Arsenic intake via water and food by a population living in an arsenic-affected area of Bangladesh

More and more people in Bangladesh have recently become aware of the risk of drinking arsenic-contaminated groundwater, and have been trying to obtain drinking water from less arsenic-contaminated sources. In this study, arsenic intakes of 18 families living in one block of a rural village in an arsenic-affected district of Bangladesh were evaluated to investigate their actual arsenic intake via food, including from cooking water, and to estimate the contribution of each food category and of drinking water to the total arsenic intake. Water consumption rates were estimated by the self-reporting method. The mean drinking water intake was estimated as about 3 L/d without gender difference. Arsenic intakes from food were evaluated by the duplicate portion sampling method. The duplicated foods from each family were divided into four categories (cooked rice, solid food, cereals for breakfast, and liquid food), and the arsenic concentrations of each food category and of the drinking water were measured. The mean arsenic intake from water and food by all 18 respondents was 0.15 +/-0.11 mg/d (range, 0.043 - 0.49), that by male subjects was 0.18 +/- 0.13 mg/d (n = 12) and that by female subjects was 0.096 +/- 0.007 mg/d (n = 6). The average contributions to the total arsenic intake were, from drinking water, 13%; liquid food, 4.4%; cooked rice, 56%; solid food, 11%; and cereals, 16%. Arsenic intake via drinking water was not high despite the highly contaminated groundwater in the survey area because many families had changed their drinking water sources to less-contaminated ones. Instead, cooked rice contributed most to the daily arsenic intake. Use of contaminated water for cooking by several families was suspected based on comparisons of arsenic concentrations between drinking water and liquid food, and between rice before and after cooking. Detailed investigation suggested that six households used contaminated water for cooking but not drinking, leading to an increase of arsenic intake via arsenic-contaminated cooking water.     

基于GIS区域边坡失稳灾害预测与评价

 滑坡和泥石流是边坡失稳后两种主要的运动方式,是山区重大的地质灾害。对既往滑坡和泥石流进行研究,以此作为基础来预测和评价本地区潜在的滑坡和泥石流灾害,是防灾减灾的一个重要措施。大多数泥石流是在强降雨的情况下,由滑坡滑入山谷河道而形成的。基于地理信息系统(GIS)和数值模型相结合的方法,采用两步骤方法预测和评价日本熊本县水俣市宝川区集地区的滑坡和泥石流灾害。首先分析该区域可能存在的新滑坡,然后假定这些滑坡在遇到强降雨时形成泥石流,利用数值模拟流动过程分析其在三维复杂地形下的泛滥过程,预测可能受害的房屋和路段。     

Dietary conjugated linoleic acid increases endurance capacity and fat oxidation in mice during exercise

Ingestion of CLA activates β-oxidation and causes loss of body fat in rodents. We investigated the effects of dietary CLA on endurance capacity and energy metabolism during exercis in mice. Five-week-old male BALB/c mice were fed a control diet containing 1.0% linoleic acid or a diet containing 0.5% CLA that replaced an equivalent amount of linoleic acid for 1 wk. The maximum swimming time until fatigue was significantly higher in the CLA-fed group than in the control group. During treadmill running, the respiratory exchange ratio was significantly lower in the CLA-fed group, but oxygen consumption did not differ significantly between groups, suggesting that FA contributed more as an energy substrate in the CLA-fed mice. The muscle lipoprotein lipase activity was significantly higher in the CLA-fed group than in the control group. These results suggest that CLA ingestion increases endurance exercise capacity by promoting fat oxidation during exercise.     

Nuclear magnetic relaxation studies of coal

The techniques of both pulsed nuclear magnetic resonance (n.m.r.) and electron spin resonance (e.s.r.) were applied to clarify the nature of coal. The spin-lattice relaxation time (T_1n) and the spin-spin relaxation time (T_2n) for protons were measured. At room temperature T_1n varies with rank of coal and shows a maximum value at about 86% carbon of coal. The values of T_1n for the samples selected increase in the order of extraction residue, parent coal and pyridine extract respectively. The variation of T_1n during solvent treatment reflects the different circumstances of protons in such a heterogeneous system as coal. From spin-spin relaxation time (T_2n) measurements two relaxation regions, that is an immobile region and a relatively free one, are deduced.     

