全文获取类型
收费全文 | 212715篇 |
免费 | 12167篇 |
国内免费 | 593篇 |
专业分类
耳鼻咽喉 | 2727篇 |
儿科学 | 6558篇 |
妇产科学 | 4562篇 |
基础医学 | 29036篇 |
口腔科学 | 9680篇 |
临床医学 | 16209篇 |
内科学 | 47562篇 |
皮肤病学 | 5506篇 |
神经病学 | 18208篇 |
特种医学 | 6366篇 |
外国民族医学 | 26篇 |
外科学 | 25578篇 |
综合类 | 1673篇 |
现状与发展 | 1篇 |
一般理论 | 77篇 |
预防医学 | 21601篇 |
眼科学 | 3939篇 |
药学 | 13531篇 |
中国医学 | 924篇 |
肿瘤学 | 11711篇 |
出版年
2023年 | 1226篇 |
2022年 | 2664篇 |
2021年 | 4964篇 |
2020年 | 3198篇 |
2019年 | 4691篇 |
2018年 | 6296篇 |
2017年 | 4635篇 |
2016年 | 4451篇 |
2015年 | 5218篇 |
2014年 | 7083篇 |
2013年 | 9014篇 |
2012年 | 13789篇 |
2011年 | 14379篇 |
2010年 | 7465篇 |
2009年 | 6597篇 |
2008年 | 11133篇 |
2007年 | 11654篇 |
2006年 | 10776篇 |
2005年 | 11010篇 |
2004年 | 10429篇 |
2003年 | 9384篇 |
2002年 | 7340篇 |
2001年 | 5863篇 |
2000年 | 5793篇 |
1999年 | 5053篇 |
1998年 | 1822篇 |
1997年 | 1495篇 |
1996年 | 1481篇 |
1995年 | 1235篇 |
1994年 | 1210篇 |
1993年 | 1092篇 |
1992年 | 2939篇 |
1991年 | 2869篇 |
1990年 | 2621篇 |
1989年 | 2567篇 |
1988年 | 2329篇 |
1987年 | 2155篇 |
1986年 | 2005篇 |
1985年 | 1917篇 |
1984年 | 1407篇 |
1983年 | 1124篇 |
1982年 | 642篇 |
1981年 | 592篇 |
1980年 | 566篇 |
1979年 | 1009篇 |
1978年 | 675篇 |
1977年 | 522篇 |
1975年 | 600篇 |
1974年 | 598篇 |
1973年 | 589篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
41.
42.
43.
44.
Aneurisma de aorta abdominal infrarrenal en asociación con riñón en herradura: aportación de un caso
Nerea Senarriaga Ruiz de la Illa Reyes Vega Manrique Isabel Lacasa Viscasillas Iñaki Iriarte Soldevilla Miguel Unda Urzaiz 《Actas urologicas espa?olas》2009,33(10):1141-1144
We review the association between surgically resolvable aortic disease and horseshoe kidney with a discussion of diagnostic problems and therapeutic options.Male patient 81 years of age with horseshoe kidney and an abdominal aortic aneurysm that was discovered by chance in an abdominal ultrasound during a check-up for his prostate condition.A retroperitoneal approach was used in order to resect the aneurysm and perform an aorto-aortic bypass with no complications occurring. Two years after the diagnosis, the patient is still asymptomatic from a vascular point of view.The co-presence of horseshoe kidney and aortic disease needing surgical correction is infrequent, but it significantly increases the technical complexity of aortic reconstruction. A literature review is included. 相似文献
45.
Human immunodeficiency virus infection in urban Rwanda. Demographic and behavioral correlates in a representative sample of childbearing women 总被引:9,自引:0,他引:9
S Allen C Lindan A Serufilira P Van de Perre A C Rundle F Nsengumuremyi M Carael J Schwalbe S Hulley 《JAMA》1991,266(12):1657-1663
OBJECTIVE.--To determine behavioral and demographic risk factors for human immunodeficiency virus (HIV) infection in central Africa. DESIGN.--Cross-sectional survey. SETTING.--Kigali, Rwanda. PARTICIPANTS.--A representative sample of 1458 childbearing women aged 19 to 37 years who were recruited from outpatient prenatal and pediatric clinics at the only community hospital in the city. MAIN OUTCOME MEASURE.--Antibodies to HIV assessed by enzyme immunoassay and confirmed by Western blot or indirect immunofluorescence. RESULTS.--The HIV seroprevalence was 32% overall. Infection rates were higher in women who were single, in those in steady relationships that began after 1981, and in the 33% of women reporting more than one lifetime sexual partner. Women in legal marriages or monogamous partnerships had lower rates of infection, but even low-risk women had prevalences on the order of 20%. History of venereal disease in the past 5 years, although the strongest risk factor in a multiple logistic analysis (odds ratio, 2.7; 95% confidence interval, 2.0 to 3.7), was reported by only 30% of those infected. Having a male sexual partner who drank alcohol or who had higher income were significant risk factors for HIV infection in the multivariate analysis, but use of oral contraceptives and having an uncircumcised partner were not. CONCLUSIONS.--The epidemic of the acquired immunodeficiency syndrome in Rwanda has spread beyond high-risk groups to the general population of women without known risk factors. For most of these women, a steady male partner is the source of their HIV risk and therefore a vital target for intervention efforts. 相似文献
46.
47.
