全文获取类型
收费全文 | 149425篇 |
免费 | 30893篇 |
国内免费 | 2390篇 |
专业分类
耳鼻咽喉 | 5160篇 |
儿科学 | 5339篇 |
妇产科学 | 2394篇 |
基础医学 | 2904篇 |
口腔科学 | 1463篇 |
临床医学 | 26509篇 |
内科学 | 46857篇 |
皮肤病学 | 7414篇 |
神经病学 | 14625篇 |
特种医学 | 6302篇 |
外科学 | 40708篇 |
综合类 | 232篇 |
现状与发展 | 72篇 |
预防医学 | 6931篇 |
眼科学 | 3311篇 |
药学 | 859篇 |
中国医学 | 6篇 |
肿瘤学 | 11622篇 |
出版年
2024年 | 684篇 |
2023年 | 4782篇 |
2022年 | 1181篇 |
2021年 | 3044篇 |
2020年 | 6010篇 |
2019年 | 2124篇 |
2018年 | 7346篇 |
2017年 | 7303篇 |
2016年 | 8383篇 |
2015年 | 8367篇 |
2014年 | 15435篇 |
2013年 | 15538篇 |
2012年 | 5330篇 |
2011年 | 5331篇 |
2010年 | 10273篇 |
2009年 | 14164篇 |
2008年 | 5656篇 |
2007年 | 3883篇 |
2006年 | 6356篇 |
2005年 | 3640篇 |
2004年 | 2913篇 |
2003年 | 1898篇 |
2002年 | 1990篇 |
2001年 | 3773篇 |
2000年 | 2985篇 |
1999年 | 3188篇 |
1998年 | 3626篇 |
1997年 | 3450篇 |
1996年 | 3350篇 |
1995年 | 3200篇 |
1994年 | 1933篇 |
1993年 | 1556篇 |
1992年 | 1366篇 |
1991年 | 1400篇 |
1990年 | 1049篇 |
1989年 | 1172篇 |
1988年 | 1010篇 |
1987年 | 848篇 |
1986年 | 882篇 |
1985年 | 713篇 |
1984年 | 545篇 |
1983年 | 517篇 |
1982年 | 511篇 |
1981年 | 398篇 |
1980年 | 359篇 |
1979年 | 311篇 |
1978年 | 332篇 |
1977年 | 397篇 |
1975年 | 279篇 |
1972年 | 302篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Two hundred forty-two patients referred for various gastrointestinal complaints were evaluated for clinical parameters that would predict findings of lactose malabsorption. Breath hydrogen and blood glucose lactose tests were performed after ingestion of 50 g lactose. Presenting complaints, duration of symptoms, and patient demographics such as age, sex, and ethnic heritage were not different between lactose malabsorbers and absorbers as defined by the breath hydrogen lactose test. Foodrelated symptoms in general and after specific foods such as milk, ice cream, cheese, and yogurt were also similar between groups. Prior to testing, 30% of malabsorbers (N=161) and 36% of absorbers (N=81) reported lactoserelated symptoms (P=NS). The blood glucose response to lactose was abnormal in 60% of malabsorbers and 15% of absorbers. This study confirmed our impression that it is difficult to predict lactose absorption status by clinical parameters. The majority of our lactose malabsorber patients were unaware of lactose-associated symptoms. Furthermore, symptom assessment, demographics, food history, and blood glucose testing did not predict abnormal hydrogen responses to lactose.The opinions and assertations expressed herein are those of the authors and are not to be construed as reflecting opinions of the United States Air Force or the Department of Defense.This work has been presented in part at the Annual Scientific Session of the American Gastroenterological Association, San Francisco, California, May 19, 1986, and published as an abstract (Gastroenterology 90:1562, 1986). 相似文献
992.
The purpose of this study was to investigate the histogenesis of experimental tumors in the rat esophagus. Thirty rats received 0.0015% N-methyl-N-amylnitrosamine (MNAN) in the drinking water for 12 weeks. Another 30 rats received tap water. All rats then received tap water until sacrifice. Rats from each group were sacrificed immediately after MNAN administration, four weeks after, and eight weeks after. One hour before sacrifice, [3H]TdR was injected by tail vein to label proliferating cells. The entire esophagus and stomach were removed and processed for light and electron microscopy and autoradiography. The overall frequency of esophageal tumors after MNAN was 83% and did not differ significantly among the three experimental groups. Tumors were primarily papillomas and squamous cell carcinomas and occurred with equal frequency in the upper, middle, and lower thirds of the esophagus. No tumors were found in the squamous-lined forestomach. Electron microscopy revealed abundant tonofilaments, free ribosomes, and mitochondria accompanied by vacuoles. By autoradiography, esophageal epithelial proliferation was markedly stimulated in nontumorous mucosa from all three experimental groups. We conclude that MNAN ingestion for 12 weeks reliably produces papillomas and squamous cell carcinomas throughout the rat esophagus, but not in the squamouslined forestomach, and that MNAN stimulated marked epithelial proliferation which is accompanied by thickening of the epithelium in nontumorus esophageal mucosa. 相似文献
993.
Stuart Sherman MD Nancy S. Nieland MD David H. Van Thiel MD 《Digestive diseases and sciences》1988,33(3):368-374
Summary An unusual case of a woman with primary biliary cirrhosis and cutaneous sarcoidosis is described. The factors that allow a specific diagnosis of each condition are presented and the literature pertaining to such complex and unusual cases is presented.This work was supported in part by a grant from the Gastroenterology Medical Research Foundation of Southwestern Pennsylvania. 相似文献
994.
S. Hucker MD R. Langevin PhD J. Bain MD 《Sexual abuse : a journal of research and treatment》1988,1(2):227-242
A sample of 100 men accused of sexual assault on a child and referred to a forensic clinic were approached for assessment and treatment in a double blind study of MPA (Provera). A total of 48 men completed assessment and 18 agreed to participate in the drug trial. Only 11 completed a 3-month course of MPA or placebo therapy. Those refusing treatment were less intelligent and less impaired on the Luria-Nebraska Neuropsychological Test Battery but were more impaired on the Halstead-Reitan Neuropsychological Test Battery. Dropouts differed only in reporting more frequent sexual fantasies of children. Of a possible 27 side effects for MPA, only two were statistically significant. MPA led to more depression and excess salivation than did the placebo, although the frequency of fatigue was noteworthy. MPA appeared as a useful sex drive reducing medication with few side effects but compliance in taking the drug was seen as a major obstacle in its use with pedophiles. 相似文献
995.
996.
997.
998.
Occasionally, a dental patient presents his/her dentist with a history of hypersensitivity to local anesthetic agents. The symptoms may include immediate reactions to the injection procedure (dizziness, shortness of breath, tachycardia, etc), or delayed reactions to the anesthetic (swelling, urticaria, etc). Although the true incidence of local anesthetic allergy is low, such a history often involves the patient's anxiety regarding the use of the drug in question, and the dentist's apprehension to treat the "problematic" patient. In such cases, hypnosis can play a major role in controlling pain and the associated distress. In the present article, the method concerning the implementation of hypnosis to induce local anesthesia is described and illustrated through case demonstrations. 相似文献
999.
1000.