全文获取类型
收费全文 | 1911篇 |
免费 | 113篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 82篇 |
妇产科学 | 55篇 |
基础医学 | 162篇 |
口腔科学 | 59篇 |
临床医学 | 386篇 |
内科学 | 406篇 |
皮肤病学 | 22篇 |
神经病学 | 90篇 |
特种医学 | 266篇 |
外科学 | 91篇 |
综合类 | 19篇 |
预防医学 | 114篇 |
眼科学 | 9篇 |
药学 | 89篇 |
中国医学 | 1篇 |
肿瘤学 | 174篇 |
出版年
2023年 | 8篇 |
2022年 | 9篇 |
2021年 | 18篇 |
2020年 | 12篇 |
2019年 | 12篇 |
2018年 | 21篇 |
2017年 | 27篇 |
2016年 | 27篇 |
2015年 | 27篇 |
2014年 | 47篇 |
2013年 | 59篇 |
2012年 | 50篇 |
2011年 | 45篇 |
2010年 | 63篇 |
2009年 | 65篇 |
2008年 | 62篇 |
2007年 | 61篇 |
2006年 | 69篇 |
2005年 | 52篇 |
2004年 | 64篇 |
2003年 | 53篇 |
2002年 | 52篇 |
2001年 | 51篇 |
2000年 | 41篇 |
1999年 | 61篇 |
1998年 | 57篇 |
1997年 | 82篇 |
1996年 | 55篇 |
1995年 | 48篇 |
1994年 | 59篇 |
1993年 | 61篇 |
1992年 | 36篇 |
1991年 | 35篇 |
1990年 | 34篇 |
1989年 | 59篇 |
1988年 | 57篇 |
1987年 | 42篇 |
1986年 | 52篇 |
1985年 | 46篇 |
1984年 | 31篇 |
1983年 | 34篇 |
1982年 | 28篇 |
1981年 | 25篇 |
1980年 | 22篇 |
1979年 | 14篇 |
1978年 | 11篇 |
1977年 | 15篇 |
1976年 | 13篇 |
1975年 | 20篇 |
1968年 | 5篇 |
排序方式: 共有2027条查询结果,搜索用时 15 毫秒
1.
Two experiments examined the ingestive responses of streptozotocin-diabetic rats fed low-fat or high-fat diets to glucose, fructose, sucrose and maltose solutions in brief (30 min) intake tests. In Experiment 1, one-bottle acceptability tests were used whereas two-bottle preference tests were used in Experiment 2. Three main findings resulted from these studies. Firstly, diabetic rats fed the low-fat diet displayed a reduced acceptance of and preference for all concentrated sugar solutions. Secondly, glucose consumption patterns of diabetic rats fed the low-fat diet were distinctly different from their responses to the other sugars. Thirdly feeding high-fat diets, either high or low in carbohydrate, normalized the responses of diabetic rats to the sugar solutions. The results suggest that feeding high-fat diets to diabetic rats normalizes their responses to sugar solutions because of reductions in hunger and thirst associated with the provision of a utilizable source of calories and an improvement in body fluid balance. 相似文献
2.
Many women report an increased frequency of headaches around the time of menses. For some women, these headaches are more severe, of longer duration, and lead to greater disability than those occurring at other times in the menstrual cycle. A headache diary is critical to properly diagnose menstrual migraine (MM) by prospectively documenting headache days, severity of headache, and the headaches' relationship to menses. In women with diagnosed MM, acute treatment has been proven to be effective in randomized clinical trials. For those women who have predictable periods and may require preventive therapy, short-term prevention is a reasonable approach due to the predictability of MM. Although several agents (eg, naproxen sodium, magnesium, triptans) have been evaluated for prevention of MM, all but triptans have been assessed in small trials of between 20 and 35 women. Naratriptan, frovatriptan, and, most recently, zolmitriptan have been proven effective in preventing MM. Triptans are generally well tolerated, and the long-term safety of these agents is currently being evaluated. The flexibility of using acute and preventive therapy allows physicians to tailor treatment of MM and meet the needs of individual patients. 相似文献
3.
4.
The potential antipsychotic activity of the partial dopamine receptor agonist (+)N-0437 总被引:1,自引:0,他引:1
The (+) enantiomer of the very potent and selective dopamine D-2 agonist, 2-(N-propyl-N-2-thienylethylamino)-5-hydroxytetralin (N-0437), displays partial agonistic activity at dopamine D-2 receptors. In this study (+)N-0437 was investigated for its antagonistic activity at postsynaptic DA receptors in four behavioural tests which are commonly used to evaluate potential neuroleptic activity, i.e. d-amphetamine-induced stereotypy, passive avoidance responding, intracranial self-stimulation behaviour, and catalepsy. (+)N-0437 (25-50 mumol/kg) was active in the first three models, but did not cause catalepsy. Haloperidol, which was used as a reference compound for classical DA antagonists, showed clear activity in all four models at low doses (0.5-1.0 mumol/kg). (-)N-0437, a full D-2 agonist, displayed no activity in these behavioural models. These results suggest that (+)N-0437 could be used to examine the hypothesis that the use of partial agonists could provide a new treatment for schizophrenia. 相似文献
5.
Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk 总被引:1,自引:0,他引:1
Olmer M; Renucci JE; Planells R; Bouchouareb D; Purgus R 《Nephrology, dialysis, transplantation》1997,12(4):691-693
Conventional risk factors have very low predictive power in identifying
haemodialysis patients at high risk of vascular accidents. A role for
apolipoprotein E isotypes was looked for in a small, but rigorously
defined, cohort of longterm haemodialysis patients. In individuals with
high vascular risk, as identified by higher common carotid intima/media
thickness, we found an excess of apolipoprotein E4 alleles. This
preliminary result requires confirmation in large patient cohorts.
相似文献
6.
7.
8.
Hodgkin disease: CT of the thymus 总被引:2,自引:0,他引:2
The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement. 相似文献
9.
Solitary bronchioloalveolar carcinoma: CT criteria 总被引:14,自引:0,他引:14
Kuhlman JE; Fishman EK; Kuhajda FP; Meziane MM; Khouri NF; Zerhouni EA; Siegelman SS 《Radiology》1988,167(2):379-382
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis. 相似文献
10.