Friedel-Crafts Polymers. 6. Friedel-Crafts Polycondensation of p-Xylylerte Dibromide with Salicylic Acid and β-Resorcyiic Acid

Polymers were prepared by condensing p-xylylene dibromide separately with salicylic acid and β-resorcylic acid in the presence of anhydrous ferric chloride in dioxane. The polymer samples_were characterized by elemental analysis, by IR spectral study, by M determined by vapor pressure osmometry, by nonaqueous conducto-metric titration in pyridine, by TGA in air, and by viscosity measurements of polymer solutions in DMF. Polymeric metal chelates of Cu²⁺, Co²⁺, Zn²⁺, Ni²⁺, and Fe³⁺ with polymer samples were prepared and characterized by elemental analysis, by IR spectral study, and by TGA in air. The chelation ion-exchange properties of the polymer samples were studied by employing the batch equilibration method.     

Akt is involved in the inhibition of cell proliferation by EGF

Axin is a negative regulator of the Wnt/beta-catenin pathway and is involved in the regulation of axis formation and proliferation. Involvement of Axin in the regulation of other signaling pathways is poorly understood. In this study, we investigated the involvement of Akt in growth regulation by Axin in L929 fibroblasts stimulated by EGF. Akt activity was increased by EGF treatment and Ras activation, respectively. Both the EGF- and Ras-induced Akt activations were abolished by Axin induction, as revealed by both Western blot and immunocytochemical analyses. The proliferation and Akt activation induced by EGF were decreased by Axin induction, and the effects of EGF were abolished by treatment of an Akt-specific inhibitor. Therefore, Axin inhibits EGF-induced proliferation of L929 fibroblasts by blocking Akt activation.     

湿化学法制备硅纳米线阵列及其光电化学产氢性能分析

为了探究不同方法条件下制备的硅纳米线阵列电极产氢性能异同,文中分别采用了两步金属辅助催化无电刻蚀法、一步金属辅助催化无电刻蚀法以及阳极氧化法来制备硅纳米线阵列用作为光电分解水电池光阴极材料.通过FESEM、XRD和UV-Vis-IRDRS等手段对实验样品的形貌、晶型、减反性表征,发现相比于其他2种方法所得硅纳米线样品,两步金属辅助催化无电刻蚀法制备的硅纳米线结构晶型保持更好,表面缺陷更少.光电化学测试表明两步金属辅助催化无电刻蚀法制备的硅纳米线光电化学性能表现最优,其光电流密度值是一步法的4倍,阳极氧化法的40倍;转移电荷电阻仅是一步法制备的硅纳米线阵列阻值的1/3,阳极氧化法制备的1/1000.     

Oxidations and reductions of iron-cyanogen compounds of cobalt,nickel, cadmium and zinc

I. Cobalt ferrocyanide is oxidized by bromine water, by nitrous acid or by hydrogen peroxide in presence of acids to cobalt ferroferricyanide (cobalt Prussian blue), while cobalt ferricyanide is reduced by sulfurous acid to cobalt Prussian blue.II. Nickel ferrocyanide is oxidized by nitrous acid or by hydrogen peroxide in presence of acids to nickel ferricyanide.III. Nickel ferrocyanide and cadmium ferrocyanide are oxidized by bromine water to the ferricyanides.IV. The ferricyanides of nickel, cadmium and zinc are reduced by sulfurous acid to the ferrocyanides.     

湿化学法制备硅纳米线阵列及其光电化学产氢性能分析

为了探究不同方法条件下制备的硅纳米线阵列电极产氢性能异同,文中分别采用了两步金属辅助催化无电刻蚀法、一步金属辅助催化无电刻蚀法以及阳极氧化法来制备硅纳米线阵列用作为光电分解水电池光阴极材料。通过FESEM、XRD和UVVis-IR DRS等手段对实验样品的形貌、晶型、减反性表征,发现相比于其他2种方法所得硅纳米线样品,两步金属辅助催化无电刻蚀法制备的硅纳米线结构晶型保持更好,表面缺陷更少。光电化学测试表明两步金属辅助催化无电刻蚀法制备的硅纳米线光电化学性能表现最优,其光电流密度值是一步法的4倍,阳极氧化法的40倍;转移电荷电阻仅是一步法制备的硅纳米线阵列阻值的1/3,阳极氧化法制备的1/1 000。     

Synthesis of polyphenylacetylene by radiation-induced polymerization in deoxycholic acid clathrate

