1000 resultados para 675.4


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扇贝养殖是我国重要的海水养殖产业,然而自1997 年以来,养殖扇贝陆续爆发的大规模死亡,不但造成了巨大的经济损失,而且严重影响了该产业的健康发展。丝氨酸蛋白酶抑制因子及丝氨酸蛋白酶在无脊椎动物的免疫应答中起着核心作用,它们的协同作用直接导致外界病源入侵的信号转导和级联放大,并进一步激活一系列防御体系,如黑化反应、血液凝结和抗菌肽的合成等。因此,克隆扇贝参与免疫防御的丝氨酸蛋白酶抑制剂基因并对其功能进行研究,将有助于进一步研究扇贝的免疫防御机制,丰富和发展无脊椎动物免疫学的内容。 运用大规模EST技术和RACE技术从栉孔扇贝中克隆出一个Kazal型丝氨酸蛋白酶抑制剂基因,定名为CfKZSPI。该基因cDNA序列全长1788bp,其中5' 非编码区(Untranslated Region, UTR)为97 bp,3' UTR161 bp,有一个典型的多聚腺苷酸信号序列(AATAAA)和一个ploy A 尾巴,开放阅读框(Open Reading Frame, ORF)含有1530 bp,编码509 个氨基酸残基。对其推测氨基酸序列进行分析,发现其中包括22个氨基酸残基组成的信号肽序列和12个Kazal型丝氨酸蛋白酶抑制剂结构域。采用QRT-PCR(quantitative real time PCR)对鳗弧菌浸泡刺激后栉孔扇贝血淋巴中CfKZSPI 的 mRNA表达量进行了检测,发现其mRNA 的表达量在鳗弧菌刺激后3h明显上升,达到空白组的43.6倍;然后在6h时有所下降,为空白组的15.0倍;随着菌刺激时间的增长,CfKZSPI基因的 mRNA 表达量急剧增加,在刺激后8h,12h,24h分别达到空白组的174.1,207.8,675.4倍。统计分析发现3h(P=0.019<0.05)和12h(P=0.020<0.05)时,CfKZSPI基因mRNA表达量与空白组差异均显著。为了研究栉孔扇贝CfKZSPI的蛋白活性,将其第十二个结构域克隆到pET-32a(+)载体中,转化大肠杆菌Rosetta-gami(DE3)表达菌株,获得可溶性表达的蛋白rCfKZSPI-12,对其进行抑制蛋白酶活性的分析,发现其对胰蛋白酶有很强的抑制活性,而对凝血酶没有抑制活性。当rCfKZSPI-12与胰蛋白酶分子比率为1:1时,约90%的蛋白酶活性被抑制。运用狄更斯作图法研究rCfKZSPI-12对胰蛋白酶的抑制能力,结果发现其对胰蛋白酶的抑制常数为173 nmol L-1。 采用同样方法从海湾扇贝cDNA文库中克隆出一个Kunitz型丝氨酸蛋白酶抑制剂基因,定名为Aikunitz。该基因全长632 bp,其中5' UTR 为105 bp,3' UTR 为 245 bp,有一个典型的多聚腺苷酸信号序列(AATAAA)和一个ploy A 尾巴,ORF 含有282 bp,编码93 个氨基酸残基。推测的氨基酸序列N末端有一个20个氨基酸残基组成的信号肽序列,成熟蛋白包括一个Kunitz型丝氨酸蛋白酶抑制剂结构域。采用QRT-PCR对鳗弧菌和藤黄微球菌感染后海湾扇贝血淋巴中Aikunitz 的mRNA的表达量进行了检测,结果发现其在鳗弧菌刺激后3h到9h持续上升,9h时表达量为PBS对照组的4.49倍(P=0.008<0.05),然后开始下降,在72h时表达量为对照组的0.24倍(P=0.021<0.05);而在藤黄微球菌刺激后3h到12h其表达量上升,其中6h时为空白组的5.95倍(P=0.0004<0.01);12h以后迅速下降,其中24h的表达量为对照组的0.38倍(P=0.028<0.05)。将Aikunitz基因编码的成熟蛋白按照重组CfKZSPI-12的方法进行重组表达,并对重组蛋白进行抑制蛋白酶和抑菌活性分析。结果发现其对胰蛋白酶和弹性蛋白酶两种丝氨酸蛋白酶都没有抑制作用。抑菌实验同样发现,重组Aikunitz 对供试的革兰氏阳性菌藤黄微球菌和革兰氏阴性菌鳗弧菌和大肠杆菌都不显示明显抑菌活性。

