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111.
Resolution of freshly prepared and of commercially available (degraded) samples of cardiolipin into 15-30 components has been accomplished by reversed-phase high-performance liquid chromatography using a 3-micron particulate Microsorb C18 column irrigated with linear gradients of acetonitrile--methanol--10 mM phosphate buffer pH 7.4. Selected resolved components were crystallized and characterized by infrared absorption spectra. Saponification of other components and identification of component fatty acids by reversed-phase high-performance liquid chromatography demonstrated the presence of ten fatty acids (14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2, 18:3, 20:0, 20:4), with linoleic acid (18:2) identified in all resolved components. From fatty acid composition data it appears that several resolved fractions consist of single cardiolipin molecular species. 相似文献
112.
G. K. Bratspies J. F. Smith J. O. Hill P. J. Derrick 《Journal of Thermal Analysis and Calorimetry》1979,16(2):369-379
A new tin dithiocarbamate containing sulphur bridges, di--sulphidobis [bis(N,N-diethyldithiocarbamato)tin(IV)], has been isolated from the thermal decomposition of tetrakis(N,N-diethyldithiocarbamato)tin(IV). A dimeric structure is proposed on the basis of results from mass spectrometry, infrared spectroscopy, thermal analysis and vapour pressure osmometry.
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
Zusammenfassung Ein neues, Schwefelbrücken enthaltendes Zinn-Dithiocarbamat, Di--sulfidobis[bis(N,N-diäthyldithiocarbamato)Zinn(IV)], wurde bei der Zersetzung von Tetrakis(N,N-diäthyl-dithiocarbamato)Zinn(IV) isoliert. Aufgrund der Ergebnisse der Massenspektrometrie, der Infrarotspektroskopie, der Thermoanalyse und der Dampfdruck-Osmometrie wird eine Dimerstruktur vorgeschlagen.
Résumé Un nouveau dithiocarbamate d'étain contenant des ponts de soufre, le di--sulfidobis[bis(N,N-diéthyl-dithiocarbamato)é tain(IV)], a été isolé lors de la décomposition thermique du tétrakis(N,N-diethyl-dithiocarbamato) étain(IV). Une structure dimère est proposéeà partir des résultats obtenus par spectrométrie de masse, spectroscopie infrarouge, analyse thermique et osmométrie sous pression de vapeur.
—-- [/N,N- (/IV)], [/N,N- (/IV)], , (N,N- ) (IV). - , , .
The authors gratefully acknowledge the assistance given by Dr. A. G. Wedd with the vacuum sublimation technique. One of us, G. K. B., is grateful for a research scholarship provided by La Trobe University. 相似文献
113.
Abstract —Various low-potential viologen dyes enhance light-induced absorption changes in the near-infrared region (ΔA870) in chromatophore preparations from Rhodospirillum rubrum in the presence of dichlorophenol indophenol and a high concentration of ascorbate (DCPIP + asc). An increase in ΔA870 was also observed in large reaction-center preparations from R. rubrum with viologens in the presence of ascorbate. Our results indicate that E'0 , of the primary electron acceptor X may be as low as -0.37 V, as suggested recently by P. A. Loach (1973, personal communication). 相似文献
114.
Smith JT Tomfohr JK Wells MC Beebe TP Kepler TB Reichert WM 《Langmuir : the ACS journal of surfaces and colloids》2004,20(19):8279-8286
A novel technique for the quantitative observation of cell migration along linear gradient substrates functionalized with adhesive proteins is presented. Gradients of the cell adhesion molecule fibronectin are generated by the cross diffusion of functionalizable alkanethiols on gold and characterized by X-ray photoelectron spectroscopy and surface plasmon resonance. Two distinct migration assays are described that characterize the movement of either sparsely populated noncontacting cells or a confluent monolayer of cells into free space. The drift speed of bovine aortic endothelial cells is measured and shown to increase along a fibronectin gradient when compared to a uniform control substrate using both assays. The results of these experiments establish reproducible conditions for studies of cell migration on gradients of surface-bound ligands. 相似文献
115.
Douglas F. Foster Barry S. Nicholls Anthony K. Smith 《Journal of organometallic chemistry》1982,236(3):395-402
Reactions of Rh6(CO)16 with bis(diphenylphosphino)methane (dppm) gave Rh6(CO)14(dppm), Rh6(CO)12(dppm)2, or Rh6(CO)10(dppm)3, depending upon the reaction conditions. Rh4(CO)10(dppm) may be obtained from the reaction of Rh4(CO)12 with dppm, but this derivative rapidly decomposes in solution to give Rh4(CO)8(dppm)2, Rh6(CO)14(dppm), and Rh6(CO)12(dppm)2. Ir4(CO)10(dppm) and Ir4(CO)8(dppm)2 have also been prepared, and their structures are discussed on the basis of infrared and 31P NMR spectroscopic data. 相似文献
116.
