假单胞菌S-2降解甲胺磷性能的研究

从甲胺磷生产车间分离到一株假单胞菌编号为S-2。S-2可利用甲胺磷为唯一氮源,但不能利用甲胺磷为唯一磷源。该文对S-2体内具有的降解甲胺磷的酶类进行了研究,初步断定：S-2可代谢产生酸性磷酸酶,主要在胞外降解甲胺磷。S-2在甲胺磷诱导的情况下,这些降解酶类可大量聚积。用诱导过的菌液降解甲胺磷比未经诱导的快了2d左右。     

麦茬处理方式对夏玉米光合特性的影响

采用两年三点的大田试验,研究了麦茬处理方式（平茬、立茬、除茬）对机播夏玉米光合特性及其产量的影响。结果表明,不同麦茬处理方式的夏玉米光合参数存在明显差异。夏玉米Pn、Gs表现为吐丝期最大,处理间表现为平茬〉立茬〉除茬;Tr在处理间表现为除茬〉立茬〉平茬,叶片水平上的WUE表现为为平茬〉立茬〉除茬;不同麦茬处理夏玉米的产量差异显著。     

Versatile acetylation of carbohydrate substrates with bench-top sulfonic acids and application to one-pot syntheses of peracetylated thioglycosides

Inexpensive and readily available sulfonic acids, p-toluenesulfonic acid, and sulfuric acid are versatile and efficient catalysts for the peracetylation of a broad spectrum of carbohydrate substrates in good yield and in a practical time frame. Three appealing features in sulfonic acid-catalyzed acetylation of free sugars were explored including (1) suppression of furanosyl acetate formation for D-galactose and L-fucose; (2) high yielding chemoselective acetylation of sialic acid under appropriate conditions; and (3) peracetylation of amino sugars with different amino protecting functions. Simple one-pot two step acetylation-thioglycosidation methods for the expeditious synthesis of p-tolyl per-O-acetyl thioglycosides were also delineated.     

Decoloration of azo dyes by three whiterot fungi: influence of carbon source

Two strains of Phanerochaete chrysosporium and a local isolate of white-rot fungus, if pre-cultured in a high nitrogen medium with glucose, could decolorize two azo dyes (Amaranth and Orange G) and a heterocyclic dye (Azure B). When starch was used in the pre-cultivation medium, decoloration of Orange G occurred if the medium also contained 12mM NH₄Cl, whether or not veratric acid was present. In medium containing 1.2mM NH₄Cl and veratric acid, greater decoloration occurred with one strain of P. chrysosporium and the local isolate. In preculture medium with cellulose and 1.2mM NH₄Cl, decoloration by the local isolate was enhanced but not that by the other strains.The authors are with the Department of Microbiology, Soochow University, Shih Lin, Taipei, Taiwan     

CREB Is One Component of the Binding Complex of the Ces-2/E2A-HLF Binding Element and Is an Integral Part of the Interleukin-3 Survival Signal

The Ces-2/E2A-HLF binding element (CBE) is recognized by Caenorhabditis elegans death specification gene product Ces-2 and human acute lymphocytic leukemia oncoprotein E2A-HLF. In an attempt to identify a cellular CBE-binding protein(s) that may be involved in apoptosis regulation in mammals, multiple nuclear binding complexes of CBE were identified in various mammalian cell lines and tissues by electrophoretic mobility shift assay. Cyclic AMP (cAMP)-responsive element (CRE)-binding protein (CREB) was present in one major CBE complex of Ba/F3 and TF-1 cells, and both in vitro-translated and Escherichia coli-synthesized CREB bound to CBE. Activation of CREB by cAMP-elevating chemicals or the catalytic subunit of protein kinase A (PKAc) resulted in induction of the CBE-driven reporter gene. Stimulation of Ba/F3 cells with interleukin-3 (IL-3) promptly induced phosphorylation of CREB at serine(133) partially via a PKA-dependent pathway. Consistently, Ba/F3 cell survival in the absence of IL-3 was prolonged by activation of PKA. Conversely, treatment of cells with a PKA inhibitor or expression of the dominant negative forms of the regulatory subunit type I of PKA and CREB overrode the survival activity of IL-3. Last, the bcl-2 gene was demonstrated to be one candidate cellular target of the CREB-containing CBE complex, as mutations in the CRE and CBE sites significantly reduced the IL-3 inducibility of the bcl-2 promoter. Together, our results suggest that CREB is one cellular counterpart of Ces-2/E2A-HLF and is part of IL-3 dependent apoptosis regulation in hematopoietic cells.     

