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   589篇
  免费   20篇
  国内免费   1篇
耳鼻咽喉   3篇
儿科学   47篇
妇产科学   9篇
基础医学   68篇
口腔科学   19篇
临床医学   43篇
内科学   98篇
皮肤病学   4篇
神经病学   52篇
特种医学   4篇
外科学   67篇
综合类   8篇
预防医学   45篇
眼科学   52篇
药学   69篇
中国医学   2篇
肿瘤学   20篇
  2023年   7篇
  2022年   15篇
  2021年   23篇
  2020年   19篇
  2019年   15篇
  2018年   18篇
  2017年   15篇
  2016年   23篇
  2015年   25篇
  2014年   39篇
  2013年   33篇
  2012年   56篇
  2011年   44篇
  2010年   29篇
  2009年   28篇
  2008年   29篇
  2007年   45篇
  2006年   28篇
  2005年   23篇
  2004年   25篇
  2003年   21篇
  2002年   12篇
  2001年   4篇
  1999年   1篇
  1998年   3篇
  1997年   1篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1991年   2篇
  1989年   2篇
  1988年   2篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1983年   1篇
  1982年   4篇
  1981年   3篇
  1980年   1篇
  1976年   2篇
  1972年   2篇
排序方式: 共有610条查询结果,搜索用时 15 毫秒
51.
52.

Background  

Most individuals who died of trauma were found to harbour microscopic primary cancers at autopsies. Surgical excision of the primary tumour, unfortunately, seems to disturb tumour dormancy in over half of all metastatic relapses.  相似文献   
53.
Inflammatory pseudotumour (IPT), also known as inflammatory myofibroblastic tumour, is a rare cause of benign cervical lymphadenopathy. In its acute clinical presentation it mimics malignant and infective causes of cervical lymphadenopathy. The combined clinical history, histopathological findings, and imaging features of an infiltrating soft-tissue mass should lead to the possibility of IPT. Radical surgery should be avoided before there is histological proof of a malignant tumor.  相似文献   
54.

Background/Aim:

This study was designed to investigate the possible effect of exenatide (Glucagon like Peptide-1 receptor agonist) on liver injury (distant organ) induced by renal ischemia reperfusion (IR) in diabetic rats.

Materials and Methods:

In vivo renal IR was performed in both type 2 diabetic and normal rats. Each protocol comprised ischemia for 30 minutes followed by reperfusion for 24 hours and a treatment period of 14 days before induction of ischemia.

Results:

Lipid peroxidation, xanthine oxidase activity, myeloperoxidase activity and nitric oxide level in liver tissue were significantly increased (P < 0.01, P < 0.001, P < 0.001, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Antioxidant enzymes like glutathione, superoxide dismutase, catalase and glutathione peroxidase were significantly reduced (P < 0.05, P < 0.05, P < 0.01, P < 0.05, respectively), after IR in diabetic rats compared to normal rats. Exenatide treatment significantly normalized (P < 0.01), these biochemical parameters in treated rats compared to diabetic IR rats. Serum creatinine phosphokinase activity and liver function enzymes were also significantly normalized (P < 0.001, P < 0.001, respectively), after administration of exenatide.

Conclusion:

