具有对称不均等负重合量的气动伺服阀特性

分析了具有负重合量的气动伺服阀特性及各节流口的流动形式.理论分析和实验结果表明：具有均等负重合量的气动伺服阀的零位压力约为供气压力的80%;当供气侧对称不均等负重合量小于排气侧负重合量时,零位压力小于供气压力的80%;当供气侧对称不均等负重合量大于排气侧负重合量时,零位压力大于供气压力的80%;具有对称均等负重合量或对称不均等负重合量的伺服阀的最大泄漏量发生在零位附近.     

Periostin in inflammation and allergy

We found for the first time that IL-4 and IL-13, signature type 2 cytokines, are able to induce periostin expression. We and others have subsequently shown that periostin is highly expressed in chronic inflammatory diseases―asthma, atopic dermatitis, eosinophilc chronic sinusitis/chronic rhinosinusitis with nasal polyp, and allergic conjunctivitis—and that periostin plays important roles in the pathogenesis of these diseases. The epithelial/mesenchymal interaction via periostin is important for the onset of allergic inflammation, in which periostin derived from fibroblasts acts on epithelial cells or fibroblasts, activating their NF-κB. Moreover, the immune cell/non-immune cell interaction via periostin may be also involved. Now the significance of periostin has been expanded into other inflammatory or fibrotic diseases such as scleroderma and pulmonary fibrosis. The cross-talk of periostin with TGF-β or pro-inflammatory cytokines is important for the underlying mechanism of these diseases. Because of its pathogenic importance and broad expression, diagnostics or therapeutic drugs can be potentially developed to target periostin as a means of treating these diseases.     

Variation in the DEPDC5 locus is associated with progression to hepatocellular carcinoma in chronic hepatitis C virus carriers

Chronic viral hepatitis is the most important risk factor for progression to hepatocellular carcinoma (HCC). To identify genetic risk factors for progression to HCC in individuals with chronic hepatitis C virus (HCV), we analyzed 467,538 SNPs in 212 Japanese individuals with chronic HCV with HCC and 765 individuals with chronic HCV without HCC. We identified one intronic SNP in the DEPDC5 locus on chromosome 22 associated with HCC risk and confirmed the association using an independent case-control population (710 cases and 1,625 controls). The association was highly significant when we analyzed the stages separately as well as together (rs1012068, P(combined) = 1.27 × 10(-13), odds ratio = 1.75). The significance level of the association further increased after adjustment for gender, age and platelet count (P = 1.35 × 10(-14), odds ratio = 1.96). Our findings suggest that common variants within the DEPDC5 locus affect susceptibility to HCC in Japanese individuals with chronic HCV infection.     

Blue emission from hydrogen-containing a-Si：H／SiO2 multilayers and the investigation of its mechanism

A series of hydrogen-containing a-Si:H/SiO2 multilayers with different a-Si:H sublayer thickness were fabricated by layer-by-layer deposition and in situ plasma oxidation in a plasma-enhanced chemical vapor deposition system (PECVD). Optical induced blue emission from the samples was observed by the naked eye at room temperature, which has never been reported in the luminescence study of Si/SiO2 multilayers up to now. Both the photoluminescence (PL) peak and the absorption edge show a blue shift as the a-Si:H sublayer thickness decreases. The origin of the blue emission and the effect of hydrogen are discussed.     

Insight into a natural Diels-Alder reaction from the structure of macrophomate synthase

The Diels-Alder reaction, which forms a six-membered ring from an alkene (dienophile) and a 1,3-diene, is synthetically very useful for construction of cyclic products with high regio- and stereoselectivity under mild conditions. It has been applied to the synthesis of complex pharmaceutical and biologically active compounds. Although evidence on natural Diels-Alderases has been accumulated in the biosynthesis of secondary metabolites, there has been no report on the structural details of the natural Diels-Alderases. The function and catalytic mechanism of the natural Diels-Alderase are of great interest owing to the diversity of molecular skeletons in natural Diels-Alder adducts. Here we present the 1.70 A resolution crystal structure of the natural Diels-Alderase, fungal macrophomate synthase (MPS), in complex with pyruvate. The active site of the enzyme is large and hydrophobic, contributing amino acid residues that can hydrogen-bond to the substrate 2-pyrone. These data provide information on the catalytic mechanism of MPS, and suggest that the reaction proceeds via a large-scale structural reorganization of the product.     

