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   1875篇
  免费   130篇
  国内免费   122篇
耳鼻咽喉   24篇
儿科学   76篇
妇产科学   85篇
基础医学   188篇
口腔科学   63篇
临床医学   244篇
内科学   418篇
皮肤病学   25篇
神经病学   93篇
特种医学   52篇
外科学   316篇
综合类   57篇
预防医学   69篇
眼科学   70篇
药学   176篇
中国医学   6篇
肿瘤学   165篇
  2024年   2篇
  2023年   10篇
  2022年   17篇
  2021年   37篇
  2020年   25篇
  2019年   40篇
  2018年   44篇
  2017年   32篇
  2016年   39篇
  2015年   55篇
  2014年   52篇
  2013年   84篇
  2012年   104篇
  2011年   134篇
  2010年   88篇
  2009年   80篇
  2008年   119篇
  2007年   155篇
  2006年   93篇
  2005年   133篇
  2004年   102篇
  2003年   90篇
  2002年   77篇
  2001年   64篇
  2000年   68篇
  1999年   53篇
  1998年   26篇
  1997年   35篇
  1996年   27篇
  1995年   19篇
  1994年   27篇
  1993年   16篇
  1992年   29篇
  1991年   25篇
  1990年   29篇
  1989年   35篇
  1988年   16篇
  1987年   11篇
  1986年   2篇
  1985年   10篇
  1984年   7篇
  1983年   3篇
  1981年   1篇
  1980年   2篇
  1978年   3篇
  1977年   1篇
  1973年   1篇
  1972年   3篇
  1970年   1篇
  1962年   1篇
排序方式: 共有2127条查询结果,搜索用时 15 毫秒
31.
32.
33.
BACKGROUND: To evaluate the efficacy and toxicity of cisplatin/etoposide continuous infusion chemotherapy for cancer of unknown primary site in Taiwan, a region with a high prevalence of endemic viral infections. METHOD: Between April 1994 and February 1996, 20 patients with a diagnosis of CUPS were treated, including 15 males and five females, of average age 63.3 years (range 41-83 years). Continuous intravenous infusion of etoposide 80 mg/m2 and cisplatin 25 mg/m2 was given for 3 days every 3 weeks. Pretreatment tumor marker and viral serology studies were performed for baseline evaluation. Nearly two-thirds of the patients had poorly differentiated carcinoma. The average number of metastatic sites was 2.65 (range 1-4), with liver and lymph node involvement predominating. RESULTS: The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorly differentiated cancers and 25% for well differentiated cancers. Median survival was 4 months (range 1-12 months), 4.8 months for patients attaining partial response. Toxicity was moderate, grade 3 and 4 neutropenia occurred in 55% and grade 3 and 4 thrombocytopenia in 40%; other toxicities were mild. CA125 and CA199 were elevated in more than 50% of patients. Viral serology studies were not significantly different from those of the indigenous population. CONCLUSION: Etoposide and cisplatin combination chemotherapy has modest activity in patients with extensive CUPS and, at the schedule and dosage given, it is associated with moderate toxicity.   相似文献   
34.
35.
BACKGROUND AND PURPOSE: Although chronic inflammatory bowel disease (IBD) is rare in Asian children, increasing numbers of pediatric patients with chronic IBD worldwide have been noted in recent years. This study was conducted to delineate the trend in incidence and clinical patterns of childhood IBD in Taiwan. METHODS: All children admitted to National Taiwan University Hospital (NTUH) between 1979 and 2000 who met the criteria for IBD, Crohn's disease (CD), ulcerative colitis (UC), probable CD (PCD), or indeterminate colitis were included. The clinical features and outcomes were analyzed retrospectively. Incidence was calculated using cases of chronic diarrhea during the same period of time as the risk population. RESULTS: IBD was diagnosed in 17 children (9 females and 8 males, aged 2 months to 18 years) during the study period. Six (35%) of these children had UC, 9 (53%) had CD, and 2 (12%) had PCD. The cumulative incidence of CD during 1979-1995 was 0.85%, and increased to 2.6% during 1996-2000 (p < 0.001), while the incidence of UC did not change significantly between these periods (from 0.85% to 0.99%, p = 0.16). The median interval from onset to diagnosis was 7.7 months. Eighty percent of patients had moderate to severe disease activity at diagnosis. The follow-up duration ranged from less than 1 year to 20 years, with a mean of 4.3 years. Two patients were lost to follow-up. Eighty six percent of patients responded to treatment, and 80% of patients had inactive to mild disease activity when re-evaluated at the end of 2000. CONCLUSION: There has been a marked recent increase in the incidence of childhood CD in Taiwan but the rate of childhood UC has remained unchanged. Eighty percent of cases of childhood IBD responded well to treatment.  相似文献   
36.
