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   4910篇
  免费   295篇
  国内免费   20篇
耳鼻咽喉   36篇
儿科学   118篇
妇产科学   66篇
基础医学   752篇
口腔科学   76篇
临床医学   331篇
内科学   1288篇
皮肤病学   256篇
神经病学   332篇
特种医学   104篇
外科学   460篇
综合类   21篇
一般理论   1篇
预防医学   263篇
眼科学   147篇
药学   367篇
中国医学   14篇
肿瘤学   593篇
  2024年   5篇
  2023年   29篇
  2022年   91篇
  2021年   156篇
  2020年   103篇
  2019年   97篇
  2018年   161篇
  2017年   123篇
  2016年   148篇
  2015年   116篇
  2014年   170篇
  2013年   242篇
  2012年   344篇
  2011年   366篇
  2010年   198篇
  2009年   197篇
  2008年   343篇
  2007年   360篇
  2006年   336篇
  2005年   317篇
  2004年   319篇
  2003年   283篇
  2002年   275篇
  2001年   42篇
  2000年   29篇
  1999年   41篇
  1998年   53篇
  1997年   51篇
  1996年   33篇
  1995年   27篇
  1994年   20篇
  1993年   26篇
  1992年   14篇
  1991年   6篇
  1990年   6篇
  1989年   16篇
  1988年   9篇
  1987年   5篇
  1986年   4篇
  1985年   4篇
  1984年   7篇
  1983年   4篇
  1982年   8篇
  1981年   3篇
  1975年   2篇
  1974年   4篇
  1973年   4篇
  1972年   13篇
  1971年   3篇
  1969年   3篇
排序方式: 共有5225条查询结果,搜索用时 15 毫秒
81.
Humic acid (HA) has been implicated as a contributory factor for blackfoot disease, which is an endemic peripheral vascular disease. We investigated the effect of HA on the regulation of endothelial nitric oxide (NO) synthase (eNOS) in human umbilical vein endothelial cells (HUVECs) to evaluate the involvement of eNOS and related factors in peripheral vascular impairment with HA exposure. Treatment of HUVECs with HA induced upregulation of eNOS. This result coincides with those of previous studies. Furthermore this is the first study to report that HA induces upregulation of heat shock protein (Hsp)90α, Hsp90β, eNOS phosphorylation at Ser1177, and eNOS phosphorylation at Thr495, as compared to that in the control. In contrast, treatment with BAPTA, an intracellular Ca2+ chelator, inhibited upregulation of these proteins induced by HA. This study demonstrates that HA treatment leads to increases in both Hsp90α and Hsp90β proteins and indicates that Hsp90α leads to eNOS phosphorylation at Ser1177 and that Hsp90β leads to eNOS phosphorylation at Thr495, respectively. Upregulation of eNOS, Hsp90α, and Hsp90β in HUVECs is regulated by intracellular Ca2+ accumulation induced by HA. These results suggest that upregulation of eNOS phosphorylation at Ser1177 and eNOS phosphorylation at Thr495 produce NO and superoxide anions, respectively, resulting in generation of peroxynitrite, which causes impairment of vascular endothelial cells. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 223–231, 2015.  相似文献   
82.
83.
84.
A 9‐year‐old girl developed influenza A H1N1 pdm09‐associated myocarditis and pericarditis 2 days after starting zanamivir therapy. The virus was detected in the respiratory tract but not in the serum or pericardial effusion. The virus sampled from the respiratory tract had normal susceptibility to neuraminidase inhibitors. Although no differences in interferon‐γ, interleukin (IL)‐1β, and tumor necrosis factor‐α were observed between the plasma and pericardial effusion, some inflammatory cytokines or chemokines (IL‐6 and IL‐8) and vascular endothelial growth factor were remarkably elevated in the pericardial effusion compared with the plasma. This suggested that the influenza virus, after infecting the respiratory tract, affected the myocardium, causing myocarditis to gradually develop, which might have been followed by an autoreactive pericarditis causing increased pericardial effusion. Therefore, influenza‐associated myocarditis should be considered when influenza patients have respiratory and cardiac involvement, even during treatment with a neuraminidase inhibitor.  相似文献   
85.
