空心莲子草对钉螺组织影响的扫描电镜观察

研究空心莲子草（Alternanthera philoxeroides）杀灭钉螺的作用机理。将空心莲子草水浸液（1g／100ml）及去氯水分别浸泡钉螺12h、18h、24h后，用扫描电镜观察各组钉螺组织形态结构的变化。结果显示：12h浸泡组的钉螺壳轴肌呈明显收缩状态，其它部位的形态结构与对照组钉螺无明显区别。18h浸泡组钉螺的壳轴肌仍呈明显收缩状态，且有轻度肿胀；头部及触角表面皱褶变平坦；足跖肌表面绒毛紊乱、部分缺失；肝脏轻度肿胀、部分组织融合。24h浸泡组钉螺的壳轴肌断裂；头部及触角、足跖肌、肝脏等组织均出现明显损伤。结果提示：空心莲子草能使钉螺壳轴肌收缩，同时时钉螺组织具有机械性破坏作用，且与浸泡时间有关。     

夹竹桃对钉螺肝损伤的超微结构观察

钉螺经夹竹桃叶水浸液处理后，用扫描电镜和透射电镜分别观察了其肝表面及肝细胞结构的变化。处理后的肝表肿胀，明显的沟纹消失，其上的孔隙破损；24h后肝细胞核肿胀，核仁消失，核质稀疏，内质网断裂，线粒体增多，且随处理时间的延长（48h），损伤加重，内质网几乎全部囊泡化，细胞核开始破裂，线粒体也破裂。文中也讨论了钉螺可能致死的原因，为探明夹竹桃对钉螺的损伤程度和灭螺机制提供了亚显微结构依据。     

纯氧与空气复苏对窒息新生大鼠心肌细胞超微结构的影响

目的：在建立新生大鼠窒息的动物模型基础上,研究纯氧与空气复苏对窒息新生大鼠心肌细胞超微结构的影响。方法：采用SD新生大鼠建立窒息模型,并分组进行纯氧与空气复苏。实验分组：1．正常对照组（n=5）;2．缺氧组（n=5）;3．纯氧复苏后24h组（n=5）;4．纯氧复苏后72h组（n=5）;5．空气复苏后24h组（n=5）;6．空气复苏后72h组（n=5）。按时间点取心肌组织,制作超薄切片,在透射电镜下观察各组心肌细胞超微结构变化。结果：与正常对照组相比,缺氧组心肌细胞的线粒体肿胀,嵴断裂,肌原纤维扭曲,肌丝断裂,细胞核内染色质边集。氧气复苏组肌原纤维间水肿,肌丝扭曲,线粒体肿胀,核膜不清,染色质浓集。空气复苏组,特别是24h组,心肌细胞严重水肿,肌丝断裂溶解,线粒体空泡化明显,细胞核肿胀,染色质淡染。结论：空气复苏较纯氧复苏后心肌细胞损伤严重,各组均以复苏后24h出现较明显变化,而复苏后72h心肌细胞有一定程度的再生修复。     

应用细胞化学法与X-射线能谱仪对深低温停循环后脑神经细胞中Ca++浓度的定量研究

用草酸－焦锑酸钾细胞化学法显示深低温（１８℃）停循环（ＤＨＣＡ）１２０ｍｉｎ后脑神经细胞内Ｃａ＋＋的分布及超微结构改变，同时利用Ｘ－射线能谱仪测量细胞内Ｃａ＋＋浓度以及停循环时应用１．６－二磷酸果糖（ＦＤＰ）保护液后细胞内Ｃａ＋＋浓度的变化。结果显示：（ＤＨＣＡ）１２０ｍｉｎ后脑神经细胞超微结构破坏严重，细胞内Ｃａ＋＋浓度明显增加。但在（ＤＨＣＡ）期间应用（ＦＤＰ）脑保护液后可以明显减轻术后神经细胞内Ｃａ＋＋聚积与脑损伤，是（ＤＨＣＡ）下脑保护的可行方法。     