HYPOTHESIS: Mutant p53 gene has lost its tumor suppression function and is considered to be a very important step in hepatocellular carcinoma development. We propose that the mutant p53 gene plays a role in its invasiveness and prognosis after resection. DESIGN: A case-controlled study. SETTING: A referral center. PATIENTS: Seventy-nine consecutive patients who underwent surgical resection for hepatocellular carcinoma entered this study. INTERVENTION: Tissue sections of resected hepatocellular carcinoma (deparaffinized and rehydrated from formalin-fixed and paraffin-embedded sections) were incubated with antihuman p53 monoclonal antibody and immunostained. The p53 result was scored without prior knowledge of the patients' status. A 10% immunopositivity was regarded as the threshold value. MAIN OUTCOME MEASURE: The immunopositive rate of p53 was 69.6% (55 of 79 patients). The clinical variables (age, sex, associated liver cirrhosis, hepatitis B virus infection, hepatitis C virus infection, serum alpha-fetoprotein, and Child-Pugh class); the histological variables (size, capsule, vascular permeation; grade of differentiation, and multinodularity); and postoperative course (recurrence, tumor-free interval, death, and survival period) were correlated with p53 immunopositivity. RESULTS: From univariate analysis, more patients with p53 positivity were male (92.7 vs 0%) (P<.001); had vascular permeation (80% vs 50%) (P =.007) (odds ratio [OR], 4.0); no complete capsule (83.6% vs 62.5%) (P =.04) (OR, 3.1); and daughter nodules (90.9% vs 70.8%) (P =.04) (OR, 4.1) than patients with negative p53 staining. From multivariate analysis, only sex and vascular permeation remained significant (P =.001 and P =.008, respectively). Although more patients with p53 positivity had tumor recurrence (78% vs 50%) (P =.01) and death (64% vs 33%) (P =. 01), the Cox proportional hazards model showed that p53 overexpression had only weak correlations with tumor-free interval and survival time (P =.09 and P =.08, respectively). CONCLUSIONS: Our results show that the biological behavior of the mutant p53 gene is strongly related to the invasiveness of hepatocellular carcinoma and may also influence the postoperative course. We suggest that the immunopositivity of the mutant p53 gene has a predictive role in the prognosis of patients with resected hepatocellular carcinoma.  相似文献   
37.
PURPOSE: Cysteine-rich 61 (Cyr61/CCN1) is involved in many different types of tumor development and progression. Nonetheless, the role of Cyr61 in human gastric cancer has not yet been fully characterized.Experimental design: We addressed the issue by immunohistochemical staining of 81 gastric adenocarcinoma specimens. Liposome-mediated transfection was used to introduce a Cyr61 expression vector into gastric cancer AGS cell lines. Transfectants were tested in invasion assay by a Boyden chamber. Furthermore, a cyclooxygenase-2 (COX-2) reporter assay and gel mobility shift assay were done to investigate the potential signal pathway of Cyr61. RESULTS: Patients with gastric adenocarcinoma whose tumor displayed high expression of Cyr61 correlated well with aggressive lymph node metastasis, more advanced tumor stage, histologic diffuse type, and early recurrence. Stable transfection of Cyr61 into the AGS cell line strongly enhanced its invasive activity. The overexpression of Cyr61 into AGS cells significantly increased the expression of COX-2 mRNA, protein, and enzymatic activity. Gel mobility shift assays further showed that the nuclear factor-kappaB (NF-kappaB) pathway was evidently activated in Cyr61-expressing AGS cells. Function-neutralizing antibody to alphavbeta3 but not alphavbeta5 effectively suppressed Cyr61-mediated NF-kappaB activation, COX-2 gene expression, and cell invasiveness. CONCLUSIONS: Cyr61 may contribute to the malignant progression of gastric cancer by promoting tumor cell motility/invasion through up-regulation of the functional COX-2 via an integrin alphavbeta3/NF-kappaB-dependent pathway.  相似文献   
38.
39.
Tsai J‐H, Huang W‐C, Kuo K‐T, Yuan R‐H, Chen Y‐L & Jeng Y‐M
(2012) Histopathology
S100P immunostaining identifies a subset of peripheral‐type intrahepatic cholangiocarcinomas with morphological and molecular features similar to those of perihilar and extrahepatic cholangiocarcinomas Aims: S100P is a calcium‐binding protein that is frequently expressed in pancreatic adenocarcinoma and perihilar cholangiocarcinoma. The aim of this study was to investigate the pathological significance of the expression of S100P in peripheral intrahepatic cholangiocarcinoma (ICC). Methods and results: Immunohistochemical staining was used to investigate S100P expression in 112 cases of peripheral ICC. The results were compared with those for perihilar and extrahepatic cholangiocarcinomas. Patients with S100P‐positive peripheral ICC were more likely to have elevated serum levels of carcinoembryonic antigen (CEA) and CA19‐9 than those with S100P‐negative peripheral ICCs. All cases of peripheral ICC associated with intrahepatic lithiasis and all cases with intraductal/periductal growth patterns were positive for S100P. S100P‐positive peripheral ICCs were highly associated with ‘bile duct’ morphology rather than cholangiolar differentiation. Nearly all cases of perihilar and extrahepatic cholangiocarcinoma were positive for S100P. Similarly to perihilar and extrahepatic cholangiocarcinomas, S100P‐positive peripheral ICCs showed more frequent expression of CEA and MUC2, and were more likely to be N‐cadherin‐negative, than S100P‐negative cases. Notably, K‐RAS mutations were only detected in S100P‐positive peripheral ICCs, with a frequency similar to that in perihilar and extrahepatic cholangiocarcinomas. Patients with S100P‐positive peripheral ICC were more likely to have poor prognoses than those with S100P‐negative tumours. Conclusions: S100P immunostaining identifies a subset of peripheral ICC that probably originates from larger bile ducts. This subset of peripheral ICCs shares common morphological and molecular features with perihilar and extrahepatic cholangiocarcinomas.  相似文献   
40.
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