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   2638812篇
  免费   203059篇
  国内免费   4987篇
耳鼻咽喉   37874篇
儿科学   84186篇
妇产科学   76202篇
基础医学   371729篇
口腔科学   79672篇
临床医学   229619篇
内科学   513040篇
皮肤病学   58466篇
神经病学   213270篇
特种医学   105624篇
外国民族医学   879篇
外科学   404385篇
综合类   64424篇
现状与发展   9篇
一般理论   981篇
预防医学   196074篇
眼科学   62113篇
药学   199608篇
  6篇
中国医学   5391篇
肿瘤学   143306篇
  2018年   24117篇
  2015年   24316篇
  2014年   33758篇
  2013年   51806篇
  2012年   68895篇
  2011年   72809篇
  2010年   43229篇
  2009年   41382篇
  2008年   69982篇
  2007年   74833篇
  2006年   75804篇
  2005年   73754篇
  2004年   72172篇
  2003年   69611篇
  2002年   68400篇
  2001年   122489篇
  2000年   126229篇
  1999年   107515篇
  1998年   29337篇
  1997年   26682篇
  1996年   26175篇
  1995年   25159篇
  1994年   23646篇
  1993年   22186篇
  1992年   86712篇
  1991年   84084篇
  1990年   82299篇
  1989年   80203篇
  1988年   74689篇
  1987年   73542篇
  1986年   70232篇
  1985年   67368篇
  1984年   50461篇
  1983年   43342篇
  1982年   25754篇
  1981年   23282篇
  1980年   21823篇
  1979年   48361篇
  1978年   34090篇
  1977年   29117篇
  1976年   26872篇
  1975年   29350篇
  1974年   35503篇
  1973年   34265篇
  1972年   32067篇
  1971年   30157篇
  1970年   28164篇
  1969年   26761篇
  1968年   24880篇
  1967年   22411篇
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
Kinase alterations are increasingly recognised as oncogenic drivers in mesenchymal tumours. Infantile fibrosarcoma and the related renal tumour, congenital mesoblastic nephroma, were among the first solid tumours shown to harbour recurrent tyrosine kinase fusions, with the canonical ETV6::NTRK3 fusion identified more than 20 years ago. Although targeted testing has long been used in diagnosis, the advent of more robust sequencing techniques has driven the discovery of kinase alterations in an array of mesenchymal tumours. As our ability to identify these genetic alterations has improved, as has our recognition and understanding of the tumours that harbour these alterations. Specifically, this study will focus upon mesenchymal tumours harbouring NTRK or other kinase alterations, including tumours with an infantile fibrosarcoma-like appearance, spindle cell tumours resembling lipofibromatosis or peripheral nerve sheath tumours and those occurring in adults with a fibrosarcoma-like appearance. As publications describing the histology of these tumours increase so, too, do the variety kinase alterations reported, now including NTRK1/2/3, RET, MET, RAF1, BRAF, ALK, EGFR and ABL1 fusions or alterations. To date, these tumours appear locally aggressive and rarely metastatic, without a clear link between traditional features used in histological grading (e.g. mitotic activity, necrosis) and outcome. However, most of these tumours are amenable to new targeted therapies, making their recognition of both diagnostic and therapeutic import. The goal of this study is to review the clinicopathological features of tumours with NTRK and other tyrosine kinase alterations, discuss the most common differential diagnoses and provide recommendations for molecular confirmation with associated treatment implications.  相似文献   
3.

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   
4.
5.
Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster...  相似文献   
6.
7.
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