全文获取类型
收费全文 | 45001篇 |
免费 | 3355篇 |
国内免费 | 1796篇 |
专业分类
耳鼻咽喉 | 378篇 |
儿科学 | 1410篇 |
妇产科学 | 304篇 |
基础医学 | 4671篇 |
口腔科学 | 189篇 |
临床医学 | 4534篇 |
内科学 | 3288篇 |
皮肤病学 | 81篇 |
神经病学 | 14251篇 |
特种医学 | 3006篇 |
外国民族医学 | 5篇 |
外科学 | 3209篇 |
综合类 | 5807篇 |
现状与发展 | 2篇 |
预防医学 | 1455篇 |
眼科学 | 174篇 |
药学 | 3647篇 |
13篇 | |
中国医学 | 1210篇 |
肿瘤学 | 2518篇 |
出版年
2024年 | 97篇 |
2023年 | 603篇 |
2022年 | 1120篇 |
2021年 | 1653篇 |
2020年 | 1500篇 |
2019年 | 1388篇 |
2018年 | 1281篇 |
2017年 | 1430篇 |
2016年 | 1466篇 |
2015年 | 1548篇 |
2014年 | 2519篇 |
2013年 | 3207篇 |
2012年 | 2371篇 |
2011年 | 2486篇 |
2010年 | 2207篇 |
2009年 | 2003篇 |
2008年 | 2178篇 |
2007年 | 2234篇 |
2006年 | 2156篇 |
2005年 | 1891篇 |
2004年 | 1467篇 |
2003年 | 1446篇 |
2002年 | 1182篇 |
2001年 | 1049篇 |
2000年 | 822篇 |
1999年 | 766篇 |
1998年 | 684篇 |
1997年 | 762篇 |
1996年 | 618篇 |
1995年 | 520篇 |
1994年 | 542篇 |
1993年 | 389篇 |
1992年 | 402篇 |
1991年 | 339篇 |
1990年 | 309篇 |
1989年 | 296篇 |
1988年 | 294篇 |
1987年 | 246篇 |
1986年 | 318篇 |
1985年 | 381篇 |
1984年 | 384篇 |
1983年 | 254篇 |
1982年 | 321篇 |
1981年 | 271篇 |
1980年 | 242篇 |
1979年 | 132篇 |
1978年 | 96篇 |
1977年 | 79篇 |
1976年 | 69篇 |
1975年 | 36篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
141.
采用一期切开挂线术治疗肛周脓肿305例,全瓿期治愈,无发生肛瘘及并发症者。作者认为手术成功的关键是正确处理内口及原发灶,良好通畅的切口引流以及合理的术后处理,对提高疗效,防止复发有重要意义。 相似文献
142.
Protein kinase C (PKC) activity was measured in rat brain with 2 h of middle cerebral artery (MCA) and common carotid artery (CCA) occlusion, using dual autoradiography of [14C]iodoantipyrine (IAP) and [3H]phorbol-12,13-dibutyrate (PDBu). In the ischemic brain, it required more than 120 min of incubation to obtain a plateau in PDBu binding. In contrast, the binding of PDBu in non-ischemic brain reached a plateau with incubation for 60 min. This delay of PDBu binding in the ischemic brain suggests that the affinity of this ligand is reduced due to a change in structure of the cell membrane caused by ischemia. PDBu binding in the ischemic brain increased significantly compared to the non-ischemic brain. This finding provides further evidence that excessive activation of PKC in the ischemic brain may play an important role in ischemic neuronal damage. ©1997 Elsevier Science B.V. All rights reserved. 相似文献
143.
MASATO FUKUDA MD AKINOBU HATA MD SHIN-ICHI NIWA MD KEN-ICHI HIRAMATSU MD MASAFUMI YOKOKOJI MD SEIKI HAYASHIDA AM KENJI ITOH DENG KAZUYUKI NAKAGOME MD AKIRA IWANAMI MD 《Psychiatry and clinical neurosciences》1996,50(2):85-88
Abstract A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event-related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was 'repressed'. Event-related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature. 相似文献
144.
Streptococcus sanguis, usually considered a nonpathogen of the oral cavity, was isolated from blood cultures from a patient who was subsequently found to have a cecal adenocarcinoma. Further studies are needed to determine if Streptococcus sanguis infections have diagnostic implications similar to those of Streptococcus bovis. © 1995 Wiley-Liss, Inc. 相似文献
145.
烟碱对脑M胆碱能受体信息跨膜转导的调节 总被引:1,自引:1,他引:0
采用体外实验研究烟碱对大鼠脑M受体信息跨膜转导的调节作用.脑突触体以烟碱1.0μmol·L-1预处理后,[3H]l-二苯羟乙酸奎宁酯与M受体结合及解离动力学过程减慢.在溶脱的大脑皮层M受体与G蛋白复合体上,烟碱1.0μmol·L-1可减慢[35S]-腺苷5'-[γ-硫]三磷酸与G蛋白的结合,并增强M受体与G蛋白之间的偶联关系.烟碱0.1~1000μmol·L-1既不影响纹状体腺苷酸环化酶的基础活性,也不影响氟化钠激活腺苷酸环化酶的作用.烟碱0.1~30μmol·L-1浓度依赖性地提高脑细胞内Ca2+浓度.据此提出烟碱对脑M受体信息跨膜转导系统有多点调节作用. 相似文献
146.