Forkhead box A1 (FOXA1) tagging polymorphisms and esophageal cancer risk in a Chinese population: a fine-mapping study

Esophageal cancer was the fifth most commonly diagnosed cancer and the fourth leading cause of cancer-related death in China in 2009. Esophageal squamous cell carcinoma (ESCC) accounts for more than 90% of esophageal cancers. Besides environmental risk factors, genetic factors such as single-nucleotide polymorphisms (SNPs) play an important role in ESCC carcinogenesis. We performed a hospital-based case–control study to evaluate the Forkhead-box protein A1 (FOXA1) rs12894364 C?>?T, rs2145146 C?>?A and rs7144658 T?>?C tag SNPs in the risk of developing ESCC. We recruited 629 ESCC cases and 686 controls. Genotypes were determined using ligation detection reaction. Logistic regression analyses revealed that the three FOXA1 SNPs were not associated with ESCC risk. However, there was significantly decreased ESCC risk associated with the FOXA1 rs12894364 C?>?T and rs2145146 C?>?A polymorphisms among older patients. There was significantly increased ESCC risk associated with the FOXA1 rs7144658 T?>?C polymorphism among male patients. This study demonstrates an association between FOXA1 polymorphisms and ESCC susceptibility. Additional larger studies are required to confirm our findings.     

直播羊草在不同pH土壤环境下的生物学特性和生理反应

采用人工配制的不同pH梯度的碱化土进行盆栽试验,研究了直播羊草在不同pH土壤环境下的生物学特性和生理反应.结果表明:pH 8.50以下的弱碱性土壤环境有利于直播羊草的生长,但随着土壤pH的升高其分蘖和地上部生物量均呈下降趋势;当土壤pH达到9.78时,直播后第2年羊草总株数比对照(pH 7.15)降低了42.0%,地上部干质量比对照降低了74.1%.此外,在盐碱胁迫下,羊草地上部含水量、可溶性糖、叶绿素和K 含量亦呈下降趋势,Na 含量和叶片外渗液电导率显著升高,地上部K /Na 比值从对照的28.5下降到1.6(pH 9.78),说明较高的K 水平以及较高的K /Na 比值可能是羊草耐盐碱的重要生理机制.     

海南黄牛HSF1 cDNA全长的克隆与序列分析

目的：根据人、小鼠HSF1cDNA保守区序列设计引物,通过PCR方法扩增海南黄牛HSF1cDNA,并进行序列分析。方法：利用RT-PCR、半巢式PCR以及3＇-RACE技术分段扩增得到了海南黄牛HSF1cDNA序列,测序正确后进行拼接。用DNAMAN 生物信息学软件分析海南黄牛HSF1 cDNA与赫里福德牛、人、小鼠同源性和海南黄牛HSF1蛋白的氨基酸组成、等电点、亲/疏水区等蛋白质性质,并根据各种动物HSF1蛋白绘制进化树。结果：（1）海南黄牛的HSF1 cDNA序列全长为1 993bp,包括150bp的5＇非翻译区,1 578bp的开放阅读框以及264bp（不含poly（A）尾）的3＇非翻译区,编码524个氨基酸,分子量为56.42 kD,等电点（pI）为 4.79。（2）海南黄牛的HSF1 cDNA与赫里福德牛、小鼠和人HSF1 cDNA的同源性分别为98.99 %、81.78 %、87.82 %,相应编码蛋白氨基酸序列的同源性分别为98.86 %、83.84 %、89.06 %,其中N-末端和C-末端高度保守,而中间区域存在缺失或替换。（3）根据氨基酸序列构建不同动物HSF1蛋白的进化树,与采用经典遗传分类法构建的进化树基本一致。结论：首次克隆了海南黄牛 HSF1 cDNA全长,分析表明：海南黄牛HSF1蛋白是亲水性蛋白,在8种动物中,其同源性大于73 %,高度保守。海南黄牛与赫里福德牛HSF1蛋白同源性高达98.86 %,在三聚体化区域、转录调节域和激活域存在6个位点的单氨基酸突变,这些发现为进一步揭示海南黄牛抗热性状形成的分子机制提供了重要依据。