Interactions between tellurium and mercury in murine lung and other organs after metallic mercury inhalation: a comparison with selenium

Selenium is known to form complexes with heavy metals in the blood and thus increase the retention time of the metals in several organs, especially in the reticulo-endothelial system. Selenium may similarly cause retention of mercury in the lung after metallic mercury (Hg0) inhalation. This study, comparing the effects of tellurium with those of selenium (both in group '6b' of the periodical system), showed that Te(IV) was as effective as Se(IV) and Se(VI) (all given in a dose of 10 mumol/kg body wt.) in retaining inhaled 203Hg0 (1.5 mumol/kg body wt.) in the lung (presumably 203Hg2+ after oxidation). Te(VI) had to be given in a dose of 100 mumol/kg body wt to produce the same effect. As in the lung, also in other organs tellurium caused a dose-dependent increase in mercury retention. At a dose level of 10 mumol Te(IV) per kg body wt. the mercury retention ratios (treated/control) were 140 for the lung and 8.6 for the whole body. The corresponding figures for Te(VI) (10, 30 and 100 mumol/kg body wt.) were 10, 73 and 120 and 3.7, 3.9 and 4.3, respectively. Retention of i.v. injected 203HgCl2 was increased by pre-administration of tellurium, again in a dose-dependent manner and Te(IV) being 3-10 times more effective than Te(VI). The kidney and the spleen were the dominant organs, as is the case after Se pretreatment. Anions of other elements, arsenite, arsenate, chromate, molybdate and wolframate (30 mumol/kg body wt.), did not affect the retention of 203Hg in lung or any other organ, or in the whole body after inhalation of 203Hg0. It is suggested that Te(IV) may easily be reduced to Te2- (in analogy with selenium) which may complex with Hg2+. The liability for Te(VI) to be reduced to Te2- appears to be approx. 10 times lower.     

Temporal variations of metallothionein and metal concentrations in the digestive gland of oysters (Crassostrea gigas) from a clean and a metal-rich site

The concentrations of metallothionein (MT) in bivalves, a potential biomarker of metal pollution, are variable according to specific organs, the highest concentrations being encountered in the digestive glands of oysters. Thus, the present study has been focussed on this organ with a view to validate the use of MT as a biomarker in the field, the temporal changes of metal and metallothionein concentrations have been examined from March to October 1997 in the digestive gland of resident oysters from a clean site (Bay of Bourgneuf, France) and a metal-rich site, the Gironde estuary which has been shown as the most Cd-contaminated marine area in France but is also enriched with Cu and Zn. Moreover, oysters from the clean site have been translocated to the Gironde estuary over the same period. Taking into account all the samples collected over the 7 months of the study, MT concentrations in the digestive gland were positively correlated with weight whereas metal levels were negatively correlated with weight. However, considering monthly samples including specimens from both sites (resident or translocated oysters), a positive correlation was shown between MT and metal concentrations in autumn (September and October) but not in spring and summer. These findings limit the interest of using the digestive gland of oysters as the preferred tissue for the determination of MT concentration as a biomarker.The alternative use of gills should be considered.     

Label-free THz sensing of living body-related molecular binding using a metallic mesh

We have demonstrated label-free THz sensing of living body-related molecular binding using a thin metallic mesh and a polyvinylidene difluoride (PVDF) membrane. Metallic meshes in the THz region are designed for anomalous transmission phenomena derived from a resonant excitation of surface waves. Additionally, they are designed to have a sharp dip in transmittance. The metallic mesh is very sensitive to a change of the refractive index of materials attached to the metallic mesh. In this paper, we report sensing of interactions between lectin and sugar using this technique. We found that the dip frequency shift, transmittance attenuation of the dip frequency, and peak shift of the derivative spectrum of the phase shift depend on the bonding amount of lectin–sugar interactions. We also applied this technique to detect avidin–biotin interactions, leading to the detection of a small amount of biotin (0.17 pg/mm²).     

Fabrication of VB2/Air Cells for Electrochemical Testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB₂ is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB₂ particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB₂ anode. Finally, discharge of the completed VB₂/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB₂ anode.     

