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31.
扬子鳄(Alligator sinensis)是我国特有的古老而珍稀的爬行动物,现阶段野生扬子鳄的分布区域进一步萎缩,成为彼此孤立的点状,残存栖息地的生态环境趋于恶化,野生鳄数量估计为120~150条,老年化程度高。扬子鳄的保护管理依据现实状况及时加以调整,加大了野外保护力度,逐步改善野生鳄的栖息生境,实施野外放归工程,初步遏制了野生鳄数量迅速下滑的局面。人工饲养种群数量已逾10 000条,当前人工饲养繁殖的重点是管理好有限的遗传多样性资源。扬子鳄的研究主要涉及形态学、解剖学、组织胚胎学、生态学、生理生化、细胞及分子生物学,人工饲养繁殖技术等方面。营养生理和保护遗传学的应用研究有待加强。  相似文献   
32.
云南省西双版纳州南拉河鱼类组成及其现状   总被引:1,自引:0,他引:1  
分别于2008年1月和5—6月对位于中国西南边陲的中缅界河——南拉河进行了鱼类资源调查。从野外调查结果及文献资料得知,南拉河共有鱼类42种,隶属4目14科34属。鲤形目的鱼类最多,共有27种,占总种数的64.3%;鲇形目和鲈形目均为6种,占总种数的14.3%;合鳃鱼目2种,占总种数的4.8%。其中,丝尾鳠(Hemibagrus wyckioides)被列入《中国物种红色名录》。疑似分布种类——长丝鱼芒(Pangasius sanitwangsei)被列入《中国濒危动物红皮书》和《中国物种红色名录》。南拉河鱼类区系是以喜温的“老第三纪类群”中的热带河平原鱼类为主要成分的,为典型的东南亚热带鱼类区系类型;以底栖鱼类和杂食性鱼类居多。导致南拉河鱼类现状的原因主要为水质污染、过度捕捞、外来种的影响。  相似文献   
33.
目的观察重组人红细胞生成素(recombinant human epo,rHuEPO)对戊四氮(pentylenetetrazol,PTZ)点燃的癫痫持续状态(status epilepticus,SE)的SD大鼠海马神经元凋亡的影响,应用PI3K(phosphatidyl inositol 3 kinase磷脂酰肌醇3激酶)抑制剂LY294002进一步探讨rHuEPO作用的可能机制。方法采用PTZ点燃大鼠SE模型,将大鼠随机分为A组:正常对照组(生理盐水normal saline NS)、B组:PTZ组(PTZ+NS)、C组:rHuEPO组(PTZ+rHuE-PO)、D组:LY294002组(PTZ+LY294002+rHuEPO)、E组:LY294002溶剂DMSO(二甲基亚砜)对照组(PTZ+DMSO+rHuEPO),检测大鼠行为学和脑电图的改变及HE染色观察海马病理学的改变;用TUNEL方法检测海马神经细胞的凋亡情况;免疫组织化学法观察磷酸化蛋白激酶B、半胱氨酸天冬氨酸蛋白酶9(Caspase-9)、X-连锁凋亡抑制蛋白(XIAP)的表达。结果在PTZ点燃大鼠SE后rHuPO活化了磷脂酰肌醇3激酶/蛋...  相似文献   
34.
Behavioral comparisons between six caged baboon groups indicate that the groups have consistent and similar behavioral attributes. At the same time it is possible to distinguish between classes of animals in each group such as males versus females and high status versus low status rank. Comparable results are obtained in both ANOVA and Kruskal-Wallis one-way analysis of variance by ranks. This investigation supports the assumption that baboon groups exhibit behaviors that are both consistent and predictable where environment and group composition are controlled. Thus there appears to be a strong species-appropriate set of behaviors. Behavioral plasticity and group variability might be due largely to a combination of environmental stimuli and the particular history of that group. Differential individual histories or idiosyncracies do not invalidate experimental designs which rely on randomization to structure control groups.  相似文献   
35.
What leads some people to perform better than others on certain cognitive tasks? One explanation involves individual differences in testosterone. Testosterone is associated with higher performance on spatial tests, and lower performance on verbal tests. However, a large literature suggests that testosterone only predicts behavior when status is in jeopardy. In the present study, we manipulated status before administering a spatial and verbal test. In a high-status position, high-testosterone individuals performed well on both tests, and blood pressure dropped. In a low-status position, high-testosterone individuals performed relatively poorly on both tests, and blood pressure did not change. These data suggest that differences in cognitive performance stem from an interaction between testosterone and the social situation.  相似文献   
36.
