首页 | 官方网站   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   1057篇
  免费   44篇
  国内免费   3篇
医药卫生   1104篇
  2023年   8篇
  2022年   5篇
  2021年   30篇
  2020年   19篇
  2019年   25篇
  2018年   34篇
  2017年   20篇
  2016年   25篇
  2015年   41篇
  2014年   51篇
  2013年   67篇
  2012年   91篇
  2011年   65篇
  2010年   47篇
  2009年   39篇
  2008年   74篇
  2007年   47篇
  2006年   61篇
  2005年   57篇
  2004年   55篇
  2003年   46篇
  2002年   33篇
  2001年   21篇
  2000年   20篇
  1999年   26篇
  1998年   12篇
  1997年   9篇
  1996年   7篇
  1995年   2篇
  1994年   3篇
  1993年   6篇
  1992年   12篇
  1991年   10篇
  1990年   7篇
  1989年   5篇
  1988年   6篇
  1987年   7篇
  1986年   1篇
  1985年   1篇
  1983年   2篇
  1978年   1篇
  1977年   1篇
  1974年   2篇
  1973年   2篇
  1967年   1篇
排序方式: 共有1104条查询结果,搜索用时 140 毫秒
101.
Purpose: This narrative review summarizes the evidence derived from randomized controlled trials (RCTs) offering blinded assessment and sample size justification, in order to determine the benefits associated with adjunctive ultrasonography (US) and stimulating perineural catheters for nerve blocks. Source: The literature search for this review was conducted during the second week of December 2007 using the MEDLINE (January 1950 to November 2007) and EMBASE (January 1980 to November 2007) databases. For US-guided peripheral and neuraxial blocks, the following medical subject heading (MeSH) terms were searched: “nerve block”, “epidural anesthesia”, “epidural analgesia”, “epidural injection”, “epidural space”, “spinal anesthesia”, and “spinal injection”, the results were combined with “ultrasonography” (MeSH term) and “ultrasound” (key word). For stimulating perineural catheters, the following MeSH terms were cross referenced with the MeSH term, “nerve block”: “peripheral catheterization”, “indwelling catheterization”, “catheterization”, and keywords, “nerve catheter” and “continuous”. Subsequently, the result of this search was combined to “stimulating” (key word). Fifteen RCTs, offering blinded assessment and sample size justification, were retained for analysis. Principal findings: For axillary blocks, US guidance yields a higher success rate than a double-injection, transarterial and a triple-injection, neurostimulation-guided technique. Compared to a quadruple-stimulation technique, no major differences can be found. The addition of nerve stimulation to US guidance offers no clear benefits for axillary blocks. For femoral blocks, compared to neurostimulation, echoguidance is associated with a local anesthetic (LA) sparing effect (up to 42%). In children, US guidance yields a LA sparing effect and a longer duration of action for lower extremity nerve blocks. Compared to their blind counterparts, stimulating catheters seem to offer limited clinical benefits. Despite providing a sparing effect on LA and opioid consumption, stimulating catheters are not associated with a decrease in side effects or analgesia-related expenditures. Conclusions: Published reports of RCTs provide evidence to formulate limited recommendations regarding the use of adjunctive US and stimulating perineural catheters. Further well-designed and meticulously executed RCTs are warranted.  相似文献   
102.
103.
J Oral Pathol Med (2011) 40 : 587–592 Lubricin is a chondroprotective, mucinous glycoprotein which contribute to joint lubrication, especially to boundary lubrication and maintains joint integrity. The present investigation aimed to study the immunolocalization of lubricin in TMJ discs from patients affected by anterior disc displacement with reduction (ADDwR) ADDwoR. Eighteen TMJ displaced disc affected by ADDwoR were processed immunohistochemically, with a polyclonal anti‐lubricin antibody, used at 1:50 working dilution. The percentage of lubricin immunopositive cells (extent score = ES) and the extent of lubricin staining of the disc extracellular matrix (ECM), were evaluated. Each sample was scored for histopathological changes. Percentage of immunostained surface disc cells was the same (ES = 4) in both control and ADDwOR cells, being this data not statistically significant (P < 0.05). In pathological specimens the percentages of lubricin‐stained cells was very high with an ES of 4 respect to control specimen, and this difference was statistically significant different (P > 0.05). The extracellular matrix (ECM) of discs at the disc surfaces of both pathological and normal specimens was very heavily stained (++++). Both the ES and ECM staining were not statistically correlated to the TMJ degeneration score according to the Spearman’s rank correlation coefficient. According to our findings, a longstanding TMJ disc injury, affects lubricin expression in the TMJ disc tissue and not its surfaces, moreover, lubricin immunostaining is not correlated to TMJ disc histopathological changes.  相似文献   
104.
105.
In two different experiments, serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured in rats, using HPLC with electrochemical detection, in 3 brain regions (hippocampus, cerebral cortex and hypothalamus) after acute i.p. treatment with diazepam (4 mg/kg), alprazolam (1.25 mg/kg) or vehicle. In the first experiment, rats received the acute treatment 30 min before they were sacrificed. In the second, the animals were previously habituated to handling (involving the maneuvers of injecting and sacrificing at the guillotine) daily for 15 days, before the acute administration of the drugs. Results of the acute treatment alone showed a significant increase in 5-HT levels in hippocampus and cerebral cortex, and a decrease in hypothalamus, but not differences in 5-HIAA levels, for the diazepam- and alprazolam-treated groups. After handling-habituation, no effect in the monoamine or metabolite levels appeared when the rats were treated with diazepam or alprazolam. The results are discussed in relation to the emotional changes induced by the handling procedure, and for possible connections between the mechanisms of action of handling-habituation and benzodiazepine treatments at CNS level.  相似文献   
106.
Abstract: B-cell non-Hodgkin's lymphomas (B-NHL) and B-cell areas of reactive lymphadenopathies were investigated immunohistochemically for expression of two distinct ICAM-1 epitopes, Me14/D12 and P3-58, and the LFA-1 α and β chains. Partial or total loss of expression of one or both epitope(s) and/or chain(s) was evident in all B-NHL in function of increasing Working Formulation (WF) malignancy grade, with most defects in the high-grade tumors, namely the lowest detectability of the ICAM-1 Me14/D12 and LFA-1 α chain, the lowest co-expression of ICAM-1 epitopes and LFA-1 chains, and the most frequent simultaneous loss. The ICAM-1 and LFA-1 profiles overlapped within the low- and intermediate-grades, whereas striking differences between the high-grade subtypes were detected. Specifically, Burkitt's and lymphoblastic tumors always lost both epitopes and both chains. Large cell, immunoblastic tumors occasionally did so, and also showed either uncoordinated expression or co-expression of these constituents. It is suggested that expression defects of this type may help differentiate malignant from benign lymphoproliferations, and also be involved in the progression of B-NHL, since most are observed in high-grade tumors, whose ICAM-1 and LFA-1 profiles indicate that their subtypes are the expression of distinct normal B-cell differentiation stages.  相似文献   
107.
A new 4-antigen recombinant immunoblot assay (4-RIBA) for confirmation of hepatitis C virus (HCV) C-100 enzyme-linked immunosorbent assay (ELISA) reactivity was tested in serum samples of 11 pediatric patients on dialysis. Of 6 HCV C-100 ELISA-positive samples, all were 4-RIBA positive. The 2nd generation ELISA picked up 1 additional case confirmed by 4-RIBA. The 2nd generation tests increased the prevalence of HCV-positive cases.  相似文献   
108.
The authors present their experience in the medical treatment of 1,296 caustic esophageal injuries in children over the last 20 years in two study groups, one comprising the period up to 1989 and the other 1990 to 1996, comparing the different treatments used in each group. The treatment was based fundamentally on dilatations with anterograde mercury bougies, Savary bougies, or retrograde thread-guided bougies with gastrostomy. Pneumatic balloons or stenting procedures have also been employed in the last 3 years. Early fiberendoscopy was used systematically in the second group, which provides a more accurate evaluation of the esophageal lesions. Antibiotic coverage was done systematically during the first 10 days in all serious cases, while steroids were employed routinely only in the last 3 years. The results were similar in both groups, with a dilatation average of 32 in the first and 30 in the second group and an initial dilatation interval of 3 to 4 weeks in both. Using updated exploration and dilatation techniques, we drastically reduced the number of gastrostomies needed for retrograde thread-guided dilatations from 51 in the first group to 5 in the second, consequently improving the patients' life quality. There was no mortality and only five esophageal perforations, which did not require surgical treatment. Accepted: 5 January 1999  相似文献   
109.
We report a 21 year-old girl with classical Rett syndrome (RS) based on clinical diagnosis. The molecular testing of MECP2 gene revealed that the patient is homozygous for a de novo 473C > T mutation, causing the T158M amino acid change. Chromosome analysis showed a normal karyotype, and the haplotype analysis ruled out the possibility of parental disomy or microdeletion in MECP2 gene. Cultured fibroblast analysis reveals a mosaic for the mutation. This is a documented case of a homozygous female with RS.  相似文献   
110.

