BACKGROUND & AIMS: :The lack of highly efficient, inexpensive catalysts severely hinders large-scale application of electrochemical hydrogen evolution reaction (HER) for producing hydrogen. MoS2 as a low-cost candidate suffers from low catalytic performance. Herein, taking advantage of its tri-layer structure, we report a MoS2 nanofoam catalyst co-confining selenium in surface and cobalt in inner layer, exhibiting an ultra-high large-current-density HER activity surpassing all previously reported heteroatom-doped MoS2. At a large current density of 1000 mA cm-2, a much lower overpotential of 382 mV than that of 671 mV over commercial Pt/C catalyst is achieved and stably maintained for 360 hours without decay. First-principles calculations demonstrate that inner layer-confined cobalt atoms stimulate neighbouring sulfur atoms while surface-confined selenium atoms stabilize the structure, which cooperatively enable the massive generation of both in-plane and edge active sites with optimized hydrogen adsorption activity. This strategy provides a viable route for developing MoS2-based catalysts for industrial HER applications.

背景与目标： : 缺乏高效，廉价的催化剂严重阻碍了电化学析氢反应 (HER) 用于制氢的大规模应用。MoS2作为一种低成本候选产品，催化性能低下。在此，利用其三层结构，我们报告了一种MoS2纳米foam催化剂，将硒共约束在表面和钴在内层，表现出超高的大电流密度HER活性，超过了所有先前报道的杂原子掺杂MoS2。在1000  ma   cm-2的大电流密度下，在商用Pt/C催化剂上实现了比671  mV低得多的382  mV的过电位，并稳定地保持360小时而没有衰减。第一性原理计算表明，内层约束的钴原子会刺激相邻的硫原子，而表面约束的硒原子会稳定结构，从而可以协同产生大量的面内和边缘活性位点，并具有优化的氢吸附活性。该策略为开发用于工业HER应用的MoS2-based催化剂提供了可行的途径。

BACKGROUND & AIMS: :The ELISPOT assay is increasingly being used for the monitoring of the induction of antigen-reactive T cells in cancer vaccination trials. In order to evaluate the reliability of T cell frequency analysis with the ELISPOT assay, a comparative study was performed in four European laboratories. Six samples from healthy subjects were analyzed for the frequency of influenza-reactive CD8+ T cells in peripheral blood mononuclear cells (PBMC) by IFNgamma-ELISPOT assay. In addition, one laboratory determined cytotoxic T cell precursor (CTL) frequencies in these samples by limiting dilution chromium-release assay (LDA), and three laboratories performed a variant of the LDA, the multiple microculture assay (MMA). Consistent frequencies of influenza peptide-reactive T cells were obtained with the ELISPOT assay in all four laboratories. The numbers detected by ELISPOT assay correlated closely with those determined by LDA. In contrast, the frequencies obtained with the MMA differed considerably and showed little correlation with the other two assays. This study shows that it is possible to use the ELISPOT assay to determine with reliability antigen-reactive T cells in a multicenter setting. We suggest that this assay may be suitable for monitoring cancer vaccine trials.

背景与目标： : ELISPOT测定法越来越多地用于监测癌症疫苗接种试验中抗原反应性T细胞的诱导。为了评估使用ELISPOT测定法进行T细胞频率分析的可靠性，在四个欧洲实验室进行了比较研究。通过IFNgamma-ELISPOT测定法分析了来自健康受试者的六个样本的外周血单核细胞 (PBMC) 中流感反应性CD8 T细胞的频率。此外，一个实验室通过限制稀释铬释放测定 (LDA) 确定了这些样品中的细胞毒性T细胞前体 (CTL) 频率，三个实验室进行了LDA的变体，即多重微培养测定 (MMA)。在所有四个实验室中，通过ELISPOT测定法获得了一致的流感肽反应性T细胞频率。ELISPOT测定法检测到的数字与LDA测定的数字密切相关。相反，用MMA获得的频率差异很大，并且与其他两种测定几乎没有相关性。这项研究表明，可以使用ELISPOT测定法在多中心环境中可靠地确定抗原反应性T细胞。我们建议该测定法可能适用于监测癌症疫苗试验。

