全文获取类型
收费全文 | 187620篇 |
免费 | 34741篇 |
国内免费 | 1529篇 |
专业分类
耳鼻咽喉 | 3486篇 |
儿科学 | 4710篇 |
妇产科学 | 3591篇 |
基础医学 | 14276篇 |
口腔科学 | 7198篇 |
临床医学 | 34621篇 |
内科学 | 44169篇 |
皮肤病学 | 4673篇 |
神经病学 | 20595篇 |
特种医学 | 7240篇 |
外国民族医学 | 1篇 |
外科学 | 32823篇 |
综合类 | 895篇 |
现状与发展 | 40篇 |
一般理论 | 194篇 |
预防医学 | 19281篇 |
眼科学 | 3864篇 |
药学 | 6642篇 |
中国医学 | 144篇 |
肿瘤学 | 15447篇 |
出版年
2024年 | 803篇 |
2023年 | 5678篇 |
2022年 | 2500篇 |
2021年 | 5754篇 |
2020年 | 6857篇 |
2019年 | 4634篇 |
2018年 | 9845篇 |
2017年 | 9402篇 |
2016年 | 10119篇 |
2015年 | 10481篇 |
2014年 | 13913篇 |
2013年 | 16653篇 |
2012年 | 10903篇 |
2011年 | 10764篇 |
2010年 | 10702篇 |
2009年 | 12407篇 |
2008年 | 9442篇 |
2007年 | 8174篇 |
2006年 | 9134篇 |
2005年 | 7646篇 |
2004年 | 6484篇 |
2003年 | 5756篇 |
2002年 | 5194篇 |
2001年 | 2363篇 |
2000年 | 1575篇 |
1999年 | 2294篇 |
1998年 | 2879篇 |
1997年 | 2549篇 |
1996年 | 2462篇 |
1995年 | 2211篇 |
1994年 | 1493篇 |
1993年 | 1337篇 |
1992年 | 1077篇 |
1991年 | 936篇 |
1990年 | 788篇 |
1989年 | 786篇 |
1988年 | 778篇 |
1987年 | 630篇 |
1986年 | 621篇 |
1985年 | 568篇 |
1984年 | 596篇 |
1983年 | 600篇 |
1982年 | 557篇 |
1981年 | 529篇 |
1980年 | 378篇 |
1979年 | 211篇 |
1978年 | 310篇 |
1977年 | 296篇 |
1976年 | 212篇 |
1974年 | 200篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
A Goldfarb J Weinreb W G Daniel I Kronzon 《Journal of the American Society of Echocardiography》1989,2(5):350-353
A patient who had right and left atrial membranes was examined. The diagnosis and the hemodynamic significance of both membranes were detailed by transesophageal echocardiography and were confirmed by magnetic resonance imaging. Transesophageal imaging was found to be superior to routine echocardiography in visualization of these atrial structures. 相似文献
92.
93.
This column contains the presidential address presented during the Third Annual Meeting of the American Association of Heart Failure Nurses on June 28, 2007, in San Diego, California, titled "Building the Foundation of Excellence in Heart Failure Nursing." 相似文献
94.
95.
Incidence of BK with Tacrolimus Versus Cyclosporine and Impact of Preemptive Immunosuppression Reduction 总被引:8,自引:0,他引:8
Daniel C. Brennan Irfan Agha Daniel L. Bohl Mark A. Schnitzler Karen L. Hardinger Mark Lockwood Stephanie Torrence Rebecca Schuessler Tiffany Roby Monique Gaudreault-Keener Gregory A. Storch 《American journal of transplantation》2005,5(3):582-594
Our purposes were to determine the incidence of BK viruria, viremia or nephropathy with tacrolimus (FK506) versus cyclosporine (CyA) and whether intensive monitoring and discontinuation of mycophenolate (MMF) or azathioprine (AZA), upon detection of BK viremia, could prevent BK nephropathy. We randomized 200 adult renal transplant recipients to FK506 (n = 134) or CyA (n = 66). Urine and blood were collected weekly for 16 weeks and at months 5, 6, 9 and 12 and analyzed for BK by polymerase chain reaction (PCR). By 1 year, 70 patients (35%) developed viruria and 23 (11.5%) viremia; neither were affected independently by FK506, CyA, MMF or AZA. Viruria was highest with FK506-MMF (46%) and lowest with CyA-MMF (13%), p = 0.005. Viruria >/= 9.5 log(10) copies/mL was associated with a 3-fold increased risk of viremia and a 13-fold increased risk of sustained viremia. After reduction of immunosuppression, viremia resolved in 95%, without increased acute rejection, allograft dysfunction or graft loss. No BK nephropathy was observed. Choice of calcineurin inhibitor or adjuvant immunosuppression, independently, did not affect BK viruria or viremia. Viruria was highest with FK506-MMF and lowest with CyA-MMF. Monitoring and preemptive withdrawal of immunosuppression were associated with resolution of viremia and absence of BK nephropathy without acute rejection or graft loss. 相似文献
96.