Harwant S. Gill Michael W. O'Boyle Julie Hathaway 《Cortex; a journal devoted to the study of the nervous system and behavior》1998,34(5):707-718
Alpha power (8–12 Hz) was monitored over the frontal, temporal, parietal and occipital lobes of the left and right cerebral hemispheres while participants mentally rotated three-dimensional shapes to match a specified target. By comparing the activational patterns generated during three experimental conditions, each designed to systematically isolate the involvement of the various subcomponents comprising this mental rotation task, it was suggested that the right frontal lobe mediates encoding and comparison/decision processes, while the left parietal and the left temporal region appear most involved in the generation of images and their mental rotation. A preliminary model describing the cooperative interaction of these cortical regions during mental rotation tasks is proposed. 相似文献
147.
Localized proton spectroscopy of inoperable brain gliomas. Response to radiation therapy 总被引:3,自引:0,他引:3
M. A. A. M. Heesters R. L. Kamman E. L. Mooyaart K. G. Go 《Journal of neuro-oncology》1993,17(1):27-35
Within vivo 1H-MRS resonances of several metabolites were simultaneously measured in cerebral gliomas and adjacent normal brain. 15 patients with inoperable brain gliomas all histologically verified were monitored with 1H-MRS and MRI before and after radiotherapy. 11 patients were evaluable. 1H-MRS technique evolved from single volume measurements to one dimensional and two dimensional 1H spectroscopic imaging. In all patients N-acetyl-aspartate signals were decreased in tumour areas compared to the normal brain hemisphere. No recovery was seen after radiotherapy. Choline signals were increased in tumour margins of high grade gliomas and more diffusely in low grade gliomas. In 5 patients the choline resonance decreased after radiotherapy, accompanied by a shrinkage of tumour diameter on MRI. Lactate signals were present in high grade and unspecified astrocytomas and absent in most low grade gliomas. In 3 patients the lactate signal disappeared after radiotherapy. These observations indicate the feasibility of 1H-MRS in monitoring metabolic responses on radiotherapy of brain gliomas. 相似文献
148.
VIM thalamic stimulation for tremor in a patient with IgM paraproteinaemic demyelinating neuropathy. 总被引:1,自引:0,他引:1
Evzen R?zicka Robert Jech Katerina Zárubová Jan Roth Dusan Urgosík 《Movement disorders》2003,18(10):1192-1195
We demonstrate the effect of deep brain stimulation of the ventral intermediate thalamic nucleus on intractable action tremor, in a 72-year-old man suffering from neuropathy associated with monoclonal gammopathy. 相似文献
149.
Yoshimasa Mori Masakazu Takayasu Yoshio Suzuki Masato Shibuya Jun Yoshida Hiroyoshi Hidaka 《European journal of pharmacology》1997,320(2-3):183-186
The vasodilator effects of C-type natriuretic peptide (CNP) were investigated in isolated rat cerebral arterioles. CNP caused dose-dependent vasodilation, maximally by 10.0±2.2% at 10−6 M. The median effective concentration (EC50) was 5.2×10−10 M. In contrast, atrial natriuretic peptide and B-type natriuretic peptide, other members of the natriuretic peptide family, produced little or no vasodilation. Pretreatment with methylene blue (10−4 M) abolished CNP-induced vasodilation, whereas pretreatment with NG-monomethyl--arginine or indomethacin did not inhibit vasodilation. Thus, CNP is suggested to cause significant vasodilation in cerebral arterioles via a cyclic guanosine monophosphate-dependent mechanism. © 1997 Elsevier Science B.V. All rights reserved. 相似文献
150.
电针对沙鼠急性脑缺血再灌注后神经原损伤的保护作用 总被引:9,自引:0,他引:9
本实验利用沙鼠急性脑缺血再灌注模型,研究电针对脑缺血及再灌注各期脑电活动的影响及组织病理学的改变。结果表明:缺血10mln,脑电幅度受到严重抑制,甚至变平坦,总功率大大下降,再灌注后总功率难以恢复,在120min时仅恢复到缺血前的27.39±11.31%,以后即不再进一步恢复,电针组动物缺血10min再灌注后,脑电的恢复明显比对照组快,120min时恢复至缺血前的71.45±16.46%(P<0.01),240min时继续恢复至缺血前的75.27±18.43%。同时电针能明显减轻缺血10min后再灌注24小时的神经原缺血性损伤。结果提示:电针对急性脑缺血引起的神经原损伤具有保护作用,并能促进脑功能的恢复。 相似文献