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   2913831篇
  免费   225906篇
  国内免费   5131篇
耳鼻咽喉   41133篇
儿科学   89525篇
妇产科学   75158篇
基础医学   426005篇
口腔科学   80464篇
临床医学   267978篇
内科学   562364篇
皮肤病学   58998篇
神经病学   238518篇
特种医学   115040篇
外国民族医学   946篇
外科学   441215篇
综合类   64166篇
现状与发展   5篇
一般理论   1316篇
预防医学   235551篇
眼科学   67635篇
药学   219631篇
  6篇
中国医学   5434篇
肿瘤学   153780篇
  2018年   30935篇
  2017年   23858篇
  2016年   26438篇
  2015年   29879篇
  2014年   42642篇
  2013年   64722篇
  2012年   88982篇
  2011年   95015篇
  2010年   55598篇
  2009年   52287篇
  2008年   89879篇
  2007年   96066篇
  2006年   96238篇
  2005年   94227篇
  2004年   90911篇
  2003年   87734篇
  2002年   86224篇
  2001年   127645篇
  2000年   131690篇
  1999年   111641篇
  1998年   33603篇
  1997年   30228篇
  1996年   29947篇
  1995年   28749篇
  1994年   26947篇
  1993年   25288篇
  1992年   89930篇
  1991年   88653篇
  1990年   86111篇
  1989年   83116篇
  1988年   77387篇
  1987年   76292篇
  1986年   72015篇
  1985年   68931篇
  1984年   52443篇
  1983年   44842篇
  1982年   27373篇
  1981年   24454篇
  1979年   48992篇
  1978年   34804篇
  1977年   29061篇
  1976年   27937篇
  1975年   29950篇
  1974年   36285篇
  1973年   34365篇
  1972年   32118篇
  1971年   29693篇
  1970年   27949篇
  1969年   25860篇
  1968年   23683篇
排序方式: 共有10000条查询结果,搜索用时 984 毫秒
1.
Molnár  B.  Aroca  S.  Dobos  A.  Orbán  K.  Szabó  J.  Windisch  P.  Stähli  A.  Sculean  A. 《Clinical oral investigations》2022,26(12):7135-7142
Clinical Oral Investigations - To evaluate t he long-term outcomes following treatment of RT 1 multiple adjacent gingival recessions (MAGR) using the modified coronally advanced tunnel (MCAT) with...  相似文献   
2.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
3.
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered.  相似文献   
4.
5.
6.
Journal of Behavioral Medicine - Evidence supports the use of graphic warnings to educate the public about the health harms of smoking and suggests warnings eliciting negative emotional responses...  相似文献   
7.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
8.
9.
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.  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