全文获取类型
收费全文 | 11633篇 |
免费 | 690篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 170篇 |
儿科学 | 192篇 |
妇产科学 | 197篇 |
基础医学 | 1649篇 |
口腔科学 | 1464篇 |
临床医学 | 898篇 |
内科学 | 2203篇 |
皮肤病学 | 271篇 |
神经病学 | 874篇 |
特种医学 | 285篇 |
外科学 | 1115篇 |
综合类 | 44篇 |
一般理论 | 4篇 |
预防医学 | 1414篇 |
眼科学 | 192篇 |
药学 | 918篇 |
中国医学 | 130篇 |
肿瘤学 | 352篇 |
出版年
2023年 | 104篇 |
2022年 | 176篇 |
2021年 | 438篇 |
2020年 | 286篇 |
2019年 | 398篇 |
2018年 | 460篇 |
2017年 | 319篇 |
2016年 | 339篇 |
2015年 | 394篇 |
2014年 | 561篇 |
2013年 | 662篇 |
2012年 | 968篇 |
2011年 | 995篇 |
2010年 | 582篇 |
2009年 | 424篇 |
2008年 | 650篇 |
2007年 | 665篇 |
2006年 | 555篇 |
2005年 | 504篇 |
2004年 | 440篇 |
2003年 | 367篇 |
2002年 | 321篇 |
2001年 | 237篇 |
2000年 | 208篇 |
1999年 | 161篇 |
1998年 | 72篇 |
1997年 | 51篇 |
1996年 | 39篇 |
1995年 | 32篇 |
1994年 | 20篇 |
1993年 | 30篇 |
1992年 | 56篇 |
1991年 | 91篇 |
1990年 | 75篇 |
1989年 | 76篇 |
1988年 | 75篇 |
1987年 | 65篇 |
1986年 | 39篇 |
1985年 | 48篇 |
1984年 | 34篇 |
1983年 | 23篇 |
1982年 | 23篇 |
1981年 | 23篇 |
1980年 | 26篇 |
1979年 | 27篇 |
1978年 | 22篇 |
1975年 | 19篇 |
1974年 | 33篇 |
1973年 | 19篇 |
1971年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
91.
Cordeiro R Peñaloza ER Cardoso CF Cortez DB Kakinami E Souza JJ Souza MT Fernandes RA Guercia RF Adoni T 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1999,15(4):719-728
The aim of this paper was to evaluate the accuracy of data on death certificates for occupation and main cause of death. Measure of agreement was assessed comparing data from death certificates with those from both medical records and next-of-kin interviews, analyzing information for 552 residents of Botucatu, Southeast Brazil, who died in 1997. Kappa coefficients of 0.31 (95% C.I. 0. 29-0.34) and 0.76 (95% C.I. 0.75-0.76) were obtained for data on occupation and main cause of death, coded by a Brazilian two-digit classification and the three-digit ICD-10 classification, respectively. One can conclude that, although quality of the main cause of death is acceptable for pilot studies, data on occupation taken only from death certificates is not accurate enough to be used in epidemiological research. 相似文献
92.
Oliveira MA Bermudez JA Souza AC 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1999,15(1):99-112
This paper discusses issues related to the regulation and rational use of thalidomide in Brazil, by means of a historical approach comprising three different stages. The first part is a historical review of the controversial drug since it was first synthesized, then marketed and subsequently banned during the 1950s and 60s, until the present, when an apparently irreversible process of rehabilitating the drug is under way. Brazilian experience with the use of thalidomide is described, emphasizing legal, political, and institutional work led by two social movements, the Brazilian Association of People with Thalidomide Syndrome (ABPST) and the Movement for Reintegration of People with Hansen's Disease (Morhan). The article describes the results and analyzes an active search of new cases in what is a second generation of thalidomide syndrome in Brazil. Finally, based on clinical and scientific evidence of thalidomide's therapeutic efficacy, the growth of social movements struggling both for and against authorization of the drug, and a restrictive regulation proposed by the Ministry of Health, the article discusses the implementation of policies for the regulation and rational use of thalidomide in Brazil. 相似文献
93.