Phenylacetylene was polymerized as inclusion compound (clathrate) inside deoxycholic acid (DOCA) crystals. The polymerization was initiated by γ radiation and a total dose of 320 kGy was employed. The resulting polyphenylacetylene (PPA) was isolated by dissolution of deoxycholic acid in boiling ethanol. PPA high polymer was accompanied by a series of phenylacetylene oligomers, which were detected by liquid chromatographic analysis (HPLC). PPA was characterized by electronic absorption spectroscopy and by FT-IR spectroscopy in comparison to a reference PPA prepared by a stereospecific catalyst. The microstructure of PPA from inclusion polymerization was highly trans type, similar to that observed on PPA prepared by bulk radiolysis. No optical activity was detected by polarimetry on PPA prepared by inclusion polymerization.The host–guest complex PPA/DOCA was studied by differential thermal analysis (DTA) and by thermogravimetry (TGA). DTA provided evidences of the host–guest complex formation from the shift of the melting point of DOCA while the TGA confirmed the identity – in terms of thermal behaviour – of the PPA from inclusion polymerization with that from stereospecific polymerization.     

Substoichiometric determination of phosphorus

Phosphorus in orchard leaves (NBS SRM-1571) and spinach (SRM-1570) was determined by various substoichiometric analytical methods such as the direct method, GRASHCHENKO's method and the method of carrier amount variation. All samples were labelled with³²P radioisotope. The data obtained by the method of carrier amount variation were also treated by the method of least squares instead of De VOE's method. Phosphorus concentration in orchard leaves was 0.206±0.011% by the direct method, 0.219±0.011% by GRASHCHENKO's method, 0.211±0.011% by the method of carrier amount variation and 0.207±0.007% by the method of least squares, respectively. These values agree with the value reported by NBS (0.21±0.01%). Furthermore, these concentrations obtained by various substoichiometric methods were compared with those by radioactivation reported in a prevoius paper.     

锰离子控制掺杂二氧化钛薄膜光催化活性增强的机理探讨

采用溶胶-凝胶法通过工艺控制制备了锰离子以不同形式掺杂TiO₂的光催化剂薄膜,并通过XPS和SEM对薄膜的结构进行表征.通过UV-Vis分光光度计及电化学工作站表征了薄膜的光吸收性能和光电化学性能,通过甲基橙溶液的光催化降解脱色率来表征催化剂薄膜的光催化活性.结果表明,以锰离子MT掺杂方式制备的TiO₂薄膜可明显增强TiO₂的光催化活性,而以MM掺杂方式制备的TiO₂薄膜反而降低了TiO₂的光催化活性;锰离子MT掺杂方式的最佳掺杂质量分数为0.8%.催化剂薄膜的电化学行为显示,薄膜具有p-n结的电容-电压特性,锰离子MT掺杂TiO₂薄膜的开路电位和瞬时光电流信号较强,说明其光生载流子易于生成并且分离效果较好.依据半导体的p-n结原理探讨了锰离子控制掺杂TiO₂的光催化活性机理.     

Fermented Oyster Extract Attenuated Dexamethasone-Induced Muscle Atrophy by Decreasing Oxidative Stress

It is well known that oxidative stress induces muscle atrophy, which decreases with the activation of Nrf2/HO-1. Fermented oyster extracts (FO), rich in γ-aminobutyric acid (GABA) and lactate, have shown antioxidative effects. We evaluated whether FO decreased oxidative stress by upregulating Nrf2/HO-1 and whether it decreased NF-κB, leading to decreased IL-6 and TNF-α. Decreased oxidative stress led to the downregulation of Cbl-b ubiquitin ligase, which increased IGF-1 and decreased FoxO3, atrogin1, and Murf1, and eventually decreased muscle atrophy in dexamethasone (Dexa)-induced muscle atrophy animal model. For four weeks, mice were orally administered with FO, GABA, lactate, or GABA+Lactate, and then Dexa was subcutaneously injected for ten days. During Dexa injection period, FO, GABA, lactate, or GABA+Lactate were also administered, and grip strength test and muscle harvesting were performed on the day of the last Dexa injection. We compared the attenuation effect of FO with GABA, lactate, and GABA+lactate treatment. Nrf2 and HO-1 expressions were increased by Dexa but decreased by FO; SOD activity and glutathione levels were decreased by Dexa but increased by FO; NADPH oxidase activity was increased by Dexa but decreased by FO; NF-κB, IL-6, and TNF-α activities were increased by Dexa were decreased by FO; Cbl-b expression was increased by Dexa but restored by FO; IGF-1 expression was decreased by Dexa but increased by FO; FoxO3, Atrogin-1, and MuRF1 expressions were increased by Dexa but decreased by FO. The gastrocnemius thickness and weight were decreased by Dexa but increased by FO. The cross-sectional area of muscle fiber and grip strength were decreased by Dexa but increased by FO. In conclusion, FO decreased Dexa-induced oxidative stress through the upregulation of Nrf2/HO-1. Decreased oxidative stress led to decreased Cbl-b, FoxO3, atrogin1, and MuRF1, which attenuated muscle atrophy.     

