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   563篇
  免费   37篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   28篇
妇产科学   24篇
基础医学   54篇
口腔科学   4篇
临床医学   51篇
内科学   128篇
皮肤病学   13篇
神经病学   66篇
特种医学   12篇
外科学   51篇
综合类   2篇
预防医学   29篇
眼科学   9篇
药学   19篇
肿瘤学   107篇
  2023年   3篇
  2022年   2篇
  2021年   9篇
  2020年   9篇
  2019年   9篇
  2018年   18篇
  2017年   15篇
  2016年   10篇
  2015年   18篇
  2014年   11篇
  2013年   25篇
  2012年   29篇
  2011年   34篇
  2010年   17篇
  2009年   15篇
  2008年   23篇
  2007年   31篇
  2006年   17篇
  2005年   34篇
  2004年   33篇
  2003年   33篇
  2002年   21篇
  2001年   9篇
  2000年   13篇
  1999年   12篇
  1998年   7篇
  1997年   3篇
  1996年   5篇
  1995年   6篇
  1994年   5篇
  1993年   5篇
  1992年   11篇
  1991年   4篇
  1990年   14篇
  1989年   11篇
  1988年   8篇
  1987年   8篇
  1986年   8篇
  1985年   13篇
  1984年   9篇
  1983年   6篇
  1982年   4篇
  1981年   3篇
  1980年   2篇
  1979年   5篇
  1978年   1篇
  1974年   5篇
  1973年   3篇
  1972年   3篇
  1971年   2篇
排序方式: 共有601条查询结果,搜索用时 15 毫秒
51.
52.
53.
The clavicle is frequently incorporated into the radiation field in the treatment of malignant tumors located in the head and neck. From 1954 to 1995, 499 pediatric patients were treated with moderate to high-dose radiation therapy to the head and neck at the University of Texas M.D. Anderson Cancer Center. The medical records of 312 of these patients were available and were reviewed. The period of observation ranged from 5 to 30 years. Five late radiation-induced abnormalities of the clavicle were encountered: osteosarcoma; osteochondroma; malignant fibrous histiocytoma; radionecrosis and impaired healing following trauma and radionecrosis and lysis. The doses of radiation therapy which induced the abnormalities varied from 35 to 60.5 Gy (median 34.75 Gy). The interval from radiation therapy to discovery of the complications varied from 6 to 11 years. Two patients died: one from malignant fibrous histiocytoma and another from a radiation-induced meningioma of the brain (which accompanied radionecrosis of the clavicle). We conclude that the incidence of radiation-induced abnormalities of the clavicle in pediatric long-term survivors is low (1.5%). However, some of the late sequela are potentially fatal. The clavicle should be considered a vulnerable bone to radiation therapy and should be monitored in long-term survivors of childhood cancer. The experience is compared to radiation-induced abnormalities recorded in the literature.  相似文献   
54.
123 healthy Jewish women (18-22 years) were divided into OC (oral contraceptives) users (n=75), and controls (n=48). All women were on a similar diet. The OC users were divided into 3 groups (1, 2 and 3) based on the OC preparations they were taking. Venous blood samples were collected; serum copper levels were measured using atomic absorption spectrophotometry (Parker et al.'s method). Serum copper levels did not correlate with time of menstrual cycle for each group, and for all groups considered together. Mean serum copper level in the control group, 120 ug/100 ml +/- 15 SD (standard deviation), was significantly lower than the serum copper level of all contraceptive groups considered together. Of the 3 groups, group 3 (those taking Neogynon) showed a steady and progressive rise in serum copper level. The mechanism of action of the rise of serum copper and ceruplasmin levels following OC intake is not clear. Hypercupremia may be due to excessive absorption of copper by the intestines, to a shift of copper from tissue to blood compartment, or to both. Chronic copper intoxication could result from hypercupremia associated with chronic OC use. Studies of Wilson's disease show that severe damage could result from excessive copper deposition in various tissues. Further research should be done to determine the potential hazards of chronic copper intoxication, particularly in patients taking Neogynon.  相似文献   
55.
