全文获取类型
收费全文 | 919778篇 |
免费 | 56955篇 |
国内免费 | 2326篇 |
专业分类
耳鼻咽喉 | 12653篇 |
儿科学 | 28901篇 |
妇产科学 | 26326篇 |
基础医学 | 128337篇 |
口腔科学 | 25035篇 |
临床医学 | 75963篇 |
内科学 | 186139篇 |
皮肤病学 | 19205篇 |
神经病学 | 72996篇 |
特种医学 | 37171篇 |
外国民族医学 | 336篇 |
外科学 | 144659篇 |
综合类 | 19075篇 |
一般理论 | 249篇 |
预防医学 | 65260篇 |
眼科学 | 20383篇 |
药学 | 64509篇 |
13篇 | |
中国医学 | 1810篇 |
肿瘤学 | 50039篇 |
出版年
2018年 | 9390篇 |
2017年 | 7503篇 |
2016年 | 8115篇 |
2015年 | 9156篇 |
2014年 | 12856篇 |
2013年 | 19877篇 |
2012年 | 26578篇 |
2011年 | 28253篇 |
2010年 | 17107篇 |
2009年 | 16293篇 |
2008年 | 27029篇 |
2007年 | 28616篇 |
2006年 | 28731篇 |
2005年 | 28192篇 |
2004年 | 26938篇 |
2003年 | 26056篇 |
2002年 | 25611篇 |
2001年 | 41464篇 |
2000年 | 42611篇 |
1999年 | 36352篇 |
1998年 | 10068篇 |
1997年 | 9239篇 |
1996年 | 9147篇 |
1995年 | 8499篇 |
1994年 | 8129篇 |
1993年 | 7638篇 |
1992年 | 28240篇 |
1991年 | 27018篇 |
1990年 | 26444篇 |
1989年 | 25383篇 |
1988年 | 23590篇 |
1987年 | 23196篇 |
1986年 | 22271篇 |
1985年 | 21176篇 |
1984年 | 15827篇 |
1983年 | 13508篇 |
1982年 | 8114篇 |
1979年 | 14600篇 |
1978年 | 10223篇 |
1977年 | 8641篇 |
1976年 | 8160篇 |
1975年 | 8972篇 |
1974年 | 10706篇 |
1973年 | 10189篇 |
1972年 | 9670篇 |
1971年 | 8919篇 |
1970年 | 8587篇 |
1969年 | 8033篇 |
1968年 | 7687篇 |
1967年 | 7093篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
DNR in the operating room. Not really a paradox 总被引:1,自引:0,他引:1
153.
154.
155.
Release of cortical catecholamines by visual stimulation requires activity in thalamocortical afferents of monkey and cat 总被引:3,自引:0,他引:3
R T Marrocco R F Lane J W McClurkin C D Blaha M F Alkire 《The Journal of neuroscience》1987,7(9):2756-2767
Catecholamine (CA) release was measured in vivo in the monkey and cat visual cortices electrochemically. Stereate-modified, graphite-paste electrodes were used to monitor changes in norepinephrine and dopamine release. Micromolar changes in CA concentration were obtained by stimulation of the eye with nonspecific (strobe) or specific (oriented bars, radial gratings) stimuli. CA release depended on which eye was illuminated. Electrodes passed tangentially through the striate area recorded release following visual stimulation of one eye or the other in succession, and the shift in eye dominance occurred at about 500 microns intervals. The magnitude of CA release was highly correlated with the ocular dominance of neuronal activity measured with tungsten microelectrodes. Light-stimulated release was not recorded in monkey area V2, V4, or somatosensory area 1, but was recorded in cat V2, suggesting that the presence of LGN afferents is associated with CA release. Results are discussed in terms of the role of geniculate activity and the specific role of CAs in cortical information processing. 相似文献
156.
157.
G.E. ORLANDINI S. ZECCHI ORLANDINI A.F. HOLSTEIN R. EVANGELISTI and R. PONCHIETTI 《Andrologia》1987,19(3):315-321
The human prostatic urethra has been investigated by means of scanning electron microscopy. On the posterior wall of the urethra, the seminal colliculus with the orifices of the ejaculatory ducts is clearly detectable. The upper portion of the prostatic urethra shows a typical transitional epithelium with large superficial cells of a ruffled appearance. In the lower portion of the organ (underneath the openings of the ejaculatory ducts), the apical pattern of the cells varies considerably. Four main aspects are recognizable: apices provided with microvilli, dome-shaped apices with an almost smooth surface, large apices with labyrinthic microplicae and ciliated apices. Also, apices showing intermediate characteristics can be noted. The functional significance of the morphological patterns as well as the possibility of a transition among the various types of surface structures are discussed. 相似文献
158.
159.
F Mandelli G De Rossi P Mancini A Alberti A Cajozzo F Grignani P Leoni V Liso M Martelli A Neri 《Journal of clinical oncology》1987,5(3):398-406
Clinical and biological data were evaluated using Desu univariate analyses or Cox multivariate analyses in a series of 1,777 chronic lymphocytic leukemia (CLL) patients from an Italian Cooperative Group. In univariate analyses, age and sex of patients, presence of bone marrow (BM; greater than or equal to 50%), and peripheral blood (PB; greater than or equal to 60,000/microL) lymphocytosis, anemia (hemoglobin [Hb] less than 11 g/dL), thrombocytopenia (less than 100,000/microL), direct Coombs' test positivity, hepatomegaly, splenomegaly, and extent of lymph node involvement were shown to be of significant prognostic value. Multivariate analyses, through a stepwise procedure, showed that the most important prognostic variables are Hb, hepatomegaly, lymph node involvement, PB lymphocytosis, and age and sex of patients. Further covariates would produce an improvement having a nonsignificant P value. Based on the results of multivariate analyses, a four-step staging using the significant variables of the Cox model is proposed. 相似文献
160.
The records of 29 consecutive patients treated by a pure, open, anterior acromioplasty were reviewed retrospectively. Excluded from consideration were patients with the following pathologic diagnoses or histories: (1) previously attempted acromioplasty on the same shoulder; (2) intraoperatively confirmed rotator cuff tear; (3) any surgically treatable biceps tendon or acromioclavicular abnormality; (4) lost to follow-up study. Three different techniques were employed to perform the acromioplasties. The first technique required partial deltoid origin detachment with an osteotome. The second technique spared the deltoid origin, while again using an osteotome to perform the acromioplasty. The third technique also spared the deltoid origin but used a high-speed burr to perform the acromioplasty. Evaluated in terms of patient satisfaction, residual pain, length of convalescence, suboptimal results, and complications, the first technique proved to be the least effective. The second technique produced early, excellent results. The third technique, in which a burr was employed through an intact deltoid origin, was most effective; technically, the method was also relatively simple and reliable. 相似文献