DNA-protein interaction at erythroid important regulatory elements of MEL cells byin vivo footprinting

Using ligation-mediated PCR method to study the status of DNA-protein interaction at hypersensitive site 2 of locus control Region and β^maj promoter of MEL cell line before and after induction, MEL cell has been cultured and induced to differentiation by Hemin and DMSO, then the live cells have been treated with dimethyl sulfate. Ligation mediated PCR has been carried out following the chemical cleavage. The results demonstrate that before and after induction, the status of DNA-protein interaction at both hypersensitive site 2 and β^maj promoter change significantly, indicating that distal regulatory elements (locus control region, hypersensitive sites) as well as proximal regulatory elements (promoter, enhancer) of β-globin gene cluster participate in the regulation of developmental specificity.     

Prediction of nonregular secondary structures of proteins based on wavelet analysis

The secondary structures of proteins fall into two classes: regular structure and nonregular structure. Helices and sheets are termed "regular" structures because their residues have repeating main-chain torsion angles, and their backbone N-H and C-O groups are arranged in a periodic pattern of hydrogen bonding. In contrast, the remaining structures with nonrepeating backbone torsion angles are called nonregular secondary structures. In this note, we performed an extensive sequence analysis of nonregular secondary structures and showed that these nonregular parts could be effectively predicted by continuous wavelet transform.     

CAPM模型对中国资本市场的检验分析

CAPM模型中的贝塔系数是用来衡量资本市场系统风险的基本参数，一个完备的具有有效性的资本市场，它的贝塔系数是不变的，传统的CAPM模型中也要求贝塔系数是固定不变的。沪市15家上市公司的数据样本，说明在我国资本市场，贝塔系数具有不稳定性，从而进一步说明，当前的资本市场并不具备有效性，并进一步对其成因进行分析并加以说明和解释。     

PREPARATION AND MORPHOLOGY OF ISOTACTIC POLYPROPYLENE WITH HIGH CONTENT OF β CRYSTALLINE FORM

Isotactic polypropylene (iPP) with high content of ~ crystalline form was prepared by adding a series of new p form nucleators. The spherulites and morphology of//farm iPP (//-iPP) were investigated by wide-angle X-ray diffraction(WAXD), polarizing microscope (PLM), scanning electron microscope (SEM) and small-angle light scattering (SALS). WAXD experimental results indicate that the amount of p form in iPP (K_x) increases with increasing /~ nucleator content from zero to 0.07 wt% or crystallization temperature T_c from 20 to 120℃ and that the highest K_x value is up to 0.95. PLM observations suggest that p spherulites exhibit bright color and that their Maltese Crosses display some concentric banding of a rather spiky, jagged character. Their !amellae are smooth and relaxed layer-plate like structure by SEM and their SALS H_v patterns arc four-petalled.     

两端任意支承的矩形截面钢筋混凝土梁可靠性优化设计

利用雷－莉法把非正态变量转换为当量正态变量,建立了在多个任意分布基本变量情况下的２性结构优化的设计数学模型。最后给出了设计人格最小的矩形截面钢筋混凝土梁的可靠性优化设计实例。     

Interaction between integrin a Ⅱbβ 3 and synthesized cyclic hexapeptide containing RGD

The RGD sequence generally exists in the extracellular matrix proteins and can be recognized by many integrin proteins. The binding ability of immobilized biotinylated cyclic hexapeptide [cyclo(-Arg-Gly-Asp-D-Phe-Lys-Gly-)] containing RGD to integrin a ab β3 was tested by the methods of ELISA and SPR. Results showed that a spacer of 1.48-2.2 nm between the peptide and the biotin residue was long enough to send the RGD sequence into the binding center embedded within a Ⅱbβ 3, and the equilibrium dissociation constant was 1.1 μm. The work provides an ideal model system for the research of cell adhesion on solid surfaces.     

Review： Protein folding pathology in domestic animals

Fibrillar proteins form structural elements of cells and the extracellular matrix. Pathological lesions of fibrillar microanatomical structures, or secondary fibrillar changes in globular proteins are well known. A special group concerns histologically amorphous deposits, amyloid. The major characteristics of amyloid are: apple green birefringence after Congo red staining of histological sections, and non-branching 7-10nm thick fibrils on electron microscopy revealing a high content of cross beta pleated sheets. About 25 different types of amyloid have been characterised. In animals, AA-amyloid is the most frequent type. Other types of amyloid in animals represent: AIAPP (in cats), AApoAⅠ, AApoAⅡ, localised AL-amyloid, amyloid in odontogenic or mammary tumors and amyloid in the brain. In old dogs Aβ and in sheep APrP^sc-amyloid can be encountered. AA-amyloidosis is a systemic disorder with a precursor in blood, acute phase serum amyloid A (SAA). In chronic inflammatory processes AA-amyloid can be deposited. A rapid crystallization of SAA to amyloid fibrils on small beta-sheeted fragments, the ‘amyloid enhancing factor‘ (AEF), is known and the AEF has been shown to penetrate the enteric barrier. Amyloid fibrils can aggregate from various precursor proteins in vitro in particular at acidic pH and when proteolytic fragments are formed. Molecular chaperones influence this process. Tissue data point to amyloid fibrillogenesis in lysosomes and near cell surfaces. A comparison can be made of the fibrillogenesis in prion diseases and in enhanced AA-amyloidosis. In the reactive form, acute phase SAA is the supply of the precursor protein, whereas in the prion diseases, cell membrane proteins form a structural source. AI3-amyloid in brain tissue of aged dogs showing signs of dementia forms a canine counterpart of senile dementia of the Alzheimer type (ccSDAT) in man. Misfolded proteins remain potential food hazards. Developments concerning prevention of amyloidogenesis and therapy of amyloid deposits are shortly commented.     

