applications. In this paper, we are presenting ‘Moving shot’ to demonstrate direct imaging of fast-moving droplets in microfluidic channels at an affordable cost. A microfluidic device is translated at the same velocity but in the opposite direction of moving droplets in it, so that the droplets are stationary with respect to the objective lens. With this approach, we can image fluorescent droplets moving at 0.34 cm s−1 with an exposure time up to 2 s without motion blur. We strongly believe that the proposed technique can enable cost-effective and high-throughput imaging of fast-moving droplets in a microfluidic channel.

Since the emergence of hydrogen generation by water-splitting as a core renewable-energy technology, the development of related catalysts with high efficiency, long-term stability, and low cost has been vigorously pursued. We report the temperature-controlled synthesis of two nickel phosphide polymorphs, Ni2P and Ni5P4, by phosphorization of Ni foil or foam using phosphine gas. The hexagonal phase Ni2P nanowires and Ni5P4 nanosheets were grown on Ni substrates with vertical alignment, and uniformly exposed active (001) planes. The Ni5P4 nanosheets possess significant stacking faults along the [0001] direction. Both Ni2P and Ni5P4 exhibit excellent electrocatalytic activity toward the hydrogen evolution reaction (HER). Their overpotential for 10 mA cm−2 was 0.126 and 0.114 V, and the Tafel slope was 42 and 34 mV dec−1 in 0.5 M H2SO4 electrolyte, respectively. A decrease in HER performance was observed for Ni5P4, but the change was negligible for Ni2P. Strain mapping using a precession-assisted nanobeam electron diffraction technique showed that only Ni5P4 underwent degradation of basal (001) planes during HER, which explains the lower stability of catalytic activity. Furthermore, the Ni2P nanowires demonstrated excellent catalytic activity toward overall water splitting, which could be attributed to the stable surface as well as the highly conductive crystal structures.

Recently there have been extensive efforts to develop novel two-dimensional (2D) layered structures, owing to their fascinating thickness-dependent optical/electrical properties. Herein, we synthesized thin GeP nanosheets that had a band gap (Eg) of 2.3 eV, which is a dramatic increase from the value in the bulk (0.9 eV) upon exfoliation. This Eg value is close to that of the GeP monolayer predicted by first-principles calculations (HSE06 functional). The calculations also indicate a strong dependence of Eg on the number of layers (2.306, 1.660, 1.470, and 1.397 eV for mono-, bi-, tri-, and tetralayers, respectively), and that the band edge positions are suitable for water splitting reactions. Field-effect transistor devices were fabricated using the p-type GeP nanosheets of various thicknesses, and the devices demonstrated a significant decrease in the hole mobility but an increased on–off ratio as the layer number decreased. The larger on–off ratio (104) for the thinner ones is promising for use in novel 2D (photo)electronic nanodevices. Further, liquid-exfoliated GeP nanosheets (thickness = 1–2 nm) deposited on Si nanowire arrays can function as a promising photoanode for solar-driven water-splitting photoelectrochemical (PEC) cells. Based on the calculated band offset with respect to the Fermi levels for the two half-reactions in the water splitting reaction, the performance of the PEC cell can be explained by the formation of an effective p-GeP/n-Si heterojunction.

Two-dimensional MoS2 meets porphyrin molecules to form unique 1T′ phase intercalated complexes via a one-step procedure of hydrothermal reactions. The resultant Mn-porphyrin-MoS2 exhibits excellent electrocatalytic activity toward the hydrogen evolution reaction, with a Tafel slope of 35 mV dec−1 and 10 mA cm−2 at an overpotential of 0.125 V. Spin-polarized density functional theory calculations confirmed that the intercalation of Mn-porphyrin into 1T′-MoS2 is quite favourable due to strong charge transfer from Mn metals. Their outstanding catalytic performance could be ascribed to the high electron concentration as well as the low activation barrier of the Heyrovsky reaction.

For the electrochemical reduction of CO2 (CRR) with high selectivity for HCOOH, In–Zn bimetallic nanocrystals (NCs) were synthesized as catalysts by in situ reduction of In2O3–ZnO NCs with various compositions. All In-containing bimetallic catalysts exhibited excellent selectivity to produce HCOOH, while Zn NCs favor CO production. A composition with In : Zn = 0.05 has higher catalytic activity than In NCs, with a faradaic efficiency of 95% and a HCOOH production rate of 0.40 mmol h−1 cm−2 at −1.2 V vs. RHE. The enhanced catalytic performance is in part ascribed to the fewer surface oxide layers, which increase the conductivity and facilitate the charge transfer. Density functional theory calculations revealed that the In–Zn interfacial sites make the HCOOH pathway significantly energy-favorable, which supports the higher production rate of Zn0.95In0.05 than that of In.

