全文获取类型
收费全文 | 1759篇 |
免费 | 111篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 41篇 |
妇产科学 | 35篇 |
基础医学 | 233篇 |
口腔科学 | 43篇 |
临床医学 | 215篇 |
内科学 | 389篇 |
皮肤病学 | 44篇 |
神经病学 | 171篇 |
特种医学 | 44篇 |
外科学 | 191篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 206篇 |
眼科学 | 12篇 |
药学 | 153篇 |
中国医学 | 4篇 |
肿瘤学 | 75篇 |
出版年
2023年 | 10篇 |
2022年 | 28篇 |
2021年 | 27篇 |
2020年 | 33篇 |
2019年 | 46篇 |
2018年 | 53篇 |
2017年 | 61篇 |
2016年 | 45篇 |
2015年 | 51篇 |
2014年 | 45篇 |
2013年 | 73篇 |
2012年 | 116篇 |
2011年 | 112篇 |
2010年 | 69篇 |
2009年 | 58篇 |
2008年 | 103篇 |
2007年 | 124篇 |
2006年 | 111篇 |
2005年 | 105篇 |
2004年 | 88篇 |
2003年 | 75篇 |
2002年 | 61篇 |
2001年 | 17篇 |
2000年 | 21篇 |
1999年 | 14篇 |
1998年 | 12篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 22篇 |
1991年 | 20篇 |
1990年 | 23篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 20篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1981年 | 5篇 |
1979年 | 5篇 |
1978年 | 14篇 |
1977年 | 4篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1970年 | 5篇 |
1969年 | 4篇 |
1966年 | 11篇 |
排序方式: 共有1872条查询结果,搜索用时 15 毫秒
1.
K Thomsen B J Riis J S Johansen C Christiansen P R?dbro 《Gynecological endocrinology》1987,1(2):169-175
Bone turnover before and after withdrawal of estrogen/gestagen treatment was studied in a randomized trial with 110 healthy female volunteers, who had passed a natural menopause 6 months to 3 years before the start of the study. Urinary excretion of intravenously injected 99m-technetium diphosphonate was measured as an index of bone turnover; plasma bone Gla protein and serum alkaline phosphatase were measured as indices of bone formation; and fasting urinary excretion of hydroxyproline and calcium were measured as estimates of bone resorption. During 2 years of hormone treatment, all variables decreased highly significantly (p less than 0.001) to a constant low level. Three months after withdrawal all variables increased highly significantly (p less than 0.001) towards, but not above, pretreatment and placebo levels. We conclude that withdrawal of estrogen/gestagen replacement therapy in postmenopausal women increases bone turnover, but not in excess of pretreatment values. This indicates that bone loss (after withdrawal) is similar to that seen in the placebo group and that a rebound phenomenon is unlikely. 相似文献
2.
3.
4.
Conservative treatment for acute rupture of the Achilles tendon 总被引:1,自引:0,他引:1
Summary Sixty-six patients with acute ruptures of the Achilles tendon were treated by immobilisation in a plaster cast for 12 weeks. Fifty-seven were followed up for a mean time of 70 months. Four re-ruptures occurred shortly after the initial treatment. Most patients had no or only slight complaints, three had moderate and one severe, problems. The activity level dropped slightly from 5.3 to 5.03 (Tegner score). The results are satisfactory with a low complication rate. The method is an alternative to operative repair, especially in patients declining operation and in those in whom operation or anaesthesia is contraindicated.
Résumé Soixante-six malades ont fait l'objet d'une étude à long terme concernant le traitement non-chirurgical des ruptures aiguës du tendon d'Achille. Le recul moyen était de 70 mois. Les patients avaient été immobilisés dans un plâtre pendant 12 semaines. 4 ruptures itératives survinrent précocément (6%). La plupart des malades n'avaient pas ou peu de séquelles, trois seulement se plaignaient d'une gêne modérée et 1 d'une gêne importante. Le niveau d'activité avait légérement diminué, de 5.3 à 5.03 (selon le score de Tegner). Les résultats paraissaient satisfaisants dans l'ensemble, avec une taux peu élevé de ruptures itératives ou d'autres complications. La méthode constitue une alternative valable au traitement chirurgical, notamment chez les sujets qui ne veulent pas être opérés ou chez ceux qui présentent des contrindications à l'anesthésie ou à la chirurgie.相似文献
5.
Bente E. Moen Bjrg E. Hollund Morten Berntsen Ragnar Flo Knut Rasmus Kyvik Trond Riise 《American journal of industrial medicine》1995,27(4):555-564
Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated. 相似文献
6.
