全文获取类型
收费全文 | 7844篇 |
免费 | 640篇 |
国内免费 | 275篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 63篇 |
妇产科学 | 75篇 |
基础医学 | 1344篇 |
口腔科学 | 108篇 |
临床医学 | 459篇 |
内科学 | 726篇 |
皮肤病学 | 93篇 |
神经病学 | 483篇 |
特种医学 | 88篇 |
外国民族医学 | 1篇 |
外科学 | 320篇 |
综合类 | 1769篇 |
一般理论 | 1篇 |
预防医学 | 462篇 |
眼科学 | 74篇 |
药学 | 645篇 |
5篇 | |
中国医学 | 1659篇 |
肿瘤学 | 334篇 |
出版年
2024年 | 34篇 |
2023年 | 63篇 |
2022年 | 170篇 |
2021年 | 254篇 |
2020年 | 277篇 |
2019年 | 244篇 |
2018年 | 212篇 |
2017年 | 270篇 |
2016年 | 261篇 |
2015年 | 256篇 |
2014年 | 596篇 |
2013年 | 551篇 |
2012年 | 610篇 |
2011年 | 551篇 |
2010年 | 506篇 |
2009年 | 408篇 |
2008年 | 372篇 |
2007年 | 391篇 |
2006年 | 313篇 |
2005年 | 289篇 |
2004年 | 228篇 |
2003年 | 191篇 |
2002年 | 131篇 |
2001年 | 169篇 |
2000年 | 186篇 |
1999年 | 129篇 |
1998年 | 97篇 |
1997年 | 124篇 |
1996年 | 84篇 |
1995年 | 67篇 |
1994年 | 86篇 |
1993年 | 72篇 |
1992年 | 71篇 |
1991年 | 54篇 |
1990年 | 48篇 |
1989年 | 30篇 |
1988年 | 26篇 |
1987年 | 18篇 |
1985年 | 63篇 |
1984年 | 46篇 |
1983年 | 27篇 |
1982年 | 33篇 |
1981年 | 23篇 |
1980年 | 25篇 |
1979年 | 24篇 |
1978年 | 19篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1974年 | 10篇 |
排序方式: 共有8759条查询结果,搜索用时 31 毫秒
91.
目的 研究精神分裂症脑脊液中存在的特异性IgG抗体。方法 应用SOS-聚丙烯酰胺凝胶电泳及蛋白印迹技术对精神分裂症脑脊液与对照脑脑液同时进行检查。结果 精神分裂症脑脊液中相对分子质量130ku的蛋白质含量显著增加,在蛋白印迹分析中发现此蛋白质可与羊抗人IgG抗体发生免疫结合反应,结论 提示该蛋白质组分可能是一种与IgG相关的蛋白质。 相似文献
92.
8—Br—cAMP对人视网膜母细胞瘤HXO—Rb44细胞癌基因的表达效应 总被引:2,自引:2,他引:0
目的 研究8-Br-cAMP对培养的人视网膜母细胞瘤HXO-Rb44细胞癌基因表达的效应及其与该细胞生长的关系。方法 c-fos mRNA,N-myc mRNA及p21ras mRNA均以原位杂交RNA斑点印迹技术检测,对繁殖细胞核抗原,v-Fos,N-Myc和P^21ras蛋白表达的免疫反应性则采用免疫组化及收白质斑点印迹技术检测。 相似文献
93.
Insulin-like growth factor (IGF)-I,-II and IGF-binding proteins (IGFBPs) were demonstrated in the cyst fluid of a patient with a hypothalamic astrocytoma. The astrocytoma cyst fluid was subjected to gel chromatography at low pH and the IGF-I and IGF-II levels were measured by specific radioimmunoassays. Immunoreactive IGF-I and IGF-II levels were 19 ng/ml and 78 ng/ml respectively. Several-fold higher IGF-II values were obtained when cyst fluid was not extracted or was extracted with acid ethanol before radioimmunoassay analysis. The immunoreactive IGFBP-1 concentration was 26 ng/ml. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and subsequent Western ligand blotting with [125I]IGF-II revealed bands at 200, 34.5, 29.5, 24 and 21 kD as visualized by autoradiography. Binding studies demonstrated that these binding proteins bind specifically [125I]IGF-I and [125I]IGF-II. These observations suggest that IGFs as well as IGF-binding proteins are produced by astrocytoma cells and may act in a paracrine or autocrine fashion capable of modulating the growth of astrocytoma tumours. 相似文献
94.
