Recently, Jatropha, a fast growing tropical plant, has caught the attention of researchers because the oil produced from Jatropha is a non-edible. However, worse emissions, when using raw Jatropha ...oil in diesel engines, have been reported in the literature due to its higher viscosity and lower volatility. Therefore, it is necessary to find some way to reduce the emissions of diesel engines.
In the present research, experiments have been designed and performed to study the effects of Jatropha hydrogen peroxide emulsion on combustion, performance, and the emission characteristics of a diesel engine. Hydrogen peroxide in a solution of water at a concentration of 30% was used for making the emulsions with mixing mass ratios of 5%, 10%, and 15%. A single cylinder, four-stroke, high speed, direct injection diesel engine was used for the experiments. The acquired data were analyzed for various combustion parameters such as in-cylinder pressure, ignition delay, ignition duration, heat release, for performance parameters and emissions of CO, CO2 (carbon dioxide), HC, NOx, and PM as well. While running the engine on the Jatropha hydrogen peroxide emulsion fuel, improvements in performance and emissions were found and the optimum mixing ratio of the solution with hydrogen peroxide was 15%.
•Emulsion combustion shifted to the earlier stage and extended to the later stage.•Higher heat release rate at later stages and heat release for emulsified fuels.•Higher in-cylinder, and exhaust temperatures, and thermal efficiency for JHE15%.•Lower NOx (nitrogen oxides), CO2 (carbon dioxide), PM (particulate matter), soot at medium and high loads, higher HC for JHE15%.•Optimum mixing ratio of the solution of hydrogen peroxide is 15%.
Dementia is a global public health priority. The World Health Organization adopted a Global Action Plan on Dementia, with dementia awareness a priority. This study examined the knowledge, attitudes, ...and self-confidence with skills required for providing dementia care among primary health care providers in Vietnam.
A cross-sectional study was conducted with 405 primary health care providers who worked at commune health stations and district health centers in eight provinces across Vietnam.
The results showed that primary health care providers had poor knowledge and little confidence but more positive attitudes toward dementia care and management.
The results suggest the training needs for building capacity amongst primary health care providers, which will be critical as Vietnam's population ages.
The experimental study was carried out using a four-stroke, high speed, DI (direct-injection) diesel engine with double fuel injections. In this study, Jatropha water emulsion was made by mixing a ...mass ratio of 10% of water. While fixing the first injection timing, we tested the engine on JWE (Jatropha water emulsion) with various injection timings and quantities of second injections. The acquired data was analyzed for various combustion parameters such as heat release rate, combustion center (timing of 50% of total heat release), ignition delay, and combustion duration; for performance parameters such as in-cylinder temperature, exhaust gas temperature, brake thermal efficiency; and emissions of CO (carbon monoxide), CO2 (carbon dioxide), HC (hydrocarbons), NOx (nitrogen oxides), as well as dust and smoke opacity. When using a large second injection amount, we found a significant reduction in the peaks of the in-cylinder pressure, HRR (heat release rate), and average in-cylinder temperatures. We also found a drastic increase in the ignition delay, combustion duration, and a shift in the combustion center toward the later combustion stage, as well as increased exhaust gas temperatures, and reduced brake thermal efficiency compared with those of the Light oil. A large second injection amount reduced NOx emissions up to 48%, and drastically reduced HC emissions at higher loads of the engine.
•Jatropha water emulsion with double injection was tested experimentally.•Significantly reduced in-cylinder pressure, HRR with large second injection mass.•Lower in-cylinder temperature and BTE with large second injection amount.•Double injection with emulsion reduced significantly NOx, increased CO2, CO, HC.•Large second injection quantity increased ISF, and dust concentration.
