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   44073篇
  免费   6182篇
  国内免费   1097篇
耳鼻咽喉   441篇
儿科学   728篇
妇产科学   684篇
基础医学   5734篇
口腔科学   1170篇
临床医学   5355篇
内科学   5506篇
皮肤病学   400篇
神经病学   2866篇
特种医学   1279篇
外国民族医学   3篇
外科学   3510篇
综合类   4345篇
一般理论   2篇
预防医学   4852篇
眼科学   658篇
药学   3957篇
  16篇
中国医学   1699篇
肿瘤学   8147篇
  2023年   1111篇
  2022年   1435篇
  2021年   2150篇
  2020年   1874篇
  2019年   2440篇
  2018年   2583篇
  2017年   2105篇
  2016年   2026篇
  2015年   2338篇
  2014年   3505篇
  2013年   3363篇
  2012年   2606篇
  2011年   2622篇
  2010年   2112篇
  2009年   1953篇
  2008年   2054篇
  2007年   1615篇
  2006年   1371篇
  2005年   1164篇
  2004年   1473篇
  2003年   912篇
  2002年   691篇
  2001年   654篇
  2000年   460篇
  1999年   453篇
  1998年   471篇
  1997年   508篇
  1996年   515篇
  1995年   421篇
  1994年   536篇
  1993年   380篇
  1992年   368篇
  1991年   359篇
  1990年   323篇
  1989年   261篇
  1988年   252篇
  1987年   144篇
  1986年   162篇
  1985年   225篇
  1984年   232篇
  1983年   168篇
  1982年   237篇
  1981年   174篇
  1980年   135篇
  1979年   108篇
  1978年   73篇
  1977年   57篇
  1976年   47篇
  1975年   39篇
  1974年   28篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Drug discovery today》2022,27(3):808-821
Tyrosine kinases are enzymes that can transfer a phosphate group from ATP to a specific protein tyrosine, serine or threonine residue within a cell, operating as a switch that can turn ‘on’ and ‘off’ causing different physiological alterations in the body. Mutated kinases have been shown to display an equilibrium shift toward the activated state. Types I–III have been studied intensively leading to drugs like imatinib (type II), cobimetinib (type III), among others. It is the same scenario for types V–VII; however, there is a lacuna in information regarding type IV inhibitors, although recently some advances have surfaced. This review aims to accumulate the knowledge gained so far about type IV inhibitors.  相似文献   
2.
The COVID-19 pandemic caused by the SARS-CoV-2 virus has significantly disrupted and burdened the diagnostic workup and delivery of care, including transfusion, to cancer patients across the globe. Furthermore, cancer patients suffering from solid tumors or hematologic malignancies were more prone to the infection and had higher morbidity and mortality than the rest of the population. Major signaling pathways have been identified at the intersection of SARS-CoV-2 and cancer cells, often leading to tumor progression or alteration of the tumor response to therapy. The reactivation of oncogenic viruses has also been alluded to in the context and following COVID-19. Paradoxically, certain tumors responded better following the profound infection-induced immune modulation. Unveiling the mechanisms of the virus-tumor cell interactions will lead to a better understanding of the pathophysiology of both cancer progression and virus propagation. It would be challenging to monitor, through the different cancer registries, retrospectively, the response of patients who have been previously exposed to the virus in contrast to those who have not contracted the infection.  相似文献   
3.
4.
IntroductionThis study was designed to assess whether a dental caries management protocol combining a single application of 38% silver diamine fluoride (SDF) with comprehensive oral health education will successfully divert high-risk children from dental treatment under dental general anaesthesia (DGA), arrest active caries in primary teeth, and improve parent-reported child oral health–related quality of life (OHRQoL).MethodsChildren aged 2 to 10 years, who attended two public dental agencies in Victoria, Australia, and were unable to tolerate restorative treatments in the clinic setting, elected to participate in either a 38% SDF intervention protocol or, alternatively, referral for DGA. Follow-up examinations were completed at 6 months to assess caries progression, decayed missing filled tooth index, PUFA index (pulpal involvement, ulceration, fistula, abscess), DGA referral rates, and OHRQoL (Early Childhood Oral Health Impact Scale [ECOHIS]).ResultsOf the total sample, 89.5% of children (n = 102) [mean (SD) age, 4.1 (1.0) years] with 401 active carious lesions elected to participate in the 38% SDF protocol; 10.5% (n = 12) of parents opted for referral for treatment under DGA. The proportion of active caries subsequently arrested at follow-up (number of arrested lesions/number of lesions treated) was 0.78 (95% CI, 0.69 to 0.87). There was an 88% reduction in referrals for DGA in eligible children over the 6-month period. The 38% SDF intervention group showed a significant improvement in ECOHIS scores at follow-up (P < .001).DiscussionAdoption of the 38% SDF intervention protocol resulted in a significant reduction in the rate of preventable dental hospitalisations. Most parents opted against referral for DGA. Parent-reported OHRQoL for children improved significantly.  相似文献   
5.
