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   596篇
  免费   27篇
  国内免费   2篇
耳鼻咽喉   10篇
儿科学   44篇
妇产科学   4篇
基础医学   61篇
口腔科学   5篇
临床医学   37篇
内科学   74篇
皮肤病学   9篇
神经病学   52篇
特种医学   5篇
外科学   31篇
预防医学   22篇
眼科学   6篇
药学   92篇
中国医学   1篇
肿瘤学   172篇
  2023年   2篇
  2022年   8篇
  2021年   7篇
  2020年   6篇
  2019年   5篇
  2018年   4篇
  2017年   6篇
  2016年   2篇
  2015年   12篇
  2014年   6篇
  2013年   16篇
  2012年   34篇
  2011年   31篇
  2010年   22篇
  2009年   20篇
  2008年   36篇
  2007年   43篇
  2006年   35篇
  2005年   40篇
  2004年   38篇
  2003年   41篇
  2002年   36篇
  2001年   27篇
  2000年   21篇
  1999年   20篇
  1998年   4篇
  1997年   4篇
  1996年   4篇
  1995年   3篇
  1994年   4篇
  1993年   2篇
  1992年   8篇
  1991年   6篇
  1990年   11篇
  1989年   7篇
  1987年   4篇
  1986年   7篇
  1985年   1篇
  1984年   2篇
  1983年   7篇
  1982年   6篇
  1981年   6篇
  1980年   1篇
  1979年   4篇
  1978年   4篇
  1977年   4篇
  1974年   3篇
  1973年   1篇
  1971年   2篇
  1967年   1篇
排序方式: 共有625条查询结果,搜索用时 15 毫秒
91.

BACKGROUND:

The aim of the current study was the investigation of the value of bevacizumab + 5‐fluorouracil(5–FU)/folinic acid in patients with advanced colorectal cancers who have exhausted standard chemotherapy options.

METHODS:

The authors included 48 heavily pretreated patients (colon:rectum, 33:15; men:women, 23:25; median age, 63 years; range, 27‐79 years) whose disease had progressed during or within an oxaliplatin‐based first‐line chemotherapy, an irinotecan‐based second‐line regimen, and a third‐line treatment with cetuximab plus weekly irinotecan. Bevacizumab was given at a dose of 5 mg/kg. 5‐FU/folinic acid was administered according to the de Gramont schedule.

RESULTS:

The response rate was 6.25%, and 30.4% of patients demonstrated stable disease as the best response. The median time to disease progression was 3.5 months (95% confidence interval [95% CI], 2.3‐6.9 months), and the median survival time was 7.7 months (95% CI, 3.9‐11.9 months). The most common grade 3 to 4 side toxicities (graded according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) were: diarrhea (20.8%), fatigue (14.5%), and stomatitis (12.5%). Grade 3 to 4 hemorrhage occurred in 8 patients (16.6%), including 4 cases of bleeding in the gastrointestinal tract. Other relatively common adverse events such as hypertension, thrombosis, and bowel perforation were reported in 50%, 18.7%, and 4.16%, of patients respectively.

CONCLUSIONS:

The data from the current study suggest a modest but significant clinical benefit of bevacizumab + de Gramont schedule in heavily pretreated colorectal cancer patients. Cancer 2009. © 2009 American Cancer Society.  相似文献   
92.
Circumvention of the p53 checkpoint in neuroblastoma (NB) might arise from increased expression of its main negative regulator MDM2. The SNP309, a T-to-G substitution in the MDM2 promoter, was associated with higher levels of MDM2 mRNA and protein, with consequent attenuation of the p53 pathway. The association between MDM2 SNP309 and disease progression and survival was evaluated in a cohort of 142 children with stage 4 NB. The SNP309 GG patients had a worse overall survival and a worse survival after relapse than the TT ones, whereas the heterozygotes showed an intermediate behaviour (p=0.043 and p=0.049, respectively, log-rank test for trend). No evident association between SNP309 and event free survival was found. The lack of association between SNP309 and MYCN status indicates that MDM2 SNP309 may be a new independent prognostic factor for stage 4 NB.  相似文献   
93.

Background:

KRAS codons 12 and 13 mutations predict resistance to anti-EGFR monoclonal antibodies (moAbs) in metastatic colorectal cancer. Also, BRAF V600E mutation has been associated with resistance. Additional KRAS mutations are described in CRC.

Methods:

We investigated the role of KRAS codons 61 and 146 and BRAF V600E mutations in predicting resistance to cetuximab plus irinotecan in a cohort of KRAS codons 12 and 13 wild-type patients.

