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   910篇
  免费   126篇
  国内免费   9篇
耳鼻咽喉   3篇
儿科学   42篇
妇产科学   24篇
基础医学   181篇
口腔科学   16篇
临床医学   78篇
内科学   121篇
皮肤病学   19篇
神经病学   50篇
特种医学   73篇
外科学   77篇
综合类   21篇
预防医学   72篇
眼科学   21篇
药学   126篇
中国医学   72篇
肿瘤学   49篇
  2022年   6篇
  2021年   10篇
  2020年   5篇
  2019年   13篇
  2018年   12篇
  2017年   16篇
  2016年   12篇
  2015年   12篇
  2014年   20篇
  2013年   14篇
  2012年   38篇
  2011年   35篇
  2010年   29篇
  2009年   21篇
  2008年   24篇
  2007年   41篇
  2006年   32篇
  2005年   37篇
  2004年   42篇
  2003年   37篇
  2002年   31篇
  2001年   27篇
  2000年   23篇
  1999年   32篇
  1998年   20篇
  1997年   15篇
  1996年   23篇
  1995年   25篇
  1994年   10篇
  1993年   23篇
  1992年   31篇
  1991年   21篇
  1990年   28篇
  1989年   29篇
  1988年   24篇
  1987年   19篇
  1986年   32篇
  1985年   31篇
  1984年   19篇
  1983年   10篇
  1982年   10篇
  1981年   14篇
  1980年   7篇
  1979年   12篇
  1978年   11篇
  1977年   10篇
  1976年   5篇
  1975年   9篇
  1971年   8篇
  1969年   4篇
排序方式: 共有1045条查询结果,搜索用时 31 毫秒
1.
We describe a familial case of Marfan's syndrome with associated intrathoracic stomach detected during the neonatal period. The patient developed a primitive leukemia at 3 months of age. Acute leukemia in a patient with Marfan's syndrome has not previously been reported.  相似文献   
2.
Magnetic resonance imaging of foot and ankle trauma   总被引:2,自引:0,他引:2  
MRI is a useful diagnostic tool in the assessment of traumatic lesions of the foot and ankle. It is especially useful in demonstrating acute and chronic tendon and ligament injuries. Subtle fractures, including osteochondral, nondisplaced, and stress fractures, are well shown with MRI but may be difficult to detect on radiographs. A bone scan may also be used to detect these fractures; however, with MRI the fracture extent may be determined. MRI is also useful in diagnosing complication of trauma, such as ischemic necrosis and bone and soft-tissue infections.  相似文献   
3.
We have carried out a systematic analysis of the protein composition of highly purified mammalian spliceosomes. We show that > 30 distinct proteins, including 20 previously unidentified components [designated spliceosome-associated proteins (SAPs)], are specifically associated with the spliceosome in a salt-resistant complex. In contrast to these spliceosome-specific proteins, we show that hnRNP proteins are not tightly associated with purified prespliceosome and spliceosome complexes. The splicing factor U2AF65, U1 snRNP-specific proteins, and several SAPs are present in the earliest prespliceosome complex (E). A set of 10 proteins is then added to the first ATP-dependent prespliceosome complex (A), and concomitantly, a significant decrease in the level of U2AF65 is observed. The fully assembled spliceosome is formed by the addition of 12 proteins in a reaction that requires ATP and both the 5' and 3' splice sites.  相似文献   
4.
白蛋白微球作为肝靶向给药载体的研究   总被引:16,自引:0,他引:16  
用均匀设计方法和计算机技术筛选了乳化化学交联法制备白蛋白微球的六个因素,十二个水平。优化出最佳制备工艺,制备了平均粒径0.41~0.47μm的白蛋白微球。将此工艺制备的125I-白蛋白微球做动物体内研究,结果表明微球iv后主要浓集在肝脏,可达注入总剂量的68%,此微球在靶组织肝脏的变化规律可用二室模型契合。  相似文献   
5.
This article reviews the pertinent anatomy of each body system involved in the assessment of the head and neck (including the eyes, ears, nose, and throat) and describes the basic elements of the comprehensive health assessment. Frequently encountered chief complaints are discussed. Aspects of the health assessment that will assist the primary care provider in making a differential diagnosis and determining the need for referral are presented. This article is the first of two articles on this topic; the subsequent article will address primary care management of common conditions of the head and neck.  相似文献   
6.