应用细胞化学法与X—射线能谱仪对深低温停循环后脑神经细胞中Ca …

用草酸－焦锑酸钾细胞化学法显示深低温（１８℃）停循环（ＤＨＣＡ）在１２０ｍｉｎ后脑神经细胞内Ｃａ＾＋＋的分布及超微结的改变，同时利用Ｘ－射线能谱仪测量细胞内Ｃａ＾＋＋浓度以及停循环时应用１．６－二磷酸果糖（ＦＤＰ）保护液后细胞内Ｃａ＾＋＋浓度的变化，结果显示：（ＤＨＣＡ）１２０ｍｉｎ后脑神经细胞超微结构破坏严重，细胞内Ｃａ＾＋＋浓度明显增加，但在（ＤＨＣＡ）期间应用（ＦＤＰ）脑保护液后可以明业减轻     

银杏花粉萌发生长与分枝式花粉管形成的观察

本研究采用半薄切片法和扫描电镜等技术对银杏（Ginkgo bilobaL.）花粉管的体内萌发与生长以及花粉的离体培养进行了观察,结果表明：（1）银杏花粉粒通过传粉滴收缩后到达胚珠珠孔处,并经珠孔道进入贮粉室内停留,约7 d后花粉粒开始萌发;（2）贮粉室内的花粉最初萌发出的花粉管与花粉粒的四细胞轴几乎垂直,表现出明显的侧向萌发特征。初始花粉管在贮粉室内的生长方向无规律,有的通过一定的贮粉室空间向较远的珠心组织细胞间隙生长,有的直接进到较近的珠心组织细胞间隙,花粉管的生长不损伤珠心组织细胞;（3）花粉离体培养过程中会迅速发生水合作用,花粉粒由船形变为圆球形。48 h后花粉外壁脱落,管细胞膨大,花粉管自管细胞膨大处萌发。随着花粉管的生长,管细胞核移动进入花粉管内,而生殖细胞仍留在花粉粒内。伸长的花粉管可分为淀粉粒区和透明区,花粉管末端易形成多种类型的分枝。花粉管内原生质呈喷泉状流动。     

电针对局灶脑缺血／再灌注大鼠海马内NF-κB旁路途经的调节作用

目的：观察局灶脑缺血/再灌注后不同阶段大鼠海马内IKKα及NF-κBp52的表达及电针对NF -κB旁路途径的调节作用。方法：SD健康雄性大鼠（280-300g）108只随机分为假手术组（n＝12）,电针组（n＝48）及模型组（n＝48）,按照再灌注后24h与7d将电针组及模型组分为2个亚组。采用右侧大脑中动脉闭塞/再通线栓法建立局灶脑缺血/再灌注模型。电针组取“合谷”穴、“太冲”穴,选用G6805-1型针灸治疗仪进行电针治疗。用FJB染色观察脑缺血/再灌注后海马区内神经细胞的损伤情况;利用免疫组化、Western blot 检测不同时间点海马区内IKKα的蛋白表达及NF-κB p52胞核内的蛋白表达变化。结果：FJB染色显示局灶脑缺血/再灌注后,海马区内神经细胞变性损伤明显（P＜0．05）;与模型组比较,电针干预后海马区内神经细胞变性损伤减少（P＜0．05）。免疫组化及Western blot 显示模型组大鼠海马内IKKα表达于再灌注后24h及7d均显著升高（P＜0．05）;胞核内NF-κB p52的蛋白表达随IKKα表达增加而增加（P＜0．05）。电针组与模型组比较,海马内IKKα蛋白表达及胞核内p52的蛋白表达明显减少（P＜0．05）。结论：脑缺血/再灌注刺激能诱发海马区内IKKα表达升高,活化p52入核激活信号通路造成海马区内神经细胞的损害;电针干预后能明显抑制IKKα的表达,阻止其活化p52进而有效缓解缺血/再灌注后海马内神经细胞的损伤。     

