Copper-containing hexagonal mesoporous silicas for styrene epoxidation using tert-butylhydroperoxide

Copper-containing hexagonal mesoporous silicas (Cu-HMS) with different Si/Cu atomic ratios were synthesized by one-pot sol-gel method using dodecylamine surfactant as templating agent. The Structure was characterized by X-ray diffraction, N-2 adsorption-desorption, infrared spectroscopy, transmission electron microscopy, ultraviolet and visible diffuse reflectance spectroscopy, electron spin resonance and H-2 temperature-programmed reduction. The results show that the Cu-HMS material is an efficient catalyst for epoxidation of styrene with use of aqueous tert-butylhydroperoxide. The catalytic performance is dependent on Si/Cu atomic ratio and reaction solvent. A styrene conversion of 99% with epoxide selectivity up to 84% can be obtained over the Cu-HMS material with Si/Cu atomic ratio of 40 in the case of using a mixed solvent of acetonitrile and N,N-dimethylformamide. No significant loss in the catalytic performance is observed during catalyst reuse. The enhanced catalytic performance over Cu-HMS material may be attributed to the homogeneous dispersion and uniformity of active Cu2+ species. (C) 2009 Elsevier B.V. All rights reserved.NSFC [20433030, 20873108]; 973 program [2009CB939804]; NSF of Fujian Province [2007J0013, 2009HZ10102

Superior Performance of Gold Supported on Titanium-Containing Hexagonal Mesoporous Molecular Sieves for Gas-Phase Epoxidation of Propylene with Use of H-2 and O-2

Titanium-containing hexagonal mesoporous silicas (Ti-HMS) with wormhole structure and Si/Ti molar ratios ranging from 10 to 40 have been prepared by using long-chain alkyl primary amines as template agents. The Ti-HMS supported Au catalyst (Au/Ti-HMS) was obtained by a deposition-precipitation method for direct gas-phase epoxidation of propylene with use of O-2 and H-2. The structures of Ti-HMS and Au/Ti-HMS samples were characterized by X-ray diffraction, N-2-physisorption, scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, UV Raman spectroscopy, ammonia-temperature-programmed desorption, and atomic adsorption spectroscopy. The results showed that the Au/Ti-HMS catalyst exhibited superior performance in terms of propylene conversion, propylene oxide (PO) selectivity, and H-2 efficiency in comparison with the Au catalysts supported on the conventional Ti-containing mesoporous materials. Besides the Si/Ti molar ratio, the chain length of alkylamine for the Ti-HMS preparation was crucial for the enhancement of catalytic performance. Specifically, 9.0% of propylene conversion, 97.3% of PO selectivity, and 30.4% of H efficiency can be obtained at 373 K in the initial 30 min of time-on-stream on the Au/Ti-HMS catalyst, where the Ti-HMS having a Si/Ti molar ratio at 20 was prepared by using tetradecylamine as the template agent. Regeneration of the spent catalyst by calcination in air gave almost no change in the PO selectivity but about 25% loss in the propylene conversion. The enhanced catalytic performance of Au/Ti-HMS catalyst may be essentially attributed to the homogeneous dispersion and uniformity of titanium species in combination with accessible pore structure.NSFC [20433030, 20873108, 20423002]; NSF of Fujian Province [2007J0013]; Doctoral Program of Higher Education [20050384011]; Chinese Ministry of Education [106099]; [2009CB939804

Bronsted acidic ionic liquid as an efficient and recyclable promoter for hydroesterification of olefins catalyzed by a triphenylphosphine-palladium complex

Several Bronsted acidic ionic liquids (BAILs) with different acidic scales were synthesized and employed as acid promoters for the hydroesterification of olefins catalyzed by a triphenylphosphine-palladium complex. The results showed that catalysts with BAIL promoters resulted in moderate to high conversions to the ester product with excellent selectivity, depending on the acidity of BAIL used. The reaction conversion reached a plateau when the catalyst was promoted using BAIL with a Hammett acidity function less than or equal to -0.11. This catalyst system could be reused several times for the hydroesterification of 1-hexene without a considerable decrease in the catalytic performance. (C) 2010 Elsevier B.V. All rights reserved.National Natural Science Foundation of China [20873108, 20923004]; National Basic Research Program of China [2009CB939804]; Key Scientific Project of Fujian Province [2009HZ0002-1

Integrating Morphology, Breeding Ground and Mitochondrial COI Gene Analysis for Species Identification of Bellamya lithophaga (Gastropoda: Viviparidae) in China

