首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7696篇
  免费   498篇
  国内免费   20篇
耳鼻咽喉   78篇
儿科学   173篇
妇产科学   140篇
基础医学   1357篇
口腔科学   111篇
临床医学   708篇
内科学   1797篇
皮肤病学   216篇
神经病学   801篇
特种医学   341篇
外国民族医学   10篇
外科学   738篇
综合类   42篇
一般理论   9篇
预防医学   499篇
眼科学   94篇
药学   524篇
中国医学   10篇
肿瘤学   566篇
  2023年   38篇
  2022年   73篇
  2021年   153篇
  2020年   87篇
  2019年   137篇
  2018年   140篇
  2017年   113篇
  2016年   137篇
  2015年   222篇
  2014年   247篇
  2013年   298篇
  2012年   524篇
  2011年   547篇
  2010年   312篇
  2009年   308篇
  2008年   534篇
  2007年   547篇
  2006年   452篇
  2005年   501篇
  2004年   414篇
  2003年   414篇
  2002年   385篇
  2001年   147篇
  2000年   122篇
  1999年   159篇
  1998年   107篇
  1997年   86篇
  1996年   70篇
  1995年   61篇
  1994年   54篇
  1993年   44篇
  1992年   80篇
  1991年   65篇
  1990年   64篇
  1989年   63篇
  1988年   72篇
  1987年   45篇
  1986年   40篇
  1985年   40篇
  1984年   41篇
  1983年   34篇
  1982年   18篇
  1981年   19篇
  1980年   20篇
  1979年   22篇
  1977年   15篇
  1975年   12篇
  1974年   17篇
  1973年   13篇
  1972年   14篇
排序方式: 共有8214条查询结果,搜索用时 0 毫秒
21.
AIMS: The aim of this study was to document the early outcome of coronary-like revascularization for atherosclerotic renal artery stenosis (ARAS). METHODS AND RESULTS: A total of 181 consecutive patient, 102 men, mean age 66.1 (+/- 9.2) years and 79 females, mean age 68.4 (+/- 9.2) years and 198 lesions were treated between February 1999 and May 2004 for ARAS and retrospectively analyzed. At least one major cardiovascular risk factor was present in 179 (98.9%) patients. Pre-dilatation ARAS was 81.3+/-9.6%, 27 ARAS were 50-70% and no ARAS was <50%. 135 (68.2%) of the ARAS lesions were ostial and 63 (31.8%) were non-ostial. In 17 (9.4%) patients bilateral ARAS were present. Technical success defined as residual stenosis < or =30% was achieved in 178 (98.3%) of patients and 195 (98.5%) of lesions. In one patient (0.5%) the target ARAS could not be crossed, in two (1.1%) patients residual stenosis was >30%. No major adverse cardiac or cerebral effects were observed. In 3.9% of patients minor local complications of the access site occurred; 4 (2.2%) inguinal hematoma, 3 (1.7%) pseudoaneurysm were documented. Serum creatinine concentrations and systolic and diastolic blood pressure before and after the intervention were not statistically different. CONCLUSIONS: Coronary-like approach to ARAS revascularization is technically feasible and associated with a very low complication rate.  相似文献   
22.
To describe the determinants of patient satisfaction with medical care, self-administered questionnaires were given to a consecutive sample of 237 patients coming to an ambulatory care practice for the treatment of upper respiratory infections (URIs). Patients' most important goal was to obtain a diagnosis (57%). They usually got more reassurance, medication, and personal interest than they had expected (p = 0.0001). In a multivariate model, patients' satisfaction was related to the degrees of personal interest and reassurance they had received and to whether they felt they had received the right medication (r2 = 0.45, p = 0.0001). The authors concluded that patients with URIs generally want a diagnosis but are primarily satisfied by the personal interest, the reassurance, and the medication they receive.  相似文献   
23.
24.
