全文获取类型
收费全文 | 9426篇 |
免费 | 570篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 224篇 |
妇产科学 | 158篇 |
基础医学 | 1184篇 |
口腔科学 | 890篇 |
临床医学 | 736篇 |
内科学 | 2106篇 |
皮肤病学 | 218篇 |
神经病学 | 667篇 |
特种医学 | 375篇 |
外科学 | 930篇 |
综合类 | 65篇 |
一般理论 | 4篇 |
预防医学 | 1021篇 |
眼科学 | 189篇 |
药学 | 691篇 |
中国医学 | 97篇 |
肿瘤学 | 363篇 |
出版年
2023年 | 82篇 |
2022年 | 228篇 |
2021年 | 348篇 |
2020年 | 251篇 |
2019年 | 293篇 |
2018年 | 366篇 |
2017年 | 230篇 |
2016年 | 268篇 |
2015年 | 339篇 |
2014年 | 474篇 |
2013年 | 510篇 |
2012年 | 684篇 |
2011年 | 823篇 |
2010年 | 417篇 |
2009年 | 352篇 |
2008年 | 555篇 |
2007年 | 570篇 |
2006年 | 403篇 |
2005年 | 413篇 |
2004年 | 315篇 |
2003年 | 301篇 |
2002年 | 248篇 |
2001年 | 170篇 |
2000年 | 149篇 |
1999年 | 126篇 |
1998年 | 79篇 |
1997年 | 81篇 |
1996年 | 75篇 |
1995年 | 53篇 |
1994年 | 37篇 |
1993年 | 43篇 |
1992年 | 48篇 |
1991年 | 71篇 |
1990年 | 56篇 |
1989年 | 59篇 |
1988年 | 48篇 |
1987年 | 48篇 |
1986年 | 47篇 |
1985年 | 53篇 |
1984年 | 36篇 |
1983年 | 41篇 |
1982年 | 22篇 |
1981年 | 26篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 15篇 |
1977年 | 16篇 |
1973年 | 14篇 |
1970年 | 13篇 |
1966年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Cornélio DA Schmid-Braz AT Cavalli LR Lima RS Ribeiro EM Cavalli IJ 《Cancer Genetics and Cytogenetics》1999,115(2):128-133
Gynecomastia is a benign condition that frequently occurs in the male breast gland; however, the cytogenetic data on this entity are very limited. To our knowledge, three cases have been reported in the literature, and the only one with an abnormal karyotype had a concomitant breast carcinoma. In this study we report clonal chromosomal alterations in a gynecomastia sample without any signs of adjacent malignant tissue. The nonrandom abnormalities observed were a deletion of 12p, monosomies of chromosomes 9, 17, 19, and 20, and the presence of a marker chromosome. Most of these alterations have been previously described in the literature in other breast lesions, including benign and malignant (male and female) tumors, indicating their recurrence and nonrandomness in abnormal processes of the mammary gland. 相似文献
42.
Dòmini M Aquino A Rossi F Lima M Ruggeri G Dòmini R 《Journal of pediatric surgery》1999,34(12):1865-1868
The authors describe the results of an application of the surgical technique called ASTRA (anterior sagittal transrectal approach) in a 16-year-old girl with recurrent urethro-vaginal fistula. The young girl had a posttraumatic urethro-vaginal fistula. It recurred after 4 operations by a direct vaginal approach before definitive correction with the ASTRA. Three years after the operation the patient has remained well with complete healing and no fistula recurrence confirmed by a voiding cystourethrogram and urodynamic and rectal manometric tests. This report suggests that ASTRA is a useful method of treating acquired or developmental anomalies of the perineal region. 相似文献
43.
