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   225篇
  免费   9篇
  国内免费   5篇
儿科学   19篇
妇产科学   7篇
基础医学   12篇
口腔科学   2篇
临床医学   19篇
内科学   41篇
皮肤病学   4篇
神经病学   3篇
特种医学   28篇
外科学   68篇
综合类   13篇
预防医学   9篇
药学   6篇
中国医学   3篇
肿瘤学   5篇
  2018年   2篇
  2017年   4篇
  2015年   7篇
  2014年   11篇
  2013年   5篇
  2012年   3篇
  2011年   9篇
  2010年   12篇
  2009年   11篇
  2008年   2篇
  2007年   3篇
  2006年   12篇
  2005年   2篇
  2004年   4篇
  2003年   2篇
  2000年   2篇
  1999年   2篇
  1998年   3篇
  1997年   6篇
  1996年   3篇
  1995年   5篇
  1994年   7篇
  1993年   7篇
  1992年   8篇
  1991年   4篇
  1990年   8篇
  1989年   2篇
  1988年   3篇
  1987年   6篇
  1986年   5篇
  1985年   5篇
  1984年   3篇
  1983年   5篇
  1982年   2篇
  1981年   3篇
  1979年   2篇
  1978年   3篇
  1976年   3篇
  1975年   2篇
  1967年   2篇
  1966年   5篇
  1959年   4篇
  1958年   4篇
  1957年   9篇
  1956年   4篇
  1955年   4篇
  1954年   5篇
  1949年   4篇
  1948年   3篇
  1940年   1篇
排序方式: 共有239条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
This study compares the efficacy of omeprazole and ranitidine at reducing gastric secretion in obstetric patients. Sixty-five women scheduled to undergo elective Caesarean section under general anaesthesia were randomly allocated to receive either omeprazole 40 mg or ranitidine 150 mg orally at 2200 hours the night before and at 0600 hours on the morning of surgery. Intragastric pH and volume were measured immediately after induction of anaesthesia and on completion of surgery. All patients had gastric aspirates less than 25 ml. None of the omeprazole group had an aspirate of pH less than 3.5. Six patients (19%) in the ranitidine group had aspirates of pH less than 3.5, a significant difference from the omeprazole group (p less than 0.05). Of these six, two (6%) had aspirates of pH less than 2.5. Hence this study showed that omeprazole was more effective and consistent than ranitidine at maintaining gastric pH greater than 3.5.  相似文献   
5.
To identify the factors that may predict the progression or persistence of untreated mild dysplasia of the uterine cervix, we performed a retrospective review of 118 patients with histologically verified mild dysplasia who underwent colposcopic biopsies between January 1999 and December 2003. Regression to normal occurred in 70.3%, progression to moderate dysplasia or worse occurred in 11.0%, and persistence of mild dysplasia occurred in 18.7%. In regression/progression analysis, progression of untreated mild dysplasia was 34.5% (10/29) in patients with high viral loads (> or =100 relative light units/positive control [RLU/PC]) and 4.5% (3/67) in those with low viral loads (1 to <100 RLU/PC) and negative human papillomavirus (HPV) tests (P < 0.001). Women with high viral loads had a 13-fold greater chance of progression of untreated mild dysplasia than those with low viral loads and negative HPV tests (CI: 2.494-95.297; P = 0.0022). Those associated with both positive smear and positive HPV test (12/45 = 26.7%) were at a greater risk of progression of untreated mild dysplasia as compared with those with positive smear and negative HPV (0/17 = 0.0%) or those with negative smear and positive HPV test (1/18 = 5.6%). Those with high viral loads and both with positive smear and positive HPV test should be followed closely because of their increased risk of progression of untreated mild dysplasia.  相似文献   
6.
RP-HPLC测定糙叶五加不同药用部位中槲皮素和山柰酚   总被引:2,自引:0,他引:2  
目的 建立同时测定糙叶五加不同药用部位中槲皮素和山柰酚的方法.方法采用RP-HPLC法,色谱柱为AT.Lichrom ODS-C18柱(250 mm×4.6 mm,5μm),以甲醇-磷酸-水(50∶0.2∶49.8)为流动相,柱温30℃,体积流量1.0 mL/min,检测波长360 nm,进样量10μL.结果槲皮素在0...  相似文献   
7.
AIM:To investigate our clinical experience with the colonic manifestations of phosphatase and tensin homolog on chromosome ten(PTEN)hamartoma tumor syndrome(PHTS)and to perform a systematic literature review regarding the same.METHODS:This study was approved by the appropriate institutional review board prior to initiation.A clinical genetics database was searched for patients with PHTS or a component syndrome that received gastrointestinal endoscopy or pathology interpretation at our center.These patient’s records were retrospectively reviewed for clinical characteristics(including family history and genetic testing),endoscopy results and pathology findings.We also performed a systematic review of the literature for case series of PHTS or component syndromes that reported gastrointestinal manifestations and investigations published after consensus diagnostic criteria were established in 1996.These results were compiled and reported.RESULTS:Eight patients from our institution met initial inclusion criteria.Of these,5 patients underwent4.2 colonoscopies at mean age 45.8±10.8 years.All were found to have colon polyps during their clinical course and polyp histology included adenoma,hyperplastic,ganglioneuroma and juvenile.No malignant lesions were identified.Two had multiple histologic types.One patient underwent colectomy due to innumerable polyps and concern for future malignant potential.Systematic literature review of PHTS patients undergoing endoscopy revealed 107 patients receiving colonoscopy at mean age 37.4 years.Colon polyps were noted in92.5%and multiple colon polyp histologies were reported in 53.6%.Common polyp histologies included hyperplastic(43.6%),adenoma(40.4%),hamartoma(38.3%),ganglioneuroma(33%)and inflammatory(24.5%)polyps.Twelve(11.2%)patients had colorectal cancer at mean age 46.7 years(range 35-62).Clinical outcomes secondary to colon polyposis and malignancy were not commonly reported.CONCLUSION:PHTS has a high prevalence of colon polyposis with multiple histologic types.It should be considered a mixed polyposis syndrome.Systematic review found an increased prevalence of colorectal cancer and we recommend initiating colonoscopy for colorectal cancer surveillance at age 35 years.  相似文献   
8.

