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1.
A method is described for the analysis of microgram quantities of tin in dilute hydrofluoric acid. The tin is extracted onto anion-exchange resin loaded paper discs by a very simple technique and the papers are examined by X-ray fluorescence spectrography. The solutions are obtained by the dissolution of tin-containing glasses, and the normal glass-forming elements do not interfere. The method is intended for the determination of 1-20 mug of tin but may be used for up to at least 250 mug; 5 mug can be determined with a precision of +/- 10%. 相似文献
2.
Differential expression of the skeletal muscle proteome in mdx mice at different ages 总被引:2,自引:0,他引:2
The mdx mouse is the most commonly used animal model for Duchenne muscular dystrophy (DMD), a disease caused by the absence of dystrophin. Although much has been done to elucidate the structure and function of dystrophin and the dystrophin-associated glycoprotein complex (DGC), little is known about the cascade of molecular events triggered by the absence of dystrophin that lead to muscle degeneration. To study the molecular basis of DMD, we decided to systematically study the skeletal muscle proteome in mdx mice at different ages. By using two-dimensional (2-D) gel electrophoresis, we defined changes in the protein expression pattern between mdx and control muscles. Approximately 46 differentially expressed proteins from the cytosolic fraction of mdx hindlimb muscles at three months of age were detected by 2-D gel analysis, of which 24 were identified by matrix assisted laser desorption/ionization- mass spectrometry. Most of the proteins fell into five groups of functionally related proteins. These functional categories are (i) metabolism and energy production, (ii) serine protease inhibitor family, (iii) growth and differentiation, (iv) calcium homeostasis, and (v) cytoskeletal reorganization and biogenesis. The potential roles of the differentially expressed proteins are discussed in the context of the mdx phenotype. Finally, we analyzed alterations of protein expression in mdx mice at one and six months of age to determine how protein expression changes with disease progression. 相似文献
3.
Zaharescu M. Jitianu A. Brăileanu A. Madarász J. Novák CS. Pokol G. 《Journal of Thermal Analysis and Calorimetry》2003,71(2):421-428
Hybrid materials with different amounts of organics permanently bound on the inorganic network obtained in the TEOS-MTEOS
(tetraethoxysilan-methyltriethoxysilan) system are used for obtaining coatings with different optical and mechanical properties.
To study the thermal stability of the mentioned materials, compositions with different molar ratios of the precursors were
prepared. The influence of the solvent and water amounts on the gelation process was also investigated. The gels obtained
were characterised by IR spectrometry and their decomposition temperatures were determined by DTA/TG. Thermal stability of
the gels is rather influenced by their composition than the conditions of the gelation process.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
Aihara H Alston-Garnjost M Bakken JA Barbaro-Galtieri A Barnes AV Barnett BA Bengtsson H Blumenfeld BJ Bross AD Buchanan CD Chamberlain O Chien C Clark AR Cordier A Dahl OI Day CT Derby KA Eberhard PH Fancher DL Fujii H Fujii T Gabioud B Gary JW Gorn W Hadley NJ Hauptman JM Hofmann W Huth JE Hylen J Kamae T Kaye HS Kenney RW Kerth LT Koda RI Kofler RR Kwong KK Layter JG Lindsey CS Loken SC Lu X Lynch GR Madansky L Madaras RJ Maruyama K Marx JN Matthews JA Melnikoff SO Moses W Nemethy P 《Physical review letters》1985,54(4):270-273
5.
