有机锗对铅所致小鼠学习记忆障碍的拮抗作用

用避暗法和水迷宫法研究了对铅所致的小鼠记忆障碍的影响。ＩＣＲ系小鼠隔日腹腔注射羧乙基锗 半氧化物（Ｇｅ－１３２,２５ｍｇ／ｋｇ）,和／或醋酸铅（１５ｍｇ／ｋｇ）２８ｄ。结果表明暴露于铅２０ｄ后小鼠学习记忆能力受障碍,同时给予Ｇｅ－１３２能明显拮抗铅的毒性作用。试验提示Ｇｅ－１３２能拮抗所致的神经行为为功能的破坏作用。     

Ge—132对小鼠H22肝癌移植瘤的影响

Ｇｅ－１３２对小鼠Ｈ２２肝癌移植瘤的实验研究证明：１．Ｇｅ－１３２对Ｈ２２肝癌移植瘤有一定的抑制作用，３００ｍｇ／ｋｇ体重剂量抑瘤率达到３６．１９％；２．增强机体的抗氧化作用，抑制脂质的过氧化物水平；３．促进免疫功能，当Ｇｅ－１３２和环磷酰胺联合使用时，可抵抗环磷酰胺的免疫抑制作用，而且并不减弱其抑制瘤作用。     

临床观察Ge—132的毒副反应

为探讨Ｇｅ－１３２的毒副反应，对服用Ｇｅ－１３２的肺癌患者３０８３例进行长期观察。结果发现各项观察指标，治疗组与对照组均无明显差异，可认为在合理剂量下，临床长期应用Ｇｅ－１３２是安全的。     

乙二胺四乙酸对锗（Ⅳ）—没食子酸体系及钒（Ⅳ）的示波极谱电流的影响

用分光光度法及电化学法详细研究了在稀硫酸介质，分别加ＥＤＴＡ到锗－没食子酸，Ｇｅ－ＧＡ－Ｖ体系以及Ｖ溶液中，所产生的影响。结果表明，ＥＤＴＡ使Ｇｅ－ＧＡ体系的两步２电子反应过程变得清Ｇｅ－ＧＡ－Ｖ体系因Ｖ２Ｈ３Ｙ＾－Ｇ形成，增强了Ｖ的化学氧化力。     

Ge—132在机体内代谢产物的实验证实

评述了Ｇｅ－１３２的安全性，对大鼠口服Ｇｅ－１３２代谢产物的研究表明，Ｇｅ－１３２的基本骨架ＧｅＣＨ２ＣＨ２ＣＯＯＨ没有变化，即它不会降解为ＧｅＯ２或其他的无机锗化合物。     

关于合成Ge—132所用Ge原料其残留无机锗的问题

Ｇｅ－１３２中的无机锗含量是一个重要的质量指标。它主要来自ＧｅＨＣｌ３中的ＧｅＣｌ４,而无论哪种锗原料合成Ｇｅ－１３２,ＧｅＨＣｌ３都是中间产物。与用金属Ｇｅ和ＧｅＯ２制备Ｇｅ－１３２的工艺比较,用ＧｅＯ２的盐酸溶液比用金属Ｇｅ在高温下与ＨＣｌ气反应制备ＧｅＨＣｌ３更利于降低Ｇｅ－１３２中残留的无机锗含量。     

元素在石墨炉内石墨探针表面上的原子化机理研究：Ⅶ.锗的原子化机理

本文应用Ｘ－射线衍射，Ｘ－射线光电子能谱，俄歇电子能谱和其它一些实验，考察石墨炉升温过程中氟化锗，锗酸钠在石墨探针表面上的形态变化，阐明了它们的原子化机理：ＧｅＦ２与Ｎａ２ＧｅＯ３首先分解为ＧｅＯ２，ＧｅＯ２还原为ＧｅＯ，后者在＞２４００Ｋ热分解产生自由态的锗原子，ＧｅＦ２和Ｎａ２ＧｅＯ３的原子化均源于ＧｅＯ（ｇ）的气相分解。原子化的升温过程中，在１４００－２４００Ｋ ＧｅＦ２和Ｎａ２ＧｅＯ３都产     