《Pancreatology》2022,22(2):270-276
Backgroundand purpose: Zinc is an essential element for human health and plays an important role in metabolic, immunological and other biological processes. The present study was conducted to investigate the association between zinc deficiency (ZD) and the perioperative clinical course in patients with pancreatic ductal adenocarcinoma (PDAC).MethodsOf 216 patients with PDAC who underwent elective pancreatectomy between 2013 and 2017 at our institution, 206 patients with sufficient clinical data were retrospectively reviewed. The perioperative variables were compared and the risk factors associated with infectious complications were identified.ResultsZD was preoperatively present in 36 (17.5%) of 206 patients with PDAC. In the patients of the ZD group, a higher proportion of males, higher preoperative modified Glasgow prognostic scores, a higher neutrophil-to-lymphocyte ratio, and a higher occurrence of postoperative infectious complications after pancreatectomy were observed, compared to the non-ZD group. By a univariate analysis, three risk factors were significantly associated with infectious complications after pancreatectomy: ZD (vs non-ZD: p = 0.002), serum albumin <3.5 g/dl (vs ≥ 3.5 g/dl: p = 0.005), and the procedure of pancreaticoduodenectomy (vs others: p = 0.013). By multivariate logistic regression analysis, the occurrence of infectious complications was significantly associated with ZD (OR 3.430, 95%CI 1.570 to 7.490, p = 0.002) and the procedure of pancreaticoduodenectomy (OR 2.030, 95%CI 1.090 to 3.770, p = 0.025).ConclusionsThe current study newly demonstrated that ZD could serve as a preoperative predictor of infectious complications after pancreatectomies in the patients with PDAC.  相似文献   
6.
《Cancer radiothérapie》2022,26(3):502-516
The aim of the review was to present the current literature status about replanning regarding anatomical and dosimetric changes in the target and OARs in the head and neck region during radiotherapy, to discuss and to analyze factors influencing the decision for adaptive radiotherapy of head and neck cancer patients. Significant progress has been made in head and neck patients’ evaluation and qualification for adapted radiotherapy over the past ten years. Many factors leading to anatomical and dosimetric changes during treatment have been identified. Based on the literature, the most common factors triggering re-plan are weight loss, tumor and nodal changes, and parotid glands shrinkage. The fluctuations in dose distribution in the clinical area are significant predictive factors for patients’ quality of life and the possibility of recovery. It has been shown that re-planning influence clinical outcomes: local control, disease free survival and overall survival. Regarding literature studies, it seems that adaptive radiotherapy would be the most beneficial for tumors of immense volume or those in the nearest proximity of the OARs. All researchers agree that the timing of re-planning is a crucial challenge, and there are still no clear consensus guidelines for time or criteria of re-planning. Nowadays, thanks to significant technological progress, the decision is mostly made based on observation and supported with IGRT verification. Although further research is still needed, adaptive strategies are evolving and now became the state of the art of modern radiotherapy.  相似文献   
7.
间歇性禁食是一种新的饮食干预策略,其可能改善恶性肿瘤治疗的疗效并减少并发症。 限时进食是间歇性禁食的 一种特殊形式,通常仅限制每天的进食时间窗而不限制热量,除了和其他间歇性禁食手段一样能够控制体重并改善代谢紊乱 以外,限时进食还能调节昼夜节律并影响自噬水平,具有潜在的抗衰作用,相关研究已经表明了它预防肿瘤发生以及减缓肿 瘤发展的潜力。 同时,由于实施方案便利、不良反应轻微,限时进食有着不错的依从性及安全性,有可能成为一种适合肿瘤患 者长期实施的辅助治疗方案乃至健康生活方式。 本文从改善肥胖和代谢紊乱、调节昼夜节律和自噬水平以及目前与肿瘤相 关的研究进展这三个方面阐述了限时进食对恶性肿瘤的潜在作用,旨在为将来的相关研究提供理论依据和探索方向,探讨限 时进食作为一种营养干预手段对恶性肿瘤发生的潜在预防作用以及对恶性肿瘤的治疗或辅助治疗作用,以期可以完善对肿 瘤患者的营养干预策略,改善患者的生活质量及预后。  相似文献   
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