This study investigates the effects of intracerebroventricular injection of selective agonists and antagonists of tachykinin NK(3)receptor on performance of mice in the elevated plus-maze test. Mice were treated with either vehicle or 1, 10, 100 or 500 pmol of neurokinin B or senktide ([succinil-Asp(6), MePhe(8)]substance P(6-11), a natural and synthetic selective NK(3)receptor agonists, respectively. Other mice received similar doses of [Trp(7)beta-Ala(8)]NKA(4-10)or SR 142801 ((S)-N-(1-(3-(1-benzoyl-3-(3, 4-dichlorophenyl)-piperidin-3-yl)propyl)-4-phenyl-piperidin- 4-yl)-N-m ethylacetamide) tachykinin NK(3)receptor selective peptide and non-peptide antagonists, respectively. Senktide significantly increased the frequency of entries and the time spent in the open arms, which is compatible with an anxiolytic action. Neurokinin B treatment did not alter the plus-maze parameters in a significant way. Conversely, the NK(3)peptide antagonist [Trp(7)beta-Ala(8)]NKA(4-10), but not SR142801 non-peptide antagonist, showed a reverse effect, i.e. an anxiogenic profile of action, reducing the frequency and the time spent in the open arms. Co-injection of either senktide plus [Trp(7)beta-Ala(8)]NKA((4-10)), or senktide plus SR 142801, blocked the effects promoted by senktide, indicating that centrally-administered NK(3)receptor agonists and antagonists can modulate experimental anxiety. 相似文献
44.
Lewis (LEW) is an inbred strain of rats frequently used as an animal model of autoimmune diseases. However, there is evidence that some lines of LEW rats develop autoimmune diseases more readily than do other LEW rat lines. Because the hypothalamus-pituitary-adrenal system is involved in the pathophysiology of these diseases, we compared two LEW lines (SsNHsd and HANRijHsd) in their behavioural and neuroendocrine response to stress. In addition, we studied the psychostimulant effects of acute and repeated amphetamine in these two LEW rat lines. HAN rats were less active in the open field test and showed faster habituation of novelty-induced locomotion. The acoustic startle response was lower in HAN than in SSN rats, whereas prepulse inhibition of the startle response was greater in the HAN than in the SSN LEW subline. Moreover, HAN rats showed impaired acquisition of the two-way active avoidance response relative to SSN rats. The psychostimulant effects of acute amphetamine were smaller in HAN rats. Following repeated injections of amphetamine, behavioural sensitization to the psychostimulant effects of amphetamine was more pronounced in HAN than in SSN rats. Basal concentrations of serum corticosterone did not differ between the two rat lines. Following stress, however, HAN rats showed slightly higher corticosterone secretion than SSN rats. Our results show that two sublines of the LEW inbred strain of rats show profound behavioural differences which are only marginally paralleled by differences at the level of the HPA system. 相似文献
45.
46.
47.
de Oliveira Elias M Tavares de Lima W Vannuchi YB Marcourakis T da Silva ZL Trezena AG Scavone C 《European journal of pharmacology》1999,367(2-3):307-314
The present work demonstrated that nitric oxide (NO) modulates Na+, K+-ATPase activity in the proximal rat trachea. Sodium nitroprusside induced concentration-dependent (10-100 microM) stimulation in proximal trachea Na+, K+-ATPase activity. The effect was specific for Na+, K+-ATPase since Mg-ATPase activity was unaffected. This NO-donor changed neither Na+, K+-ATPase nor Mg-ATPase activity in the distal segment. The modulatory action on Na+, K+-ATPase induced by sodium nitroprusside was linked to an increase in nitrates/nitrites and cyclic GMP levels in proximal segments. Modulation of proximal Na+, K+-ATPase activity by sodium nitroprusside was mimicked by S-nitroso-N-acetylpenicillamine (100 microM) and 8-bromo-cyclic GMP (100 microM). Both sodium nitroprusside and 8-bromo-cyclic GMP effects on Na+, K+-ATPase activity of proximal segments of trachea were blocked by 2 microM of KT 5823 (a cyclic GMP-dependent protein kinase inhibitor), but not by 0.5 microM of KT 5720 (a cyclic AMP-dependent protein kinase inhibitor). Both kinase inhibitors decreased proximal Na+, K+-ATPase activity, but did not change Mg-ATPase activity. Okadaic acid (1 microM), a phosphatase-1 inhibitor, increased proximal Na+, K+-ATPase but not Mg-ATPase activity. The effect of okadaic acid was non-additive with that of 8-bromo-cGMP on Na+, K+-ATPase activity. Our results suggest that NO modulates proximal rat trachea Na+, K+-ATPase activity through cyclic GMP and cyclic GMP-dependent protein kinase. 相似文献
48.