Jensen BP Smith CJ Bailey CJ Rodgers C Wilson ID Nicholson JK 《Rapid communications in mass spectrometry : RCM》2005,19(4):519-524
Inductively coupled plasma mass spectrometry (ICPMS) has been used to determine the rate and routes of excretion of bromine following the intraperitoneal administration (50 mg kg(-1)) of 2-, 3- and 4-bromobenzoic acids to male bile-duct-cannulated rats. Analysis of urine and bile for (79/81)Br using ICPMS showed that all three bromobenzoic acids were rapidly excreted (82-98%) within 48 h of dosing, primarily via the urine. High-performance liquid chromatography/inductively coupled plasma mass spectrometry (HPLC/ICPMS) was then used to obtain metabolite profiles for bile and urine. These profiles revealed that extensive metabolism had taken place, with the unchanged bromobenzoic acids forming a minor part of the total of compound-related material detected. Concomitant MS studies, supplemented by alkaline hydrolysis, enabled the identification of the major metabolite of all three of the bromobenzoic acids as a glycine conjugate. Ester glucuronide conjugates were also identified, but formed only a small proportion of total. 相似文献
117.
D. H. Davies D. C. Phillips J. D. B. Smith 《Journal of polymer science. Part A, Polymer chemistry》1972,10(11):3253-3265
A comparative analysis of photoinitiation and electroinitiation can help elucidate initiation processes in donor-acceptor charge-transfer copolymerization. The technique has been applied to the zinc bromide-catalyzed copolymerization of styrene and diethyl fumarate in methanol. The photocopolymer product was analyzed by GPC, NMR, and elemental analysis. The results showed that 1:1 copolymers were formed initially, but changes occurred in both the kinetics and products after the early stages of the reaction. Significant correlations found between the two initiation methods included the initial kinetic order with respect to the initiating process and the effect on product yield of equivalent increases in total initiation energy. The limiting value of zinc bromide for both initiation methods was found to be the same. The data obtained support the contention that the copolymerization proceeds through a donor–acceptor process and that photoactivation of the preformed complex, inducing electron transfer, is a likely initiation process. 相似文献
118.
Initial rates of grafting, Rg, have been determined for film of nylon-6, which had been -,,-irradiated in vacuo and subsequently immersed in outgassed, aqueous, acrylic acid at 50'. Equilibrium swellings due to water and to monomer are attained rapidly by nylon-6 and give rise to a high Rg. During grafting a constant swelling due to water occurs immediately but the rate of uptake of monomer is less than Rg, These effects are discussed on the basis of compatibility. At a fixed equilibrium monomer concentration, [AA], in the film, Rg ∝ Dβ where D is the dose and β = 0.94. At a fixed dose, Rg ∝ [AA]α where α = 1.04. The value of β indicates mainly monomolecular termination by radical burial. This is postulated to occur by trapping of growing grafts in crystalline regions and/or transfer from them to such regions. By selectively dyeing and sectioning films of different degrees of grafting (DG), the progress of the grafting front inwards has been shown to follow closely the corresponding grafting curve of DG vs time. Grafting does not alter the moisture regain of nylon. Surface resistance and swelling in water change with DG, the effect being enhanced markedly by converting the grafts to their sodium salts. 相似文献
119.
Methods of detection of amphetamine sulfate using surface enhanced Raman scattering (SERS) from colloidal suspensions and vapour deposited films of both silver and gold are compared. Different aggregating agents are required to produce effective SERS from silver and gold colloidal suspensions. Gold colloid and vapour deposited gold films give weaker scattering than the equivalent silver substrates when high concentrations of drug are analysed but they also give lower detection limits, suggesting a smaller surface enhancement but stronger surface adsorption. A 10(-5) mol dm(-3) solution (the final concentration after addition of colloid was 10(-6) mol dm(-3)) of amphetamine sulfate was detected from gold colloid with an RSD of 5.4%. 25 microl of the same solution could be detected on a roughened gold film. The intensities of the spectra varied across the film surface resulting in relatively high RSDs. The precision was improved by averaging the scattering from several points on the surface. An attempt to improve the detection limit and precision by concentrating a suspension of gold colloid and amphetamine sulfate in aluminium wells did not give effective quantitation. Thus, positive identification and semi-quantitative estimation of amphetamine sulfate can be made quickly and easily using SERS from suspended gold colloid with the appropriate aggregating agents. 相似文献
120.
The reactions of various fluoroaromatics, C6F6?xHx, and C6F5X (X = C6F6, Cl, Me, NO2, CF3, COCl, CH2Br, OMe, and NH2) with lead(II) benzenethiolate in DMF have been examined. Lead thiolate acted as an excellent source of benzenethiolate anions and displacement of fluorine, chlorine or the nitro group was observed. The new products have been characterized by elemental analysis, and NMR (H?1 and F?19), infrared and mass spectroscopy. 相似文献