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   195901篇
  免费   19195篇
  国内免费   12580篇
耳鼻咽喉   1762篇
儿科学   2177篇
妇产科学   2522篇
基础医学   23183篇
口腔科学   3558篇
临床医学   25583篇
内科学   28202篇
皮肤病学   2332篇
神经病学   10139篇
特种医学   7014篇
外国民族医学   100篇
外科学   19882篇
综合类   32535篇
现状与发展   40篇
一般理论   22篇
预防医学   13741篇
眼科学   5011篇
药学   21231篇
  204篇
中国医学   12094篇
肿瘤学   16344篇
  2024年   788篇
  2023年   3195篇
  2022年   8363篇
  2021年   10491篇
  2020年   7953篇
  2019年   6748篇
  2018年   7102篇
  2017年   6572篇
  2016年   6117篇
  2015年   9450篇
  2014年   11422篇
  2013年   10648篇
  2012年   15488篇
  2011年   16659篇
  2010年   10797篇
  2009年   8334篇
  2008年   10994篇
  2007年   10373篇
  2006年   9921篇
  2005年   9575篇
  2004年   6122篇
  2003年   5495篇
  2002年   4609篇
  2001年   3841篇
  2000年   3979篇
  1999年   3997篇
  1998年   2367篇
  1997年   2394篇
  1996年   1842篇
  1995年   1785篇
  1994年   1556篇
  1993年   934篇
  1992年   1309篇
  1991年   1146篇
  1990年   914篇
  1989年   866篇
  1988年   783篇
  1987年   640篇
  1986年   467篇
  1985年   407篇
  1984年   199篇
  1983年   169篇
  1982年   100篇
  1981年   128篇
  1980年   82篇
  1979年   116篇
  1978年   58篇
  1977年   56篇
  1976年   44篇
  1974年   51篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
习洋  陶泽璋 《疑难病杂志》2020,(2):207-211,216
慢性鼻窦炎(CRS)是一种常见的慢性非特异感染性鼻部疾病,病理分型主要分为Th2细胞介导的嗜酸性粒细胞性鼻窦炎(ECRS)和Th1细胞介导的非嗜酸性粒细胞性鼻窦炎(非ECRS)2种表型。欧洲国家CRS患病人群主要表现为ECRS,而随着亚洲国家的急剧工业化发展,其ECRS的比例也在急剧增加。ECRS发病机制复杂,涉及多种免疫细胞和相关因子相互作用。其治疗方法包括抗生素、激素药物治疗及手术治疗等,但仍有部分患者症状难以改善或存在复发的风险。Ⅱ型固有淋巴样细胞(ILC2s)是一种非B、非T的新型淋巴细胞,与Th2免疫应答关系密切。文章就ILC2s在ECRS发病机制中的作用进行综述,以期为ECRS的诊断和治疗提供理论参考。  相似文献   
82.
Malaria, one of the most striking, re-emerging infectious diseases caused by the genus Plasmodium, places a huge burden on global healthcare systems. A major challenge in the control and eradication of malaria is the continuous emergence of increasingly widespread drug-resistant malaria, creating an urgent need to develop novel antimalarial agents. Chalcone derivatives are ubiquitous in nature and have become indispensable units in medicinal chemistry applications due to their diverse biological profiles. Many chalcone derivatives demonstrate potential in vitro and in vivo antimalarial activity, so chalcone could be a useful template for the development of novel antimalarial agents. This review covers the recent development of chalcone hybrids as antimalarial agents. The critical aspects of the design and structure–activity relationship of these compounds are also discussed.  相似文献   
83.
84.
目的:分析腹腔镜胆囊切除术的临床疗效,分析其对血清应激指标的影响。方法:将160例来我院行胆囊切除术的患者随机分为两组,对照组和观察组各80例。对照组采用开腹胆囊切除术,观察组则采用腹腔镜胆囊切除术。比较两组间手术时间、术中出血量、肠功能恢复时间以及住院天数差异,比较治疗前后两组患者间血清应激相关指标皮质醇(COR)、去甲肾上腺素(NE)、促肾上腺皮质激素(ACTH)、多巴胺(DA)以及胰岛素(INS)、三碘甲状腺原氨酸(T3)、甲状腺素(T4)、促甲状腺激素释放激素(TSH)水平差异。结果:观察组患者手术时间、术中出血量、肠功能恢复时间以及住院天数均显著少于对照组(P<0.05)。血清COR、NE、ACTH、DA和INS、T3水平在围手术期均发生了显著变化,各项指标均在胆囊分离时就明显升高,术后24 h开始下降(P<0.05);术后观察组上述指标均显著低于对照组(P<0.05)。结论:腹腔镜胆囊切除术对机体应激反应影响小于开腹手术,更利于患者术后康复。  相似文献   
85.
植物药对结肠癌具有良好的防治作用。姜黄素、多糖(苹果多糖、香菇多糖)、皂苷(重楼皂苷、人参皂苷)、白藜芦醇、槲皮素等植物药可通过不同信号通路抑制结肠癌细胞的增殖,促进细胞凋亡。此外,植物药还具有抗炎、抗氧化、抗血管生成、减轻化疗药物不良反应、逆转肿瘤细胞耐药等作用。了解植物药对结肠癌的防治作用及其可能的作用机制,能为结肠癌的临床防治提供更多的理论依据及治疗思路。  相似文献   
86.
Acid-suppressive drugs, including histamine-2 receptor antagonists (H2RAs) and proton pump inhibitors (PPIs), are common medications used for treating upper gastrointestinal tract disorders. However, acid-suppressive drugs have been reported to increase the risk of pneumonia in numerous disease populations. However, the relationship between acid-suppressive drugs and stroke-associated pneumonia (SAP) remains controversial.The purpose of this study was to investigate the association between acid-suppressive drug usage and pneumonia among patients with stroke by using a nationwide data set.A population-based cohort study was conducted using a data set from the Taiwanese National Health Insurance Research Database. Data on patients with new-onset stroke from 2010 to 2011 were collected. Patients with and without acid-suppressive drug usage were followed up to identify