BACKGROUND & AIMS: :The present work demonstrates the heavy metal resistance and detoxification of Cr(VI) by the probiotic actinobacterial cultures isolated from chicken and goat feces. The actinobacterial isolates were screened for heavy metal resistance by qualitative, semiquantitative assays and Cr(VI) biosorption was determined by analytical techniques such as atomic absorption spectrophotometry and Fourier transform infrared spectrometry (FT-IR). All the tested actinobacterial isolates (n = 20) showed resistance toward K2Cr2O7, NiCl2, ZnCl2, CuSO4 and PbNO3 at 20 mg L-1 concentration. The maximum tolerance concentration values were found to be 200-250 mg L-1 for K2Cr2O7, 100-250 mg L-1 for PbNO3 and <50-250 mg L-1 for NiCl2, ZnCl2 and CuSO4. Among the five tested heavy metals, Cr(VI) was resisted by 95 % of the tested actinobacterial cultures up to 250 mg L-1 concentration; particularly, the isolate LD22 exhibited a high degree of tolerance to all the tested heavy metals. Thus, the isolate was justifiably chosen for Cr(VI) biosorption study and the biosorption efficacy was found maximum at 100 mg L-1 of metal ion concentration (3 g L-1 of biomass dosage and pH 7.0). FT-IR spectrum revealed the chemical interactions between the hydroxyl, amine and carboxyl groups of the biomass and the metal ions. On the basis of phenotypic, physiological, biochemical and molecular characteristics the isolate LD22 was identified as Streptomyces werraensis LD22 (JX524481) which could be used to develop a biosorbent for adsorbing Cr(VI) metal ions.

背景与目标： : 本工作证明了从鸡和山羊粪便中分离出的益生菌放线菌培养物对Cr(VI) 的重金属抗性和解毒作用。通过定性，半定量分析筛选放线菌分离株的重金属抗性，并通过原子吸收分光光度法和傅里叶变换红外光谱法 (ft-ir) 等分析技术测定Cr(VI) 的生物吸附。所有测试的放线菌分离株 (n = 20) 在20 mg L-1浓度下均显示出对K2Cr2O7，NiCl2，ZnCl2，CuSO4和PbNO3的抗性。发现最大耐受浓度值对于K2Cr2O7为200-250 mg L-1，对于PbNO3为100-250 mg L-1，对于NiCl2，ZnCl2和cuso4为 <50-250 mg L-1。在五种测试的重金属中，Cr(VI) 被95% 测试的放线菌培养物抵抗高达250 mg L-1浓度; 特别地，分离物LD22对所有测试的重金属表现出高度的耐受性。因此，合理地选择分离物进行Cr(VI) 生物吸附研究，发现在L-1 100 mg金属离子浓度 (3g L-1生物质剂量和pH 7.0) 时，生物吸附效力最大。Ft-ir光谱揭示了生物质的羟基，胺和羧基与金属离子之间的化学相互作用。根据表型，生理，生化和分子特征，将分离物LD22鉴定为werraensis链霉菌LD22 (JX524481)，可用于开发吸附Cr(VI) 金属离子的生物吸附剂。

BACKGROUND & AIMS: :With the increasing human exposure to nanoparticles (NP), the evaluation of their genotoxic potential is of significant importance. However, relevance for NP of the routinely used in vitro genotoxicity assays is often questioned, and a nanoparticulate reference positive control would therefore constitute an important step to a better testing of NP, ensuring that test systems are really appropriate. In this study, we investigated the possibility of using tungsten carbide-cobalt (WC-Co) NP as reference positive control in in vitro genotoxicity assays, including 2 regulatory assays, the mouse lymphoma assay and the micronucleus assay, and in the Comet assay, recommended for the toxicological evaluation of nanomedicines by the French Agency of Human Health Products (Afssaps). Through these assays, we were able to study different genetic endpoints in 2 cell types commonly used in regulatory genotoxicity assays: the L5178Y mouse lymphoma cell line and primary cultures of human lymphocytes. Our results showed that the use of WC-Co NP as positive control in in vitro genotoxicity assays was conceivable, but that different parameters have to be considered, such as cell type and treatment schedule. L5178Y mouse lymphoma cells did not provide satisfactory results in the 3 performed tests. However, human lymphocytes were more sensitive to genotoxic effects induced by WC-Co NP, particularly after a 24-h treatment in the in vitro micronucleus assay and after a 4-h treatment in the in vitro Comet assay. Under such conditions, WC-Co could be used as a nanoparticulate reference positive control in these assays.

