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   1303篇
  免费   46篇
  国内免费   27篇
儿科学   47篇
妇产科学   5篇
基础医学   142篇
口腔科学   42篇
临床医学   94篇
内科学   463篇
皮肤病学   6篇
神经病学   87篇
特种医学   13篇
外科学   217篇
综合类   6篇
一般理论   1篇
预防医学   26篇
眼科学   3篇
药学   135篇
中国医学   1篇
肿瘤学   88篇
  2023年   2篇
  2022年   5篇
  2021年   11篇
  2020年   9篇
  2019年   13篇
  2018年   11篇
  2017年   13篇
  2016年   21篇
  2015年   14篇
  2014年   19篇
  2013年   45篇
  2012年   66篇
  2011年   97篇
  2010年   40篇
  2009年   34篇
  2008年   77篇
  2007年   96篇
  2006年   101篇
  2005年   102篇
  2004年   91篇
  2003年   89篇
  2002年   88篇
  2001年   23篇
  2000年   21篇
  1999年   29篇
  1998年   30篇
  1997年   25篇
  1996年   20篇
  1995年   19篇
  1994年   16篇
  1993年   15篇
  1992年   22篇
  1991年   15篇
  1990年   9篇
  1989年   4篇
  1988年   8篇
  1987年   8篇
  1986年   5篇
  1985年   7篇
  1984年   4篇
  1983年   7篇
  1982年   6篇
  1981年   8篇
  1980年   5篇
  1979年   4篇
  1975年   2篇
  1974年   5篇
  1973年   3篇
  1972年   3篇
  1964年   2篇
排序方式: 共有1376条查询结果,搜索用时 171 毫秒
51.

Background

The aim of this study was to investigate the efficacy of rikkunshito (RKT), a traditional Japanese medicine, combined with proton pump inhibitor (PPI) in patients with PPI-refractory non-erosive reflux disease (NERD).

Methods

Patients with PPI-refractory NERD (n = 242) were randomly assigned to the RKT group [rabeprazole (10 mg/day) + RKT (7.5 g/t.i.d.) for 8 weeks] or the placebo group (rabeprazole + placebo). After the 4- and 8-week treatments, we assessed symptoms and quality of life (QOL) using the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG), Gastrointestinal Symptom Rating Scale (GSRS), and Short-Form Health Survey-8 (SF-8).

Results

There were no significant differences in FSSG and GSRS score improvement between these groups after the 4- and 8-week treatments. The mental component summary (MCS) scores of the SF-8 improved more in the RKT group (from 45.8 ± 8.1 to 48.5 ± 7.4) than in the placebo group (from 47.7 ± 7.1 to 48.4 ± 7.5) after the 4-week treatment (P < 0.05). The 8-week treatment with RKT was more effective for improvement of the degree of MCS score in patients with a low body mass index (<22) (P < 0.05) and significantly improved the acid-related dysmotility symptoms of FSSG in female and elderly patients (≥65 years).

