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71.
A study was made by histochemical methods of the activity of the enzymatic systems of macrophages from normal rabbits and those immunized with staphylococcus alpha-toxoid per se and infected with the strains of staphylococcus--producers of alpha-toxin or leukocydin. Immunization of rabbits was accompanied by a reduction in macrophages of the activity of the group of lysosomal enzymes and by an increase in the activity of the redox enzymes. In infection of "immune" macrophages with the living culture of the alpha-toxigenic strains the mentioned changes were more pronounced; no such changes were found after the infection with the leukocydin-active strain. The data obtained suggested that the lysosomal enzymes played a definite role in the process of phagocytosis.  相似文献   
72.
Aging is a major risk factor for many diseases,especially in highly prevalent cardiopulmonary comorbidities and infectious diseases including Coronavirus Diseas...  相似文献   
73.
Podocyte injury induced by hyperglycemia is the main cause of kidney dysfunction in diabetic nephropathy. However, the underlying mechanism is unclear. Store-operated Ca2+ entry (SOCE) regulates a diversity of cellular processes in a variety of cell types. Calpain, a Ca2+-dependent cysteine protease, was recently shown to be involved in podocyte injury. In the present study, we sought to determine whether increased SOCE contributed to high glucose (HG)–induced podocyte injury through activation of the calpain pathway. In cultured human podocytes, whole-cell patch clamp indicated the presence of functional store-operated Ca2+ channels, which are composed of Orai1 proteins and mediate SOCE. Western blots showed that HG treatment increased the protein abundance of Orai1 in a dose-dependent manner. Consistently, calcium imaging experiments revealed that SOCE was significantly enhanced in podocytes following HG treatment. Furthermore, HG treatment caused overt podocyte F-actin disorganization as well as a significant decrease in nephrin protein abundance, both of which are indications of podocyte injury. These podocyte injury responses were significantly blunted by both pharmacological inhibition of Orai1 using the small molecule inhibitor BTP2 or by genetic deletion of Orai1 using CRISPR-Cas9 lentivirus. Moreover, activation of SOCE by thapsigargin, an inhibitor of Ca2+ pump on the endoplasmic/sarcoplasmic reticulum membrane, significantly increased the activity of calpain, which was inhibited by BTP2. Finally, the calpain-1/calpain-2 inhibitor calpeptin significantly blunted the nephrin protein reduction induced by HG treatment. Taken together, our results suggest that enhanced signaling via an Orai1/SOCE/Calpain axis contributes to HG-induced podocyte injury.  相似文献   
74.
75.
Callus induction,which results in fate transition in plant cells,is considered as the first and key step for plant regeneration.This process can be stimulated in different tissues by a callus-inducing medium(CIM),which contains a high concentration of phytohormone auxin.Although a few key regulators for callus induction have been identified,the multiple aspects of the regulatory mechanism driven by high levels of auxin still need further investigation.Here,we find that high auxin induces callus ...  相似文献   
76.
彩色真菌培养基具有选择性强、分辨率高、易生长、易观察的特点。在真菌培养方面优于其它培养基,其主要作用机理在于应用了化学生物效应促进真菌生长。  相似文献   
77.
携起手来,共同解决生态环境问题   总被引:1,自引:1,他引:0  
生态环境恶化是当代各国面临的共同问题,它直接威胁着人类的健康与生存。如何控制这种恶化趋势的发展,恢复自然生态系统的正常物质代谢功能,以适应人口不断增长的需要,已成为全世界生态学家的迫切任务。这项伟大任务需要各国科学家及其政府与人民携起手来、共同努力来完成。  相似文献   
78.
Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high‐throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate‐ and iron‐reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane‐cycling microbes and their partners being observed in the iron/sulfate‐rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane‐rich environments.  相似文献   
79.
3种燕麦的核型研究   总被引:2,自引:0,他引:2  
3种燕麦的核型研究余懋群,马欣荣,张庆勤(中国科学院成都生物研究所成都610041)(贵州农学院麦作研究中心贵阳550025)关键词砂燕麦,野生大燕麦,黑龙江野燕麦,核型KARYOTYPESTUDYOFTHREEOATSINCHINA¥YuMaoqu...  相似文献   
80.
本文采用田间温度控制试验资料,用数理统计的方法分析高温控制范围、控制时间和控制频率与大棚黄瓜霜霉病的发生期、流行期、发生程度以及产量的关系,并建立了统计相关模式,确定了高温控制生态防治方法的技术指标。最高温度、高温控制时间和控制频率这3个主要指标与病情和黄瓜产量的关系非常密切,最高气温每升高1℃,发病期和流行期将推迟3—5天,病叶率降低13—15%,黄瓜产量可增长10%左右。在一定范围内,控制时间越长,频率越高,则发病期和流行期越晚,病情越轻,产量越高。研究证明,高温控制方法是一个有效的生态防治方法,具有明确的气候生态学依据。  相似文献   
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