Objective

The aim of this study was to evaluate the effect of multiple layers of an infection control barrier on the micro-hardness of a composite resin.

Material and Methods

One, two, four, and eight layers of an infection control barrier were used to cover the light guides of a high-power light emitting diode (LED) light curing unit (LCU) and a low-power halogen LCU. The composite specimens were photopolymerized with the LCUs and the barriers, and the micro-hardness of the upper and lower surfaces was measured (n=10). The hardness ratio was calculated by dividing the bottom surface hardness of the experimental groups by the irradiated surface hardness of the control groups. The data was analyzed by two-way ANOVA and Tukey''s HSD test.

Results

The micro-hardness of the composite specimens photopolymerized with the LED LCU decreased significantly in the four- and eight-layer groups of the upper surface and in the two-, four-, and eight-layer groups of the lower surface. The hardness ratio of the composite specimens was <80% in the eight-layer group. The micro-hardness of the composite specimens photopolymerized with the halogen LCU decreased significantly in the eight-layer group of the upper surface and in the two-, four-, and eight-layer groups of the lower surface. However, the hardness ratios of all the composite specimens photopolymerized with barriers were <80%.

Conclusions

The two-layer infection control barrier could be used on high-power LCUs without decreasing the surface hardness of the composite resin. However, when using an infection control barrier on the low-power LCUs, attention should be paid so as not to sacrifice the polymerization efficiency.  相似文献   
9.
10.
Aim: To assess a possible therapeutic effect in children and adolescents with cerebral palsy of a habilitation programme in a warm sunny climate.
Methods: Fifty-seven children and adolescents with cerebral palsy, all integrated with normal functioning children through mainstream schooling, received an individualized four-week habilitation programme at a habilitation centre in Lanzarote in the Canary Islands. They were clinically assessed before and after treatment, and again after three and six months. The clinical tests included gross motor function measure (GMFM) and the paediatric evaluation of disability inventory (PEDI). Mental health and self-esteem were assessed by using the youth self report (YSR), the child behaviour checklist (CBCL) and the Harter's self-perception profile. We also used focus-group interviews on all 57 parents by the end of the treatment period.
Results: The study revealed some improvements in the level of physical performance. The most striking finding, however, was the lasting effect on behavioural and emotional parameters and the children's self-esteem.
Conclusion: Training in a warm climate may explain some of this positive effect. However, based on the focus-group interviews and its quantitative findings a more plausible explanation may be the interaction in a social setting with others in a similar situation.  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