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現在中国において物流サービスを提供している企業は約1万社あるとされる。筆者の見るところ、これら企業には大きく分けて三つのタイプがある。第一は外資系企業で、改革・開放の初期にはフォワーダー(貨物運送代理業者)が参入し、やがて各種の物流合弁企業が設立された。第二は旧来の運輸・倉庫企業、卸売り企業から発展したもので、既存設備や顧客を基礎に本格的物流企業への脱皮を図っている。第三が新しいビジネスモデルで参入したベンチャー系企業である。本稿では、第三の企業を紹介しつつ、激化する市場競争の中で進む業界再編の行方について展望を試みる。

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This paper examines factors that encourage firms to go into supply chain collaborations (SCC) and relationships between SCC and supply chain performances (SCP), using a questionnaire survey on Thai automotive and electronics industries in 2012. OLS regression results show firms established supplier evaluation and audit system, system of rewards for high-performance supplier and long-term transactions with their supply chain partners under a competitive pressure are more closely cooperate with these partners on information sharing and decision synchronization. Instrumental variables regression indicates SCC arisen from competitive pressure, supplier evaluation and audit, a system of rewards for high-performance supplier and long-term relationship causally influence SCP such as on-time delivery, responsiveness to fast procurement, flexibility to customer need, and profit.

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This paper examines factors that promote firms to develop supply chain collaborations (SCC) with their partners and relationships between SCC and supply chain operational performances (SCOP), using a questionnaire survey on Thai automotive and electronics industries in 2012. This paper also carries out a comparative study on these questions between the electronics and automotive industries. Two-stage least squares (2SLS) regressions verifY that supplier evaluation and audit is a foundation for firms to share information and synchronize decision makings with their partners, and that such SCC are significantly related to SCOP indictors such as on-time delivery, fast procurement, and flexibility to customer need irrespective of industry type. On the other hand, competitive pressure motivates only electronics firms to develop sec in order to be more innovative.

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A compiled set of in situ data is important to evaluate the quality of ocean-colour satellite-data records. Here we describe the data compiled for the validation of the ocean-colour products from the ESA Ocean Colour Climate Change Initiative (OC-CCI). The data were acquired from several sources (MOBY, BOUSSOLE, AERONET-OC, SeaBASS, NOMAD, MERMAID, AMT, ICES, HOT, GeP&CO), span between 1997 and 2012, and have a global distribution. Observations of the following variables were compiled: spectral remote-sensing reflectances, concentrations of chlorophyll a, spectral inherent optical properties and spectral diffuse attenuation coefficients. The data were from multi-project archives acquired via the open internet services or from individual projects, acquired directly from data providers. Methodologies were implemented for homogenisation, quality control and merging of all data. No changes were made to the original data, other than averaging of observations that were close in time and space, elimination of some points after quality control and conversion to a standard format. The final result is a merged table designed for validation of satellite-derived ocean-colour products and available in text format. Metadata of each in situ measurement (original source, cruise or experiment, principal investigator) were preserved throughout the work and made available in the final table. Using all the data in a validation exercise increases the number of matchups and enhances the representativeness of different marine regimes. By making available the metadata, it is also possible to analyse each set of data separately.