Patients with retinoblastoma diagnosed from 1969 to 1980 have been followed up for periods of up to 17 years. Data from a previous study of patients diagnosed from 1962 to 1968 have been included for analysis of incidence and second primary tumours, and for study of trends in treatment. The registration rate in Britain (which may be about 10% less than the true incidence) is about one in 23,000 live births, approximately 40% of cases being known to be genetic. There is no apparent trend in incidence during the period covered by these two studies. The three-year survival rate in 88%. Patients with bilateral tumours have a better survival rate than those with unilateral tumours for the first few years, but their long-term survival rate is worse because of later deaths from ectopic intracranial retinoblastoma or second primary neoplasms. Older children tend to have a worse prognosis, which is related to the fact that their tumours are diagnosed at a more advanced stage. There is a significantly higher survival rate for boys than for girls; this is partly accounted for by difference in age and stage at diagnosis between the sexes. Children referred to units specialising in the treatment of retinoblastoma have a higher three-year survival rate than those treated at other hospitals. Comparing methods of treatment between the periods 1962-8 and 1969-80, we find there has been a trend towards more conservative treatment. The use of chemotherapy is now usually reserved for recurrences and metastases and for palliative treatment in terminal retinoblastoma.  相似文献   
7.
A retrospective analysis has been performed of the results of external beam radiotherapy for retinoblastoma using a whole eye technique. Local tumour control has been assessed in a consecutive series of 175 eyes in 142 children all of whom received external beam radiotherapy as the primary treatment for retinoblastoma. Follow up ranged from 2 to 17 years (median 9 years). Tumour control rates have been analysed with respect to the Reese Ellsworth classification and the series includes eyes in groups I to V. Focal salvage therapy was given for persistent, recurrent, or new tumours after radiotherapy. Following whole eye radiotherapy alone, the overall ocular cure rate was 57%, though with salvage therapy 80% of eyes could be preserved.  相似文献   
8.
The determination of malignancy preoperatively or intraoperatively is difficult in patients with follicular neoplasms of the thyroid. This study reviews a series of 395 patients treated for follicular neoplasms at the Vancouver General Hospital and the British Columbia Cancer Agency between the years of 1955 and 1988, 198 of whom had frozen section at the time of surgery. Frozen section was 79% accurate in differentiating follicular adenomas from carcinomas, with a sensitivity of 52% and a specificity of 100%. The positive predictive value of a frozen section showing carcinoma was 100%, and the negative predictive value was 73%. An incorrect diagnosis of a benign lesion was made in 21% of patients in whom the final diagnosis by fixed section was carcinoma. These same statistics were calculated for patients aged greater than 50 years, tumor size greater than 3 cm, and patients with a history of previous neck irradiation, three clinical factors shown in a previous study to be strong prognostic indicators of malignancy. The results were compared with those found by frozen section. The implications of these results in terms of patient management are discussed.  相似文献   
9.
10.
Now that most patients with Wilms' tumour are cured, it is practicable to study the long-term morbidity of their treatment and use this information to reduce treatment sequelae in the future. In this study we evaluate the size and function of the remaining kidney in 53 survivors of Wilms' tumour with a mean off treatment follow-up of 13 years. There was evidence of renal dysfunction in 17 (32%), including ten (19%) with a low GFR (< 80 ml/min/1.73 m2SA), six (11%) with hypertension and five (9%) with increased urinary albumin excretion. Measurements of renal size showed 'good' renal compensatory hypertrophy in only 55% of patients. 'Good' refers to renal size of more than 2 s.d. above the mean renal length for children with two kidneys. There were no correlations between GFR, renal size, blood pressure, microalbuminuria or type of treatment. However, children less than 24 months at diagnosis and children receiving chemotherapy with radiation doses to remaining kidney of more than 1200 cGy had a worse renal prognosis. Patients whose Wilms' tumour is diagnosed in infancy should have careful long-term follow-up of renal function and size. Older patients may safely be followed up less often, unless their remaining kidney was received > 1200 cGy.  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