空气污染对手足口病传播的短期影响效应研究——以温州市为例

基于温州市手足口病2014—2017年周发病数据及同期空气质量数据,建立了广义加性模型,研究了空气污染对周发病数影响的短期效应.结果表明,4种空气污染物SO_2、CO、NO_2和O_3对手足口病周发病数的影响显著且存在滞后效应,滞后期均为1周.单污染物模型显示,SO_2、CO和NO_2这三种气态污染物都是手足口病发病的危险因素,在滞后1周时周平均浓度每增加1μg/m3SO_2、1 mg/m3CO、1μg/m3NO_2,手足口周发病数将分别增加2.8%、43.8%、0.9%;而O_3在滞后1周时周平均浓度每增加1μg/m3,手足口周发病数将减少0.4%.在SO_2、CO、NO_2和O_3组成的11种多污染物模型中,依据QAIC最小原则选出最优模型为双因素SO_2+CO模型.研究结果将为手足口病的防控提供科学依据.     

基于初始缺陷形状的混凝土结构锈胀开裂理论模型

为考虑材料初始缺陷形状的影响,将其假定为三维半椭球形.基于断裂力学理论将锈胀裂缝扩展过程划分为两个临界阶段:初始开裂阶段和完全开裂阶段,并分别对两组临界阶段进行了分析,建立了混凝土构件保护层胀裂时的锈胀力及开裂时间预测模型.为了验证所提出预测模型的正确性,分别采用已有的室内锈蚀实验、现场测试数据进行验证,计算结果吻合较好,说明本文预测模型具有一定合理性.在此基础上,对初始缺陷长度、混凝土保护层厚度、钢筋半径、相对保护层厚度等参数进行敏感性分析,结果表明增加混凝土保护层厚度和相对保护层厚度,有利于提高钢筋混凝土结构的服役性能.     

定量蛋白质组学及其在颅内动脉瘤中的研究进展

 颅内动脉瘤（IA）是颅内动脉壁的某一部分因病变而向外突出所形成的永久性扩张,是造成蛛网膜下腔出血的首位病因。定量蛋白质组学,作为新近出现的一种崭新的研究手段,为治疗颅内动脉瘤提供了新的研究思路。通过同位素标记相对和绝对定量（iTRAQ）技术及二维液相色谱-串联质谱（2D-LC-MS/MS）法筛选动脉瘤壁差异表达蛋白质,为动脉瘤形成和破裂的分子机制研究提供了帮助。本文综述了颅内动脉瘤的研究进展以及定量蛋白质组学技术在颅内动脉瘤研究中的应用。     

阿尔茨海默症发病机制及治疗方法研究进展

 阿尔茨海默症（Alzheimer's disease,AD）是以β淀粉样蛋白斑块及神经元纤维缠结为主要病理特征的神经退行性疾病,是痴呆中最常见的一种,也是一种常见的老年人疾病。AD的发病机制可能由多种发病因素、多种通路和分子机制的相互参与引起。由于AD的发病主要同老年人有关,故研究治疗AD的方法对于提高人类健康和生活水平至关重要。虽然目前并没有一种治疗方法可以完全治愈AD,但有多种治疗策略。本文对AD的发病机制及治疗方法的研究进展进行简要综述。     

衰老叶片叶绿素荧光动力学变化及6-BA延缓衰老的机理研究

观测了离体小麦叶片衰老进程中685nm光诱导荧光动力学的变化,发现曲线的第二峰首先消失,F_v(F_p-F_t)、F_p-F_t和F_v/F_o比值迅速下降,达最大荧光P点的时间缩短。推测衰老叶片中PQ分子数目的减少是光合能力丧失的主要原因。用6-BA处理叶片,阻止了F_v和F_v/F_o比值的下降,与对照相比,衰老第三天仍保持第二峰;此外,核黄素使第二峰消失,而核黄素+BA与BA效果相似;同时叶片衰老时SOD活性的下降和膜脂过氧化作用均被延缓,据此探讨了BA作为自由基清除剂延缓叶片衰老的可能机理。     