一种电压/电流和电流/电流转换电路的设计

根据传感器应用要求,介绍了一种实用的电压/电流(V/I)和电流/电流(I/I)转换电路的设计。其中V/I电路可以将传感器提供的0～5V的电压信号转换为1～5mA的电流信号,I/I电路可以将4～20mA的电流信号转换为1～5mA的电流信号,实验结果表明两种转换电路均满足设计要求。     

PKB negatively modulates TGF-β responsiveness in prostate carcinoma PC-3 cells through its interaction with Smad3

Transforming growth factor-β (TGF-β) is a multi- functional growth regulator belonging to the TGF-β superfamily consisting of TGF-β, activin, bone mor- phological proteins and other factors. It regulates many aspects of cellular behavior, including mi…     

using Enterprise Use Case

-61试论企业反竞争情报活动李映洲;欧阳霞;兰州大学管理学院,湘南学院数学系信息管理教研室 甘肃兰州730000,湖南郴州423000反竞争情报;;反竞争情报活动;;OPSEC随着竞争情报活动的开展,企业获取竞争情报的手段越来越多样化,于是,一个企业在获取竞争对手情报的同时,如何最大限度地保护自身秘密信息,并有针对性地进行还击成为企业赢得竞争优势的关键。本文以反竞争情报活动为主线,具体论述了反竞争情报原理、反竞争情报分析、反竞争情报     

以Aβ为靶的老年性痴呆的治疗策略

老年性痴呆（Alzheimerdisease，AD）是以进行性认知障碍和记忆能力损害为主的中枢神经系统退变性疾病。其主要病理变化包括老年斑（senileplaque，SP）、神经纤维缠结（neurofibrillarytungle，NFT）和选择性神经元及突触的丢失。由于AD病因和病理机制尚不清楚，其治疗亦缺乏理想的方法。传统的治疗方法主要有：脑细胞活化剂、心理治疗、拟胆碱药物治疗等等。前者似乎疗效不大，后者因其义才神经有一定的毒性，限制了临床应用。现行的AD治疗研究策略主要包括两个方面：（1）开发新的低毒性的拟胆碱药物；（2）神经营养物质的应用，包…     

运动与促炎性细胞因子

细胞因子是糖基化的多肽。它们介导整个机体的免疫细胞和非免疫细胞之间、器官和器官系统之间及器官、系统内部的联系。炎症性细胞因子包括前炎症性和抗炎症性细胞因子：它们受体育运动、组织损伤和感染等刺激的调节。体育运动可调节局部和全身细胞因子的产生。本综述论述了炎症性细胞因子的作用及细胞因子对运动的反应。同时讨论了IL-6的来源。     

一种基于I／O通道的智能控制接口设计

在分析了ＰＣ系列微型机Ｉ／Ｏ接口现状的基础上，提出了一种适用于微机控制领域的通用智能接口的设计方法，并对接口的编程和调试作了详细的讨论。     

FPGA与I2C总线器件接口设计

本文介绍了现场可编程门阵列FPGA与I2C总线器件接口的设计方法.其特点是用VHDL语言编程,利用FPGA的普通I/O口模拟产生I2C总线规程的接口信号时序,实现PFGA与I2C总线器件的数据通信.本文给出了PFGA与I2C总线存储器件24CO1/02连接的硬件和软件设计的应用实例.     

与含卫星DNA的烟草曲茎病毒伴随的nanovirus类DNA分子鉴定

利用已报道的两种粉虱传双生病毒DNA1分子的全长特异性引物进行PCR扩增,在含有卫星DNAβ的烟草曲茎病毒(TbCSV)Y35和Y115分离物中扩增到一种单链环状DNA小分子(命名为DNA1),而在不含有卫星DNAβ的TbCSV Y1和Y121分离物中没有扩增到DNA1分子. 免疫捕获PCR表明DNA1分子包裹在双生病毒粒子中. Southern blot检测进一步证实仅在含卫星DNAβ的TbCSV Y35和Y115分离物中存在DNA1分子. 序列分析表明,Y35 和Y115 DNA1序列全长分别为1367和1368?nt,各有一个较保守的开放阅读框(ORF),编码类似nanovirus 的Rep蛋白. 两个DNA1分子与辅助病毒DNA-A序列无同源性. Y35和Y115 DNA1全长核苷酸序列同源性为92%,ORF编码的氨基酸同源性为96%,而与已报道的胜红蓟黄脉病毒和木尔坦棉花曲叶病毒的DNA1的核苷酸序列同源性为70%～79%,氨基酸序列同源性为87%～90%. 将DNA1与nanoviruses DNA比较后发现,两者有较远的亲缘关系.     

正电子发射断层扫描仪的研究

探讨了正电子发射断层扫描仪的工作原理、基本结构和发展状况,阐述了PESS在核医学成像技术中的重要作用。