全文获取类型
收费全文 | 24467篇 |
免费 | 1407篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 275篇 |
儿科学 | 773篇 |
妇产科学 | 461篇 |
基础医学 | 3389篇 |
口腔科学 | 751篇 |
临床医学 | 1944篇 |
内科学 | 6284篇 |
皮肤病学 | 829篇 |
神经病学 | 2039篇 |
特种医学 | 371篇 |
外科学 | 2329篇 |
综合类 | 138篇 |
一般理论 | 11篇 |
预防医学 | 2664篇 |
眼科学 | 356篇 |
药学 | 1902篇 |
中国医学 | 127篇 |
肿瘤学 | 1330篇 |
出版年
2024年 | 23篇 |
2023年 | 253篇 |
2022年 | 155篇 |
2021年 | 766篇 |
2020年 | 387篇 |
2019年 | 827篇 |
2018年 | 1283篇 |
2017年 | 730篇 |
2016年 | 682篇 |
2015年 | 811篇 |
2014年 | 843篇 |
2013年 | 1184篇 |
2012年 | 2247篇 |
2011年 | 2279篇 |
2010年 | 1126篇 |
2009年 | 807篇 |
2008年 | 1678篇 |
2007年 | 1685篇 |
2006年 | 1577篇 |
2005年 | 1582篇 |
2004年 | 1364篇 |
2003年 | 1191篇 |
2002年 | 1073篇 |
2001年 | 200篇 |
2000年 | 201篇 |
1999年 | 163篇 |
1998年 | 60篇 |
1997年 | 39篇 |
1996年 | 44篇 |
1995年 | 41篇 |
1994年 | 32篇 |
1993年 | 20篇 |
1992年 | 69篇 |
1991年 | 58篇 |
1990年 | 43篇 |
1989年 | 45篇 |
1988年 | 46篇 |
1987年 | 38篇 |
1986年 | 41篇 |
1985年 | 37篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 18篇 |
1980年 | 20篇 |
1979年 | 19篇 |
1978年 | 12篇 |
1976年 | 10篇 |
1975年 | 11篇 |
1974年 | 19篇 |
1971年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Hospital outbreak caused by a carbapenem-resistant strain of Acinetobacter baumannii: patient prognosis and risk-factors for colonisation and infection 总被引:10,自引:0,他引:10
M. del Mar Tomas M. Cartelle S. Pertega A. Beceiro P. Llinares D. Canle F. Molina R. Villanueva J. M. Cisneros G. Bou 《Clinical microbiology and infection》2005,11(7):540-546
Between October 2001 and August 2002, 30 hospital patients became infected or colonised by a multiresistant (including to carbapenems) epidemic strain of Acinetobacter baumannii (AbMR) in a hospital outbreak. This study analysed the risk-factors associated with acquisition of this epidemic strain and investigated the prognosis of patients infected by AbMR, with the aim of elucidating factors which lead to mortality. A case-control study of the acquisition of AbMR in patients infected or colonised in the hospital outbreak was performed. Independent risk-factors leading to death were studied by logistic regression analysis. Multivariate analysis of the risk-factors for colonisation/infection with AbMR revealed an independent association with the presence of an arterial catheter (OR, 1.13; 95% CI, 1.03-1.25) and administration of imipenem as monotherapy (OR, 11.12; 95% CI, 2.33-53.09). Multivariate analysis of the prognostic features leading to mortality revealed a significant association with hypotension or shock (OR, 24.63; 95% CI, 1.56-387.56) at the time of bacterial isolation. 相似文献
22.
Ana Martín-Ancel María Luisa Casas Bartolomé Bonet 《Infection control and hospital epidemiology》2004,25(7):611-613
A neonate vaccinated against HBV was the source of an occupational exposure to blood. She was tested for hepatitis B surface antigen and found to be positive, leading to unnecessary treatment, retesting, and concern. Evaluation of the infectious status of HBV should rely on other means if vaccination has recently occurred. 相似文献
23.
24.
J San Cristóbal I Cearra B Otero T Martínez-Astorquiza H Marín I García-Alonso 《Revista española de enfermedades digestivas》2007,99(1):25-32
OBJECTIVE: An intestinal reperfusion study with two aims: a) to assess the usefulness of intestinal capillary blood flow measurement by laser-Doppler for intestinal reperfusion studies; and b) to compare the effects of racemic and levo forms of folinic acid in treating the syndrome. EXPERIMENTAL DESIGN: A murine model of intestinal ischemia by completely clamping the superior mesenteric artery for 90 minutes. A comparison was made of three treatment groups: saline, folinic acid, and levo-folinic acid. The following factors were analyzed: changes in biochemical parameters (levels of creatine kinase, lactic dehydrogenase, and alkaline phosphatase at 60 minutes, and at two and seven days after restoring blood flow), capillary flow in the jejunum and ileum by laser-Doppler (during ischemia and after the first hour of reperfusion), intestinal mucosa injury, and survival curve. RESULTS: Laser-Doppler provided reliable data on how the different treatments affected capillary flow during intestinal reperfusion. Levo-folinic acid improved capillary flow in the ileum after 25 minutes of reperfusion, and also reduced mucosal injury in the same stretch of intestine by the seventh day post-reperfusion (p<0.05). On the other hand, it produced an initial increase in serum enzymes during reperfusion, and did not modify survival. CONCLUSIONS: The changes observed in intestinal capillary blood flow measurement by laser-Doppler have similarities with the effects of drugs on pathological mucosal changes. We could not prove that the levo form of folinic acid has a stronger protective effect versus racemic folinic acid in intestinal ischemia-reperfusion syndrome. 相似文献
25.
