全文获取类型
收费全文 | 2133篇 |
免费 | 146篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 63篇 |
妇产科学 | 53篇 |
基础医学 | 328篇 |
口腔科学 | 32篇 |
临床医学 | 166篇 |
内科学 | 671篇 |
皮肤病学 | 26篇 |
神经病学 | 179篇 |
特种医学 | 94篇 |
外科学 | 291篇 |
综合类 | 13篇 |
预防医学 | 114篇 |
眼科学 | 43篇 |
药学 | 105篇 |
中国医学 | 6篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 9篇 |
2022年 | 26篇 |
2021年 | 36篇 |
2020年 | 27篇 |
2019年 | 44篇 |
2018年 | 47篇 |
2017年 | 35篇 |
2016年 | 48篇 |
2015年 | 61篇 |
2014年 | 64篇 |
2013年 | 77篇 |
2012年 | 172篇 |
2011年 | 159篇 |
2010年 | 71篇 |
2009年 | 63篇 |
2008年 | 117篇 |
2007年 | 138篇 |
2006年 | 120篇 |
2005年 | 105篇 |
2004年 | 107篇 |
2003年 | 110篇 |
2002年 | 87篇 |
2001年 | 36篇 |
2000年 | 49篇 |
1999年 | 52篇 |
1998年 | 29篇 |
1997年 | 15篇 |
1996年 | 15篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 25篇 |
1991年 | 27篇 |
1990年 | 15篇 |
1989年 | 15篇 |
1988年 | 19篇 |
1987年 | 28篇 |
1986年 | 13篇 |
1985年 | 18篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1979年 | 16篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1974年 | 7篇 |
1971年 | 7篇 |
1969年 | 9篇 |
1933年 | 13篇 |
1932年 | 10篇 |
排序方式: 共有2284条查询结果,搜索用时 15 毫秒
991.
Kapanen M Bly R Sipilä P Järvinen H Tenhunen M 《Physics in medicine and biology》2011,56(7):2119-2130
We estimated cost/benefit ratios for different quality control programs of radiation output measurements of medical linear accelerators. The cost/benefit ratios of quality control (QC) programs (a combination of output measurement time interval and measurement action levels) were defined as workload divided by achievable dose accuracy. Dose accuracy was assumed to be inversely proportional to the 99% confidence limit of shifts of total treatment doses and workload as inversely proportional to the output measurement time interval. Our previously reported method was used to estimate the distribution of shifts of total treatment doses due to changes in accelerator radiation output (Gy/MU). The confidence limits of dose shifts were estimated for different QC programs and for different levels of output measurement reproducibility. Output shifts used in the estimations had previously been observed for four linear accelerators over 5 years. We observed that the cost/benefit ratio increases remarkably when the output measurement time interval is less than 1 month. The ratio depends strongly on the action levels and reproducibility of the QC measurements. Improvement of these factors optimizes the cost/benefit ratio by a factor of several times. The most cost-effective output measurement time interval to achieve 99% confidence limits of ±2, ±2.5 or ±3% for dose shifts ranged from 0.25 month to as much as 6 months depending on the factors given above and the intended accuracy level. It is several times more cost effective to increase dose accuracy by lowering the action levels of the QC measurements and by attempting to improve their reproducibility than by simply shortening the time interval of the output measurements. Methods improving utilization and interpretation of the results of the QC measurements play a key role in further optimization of cost/benefit ratios in dosimetric QC. 相似文献
992.