Synthesis, properties, and applications of urethane-modified acrylated poly(ester-amide)s

Epoxy resin-based unsaturated poly(ester-amide) resins (UPEAs) were treated with acryloyl chloride to afford acrylated UPEAs resins (AUPEAs). Urethane-based acrylated poly(ester-amide)s prepared by reaction with diisocyanate were characterized by elemental analysis, by molecular weight determination (by vapour pressure osmometry), by IR spectral study, and by thermogravimetry. The curing of interacting blends was monitored by differential scanning calorimetry (DSC). On the basis of DSC data in-situ glass-reinforced composites were prepared from the resulting materials and their mechanical, electrical, and chemical properties were characterized. Unreinforced blends were characterized by thermogravimetry.     

Synthesis of an essentially alternating,aliphatic copolyamide

An essentially alternating copolyamide of 6-aminohexanoic acid and 11-aminoundecanoic acid was obtained by the condensation polymerization of methyl 11-(6-aminohexanamido)undecanoate. The monomer was synthesized by the following reaction steps: (1) nitration of cyclohexanone to α-nitrocyclohexanone; (2) cleavage of α-nitrocyclohexanone by methyl 11-aminoundecanoate to obtain methyl 11-(6-nitrohexanamido)undecanoate; (3) hydrogenation of the nitro group of the cleavage product. The polymer was characterized by its melting and crystallization behavior as determined by differential scanning calorimetry, by x-ray analysis, and by comparison with an equimolar, random copolyamide of the two amino acids.     

Comparison of monolithic approaches for enantioselective capillary electrochromatography involving cyclodextrins

The access to CD-modified monoliths for enantiomeric separation by CEC can be divided into two main approaches. (i) Silica-based monoliths, prepared by either a sol-gel process or by sintering of silica particles, are modified after fabrication by coating with a CD selector. Alternatively the fusion of CD functionalized silica particle via gluing is feasible. (ii) Rigid or homogeneous organic polymer-based monoliths, prepared by polymerization of organic monomers in the presence of a porogen, are modified with the CD selector either by copolymerization or by physical incorporation into the continuous bed.     

方波伏安法评估聚苯胺膜修饰电极的电荷传输速度

研究导电聚合物的电荷传输机制与速度对于其在应用方面的研究极为重要［‘］．例如在电池的研究中，充放电的速度决定于导电聚合物的电荷传输速度；在电致变色器件的研究中，响应时间也是决定于导电聚合物在氧化还原态间的变化速度，即电荷传输速度．显然较低的电荷传输速度不利于器件的实用化，因此人们必须找到一种能够迅速准确评价电荷传输速度的方法，由于导电聚合物是一个特殊的体系，用一般的电化学方法对其电荷传输速度进行测定时常常遇到这样或那样的问题［‘j．一般说来，导电聚合物的氧化还原过程中均伴随着抗衡离子的运动．体系…     

A nanocatalyst-based assay for proteins: DNA-free ultrasensitive electrochemical detection using catalytic reduction of p-nitrophenol by gold-nanoparticle labels

This communication reports a nanocatalyst-based electrochemical assay for proteins. Ultrasensitive detection has been achieved by signal amplification combined with noise reduction: the signal is amplified both by the catalytic reduction of p-nitrophenol to p-aminophenol by gold-nanocatalyst labels and by the chemical reduction of p-quinone imine to p-aminophenol by NaBH4; the noise is reduced by employing an indium tin oxide electrode modified with a ferrocenyl-tethered dendrimer and a hydrophilic immunosensing layer.     

