高血压病患者血清肝细胞生长因子与低密度脂蛋白的关系

目的 :探讨血清肝细胞生长因子 (HGF)水平与低密度脂蛋白 (LDL)的关系。方法 :将 45例原发性高血压 (EH )患者分成高LDL组、单纯高血压组。用酶联免疫吸附法 (ELISA )测定血清HGF水平。结果 :高LDL组血清HGF较单纯高血压组及正常对照组显著升高 (均P <0 .0 1) ,单纯高血压组较正常对照组明显升高 ,但差异无显著性 (P >0 .0 5 )。血清HGF浓度与收缩压和舒张压均无显著相关 (r =0 .0 3 9,P >0 .0 5 ) ;与LDL浓度呈中度正相关 (r =0 .66,P <0 .0 5 )。结论 :血清HGF水平与LDL密切相关 ,HGF可作为反映动脉粥样硬化严重程度指标之一。     

TGF-beta signaling in fibroblasts modulates the oncogenic potential of adjacent epithelia

Stromal cells can have a significant impact on the carcinogenic process in adjacent epithelia. The role of transforming growth factor-beta (TGF-beta) signaling in such epithelial-mesenchymal interactions was determined by conditional inactivation of the TGF-beta type II receptor gene in mouse fibroblasts (Tgfbr2fspKO). The loss of TGF-beta responsiveness in fibroblasts resulted in intraepithelial neoplasia in prostate and invasive squamous cell carcinoma of the forestomach, both associated with an increased abundance of stromal cells. Activation of paracrine hepatocyte growth factor (HGF) signaling was identified as one possible mechanism for stimulation of epithelial proliferation. Thus, TGF-beta signaling in fibroblasts modulates the growth and oncogenic potential of adjacent epithelia in selected tissues.     

酪氨酸蛋白激酶受体c-Met及靶点药物研究进展

酪氨酸激酶受体c-Met在细胞的代谢、分化以及死亡细胞的信号传导过程中起着重要的作用,其与配体结合,可活化其信号通路,参与胚胎发育、组织损伤修复以及肿瘤的发生和发展。因而,以酪氨酸激酶受体c-Met为靶点的抗肿瘤药物已经成为肿瘤研究中十分活跃的领域,为抗肿瘤治疗提供了新方法。     

6-苄氨基嘌呤的合成研究

[目的]系统研究脱水法合成6-苄氨基嘌呤（6-BA）的反应条件。[方法]以一定比例的腺嘌呤和苯甲醇为原料制备6-BA，用紫外分光光度计测定产品含量。[结果]随着反应时间的增加，反应物中产品的含量逐渐增大，2．5h以后，产品含量增加速度变缓，3．0h以后基本不再增加。PEG的用量在0．5％时，产品产率最高。当氢氧化钠与腺嘌呤的摩尔比小于1．0：1．0时，得不到产品。当氢氧化钠与腺嘌呤的摩尔比大于1．0：1．0时，产率很高，并且氢氧化钠的用量与产率无明显的相关关系。当氢氧化钠与腺嘌呤的摩尔比大于1．1：1．0时，产率基本不变。[结论]脱水法合成6-苄氨基嘌呤的最佳反应条件为：腺嘌呤：NaOH：苯甲醇：PEG400=1．0：1．1：6～7：0．03，反应时间为2．5～3．0h，反应温度低于250℃。     

Induction by NGF of meiotic maturation of Xenopus oocytes expressing the trk proto-oncogene product.

The effect of nerve growth factor (NGF) was assessed in Xenopus oocytes expressing the human trk proto-oncogene product, p140prototrk. Oocytes injected with trk messenger RNA expressed polypeptides recognized by antibodies to the trk gene product. Exposure of these oocytes to nanomolar amounts of NGF resulted in specific surface binding of 125I-labeled NGF, tyrosine phosphorylation of p140prototrk, and meiotic maturation, as determined by germinal vesicle breakdown and maturation promoting factor (p34cdc2) kinase activation. Thus the trk proto-oncogene product can act as a receptor for NGF in a functionally productive manner.     

