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The effects of toxic effects of cadmium and lead on vegetation are revealed. As the experimental culture selected rice, cultivated in the site Long-Khanh in Vietnam. The experimental system included the saturation of soil samples with solutions of toxic metals in 7 concentration levels. As assessment criteria are determined: growth, ramification of rice, the state of the root system, the definition of places of maximum accumulation. The patterns of toxicological effects of lead and cadmium are revealed. Concentration of Cd2+ 0.1 mg/kg stimulates growth, as well as ramification of rice. The concentration of Cd2+ ≥ 30 mg/kg inhibits plant growth. Pb2+ < 10 mg/kg can promote plant growth, increase plant productivity (stimulate very high branched rice, increase root length). At higher concentrations, the tillering tendency tends to decrease. Coefficients of concentrations between pollution levels and estimated state criteria were determined. They characterize the high levels of interconnections from 0.7 to 0.9. Levels of accumulation of heavy metals in parts of plants are revealed. The maximum values are determined in the branches, leaves and roots. The accumulation of Pb in ecosystems is higher than Cd.

An extremely dynamic morphology of the estuary is observed in the coastal regions of Vietnam under the governing processes of tides, waves, and river system flows. The primary target of this paper is to provide insight into the governing processes and morphological behavior of the NhatLe estuary, located in the north-central coast of Vietnam. Based on measured data from field surveys and satellite images combined with numerical model simulations of MIKE and Delft3D, the influences of seasonal river flow, tides, and wave dynamics on the sediment transport and morphological changes are fully examined. The study showed that freshwater flow in the flood season plays a central role in cutting off the southern sandspit, maintain and shaping the main channel. The prevailing waves in winter and summer induce longshore drift and sediment transport in the southeast to northwest direction. In the low flow season, this longshore sediment transport is dominant, causing sediment to deposit on the southern side of the ebb tidal delta and elongating the southern sandspit which narrows the estuary entrance and reorients the main channel.

New (1-x)Bi0.5Na0.5TiO3 + xCaFeO3-δ solid solution compounds were fabricated using a sol–gel method. The CaFeO3-δ materials were mixed into host Bi0.5Na0.5TiO3 materials to form a solid solution that exhibited similar crystal symmetry to those of Bi0.5Na0.5TiO3 phases. The random distribution of Ca and Fe cations in the Bi0.5Na0.5TiO3 crystals resulted in a distorted structure. The optical band gaps decreased from 3.11 eV for the pure Bi0.5Na0.5TiO3 samples to 2.34 eV for the 9 mol% CaFeO3-δ-modified Bi0.5Na0.5TiO3 samples. Moreover, the Bi0.5Na0.5TiO3 samples exhibited weak photoluminescence because of the intrinsic defects and suppressed photoluminescence with increasing CaFeO3-δ concentration. Experimental and theoretical studies via density functional theory calculations showed that pure Bi0.5Na0.5TiO3 exhibited intrinsic ferromagnetism, which is associated with the possible presence of Bi, Na, and Ti vacancies and Ti3+-defect states. Further studies showed that such an induced magnetism by intrinsic defects can also be enhanced effectively with CaFeO3-δ addition. This study provides a basis for understanding the role of secondary phase as a solid solution in Bi0.5Na0.5TiO3 to facilitate the development of lead-free ferroelectric materials.

The objective of the article is the discussion the different behaviors of several concrete types based on the DIC method. The three various concrete mixes were tested. They include two ordinary Portland cemented concrete mixtures having difference concrete grades and another concrete in which the steel slag replaced for coarse aggregate. During the beam-bending test, strain contour plots on the surface of reinforcement concrete beams and the crack development were captured of the digital image correlation (DIC) technique. The DIC method was verified by comparing the actual strain measured from the strain gauge and that determined from DIC. The results show the feasibility of using this method for present the strain contour plots of the reinforcement concrete beams. The crack development in various mixtures of concrete was compared and discussed within the article.