铂配合物cis—[Pt（nh3）2（4—mepy）Cl]NO3与甲在—谷胱甘肽作…

使用质子核磁共振方法了新的抗癌活性配合物ｃｉｓ」Ｐｔ（ＮＨ３）２（４－ｍｅｐｙ）Ｃｌ「＾＋与甲基－谷胱甘应及其动力学。结果表明Ｐｔ与ＧＳ－Ｍｅ间形成１：１加合物。为了解结合部位，对Ｐｔ－ＧＳ－Ｍｅ配合物进行ｐＨ滴定，由ＧＳ－Ｍｅ的质子核磁共振谱对ｐＨ的依赖关系判断Ｇｓ－Ｍｅ只通过Ｓ原子与Ｐｔ配位，而氨基和羧基不参与配位反应。     

Ge—132抑制Maillard反应的临床意义

根据文献介绍了Ｇｅ－１３２在梅拉德氏反应中抑制ＡＧＥ的效果。体外模型实验表明,Ｇｅ－１３２可抑制Ｐｅｎｔｏｓｉｄｉｅｎ的形成;体内模型实验表明,Ｇｅ－１３２成功改善了ＳＴＺ引起的病态,可延迟白内障的发生等;人体实验表明,Ｇｅ－１３２可使５０％患者果糖胺恢复正常,治疗白内障有效。Ｇｅ－１３２可望用于糖尿病并发症的治疗中。     

Ge-132稀土配合物及其对单核苷酸磷酯键的催化水解作用

Ｇｅ－１３２是具有广泛生物活性的一元羧酸有机锗倍半氧化物的低聚物,分子中存在类似冠醚的Ｇｅ－Ｏ－Ｇｅ大环结构．因此,有人认为Ｇｅ－１３２的生物活性可能与这种大环结构与体内金属离子形成配合物有关［１］,但尚无直接的实验证据．因此,合成Ｇｅ－１３２稀土配...     

Deposition studies of carbon particles on stainless steel surfaces from hydrocarbon media

The adsorption isotherms for carbon particles of about 200 nm size, in the presence of various combinations of a terminally functionalised (amine) polyisobutylene polymer and alkylpropoxylate/alkylbutoxylate surfactant molecules, on 7 μm diameter stainless steel beads from isooctane solutions have been obtained. The deposition of carbon particles on stainless steel plates was achieved using a flow-cell and analysed using scanning electron microscopy. The flow-cell was also used to study the “cleaning” properties of various polymer/surfactant solutions, in their ability to remove deposited particles. It was found that the polymer molecules were much more effective dispersants and stabilisers for the carbon particles, but the surfactant molecules were much better at effecting anti-deposition and subsequent removal of deposited carbon particles, and provide carried adsorbed polymer chains.     

Esca studies of polyurethanes: blood platelet activation in relation to surface composition

Segmented polyurethanes (SPU) were synthesized with polyethylene oxide (PEO), polypropylene oxide, or polytetramethylene oxide as the “soft segment,” from the respective polyether diols, of which molecular weight varied from 600 to 2000. The “hard segment” was created from ethylene diamine and tolylene diisocyanate or 4,4′-diphenylmethane diisocyanate. Platelet activation was assessed using columns packed with beads coated with each of the SPU by solutions from which the solvent was subsequently evaporated. Citrated whole human blood was passed through the columns and the platelet count in aliquots leaving the columns was compared with the platelet count in blood that had not contacted the column surface. By this method the fraction of platelets retained in the column averaged for several donors, ρ, was determined. In parallel experiments, SPU surfaces formed under identical conditions by evaporation of solvent were examined by X-ray electron spectroscopy for carbon, oxygen, and nitrogen content of the surface. The carbon C_1s spectra proved to be particularly useful, when analyzed for the components with peaks respectively at 286 eV (carbon not bonded to an ether oxygen) and at 288 eV (carbon bonded to an ether oxygen). The platelet retention index ρ was found to increase nearly linearly with the ratio of the 286-eV intensity to the 288-eV intensity, and extrapolated to nearly zero for zero value of the intensity ratio, which would correspond to amorphous PEO, suggesting that if a surface were only amorphous PEO it would be remarkably inactive toward platelets. In contrast, nitrogen spectra show no systematic relationship with ρ.     

