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   7911篇
  免费   549篇
  国内免费   23篇
耳鼻咽喉   53篇
儿科学   149篇
妇产科学   74篇
基础医学   1345篇
口腔科学   80篇
临床医学   775篇
内科学   1651篇
皮肤病学   168篇
神经病学   1121篇
特种医学   412篇
外国民族医学   8篇
外科学   1188篇
综合类   26篇
预防医学   356篇
眼科学   60篇
药学   412篇
中国医学   9篇
肿瘤学   596篇
  2023年   72篇
  2022年   142篇
  2021年   314篇
  2020年   179篇
  2019年   276篇
  2018年   308篇
  2017年   212篇
  2016年   209篇
  2015年   257篇
  2014年   310篇
  2013年   408篇
  2012年   628篇
  2011年   604篇
  2010年   329篇
  2009年   304篇
  2008年   368篇
  2007年   364篇
  2006年   348篇
  2005年   310篇
  2004年   277篇
  2003年   223篇
  2002年   199篇
  2001年   141篇
  2000年   139篇
  1999年   125篇
  1998年   55篇
  1997年   57篇
  1996年   36篇
  1995年   41篇
  1994年   49篇
  1993年   44篇
  1992年   105篇
  1991年   80篇
  1990年   81篇
  1989年   83篇
  1988年   70篇
  1987年   79篇
  1986年   75篇
  1985年   66篇
  1984年   58篇
  1983年   39篇
  1979年   41篇
  1978年   22篇
  1977年   34篇
  1975年   23篇
  1974年   28篇
  1973年   29篇
  1972年   24篇
  1971年   22篇
  1970年   35篇
排序方式: 共有8483条查询结果,搜索用时 0 毫秒
41.
42.
Totally implantable venous access ports (TIVAP) are valuable medical devices for long-term intravenous treatment such as parenteral nutrition, cancer chemotherapy or antiviral therapy. Implantation and use of these devices are each associated with infectious or mechanical complications. AIMS OF THE STUDY: To determine the frequency of complications and to analyze bacterial contamination of different parts of TIVAP (tip, septum, internal lumen of the port). MATERIAL AND METHODS: Clinical charts of patients, which TIVAP was removed between April 20th to December 31st 2003, were retrospectively reviewed. Infectious complications (local and septicemic) and non-infectious complications (i.e. obstruction, thrombosis, drug extravasation...) were defined using clinical and/or microbiological criteria. Quantitative culture from different parts of the TIVAP was performed. RESULTS: One hundred and ten patients (age 57 +/- 14-years-old, 94.3% cancers) were included, corresponding to 57,018 catheter-days: 39.1% had one or more non-infectious complications (density incidence: 0.86 for 1000 catheter-days). Among the 49 complications, obstruction, thrombosis, extravasations and malposition accounted for 30.6%, 30.6% 4.1% and 6% of cases. Twenty-one patients (19.1%) had an infectious complication: 11 were local and 14 were systemic (density incidence 0.43 for 1000 catheter-days). Bacteria responsible for TIVAP-associated bacteraemia were coagulase negative staphylococci (N = 2), Staphylococcus aureus susceptible to methicilline (N = 3), micrococci (N = 1), corynebacteria (N = 1) or Gram-negative bacilli (N = 8). Comparison of quantitative culture of the different parts of TIVAP with a threshold at 10(3) CFU/ml showed that culture of tip, septum and port has a sensitivity of 47.6% 57.1% and 61.9 %, respectively and a specificity of 100% 92.1% and 92.1%, respectively for the diagnosis of TIVAP infection. CONCLUSION: Complications associated to TIVAP are frequent but incidence that we have reported is comparable with previous studies. Analysis of internal lumen of the port is the most sensitive method for the diagnosis of TIVAP-associated infections.  相似文献   
43.
44.
Sixteen unrelated Southern European patients with the mitochondrial depletion syndrome (MDS) were analyzed for mutations in the TK2 and DGUOK genes. Three novel mutations were identified in TK2 (R183G, R254X, and 142insG). When we analyzed additional genes involved in the dNTPs pool, such as SLC25A19 (DNC) and NT5M (d-NT2), we did not detect mutations. The current study suggest that scanning the TK2, DGUOK, SLC25A19, and NT5M genes is likely to help about 10% of MDS families in terms of genetic counseling. Also, our findings indicate that genotype-phenotype correlations are not straightforward in MDS.  相似文献   
45.
Two patients with true synovial cysts in atypical sites (internal compartment of knee and inguinal hollow) were investigated by radioarthrography, ultrasound and computed tomography imaging. The cyst in the hip region originated from a dilated serous bursa of the iliopsoas muscle that did not communicate or was no longer in communication with the joint. In contrast, the cyst of the knee appeared to be a lateral synovial capsule hernia. Positive diagnosis in both cases was dependent on combined ultrasound-CT scan imaging, this eliminating a tumor (sarcoma) of soft tissues. However, affirmation of the synovial origin (mesothelial covering of the wall) of the lesion was obtained by histology only, this allowing differentiation from a "capsular" (fibrous wall) cyst, which probably provokes similar ultrasound and CT scan images.  相似文献   
46.
47.
48.
Quality of Life Research - The Adult Social Care Outcomes Toolkit for Carers (ASCOT-Carer), developed in England, measures the effects of long-term care (LTC) services and carer support on informal...  相似文献   
49.
Background

Colorectal cancer (CRC) has a high incidence worldwide, especially in high-income countries. In France, a national CRC screening program targeting residents aged 50–74 years has been in place since 2009. Little is known about CRC screening practices in cancer survivors, even though some have an increased risk of developing a second cancer in the colorectum. This study aims to identify the barriers to CRC screening among cancer survivors.

Methods

This cross-sectional study based on the French national VICAN survey included individuals diagnosed in 2010 with a cancer in 1 of 11 locations other than the colorectum and interviewed 5 years after diagnosis about various health-related issues. Binary logistic regression was used to identify the factors associated with lack of up-to-date CRC screening in cancer survivors without cancer progression.

Results

Of the 2935 cancer survivors included in the study, 35.3% reported undergoing a screening test in the previous 2 years. The rate of up-to-date CRC screening rose to 49.3% in survivors aged 51–75 years. Among these, lack of CRC screening in the recommended time frame was associated with obesity, current smoking, non-use of complementary medicine, perceived financial difficulties, and poor access to general practitioners.

Conclusions

Barriers to CRC screening can be personal and/or institutional.

  相似文献   
50.
Pain in the lesser metatarsophalangeal area of the foot remains a diagnostic challenge. This pathology often is attributed to neuromas. These painful lesions, although predisposed to this area, are not nearly as common as they are thought to be. The "systems approach" to diagnosis can be extremely helpful in establishing an accurate cause and subsequent proper diagnosis of lesser metatarsophalangeal joint pain.  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