全文获取类型
收费全文 | 1673篇 |
免费 | 73篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 45篇 |
妇产科学 | 13篇 |
基础医学 | 193篇 |
口腔科学 | 26篇 |
临床医学 | 267篇 |
内科学 | 558篇 |
皮肤病学 | 10篇 |
神经病学 | 42篇 |
特种医学 | 224篇 |
外科学 | 94篇 |
综合类 | 25篇 |
预防医学 | 120篇 |
眼科学 | 9篇 |
药学 | 96篇 |
肿瘤学 | 61篇 |
出版年
2023年 | 5篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 16篇 |
2019年 | 16篇 |
2018年 | 27篇 |
2017年 | 20篇 |
2016年 | 14篇 |
2015年 | 17篇 |
2014年 | 37篇 |
2013年 | 36篇 |
2012年 | 51篇 |
2011年 | 57篇 |
2010年 | 49篇 |
2009年 | 69篇 |
2008年 | 87篇 |
2007年 | 103篇 |
2006年 | 78篇 |
2005年 | 83篇 |
2004年 | 55篇 |
2003年 | 51篇 |
2002年 | 36篇 |
2001年 | 38篇 |
2000年 | 44篇 |
1999年 | 41篇 |
1998年 | 61篇 |
1997年 | 54篇 |
1996年 | 46篇 |
1995年 | 38篇 |
1994年 | 27篇 |
1993年 | 40篇 |
1992年 | 35篇 |
1991年 | 29篇 |
1990年 | 24篇 |
1989年 | 46篇 |
1988年 | 37篇 |
1987年 | 43篇 |
1986年 | 33篇 |
1985年 | 28篇 |
1984年 | 23篇 |
1983年 | 24篇 |
1982年 | 18篇 |
1981年 | 22篇 |
1980年 | 24篇 |
1979年 | 8篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 12篇 |
1975年 | 9篇 |
1968年 | 4篇 |
排序方式: 共有1787条查询结果,搜索用时 10 毫秒
101.
van der Werf TS Zijlstra JG Ligtenberg JJ Tulleken JE 《Nederlands tijdschrift voor geneeskunde》2005,149(14):742-746
The decision to move from curative treatment to palliative care in the intensive-care situation is less related to morals and ethics than it is to the assessment of medical issues, professionalism, communication and orchestration. Treatment should be considered medically pointless if, in the view of the treating physicians, it does not offer realistic chance to return to a meaningful life. Continuing futile care can be seen as disrespectful, both to the patient, his partner and the family, as well as to the members of the ICU team. Intensivists are responsible for withholding or withdrawing life support to patients in whom further life support is considered futile and who are unable to express their wishes due to critical illness and sedation. The intensivist typically makes this type of decision after a period in which medical and other information has been collected and after intensive discussions with other medical professionals as well as the partner and family. This is based on the trust that is built up through their skill, attitude and behaviour and that is perpetuated in a continuing process of intensive communication. Conflicts should be prevented, or at least recognised early and discussed. Ifa conflict is ongoing then it should be tackled by planning a number of consecutive consultations. 相似文献
102.
Zijlstra F 《Nederlands tijdschrift voor geneeskunde》2007,151(18):1005-1007
The March 8, 2007-issue of the New England Journal of Medicine contained 5 original articles, 2 commentaries and 1 editorial on drug-eluting coronary stents versus bare metal stents. Over the past 5 years, multiple randomised, controlled trials have shown that drug-eluting stents reduce recurrent stenosis and the need for additional revascularisation procedures. Drug-eluting stents are now used in a large proportion of percutaneous coronary interventions. Following publications reporting a risk of late thrombosis with sudden occlusion, the promises and uncertainties regarding the benefits and risks are now heavily debated. It can be concluded that these first-generation drug-eluting stents, provided that they are used for indications in accordance with the randomised trials, result in a clear reduction in the need for additional revascularisation procedures without an effect on long-term case fatality and myocardial infarction. There is a small but serious risk of sudden thrombosis and occlusion. The task for the future will be to develop stents that do reduce recurrent stenosis but allow a normal endothelisation of the treated coronary artery segment. When drug-eluting stents have reached that stage, they will be clearly advantageous. 相似文献
103.
N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性 总被引:1,自引:0,他引:1
报道25个N-甲基-N-(α-取代萘甲基)取代苄胺类化合物的合成及抗真菌活性。抑菌测试结果表明,目标化合物对于8种试验菌种均有不同程度的抑菌活性,化合物6,7,8,10,11和21等活性为naftifine的4~20倍,化合物8,10,11和21等活性为butenafine的2~10倍,化合物8,9,10,11和21等对Sporotrichumschenckii及Aspergillusfumigatus的活性为clotrimazole的8~15倍,化合物7,8,9和21等对Cryptoccocusneoformans亦表现出较高活性,MIC为0.31~1.25μg·ml-1。 相似文献
104.
