全文获取类型
收费全文 | 138458篇 |
免费 | 6067篇 |
国内免费 | 365篇 |
专业分类
耳鼻咽喉 | 2109篇 |
儿科学 | 4363篇 |
妇产科学 | 2973篇 |
基础医学 | 18839篇 |
口腔科学 | 4514篇 |
临床医学 | 8678篇 |
内科学 | 34183篇 |
皮肤病学 | 4353篇 |
神经病学 | 11213篇 |
特种医学 | 3152篇 |
外国民族医学 | 1篇 |
外科学 | 16720篇 |
综合类 | 703篇 |
一般理论 | 43篇 |
预防医学 | 13341篇 |
眼科学 | 3087篇 |
药学 | 9598篇 |
中国医学 | 647篇 |
肿瘤学 | 6373篇 |
出版年
2023年 | 939篇 |
2022年 | 965篇 |
2021年 | 3245篇 |
2020年 | 1603篇 |
2019年 | 3338篇 |
2018年 | 5411篇 |
2017年 | 3170篇 |
2016年 | 3043篇 |
2015年 | 3414篇 |
2014年 | 3929篇 |
2013年 | 5847篇 |
2012年 | 10078篇 |
2011年 | 10727篇 |
2010年 | 5453篇 |
2009年 | 3855篇 |
2008年 | 8480篇 |
2007年 | 9049篇 |
2006年 | 8346篇 |
2005年 | 8238篇 |
2004年 | 7227篇 |
2003年 | 6757篇 |
2002年 | 6341篇 |
2001年 | 3870篇 |
2000年 | 4473篇 |
1999年 | 3356篇 |
1998年 | 576篇 |
1997年 | 384篇 |
1996年 | 349篇 |
1995年 | 273篇 |
1994年 | 213篇 |
1992年 | 1278篇 |
1991年 | 1061篇 |
1990年 | 943篇 |
1989年 | 766篇 |
1988年 | 641篇 |
1987年 | 625篇 |
1986年 | 626篇 |
1985年 | 530篇 |
1984年 | 392篇 |
1983年 | 308篇 |
1979年 | 334篇 |
1975年 | 270篇 |
1974年 | 323篇 |
1973年 | 353篇 |
1972年 | 291篇 |
1971年 | 314篇 |
1970年 | 292篇 |
1969年 | 293篇 |
1968年 | 267篇 |
1967年 | 237篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
José Abal Arca Isaura Parente Lamelas Raquel Almazán Ortega José Blanco Pérez María Elena Toubes Navarro Pedro Marcos Velázquez 《Archivos de bronconeumologia》2009,45(10):502-507
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group. 相似文献
43.
Generoso Gómez Cruz Miguel Barrueco Ferrero Irene Aparicio Coca José Ángel Maderuelo Miguel Torrecilla García 《Archivos de bronconeumologia》2009,45(1):16-23
Background and ObjectiveSchool smoking prevention programs have never yielded the expected results. The aim of this study was to analyze the efficacy of an intensive smoking prevention program created by the educational community in which it was to be applied.Population and MethodA 3-year smoking prevention program was carried out among the students of Fuentesaúco Secondary School in Zamora, Spain. The Babilafuente Secondary School in Salamanca, Spain was the control group. The program included both prevention and treatment activities. The former were carried out in the school, in out-of-school situations, and in the community. The questionnaire of the European Smoking Prevention Framework Approach was used.ResultsA total of 417 students aged 12 to 17 years participated in the study. Of these, 54.4% belonged to the intervention group and 45.6% to the control group. Smokers represented 36.7% of the population. After the intervention smokers represented 40.1% of the Fuentesaúco students compared with 46.1% of the Babilafuente students, though the difference was not statistically significant. With respect to the cognitive determinants of smoking behavior, after the intervention significant differences in favor of the intervention group were only observed in the subjects’ perception of the behavior of their siblings, peers, and teachers.ConclusionsThe use of smoking prevention programs in schools should be reconsidered, and their evaluation should be based on educational rather than clinical criteria. Proposed changes in the program include decreasing its intensity, starting with students of an earlier age and seeking greater involvement of parents. 相似文献
44.
45.
46.
Eduardo Carracedo-Martínez Agustin Pia-Morandeira 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(6):324-328
ObjectiveTo assess whether the release of the new consensus algorithms in August 2006, along with the consensus recommendation of also using metformin as first choice in patients with normal weight, has led to an increase in the use of this drug in the period immediately after.DesignRetrospective longitudinal Study.SitesSantiago de Compostela Health District (A Coruña).ParticipantsUsers of the Galician health service in the Santiago de Compostela Health District.MethodsThe evolution of the monthly number of DHD (Daily Defined Doses/1000 inhabitants/day) of metformin from early 2003 until 12 months after the issuing of new algorithms was analysed graphically and using a multiple regression model.ResultsThe graphical representation of the DHD of metformin over time shows a linear growth for the period, but there is an increasing trend after the publication of the new consensus algorithm. The multiple regression showed that the increase is statistically significant.ConclusionsFollowing the publication of the new consensus algorithm an increasing trend in the use of metformin is observed in the short term. 相似文献
47.
48.
David Jiménez Castro Gema Díaz David Martí Carlos Escobar Javier Ortega Sergio García-Rull Joaquin Picher Antonio Sueiro 《Blood coagulation & fibrinolysis》2007,18(2):173-177
This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization. 相似文献
49.
D-dimer has proved a useful diagnostic tool for the exclusion of deep venous thrombosis (DVT). The objective of this paper was to evaluate the diagnostic performance of a diagnostic algorithm combining clinical probability and D-dimer in outpatients receiving oral anticoagulant treatment (OAT) similar to those regularly applied to nonanticoagulated individuals. We enrolled 70 outpatients on OAT who presented with clinically suspected DVT; a standard diagnostic algorithm including clinical evaluation using the modified Wells score and a quantitative immunoturbidimetric D-dimer assay (STA Liatest D-Di; Diagnostica Stago, Asniéres sur Seine, France) was used. A 3-month follow-up period was applied for those patients in whom DVT was initially excluded. The prevalence of DVT was 18.5% (13/70); four of the diagnoses were made during the 3-month follow-up period. The sensitivity, specificity and negative predictive value of D-dimer were 69.2% (95 confidence interval, 42.4-87.3), 47.4% (95% confidence interval, 35.0-60.1) and 87.1% (95% confidence interval, 71.1-94.9), respectively. In conclusion, D-dimer is of limited value in outpatients on OAT presenting with clinically suspected DVT and should be omitted in such individuals; these patients should always undergo compression venous ultrasound, and repeat ultrasonography within 1 week might be warranted in cases with an initial negative examination. 相似文献
50.