全文获取类型
收费全文 | 978911篇 |
免费 | 78610篇 |
国内免费 | 2427篇 |
专业分类
耳鼻咽喉 | 14238篇 |
儿科学 | 27656篇 |
妇产科学 | 27254篇 |
基础医学 | 139105篇 |
口腔科学 | 28041篇 |
临床医学 | 86909篇 |
内科学 | 188293篇 |
皮肤病学 | 18462篇 |
神经病学 | 80292篇 |
特种医学 | 39850篇 |
外国民族医学 | 171篇 |
外科学 | 154697篇 |
综合类 | 26287篇 |
现状与发展 | 3篇 |
一般理论 | 427篇 |
预防医学 | 77666篇 |
眼科学 | 23113篇 |
药学 | 73027篇 |
2篇 | |
中国医学 | 1762篇 |
肿瘤学 | 52693篇 |
出版年
2018年 | 9863篇 |
2016年 | 8477篇 |
2015年 | 10100篇 |
2014年 | 14552篇 |
2013年 | 22058篇 |
2012年 | 30306篇 |
2011年 | 31959篇 |
2010年 | 18409篇 |
2009年 | 17232篇 |
2008年 | 29820篇 |
2007年 | 32342篇 |
2006年 | 31894篇 |
2005年 | 31668篇 |
2004年 | 30867篇 |
2003年 | 29567篇 |
2002年 | 28511篇 |
2001年 | 36917篇 |
2000年 | 37337篇 |
1999年 | 32091篇 |
1998年 | 10613篇 |
1997年 | 9624篇 |
1996年 | 9546篇 |
1995年 | 9032篇 |
1994年 | 8601篇 |
1992年 | 27375篇 |
1991年 | 26830篇 |
1990年 | 26234篇 |
1989年 | 25302篇 |
1988年 | 23839篇 |
1987年 | 23498篇 |
1986年 | 22379篇 |
1985年 | 21796篇 |
1984年 | 17146篇 |
1983年 | 14734篇 |
1982年 | 9811篇 |
1981年 | 9183篇 |
1980年 | 8468篇 |
1979年 | 17247篇 |
1978年 | 12641篇 |
1977年 | 10669篇 |
1976年 | 9772篇 |
1975年 | 10524篇 |
1974年 | 13034篇 |
1973年 | 12515篇 |
1972年 | 11791篇 |
1971年 | 10944篇 |
1970年 | 10454篇 |
1969年 | 10074篇 |
1968年 | 9053篇 |
1967年 | 8350篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
101.
In 1981 a statewide program supplying free insulin to 3,720 patients of state health clinics was discontinued. We attempted to assess whether this action had an adverse effect medically and financially on those concerned. A computer randomized sample of 351 patients (9%) was studied by personal interview and questionnaire. Information obtained focused on certain events that occurred 18 months before and after the program ceased. Measurements used to determine medical impact were number of hospitalizations, emergency room and physician visits, changes in weight and glucose levels, and episodes of ketoacidosis. Financial impact was measured by cost of hospitalization and physician visits. Our results revealed no significant changes in any of the medical parameters studied except for fasting serum glucose levels above 300 mg/dl, which occurred less frequently after the free insulin program was discontinued. There were fewer hospitalizations, more visits to physicians, and no change in number of emergency room visits after discontinuance of the free program. The overall cost saving was estimated to be +883,558 for the 18-month study period, in addition to the +550,000 the plan had been costing the state. 相似文献
102.
103.
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
104.
Uptake of iodine-123 MIBG by pheochromocytomas, paragangliomas, and neuroblastomas: a histopathological comparison 总被引:2,自引:0,他引:2
J Bomanji D A Levison W D Flatman T Horne P M Bouloux G Ross K E Britton G M Besser 《Journal of nuclear medicine》1987,28(6):973-978
The percentage uptake of [123I]metaiodobenzylguanidine (MIBG) by tumors of the paraganglion system is compared with the number of neurosecretory granules (assessed by both light and electron microscopy) in the subsequently resected tumors in six patients. Iodine-123 MIBG was injected intravenously; the tumor uptake of [123I]MIBG varied between 0.001% and 0.14% of the injected dose per gram of tumor tissue at 22 hr. The number of neurosecretory granules in tissue sections was scored on a scale of I-III. A direct proportional correlation was found between the percentage uptake of [123I]MIBG by the tumor and the number of neurosecretory granules in the tissue sections but not with plasma or urinary catecholamines. This technique for imaging reflects the storage status of the tumor better than plasma and urinary catecholamine measurements. 相似文献
105.
106.
A HIGH FREQUENCY OF INHERITED DEFICIENCY OF COMPLEMENT COMPONENT C4 IN DARWIN ABORIGINES 总被引:2,自引:0,他引:2
Abstract A high frequency of serum complement component C4A deficiency may explain the higher prevalence and greater severity of systemic lupus erythematosus reported in Australian Aborigines. Inherited deficiencies of serum complement components C4A, C4B, and C2 were examined in two Australian Aboriginal populations from Darwin and Alice Springs and compared with the prevalence of complement deficiencies in white Australian blood donors. The frequency of C4A deficiency alleles was 29% in Darwin Aborigines compared with 12% in Alice Springs and 17% in Canberra blood donors. Partial C4B deficiency was also higher in Darwin Aborigines than in the other populations. Inherited deficiency of serum complement component C2 was not observed. 相似文献
107.
108.
109.
Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems 总被引:1,自引:0,他引:1
Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 +/- 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10(-6)-10(-4) M) of kainic acid (10(-8)-10(-6) M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10(-4) M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not by electrical stimulation. The addition of GABA (10(-5)-10(-3) M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10(-6)-10(-4) M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation. 相似文献
110.