全膝关节置换围手术期多模式和超前镇痛方案的临床研究

目的：评价围手术期超前联合多模式镇痛方案在全膝关节置换术中的镇痛作用。方法：接受单侧全膝关节置换的患者54例,随机分成三组,每组18例,A组联合应用术前及活动前口服塞来昔布和氨酚曲马多及术中关节腔内注射鸡尾酒式镇痛混合剂多模式镇痛（联合组）,B组应用术中关节腔内注射鸡尾酒式镇痛混合剂镇痛（多模式组）,C组术后单独应用自控镇痛（对照组）。三组患者均在全麻下完成手术,记录三组患者术后6h、24h、72h以及术后7d静息状态下疼痛视觉模拟评分（visual analogue score,vas）,记录术后24h、48h、72h以及7d患者活动状态下VAS评分,并记录术后24h、72h以及30d膝关节活动度及术后并发症的发生情况。结果：静息痛评分术后6h、24h、72h联合组与多模式组患者均显著低于对照组（P〈0．01）,术后6h、24h联合组患者低于多模式组（P〈0．01）。活动痛评分术后24h、48h、72h比较联合组〈多模式组〈对照组（P〈0．01）。膝关节活动度术后24h、72h比较联合组〉多模式组〉对照组（P〈0．01）。术后并发症发生情况对照组明显高于其它两组。结论：全膝关节置换术围手术期超前联合多模式镇痛方案是一种简单、安全、有效的镇痛方法。     

竹红菌乙素光动力对人舌鳞癌Tca8113细胞杀伤作用的初步研究

目的：本文是用实验的方法,初步探讨中药光敏剂竹红菌乙素（HB）在光动力（PDT）作用下,对体外人舌鳞癌Tca8113细胞的杀伤作用。方法：常规培养、选取对数生长期人舌鳞癌Tca8113细胞,用含有竹红菌乙素（HB）浓度分别为0μM、0．25μM、0．5μ／M、1μM、2μM的RPMI-1640培养液孵育细胞4h后,经470nmLED定制多光源半导体激光光照处理（PDT）,能量密度设置分别为0J／CM^2、1J／CM^2、2J／CM^2、3J／CM^2、4J／CM^2。PDT处理后细胞继续孵育24h后,分别在光学显微镜和荧光显微镜下观察细胞形态学变化,并用甲基噻唑四唑法（MIT法）检测竹红菌乙素（HB）对细胞的抑制作用。并分别在激光照射6h及24h后,用流式细胞仪测定细胞凋亡率。结果：经PDT处理后细胞在光学显微镜及荧光显微镜下均可观察到细胞坏死和凋亡样改变;在一定浓度范围和光照能量密度范围内,竹红菌乙素（HB）在PDT作用下对人舌鳞癌Tca8113细胞生长增殖的抑制和诱导凋亡作用与药物浓度和能量密度成正相关变化。结论：竹红菌乙素（HB）在光动力（PDT）作用下,对人舌鳞癌Tca8113细胞具有显著的杀伤作用,并在一定范围内呈浓度剂量和光剂量正相关依赖性。     

APM对黄瓜幼叶细胞超微结构冷稳定性的影响

为了解微管骨架在维持植物抗寒力中的作用机理，本文采用透射电镜技术，以微管解聚剂APM（amiprophos-methyl,甲基氨草磷）喷洒黄瓜幼苗，继之低温处理，从超微结构水平上研究了微管解聚对黄瓜幼叶细胞超微结构冷稳定性的影响。结果表明：用浓度为15mg/L的APM喷洒黄瓜叶片48h后，幼苗生长缓慢，继之于4℃下低温处理48h、72h，超微结构显示APM处理过的幼叶，其叶肉细胞超微结构受到的损伤，尤其是质膜及其细胞内膜系统受到的损伤程度明显严重于未经APM处理的。这表明APM对微管骨架的破坏加得了低温对黄瓜幼叶细胞超微结构的损伤，从而使植株的抗寒力下降，这与观察到的各组处理幼苗的的外观形态表现是一致的。     

Al(H_2PO_4)_3和H_3PO_4改性AlN粉末的研究

采用机械球磨法,以Al(H2PO4)3和H3PO4为改性剂,制备了具有较高抗水解能力的AlN粉末,研究了改性AlN粉末在水基球磨过程中的稳定性。通过XRD,FT-IR,SEM,TG-DSC和氮含量测定对改性前后AlN粉末进行了表征。改性AlN粉末在60℃水中浸泡24h后,其w(N)为32.97%,且其XRD谱中未发现Al(OH)3相,其抗水解能力得到显著提高。改性AlN粉末在水中高速球磨16h后,其w(N)约为32%,AlN悬浮液的pH值约为6,说明改性AlN粉末在水中球磨过程中具有较好的稳定性。     

An ultrastructural study on the effect of streptozotocin on the islets of Langerhans in mice