New designer drug 2,5-dimethoxy-4-ethylthio-beta-phenethylamine (2C-T-2): studies on its metabolism and toxicological detection in rat urine using gas chromatography/mass spectrometry

Studies are described on the metabolism and the toxicological analysis of the phenethylamine-derived designer drug 2,5-dimethoxy-4-ethylthio-beta-phenethylamine (2C-T-2) in rat urine using gas chromatography/mass spectrometry (GC/MS) after enzymatic cleavage of conjugates, liquid-liquid extraction and derivatization. The structures of 14 metabolites were assigned tentatively by detailed interpretation of their mass spectra. Identification of these metabolites indicated that 2C-T-2 was metabolized by sulfoxidation followed by N-acetylation and either hydroxylation of the S-ethyl side chain or demethylation of one methoxy group, O-demethylation of the parent compound followed by N-acetylation and sulfoxidation, deamination followed by reduction to the corresponding alcohol followed by partial glucuronidation and/or sulfation or by oxidation to the corresponding acid followed either by partial glucuronidation or by degradation to the corresponding benzoic acid derivative followed by partial glucuronidation. Furthermore, 2C-T-2 was metabolized by N-acetylation of the parent compound followed either by O-demethylation and sulfoxidation or by S-dealkylation, S-methylation and sulfoxidation. The authors' systematic toxicological analysis (STA) procedure using full-scan GC/MS after acid hydrolysis, liquid-liquid extraction microwave-assisted acetylation allowed the detection of an intake of a dose of 2C-T-2 in rat urine, which corresponds to a common drug users' dose. Assuming similar metabolism, the described STA procedure should be suitable for proof of an intake of 2C-T-2 in human urine.     

Comparison study of several numerical integration schemes used in calculations of density functional theory

Several numerical integration schemes for the evaluation of matrix elements in density functional theory calculations have been studied and compared by computational practice. The best scheme was found to be the combination of the atomic partition function proposed by Becke with the scaled generalized Gauss-Laguerre quadrature formula for radial integration suggested by Yang, which achieve the highest convergence rate to the numerical integration. With the same number of integration points, the accuracy of the calculated results by this scheme is higher by 1 to 2 orders of magnitudes than that by other schemes. The reason for achieving higher accuracy by this scheme has been proposed preliminarily.     

Preparation of cyclopentadienes and diazocyclopentadienesvia cyclopentenolones and cyclopentenones

The structure and stereochemistry of the cyclopentenolones obtained by condensation of dialkyl ketones with benzil have been studied by NMR spectroscopy. These enolones were converted into cyclopentenones and cyclopentadienes. Alkyl-substituted cyclopentadienes required phenyllithium to effect their conversion by toluenesulphonyl azide into diazo-cyclopentadienes; otherwise piperidine sufficed as base catalyst.2,3,4-Triphenyldiazocyclopentadiene was simply procured by reaction of the condensation product of benzil and phenylacetone with toluenesulphonylhydrazone followed by alkali. Cyclohexyl- and methoxy-triphenylcyclopentadienes were prepared by photolytic decomposition of diazotriphenylcyclopentadiene in cyclohexane or methanol respectively.     

铂修饰光阴极及其在纳晶太阳能电池中的应用

分别用真空镀膜法、热分解法和电化学法制备了铂金修饰导电玻璃,并以此作为光阴极组装了染料敏化纳晶TiO₂太阳能电池.用SEM观察了铂金修饰导电玻璃表面形貌,发现用真空镀膜法制备的铂金膜结构缺陷多、不均匀,存在较多的污点.用热分解法制备的铂金膜具有多孔状结构,但存在较多的有机物分解的残留物.用电镀法制备的铂金膜结构均匀、排列规则、缺陷少、污染少.测定了所制备铂金膜的电阻,结果表明由电镀法所制得的铂金膜电阻最小,用热解法和真空镀膜法制得的铂金膜电阻较大.测定了DSSC电池的光电性能,发现用电镀法制得的铂金膜的催化性能最好,大大提高了DSSC电池的性能;其次是热分解法,由真空镀膜法制备的铂金膜对电池的性能没有多大改善.     

β-沸石骨架铝化改性的红外光谱

β沸石是以有机胺为模板剂合成的高硅沸石．为在孔道中进行吸附和催化反应,通常是在空气中 (５５０℃ )进行焙烧,将有机胺脱除并使质子酸中心形成．但这种脱模板剂方法,会造成骨架脱铝［１ -４］,使质子酸中心显著减少．β沸石固有结构中存在着孔道位错和结构空穴,空气中焙烧脱有机胺可能会进一步损伤沸石的骨架结构［４,５］．沸石骨架改性已发展了多种铝化方法［６ -８］．有的研究工作表明,通常用红外光谱和ＭＡＳＮＭＲ表征的非骨架铝,在温和的条件下,例如回馏温度下的离子交换或者在较低温度下 (１００℃或室温 )与碱反应就可…