97.
Molecular determinants of cetuximab efficacy. 总被引:17,自引:0,他引:17
Daniel Vallb?hmer Wu Zhang Michael Gordon Dong Yun Yang Jim Yun Oliver A Press Katrin E Rhodes Andy E Sherrod Syma Iqbal Kathleen D Danenberg Susan Groshen Heinz-Josef Lenz 《Journal of clinical oncology》2005,23(15):3536-3544
PURPOSE: To investigate whether mRNA expression levels of cyclin D1 (CCND1), cyclooxygenase 2 (Cox-2), epidermal growth factor receptor (EGFR), interleukin 8 (IL-8), and vascular endothelial growth factor (VEGF), all members of the EGFR signaling pathway, are associated with clinical outcome in patients with EGFR-expressing metastatic colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS: Thirty-nine patients with metastatic CRC, refractory to both irinotecan and oxaliplatin, were enrolled on IMCL-0144 and treated with single-agent cetuximab. The intratumoral mRNA levels of CCND1, Cox-2, EGFR, IL-8, and VEGF were assessed from paraffin-embedded tissue samples using laser-capture microdissection and quantitative real-time polymerase chain reaction. RESULTS: There were 21 women and 18 men with a median age of 64 years (range, 35 to 83 years). Higher gene expression levels of VEGF were associated with resistance to cetuximab (P = .038; Kruskal-Wallis test). The combination of low gene expression levels of Cox-2, EGFR, and IL-8 was significantly associated with overall survival (13.5 v 2.3 months; P = .028; log-rank test). Both findings were independent of skin toxicity that was itself significantly correlated to survival. Patients with a lower mRNA amount of EGFR had a longer overall survival compared with patients that had a higher mRNA amount (7.3 v 2.2 months; P = .09; log-rank test). Patients with lower expression of Cox-2 had a significantly higher rate of grade 2 to 3 skin reactions under cetuximab treatment. CONCLUSION: This pilot study suggests that gene expression levels of Cox-2, EGFR, IL-8, and VEGF in patients with metastatic CRC may be useful markers of clinical outcome in single-agent cetuximab treatment. 相似文献
98.
An examination of depression through the lens of spinal cord injury: Comparative prevalence rates and severity in women and men 总被引:1,自引:0,他引:1
PURPOSE: This study describes the prevalence of probable major depressive disorder (MDD) as well as other depressive disorders (ODD) and severity of depressive symptoms in a national sample of women with spinal cord injury (SCI) and compares them with a case-matched sample of men with SCI. METHODS: A sample of 585 women was drawn and case-matched with men from the SCI Model System National SCI Database according to level/completeness of injury, follow-up year, and age. The outcome measure of depression was the Patient Health Questionnaire. MAIN FINDINGS: Prevalence rates for women were 7.9% for probable MDD and 9.7% for ODD; rates for men were 9.9% and 10.3%, respectively. Logistic regression revealed that women who were divorced or at year 1 follow-up had a higher odds of having probable MDD (odds ratio [OR], 3.4 and 2.9, respectively). Employed women and men had significantly lower odds of probable MDD (OR, 0.274 and 0.358, respectively). Statistically significant differences were not found in gender comparisons for either probable MDD or symptom severity, which also were not associated with injury characteristics. CONCLUSION: The most significant, and unexpected, research finding is the absence of gender differences in probable MDD and symptom severity. Results challenge notions that depression will necessarily follow SCI; that injury characteristics determine the development and severity of depression; and that women experience a greater burden of depression than men. The main clinical implication is that depression screening and referral should be a routine feature of health care for women living with SCI, as well as for their male counterparts. Furthermore, nearly one fourth of women and men reported experiencing some or greater difficulty in daily life and relationships in the absence of probable depressive disorder, warranting monitoring of subsyndromal depression as well. 相似文献
99.
100.
BACKGROUND CONTEXT: Multiple lytic lesions of the spine usually represent metastatic or infectious disease processes. PURPOSE: To describe an extremely rare presentation of an uncommon disease process. STUDY DESIGN/SETTING: Case report/university hospital. METHODS: We describe the management of a patient who presented with a pathological fracture of C3 and multiple lytic lesions of the cervical spine. RESULTS: After reconstructive surgery, the final pathological diagnosis was fibrous dysplasia. CONCLUSION: Fibrous dysplasia is rarely seen in the cervical spine and may mimic other pathological processes. The surgical and medical management of spinal fibrous dysplasia is described. 相似文献