Human pluripotent stem cell-based in vitro models that reflect human physiology have the potential to reduce the number of drug failures in clinical trials and offer a cost-effective approach for ...assessing chemical safety. Here, human embryonic stem (ES) cell-derived neural progenitor cells, endothelial cells, mesenchymal stem cells, and microglia/macrophage precursors were combined on chemically defined polyethylene glycol hydrogels and cultured in serum-free medium to model cellular interactions within the developing brain. The precursors self-assembled into 3D neural constructs with diverse neuronal and glial populations, interconnected vascular networks, and ramified microglia. Replicate constructs were reproducible by RNA sequencing (RNA-Seq) and expressed neurogenesis, vasculature development, and microglia genes. Linear support vector machines were used to construct a predictive model from RNA-Seq data for 240 neural constructs treated with 34 toxic and 26 nontoxic chemicals. The predictive model was evaluated using two standard hold-out testing methods: a nearly unbiased leave-one-out cross-validation for the 60 training compounds and an unbiased blinded trial using a single hold-out set of 10 additional chemicals. The linear support vector produced an estimate for future data of 0.91 in the cross-validation experiment and correctly classified 9 of 10 chemicals in the blinded trial.
RNA sequencing has increasingly become an indispensable tool for biological research. While sequencing costs have fallen dramatically in recent years, the current cost of RNA sequencing, nonetheless, ...remains a barrier to even more widespread adoption. Here, we present a simple RNA sequencing protocol with substantially reduced costs. This protocol uses as little as 10 ng of total RNA, allows multiplex sequencing of up to 96 samples per lane, and is strand specific. Extensive validation using human embryonic stem cells showed high consistency between technical replicates at various multiplexing levels.
Objectives
We report the prevalence of tobacco smoking among adult populations in Vietnam, 2015.
Methods
The Vietnam GATS 2015 was a nationally representative survey. 9513 households were selected ...using two-stage random systematic sampling method. Handheld computers were used for capturing data. Data collection was carried-out by National Statistics Office of Vietnam in 2015. Weight was used in all estimates.
Results
The Vietnam GATS 2015 found that the prevalence of smoking in Vietnam was 22.5% overall, 45.3% among men, and 1.1% among women. The overall 2015–2010 reduction in prevalence of any tobacco product was 5.3%. However, the reduction was not statistically significant. The significant reduction in prevalence of tobacco smoking was found for any type of cigarette (−8.4%), and especially for hand-rolled cigarettes (−38.3%). The use of cigarettes significantly decreased in urban areas (−14.7%).
Conclusion
The reduction in the prevalence of tobacco smoking in Vietnam during the last 5 years (2010–2015) has not been as high as expected, especially in rural areas. Further efforts are needed to continue to reduce the harms caused by tobacco smoking.
The COVID-19 pandemic and governments' response lead to dramatical change in quality of life worldwide. However, the extent of this change in Vietnamese medical and nursing students has not been ...documented.
The study aims to describe the quality of life and changes in quality of life of medical and nursing students during the COVID-19 pandemic and examine the association of quality of life and changes in quality of life with fear of COVID-19 and other socio-economic and demographic factors.
The study was a cross-sectional study on all students of Hanoi Medical University from 3 majors: General Medicine, Preventive Medicine, Nursing (3672 invited students); from 7th to 29th of April 2020; using an online questionnaire that included demographic and academic information, the Vietnamese version of the SF-36 Quality of Life questionnaire and the Fear of COVID-19 Scale (FCV-19S). Linear and modified Poisson regression was used to examine the association between quality of life, changes in quality of life and other factors.
The number of participants was 1583 (response rate 43%). Among 8 dimensions of the SF-36 (ranged 0-100), Vitality had the lowest score with a median score of 46. The median physical composite score (PCS) of the sample was 40.6 (IQR:20.8-53.2), 33.5% of the sample had an above-population average PCS score. The median mental composite score (MCS) of the sample was 20.3 (IQR:3.8-31.7), and 98.2% had an MCS score below average. 9.9% (95%CI:8.5%-11.4%) of the population reported a significant negative change in the quality of life. Fear of COVID-19 was not associated with significant changes in quality of life, nor MCS while having some association with PCS (Coef:-5.39;95%CI:-3to-7.8). Perceived reduction in quality of life was also associated with: being on clinical rotation COVID-19 (PR:1.5;95%CI:1.05-2.2), difficulties affording health services (PR:1.4;95%CI:1.02-1.95), obesity (PR:2.38;95%CI:1.08-5.25) and chronic disease (PR:1.92;95%CI:1.23-3), typical symptoms (PR:1.85; 95%CI:1.23-2.78) and atypical symptoms of COVID-19 (PR:2.32;95%CI:1.41-3.81).