Experimental observations on the arrenotokous reproductive patterns of two spider mite species (Acari: Tetranychidae), the long-seta form of Schizotetranychus celarius (Banks ) and Tetranychus urticaeKoch , revealed that reproduction of unfertilized females of the former is very differnt from that of the latter. Unfertilized females of S. celarius, which has a subsocial life, laid a few eggs and then became inactive. In contrast, the fecundity of unfertilized T. urticae females was only slightly reduced as compared with fertilized females. Mother-son matings may thus sometimes occur in natural S. celarius populations. A two-year field survey revealed that, in the absence of males, overwintering females of S. celarius occasionally remain unfertilized until early spring. Furthermore, nest foundation observed in late spring indicated that most of the season's first nests were founded by single females. These two sets of observations strongly suggest that motherson mating takes places in nature, corresponding to the reproductive trait seen in the experiment. Mother-son mating inevitably increases the relatedness between nest members. The estimated father's relatedness to its offspring is extraordinarily high under such condition. The possibility that kin-selection in the long seta-form of S. celarius led to subsociality, especially paternal care, is suggested.  相似文献   
37.
Status epilepticus (SE), one of the most severe forms of epilepsy is regarded a medical emergency with considerable morbidity and mortality. Due to the limited efficacy and enormous side effects of currently available drugs, a search for new safe and effective therapeutic agents is critical using experimentally induced SE in animals. The lithium–pilocarpine (Li–Pc) model of SE is most suitable and frequently used for pathophysiological and management strategies of SE. Recent studies have shown significant potential of pharmacological, prophylactic or therapeutic use of curcumin (Cur) in many beneficial activities in the body including neuroprotection in neurodegenerative diseases and antioxidant properties. The present study describes anticonvulsive effects of Cur in Li–Pc induced SE in young rats. The effect of Cur was examined on the intensity and frequency of SE, cognitive behavior in water maze as well as on oxidative stress related enzymes in the brain. Besides its anticonvulsant effect, Cur significantly ameliorates SE-induced cognitive dysfunction and oxidative damages in the hippocampus and striatum areas of the brain. Possible therapeutic application of Cur as an anticonvulsant and as an antioxidant for the treatment of SE has a great potential and warrants further studies.  相似文献   
38.
This study reports the effects of long-term ethanol consumption on kidney redox status, in terms of enzymatic mechanisms involved in regulating the cytosolic [NADH]/[NAD(+) ] balance. Wistar rats were treated with ethanol (2 g/kg body weight/24 h) via intragastric intubation for 10 and 30 weeks, respectively. Ethanol administration induced an enhancement of alcohol dehydrogenase activities and affected the capacity of the kidney to prevent NADH accumulation in the cytosol. After 10 weeks, the excess of NADH was balanced by increased activities of malate dehydrogenase and aspartate transaminase. In the event of a longer period of ethanol intake, the kidney was not able to balance the NADH excess, even though an increase in malate dehydrogenase, lactate dehydrogenase, aspartate transaminase, and alanine transaminase activities was noted. The electrophoretic analysis of alcohol dehydrogenase, lactate dehydrogenase, and malate dehydrogenase isoforms revealed differences between control and ethanol-treated animals. The results suggest that rat kidneys have a multicomponent metabolic response to the same daily dose of ethanol that functions to maintain the redox status and which varies with the length of the administration period.  相似文献   
39.
Long non‐coding RNAs (lncRNAs) have been implicated in the regulation of gene expression at various levels. However, to date, the expression profile of lncRNAs in status epilepticus (SE) was unclear. In our study, the expression profile of lncRNAs was investigated by high‐throughput sequencing based on a lithium/pilocarpine‐induced SE model in immature rats. Furthermore, weighted correlation network analysis (WGCNA), gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to construct co‐expression networks and establish functions of the identified hub lncRNAs in SE. The functional role of a hub lncRNA (NONRATT010788.2) in SE was investigated in an in vitro model. Our results indicated that 7082 lncRNAs (3522 up‐regulated and 3560 down‐regulated), which are involved in cell proliferation, inflammatory responses, angiogenesis and autophagy, were dysregulated in the hippocampus of immature rats with SE. Additionally, WGCNA identified 667 up‐regulated hub lncRNAs in turquoise module that were involved in apoptosis, inflammatory responses and angiogenesis via regulation of HIF‐1, p53 and chemokine signalling pathways and via inflammatory mediator regulation of TRP channels. Knockdown of an identified hub lncRNA (NONRATT010788.2) inhibited neuronal apoptosis in vitro. Taken together, our study is the first to demonstrate the expression profile and potential function of lncRNAs in the hippocampus of immature rats with SE. The defined hub lncRNAs may participate in the pathogenesis of SE via lncRNA‐miRNA‐mRNA network.  相似文献   
40.
程海水生植被现状及其演变趋势   总被引:3,自引:0,他引:3  
近20年来,程海水生植物种类和群落类型进一步趋于简单化,水生植被覆盖度由24%~75%变为0.2%~85%,分布最大水深虽由4.5m延伸至5.5m,分布面积却由527.8hm2缩减为73.05hm2,资源蕴藏量由4766吨降低至314.53吨。分析认为:程海南部大面积适生生境破坏、水质污染、水体富营养化、不合理放养草鱼是加剧其水生植被衰退的主要原因。提出了恢复南部湿地、削减入湖污染物、禁止投放草鱼、控制水质污染和水体富营养化等保护对策。  相似文献   
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