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   2270篇
  免费   257篇
  国内免费   3篇
耳鼻咽喉   39篇
儿科学   68篇
妇产科学   37篇
基础医学   382篇
口腔科学   108篇
临床医学   272篇
内科学   511篇
皮肤病学   45篇
神经病学   202篇
特种医学   76篇
外科学   299篇
综合类   8篇
一般理论   3篇
预防医学   187篇
眼科学   45篇
药学   149篇
中国医学   2篇
肿瘤学   97篇
  2023年   37篇
  2022年   11篇
  2021年   40篇
  2020年   46篇
  2019年   48篇
  2018年   83篇
  2017年   87篇
  2016年   87篇
  2015年   109篇
  2014年   100篇
  2013年   213篇
  2012年   153篇
  2011年   142篇
  2010年   103篇
  2009年   47篇
  2008年   81篇
  2007年   86篇
  2006年   98篇
  2005年   80篇
  2004年   111篇
  2003年   75篇
  2002年   78篇
  2001年   28篇
  1999年   21篇
  1998年   16篇
  1997年   11篇
  1996年   17篇
  1995年   21篇
  1992年   18篇
  1991年   17篇
  1989年   12篇
  1988年   12篇
  1987年   11篇
  1986年   21篇
  1985年   14篇
  1984年   22篇
  1983年   10篇
  1982年   16篇
  1981年   10篇
  1980年   10篇
  1979年   13篇
  1978年   10篇
  1977年   10篇
  1976年   10篇
  1974年   10篇
  1955年   38篇
  1954年   88篇
  1949年   20篇
  1948年   17篇
  1943年   11篇
排序方式: 共有2530条查询结果,搜索用时 15 毫秒
81.
We present a case of a gastric neuroendocrine carcinoma in a patient with a history of long-term proton pump inhibitor (PPI) use. A 49-year-old man using PPI for the last 15 years due to gastroesophageal reflux disease developed progressive dysphagia, dyspepsia and weight loss. Upper gastrointestinal endoscopy, endoscopic ultrasonography and abdominal CT diagnosed a malignant tumor localized to a hiatal hernia. Fasting serum chromogranin A and gastrin concentrations were elevated (32 nmol/l and 159 pmol/l, respectively). Helicobacter pylori PCR analysis of antral biopsies was negative. Biopsies from endoscopically normal oxyntic mucosa showed enterochromaffin-like (ECL) cell hyperplasia. Tumor biopsies revealed a poorly differentiated neuroendocrine carcinoma. Sevier-Munger staining, immunohistochemistry and electron microscopy indicated ECL cell as origin of the tumor cells. Concerns have previously been raised about the safety of long-term PPI use due to a possible increased risk of cancer. This case illustrates a patient with a poorly differentiated neuroendocrine carcinoma with ECL cell characteristics probably induced by hypergastrinemia secondary to long-term PPI use.  相似文献   
82.
83.
84.
85.
86.
87.
Summary. N8 is a new recombinant factor VIII (rFVIII) compound produced and formulated without human‐ or animal‐derived protein. The aims of the present studies were to evaluate the pharmacokinetics and pharmacodynamics properties of N8 and to compare with a commercially available rFVIII product (Advate®) in haemophilia A mice. The pharmacokinetics were evaluated after single i.v. administration of 80, 120 and 280 IU kg?1 of N8 and Advate® and measurements of FVIII blood concentrations as a function of time. The efficacy and dose response curves of N8 and Advate® (1–200 IU kg?1) were evaluated in a tail bleeding model. Furthermore, the effects in a newly developed haemophilia knee joint haemarthrosis model were investigated. No significant differences were found in the pharmacokinetic parameters between N8 and Advate®. The clearances were 11 ± 1 vs. 10 ± 2 mL h?1 kg?1 (P = 0.14) and the half‐lives 7.2 ± 0.9 vs. 7.7 ± 1.4 h (P = 0.31) after administration of N8 and Advate® respectively. Dose‐independent pharmacokinetics was shown, and comparable efficacy and potency were shown between N8 and Advate® in the tail bleeding model. Both compounds normalized the bleeding at the dose of 200 IU kg?1, and for blood loss ED50 values of 27 IU kg?1 (N8) and 28 IU/kg (Advate®) were found (P = 0.97). In the haemarthrosis model, treatment with N8 and Advate® at 200 IU kg?1 reduced the mean increase in the joint diameter significantly from 1.23 ± 0.19 to 0.32 ± 0.08 mm (P < 0.01) and 0.25 ± 0.08 mm (P < 0.001) respectively. Pharmacokinetics and pharmacodynamics of N8 and Advate® were comparable after i.v. administration to haemophilia A mice.  相似文献   
88.
