全文获取类型
收费全文 | 1996487篇 |
免费 | 148378篇 |
国内免费 | 4300篇 |
专业分类
耳鼻咽喉 | 29909篇 |
儿科学 | 59101篇 |
妇产科学 | 57641篇 |
基础医学 | 281648篇 |
口腔科学 | 60612篇 |
临床医学 | 171608篇 |
内科学 | 385000篇 |
皮肤病学 | 43156篇 |
神经病学 | 160869篇 |
特种医学 | 79935篇 |
外国民族医学 | 590篇 |
外科学 | 311498篇 |
综合类 | 50782篇 |
现状与发展 | 7篇 |
一般理论 | 672篇 |
预防医学 | 145944篇 |
眼科学 | 47896篇 |
药学 | 150098篇 |
4篇 | |
中国医学 | 4121篇 |
肿瘤学 | 108074篇 |
出版年
2018年 | 17378篇 |
2015年 | 17821篇 |
2014年 | 25259篇 |
2013年 | 38670篇 |
2012年 | 50996篇 |
2011年 | 53749篇 |
2010年 | 31803篇 |
2009年 | 30541篇 |
2008年 | 51493篇 |
2007年 | 56134篇 |
2006年 | 56514篇 |
2005年 | 55030篇 |
2004年 | 53895篇 |
2003年 | 52050篇 |
2002年 | 50777篇 |
2001年 | 88675篇 |
2000年 | 91096篇 |
1999年 | 77346篇 |
1998年 | 21753篇 |
1997年 | 19944篇 |
1996年 | 19250篇 |
1995年 | 18237篇 |
1994年 | 17315篇 |
1992年 | 62585篇 |
1991年 | 60648篇 |
1990年 | 59665篇 |
1989年 | 58034篇 |
1988年 | 54303篇 |
1987年 | 53512篇 |
1986年 | 51178篇 |
1985年 | 48955篇 |
1984年 | 37297篇 |
1983年 | 31730篇 |
1982年 | 19505篇 |
1981年 | 17958篇 |
1980年 | 16711篇 |
1979年 | 36730篇 |
1978年 | 26338篇 |
1977年 | 22664篇 |
1976年 | 20594篇 |
1975年 | 22969篇 |
1974年 | 27848篇 |
1973年 | 26935篇 |
1972年 | 25741篇 |
1971年 | 24044篇 |
1970年 | 22881篇 |
1969年 | 22002篇 |
1968年 | 20281篇 |
1967年 | 18487篇 |
1966年 | 17267篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
Treatment of thrombocytopenia with alfa interferon 总被引:1,自引:0,他引:1
A M Lever M G Brook I Yap H C Thomas 《British medical journal (Clinical research ed.)》1987,295(6612):1519-1520
952.
Weaver mutant mice are characterized by a decrease in striatal dopamine (DA), which is associated with a progressive loss of DA neurones in the substantia nigra. This mutant thus provides the opportunity to examine the functional effects of DA neurones grafted to the striatum in a genetic model of parkinsonism. Ventral mesencephalic tissue from normal foetuses was placed on the surface of the right dorsal striatum of adult weaver mutants. After grafting, animals were tested for methamphetamine-induced circling behaviour. Mutants with DA containing grafts displayed a significant circling bias toward the left, non-grafted side. Mutants without grafts did not display any rotational bias to either side. These results demonstrate that grafted DA containing neurones establish a functional innervation of the weaver striatum and suggest that grafting of neural tissue is a viable approach in restoring function in genetic degenerative disorders of the nigrostriatal system. 相似文献
953.
R H Miller M S Linet M L Van Natta L D McCaffrey R L Humphrey 《Archives of internal medicine》1987,147(9):1614-1617
Serum protein electrophoresis (SPEP) data obtained at diagnosis were available for 98 of 342 patients with chronic lymphocytic leukemia (CLL) identified in a population-based case-control epidemiologic study. Patients tested with SPEP at diagnosis were significantly younger, more likely to have lymphadenopathy, and more likely to have had their conditions diagnosed at a university hospital than those not tested. Four categories of electrophoretic patterns were identified: normal (N = 56), hypogammaglobulinemia (N = 28), hypergammaglobulinemia (N = 11), and monoclonal gammopathy (N = 3). A higher proportion of those with hypergammaglobulinemia were black, and patients with hypergammaglobulinemia and monoclonal gammopathy were more likely to die within the first year following diagnosis than patients in the other SPEP groups. No association was found, however, between SPEP pattern and a clinical staging classification for CLL. These findings suggest that SPEP may be a useful adjunct in categorizing possible subtypes of CLL and developing future clinical staging classifications. 相似文献
954.
