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   653篇
  免费   44篇
  国内免费   18篇
耳鼻咽喉   3篇
儿科学   23篇
妇产科学   31篇
基础医学   55篇
口腔科学   44篇
临床医学   54篇
内科学   128篇
皮肤病学   25篇
神经病学   12篇
特种医学   98篇
外科学   78篇
综合类   30篇
预防医学   37篇
眼科学   9篇
药学   31篇
  1篇
中国医学   1篇
肿瘤学   55篇
  2023年   7篇
  2022年   6篇
  2021年   8篇
  2020年   7篇
  2019年   9篇
  2018年   20篇
  2017年   17篇
  2016年   16篇
  2015年   14篇
  2014年   14篇
  2013年   20篇
  2012年   25篇
  2011年   23篇
  2010年   24篇
  2009年   32篇
  2008年   16篇
  2007年   39篇
  2006年   14篇
  2005年   14篇
  2004年   18篇
  2003年   13篇
  2002年   13篇
  2001年   5篇
  2000年   9篇
  1999年   9篇
  1998年   22篇
  1997年   37篇
  1996年   33篇
  1995年   18篇
  1994年   16篇
  1993年   18篇
  1991年   9篇
  1990年   4篇
  1989年   18篇
  1988年   20篇
  1987年   11篇
  1986年   14篇
  1985年   13篇
  1984年   9篇
  1983年   11篇
  1982年   6篇
  1981年   11篇
  1980年   8篇
  1979年   5篇
  1978年   5篇
  1977年   5篇
  1976年   5篇
  1975年   3篇
  1967年   4篇
  1965年   5篇
排序方式: 共有715条查询结果,搜索用时 46 毫秒
21.
Patients undergoing evaluation for solid organ transplantation (SOT) often have a history of malignancy. Although the cancer has been treated in these patients, the benefits of transplantation need to be balanced against the risk of tumor recurrence, especially in the setting of immunosuppression. Prior guidelines of when to transplant patients with a prior treated malignancy do not take in to account current staging, disease biology, or advances in cancer treatments. To develop contemporary recommendations, the American Society of Transplantation held a consensus workshop to perform a comprehensive review of current literature regarding cancer therapies, cancer stage-specific prognosis, the kinetics of cancer recurrence, and the limited data on the effects of immunosuppression on cancer-specific outcomes. This document contains prognosis based on contemporary treatment and transplant recommendations for breast, colorectal, anal, urological, gynecological, and nonsmall cell lung cancers. This conference and consensus documents aim to provide recommendations to assist in the evaluation of patients for SOT given a history of a pretransplant malignancy.  相似文献   
22.
Lymphoblasts in bone marrow samples, obtained from 43 children with acute lymphoblastic leukemia at diagnosis, were incubated with 1.0 mumols/L [3H] methotrexate for 24 hours in vitro. Nonexchangeable methotrexate and methotrexate polyglutamates were separated and quantitated. Event-free survival at 5 years was 38% +/- 9% for all 43 patients (27 failures), and 44% +/- 10% for the 35 with non-T, non-B- cell acute lymphoblastic leukemia (20 failures). Of these 35 children, those whose lymphoblasts accumulated more than 100 pmol methotrexate and 500 pmol methotrexate polyglutamates per billion cells experienced better 5-year event-free survival than those whose lymphoblasts did not (65% +/- 12% v 22% +/- 9%, P = .010). This difference characterized "good-risk" patients who were female (P = .014), less than age 7 at diagnosis (P = .005), or had low initial white blood cell counts (less than 20 X 10(9)/L, P = .018). Findings were similar for the 43 children with acute lymphoblastic leukemia and for the "good-risk" children in this total group. Thus, the ability of lymphoblasts to accumulate methotrexate and form methotrexate polyglutamates may be important to the curative properties of current therapy of acute lymphoblastic leukemia in children, particularly for "good-risk" patients. In such patients, inherent rather than acquired drug resistance may be the initial event leading to treatment failure.  相似文献   
23.
24.
普鲁卡因选择性涂丝电极稳定性的研究   总被引:2,自引:0,他引:2  
涂丝电极的应用已很广泛,但其稳定性差限制了它的进一步推广应用。本文找出普鲁卡因涂丝电极稳定性差的原因,制备了以聚乙烯醇(含盐酸普鲁卡因)为内参的Ag-Agcl丝涂(PVC)膜电极,其稳定性大为提高,并有良好的响应性能。  相似文献   
25.