Treatment studies in haemophilia focus on joint bleeds; however, some 10-25% of bleeds occur in muscles. This review addresses management of muscle haematoma in severe haemophilia, defines gaps in the published evidence, and presents a combined clinician and physiotherapist perspective of treatment modalities. The following grade 2C recommendations were synthesized: (i) Sport and activity should be based on individual factor levels, bleeding history and physical characteristics, (ii) Musculoskeletal review aids the management of children and adults, (iii) 'Time to full recovery' should be realistic and based on known timelines from the healthy population, (iv) Diagnosis should be carried out by both a clinician and physiotherapist, (v) Severe muscle bleeds should be treated similarly to surgical patients: a 50% trough for 10-14 days followed by high-level prophylaxis, (vi) Protection, rest, ice, compression and elevation should be implemented in the acute stage, and (vii) Physiotherapy and rehabilitation should be divided into: control of haemorrhage (phase 1); restoration of Range of Movement (ROM) and strength (phase 2); functional rehabilitation and return to normal living (phase 3). Recommendations specifically for inhibitor patients include: (i) Minor to moderate bleeds should be managed by home-treatment within 1 h of bleed onset using either one injection of rFVIIa 270 μg kg(-1), or two to three injections of rFVIIa 90 μg kg(-1) (2-3 h intervals), or FEIBA 50-100 U kg(-1) (repeated at 12-hourly intervals, if necessary) and (ii) Severe muscle bleeds should be supervised by the treatment centre and include bypassing agents until clinical improvement is observed.  相似文献   
89.
Objective: To examine and compare the prospective effect of the common mental disorders (CMD) anxiety and depression on duration and recurrence of sickness absence (SA), and to investigate whether the effect of CMD on SA is detectable over time. Method: Information from a large epidemiological health study (N = 13 436) was linked with official records of SA episodes lasting ≥16 days up to 6 years after participation. Common mental disorders were assessed with the Hospital Anxiety and Depression Scale (HADS). Associations were analysed with Cox regression and multinomial logistic regression models controlling for potential covariates. Results: Comorbid anxiety and depression, and anxiety only were significant risk factors for SA after adjusting for covariates, whilst depression only was not. Anxiety and depression were stronger predictors for longer duration of SA episodes compared with shorter duration and associated with more frequent recurrence of SA. There was a general trend toward the effect of CMD on SA becoming weaker over time; however, the effect of anxiety only on SA remained stable throughout the follow‐up. Conclusion: Common mental disorders are long‐lasting predictors of onset, duration and recurrence of SA. Anxiety appears to be a more important contributor to long‐term SA than previously described in the literature.  相似文献   
90.
Introduction: The pathogenesis of muscle involvement in patients with myotonic dystrophy type 1 (DM1) is not well understood. In this study, we characterized the muscle phenotype in patients with confirmed DM1. Methods: In 38 patients, muscle strength was tested by hand‐held dynamometry. Myotonia was evaluated by a handgrip test and by analyzing the decrement of the compound muscle action potential. Muscle biopsies were assessed for morphological changes and Na+‐K+ pump content. Results: Muscle strength correlated with a decline in Na+‐K+ pump content (r = 0.60, P < 0.001) and with CTG expansion. CTG expansion did not correlate with severity of myotonia, proximal histopathological changes, or Na+‐K+ pump content. Histopathologically, we found few centrally placed nuclei (range 0.2–6.9%). Conclusions: The main findings of this study are that muscle weakness correlated inversely with CTG expansion and that central nuclei are not a prominent feature of proximal muscles in DM1. Muscle Nerve 47:409‐415, 2013  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