Mentally retarded adolescents and MA-matched nonretarded children participated in three experiments designed to examine differences in language-processing efficiency. A compressed speech technique was used in Experiments 1 and 2. Experiment 3 relied on a sentence-picture verification procedure. Our results suggest that retarded and nonretarded individuals differ in the speed with which they are able to execute the semantic-analytic processes but not necessarily the phonological encoding processes that are involved in auditory language comprehension. In addition, the data suggest a possible group difference in the quality of the semantic representation encoded during sentence processing. 相似文献
955.
Characterization of gp 50, a major glycoprotein present in rat brain synaptic membranes, with a monoclonal antibody 总被引:4,自引:0,他引:4
Philip W. Beesley Toni Paladino Claude Gravel Richard A. Hawkes James W. Gurd 《Brain research》1987,408(1-2):65-78
Several cell lines secreting monoclonal antibodies (Mabs) against a major forebrain synaptic membrane (SM) glycoprotein, gp 50, have been raised. Western blots show that the Mabs react with a polypeptide doublet of Mrs 49 and 45 kDa. These polypeptides exist solely in a concanavalin A (Con A) binding form. Removal of the Con A receptors by digestion with endo-beta-N-acetylglucosaminidase H (endo H) lowers the Mrs of the glycoprotein doublet to 36.5 and 34 kDa. Western blots of 2D polyacrylamide gels indicate that gp 50 exists in several isoforms. Solid phase radioimmunoassay (RIA) and Western blots of brain subcellular fractions show the antigenic material to be concentrated in the SM fraction, but to be present in much lower amounts in synaptic junctions and postsynaptic densities. Gp 50 appears to be brain specific. Regional distribution studies show that it is present in all brain regions but is two-fold concentrated in cerebellum, brainstem and midbrain compared to forebrain. Immunocytochemical studies of several brain regions show that gp 50-like immunoreactivity is neuron specific and is concentrated in selected neuronal species, particularly granule cells. In both cerebellar and hippocampal granule cells gp 50-like immunoreactivity is localized in the perikarya and primary dendrites. Though immunocytochemistry did not show staining of synaptic regions this may be due to masking of the reactive epitope. The results are discussed in terms of the molecular properties of gp 50 and its subcellular localization in brain tissue. 相似文献
956.
B Lindblad D Bergqvist H Fredin H Jaroszewski B Nosslin 《VASA. Zeitschrift für Gef?sskrankheiten》1987,16(3):251-255
957.
Utility of operative ultrasound in the surgical management of liver tumors. 总被引:5,自引:2,他引:3 下载免费PDF全文
In this study the utility of operative ultrasound in the surgical management of 98 consecutive patients with liver and gastrointestinal tumors was assessed. All patients had preoperative work-up including ultrasound study of the liver as well as selective hepatic arteriography (50 patients) and computerized tomography of the liver (45 patients). At surgery, inspection and palpation of the liver as well as operative ultrasound examination were performed in all cases. Fifty-six patients were known to have liver tumors before operation, while 42 patients had their liver examined as part of the treatment of a primary gastrointestinal malignancy. A total of 126 liver tumors were found in 58 patients, all of whom were confirmed histologically. Eighteen nodules unsuspected before operation were found at surgery--nine by inspection and palpation of the liver, and nine others that were nonpalpable were found by operative ultrasound only. Eighteen lesions that were missed by all diagnostic modalities were found as secondary lesions on pathologic examination of the resected specimens. In addition to diagnostic applications, operative ultrasound was useful in localizing nodules and permitting guided biopsies deep in the hepatic parenchyma. In eight cases, segmental resections were performed with operative ultrasound to localize the plane of section and to catheterize the intrahepatic portal vein branch afferent to the tumor in order to perform balloon catheter occlusion of the vessel for control of bleeding. Operative ultrasound was found to be important in the surgical management of 19 of 98 patients (19%). 相似文献
958.
A H Myers B Rosner H Abbey W Willet M J Stampfer C Bain R Lipnick C Hennekens F Speizer 《American journal of public health》1987,77(5):628-630
We analyzed smoking behavior of 91,651 married female nurses, aged 30-55 years in 1976. The prevalence of smoking was similar among all birth cohorts. The largest percentage increase in starting to smoke occurred between ages 15 and 25 years; by age 25, 50 per cent had started smoking. The cessation rate was lowest in earlier birth cohorts and among nurses starting to smoke at earlier ages. The cessation rate increased substantially between 1963-73 compared with the period 1948-58. 相似文献
959.
L H Phillips 《Neurology》1986,36(9):1251-1253
Long thoracic nerve palsy causes weakness of the serratus anterior muscle and winging of the scapula. It is usually traumatic in origin. Isolated long thoracic nerve palsy has not been recognized as the major manifestation of familial brachial plexus neuropathy, but I have studied the syndrome in four members of three generations of one family. One individual suffered an episode of facial paresis. The inheritance pattern was autosomal dominant. 相似文献
960.