全文获取类型
收费全文 | 13905篇 |
免费 | 1302篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 520篇 |
妇产科学 | 384篇 |
基础医学 | 1825篇 |
口腔科学 | 405篇 |
临床医学 | 1702篇 |
内科学 | 2696篇 |
皮肤病学 | 155篇 |
神经病学 | 1094篇 |
特种医学 | 583篇 |
外科学 | 2021篇 |
综合类 | 407篇 |
一般理论 | 11篇 |
预防医学 | 1593篇 |
眼科学 | 151篇 |
药学 | 881篇 |
1篇 | |
中国医学 | 17篇 |
肿瘤学 | 747篇 |
出版年
2021年 | 187篇 |
2020年 | 115篇 |
2019年 | 198篇 |
2018年 | 240篇 |
2017年 | 192篇 |
2016年 | 197篇 |
2015年 | 236篇 |
2014年 | 299篇 |
2013年 | 450篇 |
2012年 | 617篇 |
2011年 | 653篇 |
2010年 | 360篇 |
2009年 | 379篇 |
2008年 | 549篇 |
2007年 | 643篇 |
2006年 | 546篇 |
2005年 | 533篇 |
2004年 | 501篇 |
2003年 | 465篇 |
2002年 | 452篇 |
2001年 | 428篇 |
2000年 | 510篇 |
1999年 | 455篇 |
1998年 | 220篇 |
1997年 | 214篇 |
1996年 | 215篇 |
1995年 | 209篇 |
1994年 | 165篇 |
1993年 | 169篇 |
1992年 | 330篇 |
1991年 | 327篇 |
1990年 | 353篇 |
1989年 | 315篇 |
1988年 | 279篇 |
1987年 | 279篇 |
1986年 | 249篇 |
1985年 | 263篇 |
1984年 | 181篇 |
1983年 | 150篇 |
1980年 | 101篇 |
1979年 | 154篇 |
1978年 | 131篇 |
1977年 | 112篇 |
1976年 | 105篇 |
1975年 | 98篇 |
1974年 | 124篇 |
1973年 | 117篇 |
1972年 | 117篇 |
1971年 | 114篇 |
1970年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
A technique to anesthetize turtles with ether is presented, in which a plastic cannula is passed through the glottis into the trachea. This procedure avoids apnea and allows ether vapours obtained from a chamber to be introduced, by the animal respiratory movements or by means of a pump, into the animal lungs. The anesthesia is rapidly obtained and lasts from 45-90 minutes. The time of recovery from anesthesia ranged from 60-90 minutes. With this technique no deaths were observed and the same animal could be anesthetized repeatedly. 相似文献
42.
Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells 总被引:3,自引:0,他引:3
Stefan Heller Andrea M. Bell Charlotte S. Denis Yong Choe A.J. Hudspeth 《Journal of the Association for Research in Otolaryngology》2002,3(4):488-498
Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates
adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic
active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the
K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the
three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a
gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin
3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear
libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin
3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well
in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration
of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer,
and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing
hair cells in the frog, chicken, and zebrafish. 相似文献
43.
LY Chow MRCPsych D Chung MRCPsych V Leung MB BS TF Leung MB ChB CM Leung MRCPsych 《International journal of clinical practice》1997,51(5):330-331
Akathisia as a side-effect of metoclopramide has received increasing attention in consultation-liaison psychiatry in recent years. A case of metoclopramide-induced akathisia resulting in a suicide attempt is reported in order to highlight the suffering of such patients and the factors that lead to misdiagnosis. 相似文献
44.
45.
46.
The phospholipid-hydrolyzing enzyme phospholipase A2 (PLA2) (EC 3.1.1.4) exists in several forms which can be located in the cytosol or on cellular membranes. We review briefly cellular regulatory mechanisms involving covalent modification by protein kinase C and the action of Ca2+, cytokines, G proteins and other cellular proteins. The major focus is the role of phospholipid structure on PLA2 activity, including (1) the mechanism of PLA2 action on synthetic phospholipid bilayers, (2) perturbation of synthetic and cellular membranes with lipophilic agents and membrane-interactive peptides and (3) the ability of these agents to activate endogenous PLA2 activity, with emphasis on the venom and plant toxins melittin, cardiotoxin and Pyrularia thionein. 相似文献
47.
David S H Bell James H O'Keefe 《Journal of the American College of Cardiology》2007,50(18):1810; author reply 1810-1810; author reply 1811
48.
Caporale CM Capasso M Lucani M Gandolfi P De Angelis MV Di Muzio A Caporale V Uncini A . 《Journal of the peripheral nervous system : JPNS》2004,9(2):114-115
Campylobacter jejuni (C. jejunj) infection is the most common antecedent in the axonal variant of Guillain‐Barré syndrome (GBS). Antibodies against nerve gangliosides found in GBS patients recognize cross‐reactive epitopes in the lipopolysaccharide (LPS) of C. jejuni. This led to the molecular mimicry hypothesis of GBS. We immunized eleven rabbits with a LPS extracted from HS:19 C. jejuni strain isolated from a patient with GBS and complete Freund's adjuvant (CFA)(group I). In a second experiment we immunized seven rabbits with LPS, CFA and keyhole limpet hemocyanin (KLH)(group II). All group I rabbits developed high titers of anti‐LPS, anti‐GM1, anti‐GD1b antibodies and lower titers of anti‐GD1a. One rabbit, 50 days after initial inoculation, showed tremor and weakness. All rabbits of group II developed high titres of antiganglioside antibodies and six animals showed weakness 59–113 days after initial inoculation. Two rabbits died. Pathology showed mild to moderate, tendentially grouped, axonal degeneration in sciatic nerves of four out of five animals. Control rabbits of group I (immunized with CFA only) did not develop antibodies, controls of group II (immunized with CFA + KLH) developed low titers of IgG anti‐GM1. None developed neurological signs or showed axonal degeneration. C. jejuni LPS is a potent B‐cell stimulator capable to induce a strong antiganglioside response in rabbits. However, to induce the neuropathy is crucial to employ KLH, a glycoprotein known to stimulate both humoral and cellular responses. This animal model reproduces the pathogenetic process hypothesized in axonal GBS with antiganglioside antibodies post C. jejuni infection. 相似文献
49.
50.