Objective

To estimate fluoride intake through consumption of water from the municipal network in pregnant women and their children from the INMA-Gipuzkoa cohort and to compare these intakes with recommended levels. In Euskadi (Spain), fluoridation of drinking water is compulsory in water supplies for more than 30,000 inhabitants.

Method

575 pregnant women (recruitment, 2006-2008) and 424 4-year-old children (follow-up, 2010-2012) have been included. Fluoride levels in drinking water were obtained from the water consumption information system of the Basque Country (EKUIS). Water consumption habits and socioeconomic variables were obtained by questionnaire.

Results

74.9% and 87.7% of women and children consumed water from the municipal network. Average fluoride levels in fluoridated water were 0.805 (SD: 0.194) mg/L during baseline recruitment and 0.843 (SD: 0.080) mg/L during follow up, at 4 years old of the children. Average and 95th percentile of fluoride intake were 0.015 and 0.026 mg/kg per day in women and 0.033 and 0.059 mg/kg per day in children. Considering only fluoride provided by drinking water, 8.71% of children living in fluoridated areas exceeded intake level recommended by the European Food Safety Authority, consisting in 0.05 mg/kg per day.

Conclusion

The results show that ingested levels of fluoride through consumption of municipal water can exceed the recommended levels in children and encourages further studies that will help in fluoridation policies of drinking water in the future.  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-23

京公网安备 11010802026262号