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   1239篇
  免费   187篇
  国内免费   18篇
耳鼻咽喉   20篇
儿科学   53篇
妇产科学   20篇
基础医学   83篇
口腔科学   38篇
临床医学   206篇
内科学   269篇
皮肤病学   104篇
神经病学   39篇
特种医学   132篇
外科学   186篇
综合类   94篇
现状与发展   30篇
预防医学   51篇
眼科学   15篇
药学   31篇
中国医学   3篇
肿瘤学   70篇
  2024年   18篇
  2023年   179篇
  2022年   12篇
  2021年   16篇
  2020年   55篇
  2019年   21篇
  2018年   51篇
  2017年   45篇
  2016年   39篇
  2015年   56篇
  2014年   82篇
  2013年   60篇
  2012年   27篇
  2011年   29篇
  2010年   73篇
  2009年   87篇
  2008年   28篇
  2007年   50篇
  2006年   18篇
  2005年   17篇
  2004年   10篇
  2003年   14篇
  2002年   15篇
  2001年   10篇
  2000年   13篇
  1999年   25篇
  1998年   35篇
  1997年   49篇
  1996年   40篇
  1995年   35篇
  1994年   29篇
  1993年   34篇
  1992年   7篇
  1991年   7篇
  1990年   9篇
  1989年   22篇
  1988年   20篇
  1987年   14篇
  1986年   4篇
  1985年   11篇
  1984年   4篇
  1983年   3篇
  1982年   8篇
  1981年   10篇
  1980年   12篇
  1978年   5篇
  1977年   3篇
  1976年   13篇
  1975年   10篇
  1974年   3篇
排序方式: 共有1444条查询结果,搜索用时 15 毫秒
961.

Background

The significance of surgery in the treatment of hepatocellular carcinoma (HCC) extending into the inferior vena cava (IVC)/right atrium (RA) is currently unclear. We sought to clarify whether surgical treatment can improve survival in such patients.

Methods

A retrospective review was undertaken of patients with HCC and IVC/RA tumor thrombus who were potential candidates for surgery but who were finally treated surgically and nonsurgically between September 2000 and October 2010. The patients were subdivided according to therapeutic modalities, and the results for each group were compared.

Results

A total of 56 patients were included in this study. They were divided into three groups. Twenty-five patients underwent hepatectomy plus thrombectomy (surgical group), with minor morbidity and no mortality; the patients in this group had 1-, 3-, and 5-year survival rates of 68.0, 22.5, and 13.5 %, respectively, with a median survival of 19 months. Twenty patients were treated with transcatheter arterial chemoembolization, with 1- and 3-year survival rates of 15.0 and 5.0 %, respectively (median survival 4.5 months). Eleven patients received symptomatic treatment only, and no one in this group survived longer than 1 year (median survival 5 months). The patients in surgical group survived significantly longer than the patients in the other two groups (p < 0.001).

Conclusions

Although technically challenging, surgery for HCC with IVC/RA tumor thrombus can be safely performed and should be considered in patients with resectable primary tumor and sufficient hepatic reservoir because compared with transcatheter arterial chemoembolization or symptomatic treatment, it significantly improved patient survival.  相似文献   
962.

Purpose

To investigate whether Ivor-Lewis esophagectomy combined with adjuvant radiotherapy prevents lymphatic metastatic recurrence in esophageal cancer patients.

Methods

A total of 113 stage IIA esophageal squamous cell carcinoma patients after Ivor-Lewis esophagectomy were accepted mRNA expression of Mucoid 1 (MUC1) gene detection. Positive patients were enrolled onto the adjuvant radiotherapy group (with postoperative adjuvant radiotherapy). Negative patients were enrolled onto the control group (without postoperative adjuvant radiotherapy or chemotherapy). The radiotherapy area consisted of the neck, supraclavicular region, and superior mediastinum (including paraesophageal and paratracheal region). Survival difference was compared by the χ2 test, and the Kaplan–Meier method was performed to calculate the survival rate and recurrence rate. Logistic regression analysis was performed to determined independent risk factors.

Results

The radiotherapy area lymphatic metastatic recurrence rate in adjuvant radiotherapy group (16.7 %, 5 of 30) was lower than patients without postoperative adjuvant radiotherapy (45.8 %, 38 of 83) (P < 0.05). Only compared to positive patients without postoperative adjuvant radiotherapy (60.0 %, 6 of 10) was the rate (16.7 %, 5 of 30) significantly lower (P < 0.01). Cancer recurrence was recognized in 48.6 % (55 of 113) patients within 3 years after surgery, including 38.1 % (43 of 113) patients with radiotherapy area recurrence. Logistic analysis revealed that T status (P < 0.01) and adjuvant radiotherapy (P < 0.05) were independent risk factors of lymph node metastasis in the first 3 years after surgery.

