全文获取类型
收费全文 | 92050篇 |
免费 | 8509篇 |
国内免费 | 6770篇 |
专业分类
耳鼻咽喉 | 757篇 |
儿科学 | 962篇 |
妇产科学 | 1118篇 |
基础医学 | 11090篇 |
口腔科学 | 1767篇 |
临床医学 | 12540篇 |
内科学 | 13666篇 |
皮肤病学 | 889篇 |
神经病学 | 4911篇 |
特种医学 | 3384篇 |
外国民族医学 | 63篇 |
外科学 | 8929篇 |
综合类 | 15907篇 |
现状与发展 | 37篇 |
一般理论 | 5篇 |
预防医学 | 5515篇 |
眼科学 | 2614篇 |
药学 | 9661篇 |
82篇 | |
中国医学 | 5192篇 |
肿瘤学 | 8240篇 |
出版年
2024年 | 366篇 |
2023年 | 1735篇 |
2022年 | 4131篇 |
2021年 | 5030篇 |
2020年 | 3785篇 |
2019年 | 3252篇 |
2018年 | 3297篇 |
2017年 | 3079篇 |
2016年 | 2753篇 |
2015年 | 4370篇 |
2014年 | 5212篇 |
2013年 | 4427篇 |
2012年 | 6577篇 |
2011年 | 7408篇 |
2010年 | 4493篇 |
2009年 | 3441篇 |
2008年 | 4397篇 |
2007年 | 4685篇 |
2006年 | 4598篇 |
2005年 | 4671篇 |
2004年 | 2898篇 |
2003年 | 2638篇 |
2002年 | 2320篇 |
2001年 | 1980篇 |
2000年 | 2215篇 |
1999年 | 2556篇 |
1998年 | 1692篇 |
1997年 | 1620篇 |
1996年 | 1244篇 |
1995年 | 1072篇 |
1994年 | 898篇 |
1993年 | 618篇 |
1992年 | 721篇 |
1991年 | 614篇 |
1990年 | 558篇 |
1989年 | 482篇 |
1988年 | 394篇 |
1987年 | 350篇 |
1986年 | 247篇 |
1985年 | 191篇 |
1984年 | 92篇 |
1983年 | 76篇 |
1982年 | 41篇 |
1981年 | 45篇 |
1980年 | 29篇 |
1979年 | 30篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
LJM, a 41-year-old schizophrenic Chinese man with bilateral anterior cingulate gyrus (Brodmann's area 24) lesions and also a small lesion in right amygdala after an operation, was compared with normal as well as brain-damaged and schizophrenic controls in identification of morphed facial expressions of six basic emotions. In repeated administrations of the test for recognition of facial emotions, over a 1- year period, LJM performed significantly worse for expressions of fear compared with the three groups of controls. Recognition of other emotions was not significantly different from that of the controls, except that his recognition of disgust during the first session (but not in two subsequent sessions) was worse than normal and brain-damaged controls but not worse than schizophrenic controls. The dissociation between recognition of fear and other emotions supported the view that the brain has separable networks for processing different emotions, and that the right amygdala as well as the anterior part of bilateral cingulate gyrus are possible substrates involved in the special network for perception of fear. The results from the various groups of Chinese subjects indicate that they perceive emotions in a categorical manner, and that the six basic emotions are likely to be cross-cultural universals. 相似文献
92.
Alessandra Renieri Maria Teresa Bassi Lucia Galli Jing Zhou Marisa Giani Mario de Marchi Andrea Ballabio 《Human mutation》1994,4(3):195-198
Alport's syndrome is characterized clinically by a nonimmune glomerulopathy, often accompanied by sensorineural hearing loss and lens abnormalities, frequently due to mutations in the COL4A5 gene. The association of AS with diffuse leiomyomatosis, a benign proliferation of smooth muscle that occurs most often in the esophagus, trachea, and female genitalia, has been reported. Recently, a deletion involving both the COL4A5 and COL4A6 genes has been reported in four unrelated families. We report an additional case with Alport's syndrome associated with leiomyomatosis carrying a deletion of both COL4A5 and COL4A6 genes. A detailed characterization of the genomic region involved in the deletion event has been performed. Our results demonstrate that the deletion removed exon l of COL4A5 and exons l and 2 of COL4A6. © 1994 Wiley-Liss, Inc. 相似文献
93.
94.
95.
TLR2(-/-)/scid double-mutant mice were infected with B. burgdorferi to assess the relative importance of acquired and innate host defenses. Although spirochete levels at 4 weeks were lower in TLR2(-/-) mice than in TLR2(-/-)/scid mice, the increased arthritis severity of TLR2 (Toll-like receptor 2)-deficient mice was reduced by the presence of the scid mutation. 相似文献
96.
