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   782篇
  免费   39篇
耳鼻咽喉   4篇
儿科学   24篇
妇产科学   27篇
基础医学   142篇
口腔科学   7篇
临床医学   70篇
内科学   226篇
皮肤病学   23篇
神经病学   13篇
特种医学   13篇
外科学   112篇
综合类   45篇
一般理论   4篇
预防医学   37篇
眼科学   3篇
药学   63篇
肿瘤学   8篇
  2013年   4篇
  2010年   10篇
  2009年   4篇
  2008年   4篇
  2007年   6篇
  2005年   5篇
  2004年   6篇
  2003年   6篇
  1999年   9篇
  1998年   5篇
  1997年   18篇
  1996年   14篇
  1995年   11篇
  1994年   20篇
  1993年   15篇
  1992年   15篇
  1991年   9篇
  1990年   13篇
  1989年   21篇
  1988年   10篇
  1987年   12篇
  1986年   12篇
  1985年   16篇
  1984年   11篇
  1983年   17篇
  1982年   10篇
  1981年   5篇
  1980年   12篇
  1979年   10篇
  1978年   8篇
  1977年   8篇
  1976年   10篇
  1975年   4篇
  1974年   5篇
  1970年   4篇
  1968年   8篇
  1965年   3篇
  1964年   4篇
  1963年   5篇
  1962年   4篇
  1960年   9篇
  1959年   44篇
  1958年   83篇
  1957年   73篇
  1956年   55篇
  1955年   57篇
  1954年   49篇
  1949年   12篇
  1948年   32篇
  1947年   3篇
排序方式: 共有821条查询结果,搜索用时 15 毫秒
31.
32.
33.
34.
Since April 1974, 60 patients with squamous cell carcinoma of the head and neck region, of poor prognosis and generally in advanced stages, were treated with the combination of a cytotoxic regimen–VBM (Vincristine, Bleomycin and Methotrexate) and radical radiotherapy. The essential feature of the combination is the administration of pulses of VBM synchronous with a course of fractionated external radiotherapy in order to achieve potentiation of radiotherapy. On average 4-5 pulses of VBM were given during treatment, combined with radiotherapy on a Cobalt unit. The selection, preparation and management of the patients are described. Intense mucositis and intercurrent infection provide the main problems during treatment and close management is essential. Late complications have not been a serious problem. The crude actuarial survival rate at 24 months is 61%. The probability of survival without any recurrence to 24 months following initial treatment is 46%. Local control was achieved by the initial treatment in 43 patients. These results suggest that potentiation of radiotherapy and an increased therapeutic ratio has been obtained by the addition of VBM to radiotherapy and there is a possibility that the occurrence of distant metastases has been reduced or postponed.  相似文献   
35.
A single-dose pharmacokinetic study to determine the effectof age on the disposition of isoxicam and piroxicam was carriedout on a group of old and a group of young subjects Althoughthere was no significant difference with either drug in themean elimination half-time between the group of young and thegroup of old subjects, there was considerable individual variation.Steady-state levels were calculated to be three times as highin subjects with slow clearance as in those with more rapidclearance. Three weeks would be required with either drug toachieve steady-state drug levels in those subjects with slowdrug-clearance KEY WORDS: Pharmacokinetics, Nonsteroidal drugs, Elderly  相似文献   
36.
37.
Pharmacological doses of glucocorticoids inhibit TSH release both in vivo and in vitro and since the circadian rhythms of TSH and cortisol show a reciprocal relationship, the hypothesis has been advanced that changes in cortisol levels may be a primary determinant of circadian TSH changes. We have tested this hypothesis by studying the relationship between circadian cortisol and TSH rhythms in subjects before and during blockade with metyrapone. Seven patients were studied during their routine post-operative assessment following selective transethmoidal adenomectomy for microprolactinomas. PRL levels were restored to normal (less than 420 mU/l) in all patients by surgery (pre-op: 930-2752 mU/l, post-op: 33-376 mU/l) and the patients also had normal pituitary function in other respects. Blood was sampled hourly for 24 h before and on the third day of treatment with metyrapone (250 mg, 2 hourly). In order to compare circadian rhythms, hormonal data were subjected to cosinor analysis which involved fitting of the data with a cosine function using the method of least squares. The 6% cross reactivity of the cortisol antibody with 11-deoxycortisol was taken into account during the calculation of results. All subjects showed a normal cortisol rhythm which was strikingly blunted during metyrapone treatment. Group mean (+/- SD) TSH mesors, amplitudes and acrophases for control and metyrapone treated subjects were 1.5 +/- 0.26, 1.29 +/- 0.48; 0.46 +/- 0.26, 0.23 +/- 0.13 and -49 degrees +/- 9.8 degrees; -62 degrees +/- 2.7 degrees respectively.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
38.
The light microscopic appearance of the human tibialis anterior muscle is described based on conchotome biopsy specimens from seven healthy volunteers and 20 patients who presented with myalgia but who had no evidence of neuromuscular disease. The morphometric characteristics of these normal muscles are documented and the similarities and differences between the appearances of the tibialis anterior and other muscles discussed.  相似文献   
39.
Summary. Forty women with premenstrual tension received either placebo, 100, 200 or 400 mg danazol daily for 3 months in a pilot study arranged as a double-blind trial. Thirteen patients withdrew by the third month usually because they complained of no improvement. They had significantly higher pretrial symptom scores than those who continued. In patients treated with danazol, symptom scores for breast pain during the second and third months and for irritability, anxiety and lethargy during the third month were significantly ( P <0.05) lower than scores in those given placebo. Most symptoms improved on placebo in the first month but by the third month only three remained improved. In contrast eight symptoms were improved on 200 mg danazol by the third month. By the end of the trial more than 75% of patients who were still taking danazol were essentially free of breast pain, lethargy, anxiety and increased appetite, but results for other common symptoms were no better than with placebo.  相似文献   
40.
In order to investigate the role of melatonin on the neuroregulation of GH secretion, eight healthy male volunteers each underwent four separate tests in random order separated by at least 1 week. Following oral administration of melatonin (500 mg at -60 min and at -30 min) plasma GH levels were higher than after placebo at 45 min (mean +/- SEM 2.9 +/- 0.8 vs 0.9 +/- 0.4 ng/ml, P less than 0.01) and 60 min (mean +/- SEM 2.9 +/- 0.4 vs 0.8 +/- 0.1 ng/ml, P less than 0.05). Likewise, after prior administration of melatonin, GH responses to GRF 1-44 (1 micrograms/kg i.v. at 0 min) were greater than placebo plus GRF at 15 min (mean +/- SEM 22.4 +/- 6.1 ng/ml vs 11.3 +/- 2.3 ng/ml, P less than 0.05), 45 min (mean +/- SEM 26.2 +/- 5.3 ng/ml vs 13.3 +/- 2.5 ng/ml, P less than 0.01) and 60 min (mean +/- SEM, 24.7 +/- 7.4 ng/ml vs 11.1 +/- 2.5 ng/ml, P less than 0.05). In contrast we did not observe any effect of either 10(-9)M, 10(-7)M melatonin on in-vitro basal GH release and GH responses to 10(-8)M GRF by rat anterior pituitary cells in monolayer culture. These data suggest that melatonin plays a facilitatory role in the neuroregulation of GH secretion, probably by acting at the hypothalamic level.  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