J. G. Dunn A. C. Chamberlain N. G. Fisher J. Avraamides 《Journal of Thermal Analysis and Calorimetry》1997,49(3):1399-1408
The thermal decomposition of SEX in a nitrogen atmosphere was studied by coupled thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR), and by pyrolysis-gas chromatography-mass spectrometry (py-GC-MS). The TG curve exhibited two discrete mass losses of 45.8% and 17.8% respectively, at 200 and 257–364°C. The evolved gases identified as a result of the first mass loss were carbonyl sulfide (COS), ethanol (C2H5OH), ethanethiol (C2H5SH), carbon disulfide (CS2), diethyl sulfide ((C2H5)2S), diethyl carbonate ((C2H5O)2CO), diethyl disulfide ((C2H5)2S2), and carbonothioic acid, O, S, diethyl ester ((C2H5S)(C2H5O)CO). The gases identified as a result of the second mass loss were carbonyl sulfide, ethanethiol, and carbon disulfide. Hydrogen sulfide was detected in both mass losses by py-GC-MS, but not detected by FTIR. The solid residue was sodium hydrogen sulfide (NaSH).SEX was adsorbed onto activated carbon, and heated in nitrogen. Two discrete mass losses were still observed, but in the temperature ranges 100–186°C (7.8%) and 186–279°C (11.8%). Carbonyl sulfide and carbon disulfide were now the dominant gases evolved in each of the mass losses, and the other gaseous products were relatively minor. It was demonstrated that water adsorbed on the carbon hydrolysed the xanthate to cause the first mass loss, and any unhydrolysed material decomposed to give the second mass loss.Mr. N. G. Fisher would like to thank the A. J. Parker CRC for Hydrometallurgy for the provision of a PhD scholarship. 相似文献
6.
Summary The applicability of capillary electrochromatography to the automated analysis of pesticides and phthalate esters that are
of environmental concern was assessed. Reversed phase packing materials were compared. Column to column and run to run reproducibility
was established. Peak height with an internal standard gave the best reproducibility. Faster analysis than alternative HPLC
methods was demonstrated for a mixture of the insecticide pirimicarb and related pyrimidines. The relationship between the
concentration of an analyte in a sample and at the detector was determined by the use of radio-labelled14C-pirimicarb. The volume fraction of the liquid zone was 0.64. The possibility of electroosmosis through the pores is discussed
with reference to the Rice-Whitehead model for electroosmotic flow in a capillary. A new parameter, the effective pore size
is used in equations for electroosmosis through porous packings. 相似文献
7.
J. Somlai B. Kanyár R. Bodnár CS. Németh Z. Lendvai 《Journal of Radioanalytical and Nuclear Chemistry》1996,207(2):437-443
A significant dose contribution on the population could be derived from coal slags used as isolation material. Extremely high natural activities are measured in the coal slag, derived from the region of the settlement Ajka, Hungary. In some buildings monitored, the elevated -doses were nearly 5–10 times higher than the world average ones. The annual average indoor radon concentrations from the slag exceeded 400 Bq/m3 and in some cases up to 1200 Bq/m3. Due to the elevated exposure and the radon concentrations in the dwellings the annual dose was estimated to 8–24 mSv/y more than 5–10 times of the world average one. 相似文献
8.
9.
Maria A. Lebedeva Dr. Thomas W. Chamberlain Dr. E. Stephen Davies Dr. Dorothée Mancel Bradley E. Thomas Dr. Mikhail Suyetin Dr. Elena Bichoutskaia Prof. Dr. Martin Schröder Prof. Dr. Andrei N. Khlobystov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(36):11999-12008
A covalently‐linked salen–C60 (H2L) assembly binds a range of transition metal cations in close proximity to the fullerene cage to give complexes [M(L)] (M=Mn, Co, Ni, Cu, Zn, Pd), [MCl(L)] (M=Cr, Fe) and [V(O)L]. Attaching salen covalently to the C60 cage only marginally slows down metal binding at the salen functionality compared to metal binding to free salen. Coordination of metal cations to salen–C60 introduces to these fullerene derivatives strong absorption bands across the visible spectrum from 400 to 630 nm, the optical features of which are controlled by the nature of the transition metal. The redox properties of the metal–salen–C60 complexes are determined both by the fullerene and by the nature of the transition metal, enabling the generation of a wide range of fullerene‐containing charged species, some of which possess two or more unpaired electrons. The presence of the fullerene cage enhances the affinity of these complexes for carbon nanostructures, such as single‐, double‐ and multiwalled carbon nanotubes and graphitised carbon nanofibres, without detrimental effects on the catalytic activity of the metal centre, as demonstrated in styrene oxidation catalysed by [Cu(L)]. This approach shows promise for applications of salen–C60 complexes in heterogeneous catalysis. 相似文献
10.
In view of current interest in the trapping of antihydrogen atoms at low temperatures [1–3], we have investigated the reasons for considering that does not have a bound state. We go on to carry out a four-body variational calculation for s-wave hydrogen-antihydrogen scattering, using the Kohn variational method. This is a continuation of earlier work on interactions [5–7].
Received October 30, 2001; accepted for publication November 21, 2001 相似文献