The ultrastructural changes in the morphology of the islets of Langerhans in response to streptozotocin were studied in the mice pancreas. Male white albino CSI mice were given a single intravenous injection of 75 mg kg(-1) body weight streptozotocin, and were sacrificed at different time intervals up to 48 h following the treatment. Their pancreases were excised and randomly processed for electron microscopic examination. Hyperglycaemia and glucosuria were detected 8 h after treatment, became remarkably high at 24 h and persisted then after. Light and electron microscopic examination of the islets of Langerhans from treated mice revealed an early chromatin aggregation and cytoplasmic vesiculation in the central B cells during the first 2 h of treatment. Nuclear shrinkage and pyknosis with swelling of mitochondria and endoplasmic reticulum were evident 8 h later, and lysis of B cells occurred 12 h after treatment. The morphology of A and D cells at the margin of the islets and in between B cell debris looked perfectly unaltered. Macrophage infiltration among lytic B cells was seen 24 h after drug administration, which contained clear and large phagocytic vacuoles. The necrobiotic and phagocytic figures disappeared from the pancreatic sections of 48 h treated mice, and the islets were smaller in size and consisted entirely of intact A and D cells with occasional degranulated B cells. No features of apoptosis were ever recorded, and the exocrine pancreatic tissue was protected from the effect of streptozotocin. In conclusion, the present study illustrates the sequence of morphological changes that occurs in the islets of Langerhans of mice after streptozotocin administration. It also confirms that streptozotocin at a high single dose in mice produces a specific necrosis of B cells with no evidence of apoptotic figures as another mechanism of cell death.     

Rapid Self‐Assembly of Macroscale Tissue Constructs at Biphasic Aqueous Interfaces

An entirely new approach to tissue engineering is presented that uses the interfacial forces between aqueous solutions of phase‐separating polymers to confine cells and promote their assembly into interconnected, macroscopic tissue constructs. This simple and inexpensive general procedure creates free‐standing, centimeter‐scale constructs from cell suspensions at the interface between poly(ethylene glycol) and dextran aqueous two‐phase systems in as little as 2 h. Using this method, skin constructs are produced that integrate with decellularized dermal matrices, on which they differentiate and stratify into skin equivalents. It is demonstrated that the constructs produced by this method have appropriate integrity and mechanical properties for use as in vitro tissue models.     

Calculation of the far-field halfpower width and mirror reflection coefficients of double-heterostructure lasers

A comparison is made between theoretical and experimental values of the beamwidth of a d.h. injection laser. The importance of the obliquity factor is pointed out. The good agreement between theory and experiment permits the determination of material properties from laser-diode measurements. Further, mirror reflection coefficients for lasers immersed in different liquids are calculated. Marked differences in the values of the Fresnel reflection coefficients, for normal incidence, are found.     

Conductive aqueous layer formation at the gel-substrate interfacein equilibrium with 100% RH environment

The paper describes results of theoretical modeling and experimental verification of conditions leading to the formation of a conductive aqueous layer at the interface between gels and substrates at 100% RH or equivalent (water immersed) conditions. Thermodynamic analysis of clean surfaces and interfaces shows that displacement of the interface between gels and inorganic substrates (e.g., ceramics and integrated circuits) by water is thermodynamically favorable while gel-organic substrate interfaces are stable versus such displacement. The presence of a water-soluble contaminant on the substrate will cause formation of water droplets whose diameter can be determined from the balancing of the osmotic and interfacial tension effects. If the total surface coverage by droplets (which is independent of the contaminant particle size distribution) exceeds the critical two-dimensional (2-D) percolation threshold, a continuous path of electrical conductivity is formed. For sodium chloride contaminant the critical surface concentration leading to such event was calculated and shown experimentally to be 10^-7 g/cm². Inorganic filler in the gel in the amount exceeding the three-dimensional (3-D) percolation limit can cause bulk conductivity of the gel material at high humidity due to formation of an aqueous layer at the gel-filler interface     

纳米氮化铝粉末表面修饰的研究

以活化指数和pH值为考核指标,通过变化改性剂的用量、处理温度以及处理时间等,研究了偶联剂–苯乙烯接枝改性剂对纳米AlN粉末的表面改性效果。结果表明:纳米AlN粉末经偶联剂–苯乙烯接枝进行表面修饰可显著提高其抗水解的能力,室温下长达一个月遇水不发生变化;在70℃的热水浴浸泡24h,其悬浮液pH值仍能保持在7.0。并对工艺条件进行了优化,其最佳工艺条件是:以无水乙醇为溶剂、处理剂的加入量为5%(质量分数)、70℃反应3h,活化指数可以达到1.0。     

