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   695篇
  免费   70篇
  国内免费   2篇
耳鼻咽喉   6篇
儿科学   4篇
妇产科学   5篇
基础医学   50篇
口腔科学   13篇
临床医学   50篇
内科学   176篇
皮肤病学   5篇
神经病学   52篇
特种医学   38篇
外科学   207篇
综合类   2篇
预防医学   31篇
眼科学   2篇
药学   37篇
中国医学   4篇
肿瘤学   85篇
  2023年   14篇
  2022年   18篇
  2021年   36篇
  2020年   22篇
  2019年   27篇
  2018年   38篇
  2017年   22篇
  2016年   25篇
  2015年   29篇
  2014年   34篇
  2013年   37篇
  2012年   28篇
  2011年   39篇
  2010年   22篇
  2009年   22篇
  2008年   27篇
  2007年   26篇
  2006年   30篇
  2005年   30篇
  2004年   34篇
  2003年   19篇
  2002年   23篇
  2001年   14篇
  2000年   13篇
  1999年   8篇
  1998年   8篇
  1997年   8篇
  1996年   3篇
  1995年   4篇
  1994年   4篇
  1993年   3篇
  1992年   13篇
  1991年   5篇
  1990年   8篇
  1989年   12篇
  1988年   10篇
  1987年   8篇
  1986年   4篇
  1985年   6篇
  1984年   3篇
  1983年   3篇
  1979年   2篇
  1977年   2篇
  1976年   3篇
  1973年   5篇
  1972年   4篇
  1971年   2篇
  1970年   3篇
  1969年   4篇
  1966年   1篇
排序方式: 共有767条查询结果,搜索用时 15 毫秒
631.
In this study, we evaluated the three-dimensional (3D) soft tissue configuration of Japanese females with/without jaw deformity in order to establish the polygonal view of facial soft tissue deformity three-dimensionally. A polygonal chart was applied to assess the outcomes of orthognathic surgery for patients with mandibular hyperplasia with/without deviation. The study included 20 Japanese females with mandibular hyperplasia with/without deviation. All patients received mandibular setback surgery, and 3D measurements were carried out pre-operation, and at 1, 3 and 6 months postoperatively using a non-contact laser scanning system. Eighteen soft tissue landmarks were set on each 3D image and used to calculate a set of selected parameters. As controls, 20 Japanese females with class I occlusion were included. A polygonal chart was constructed based on the mean and S.D. of the control group. Patients with mandibular protrusion characteristically demonstrated significant variances in the items around the lower face. In asymmetric patients, deviation in the mental area disappeared postoperatively, but a small deviation remained when compared to the controls. The method used in this study seems to be a useful index for diagnosis and as a treatment plan for patients with mandibular hyperplasia with/without deviation.  相似文献   
632.
633.
634.
Patients with end-stage renal disease are exposed to increased oxidative stress and impairment of antioxidant mechanisms. We focused on dialysis renal cell carcinoma (RCC), including epithelial hyperplasia in acquired cystic disease of the kidney (ACDK). We attempted to obtain insight into the carcinogenesis and tumor progression in terms of cellular defense mechanisms associated with oxidative stress by investigating the expression of antioxidant proteins by immunohistochemistry. We evaluated retrospectively 43 cases of dialysis RCC and, as a control group, 49 cases of sporadic RCC. Peroxiredoxin (Prx) 1, 3, 4, 5, and 6 expression in dialysis RCC was positively correlated with the duration of dialysis. In epithelial hyperplasia, in 17 cases of acquired cystic disease of the kidney, Prxs and thioredoxin were highly expressed. Moreover, in dialysis RCC, Prx 3, 4, and 5 immunoreactivity and nuclear expression of Y-box-binding protein-1 were higher than in sporadic RCC. In dialysis RCC, Prx 3, 4, and 5 immunoreactivity positively correlated with the Fuhrman nuclear grade. These data suggest that oxidative stress during dialysis enhances antioxidant activity, with an inhibiting effect on carcinogenesis. Once cancer has developed, antioxidant activity might have a stimulating effect on the progression of dialysis RCC.  相似文献   
635.
Increasing evidence suggests that tumour‐initiating cells (TICs) contribute to the development of prostate cancer. Here, we identified syndecan‐1 as a key molecule maintaining the stability of prostate cancer TICs. Holoclones harbouring the biological properties of stemness were derived from single‐cell cultures of the PC3 human prostate cancer cell line. These holoclones over‐expressed syndecan‐1, but showed reduced expression of NADPH oxidase (NOX) and synthesis of hydrogen peroxide and oxygen radicals. Stable RNA‐mediated silencing of syndecan‐1 gene expression up‐regulated NOX‐dependent generation of reactive oxygen species and reduced the survival of holoclones in vitro. Syndecan‐1 down‐regulation also strongly reduced the number of CD133+/CD44+ primitive cancer cells and tumour growth in vivo. Interestingly, syndecan‐1 gene knockdown significantly enhanced the tumour‐suppressive effects of docetaxel by inhibiting the docetaxel‐induced increase in CD133+/CD44+ cells in vivo. In the transgenic adenocarcinoma of the mouse prostate (TRAMP) mouse model of prostate cancer, early intervention with a syndecan‐1 inhibitor (OGT2115) or syndecan‐1 RNAi reduced the incidence of adenocarcinoma and the number of c‐kit+/CD44+ cells in cancer foci. Finally, we found that syndecan‐1 immunopositivity in prostate cancer cells was significantly associated with biochemical recurrence after radical prostatectomy. Taken together, our results show that syndecan‐1 contributes to prostatic carcinogenesis by maintaining TICs and may be a target molecule for therapy. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.  相似文献   
636.
We demonstrate immunoglobulin-complexed aspartate aminotransferase (macro-AST) in a 14-year-old boy with rectitis-type ulcerative colitis by using both gel filtration and electrophoresis methods. The immunoglobulin complexed with AST in this case was identified as an IgG kappa both by electrosyneresis and immunoprecipitation reactions. The present case was noted to have a concomitant elevation of macro-AST associated with deterioration of ulcerative colitis. However, macro-AST has continued to exist when the activity of ulcerative colitis subsided, and the serum level of AST became normal. Thus, macro-AST might be related to an immunological component of ulcerative colitis as well as to the activity of the disease.  相似文献   
637.
Angiography was performed in 2 patients with chronic relapsing pancreatitis. Marked hypervascularity and early arteriovenous shunting with portal vein filling were demonstrated. Increased capillary vessels in the thickened capsule due to inflammation were observed in the pathologic specimen. The angiographic findings we report here are quite similar to those of pancreatic arteriovenous malformation.  相似文献   
638.
We present a case of an extremely rare portosystemic collateral pathway which arose from the right intrahepatic portal vein, passed through the liver parenchyma, and terminated into the inferior vena cava. We demonstrate the findings of diagnostic imaging and discuss the etiology of the collateral circulation in this unusual case.  相似文献   
639.