背景与目标： : 随着人类对纳米颗粒 (NP) 的暴露增加，对其遗传毒性潜力的评估非常重要。然而，通常使用的体外遗传毒性测定与NP的相关性经常受到质疑，因此，纳米颗粒参考阳性对照将构成更好地测试NP的重要步骤，从而确保测试系统确实合适。在这项研究中，我们研究了在体外遗传毒性试验中使用碳化钨-钴 (WC-Co) NP作为参考阳性对照的可能性，包括2项调节试验，小鼠淋巴瘤试验和微核试验，以及在彗星试验中，法国人类健康产品局 (Afssaps) 推荐用于纳米药物的毒理学评估。通过这些测定，我们能够研究调节性遗传毒性测定中常用的2种细胞类型的不同遗传终点: L5178Y小鼠淋巴瘤细胞系和人类淋巴细胞的原代培养物。我们的结果表明，在体外遗传毒性测定中使用WC-Co NP作为阳性对照是可以想象的，但是必须考虑不同的参数，例如细胞类型和治疗时间表。L5178Y小鼠淋巴瘤细胞在3次进行的测试中均未提供令人满意的结果。然而，人类淋巴细胞对WC-Co NP诱导的遗传毒性作用更为敏感，尤其是在体外微核试验中进行24小时处理后以及在体外彗星试验中进行4小时处理后。在这种条件下，WC-Co可以在这些测定中用作纳米颗粒参考阳性对照。

BACKGROUND & AIMS: :Maternal malnutrition leads to the incidence of metabolic diseases in offspring. The purpose of this project was to examine whether maternal low chromium could disturb normal lipid metabolism in offspring, altering adipose cell differentiation and leading to the incidence of lipid metabolism diseases, including metabolic syndrome and obesity. Female C57BL mice were given a control diet (CD) or a low chromium diet (LCD) during the gestational and lactation periods. After weaning, offspring was fed with CD or LCD. The female offspring were assessed at 32 weeks of age. Fresh adipose samples from CD-CD group and LCD-CD group were collected. Genome mRNA were analysed using Affymetrix GeneChip Mouse Gene 2.0 ST Whole Transcript-based array. Differentially expressed genes (DEGs) were analysed based on gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis database. Maternal low chromium irreversibly increased offspring body weight, fat-pad weight, serum triglyceride (TG) and TNF-α. Eighty five genes increased and 109 genes reduced in the offspring adipose of the maternal low chromium group. According to KEGG pathway and String analyses, the PPAR signalling pathway may be the key controlled pathway related to the effect of maternal low chromium on female offspring. Maternal chromium status have long-term effects of lipid metabolism in female mice offspring. Normalizing offspring diet can not reverse these effects. The potential underlying mechanisms are the disturbance of the PPAR signalling pathway in adipose tissue.

背景与目标： : 产妇营养不良导致后代代谢性疾病的发生。本课题的目的是研究母体低铬是否会干扰后代正常的脂质代谢，改变脂肪细胞的分化并导致脂质代谢疾病 (包括代谢综合征和肥胖) 的发生。在妊娠和哺乳期，对雌性C57BL小鼠进行对照饮食 (CD) 或低铬饮食 (LCD)。断奶后，用CD或LCD喂养后代。在32周龄时对雌性后代进行评估。收集cd-cd组和lcd-cd组的新鲜脂肪样品。使用Affymetrix GeneChip小鼠基因2.0 ST全转录物基阵列分析基因组mRNA。基于基因本体论 (GO) 和京都基因和基因组百科全书 (KEGG) 途径分析数据库对差异表达基因 (DEGs) 进行分析。母体低铬不可逆地增加了后代体重，脂肪垫重量，血清甘油三酸酯 (TG) 和TNF-α。母体低铬组子代脂肪的85个基因增加，109个基因减少。根据KEGG途径和字符串分析，PPAR信号途径可能是与母体低铬对雌性后代影响有关的关键控制途径。母体铬状态对雌性小鼠后代的脂质代谢具有长期影响。使后代饮食正常化不能逆转这些影响。潜在的潜在机制是脂肪组织中PPAR信号通路的紊乱。