The majority of medical and nursing students had below average quality of life, with lower vitality and mental composite health score in the settings of COVID-19. Perceived decrease in quality of life was associated with clinical rotation, difficulties affording healthcare services and was not associated with Fear of COVID-19.
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Here, we describe an in vitro strategy to model vascular morphogenesis where human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) are encapsulated in ...peptide-functionalized poly(ethylene glycol) (PEG) hydrogels, either on standard well plates or within a passive pumping polydimethylsiloxane (PDMS) tri-channel microfluidic device. PEG hydrogels permissive towards cellular remodeling were fabricated using thiol-ene photopolymerization to incorporate matrix metalloproteinase (MMP)-degradable crosslinks and CRGDS cell adhesion peptide. Time lapse microscopy, immunofluorescence imaging, and RNA sequencing (RNA-Seq) demonstrated that iPSC-ECs formed vascular networks through mechanisms that were consistent with in vivo vasculogenesis and angiogenesis when cultured in PEG hydrogels. Migrating iPSC-ECs condensed into clusters, elongated into tubules, and formed polygonal networks through sprouting. Genes upregulated for iPSC-ECs cultured in PEG hydrogels relative to control cells on tissue culture polystyrene (TCP) surfaces included adhesion, matrix remodeling, and Notch signaling pathway genes relevant to in vivo vascular development. Vascular networks with lumens were stable for at least 14days when iPSC-ECs were encapsulated in PEG hydrogels that were polymerized within the central channel of the microfluidic device. Therefore, iPSC-ECs cultured in peptide-functionalized PEG hydrogels offer a defined platform for investigating vascular morphogenesis in vitro using both standard and microfluidic formats.
Human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) cultured in synthetic hydrogels self-assemble into capillary networks through mechanisms consistent with in vivo vascular morphogenesis.
Here, we report the derivation of arterial endothelial cells from human pluripotent stem cells that exhibit arterial-specific functions in vitro and in vivo. We combine single-cell RNA sequencing of ...embryonic mouse endothelial cells with an EFNB2-tdTomato/EPHB4-EGFP dual reporter human embryonic stem cell line to identify factors that regulate arterial endothelial cell specification. The resulting xeno-free protocol produces cells with gene expression profiles, oxygen consumption rates, nitric oxide production levels, shear stress responses, and TNFα-induced leukocyte adhesion rates characteristic of arterial endothelial cells. Arterial endothelial cells were robustly generated from multiple human embryonic and induced pluripotent stem cell lines and have potential applications for both disease modeling and regenerative medicine.
Novel donor–acceptor (D-A) conjugated polymers containing phenothiazine and diketopyrrolopyrrole derivatives were successfully synthesized via direct arylation polymerization using the palladium ...catalyst system. The C-N coupling reaction was performed for the synthesis of 4-(10H-phenothiazin-10-yl)-N,N-diphenylaniline (PDA) and 10-(pyren-1-yl)-10H-phenothiazine (PYP) as donor monomers. The D-A conjugated polymers synthesized by polymerization of PDA/PY with diketopyrrolopyrrole have been characterized via GPC,
1
H NMR, FTIR, XRD, DSC, PL and UV-Vis spectroscopy, and used for fabrication of organic field effect transistors.
Graphical abstract
The novel D-A conjugated polymers containing phenothiazine derivatives and diketopyrrolopyrrole were successfully synthesized via direct (hetero)arylation polymerization. The obtained conjugated polymers have been applied for the fabrication of organic filed effect transistors. The conjugated polymers showed a hole mobility of 10
−5
cm2/Vs in top contact OFET devices.
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