A 9-year-old boy presented with a small subcutaneous tumor of the trunk and diffuse bone marrow involvement. The first histological diagnosis given was undifferentiated malignancy possibly of neural crest origin and chemotherapy was started immediately using vincristine, cyclophosphamide, cisplatin, and teniposide (OPEC). Complete response was achieved after four courses of chemotherapy. Histological slides were then reviewed and the final diagnosis of alveolar rhabdomyosarcoma (RMS) was retained. Moreover, chromosome analysis of malignant cells in the bone marrow revealed a translocation involving chromosomes 2 and 13:t(2;13) (q35;q14). This specific karyotype finding has been recently reported in a few cases and could be specific for alveolar RMS. The patient had a relapse 7 months after diagnosis and died 4 months later.  相似文献   
25.
26.
The susceptibility of human immunodeficiency virus type 2 (HIV-2) to protease inhibitors (PI) is largely unknown. We studied HIV-2 protease genes from 21 HIV-2-infected patients who were exposed or not exposed to PI. The aim of this study was (i). to characterize the polymorphism of HIV-2 protease in the absence of drug, (ii). to know whether the HIV-2 protease gene naturally harbors HIV-1 drug resistance codons, and (iii). to identify mutations emerging under PI-selective pressure. Sixty-five HIV-2 RNA or proviral DNA samples were directly sequenced from the plasma or peripheral blood mononuclear cells of 8 patients who had received PI and 13 patients who had never received any antiretroviral. In untreated patients, the highest amino acid variability in HIV-2 protease was observed at positions 14, 40, 43, 46, 65 and 70, and seven codons (10V, 32I, 36I, 46I, 47V, 71V, and 73A) associated with drug resistance in HIV-1 were highly prevalent. In addition, at six positions (positions 7, 46, 62, 71, 90, and 99), the amino acid variability or the amino acid frequencies or both differed significantly in PI-treated and untreated patients, suggesting that mutations 7K-->R, 46V-->I, 62V-->A/T, 71V-->I, 90L-->M and 99L-->F were occurring under PI-selective pressure. At these positions, at least one sample simultaneously harbored both wild-type and mutated codons, while substitutions at positions 62, 71, 90, and 99 were confirmed in a longitudinal analysis. Moreover, the presence of codons 46I and 99F in the absence of drug in HIV-2 subtype B proteases may reflect natural resistance to PI. In conclusion, the present study revealed that HIV-2 strains harbor specific patterns of natural polymorphism and resistance.  相似文献   
27.
To reduce the risks associated with live-attenuated immunodeficiency virus vaccines, single-cycle immunodeficiency viruses (SCIVs) were developed by primer complementation and production of the vaccine in the absence of vif in a vif-independent cell line. After a single intravenous injection of SCIVs into rhesus monkeys, peak viral RNA levels of 10(3) to 10(4) copies/ml plasma were observed, indicating efficient expression of SCIV in the vaccinee. After booster immunizations with SCIVs, SIV-specific humoral and cellular immune responses were observed. Although the vaccine doses used in this pilot study could not protect vaccinees from subsequent intravenous challenge with pathogenic SIVmac239, our results demonstrate that the novel SCIV approach allows us to uncouple in vivo expression levels from the viral replicative capacity facilitating the analysis of the relationship between viral expression levels or viral genes and immune responses induced by SIV.  相似文献   
28.
Summary The arteries of the gut, and in particular in the inferior mesenteric artery (a. mesenterica inferior), normally play a minimal role in supplying blood to the lower limbs. However, this is far from being the case in aorto-iliac obstruction. The anatomical anastomoses between the intestinal arterial system and the arteries of the lower limb hypertrophy and in one case out of ten become predominant.In the present study the path taken and the relations of the collaterals of the intestinal arteries and of their anastomoses have been traced, and several collateral pathways are described.
Rôle des artères mésentériques dans la revascularisation artérielle des membres inférieurs
Résumé Les artères digestives, et en particulier l'artère mésentérique inférieure (a. mesenterica inferior), jouent à l'état normal un rôle minime dans la vascularisation des membres inférieurs. Il n'en est pas de même en cas d'oblitération aorto-iliaque. Les anastomoses anatomiques entre le système artériel digestif et les artères du membre inférieur s'hypertrophient et, dans un cas sur 10, deviennent prédominantes.Dans cette étude, le trajet et les relations des collatérales des artères digestives et leurs anastomoses sont étudiés. Plusieurs voies collatérales sont possibles.