Patients with untreated squamous cell cancer of the head and neck region were randomized to receive either a boost of 25-30 Gy using photon-beam irradiation (photons) or an equivalent boost using neutron-beam irradiation (neutrons). All patients received an initial 45-50 Gy of wide-field photon irradiation. A total of 57 patients was evaluable on the neutron arm and 58 were evaluable on the photon arm. The proportion of patients with complete responses was 60 and 64% on the neutron and photon arms, respectively. The locally disease-free proportion at 2 years was estimated to be 20 and 31%, and the 2-year survival was estimated to be 32 and 41%, respectively. These differences are not statistically significant. There was a higher rate of severe complications on the neutron arm, 16 versus 7%. Thus, there was no evidence that a neutron boost produces better initial tumor clearance, local tumor control, or survival than a photon boost, and it may produce more complications.  相似文献   
56.
Posterior mitral valve (MV) leaflet aneurysms are extremely rare complications of infective endocarditis (IE). When MV aneurysms occur, they usually involve the anterior leaflet. Real time three-dimensional transesophageal echocardiography (RT3D TEE) has been recently developed and provides views of unparalleled quality by optimizing visualization of spatial relationships. We present a rare case of a posterior MV leaflet aneurysm due to IE in a 64-year-old woman, best visualized by RT3D TEE.  相似文献   
57.
We present an adult patient with cor triatriatum (CTT) due toa left atrial (LA) membrane. Two-dimensional and real-time three-dimensionaltransthoracic echocardiography (3DE) were performed as wellas echocardiographic examination after exercise. These non-invasivemodalities provided a comprehensive anatomic and hemodynamicevaluation of the anomaly.  相似文献   
58.
Eighty-five patients (37 female, 48 male; median age 14 years) with non-metastatic Ewing's sarcoma received definitive treatment at the University of Texas M.D. Anderson Cancer Center between 1969 and 1988. Multidisciplinary therapy was administered as follows: combination chemotherapy (CC) and local radiotherapy (XRT): 65 patients; CC, XRT and surgery, 19 patients; and XRT and surgery, 1 patient. This permitted a 10-20 year follow-up for 75% of our patients. The overall survival at 5 and 10-20 years was 46.1%, and 37.2%, respectively. At 5 years, 80.5% of live patients had control of local disease. The influence of sex, age, ethnicity, primary site, size, lactic dehydrogenase (LDH) level, presence or absence of systemic symptoms, and XRT dose (<60 Gy and 相似文献   
59.
From July 1979 through March 1984 the Radiation Therapy Oncology Group conducted a randomized study comparing fast neutron radiotherapy versus mixed beam (neutron/photon) radiotherapy versus conventional radiotherapy for patients with non-small cell carcinoma of the lung. Patients were either medically or technically inoperable. One hundred two evaluable patients were placed on the study. The radiation doses were approximately 60 Gy-equivalent on each arm. Patients were stratified according to size of primary, histology, Karnofsky performance status, and age distribution. Overall local response rates as measured by serial radiographs were the same on the three arms, and an actuarial analysis showed no significant differences in either median or long-term survival. However, for the subgroup of patients exhibiting a complete or partial tumor response at 6 months there was a suggestion of improved 3-year survival on the two experimental arms (mixed beam, 37%; neutrons, 25%; photons, 12%). The p value for the difference between the mixed beam and photon curves is 0.14 (two-sided test). The incidence of major complications was higher on the neutron and mixed beam arms. These complications included four cases of myelitis which are analyzed in detail. The results are placed in the context of other published work on the use of neutrons in the treatment of lung cancer.  相似文献   
60.
A case of early childhood Coats's disease in a ten-month-old boy is presented. The lactic dehydrogenase aqueous:serum ratio was very high (6:1). A ratio higher than 3:1 in Coats's disease or in any other eye infection has never been reported except in cases of retinoblastoma. Since retinoblastoma does not always show calcification in x-rays, it may be concluded that in certain cases it would be impossible to discriminate between Coats's disease and retinoblastoma (except in pathologic analysis) with any available diagnostic tools.  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