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   31382篇
  免费   2675篇
  国内免费   965篇
耳鼻咽喉   73篇
儿科学   675篇
妇产科学   375篇
基础医学   3914篇
口腔科学   339篇
临床医学   2834篇
内科学   5625篇
皮肤病学   369篇
神经病学   2127篇
特种医学   691篇
外国民族医学   13篇
外科学   2000篇
综合类   4970篇
现状与发展   5篇
预防医学   1142篇
眼科学   718篇
药学   5333篇
  16篇
中国医学   930篇
肿瘤学   2873篇
  2024年   15篇
  2023年   425篇
  2022年   513篇
  2021年   1084篇
  2020年   984篇
  2019年   1028篇
  2018年   964篇
  2017年   1047篇
  2016年   1129篇
  2015年   1239篇
  2014年   2015篇
  2013年   2405篇
  2012年   1902篇
  2011年   2014篇
  2010年   1728篇
  2009年   1556篇
  2008年   1534篇
  2007年   1564篇
  2006年   1351篇
  2005年   1213篇
  2004年   1017篇
  2003年   985篇
  2002年   797篇
  2001年   737篇
  2000年   625篇
  1999年   514篇
  1998年   412篇
  1997年   448篇
  1996年   354篇
  1995年   346篇
  1994年   363篇
  1993年   335篇
  1992年   296篇
  1991年   252篇
  1990年   243篇
  1989年   232篇
  1988年   197篇
  1987年   171篇
  1986年   154篇
  1985年   164篇
  1984年   114篇
  1983年   106篇
  1982年   94篇
  1981年   95篇
  1980年   76篇
  1979年   64篇
  1978年   39篇
  1977年   22篇
  1976年   18篇
  1974年   10篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
利用生物信息学技术初步探索芫根调控肠道免疫功能的分子生物学机制。方法 选择雄性SPF级BALB/c小鼠18只,随机分为3组,每组6只。SC1组小鼠每只每次灌胃芫根提取液150 μL,SC2组小鼠每只每次灌胃绞碎芫根原浆悬液150 μL,NC组小鼠每只每次灌胃生理盐水150 μL,连续7 d每日灌胃一次。分别取每组小鼠小肠组织样品提取RNA,总RNA的质检合格后,进行转录组测序。按GO功能和KEGG信号通路对差异表达基因聚类分析揭示差异表达高度富集的免疫相关通路。从免疫角度分析芫根灌胃小鼠小肠组织的基因表达变化情况。结果 转录组测序共检测到27733条 mRNA的表达,SC1组与NC组比较,显著差异表达基因1635个,其中上调差异表达基因1236个,下调差异表达基因399个;SC2组与NC组比较,显著差异表达基因2872个,其中上调差异表达基因2233个,下调差异表达基因639个(P<0.05)。按GO功能和KEGG信号通路聚类分析显示差异表达基因在白介素分泌、干扰素反应、T细胞受体信号通路及维生素和脂肪消化吸收等途径的富集度在两个芫根组中均居于前20位(P<0.01),肠黏膜趋化因子CCL20和巨噬细胞极化标志物CD274等免疫蛋白编码基因差异表达显著且同属于上述多个免疫通路。结论 芫根灌胃小鼠小肠的差异表达基因在白介素分泌、干扰素反应、T细胞受体信号通路、营养物质消化吸收等途径高度富集,提示芫根对肠道免疫系统及肠黏膜功能的调节,其中CD274的表达上调和CCL20的表达下调提示诱导M1型巨噬细胞极化和T细胞活化可能是芫根调控免疫和维护肠道正常结构功能的重要途径。  相似文献   
2.
Mixed lineage leukemia 1(MLL1)是组蛋白甲基转移酶SET家族的成员之一。MLL1与WDR5、RbBP5、Ash2L和DPY-30组成MLL1甲基转移酶复合物调控组蛋白H3的第4位赖氨酸的甲基化水平,对造血系统的发育和血细胞的更新至关重要。部分白血病患者体内存在因MLL1基因易位而产生的致癌蛋白——MLL1融合蛋白,MLL1融合蛋白在发挥其致癌作用时需要功能完整的MLL1酶复合物,故靶向MLL1-WDR5的蛋白-蛋白相互作用成为治疗MLL1融合型白血病的潜在策略。本文对MLL1-WDR5蛋白-蛋白相互作用的生物学机制、结构信息以及抑制剂进行了系统的总结,并结合已报道数据对该领域进行了展望,以期为后续研究提供参考。  相似文献   
3.
4.
ObjectiveSeveral trials have recently reported the safety of pulmonary resection after neoadjuvant immunotherapy with encouraging major pathological response rates. We report the detailed adverse events profile from a recently conducted randomized phase II trial in patients with resectable non–small cell lung cancer treated with neoadjuvant durvalumab alone or with sub-ablative radiation.MethodsWe conducted a randomized phase II trial in patients with non–small cell lung cancer clinical stages I to IIIA who were randomly assigned to receive neoadjuvant durvalumab alone or with sub-ablative radiation (8Gyx3). Secondary end points included the safety of 2 cycles of preoperative durvalumab with and without radiation followed by pulmonary resection. Postoperative adverse events within 30 days were recorded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.0).ResultsSixty patients were enrolled and randomly assigned, with planned resection performed in 26 patients in each arm. Baseline demographics and clinical variables were balanced between groups. The median operative time was similar between arms: 128 minutes (97-201) versus 146 minutes (109-214) (P = .314). There was no 30- or 90-day mortality. Grade 3/4 adverse events occurred in 10 of 26 patients (38%) after monotherapy and in 10 of 26 patients (38%) after dual therapy. Anemia requiring transfusion and hypotension were the 2 most common adverse events. The median length of stay was similar between arms (5 days vs 4 days, P = .172).ConclusionsIn this randomized trial, the addition of sub-ablative focal radiation to durvalumab in the neoadjuvant setting was not associated with increased mortality or morbidity compared with neoadjuvant durvalumab alone.  相似文献   
5.
