[en] The compounds can be prepared by stirring the neat aromatics with a 1:1 molar strong acid system of boron trifluoride: deuterium oxide. Reaction proceeds with polycyclic aromatics and others whose electrophilic reactivity is as great or greater than that of benzene. Compounds deuterated include benzene, toluene, chlorobenzene, toluene, cumene, o-xylene, m-xylene, p-xylene, tertiary-butyl benzene, n-butylbenzene, phenanthrene, naphthalene, and tetralin. The possibility of deuterium incorporation into the aliphatic groups was examined by looking aliphatic C D stretching bands in the ir spectrum. Mass spectra indicated that a mixture of deuterated compounds was present in each reaction product. Extent of deuterium incorporation was measured by comparing the areas of the aromatic and aliphatic NMR peaks in the deuterated products

[en] There have been a number of reports in the literature concerning the uptake and distribution of cadmium by different tissues following various routes of exposure. It was reported earlier that following a 4 hr sc cadmium exposure, lung damage can be induced in mice and rats. The catabolic fate of the cadmium in these early events appeared to be very important as the damage seen in the lung may be either cytotoxic or due to direct tissue deposition of cadmium in lung tissues. Further studies on rats for a 72 hr exposure period also indicated that significantly large amounts of cadmium remain deposited in the organs of gastrointestinal tract, lung, liver, and kidney. The present study is concerned with the catabolic fate of cadmium at early time periods via a bolus or constant infusion and its simultaneous organ distribution in the same experimental animal

[en] Despite various information on the organ distribution of Cd, relatively little published data are available in the literature about the gastrointestinal absorption and retention of cadmium. Estimates show that absorption of cadmium by the gastrointestinal tract are between 5-10% of the ingested dose. Our recent studies indicated that some gastrointestinal hormones - cholecystokinin (CCK), pancreatic polypeptide (PP) and gastrin - were affected with cadmium was infused in combination with bombesin (BBS), a peptide known to stimulate the release of gastrointestinal hormones. whether Cd accumulates in parts of the digestive tract which synthesize these hormones is not known. This study was conducted to determine if Cd is accumulated and retained by organs of the gastrointestinal tract that synthesize these gastrointestinal hormones

[en] This review presents the roles of some essential metalloelement-dependent enzymes in tissue maintenance and function, and their responses to radiation injury in accounting for radiation protection and recovery effects observed for nontoxic doses of essential metalloelement compounds. Effects of biochemicals including water undergoing bond radiolysis and the effects of free radicals derived from diatomic oxygen account for the acute and chronic aspects of radiation injury. Copper chelates have radiation protection and radiation recovery activities and cause rapid recovery of immunocompetency and recovery from radiation-induced histopathology. Mice treated with Cu(II)₂(3,5-disopropylsalicy-late)₄[Cu(II)₂(3,5-DIPS)₄] had increased survival and corresponding increases in numbers of myeloid and multipotential progenitor cells early after irradiation and earlier recovery of immune reactivity. Examination of radiation-induced histopathology in spleen, bone marrow, thymus, and small intestine also revealed Cu(II)₂(3,5-DIPS)₄-mediated rapid recovery of radiation-induced histopathology. Most recently, Fe, Mn, and Zn complexes have also been found to prevent death in lethally irradiated mice. These pharmacological effects of essential metalloelement chelates can be understood as due to facilitation of de novo synthesis of essential metalloelement-dependent enzymes which have roles in preventing the accumulation of pathological concentrations of oxygen radicals or repairing biochemical damage caused by radiation-induced bond homolysis. Essential metalloelement chelates offer a physiological approach to prevention and/or treatment of radiation injury. 97 refs., 5 figs., 1 tab

