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   333篇
  免费   23篇
  国内免费   10篇
耳鼻咽喉   1篇
儿科学   32篇
基础医学   28篇
口腔科学   6篇
临床医学   42篇
内科学   53篇
皮肤病学   4篇
神经病学   4篇
特种医学   132篇
外科学   8篇
综合类   6篇
预防医学   10篇
药学   19篇
  1篇
肿瘤学   20篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   4篇
  2017年   3篇
  2016年   1篇
  2015年   2篇
  2013年   5篇
  2012年   3篇
  2011年   3篇
  2010年   4篇
  2009年   8篇
  2008年   5篇
  2007年   12篇
  2006年   11篇
  2005年   3篇
  2004年   4篇
  2003年   2篇
  2002年   1篇
  2001年   6篇
  2000年   4篇
  1999年   10篇
  1998年   18篇
  1997年   15篇
  1996年   27篇
  1995年   15篇
  1994年   21篇
  1993年   16篇
  1992年   3篇
  1991年   6篇
  1990年   6篇
  1989年   18篇
  1988年   15篇
  1987年   19篇
  1986年   11篇
  1985年   10篇
  1984年   8篇
  1983年   12篇
  1982年   10篇
  1981年   9篇
  1980年   8篇
  1979年   5篇
  1978年   1篇
  1977年   6篇
  1976年   9篇
  1975年   2篇
排序方式: 共有366条查询结果,搜索用时 15 毫秒
21.
Serum thyrotrophin (TSH) was estimated by double-antibody radioimmunoassay in 200 children aged 2 months to 16 years with normal thyroid function. There was no apparent variation in TSH with age or sex and only 4 children had TSH levels greater than 5 muU/ml. High TSH values were obtained in 9 children with primary hypothyroidism, in 3 children with thyroiditis, and in one girl with a lingual thyroid. Moderately raised TSH was found in 3 girls with thyroiditis, 2 brothers with goitres due to enzyme defect, and a girl with an ectopic thyroid. In one girl with a defect of iodine organification and in 3 boys with thyroxine binding globulin deficiency the TSH levels were normal despite very low serum thyroxine values. Serum TSH was also estimated in 20 children during treatment for primary hypothyroidism. 3 of these children showed slightly raised TSH levels despite apparently adequate replacement therapy with L-thyroxine. One girl showed a very high TSH level 3 weeks after treatment had been temporarily withdrawn.  相似文献   
22.
23.
美国约有30%的糖尿病患者(约620万人)被漏诊。超过25%的新诊断糖尿病患者已经患有糖尿病视网膜病变或出现微量白蛋白尿,这意味着患者在2型糖尿病发病和确诊之间被“忽视”了7年。有时发现在糖尿病前期,即空腹血糖(FPG)略有偏高(IFG,空腹血糖受损)或口服葡萄糖耐量试验(OGTT)略有偏高,甚至已存在微血管和大血管并发症。  相似文献   
24.
BACKGROUND: By 2016, the proportion of Canadians older than 65 years of age will increase to 16%, and there will be an increase in the absolute number of cases of cardiovascular disease in older Canadians. The Canadian Heart Health Surveys database provides information about this population upon which health policy related to cardiovascular disease can be based. This paper presents for the first time population-based data on the risk factors for cardiovascular disease in older Canadians. METHODS: Canadians from all 10 provinces participated in surveys of cardiovascular risk factors; health insurance registries were used as sampling frames. In each province, probability samples of 2200 adults 18 to 74 years old not living in institutions, on reserves or in military camps were asked to participate in interviews and to undergo testing at clinics for major risk factors for cardiovascular disease. RESULTS: A total of 2739 men (response rate 70%) and 2617 women (response rate 66%) aged 55 to 74 years participated in the survey and also provided follow-up clinical measurements at the clinic. Overall, 52% of participants were hypertensive, 26% had isolated systolic hypertension, and 30% had a total blood cholesterol level of 6.2 mmol/L or greater. Rates of current smoking were lower in women than men (17% v. 22%). Overall, 87% of men and 78% of women who were current smokers smoked at least 10 cigarettes per day. Only slightly more than half of participants exercised at least once a week for at least 15 minutes, and almost half had a body mass index of 27 or greater. In only 4% was no major risk factor for cardiovascular disease detected. INTERPRETATION: Significant numbers of older Canadians have one or more major risk factors for cardiovascular disease. Many of these risk factors are amenable to modification.  相似文献   
25.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml ̄(-1)诱导HL-60细胞发生凋亡,而阻断HR20细胞于G_1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml ̄(-1)处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G_1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关  相似文献   
26.
进一步研究了抗三尖杉酯碱的HL-60细胞(HR20)抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明,环孢菌素A(CsA)20,10μg·ml-1诱导HL-60细胞发生凋亡,而阻断HR20细胞于G1期,就不能诱导细胞发生凋亡。低浓度的CsA明显增加柔红霉素在HR20细胞内的积聚,其逆转抗药性作用与阻断细胞周期运行无关。CsA10μg·ml-1处理HR20细胞,可引起50kDa的蛋白质高度磷酸化。结果提示:环孢菌素A阻断抗三尖杉酯碱的HL-60细胞于G1期,而诱导敏感的HL-60细胞发生凋亡,其阻断作用与抗药性无关。  相似文献   
27.
28.
Mediastinal tumors: biopsy under US guidance   总被引:8,自引:0,他引:8  
Percutaneous biopsies of mediastinal tumors were successfully performed under sonographic guidance in 14 of 21 patients. In 10 of 11 malignant lesions, malignancy was determined by means of cytologic and histologic examination of the specimens obtained. A histologic diagnosis was reached in seven patients with malignant mediastinal tumors, including all four cases of Hodgkin lymphoma. Mediastinal biopsy under sonographic guidance is a technically simple, rapid, and accurate procedure, but its application is limited to tumors of the anterior mediastinum.  相似文献   
29.
Occult cerebral vascular malformations: high-field MR imaging   总被引:4,自引:0,他引:4  
Occult cerebral vascular malformations (OCVMs) have characteristic appearances on high-field magnetic resonance (MR) images. These consist of circumscribed regions of low intensity, most prominent on T2-weighted images and representing hemosiderin deposits. Interspersed within most of these lesions are multiple areas of various signal intensity patterns, which correspond to hematomas in different stages of evolution and to fibrous regions containing calcium as well as hemosiderin. Forty-six lesions were found in 19 patients (34 supratentorial and 12 infratentorial). The supratentorial lesions tended to be subcortical or periventricular. Computed tomography depicted 24 of the 46 lesions demonstrated by high-field MR. Comparison of images obtained with both low-field MR (0.12 T and 0.35 T) and high-field MR (1.5 T) revealed that high-field MR imaging was superior in depicting OCVMs. High-field MR appears to be both sensitive and specific for OCVMs and may obviate the need for possible biopsy of these lesions.  相似文献   
30.
Classification of familial amyloidosis by the chemical natureof the fibrillar protein has become possible. Most such amyloidogenicproteins so far recognized are variant transthyretins, but twokindreds with the same apolipoprotein AI modification have beenreported. We describe the clinical features of another suchfamily in whom petechial skin rash appeared to be a marker forthe disease, which was non-neuropathic and of the Ostertag-type.Immunohistochemistry showed the protein to be apolipoproteinAI, but allele-specific DNA amplification indicated that itwas not the Arg26 variant previously identified.  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