PurposeTo assess the cost effectiveness of microwave ablation (MWA) and stereotactic body radiotherapy (SBRT) for patients with inoperable stage I non–small cell lung cancer (NSCLC).Materials and MethodsA literature search was performed in MEDLINE with broad search clusters. A decision-analytic model was constructed over a 5-year period. The model incorporated treatment-related complications and long-term recurrence. All clinical parameters were derived from the literature with preference to long-term prospective trials. A healthcare payers’ perspective was adopted. Outcomes were measured in quality-adjusted life years (QALYs) extracted from prior studies and U.S. dollars from Medicare reimbursements and prior studies. Base case calculations, probabilistic sensitivity analysis with 10,000 Monte Carlo simulations, and multiple 1- and 2-way sensitivity analyses were performed.ResultsMWA yielded a health benefit of 2.31 QALYs at a cost of $195,331, whereas SBRT yielded a health benefit of 2.33 QALYs at a cost of $225,271. The incremental cost-effectiveness ratio was $1,480,597/QALY, indicating that MWA is the more cost-effective strategy. The conclusion remains unchanged in probabilistic sensitivity analysis with MWA being the optimal cost strategy in 99.84% simulations. One-way sensitivity analyses revealed that MWA remains cost effective when its annual recurrence risk is <18.4% averaged over 5 years, when the SBRT annual recurrence risk is >1.44% averaged over 5 years, or when MWA is at least $7,500 cheaper than SBRT.ConclusionsMWA appears to be more cost effective than SBRT for patients with inoperable stage I NSCLC.  相似文献   
6.
7.
Background: Considering the poor prognosis of non-small cell lung cancer (NSCLC), the objective of this study was to examine the potential of plasma-derived vesicles as a source of lung cancer-specific proteins. Extracellular vesicle (EV) cargos are specific to the source cells, hence they have the potential of being a source of cancer-specific proteins.  Methods: The proteins differently expressed in cancer were determined and derived from EVs isolated from the plasma of NSCLC patients at the National Lung Hospital. To this end, purification was done using gel filtration chromatography and ultracentrifugation. In addition, nano liquid chromatography mass spectrometry (LC–MS/MS) was used for analyzing. Results: Fifty-seven EV-derived proteins related to NSCLC were highlighted in this research. Some of them have not been addressed before, such as EEF1A1 (elongation factor 1-α1), KPNB1 (Importin subunit beta 1), SRC (proto-oncogene tyrosine-protein kinase) and ACTC1 (actin, alpha cardiac muscle 1). This list was further confirmed through a comparison with ExoCarta and Vesiclepedia. Conclusion: This study is the first work to show the involvement of several novel proteins of small EV (EEF1A1, KPNB1, SRC, and ACTC1) in the progression of NSCLC. The results suggested that they could serve as novel biomarkers for non-small cell lung cancer in the future.  相似文献   
8.
1文献来源Jabbour SK,Lee KH,Frost N,et al.Pembrolizumab plus concurrent chemoradiation therapy in patients with unresectable,locally advanced,stageⅢnon?small cell lung cancer.The phase 2 KEYNOTE?799 nonrandomized trial[J].JAMA Oncol,2021,7(9):1-9.  相似文献   
9.
10.
In the past 10 years, a deeper understanding of the immune landscape of cancers, including immune evasion processes, has allowed the development of a new class of agents. The reactivation of host antitumor immune response offers the potential for long-term survival benefit in a portion of patients with thoracic malignancies.The advent of programmed cell death protein 1/programmed death ligand-1 immune checkpoint inhibitors (ICIs), both as single agents and in combination with chemotherapy, and more recently, the combination of ICI, anti–programmed cell death protein 1, and anticytotoxic T-lymphocyte antigen 4 antibody, have led to breakthrough therapeutic advances for patients with advanced NSCLC, and to a lesser extent, patients with SCLC. Encouraging activity has recently emerged in pretreated patients with thymic carcinoma (TC). Conversely, in malignant pleural mesothelioma, pivotal positive signs of activity have not been fully confirmed in randomized trials. The additive effects of chemoradiation and immunotherapy suggested intriguing potential for therapeutic synergy with combination strategies. This has led to the introduction of ICI consolidation therapy in stage III NSCLC, creating a platform for future therapeutic developments in earlier-stage disease. Despite the definitive clinical benefit observed with ICI, primary and acquired resistance represent well-known biological phenomena, which may affect the therapeutic efficacy of these agents.The development of innovative strategies to overcome ICI resistance, standardization of new patterns of ICI progression, identification of predictive biomarkers of response, optimal treatment duration, and characterization of ICI efficacy in special populations, represent crucial issues to be adequately addressed, with the aim of improving the therapeutic benefit of ICI in patients with thoracic malignancies.In this article, an international panel of experts in the field of thoracic malignancies discussed these topics, evaluating currently available scientific evidence, with the final aim of providing clinical recommendations, which may guide oncologists in their current practice and elucidate future treatment strategies and research priorities.  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