卟啉金属有机骨架材料在肿瘤治疗中的应用

目前,恶性肿瘤严重威胁人类健康和生命。临床上常用放疗法和化疗法治疗肿瘤,在一定程度上抑制肿瘤的生长和转移。但是,传统的化疗药物在给药过程中缺乏靶向性、副作用大,而且大多数化疗药物水溶性差,效果有限,高剂量的重复给药会导致耐药,单一模式的治疗策略效果不佳。因此通过构建靶向智能多功能纳米载药系统实现肿瘤精准诊断和治疗成为近年来的研究热点。卟啉金属有机骨架（MOFs）材料具有多孔性、大比表面积、表面可修饰等特性,有望成为良好的靶向刺激响应型药物载体。而且卟啉MOFs可以避免卟啉分子的自聚集以及在激发态的自猝灭,还具有卟啉分子的宽光谱响应范围,是一类具有广阔应用前景的固体光敏剂,因此卟啉MOFs近年来成为构建靶向智能多功能纳米载药系统的重要平台。本论文综述了近年来基于卟啉金属有机骨架材料的肿瘤治疗策略,特别是基于肿瘤内源性组分（pH、酶、氧化还原）和外源性物理信号（声、磁、光）刺激触发的多功能纳米平台用于肿瘤精准诊断和治疗的最新研究进展,并讨论了卟啉MOFs在未来肿瘤治疗中面临的挑战和机遇。     

面部表情的阈下情绪启动效应及其机制

人类大脑是否可以加工阈下情绪信息?阈下情绪启动效应为此提供了直接证据。使用视觉掩蔽和连续闪烁抑制范式,以面部表情作为启动刺激的研究发现,个体在注意和记忆、社会性评价和行为倾向中都受先前启动刺激情绪属性的影响,即表现出了阈下情绪启动效应。还有研究发现,阈下面部表情增强了个体的皮肤电导水平和心血管系统反应。而神经机制的研究发现,阈下面部表情对目标刺激的早期知觉加工和晚期情绪意义分析产生了影响,杏仁核等脑区在其中具有重要作用。情绪优先假设和感受即信息理论分别从情绪系统领域特殊性和情绪归因的角度试图阐释该效应产生的机制。在总结和分析以往研究基础上,本文对这一领域的未来研究提出了具体建议。     

维拉帕米对三磷酸肌醇引起的大鼠肝细胞钙释放激活的钙电流的影响

目的 :观察维拉帕米 (verapamil,VP)对三磷酸肌醇 (IP3)引起的大鼠肝细胞钙释放激活的钙电流 (ICRAC)的影响。方法 :采用标准全细胞膜片钳技术。结果 :IP3 激活的ICRAC的峰电流为 (- 0 .2 6± 0 .0 8)nA(n =7) ;5 μmol/L维拉帕米对ICRAC的抑制率为 30 .9%± 7.8% (从 - 0 .2 5± 0 .10nA到 - 0 .17± 0 .0 5nA ,n =5 ,P <0 .0 1)。结果 :维拉帕米能有效抑制IP3 引起的ICRAC。     

杭州西湖水域微生物的生态调查

对杭州西湖水域微生物生态调查结果表明:(1)有机营养型细菌在富营养化程度较重的岳湖分布较多,而无机营养型细菌在水质较好的小南湖丰度较大;(2)许多微生物类群在温度较高的季节数量反而较少;(3)西湖经综合治理后,异养型细菌和大肠菌群数量有显着减少,但近年又有增加的趋势;(4)西湖水体中的微生物以假单胞菌属的细菌较多,而底泥中芽孢杆菌属的细菌占优势。       

黄胫小车蝗室内种群的建立及亚洲小车蝗痘病毒的增殖

1966年美国人最早从草地血黑蝗Ｍｅｌａｎｏｐｌｕｓｓａｎｇｕｉｎｉｐｅｓ上分离到病毒[1] ,1969年确认为是一种痘病毒(ｅｎｔｏｍｏｐｏｘｖｉｒｕｓ ,ＥＰＶ) [2 ] ,其后他们用这种草地蝗虫大量增殖痘病毒 ,现已进入了田间试验阶段[3] 。 1981年我国也从草地蝗虫中分离到痘病毒[4 ] ,但我国没有人研究过草地蝗虫的大量饲养问题 ,草地蝗虫的大量饲养与鳞翅目昆虫不同 ,即使在当地条件下饲养也很困难 ,这使得我国利用痘病毒防治草地蝗虫的研究一直停滞不前。2 0世纪 80年代末 ,我们从新疆和内蒙古的其它重要草地蝗虫中分离到痘病毒[5] ,能…     