We characterized the photosynthetic growth of wild-type (WT) and QC-site mutant cells of the cyanobacterium Synechocystis sp. PCC 6803 grown in a photobioreactor under medium-intensity [~70 μmol(photon) m–2 s–1] and high-intensity [~200 μmol(photon) m–2 s–1] light conditions. Photosynthetic growth rate (the exponential phase) increased about 1.1–1.2 fold for the A16FJ, S28Aβ, and V32Fβ mutant compared with WT cells under medium-intensity light and about 1.2–1.3 fold under high-intensity light. Biomass production increased about 17–20% for A16FJ and S28Aβ mutant cells as compared with WT cells under medium-intensity light and about 14–17% for A16FJ and V32Fβ mutant cells under high-intensity light. The greater photosynthetic growth rate and biomass production of these QC-site mutant cells could be attributed to the increased photosynthesis efficiency and decreased dissipation of wasteful energy from phycobilisomes in mutants vs. WT cells. Our results support that manipulation of photoprotection may improve photosynthesis and biomass production of photosynthetic organisms.

New (1-x)Bi0.5Na0.5TiO3 + xCaFeO3-δ solid solution compounds were fabricated using a sol–gel method. The CaFeO3-δ materials were mixed into host Bi0.5Na0.5TiO3 materials to form a solid solution that exhibited similar crystal symmetry to those of Bi0.5Na0.5TiO3 phases. The random distribution of Ca and Fe cations in the Bi0.5Na0.5TiO3 crystals resulted in a distorted structure. The optical band gaps decreased from 3.11 eV for the pure Bi0.5Na0.5TiO3 samples to 2.34 eV for the 9 mol% CaFeO3-δ-modified Bi0.5Na0.5TiO3 samples. Moreover, the Bi0.5Na0.5TiO3 samples exhibited weak photoluminescence because of the intrinsic defects and suppressed photoluminescence with increasing CaFeO3-δ concentration. Experimental and theoretical studies via density functional theory calculations showed that pure Bi0.5Na0.5TiO3 exhibited intrinsic ferromagnetism, which is associated with the possible presence of Bi, Na, and Ti vacancies and Ti3+-defect states. Further studies showed that such an induced magnetism by intrinsic defects can also be enhanced effectively with CaFeO3-δ addition. This study provides a basis for understanding the role of secondary phase as a solid solution in Bi0.5Na0.5TiO3 to facilitate the development of lead-free ferroelectric materials.

The aim of this study was to investigate the impact of gender on outcomes among adult burn patients. A retrospective study was conducted on 5061 adult burn patients (16 - 64 years old) admitted to the Vietnam National Burn Hospital over a three-year period (2016 - 2018). Demographic data, burn features and outcome including complications, length of hospital stay and mortality of male and female groups were compared. Results indicated that male patients were predominant (72.8%), younger (35.5 vs. 37.2 years old; p.001) and admitted sooner to hospital. A greater number of males suffered electrical and flame/heat direct contact injuries, whereas more females suffered scald injury (34.7% vs. 12.2%; p.001). Burn extent was larger among males (14.9% vs. 12.1%; p.001). In addition, a higher proportion of deep burn injuries (44.8% vs. 41.2%; p.05) and number of surgeries (1.2 vs. 1; p.05), and longer hospital stay (17.8 vs. 15.8 days; p.001) was recorded among the male group. Post burn complication and overall mortality rate did not differ between the two groups. However, death rate was remarkably higher in the female group when burn extent was ≥ 50% TBSA (72.4% vs. 57.3%; p.05). In conclusion, burn features and outcomes were not similar between the male and female group. Male patients appear to suffer more severe injury requiring more surgeries and longer hospital stay. However, more attention should be paid to the significantly higher mortality rate among females with extensive burn.Le but de ce travail était d’étudier l’impact du sexe sur le devenir d’adultes brûlés. Cette étude rétrospective a été conduite sur 5 601 patients âgés de 16 à 64 ans admis dans le CTB national du Vietnam entre 2016 et 2018 inclus. Les données démographiques, celles concernant la brûlure, les complications, la durée d’hospitalisation et la mortalité ont été comparées selon le sexe des patients. Les hommes prédominent (72,8%), sont plus jeunes (35,5 VS 37,2 ans - p0,001) et sont hospitalisés plus rapidement. Les ébouillantements sont plus fréquents chez les femmes (34,7 VS 12,2% - p0,001), les autres causes (électriques, flammes, contact) étant donc plus habituelles chez les hommes. Les brûlures des hommes sont plus étendues (14,9 VS 12,1% SCB - p0,001), plus profondes (44,8% de profond VS 41,2% - p0,05 ; 1,2 séances chirurgicales VS 1 - p0,05) et leur durée de séjour est plus longue (17,8 VS 15,8 j - p0,001). Le nombre de complications et la mortalité sont comparables. Toutefois, la mortalité des femmes brûlées sur ≥ 50% SCT était nettement plus élevée que celle des hommes (72,4% VS 57,3% - p0,05). En conclusion, les hommes ont des brûlures plus sévères nécessitant plus d’interventions chirurgicales et une hospitalisation plus longue. Il faut cependant être attentifs à la mortalité élevée des femmes extensivement brûlées.