BACKGROUND & AIMS: :Chromium has long been known as an enhancer of insulin action. However, the role of chromium in the development of type 2 diabetes mellitus (T2DM) in humans remains controversial. The current study aimed to examine the associations of plasma chromium levels with T2DM and pre-diabetes mellitus (pre-DM). We conducted a case-control study involving 1471 patients with newly diagnosed T2DM, 682 individuals with newly diagnosed pre-DM, and 2290 individuals with normal glucose tolerance in a Chinese population from 2009 to 2014. Plasma chromium was measured by inductively coupled plasma mass spectrometry. Plasma chromium levels were lower in the T2DM and pre-DM groups than in the control group (median: 3.68 μg/L, 3.61 μg/L, 3.97 μg/L, respectively, p < 0.001). After adjustment for potential confounding factors, the odds ratios (95% confidence interval) for T2DM across increasing quartiles of plasma chromium levels were 1 (referent), 0.67 (0.55-0.83), 0.64 (0.51-0.79), and 0.58 (0.46-0.73), respectively (p for trend <0.001). The corresponding odds ratios (95% confidence interval) for pre-DM were 1 (referent), 0.70 (0.54-0.91), 0.67 (0.52-0.88), and 0.58 (0.43-0.78), respectively (p for trend < 0.001). Our results indicated that plasma chromium concentrations were inversely associated with T2DM and pre-DM in Chinese adults.

背景与目标： : 铬长期以来被认为是胰岛素作用的增强剂。然而，铬在人类2型糖尿病 (T2DM) 发展中的作用仍存在争议。当前的研究旨在检查血浆铬水平与T2DM和糖尿病前期 (pre-DM) 的关系。我们进行了一项病例对照研究，纳入了1471例新诊断的T2DM患者，682例新诊断的糖尿病前期患者和2290例葡萄糖耐量正常的中国人群2009年2014年。通过电感耦合等离子体质谱法测量等离子体铬。T2DM组和pre-DM组的血浆铬水平低于对照组 (中位数: 3.68 μ g/L，3.61 μ g/L，3.97 μ g/L，p <0.001)。在调整了潜在的混杂因素后，血浆铬水平增加的四分位数中T2DM的比值比 (95% 置信区间) 为1 (参照)，0.67 (0.55-0.83)，0.64 (0.51-0.79) 和0.58 (0.46-0.73)，分别 (p表示趋势 <0.001)。前DM的相应优势比 (95% 置信区间) 分别为1 (参照) 、0.70 (0.54-0.91) 、0.67 (0.52-0.88) 和0.58 (0.43-0.78) (p表示趋势 <0.001)。我们的结果表明，中国成年人血浆铬浓度与T2DM和前DM呈负相关。

BACKGROUND & AIMS: :High incidence of cobalt deficiency (89%) was found in 7-8-year-old girls residents of the Republic of Tatarstan. Significant correlations were revealed between parameters of physical development and cardiovascular system and hair cobalt content. These data suggest that positive balance of cobalt is essential for normal growth and development of child's body and function of the cardiovascular system.

背景与目标： : 在ta斯坦共和国的7-8岁女孩居民中发现钴缺乏症 (89%) 的高发生率。身体发育和心血管系统参数与头发钴含量之间存在显着相关性。这些数据表明，钴的正平衡对于儿童身体的正常生长和发育以及心血管系统的功能至关重要。

BACKGROUND & AIMS: :The nickel (Ni) hyperaccumulator Alyssum murale has been developed as a commercial crop for phytoremediation/phytomining Ni from metal-enriched soils. Here, metal co-tolerance, accumulation and localization were investigated for A. murale exposed to metal co-contaminants. A. murale was irrigated with Ni-enriched nutrient solutions containing basal or elevated concentrations of cobalt (Co) or zinc (Zn). Metal localization and elemental associations were investigated in situ with synchrotron X-ray microfluorescence (SXRF) and computed-microtomography (CMT). A. murale hyperaccumulated Ni and Co (> 1000 microg g(-1) dry weight) from mixed-metal systems. Zinc was not hyperaccumulated. Elevated Co or Zn concentrations did not alter Ni accumulation or localization. SXRF images showed uniform Ni distribution in leaves and preferential localization of Co near leaf tips/margins. CMT images revealed that leaf epidermal tissue was enriched with Ni but devoid of Co, that Co was localized in the apoplasm of leaf ground tissue and that Co was sequestered on leaf surfaces near the tips/margins. Cobalt-rich mineral precipitate(s) form on leaves of Co-treated A. murale. Specialized biochemical processes linked with Ni (hyper)tolerance in A. murale do not confer (hyper)tolerance to Co. A. murale relies on a different metal storage mechanism for Co (exocellular sequestration) than for Ni (vacuolar sequestration).