Results:

Among 87 KRAS codons 12 and 13 wild-type patients, KRAS codons 61 and 146 were mutated in 7 and 1 case, respectively. None of mutated patients responded vs 22 of 68 wild type (P=0.096). Eleven patients were not evaluable. KRAS mutations were associated with shorter progression-free survival (PFS, HR: 0.46, P=0.028). None of 13 BRAF-mutated patients responded vs 24 of 74 BRAF wild type (P=0.016). BRAF mutation was associated with a trend towards shorter PFS (HR: 0.59, P=0.073). In the subgroup of BRAF wild-type patients, KRAS codons 61/146 mutations determined a lower response rate (0 vs 37%, P=0.047) and worse PFS (HR: 0.45, P=0.023). Patients bearing KRAS or BRAF mutations had poorer response rate (0 vs 37%, P=0.0005) and PFS (HR: 0.51, P=0.006) compared with KRAS and BRAF wild-type patients.

Conclusion:

Assessing KRAS codons 61/146 and BRAF V600E mutations might help optimising the selection of the candidate patients to receive anti-EGFR moAbs.  相似文献   
94.

Background

The combination of docetaxel, cisplatin, and 5-fluorouracil (5-FU) has demonstrated a survival advantage over cisplatin and 5-FU, but with substantial hematological toxicity. We aimed to evaluate the efficacy and toxicity of a sequential regimen with cisplatin, leucovorin, and 5-FU (PLF) followed by docetaxel in metastatic gastric cancer patients.

Methods

Treatment consisted of 4 cycles of biweekly PLF (cisplatin 50?mg/m2 as a 30-min infusion on day 1, leucovorin 200?mg/m2 in a 2-h infusion, and 5-FU 2,800?mg/m2 in a 48-h continuous infusion starting on day 1) followed, in cases of response or stable disease, by 3 cycles of docetaxel (75?mg/m2, every 3?weeks).

Results

Thirty-four patients were enrolled, with an average age of 64?years (range 34–69). The main cumulative grade 3–4 toxicities were: neutropenia (38.2%), febrile neutropenia (11.8%), and fatigue (14.7%). After the planned 7 cycles of treatment, the overall response rate was 38.2% (95% confidence interval [CI] 21.9–54.6), with 3 complete and 10 partial responses. Median progression-free survival and overall survival were 4.8 and 10.6?months, respectively.

