全文获取类型
收费全文 | 234840篇 |
免费 | 15373篇 |
国内免费 | 988篇 |
专业分类
耳鼻咽喉 | 2556篇 |
儿科学 | 6009篇 |
妇产科学 | 4426篇 |
基础医学 | 29472篇 |
口腔科学 | 4320篇 |
临床医学 | 24023篇 |
内科学 | 49208篇 |
皮肤病学 | 3255篇 |
神经病学 | 23760篇 |
特种医学 | 10145篇 |
外国民族医学 | 13篇 |
外科学 | 36996篇 |
综合类 | 2523篇 |
现状与发展 | 1篇 |
一般理论 | 177篇 |
预防医学 | 16449篇 |
眼科学 | 5586篇 |
药学 | 15683篇 |
1篇 | |
中国医学 | 319篇 |
肿瘤学 | 16279篇 |
出版年
2023年 | 1232篇 |
2022年 | 1252篇 |
2021年 | 5343篇 |
2020年 | 3051篇 |
2019年 | 5063篇 |
2018年 | 6068篇 |
2017年 | 4454篇 |
2016年 | 4872篇 |
2015年 | 5750篇 |
2014年 | 8372篇 |
2013年 | 11282篇 |
2012年 | 17338篇 |
2011年 | 18096篇 |
2010年 | 10124篇 |
2009年 | 9334篇 |
2008年 | 15907篇 |
2007年 | 16704篇 |
2006年 | 16264篇 |
2005年 | 16113篇 |
2004年 | 15155篇 |
2003年 | 13858篇 |
2002年 | 13229篇 |
2001年 | 1987篇 |
2000年 | 1479篇 |
1999年 | 2050篇 |
1998年 | 2800篇 |
1997年 | 2224篇 |
1996年 | 1931篇 |
1995年 | 1773篇 |
1994年 | 1530篇 |
1993年 | 1502篇 |
1992年 | 1002篇 |
1991年 | 957篇 |
1990年 | 818篇 |
1989年 | 765篇 |
1988年 | 705篇 |
1987年 | 627篇 |
1986年 | 653篇 |
1985年 | 697篇 |
1984年 | 903篇 |
1983年 | 781篇 |
1982年 | 1030篇 |
1981年 | 949篇 |
1980年 | 831篇 |
1979年 | 465篇 |
1978年 | 508篇 |
1977年 | 438篇 |
1976年 | 410篇 |
1975年 | 303篇 |
1974年 | 317篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Matthias C Angermeyer Michael Beck Herbert Matschinger 《Revue canadienne de psychiatrie》2003,48(10):663-668
OBJECTIVE: To examine the extent to which the public's desire for social distance from people with schizophrenia is influenced by beliefs about the disorder and stereotypes about those suffering from it. METHODS: In spring 2001, we carried out a representative survey of individuals of German nationality aged 18 years and over (n = 5025). Each subject was given a fully structured interview that began with the presentation of a vignette. RESULTS: Both labelling and beliefs about the disorder's causes and prognosis, as well as the perception that those suffering from it are unpredictable and dangerous, had an impact on the public's desire for social distance. However, the latter proved to be more important. As expected, respondents who identified the disorder depicted in the vignette as mental illness, those who blamed the individual for its development, and those who anticipated a poor prognosis expressed a stronger desire for social distance. Endorsing biological factors as a cause was also associated with increased social distance. CONCLUSIONS: Our findings have important implications for interventions aimed at reducing stigma and discrimination related to schizophrenia. Targeting the stereotype of unpredictability and dangerousness appears to be particularly important. 相似文献
992.
993.