Geo-ecological assessments are widely used in the practice of modern environmental management. Dong Nai has favorable geographical features for developing high quality agriculture. The analyzed data indicated that the northeast region has prospects for agricultural development with food crops and fruit trees. The south and southwest areas are suitable for industrial-urban development combined with the development of perennial industrial crops. Organic agriculture will be the main trend in agricultural production of Dong Nai province, in order to improve the efficiency of agriculture and maintain the ecological environmental quality.

In this letter, we report, for the first time, an experimental study on improving modulation rate of a ZnSe-based white light emitting diode (LED). The white LED exhibits a color temperature of $\sim 6400$ K ( ${x}$ = 0.31 and ${y}$ = 0.37), which is almost independent of the injected current. In order to improve the LED’s modulation rate, we use peaking and carrier sweep-out effects generated by our proposed current-shaping circuit. The experimental results confirm that we can significantly improve the ON–OFF keying modulation rate of a 30 MHz-bandwidth ZnSe-based white LED by a factor of 7. An error free transmission link has been demonstrated at a data rate of 400 Mb/s.

Casein kinase 1 delta and epsilon (CK1δ/ɛ) are key regulators of diverse cellular growth and survival processes including Wnt signaling, DNA repair and circadian rhythms. Recent studies suggest that they have an important role in oncogenesis. RNA interference screens identified CK1ɛ as a pro-survival factor in cancer cells in vitro and the CK1δ/ɛ-specific inhibitor IC261 is remarkably effective at selective, synthetic lethal killing of cancer cells. The recent development of the nanomolar CK1δ/ɛ-selective inhibitor, PF670462 (PF670) and the CK1ɛ-selective inhibitor PF4800567 (PF480) offers an opportunity to further test the role of CK1δ/ɛ in cancer. Unexpectedly, and unlike IC261, PF670 and PF480 were unable to induce cancer cell death. PF670 is a potent inhibitor of CK1δ/ɛ in cells; nanomolar concentrations are sufficient to inhibit CK1δ/ɛ activity as measured by repression of intramolecular autophosphorylation, phosphorylation of disheveled2 proteins and Wnt/β-catenin signaling. Likewise, small interfering RNA knockdown of CK1δ and CK1ɛ reduced Wnt/β-catenin signaling without affecting cell viability, further suggesting that CK1δ/ɛ inhibition may not be relevant to the IC261-induced cell death. Thus, while PF670 is a potent inhibitor of Wnt signaling, it only modestly inhibits cell proliferation. In contrast, while sub-micromolar concentrations of IC261 neither inhibited CK1δ/ɛ kinase activity nor blocked Wnt/β-catenin signaling in cancer cells, it caused a rapid induction of prometaphase arrest and subsequent apoptosis in multiple cancer cell lines. In a stepwise transformation model, IC261-induced killing required both overactive Ras and inactive p53. IC261 binds to tubulin with an affinity similar to colchicine and is a potent inhibitor of microtubule polymerization. This activity accounts for many of the diverse biological effects of IC261 and, most importantly, for its selective cancer cell killing.