We investigaed changes in the anterior tibial muscle during lengthening of the lower leg in rabbits. In 37 rabbits, an osteotomy of the right middle tibia was performed and was fixed by a unilateral external fixator. The rabbits were randomized into 6 groups. In groups 1, 2, and 3 the tibiae were distracted 0.5 mm/day. In groups 1 and 2, the rabbits were killed after 14 and 28 days of distraction, respectively, and in group 3 after 28 days of distraction, followed by 14 days of rest. Groups 1a, 2a, and 3a served as controls. They were treated similarly as groups 1, 2, and 3, but no distracton was performed. Proliferating cell nuclei were labeled with 5-bromo-2-deoxyuridine and were identified by immunohistochemical staining. The weight of the muscle was measured. During bone lengthening the muscle showed signs of growth, as indicated by increasing weight and number of proliferating cell nuclei. This was observed only during lengthening and it ceased when the lengthening was stopped. 相似文献
7.
P Riis 《Journal of medical ethics》1991,17(1):41
The complex of cultural, political and societal affiliations, both in a historic and a contemporary perspective, is expressed by a special term in the Nordic languages, 'faellesskab', often with the addition of 'folkelig', as 'folkeligt faellesskab', where 'folkelig' means of the people. No corresponding term exists in English. For medical ethics the concept 'faellesskab', or whatever wording is chosen to serve the semantics of this term, is vital. In research ethics and clinical decision-making complex ethical analyses and normative evaluations are necessary. They cannot be based solely on moral relativism, whether being based on results of opinion polls or on a widespread 'every man minds his own business' concept. 'Faellesskab' possesses the necessary base of common values. 相似文献
8.
Background
Despite considerable knowledge about musculoskeletal disorders (MSD) and physical, psychosocial and individual risk factors there is limited knowledge about physical activity as a factor in preventing MSD. In addition, studies of physical activity are often limited to either leisure activity or physical activity at work. Studies among military personnel on the association between physical activity at work and at leisure and MSD are lacking. This study was conducted to find the prevalence of MSD among personnel in the Royal Norwegian Navy and to assess the association between physical activity at work and at leisure and MSD. 相似文献9.
Erik A. Richter Bente Sonne Kari J. Mikines Thorkil Ploug Henrik Galbo 《European journal of applied physiology》1984,52(3):346-350
Summary We have previously found that during exercise net muscle glycogen breakdown is impaired in adrenodemedullated rats, as compared with controls. The present study was carried out to elucidate whether, in rats with deficiencies of the sympatho-adrenal system, diminished exercise-induced glycogenolysis in skeletal muscle was accompanied by increased breakdown of triglyceride and/or protein. Thus, the effect of exhausting swimming and of running on concentrations of glycogen, protein, and triglyceride in skeletal muscle and liver were studied in rats with and without deficiencies of the sympatho-adrenal system. In control rats, both swimming and running decreased the concentration of glycogen in fast-twitch red and slow-twitch red muscle whereas concentrations of protein and triglyceride did not decrease. In the liver, swimming depleted glycogen stores but protein and triglyceride concentrations did not decrease. In exercising rats, muscle glycogen breakdown was impaired by adrenodemedullation and restored by infusion of epinephrine. However, impaired glycogen breakdown during exercise was not accompanied by a significant net breakdown of protein or triglyceride. Surgical sympathectomy of the muscles did not influence muscle substrate concentrations. The results indicate that when glycogenolysis in exercising muscle is impeded by adrenodemedullation no compensatory increase in breakdown of triglyceride and protein in muscle or liver takes place. Thus, indirect evidence suggests that, in exercising adrenodemedullated rats, fatty acids from adipose tissue were burnt instead of muscle glycogen. 相似文献
10.
Penkowa M Keller P Keller C Hidalgo J Giralt M Pedersen BK 《Experimental physiology》2005,90(4):477-486
Exercise induces free oxygen radicals that cause oxidative stress, and metallothioneins (MTs) are increased in states of oxidative stress and possess anti-apoptotic effects. We therefore studied expression of the antioxidant factors metallothionein I and II (MT-I + II) in muscle biopsies obtained in response to 3 h of bicycle exercise performed by healthy men and in resting controls. Both MT-I + II proteins and MT-II mRNA expression increased significantly in both type I and II muscle fibres after exercise. Moreover, 24 h after exercise the levels of MT-II mRNA and MT-I + II proteins were still highly increased and the MT-II mRNA expression reached a 15-fold increase. As expected, immunohistochemical detection of malondialdehyde (MDA) and nitrotyrosine (NITT) showed that formation of free radicals and oxidative stress were clearly increased in exercising muscle peaking shortly after the end of exercise in both type I and II muscle fibres. This is the first report demonstrating that MT-I + II are significantly induced in human skeletal muscle fibres following exercise. As MT-I + II are antioxidant factors that protect various tissues during pathological conditions, the MT-I + II increases post exercise may represent a mechanism whereby contracting muscle fibres are protected against cellular stress and injury. 相似文献