全文获取类型
收费全文 | 6294篇 |
免费 | 834篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 156篇 |
妇产科学 | 85篇 |
基础医学 | 840篇 |
口腔科学 | 140篇 |
临床医学 | 634篇 |
内科学 | 1443篇 |
皮肤病学 | 63篇 |
神经病学 | 471篇 |
特种医学 | 460篇 |
外科学 | 936篇 |
综合类 | 218篇 |
一般理论 | 2篇 |
预防医学 | 700篇 |
眼科学 | 54篇 |
药学 | 529篇 |
中国医学 | 3篇 |
肿瘤学 | 389篇 |
出版年
2021年 | 97篇 |
2020年 | 47篇 |
2019年 | 79篇 |
2018年 | 100篇 |
2017年 | 88篇 |
2016年 | 108篇 |
2015年 | 103篇 |
2014年 | 152篇 |
2013年 | 187篇 |
2012年 | 272篇 |
2011年 | 305篇 |
2010年 | 197篇 |
2009年 | 176篇 |
2008年 | 252篇 |
2007年 | 266篇 |
2006年 | 280篇 |
2005年 | 250篇 |
2004年 | 256篇 |
2003年 | 233篇 |
2002年 | 243篇 |
2001年 | 201篇 |
2000年 | 222篇 |
1999年 | 188篇 |
1998年 | 129篇 |
1997年 | 98篇 |
1996年 | 88篇 |
1995年 | 84篇 |
1994年 | 79篇 |
1993年 | 75篇 |
1992年 | 124篇 |
1991年 | 120篇 |
1990年 | 114篇 |
1989年 | 133篇 |
1988年 | 120篇 |
1987年 | 143篇 |
1986年 | 127篇 |
1985年 | 116篇 |
1984年 | 109篇 |
1983年 | 89篇 |
1982年 | 71篇 |
1981年 | 72篇 |
1980年 | 50篇 |
1979年 | 78篇 |
1978年 | 54篇 |
1977年 | 57篇 |
1974年 | 54篇 |
1972年 | 62篇 |
1970年 | 53篇 |
1969年 | 45篇 |
1968年 | 44篇 |
排序方式: 共有7152条查询结果,搜索用时 328 毫秒
1.
2.
Akira Sawaki Nobumasa Mizuno Kuniyuki Takahashi Tsuneya Nakamura Masahiro Tajika Hiroki Kawai Toshifumi Isaka Hiroshi Imaoka Yasuyuki Okamoto Masatoshi Aoki Hiroyuki Inoue Ahmed AS Salem Yasushi Yatabe Kenji Yamao 《Digestive endoscopy》2006,18(1):40-44
Background: Gastrointestinal stromal tumors (GIST) are one of the most common mesenchymal tumors of the gastrointestinal tract. GIST are defined by positive immunohistochemical staining for KIT or CD34 and thus are generally diagnosed after surgery. Because small GIST are rarely diagnosed before surgery, the clinical course of these small tumors is not clear. The aim of the present study was to follow changes in size and configuration of small GIST that were pathologically confirmed using endoscopic ultrasonography‐guided fine‐needle aspiration biopsy (EUS‐FNAB). Methods: Between July 1997 and December 2003, 16 tumors in 16 patients (10 men and 6 women) with an immunohistochemical diagnosis of GIST were regularly followed in our hospital. The median patient age when EUS‐FNAB was performed was 62 years (range 26–82 years) and the median follow‐up period was 4.9 years (range 0.5–9.6 years). Results: Fourteen tumors showed no remarkable changes in size and shape during follow up compared with the initial diagnosis. Two tumors enlarged: one tumor approximately doubled its diameter in 8 years and the other tumor increased from 1.8 cm at diagnosis to up to 10 cm after only 2 years. Doubling time of the latter tumor was calculated as 3.1 months. Conclusions: We conclude that EUS‐FNAB might be a good modality for final diagnosis of GIST without surgery, and that GIST without rapid growth on follow up can be endoscopically followed. 相似文献
3.
