首页 | 官方网站   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   817篇
  免费   63篇
  国内免费   63篇
医药卫生   943篇
  2023年   1篇
  2022年   2篇
  2021年   11篇
  2020年   3篇
  2019年   2篇
  2018年   7篇
  2017年   6篇
  2016年   8篇
  2015年   11篇
  2014年   16篇
  2013年   15篇
  2012年   2篇
  2011年   6篇
  2010年   18篇
  2009年   27篇
  2008年   9篇
  2007年   38篇
  2006年   16篇
  2005年   27篇
  2004年   8篇
  2003年   11篇
  2002年   10篇
  2001年   24篇
  2000年   11篇
  1999年   23篇
  1998年   56篇
  1997年   63篇
  1996年   57篇
  1995年   57篇
  1994年   34篇
  1993年   42篇
  1992年   14篇
  1991年   18篇
  1990年   20篇
  1989年   47篇
  1988年   35篇
  1987年   32篇
  1986年   17篇
  1985年   21篇
  1984年   12篇
  1983年   7篇
  1982年   15篇
  1981年   18篇
  1980年   19篇
  1979年   11篇
  1978年   5篇
  1977年   14篇
  1976年   10篇
  1975年   7篇
排序方式: 共有943条查询结果,搜索用时 0 毫秒
51.
赤芝子实体中灵芝酸类成分的研究   总被引:15,自引:1,他引:15  
自赤芝[Ganodermalucidum(Fr.)Karst.]子实体的二氯甲烷提取物中分离得到一个新的四环三萜化合物,命名为灵芝酸DM(ganodericacidDM,I)。根据光谱(UV,IR,1HNMR,13CNMR,MS2DNMR)分析,确定其结构为I式。同时还分离得到二个已知的灵芝酸类化合物,即灵芝酸A(ganodericacidA,I)和灵芝酸C(ganodericacidC,II)。  相似文献   
52.
53.
The aim of this study was to review the life of Mary E. O'Sullivan and to summarize her important contributions to the study of migraine. Mary E. O'Sullivan underwent extensive training to become a neurologist at a time when only 5% of women in America were physicians. She published five papers on migraine. In a 1936 Journal of the American Medical Association article, she described a patient with ergotamine overuse headache and recommended that daily doses of oral ergotamine should be avoided. Three years later she described migraine as a 'complex' syndrome with multiple causes and multiple cures. Mary E. O'Sullivan, an ambitious female headache specialist of the 1930s, was an early advocate of the use of ergotamine to treat migraine, yet she was one of the first to report ergotamine overuse headache. Although her life was short, her research, knowledge and ambition at a time when women had limited opportunities in medicine have left a mark.  相似文献   
54.
王继琛  王乐  李海  柯茂林 《医学争鸣》2005,26(14):1278-1278
1临床资料2003-06/2004—12收治髋部骨质疏松性骨折患20(男14,女6)例,年龄58—80(平均68.5)岁,股骨颈骨折13例,粗隆间骨折7例.对照组为老年性骨关节病或颈腰椎病患20例.均抽空腹静脉血4mL,3000r/min离心5min分离血清,4h内测定血清钙、磷,留血清-20℃保存备用,测定TGF-β1.用Au-2700全自动生化分析仪测定血清钙、磷,试剂由日本欧林巴斯公司提供.血清TGF-β1检测采用ELISA法,  相似文献   
55.
To estimate the incidence and causes of secondary thrombocytosis in children, a 12 month study of all patients attending a children's hospital and discovered to have a platelet count over two times the upper normal limit (> 800 x 10(9)/l) was undertaken. Data so obtained were analysed both separately and together with those from two previous studies to gain as broad a perspective as possible. Of 7916 children who had platelet counts during the study period, 36 (0.5%) produced a value > 800 x 10(9)/l; there were 19 boys and 17 girls. There was a preponderance of young infants (median age 13 months). Twenty seven of the 36 had some sort of associated infection, bacterial in 18 and viral in nine. The other nine were either recovering from anti-neoplastic chemotherapy (n = 6), were post-operative (n = 2), or simply iron deficient (n = 1). Combining these patients with those described in previous studies allowed a review of 139 unselected children with very high platelet counts. Fifty three (38%) had infections, 29 (20%) had traumatic or surgical tissue damage, 16 (11%) had malignant disease undergoing chemotherapy or surgery, and 13 (9%) had connective tissue or autoimmune disorders. Secondary thrombocytosis is not rare and is most frequently seen in very young infants after infection. It can arise in a wide variety of other circumstances including rebound from myelosuppression, iron lack, or as part of an acute phase response. It is clinically unimportant in terms of morbidity and requires no treatment other than that for the primary condition.  相似文献   
56.
Two children with acute lymphoblastic leukaemia (ALL) taking daily 6-mercaptopurine as part of a national UK therapeutic trial repeatedly developed profound myelosuppression on 25% of the standard protocol dose. Both were found to have undetectable intracellular activity of thiopurine methyltransferase (TPMT), an enzyme controlling one of the major alternative catabolic pathways of 6-mercaptopurine, and both produced higher concentrations of cytotoxic drug metabolites at 10-25% of the protocol dose than other patients taking 100%. It is supposed that these patients represent the 0.33% of the normal population constitutionally lacking TPMT. It is important to recognise such individuals both to avoid fatal bone marrow failure through inadvertent overdosage, and to be reassured that an adequate drug effect can be achieved at around 10% of the standard dose.  相似文献   
57.
Multiple myeloma: evaluation by CT   总被引:3,自引:0,他引:3  
Schreiman  JS; McLeod  RA; Kyle  RA; Beabout  JW 《Radiology》1985,154(2):483-486
Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs.  相似文献   
58.
59.
60.
Tarsal navicular stress fractures: radiographic evaluation   总被引:3,自引:0,他引:3  
Pavlov  H; Torg  JS; Freiberger  RH 《Radiology》1983,148(3):641-645
Tarsal navicular stress fractures are a potential source of disabling foot pain in physically active individuals. The diagnosis of tarsal navicular stress fracture requires a high index of clinical and radiographic suspicion because the fracture is only rarely evident on routine radiographs or standard tomograms. The radiographic diagnosis of a tarsal navicular stress fracture may require anatomic anteroposterior tomograms or a radionuclide bone scan with plantar views. Radiographic examinations of 23 fractures in 21 patients are evaluated.  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-23

京公网安备 11010802026262号