高聚物基PCR微流控芯片技术

PCR微流控芯片是一种完美的体外无限扩增核酸的技术 ,是第三代PCR技术。目前英国、德国、日本、中国等多家研究单位已经成功地应用自己研制的PCR微流控芯片在实验室完成了DNA扩增。基于目前大多芯片采用硅或者玻璃作为基片 ,存在加工工艺复杂和价格昂贵的缺点 ,通过对不同材料性能比较 ,认为价格便宜、加工方法简单的高聚物是今后芯片材料发展的趋势。通过对三种高聚物加工方法的比较 ,认为准分子激光直写入微加工方法因其灵活性大 ,加工质量高 ,将成为高聚物加工方法的主流。最后针对PCR微流控芯片的温控系统提出了优化方案。     

Role of two sequence motifs of mesencephalic astrocyte-derived neurotrophic factor in its survival-promoting activity

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a prosurvival protein that protects the cells when applied intracellularly in vitro or extracellularly in vivo. Its protective mechanisms are poorly known. Here we studied the role of two short sequence motifs within the carboxy-(C) terminal domain of MANF in its neuroprotective activity: the CKGC sequence (a CXXC motif) that could be involved in redox reactions, and the C-terminal RTDL sequence, an endoplasmic reticulum (ER) retention signal. We mutated these motifs and analyzed the antiapoptotic effect and intracellular localization of these mutants of MANF when overexpressed in cultured sympathetic or sensory neurons. As an in vivo model for studying the effect of these mutants after their extracellular application, we used the rat model of cerebral ischemia. Even though we found no evidence for oxidoreductase activity of MANF, the mutation of CXXC motif completely abolished its protective effect, showing that this motif is crucial for both MANF''s intracellular and extracellular activity. The RTDL motif was not needed for the neuroprotective activity of MANF after its extracellular application in the stroke model in vivo. However, in vitro the deletion of RTDL motif inactivated MANF in the sympathetic neurons where the mutant protein localized to Golgi, but not in the sensory neurons where the mutant localized to the ER, showing that intracellular MANF protects these peripheral neurons in vitro only when localized to the ER.The prosurvival proteins that actively keep the cells alive function as a counterbalance to the prodeath programs of the cell and are thereby essential players in morphogenesis and adult tissue homeostasis. Such survival-promoting proteins are also potential candidates for the treatment of pathological conditions, especially in the nervous system where the lost neurons are only rarely replaced by new ones. Some prosurvival proteins act extracellularly. For example, neurotrophic factors (NTFs) are secreted proteins that bind the cognate receptors on the surface of the cells, thereby triggering prosurvival signaling cascades.^{1, 2, 3} Other prosurvival proteins, such as Akt kinase, antiapoptotic Bcl2 family members, inhibitor of apoptosis (IAP) proteins and so on are not secreted and protect the cells intracellularly. A new family of survival-promoting proteins has recently been described⁴ that can act in both ways. This family consists of two proteins, mesencephalic astrocyte-derived neurotrophic factor (MANF)⁵ and cerebral dopamine neurotrophic factor (CDNF).⁶ Both factors, when delivered into the extracellular space of the brain or applied via viral vectors potently antagonize neurological damage in the rodent models of Parkinson''s disease. MANF is also protective against cerebral ischemia^{6, 7, 8, 9, 10} and prevents degeneration of Purkinje cells in spinocerebellar ataxia.¹¹ In these experiments, MANF and CDNF halted the death of the neurons and also stimulated regrowth of the dopaminergic fibers, acting thus as typical NTFs. On the other hand in non-neuronal cells, MANF was also shown to be a resident protein of the endoplasmic reticulum (ER) protecting the cells intracellularly against ER stress.^{12, 13, 14, 15, 16, 17}In line with its role in counteracting cell death, MANF promotes pancreatic β-cell proliferation and survival in vivo, and lack of MANF leads to chronic unfolded protein response (UPR) activation in pancreatic islets.¹⁸ We have also shown that microinjected intracellular MANF protects cultured sympathetic neurons of the superior cervical ganglion (SCG) against apoptosis-inducing toxins, whereas it does not protect or bind these neurons when applied to the culture medium.¹⁹ Thus, MANF can protect the neurons when applied extracellularly (at least in vivo) and intracellularly. Of note, MANF also has both intra- and extracellular activities on the pancreatic β cells.¹⁸ However, the mechanisms of intra- and extracellular action of MANF are currently not well defined.Structurally MANF consists of amino- (N) terminal saposin-like domain and carboxy-(C) terminal SAP domain-like domain that are connected by a flexible linker.^{19, 20} From the amino-acid sequence and structure, two potentially functional motifs can be distinguished in the carboxy-terminal domain of MANF (C-MANF).^{19, 20} First, a conserved^{21, 22} CXXC motif (CKGC) was found in the loop connecting the helices α7 and α8 where two cysteines were connected with a disulfide bond. The CXXC motif is found in the active center of the enzymes of thiol-disulfide oxidoreductase superfamily.²³ Second, a conserved RTDL sequence belonging to the class of KDEL-like ER retention signal²⁴ is found at the very end of C terminus of MANF^{19, 20} and is shown to be required for its retrieval from the Golgi to ER.^{15, 16, 25} The role of the RTDL motif in the survival-promoting activity of MANF has not been studied.In this study, we set up to investigate the importance of these motifs of MANF for its survival-promoting activity both in the intracellular in vitro as well as extracellular in vivo paradigms. We mutated the CXXC and RTDL motifs and tested the activity of the mutants by microinjecting plasmid DNAs encoding the mutant proteins into apoptotic sympathetic SCG neurons, our validated model for testing the neuroprotective bioactivity of MANF,^{19, 21} and sensory dorsal root ganglion (DRG) neurons. Subcellular localization of the MANF mutants was also studied in the same neurons. We show that the CXXC motif is critically required for the survival-promoting activity of MANF, as mutation of this motif prevents MANF from being neuroprotective in both types of neurons in vitro and also in the in vivo rat model of cerebral ischemia. In addition, we show, using the same in vivo model, that the RTDL motif is not required for the neuroprotective activity of extracellularly applied MANF. However, intracellularly the mutant without RTDL motif was inactive only when it was not retrieved to the ER.     