背景与目标： : 镍 (Ni) 超积累的阿利苏姆·穆拉勒 (Alyssum murale) 已被开发为一种商业作物，用于从富含金属的土壤中进行植物修复/植物化镍。在这里，研究了暴露于金属共污染物的A. murale的金属共耐受性，积累和定位。A. murale用富含镍的营养液灌溉，该营养液含有基础或高浓度的钴 (Co) 或锌 (Zn)。使用同步加速器x射线微荧光 (SXRF) 和计算机微断层扫描 (CMT) 原位研究了金属定位和元素缔合。A. murale从混合金属体系中累积的Ni和Co (> 1000微克 (-1) 干重)。锌没有过度蓄积。升高的Co或Zn浓度不会改变Ni的积累或定位。SXRF图像显示叶片中Ni分布均匀，并且Co在叶尖/边缘附近优先定位。CMT图像显示，叶片表皮组织富含Ni，但不含Co，Co位于叶地组织的质膜中，Co被隔离在尖端/边缘附近的叶片表面。在共同处理的A. murale的叶片上形成富钴矿物沉淀。与A. murale中的Ni (超) 耐受性相关的专门生化过程不赋予Co (超) 耐受性。A. murale对Co (胞外隔离) 的金属存储机制与对Ni (液泡隔离) 的金属存储机制不同。

BACKGROUND & AIMS: :The effects of application of two anions commonly found in subsurface environments, phosphate (PO43-) and sulfate (SO42-), on hexavalent chromium (Cr(VI)) uptake and translocation by Zea mays, were investigated using pot-culture experiments. The two anions were tested as potential agents to mobilize Cr(VI) from polluted soil (50, 75 and 100 mg kg-1 dw) at a dose of 16.7 mmol kg-1. Metal uptake from soil to roots and subsequent transfer to shoots was discussed in terms of bioconcentration factor (BCF) and translocation factor (TF). The overall order of BCFs and TFs which resulted from this study was: PO43- > H2O > SO42-; in the same time, metal concentration in plants tissues decreased in the order: root > stem > leaf. The present study suggests that PO43- may be used as an environmentally compatible alternative to non-biodegradable synthetic chelants, to enhance the efficiency of Cr(VI) phytoextraction with Z. mays.

背景与目标： : 使用盆栽实验研究了在地下环境中常见的两种阴离子磷酸盐 (PO43-) 和硫酸盐 (SO42-) 对玉米吸收和转运六价铬 (Cr(VI)) 的影响。测试了这两种阴离子作为潜在的试剂，以16.7 mmol kg-1的剂量从污染的土壤 (50,75和100 mg kg-1 dw) 中动员Cr(VI)。根据生物浓缩因子 (BCF) 和易位因子 (TF) 讨论了金属从土壤到根部的吸收以及随后向芽的转移。本研究产生的bcf和TFs的总体顺序为: PO43- > H2O > SO42-; 同时，植物组织中的金属浓度按以下顺序降低: 根> 茎> 叶。本研究表明，PO43-可以用作不可生物降解的合成螯合剂的环境相容性替代品，以提高Z. mays提取Cr(VI) 植物的效率。

BACKGROUND & AIMS: :Diabetes results in several metabolic changes, including alterations in the transport, distribution, excretion, and accumulation of metals. While changes have been examined in several rat models of insulin resistance and diabetes, the metal ion concentrations in the tissues of Zucker lean, Zucker obese (an insulin resistance and early stage diabetes model), and Zucker diabetic fatty (ZDF, a type 2 diabetes model) have not previously been examined in detail. The concentration of Cu, Zn, Fe, Mg, and Ca were examined in the liver, kidney, heart and spleen, and Cr concentration in the liver and kidney of these rats were examined. Zucker obese rats have a reduction in the concentration of Cu, Zn, Fe, Mg in the liver compared to ZDF and/or lean Zucker rats, presumably as a result of the increased fat content of the liver of the obese rats. ZDF rats have increased concentrations of kidney Cu compared to the lean rats, while kidney Ca concentrations are increased in the Zucker obese rats. Spleen Fe concentrations are decreased in Zucker obese rats compared to the lean rats. No effects on metal concentrations in the heart were observed between the lean, obese, and ZDF rats, and no effects on Cr concentrations were identified. Cr(III) complexes have previously been shown to have beneficial effects on the signs of insulin resistance in Zucker obese and ZDF rats. The effects of daily gavage administration of chromium picolinate ([Cr(pic)(3)]) (1 mg Cr/kg body mass), CrCl(3) (1 mg Cr/kg body mass), and Cr3 ([Cr(3)O(propionate)(6)(H(2)O)(3)](+)) (33 μg and 1 mg Cr/kg body mass) on metal concentrations in these tissues were examined. Treatment with CrCl(3) and Cr3, but not [Cr(pic)(3)], at 1 mg Cr/kg resulted in a statistically significant accumulation of Cr in the kidney of lean and obese but not ZDF rats but resulted in lowering the elevated levels of kidney Cu in ZDF rats, suggesting a beneficial effect on this symptom of type 2 diabetes.

