首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3121篇
  免费   216篇
  国内免费   16篇
耳鼻咽喉   51篇
儿科学   109篇
妇产科学   126篇
基础医学   510篇
口腔科学   100篇
临床医学   279篇
内科学   689篇
皮肤病学   44篇
神经病学   283篇
特种医学   47篇
外科学   334篇
综合类   12篇
现状与发展   1篇
一般理论   3篇
预防医学   312篇
眼科学   16篇
药学   219篇
中国医学   15篇
肿瘤学   203篇
  2023年   37篇
  2022年   39篇
  2021年   151篇
  2020年   73篇
  2019年   134篇
  2018年   127篇
  2017年   89篇
  2016年   109篇
  2015年   117篇
  2014年   144篇
  2013年   166篇
  2012年   289篇
  2011年   289篇
  2010年   141篇
  2009年   120篇
  2008年   187篇
  2007年   186篇
  2006年   185篇
  2005年   178篇
  2004年   149篇
  2003年   131篇
  2002年   113篇
  2001年   32篇
  2000年   23篇
  1999年   16篇
  1998年   8篇
  1997年   7篇
  1996年   6篇
  1995年   9篇
  1994年   4篇
  1993年   7篇
  1992年   8篇
  1991年   6篇
  1990年   2篇
  1988年   5篇
  1987年   5篇
  1986年   6篇
  1985年   5篇
  1983年   8篇
  1982年   3篇
  1981年   8篇
  1980年   4篇
  1979年   5篇
  1976年   4篇
  1974年   3篇
  1973年   2篇
  1972年   3篇
  1969年   2篇
  1936年   1篇
  1935年   2篇
排序方式: 共有3353条查询结果,搜索用时 46 毫秒
1.
Cognitive Therapy and Research - Individuals with Social Anxiety Disorder (SAD) may be at a higher risk for negative outcomes during the COVID-19 pandemic due to isolation that is both...  相似文献   
2.
3.
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most.  相似文献   
4.
5.
6.

Background

Irreversible electroporation (IRE) has the potential to overcome limitations of thermal ablation, enabling small renal mass (SRM) ablation near vital structures.

Purpose

To assess feasibility and safety of percutaneous IRE for the treatment of SRMs.

Materials and methods

This prospective study is a phase 2 trial (NCT02828709) of IRE for patients with SRMs. Primary endpoints are feasibility and safety. Device- and procedural-adverse events were assessed by Clavien-Dindo and Common Terminology Criteria for Adverse Events version 4.0 grading systems. Technical feasibility was assessed by recording the technical success of the procedures. Technical success was evaluated by performing a CT immediately after ablation where complete tumor coverage and nonenhancement were evaluated. Tumor charcateristics and patient characteristics, procedural and anesthesia details, postprocedural events, and perioperative complications were recorded.

Results

Ten SRMs were included with a mean tumor size of 2.2 cm (range 1.1–3.9 cm) were treated with IRE. Renal mass biopsies revealed 7 clear cell and 1 papillary renal cell carcinoma. Two renal mass biopsies were nondiagnostic. The median follow-up was 6 months (range 3–12 months). Technical success was achieved in 9 out of 10 cases. One patient had a grade 3 Clavien-Dindo complication (1/10, 95% Confidence interval (CI) 0.0179–0.4041). Mean anesthesia time was 3.7 hours (range 3–5 hours), mean procedural time was 2.1 hours (range 1 hour 45 minutes–2 hours 30 minutes) and mean ablation time was 50 minutes (range 20 minutes–1 hour 45 minutes). The creatinine preoperative and postoperative (1 week, 3 months, 6 months, and 12 months) did not significantly differ. In total, 8 out of 10 cases did not experience postoperative pain.

Conclusion

IRE in SRMs is safe and feasible. Renal function is not affected by IRE and postoperative pain is rare. Anesthesia time and procedural time are a potential concern.  相似文献   
7.
8.
Breast cancer has been suggested to potentially have prenatal origins. We examined associations between birth weight, body mass index (BMI) at four-time points over 25 years of adulthood, and risk of postmenopausal breast cancer, with emphasis on whether the association between birth weight and risk of breast cancer was mediated by weight and height changes over the adult life course. Postmenopausal women (n = 70,397) aged 50–79 years without breast cancer at enrollment (1993–1998) were followed up to 25 years. Weight and height were measured at baseline. Birth weight, and weights at ages 18, 35 and 50 were self-reported. Breast cancer cases were centrally adjudicated. Compared to women with birth weight of 6–8 pounds, women with birth weight of <6 pounds had lower risk of breast cancer (HR = 0.88 95% CI: 0.79–0.99). 44% and 21% of the relationship between birth weight and breast cancer risk was mediated by adult height and weight at baseline, respectively. Birth weight of 8 pounds or more was not associated with risk of postmenopausal breast cancer. Weight gain in adulthood was associated with increased risk of breast cancer regardless of time periods. In conclusion, lower birthweight was associated with lower risk of postmenopausal breast cancer, and this reduction in risk was significantly mediated by childhood or adolescent growth, especially by adult height. Our data suggest that reaching and maintaining a healthy weight during adulthood is key in the prevention of breast cancer.  相似文献   
9.
Journal of NeuroVirology - We assessed changes in functional connectivity by fMRI (functional magnetic resonance imaging) and cognitive measures in otherwise neurologically asymptomatic people with...  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号