Investigation on the application of ZnO nanostructures to improve the optical performance of white light-emitting diodes

Though combining blue LED chips with yellow phosphor has been the most common method in white light-emitting diode (WLED) production, the attained angular correlated color temperature (CCT) uniformity is still poor. Thus, this article proposes to add ZnO nanostructures to WLED packages to promote the color uniformity of the WLEDs. The outcomes of the research demonstrate that utilizing ZnO at different amount can affect the scattering energy and the CCT deviations in WLEDs packages in different extents. Particularly, adding the node-like (N-ZnO), sheet-like (S-ZnO), and rod-like (R-ZnO) leads to the corresponding decreases of CCT deviations from 3455.49 K to 96.30 K, 40.03 K, and 60.09 K, respectively. Meanwhile, with 0.25% N-ZnO, 0.75% S-ZnO, and 0.25 % R-ZnO, WLED devices can achieve both better CCT homogeneity and lower reduction in luminous flux. The results of this article can be a valuable document for the manufacturer to use as reference in improving their WLED products

The application of dual-layer remote phosphor geometry in achieving higher color quality of WLEDs

If remote phosphor structures are put into comparison with conformal phosphor or in-cup phosphor, their luminous flux are better, but the color quality is not as elevated. This leads to an obvious need of a practical solution to enhance color quality. Therefore, many studies were carried out to achieve this purpose, and so is ours. We proposed using two layers of phosphor in WLEDs to achieve better rendering ability and chromatic performance. The identical WLEDs with different color temperatures, 5600 K-8500 K, were used and reported in this paper. Our research consists of two parts, which are placing a layer of red phosphor SrwFxByOz:Eu2+,Sm2+on the yellow YAG:Ce3+ phosphor layer at first, and then specifying an appropriate SrwFxByOz:Eu2+,Sm2+ concentration to reach the highest color performance. It is shown that with the contribution of SrwFxByOz:Eu2+,Sm2+,the color rendering index (CRI) and color quality scale (CQS) are increased. This can be explained by the increased amount of red light components in the WLEDs when the concentration of SrwFxByOz:Eu2+,Sm2+ was greater. However, excessive SrwFxByOz:Eu2+,Sm2+ will cause the reduction in the flux, which has been proven by the application of Mie scattering and the Lambert-Beer law. Therefore, the conclusion will present an optimal amount of SrwFxByOz:Eu2+,Sm2+ to obtain high color quality while minimizing the light loss

LAYERED O3-NaFe0.5Co0.5O2 AS HIGH CAPACITY AND LOW- COST MATERIAL FOR SODIUM ION BATTERIES

O3-NaFe0.5Co0.5O2 layered cathode material was synthesized by solid state reaction at 900 oC followed by a quenching step in argon atmosphere. The chemical composition and morphology of synthesized material were analyzed by Atomic Absorption Spectroscopy (AAS) and Scanning Electron Microscopy (SEM). The electrochemical properties were evaluated by Cyclic Voltammetry (CV) and charge-discharge cycling. The material NaFe0.5Co0.5O2 shows the sloped discharge curves with high flat voltage plateau and excellent cycling stability. The reversible capacity of about 120 mAh/g at rate C/10 and good capacity retention after 100 cycles were obtained

Assessing the efficacy and safety of magnesium sulfate for management of autonomic nervous system dysregulation in Vietnamese children with severe hand foot and mouth disease.

BACKGROUND: Brainstem encephalitis is a serious complication of hand foot and mouth disease (HFMD) in children. Autonomic nervous system (ANS) dysregulation and hypertension may occur, sometimes progressing to cardiopulmonary failure and death. Vietnamese national guidelines recommend use of milrinone if ANS dysregulation with Stage 2 hypertension develops. We wished to investigate whether magnesium sulfate (MgSO4) improved outcomes in children with HFMD if used earlier in the evolution of the ANS dysregulation (Stage 1 hypertension). METHODS: During a regional epidemic we conducted a randomized, double-blind, placebo-controlled trial of MgSO4 in children with HFMD, ANS dysregulation and Stage 1 hypertension, at the Hospital for Tropical Diseases in Ho Chi Minh city. Study participants received an infusion of MgSO4 or matched placebo for 72 h. We also reviewed data from non-trial HFMD patients in whom milrinone failed to control hypertension, some of whom received MgSO4 as second line therapy. The primary outcome for both analyses was a composite of disease progression within 72 h - addition of milrinone (trial participants only), need for ventilation, shock, or death. RESULTS: Between June 2014 and September 2016, 14 and 12 participants received MgSO4 or placebo respectively, before the trial was stopped due to futility. Among 45 non-trial cases with poorly controlled hypertension despite high-dose milrinone, 33 received MgSO4 while 12 did not. There were no statistically significant differences in the composite outcome between the MgSO4 and the placebo/control groups in either study (adjusted relative risk (95%CI) of [6/14 (43%) vs. 6/12 (50%)], 0.84 (0.37, 1.92), p = 0.682 in the trial and [1/33 (3%) vs. 2/12 (17%)], 0.16 (0.01, 1.79), p = 0.132 in the observational cohort). The incidence of adverse events was similar between the groups. Potentially toxic magnesium levels occurred very rarely with the infusion regime used. CONCLUSION: Although we could not demonstrate efficacy in these studies, there were no safety signals associated with use of 30-50 mg/kg/hr. MgSO4 in severe HFMD. Intermittent outbreaks of HFMD are likely to continue across the region, and an adequately powered trial is still needed to evaluate use of MgSO4 in controlling hypertension in severe HFMD, potentially involving a higher dose regimen. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01940250 (Registered 22 AUG 2013). Trial sponsor: University of Oxford

