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   336篇
  免费   17篇
  国内免费   6篇
儿科学   3篇
妇产科学   2篇
基础医学   51篇
临床医学   24篇
内科学   111篇
神经病学   49篇
特种医学   8篇
外科学   44篇
综合类   3篇
预防医学   9篇
眼科学   1篇
药学   28篇
中国医学   3篇
肿瘤学   23篇
  2022年   4篇
  2020年   4篇
  2018年   4篇
  2017年   2篇
  2016年   3篇
  2015年   4篇
  2014年   12篇
  2013年   10篇
  2012年   16篇
  2011年   24篇
  2010年   14篇
  2009年   15篇
  2008年   27篇
  2007年   23篇
  2006年   19篇
  2005年   16篇
  2004年   13篇
  2003年   12篇
  2002年   18篇
  2001年   9篇
  2000年   8篇
  1999年   16篇
  1998年   6篇
  1997年   4篇
  1995年   4篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1991年   5篇
  1990年   3篇
  1989年   6篇
  1988年   3篇
  1987年   3篇
  1986年   3篇
  1985年   2篇
  1983年   2篇
  1980年   3篇
  1978年   2篇
  1977年   3篇
  1976年   2篇
  1975年   3篇
  1974年   4篇
  1973年   1篇
  1972年   3篇
  1971年   2篇
  1969年   1篇
  1968年   2篇
  1967年   3篇
  1966年   3篇
  1965年   1篇
排序方式: 共有359条查询结果,搜索用时 15 毫秒
11.
We performed morphological and physiological studies in 43 male patients with alcohol dependence (ALC) who had no other apparent lesions in the upper gastrointestinal tract except atrophic and erosive gastritis. A gastric secretory study in which tetragastrin was used as the stimulant revealed that acid and pepsin secretion was less in ALC patients than in hospital controls (p less than 0.001). Endoscopic biopsy specimens of gastric mucosa from ALC patients revealed that atrophy of the gastric mucosa advanced with age. A strong negative correlation was also found between the secretory capacity of the stomach and the degree of atrophy. Possibly, the interval between recurrent episodes of acute mucosal damage was too short to allow complete healing of mucosal lesions. Failure to regenerate denuded epithelium would result in a decrease in the gastric secretory area. Thus, chronic alcohol abuse seems to be an etiological factor in atrophic gastritis.  相似文献   
12.
To clarify the role of mucosal blood flow in the pathogenesis of ulcer formation, the authors investigated dulcerozine-induced duodenal ulcers in rats. Administration of dulcerozine, 500 mg/kg by intragastric route or 250 mg/kg given intraperitoneally, induced acute ulcers in the duodenum, but not the stomach, in all rats. Using the pyloric ligation method, it was determined that although dulcerozine significantly increased gastric acid secretion, no duodenal ulcers were observed in these animals. The administration of 1 ml of 0.1 N HC1 every hour for 6 hours did not induce duodenal ulceration. The mucus glycoprotein content of the corpus, antrum and proximal duodenum did not differ following dulcerozine administration. Duodenal mucosal blood flow, which was measured by an electrolytically generated hydrogen gas clearance technique, decreased significantly following dulcerozine administration even in pylorus-ligated rats. In contrast, there was an increase in the gastric mucosal blood flow following administration of the drug. Therefore, not only an increase in gastric acid secretion but also a decrease in duodenal mucosal blood flow are suggested to be responsible for dulcerozine-induced duodenal ulceration.  相似文献   
13.

Aims

Two double-blind, randomized studies were conducted to assess the tolerability, pharmacokinetics and pharmacodynamics of oral TA-8995, a new cholesteryl ester transfer protein (CETP) inhibitor, in healthy subjects.

Methods

Study 1: Subjects received single doses of TA-8995 or placebo (fasted). Doses were 5, 10, 25, 50 (fed/fasted), 100 and 150 mg (Caucasian males, 18–55 years), 25 mg (Caucasian males, > 65 years and Caucasian females, 18–55 years), 25, 50, 100 and 150 mg (Japanese males, 18–55 years). Study 2: Caucasian males (18–55 years) received 1, 2.5, 10 or 25 mg once daily TA-8995 or placebo for 21–28 days. Blood and urine for pharmacokinetics and/or pharmacodynamics were collected. Tolerability was assessed by adverse events, vital signs, electrocardiograms and laboratory safety tests.

Results

Peak TA-8995 concentrations occurred approximately 4 h post-dose. Mean half-lives ranged from 81 to 166 h, without an obvious dose relationship. Exposure increased less than proportionally to dose. TA-8995 was not excreted in urine. Following 2.5 to 25 mg once daily dosing, TA-8995 demonstrated nearly complete inhibition of CETP activity (92–99%), increased high density lipoprotein-cholesterol (HDL-C) by 96 to 140% and decreased low density liporotein-cholesterol (LDL-C) by 40% to 53%. There were dose-related increases in apolipoproteins A-1 and E, HDL2-C and HDL3-C, and decreases in apolipoprotein B and lipoprotein A. There was no evidence of significant effects of age, gender, ethnicity or food on pharmacokinetics or pharmacodynamics. All doses were well tolerated.

