全文获取类型
收费全文 | 273345篇 |
免费 | 11513篇 |
国内免费 | 5654篇 |
专业分类
耳鼻咽喉 | 3345篇 |
儿科学 | 8415篇 |
妇产科学 | 7096篇 |
基础医学 | 34687篇 |
口腔科学 | 7332篇 |
临床医学 | 25219篇 |
内科学 | 47050篇 |
皮肤病学 | 5338篇 |
神经病学 | 15912篇 |
特种医学 | 13484篇 |
外国民族医学 | 129篇 |
外科学 | 36669篇 |
综合类 | 14043篇 |
现状与发展 | 14篇 |
一般理论 | 13篇 |
预防医学 | 21629篇 |
眼科学 | 6380篇 |
药学 | 22115篇 |
82篇 | |
中国医学 | 4457篇 |
肿瘤学 | 17103篇 |
出版年
2022年 | 2929篇 |
2021年 | 4186篇 |
2020年 | 3177篇 |
2019年 | 2705篇 |
2018年 | 6264篇 |
2017年 | 6341篇 |
2016年 | 5484篇 |
2015年 | 8377篇 |
2014年 | 8573篇 |
2013年 | 7419篇 |
2012年 | 15860篇 |
2011年 | 11104篇 |
2010年 | 6318篇 |
2009年 | 7095篇 |
2008年 | 6390篇 |
2007年 | 6903篇 |
2006年 | 6789篇 |
2005年 | 14811篇 |
2004年 | 15230篇 |
2003年 | 10589篇 |
2002年 | 5558篇 |
2001年 | 6156篇 |
2000年 | 3598篇 |
1999年 | 7828篇 |
1998年 | 1809篇 |
1997年 | 1539篇 |
1992年 | 7420篇 |
1991年 | 7609篇 |
1990年 | 7774篇 |
1989年 | 7338篇 |
1988年 | 6785篇 |
1987年 | 6540篇 |
1986年 | 6204篇 |
1985年 | 5435篇 |
1984年 | 3729篇 |
1983年 | 3003篇 |
1979年 | 3883篇 |
1978年 | 2388篇 |
1977年 | 1804篇 |
1976年 | 1587篇 |
1975年 | 2495篇 |
1974年 | 3128篇 |
1973年 | 2760篇 |
1972年 | 2782篇 |
1971年 | 2756篇 |
1970年 | 2579篇 |
1969年 | 2480篇 |
1968年 | 2248篇 |
1967年 | 2181篇 |
1966年 | 1919篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
181.
C. Sch?fer H. H. Klünemann B. Ibach J. Mueller A. Putzhammer I. Trender-Gerhard G. Schuierer H. E. Klein 《Der Nervenarzt》2002,24(1):879-882
Wir berichten über den ersten Fall von polyzystischer lipomembran?ser Osteodysplasie oder “brain, bone and fat disease” in
Deutschland. Die nach dem Erstbeschreibern auch als Morbus J?rvi-Hakola-Nasu bezeichnete Erkrankung ist bisher vor allem in
Japan und in Finnland beschrieben worden. Einzelne F?lle wurden aus Schweden, Norwegen, Italien, Südafrika, Belgien und den
USA berichtet. Im deutschsprachigen Raum ist bisher ein Fall aus ? ver?ffentlicht worden. 相似文献
182.
目的:探讨精索静脉血张患者血浆睾酮水平的变化及其机制。方法:对25例精索静脉曲张患者与22例腹股沟斜疝患者精索静脉和外周血睾酮水平进行对照研究。结果:精索静脉曲张组外周血睾酮浓度与腹股沟斜疝组无差别(P>0.05),而精索静脉血睾酮浓度两组则有明显差异,精索静脉曲张组精索静脉血中睾酮浓度较腹股沟斜疝组低(P<0.05)。结论:多种因素可影响外周血睾酮浓度,使其难以准确地反映睾丸分泌睾酮的实际水平,而精索静脉血中的睾酮浓度则能较为直接地反映睾丸的睾酮分泌能力。 相似文献
183.
复方华蟾胶囊抗小鼠肿中瘤作用的实验研究 总被引:2,自引:0,他引:2
目的了解复方华蟾胶囊抗小鼠移植性肿瘤的作用.方法以小鼠肝癌22(H22)、小鼠肉瘤180(S180)为瘤株,应用动物移植性肿瘤的体内试验法对药物进行抗癌药效学试验.结果复方华蟾胶囊灌胃4,2 g/kg@d,连续14 d,对小鼠移植性肝癌实体型生长有明显的抑制作用,抑瘤率分别为38.09%,30.95%.对小鼠移植性S180实体型生长有明显的抑制作用,抑瘤率分别为34.7%,30.08%.复方华蟾胶囊对荷瘤小鼠的胸腺和脾脏重量无影响.结论复方华蟾胶囊在试验条件下有一定抗肿瘤作用. 相似文献
184.
P Rubin S Holm L Friberg P Videbech H S Andersen B B Bendsen N Str?ms? J K Larsen N A Lassen R Hemmingsen 《Archives of general psychiatry》1991,48(11):987-995
To measure prefrontal and subcortical activity during a cognitive task, we examined 19 newly diagnosed schizophrenics and patients with schizophreniform psychosis. Seven healthy volunteers served as controls. The patients were drug naive or had received neuroleptics for a few days only. Cerebral blood flow distribution was depicted by single photon emission computed tomography at rest and during activation with the Wisconsin Card Sorting Test. A significant relative activation deficit in the left inferior-prefrontal region was revealed during the Wisconsin Card Sorting Test in the patient group. Furthermore, the patients had impaired striatal suppression on the left side during the cognitive task. The test performance was significantly impaired in the patients. The inability to reduce striatal activity may be due to a lack of corticostriatal feedback during prefrontal activation. 相似文献
185.