背景与目标： 糖尿病会导致多种代谢变化，包括运输，分布，排泄和金属积累的改变。虽然已在几种胰岛素抵抗和糖尿病大鼠模型中检查了变化，但Zucker瘦肉，Zucker肥胖 (胰岛素抵抗和早期糖尿病模型) 和Zucker糖尿病脂肪 (ZDF，2型糖尿病) 组织中的金属离子浓度以前尚未详细检查。检查了这些大鼠的肝脏，肾脏，心脏和脾脏中Cu，Zn，Fe，Mg和Ca的浓度，并检查了这些大鼠的肝脏和肾脏中的Cr浓度。与ZDF和/或瘦Zucker大鼠相比，Zucker肥胖大鼠的肝脏中Cu，Zn，Fe，Mg的浓度降低，这可能是由于肥胖大鼠肝脏脂肪含量增加的结果。与瘦大鼠相比，ZDF大鼠的肾脏Cu浓度增加，而Zucker肥胖大鼠的肾脏Ca浓度增加。与瘦大鼠相比，Zucker肥胖大鼠的脾脏Fe浓度降低。在瘦弱，肥胖和ZDF大鼠之间未观察到对心脏中金属浓度的影响，并且未发现对Cr浓度的影响。先前已显示Cr(III) 复合物对Zucker肥胖和ZDF大鼠的胰岛素抵抗迹象具有有益作用。日灌胃给药吡啶甲酸铬 ([Cr(pic)(3)]) (1 mg Cr/kg体重)，CrCl(3) (1 mg Cr/kg体重)，和Cr3 ([Cr(3)O (丙酸)(6)(H(2)O)(3)]()) (33μg和1 mg Cr/kg体重) 检查了这些组织中的金属浓度。以1 mg Cr/kg的CrCl(3) 和Cr3 (但不包括 [Cr(pic)(3)]) 治疗，导致瘦弱和肥胖但ZDF大鼠肾脏中Cr的统计学显着积累，但ZDF大鼠肾脏Cu水平降低，提示对2型糖尿病的这种症状有有益作用。

BACKGROUND & AIMS: :Instantaneous (discrete) and time-integrated (composed) samples were collected during a 19-week period in a watershed impacted by discontinuous discharges from local tanneries (Carpathians Mountains, Poland). Existence of the impoundment reservoir in this watershed allowed investigation of its role in chromium transport. In collected samples, dissolved and particulate chromium concentrations were measured to apportion both loads. This study has demonstrated that the impoundment reservoir retains not only particulate but also a dissolved form of chromium and its efficiency reaches 74-94 %. Sampling results proved that chromium contamination in the investigated river is variable and discontinuous. Discrete sampling can lead to an underestimation of chromium contamination level (up to 78 %), especially when illegal/unexpected discharges occur in the watershed. A discrete sampling regime also produces less reliable data for contaminant budget calculations, especially in sites where strong variability of contamination is anticipated, while at the output from reservoirs, the load can be reasonably estimated using this mode of sampling.

背景与目标： : 在受当地制革厂 (波兰喀尔巴阡山脉) 不连续排放影响的分水岭中，在19周内收集了瞬时 (离散) 和时间积分 (合成) 样品。该流域中蓄水池的存在允许研究其在铬运输中的作用。在收集的样品中，测量了溶解和颗粒铬的浓度，以分摊两种负荷。这项研究表明，蓄水储层不仅保留了颗粒，而且保留了溶解形式的铬，其效率达到74-94%。采样结果证明，所调查河流中的铬污染是可变且不连续的。离散采样可能导致铬污染水平的低估 (高达78%)，尤其是在分水岭中发生非法/意外排放时。离散的采样方式也会产生不太可靠的污染物预算计算数据，尤其是在预计污染会发生强烈变化的地点，而在水库的输出处，可以使用这种采样方式合理地估算负荷。

