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   1710篇
  免费   108篇
  国内免费   24篇
耳鼻咽喉   11篇
儿科学   31篇
妇产科学   40篇
基础医学   187篇
口腔科学   22篇
临床医学   116篇
内科学   523篇
皮肤病学   26篇
神经病学   148篇
特种医学   180篇
外科学   205篇
综合类   13篇
预防医学   121篇
眼科学   54篇
药学   99篇
中国医学   2篇
肿瘤学   64篇
  2022年   18篇
  2021年   36篇
  2020年   19篇
  2019年   40篇
  2018年   51篇
  2017年   26篇
  2016年   39篇
  2015年   44篇
  2014年   49篇
  2013年   50篇
  2012年   85篇
  2011年   71篇
  2010年   62篇
  2009年   41篇
  2008年   75篇
  2007年   100篇
  2006年   80篇
  2005年   87篇
  2004年   80篇
  2003年   82篇
  2002年   79篇
  2001年   62篇
  2000年   67篇
  1999年   70篇
  1998年   38篇
  1997年   25篇
  1996年   16篇
  1995年   22篇
  1994年   21篇
  1993年   15篇
  1992年   23篇
  1991年   28篇
  1990年   17篇
  1989年   25篇
  1988年   31篇
  1987年   17篇
  1986年   22篇
  1985年   20篇
  1984年   17篇
  1983年   9篇
  1982年   6篇
  1981年   5篇
  1980年   7篇
  1979年   6篇
  1977年   11篇
  1976年   9篇
  1975年   12篇
  1974年   4篇
  1971年   3篇
  1970年   5篇
排序方式: 共有1842条查询结果,搜索用时 593 毫秒
1.
2.

Background

Arterial vascular anomalies in patients undergoing kidney transplantation (KT) are correlated with a higher incidence of early surgical complications, potentially causing graft loss. Arterial reconstruction allows patients to overcome these surgical challenges, thus minimizing the risk of poor outcomes. The aim of the present study is to retrospectively investigate the safety and effectiveness of the multiple arterial reconstruction technique with a Teflon patch in case of an unavailable aortic patch: to do so, surgical complications, graft function, and patient survival were evaluated.

Methods

During the period January 2009 to August 2016, 202 adult deceased-donor KTs were performed at our center. Group A (n = 27; reconstruction of multiple arteries) and Group B (n = 175; control group) were compared.

Results

No differences were observed between the 2 groups in terms of early postoperative course, with no vascular complication observed in Group A. No vascular patch infections were reported, nor longer cold ischemia time rates. Similarly, long-term survival rates were similar between the 2 groups.

Conclusions

The Teflon-patch arterial reconstruction technique appears to be safe and effective, with an acceptable balance of benefits and potential risks of using a prosthetic material. Studies based on larger series are needed to further validate this approach.  相似文献   
3.
4.
Intratemporal vascular tumors: detection with CT and MR imaging   总被引:1,自引:0,他引:1  
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion.  相似文献   
5.
6.
Preliminary data suggest that lactitol (beta-galactoside-sorbitol), a new synthetic non-absorbable disaccharide, has beneficial effects on chronic portal systemic encephalopathy. To compare the efficacy of lactitol vs. lactulose in the treatment of acute portal systemic encephalopathy (PSE), 40 cirrhotic patients with an acute episode of PSE were randomly allocated to one of two groups: group A (20 patients) received lactulose (30 ml/6 h) and group B (20 patients) lactitol (12 g/6 h). These doses were adjusted daily to obtain two bowel movements per day. The duration of treatment was 5 days. Age, sex, hepatic and renal function, precipitating factors and level of PSE measured by clinical examination, EEG and number connection test were similar in the two groups. A complete clinical resolution of PSE occurred in 11 patients in each group. In 5 patients of the lactulose group and in 6 of the lactitol group there was a moderate improvement of PSE during the study. Finally, 4 patients in the lactulose group and 3 in the lactitol group did not respond to treatment. No side effects attributable to therapy were observed in either group. These results indicate that lactitol is as effective as lactulose in the management of patients with cirrhosis and acute PSE.  相似文献   
7.
Two alternatives for the treatment of lead intoxication, administration of zinc or a thiol donor, S-adenosyl-L-methionine (SAM), were analysed. Rats were exposed to lead (Pb)-acetate (60 mg/1) in drinking water during 90 days; one group also received SO4Zn in water (40 mg/l), while another received both Pb and SAM (5 mg/24 hr intraperitoneally. Erythrocytic δ-aminolaevulinic dehydratase (ALA-D) activity was significantly reduced (P<0.001) both in rats receiving Pb alone and in rats receiving Pb and each of the other two treatments. The high erythrocytic uroporphyrinogen synthetase (URO-S) activity noticed in Pb administered rats, was significantly (P< 0.001) reduced in animals treated either with zinc or with SAM. Hepatic ALA-D activity tended to decrease while renal enzyme activity was not modified by the low level Pb exposure used in this work. Interestingly, SAM treated rats in both tissues exhibited significantly (P<0.01) higher activities of the enzyme. It is argued that SAM treatment causes a surplus of thiols that allows the full expression of ALA-D catalytic activity.  相似文献   
8.
Although some behavioral effects of cocaine are hypothesized to be due to blockade of dopamine uptake in nucleus accumbens, it has been reported that in nucleus accumbens there are no specific cocaine binding sites and that cocaine is a weak inhibitor of dopamine uptake. [3H]GBR 12935 and an unlabelled analog, GBR 12909, are ligands that bind with great affinity and specificity to a site on dopamine uptake complex in striatum. We therefore investigated the interaction of these GBR compounds with the dopamine uptake complex in nucleus accumbens. We found specific high affinity [3H]GBR 12935 binding and a significant correlation between displacement of [3H]GBR 12935 binding by a series of compounds in striatum and nucleus accumbens. GBR 12909 inhibited dopamine uptake with equal potency in nucleus accumbens and striatum. Thus, there appear to be some aspects of the dopamine uptake complex in nucleus accumbens and striatum that are similar.  相似文献   
9.
Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth.  相似文献   
10.
In order to gain a longitudinal perspective of the benefits, complications, and role of the neodymium yttrium aluminum garnet (Nd-YAG) laser in the treatment of colorectal neoplasms, we performed a review of endoscopies using the laser during a 53-month period ending in January 1989. We reviewed the records of 100 patients for details of the endoscopic procedure and demographic data. Performance status and survival were critically assessed. We performed 275 procedures on 57 men and 43 women with an average age of 76.5 years. An average of 2.75 procedures, each lasting an average of 45 minutes, were performed per patient. Half of the patients had fulgurations of rectal tumors with the common indication being bleeding. Thirteen morbid events and no deaths occurred. Ninety-six per cent of the procedures were performed with the patient under intravenous sedation. The Karnofsky performance scale applied to surviving patients revealed that 90 per cent were able to care for themselves and scored greater than 70. Average survival was 5.58 months. Our results indicate that the Nd-YAG is a safe and effective tool in the treatment of colorectal neoplasms offering palliation as well as maintenance of quality of life.  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