全文获取类型
收费全文 | 705887篇 |
免费 | 48879篇 |
国内免费 | 1305篇 |
专业分类
耳鼻咽喉 | 9167篇 |
儿科学 | 23268篇 |
妇产科学 | 17608篇 |
基础医学 | 110422篇 |
口腔科学 | 19955篇 |
临床医学 | 63758篇 |
内科学 | 134342篇 |
皮肤病学 | 16159篇 |
神经病学 | 49434篇 |
特种医学 | 25737篇 |
外国民族医学 | 76篇 |
外科学 | 104483篇 |
综合类 | 14819篇 |
现状与发展 | 2篇 |
一般理论 | 160篇 |
预防医学 | 51387篇 |
眼科学 | 16318篇 |
药学 | 53945篇 |
3篇 | |
中国医学 | 2359篇 |
肿瘤学 | 42669篇 |
出版年
2019年 | 5431篇 |
2018年 | 7859篇 |
2017年 | 6107篇 |
2016年 | 6821篇 |
2015年 | 7549篇 |
2014年 | 10266篇 |
2013年 | 15383篇 |
2012年 | 20490篇 |
2011年 | 21492篇 |
2010年 | 12725篇 |
2009年 | 11935篇 |
2008年 | 19989篇 |
2007年 | 21505篇 |
2006年 | 21900篇 |
2005年 | 20444篇 |
2004年 | 19986篇 |
2003年 | 18939篇 |
2002年 | 18450篇 |
2001年 | 36331篇 |
2000年 | 36897篇 |
1999年 | 30380篇 |
1998年 | 7879篇 |
1997年 | 6663篇 |
1996年 | 6971篇 |
1995年 | 6628篇 |
1994年 | 6099篇 |
1993年 | 5590篇 |
1992年 | 22969篇 |
1991年 | 22925篇 |
1990年 | 22312篇 |
1989年 | 22078篇 |
1988年 | 20040篇 |
1987年 | 19420篇 |
1986年 | 18469篇 |
1985年 | 17306篇 |
1984年 | 12697篇 |
1983年 | 10741篇 |
1982年 | 5922篇 |
1979年 | 11520篇 |
1978年 | 8130篇 |
1977年 | 6833篇 |
1976年 | 6594篇 |
1975年 | 7268篇 |
1974年 | 8499篇 |
1973年 | 8141篇 |
1972年 | 7658篇 |
1971年 | 7128篇 |
1970年 | 6878篇 |
1969年 | 6307篇 |
1968年 | 5783篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Spectral analysis of the electroencephalogram in neonatal rats chronically treated with the NMDA antagonist MK-801. 总被引:1,自引:0,他引:1
J A Gorter M Veerman M Mirmiran N P Bos M A Corner 《Brain research. Developmental brain research》1991,64(1-2):37-41
In order to study the involvement of NMDA-receptor activation in brain development, rat pups were chronically treated with the non-competitive NMDA antagonist MK-801 during the neonatal period. We recorded the cortical EEG at various vigilance states throughout the treatment period. Spectral analysis of the EEG showed reduced power in the delta (delta) frequency range (1.5-4 Hz) during quiet sleep and less power in the theta (theta) range (4-7 Hz) during REM-sleep in MK-801 animals than in controls. No significant differences were found for the total time spent in each of the different vigilance states. We conclude that chronic MK-801 treatment probably causes a developmental retardation in state-related brain activities. 相似文献
73.
74.
75.
The administration of prophylactic antibiotics in surgery is appropriate for many patients. Data have shown extending the duration of prophylaxis beyond 48 hours does not lower the rate of postoperative-infection. The purpose of this project was to concurrently assess the duration of prophylactic antibiotic use. A total of 95 patients were monitored over 3 weeks. Eighty patients (84.2%) received antimicrobial therapy. In 23 of these patients (28.75%) the duration of antibiotic administration was longer than 2 days without clinical or microbiological evidence of infection. In 5 other patients only postoperative antibiotics were prescribed. The cost difference between the actual duration of antibiotic administration and 2 days of the same regimen was +1,364.58. Extrapolating for one year, it can be estimated that antibiotic costs could be reduced about +23,600. Pharmacists can focus on the duration of antibiotic prophylaxis as a cost containment measure. 相似文献
76.
Endogenous opioids are present in neurons of the vagus and the intrinsic nervous system and they are colocalized with gastrin in antral G-cells. This raises the possibility that endogenous opioids modulate gastrin release. Stimulation of both cervical vagi (10V, 5Hz, 5ms) elicited an increase of arterial plasma gastrin levels at intragastric pH7 or pH2. The response at pH2 was 30% of that at luminal pH7. Atropine reduced vagally stimulated gastrin levels substantially. At luminal pH2 the small residual noncholinergic response was mediated neither by adrenergic mechanisms nor by endogenous opioids. At luminal pH 7 adrenergic blockade with phentolamine and propranolol reduced vagally stimulated gastrin by 60%. In the presence of atropine adrenergic blockade elicited only a small inhibitory effect suggesting that vagal activation of adrenergic mechanisms depends on atropine-sensitive cholinergic pathways. Blockade of opiate receptors by naloxone had no effect on vagal gastrin release, however, the noncholinergic gastrin response was reduced significantly by naloxone, suggesting that cholinergic mechanisms normally restrain activation of endogenous opioids during vagal stimulation. Naloxone had no effect on the noncholinergic, nonadrenergic stimulation of gastrin levels. These data suggest that endogenous opioids can contribute to vagal gastrin release provided the cholinergic restraint is blocked and adrenergic mechanisms stimulate endogenous opioids. In conclusion a major role of endogenous opioids in the regulation of vagal gastrin release can not be detected. 相似文献
77.
N Leygraf 《Fortschritte der Neurologie-Psychiatrie》1987,55(7):231-237
The article presents part of the results of a Federal German investigation of psychiatric confinement in cases of delinquency in accordance with German law. Among the 674 inmates whose case history could be included in the investigation, there was a predominance of alcohol dependence in two-thirds of them. Confinement occurred mostly only after addiction and delinquencies had been going on for a long time. In more than one-half of the patients no attempt had previously been made to treat and manage their alcohol addiction. Every fourth patient is confined without first consulting a psychiatric expert. Basing on sociobiographic characteristics it is possible to form two contrasting groups of patients: a smaller group where addiction has set in early and delinquency at a late stage, and a larger one with early onset of delinquency developing parallel to the abuse of alcohol. This leads to conclusions with regard to the development of specific treatment guidelines. 相似文献
78.
79.
80.
S B Wieslander B T Mortensen L Binderup N I Nissen 《European journal of haematology》1987,39(1):35-38
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily. 相似文献