全文获取类型
收费全文 | 11032篇 |
免费 | 834篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 248篇 |
妇产科学 | 249篇 |
基础医学 | 2086篇 |
口腔科学 | 143篇 |
临床医学 | 1182篇 |
内科学 | 2299篇 |
皮肤病学 | 217篇 |
神经病学 | 731篇 |
特种医学 | 429篇 |
外科学 | 1537篇 |
综合类 | 91篇 |
一般理论 | 2篇 |
预防医学 | 702篇 |
眼科学 | 130篇 |
药学 | 1045篇 |
中国医学 | 11篇 |
肿瘤学 | 705篇 |
出版年
2023年 | 70篇 |
2022年 | 68篇 |
2021年 | 166篇 |
2020年 | 146篇 |
2019年 | 202篇 |
2018年 | 251篇 |
2017年 | 220篇 |
2016年 | 214篇 |
2015年 | 244篇 |
2014年 | 313篇 |
2013年 | 428篇 |
2012年 | 562篇 |
2011年 | 510篇 |
2010年 | 290篇 |
2009年 | 305篇 |
2008年 | 458篇 |
2007年 | 473篇 |
2006年 | 432篇 |
2005年 | 401篇 |
2004年 | 385篇 |
2003年 | 331篇 |
2002年 | 310篇 |
2001年 | 317篇 |
2000年 | 318篇 |
1999年 | 301篇 |
1998年 | 146篇 |
1997年 | 107篇 |
1996年 | 124篇 |
1995年 | 91篇 |
1994年 | 116篇 |
1993年 | 91篇 |
1992年 | 239篇 |
1991年 | 233篇 |
1990年 | 272篇 |
1989年 | 283篇 |
1988年 | 255篇 |
1987年 | 220篇 |
1986年 | 236篇 |
1985年 | 236篇 |
1984年 | 176篇 |
1983年 | 157篇 |
1982年 | 89篇 |
1981年 | 83篇 |
1979年 | 111篇 |
1978年 | 77篇 |
1976年 | 64篇 |
1975年 | 71篇 |
1974年 | 99篇 |
1973年 | 91篇 |
1972年 | 69篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
33.
H S Thomsen K Rasmussen F Burcharth S L Nielsen 《Acta radiologica (Stockholm, Sweden : 1987)》1988,29(1):138-140
The perfusion of two pancreatic transplants were examined three times a week for the first five postoperative weeks by intravenous angiography using 99Tcm-pertechnetate. Worsening of the perfusion always preceded or was associated with deterioration of the pancreatic function. Accordingly, radionuclide angiography may have an important place in the systematic monitoring of pancreatic transplants in the critical postoperative period. 相似文献
34.
O. May M.D. H. Kirkegaard Nielsen M. U. Werner 《Acta anaesthesiologica Scandinavica》1988,32(3):239-243
A new and simple acceleration transducer (ACT)–based system of neuromuscular monitoring has recently been introduced. The precision of this transducer has been evaluated as compared to a conventional force displacement transducer (FDT) in the present study. Ten progressions of spontaneous recovery from atracurium–induced block with simultaneous measurements using the ACT on one hand and the FDT on the other were studied. Five individuals undergoing elective surgery in modified neurolept anaesthesia and one ICU–patient requiring prolonged neuromuscular blockade, sedated with pentobarbital, were included. Measurements were carried out on the latter patient on 5 consecutive days. Train–of–four (TOF) stimulation was used, readings were given in twitch heights (TH) (Tl/control value), and when four responses were obtained in TOF–ratios (T4/T1). Linearity was achieved after logit–transformation and the values regressed on time for each progression of recovery. Analysis of variance was applied to the regressions for the TH and TOF–ratio readings of each transducer. No significant differences were found, either between variation due to differences between slopes or variation due to technical error between the two transducers. The study indicates that the ACT is equal to the FDT with regard to precision in clinical recordings on atracuriumrelaxed individuals. 相似文献
35.
B Kappel J Nielsen K Brogaard Hansen M Mikkelsen A J Therkelsen 《British journal of obstetrics and gynaecology》1987,94(1):50-54
The clinical significance of placental perforation and blood-stained amniotic fluid was studied in a group of 7238 Danish women undergoing mid-trimester amniocentesis for prenatal diagnosis under ultrasound guidance. The risk of spontaneous abortion was significantly increased both in pregnancies where the placenta was perforated and in those with blood-stained amniotic fluid. The risk estimate nearly doubled after placental perforation and more than doubled with a bloody tap. It is concluded that for women at relatively low risk of a fetal genetic abnormality, the indication of the amniocentesis should be reconsidered if a placental perforation is unavoidable. 相似文献
36.
