Improvement and induction property of radiation-responsive promoter through DNA shuffling of 5′-flanking regions of the human p21 gene

A promoter that augments gene expression in response to stimulation of ionizing radiation would be a desired tool for radiogenetic therapy, a combination of radiotherapy and gene therapy. Although various promoters occurring naturally or artificially have been used for researches, one showing higher reactivity to ionizing radiation is desirable. In the present study, we attempted to improve a radiation-responsive promoter of the p21 through a technique called DNA shuffling. A library of DNA fragments was constructed by re-ligation of randomly digested promoter fragments and improved promoters were chosen out of the library. We repeated this process twice to obtain a promoter showing 2.6-fold better reactivity to ionizing radiation compared with its parent, p21 promoter after 10 Gy γ-ray irradiation. Nucleotide sequence analyses revealed that the obtained promoter was densely packed with some of the cis-acting elements including binding sites for p53, NF-κB, NRF-2, AP-1 and NF-Y more than p21 promoter. In addition, it was shown that its induction by ionizing radiation was dependent upon p53 status of a cell line, suggesting that the promoter retained properties of the p21 promoter. This technique is simple and efficient to improve a promoter responsive to other stimulus of interest besides IR.     

桐油制备C_(21)聚酰胺环氧固化剂的性能及固化反应动力学研究

以桐油的甲醇酯交换产物桐酸甲酯和丙烯酸为原料,通过Diels-Alder加成反应合成了C21二元酸单甲酯(TMAA),桐酸甲酯和丙烯酸的加成温度为180℃,反应时间3 h,比通用C21二元酸的合成反应温度低70℃。然后用C21二元酸单甲酯和不同多元胺酰胺化制备了3种不同胺值的C21二酸聚酰胺环氧固化剂。机械性能测试显示,C21二元酸聚酰胺和双酚A环氧树脂(DGEBA)的环氧固化物和C36二聚酸聚酰胺650C的DGEBA固化物相比,具有更高的机械强度和模量。胺值为496 mg/g的C21二元酸聚酰胺与DGEBA的固化产物拉伸强度达58.63 MPa,断裂伸长率为3.27%,弹性模量达2 635.84 MPa,弯曲强度达99.9 MPa。差示扫描热分析法(DSC)测得C21二元酸聚酰胺的DGEBA固化物的玻璃化温度分别为108、109和116℃,比C36二聚酸聚酰胺的DGEBA固化物的玻璃化温度高出50℃左右。n级反应机理求取的3种固化剂与DGEBA的固化反应活化能分别为62.179、56.551和59.761 kJ/mol,比C36二聚酸聚酰胺与DGEBA的固化反应活化能高出约10 kJ/mol。固化反应动力学得出固化剂与DGEBA的凝胶温度、固化温度和后固化温度分别为40、90和150℃左右。     

Cultivating Smartcities

On 9 April 2009, Michelle Obama planted the first seedlings of onion, lettuce, peas and peppers in the 102-square-metre (1,100-square-foot) White House Kitchen Garden. She may have planted the green shoots for a smartcity. CJ Lim , author of Smartcities + Eco-warriors (Routledge, 2010), describes sustainable urban developments in the form of smartcities – a new urban exuberance reintegrating cultivated land within an urban economic and ecological context system. These verdant edible edifices of urban spatial theatre are aesthetically and culturally engaging. Soliciting an emotional as well as intellectual response they have the potential to connect with the public and involve them in the architectural possibilities of the city. Copyright © 2010 John Wiley & Sons, Ltd.     

The Story of Istanbul's Modernisation

Since reform started under Ottoman rule in the early 19th century, Istanbul has undergone a substantial period of modernisation that has spanned more than 150 years. İlhan Tekeli outlines the metropolis' enduring development, characterising Istanbul's transformation into a modern city into four distinct periods. It is a story that bridges the collapse of the Ottoman Empire and the reconstruction of the Turkish Republic as a nation-state, with the initial demise of the city in favour of Ankara; and continues with Istanbul regaining its status as a world city; as it evolves from a monstrous industrial city to an urban region and global centre. Copyright © 2010 John Wiley & Sons, Ltd.     