Conclusions

TA-8995 is a potent CETP inhibitor and warrants further investigation.  相似文献   
14.
Antigen stimulation induces a rapid proliferation of B cells for expansion of specific B cell clones and their further differentiation into antibody-producing cells in germinal centers of T-dependent antigen-immunized mice. Previously, we identified a 210-kDa germinal center-associated nuclear protein (GANP) that is up-regulated selectively in germinal centers and carries an MCM-binding domain in the carboxyl-terminal side. In addition, here, we found a region (from 414 to 550 aa) in GANP molecule that is slightly similar to the known DNA-primase component p49. The recombinant GANP fragment covering this region synthesizes RNA primers for extension by DNA polymerase I with single-stranded DNA templates in vitro. GANP DNA-primase activity is controlled by phosphorylation at Ser(502) that is induced by CD40-mediated signaling in vitro and in the germinal center B cells stimulated with antigen in vivo. Overexpression of ganp cDNA in Daudi B cells caused the increased DNA synthesis more than the levels of the mock-transfectants. These evidences suggested that the novel DNA-primase GANP is involved in regulation of cell proliferation of antigen-driven B cells in germinal centers.  相似文献   
15.
Background The relationship between endoscopic appearances such as endoscopic gastritis and duodenitis and dyspeptic symptoms has not been clearly demonstrated. We aimed to clarify the association of endoscopic appearances with Helicobacter pylori infection, histological severity of gastritis, and dyspeptic symptoms in a Japanese population. Methods We enrolled 87 dyspeptic and 93 nondyspeptic subjects in this study. All subjects underwent gastroscopy, and patients with active peptic ulcer disease, reflex esophagitis with erosion, polyps >1 cm, or cancer were excluded. Endoscopic appearances in patients with dyspeptic symptoms and in those without were assessed retrospectively on the basis of endoscopic images. The degree of atrophy by the Kimura-Takemoto classification system was also assessed. Helicobacter pylori infection status was examined by histology or antibody against H. pylori. Histological severity of inflammation and glandular atrophy in the antrum were assessed according to the updated Sydney System. The odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression using the variables age, sex, H. pylori infection status, and all endoscopic appearances. Results The degree of atrophy tended to be lower among dyspeptic patients (P = 0.06). Among all endoscopic appearances, the liner redness (friability) in the antrum (OR = 3.90, 95% CI = 1.20−12.64) and duodenal ulcer (DU) scarring (OR = 3.41, 95% CI = 1.08−10.79) were independently associated with dyspepsia. Histological severity of inflammation and glandular atrophy were not associated with dyspeptic symptoms. Also, no correlation was found between endoscopic appearances and any of the different subgroups of dyspeptic symptoms. Patients with friability in the antrum and DU scar, which correlated with dyspeptic symptom showed some of communal symptoms such as epigastric pain, epigastric discomfort, hypochondriac pain, early satiation/postprandial fullness, and belching, but they differed considerably with respect to H. pylori positivity and the histological severity of gastritis. Conclusions Some endoscopic appearances such as friability in the antrum and DU scarring may be associated with dyspeptic symptoms, and endoscopic appearances may be useful markers to perform clinical implementation reflecting an individual’s pathophysiology of dyspeptic symptoms.  相似文献   
16.

Objective

Bilirubin has been recognized as an important endogeneous antioxidant. Previous studies reported that bilirubin could prevent atherosclerosis. The aim of this study was to investigate if serum bilirubin concentration could be a predictor for the development of albuminuria in patients with type 2 diabetes.

Materials and Methods

We measured serum bilirubin in 320 consecutive patients with normoalbuminuria. We performed follow-up study to assess the development of albuminuria, mean interval of which was 3.2 ± 0.9 years. Cox proportional hazards regression was used to examine the relationship between serum bilirubin concentration and the development of albuminuria.

Results

During follow-up duration, 43 patients have developed albuminuria. In multivariate analysis, after adjusting for comprehensive risk factors, the risk of developing albuminuria was higher in the lowest quartile of serum bilirubin concentrations than that in the highest quartile of serum bilirubin concentrations (Hazard ratio, 5.76; 95% CI, 1.65 to 24.93).

Conclusions

Low serum bilirubin concentration could be a novel risk factor for the development of albuminuria in patients with type 2 diabetes.  相似文献   
17.
18.
19.
Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator, which plays a pivotal role in inflammatory and immune diseases. We attempted to clarify associations of the functional polymorphisms of the MIF gene promoter with the development of chronic gastritis. The study was performed with 290 stocked DNAs from subjects with no evidence of gastric malignancy. We employed the PCR-SSCP method to detect gene polymorphisms. The severity of histological chronic gastritis in antral biopsy specimens was classified according to the updated Sydney system. Both the 7/7-CATT repeat at position -794 and the -173 C/C genotypes were significantly associated with a risk of developing severe gastric mucosal atrophy (OR, 9.69; 95% CI, 1.29-72.5; and OR, 4.60; 95% CI, 1.05-20.2, respectively). In subjects younger than 60 years old, the number of 7-CATT alleles was significantly correlated with both the activity and inflammation scores (p=0.0079 and 0.0080, respectively). Our results suggested that functional promoter polymorphisms of the MIF gene might be associated with the severity of gastric mucosal inflammation in younger subjects and with the subsequent development of mucosal atrophy.  相似文献   
20.
We report a case of adenocarcinoma of the minor duodenal papilla, a rare type of duodenal neoplasm. A 76-year-old man with a history of surgery for rectal cancer and gastric cancer was referred to us after a follow-up upper gastrointestinal endoscopy revealed an abnormal elevation in the minor duodenal papilla. The pathological diagnosis of a biopsy specimen was adenocarcinoma. Preoperative examination of other organs revealed a tumor in the ascending colon, which was also identified as adenocarcinoma. We performed synchronous pancreatoduodenectomy and ileocecal resection with lymph node dissection. Histopathological examination of the resected specimen revealed that the papilla tumor arose from the duodenal mucosa and infiltrated the submucosa of the duodenal wall, but not the pancreatic parenchyma. Based on these findings, we diagnosed primary adenocarcinoma of the minor duodenal papilla. To our knowledge, this is only the sixth such case reported in the English-language literature, and we review all six cases after this case report.  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