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   106650篇
  免费   45374篇
  国内免费   424篇
耳鼻咽喉   2187篇
儿科学   4691篇
妇产科学   1266篇
基础医学   20690篇
口腔科学   5584篇
临床医学   15135篇
内科学   29122篇
皮肤病学   8803篇
神经病学   15356篇
特种医学   4501篇
外科学   18291篇
综合类   230篇
现状与发展   1篇
一般理论   32篇
预防医学   5180篇
眼科学   1950篇
药学   8536篇
中国医学   1365篇
肿瘤学   9528篇
  2023年   223篇
  2022年   912篇
  2021年   2651篇
  2020年   5569篇
  2019年   11455篇
  2018年   11027篇
  2017年   12058篇
  2016年   13079篇
  2015年   13457篇
  2014年   13717篇
  2013年   14273篇
  2012年   7451篇
  2011年   7111篇
  2010年   10627篇
  2009年   6652篇
  2008年   4112篇
  2007年   2811篇
  2006年   2605篇
  2005年   2244篇
  2004年   1887篇
  2003年   1718篇
  2002年   1679篇
  2001年   1270篇
  2000年   1141篇
  1999年   615篇
  1998年   208篇
  1997年   158篇
  1996年   143篇
  1995年   109篇
  1994年   108篇
  1993年   68篇
  1992年   147篇
  1991年   140篇
  1990年   116篇
  1989年   79篇
  1988年   72篇
  1987年   83篇
  1986年   63篇
  1985年   55篇
  1984年   50篇
  1981年   25篇
  1980年   28篇
  1979年   35篇
  1977年   32篇
  1976年   27篇
  1975年   25篇
  1974年   32篇
  1973年   28篇
  1972年   34篇
  1969年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Aim The magnetic anal sphincter (MAS) is a recent surgical innovation for severe faecal incontinence (FI). With its place in the treatment algorithm of FI yet to be defined, we report a nonrandomized comparison between MAS and sacral nerve stimulation (SNS) in a single‐centre cohort of patients with FI. Method Data were reviewed from prospective databases. From December 2008 to December 2010, 12 women [median age 65 (42–76) years], having FI for a median of 6.5 years, were implanted with a MAS. Sixteen women, of similar age, preoperative function scores, aetiology and duration of incontinence, and implanted with a permanent SNS pulse generator during the same period, served as a reference group. The duration of hospital stay, complications, change in incontinence and quality of life scores and anal physiology were compared between the two groups. Results The duration of follow up was similar [MAS = 18 (8–30) months vs SNS = 22 (10–28) months; P = 0.318]. Four patients with MAS experienced a 30‐day complication, and the device was removed from one patient in each group. A significant improvement in incontinence (P < 0.001) and quality‐of‐life scores (P < 0.04) occurred in both groups. Mean anal resting pressure increased significantly in patients implanted with a MAS (P = 0.027). Conclusion In this single‐centre nonrandomized cohort of FI patients, MAS was as effective as SNS in improving continence and quality of life, with similar morbidity. These results can now serve as a prelude to a randomized trial comparing the procedures.  相似文献   
992.
993.
994.
995.
NACHT leucine‐rich repeat‐ and PYD‐containing (NLRP)3 protein controls the inflammasome by regulating caspase‐1 activity and interleukin (IL)‐1β processing. The contribution of IL‐1β in the pathogenesis of psoriasis is well recognized. Polymorphisms in NLRP3 and caspase recruitment domain–containing protein (CARD)8, a negative regulator of caspase‐1 activity, have been associated with susceptibility to common inflammatory diseases, such as Crohn's disease and rheumatoid arthritis. To investigate the role for genetic variants in the NLRP3 inflammasome in psoriasis susceptibility. In a patient sample comprising 1988 individuals from 491 families and 1002 healthy controls, genotypes for four selected single‐nucleotide polymorphisms (SNPs) in NLRP3 (three SNPs) and CARD8 (one SNP) were determined by TaqMan® Allelic Discrimination. Using the transmission disequilibrium test (TDT), a significant increase in the transmission of the NLRP3 rs10733113G genotype to a subgroup of patients with more widespread psoriasis was demonstrated (P = 0.015). Using logistic regression analysis in 741 patients with psoriasis and 1002 controls, the CARD8 rs2043211 genotype was significantly different in cases and controls in overall terms [OR 1.3 (1.1–1.5), P = 0.004] and for both genders. Our data support the hypothesis that the inflammasome plays a role in psoriasis susceptibility.  相似文献   
996.
997.
998.
The aim of this study was to evaluate the change of breast density in the normal breast of patients receiving neoadjuvant chemotherapy (NAC). Forty‐four breast cancer patients were studied. MRI acquisition was performed before treatment (baseline), and 4 and 12 weeks after treatment. A computer‐algorithm‐based program was used to segment breast tissue and calculate breast volume (BV), fibroglandular tissue volume (FV), and percent density (PD) (the ratio of FV over BV × 100%). The reduction of FV and PD after treatment was compared with baseline using paired t‐tests with a Bonferroni–Holm correction. The association of density reduction with age was analyzed. FV and PD after NAC showed significant decreases compared with the baseline. FV was 110.0 ml (67.2, 189.8) (geometric mean (interquartile range)) at baseline, 104.3 ml (66.6, 164.4) after 4 weeks (p < 0.0001), and 94.7 ml (60.2, 144.4) after 12 weeks (comparison with baseline, p < 0.0001; comparison with 4 weeks, p = 0.016). PD was 11.2% (6.4, 22.4) at baseline, 10.6% (6.6, 20.3) after 4 weeks (p < 0.0001), and 9.7% (6.2, 17.9) after 12 weeks (comparison with baseline, p = 0.0001; comparison with 4 weeks, p = 0.018). Younger patients tended to show a higher density reduction, but overall correlation with age was only moderate (r = 0.28 for FV, p = 0.07, and r = 0.52 for PD, p = 0.0003). Our study showed that breast density measured from MR images acquired at 3T MR can be accurately quantified using a robust computer‐aided algorithm based on non‐parametric non‐uniformity normalization (N3) and an adaptive fuzzy C‐means algorithm. Similar to doxorubicin and cyclophosphamide regimens, the taxane‐based NAC regimen also caused density atrophy in the normal breast and showed reduction in FV and PD. The effect of breast density reduction was age related and duration related. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
999.
1000.
Venous access required both for blood sampling and for the delivery of medicines and nutrition is an integral element in the care of sick infants and children. Peripherally inserted central catheters (PICCs) have been shown to be a valuable alternative to traditional central venous devices in adults and neonates. However, the evidence may not extrapolate directly to older paediatric patients. In this study, we therefore review the indications, methods of insertion and complications of PICC lines for children beyond the neonatal age to provide clinical recommendations based on a search of the current literature. Although the literature is heterogeneous with few randomised studies, PICCs emerge as a safe and valuable option for intermediate‐ to long‐term central venous access in children both in and out of hospital. Insertion can often be performed in light or no sedation, with little risk of perioperative complications. Assisted visualisation, preferably with ultrasound, yields high rates of insertion success. With good catheter care, rates of mechanical, infectious and thrombotic complications are low and compare favourably with those of traditional central venous catheters. Even in the case of occlusion or infection, fibrinolytics and antibiotic locks often allow the catheter to be retained.  相似文献   
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