论海子的创作心理

海子是当代诗坛上重要的抒情诗人与史诗诗人，是80年代后期新诗潮的重要代表人物。本文从创作心理角度分析海子诗歌创作的特点，指出早熟与早慧的内在分裂构成其创作心理的基本面貌，并导致了他最终以极端的方式结束自己的生命。     

Isolation and physiological characteristics of a premature senescence mutant in rice(Oryza sativa L.)

INTRODUCTION Leaf senescence is a kind of programmed cell death (PCD) in plants that is highly controlled by a genetically programmed process involving degrada-tion of cellular structures, decline of photosynthesis massive generation of active oxygen species (AOS) and mobilization of nutrients (Nam, 1997; Lim et al.,2003). Many environmental factors have been shown to play a role in causing the photosynthetic decline to lead to premature senescence. Leaves exposed to ultraviolet radia…     

Isolation and physiological characteristics of a premature senescence mutant in rice （Oryza sativa L.）

A rice pse(t) (premature senescence, tentatively) mutant line, was isolated from 4500 independent T-DNA inserted transgenic lines. The symptoms of premature senescence appeared more severely than those of the control plants (Zhonghua 11,japonica) at the last development stage. To characterize the mutant and provide basic information on the candidate genes by mapping to a physical region of 220-kb, experiments were carried out in two phytotrons under controlled temperature of 24 ℃ and28 ℃, respectively. The content of chlorophyll, soluble protein and MDA (malondialdehyde), net photosynthesis, the antioxidant enzyme activities of SOD (superoxide dismuase) (EC 1.15.1.1) and POD (peroxidase) (EC 1.11.1.7) and the peptidase activities of leaves were measured from top to bottom according to the leaf positions at the flowering stage. Compared with the control plant,the mutant showed the following characteristics: (1) Higher net photosynthesis rate (Pn) appeared in the 1 st and 2nd leaves, contents of chlorophyll and soluble protein were also higher in the 1 st leaf; (2) The activities of SOD, POD and peptidase were higher according to the leaf position from top to bottom; (3) The symptom of premature senescence was accelerated in the mutant at 28℃treatment. The MDA content and the SOD and POD activities between the 24 ℃ and 28 ℃ treatment mutants were not significantly different. Content of chlorophyll and soluble protein of leaves mutant decreased rapidly at 28 ℃ treatment. The results show that pse(t) is sensitive to high temperature. The probable function of PSE(T) is discussed.     

平板运动试验对大学生室性早搏的评价

应用美国MAX运动平板试验系统,观察了16名大学生不明原因室早患者与16名健康对照者运动平板试验过程中心率、早搏、心电图Q—T间期、Q—T离散度的变化。结果是室早组次极量运动时室早明显减少或消失14例,良性早搏占87．5％,对照组中1名运动过程中出现偶发室早。与对照组相比,两组运动前后心率、心电图Q—Td、Q-Tcd差异均无统计学意义（P〉0．05）：运动平板试验能够作为评价青年人不明原因室早的依据,有益于指导临床治疗。     

参麦注射液对急性心肌梗死大鼠心室重构的影响

目的：探讨参麦注射液对急性心肌梗死（AMI）大鼠心室重构的影响。方法：通过结扎冠状动脉前降支建立AMI模型大鼠，AMI后24h存活的48只大鼠随机分为四组：AMI后1周模型组；AMI后参麦注射液治疗1周组；AMI后2周模型组；AMI后参麦注射液治疗2周组。另设1周、2周假手术组各8只。治疗组每日腹腔注射参麦注射液1次，AMI模型组和假手术组大鼠腹腔注射等量的生理盐水。测量各组心室重构参数。结果：与假手术组比较，AMI后1周时，心室腔已明显扩大（P〈0．05）；到梗死后2周时，心室腔内径扩大更明显，与假手术组相比有显著性差异（P〈0．01），且心室重量指数（VWI）比假手术组明显增加（P〈0．05）。参麦注射液治疗2周后可改善心梗后心室重量指数增加、心室腔扩大的病理变化（P〈0．05）。结论：参麦注射液能改善大鼠AMI后心室重构。     

Improved genetic operator for genetic algorithm

The mutation operator has been seldom improved because researchers hardly suspect its ability to prevent genetic algorithm (GA) from converging prematurely. Due to its importance to GA, the authors of this paper study its influence on the diversity of genes in the same locus, and point out that traditional mutation, to some extent, can result in premature convergence of genes (PCG) in the same locus. The above drawback of the traditional mutation operator causes the loss of critical alleles. Inspired by digital technique, we introduce two kinds of boolean operation into GA to develop a novel mutation operator and discuss its contribution to preventing the loss of critical alleles. The experimental results of function optimization show that the improved mutation operator can effectively prevent premature convergence, and can provide a wide selection range of control parameters for GA.     

维拉帕米对自发性高血压大鼠左心室流出道自发慢反应电位的影响

目的:探讨高血压大鼠左室流出道自发性慢反应电位0相和4相去极离子流中Ca2 的作用.方法:利用自发性高血压大鼠(SHR)的离体心脏,常规玻璃微电极细胞内记录方法和Ca2 离子通道阻断剂维拉帕米(VER),观测最大舒张电位(MDP)、0相除极幅度(APA)、0相最大除极速度(Vmax)、4相自动除极速度(VDD)、复极50%(APD50)和90%(APD90)的时间以及自发放电频率(RPF).结果:1.0μmol/L维拉帕米可使该慢电位的APA、Vmax、VDD明显减小,RPF减慢(P＜0.01);APD、APD90延长(P＜0.05).结论:(1)该区域的自发慢电位0相去极离子流主要为Ca2 内流.(2)4相去极离子流中,Ca2 内流起部分作用.     

剖宫产427例原因分析

目的:探讨剖宫产率上升原因,寻找降低剖宫产率的可能途径。方法:统计1999-3-12～2000-4-8在张家口医学院第一附属医院427例剖宫产病历,分析各种剖宫产原因及所占比例。结果:胎儿因素197例(46.1％),其中胎儿宫内窘迫86例(20.1％);母体因素104例(24.4％),其中胎膜早破37例(8.796);母儿因素72例(16.9％);社会因素54例(12.6％)。结论:胎儿因素是剖宫产率上升的主要原因,要求剖宫产也占了很大比例,要降低剖宫产率需要医生和社会共同提高认识。     

室性早搏患者的心阻抗图分析

心阻抗图(ICG)能反映心脏泵血功能状态、心肌收缩力和心室顺应性等。作者采用心阻抗图对25例室性早搏患者进行了观查,发现在一次室性早搏后心肌收缩力明显加强,其中C-dz/dt、HI、SV、EF、SW明显增加,而PEP/LVET明显变小,Q-Z间期显著缩短。     

Myths and Heroes:

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