全文获取类型
收费全文 | 377711篇 |
免费 | 35038篇 |
国内免费 | 26157篇 |
专业分类
耳鼻咽喉 | 2872篇 |
儿科学 | 4914篇 |
妇产科学 | 4225篇 |
基础医学 | 41291篇 |
口腔科学 | 6166篇 |
临床医学 | 53022篇 |
内科学 | 50924篇 |
皮肤病学 | 4153篇 |
神经病学 | 18261篇 |
特种医学 | 13852篇 |
外国民族医学 | 224篇 |
外科学 | 33388篇 |
综合类 | 70757篇 |
现状与发展 | 87篇 |
一般理论 | 31篇 |
预防医学 | 27717篇 |
眼科学 | 10817篇 |
药学 | 40937篇 |
449篇 | |
中国医学 | 25127篇 |
肿瘤学 | 29692篇 |
出版年
2024年 | 1960篇 |
2023年 | 5657篇 |
2022年 | 14539篇 |
2021年 | 18457篇 |
2020年 | 14843篇 |
2019年 | 11949篇 |
2018年 | 12299篇 |
2017年 | 11844篇 |
2016年 | 10929篇 |
2015年 | 16936篇 |
2014年 | 21040篇 |
2013年 | 19166篇 |
2012年 | 28516篇 |
2011年 | 31960篇 |
2010年 | 21561篇 |
2009年 | 17574篇 |
2008年 | 21492篇 |
2007年 | 21185篇 |
2006年 | 20218篇 |
2005年 | 19304篇 |
2004年 | 12757篇 |
2003年 | 12285篇 |
2002年 | 10049篇 |
2001年 | 8574篇 |
2000年 | 8339篇 |
1999年 | 8425篇 |
1998年 | 5317篇 |
1997年 | 5103篇 |
1996年 | 3962篇 |
1995年 | 3720篇 |
1994年 | 3135篇 |
1993年 | 2031篇 |
1992年 | 2429篇 |
1991年 | 2129篇 |
1990年 | 1797篇 |
1989年 | 1557篇 |
1988年 | 1284篇 |
1987年 | 1183篇 |
1986年 | 957篇 |
1985年 | 678篇 |
1984年 | 369篇 |
1983年 | 271篇 |
1982年 | 142篇 |
1981年 | 169篇 |
1980年 | 115篇 |
1979年 | 154篇 |
1978年 | 73篇 |
1977年 | 53篇 |
1974年 | 42篇 |
1972年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
目的:对紫苏子油-β-环糊精包合物的制备工艺及其性能进行研究。方法:采用正交试验研究制备工艺,利用同步热分析仪对产物的性能进行表征,获得了脱包曲线研究产物的稳定性。结果:通过正交试验及其数据分析,确定制备紫苏子油-β-环糊精包合物的最优工艺为A3B2C1D2和A3B2C3D2,紫苏子油与环糊精的比例对包合率、收率的影响较大;TGA曲线和DSC曲线证明了包合物的生成,显示经过包合后热稳定性增强;脱包曲线显示包合物脱包速率降低,稳定性增强。结论:紫苏子油-β-环糊精包合物的差热、热重和脱包性质,以及包合反应的最佳工艺为紫苏子油的微粉化和制剂的研究、开发提供了依据。 相似文献
995.
环磷酰胺致脑血管痉挛 总被引:2,自引:0,他引:2
患者女,54岁。因左乳浸润性导管癌,于2005年4月18日行乳腺切除根治术,术后恢复良好。既往无脑血管病史,无药物过敏史。5月3日开始化疗,当天给药:环磷酰胺1.0g,表柔比星50mg,地塞米松5mg,百宏100ml,静脉滴注。静滴约1.5h,患者出现严重头痛、头晕、颈部不能转动、呕吐等症状,当即停止用药。第二天症状仍无缓解,随即作脑彩超,检查结果:脑基底动脉、椎动脉血管痉挛,之后又作脑CT等相关检查,排除脑血管痉挛的其他因素。5d后症状缓解,脑彩超结果:血管恢复正常。于5月10日重新化疗,此次用长春瑞宾替代环磷酰胺,其它药物未改变,没有发生上述反应。… 相似文献
996.
997.