Brain spectrin, a membrane-related cytoskeletal protein, exists as two isoforms. Brain spectrin 240/235 is localized preferentially in the perikaryon and axon of neuronal cells and brain spectrin 240/235E is found essentially in the neuronal soma and dendrites and in glia (Riederer et al., 1986, J. Cell Biol., 102, 2088 - 2097). The sensory neurons in dorsal root ganglia, devoid of any dendrites, make a good tool to investigate such differential expression of spectrin isoforms. In this study expression and localization of both brain spectrin isoforms were analysed during early chicken dorsal root ganglia development in vivo and in culture. Both isoforms appeared at embryonic day 6. Brain spectrin 240/235 exhibited a transient increase during embryonic development and was first expressed in ventrolateral neurons. In ganglion cells in situ and in culture this spectrin type showed a somato - axonal distribution pattern. In contrast, brain spectrin 240/235E slightly increased between E6 and E15 and remained practically unchanged. It was localized mainly in smaller neurons of the mediodorsal area as punctate staining in the cytoplasm, was restricted exclusively to the ganglion cell perikarya and was absent from axons both in situ and in culture. This study suggests that brain spectrin 240/235 may contribute towards outgrowth, elongation and maintenance of axonal processes and that brain spectrin 240/235E seems to be exclusively involved in the stabilization of the cytoarchitecture of cell bodies in a selected population of ganglion cells. 相似文献
95.
96.
Cadiou H Sienaert I Vanlingen S Parys JB Molle G Duclohier H 《The European journal of neuroscience》2000,12(8):2805-2811
In addition to the activation of cAMP-dependent pathways, odorant binding to its receptor can lead to inositol 1,4,5-trisphosphate (InsP3) production that may induce the opening of plasma membrane channels. We therefore investigated the presence and nature of such channels in carp olfactory cilia. Functional analysis was performed by reconstitution of the olfactory cilia in planar lipid bilayers (tip-dip method). In the presence of InsP3 (10 microM) and Ca2+ (100 nM), a current of 1.6 +/- 0.1 pA (mean +/- SEM, n = 4) was measured, using Ba2+ as charge carrier. The I/V curve displayed a slope conductance of 45 +/- 5 pS and a reversal potential of -29 mV indicating a higher selectivity for divalent cations. This current was characterized by two mean open times (3.0 +/- 0.4 ms and 42.0 +/- 2.6 ms, n = 4) and was strongly inhibited by ruthenium red (30 microM) or heparin (10 microg/mL). Importantly, the channel activity was closely dependent on the Ca2+ concentration, with the highest open probability (Po) at 100 nM Ca2+ (Po = 0.50 +/- 0.02, n = 4). Po is lower at both higher and lower Ca2+ concentrations. A structural identification of the channel was attempted by using a large panel of antibodies, raised against several InsP3 receptor (InsP3R)/Ca2+ release channel isoforms. The type 1 InsP3R was detected in carp cerebellum and whole brain, while a lower molecular mass InsP3R, which may correspond to type 2 or 3, was detected in heart, whole brain and the soma of the olfactory neurons. None of the antibodies, however, cross-reacted with olfactory cilia. Taken together, these results indicate that in carp olfactory cilia an InsP3-dependent channel is present, distinct from the classical InsP3Rs localized on intracellular membranes. 相似文献
98.
目的 通过体外实验研究雌激素、孕激素、胰岛素 /胰岛素样生长因子Ⅰ (Insulin -likegrowthfactorⅠ ,IGF -Ⅰ )对内膜癌细胞中孕激素受体 (Progesteronereceptor,PR )亚型表达的调节 ,探讨内膜癌细胞中PR亚型表达的意义。方法 体外培养高分化子宫内膜癌细胞Ishikawa ,按实验目的分别加入雌激素、孕激素、雌激素孕激素联合、胰岛素及IGF -Ⅰ刺激 2 4h、 4 8h后 ,采用Westernblot方法测定各个条件下内膜癌细胞中两种孕激素受体亚型的表达。结果 内膜癌细胞Ishikawa在自然状态下 ,PR -A和PR -B均阳性表达 ;细胞经血清限制后 ,总PR及两种亚型都明显下调。雌激素可以上调细胞中PR -A和PR -B表达水平 ,但在高血清时明显。孕激素单独或雌、孕激素联合应用在 4 8h时都可以降低Ishikawa细胞中PR表达。胰岛素 /IGF -Ⅰ在 2 4h时可以上调PR -B水平 ,4 8h时此上调作用消失。结论 ①雌激素对PR的上调作用与血清浓度有关 ,血清中可能含有雌激素作用所需要的某些因子 ;②孕激素对内膜癌细胞Ishikawa中PR有下调作用 ;③胰岛素 /IGF -Ⅰ可以上调内膜癌细胞中PR表达 ,主要是PR -B表达 ,但此作用持续时间短 相似文献
99.
目的:观察中西医结合治疗胃癌根治术后胃轻瘫的疗效.方法:对19例胃癌根治术后胃轻瘫患者进行中西医结合治疗.结果:19例均痊愈,治疗时间7~49天,平均23.5天.结论:中西医结合治疗胃轻瘫有较好效果. 相似文献
100.
突破传统适应需要创建中西医结合人才培养模式 总被引:1,自引:1,他引:1
湖南中医学院1993年率先开办中西医结合临床医学本科专业;创建"两个基础,一个临床"的人才培养模式和一套适应新的培养模式的课程体系;首编中西医结合临床主体课程系列教材;在教学实践中创建适应新培养模式的实践教学体系和创新思维培养方法;为保证人才培养质量,造就了一批高素质的中西医结合专业教师队伍."两个基础,一个临床"培养模式的实践产生了显著的办学效益和社会影响. 相似文献