Esparza-Gordillo Jorge; Goicoechea de Jorge Elena; Buil Alfonso; Berges Luis Carreras; Lopez-Trascasa Margarita; Sanchez-Corral Pilar; Rodriguez de Cordoba Santiago 《Human molecular genetics》2005,14(8):1107
Some MCP SNP and aHUS-associated MCP mutation 相似文献
48.
B Sarmento D C Ferreira L Jorgensen M van de Weert 《European journal of pharmaceutics and biopharmaceutics》2007,65(1):10-17
The aim of the present study was to probe the structural integrity of insulin after being entrapped into chitosan/alginate nanoparticles produced by ionotropic polyelectrolyte pre-gelation. By manipulating the alginate:chitosan mass ratio and the pH during nanoparticle production, desired nanoparticles with a mean size of 850 (+/-88)nm and insulin association efficiency of 81 (+/-2)% were obtained. Insulin secondary structure was assessed by Fourier transform infrared (FTIR) and circular dichroism (CD) after entrapment into nanoparticles and after release from the particles under gastrointestinal simulated conditions. FTIR second-derivative spectra and area-overlap compared to an insulin standard confirmed that no significant conformational changes of insulin occurred in terms of alpha-helix and beta-sheet content. Far-UV-CD spectra corroborated the preservation of insulin structure during the nanoparticle production procedure. The presented nanoparticulate system is a promising carrier for insulin oral delivery since it preserves insulin structure and therefore also, potentially, its bioactivity. 相似文献
49.
L. van den Bemt M. P. de Vries L. van Knapen M. Jansen M. Goossens J. W. M. Muris C. P. van Schayck 《Clinical and experimental allergy》2006,36(2):233-237
BACKGROUND: Exposure to a high level of house dust mite allergens (HDMAs) is considered as a risk factor for HDM sensitization and development of asthma in genetically disposed people. Mattresses are one of the most important sources of HDMA in people's living environment. OBJECTIVE: The aim of this study was to evaluate the association between mattress characteristics and HDMA concentrations on mattresses. METHODS: Dust samples of mattress surfaces were taken to evaluate the level of Der p 1 allergen. All participants filled in a questionnaire about the type of mattress, the type of covering (upper layer) of the mattress, dwelling characteristics and cleaning habits. Humidity and temperature of the bedroom were measured at the time of dust sampling. RESULTS: One hundred and sixty-eight questionnaires were filled in. Synthetic upper layer of the mattress was associated with a higher level of Der p 1 compared with cotton upper layer (2.6 vs. 0.8 microg/g Der p 1). Moreover, higher relative humidity (RH) was associated with significant higher concentrations and density of Der p 1. CONCLUSIONS: Two factors were associated with lower levels of Der p 1 found on mattresses, namely: a cotton upper layer of the mattress compared with a layer of synthetic material and lower RH at the time of sampling. As far as we know, the association between type of upper layer and concentration of Der p 1 has not been described before and could lead to the formulation of practical advices in order to reduce HDMA concentrations on mattresses. 相似文献
50.
Francisco Sampaio Pedro Mateus Nuno Bettencourt Carla Costa Dias Luís Ad?o Lino Santos Madalena Teixeira Lino Sim?es Vasco Gama 《Revista portuguesa de cardiologia》2006,25(3):321-327
INTRODUCTION: Ischemic heart disease is a major cause of heart failure in western societies. However, the factors that may influence left ventricular function (LVF) recovery after an acute coronary syndrome (ACS) are still unclear. OBJECTIVE: To identify variables that may influence LVF evolution one year after ACS. METHODS: 104 patients hospitalized with ACS between 7/1/2001 and 12/31/2002 and with systolic dysfunction--defined as an echocardiographic ejection fraction (EF) < or = 45%--were randomly allocated to a planned coronary follow-up program (FUP) or a general cardiology clinic (GC); patients from both groups were also randomly referred to a structured cardiac rehabilitation program (CRP). EF was re-assessed at one year. We compared differences between patients who recovered left ventricular function (EF > 45%; group 1) and those who did not (group 2). RESULTS: One year after discharge, 44.2% of the patients had recovered function. There were no significant differences between the groups in gender (77.7 vs. 76.5% male), age (56 vs. 59 years), hypertension, diabetes, dyslipidemia, smoking habits or family history. A previous history of cardiovascular events was more frequent in group 2 (11.1% vs. 35.3%, p = 0.03). Cardiac catheterization was performed before discharge in 88.8% and 88.2% in groups 1 and 2 respectively (p = NS); no differences were found in coronary anatomy between the two groups. Angioplasty was performed in 54.2% in group 1 and 50% in group 2 (p = NS). There were no differences in the use of angiotensin-converting enzyme inhibitors (83.3% vs. 87.5%), beta-blockers (87.5% vs. 87.5%), nitrates (37.5% vs. 33.3%), aspirin (95.8% vs. 95.8%), statins (79.1% vs. 75%) or diuretics (20.8% vs. 45.8%). There was no significant difference in LVF recovery between patients randomized to FUP or GC (38.5% vs. 54.5%). 87.5% of patients who completed the CRP had normal EF at one year compared to 32.7% of patients not referred to the program (p = 0.009). Although EF improved in both groups, this improvement was greater in patients who completed a CRP (EF 8% vs. 5%, p = 0.003). CONCLUSION: A previous cardiovascular event and completion of a CRP were the only variables that influenced LVF recovery. Thus, enrollment in a CRP, in addition to standard therapy, could be an important therapeutic measure in patients with systolic dysfunction after ACS; our data suggest that these programs should be more widely used. 相似文献