B. W. Nielsen T. Bjerke T. M. E. Damsgaard T. Herlin K. Thestrup-Pedersen P. O. Schiøtz 《Inflammation research》1992,35(3-4):170-178
Increased osmotic pressure has been reported to cause non-cytotoxic histamine release (HR) from human basophils, as well as a potentation of HR induced by anti-IgE. In this study, the effects of hyperosmolar Na–K-acetate (300–600 mOsm/kg H2O) on HR was studied in washed human blood cells from newborns, adult volunteers and patients with severe atopic dermatitis. These three patient groups represesented 3 very distinct populations with respect to total plasma IgE content, medians were <0.2 IU/ml, 20.5 IU/ml and 2508 IU/ml, respectively. Increasing osmolarity to 500 mOsm/kg H2O caused little HR in the absence of other stimuli, whereas at 600 mOsm/kg H2O a significant increase in spontaneous HR was seen. The HR induced by anti-IgE and Concanavalin A, acting through the IgE-receptor, was increased approximately twofold at 500 mOsM/kg H2O. Responses were highly correlated to results at 300 mOsm/kg H2O. The use of 600 mOsm/kg H2O buffers caused a further increase in most, but not all blood samples. The potentiation of IgE-receptor-mediated HR when using hyperosmolar media was clearly independent of plasma IgE contents, and did not change the concentration-response to anti-IgE. In contrast, HR induced by the IgE-receptor-independent stimuli, Formyl-met-leu-phe and calcium ionophore A 23187, were not enhanced at all by incrased osmotic pressure. We conclude, that hyperosomolar media selectively enhance IgE-receptor-mediated HR. The use of hyperosmolar media may therefore be beneficial in a diagnostic application of washed blood HR assays use in allergy diagnosis. 相似文献
37.
A prospective, consecutive study of the aetiology of treatment-associated diarrhoea was conducted in 25 patients with disseminated germ cell cancer treated with intensive chemotherapy. Clostridium difficile was isolated in 45% of the diarrhoea episodes, which makes this species the most important bacterial pathogen in the development of clinically significant diarrhoea in this group of immunocompromised patients. 相似文献
38.
39.
J. Viby Mogensen M.D. Ph.D. E. Jensen M. Werner H. Kirkegaard Nielsen 《Acta anaesthesiologica Scandinavica》1988,32(1):45-48
A new method for monitoring neuromuscular function based on measurement of acceleration is presented. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. For measurement of acceleration, a piezo-electric ceramic wafer was used. When this piezo electrode was fixed to the thumb, an electrical signal proportional to the acceleration was produced whenever the thumb moved in response to nerve stimulation. The electrical signal was registered and analysed in a Myograph 2000 neuromuscular transmission monitor. In 35 patients anaesthetized with halothane, train-of-four ratios measured with the accelerometer (ACT-TOF) were compared with simultaneous mechanical train-of-four ratios (FDT-TOF). Control ACT-TOF ratios were significantly higher than control FDT-TOF ratios: 116 +/- 12 and 98 +/- 4 (mean +/- s.d.), respectively. In five patients not given any relaxant during the anaesthetic procedure (20-60 min), both responses were remarkably constant. In 30 patients given vecuronium, a close linear relationship was found during recovery between ACT-TOF and FDT-TOF ratios. It is concluded that the method fulfils the basic requirements for a simple and reliable clinical monitoring tool. 相似文献
40.
C Nielsen P C G?tzsche C M Nielsen J Gerstoft B F Vestergaard 《Antiviral research》1992,18(3-4):303-316
An assay based on production of HIV antigen in cultures of CD4+ lymphocytes infected 'in vitro' with cell-free virus was established. Using this assay it was possible to isolate, propagate and reliably determine the zidovudine susceptibility of HIV isolates from all patients despite differences in cellular tropism and syncytium inducing capacity. Using this assay, differences in zidovudine susceptibility of 52 serial isolates obtained from 16 patients before and after initiation of therapy were examined. HIV with a 10- to 100-fold reduced susceptibility to zidovudine were isolated from 13 patients as early as 4 months after initiation of therapy. Number of months of zidovudine treatment was strongly associated with development of viral resistance, and high CD4 cell counts tended to be associated with lower rates of development of resistance. That patients can harbor mixtures of virus strains with different susceptibility to zidovudine was confirmed by the differences in susceptibility between isolates obtained simultaneously from CD4+ lymphocyte and plasma, and by the differences in susceptibility between virus strains isolated from clones of CD4+ lymphocytes. 相似文献