全文获取类型
收费全文 | 242047篇 |
免费 | 21521篇 |
国内免费 | 5355篇 |
专业分类
耳鼻咽喉 | 3902篇 |
儿科学 | 4770篇 |
妇产科学 | 4008篇 |
基础医学 | 20919篇 |
口腔科学 | 8182篇 |
临床医学 | 22575篇 |
内科学 | 23271篇 |
皮肤病学 | 3396篇 |
神经病学 | 11870篇 |
特种医学 | 7139篇 |
外国民族医学 | 45篇 |
外科学 | 24904篇 |
综合类 | 38592篇 |
现状与发展 | 12篇 |
一般理论 | 24篇 |
预防医学 | 29564篇 |
眼科学 | 2512篇 |
药学 | 21909篇 |
380篇 | |
中国医学 | 26787篇 |
肿瘤学 | 14162篇 |
出版年
2024年 | 1049篇 |
2023年 | 4742篇 |
2022年 | 8914篇 |
2021年 | 11803篇 |
2020年 | 11545篇 |
2019年 | 12788篇 |
2018年 | 11145篇 |
2017年 | 9900篇 |
2016年 | 9151篇 |
2015年 | 8530篇 |
2014年 | 16244篇 |
2013年 | 16438篇 |
2012年 | 14367篇 |
2011年 | 15425篇 |
2010年 | 12374篇 |
2009年 | 10677篇 |
2008年 | 10038篇 |
2007年 | 10119篇 |
2006年 | 8733篇 |
2005年 | 7452篇 |
2004年 | 6218篇 |
2003年 | 5544篇 |
2002年 | 4331篇 |
2001年 | 3707篇 |
2000年 | 3238篇 |
1999年 | 2676篇 |
1998年 | 2243篇 |
1997年 | 1999篇 |
1996年 | 1711篇 |
1995年 | 1625篇 |
1994年 | 1475篇 |
1993年 | 1291篇 |
1992年 | 1169篇 |
1991年 | 1110篇 |
1990年 | 941篇 |
1989年 | 912篇 |
1988年 | 809篇 |
1987年 | 734篇 |
1986年 | 705篇 |
1985年 | 1989篇 |
1984年 | 2253篇 |
1983年 | 1428篇 |
1982年 | 1869篇 |
1981年 | 1342篇 |
1980年 | 1174篇 |
1979年 | 995篇 |
1978年 | 826篇 |
1977年 | 651篇 |
1976年 | 775篇 |
1975年 | 523篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Benign positional vertigo is a potentially disabling condition characterized by episodic vertigo following certain provocative head movements. In most patients it is self limiting; however, in a few it may prove intractable, causing considerable social morbidity. In these patients surgery may be considered. Surgery previously involved section of the vestibular or singular nerves, involving a significant risk to hearing and to the facial nerve. Ablation of the labyrinth may even be considered. The new surgical technique of occlusion of the posterior semicircular canal has proved to be curative in most patients with benign positional vertigo with little risk to hearing. This paper describes our experience of fenestration and occlusion of the posterior semicircular canal in four patients. 相似文献
83.
LYNDA E ALBERTYN 《Journal of Medical Imaging and Radiation Oncology》1992,36(1):17-22
Both systemic and local therapy, for conditions of the breast and unrelated to it, may produce manuno-graphic changes. Some of these are characteristic, such as the pattern of scarring seen in reduction mammo-plasty. In many other instances, however, the changes produced overlap features commonly seen in malignancy. A knowledge of the timing, natural history and spectrum of these changes will aid mammographic interpretation. 相似文献
84.
Andreas Jovanovic Engelbert A.J.M. Schulten Isaäc van der Waal 《Community dentistry and oral epidemiology》1992,20(2):94-96
The referral pattern of 140 Dutch patients with oral mucosal lesions, who had been referred to a Department of Oral & Maxillofacial Surgery and Oral Pathology, shows that patients with oral mucosal lesions consult the dentist as often as the family doctor as the first source of help or information. Furthermore, family doctors were much more used to refer patients with oral mucosal disease to medical specialists rather than to the dentist or the oral and maxillofacial surgeon. 相似文献
85.