NOD background genes influence T cell responses to GAD 65 in HLA-DQ8 transgenic mice. 总被引:3,自引:0,他引:3
R S Abraham S B Wilson N F de Souza J L Strominger S R Munn C S David 《Human immunology》1999,60(7):583-590
The major histocompatibility complex (MHC) genes play a significant role in the predisposition to insulin-dependent diabetes mellitus or type 1 diabetes. HLA-DQ8 (DQB1*0302, DQA 1*0301) genes have been shown to have the highest relative risk for human type 1 diabetes. To develop a "humanized" mouse model of diabetes, HLA-DQ8 was transgenically expressed in mice lacking endogenous class II genes. Since non-MHC background genes of the NOD influence the disease process, AP"/DQ8 mice were mated with the NOD strain and backcrossed to generate Abeta degree/DQ8/NOD mice. These mice have DQ8 as the sole MHC class II restriction element with NOD background genes at the N 2 generation. The DQ8 transgenic mice were used to identify T cell epitopes on glutamic acid decarboxylase (GAD 65), an important putative autoantigen in type 1 diabetes. The NOD background genes strongly influenced antigen processing, that is, different T cell epitopes were generated from the processing of GAD 65 in vivo in the Abeta degree/DQ8 and in the Abeta degree/DQ8/NOD mice. 相似文献
94.
Substernal goiter is an infrequent occurrence and is found in two to five per cent of all patients undergoing thyroid surgery. These lesions are well known to cause respiratory symptoms and alterations in phonation due to direct compression of airway structures. Infrequently, unilateral recurrent nerve palsy has been reported in patients with substernal goiter. We report a case of bilateral recurrent nerve palsy associated with multinodular substernal goiter in an 89-year-old female who presented in respiratory distress. 相似文献
95.
Self-expanding endovascular stent-graft implant for treatment of descending aortic diseases 总被引:1,自引:0,他引:1
Stolf NA Pêgo Fernandes PM Souza LR Moitinho R Arteaga E Jatene AD 《Journal of cardiac surgery》1999,14(1):9-15
A bstract Background: Aneurysms and dissections involving the descending thoracic aorta and the distal portion of the aortic arch are difficult to resolve surgically. The introduction of endovascular self-expanding stent-grafts has simplified the operation. Given the complications associated with their peripheral placement, we explored the feasibility of surgical insertion. Methods: Thirteen patients underwent surgical insertion of a stent-graft into the aortic arch via longitudinal aortotomy. Six patients had aneurysms (ruptured in two, and seven dissections (acute in two, ruptured in one). Five patients also underwent associated procedures including aortic valve replacement (one), ascending aorta replacement (two), arch replacement (one), and coronary artery bypass (one). Results: There was one intraoperative death due to ascending aortic dissection, and two hospital deaths due to multiple complications. Of ten patients discharged, one died 3 months postoperatively. The remaining survivors are well, and imaging studies confirmed adequate correction of the aortic disease. Conclusions: The use of this technique simplifies the operation and treatment of particular cases of aortic disease. The observed morbidity and mortality are due to factors independent of the technique. 相似文献
96.
Saldiva Silveira Philippi Torres Mangini de Souza Dias da Silva Buratini & Massad 《Paediatric and perinatal epidemiology》1999,13(1):89-98
This work was designed to evaluate the role of intestinal parasites on nutritional status in three rural areas of Brazil. A total of 520 children aged 1–12 years were studied through a questionnaire concerning housing, socio-economic conditions and a 24-h food intake recall. Measurements of weight and height were also performed, and three stool samples were collected on consecutive days for parasitological analysis. Scores of the standard deviation (z-scores) for the weight-for-height and height-for-age were used to characterise the growth profile. A high prevalence of intestinal parasites was detected, with Giardia lamblia (44%), Endolimax nana (43%), Ascaris lumbricoides (41%) and Trichuris trichiura (40%) being the most prevalent. Eleven per cent of the children were classified as showing stunting. Inadequate daily caloric intake was observed in 78% of the population and the proportion of those with inadequate protein intake was 34%. Logistic regression analysis was employed for the multivariate study. Stunting was significantly associated with estimators of low economic income, inadequate protein intake and polyparasitism, especially the association between Ascaris lumbricoides and Trichuris trichiura . 相似文献
97.
98.