Conclusions

For patients with metastatic gastric cancer, the sequential administration of cisplatin, leucovorin, 5-FU, and docetaxel may be an effective palliative option and offers a far more favorable toxicity profile than the simultaneous use of docetaxel, cisplatin, and 5-FU.  相似文献   
95.
PURPOSE: The commercial availability of zoledronic acid, a third generation bisphosphonate, prompted us to evaluate the modifications in angiogenic cytokines levels after a single i.v. infusion of this drug. Experimental Design: Thirty consecutive cancer patients with scintigraphic and radiographic evidence of bone metastases were treated with a single infusion of 4 mg of zoledronic acid before any chemotherapy. The patients were prospectively evaluated for circulating levels of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) just before and at 1, 2, 7, and 21 days after zoledronic acid infusion. RESULTS: Basal serum VEGF median levels were significantly decreased at days 2 (-23%), 7 (-28%), and 21 (-34%) after zoledronic acid infusion (P = 0.0498, 0.0090, and 0.0011, respectively). Serum PDGF levels were significantly decreased by 25% 1 day after zoledronic acid infusion (P = 0.0032). This effect on circulating PDGF levels persisted for 2 days after bisphosphonate infusion (P = 0.0050). PDGF levels had returned to values similar to the median basal value at 7 and 21 days. Moreover, a linear regression model with variance analysis showed a significant positive correlation between basal VEGF and PDGF values but not at the following time points. No significant differences were recorded in platelet levels, WBC count, or hemoglobin concentration before and after zoledronic acid single infusion. CONCLUSIONS: This study confirms that zoledronic acid could have an in vivo antiangiogenic property through a significant and long-lasting reduction in serum VEGF levels.  相似文献   
96.
In this minireview the authors examine and discuss the radioprotective compounds and the new combination therapies for the prophylaxis of radiation-induced emesis. Radiation-induced emesis is an important secondary effect of this anticancer treatment and it represents one of the causes of therapy interruption and decay of life quality before the introduction of optimal control of radiation-induced emesis with new antiemetic drugs which ensure the continuance of radiotherapy and avoid time breaks, that could negatively influence the efficacy of anticancer treatment. The incidence, the severity or the latency of radiotherapy-induced nausea and vomiting are correlated both with the treatment features (fractions, total dose, irradiation site) and with the main clinical characteristics of the patients. In contrast to the very extensive literature on the prevention of chemotherapy-induced emesis, relatively few studies about the prevention of nausea and vomiting in patients submitted to radiotherapy have been published. Among antiemetic drugs for the prevention of emesis, benzamides and in particular metoclopramide, are widely used in clinical practice. The introduction of selective 5-HT3 antagonists in clinical practice produced an important improvement in control of chemotherapy induced emesis, but few published studies were aimed at evaluating the efficacy of these drugs in the prophylaxis of nausea and vomiting due to radiation exposure. We herewith present a brief summary of Clinical practice guidelines for the use of antiemetics in anticancer therapy recently published by ASCO (American Society of Clinical Oncology).  相似文献   
97.
AIMS AND BACKGROUND: Emergency surgery for colorectal cancer is associated with a higher postoperative morbidity and mortality rate and a poor long-term outcome compared with elective surgery. The aim of the present study was to compare early and late outcome after elective and emergency surgery for malignant colorectal cancer, looking for the principal determinants of a worse outcome after emergency colorectal surgery. METHODS: A retrospective study of 236 patients presenting with colorectal cancer over an 8-year period was undertaken. Of these, 118 presented as emergencies, whereas 118 patients, well matched for age, sex, site of tumor and TNM admitted as elective, were included in the study. Data reviewed included postoperative mortality and morbidity and long-term outcome. RESULTS: The 30-day operative mortality rate was significantly higher in the emergency group than in the electively treated group (11.9% versus 3.4%, P < 0.01). The higher mortality rate was observed in the perforation group. The 30-day operative morbidity was higher in the emergency group (27.1% versus 12.7%, P < 0.05). Anastomotic failure was a serious complication: following primary resection, we observed 4 non-fatal (5.4%) and two fatal (2.7%) anastomotic leaks after 74 primary anastomoses. Among emergency-treated patients, the procedures characterized by the highest percentage of postoperative complications were three-stage resections (63.6%). The 5-year survival rate was greater after elective surgery (59% versus 39%). CONCLUSIONS: The early and long-term outcome following emergency colorectal surgery was significantly lower than that after elective surgery. Although medical complications in patients with end-stage cancer played an important role, surgical failures still had an important impact on outcome.  相似文献   
98.
The aim of our study was to identify threshold levels of DNA methylation predictive of the outcome to better define the risk group of stage 4 neuroblastic tumor patients. Quantitative pyrosequencing analysis was applied to a training set of 50 stage 4, high risk patients and to a validation cohort of 72 consecutive patients. Stage 4 patients at lower risk and ganglioneuroma patients were included as control groups. Predictive thresholds of methylation were identified by ROC curve analysis. The prognostic end points of the study were the overall and progression‐free survival at 60 months. Data were analyzed with the Cox proportional hazard model. In a multivariate model the methylation threshold identified for the SFN gene (14.3.3σ) distinguished the patients presenting favorable outcome from those with progressing disease, independently from all known predictors (Training set: Overall Survival HR 8.53, p = 0.001; Validation set: HR 4.07, p = 0.008). The level of methylation in the tumors of high‐risk patients surviving more than 60 months was comparable to that of tumors derived from lower risk patients and to that of benign ganglioneuroma. Methylation above the threshold level was associated with reduced SFN expression in comparison with samples below the threshold. Quantitative methylation is a promising tool to predict survival in neuroblastic tumor patients. Our results lead to the hypothesis that a subset of patients considered at high risk—but displaying low levels of methylation—could be assigned at a lower risk group.  相似文献   
99.
Concentrations of dilazep which were ineffective in altering the muscular tone of the guinea-pig taenia caeci (0.03, 0.3 microM) or the phasic mechanical activity of the rabbit proximal ileum (0.03 microM) markedly potentiated the inhibitory action of adenosine on both these parameters. Dilazep, 0.3 microM or greater, dose-dependently inhibited the mechanical activity of the proximal ileum. This inhibitory action was probably mediated by more than one mechanism, as shown by the fact that theophylline (50, 100 microM) antagonized the effect at lower dilazep concentrations (up to 3 microM) leaving essentially unchanged the response to higher concentrations (6, 10 microM). Similarly, the responses to low doses of dilazep were reduced after desensitization of the organ to adenosine, whilst the responses to higher doses were unaffected by this procedure. In a Ca2+-free, high-K+ medium, dilazep (1-10 microM) caused a parallel shift to the right of the Ca2+-induced contractions of the guinea-pig taenia caeci. Adenosine showed only slight Ca2+-antagonistic properties within the mM range of concentrations. These findings suggest that, at the higher concentration tested, dilazep exhibits Ca2+-antagonistic properties unrelated to its adenosine-mediated mode of action.  相似文献   
100.
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