Mertens M Hofmann J Petraityte-Burneikiene R Ziller M Sasnauskas K Friedrich R Niederstrasser O Krüger DH Groschup MH Petri E Werdermann S Ulrich RG 《Medical microbiology and immunology》2011,200(4):263-268
Highly endemic and outbreak regions for human hantavirus infections are located in the southern, southeastern, and western parts of Germany. The dominant hantavirus is the bank vole transmitted Puumala virus (PUUV). In the eastern part of Germany, previous investigations revealed Tula virus (TULV) and Dobrava-Belgrade virus (DOBV) infections in the respective rodent reservoirs. Here, we describe a seroprevalence study in forestry workers from Brandenburg, eastern Germany, using IgG ELISA and immunoblot tests based on recombinant TULV, DOBV, and PUUV antigens. Out of the 563 sera tested, 499 from male and 64 from female workers, we found 41 out of the 499 (8.2%) sera from men (mean age 47 years) and 10 out of 64 (15.6%) from the women (mean age 48 years) anti-hantavirus-positive. The majority of the 51 seropositive samples reacted exclusively in the TULV (n=22) and DOBV tests (n=17). Focus reduction neutralization assay investigations on selected sera confirmed the presence of TULV- and DOBV-specific antibodies in the forestry workers. These investigations demonstrated a potential health threat for forestry workers and also the average population in non-endemic geographical regions where TULV and DOBV are circulating in the corresponding reservoir hosts. The infections in this region might be frequently overlooked due to their unspecific and mild symptoms. 相似文献
993.
Hanly JG Urowitz MB Jackson D Bae SC Gordon C Wallace DJ Clarke A Bernatsky S Vasudevan A Isenberg D Rahman A Sanchez-Guerrero J Romero-Diaz J Merrill JT Fortin PR Gladman DD Bruce IN Steinsson K Khamashta M Alarcón GS Fessler B Petri M Manzi S Nived O Sturfelt G Ramsey-Goldman R Dooley MA Aranow C Van Vollenhoven R Ramos-Casals M Zoma A Kalunian K Farewell V;Systemic Lupus International Collaborating Clinics 《Annals of the rheumatic diseases》2011,70(6):961-967
994.
Sanchez E Nadig A Richardson BC Freedman BI Kaufman KM Kelly JA Niewold TB Kamen DL Gilkeson GS Ziegler JT Langefeld CD Alarcón GS Edberg JC Ramsey-Goldman R Petri M Brown EE Kimberly RP Reveille JD Vilá LM Merrill JT Anaya JM James JA Pons-Estel BA Martin J Park SY Bang SY Bae SC Moser KL Vyse TJ Criswell LA Gaffney PM Tsao BP Jacob CO Harley JB Alarcón-Riquelme ME;BIOLUPUS GENLES Sawalha AH 《Annals of the rheumatic diseases》2011,70(10):1752-1757
995.
996.
DeZern AE Petri M Drachman DB Kerr D Hammond ER Kowalski J Tsai HL Loeb DM Anhalt G Wigley F Jones RJ Brodsky RA 《Medicine》2011,90(2):89-98
High-dose cyclophosphamide has long been used as an anticancer agent, a conditioning regimen for hematopoietic stem cell transplantation, and a potent immunosuppressive agent in autoimmune diseases including aplastic anemia. High-dose cyclophosphamide is highly toxic to lymphocytes but spares hematopoietic stem cells because of their abundant levels of aldehyde dehydrogenase, the major mechanism of cyclophosphamide inactivation. High-dose cyclophosphamide therapy induces durable remissions in most patients with acquired aplastic anemia. Moreover, high-dose cyclophosphamide without hematopoietic stem cell rescue has shown activity in a variety of other severe autoimmune diseases. Here we review the history of cyclophosphamide as it applies to aplastic anemia and other autoimmune diseases. We include historical data from early patients treated for aplastic anemia as well as data from 140 patients from an observational retrospective study in a single tertiary care hospital. This latter component was designed to assess the safety and efficacy of high-dose cyclophosphamide therapy without stem cell rescue in patients with refractory autoimmune diseases. We analyzed the 140 patients with severe, progressive autoimmune diseases treated. All patients discussed here received cyclophosphamide, 50 mg/kg per day for 4 consecutive days. Response, relapse, and overall survival were measured. Response was defined as a decrease in disease activity in conjunction with a decrease or elimination of immune-modulating drugs. Relapse was defined as worsening disease activity and/or a requirement for an increase in dose of, or administration of new, immunosuppressive medications. Hematologic recovery occurred in all patients. The overall response rate was 94%, and 44% of those patients remained progression free with a median follow-up of 36 months (range, 1-120 mo) for the 140 patients analyzed together. The overall actuarial and event-free survival across all diseases at 60 months was 90.7% and 20.6%, respectively. High-dose cyclophosphamide without stem cell rescue is well tolerated and induces a high rate of remission in severe autoimmune diseases. 相似文献
997.