BACKGROUND & AIMS: Historical uses of chromium have resulted in its widespread release into the environment. In recent years, a significant amount of research has evaluated the impact of chromium on human health and the environment. Additionally, numerous analytical methods have been developed to identify and quantitate chromium in environmental media in response to various state and federal mandates such as CERCLA, RCRA, CWA, CAA, and SWDA. Due to the significant toxicity differences between trivalent [Cr(III)] and hexavalent [Cr(VI)] chromium, it is essential that chromium be quantified in these two distinct valence states to assess the potential risks to exposure to each in environmental media. Speciation is equally important because of their marked differences in environmental behavior. As the knowledge of risks associated with each valence state has grown and regulatory requirements have evolved, methods to accurately quantitate these species at ever-decreasing concentrations within environmental media have also evolved. This paper addresses the challenges of chromium species quantitation and some of the most relevant current methods used for environmental monitoring, including ASTM Method D5281 for air, SW-846 Methods 3060A, 7196A and 7199 for soils, sediments, and waste, and U.S. EPA Method 218.6 for water.

背景与目标： 铬的历史用途导致其广泛释放到环境中。近年来，大量研究评估了铬对人类健康和环境的影响。此外，针对各种州和联邦法规 (例如CERCLA，RCRA，CWA，CAA和SWDA)，已经开发了许多分析方法来识别和定量环境介质中的铬。由于三价 [Cr(III)] 和六价铬 [Cr(VI)] 铬之间的显着毒性差异，因此必须在这两种不同的价态中对铬进行定量，以评估环境介质中暴露于每种价态的潜在风险。物种形成同样重要，因为它们在环境行为上存在明显差异。随着与每种价态相关的风险知识的增长和监管要求的发展，在环境介质中以不断降低的浓度准确定量这些物种的方法也在发展。本文讨论了铬物种定量的挑战以及当前用于环境监测的一些最相关的方法，包括针对空气的ASTM方法D5281，针对土壤，沉积物和废物的SW-846方法3060A，7196A和7199，以及针对水的美国EPA方法218.6。

BACKGROUND & AIMS: :Hexavalent chromium in cement 5-8 mg/kg hexavalent chromium (Cr(VI)) was found in Honduran cement samples, which was slightly higher than in Swedish samples. Variable amounts of Cr(VI) (0.4 and 4.7 mg/kg) found in Swedish cement samples that were older than 1 year. There are still many countries that do not have a compulsory reduction of Cr(VI) in cement. Several measures can be employed to reduce risks related to Cr(VI) in cement.

背景与目标： : 在洪都拉斯水泥样品中发现水泥中的六价铬5-8 mg/kg六价铬 (Cr(VI))，略高于瑞典样品。在超过1年的瑞典水泥样品中发现的可变量的Cr(VI) (0.4和4.7 mg/kg)。仍有许多国家没有强制减少水泥中的Cr(VI)。可以采取多种措施来降低水泥中与Cr(VI) 相关的风险。

BACKGROUND & AIMS: :Longitudinal hair chromium (H-Cr) profiles in a group of patients with type 2 diabetes mellitus (n = 59; age, 62 +/- 9 years) and healthy elderly (control) subjects (n = 49; age, 59 +/- 10 years) matched by age and sex were measured by solid sampling electrothermal atomic absorption spectrometry, providing data on the magnitude of variation of Cr content along the hair length. H-Cr average (H-Cr(av)) and H-Cr proximal (H-Cr(pr))(.), relating to the average Cr content of the whole hair and the proximal 3-mm hair length, respectively, were also obtained. No significant difference between the healthy and diabetic group was found in mean H-Cr(av) or H-Cr(pr) contents (248 +/- 108 vs 247 +/- 143 and 233 +/- 98 vs 278 +/- 195 ng/g, respectively. However, women in the control group had significantly lower H-Cr values (P < .01) compared with men, but this difference was absent in the diabetic population. The distribution of log H-Cr(pr) values in the control population displayed a Gaussian shape, in contrast to the substantially wider distribution, skewed toward lower H-Cr(pr) values, observed in the diabetic group. The magnitude of variation in H-Cr content in the patient group over an interval of approximately 2 to 3 months (time of growth of the hair sampled) was found to be a factor of more than 2 larger than that in the control population (+/- 58% vs +/- 26%). A strong relationship (R = 0.656; P < .01) between log H-Cr(pr) and log fasting plasma Cr was observed in the diabetic group (n = 20). The mean fasting plasma Cr value of this group was 0.41 +/- 0.10 microg Cr per liter. No correlation between H-Cr(av.) and duration of diabetes was observed. A strong positive association was observed in the control population between H-Cr(pr) and fasting plasma insulin (n = 22; R = 0.6157; P < .01), and H-Cr(pr) and fasting plasma glucose (n = 24; R = 0.4118; P < .05), which is indicative of the interrelation of these parameters. In the control population, H-Cr(av) showed a slight decrease with age (n = 54; R = 0.2691; P < .05), which is assumed to be the result of increased insulin resistance caused by various age-associated factors including Cr deficiency. None of the above relationships was significant in the diabetic group. Evidence is presented that justifies the assumption that the longitudinal H-Cr profile resembles the variation in Cr metabolic rate over the time span of growing hair, which is not appreciably affected by external contamination. This suggests that glucose intolerance (type 2 diabetes mellitus) is an important factor that disturbs Cr metabolism.