小包装全氟丙烷气体动力学实验研究 总被引:1,自引:0,他引:1
为检验塑料小包装全氟丙烷气体(C3F8)在不同包装和储存方法时浓度变化,将装有5~7mlC3F8的聚氯乙烯小袋,根据不同储藏温度和外包装方法随机分成四组:(1)22℃聚乙烯外包装,(2)36℃聚乙烯外包装,(3)22℃铝箔真空外包装,(4)-29℃聚乙烯外包装;每一组C3F8小袋气体存放一定时间后,应用气相色谱分析方法进行浓度测量。结果:第3组C3F8浓度最高和稳定,第2组浓度随放置时间降低最明显,第4组是临床应用气体的储藏和包装方法,其30天样本浓度和第3组相等,但放置一年时浓度降低。结果显示:塑料小包装C3F8予以铝箔真空外包装是一种可行的方法,利于C3F8运输和普及;聚乙烯外包装的C3F8,应放在-29℃保存,时间不超过一年。 相似文献
86.
Systolic and diastolic blood pressures were measured on 254 monozygotic (MZ) and 260 dizygotic (DZ) male twin pairs, during middle age (average age 48 years) and at two later age points. Genetic and environmental components of covariation were modeled by time series. For both measures, shared environmental influences were absent and specific environmental influences were largely time-specific. Although heritability was about 0.5 at each time point, genetic variation present at middle age contributed only about 60% to that present 9 years later, the remaining 40% being new. Fifteen years later, at the third time point, no new genetic variation was evident, variation in individual differences being entirely attributable to genetic differences laid down at the two earlier ages. © 1993 Wiley-Liss, Inc. 相似文献
87.
88.
J. C. Mathers 《Journal of human nutrition and dietetics》1988,1(3):155-161
Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived. 相似文献
89.
Susumu Akimoto Yuzo Furuya Koichiro Akakura Jun Shimazaki Haruo Ito 《International journal of urology》1997,4(6):580-582
Background :
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
The aim of this study was to investigate the influence of osteoarthritis of lumbar vertebrae on serum bone formation and resorption marker levels of patients with benign prostatic hypertrophy (BPH).
Methods :
Serum levels of carboxyterminal propeptide of type I procollagen (PICP), alkaline phosphatase (ALP), carboxyterminaltelopeptide of type I collagen (ICTP), and prostate-specific antigen (PSA) were examined in 40 patients with BPH, and the presence of osteoarthritis at the lumbar vertebrae of the patients was evaluated by plain x-ray-p.
Results :
Findings of osteoarthritis were observed in 23 of the 40 patients (58%), and 10 of the patients had severe osteoarthritis (involving at least 2 lumbar vertebral bodies). The serum levels of PICP, ALP, ICTP, and PSA of the patients without osteoarthritis findings were not different from those of the patients with osteoarthritis or severe osteoarthritis.
Conclusion :
The influence of osteoarthritis on serum bone formation and resorption marker levels of patients with BPH appears to be rather slight, if there is any influence at all. 相似文献
90.
Mentosternal contractures still represent a surgical challenge due to their prominent position. They require early operative treatment for both function and aesthetic reasons. Careful clinical examination of scar position and traction forces, both at rest and when functioning, in addition to proper evaluation of the surrounding soft tissue are mandatory for precise preoperative planning of the required reconstruction. In general, the technically most feasible operation is favored if the functional and aesthetic results are good and postoperative risk for recurrence is low. Between 1987 and 1994, 21 patients with cervical, mentosternal, and mentothoracic contractures were operated upon. Eight patients were reconstructed with local flaps and 13 with microvascular free flaps. 相似文献