Hybrid tumours of the salivary glands. A report of two cases involving the palate and a review of the literature 总被引:1,自引:0,他引:1
Luz María Ruíz-Godoy R Adalberto Mosqueda-Taylor Lourdes Suárez-Roa Adela Poitevin Esther Bandala-Sánchez Abelardo Meneses-García 《European archives of oto-rhino-laryngology》2003,260(6):312-315
Hybrid tumours are very rare salivary gland lesions composed of two or more different tumoural entities in a single neoplasm that arise within a definite topographical region. In most cases adenoid cystic carcinoma has been the predominant component in these lesions. In this study we describe two patients with hybrid tumours located in the palate, one in a 49-year-old woman and one in a 71-year-old man. The first case involved adenoid cystic carcinoma and mucoepidermoid carcinoma, and the patient in the second case exhibited adenoid cystic carcinoma and epithelial-myoepithelial carcinoma. Both patients were treated with surgery and radiotherapy, and there has been no evidence of recurrence after 13 and 36 months of follow-up, respectively. The recognition of the histologic component with the higher grade of malignancy in every case of hybrid tumour of the salivary glands is a necessary step to determine the biological behaviour and, consequently, to determine the proper therapeutic approach. 相似文献
26.
Background
Induction of apoptosis is one strategy for treatment of prostate cancer. The Shb adapter protein has been found to regulate apoptosis in various cell types and consequently human prostate cancer 3 (PC3) cells were transfected to obtain cells overexpressing Shb in order to increase our understanding of the mechanisms regulating PC3 cell apoptosis. 相似文献27.
María de Oña Navarro Santiago Melón Susana Méndez Beatriz Iglesias Ana Palacio María J. Bernardo José L. Rodriguez-Lambert Ernesto Gómez 《Transplant international》2002,15(11):570-573
Ganciclovir (GCV) prophylaxis or pre-emptive therapy significantly reduce the rate of cytomegalovirus (CMV) disease and viremia, but increase the potential for emergence of ganciclovir-resistant CMV strains. The inhibitor concentration at 50% (IC(50)) of GCV from 156 CMV isolates from 59 renal or heart transplant recipients was calculated by means of a rapid phenotypic susceptibility assay. Twenty-seven strains were from 14 patients undergoing GCV therapy. The IC(50) was higher in patients under the prophylaxis regimen. One CMV strain, from a heart transplant recipient, became GCV-resistant after 1 month of therapy (IC(50)=13.7 micromol/l). These data, together with clinical and virological markers, suggested that a switch to foscarnet was necessary, and good evolution was observed. Thus, assay of CMV susceptibility to GCV could be helpful in clinical management. 相似文献
28.
Julien Fey André Dietrich Anne Cosset T. Desprez L. Maréchal-Drouard 《Current genetics》1997,32(5):358-360
Two identical “chloroplast-like” tRNAAsn genes, trnN1 and trnN2, have been identified in the potato (Solanum tuberosum) mitochondrial genome. The flanking sequences of trnN1 are unrelated to the corresponding authentic potato chloroplast regions, whilst those of trnN2 are very similar to the chloroplast sequences. The trnN1 copy is present in the mitochondrial genome of various plants whereas the second copy, trnN2, is absent from all the other plant genomes studied so far. Interestingly, both trnN copies are expressed in potato mitochondria. Sequences flanking the chloroplast-like tRNAHis gene (trnH), present as a single copy in the potato mitochondrial DNA, are unrelated to the corresponding chloroplast sequences, whereas
chloroplast-derived sequences have been maintained in the vicinity of the maize chloroplast-like mitochondrial trnH gene. However, both the potato and the maize trnH are expressed in mitochondria.
Received: 10 April / 1 August 1997 相似文献
29.
Christopher Del Mar FRACGP FAFPHM Vivienne O'Connor FRACOG 《The Australian & New Zealand journal of obstetrics & gynaecology》1994,34(1):35-38
Summary: We questioned 229 general practitioners (GPs), 288 women who had recently delivered babies in public hospitals, 26 public hospital doctors, and 33 midwives in South Brisbane. Shared antenatal care was undertaken by 84% of mothers, and recently provided by 88% GPs. Mothers valued having sufficient time with their antenatal clinician, continuity of care, and short waiting and travel times. They preferred a GP to provide antenatal care, and a hospital midwife to deliver them. GPs were interested in providing even more obstetric care - one third in providing intrapartum care - and in gaining continuing education in obstetrics. Hospital doctors and midwives were supportive of women choosing the personnel to deliver them, and of an increased GP and midwife role in public hospital obstetrics, but unenthusiastic about home deliveries. There is widespread support for an increased role for GPs in public obstetrics. 相似文献
30.
P Lopez-Sela J Brime F Díaz B Marín M Costales M Vijande 《European journal of pharmacology》1991,200(1):125-129
Insulin-induced drinking (IID) in male Wistar rats, evoked by administering 5 U/kg of crystalline porcine insulin i.p., was significantly decreased by propranolol (0.1 and 0.5 mg/kg s.c.) after 1 and 2 h. The blood glucose of rats treated with a much higher dose of propranolol (10 mg/kg body weight) and insulin did not differ from that of rats treated solely with insulin after 30 and 120 min. Atenolol (0.5 mg/kg s.c.) caused a reduction in IID after 1 and 2h. Butoxamine (1 mg/kg s.c.) also reduced IID after 1 and 2h, and at 0.5 mg/kg after 1h. The alpha-blocker, phenoxybenzamine (10 mg/kg s.c.), had the opposite effect, stimulating IID after 2h. There is no direct evidence that insulin activated the sympathetic system at the doses used in these experiments. Nevertheless, the results reported here seem to be compatible with the involvement of the sympathetic system in IID, possible through the renin-angiotensin system. 相似文献