收费全文 | 28108篇 |
免费 | 2248篇 |
国内免费 | 69篇 |
耳鼻咽喉 | 245篇 |
儿科学 | 1014篇 |
妇产科学 | 780篇 |
基础医学 | 3671篇 |
口腔科学 | 398篇 |
临床医学 | 4706篇 |
内科学 | 4951篇 |
皮肤病学 | 342篇 |
神经病学 | 2590篇 |
特种医学 | 504篇 |
外科学 | 2500篇 |
综合类 | 479篇 |
一般理论 | 52篇 |
预防医学 | 4071篇 |
眼科学 | 319篇 |
药学 | 1869篇 |
中国医学 | 22篇 |
肿瘤学 | 1912篇 |
2023年 | 129篇 |
2022年 | 210篇 |
2021年 | 556篇 |
2020年 | 363篇 |
2019年 | 555篇 |
2018年 | 594篇 |
2017年 | 440篇 |
2016年 | 482篇 |
2015年 | 539篇 |
2014年 | 744篇 |
2013年 | 1283篇 |
2012年 | 1803篇 |
2011年 | 1806篇 |
2010年 | 978篇 |
2009年 | 926篇 |
2008年 | 1761篇 |
2007年 | 1985篇 |
2006年 | 1786篇 |
2005年 | 1776篇 |
2004年 | 1758篇 |
2003年 | 1579篇 |
2002年 | 1590篇 |
2001年 | 380篇 |
2000年 | 346篇 |
1999年 | 337篇 |
1998年 | 404篇 |
1997年 | 305篇 |
1996年 | 295篇 |
1995年 | 248篇 |
1994年 | 240篇 |
1993年 | 213篇 |
1992年 | 240篇 |
1991年 | 209篇 |
1990年 | 228篇 |
1989年 | 176篇 |
1988年 | 212篇 |
1987年 | 170篇 |
1986年 | 162篇 |
1985年 | 164篇 |
1984年 | 156篇 |
1983年 | 132篇 |
1982年 | 200篇 |
1981年 | 169篇 |
1980年 | 160篇 |
1979年 | 111篇 |
1978年 | 114篇 |
1977年 | 108篇 |
1976年 | 109篇 |
1974年 | 98篇 |
1973年 | 125篇 |
Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.
Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings. 相似文献
Background
Current blunt cerebrovascular injury (BCVI) grading grossly differentiates injury characteristics such as luminal stenosis (LS) and aneurysmal disease. The effect of increasing degree of LS beyond the current BCVI grading scale on stroke formation is unknown.Study Design
BCVI over a 3-year period were retrospectively reviewed. To investigate influence of LS beyond the BCVI grading scale within aneurysmal and non-aneurysmal BCVI, grade 2 BCVI were subdivided into BCVI with ≥ 25% and ≤ 50% LS and BCVI with > 50% and ≤ 99% LS. Grade 3 BCVI were subdivided into BCVI with pseudoaneurysm (PSA) without LS and BCVI with PSA and LS. We hypothesized increased LS beyond the current BCVI grade distinctions would be associated with higher rates of stroke formation.Results
312 BCVI were included, of which 140 were carotid BCVI and 172 vertebral BCVI. Sixteen carotid BCVI underwent endovascular intervention (EI) and 19 suffered a stroke. In carotid BCVI stroke rates increased sequentially with BCVI grade except in grade 3. There was a stroke rate of 12% in grade 1 carotid BCVI, 18% in grade 2, 6% in grade 3, and 31% in grade 4. In subgroup analysis for grade 2 carotid BCVI, BCVI with > 50% and ≤ 99% LS had higher rates of stroke (22% vs. 15%, p?=?0.44) than BCVI with ≥ 25% and ≤ 50% LS. In subgroup analysis of grade 3 carotid BCVI, BCVI with PSA and LS had higher rates of stroke (9% vs. 4%, p?=?0.48) than BCVI with PSA without LS. Higher rates of EI in grade 2 carotid BCVI with > 50% and ≤ 99% LS (22% vs. 5%, p?=?0.14) and grade 3 carotid BCVI with PSA and LS (35% vs. 4%, p?=?0.01) were noted in subgroup analysis.Conclusion
Higher percentage LS beyond the currently used BCVI grading scale has a non-significantly increased rate of stroke in both aneurysmal and non-aneurysmal BCVI. Grade 3 BCVI with PSA and LS seems to be a high-risk subgroup. Use of EI confounds modern measurement of stroke risk in higher LS BCVI. 相似文献Methods: A retrospective analysis was performed to identify patients with isolated PCL injuries that underwent reconstruction between 2001 and 2014. Patients with multi-ligamentous injury or another concomitant knee pathology were excluded. Medical records were reviewed for demographic, clinical and operative data. Patients were contacted for administration of a telephone-based questionnaire which included the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation form, Lysholm-Tegner scales, Marx activity scale (MAS), return to sport status, and patient satisfaction instruments.
Results: A total of 15 isolated PCL reconstructions in 14 patients with a mean age of 27.5 years (range 17–43) met the study inclusion criteria; mean follow up was 6.3 years (range 1.4–15.2). Pre-operatively, the primary complaint was knee instability in all patients; on physical examination, lack of a firm end point during posterior drawer testing was found in 93% (14/15) of the knees. In total, 12 of 15 knees underwent transtibial, single-bundle PCLR and three of 15 underwent tibial inlay, double bundle PCLR. Graft types included: quadriceps autograft (7/15), Achilles allograft (6/15), and hamstring autograft (2/15). There were no graft failures in our patient cohort. At most recent follow up the mean scores respectively on the IKDC form, Lysholm-Tegner scales and MAS were (standard deviation): 77.3 (16.5), 83.1 (17.9), 6.13 (2.6), and 7.1 (6.0). All fourteen patients were athletes prior to their injury and 79% (11/14) returned to sport and overall patient satisfaction was 9.2/10.
Conclusions: Isolated PCLR provides good outcomes at mean medium-term follow up with restoration of function, high rate of return to sport and overall patient satisfaction. 相似文献