Surface characteristic and cell response of CVD SiC coating for carbon/carbon composites used for hip arthroplasty

SiC coatings were applied on carbon/carbon composites by chemical vapor deposition for potential application in hip arthroplasty. The surface morphology, roughness, and wettability of the coatings were evaluated by scanning electron microscopy, laser confocal scanning microscope, and video‐based contact angle measuring device, respectively. The bonding strength between the coatings and carbon/carbon composites was analyzed by scratch testing. The cell responses to coatings were studied by analyzing the cell morphology and cell proliferation. The results showed that SiC coatings showed spherical morphology with a roughness of R_a = 1.0 ± 0.2 µm and a contact angle of 64.7 ± 4.0°. The coatings had lower surface roughness and better surface hydrophilicity compared with those of the uncoated carbon/carbon composites. A strong shear strength averaging 120.0 MPa between the coating and carbon/carbon composites was achieved. The cell culture experiments showed that cell spreading was improved, and cell proliferation was increased with the SiC coatings. It was demonstrated that CVD‐SiC‐coated carbon/carbon composites were good candidates as artificial hip joint materials. Copyright © 2012 John Wiley & Sons, Ltd.     

Concise total syntheses of Marinoquinolines A–C

The first concise total syntheses of pyrroloquinoline natural products, Marinoquinolines A–C, have been achieved in six linear steps from commercially available starting materials. The key steps were a reaction between (p-tolylsulfonyl)methylisocyanide (TosMIC) and α, β-unsaturated ester under basic condition to prepare the pyrrole moiety and Morgen-Walls reaction to construct quinoline ring.     

A NAA collaborative study in white rice performed in seven Asian countries

Since 2000, collaborative studies for applying NAA have been performed through the Forum for Nuclear Cooperation in Asia (FNCA) sponsored by the Japanese Government. White rice is a main food for Asians and thus was selected as a common target sample for a collaborative study in 2008. Seven Asian countries including China, Indonesia, Japan, Korea, Malaysia, Philippines and Thailand, are greatly concerned about the composition of arsenic, heavy metals, and essential trace elements and took part in this study. Rice samples were purchased and prepared by following a protocol that had been proposed for this study. Samples were analyzed by their own NAA systems. In each country, more than 10 elements were examined and the results were compared. These data will be very useful in the monitoring of the levels of food contamination and to evaluate the nutritional status for people living in Asia.     

吡唑并[1,5-a]嘧啶类c-Met激酶抑制剂的合成及生物活性研究

设计并合成了5,6-二甲基-7-(2-氟-4-氨基苯氧基)吡唑并[1,5-a]嘧啶类c-Met激酶抑制剂.以3-氨基吡唑和2-甲基-乙酰乙酸乙酯为起始原料,经5步反应合成了11个未见文献报道的吡唑并[1,5-a]嘧啶类衍生物,通过氢谱、碳谱、高分辨质谱等方法对所合成的化合物进行了结构表征.采用噻唑蓝法(MTT)的方法和酶联免疫吸附测定(ELISA)方法检测部分新化合物的生物活性.     

解吸附电晕束电离质谱法快速筛选保健食品中非法添加的5型磷酸二酯酶抑制剂

建立了解吸附电晕束离子源(DCBI)结合离子阱质谱快速检测保健食品中非法添加的3种磷酸二酯酶5(PDE5)抑制剂(伐地那非、西地那非、他达拉非)的方法。采用一级质谱筛选,二级质谱确证,对样品中非法添加物进行定性鉴别;通过二级特征碎片离子进行半定量分析,并与传统高效液相色谱-紫外(HPLC-UV)定量检测法对比。对12个市售保健品进行检测,DCBI-MS定性检测结果与HPLC-UV检测结果一致,有7个样品检出他达拉非,3个样品检出西地那非,1个样品检出伐地那非。通过研究3种PDE5抑制剂的二级质谱裂解规律,推测一个样品中含有羟基豪莫西地那非。本方法快速准确,适用于大批量复杂基质样品中PDE5抑制剂的筛查。     

Highly regio-, diastereo- and enantioselective one-pot gold/chiral Brønsted acid-catalysed cascade synthesis of bioactive diversely substituted tetrahydroquinolines

One-pot sequential asymmetric reactions of aminobenzaldehydes or aminophenones with alkynes catalysed by a gold(i)/Br?nsted acid cooperative system are reported. This process provides a highly efficient method for the synthesis of optically active tetrahydroquinolines, with one or two chiral centres at different positions as well as highly divergent functional groups, in good to excellent yields and with high regio-, diastereo- and enantioselectivities. A preliminary study on the effect of stereochemistry on biological activity suggests a potential application of these optically active tetrahydroquinolines in drug discovery processes.     

Synthesis, structural investigation and computational modelling of water-binding aquafoldamers

Detailed studies on water-binding aquafoldamers are presented that illustrate the potential use of the elongated larger aquafoldamers for recognizing larger water clusters of diverse topologies. A novel self-trapping dimerization mode involving two tetramer molecules is proposed, which is consistent with the obtained varying experimental evidences.     

Palladium-catalyzed intramolecular decarboxylative coupling of arene carboxylic acids/esters with aryl bromides

Give me a ring? An efficient approach has been developed for the intramolecular decarboxylative coupling of arene carboxylic acids/esters with aryl bromides catalyzed by palladium (see scheme). From a synthetic viewpoint, this method is highly attractive because the catalyst loading is low, the optimized reaction conditions are mild, and the substrate scope is broad.     

Conjugated hyperbranched poly(aryleneethynylene)s: synthesis, photophysical properties, superquenching by explosive, photopatternability, and tunable high refractive indices

Triphenylamine (TPA)-based conjugated hyperbranched poly(aryleneethynylene)s (PAEs), hb-P1/2, hb-P1/3, and hb-P1/4, were synthesized with high molecular weights and good solubilities through Sonogashira coupling reactions. These PAEs exhibited outstanding thermal stabilities and different emission behaviors. Tetraphenylethene (TPE)-containing hb-P1/2 fluoresced faintly in THF, although its light emission was enhanced by aggregate formation in aqueous media or in thin films, thereby exhibiting an aggregation-induced emission-enhancement (AIEE) effect. Whereas 1,1,2,3,4,5-hexaphenylsilole (HPS)-bearing hb-P1/3 showed no significant change in emission intensity with increasing water content in aqueous media, hb-P1/4, which consisted of TPA-fluorenone donor-acceptor groups, presented almost identical absorptions, but both positive and negative solvatochromic emissions in various solvents. A superquenching effect was observed in the picric-acid-detection process by using nanosuspensions of hb-P1/2. All of the polymers possessed good film formability. UV irradiation of the thin films induced simultaneous photobleaching and cross-linking, thus making them applicable in the fabrication of 2D and 3D patterns. Furthermore, the polymer films also showed high refractive indices, which were tunable upon exposure to UV light.