the occurrence of any type of pneumonia. We estimated the adjusted hazard ratios (HRs) by using the Cox proportional hazards model.The study cohort comprised 7965 patients with new-onset stroke. The incidence of pneumonia was 6.9% (552/7965) and more than 40% (225/552) of patients developed pneumonia within 3 months after an acute stroke. Acid-suppressive drug usage was an independent risk factor of pneumonia. The adjusted HR for the risk of pneumonia in patients with new-onset stroke using acid-suppressive drugs was 1.44 (95% confidence interval [CI] = 1.18–1.75, P < 0.01). Only PPI usage increased risk of chronic SAP (adjusted HR = 1.46, 95% CI = 1.04–2.05).Acid-suppressive drug usage was associated with a slightly increased risk of SAP. Physicians should exercise caution when prescribing acid-suppressive drugs to patients with stroke, particularly at the chronic stage.  相似文献   
87.
88.
Interleukin‐37 (IL‐37) is closely associated with several inflammatory diseases. However, the role of IL‐37 in the pathogenesis of rheumatoid arthritis (RA) remains unclear. The aim of this study was to assess the associations between serum levels of IL‐37 and disease activity, inflammatory cytokines, and bone loss in patients with RA. Serum cytokines levels were examined by Enzyme‐linked immunosorbent assay (ELISA). Radiographic bone erosion was assessed using the van der Heijde‐modified Sharp score and bone mineral density (BMD) was measured using DXA. Serum IL‐37 levels in RA patients were significantly higher than those in HCs (p < 0.001), and were significantly positively correlated with clinical parameters of disease activity and serum levels of IL‐17 and IL‐23. In addition, serum IL‐37 levels were significantly higher in patients with stage IV of radiographic bone erosion than those with stage III and stage I–II, and they were significantly higher in those with osteopenia and osteoporosis than in those with normal BMD. Our results suggest that serum IL‐37 levels were increased in patients with RA and were positively associated with disease activity, IL‐17/IL‐23 and bone loss in RA, suggesting that IL‐37 may play a critical role in the pathogenesis of RA.  相似文献   
89.
90.
Background: The key factors of inducing drug cravings in persons abstaining from drug use remain a focus of addictions research. Given the accumulating evidences, the scope of cues investigated in the cue-reactivity paradigm has increased considerably. Yet, few studies have examined the effects of the intensity and endurance of different types of cues on their ability to induce craving. This study investigated differences among drug-cue words, negative physiological-cue words, and negative social-cue words in the induction of drug cravings among persons abstaining from heroin.

Methods: The sample consisted of 149 male abstinent heroin abusers from four addiction rehabilitation centers in China. Based on their abstinence lengths, they were labeled as short-term, medium-term, and long-term abstainer participants respectively. All participants completed a stress-imagery task and rated craving by visual analog scale.

Results: There was a significant interaction of cue type and abstinence length. There was no difference on the craving induced by three types of cue words in the short-term group. In the medium-term group, craving induced by negative social-cue words was significantly stronger than that by negative physiological-cue words, but not that by drug-cue words. In the long-term group, the craving induced by negative social-cue words remained the strongest, significantly stronger than that by both drug-cue words and negative physiological-cue words.

Conclusion: Negative social-cue words presented in the current study retain the ability to induce craving in heroin abstainers; this finding suggests that negative social cues encountered under more general circumstances could be a risk factor for relapse.  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