Dependence of blood clot lysis on the mode of transport of urokinase into the clot--a magnetic resonance imaging study in vitro 总被引:4,自引:0,他引:4
A Blinc G Planinsic D Keber O Jarh G Lahajnar A Zidans?k F Demsar 《Thrombosis and haemostasis》1991,65(5):549-552
Magnetic resonance imaging was employed to study the dependence of clot lysing patterns on two different modes of transport of urokinase into whole blood clots. In one group of clots (nonperfused clots, n1 = 10), access of urokinase to the fibrin network was possible by diffusion only, whereas in the other group (perfused clots, n2 = 10) bulk flow of plasma containing urokinase was instituted through occlusive clots by a pressure difference of 3.7 kPa (37 cm H2O) across 3 cm long clots with a diameter of 4 mm. It was determined separately that this pressure difference resulted in a volume flow rate of 5.05 +/- 2.4 x 10(-2) ml/min through occlusive clots. Perfused clots diminished in size significantly in comparison to nonperfused ones already after 20 min (p less than 0.005). Linear regression analysis of two-dimensional clot sizes measured by MRI showed that the rate of lysis was more than 50-times faster in the perfused group in comparison to the nonperfused group. It was concluded that penetration of the thrombolytic agent into clots by perfusion is much more effective than by diffusion. Our results might have some implications for understanding the differences in lysis of arterial and venous thrombi. 相似文献
186.
国产头孢三嗪在急性感染病人中的药代动力学 总被引:1,自引:0,他引:1
静脉滴注国产头孢三嗪0.5~1克,治疗8例急性感染病人的药代动力学。静注后半小时用HPLC测得的平均血药浓度为100.75μg/ml,24小时的血药浓度为11.4μg/ml,国产头孢三嗪的药代动力学特点与国外同类产品基本一致。半衰期长,清除半衰期为8.8小时,可在血液和感染部位中保持较长时间的杀菌和抑菌浓度,总表观分布容积为13.0L/kg,表明药物在组织中的浓度高。本品用量小,每日1克1~2次即可达到疗效。5例慢性胆囊炎伴胆石症患者静滴头孢三嗪1克后,2小时胆汁的平均药物浓度为1022.8μg/ml,可作为治疗胆道感染的有效药物。 相似文献
187.
本文报告用亚致死剂量的 S—31183(类保幼激素)处理三带喙库蚊幼虫对其发育影响的研究,结果表明处理后蛹期死亡率明显高于幼虫期,并且与剂量大小有关。S—31183处理幼虫并不影响幼虫的发育时间,但可使幼虫化蛹时蜕皮受阻与羽化受到一定的抑制。 相似文献
188.
H Matej M Ka?amarz B Nowakowska J Pacyńska A Myc 《Archivum immunologiae et therapiae experimentalis》1989,37(1-2):115-120
In our work we investigated factors which can influence the alloimmunization and especially the ranges of cytotoxic antibodies that develop in patients on dialysis awaiting their first graft. Up to 15 liters of administered blood the proportion of immunized patients is rather stabile, not exceeding 50%. After further transfusions the percentage of immunized patients is growing rapidly reaching about 85%. Hyperimmunization, marked by cytotoxic antibodies with more than 80% panel reactivity is significantly more frequent in patients who obtained 15 and more liters of blood. In females the hyperimmunization is about 4 times more frequent than in males. 相似文献
189.
Adult body height, self perceived health and mortality in the Swedish population. 总被引:10,自引:8,他引:2
下载免费PDF全文
![点击此处可从《Journal of epidemiology and community health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
STUDY OBJECTIVE: The purpose of the study was to examine adult body height as an indicator of general health. DESIGN: The study was a survey of a randomly selected sample of the adult Swedish population obtained by the Swedish National Central Bureau of Statistics. PARTICIPANTS: The sample studied was identified in 1980-81 and comprised 14,757 persons aged 16-74. Of these, 12,695 (86%) consented to interview. MEASUREMENTS AND MAIN RESULTS: Information was obtained on adult height, socioeconomic status in childhood and adult life, self perceived health, self reported longstanding illness, and mortality during a six year follow up. The numbers of people in three height groups who considered their general health as bad, who reported any longstanding illness or who died during the follow up were compared with the expected numbers in the same groups. The number of persons with reduced health and the number of deaths was larger than expected in the shortest height group. The excess risk of dying in the shortest group (about 20% higher compared to the tallest group) was reduced but not eliminated when present and childhood socioeconomic group was taken into account. Coronary heart disease mortality in particular was linked to height. The shortest group of men and women reported the largest proportion with bad general health and longstanding illness. For the latter the differences between height groups disappeared after controlling for present socioeconomic status. CONCLUSIONS: There is a detectable excess risk of morbidity and mortality from being short. Assuming that the childhood environment is an important determinant of adult stature it is also important for adult health. 相似文献
190.
I Immonen K Friberg C Gr?nhagen-Riska E von Willebrand F Fyhrquist 《Acta ophthalmologica》1986,64(5):519-521
Angiotensin-converting enzyme (ACE) was studied immunohistochemically in conjunctival biopsies from 6 patients with systemic sarcoidosis, 4 patients with posterior non-sarcoid uveitis and in specimens from 4 patients with chalazion of the eyelid. Specimens with sarcoid granulomas showed intense ACE-positive immunoreactivity in epitheloid cells of the granuloma, whereas chalazion granulomas did not contain ACE-immunoreactivity. There was no difference in staining patterns between specimens without granulomas. Thus immunohistochemical staining for ACE may be of help in differentiating conjunctival granulomatous tissue of a chalazion from sarcoid granuloma. 相似文献