一种基于度量距离学习的图像检索方法

CBIR系统由于受图像低层特征的限制,制约了它的检索效果。机器学习和统计方法是一种有效的提高检索性能的方法,但通常需要大量的训练样本才能达到满意的检索精度。提出一种理想的距离度量函数,在对图像进行简单分类并提供少量训练样本的基础上,通过类的距离度量矩阵M的学习来考虑分量之间的相关性。这个度量导入二次最佳化问题的解,将训练样本类结构的倾斜最小化。试验结果表明,该方法能在学习样本极少的情况下提高检索的性能。     

Fras1 deficiency results in cryptophthalmos,renal agenesis and blebbed phenotype in mice

Loss of tight association between epidermis and dermis underlies several blistering disorders and is frequently caused by impaired function of extracellular matrix (ECM) proteins. Here we describe a new protein in mouse, Fras1, that is specifically detected in a linear fashion underlying the epidermis and the basal surface of other epithelia in embryos. Loss of Fras1 function results in the formation of subepidermal hemorrhagic blisters as well as unilateral or bilateral renal agenesis during mouse embryogenesis. Postnatally, homozygous Fras1 mutants have fusion of the eyelids and digits and unilateral renal agenesis or dysplasia. The defects observed in Fras1-/- mice phenocopy those of the existing bl (blebbed) mouse mutants, which have been considered a model for the human genetic disorder Fraser syndrome. We show that bl/bl homozygous embryos are devoid of Fras1 protein, consistent with the finding that Fras1 is mutated in these mice. In sum, our data suggest that perturbations in the composition of the extracellular space underlying epithelia could account for the onset of the blebbed phenotype in mouse and Fraser syndrome manifestation in human.     

Haploinsufficiency of NSD1 causes Sotos syndrome

We isolated NSD1 from the 5q35 breakpoint in an individual with Sotos syndrome harboring a chromosomal translocation. We identified 1 nonsense, 3 frameshift and 20 submicroscopic deletion mutations of NSD1 among 42 individuals with sporadic cases of Sotos syndrome. The results indicate that haploinsufficiency of NSD1 is the major cause of Sotos syndrome.     

油菜秸秆比例对好氧堆肥过程及产品特性的影响

采用堆肥工艺将农作物秸秆转化为有机肥还田是秸秆资源化利用的有效手段.本研究以油菜秸秆为主要原料,按不同比例同辅料混合(三组实验R1、R2和R3中的油菜秸秆比例(湿重)分别为45%、65%和85%),研究了油菜秸秆比例对高温好氧堆肥过程及产品特性的影响.结果表明,在72d的堆肥过程中,R1、R2和R3的有机物降解主要发生在堆肥过程前期,堆肥结束时分别达到34.06%、35.57%和39.78%.通过比较三组实验过程中样品的理化性质,可知R3最终样品满足了堆肥腐熟的各项指标,且堆肥过程中氮损失最少;其最终堆肥产品中未检测出NH_4~+,总N含量、NO_3~-浓度和GI值分别达到2.17%、1,844.93mg·kg~(-1)干重和102.66%.     

“魔术蘑菇”(MagicMushroom)与药物滥用

"魔术蘑菇"广泛存在于自然界中,其所含裸盖菇素具有致幻作用,可使服用者产生欣快感并产生依赖性和神经毒性,在许多国家已被列为违禁物品。我国有些研究在蘑菇中毒的诊断及治疗方面取得一些成果,但还未从药物滥用方面引起人们足够认识。通过综述"魔术蘑菇"对人体的作用、国内外流通现状及常用检验方法,使从法庭科学的角度重新认识"魔术蘑菇",以期引起重视,防患于未然。