Exenatide exerted protective effect on exaggerated remote organ (liver) injury induced by renal IR in diabetes.  相似文献   
55.
56.
57.
We extend a method we had previously described (Statist. Med. 2005) to estimate the within-group variance of a continuous endpoint without breaking the blind in a randomized clinical trial. Specifically, we: (a) explain how the method may be used for a wider set of designs than we had previously indicated; (b) obtain a within-group, covariate-adjusted, blinded variance estimator; (c) illustrate use of the method for sample size re-estimation; and (d) describe a procedure to determine whether or not the blinded variance estimator works well not just on average but for the data set at hand. The proposed method is simple to use and makes no additional assumptions than is made for unblinded analysis. Simulations show that for realistic sample sizes there is virtually no inflation in the Type I error rate. When weighing the burden imposed by interim unblinded re-estimation with the loss in precision with blinded re-estimation, it may be advantageous for some trials to use the blinded method.  相似文献   
58.
OBJECTIVE: To investigate differences in lesions and surrounding normal appearing white matter (NAWM) by perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) in patients with acute and chronic ischemic stroke and multiple sclerosis (MS). METHODS: Study subjects included 45 MS patients, 22 patients with acute ischemic stroke and 20 patients with chronic ischemic stroke. All subjects underwent T2-weighted imaging (WI), flair attenuated inversion recovery (FLAIR), DWI and dynamic contrast enhanced PWI. Apparent diffusion coefficient (ADC) and mean transit time (MTT) maps were generated and values were calculated in the acute and chronic ischemic and demyelinating lesions, and in NAWM for distances of 5, 10 and 15 mm. Fifty-three acute ischemic and 33 acute demyelinating lesions, and 775 chronic ischemic and 998 chronic demyelinating lesions, were examined. Univariate, multivariate and data mining analyses were used to examine the feasibility of a prediction model between different lesion types. Correctly and incorrectly classified lesions, true positive (TP), false positive (FP) and precision rates were calculated. RESULTS: Patients with acute ischemic lesions presented more prolonged mean MTT values in lesions (p=0.002) and surrounding NAWM for distances of 5, 10 and 15 mm (all p<0.0001) than those with acute demyelinating lesions. In multinomial logistic regression analysis, 65 of 86 acute lesions were correctly classified (75.6%). The TP rates were 81.1% for acute ischemic lesions and 66.7% for acute demyelinating lesions. The FP rates were 33.3% for acute ischemic and 18.9% for acute demyelinating lesions. The precision was 79.6% for classification of acute ischemic lesions and 68.8% for prediction of acute demyelinating lesions. The logistic model tree decision algorithm revealed that prolonged MTT of surrounding NAWM for a distance of 15 mm (> or =7459.2 ms) was the best classifier of acute ischemic versus acute demyelinating lesions. Patients with chronic ischemic lesions presented higher mean ADC (p<0.0001) and prolonged MTT (p=0.013) in lesions, and in surrounding NAWM for distances of 5, 10 and 15 mm (all p<0.0001), compared to the patients with chronic demyelinating lesions. Data mining analyses did not show reliable predictability for correctly discerning between chronic ischemic and chronic demyelinating lesions. The precision was 56.7% for classification of chronic ischemic and 58.9% for prediction of chronic demyelinating lesions. DISCUSSION: We found prolonged MTT values in lesions and surrounding NAWM of patients with acute and chronic ischemic stroke when compared to MS patients. The use of PWI is a promising tool for differential diagnosis between acute ischemic and acute demyelinating lesions. The results of this study contribute to a better understanding of the extent of hemodynamic abnormalities in lesions and surrounding NAWM in patients with MS.  相似文献   
59.
BACKGROUND: The aim of this study was to compare the efficacy of single-agent weekly docetaxel with the combination of docetaxel and gemcitabine in elderly and/or poor performance status patients with advanced nonsmall cell lung cancer (NSCLC). METHODS: Previously untreated patients with stage IIIB/IV NSCLC who were either >65 years old or had an Eastern Cooperative Oncology Group (ECOG) performance status 2 were eligible. Patients were randomized to receive weekly docetaxel (36 mg/m(2)) Days 1, 8, and 15 or docetaxel (30 mg/m(2))/gemcitabine (800 mg/m(2)) Days 1, 8, and 15. Both regimens were repeated on 28-day cycles for 6 cycles or until disease progression. RESULTS: Three hundred fifty patients were randomized, and 345 received treatment. The median age of patients was 74 years; 38% were >75 years old, and 35% had ECOG performance status 2. Intent-to-treat analysis showed median survivals of 5.5 months versus 5.1 months in the groups receiving docetaxel/gemcitabine versus weekly docetaxel, respectively (P = .65). There were no survival differences detected with docetaxel/gemcitabine versus weekly docetaxel in the 223 patients with good performance status (7.2 months vs 8.0 months, respectively) or in the 122 poor performance status patients (3.8 months vs 2.9 months, respectively). Median time-to-progression was longer in patients who received docetaxel/gemcitabine (4.8 months vs 2.9 months; P = .004). Both regimens were generally well tolerated. CONCLUSIONS: Treatment with docetaxel/gemcitabine produced a modest improvement in time-to-progression but had no impact on survival when compared with single-agent weekly docetaxel in this group of patients. Results with both regimens were disappointing, particularly in patients with poor performance status. Improved treatment for these patients will require the introduction of novel, well-tolerated, targeted agents.  相似文献   
60.
Our study aims to review the literature on the management of pyogenic liver abscess, focusing on the choice of drainage. A case series of our experience with clinicopathological correlation is presented to highlight the indication and outcome of each modality of drainage. Intravenous antibiotic is the first line, and mainstay, of treatment. Drainage is necessary for large abscesses, equal to or larger than 5 cm in size, to facilitate resolution. While percutaneous drainage is appropriate as first-line surgical treatment in most cases, open surgical drainage is prudent in cases of rupture, multiloculation, associated biliary, or intra-abdominal pathology. Percutaneous drainage may help to optimize clinical condition prior to surgery. Nevertheless, in current good clinical practices, the choice of therapy needs to be individualized according to patient’s clinical status and abscess factors. They are complementary in the management of liver abscesses.  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