Dietary antioxidants in the prevention of hepatocarcinogenesis: A review

In this review, the role of dietary antioxidants in the prevention of hepatocarcinogenesis is examined. Both human and animal models are discussed. Vitamin C, vitamin E, and selenium are antioxidants that are essential in the human diet. A number of non‐essential chemicals also contain antioxidant activity and are consumed in the human diet, mainly as plants or as supplements, including β‐carotene, ellagic acid, curcumin, lycopene, coenzyme Q₁₀, epigallocatechin gallate, N‐acetyl cysteine, and resveratrol. Although some human and animal studies show protection against carcinogenesis with the consumption of higher amounts of antioxidants, many studies show no effect or an enhancement of carcinogenesis. Because of the conflicting results from these studies, it is difficult to make dietary recommendations as to whether consuming higher amounts of specific antioxidants will decrease the risk of developing hepatocellular carcinoma.     

Mercury and selenium retention in fly ashes: Influence of unburned particle content

Mercury and selenium are present as trace elements in coal and may be emitted to the environment in gas phase during coal conversion processes or be partially retained on the fly ashes. The present work explores the possibility that selenium may contribute to mercury capture in fly ashes in two different situations: firstly the power station itself, in order to evaluate the influence of typical working conditions, and secondly in a fixed bed of fly ashes enriched with Se, in order to study the capture of mercury in more severe conditions. It was found that the presence of selenium in fly ashes may improve their capacity to capture mercury. However, in the four fly ashes of different origin studied, selenium is not the most important component for mercury retention. In fact, the presence of selenium in fly ash samples enriched in unburned carbon does not have any significant effect on mercury retention.     

Effects of selenium supplementation on rat heart apex and right ventricle myocardia by using FTIR spectroscopy: A cluster analysis and neural network approach

The effects of selenium supplementation on apex and right ventricle myocardia of the rat heart were investigated using Fourier transform infrared (FTIR) spectroscopy by examining the changes in the frequency values of major absorptions arising from lipids and proteins. Cluster analysis was used to discriminate the selenium treated group from the control by utilizing two distinct spectral regions, belonging to absorptions arising from lipids and proteins, respectively. In addition, protein secondary structures were predicted using neural network analysis. The results suggest that selenium treatment at a non-toxic dose causes some significant structural alterations in lipids and proteins of rat heart apex and right ventricle myocardia, which might be revealing a slight deleterious effect of selenium supplementation.     

Interfacial electrochemistry and electrodeposition from some ionic liquids: In situ scanning tunneling microscopy, plasma electrochemistry, selenium and macroporous materials

In this paper we report on recent results from our group, namely on the interface ionic liquid/electrode, plasma electrochemistry and electrodeposition of selenium and of macroporous structures. Ionic liquids show an interesting and liquid dependent surface chemistry: in some liquids the long range “herringbone” superstructure of Au(1 1 1) is visible, in others it is not. Glow discharge plasmas can be employed as a contact free electrode to make nanoparticles in solutions, e.g. nanoparticles of germanium. Selenium can be electrodeposited from ionic liquids under environmental conditions in an open cell and both the red and the grey phases of selenium are feasible. With the help of self organized opal structures of polystyrene spheres macroporous materials of Ag, Al and conducting polymers can be made. The prospects and limits of ionic liquids in surface electrochemistry and electrodeposition are shortly discussed.     

基于Selenium对z/OS Management Facility自动化测试的研究与实现

研究并采用Selenium+Apache Ant+TestNG,编写出符合实际项目的自动化测试的类框架,并实现自动化测试,通过实验数据证明,自动化后可以使得测试结果更为稳定、可靠。     

Study of Blood Selenium Level in Thyroid Pathologies by Instrumental Neutron Activation Analysis

Abstract

Selenium deficiency constitutes a risk factor for several pathologies (congestive cardiomyopathie, cancer, etc.). It was shown, recently, that selenium is implied in thyroid metabolism. It constitutes the catalytic site of the enzymes intervening in thyroid hormone synthesis. In the present work, we determined concentrations of selenium in total blood of 39 patients suffering from thyroid pathologies (hyperthyroidism [HEP], hypothyrodism [HOP], simple goiter [SG]), and 29 normal controls using instrumental neutron activation analysis (INAA). The blood selenium concentrations of patients suffering from hyperthyroidism was 142.56±20.25 µg/L of total blood, which is significantly lower than that of normal controls (206.72±17.98 µg/L. p≤0.05). No significant differences were observed in the concentrations of Se in hypothyroidism (184.26±20.77 µg/L) and simple goiter groups (160.47±25.76 µg/L).     

Determination of the daily dietary selenium intake in Croatia

 Data about selenium (Se) concentrations in the environment and its daily dietary intake in Croatia are scarce. The aim of this study was to estimate daily dietary Se intake in a group of female subjects from the Zagreb area using three different approaches: direct measurement of Se in collected daily duplicate portions, daily dietary records and the indirect method of Se analysis in serum. The results were 33.2±8.82, 30.9±7.40 and 37.8±5.45 μg day^–1 (arithmetic mean ±SD) by duplicate portion, daily dietary records and the serum Se method, respectively. The results of dietary Se intake estimation showed that Se intake for the observed group of female subjects from Zagreb area is lower than in the majority of European countries, and lower than the value recommended by the World Health Organisation. Received: 17 May 1999     

电感耦合等离子体发射光谱法测定富硒酒中的硒含量

本文采用等离子体发射光谱法(ICP-AES)测定富硒白酒中硒元素含量。实验结果表明硒元素标准曲线线性关系良好,相关系数在0.9999以上,加标回收率在92%～109%之间,RSD(相对标准偏差)值低于3%。方法操作简便、快捷,且能同时测定铅、锰等多种金属元素,可用于富硒酒中硒的测定。