Tobacco smoking is one of the most dangerous risk behaviors, leading to many adverse human health consequences. The aims of this study is to estimate the prevalence of tobacco smoking and related factor among adolescents aged 13–17 years in Vietnam. The data were from two rounds of the Vietnam Global School-based Student Health Survey (GSHS) that is the nationally representative survey conducted in 2013 and 2019. The logistic regressions were carried out to identify factors associated with tobacco smoking among study participants. We found the prevalence of current smoking (water pipe and cigarettes) reduced significantly from 5.4% (95% CI: 4.0–7.2) in 2013 to 2.8% (95% CI: 2.2–3.6) in 2019. In 2019, 2.6% of students used electronic cigarette products in the last 30 days. Factors associated with higher odds of current smoking status included study year, gender, parental monitoring, loneliness, suicide attempt, sexual intercourse, truancy, alcohol drinking. Similar patterns were found in e-cigarette use. Smoking among adolescents in Vietnam reduced between 2013 and 2019. Further follow-up studies are needed to confirm the causal factors of the reduction and e-cigarettes use.

Youth suicide is a leading cause of death among adolescents, but evidence about the influences of parental involvement on adolescent suicidal behaviors is inconsistent and have not been well studied. We used nationally representative data from the Vietnam Global School-based Student Health Survey (GSHS) 2019 (n = 7796 students aged 13–18 years). Using the 2-level random intercept logistic regressions, we evaluated the relationship between parental involvement (high expectation, monitoring, and understanding) and suicidal ideation and identified related factors of suicidal ideation. The overall prevalence of suicidal ideation was 15.6%. While high level of parental monitoring and understanding were associated with lower odds of suicidal ideation among adolescents (OR: 0.63; 95% CI: 0.52–0.77 and OR: 0.60; 95% CI: 0.49–0.73, respectively), high parental expectation was linked to higher odds of suicidal ideation (OR: 1.42; 95% CI: 1.24–1.63). Other risk factors at the individual- and school-level for suicidal ideation included being girls, living in urban areas, having mental health problems, involving in risk behaviors, suffering from bullying and violence, and poor school quality. Targeted suicide prevention initiatives should take into account comprehensive aspects of parent-child bonding, student, and school factors to mitigate the burden of suicidal behaviors among adolescents.

We describe the first infant born to a woman with COVID‐19 in Vietnam, by Caesarean section at 36 weeks and 5 days of gestation. The mother and baby remained together during their hospital stay and prolonged skin‐to‐skin contact and early and exclusive breastfeeding were achieved. This was in line with the World Health Organization's Early Essential Newborn Care (EENC) recommendations, the national Vietnamese standard of care since 2014. The baby remained virus‐free throughout the 34‐day postpartum follow‐up. Conclusion The EENC approach can still be used with mothers who have COVID‐19 if effective infection control measures are applied.

HIV self-testing has emerged as a safe and effective approach to increase the access to and uptake of HIV testing and treatment, especially for key populations. Applying self-testing to hepatitis C virus (HCV) may also offer an additional way to address low coverage of HCV testing and to accelerate elimination efforts. To understand the potential for HCV self-testing (HCVST), an observational study was conducted to assess the acceptability and usability of the OraQuick® HCV Self-Test (prototype) among people who inject drugs (PWID) and men who have sex with men (MSM) in Thai Nguyen, a province in northern Vietnam. A total of 105 PWID and 104 MSM were eligible and agreed to participate in the study. Acceptability, defined as the proportion of participants among eligible subjects who agreed to participate in the study, was 92.9% in PWID and 98.6% in MSM. Compared to MSM, PWID were older (median age: 45 vs. 22 years, p &lt, 0.0001) and had a lower education level (high school and college: 38.1% vs. 100%, 0.0001). HCVST usability was high among MSM with fewer observed mistakes, difficulties, or participants requiring assistance (33.7%, 28.8%, and 17.3%, respectively) compared to PWID (62.9%, 53.3%, and 66.7%, respectively, all p &lt, 0.0001)). Inter-reader and inter-operator agreement were good in both groups (Kappa coefficient range: 0.61–0.99). However, the concordance between HCVST and study staff -read or performed HCV testing was lower among PWID than MSM (inter-reader concordance 88.6% vs. 99.0% and inter-operator concordance 81.9% vs. 99%). Overall, HCVST was highly acceptable with moderate to high usability among PWID and MSM in Thai Nguyen. Efforts to provide support and assistance may be needed to optimize performance, particularly for PWID populations and for those who are older and with lower literacy or education levels.