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This paper compares continuity and change in homelessness policy in Ireland, Scotland and Norway with a particular focus on the period of post-crisis austerity measures (2008-2016). The analytical approach draws on institutional theory and the notion of path dependency, which has rarely been applied to comparative homelessness research. The paper compares welfare and housing systems in the three countries prior to presenting a detailed analysis of the conceptualisation and measurement of homelessness; the institutions which address homelessness; and the evidence of change in the post-2008 period. The analysis demonstrates that challenges remain in comparing the nature of homelessness and policy responses across nation states, even where they have a number of similar characteristics, and despite some EU influence towards homelessness policy convergence. Similarly, national-level homelessness policy change could not be interpreted as entirely a result of the external shock of the 2008 general financial crisis, as existing national policy goals and programmes were also influential. Overall, embedded national frameworks and institutions were resilient, but sufficiently flexible to deliver longer term policy shifts in response to the changing nature of the homelessness problem and national policy goals. Institutionalism and path dependency were found to be useful in developing the comparative analysis of homelessness policy change and could be fruitfully applied in future longitudinal, empirical research across a wider range of countries.

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OBJECTIVE This study determined if deficits in corneal nerve fiber length (CNFL) assessed using corneal confocal microscopy (CCM) can predict future onset of diabetic peripheral neuropathy (DPN). RESEARCH DESIGN AND METHODS CNFL and a range of other baseline measures were compared between 90 nonneuropathic patients with type 1 diabetes who did or did not develop DPN after 4 years. The receiver operator characteristic (ROC) curve was used to determine the capability of single and combined measures of neuropathy to predict DPN. RESULTS DPN developed in 16 participants (18%) after 4 years. Factors predictive of 4-year incident DPN were lower CNFL (P = 0.041); longer duration of diabetes (P = 0.002); higher triglycerides (P = 0.023); retinopathy (higher on the Early Treatment of Diabetic Retinopathy Study scale) (P = 0.008); nephropathy (higher albumin-to-creatinine ratio) (P = 0.001); higher neuropathy disability score (P = 0.037); lower cold sensation (P = 0.001) and cold pain (P = 0.027) thresholds; higher warm sensation (P = 0.008), warm pain (P = 0.024), and vibration (P = 0.003) thresholds; impaired monofilament response (P = 0.003); and slower peroneal (P = 0.013) and sural (P = 0.002) nerve conduction velocity. CCM could predict the 4-year incident DPN with 63% sensitivity and 74% specificity for a CNFL threshold cutoff of 14.1 mm/mm2 (area under ROC curve = 0.66, P = 0.041). Combining neuropathy measures did not improve predictive capability. CONCLUSIONS DPN can be predicted by various demographic, metabolic, and conventional neuropathy measures. The ability of CCM to predict DPN broadens the already impressive diagnostic capabilities of this novel ophthalmic marker.

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7-Methoxy-4-methylcoumarin undergoes a solid-state photo [2 + 2] cycloaddition upon UV irradiation to yield two photodimers. The formation of the minor product appears to be a direct consequence of the formation of the topochemically controlled dimer.

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提出了一种基于同步移相技术的1/4波片相位延迟量的快速测量方法。由正交光栅、光阑、检偏器组和四象限探测器实现同步移相功能。检偏器组由4个不同方位角的检偏器组成。通过检偏器组的四束光束的光强由四象限探测器同时测量。1/4波片的相位延迟量由这四光束的光强得到。该方法中波片的快轴不需被事先确定。另外光源光强的波动对测量结果没有影响。通过实验验证了该方法的有效性。

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As one member of high performance fibers, aromatic polyimide fibers possess many advantages, such as high strength, high modulus, high and low temperature resistance, and radiation resistance. However, the preparation of the high performance fibers is so difficult that the commercial fibers have not been produced except P84 with good flame retardancy. In this report, a polyimide was synthesized from 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-oxydianiline (ODA) and the fibers were prepared from its solution by a dry-jet wet-spinning process. The formation of the as-spun fibers in different coagulation bath composition was discussed. Scanning electron microscope (SEMI) was employed to study the morphology of the as-spun fibers. As a result, the remnant solvent existed in the as-spun fibers generated from coagulation bath of alcohol and water. There were many fibrils and microvoids with the dimension of tens of nanometers in the fibers. One could observe the obvious fibrillation and the drawn fibers.