[en] Phase contrast radiology using unmonochromatic synchrotron X-ray successfully imaged the grain boundaries of Al and AlZn alloy without contrast agent. Combining the high penetration of X-ray and the possibility of 3D reconstruction by tomorgraphy or stereography method, this approach can be very used for nondestructive characterization of polycrystalline materials. By examine the images with 3D perspective, we were able locate the observed void-like defects which lies exclusively on the grain boundary and identify their origin from last stage of the rolling process. We studied the Ga Liquid metal diffusion in the AlZn alloy, under different temperature and stress conditions. High resolution images, ∼2 μm, of Ga liquid metal diffusion in AlZn were obtained in real time and diffusion paths alone grain boundaries and surfaces were clearly identified. Embrittled AlZn responses to the tensile stress and fractures in a drastic different manner than the pure AlZn. These results, although very much expected from the known weakening effect of the liquid metal embrittlement demonstrated, however, that this particular radiology method is fully capable of dynamic study in the micrometer scale

[en] We used phase contrast radiography to study the electro-deposition of Zn in real time and with high lateral resolution. Using unmonochromatic synchrotron X-rays and an optics-less imaging setup, we were able to obtain real-time radiographs of the electro-deposition in situ with μm resolution. A detailed analysis of the microstructure evolution relates the different growth parameters - such as the electric current density, the voltage bias, the pH value and the ion concentration - to very different growth morphology, ranging from film, porous, whisker and dendrite deposition. This link is both global and local. Local variations of the metal ion concentration in the electrolyte were also successfully imaged and the density profile is used to compare with the standard theory to explain the phenomenon of metal ion depletion near the electrode. The potential application of this technique to study growth with micropatterned electrodes and pulsed electric current is evaluated

[en] Epidemiological studies have demonstrated a high association of inorganic arsenic exposure with vascular diseases. Recent research has also linked this vascular damage to impairment of endothelial nitric oxide synthase (eNOS) function by arsenic exposure. However, the role of eNOS in regulating the arsenite-induced vascular dysfunction still remains to be clarified. In our present study, we investigated the effect of arsenite on Akt1 and eNOS and its involvement in cytotoxicity of vascular endothelial cells. Our study demonstrated that arsenite decreased the protein levels of both Akt1 and eNOS accompanied with increased levels of ubiquitination of total cell lysates. We found that inhibition of the ubiquitin-proteasome pathway by MG-132 could partially protect Akt1 and eNOS from degradation by arsenite together with a proportional protection from the arsenite-induced cytoxicity. Moreover, up-regulation of eNOS protein expression significantly attenuated the arsenite-induced cytotoxicity and eNOS activity could be significantly inhibited after incubation with arsenite for 24 h in a cell-free system. Our study indicated that endothelial eNOS activity could be attenuated by arsenite via the ubiquitin-proteasome-mediated degradation of Akt1/eNOS as well as via direct inhibition of eNOS activity. Our study also demonstrated that eNOS actually played a protective role in arsenite-induced cytoxicity. These observations supported the hypothesis that the impairment of eNOS function by arsenite is one of the mechanisms leading to vascular changes and diseases

[en] In the current study, we examined and compared the mixing and vitrification behavior of the Zr-Cu and Zr-Ti binary systems in the form of co-sputtered thin films with or without post-annealing. The co-sputtered Zr-Cu films are all amorphous under various co-sputtering conditions, suggesting the high vitrification tendency. The amorphous Zr-Cu thin film will start to crystallize into nano-crystalline Zr₂Cu and Zr₇Cu₁₀ phases upon long exposure at temperatures above 350 deg. C. On the other hand, it is difficult to form amorphous film with the Zr-Ti system, except at a low sputtering power of 30-50 W. The low powers enable the co-sputtered Zr-Ti thin film to exhibit the diffuse hump in the X-ray diffraction. Examination by high resolution transmission electron microscopy reveals numerous fine nano-crystalline phases around 2 nm in the amorphous matrix. Upon exposure at 700 deg. C, the Zr-Ti films transform into crystalline hexagonal close-packed α and body-centered cubic β phases.