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   366篇
  免费   18篇
  国内免费   7篇
儿科学   1篇
基础医学   29篇
口腔科学   11篇
临床医学   32篇
内科学   188篇
皮肤病学   2篇
神经病学   16篇
特种医学   4篇
外科学   33篇
综合类   2篇
预防医学   4篇
眼科学   5篇
药学   34篇
肿瘤学   30篇
  2018年   3篇
  2016年   2篇
  2015年   4篇
  2014年   3篇
  2013年   13篇
  2012年   12篇
  2011年   17篇
  2010年   8篇
  2009年   9篇
  2008年   21篇
  2007年   20篇
  2006年   31篇
  2005年   27篇
  2004年   30篇
  2003年   24篇
  2002年   24篇
  2001年   14篇
  2000年   22篇
  1999年   19篇
  1998年   4篇
  1997年   7篇
  1996年   3篇
  1995年   5篇
  1994年   1篇
  1993年   1篇
  1992年   8篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   3篇
  1987年   4篇
  1986年   2篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1980年   1篇
  1979年   2篇
  1978年   2篇
  1977年   2篇
  1976年   1篇
  1975年   4篇
  1974年   4篇
  1973年   5篇
  1972年   4篇
  1971年   7篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
  1967年   1篇
  1966年   1篇
排序方式: 共有391条查询结果,搜索用时 15 毫秒
1.
Background and Aims: Video capsule endoscopy (VCE) has become increasingly important as a simple method for observing the entire small intestine. The indications for VCE are obscure gastrointestinal bleeding and investigation of Crohn’s disease (CD). However, the correlation between endoscopic findings obtained by VCE and clinical findings in known cases of CD is not clear, and we therefore investigated this in the present study. Patients and methods: In 30 patients with known CD (Crohn’s disease activity index [CDAI] 0–420; median = 158.3), double contrast enteroclysis (ENT) was performed 1–3 weeks prior to VCE. The relationship between the VCE findings and hematological analysis/CDAI was examined. Results: In 17 of 30 patients, the entire small intestine could be investigated by VCE, whereas in the remaining 13 patients the terminal ileum could not be investigated. The following exhibited positive correlations: total lesions and CDAI (correlation coefficient values: rs = 0.661, adjusted P < 0.0061), ulcers and C‐reactive protein (CRP) (rs = 0.607, adjusted P < 0.0061), total lesions and CRP (rs = 0.604, adjusted P < 0.0061). Conclusions: Analysis with VCE suggests that CDAI and CRP indicate the activity of intestinal lesions in patients with known CD, and that CRP, in particular, is associated with the activity of ulcerative lesions of the intestine. This may contribute to revised guidelines for VCE in the future.  相似文献   
2.
The authors experienced a case of Mirizzi’s syndrome successfully treated with endoscopic nasogallbladder drainage (ENGBD). The patient was a 63‐year‐old man. He was admitted with abdominal pain and jaundice. Laboratory data indicated leukocytosis and elevation of serum bilirubin level. Abdominal ultrasound showed marked swelling of gallbladder and debris in the gallbladder, therefore, the authors strongly suspected Mirizzi’s syndrome. He had past history of acute myocardial infarction and treated with anticoagulation therapy. Then, the authors couldn’t perform surgical removal or percutaneous transhepatic drainage, and tried endoscopic transpapillary drainage. Endoscopic retrograde cholangiopancreatography revealed smooth stricture in the superior portion of common bile duct and occlusion of the cystic duct, and ENGBD was then performed. After ENGBD, his complaints, laboratory data, swelling of gallbladder and stricture of common bile duct were all remarkably improved.  相似文献   
3.
Intrahepatic bile ducts (IHBDs) are indispensable for transporting bile secreted from hepatocytes to the hepatic duct. The biliary epithelial cells (BECs) of the IHBD arise from bipotent hepatoblasts around the portal vein, suggesting the portal mesenchyme is essential for their development. However, except for Notch or Activin/TGF-beta signaling molecules, it is not known which molecules regulate IHBD development. Here, we found that FGF receptors and BMP4 are specifically expressed in the developing IHBD and the hepatic mesenchyme, respectively. Using a mesenchyme-free culture of liver bud, we showed that bFGF and FGF7 induce the hepatoblasts to differentiate into BECs, and that BMP4 enhances bFGF-induced BEC differentiation. The extracellular matrix (ECM) components in the hepatic mesenchyme induced BEC differentiation. Forced expression of a constitutively active form of the FGF receptor partially induced BEC differentiation markers in vivo. These data strongly suggest that bFGF and FGF7 promote BEC differentiation cooperatively with BMP4 and ECMs in vivo.  相似文献   
4.
Effects of rectally injected prostaglandin E2 (PGE2) in rats with dextran sodium sulphate (DSS)-induced colitis were investigated in terms of histopathology, local myeloperoxidase (MPO) activity, local mRNA expression of interleukin-1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and growth-regulated gene produced/cytokine-induced neutrophil chemoattractant (GRO/CINC)-1, and secretion of TNF-alpha and GRO/CINC-1. In animals with no PGE2 treatment, DSS-induced erosion and ulceration were particularly severe in the rectum and extended to the proximal colon. Neutrophil infiltration was characteristically present in the lesions and surrounding mucosa. MPO activity at lesion sites was increased. IL-1beta and GRO/CINC-1 mRNA expression was increased, while TNF-alpha mRNA expression was significantly decreased. GRO/CINC-1 secretion was increased but a similar elevation of TNF-alpha was not detected. In the PGE2-treated group, lesion formation was inhibited grossly and microscopically. Neutrophil infiltration and MPO activity in and around lesions were lessened. The reduction in TNF-alpha mRNA expression and secretion was not affected by PGE2. The expression of mRNA for IL-1beta and GRO/CINC-1 was reduced, as was the secretion of GRO/CINC-1. As mRNA expression and secretion of cytokines in lesions of non-PGE2-treated animals was similar to that reported in human ulcerative colitis, rectal injection of PGE2 may prove to be an effective therapy.  相似文献   
5.