背景与目标： : 一组2型糖尿病患者 (n = 59; 年龄62/- 9岁) 和健康老年人 (对照组) 受试者 (n = 49; 年龄，通过固体采样电热原子吸收光谱法测量了年龄和性别相匹配的59/- 10岁，提供了Cr含量沿头发长度变化幅度的数据。H-cr平均值 (h-cr (av)) 和h-cr近端 (h-cr (pr))(。)，分别与整个头发的平均Cr含量和近端3-mm头发长度有关，也获得了。健康组和糖尿病组的平均h-cr (av) 或h-cr (pr) 含量无显着差异 (248/- 108 vs 247/- 143和233/- 98 vs 278//- 195 ng/g)。对照组中女性的h-cr值明显低于男性 (P <.01)，但糖尿病人群中没有这种差异。对照组中log h-cr (pr) 值的分布呈高斯形，与明显较宽的分布相反，在糖尿病组中观察到，向较低的h-cr (pr) 值倾斜。发现在大约2至3个月的间隔内患者组中h-cr含量的变化幅度 (采样的头发的生长时间) 比对照人群中的高2倍以上 (+/- 58% vs +/- 26%)。在糖尿病组 (n = 20) 中观察到log h-cr (pr) 与log空腹血浆Cr之间有很强的关系 (R = 0.656; P <.01)。该组的平均空腹血浆Cr值为0.41 +/- 0.10微克Cr/l。未观察到h-cr (av。) 与糖尿病持续时间之间的相关性。在对照组人群中，h-cr (pr) 与空腹血浆胰岛素 (n = 22; R = 0.6157; P < .01) 和h-cr (pr) 与空腹血糖 (n = 24; R = 0.4118; P < .05) 之间存在很强的正相关，这表明这些参数之间的相互关系。在对照人群中，h-cr (av) 随着年龄的增长而略有下降 (n = 54; R = 0.2691; P <.05)，这被认为是由包括Cr缺乏在内的各种年龄相关因素引起的胰岛素抵抗增加的结果。在糖尿病组中，上述关系均无显着性。提出的证据证明了这样的假设，即纵向H-Cr曲线类似于生长头发的时间跨度内Cr代谢率的变化，而不受外部污染的影响。这表明葡萄糖耐受不良 (2型糖尿病) 是干扰Cr代谢的重要因素。

BACKGROUND & AIMS: :In this paper, we evaluated the long-term results of uncemented total hip arthroplasties using tapered fully porous-coated cobalt-chrome stems (Autophor 900S). The average follow-up was 206 months in 127 hips (113 patients). The articulations of the joints were ceramic-on-polyethylene in 43 hips and ceramic-on-ceramic in 84. The survival rate of the stems at 17 years was 94.5%. A stable stem with bony ingrowth was identified in all 120 hips, excluding femoral revision cases (seven hips). The causes of the seven femoral revisions were aseptic loosening in four, infection in two, and stem fracture in one. No surgical intervention was performed for osteolysis or stress shielding. The Autophor 900S tapered fully porous-coated cobalt-chrome femoral stem revealed encouraging radiographic long-term stability.

背景与目标： : 在本文中，我们评估了使用锥形完全多孔涂层的钴铬茎 (Autophor 900S) 进行非骨水泥全髋关节置换术的长期结果。127髋 (113例患者) 平均随访206个月。关节的关节为43 hips的聚乙烯陶瓷和84 hips的陶瓷陶瓷。17年时茎的存活率为94.5%。除股骨翻修病例 (7髋) 外，在所有120髋中都发现了一个稳定的茎，具有骨向内生长。七次股骨翻修的原因是四次无菌性松动，两次感染和一次骨折。未对骨溶解或应力屏蔽进行手术干预。Autophor 900S锥形完全多孔涂层的钴铬股骨干显示出令人鼓舞的影像学长期稳定性。