Noronha MF Machado CV Lima LD 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1996,12(Z2):43-58
The objectives of this article are to propose indicators for evaluation of the quality of hospital management of bronchial asthma patients, based on explicit criteria from literature reviews. The central problem identified in the literature review is the erroneous evaluation of severity of asthma crises, either by patients and their relatives, or by health professionals at all levels of care, causing serious consequences not only for the patient, but for society as a whole. Mortality figures indicate that from 1980 to 1990, an average of 2000 deaths per year from asthma occurred in Brazil, of which 70% occurred in hospital. Asthma was the fourth cause of hospitalization (hospital admissions), in the state of Rio de Janeiro in 1993. Only 12% of the admissions that resulted in death made use of the ICU. The above information highlights the need for a thorough evaluation of hospital care of bronchial asthma in Brazil, including a review of all admissions resulting in death and reviews of a sample of all bronchial asthma admissions. Proposed criteria are for this evaluation include: severity of the crise, treatment prescribed, information given to the patient and their relatives, and follow-up appointments made after discharge from hospital. 相似文献
49.
Câmara Vd Filhote MI Lima MI Alheira FV Martins MS Dantas TO Luiz RR 《Cadernos de saúde pública / Ministério da Saúde, Funda??o Oswaldo Cruz, Escola Nacional de Saúde Pública》1996,12(2):149-158
The main objective of this study was to promote the evaluation of an educational method to identify health risks among adolescents exposed to mercury by their work in gold mining production.The project was carried out with adolescents from a public school from the District of Monsenhor Horta, Municipality of Mariana, state of Minas Gerais. Statistical evaluation of the results revealed a significant increase in the amount of correct answers between the first and fifth stage concerning the definition of work accidents and its importance in relation to work-related diseases, accidents on route to and from the work place and violence at work site itself. 相似文献
50.
JP Bound PW Harvey BJ Francis F Awwad AC Gatrell 《Archives of disease in childhood》1997,76(2):107-112
OBJECTIVE: To analyse the prevalence of neural tube defects in small geographical areas and seek to explain any spatial variations with reference to environmental lead and deprivation. SETTING: The Fylde of Lancashire in the north west of England. DESIGN: Cases were ascertained as part of a prospective survey of major congenital malformations in babies born in the Fylde to residents there between 1957 and 1981. A matched case-control analysis used infants with cardiovascular system, alimentary tract, and urinary system malformations as controls. Conditional logistic regression was used to assess the effects of more than 10 micrograms/l lead in drinking water and the Townsend deprivation score. RESULTS: The prevalence of neural tube defects in 1957-73 was higher in Blackpool, Fleetwood, and North Fylde, whereas the three control groups showed no significant spatial variation. In 1957-81 mothers living in electoral wards with either a higher proportion of houses with more than 10 micrograms/l lead in the water or a higher deprivation score had a greater risk of having a baby with a neural tube defect. For spina bifida and cranium bifidum alone, this was also true. For anencephaly, deprivation was less important although the effect of lead was still seen. In some neural tube defects, lead may act independently of other possible factors associated with deprivation. It seemed unlikely that lead levels changed significantly during the survey. The percentage of houses with 10 micrograms/l or more of lead in the water in 1984-5 was similar to that found in Great Britain 10 years previously. CONCLUSION: There is evidence to suggest that lead is one cause of neural tube defects, especially anencephaly. This could link the known preventive actions of hard water and folic acid. Calcium is a toxicological antagonist of lead. One cause of a deficiency of folic acid is impaired absorption secondary to zinc deficiency, which may be produced or exacerbated by lead. 相似文献