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   3894篇
  免费   158篇
  国内免费   13篇
耳鼻咽喉   13篇
儿科学   180篇
妇产科学   51篇
基础医学   481篇
口腔科学   80篇
临床医学   274篇
内科学   690篇
皮肤病学   80篇
神经病学   272篇
特种医学   120篇
外科学   497篇
综合类   192篇
一般理论   1篇
预防医学   232篇
眼科学   206篇
药学   424篇
中国医学   24篇
肿瘤学   248篇
  2023年   30篇
  2022年   80篇
  2021年   138篇
  2020年   73篇
  2019年   74篇
  2018年   107篇
  2017年   67篇
  2016年   99篇
  2015年   111篇
  2014年   131篇
  2013年   176篇
  2012年   269篇
  2011年   268篇
  2010年   150篇
  2009年   134篇
  2008年   205篇
  2007年   220篇
  2006年   198篇
  2005年   160篇
  2004年   149篇
  2003年   135篇
  2002年   149篇
  2001年   121篇
  2000年   109篇
  1999年   81篇
  1998年   39篇
  1997年   31篇
  1996年   45篇
  1995年   16篇
  1994年   14篇
  1993年   12篇
  1992年   32篇
  1991年   32篇
  1990年   39篇
  1989年   47篇
  1988年   41篇
  1987年   36篇
  1986年   29篇
  1985年   30篇
  1984年   27篇
  1983年   22篇
  1982年   15篇
  1981年   13篇
  1980年   15篇
  1979年   26篇
  1978年   7篇
  1977年   13篇
  1974年   9篇
  1971年   7篇
  1970年   9篇
排序方式: 共有4065条查询结果,搜索用时 15 毫秒
51.
A case of Takayasu's arteritis resulting in extensive fusiform aneurysmal dilatation of the entire aorta extending from the aortic root to the abdominal bifurcation associated with aortic regurgitation is described. She underwent successful radical replacement of the aortic root, ascending, transverse arch and proximal part of the descending aorta employing simultaneous modified Bentall and Elephant trunk techniques. During aortic arch replacement the brain was protected by selective antegrade innominate perfusion under moderate hypothermia. A pattern to the best of our knowledge, has not been reported earlier.  相似文献   
52.
Efficacy of misoprostol was studied for induction of labor at term. Seventy patients were randomized to Group A (n = 36, oral misoprostol 50 microg four hourly to maximum of 5 doses) and B (n = 34, continuous oxytocin infusion). Induction-delivery interval was shorter with misoprostol (7.7 +/- 2.8 h against 14.3 +/- 4.8 h with oxytocin) but the rates of vaginal delivery, cesarean, neonatal outcome variables were similar. Hence, misoprostol is an effective agent for induction of labor at term.  相似文献   
53.
54.
Introduction: Internal fixation of diaphyseal fracture of shaft of femur in an adult by Kuntscher nail is the most common operative method of treatment in Nepal where operative facilities for the same exist. Since the complete range of K-nail sizes and length are not available in most operation theatres in Nepal, most orthopaedic surgeons assess the size and length of the K-nail pre-operatively by various methods and keep one size above and below the assessed length for the planned surgery. Materials and Methods: The following measurements were taken in five hundred people involved in the study: Measurement No. 1: Tip of the greater trochanter to lateral knee joint line minus 2cms. Measurement No. 2: Tip of the olecranon process to the tip of little finger, and Measurement No. 3: Tip of the greater trochanter to the upper pole of patella. An average of all three lengths were analysed to see if there were any differences in their mean lengths. Results: Analysis showed that there were significant differences between the mean lengths measured by the three different methods. The average length of measurement no: 2 was 3 cm longer than the average length of measurement no: 1, which is the reference pre-operative length of K.nail. Conclusion: However, in practice since measurement no:2 is more convenient to perform and can also be used when the patient has sustained bilateral fractures of femur, an accurate pre-operative K-nail length assessment can be done by subtracting 3 cm from measurement no:2, i.e. the tip of the olecranon process to the tip of the little finger.  相似文献   
55.