A comparative study in rats of the in vitro and in vivo pharmacology of the acetylcholinesterase inhibitors tacrine, donepezil and NXX-066 总被引:7,自引:0,他引:7
Snape MF Misra A Murray TK De Souza RJ Williams JL Cross AJ Green AR 《Neuropharmacology》1999,38(1):181-193
The in vitro and in vivo effects of the novel acetylcholinesterase inhibitors donepezil and NXX-066 have been compared to tacrine. Using purified acetylcholinesterase from electric eel both tacrine and donepezil were shown to be reversible mixed type inhibitors, binding to a similar site on the enzyme. In contrast, NXX-066 was an irreversible non-competitive inhibitor. All three compounds were potent inhibitors of rat brain acetylcholinesterase (IC50 [nM]; tacrine: 125 +/- 23; NXX-066: 148 +/- 15; donepezil: 33 +/- 12). Tacrine was also a potent butyrylcholinesterase inhibitor. Donepezil and tacrine displaced [3H]pirenzepine binding in rat brain homogenates (IC50 values [microM]; tacrine: 0.7; donepezil: 0.5) but NXX-066 was around 80 times less potent at this M1-muscarinic site. Studies of carbachol stimulated increases in [Ca2+]i in neuroblastoma cells demonstrated that both donepezil and tacrine were M1 antagonists. Ligand binding suggested little activity of likely pharmacological significance with any of the drugs at other neurotransmitter sites. Intraperitoneal administration of the compounds to rats produced dose dependent increases in salivation and tremor (ED50 [micromol/kg]; tacrine: 15, NXX-066: 35, donepezil: 6) with NXX-066 having the most sustained effect on tremor. Following oral administration, NXX-066 had the slowest onset but the greatest duration of action. The relative potency also changed, tacrine having low potency (ED50 [micromol/kg]; tacrine: 200, NXX-066: 30, donepezil: 50). Salivation was severe only in tacrine treated animals. Using in vivo microdialysis in cerebral cortex, both NXX-066 and tacrine were found to produce a marked (at least 30-fold) increase in extracellular acetylcholine which remained elevated for more than 2 h after tacrine and 4 h after NXX-066. 相似文献
99.
B B Lorenzetti G E Souza S J Sarti D Santos Filho S H Ferreira 《Journal of ethnopharmacology》1991,34(1):43-48
Oral administration of an infusion of lemongrass (Cymbopogon citratus) fresh leaves to rats produced a dose-dependent analgesia for the hyperalgesia induced by subplantar injections of either carrageenin or prostaglandin E2, but did not affect that induced by dibutyryl cyclic AMP. These results indicate a peripheral site of action which was confirmed with the essential oil obtained by steam distillation of the leaves. Silica gel column fractionation of the essential oil allowed the identification of myrcene as the major analgesic component in the oil. Identification of the components was made by thin-layer chromatography and checked by mass spectrometry. The peripheral analgesic effect of myrcene was confirmed by testing a standard commercial preparation on the hyperalgesia induced by prostaglandin in the rat paw test and upon the contortions induced by intraperitoneal injections of iloprost in mice. In contrast to the central analgesic effect of morphine, myrcene did not cause tolerance on repeated injection in rats. This analgesic activity supports the use of lemongrass tea as a "sedative" in folk medicine. Terpenes such as myrcene may constitute a lead for the development of new peripheral analgesics with a profile of action different from that of the aspirin-like drugs. 相似文献
100.
Abigail L. Smith S. W. Barthold M. S. de Souza Kim Bottomly 《Archives of virology》1991,121(1-4):89-100
Summary Infection of BALB/c mice with mouse hepatitis virus, strain JHM (MHV-JHM), at any of several intervals relative to ovalbumin (OVA) administration resulted in elevated OVA-specific IgG 2 a titers. Since gamma interferon (IFN) has been implicated as an up-regulator of IgG 2 a production, attempts were made to determine whether levels of this cytokine were modified in sera of infected mice. Serum IFN- was not detected, but treatment of MHV-JHM-infected mice with monoclonal anti-IFN- antibody resulted in high mortality with decreased survival times, enhanced virus titers in liver and spleen, and more severe virus-associated pathology, compared to mock-treated, infected mice. Immunotherapy with recombinant IFN- ameliorated disease as reflected by mortality rates and virus titers in target organs. 相似文献