带缝剪力墙结构与普通剪力墙结构抗震性能对比分析

运用通用有限元软件ANSYS建立了保温砌模带缝剪力墙和普通剪力墙两层有限元模型.对两种结构的基本动力特性进行了比较研究.并在此基础上对两种结构形式进行了时程分析.研究表明:保温砌模形成的带缝剪力墙结构体系在弹性范围内具有较好的整体性,刚度降低较小,具有与普通剪力墙良好的抗剪承载力.地震设防烈度范围的时程分析表明,保温砌模结构的层间位移和位移角都较小,能满足现行规范的设计要求.     

Toxicological and ecotoxic impact of secondary and tertiary treated sewage effluents

Secondary sewage effluents are discharged in significant quantities in aquatic environments delivering pollutants that were not removed during treatment; yet advanced treated effluents are not lacking of contaminants. In this study, biochemical biomarkers were measured in liver and kidney of rainbow trout (Oncorynchus mykiss) exposed to unchlorinated, chlorinated and tertiary treated secondary sewage effluents. In addition, organic matter, nitrogen and suspended solids were assayed, while a common bioassay, Daphnia magna 21d reproduction test was also applied in order to examine potential relation between the performed bioassay and the biomarkers. Processes using oxidative conditions, such as ozonation and chlorination, resulted in significantly increased breeding rate (up to 74%) of the organism. Biomarkers measurements incorporated the determination of total glutathione (GSH), glutathione S-transferases (GST), glutathione peroxidase (GPX), lipid peroxidation (LPO) and an innovative biomarker in such applications, haem peroxidase. In general, the response of biomarkers was dependent upon the treatment method and it was tissue specific. Secondary effluents inhibited liver GST and haem peroxidase, while GSH levels and LPO were significantly provoked in liver. Ozonation provoked hepatic peroxidation, in terms of haem peroxidase and LPO, and GST; while the protective (to Reactive Oxidant Species – ROS) GSH was depleted, suggesting extended ROS attack to the organism. Similar response of biomarkers (but to a lesser extend) was observed after exposure of trout to effluents submitted to both coagulation and ozonation, emphasizing the significance of removing the residual organic matter by other methods than oxidative ones. Ozonation also enhanced renal LPO and GPX; however the former employment of coagulation limited the peroxidation phenomena. Chlorination mainly affected the levels of total GSH in both tissues.     

Finite sample properties of alternative GMM estimators for random effects models with spatially correlated errors

For panel data models with error components that are spatially correlated, the finite sample properties of alternative generalized method of moments (GMM) estimators are determined. We suggest using a continuously updated GMM estimator which is invariant to curvature altering transformations and which should improve small sample efficiency. A Monte Carlo study using a wide range of settings compares the small sample efficiency of various GMM approaches and the maximum likelihood estimator (MLE). The GMM estimators turn out to perform comparably to the MLE approach and even outperform the latter for complex weighting matrices and non-normally distributed errors. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

FGF21生物学特性的研究进展

FGF21是成纤维细胞生长因子家族的一名新成员,其氨基酸序列与其他亚家族成员之间有不同程度的同源性。FGF21在肝脏中特异性表达,能降低血糖、甘油三酯、胰高血糖素和果糖胺的浓度,改善胰岛β细胞的功能,因此有望成为治疗糖尿病、肥胖症及其他一些代谢综合症的药物。FGF21还有很多不同于其他FGFs家族的特点,如FGF21的信号传导需要βKlotho协同才能稳定结合FGFR;FGF21能通过血脑屏障等。另外,在斑马鱼体内还发现FGF21能促进造血功能。本文就FGF21的分子结构及其生物学特性的研究进展作一综述。