脐带血清对骨髓粒—巨噬细胞集落形成的影响 总被引:1,自引:0,他引:1
在骨髓细胞半固体琼脂培养体系中,研究脐带血清(CBs)对骨髓粒—巨噬细胞集落形成单位(CFU-GM)的影响,单纯应用CBs培养可使骨髓CFU-GM(x±s为26.0375±10.2327)显著的高于正常成人外周血清(PBs)组(x±s为11.5917±3.6047;P<0.001)。CBs加粒-巨噬细胞刺激因子,GM-CSF组CFU-GM(x±s为119.0792±35.0991)是单纯CBs组的4.57倍;而PBs加GMC-SF组(x±s为97.125±26.7559)是单纯PBs组的8.38倍。有白细胞介素-6(IL-6)存在的CBs组,CFU-GM(x±s为31.9333±10.9144)明显的高于单纯CBs组(P<0.02)。提示CBs中含有较高水平的内源性GM-CSF。 相似文献
97.
Feldweg AM Friend DS Zhou JS Kanaoka Y Daheshia M Li L Austen KF Katz HR 《European journal of immunology》2003,33(8):2262-2268
We report that gp49B1, a mast cell membrane receptor with two immunoreceptor tyrosine-based inhibitory motifs (ITIM), constitutively inhibits mast cell activation-secretion induced by stem cell factor (SCF), a tissue-derived cytokine that also regulates mast cell development. The intradermal injection of SCF into the ears of gp49B1 null (gp49B(-/-)) mice elicited approximately 4- and 2.5-fold more degranulating mast cells and tissue swelling caused by edema, respectively, than in gp49B(+/+) mice. SCF did not induce tissue swelling in mast cell-deficient mice, and the responsiveness of gp49B(-/-) mice to mast cell-associated amine and lipid mediators was unaltered. When gp49B(+/+) and gp49B(-/-) mice were pretreated with antagonists of the amines, SCF-induced tissue swelling was reduced by >90% and 60%, respectively, and it was reduced by >90% in both genotypes when a cysteinyl leukotriene receptor antagonist was also provided. Hence, the dominant contribution of secretory granule amines to SCF-induced tissue swelling is the result of gp49B1-mediated inhibition of the production of cysteinyl leukotrienes by mast cells. Our findings also provide the first example of an ITIM-bearing receptor that constitutively suppresses inflammation generated in vivo independently of the adaptive immune response by a receptor that signals through intrinsic tyrosine kinase activity rather than immunoreceptor tyrosine-based activation motifs. 相似文献
98.
胃动素对血管灌流大鼠离体胃运动的作用 总被引:8,自引:1,他引:8
通过血管灌流大鼠离体胃,探讨胃动素对胃运动的影响。结果表明:(1)胃动素可以明显地兴奋胃窦自发的胃运动;(2)胃动素抗血清可以完全消除胃动素兴奋胃窦运动的作用;(3)阿托品可以阻断胃动素兴奋胃窦运动的作用。上述结果提示,胃动素可特异性兴奋血管灌流大鼠胃窦收缩运动,该作用通过壁内胆碱能神经介导。 相似文献
99.
100.
The medullary raphe (MR) and the retrotrapezoid nucleus (RTN) in the ventral medulla are two of many central chemoreceptor sites. We examine their combined function in conscious rats by focal inhibition using microdialysis. Inhibition of RTN neurons with the GABAA receptor agonist muscimol, with simultaneous dialysis of artificial cerebrospinal fluid (ACSF) in or near to the caudal MR, causes hypoventilation (decrease in the ratio of minute ventilation to oxygen consumption, ) and reduces the ventilatory response to 7% CO2 by 24%. Inhibition of caudal MR serotonergic neurons with the 5-HT1A receptor agonist ( R )-(+)-8-hydroxy-2(di- n -propylamino)tetralin (8-OH-DPAT), with simultaneous dialysis of ACSF in or near to the RTN, causes hypoventilation but has no significant effect on the CO2 response. Inhibition of both the RTN and the caudal MR simultaneously produces enhanced hypoventilation and a 51% decrease in the CO2 response. The effects of treatment on the CO2 response are similar in wakefulness and in non-rapid eye movement sleep. Comparison of the effect of 8-OH-DPAT microdialysed into a more rostral portion of the MR, where the CO2 response is reduced by 22%, demonstrates heterogeneity within the MR of the function of serotonergic neurons in breathing. We conclude that serotonergic neurons within the caudal MR provide a non-CO2 -dependent tonic drive to breathe and potentiate the effects of RTN neurons that contribute to a resting chemical 'drive to breathe' as well as the response to added CO2 . These effects of caudal MR serotonergic neurons could be at a chemoreceptor site, e.g. the RTN, or at 'downstream' sites involved in rhythm and pattern generation. 相似文献