Water is the important constituent of life support system. No one can live and even dream to live without water. Most of our water bodies have become polluted due to industrial growth; urbanization and man-made problems mainly the result of population growth. Poor sanitation and contaminated drinking water arising from human activity and natural phenomena create serious problems in human health. The chief sources of water pollution are sewage and other waste, industrial effluents, agricultural discharges and industrial wastes from chemical industries, fossils fuel plants and nuclear power plants. They create a larger problem of water pollution rendering water no longer fit for drinking, agriculture and, as well as for aquatic life. More than 2.6 billion people--40% of the world's population--lack basic sanitation facilities and over one billion people still use unsafe drinking water sources. As a result thousands of children die everyday from diarrhoea and other water, sanitation and hygiene-related diseases and many suffer and are weakened by illness.  相似文献   
56.
57.
58.
Intralesional sclerotherapy for lymphatic malformations (LMs) has become a modality of choice because of the high morbidity and recurrence rates with surgical excision. Traditionally, the macrocystic variant has shown good results with sclerotherapy. This prospective study was performed to evaluate the role of bleomycin sclerotherapy in the management of different radiological variants of LM. A total of 142 patients were included in this study. The lesions were classified as macrocystic, microcystic, or mixed LMs on the basis of ultrasonography. All patients were managed by intralesional injection of bleomycin and were recalled after 4 weeks for evaluation. Colour photographs of the patients were taken before the onset of treatment and at each monthly visit, and were utilized to assess the response. Following the second, third, and fourth doses, the response was better in patients with the macrocystic variant than in those with the other two variants. However, after the completion of six doses, 80.3% of patients with the macrocystic variant, 67.4% with the microcystic variant, and 71.4% with the mixed type had a complete response. There was no difference in the overall response between the three types (P = 0.28). Oedema, erythema, and local induration with fever were the most common adverse effects and were more common in younger children.  相似文献   
59.
MicroRNAs (miRNAs) are 22- to 24-nucleotide, small, non-coding RNAs that bind to the 3′UTR of target genes to control gene expression. Consequently, their dysregulation contributes to many diseases, including diabetes and cancer. miR-22 is up-regulated in numerous metastatic cancers and recent studies have suggested a role for miR-22 in promoting stemness and metastasis. TIP60 is a lysine acetyl-transferase reported to be down-regulated in cancer but the molecular mechanism of this reduction is still unclear. In this study, we identify TIP60 as a target of miR-22. We show a negative correlation in the expression of TIP60 and miR-22 in breast cancer patients, and show that low levels of TIP60 and high levels of miR-22 are associated with poor overall survival. Furthermore, pathway analysis using high miR-22/low TIP60 and low miR-22/high TIP60 breast cancer patient datasets suggests association of TIP60/miR-22 with epithelial-mesenchymal transition (EMT), a key alteration in progression of cancer cells. We show that blocking endogenous miR-22 can restore TIP60 levels, which in turn decreases the migration and invasion capacity of metastatic breast cancer cell line. These results provide mechanistic insight into TIP60 regulation and evidence for the utility of the combination of TIP60 and miR-22 as prognostic indicator of breast cancer progression.  相似文献   
60.
Self-controlled hyperthermia is a non-invasive technique used to kill or destroy cancer cells while preserving normal surrounding tissues. We have explored bulk magnetic Ni-Si and Ni-Al alloys as a potential thermoseeds. The structural, magnetic and magnetocaloric properties of the samples were investigated, including saturation magnetisation, Curie temperature (TC), and magnetic and thermal hysteresis, using room temperature X-ray diffraction and magnetometry. The annealing time, temperature and the effects of homogenising the thermoseeds were studied to determine the functional hyperthermia applications. The bulk Ni-Si and Ni-Al binary alloys have Curie temperatures in the desired range, 316?K–319?K (43?°C–46?°C), which is suitable for magnetic hyperthermia applications. We have found that TC strictly follows a linear trend with doping concentration over a wide range of temperature. The magnetic ordering temperature and the magnetic properties can be controlled through substitution in these binary alloys.  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