全文获取类型
收费全文 | 7722篇 |
免费 | 541篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 224篇 |
妇产科学 | 175篇 |
基础医学 | 1233篇 |
口腔科学 | 196篇 |
临床医学 | 764篇 |
内科学 | 1616篇 |
皮肤病学 | 201篇 |
神经病学 | 580篇 |
特种医学 | 438篇 |
外科学 | 772篇 |
综合类 | 173篇 |
一般理论 | 4篇 |
预防医学 | 721篇 |
眼科学 | 248篇 |
药学 | 493篇 |
中国医学 | 14篇 |
肿瘤学 | 395篇 |
出版年
2021年 | 101篇 |
2019年 | 88篇 |
2018年 | 112篇 |
2017年 | 83篇 |
2016年 | 83篇 |
2015年 | 95篇 |
2014年 | 125篇 |
2013年 | 250篇 |
2012年 | 260篇 |
2011年 | 288篇 |
2010年 | 205篇 |
2009年 | 185篇 |
2008年 | 243篇 |
2007年 | 279篇 |
2006年 | 309篇 |
2005年 | 296篇 |
2004年 | 303篇 |
2003年 | 293篇 |
2002年 | 254篇 |
2001年 | 195篇 |
2000年 | 186篇 |
1999年 | 179篇 |
1998年 | 149篇 |
1997年 | 151篇 |
1996年 | 147篇 |
1995年 | 118篇 |
1994年 | 131篇 |
1993年 | 133篇 |
1992年 | 146篇 |
1991年 | 155篇 |
1990年 | 148篇 |
1989年 | 155篇 |
1988年 | 151篇 |
1987年 | 142篇 |
1986年 | 144篇 |
1985年 | 107篇 |
1984年 | 121篇 |
1983年 | 81篇 |
1982年 | 88篇 |
1981年 | 85篇 |
1980年 | 110篇 |
1979年 | 78篇 |
1978年 | 92篇 |
1977年 | 96篇 |
1976年 | 87篇 |
1975年 | 68篇 |
1974年 | 63篇 |
1972年 | 64篇 |
1965年 | 66篇 |
1960年 | 80篇 |
排序方式: 共有8306条查询结果,搜索用时 0 毫秒
1.
2.
Objective
The aim of this paper is to study the opportunity costs (OC) that are involved in being a caregiver and to compare them with the direct costs assumed by the State and the families. We evaluate direct cost (those that imply a payment-out-of-pocket) and indirect cost (those that imply a dedication in time). We hypothesized that costs increase with the severity of the dementia, with the educational level and active occupational situation of caregiver. They are greater if the caregiver is male, but if the patient and caregiver cohabit they are reduced.Method
778 surveys were analyzed. Data was collected using a questionnaire specifically designed for the purpose, with the collaboration of Alzheimer's Diseases Associations in Andalusia (Spain). For the indirect cost, we used the reveal preferences method. For the comparison between groups an ANOVA and a MANOVA was done.Results
The hypotheses were confirmed. The OC exponentially increases with severity. More than 55% of costs are assumed by families. Occupied people have higher educational level and incomes and contract more external support. Costs are significantly higher for male caregivers. Cohabiting reduces all kinds of costs.Conclusions
The relationship between educational level and employment situation lead to think that if these variables are greater more people will seek professional support. Cultural reasons still maintain women as main caregivers for all educational levels. The existence of these informal caregivers as the main care providers is a saving for the State, and a brake for the development of professional supply. 相似文献3.
4.
K. KARNICKI† R. D. MCBANE II † R. S. MILLER† R. J. Leadley JR ¶ J. MORSER W. G. OWEN†‡ J. H. CHESEBRO§ 《Journal of thrombosis and haemostasis》2004,2(12):2162-2169
BACKGROUND/OBJECTIVE: The efficacy of a direct factor (F)Xa inhibitor, ZK-807834, was compared with indirect inhibition by enoxaparin for inhibition and deaggregation of acute platelet-rich thrombi in a well-characterized porcine carotid injury model. METHODS: A crush injury was performed on a randomly chosen carotid artery and the thrombus allowed to propagate for 30 min. Pigs then received intravenous drug for 35 min: ZK-807834-Dose 1 (40 microg kg(-1) bolus + 1.5 microg kg(-1) min(-1) infusion, n=6); ZK-807834-Dose 2 (20 microg kg(-1) bolus + 0.75 microg kg(-1) min(-1) infusion; n=6); enoxaparin (1 mg kg(-1) bolus; n=6); or saline (n=6). Five minutes after drug initiation, the contralateral artery was injured. Thrombus size was monitored by scintillation detection of autologous 111In-platelets. RESULTS: The prothrombin time ratio was 2.2 +/- 0.1; 1.4 +/- 0.3; 1.2 +/- 0.9 and 1.1 +/- 0.2, respectively. ZK-807834-Dose 1 significantly inhibited carotid platelet deposition (525 +/- 226 x 10(6) cm(-2); P = 0.008), whereas ZK-807834-Dose 2 (2325 +/- 768) and enoxaparin (1236 +/- 383) were not different from saline (2776 +/- 642). Thrombus deaggregation was greatest for animals receiving ZK-807834-Dose 1 (473 +/- 185). Neither ZK-807834-Dose 2 (1588 +/- 480) nor enoxaparin (1618 +/- 686) was different from saline control (2222 +/- 598). CONCLUSIONS: Direct FXa inhibition with ZK-807834, at a prothrombin time ratio of 2.2, effectively inhibits thrombosis and promptly deaggregates thrombi induced by arterial injury. In contrast, indirect FXa inhibition with enoxaparin was ineffective. 相似文献
5.
6.
8.
SOLOMON HOWARD M.; FERENZ RAYANNE L.; KENNEDY GERALD L. JR.; STAPLES ROBERT E. 《Toxicological sciences》1991,16(3):414-422
Developmental Toxicity of Dimethylacetamide by Inhalation inthe Rat. SOLOMON, H. M., FERENZ, R. L., KENNEDY, G. L., ANDSTAPLES, R. E. (1991). Fundam. Appl. Toxicol. 16, 414422.Dimethylacetamide (DMAC) is a widely used industrial solvent.It has been reported to be teratogenic when given to rats byinjection or following dermal application. Most of these studiesemployed large single doses and did not examine both the fetaland the maternal response. In this study, groups of pregnantCrl:CD rats were exposed to 32, 100, or 282 ppm DMAC by inhalationfor 6 hr/day from Days 6 through 15 of gestation (day on whichcopulation plug was detected was termed Day 1G). A control groupof chambered pregnant rats was exposed simultaneously to aironly. All female rats were euthanized on Day 21G. At 282 ppm,both maternal weight gain during the exposure period and fetalweight were significantly decreased and accompanied by a significantdose-response trend. These effects were not seen in rats inhalingeither 32 or 100 ppm. Fetal resorptions were not increased inany of the groups exposed to DMAC. Fetal incidences of external,visceral, or skeletal variations and malformations were similarbetween the test and control groups. Therefore, both fetal andmaternal toxicity were noted at 282 ppm and the no-observedadverse-effect level under these experimental conditions was100 ppm for both the dam and the conceptus. DMAC was not demonstratedto produce malformations in the rat fetus even at a level thatwas toxic to the dam. 相似文献
9.
10.
D G Omdal D E Baird B S Burton W W Goodhue Jr E M Giddens 《AJNR. American journal of neuroradiology》1997,18(5):977
We describe a myelolipoma of the thoracic spine in a patient with gradual and progressive myelopathy. MR imaging showed this predominately fatty lesion to be extradural in location. 相似文献