全文获取类型
收费全文 | 4048篇 |
免费 | 332篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 95篇 |
妇产科学 | 99篇 |
基础医学 | 608篇 |
口腔科学 | 292篇 |
临床医学 | 329篇 |
内科学 | 985篇 |
皮肤病学 | 30篇 |
神经病学 | 328篇 |
特种医学 | 82篇 |
外国民族医学 | 1篇 |
外科学 | 408篇 |
综合类 | 24篇 |
一般理论 | 41篇 |
预防医学 | 521篇 |
眼科学 | 50篇 |
药学 | 145篇 |
中国医学 | 2篇 |
肿瘤学 | 323篇 |
出版年
2023年 | 20篇 |
2022年 | 34篇 |
2021年 | 60篇 |
2020年 | 50篇 |
2019年 | 101篇 |
2018年 | 96篇 |
2017年 | 83篇 |
2016年 | 88篇 |
2015年 | 82篇 |
2014年 | 114篇 |
2013年 | 140篇 |
2012年 | 152篇 |
2011年 | 167篇 |
2010年 | 113篇 |
2009年 | 120篇 |
2008年 | 226篇 |
2007年 | 169篇 |
2006年 | 173篇 |
2005年 | 152篇 |
2004年 | 156篇 |
2003年 | 151篇 |
2002年 | 160篇 |
2001年 | 138篇 |
2000年 | 129篇 |
1999年 | 142篇 |
1998年 | 57篇 |
1997年 | 47篇 |
1996年 | 50篇 |
1995年 | 39篇 |
1994年 | 41篇 |
1993年 | 29篇 |
1992年 | 124篇 |
1991年 | 113篇 |
1990年 | 98篇 |
1989年 | 93篇 |
1988年 | 73篇 |
1987年 | 62篇 |
1986年 | 68篇 |
1985年 | 55篇 |
1984年 | 58篇 |
1983年 | 25篇 |
1982年 | 29篇 |
1980年 | 22篇 |
1979年 | 31篇 |
1978年 | 22篇 |
1977年 | 21篇 |
1975年 | 16篇 |
1972年 | 19篇 |
1971年 | 18篇 |
1968年 | 17篇 |
排序方式: 共有4391条查询结果,搜索用时 31 毫秒
131.
Lisa DeTora Cate Foster Mukund Nori Donna Simcoe Catherine Skobe Dikran Toroser 《International journal of clinical practice》2018,72(2)
It is relatively easy to begin policy documents with a general assertion that ethics will be followed. Less obvious is how to ensure that day‐to‐day activities are consonant with ethical standards. We suggest that using day‐to‐day publication activities as the driver for building policies and procedures can promote ethical practices from the ground up. Although basic principles of ethical publication practice may seem straightforward to some, for others this information may require explanation, interpretation and context. Effective policy development includes big‐picture items as well as more day‐to‐day tactical responsibilities such as those discussed below. Research questions, disciplinary practices, applications and team structures may vary. Thus, no single publication plan or policy solution is right for all teams. It is up to team members to review guidelines for best practices and find the optimal implementation for their situations. Experts in publication management, planning and writing can help large teams manage publication activities. These experts have an obligation to maintain and enhance their skills continually. A strong acumen in publication best practices will allow these publication professionals to better address any possible ethical dilemmas in the future. 相似文献
132.
133.
Livneh Nir Braeken Dionne Drozdinsky Genady Gafter-Gvili Anat Seelig Jaap Rozovski Uri Berger Tamar Raanani Pia Falanga Anna ten Cate Hugo Spectre Galia Leader Avi 《Journal of thrombosis and thrombolysis》2021,52(2):590-596
Journal of Thrombosis and Thrombolysis - Managing anticoagulation in hematological malignancy patients with atrial fibrillation and thrombocytopenia is a clinical challenge with limited data. We... 相似文献
134.
135.
Detection of deep vein thrombosis with impedance plethysmography and real-time compression ultrasonography in hospitalized patients. 总被引:2,自引:0,他引:2
H Heijboer A Cogo H R Büller P Prandoni J W ten Cate 《Archives of internal medicine》1992,152(9):1901-1903
BACKGROUND--Serial testing with impedance plethysmography or compression ultrasonography has been demonstrated to be feasible and accurate for the detection of deep vein thrombosis (DVT) in symptomatic outpatients, and these techniques are replacing contrast venography in this patient category. Limited data, however, are available on the clinical utility of these noninvasive tests in symptomatic hospitalized patients. The objectives of our study were to determine the feasibility of ascending contrast venography and to evaluate the accuracy of these two noninvasive methods for the detection of DVT in symptomatic hospitalized patients. METHODS--A prospective, "blind" comparison of impedance plethysmography and compression ultrasonography with ascending contrast venography was performed in consecutive hospitalized patients with clinically suspected DVT of the leg. RESULTS--Of the 127 potentially eligible patients, 44 had to be excluded; 25 of these could not undergo venography (feasibility of venography, 80.3%). The sensitivity, specificity, and positive and negative predictive values of impedance plethysmography for proximal DVT were 96%, 83%, 82%, and 97%, respectively. For compression ultrasonography, these measures for proximal DVT were 97%, 86%, 87%, and 97%, respectively. The overall prevalence of DVT was 53%, of which 85% was located proximally. CONCLUSIONS--Contrast venography cannot be performed in about 20% of consecutive symptomatic patients. Both impedance plethysmography and compression ultrasonography are feasible and valid alternatives to contrast venography in the diagnostic treatment of these patients. 相似文献
136.
