首页 | 官方网站   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   26368篇
  免费   1387篇
  国内免费   161篇
医药卫生   27916篇
  2023年   194篇
  2022年   191篇
  2021年   812篇
  2020年   506篇
  2019年   726篇
  2018年   943篇
  2017年   627篇
  2016年   704篇
  2015年   808篇
  2014年   1060篇
  2013年   1297篇
  2012年   2079篇
  2011年   2033篇
  2010年   1238篇
  2009年   1059篇
  2008年   1745篇
  2007年   1711篇
  2006年   1656篇
  2005年   1524篇
  2004年   1357篇
  2003年   1228篇
  2002年   1214篇
  2001年   239篇
  2000年   210篇
  1999年   224篇
  1998年   177篇
  1997年   139篇
  1996年   131篇
  1995年   161篇
  1994年   132篇
  1993年   121篇
  1992年   138篇
  1991年   105篇
  1990年   137篇
  1989年   111篇
  1988年   125篇
  1987年   80篇
  1986年   109篇
  1985年   91篇
  1984年   90篇
  1983年   79篇
  1982年   74篇
  1981年   50篇
  1980年   51篇
  1979年   41篇
  1978年   48篇
  1977年   29篇
  1973年   31篇
  1972年   40篇
  1971年   28篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
ABSTRACT

Introduction

Glucocorticoid (GC) induced osteoporosis (GIOP) is the most common form of secondary osteoporosis. It develops in a dose and time dependent manner, due to a rapid and transient increase in bone resorption, followed by the inhibition of bone formation.  相似文献   
2.
3.

Background

The rate of noninterventional treatment (NIT) in prostate cancer (PCa) active surveillance (AS) candidates is on the rise. However, contemporary data are unavailable. We described community-based NIT rates within 16 Surveillance Epidemiology and End Results (SEER) registries between 2010 and 2014.

Patients and Methods

We identified 23,360 PCa patients who fulfilled the University of California San Francisco AS criteria (prostate-specific antigen [PSA] < 10 ng/mL, clinical T stage ≤ T2a, Gleason score ≤ 6, and positive cores < 33%). Annual NIT rates as well as patient distribution according to PSA, age, number of positive cores, and clinical T stage were studied. Multivariable logistic regression analysis tested NIT predictors.

Results

Between 2010 and 2014, the NIT rate increased from 30.2% to 57.5% (P = .004). Within 16 SEER registries, NIT rates ranged from 25.9% to 62%. NIT rate increased uniformly within all examined registries. Of patient and tumor characteristics (PSA > 4 ng/mL, cT2a and > 1 positive core) only the proportion of NIT patients aged < 65 years increased over time from 47.3% to 53.2% (P = .03). By multivariable logistic regression analysis predicting NIT rate, older age (odd ratio [OR] = 1.05), more contemporary year of diagnosis (OR = 1.41), and being unmarried (OR = 1.45) and uninsured (OR = 2.41) were independent predictors.

Conclusion

The NIT rate has markedly increased across all examined SEER registries. Nonetheless, important differences distinguish those who received high-end NIT from low-end NIT. PCa characteristics of NIT patients remained unchanged over time. However, in addition to geographical differences in NIT rates, patient characteristics such as age, marital status, and insurance status represent potential NIT access barriers.  相似文献   
4.
ABSTRACT

Introduction

Hepatocellular carcinoma (HCC) is one of the most frequent tumors affecting the gastrointestinal tract and a universal cause of morbidity and mortality. Cabozantinib is a strong multi-inhibitor of receptor tyrosine kinases approved for renal cell carcinoma that could be useful also for the treatment of HCC.  相似文献   
5.
Microsatellite instability-high (MSI-H) and tumor mutational burden (TMB) are predictive biomarkers for immune-checkpoint inhibitors (ICIs). Still, the relationship between the underlying cause(s) of MSI and TMB in tumors remains poorly defined. We investigated associations of TMB to mismatch repair (MMR) protein expression patterns by immunohistochemistry (IHC) and MMR mutations in a diverse sample of tumors. Hypothesized differences were identified by the protein/gene affected/mutated and the tumor histology/primary site. Overall, 1057 MSI-H tumors were identified from the 32 932 tested. MSI was examined by NGS using 7000+ target microsatellite loci. TMB was calculated using only nonsynonymous missense mutations sequenced with a 592-gene panel; a subset of MSI-H tumors also had MMR IHC performed. Analyses examined TMB by MMR protein heterodimer impacted (loss of MLH1/PMS2 vs. MSH2/MSH6 expression) and gene-specific mutations. The sample was 54.6% female; mean age was 63.5 years. Among IHC tested tumors, loss of co-expression of MLH1/PMS2 was more common (n = 544/705, 77.2%) than loss of MSH2/MSH6 (n = 81/705, 11.5%; P < .0001), and was associated with lower mean TMB (MLH1/PMS2: 25.03 mut/Mb vs MSH2/MSH6 46.83 mut/Mb; P < .0001). TMB also varied by tumor histology: colorectal cancers demonstrating MLH1/PMS2 loss had higher TMBs (33.14 mut/Mb) than endometrial cancers (20.60 mut/Mb) and other tumors (25.59 mut/Mb; P < .0001). MMR gene mutations were detected in 42.0% of tumors; among these, MSH6 mutations were most common (25.7%). MSH6 mutation patterns showed variability by tumor histology and TMB. TMB varies by underlying cause(s) of MSI and tumor histology; this heterogeneity may contribute to differences in response to ICI.  相似文献   
6.
7.
8.
9.
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-23

京公网安备 11010802026262号