金红石型纳米TiO_2的液相激光烧蚀合成

利用浸入聚乙烯基吡咯烷酮(PVP)水溶液中的金属钛片为靶材,采用1064nm红外脉冲激光进行液相激光烧蚀制备了金红石型纳米TiO2。应用XRD、TEM、HRTEM和Raman对产物进行表征,并对其形成机理进行了探讨。结果表明:金红石型纳米TiO2可通过液相激光烧蚀法在室温下一步合成,颗粒平均粒径约50nm,尺寸分布比较窄,分散性较好。脉冲激光诱导的瞬间等离子体可能是金红石型纳米TiO2形成的主要原因。     

Ultrastructural basis for the transition of cell death mode from apoptosis to necrosis in menadione-treated osteosarcoma 143B cells

Time-dependent ultrastructural changes of menadione-treated human osteosarcoma 143B cells were correlated with those in their stainability to Annexin V and propidium iodide (PI). Populations of both apoptotic (Annexin V(+)/PI(-)) and necrotic (Annexin V(+)/PI(+)) cells, judged by flow cytometry, began to increase at 2 h after menadione treatment. The former reached a maximum at 6 h followed by abrupt decreases thereafter, while the latter continued to increase. Electron microscopically, cells obtained at 6 h after the menadione treatment consisted of mixed populations of cells with typical apoptotic features and those with a mixture of apoptotic and necrotic features, while cells obtained at 8-24 h consisted exclusively of cells with a mixture of apoptotic and necrotic features. Thus, necrotic cells, as judged by flow cytometry, were in a transitional state of cell death mode from apoptosis to necrosis and are thus designated as 'intermediate cells'. Lack of apoptotic bodies, judged by flow cytometric analysis on sub-G1 nuclei and by electron microscopy in menadione-treated cells, suggested that the transition of cell death mode from apoptosis to necrosis occurred before the apoptotic processes were completed. Effects of N-acetylcysteine and Z-VAD-fmk on menadione-induced ultrastructural changes were also studied.     

Entry of Bombyx mori cypovirus 1 into midgut cells in vivo

In vivo entry of Bombyx mori cypovirus 1 into the silkworm midgut was studied by electron microscopy of ultrathin sections of midguts from silkworm larvae that had been administered virus-contaminated leaves. In 3 h, virions were observed outside and inside midgut cells, including columnar cells, goblet cells and muscle cells. Virions were seen adhering to the plasma membrane of microvilli, embedding in the membrane and settling themselves intact inside the microvilli of the columnar cells. These results suggested that intact virions entered columnar cells by means of direct penetration through the cell membrane. In 12, 24 and 48 h, virogenic stromata and progeny virions were observed in columnar cells, but not in other midgut cells.     

海藻硫酸多糖对HPM辐射致GC-2细胞损伤保护作用研究

探讨了海藻硫酸多糖(SP)对高功率微波(HPM)致小鼠精母细胞系GC-2细胞的损伤防治作用及其机制,为新型抗电磁辐射药物开发提供基础。将GC-2细胞分为药物组、药物对照组、辐射组和正常对照组,采用平均功率密度为30 mW/cm2的S波段HPM辐照15 min,药物组和药物对照组于照射前24 h加入SP(终浓度25μg/ml)。辐照后立即检测细胞的活性氧(ROS)、凋亡相关蛋白Caspase3、p53、Bax和Bcl-2及氧化应激信号通路MAPK中蛋白p-38MAPK和p-JNK1/2等指标的活化,并于1 h、3 h、6 h、12 h、24 h检测细胞活力。与正常组相比,辐照后6 h辐射组细胞活力显著降低,细胞即刻的ROS、Caspase3、p53、Bax、p-38MAPK和p-JNK1/2表达显著升高,Bcl-2显著降低;与辐射组相比,药物组和药物对照组细胞即刻的ROS、Caspase3、p53、Bax、p-38MAPK以及p-JNK1/2的表达显著降低,Bcl-2显著升高。结果表明,30 mW/cm2 S-HPM辐射可引起GC-2细胞产生氧化应激损伤,预防性给予SP可通过抗氧化机制对HPM辐射损伤起保护作用。