Studies on the effect of monoamine antagonists on the morphogenesis of the newt

The effects of three monoamine antagonists, p-chlorophenylalanine, diethyldithiocarbamate and propranolol on the morphogenesis of newt embryos were studied. Antagonists were administered during late blastula through neurula stages. In a concentration of 1 mM, all three arrested gastrulation and caused disintegration of the embryos. Lower concentrations (0.1-0.5 mM) retarded morphogenetic movements in the gastrulation and caused malformations especially in the anterior parts of the embryos; pigmentation was delayed by 1 or 2 days. In addition, p-CIPhe inhibited yolk granule degradation in the notochord and DEDTC caused notochordal hypertrophy. The results show that interference with synthesis or action of catecholamines and serotonin affects morphogenesis. With the methods used it is not possible to discover exactly how monoamines regulate the morphogenetic events because of the unspecific side effects of the antagonists and the feedback interactions between the monoamines.     

花粉形态计算机量化分析研究

以白莲花粉为实验材料 ,介绍了进行花粉形态计算机量化分析的步骤。花粉经醋酸法处理后 ,用电子显微镜对花粉进行观察照相 ,尔后用计算机技术对花粉电镜照片进行处理 ,最后用C语言编制了计算花粉形态面积的计算机程序。结果表明 :花粉计算机量化分析有助于快速定量测定有关花粉形态指标 ,是花粉数量分类的一种有效方法。     

动态增强磁共振扫描与超声弹性成像对乳腺癌的诊断价值探讨

目的:探讨动态增强磁共振成像扫描与超声弹性成像对乳腺癌良恶性肿瘤的诊断价值,为临床诊断提供影像学依据。方法:回顾性分析2009年10月至2013年5月在我院经穿刺或手术病理证实为乳腺癌的59例患者的临床资料,患者术前均行超声与动态增强MR检查。依据病理组织活检和临床随访分别评价动态增强MR和UE对乳腺癌诊断的准确性。结果:DCE-MRI检测共发现病灶59个,55个初步诊断乳腺恶性肿瘤(BI-RADS 4-5),4个诊断为良性(BI-RADS 3),诊断准确率为93.22%(55/59)。UE对59个病灶进行评分,54个评分为乳腺恶性肿瘤,5个评分为良性,诊断率为91.53%(54/59)。UE检测乳腺癌的敏感性明显低于DCE-MRI及DCE-MRI+UE,DCE-MRI检测乳腺癌的特异性明显低于UE及DCE-MRI+UE,差异具有统计学意义(P0.05)。DCE-MRI+UE诊断乳腺癌的准确率为96.61%(57/59),明显高于DCE-MRI或UE单独检测的准确率(P0.05)。结论:动态增强MR诊断乳腺癌的敏感性较高,而超声弹性成像的特异性较好,两者联合可提高诊断准确率,对乳腺癌的早期诊断具有重要的临床应用价值。     

Procalpain is activated on the plasma membrane and the calpain acts on the membrane

The mechanism of activation of human erythrocyte calpain was investigated using the immunoblotting technique with anticalpain monoclonal antibody. The purified calpain underwent a Ca2+-induced fragmentation of the 80 kDa subunit to 76 kDa and 36 kDa fragments. The behavior of the 76 kDa fragment in electrophoresis corresponded to the proteinase activity of calpain, whereas the behavior of the 80 kDa subunit and the 36 kDa fragment did not. When inside-out membrane vesicles were added to the reaction mixture of calpain and Ca2+ and the vesicles were separated from the supernatant solution by centrifugation, the 80 kDa subunit and 76 kDa fragment were found in the vesicle fraction. No other fragments were found in this fraction. On the other hand, the 80 kDa subunit and 36 kDa fragment were found in the supernatant fraction. When right-side-out membrane vesicles were added to the reaction mixture and the vesicles were separated from the supernatant fraction, no fragment was found in the vesicle fraction, while only the 36 kDa fragment was found in the supernatant fraction. These results indicate that the 80 kDa subunit of procalpain was bound in a Ca2+-dependent manner to the cytosolic surface of the plasma membrane and then underwent fragmentation to produce the 76 kDa fragment (active form) and that it expressed its proteinase activity at the surface of the membrane.     

黄土高原泾河流域牲畜承载力分析

畜牧业是泾河流域北部地区的经济支柱产业。过度放牧使草地退化,土地沙化严重,是流域生态环境恶化的主要原因之一。根据降雨,植被．牲畜量之间的定量关系。利用泾河流域1971—2000年平均降雨数据,估算了泾河流域牲畜承载力的空间分布格局,并根据同期的各县市牲畜存栏数据和该区植被分布数据,分析各县市放牧压力的时空分布。对于泾河流域的牲畜承载力水平而言,目前是一个什么状况以及与理论上的最大承载力的可变动的空间如何,是研究的主要目的,以期为该区的农牧业合理布局及其退耕还林（草）工程具体实施提供科学依据和理论指导。 利用DEM对该流域近30a的降水数据空间插值,获得降雨空间数据,并以降雨．生产力．牲畜量的经验模型进行估算,研究结果表明以降雨R估算的泾河流域牲畜承载力空间分布自南向北逐渐变小。基于县域单元,对于表征放牧压力的牲畜放牧指数（SRI）而言,相对总面积的SPd只有环县、吴旗、定边、盐池和泾川5县超过1,表明这5个县属于过度放牧区域,其它地区不存在牲畜超载现象;对于基于草地面积的SPd,除了经济相对发达的西峰市、咸阳市区、兴平市和泾渭交界的地区部分县市小于1,大部分地区的SPd值都大于1,尤其是北部的环县、吴旗、盐池、定边等县。都超过10几倍。属于严重的超载放牧地区,超载放牧是北部地区土地沙漠化的主要原因,而北部区域是泾河乃至整个黄土高原的泥沙的主要来源,因此产生严重的生态影响。退耕还林（草）工程实施中应明确上述县市的严重的生态现象,并对这些区域的生态地位重点进行宣传教育。同时,表明基于草地面积计算的牲畜放牧指数较基于总面积计算的更具有现实意义。     

NaCl对光合作用影响的研究进展

对ＮａＣｌ对光合作用影响的几个重要方面的研究进展进行了综述，包括ＮａＣｌ对光合作用的影响途径，气孔效应与非气孔效应，ＮａＣｌ对光能吸收与转换、光合电子传递、光合碳素同化的影响及盐与其他胁迫因子对ＰＳＩＩ活性的协同影响等，对今后这些方面研究中的重点内容与趋势进行了评述