Mechanism of UVB-Induced Suppression of the Immune Response to Mycobacterium bovis Bacillus Calmette-Guerin: Role of Cytokines on Macrophage Function

Previously we demonstrated that treatment of mice with either UVB radiation or supernatants derived from UVB-irradiated PAM 212 keratinocytes decreased the induction of the delayed-type hypersensitivity (DTH) response to Mycobacterium bovis bacillus Calmette-Guerin (BCG), impaired the clearance of bacteria from their lymphoid organs and also altered macrophage functions. In order to characterize the cytokines involved in these phenomena, UV-irradiated mice were injected with antibodies to interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), or tumor necrosis factor-α (TNF-α). Injection of UVB-irradiated mice with anti-IL-10 immediately after UV irradiation restored the DTH response and reversed the UV-induced inhibition of bacterial clearance. Injection of UV-irradiated mice with anti-TGF-β only partially restored the DTH response although it allowed a better clearance of BCG than injection of mice with the control antibody. In contrast, injection of anti-TNF-α did not affect the UVB-induced suppression of DTH or impaired bacterial clearance. Similarly, the ability of macrophages to phagocytose BCG and kill the intracellular organisms was restored to almost normal levels after injecting UV-irradiated mice with antibodies specific for IL-10 or TGF-β. Injection of mice with either recombinant IL-10 or TGF-β mimicked the effect of whole-body UV irradiation on immune function. These results suggest that IL-10 has a major role in UV-induced suppression of both DTH to BCG and impairment in the clearance of bacteria and that TGF-β has a more significant role in blocking bacterial clearance. Furthermore, these cytokines seem to modulate immune responses by altering macrophage functions in UVB-irradiated mice.     

Ambient temperature gas purifier suitable for the trace analysis of carbon monoxide and hydrogen and the preparation of low-level carbon monoxide calibration standards in the field

A novel gas purifier based upon Sofnocat 682, a catalyst containing platinum and palladium on a hydrophobic tin oxide support, is described for the quantitative removal at ambient temperatures of ppm (v/v) and sub-ppm (v/v) levels of carbon monoxide and hydrogen from air and nitrogen gas cylinders. This method provides a simple means of generating either a laboratory or field source of “zero grade” gas for both the trace analysis of carbon monoxide and hydrogen and the preparation of working calibration gas standards of carbon monoxide by using a simple one-step dilution of a higher concentration certified gas standard.     

Investigation of the effect of carbon monoxide on the oxidative carbonylation of methanol to dimethyl carbonate over CuX and CuZSM-5 zeolites

Direct synthesis of dimethyl carbonate offers prospects for a “green chemistry” replacement to eliminate use of phosgene for polymer production and other processes. The carbonylation of methanol to produce dimethyl carbonate over Cu⁺X and Cu⁺ZSM-5 zeolites prepared by solid-state ion exchange has been investigated, focusing on the interaction of carbon monoxide with the Cu⁺ zeolites. The methanol carbonylation mechanism reported previously has been extended to account for carbon monoxide adsorption at high pressure. The comparison of the results obtained from Cu⁺X and Cu⁺ZSM-5 show that strong CO adsorption on the catalyst is not related to increased rate of dimethyl carbonate production. The rate limiting step for DMC production is best described as the Eley-Rideal reaction of gas-phase CO with surface methoxide.     

Adsorption of NOM onto Activated Carbon: Effect of Surface Charge, Ionic Strength, and Pore Volume Distribution

Adsorption of natural organic matter (NOM) onto seven activated carbons with a wide range of surface properties was studied at high and low ionic strength over a range of pH values. From adsorption isotherm studies it was found that, for six of seven carbons, at low surface concentrations, increased ionic strength decreased NOM adsorption. As the surface concentration increased, the adsorption isotherms converged and intersected, after which the addition of salt resulted in increased adsorption. This “crossover point” marked a change in the adsorption mechanism from the “screening reduced” to the “screening enhanced” adsorption regimes. The adsorption mechanisms are extremely complicated and appear attributable to various factors, including electrostatic forces, pore volume distribution, and chemical interactions between the NOM and the surface functionalities on the carbon surfaces.     

