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   528篇
  免费   18篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   40篇
妇产科学   1篇
基础医学   33篇
口腔科学   10篇
临床医学   47篇
内科学   87篇
皮肤病学   9篇
神经病学   12篇
特种医学   134篇
外科学   36篇
综合类   32篇
预防医学   22篇
眼科学   43篇
药学   33篇
肿瘤学   28篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   3篇
  2019年   4篇
  2018年   11篇
  2017年   4篇
  2016年   5篇
  2015年   8篇
  2014年   12篇
  2013年   14篇
  2012年   7篇
  2011年   14篇
  2010年   16篇
  2009年   15篇
  2008年   26篇
  2007年   33篇
  2006年   38篇
  2005年   6篇
  2004年   13篇
  2003年   7篇
  2002年   8篇
  2001年   21篇
  2000年   7篇
  1999年   10篇
  1998年   33篇
  1997年   23篇
  1996年   27篇
  1995年   22篇
  1994年   20篇
  1993年   22篇
  1992年   12篇
  1991年   6篇
  1990年   11篇
  1989年   9篇
  1988年   9篇
  1987年   5篇
  1986年   11篇
  1985年   8篇
  1984年   7篇
  1983年   9篇
  1982年   8篇
  1981年   8篇
  1980年   13篇
  1979年   4篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   2篇
  1972年   1篇
排序方式: 共有568条查询结果,搜索用时 15 毫秒
81.
82.
83.

Background:

We derived estimates of overdiagnosis by polygenic risk groups and examined whether polygenic risk-stratified screening for prostate cancer reduces overdiagnosis.

Methods:

We calculated the polygenic risk score based on genotypes of 66 known prostate cancer loci for 4967 men from the Finnish section of the European Randomised Study of Screening for Prostate Cancer. We stratified the 72 072 men in the trial into those with polygenic risk below and above the median. Using a maximum likelihood method based on interval cancers, we estimated the mean sojourn time (MST) and episode sensitivity. For each polygenic risk group, we estimated the proportion of screen-detected cancers that are likely to be overdiagnosed from the difference between the observed and expected number of screen-detected cancers.

Results:

Of the prostate cancers, 74% occurred among men with polygenic risk above population median. The sensitivity was 0.55 (95% confidence interval (CI) 0.45–0.65) and MST 6.3 (95% CI 4.2–8.3) years. The overall overdiagnosis was 42% (95% CI 37–52) of the screen-detected cancers, with 58% (95% CI 54–65) in men with the lower and 37% (95% CI 31–47) in those with higher polygenic risk.

Conclusion:

Targeting screening to men at higher polygenic risk could reduce the proportion of cancers overdiagnosed.  相似文献   
84.
Antimicrobial peptides: a potential role in ocular therapy   总被引:1,自引:0,他引:1  
Bacterial pathogens are often involved in contact lens‐related adverse responses. This study aimed to find antimicrobial peptides and proteins that effectively eradicate or inhibit ocular bacteria. The antimicrobials were screened against Gram‐ negative and Gram‐positive bacteria originating from ocular sources. The viability of these ocular bacteria was measured after exposure to the peptides and proteins. Two conditions were used to grow bacteria, low nutrient phosphate‐buffered saline and high nutrient tryptone soya broth. Samples were taken at different times up to 48 h. In low nutrient conditions, protamine was found to be the most effective against all strains. Melittin was very effective against all strains except Serratia and one Pseudomonas isolate which were partially affected. In high nutrient condition, only melittin was effective in killing Staphylococcus aureus. Protamine and the combination of protamine and melittin had the greatest effect in eradicating the bacteria tested in low nutrient condition. Protamine alone and its combination with melittin may have potential therapeutic agents for ocular infections in an era of emerging antibiotic resistance.  相似文献   
85.
To determine whether or not the frequency of migraine attacks increased at weekends in employed patients and if so, whether or not this was related to the type of migraine, 35 female patients prospectively recorded the presence or absence of migraine attacks daily over a six-week period. They were also asked to estimate the frequency with which emotional factors predisposed to their migraine attacks and to provide details of their occupation. A diagnosis of common (migraine without aura) or classical migraine (migraine with aura) was made according to both the criteria of the Ad Hoc Committee on the Classification of Headache and those of the International Headache Society. Eleven percent and 6% of patients, respectively, felt that emotional factors "usually" or "always" predisposed to migraine attacks. There was no significant increase in the frequency of migraine attacks at weekends in either the total group or in the employed patients. Similarly, the type of migraine made no difference to the results. There was therefore no evidence for a delayed onset of migraine at weekends related to the weekday stress of employment.  相似文献   
86.
This article summarises research undertaken since 1993 in the Willcox laboratory at the University of New South Wales, Sydney on the tear film, its interactions with contact lenses, and the use of tears as a source of biomarkers for ocular and non‐ocular diseases. The proteome, lipidome and glycome of tears all contribute to important aspects of the tear film, including its structure, its ability to defend the ocular surface against microbes and to help heal ocular surface injuries. The tear film interacts with contact lenses in vivo and interactions between tears and lenses can affect the biocompatibility of lenses, and may be important in mediating discomfort responses during lens wear. Suggestions are made for follow‐up research.  相似文献   
87.

Introduction  

The aim of this study was to develop and validate a prognostication model to predict overall and breast cancer specific survival for women treated for early breast cancer in the UK.  相似文献   
88.

Background

Although there is an extensive body of literature on the role of neoadjuvant chemoradiotherapy (CRT) in the management of rectal cancer, its role in primary locally advanced adherent colon cancer (LAACC) is unclear.

Objective

To analyzed the outcomes of neoadjuvant CRT and multivisceral resection in the management of LAACC patietns.

Methods

We retrospectively reviewed our institutional Colorectal Carcinoma Database for 33 patients with potentially resectable, non-metastatic primary LAACC who received neoadjuvant CRT followed by multivisceral resection. CRT consisted of external beam radiation (45–50 Gy in 25 daily fractions) and concurrent 5-FU infusion (225 mg/m2/day).

Results

There were 21 males and 12 females. Median age was 64 (31–83) and median follow-up was 36 months. All patients had microscopically clear resection margins (R0). Complete pathologic response was documented in 1 patient (3%) and 66% had ypT4b disease. Post-operative complications were observed in 36% of patients with no 30-day mortality. The 3-year overall survival and 3-year disease-free survival were 85.9% and 73.7% respectively. Two patients developed a local recurrence.

Conclusions

Neoadjuvant CRT and en-bloc multivisceral resection may result in high rates of R0 resection and excellent local control with acceptable morbidity and mortality in selected patients with LAACC.  相似文献   
89.

Background

The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear.

Methods

We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk.

Results

Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives.

Conclusion

These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found.
  相似文献   
90.
Purpose: It was investigated whether alterations in neuronal structure and function occasioned by strabismic amblyopia also may be reflected in alterations in the expression on Y type neurons of a Cat-301 antibody sensitive antigen in the lateral geniculate nucleus (LGN) and cortex of our cat model of strabismic amblyopia. Methods/Results: The percentage of positively labelled cells was reduced in LGN laminae that received input from the deviated eye in strabismic amblyopic cats compared with normal cats. In the strabismic cortex, the density of immunopositive neurons was significantly reduced compared with normal, the effect being most pronounced in layer IV Conclusions: Despite previous physiological recordings indicating a decrease in X-cell associated acuity in strabismic amblyopia, the present findings imply that the changes in the early visual experience occasioned by strabismus also produce specific molecular changes in theY neuronal class.  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