4.
Addison's disease is rarely caused by metastatic cancer. We report a unique case of hypoadrenalism owing to metastatic transitional cell carcinoma of the bladder. The relevant literature is reviewed. 相似文献
5.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
6.
White suckers, collected from lakes containing elevated levels of copper (12 micrograms liter-1) and zinc (250 micrograms liter-1), were evaluated for reproductive performance, growth and survival of the larvae, and tolerance of the larvae to waterborne copper. Fertilization success was not impaired in white suckers from contaminated sites; metal-exposed males performed better than control males in fertilization trials with control eggs. Larvae hatched from eggs collected at contaminated sites and fertilized in clean water were smaller, developed at a slightly increased rate, and exhibited poorer growth and survival than larvae from control sites. Larvae showed significant changes in resistance and tolerance to copper with age. During the period of endogenous nutrition, larvae from eggs taken at contaminated sites showed increased resistance and tolerance to waterborne copper relative to controls. The effect was not seen in larvae at first feeding, at ages older than 4 days after the onset of feeding (25 days posthatch) or in larvae hatched from control eggs fertilized with sperm from males taken at contaminated sites. This study provides evidence for a maternal yolk factor associated with increased tolerance and resistance of larvae to copper. 相似文献
7.
Inhaled sodium metabisulphite induced bronchoconstriction: inhibition by nedocromil sodium and sodium cromoglycate. 总被引:11,自引:1,他引:10 下载免费PDF全文
1. The effects of nedocromil sodium and sodium cromoglycate on bronchoconstriction induced by inhaled sodium metabisulphite have been studied in eight atopic subjects, three of whom had mild asthma. 2. Nedocromil sodium (4 mg, 7.8 X 10(-6) M), sodium cromoglycate (10 mg, 24.1 X 10(-6) M) and matched placebo were administered by identical metered dose inhalers 30 min before a dose-response to sodium metabisulphite (5-100 mg ml-1) was performed. 3. Maximum fall in sGaw after placebo pre-treatment was -43.9 +/- 3.3% baseline (mean +/- s.e. mean). At the same metabisulphite concentration maximum fall in sGaw after sodium cromoglycate was -13.0 +/- 3.6% and after nedocromil sodium was +4.3 +/- 6.8%. Nedocromil sodium prevented any significant fall in sGaw even after higher concentrations of metabisulphite. 4. Both nedocromil sodium, 4 mg, and sodium cromoglycate, 10 mg, inhibited sodium metabisulphite induced bronchoconstriction but nedocromil sodium was significantly more effective. Relative in vivo potency of the two drugs is broadly in line with other in vivo and in vitro studies. 相似文献
8.
9.
Ventilator-dependent children are surviving longer and increasing in number. This qualitative study was undertaken to describe the impact of a ventilator-dependent child on 10 families and to describe the management styles used by the parents. In five families, the child remained hospitalized due to the disability while in the other five the child primarily lived at home. Three major themes in managing were elicited: barriers, resources, and parenting. Parents believed they should try to normalize their child's experiences, that interactions with health care professionals required negotiation and assertiveness, and that they needed some support person(s) outside of the family. 相似文献
10.
In vitro and in vivo drug studies with three agents of central nervous system phaeohyphomycosis 总被引:10,自引:0,他引:10
Amphotericin B (Amph B), 5-fluorocytosine (5-FC), ketoconazole (KTZ), fluconazole (FLZ), amorolfine (AMOR) and terbinafine (TER) were tested against 3 agents of central nervous system phaeohyphomycosis in vitro and in life-threatening infections in mice. The fungi studied were Cladosporium bantianum, Dactylaria constricta and Wangiella dermatitidis. The broadest protection against this group of fungi in mice was offered by 5-FC followed by Amph B and FLZ, then KTZ. AMOR and TER were inactive in vivo. The results of in vitro susceptibility testing had no predictive value. In contrast, the data obtained from the mouse models should be useful clinically. 相似文献