Conclusions

In MUC1 mRNA-positive esophageal squamous cell carcinoma patients, adjuvant radiotherapy could significantly reduce the lymph node metastasis rate in the radiotherapy area after Ivor-Lewis esophagectomy. Compared with traditional therapeutic methods, Ivor-Lewis esophagectomy combined with adjuvant radiotherapy can achieve similar curative effects in MUC1 mRNA-positive patients.  相似文献   
963.
964.
López‐Escribano H, Parera MM, Guix P, Serra JM, Gutierrez A, Balsells D, Oliva‐Berini E, Castro JA, Ramon MM, Picornell A. Balearic archipelago: three islands, three beta‐thalassemia population patterns. The mutation spectrum of 175 β‐thalassemia (β‐thal) carriers, identified in pilot carrier screening on 22,713 individuals from Balearic Islands (Spain), is reported. The β0 CD39 (C>T) mutation is the most frequent (61.1%), followed by β+ IVS‐I‐110 (G>A) (12.0%), β+ IVS‐I‐6 (T>C) and β0 IVS‐1‐1 (G>A) (3.4% both) and eight other rare mutations (2.9–0.6%); with a distinct prevalence and distribution between islands. Minorca shows the highest prevalence in Iberian populations, with a single mutation, CD39 (C>T), present in most β‐thal carriers. Ibiza is the only Western Mediterranean population where the most frequent β‐thal mutation is IVS‐I‐110 (G>A). These results can be explained by a combination of historical–demographic characteristics together with evolutionary forces such as founder effect, genetic drift and probably selection by malaria. Knowledge of the mutational spectrum in the Balearic Islands will enable to optimize mutation detection strategy for genetic diagnosis of β‐thal in these islands.  相似文献   
965.
966.
967.
968.
The 1100delC mutation in the CHEK2 gene has a carrier frequency of up to 1.5% in individuals from North-West Europe. Women heterozygous for 1100delC have an increased breast cancer risk (odds ratio 2.7). To explore the prevalence and clinical consequences of 1100delC homozygosity in the Netherlands, we genotyped a sporadic breast cancer hospital-based cohort, a group of non-BRCA1/2 breast cancer families, and breast tumors from a tumor tissue bank. Three 1100delC homozygous patients were found in the cohort of 1434 sporadic breast cancer patients, suggesting an increased breast cancer risk for 1100delC homozygotes (odds ratio 3.4, 95% confidence interval 0.4–32.6, P=0.3). Another 1100delC homozygote was found in 592 individuals from 108 non-BRCA1/2 breast cancer families, and two more were found after testing 1706 breast tumors and confirming homozygosity on their wild-type DNA. Follow-up data was available for five homozygous patients, and remarkably, three of them had developed contralateral breast cancer. A possible relationship between 1100delC and lung cancer risk was investigated in 457 unrelated lung cancer patients but could not be confirmed. Due to the small number of 1100delC homozygotes identified, the breast cancer risk estimate associated with this genotype had limited accuracy but is probably higher than the risk in heterozygous females. Screening for CHEK2 1100delC could be beneficial in countries with a relatively high allele frequency.  相似文献   
969.
970.

Background and Purpose

Delirium is thought to be associated with systemic inflammatory response. However, its association with the most widely used inflammatory biomarker C-reactive protein (CRP) has not been well established. We aimed to examine whether CRP on intensive care unit (ICU) entry was associated with subsequent development of delirium.

Design and Setting

This prospective observational study was conducted in a mixed 24-bed ICU in a tertiary teaching hospital.

Methods

All patients admitted to the ICU from February 2011 to June 2012 were screened for eligibility. Demographic data and clinical characteristics of included patients were recorded. Patients were screened for the presence of delirium by using the tool Confusion Assessment Method for the ICU (CAM-ICU). C-reactive protein was obtained on ICU entry and 24 hours thereafter. Eligible patients were followed up for 28 days or until death. Univariate and multivariate analyses were performed to evaluate independent risk factors for delirium. Clinical outcome included the length of stay (LOS) in the ICU, 28-day mortality, and duration of mechanical ventilation. Two-tailed P < .05 was considered statistically significant.

Results

A total of 223 patients were included during study period. In univariate analysis, patients with delirium showed significantly higher CRP values than those without (120.5 vs 57.5 mg/L; P = .0001). By adjusting for confounding variables (including age, sex, Acute Physiology and Chronic Health Evaluation II, intubation, living alone, physical restraint, alcohol drinking, smoking, type of medical condition, and hospital LOS before ICU admission) in logistic regression model, CRP remained an independent predictor of delirium (odds ratio, 1.07; 95% confidence interval, 1.01-1.15). As compared with nondelirious patients, those with delirium showed longer LOS in ICU (13 vs 5 days; P < .001) and duration of mechanical ventilation (6 vs 1 days; P < .001). An increase in CRP greater than 8.1 mg/L within 24 hours was associated with 4-fold increase in the risk of delirium (odds ratio: 4.47, 95% confidence interval, 1.28-15.60).

Conclusion

C-reactive protein measured on ICU entry and its changes within 24 hours are risk indicators of delirium. Further studies exploring the treatment of delirium according to CRP levels are warranted.  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