Conclusion

There were no significant differences in improvement of GERD symptoms in patients with PPI-refractory NERD between these groups. However, RKT may be useful for improving mental QOL in non-obese patients and acid-related dyspeptic symptoms, especially in women and the elderly.  相似文献   
52.
AIM To clarify the association between aldo-keto reductase family 1 member B10(AKR1B10) expression and hepatocarcinogenesis after hepatitis C virus eradication.METHODS In this study,we enrolled 303 chronic hepatitis C patients who had achieved sustained virological response(SVR) through interferon-based antiviral therapy. Pretreatment AKR1B10 expression in the liver was immunohistochemically assessed and quantified as a percentage of positive staining area by using image-analysis software. A multivariate Cox analysis was used to estimate the hazard ratios(HRs) of AKR1B10 expression for hepatocellular carcinoma(HCC) development after achieving SVR. The cumulative incidences of HCC development were evaluated using Kaplan-Meier analysis and the log-rank test.RESULTS Of the 303 chronic hepatitis C patients,153(50.5%) showed scarce hepatic AKR1B10 expression,quantified as 0%,which was similar to the expression in control normal liver tissues. However,the remaining 150 patients(49.5%) exhibited various degrees of AKR1B10 expression in the liver,with a maximal AKR1B10 expression of 73%. During the median follow-up time of 3.6 years(range 1.0-10.0 years),8/303 patients developed HCC. Multivariate analysis revealed that only high AKR1B10 expression(≥ 8%) was an independent risk factor for HCC development(HR = 15.4,95%CI: 1. 8- 1 3 2. 5,P = 0. 0 1 2). T h e 5- y e a r c u m u l a t i v e incidences of HCC development were 13.7% and 0.5% in patients with high and low AKR1B10 expression,respectively(P 0.001). During the follow-up period after viral eradication,patients expressing high levels of AKR1B10 expressed markedly higher levels of alanine aminotransferase and α-fetoprotein than did patients exhibiting low AKR1B10 expression.CONCLUSION Chronic hepatitis C patients expressing high levels of hepatic AKR1B10 had an increased risk of HCC development even after SVR.  相似文献   
53.
54.
Objective Systemic sclerosis (SSc) is defined as an autoimmune disease presenting with fibrosis of various organs and vascular endothelial damage. Vascular lesions, including small-bowel angioectasias, are also frequently detected in SSc patients. Polidocanol injection (PDI) is a safe and effective hemostatic treatment for gastrointestinal bleeding. We evaluated the outcomes of PDI for small-bowel angioectasia in SSc patients. Methods We retrospectively evaluated 65 consecutive SSc patients (61 women; mean age, 64.3 years old) who underwent capsule endoscopy (CE) and/or double-balloon endoscopy at Hiroshima University Hospital between April 2012 and December 2019. Patients Patients were stratified according to the presence of small-bowel angioectasia. Among patients who underwent CE during the same period, those with small-bowel angioectasia without concomitant diseases were compared with SSc patients with small-bowel angioectasia. Clinical and endoscopic characteristics, treatment outcomes, and the incidence of metachronous small-bowel angioectasia after PDI were evaluated. Results SSc patients with small-bowel angioectasia exhibited significantly lower hemoglobin levels and a significantly higher incidence of skin telangiectasia than those without small-bowel angioectasia. On a multivariate analysis of the presence of small-bowel angioectasia, anemia and skin telangiectasia were significant independent factors. SSc patients with small-bowel angioectasia included a higher proportion of women and exhibited a significantly higher incidence of metachronous small-bowel angioectasia than X. The characteristics of small-bowel angioectasia and outcomes of PDI were not significantly different between the two groups. No post-treatment rebleeding cases or adverse events were noted. Conclusion CE should be performed for SSc patients with anemia and/or skin telangiectasia. PDI is effective for SSc patients with small-bowel angioectasia.  相似文献   
55.
56.
57.
Renal, adrenal, gonadal, ureteral and inferior phrenic arteries vary in their level of origin and in their calibre, number and precise anatomical relationship to other structures. Studies of the origin and early development of these arteries have evoked sharp disputes. The ladder theory of Felix, which states that ‘All the mesonephric arteries may persist; from them are formed the phrenic, suprarenal, renal and internal spermatic arteries’ has been generally quoted in the anatomical textbooks without rigorous verification for 100 years. In this study, we re-examined this theory by performing micro-injection of dye and resin into rat (Rattus norvegicus) embryos. Our results revealed that most of the mesonephric arteries had degenerated before the metanephros started its ascent. The definitive renal, adrenal, gonadal, ureteral and inferior phrenic arteries appeared as new branches from the gonadal artery and/or directly from the abdominal aorta to the para-aortic ridge. Coincidental to this, the anatomical architecture of the inter-renal vascular cage, which consists of the interlobar and arcuate arteries and their collateral veins, was completed within the developing metanephros. We demonstrated that the delicate renal vascular cage switched from the primary renal artery to the definitive renal artery and that the route of venous drainage changed from the posterior cardinal vein to the inferior (caudal) vena cava.  相似文献   