Characterization of coal fly ash components by laser-induced breakdown spectroscopy

The high sensitivity of laser-induced breakdown spectroscopy (LIBS) for the detection of most of the fly ash components enables the analysis of these residues produced during the combustion of coal. Fly ash consists of oxides (SiO₂, Al₂O₃, Fe₂O₃, CaO…) and unburnt carbon which is the major determinant of combustion efficiency in coal fired boilers. For example, an excessive amount of residual carbon dispersed in the fly ash means a significant loss of energy (Styszko et al., 2004 [1]). Standard methods employed for the analysis of fly ash make not possible a control of boiler in real time. LIBS technique can significantly reduce the time of analysis, in some cases even an online detection can be performed. For this reason, some studies have been addressed in order to demonstrate the capability of the laser-induced breakdown spectroscopy technique for the detection of carbon content in high pressure conditions typical of thermal power plants (Noda et al., 2002 [2]) and for the monitoring of unburnt carbon for the boiler control in real time (Kurihara et al., 2003[3]).In particular, the content of unburnt carbon is a valuable indicator for the control of fly ash quality and for the boiler combustion. Depending on this unburnt carbon content, fly ash can be disposed as an industrial waste or as a raw material for the production of concrete in the construction sector. In this study, analyses were performed on specimens of various forms of preparation. Pressed pellets were prepared with two different binders. Presented results concern the nature and amount of the binder used to pelletize the powder, and the laser-induced breakdown spectroscopy parameters and procedure required to draw calibration curves of elements from the fly ash. Analysis “on tape” was performed in order to establish the experimental conditions for the future “online analysis”.     

Simultaneous microdetermination of carbon, hydrogen and chlorine or bromine in organic compounds by various rapid empty-tube combustion methods

A standard Pregl absorption tube packed with polyurethane foam mixed with a cation-exchanger in the silver form, backed with a layer of “Anhydrone”, and connected between the water and carbon dioxide absorption tubes and kept at room temperature, has been employed successfully for the simultaneous determination of chlorine or bromine together with carbon and hydrogen. This foam tube is suitable for use with the Belcher-Ingram, rapid straight empty-tube and rapid flash-combustion methods.     

Structural and electronic characteristics of perhydrogenated carbon nanotubes

The structural and electronic characteristics of fully hydrogenated armchair and zigzag carbon nanotubes have been determined by quantum chemical methods. With use of line group symmetries, the structures of nanotubes up to 10 nm in diameter could be optimized by periodic B3LYP calculations. “In–out” isomerism is shown to significantly stabilize perhydrogenated carbon nanotubes, the energetically most favorable structures being those with 1/3–1/2 of the carbon atoms endo-hydrogenated. In favored nanotubes the ratio of endo- to exo-hydrogens is 1:1, the stabilities increasing as a function of the diameter of the nanotube. The calculated band gaps indicate that the perhydrogenated carbon nanotubes are insulators.     

Strong effects of the bridge configuration on photoinduced charge separation in rigidly linked donor-acceptor systems

Photoinduced electron-transfer rates are reported for two pairs of rigid bichromophoric molecules 1(6)/2(6) and 1(8)/2(8). In the first pair electron donor and acceptor are separated by six, in the second pair by eight, carbon—carbon σ bonds. While these σ bonds provide an all-trans coupling path in 1(6) and 1(8), that path contains s-cis elements in 2(6) and 2(8), which - as shown by X-ray structure data and by spectroscopic evidence - leads to a slight decrease in the effective, spatial donor-acceptor separation. Nevertheless, photoinduced electron transfer in each of the “stretched” compounds is about one order of magnitude faster than in the corresponding “bent” compound. This remarkable effect is interpreted as resulting from the unique ability of an all-trans array of σ bonds to mediate electronic through-bond interaction (TBI). Interestingly the solvent dependence of the rate of photoinduced electron transfer is significantly larger in the “bent” systems, thus indicating that superexchange via solvent molecules becomes competitive with TBI if an all-trans array is not available.