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(2,4-C7H11)(2)Yb . DME was synthesized by the reaction of YbCl3 with K(2,4-C7H11)(2,4-dimethylpentadienyl potassium), and the single crystal X-ray diffraction showed that the complex exists in a cis- staggered conformation. Thf crystal of the compound belongs to the monoclinic space group P2(1)/n with a = 0.675 2 (1) nm, b = 1.490 6 (1) nm, c = 1.529 3 (2) nm, beta = 97.55 (2)degrees, V = 1.977 79 (4) nm(3), Z = 4, F(000) = 735.8 e, mu = 49.49 cm(-1), R = 0.033 and R-w = 0.032. The title complex can be used as a catalyst for the polymerization of methyl methacrylate (MMA).

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The preparation, the IR and ligand field spectra and the structures of the mixed-ligand addition compounds [(N,N-dimethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me2en], and [(N,N,N′,N′-tetramethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me4en], are reported. The structures were determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/c, Z=4 with a=10.708(6), b=19.531(6), c=13.352(6) Å, β=111.64(10)°, R1=0.0642 and wR2=0.1719 for [Co(thtf)2(me2en)] and a=12.033(6), b=15.565(6), c=15.339(6) Å, β=92.57(6)°, R1=0.0612 and wR2=0.1504 for [Co(thtf)2me4en]). The structures are distorted octahedral and the shortest cobalt–cobalt separation distances are 5.388(2) Å in [Co(thtf)2me2en] and 8.675(3) Å in [Co(thtf)2me4en]. In both compounds the diamine molecules attain the gauche conformation. The U(Z,Z) conformation of the β-dione leads to a semi-chair conformation of the β-dionato chelate rings. The relative orientation of the groups attached to the β-dionato moiety depends on the extent of stereoelectronic effects the N-substitution of the diamine entails. In [Co(thtf)2me2en] the intraligand distance separating the trifluoromethyl carbon atoms is 5.281(18) Å while in [Co(thtf)2me2en] it increases to 8.338(9) Å. The cobalt–cobalt separation distance, the orientation of the chelate rings and the extent of N-substitution seem to affect hydrogen bonding. While in [Co(thtf)2me2en] inter- and intraligand hydrogen bonding is implicated, it is totally absent in [Co(thtf)2me4en].

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IL-23 is a heterodimeric cytokine involved in inflammatory diseases; its role in cancer progression is controversial. Here we analyse the expression of IL-23 subunits (p40 and p19) and IL-23R in colorectal cancer with regard to disease progression, clinical-pathological and molecular aspects. Immunohistochemistry for IL-23p19, IL-23p40, IL-23R and CD8 was performed on a multi-punch tissue microarray of 195 colorectal cancers (cohort 1), matched normal tissue, adenoma and lymph node metastases. Results were compared with clinical-pathological features and CD8+ T-cell counts, then validated on two patient cohorts (cohort 2: n=341, cohort 3: n=139). Cytoplasmic/membranous expression of IL-23 (p19 and p40 subunits) and IL-23R, respectively were over-expressed in carcinomas versus adenomas and normal tissues (p<0.0001) but were reduced in lymph node metastases (p<0.0001). Nuclear IL-23p19 expression was observed in 23.1% and was associated with early TNM stage (p=0.0186), absence of venous (p=0.0124) and lymphatic invasion (p=0.01493), favorable survival (p=0.014) and absence of distant metastasis (p=0.0146; specificity: 100%). This unexpected cellular localization was confirmed by cell fractionation. The beneficial effect of nuclear IL-23p19 was restricted to tumours with CD8+ high counts. Results were validated on Cohorts 2/3. This multicenter study underlines the possible CD8(+)--dependency and beneficial effect of nuclear IL-23p19 on overall patient survival.