那曲地区融水侵蚀引起沉积的影响因素

冰川、积雪融水形成的融水侵蚀是高海拔寒区土壤侵蚀的重要形式.本文对那曲地区融水侵蚀引起沉积的影响因素进行研究,提出以沉积扇面积比例作为指标反映融水侵蚀引起沉积的强弱.基于GIS空间叠加分析确定最小图斑,通过逐步回归分析,建立融水侵蚀引起沉积的影响因素回归方程,确定融水侵蚀引起沉积的主要影响因素.结果表明:那曲地区境内分布大量扇形地;不同地区分布差异明显,那曲地区扇形地集中在中部缓坡地区;扇形地多分布在山谷出口处,多数规模较大,且面积、厚度变化很大.风速、归一化植被指数(NDVI)、土壤可蚀性K值、气温年较差和陡坡面积比是研究区融水侵蚀引起沉积的主要影响因素,其中,融水侵蚀引起的沉积与风速和NDVI呈正相关关系,与K值、气温年较差和陡坡面积比呈负相关关系.     

利用聚己内酯/羟基磷灰石复合支架修复犬胸骨缺损

目的：探讨利用生物可降解支架修复动物胸骨缺损,为临床手术治疗提供新的可行性方法。方法：对于12只比格犬进行手术切除部分胸骨,并利用聚己内酯/羟基磷灰石（PCL/HA）复合支架,并制备出与临床相似的胸骨缺损模型。实验动物分成2组,分别是：空白对照组和PCL/HA支架组。分别于术后第4、12周进行胸部CT扫描,并对胸廓进行三维重建,观察胸骨缺损部位的修复情况,并在第12周取胸骨缺损部位组织进行硬组织切片,苦味酸-品红染色,观察缺损部位的骨组织修复情况,并利用软件进行骨组织比率分析,评估修复情况。结果：通过检查发现空白对照组的胸骨缺损部位未见明显骨连接,胸廓的骨性结构有明显畸形,PCL/HA支架组能很好地维持胸廓的完整性,组织学检查发现PCL/HA支架组的缺损部位有明显新生骨形成,通过软件分析可发现支架组的骨组织比率较空白组的高（P〈0.05）。结论：这些结果表明采用PCL/HA复合材料支架能很好地修复胸骨缺损。