Objective

To confirm the reproducibility of the effectiveness and safety in photodynamic diagnosis of non‐muscle‐invasive bladder cancer using 5‐aminolevulinic acid in a prospective multicenter non‐randomized phase III trial.

Methods

A total of 61 patients with primary or recurrent non‐muscle‐invasive bladder cancer were prospectively enrolled from five hospitals between May 2015 and March 2016. 5‐Aminolevulinic acid (20 mg/kg) was orally administered 3 h before transurethral resection of bladder tumors using white light or fluorescent light. Of 60 evaluable patients, 511 specimens were obtained from tumor‐suspicious lesions and normal‐looking mucosa. The primary end‐point was sensitivity. The secondary end‐points were specificity, positive and negative predictive values, and safety.

Results

The sensitivity of the fluorescent light source (79.6%) was significantly higher (P < 0.001) than that of the white light source (54.1%). In total, 25.4% (46/181) of tumor specimens were diagnosed as positive with only the fluorescent light source. In nine (15%) of 60 patients, the risk classification and recommended treatment after transurethral resection of bladder tumors were changed depending on the additional types of tumor diagnosed by the fluorescent light source. The specificity of the fluorescent light versus white light source was 80.6% versus 95.5%. No grade 4–5 adverse event was noted. Hypotension and urticaria were severe adverse events whose relationship to oral 5‐aminolevulinic acid could not be excluded.

Conclusions

These findings confirm the diagnostic efficacy and safety of photodynamic diagnosis with 20 mg/kg of oral 5‐aminolevulinic acid, and show that transurethral resection of bladder tumors with a fluorescent light source using oral 5‐aminolevulinic acid is well tolerated.  相似文献   
640.
Angelica radix (Danggui in Chinese) used in China and Japan is derived from two species of Angelica, namely Angelica sinensis and Angelica acutiloba, respectively. The differences in quality between A. sinensis radix (ASR) and A. acutiloba radix (AAR) should be therefore investigated to guide the medicinal and dietary applications of these two species. Secondary metabolites and carbohydrates have been demonstrated to be the two major kinds of bioactive components of Danggui. However, previously, quality comparison between ASR and AAR intensively concerned secondary metabolites but largely overlooked carbohydrates, thus failing to include or take into consideration an important aspect of the holistic quality of Danggui. In this study, untargeted/targeted metabolomics and glycomics were integrated by multiple chromatography-based analytical techniques for qualitative and quantitative characterization of secondary metabolites and carbohydrates in Danggui so as to comprehensively evaluate and compare the quality of ASR and AAR. The results revealed that not only secondary metabolites but also carbohydrates in ASR and AAR were different in type and amount, which should collectively contribute to their quality difference. By providing more comprehensive chemical information, the research results highlighted the need to assess characteristics of both carbohydrates and secondary metabolites for overall quality evaluation and comparison of ASR and AAR.  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