Background: Angiostrongylus cantonensis is a zoonotic public health concern that causes human severe eosinophilic meningitis in Southeast Asia and China. As a medically important intermediate host of A. cantonensis, Bellamya lithophaga (Gastrop-oda: Viviparidae) is often confused with other morphologically similar sibling spe-cies of genus Bellamya, such as B. aeruginosa and B. purificata in the past. Hence, the aim of the present study was to investigate evidences to discriminate these equivo-cal Bellamya species. Methods: This study was carried out by getting Bellamya snail samples from Fujian Province in the South-East of China. The snail morphological features，breeding grounds and phylogenetic relationship according to mitochondrial cytochrome c oxidase subunit I (COI) gene marker were analyzed. Results: Based on external morphology, radular shape and cusp formula, as well as major breeding environment, B. lithophaga could be distinguished from B. aeruginosa, B. purificata. The phylogenetic tree also unconfirmed that B. lithophaga belongs to a different genetic clade from other morphologically similar species. Conclusion: Our findings demonstrate the significant differences in B. lithophaga and other sibling species, which supports the traditional species delimitation in the genus Bellamya

Biallelic mutations in KATNAL2 cause male infertility due to oligo-astheno-teratozoospermia

Oligo-astheno-teratozoospermia (OAT) is a common cause of male infertility, and most of idiopathic OAT patients are thought to be caused by genetic defects. Here, we recruited 38 primary infertile patients with the OAT phenotype and 40 adult men with proven fertility for genetic analysis and identified biallelic mutations of KATNAL2 by whole-exome sequencing in two cases. F013/II:1, from a consanguineous family, carried the KATNAL2 c.328C > T:p.Arg110X homozygous mutations. The other carried c.55A > G: p.Lys19Glu and c.169C > T: p Arg57Trp biallelic mutations. None of the KATNAL2 variants were found in the 40 adult men with proven fertility. The spermatozoa from patients with KATNAL2 biallelic mutations exhibited conspicuous defects in maturation, head morphology, and the structure of mitochondrial sheaths and flagella. KATNAL2 was mainly expressed in the pericentriolar material and mitochondrial sheath of the spermatozoa from control subjects, but it was undetectable in the spermatozoa from the patients. Furthermore, Katnal2 null male mice were infertile and displayed an OAT phenotype. Our results proved that the biallelic mutations in KATNAL2 cause male infertility and OAT in humans for the first time, to our knowledge, which could enrich the genetic defect spectrum of OAT and be beneficial for its accurate genetic screening and clinical diagnosis

Expression of claudin-11, -23 in different gastric tissues and its relationship with the risk and prognosis of gastric cancer

<div><p>Claudins play an important role in regulating the permeability of epithelial and endothelial cells and in the maintenance of cell polarity. We aimed to investigate expression of claudin-11, -23 in different gastric tissues and its relationship with clinicopathologic parameters and prognosis of gastric cancer. We compared their expression levels in the paired cancerous tissues versus those in the adjacent noncancerous tissues by real-time PCR, western blotting and immunohistochemistry. The results showed that the expression of claudin-11, -23 was greatly increased in paracancerous gastric tissue compared with cancerous tissue. We also compared their expression levels of tissues from gastric cancer, superficial gastritis, and atrophic gastritis by immunohistochemistry. The results indicated that the expression of claudin-11 and 23 was significantly higher in superficial gastritis than that in atrophic gastritis and gastric cancer. The expression of claudin-23 was significantly lower in atrophic gastritis than that in gastric cancer, but no obviously difference was observed for claudin-11. As for analysis of clinicopathologic parameters of gastric cancer, logistic multiple regression indicated that claudin-11 was significantly associated with sex, smoking, alcohol, <i>H</i>. <i>pylori</i> infection and Borrmann classification while claudin-23 was significantly associated with vessel cancer embolus. Cox multivariate survival analysis indicated that gastric cancer patients with negative claudin-23 expression had significantly longer overall survival. In conclusion, the expression of claudin-11, -23 was remarkably downregulated in gastric cancer. Abnormal expression of these proteins was significantly correlated with some clinicopathologic parameters. In particular, claudin-23 positive expression was associated with poor prognostic outcomes of gastric cancer patients and may therefore serve as an independent prognosticator of patient survival.</p></div

Baseline information of the SG, AG and GC.

<p>Baseline information of the SG, AG and GC.</p

Association between Claudin-11,23 expression and CEA and GSTP1.

<p>Association between Claudin-11,23 expression and CEA and GSTP1.</p

Claudin-11,23 expression in SG, AG, GC tissues from different individuals.

<p>Claudin-11,23 expression in SG, AG, GC tissues from different individuals.</p

Correlation between Claudin-11,23 expression and survival in GC.

<p>Correlation between Claudin-11,23 expression and survival in GC.</p