Nicolien Zijlstra Suzanne M ten Dam Paul J M Hulshof Colette Ram Gertien Hiemstra Nicole M de Roos 《Nutrition in clinical practice》2007,22(2):250-255
BACKGROUND: Energy imbalance in critically ill, mechanically ventilated patients may lead to medical complications. The nutrition care team needs accurate, noninvasive, rapid methods to estimate energy requirements. We investigated whether brief measurements of indirect calorimetry at any time of the day would give valid estimates of 24-hour energy expenditure (EE). METHODS: EE of 12 mechanically ventilated critically ill patients (6 men, 6 women, mean +/- SD age 67 +/- 18 years, weight 70.2 +/- 8.8 kg) was recorded every minute during 24 hours by indirect calorimetry. All patients were continuously fed enteral nutrition. RESULTS: Mean +/- SD EE was 1658 +/- 279 kcal/d (6941 +/- 1167 kJ/d). Within patients, EE during the day fluctuated by 234 kcal in the most constant patient to 1190 kcal in the least constant patient, with a mean fluctuation of 521 kcal (12 patients). No statistically significant difference (p = .53) in mean EE between morning (6-12 hours, 1676 kcal), afternoon (12-18 hours, 1642 kcal), evening (18-24 hours, 1658 kcal), and night (0-6 hours, 1655 kcal) was found. A 2-hour instead of a 24-hour measurement resulted in a maximal error of 128 kcal (536 kJ), which was <10% of the average EE. The maximal error decreased with longer time intervals. CONCLUSIONS: In mechanically ventilated critically ill patients, 24-hour indirect calorimetry measurements can be replaced by shorter (>/=2 hours) measurements. Time of day did not affect EE. 相似文献
105.
106.
K-Ⅱ系k阿片激动剂U-50488的同类物。通过部分离体和整体实验比较了K-Ⅱ与U-50488的药理作用。实验发现,K-Ⅱ抑制电刺激兔输精管收缩的IC50值为0.42 nmol/L,U-50488为26.5 nmol/L;K-Ⅱ抑制小鼠运动功能(横筛法)的ED50值为1.7 mg/g,U-50488为15.3 mg/kg;K-Ⅱ的小鼠LD50值为152.5 mg/kg,U-50488为118.4 mg/g;K-Ⅱ明显降低小鼠自发活动的作用比U-50488强5倍。结果表明,K-Ⅱ是一个药理作用较U-50488强的k受体激动剂。 相似文献
107.
108.
George Groeneweg Frank JPM Huygen Sjoerd P Niehof Feikje Wesseldijk Johannes BJ Bussmann Fabienne C Schasfoort Dirk L Stronks Freek J Zijlstra 《BMC musculoskeletal disorders》2008,9(1):143
Background
This double-blind, randomized, controlled trial investigated the effect of the phosphodiesterase-5 inhibitor tadalafil on the microcirculation in patients with cold Complex Regional Pain Syndrome (CRPS) in one lower extremity. 相似文献109.
J W Fijen T S van der Werf J J Ligtenberg J E Tulleken J G Zijlstra 《The Netherlands journal of medicine》1999,55(1):23-28
The differential diagnosis of bilateral interstitial pulmonary infiltrates in immunocompromised patients is very extensive. We describe two immunocompromised patients with diffuse pulmonary infiltrative changes. Bronchoscopic bronchoalveolar lavage after orotracheal intubation using topical anaesthesia combined with mild sedation in an ICU setting is safe in critically ill patients and often yields a conclusive diagnosis. 相似文献
110.
Siebold S. N. de Graaf Arie Nijmeijer Willem G. Zijlstra 《Pediatric hematology and oncology》1986,3(4):311-318
Experimental work on the mechanisms of acute doxorubicin-induced cardiotoxicity may contribute to a better understanding of the clinical problem of cardiac failure after treatment with anthracycline derivatives. We studied aortic pressure and heart rate continuously for 1 h following a bolus injection of doxorubicin (1 mg/kg) in 7 dogs. In contrast with previous studies in intact animals, no anesthesia was used in order to eliminate possible interactions of doxorubicin with other drugs. One minute after doxorubicin injection a severe hypotension was observed, the average nadir in systolic and diastolic pressure being 62% and 42% of initial values. Surprisingly, the decrease in arterial blood pressure was not accompanied by cardiac acceleration. Doxorubicin, apparently interferes with the normal regulation of heart rate through the baroreceptor control system. Although several theories have been put forward regarding the mechanisms governing acute anthracycline cardiotoxicity, our knowledge of the phenomenon is still incomplete. 相似文献