An assessment of irrigated rice cultivation with different crop establishment practices in Vietnam

Overuse of seed and chemical inputs is a major constraint for sustainable rice production in Vietnam. In this study, two seasons of field trials were conducted to compare different crop establishment practices for rice production in the Mekong River Delta using environmental and economic sustainability performance indicators. The indicators including energy efficiency, agronomic use efficiency, net income, and greenhouse gas emissions (GHGEs) were quantified based on four treatments including manual broadcast-seeding, blower seeding, drum seeding, and mechanized transplanting. Across the four treatments, yields ranged from 7.3–7.5 Mg ha−1 and 6.2–6.8 Mg ha−1 in the Winter-Spring (WS) and Summer-Autumn (SA) seasons, respectively. In comparison with direct seeding methods, mechanized transplanting decreased the seed rate by 40%. It also led to a 30–40% reduction in pesticide use during the main crop season (WS). Mechanized transplanting required higher inputs, including machine depreciation and fuel consumption, but its net energy balance, net income and GHGE were at a similar level as the other non-mechanized planting practices. Mechanized transplanting is a technology package that should be promoted to improve the economic and environmental sustainability of lowland rice cultivation in the Mekong River Delta of Vietnam

Tissue transglutaminase (TG2) enables survival of human malignant pleural mesothelioma cells in hypoxia

Malignant pleural mesothelioma (MPM) is an aggressive tumor linked to environmental/occupational exposure to asbestos, characterized by the presence of significant areas of hypoxia. In this study, we firstly explored the expression and the role of transglutaminase 2 (TG2) in MPM cell adaptation to hypoxia. We demonstrated that cells derived from biphasic MPM express the full-length TG2 variant at higher levels than cells derived from epithelioid MPM and normal mesothelium. We observed a significant induction of TG2 expression and activity when cells from biphasic MPM were grown as a monolayer in chronic hypoxia or packed in spheroids, where the presence of a hypoxic core was demonstrated. We described that the hypoxic induction of TG2 was HIF-2 dependent. Importantly, TGM2-v1 silencing caused a marked and significant reduction of MPM cell viability in hypoxic conditions when compared with normoxia. Notably, a TG2-selective irreversible inhibitor that reacts with the intracellular active form of TG2, but not a non-cell-permeable inhibitor, significantly compromised cell viability in MPM spheroids. Understanding the expression and function of TG2 in the adaptation to the hypoxic environment may provide useful information for novel promising therapeutic options for MPM treatment

Nanoflake Manganese Oxide and Nickel-Manganese Oxide Synthesized by Electrodeposition for Electrochemical Capacitor

Nanoflake structures of electrochemical manganese oxide (EMD) and nickel mixed manganese oxide (NiMD) were directly deposited on a stainless steel by using Chronoamperometry and Cyclic Voltammetry (CV) techniques. The structure, morphology, and capacitive behavior of EMD or NIMD nanoflake were affected by the electrodeposition modes and deposition time. The highest specific capacitance (Csp) was obtained for only two-minute deposition by both methods. EMD nanoflakes electrodeposited by CV technique show higher specific capacitance values than those prepared by Chronoamperometry owing to its homogenous and highly porous surface. All EMD samples exhibited excellent cycle behavior, less than 5% capacitance loss after 1000 cycles. Ni mixed MnO2 was prepared at different Mn2+/Ni2+ ratios for 2 minutes of electrodeposition. The presence of Ni2+ ion enhanced the Csp value at high charge-discharge rate due to the decrease of the charge transfer resistance. The supercapacitor prototype of 2 cm × 2 cm was assembled using EMD and NiMD as electrode material and tested at 1 A·g−1

A third new Cyrtodactylus (Squamata: Gekkonidae) from Ba Den Mountain, Tay Ninh Province, southern Vietnam

Phung, Trung My, Schingen, Mona Van, Ziegler, Thomas, Nguyen, Truong Quang (2014): A third new Cyrtodactylus (Squamata: Gekkonidae) from Ba Den Mountain, Tay Ninh Province, southern Vietnam. Zootaxa 3764 (3): 347-363, DOI: 10.11646/zootaxa.3764.3.