大坝背管裂缝宽度计算公式的改进

指出了用现有裂缝理论计算钢衬钢筋混凝土压力管道裂缝宽度的局限性.进一步完善了"外部管壁”的力学模型,并据此导出了精确度更高的半理论半经验公式,该公式考虑了混凝土保护层内外的裂缝宽度差异.最后给出了算例.     

Formation of the inclusion complex of Orange II with β-Cyclodextrin and its photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange II is 1∶1. The formation constantK = 1.236×10³ L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constantK = 1.266×10³ L/mol was determined by¹H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange II solutions containing β-CD and TiO₂ was smaller by 51.9% than that of the Orange II solutions only containing TiO₂, while in the case of direct photolysis of Orange II solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange II under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis. Foundation item: Supported by the National Natural Science Foundation of China (20177017) Biography: Lu Ping (1958), male. Associate professor, research direction: environmental photochemistry.     

Polycystins 1 and 2 mediate mechanosensation in the primary cilium of kidney cells

Several proteins implicated in the pathogenesis of polycystic kidney disease (PKD) localize to cilia. Furthermore, cilia are malformed in mice with PKD with mutations in TgN737Rpw (encoding polaris). It is not known, however, whether ciliary dysfunction occurs or is relevant to cyst formation in PKD. Here, we show that polycystin-1 (PC1) and polycystin-2 (PC2), proteins respectively encoded by Pkd1 and Pkd2, mouse orthologs of genes mutated in human autosomal dominant PKD, co-distribute in the primary cilia of kidney epithelium. Cells isolated from transgenic mice that lack functional PC1 formed cilia but did not increase Ca(2+) influx in response to physiological fluid flow. Blocking antibodies directed against PC2 similarly abolished the flow response in wild-type cells as did inhibitors of the ryanodine receptor, whereas inhibitors of G-proteins, phospholipase C and InsP(3) receptors had no effect. These data suggest that PC1 and PC2 contribute to fluid-flow sensation by the primary cilium in renal epithelium and that they both function in the same mechanotransduction pathway. Loss or dysfunction of PC1 or PC2 may therefore lead to PKD owing to the inability of cells to sense mechanical cues that normally regulate tissue morphogenesis.     

Study of apolipoprotein E genetic polymorphism in patients with atherosclerotic cerebral infarction

Objective: To explore the frequency and significance of ApoE gene polymorphisms in Chinese patients with atherosclerotic cerebral infarction (ACI). Methods: Polymerase chain reaction and gene sequencing, single nucleotide polymorphisms of ApoE gene were used to analyze 33 cases of patients with ACI and 35 controls. Results: The frequencies of ApoE gene single nucleotide polymorphisms 465C/G, 462C/G and 451delC in the ACI group were significantly higher than those in the control group (P<0.05). The prevalence of polymorphism 486G/T in the control group was significantly higher than that in the ACI group (P=0.011). Conclusions: 465C/G,462C/G and 451delC polymorphisms might be associated with ACI.486GT allele might have protective effect on the pathogenesis of ACI.     

原位聚合法制备聚苯胺/ 聚乙烯醇导电材料的研究

采用原位聚合方法合成了聚苯胺／聚乙烯醇导电复合材料,研究了反应体系中聚苯胺的质量分数和反应时间对复合材料电导率的影响,并且通过红外光谱和热重分析对其结构和稳定性进行了表征和分析．     

Real time monitoring of nucleic acids ligation based on molecular beacon

The replication, ligation and repair of nucleic acids are essential life processes that based the survival, pro-creation and evolution of creatures. These interactions involving proteins (enzymes) and nucleic acids have fas-cinated great interest of scientists[1]. The nucleic acids ligation has been revealed that it is catalyzed by ligase and co-enzyme (ATP or NAD)[2—4]. Along with in-depth re-search, the nucleic acids ligation becomes a significant and common tool employed in bioengineerin…     

Thermodynamic characterization of two novel spin-crossover complexes

Spin-crossover complexes are of great interest to the scientists because of their potential application in molecular-based electronic devices. Some octahedral metal compounds with 3dn (4 ≤ n ≤ 7) configuration can induce a spin state conversion through a fine tuning condition (temperature, pressure, light irradiation, etc.). If the conversion occurs reversibly with a hystersis loop and color change, it will make the system possessing memory effect. The memory effect can be magnified and the …     

The protein Aly links pre-messenger-RNA splicing to nuclear export in metazoans

In metazoans, most pre-messenger RNAs contain introns that are removed by splicing. The spliced mRNAs are then exported to the cytoplasm. Recent studies showed that splicing promotes efficient mRNA export, but the mechanism for coupling these two processes is not known. Here we show that Aly, the metazoan homologue of the yeast mRNA export factor Yralp (ref. 2), is recruited to messenger ribonucleoprotein (mRNP) complexes generated by splicing. In contrast, Aly does not associate with mRNPs assembled on identical mRNAs that already have no introns or with heterogenous nuclear RNP (hnRNP) complexes. Aly is recruited during spliceosome assembly, and then becomes tightly associated with the spliced mRNP. Aly shuttles between the nucleus and cytoplasm, and excess recombinant Aly increases both the rate and efficiency of mRNA export in vivo. Consistent with its splicing-dependent recruitment, Aly co-localizes with splicing factors in the nucleus. We conclude that splicing is required for efficient mRNA export as a result of coupling between the splicing and the mRNA export machineries.