Seven cases of lipomatous masses within the liver parenchyma were demonstrated with computed tomography (CT). Five of these cases were obtained from a retrospective review of 50 cases of renal angiomyolipoma in which the liver was adequately demonstrated. The other two cases were from the files of the Armed Forces Institute of Pathology and had no associated renal lesions. Three of the five cases were associated with tuberous sclerosis. In all seven cases, the fatty tumors appeared on CT scans as a well-defined, 0.8-13-cm mass, with attenuation coefficients of less than -30 HU. On ultrasound studies, the lesions were well circumscribed, highly echogenic, and similar to hemangiomas. While distinctly rare lesions, these lipomatous masses are not as unusual as the literature would indicate. One may anticipate such masses in patients with renal angiomyolipomas and in a relatively high percentage of those with tuberous sclerosis.  相似文献   
26.
本文研究了唐松草新碱在水溶液中的氧化降解动力学。考查了pH值、离子强度、温度和氧含量的影响,水溶液中的氧化降解速率常数由荧光法测定。结果表明,唐松草新碱在过量氧存在下,其氧化降解反应服从假一级反应动力学方程式,速率常数可由下式表示:其速率常数主要受介质的pH值和氧含量的影响,在pH 7.2条件下没有观测到原盐效应。  相似文献   
27.
Titelbaum  DS; Hayward  JC; Zimmerman  RA 《Radiology》1989,173(3):663-667
Studies of 23 pediatric patients with pachygyriclike changes (PLCs) examined with computed tomography (CT) and magnetic resonance (MR) imaging were reviewed to determine topographic patterns and correlate them with various clinical syndromes and degrees of neurologic impairment. Three types of topographic distributions were identified: unilateral, diffuse, and bilateral nondiffuse (of which eight of 10 showed frontotemporal predominance). PLCs were an isolated finding in seven patients, were associated with various congenital syndromes in nine patients, and were associated with congenital infection in seven patients, six of whom showed marked white matter abnormalities. Although most patients had severe developmental delay, three with nondiffuse PLCs had less severe impairment, permitting less required care.  相似文献   
28.
Intrahepatic arterial infusion of chemotherapy: clinical results   总被引:10,自引:0,他引:10  
Approximately 60% of patients diagnosed with colorectal cancer (CRC) will go on to develop hepatic metastases. Although surgical resection is the only curative modality, a majority will not be able to undergo surgery. Alternative methods for treating this population have focused on the feasibility of hepatic arterial infusion (HAI) of chemotherapy. Randomized data in this field have been hampered due to small numbers of patients in some trials, or crossover between groups. However, most trials have suggested an improvement in both overall and progression-free survival with HAI therapy. Dose-limiting toxicity associated with HAI is related to hepatobiliary sclerosis, which has been reduced with the use of dexamethasone as part of the treatment. Current research is underway to improve the rate of extrahepatic metastases in patients undergoing HAI.  相似文献   
29.
30.
OBJECTIVE: To examine the characteristics of infants suffering from failure to thrive in a community based cohort in Israel and to ascertain the effect of failure to thrive on their cognitive development. METHODS: By review of records maintained at maternal and child health clinics in Jerusalem and the two of Beit Shemesh, epidemiological data were obtained at age 15 months on a cohort of all babies born in 1991. For each case of failure to thrive, a matched control was selected from the same maternal and child health clinic. At age 20 months, cognitive development was measured, and at 25 months a home visit was carried out to assess maternal psychiatric status by questionnaire, and the HOME assessment was performed to assess the home environment. RESULTS: 3.9% of infants were found to have fallen below the third centile in weight for at least three months during the first year of life. Infants with failure to thrive did not differ from the general population in terms of obstetric or neonatal complications, birth order, or parents' ethnic origin, age, or years of education. The infants with failure to thrive did have lower birthweights and marginally smaller head circumferences at birth. Developmental assessment at 20 months of age showed a DQ of 99.7 v 107.2 in the matched controls, with 11.5% having a DQ below 80, as opposed to only 4.6% of the controls. No differences were found in maternal psychiatric problems as measured by a self report questionnaire. There were, however, significant differences in subscales of the HOME scale. CONCLUSIONS: (1) Infants who suffered from failure to thrive had some physiological predispositions that put them at risk; (2) failure to thrive may be an early marker of families providing suboptimal developmental stimulation.  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