回肠缩短术对培植羊黄产量影响的研究

对２０头中国卡拉库尔羊，采用回肠非切除缩短术和胆囊内植核种菌进行培植羊黄的研究。实验表明回肠缩短术能够有效地阻断胆盐的肠－肝循环，显著改变胆盐与胆固醇含量比值，使胆汁成石指产大，从而提高羊黄产量，与对照组相比产黄量差异极显著。     

高技术产品开发的市场定位探析

在现代经营管理中 ,高技术产品开发被企业视为获取竞争优势、巩固市场地位最有效的手段。然而高技术产品开发是一种极富探索和创新性的工程 ,具有明显的高收益与高风险性。大量案例表明开发的风险和收益与市场变化密切相关。因此 ,在市场定位的基础上进行高技术产品开发 ,对于化解其市场风险、提高市场收益具有重要意义     

基于c-Met激酶的小分子抑制剂研究进展

HGF/c-Met信号通路在肿瘤的发生、发展和转移中起着重要的调节作用,成为抗肿瘤药物研发的热门靶点。介绍了c-Met 信号通路的作用机制以及c-Met 抑制剂的研究进展,以期能够找到一类肿瘤抑制活性高、选择性好、副作用小的抑制剂,为癌症治疗提供新的途径。     

HTLV x-gene product: requirement for the env methionine initiation codon

The human T-cell leukemia viruses (HTLV) are replication-competent retroviruses whose genomes contain gag, pol, and env genes as well as a fourth gene, termed x, which is believed to be the transforming gene of HTLV. The product of the x gene is now shown to be encoded by a 2.1-kilobase messenger RNA derived by splicing of at least two introns. By means of S1 nuclease mapping of this RNA and nucleic acid sequence analysis of a complementary DNA clone, the complete primary structure of the x-gene product has been determined. It is encoded by sequences containing the env initiation codon and one nucleotide of the next codon spliced to the major open reading frame of the HTLV-I and HTLV-II x gene.     

Angiogenesis-independent endothelial protection of liver: role of VEGFR-1

The vascular endothelium was once thought to function primarily in nutrient and oxygen delivery, but recent evidence suggests that it may play a broader role in tissue homeostasis. To explore the role of sinusoidal endothelial cells (LSECs) in the adult liver, we studied the effects of vascular endothelial growth factor (VEGF) receptor activation on mouse hepatocyte growth. Delivery of VEGF-A increased liver mass in mice but did not stimulate growth of hepatocytes in vitro, unless LSECs were also present in the culture. Hepatocyte growth factor (HGF) was identified as one of the LSEC-derived paracrine mediators promoting hepatocyte growth. Selective activation of VEGF receptor-1 (VEGFR-1) stimulated hepatocyte but not endothelial proliferation in vivo and reduced liver damage in mice exposed to a hepatotoxin. Thus, VEGFR-1 agonists may have therapeutic potential for preservation of organ function in certain liver disorders.     

绿色产品的概念、基本特征及绿色设计理论体系

讨论了现有绿色产品定义，并从产品整体性角度提出了绿色产品的新定义，同时，根据当代消费者的消费心理和产品市场竞争的特点。论述了真正的绿色产品应具备的８个基本特征；传统设计和绿色设计的不同；对绿色产品认识上的误区；绿色产品设计的理论体系和内容；绿色产品及绿色设计的意义和发展趋势等。     

四川地震资源与开发研究

界定了地震旅游资源的概念,用灾害经济学观点、旅游规划理论和系统方法分析了"5.12"汶川特大地震派生的地震旅游资源,提出了地震旅游产品开发原则和总体思路,并就龙门山断裂带整个区域地震旅游产品开发的协调互补与整合给出了框架性建议。     

农产品重金属超标风险:发生过程与预警防控

以土壤重金属为风险源,以农产品为风险受体,从风险发生过程→风险概率预测→风险控制与适宜性评估,对农产品重金属超标问题进行了综合分析。首先采用基于质量标准的四象限分区,分类解析了风险源与受体之间的非线性响应关系;然后通过系统分析农产品重金属超标的发生过程,构建了基于重金属在土壤-作物系统转移与积累的风险发生关系树,刻画了风险发生过程及主要影响因素;再通过贝叶斯分类概率统计方法,提出了农产品重金属超标风险的预警方法;最后,建立了"直角-广义仿射"双坐标系,以此来表征和评估土壤重金属污染现状与修复措施的预期结果,为农产品重金属超标风险管控提供科学依据。     

浅谈兰州畜牧业的现状与发展建议

针对兰州市畜牧业发展现状和存在问题,提出了兰州市畜牧业的发展建议是以市场为导向,建立畜产品基地;大力发展饲草产业;利用现代科技手段,加快畜牧产业的发展;依托龙头企业,推进畜牧业产业化进程;建立畜产品专业批发市场,加大销售力度;组织标准化生产,提高质量水平;大力推广畜产品生产技术,加强信息服务。     