998.
Pia Soronen Outi Mantere Tarja Melartin Kirsi Suominen Maria Vuorilehto Heikki Rytsälä Petri Arvilommi Irina Holma Mikael Holma Pekka Jylhä Hanna M. Valtonen Jari Haukka Erkki Isometsä Tiina Paunio 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2011,156(4):435-447
We investigated the effect of nine candidate genes on risk for mood disorders, hypothesizing that predisposing gene variants not only elevate the risk for mood disorders but also result in clinically significant differences in the clinical course of mood disorders. We genotyped 178 DSM‐IV bipolar I and II and 272 major depressive disorder patients from three independent clinical cohorts carefully diagnosed with semistructured interviews and prospectively followed up with life charts for a median of 60 (range 6–83) months. Healthy control subjects (n = 1322) were obtained from the population‐based national Health 2000 Study. We analyzed 62 genotyped variants within the selected genes (BDNF, NTRK2, SLC6A4, TPH2, P2RX7, DAOA, COMT, DISC1, and MAOA) against the presence of mood disorder, and in post‐hoc analyses, specifically against bipolar disorder or major depressive disorder. Estimates for time ill were based on life charts. The P2RX7 gene variants rs208294 and rs2230912 significantly elevated the risk for a familial mood disorder (OR = 1.35, P = 0.0013, permuted P = 0.06, and OR = 1.44, P = 0.0031, permuted P = 0.17, respectively). The results were consistent in all three cohorts. The same risk alleles predicted more time ill in all cohorts (OR 1.3, 95% CI 1.1–1.6, P = 0.0069 and OR 1.7, 95% CI 1.3–2.3, P = 0.0002 with rs208294 and rs2230912, respectively), so that homozygous carriers spent 12 and 24% more time ill. P2RX7 and its risk alleles predisposed to mood disorders consistently in three independent clinical cohorts. The same risk alleles resulted in clinically significant differences in outcome of patients with major depressive and bipolar disorder. © 2011 Wiley‐Liss, Inc. 相似文献
999.
Mosca M Tani C Aringer M Bombardieri S Boumpas D Cervera R Doria A Jayne D Khamashta MA Kuhn A Gordon C Petri M Schneider M Shoenfeld Y Smolen JS Talarico R Tincani A Ward MM Werth VP Carmona L 《Autoimmunity reviews》2011,10(7):383-388
The assessment of systemic lupus erythematosus (SLE) patients in routine clinical practice is mainly based on the experience of the treating physician. This carries the risk of unwanted variability. Variability may have an impact on the quality of care offered to SLE patients, thereby affecting outcomes. Recommendations represent systematically developed statements to help practitioners in reducing variability. However, major difficulties arise in the application of recommendations into clinical practice. In this respect, the use of quality indicators may raise the awareness among rheumatologists regarding potential deficiencies in services and improve the quality of health care. The aim of this study was to develop a set of quality indicators (QI) for SLE by translating into QIs the recently developed EULAR Recommendations for monitoring SLE patients in routine clinical practice and observational studies. Eleven QIs have been developed referring to the use of validated activity and damage indices in routine clinical practice, general evaluation of drug toxicity, evaluation of comorbidities, eye evaluation, laboratory assessment, evaluation of the presence of chronic viral infections, documentation of vaccination and of antibody testing at baseline. A disease specific set of quality assessment tools should help physicians deliver high quality of care across populations. Routine updates will be needed. 相似文献
1000.
Tuomainen AM Hyvärinen K Ehlers PI Mervaala E Leinonen M Saikku P Kovanen PT Jauhiainen M Pussinen PJ 《Microbial pathogenesis》2011,51(3):217-224