Background: Adolescence is a vulnerable period for many lifestyle risk behaviors. In this study, we investigated the clustering of risk behaviors and role of the school health promotion programs among adolescents in Vietnam. Methods: We analyzed data of 7,541 adolescents aged 13–17y from the 2019 nationally representative Global School-based Student Health Survey, conducted in 20 provinces and cities in Vietnam. We applied the latent class analysis to identify groups of clustering and used Bayesian 2-level logistic regressions to evaluate the effects of school health promotion programs on these clusters. We reassessed the school effect size by incorporating different informative priors to the Bayesian models. Findings: The most frequent lifestyle risk behavior among Vietnamese adolescents was unhealthy diet (~67%), followed by sedentary behavior (37% in boys and 48% in girls) and low fruit/vegetable intake (~31%). More than half of students had a cluster of at least two risk factors and a quarter with three risk factors. Latent class analysis detected 18% boys and 15% girls being at high-risk of lifestyle behaviors. Consistent through different priors, high quality of health promotion programs associated with lower the odds of lifestyle risk behaviors (highest quality schools vs. lowest quality schools; boys: Odds ratio (OR) = 0·69, 95% Highest Density Interval (HDI): 0·49 – 0·99; girls: OR = 0·62, 95% HDI: 0·42 – 0·92). Interpretation: Our findings demonstrated the clustering of specific lifestyle risk behaviors among Vietnamese adolescents, suggesting a special need for required courses in schools and join interventions that target sex-specific multiple risk behaviors. Funding Information: The 2019 Global School-based Student Health Survey was conducted with financial support from the World Health Organization. The authors received no funding for the data analysis, data interpretation, manuscript writing, authorship, and/or publication of this article. Declaration of Interests: The authors declare that they have no conflict of interest. Ethics Approval Statement: Written informed consent was obtained from all participants’ parents/guardians before the study. All procedures performed in this study followed the ethical standards of the Institution Review Board of Hanoi University of Public Health (IRB decision No. 421/2019/YTCC-HD3, dated: 06/08/2019).

The bottom-up synthesis process often allows the growth of metastable phase nanowires instead of the thermodynamically stable phase. Herein, we synthesized Cd

Introduction: Vietnam is among the countries with the highest smoking prevalence among male adults, as well as high prevalence of secondhand smoke exposure at indoor places. In many countries, including Vietnam, exposure to tobacco smoking is greatest in restaurants/bars and hotels. This study aims to analyze the compliance of hotels and restaurants to smoke-free environment regulations before and after an intervention. Methods: Direct observations were done at the receptions, conference rooms, designated smoking areas, restaurants, and lobbies of 140 hotels and the dining rooms, kitchens, and toilets of 160 restaurants before and after an intervention. The intervention was a training course conducted by police officers followed by 3 monthly supervision visits by police officers. Compliance with smoke-free enviornment regulations was observed and assessed to generate a compliance score for each location and overall. Tobit regression was used to examine the relationship between compliance scores and the intervention and other variables such as hotel and restaurant characteristics. Results: Before the intervention, the highest compliance rates were found for “no tobacco advertisement” and “no cigarette selling” regulations (95%-100%) in almost all sites in hotels and restaurants. The lowest compliance rates were found for “having nonsmoking signs.” The rate of compliance with all regulations was only 5% for hotels and 0.06% of restaurants. Improvement after intervention was clearly observed, in the rate of compliance with all regulations by more hotels (15.7%) and overall compliance scores of hotels and restaurants. Conclusions: The intervention with participation of the police officers proved to be effective in improving compliance with smoke-free regulations. It is recommended to continue this intervention in the same areas as well as to expand the intervention to other areas.

Objectives This paper explores changes in the level of secondhand smoke (SHS) exposure at indoor workplaces between 2010 and 2015 in Viet Nam and the association between the exposure and various demographic factors, using data from Viet Nam's Global Adult Tobacco Surveys (GATS) 2010 and 2015. Methods Data was pooled from the two GATS surveys and analysed using descriptive and Poisson regression analyses. Results There was a highly statistically significant reduction in the level of SHS exposure at indoor workplaces from 55.9% to 42.6% (p.

We demonstrate a controllable p-n junction in a three-dimensional Dirac semimetal (DSM) Cd

Photocatalytic water splitting is a vital technology for clean renewable energy. Despite enormous progress, the search for earth-abundant photocatalysts with long-term stability and high catalytic activity is still an important issue. We report three possible polymorphs of nickel selenide (orthorhombic phase NiSe2, cubic phase NiSe2, and hexagonal phase NiSe) as bifunctional catalysts for water-splitting photoelectrochemical (PEC) cells. Photocathodes or photoanodes were fabricated by depositing the nickel selenide nanocrystals (NCs) onto p- or n-type Si nanowire arrays. Detailed structural analysis reveals that compared to the other two types, the orthorhombic NiSe2 NCs are more metallic and form less surface oxides. As a result, the orthorhombic NiSe2 NCs significantly enhanced the performance of water-splitting PEC cells by increasing the photocurrents and shifting the onset potentials. The high photocurrent is ascribed to the excellent catalytic activity toward water splitting, resulting in a low char...