A general procedure for first/second-order reliabilitymethod (FORM/SORM)

First/second-order reliability method (FORM/SORM) is considered to be one of the most reliable computational methods for structural reliability. Its accuracy is generally dependent on three parameters, i.e. the curvature radius at the design point, the number of random variables and the first-order reliability index. In the present paper, the ranges of the three parameters for which FORM/SORM is accurate enough are investigated. The results can help us to judge when FORM is accurate enough, when SORM is required and when an accurate method such as the inverse fast Fourier transformation (IFFT) method is required. A general procedure for FORM/SORM is proposed which includes three steps: i.e. point fitting limit state surface, computation of the sum of the principal curvatures K_s and failure probability computation according to the range of K_s. The procedure is demonstrated by several examples.     

Moment methods for structural reliability

First-order reliability method (FORM) is considered to be one of the most reliable computational methods. In the last decades, researchers have examined the shortcomings of FORM, primarily accuracy and the difficulties involved in searching for the design point by iteration using the derivatives of the performance function. In order to improve upon FORM, several structural reliability methods have been developed based on FORM, such as second-order reliability method (SORM), importance sampling Monte-Carlo simulation, first-order third-moment reliability method (FOTM), and response surface approach (RSA). In the present paper, moment methods for structural reliability are investigated. Five moment method formulas are presented and investigated, and the accuracy and efficiency of these methods are demonstrated using numerical examples. The moment methods, being very simple, have no shortcomings with respect to design points, and requires neither iteration nor the computation of derivatives, and thus are convenient to be applied to structural reliability analysis.     

5-Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence Imaging for Tumor Detection: Recent Advances and Challenges

5-Aminolevulinic acid (5-ALA) is a natural amino acid and a precursor of heme and chlorophyll. Exogenously administered 5-ALA is metabolized into protoporphyrin IX (PpIX). PpIX accumulates in cancer cells because of the low activity of ferrochelatase, an enzyme that metabolizes PpIX to heme. High expression of 5-ALA influx transporters, such as peptide transporters 1/2, in cancer cells also enhances PpIX production. Because PpIX radiates red fluorescence when excited with blue/violet light, 5-ALA has been used for the visualization of various tumors. 5-ALA photodynamic diagnosis (PDD) has been shown to improve the tumor removal rate in high-grade gliomas and non-muscular invasive bladder cancers. However, 5-ALA PDD remains a challenge as a diagnostic method because tissue autofluorescence interferes with PpIX signals in cases where tumors emit only weak signals, and non-tumorous lesions, such as inflammatory sites, tend to emit PpIX fluorescence. Here, we review the current outline of 5-ALA PDD and strategies for improving its diagnostic applicability for tumor detection, focusing on optical techniques and 5-ALA metabolic pathways in both viable and necrotic tumor tissues.     

Suppressive effect of magnesium oxide materials on cadmium accumulation in winter wheat grain cultivated in a cadmium-contaminated paddy field under annual rice–wheat rotational cultivation

The effectiveness of two kinds of magnesium oxide (MgO) materials, commercial MgO (2250 kg ha⁻¹) and a material derived from MgO and magnesium silicate minerals named ‘MgO-SH-A’ (2250 and 4500 kg ha⁻¹1), in suppression of uptake and accumulation of cadmium (Cd) into grain of winter wheat (Triticum aestivum L. cv. Ayahikari) was examined in a Cd-contaminated alluvial paddy field under annual rice–wheat rotational system. The MgO materials were mixed into the plough-layer soil only once prior to the preceding rice cultivation. Cadmium concentration in wheat grain produced from the non-amendment control exceeded the maximum limit of Cd in wheat grain adopted by FAO/WHO (0.2 mg kg⁻¹). All of the treatments with the MgO materials significantly lowered plant available Cd fraction in the plough-layer soil. However, only the treatment with the commercial MgO at 2250 kg ha⁻¹ produced wheat grain whose Cd concentration was not only significantly lower than that from the control but also less than 0.2 mg kg⁻¹. It is suggested that the significant suppressive effect of the commercial MgO on Cd accumulation in wheat grain would be mainly attributed to its high soil neutralizing capacity as compared to that of MgO-SH-A.     

Synthesis of Y2O3 films on an aluminum alloy substrate using flame-spray apparatus with a H2-O2 flame

Y₂O₃ films were synthesized on an aluminum alloy (A5052) substrate directly using a flame-spray apparatus with a H₂-O₂ flame. The Y₂O₃/A5052 joining was also annealed under atmospheric conditions. Although the joining was annealed close to the melting point of the A5052 substrate, the joining showed strong adhesion without delaminations. The resultant Y₂O₃ coating exhibits a strong adhesion with the aluminum alloy substrate. Elemental diffusion in the joining was not observed from cross-sectional EDX analysis. Directly ceramic film deposition method by a reactive spraying process was proposed.