OBJECTIVE: The aim was to evaluate the applicability of myocardial contrast echocardiography in the measurement of coronary flow reserve. METHODS: Eleven anaesthetised open chest pigs were studied, in which coronary atherosclerosis had been induced by abrasion of the left anterior descending coronary artery at one month, followed by an atherogenic diet for eight months. Coronary flow reserve was determined by electromagnetic flow measurement and contrast echocardiography before and after partial occlusion of the left anterior descending coronary artery, using papaverine as a coronary vasodilator. Coronary blood flow was reduced by tightening a clamp placed around the coronary artery. Systemic haemodynamics and myocardial wall thickness (epicardial ultrasound 5 MHz transducer) were recorded simultaneously. Echocardiograms were recorded on VHS tape and analysed by digitised videodensitometry off line for construction of the time v videointensity curve (time-intensity curves). From these curves washout time (T50), area under the curve, peak contrast intensity, and time to peak intensity were calculated. RESULTS: Following papaverine, coronary blood flow increased significantly from 47 (SD 23) ml.min-1 at baseline to 88(39) ml.min-1 (p less than 0.05). During the stenosis, flow decreased to 19(16) ml.min-1 (p less than 0.01), and increased to 38(29) ml.min-1 (p less than 0.05 v stenosis) after administration of papaverine. Correlations between coronary blood flow and indices calculated from the quantitative videodensitometric analysis were poor, varying between r = 0.03 for area at control flow to r = 0.62 for T50 during stenosis. The same was true for coronary flow reserve: r = 0.09 for peak to r = 0.75 (p less than 0.05) for time to peak without the stenosis. CONCLUSIONS: Current limitations in injection, imaging, and analysis techniques cause variability in data from time-intensity curves, which precludes accurate quantification of coronary flow (reserve) by myocardial contrast echocardiography. 相似文献
137.
Meliga E Steendijk P Valgimigli M Ten Cate FJ Serruys PW 《The American journal of cardiology》2008,101(8):1179-1184
The aim of the present study was to determine the long-term effects of percutaneous transluminal septal myocardial ablation (PTSMA) on systolic and diastolic left ventricular (LV) functions in patients with obstructive hypertrophic cardiomyopathy (HC). Ten consecutive patients with symptomatic HC despite optimal medical treatment were referred for PTSMA at our center. LV systolic and diastolic functions were assessed by online LV pressure-volume loops obtained by conductance catheter at baseline and at 6 months after the procedure. At follow-up, the mean gradients at rest and after extrasystole were significantly decreased compared with baseline (88 +/- 29 to 21 +/- 11 mm Hg and 130 +/- 50 to 35 +/- 22 mm Hg, respectively, p <0.01 for the 2 comparisons). End-systolic and end-diastolic pressures significantly decreased (p <0.01), whereas end-systolic and end-diastolic LV volumes significantly increased (p <0.01 for the 2 comparisons). Cardiac output and stroke volume were unchanged, as were ejection fraction (p = 0.25) and maximum dP/dt (p = 0.13). The slope of the end-systolic pressure-volume relation was not decreased, indicating a preserved contractility. The relaxation constant time, end-diastolic stiffness, projected volume of the end-diastolic pressure-volume relation at 30 mm Hg, and diastolic stiffness constant showed a significant improvement of active and passive myocardial diastolic properties. In conclusion, PTSMA is an effective method in the treatment of symptomatic patients with HC. At 6-month follow-up, the LV-aortic gradient was decreased and active and passive LV diastolic properties were increased. Myocardial contractility was not decreased and general hemodynamics was maintained. 相似文献
138.
139.
Rahel BM Suttorp MJ ten Berg JM Bal ET Ernst SM Rensing BJ Kelder JC Plokker HW 《Journal of interventional cardiology》2004,17(4):197-201
INTRODUCTION: Conventional percutaneous coronary intervention for the treatment of in-stent restenosis (ISR) has shown a high rate of ISR (30-55%). Considering the need for both extrusion of hyperplastic intima and additional stent expansion, a cutting balloon might be more effective for the treatment of ISR. METHODS: We prospectively assessed the immediate and 8-month outcome of balloon angioplasty using the Barath Cutting Balloon in 100 consecutive patients (mean age: 60.5 +/- 10.8 years, 71% male). RESULTS: In 73 lesions (73%), a good result was reached with the cutting balloon only. In 21 lesions (21%) postdilatation and in 6 lesions (6%) predilatation with a conventional balloon was necessary. The mean inflation pressure was 8.7 +/- 2.0 (range: 6.0-18.0) atm. Before the procedure the mean minimal luminal diameter (MLD) was 0.95 +/- 0.45 mm. Quantitative coronary analysis showed a mean diameter stenosis of 65%+/- 16%. Immediately after the procedure the mean MLD was 2.42 +/- 0.54 mm with a mean diameter stenosis of 19%+/- 13%. Two patients died during the follow-up period (1 stroke, 1 nonvascular). At 8-month follow-up 26 patients (26%) reported to have anginal complaints CCS class II-IV of whom 16 (16%) needed target lesion revascularization. CONCLUSION: Treatment of ISR using the Barath Cutting Balloon can be performed safely with good immediate results and a relatively low need for repeated target lesion revascularization at 8-month follow-up. 相似文献
140.
Peter M. ten Klooster ERIK TAAL Mart A. F. J. van de Laar 《Arthritis care & research》2008,59(12):1721-1728