Japanese encephalitis (JE) occurs in rural settings in southern and eastern Asia, where diagnostic facilities are limited. For the diagnosis of JE virus (JEV) infection, we developed a nitrocellulose membrane-based immunoglobulin M (IgM) capture dot enzyme immunoassay (MAC DOT) that is rapid, simple to use, requires no specialized equipment, and can distinguish JEV from dengue infection. In a prospective field study in southern Vietnam, 155 cerebrospinal fluid (CSF) and 341 serum samples were collected from 111 children and 83 adults with suspected encephalitis. The JEV MAC DOT, performed on site, was scored visually from negative to strongly positive by two observers, and the results were compared subsequently with those of the standard IgM capture enzyme-linked immunosorbent assay. For the 179 patients with adequate specimens, the MAC DOT correctly identified 59 of 60 JEV-positive patients and 118 of 119 JEV-negative patients (sensitivity [95% confidence intervals], 98.3% [92.1 to 99.9%]; specificity, 99.2% [95.9 to 100.0%]; positive predictive value, 0.98; negative predictive value, 0.99). The MAC DOT also correctly identified three patients with dengue encephalopathy. Admission specimens were positive for 73% of JE patients. Interobserver agreement for MAC DOT diagnosis was excellent (kappa = 0.94). The JEV MAC DOT is a simple and reliable rapid diagnostic test for JE in rural hospitals.

Malaria is still the most common infectious cause of mortality and morbidity in Viet Nam as it is in many developing countries in the tropics. The presence of resistance to available antimalarials and compliance in the target population are factors that influence the choice of drugs and regimens. In order to develop an ideal treatment for malaria, we conducted several clinical trials in patients with the disease in different settings. The results of these trials suggest that a combination of single dose artemisinin (or its derivatives) and mefloquine is the most effective, safe and practical treatment for acute non-complicated malaria due to multidrug-resistant Plasmodium falciparum. Concerning severe and complicated malaria, parenteral or rectal multi-doses of artemisinin or analogues are recommended due to their rapid parasite clearance time and other possible anti-cytoadherence effects. With its rapid parasite clearance, very early treatment of uncomplicated cases with artemisinin (and derivatives), especially at a health post level may help to prevent the development of complications, consequently reducing the number of severe cases and the malaria mortality rate.

This paper studies the nonlinear coupling between an ion—acoustic wave and two Alfvén waves. On the basis of the MHD equations, this three-wave interaction is described within the coupled normal-mode theory. It is shown that a largeamplitude acoustic wave can decay into a pair of Alfvén waves in a high-β plasma. Calculations of the threshold condition and the maximum growth rate suggest that this decay process may occur both in the laboratory and in the ionosphere.

The nonlinear interaction between two Alfvén waves and a sound wave is studied, using the normal-mode approach. This leads, in a simple way to a set of coupled equations, and consequently to a dispersion relation for the waves under consideration. It is shown that a large-amplitude Alfvén wave can give rise to two distinct types of parametric instabilities, namely the oscillating and the purely growing waves. In each case, the expressions for the threshold pump intensity, the frequency shift and the growth rate of the excited waves are obtained. In particular, the results for a propagating pump under perfect frequency matching conditions are compared with those of Sagdeev & Galeev.

Weak nonlinear interactions are studied for systems of internal waves when the Brunt-Väisälä frequency is proportional to sech z, where z = 0 is the centre of the thermocline. Explicit results expressed in terms of gamma functions have been obtained for the interaction coefficients appearing in the amplitude evolution equations. The cases considered include resonant triads as well as second and third harmonic resonance. In the non-resonant situation, the Stokes frequency correction due to finite-amplitude effects has been computed and the extension to wave packets is outlined. Finally, the effect of a mean shear on resonant interactions is discussed.

A technique is presented for the analysis of deflection and stresses in helical compression or tension springs of rectangular cross-section. The technique consists in analysing a cylinder cut radially. Using theory of elasticity, a stress system is determined which gives as the resultant over any terminal cross-section, a single force parallel to the axis of the cylinder. In addition, the case where a resulting couple exists on the ends of the cylinder is analysed. If the pitch angle of the spring is neglected, the stresses in a helical spring are obtained. The deflection and stresses are evaluated in terms of the dimensions of the spring and compared with the results of other theories.

Reference CRPP-ARTICLE-1975-010View record in Web of Science Record created on 2008-04-16, modified on 2017-05-12