58.
Recent studies have indicated that heat shock proteins (HSPs), which function as molecular chaperones, play important roles in cellular responses to stress-related events. However, the gender difference in the expression of HSP in the gastric mucosa remains unclear. In order to understand the mechanism of gender difference in the prevalence or severity of gastric mucosal lesions, the expression level of HSP and the correlation of estrogen to HSP induction in the gastric mucosa were evaluated in this study. The basal expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. The gastric ulcer index was significantly higher in male rats compared to female rats observed after 12 h water immersion stress exposure. At this time point, the expression levels of HSP60 and HSP90 in the gastric mucosa were significantly higher in females than those in males. An estrogen-treatment significantly induced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Inversely, an ovariectomy dramatically reduced the expression of HSP60, HSP70 and HSP90 in the gastric mucosa. Our results suggested that estrogen might play an important role in gastric mucosal protection with the induction of gastric mucosal HSPs.  相似文献   
59.
PURPOSE: Long-standing ulcerative colitis (UC) predisposes patients to the development of colorectal cancer, but surveillance of colitis-associated cancer by detecting the precancerous lesion dysplasia is often difficult because of its rare occurrence and normal-looking appearance. In sporadic colorectal cancer, aberrant crypt foci (ACF) have been reported by many investigators to be precursor lesions of the adenoma-carcinoma sequence. In the present study, we analyzed the genetic background of ACF to determine whether they could be precursors for dysplasia, and we examined the usefulness of endoscopic examination of ACF as a surrogate marker for surveillance of colitis-associated cancer. EXPERIMENTAL DESIGN: ACF were examined in 28 UC patients (19 patients with UC alone and 9 patients with UC and dysplasia; 2 of those patients with dysplasia also had cancer) using magnifying endoscopy. K-ras, APC, and p53 mutations were analyzed by two-step PCR RFLP, in vitro--synthesized protein assay, and single-strand conformation polymorphism, respectively. Methylation of p16 was analyzed by methylation-specific PCR. RESULTS: ACF that appeared distinct endoscopically and histologically were identified in 27 out of 28 UC patients. They were negative for K-ras, APC, and p53 mutations but were frequently positive for p16 methylation (8 of 11; 73%). In dysplasia, K-ras and APC mutations were negative but p53 mutation (3 of 5; 60%) and p16 methylation (3 of 5; 60%) were positive. There was a significant stepwise increase in the number of ACF from patients with UC alone to patients with dysplasia and to patients with cancer. Univariate and multivariate analyses showed significant correlations between ACF and dysplasia. CONCLUSIONS: We have disclosed an ACF-dysplasia-cancer sequence in colitis-associated carcinogenesis similar to the ACF-adenoma-carcinoma sequence in sporadic colon carcinogenesis. This study suggests the use of ACF instead of dysplasia for the surveillance of colitis cancer and warrants further evaluation of ACF as a surveillance marker in large-scale studies.  相似文献   
60.
Cyclin D1 is one of the key regulators in G1 progression in the cell cycle and is also a candidate oncogene (termed PRAD1 or bcl -1) in several types of human tumors. We report a collaboration of the cyclin D1 gene with ras and a mutated form of p53 (p53-mt) in neoplastic transformation. Transfection of cyclin D1 alone or in combination with ras or with p53-mt was not sufficient for focus formation of rat embryonic fibroblasts. However, focus formation induced by co-transfection of ras and p53-mt was enhanced in the presence of the cyclin D1-expression plasmid. Co-transfection of ras - and p53-mt-transformants with the cyclin D1-expression plasmid resulted in reduced serum dependency in vitro , Furthermore, the transformants expressing exogenous cyclin D1 grew faster than those without the cyclin D1 plasmid when injected into nude mice. These observations strengthen the significance of cyclin D1 overexpression through gene rearrangement or gene amplification observed in human tumors as a step in multistep oncogenesis; deregulated expression of cyclin D1 may reduce the requirement for growth factors and may stimulate in vivo growth.  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