Marquis P Vawter Simon Evans Prabhakara Choudary Hiroaki Tomita Jim Meador-Woodruff Margherita Molnar Jun Li Juan F Lopez Rick Myers David Cox Stanley J Watson Huda Akil Edward G Jones William E Bunney 《Neuropsychopharmacology》2004,29(2):373-384
Gender differences in brain development and in the prevalence of neuropsychiatric disorders such as depression have been reported. Gender differences in human brain might be related to patterns of gene expression. Microarray technology is one useful method for investigation of gene expression in brain. We investigated gene expression, cell types, and regional expression patterns of differentially expressed sex chromosome genes in brain. We profiled gene expression in male and female dorsolateral prefrontal cortex, anterior cingulate cortex, and cerebellum using the Affymetrix oligonucleotide microarray platform. Differentially expressed genes between males and females on the Y chromosome (DBY, SMCY, UTY, RPS4Y, and USP9Y) and X chromosome (XIST) were confirmed using real-time PCR measurements. In situ hybridization confirmed the differential expression of gender-specific genes and neuronal expression of XIST, RPS4Y, SMCY, and UTY in three brain regions examined. The XIST gene, which silences gene expression on regions of the X chromosome, is expressed in a subset of neurons. Since a subset of neurons express gender-specific genes, neural subpopulations may exhibit a subtle sexual dimorphism at the level of differences in gene regulation and function. The distinctive pattern of neuronal expression of XIST, RPS4Y, SMCY, and UTY and other sex chromosome genes in neuronal subpopulations may possibly contribute to gender differences in prevalence noted for some neuropsychiatric disorders. Studies of the protein expression of these sex-chromosome-linked genes in brain tissue are required to address the functional consequences of the observed gene expression differences. 相似文献
998.
Su-rong YANG Li WEN Ying-qing LU Qin-yan GONG Rong YU Ming-hui YAODepartment of Pharmacology Shanghai Medical College Fudan University Shanghai China 《Acta pharmacologica Sinica》2004,(1)
AIM: To observe the effects of three cytokines on the apoptosis of Tf-1 cells induced by y irradiation and investigate the relationship between apoptosis and caspase-3 activity. METHODS: Different cytokines GM-CSF, IL-3 and GM-CS/IL-3 fusion protein were added into the irradiated Tf-1 cells. MTT assay, morphology, flow cytometry, and DNA fragmentation assay were used to observe the effects of cytokines on apoptosis. The caspase-3 activity was determined with a fluorocytometer. RESULTS: Irradiated Tf-1 cells showed typical morphological characteristic of apoptosis demonstrated by transmission electron microscopy and were accumulated in G0/G1 phase. In the groups treated with growth factors after irradiation, three cytokines significantly increased the viability rate, distinctly decreased the apoptosis rate and the proportion of DNA fragmentation. When Tf-1 cells were irradiated by y 相似文献
999.
Moclobemide up-regulates proliferation of hippocarnpal progenitor cells in chronically stressed mice 总被引:1,自引:0,他引:1
Yun-feng LI You-zhi ZHANG Yan-qin LIU Heng-lin WANG Li YUAN Zhi-pu LUOBeijing Institute of Pharmacology Toxicology Beijing Department of Anesthesiology Hospital of Beijing Beijing China 《Acta pharmacologica Sinica》2004,(11)
AIM: To explore the action mechanism of antidepressants. METHODS: The PC12 cell proliferation was detected by flow cytometry,. The proliferation of hippocampal progenitor cells and level of brain-derived neurotrophic factor (BDNF) were measured by immunohistochemistry. RESULTS: Treatment with N-methylaspartate (NMDA) 600μmol/L for 3 d significantly decreased the percentage of S-phase in PC12 cells, while in the presence of classical antidepressant, moclobemide (MOC) 2 and 10μmol/L, the percentage in S-phase increased. Furthermore, the proliferation of progenitor cells in hippocampal dentate gyrus (subgranular zone), as well as the level of BDNF in hippocampus significantly decreased in chronically stressed mice, while chronic administration with MOC 40 mg/kg (ip) up-regulated the progenitor cell proliferation and BDNF level in the same time course. CONLUSION: Up-regulation of the proliferation of hippocampal progenitor cells is one of the action mechanisms for MOC, which may be closely related to the e 相似文献
1000.