全文获取类型
收费全文 | 26187篇 |
免费 | 1770篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 222篇 |
儿科学 | 640篇 |
妇产科学 | 451篇 |
基础医学 | 3843篇 |
口腔科学 | 339篇 |
临床医学 | 2433篇 |
内科学 | 6360篇 |
皮肤病学 | 671篇 |
神经病学 | 2208篇 |
特种医学 | 798篇 |
外国民族医学 | 3篇 |
外科学 | 3815篇 |
综合类 | 270篇 |
一般理论 | 28篇 |
预防医学 | 1950篇 |
眼科学 | 489篇 |
药学 | 1611篇 |
1篇 | |
中国医学 | 56篇 |
肿瘤学 | 1851篇 |
出版年
2022年 | 134篇 |
2021年 | 335篇 |
2020年 | 226篇 |
2019年 | 360篇 |
2018年 | 423篇 |
2017年 | 290篇 |
2016年 | 354篇 |
2015年 | 414篇 |
2014年 | 627篇 |
2013年 | 943篇 |
2012年 | 1409篇 |
2011年 | 1565篇 |
2010年 | 942篇 |
2009年 | 957篇 |
2008年 | 1492篇 |
2007年 | 1656篇 |
2006年 | 1648篇 |
2005年 | 1743篇 |
2004年 | 1602篇 |
2003年 | 1528篇 |
2002年 | 1515篇 |
2001年 | 403篇 |
2000年 | 340篇 |
1999年 | 395篇 |
1998年 | 376篇 |
1997年 | 338篇 |
1996年 | 294篇 |
1995年 | 278篇 |
1994年 | 255篇 |
1993年 | 230篇 |
1992年 | 307篇 |
1991年 | 291篇 |
1990年 | 264篇 |
1989年 | 244篇 |
1988年 | 215篇 |
1987年 | 211篇 |
1986年 | 228篇 |
1985年 | 218篇 |
1984年 | 206篇 |
1983年 | 199篇 |
1982年 | 222篇 |
1981年 | 230篇 |
1980年 | 184篇 |
1979年 | 138篇 |
1978年 | 133篇 |
1977年 | 138篇 |
1976年 | 114篇 |
1975年 | 111篇 |
1974年 | 102篇 |
1973年 | 95篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
J Staessen A Bernard J P Buchet F Claeys L Dekempeneer G Ducoffre R Fagard R Lauwerys P Lijnen H Roels 《IARC scientific publications》1992,(118):263-269
This paper summarizes the findings of the Cadmibel Study, a cross-sectional population study of the health effects of cadmium, but only with respect to the cardiovascular system and calcium metabolism. The study disproved the hypothesis that exposure to cadmium would lead to an increase in blood pressure and in the prevalence of hypertension and other cardiovascular diseases. On the other hand, there was a positive relationship between urinary cadmium (Cd-U) and both serum alkaline phosphatase activity and urinary excretion of calcium. The regression coefficients obtained after adjustment for significant co-variates indicated that, when Cd-U increased two-fold, serum alkaline phosphatase and urinary calcium rose by 4% and 0.25 mmol/24 h, respectively. These findings suggest that calcium metabolism is gradually affected as cadmium accumulates in the body. The morbidity associated with the latter phenomenon is still unknown, and requires further investigation, preferably in a longitudinal prospective population study, in which the incidence of morbid events would be monitored in relation to the cadmium body burden. 相似文献
62.
Caroline Hartmann Hervé Récipon Marie-France Jubier Christiane Valon Evelyne Delcher-Besin Yves Henry Jacques De Buyser Bernard Lejeune André Rode 《Current genetics》1994,25(5):456-464
The mitochondrial genome of the selfed progeny of a plant regenerated from long-term somatic tissue culture displays specific structural rearrangements characterized by the appearance of novel restriction fragments. A mitochondrial DNA library was constructed from this selfed progeny in the SalI site of cosmid pHC79 and the novel fragments were subsequently studied. They were shown to arise from reciprocal recombination events involving DNA sequences present in the parental plant. The regions of recombination were sequenced and the nucleotide sequences were aligned with those of the presumptive parental fragments. We characterized an imperfect short repeated DNA sequence, 242 bp long, within which a 7-bb DNA repeat could act as a region of recombination. The use of PCR technology allowed us to show that these fragments were present in both parental plants and tissue cultures as low-abundance sequence arrangements. 相似文献
63.