农村劳动力流动影响农产品价格的实证研究——基于VEC模型的方法

在阐述国内外学者研究情况的基础上,依据19902007年农村劳动力流动和农产品价格数据,利用VEC模型分析了农村劳动力流动和农产品价格的动态均衡关系,采用Chow′s断点检验测算了农村劳动力流动影响农产品价格的阶段性特征。结果表明,农村劳动力流动量和农产品价格之间存在长期稳定的关系;农村劳动力流动正以一种内生的力量影响着农业生产,从而影响着农产品价格的变化;农村劳动力流动对农产品价格的影响力度呈由弱到强,又逐渐减弱的态势,峰值在1998年达到最高;随着我国市场化进程和农村社会经济的发展,农村劳动力流动影响着农产品价格,而且这种影响具有阶段的特征。为了实现农村劳动力流动和农产品价格的双重稳定,提出了相应的对策建议：一是大力发展职业教育,加大对农业生产的支持力度;二是制定积极的就业措施。     

农户安全农产品供给的影响因素分析

对农户安全农产品供给行为的影响因素进行了分析研究,结果表明：安全农产品供给是农户以利润最大风险最小为经济目标农户的理性行为,它既受到农产品价格、农产品成本、风险等经济因素的影响,又受到政策法规、中介组织、社会舆论等社会因素的制约。     

Distinguishing the direct and indirect products of a gas-surface reaction

It has long been postulated that gas-surface chemical reactions can occur by means of two distinct mechanisms: direct reaction on a single gas-surface encounter or reaction between two adsorbed species. It is shown here that these mechanisms have distinct dynamical signatures, as illustrated by the reaction of hydrogen with chlorine on gold(111). The direct reaction product leaves the surface with a high kinetic energy in a narrow angular distribution that displays a "memory" of the direction and energy of the incident hydrogen atom. The indirect reaction product has a near-thermal energy distribution and an angular distribution that is close to that of a cosine function.     

生物发光法在农产品安全性检测中的应用前景

综述了发光细菌法急性毒性检测、生物发光法基因毒性检测和生物发光ATP法微生物检测等农产品检测方法的特点和实际应用情况,并经过对比指出其中生物发光法作为一种速度快、操作方便、成本低廉的生物监测方法,将在农产品安全快速检测中有广泛的应用前景。     

C60H2: Synthesis of the Simplest C60 Hydrocarbon Derivative

The reaction of C(60) with BH(3): tetrahydrofuran in toluene followed by hydrolysis yielded C(60)H(2). This product was separated by high-performance liquid chromatography and characterized as the addition product of H(2) to a 6,6-ring fusion (1alb isomer). The (1)H nuclear magnetic resonance (NMR) spectrum of the product remained a sharp singlet between -80 degrees and +100 degrees C, which suggests a static structure on the NMR time scale. Hydrolysis of the proposed borane addition product with acetic acid-d(1) or D(2)O yielded C(60)HD, and its (3)J(HD) coupling constant is consistent with vicinal addition. The observation of a single C(60)H(2) isomer is in complete agreement with earlier calculations that indicated that at most 2 of the 23 possible isomers of C(60) would be observable at equilibrium at room temperature. These results suggest that organoborane chemistry may be applied to further functionalization of fullerenes.     

水产品全产业链物联网追溯体系研究与实践

为确保水产品的质量安全和实现水产品全产业链全程可追溯,本文以水产品产业链为视角,阐述和分析了我国水产品存在的主要质量安全问题,通过引入无线射频识别、二维码、全球定位系统和地理位置信息系统等物联网的理念和技术,提出了基于物联网的水产全产业链追溯体系,并阐述了其在产业链中各个环节的实现方法。依此,构建了面向企业、政府和消费者的政府水产品全产业链追溯监管云服务,并提出了一种基于RFID和EPC的水产品信息追溯机制,列举了溯源信息范本和EPC编码范例,从而实现从水产品全产业链的全时空静态溯源和动态追溯。最后,本文所提出的基于物联网的水产品追溯体系在上海—台湾中华绒螯蟹种输台任务中得以实践和应用,帮助225家台湾养殖户对77万只中华绒螯蟹蟹种进行溯源和投塘,形成蟹种质量全程动态追溯体系。