Michael Crotty 《Nursing inquiry》1997,4(2):88-98
In nursing literature, Heideggerian hermeneutics, as expounded in Being and Time , is taken well near unanimously to be an invitation to explore tradition and culture. Understanding, we are told in the name of Heidegger, is to be found in the realm of common meanings and shared practices. This interpretation of what Heidegger is about in Being and Time is neither unchallengeable nor unchallenged. While a number of scholars can be found to agree with it, there are many others who see it as an utter misreading of Heidegger. In their judgement, it is an interpretation diametrically opposed to what Heidegger sets forth in his treatise. For researchers interested in invoking Heidegger or following a Heideggerian approach, this is a frustrating impasse. The only valid starting point for resolving it, this article suggests, is a close reading of what Heidegger actually says in the pages of Being and Time . 相似文献
994.
Jonathan Koea M.D. F.R.A.C.S. Graeme Taylor F.R.C.P.A. Mary Miller F.R.C.P.A. Michael Rodgers F.R. A.C. S. John McCall M.D. F.R.A.C.S. 《Journal of gastrointestinal surgery》2003,7(5):627-630
Solitary necrotic nodule of the liver is an unusual lesion that is often an incidental finding on abdominal imaging, intraoperative
examination, or post mortem. Most reported cases of solitary necrotic nodule have been in males, and over three quarters of
these lesions have occurred in the right lobe of the liver. Pathologically, solitary necrotic nodule is a benign lesion characterized
by a completely necrotic core that is often partly calcified, surrounded by a dense hyalinized fibrous capsule containing
elastin fibres. The ultrasound appearance of solitary necrotic nodule is usually of a “target” lesion with a hyperechoic center,
while on CT scan they appear as non-enhancing hypodense lesions that are typical of metastatic adenocarcinoma or peripheral
cholangiocarcinoma. The impression of malignancy is further enforced with the finding of necrotic cellular material on biopsy
and the macroscopically hard and “gritty” nature of the nodules. Currently, permanent histopathology of solitary necrotic
nodules is the only accurate method of diagnosis. However, solitary necrotic nodules are usually of a bilobed or lobulated
shape that is unusual for malignant liver lesions, and they often lie in close proximity to hepatic inflow structures. Solitary
necrotic nodule should be suspected in liver lesions with this configuration, location, and on a biopsy showing a large amount
of necrosis. 相似文献
995.
996.
Marshall Alison L. Bauman Adrian E. Owen Neville Booth Michael L. Crawford David Marcus Bess H. 《Annals of behavioral medicine》2003,25(3):194-202
Background: Intervention trials with self-selected participants have shown that mailed stage-targeted print materials can increase participation
in physical activity in the short term. We examined the effects of a mailed stage-targeted print intervention designed to
promote physical activity, in a random sample of adults living in a regional city.Method: Participants (n = 462, 40–60 years of age) were randomly allocated to an intervention in - 227) or control group (n - 235).
Measures included validated 2-week physical activity recall and stage of motivational readiness for physical activity. The
intervention consisted of a single mailing of a letter and full-color stage-targeted booklets (specific to precontemplation,
contemplation, preparation, and action/maintenance) 1 week postbaseline. Follow-up interviews were conducted at 2 and 6 months
postbaseline.Results: After 2 months, participants in the intervention group were significantly More likely to meet the current American College
of Sports Medicine/Centers for Disease Control and Prevention recommendation for sufficient physical activity than those in
the control group (adjusted odds ratio [OR] - 2.40; 95% confidence interval [CI] = 1.44–3.99). After 6 months, intervention
participants who reported receiving and reading the intervention materials were significantly more likely to be meeting the
sufficient physical activity criterion compared with the control group (adjusted OR = 2.03; 95% Cl = 1.16–3.56).Conclusions: The stage-targeted print intervention was effective in promoting short-term increases in physical activity and was most
effective for participants who recognized and used the materials. This low-cost, generalizable intervention has demonstrated
potential as a practical population-based physical activity promotion strategy. Further research is required before widespread
dissemination would be justified, as additional strategies may be required to ensure sustained change.
This project was supported by a National Heart Foundation of Australia Research Project Grant. David Crawford was supported
by a Nutrition Research fellowship from the National Heart Foundation. 相似文献
997.