The purpose of this paper is to develop and apply a meta-analysis methodology, that does not require patient-level data, for comparing treatments in terms of quality-of-life-adjusted survival. As a motivating example, we considered adjuvant chemotherapy for breast cancer. This therapy has been shown to offer an improvement in recurrence-free and overall survival, especially for youger women, but its acute toxic effects discourage some physicians from prescribing it. To determine whether the benefit of adjuvant chemotherapy treatment outweighs its costs in terms of toxic effects, we performed a meta-analysis of quality-adjusted survival based on data from 1229 patients, 49 years of age or younger, randomized in eight clinical trials that compared chemotherapy versus no adjuvant systemic therapy. We conducted the meta-analysis by performing a quality-adjusted survival analysis known as a Q-TWiST analysis on each trial. A Q-TWiST analysis allows one to make treatment comparisons that incorporate differences in quality of life associated with various health states. In this analysis, we define as health states the periods of time patients spend: (i) with subjective toxic effects of chemotherapy; (ii) without symptoms of recurrence and toxicity, and (iii) following disease recurrence. We assigned weights to each health state which reflect their relative value in terms of quality of life and allowed them to vary in a sensitivity analysis. We then combined the individual trial results in a meta-analysis, using a multivariate regression model, in such a way that we could easily perform an overall sensitivity analysis. Individual patient-level data are not required to perform this meta-analysis methodology if the individual Q-TWiST analysis results for each trial are available. 相似文献
64.
65.
The aim of the present work was to assess the effects of long-term exposure to Cd on the sulfatation of glomerular membranes and their relation with proteinuria and urinary glycosaminoglycans (GAG). For this purpose the in vitro incorporation of [35S]sulfate was investigated in female Sprague-Dawley rats given 100 ppm of Cd in drinking water for 7 months. When compared with their controls, glomeruli from Cd-treated rats showed a 12.8% decrease in the incorporation of the label into glomerular membranes. This effect, which was not explained by differences in viability or in sulfate uptake by the glomeruli, suggests that sulfatation of glomerular membranes is impaired in Cd-treated rats. In support of this, in another independent experiment, a decrease, 17.4% on average, of the sulfate content of glomerular membranes was observed in long-term Cd-treated rats (100 ppm in drinking water for 4 months). This effect was significantly correlated with albuminuria and transferrinuria but not with beta 2-microglobinuria, suggesting that a loss of heparan sulfate of the glomerular capillary wall could be involved in the Cd-induced glomerular proteinuria. On the other hand an enhanced urinary excretion of GAG, negatively correlated with the sulfate content of glomerular membranes, was also observed in Cd-treated rats. Moreover GAG excretion was associated with tubular and glomerular proteinuria, which suggests that GAG might be a useful marker of Cd-induced nephrotoxicity. 相似文献
66.
Antoine Feydy MD PhD Alexandre Krainik MD Bernard Bussel MD Marc A. Maier PhD 《Journal of neuroimaging》2004,14(1):49-53
The authors report the case of a 33-year-old woman who exhibited, at the age of 17, a left-sided hemiplegia, which was followed by good motor recovery, though with a permanent deficit in fine finger movements. She had a widespread loss of neural tissue in the right hemisphere (crossed cerebrocerebellar atrophy), including (1) marked atrophy and thinning of the precentral and postcentral gyri; (2) widespread deep white matter destruction, including the corticospinal tract; and (3) crossed cerebellar atrophy. Except over the supplementary motor area (SMA), transcranial magnetic stimulation did not elicit motor evoked potentials in the affected hand. Nevertheless, during opening and closing of the affected hand, functional magnetic resonance imaging showed an activation of the lesioned primary sensorimotor cortex (SMC), as well as of the intact SMA and the parietal areas, but not of the ipsilateral motor areas. The authors speculate that recovery was achieved by a motor command generated in the SMC and the parietal cortex, passing through corticospinal axons originating in the SMA. 相似文献
67.
68.
Melissa Kang Diana Bernard Michael Booth Susan Quine Garth Alperstein Tim Usherwood David Bennett 《The British journal of general practice》2003,53(497):947-952
BACKGROUND: To adequately address the complex health needs of young people, their access to services, and the quality of services received, must be improved. AIMS: To explore the barriers to service provision for young people and to identify the training needs of primary healthcare service providers in New South Wales (NSW), Australia. DESIGN OF STUDY: A cross-sectional, qualitative study of the perspectives of a range of health service providers. SETTING: A range of primary healthcare organisations across NSW. METHODS: Samples of general practitioners (GPs), youth health workers, youth health coordinators, and community health centre staff were drawn from urban and rural clusters across NSW. Focus groups and interviews were used to identify barriers to service provision and the training needs of service providers. Data were tape recorded, transcribed, and analysed. RESULTS: Barriers to service provision among GPs and community health centre staff included inadequate time, flexibility, skills, and confidence in working with young people, and poor linkages with other relevant services. Training needs included better knowledge of and skills in adolescent health requirements, working with adolescents, and working with other services. Barriers to service provision for youth health workers and coordinators included lack of financial resources and infrastructure. There were few linkages between groups of service providers. CONCLUSION: Models of service provision that allow stronger linkages between service providers, sufficient time for consultation with young people, adequate training and support of health professionals, and flexibility of service provision, including outreach, should be explored and evaluated. 相似文献
69.
70.
A Menget A Burguet C Fromentin Y Bernard N Cardot 《Archives fran?aises de pédiatrie》1989,46(9):701-702
Through the case report of severe digitalis intoxication in a premature born after 27 weeks of gestation with a birthweight of 800 g, the authors show that anti-digoxin antibodies constitute a very efficacious therapeutic tool which, up to the present, has not been used in prematures. 相似文献