Mori Y  Kitahara Y  Miura K  Itoh Y  Tajima N 《Endocrine》2005,26(2):139-146
The age-related changes in acute insulin response after glucose loading and the influence of suppression of body weight gain were investigated by using blood samples from portal and peripheral veins. We placed indwelling catheters in the portal vein of 12- and 24- wk-old Otsuka Long-Evans Tokushima fatty (OLETF) rats (n = 8, 12), and age-matched control Long-Evans Tokushima Otsuka (LETO) rats (n = 8, 6). To suppress the body weight gain, 6 out of 12 OLETF rats were fed chow containing 50 ppm voglibose (VOG) from 8 until 24 wk of age. After fasting for 17 h, rats underwent 1 g/kg oral glucose tolerance test (OGTT). Peripheral glucose levels after glucose loading were significantly higher in 12- and 24-wk-old OLETF rats than in the age-matched LETO rats. Values for delta insulin 15 min/delta glucose 15 min (delta I15 min/delta G15 min) in portal blood were 0.029 +/- 0.011 and 0.009 +/- 0.009 (12 wk of age) and 0.03 +/- 0.03 and -0.01 +/- 0.01 (24 wk of age) in the LETO rats and OLETF rats. At the age of 24 wk, the body weights in VOG-treated OLETF rats were significantly lower than those in the OLETF rats. And there was significantly greater acute insulin response to glucose in VOG-treated OLETF rats than in the OLETF rats. Acute insulin response to glucose decreased with advancing age and the suppression of body weight gain preserved the response in spontaneously type 2 diabetic rats with visceral fat obesity.  相似文献   
86.
87.
Clinical Rheumatology - Eosinophilic fasciitis (EF) is a rare connective tissue disease that causes inflammation and fibrosis of the fascia, inducing pain and motor dysfunction. Characteristic skin...  相似文献   
88.
Miliary tuberculosis is a potentially lethal type of tuberculosis that results from the hematogenous dissemination of Mycobacterium tuberculosis bacilli. We herein describe the case of a 34-year-old man that presented with a one-month history of cough and fever, while his sputum smear results were negative. Chest computed tomography revealed bilateral centrilobular ground-glass opacification (GGO), suggestive of hypersensitivity pneumonitis; thus, bronchoscopy was performed. Cryobiopsy specimens revealed necrotic granulomas. A re-examination of sputum after bronchoscopy identified Mycobacterium tuberculosis, and miliary tuberculosis was diagnosed. A cryobiopsy might be useful for diagnosing miliary tuberculosis pathologically, particularly when miliary nodules may be masked by GGO.  相似文献   
89.
A 40-year-old Japanese woman developed malignant-phase hypertension complicated by thrombotic microangiopathy, progressing to end-stage renal disease. Five years later, she was diagnosed with pulmonary arterial hypertension and interstitial pneumonia. Despite a lack of overt skin sclerosis, nucleolar staining in our indirect immunofluorescence analysis and nailfold capillaroscopy facilitated the diagnosis of anti-PM/Scl antibody-positive systemic sclerosis. We observed the persistent presence of anti-PM/Scl antibodies throughout the clinical course, suggesting that her kidney disease was scleroderma renal crisis. Anti-PM/Scl antibodies can be associated with multiple organ diseases. Careful attention to a patient''s antinuclear antibody pattern and dermatological findings may help clarify the etiology of undiagnosed diseases.  相似文献   
90.
A 69-year-old man was admitted to our hospital for progressive muscle weakness in both lower limbs and limb ataxia (day 0). Nerve conduction studies showed low compound muscle action potential amplitudes at rest and increased amplitudes after maximum voluntary contraction. Blood testing revealed SOX-1 antibodies. He was diagnosed with paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome (PCD-LEMS). He died from aspiration pneumonia on day 9. Small-cell lung carcinoma (SCLC), which had not been obvious on computed tomography, was found during the autopsy. Patients with PCD-LEMS who test positive for SOX-1 antibodies should be carefully evaluated for SCLC.  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