冠心病患者头发锌铜硒等微量元素测定

应用催化极谱法分析34例冠心病患者头发中铜、锌、锰、硒及铬的含量,并与30例年令相近的健康成人对照,结果冠心病患者头发中微量元素铜含量高于对照组,硒、锰及铬的含量明显低于对照组,(p值<0.01)两组间有显著性差异,认为体内微量元素铜高,低硒、低锰、低铬可能与冠心病有关。     

菜豆锈病菌侵染对寄主生理代谢的影响

从细胞膜透性、呼吸强度、光合作用及游离氨基酸和蛋白质代谢等几方面,对菜豆锈病菌(Uromyces appendiculatus)侵染与菜豆生理代谢变化的关系进行了研究.结果表明U.appendiculatus侵染可导致被侵染菜豆叶片细胞膜透性的增加,但这种增加在抗感程度不同的品种中出现的早晚和程度不同; 抗感品种在接种后呼吸强度都增加,但不同品种呼吸强度升高的时间和程度有异;U.appendiculatus对寄主光合作用的影响体现在叶绿体含量的降低及光合产物(糖和淀粉)的异常积累;接种前后菜豆叶片中蛋白质含量无明显变化,但个别游离氨基酸的含量在抗病品种中有变化.     

2001～2004年小麦区试品种抗条锈性鉴定及评价

2001～2004年对陕西省181份小麦区试品种的成株期抗条锈性鉴定结果表明,区试品种对不同条锈菌流行小种的抗性存在明显差异.对条中32号的抗性最差,抗病品种数为48份,占区试品种的35.0%,其次为水源11～14和条中31号,抗病品种所占比例分别为38.0%和45.3%,对条中29号、30号、水源11～13以及太白4的抗性相对较好.调查其中128份区试品种的自然发病情况表明,表现免疫-近免疫和高抗-中抗的品种分别占7.0%和28.9%,而中感-高感品种占64.1%.     

Molecular basis of autosomal-dominant polycystic kidney disease

Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common monogenetic diseases in humans. The discovery that mutations in the PKD1 and PKD2 genes are responsible for ADPKD has sparked extensive research efforts into the physiological and pathogenetic role of polycystin-1 and polycystin-2, the proteins encoded by these two genes. While polycystin-1 may mediate the contact among cells or between cells and the extracellular matrix, a lot of evidence suggests that polycystin-2 represents an endoplasmic reticulum-bound cation channel. Cyst development has been compared to the growth of benign tumors and this view is highlighted by the model that a somatic mutation in addition to the germline mutation is responsible for cystogenesis (two-hit model of cyst formation). Since in vitro polycystin-1 and polycystin-2 interact through their COOH termini, the two proteins possibly act in a common pathway, which controls the width of renal tubules. The loss of one protein may lead to a disruption of this pathway and to the uncontrolled expansion of tubules. Our increasing knowledge of the molecular events in ADPKD has also started to be useful in designing novel diagnostic and therapeutic strategies. Received 12 September 2001; received after revision 7 November 2001; accepted 7 November 2001     

The multifaceted Paneth cell

Paneth cells (PCs) were described over a century ago as granulated cells located at the base of small intestinal crypts, the 'crypts of Lieberkühn.' Various histochemical staining procedures were developed that identified PCs based on their distinctive granule staining pattern. Early on, PCs were proposed to perform a specialized function other than absorption of digested nutrients, the predominant task of the small intestinal epithelium. Since then, many constituents of the PC granules have been biochemically characterized. The presence of various granule-associated antimicrobial substances and their release upon microbial challenge suggest that PCs function as specialized defense cells in the small intestine. Altered resistance to microbial infection in animal models with disrupted or augmented PC function provides further support for the host defense role of PCs. Other PC components suggest that PCs may also participate in the regulation of lumenal ionic composition, crypt development, digestion, and intestinal inflammation. Received 6 June 2001; received after revision 26 July 2001; accepted 27 July 2001