全文获取类型
收费全文 | 1601867篇 |
免费 | 131246篇 |
国内免费 | 2581篇 |
专业分类
耳鼻咽喉 | 21646篇 |
儿科学 | 52928篇 |
妇产科学 | 46225篇 |
基础医学 | 227759篇 |
口腔科学 | 47196篇 |
临床医学 | 140899篇 |
内科学 | 314755篇 |
皮肤病学 | 34090篇 |
神经病学 | 130109篇 |
特种医学 | 64721篇 |
外国民族医学 | 474篇 |
外科学 | 243795篇 |
综合类 | 39712篇 |
现状与发展 | 3篇 |
一般理论 | 544篇 |
预防医学 | 122856篇 |
眼科学 | 36470篇 |
药学 | 121249篇 |
3篇 | |
中国医学 | 2974篇 |
肿瘤学 | 87286篇 |
出版年
2018年 | 14763篇 |
2016年 | 12898篇 |
2015年 | 15025篇 |
2014年 | 20645篇 |
2013年 | 31349篇 |
2012年 | 42544篇 |
2011年 | 44748篇 |
2010年 | 26335篇 |
2009年 | 25302篇 |
2008年 | 42997篇 |
2007年 | 45237篇 |
2006年 | 46051篇 |
2005年 | 44672篇 |
2004年 | 44091篇 |
2003年 | 42179篇 |
2002年 | 41289篇 |
2001年 | 75681篇 |
2000年 | 78325篇 |
1999年 | 66388篇 |
1998年 | 17731篇 |
1997年 | 16334篇 |
1996年 | 16314篇 |
1995年 | 16019篇 |
1994年 | 15070篇 |
1993年 | 14217篇 |
1992年 | 55427篇 |
1991年 | 53775篇 |
1990年 | 52561篇 |
1989年 | 50832篇 |
1988年 | 47221篇 |
1987年 | 46560篇 |
1986年 | 44284篇 |
1985年 | 42843篇 |
1984年 | 32033篇 |
1983年 | 27565篇 |
1982年 | 16144篇 |
1981年 | 14436篇 |
1980年 | 13564篇 |
1979年 | 30460篇 |
1978年 | 21064篇 |
1977年 | 17764篇 |
1976年 | 16694篇 |
1975年 | 17574篇 |
1974年 | 21486篇 |
1973年 | 20672篇 |
1972年 | 18853篇 |
1971年 | 17770篇 |
1970年 | 16289篇 |
1969年 | 15268篇 |
1968年 | 13949篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
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
2.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
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
3.
4.
5.
6.
7.
8.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
9.
Tengzhi Liu Kathrine Røe Redalen Morten Karlsen 《Journal of labelled compounds & radiopharmaceuticals》2022,65(7):191-202
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies. 相似文献
10.