  相似文献   
29.
Gamma irradiation alters bluetongue virus protein antigen.   总被引:1,自引:0,他引:1  
Bluetongue virus (BTV) antigen, prepared for a monoclonal antibody (MAb)-based competitive enzyme-linked immunosorbent assay (C-ELISA), was exposed to 1, 2, 3, 4, 5 and 6 Mrad of gamma irradiation. The major group-specific BTV protein (VP7) reactive with the Mab was altered at higher doses of radiation, as revealed by immunoblotting studies. As well, a reduction in immunoreactivity was noted when irradiated antigen was used in the ELISA.  相似文献   
30.
The epicondylar axis is a reliable reference to check the rotation of the femoral implant in total knee prostheses (TKPs). However, during the operation it seems easier to use the posterior condylar axis as a landmark. The angle between these two axes is called the posterior condylar angle (PCA). The aim of this study was to measure the PCA in arthritic knees to assess the reliability of the posterior condylar axis as a reference for the control of the rotation of the femoral implant and to look for correlation with other radiological measurements. This prospective study consisted of 103 arthritic knees (81 varus, 22 valgus) before a TKP had been done in 103 patients (75 women, 28 men). The assessment of the PCA was made by computed tomographic scanning (CT). The HKA, HKS and HKT angles were measured on the pangonogram. The posterior condylar axis was internally rotated with respect to the epicondylar axis. The average value for all the patients was 2.65° degrees with a range from 0° to 7°. The PCA was significantly increased in the valgus knees. There was no correlation between the angles on the pangonogram and the posterior condylar axis. While the preoperative assessment of the PCA by CT scanning is reliable, the results obtained indicate the marked variability in its value. If one wishes to use the posterior condylar axis as a guide for rotation, it is therefore necessary to assess the PCA for each patient using adjustable jigs according to the value obtained. No measurement on standard radiographs allowed an extrapolation of the value of the PCA, and CT scanning seems to be the preferable radiological examination.

Electronic Supplementary Material The french version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at
Etude tomodensitométrique de l'angle condylien postérieur dans les genoux arthrosiques. Intérêt dans le positionnement en rotation de l'implant fémoral dans les prothèses totales de genou
Résumé L'axe épicondylien est une référence fiable pour le contrôle de la rotation de l'implant fémoral dans les prothèses totales de genou (PTG). Mais, lors de l'intervention, il semble plus facile d'utiliser l'axe condylien postérieur comme repère. L'angle entre ses deux axes est appelé angle condylien postérieur (ACP). Le but de cette étude était de mesurer l'ACP dans les genoux arthrosiques, d'évaluer la fiabilité de l'axe condylien postérieur comme référence pour le réglage de la rotation de l'implant fémoral, de rechercher une corrélation avec d'autres mesures radiologiques. Une étude prospective comportant 103 genoux arthrosiques (81 varus et 22 valgus), avant PTG a été effectuée, chez 103 patients (75 femmes et 28 hommes). L'évaluation de l'ACP a été faite par examen tomodensitométrique (TDM). Les angles HKA, HKS et HKT ont été mesurés sur le pangonogramme. L'axe condylien postérieur était en rotation interne par rapport à l'axe épicondylien. La valeur moyenne pour tous les patients était de 2.65°, avec des valeurs de 0 à 7°. La valeur de l'angle CP augmentait avec une différence significative dans le groupe des genu valgum. Il n'y avait pas de corrélation entre les angles du pangonogramme et l'ACP. Si l'évaluation pré-opératoire de l'ACP par TDM est fiable, les résultats obtenus mettent en évidence une variabilité importante de sa valeur. Il faut donc, si l'on veut utiliser l'axe condylien postérieur comme repère de rotation, évaluer pour chaque patient l'ACP, et utiliser un ancillaire réglable reportant la valeur obtenue. Aucune mesure sur des radiographies standard ne permettant d'extrapoler la valeur de l'ACP, la TDM semble l'examen radiologique de choix.
  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号