998.
Michael F. Sarosdy 《World journal of urology》1997,15(2):103-106
Summary The BTA Test is an adjunctive test for the diagnosis and management of bladder cancer. For estimation of its potential in the management of patients with transitional-cell cancer (TCC) a review of published results was undertaken. Three prospective studies were analyzed, in which a total of 699 patients with a history of TCC were enrolled. The BTA Test was performed on voided urine and compared with either voided-urine or bladder-wash cytologic analysis in a blinded fashion. In all three studies the sensitivity of the BTA Test was more than double that of cytology, irrespective of whether the cytologic analysis was performed on voided or bladder-wash samples. The third study also included an additional 225 patients undergoing evaluation for hematuria, and TCC was found in 67 cases. The BTA Test detected 70% of these tumors, whereas cytology detected only 25%. The BTA Test is a simple, rapid test that can diagnose a substantial percentage of patients having new or recurrent bladder TCC. Its complete role in the management of such patients remains to be defined. 相似文献
999.
G J Michael 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》1992,15(2):75-87
A new dual-energy x-ray CT algorithm is presented which makes use of both pre- and post-reconstruction data in an iterative manner to achieve accurate beam hardening correction and decomposition into basis materials. The technique does not require a calibration phantom and also does not require accurate estimation of the effective energies of the polyenergetic x-ray beams. It does however, require a knowledge of the incident x-ray spectra. For the situation where the incident spectra are unknown, a method is given whereby sufficiently accurate approximations to the spectra can be determined from attenuation measurements. Decomposition into basis materials makes use of spatial and energy information and an 'a priori' knowledge of the composition and attenuating properties of various tissue types. Any total number of basis materials may be used within the limitation that a subset containing a maximum of three materials is used for any individual pixel. Results of a computer simulation show that the algorithm produces accurate measurements of the concentrations of both high and low atomic number materials such as bone mineral, collagen, fat and air. However the results of a phantom study show that the measurement of the concentrations of low atomic number basis materials may be subject to systematic errors arising from uncertainties in the published values of linear attenuation coefficients. 相似文献
1000.
Juha-Matti Savola Michael Hill Mia Engstrom Hannele Merivuori Siegfried Wurster Steven G McGuire Susan H Fox Alan R Crossman Jonathan M Brotchie 《Movement disorders》2003,18(8):872-883
Previous studies in the MPTP-lesioned primate model of Parkinson's disease have demonstrated that alpha(2) adrenergic receptor antagonists such as idazoxan, rauwolscine, and yohimbine can alleviate L-dopa-induced dyskinesia and, in the case of idazoxan, enhance the duration of anti-parkinsonian action of L-dopa. Here we describe a novel alpha(2) antagonist, fipamezole (JP-1730), which has high affinity at human alpha(2A) (K(i), 9.2 nM), alpha(2B) (17 nM), and alpha(2C) (55 nM) receptors. In functional assays, the potent antagonist properties of JP-1730 were demonstrated by its ability to reduce adrenaline-induced (35)S-GTPgammaS binding with K(B) values of 8.4 nM, 16 nM, 4.7 nM at human alpha(2A), alpha(2B), and alpha(2C) receptors, respectively. Assessment of the ability of JP-1730 to bind to a range of 30 other binding sites showed that JP-1730 also had moderate affinity at histamine H1 and H3 receptors and the serotonin (5-HT) transporter (IC(50) 100 nM to 1 microM). In the MPTP-lesioned marmoset, JP-1730 (10 mg/kg) significantly reduced L-dopa-induced dyskinesia without compromising the anti-parkinsonian action of L-dopa. The duration of action of the combination of L-dopa and JP-1730 (10 mg/kg) was 66% greater than that of L-dopa alone. These data suggest that JP-1730 is a potent alpha(2) adrenergic receptor antagonist with potential as an anti-dyskinetic agent in the treatment of Parkinson's disease. 相似文献