全文获取类型
收费全文 | 2194篇 |
免费 | 175篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 107篇 |
妇产科学 | 45篇 |
基础医学 | 214篇 |
口腔科学 | 26篇 |
临床医学 | 221篇 |
内科学 | 497篇 |
皮肤病学 | 14篇 |
神经病学 | 212篇 |
特种医学 | 214篇 |
外科学 | 158篇 |
综合类 | 34篇 |
一般理论 | 117篇 |
预防医学 | 233篇 |
眼科学 | 52篇 |
药学 | 122篇 |
1篇 | |
肿瘤学 | 103篇 |
出版年
2023年 | 12篇 |
2022年 | 15篇 |
2021年 | 36篇 |
2020年 | 14篇 |
2019年 | 26篇 |
2018年 | 39篇 |
2017年 | 33篇 |
2016年 | 22篇 |
2015年 | 30篇 |
2014年 | 30篇 |
2013年 | 60篇 |
2012年 | 66篇 |
2011年 | 91篇 |
2010年 | 59篇 |
2009年 | 57篇 |
2008年 | 93篇 |
2007年 | 69篇 |
2006年 | 78篇 |
2005年 | 74篇 |
2004年 | 77篇 |
2003年 | 62篇 |
2002年 | 52篇 |
2001年 | 58篇 |
2000年 | 77篇 |
1999年 | 71篇 |
1998年 | 39篇 |
1997年 | 37篇 |
1996年 | 56篇 |
1995年 | 41篇 |
1994年 | 44篇 |
1993年 | 40篇 |
1992年 | 55篇 |
1991年 | 59篇 |
1990年 | 59篇 |
1989年 | 78篇 |
1988年 | 59篇 |
1987年 | 60篇 |
1986年 | 61篇 |
1985年 | 57篇 |
1984年 | 32篇 |
1983年 | 29篇 |
1982年 | 32篇 |
1981年 | 24篇 |
1980年 | 23篇 |
1979年 | 23篇 |
1977年 | 22篇 |
1976年 | 27篇 |
1975年 | 19篇 |
1967年 | 13篇 |
1966年 | 17篇 |
排序方式: 共有2379条查询结果,搜索用时 15 毫秒
171.
172.
To improve faculty participation in providing feedback on resident outpatient practice, we designed and implemented an Internet-based
evaluation system. Attending physicians scord residents on 7 questions related to specific practice behaviors, and completed
a free-text comment section. Between January and June 1998, 516 evaluations for 107 residents were generated using the Internet-based
system, compared with 29 handwritten evaluations for 82 residents between January and June 1997. The number of faculty evaluations
was 527 for 121 residents in the second half of 1998. An Internet-based evaluation system can improve faculty compliance with
performing evaluations. 相似文献
173.
174.
Tecle H Schwarz RD Barrett SD Callahan MJ Caprathe BW Davis RE Doyle P Emmerling M Lauffer DJ Mirzadegan T Moreland DW Lipiniski W Nelson C Raby C Spencer C Spiegel K Thomas AJ Jaen JC 《Pharmaceutica acta Helvetiae》2000,74(2-3):141-148
The five muscarinic receptor subtypes (M1-M5) are characterized by seven helices that define a transmembrane cavity which serves as the binding pocket for agonists and antagonists. The five cavities appear to be topographically different enough to permit subtype selectivity among antagonists but not among classical agonists which tend to be smaller in size than antagonists. It was reasoned that synthesis of muscarinic agonists longer/larger than their classical counterparts might result in subtype selectivity. M1 subtype selectivity was found in a class of 1-azabicyclo[2.2.1]heptan-3-one, O-(3-aryl-2-propynyl) oximes. One of these, CI-1017, improved spatial memory of hippocampally deficient mice and nbM-lesioned rats at doses of 1.0-3.2 and 0.1-0.3 mg/kg, respectively, while producing parasympathetic side effects only at very high doses (100-178 mg/kg). Additionally, CI-1017 inhibited production of amyloidogenic A beta and increased secretion of soluble APP. Thus, CI-1017, besides treating AD symptomatically, may also retard its progression. CI-1017 has recently completed phase I clinical trials. 相似文献
175.
176.
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
177.
Prevalence of risk factors for cardiovascular disease in Canadians 55 to 74 years of age: results from the Canadian Heart Health Surveys, 1986-1992 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
DB Langille MR Joffres KM MacPherson P Andreou SA Kirkland DR MacLean 《Canadian Medical Association journal》1999,161(8):S3-S9
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
178.
179.
A female infant displaying morphological and clinical abnormalities is described. She had severe developmental delay, intrauterine growth retardation, and failure to thrive. Her features included an elfin facies, body and facial hirsutism, buttonlike nipples and prominent clitoris and labia. Endocrinological evaluation revealed markedly elevated serum gonadotropin levels. An LHRH stimulation test showed no LH response to LHRH but a rapid and pronounced FSH response. The patient died at 13 months following a respiratory infection. Postmortem examination revealed normal pituitary histology but an unusual pancreatic histology characterized by total absence of acinar cells. This patient had features suggestive of several clinical syndromes including leprechaunism, Shwachman syndrome, and Johanson-Blizzard syndrome, none of which, was completely satisfied. It is concluded that the infant may represent an atypical case of leprechaunism or a previously undescribed syndrome. 相似文献
180.