Effects of Fasciola gigantica experimental infection on some inorganic elements in the snail host Lymnaea natalensis

Flame atomic absorption spectrometry was performed to determine the alteration in the concentrations of metallic ion Pb, Zn, K, Na, Fe, Cu and Co in the soft parts of the Lymnaea natalensis snails shedding Fasciola gigantica cercariae and to determine the alteration in the concentration of Ca in the soft parts and shells of the same snails. The Co was found to be present at concentration level below the detection limits of the analytical method used. Regarding detected elements, three elements Zn, K and Cu were found to be present at significantly higher concentrations in cercariae-shedding snails compared with uninfected snails. Two elements, Pb and Na, showed significant decrease in cercariae-shedding snails compared to uninfected ones. The concentration of Fe showed non-significant increase. The results showed significant lowering in the calcium content of the shells and soft parts of cercariae-shedding snails relative to the calcium content in the uninfected ones. The obtained results and the hypothesis of hypercalcification in shells of infected snails were discussed.     

介入室X线电视系统下眶内及眶周金属异物摘出术的临床观察

目的:探讨在介入室X线电视系统下摘出眶内及眶周金属异物的临床效果。方法:选择2002年7月至2012年7月我院收治的金属异物患者86例86只眼,在介入室X线电视系统直视引导下,根据影像学特点制定个体化手术方法,经皮肤或结膜进路摘出眶内及眶周金属异物。结果:86例均成功取出异物,其中一次手术取出83例(96.5%),二次手术取出3例(3.5%)。随访2~18(9.2±5.3)月。末次随访时视力达术前水平62例(72.1%),视力提高21例(24.4%)。术前及术后末次随访时眼球运动障碍分别为34例(39.5%)和16例(18.6%),术前及术后末次随访时外伤性上睑下垂分别为5例(5.8%)和3例(3.5%)。结论:在介入室X线电视系统下摘出眶内及眶周金属异物对眶内及眶周组织损伤小,手术时间短,疗效满意,便于操作,值得推广。     

Wastewater treatment efficiency of a multi-media biological aerated filter (MBAF) containing clinoptilolite and bioceramsite in a brick-wall embedded design

A multi-media biological aerated filter (MBAF) with clinoptilolite media was used to treat synthetic wastewater. Coal ash bioceramsite with supplemental metallic iron was added to the clinoptilolite media of MBAFs in a brick-wall embedded design. Performance parameters, such as hydraulic, organic, N and P loading capacity and microbial community composition were studied for different quantity of supplemental metallic iron contained in three MBAFs. The MBAFs with more metallic iron were found to have superior hydraulic and organic loading, and higher N and P capacities. COD, NH₃-N and TP removal dropped by 7-10%, 6-7% and 4-5%, respectively, with when hydraulic loading was raised from 2.8 to 7.5 m³ m⁻² d⁻¹. NH₃-N removal also decreased 8-9% when ammonia loading was elevated from 0.078 to 0.156 kg NH₃-N m⁻³ d⁻¹. Real-time PCR revealed a relatively stable bacterial community composed primarily of eubacteria that formed after an initial 120 d operational period. Doubling the amount of metallic iron in the bioceramsite media resulted in a twofold increase of eubacteria in the MBAF, but a decrease in the ratio of anaerobic ammonia-oxidizing bacteria to total bacteria.     

Colloidal Synthesis of Plasmonic Metallic Nanoparticles

Solutions of Ag and Au nanoparticles are strongly colored because of localized surface plasmon resonance in the UV/visible spectral region. The optical properties of these nanoparticles may be tuned to suit the needs of the application. This article summarizes our work in recent years on the solution synthesis of nanoparticles with tunable optical properties. The systems of interest include zero-dimensional bimetallic Ag–Au nanoparticles with different structures, one-, two-, and three-dimensional anisotropic monometallic Ag or Au nanoparticles. All of these nanosystems were prepared from colloidal synthesis through simple changes in the synthesis conditions. This is a demonstration of the versatility of colloidal synthesis as a convenient scalable technique for tuning the properties of metallic nanoparticles. Zhang, Tan, and Xie contributed equally to this article     

五种云锡矿粉和四种金属化合物诱发大鼠骨髓和肺巨噬细胞微核率的研究

本实验探讨5种云南锡矿粉及4种金属化合物的潜在诱变性以及与职业性肺癌高发率之间的关系。大鼠经气管灌注这些矿粉和金属化合物后,于不同时间进行细胞学制片,观察其对大鼠骨髓细胞和肺巨噬细胞的微核率和核碎解率的影响。发现5种云锡矿粉和2种金属化合物（SnO[2]和Fe[2]O[3]）均能诱发大鼠骨髓细胞微核和核碎解的增加,处理后1天和10天时核碎解率高于微核率,并与对照相比差异显著,20天和30天时微核率高于核碎解率,与对照相比也有显著差异。5种矿粉和4种金属化合物均能诱发大鼠肺巨噬细胞微核率和核碎解率的变化,处理后10天和20天时核碎解率高于微核率与对照相比差异显著。