6.
目的:检测γ-氨基丁酸(gamma-aminobutyricacid,GABA)和谷氨酸脱羧酶(glutamicaciddecarboxylase,GAD)在大鼠降结肠上皮的表达及分布特征,并探讨GABA与上皮细胞分化增殖的关系.方法:用免疫荧光及激光共聚焦显微扫描技术,检测GABA、GAD65及GAD67在大鼠降结肠上皮中的表达,并以麦芽凝聚素组织化学染色与免疫荧光结合的双重染色显示GABA和GAD65表达细胞的分布特征.同时,用RT-PCR和原位分子杂交方法检测GADmRNA的表达.此外,用3H-胸腺嘧啶放射自显影法显示降结肠上皮的增殖带.结果:RT-PCR显示降结肠黏膜中GAD65及GAD67mRNA均阳性,原位杂交显示阳性杂交信号主要分布在上皮细胞的隐窝和腔面,且GAD65信号较GAD67强.GABA及GAD65免疫反应阳性细胞主要分布在降结肠的腔面和隐窝的上1/3上皮细胞的胞质,而GAD67阳性细胞仅分布腔面,此外,GABA及GAD65阳性染色也见于黏膜固有层.双重染色显示杯状细胞中GABA及GAD65均阴性.3H-胸腺嘧啶标记阳性细胞主要在隐窝的中下段.结论:GABA及GAD65分布在大鼠降结肠上皮的成熟带及功能带,GABA系统可能参与上皮细胞的分化与增殖的调节.  相似文献   
7.
BACKGROUND: Salt status plays a pivotal role in angiotensin-II-induced organ damage by regulating reactive oxygen species status, and it is reported that reactive oxygen species activate mineralocorticoid receptors. METHOD: To clarify the role of reactive oxygen species-related mineralocorticoid receptor activation in angiotensin-II-induced cardiac dysfunction, we examined the effect of the following: salt status; an MR antagonist, eplerenone; and an antioxidant, tempol in angiotensin-II-loaded Sprague-Dawley rats. RESULTS: Angiotensin-II/salt-loading elevated blood pressure, and neither eplerenone nor tempol antagonized the rise in blood pressure significantly. Left ventricular diastolic function was monitored by measuring peak velocity of a mitral early inflow (E), the ratio of mitral early inflow to atrial contraction related flow (E/A), deceleration time of mitral early inflow and -dP/dt, the time constant (T), and filling pressure (left ventricular end-diastolic pressure) by echocardiography or cardiac catheterization. Despite the suppressed serum aldosterone, left ventricular diastolic function was deteriorated with angiotensin II/high salt, but not affected by angiotensin II/low salt. However, angiotensin-II/salt-induced cardiac dysfunction was restored by eplerenone and tempol. Nicotinamide adenine dinucleotide phosphateoxidase-derived superoxide formation was greater in the hearts of the angiotensin II/high-salt rats than of the angiotensin II/low-salt rats. The expression of the Na(+) -H(+) exchanger isoform 1, a target of mineralocorticoid receptor activation, was significantly increased in the angiotensin II/high-salt group. Both tempol and eplerenone inhibited the angiotensin-II/salt-induced upregulation of Na(+) -H(+) exchanger isoform 1. CONCLUSION: These findings demonstrate that mineralocorticoid receptor activation by oxidative stress can cause left ventricular diastolic dysfunction in a rat model of mild hypertension.  相似文献   
8.
9.
BACKGROUND AND AIM: Little is known about the clinical efficacy of co-therapy of ecabet sodium, a mucoprotective agent, and a histamine H2-receptor antagonist. The aim of the present study was to assess its additive benefit in combination with cimetidine for gastric ulcer. METHODS: In this prospective randomized study, after gastric ulcer was confirmed by endoscopy, 200 patients in 47 hospitals received either ecabet sodium 1 g b.i.d and cimetidine 400 mg b.i.d. (EC), or cimetidine 400 mg b.i.d. alone (C) for 8 weeks. Healing was examined by endoscopy at 4 and 8 weeks. RESULTS: Of the intention-to-treat (ITT) population (EC, 103; C, 97), 181 patients comprised the per protocol (PP) analysis (EC, 93; C, 88). At 4 weeks, healing rates were significantly higher in the EC group (60%) than in the C group (36%) ( p < 0.01). At 8 weeks, those by the ITT and PP analyses were 82% (EC) versus 58% (C), and 90% (EC) versus 64% (C), respectively ( p < 0.01 and p < 0.001). Symptom relief rates (EC vs C) at 2, 4 and 8 weeks were 73%versus 47% ( p < 0.01), 89%versus 66% ( p < 0.001), and 97%versus 73% ( p < 0.001), respectively. Significant additive effects of ecabet sodium were observed in patients aged 60 years or older, with solitary and medium to large ulcer, and without smoking or drinking habits. No adverse effects were critical. CONCLUSION: Ecabet sodium significantly augmented gastric ulcer healing and symptom relief by cimetidine, especially in the elderly.  相似文献   
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