全文获取类型
收费全文 | 1290670篇 |
免费 | 97102篇 |
国内免费 | 1754篇 |
专业分类
耳鼻咽喉 | 16593篇 |
儿科学 | 41933篇 |
妇产科学 | 35572篇 |
基础医学 | 192464篇 |
口腔科学 | 35288篇 |
临床医学 | 120284篇 |
内科学 | 253581篇 |
皮肤病学 | 27722篇 |
神经病学 | 103944篇 |
特种医学 | 47581篇 |
外国民族医学 | 265篇 |
外科学 | 182703篇 |
综合类 | 26478篇 |
现状与发展 | 3篇 |
一般理论 | 580篇 |
预防医学 | 106441篇 |
眼科学 | 29175篇 |
药学 | 94572篇 |
8篇 | |
中国医学 | 2148篇 |
肿瘤学 | 72191篇 |
出版年
2019年 | 10627篇 |
2018年 | 14248篇 |
2017年 | 10902篇 |
2016年 | 11904篇 |
2015年 | 13742篇 |
2014年 | 18900篇 |
2013年 | 28557篇 |
2012年 | 39321篇 |
2011年 | 41758篇 |
2010年 | 24111篇 |
2009年 | 23154篇 |
2008年 | 39318篇 |
2007年 | 41926篇 |
2006年 | 41357篇 |
2005年 | 40438篇 |
2004年 | 38890篇 |
2003年 | 37154篇 |
2002年 | 35918篇 |
2001年 | 56914篇 |
2000年 | 57833篇 |
1999年 | 48797篇 |
1998年 | 13672篇 |
1997年 | 12432篇 |
1996年 | 12825篇 |
1995年 | 12099篇 |
1994年 | 11274篇 |
1993年 | 10547篇 |
1992年 | 38615篇 |
1991年 | 38051篇 |
1990年 | 36787篇 |
1989年 | 35574篇 |
1988年 | 32989篇 |
1987年 | 32304篇 |
1986年 | 30787篇 |
1985年 | 29057篇 |
1984年 | 22128篇 |
1983年 | 19363篇 |
1982年 | 11485篇 |
1979年 | 21088篇 |
1978年 | 15467篇 |
1977年 | 12875篇 |
1976年 | 11903篇 |
1975年 | 12865篇 |
1974年 | 15648篇 |
1973年 | 15412篇 |
1972年 | 14561篇 |
1971年 | 13595篇 |
1970年 | 12808篇 |
1969年 | 12091篇 |
1968年 | 11244篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The limited contact dynamic compression plate (LC-DCP) 总被引:5,自引:0,他引:5
S. M. Perren K. Mane O. Pohler M. Predieri S. Steinemann E. Gautier 《Archives of orthopaedic and trauma surgery》1990,109(6):304-310
Summary To realize the new concept of biological internal fixation the limited contact dynamic compression plate was developed. It minimizes vascular damage to the plated bone segment. It should lead to a more versatile and efficient application of internal fixation using plates. 相似文献
992.
Desferrioxamine (DFO) metabolism and its pharmacokinetics were studied in a swine model using high-performance liquid chromatography. DFO and three iron-binding metabolites occurred in plasma. Interindividual differences in pharmacokinetics and metabolism were observed. Urine analysis in 4 pigs showed three iron-binding metabolites. The mean percent dose excreted in urine in the form of the parent drug was 45 +/- 10% and 10 +/- 2% (means +/- SD) in the form of metabolites. Of the total amount of the parent drug infused, 3 h after initiation, 87% was in the form of DFO, whereas 13% was present as the DFO-iron III complex which represented 45 mg of urinary iron elimination. The described DFO infusion protocol provides for sufficient DFO to chelate significant amounts of ferric iron in excess of normal levels, thus allowing experimental studies of iron chelation in a variety of disease states. 相似文献
993.
Between January and June 1988, a survey of 7516 people in aged care facilities in the Auckland region (99.4% response rate) was undertaken to ascertain the extent and provision of care for elderly people requiring ongoing care in order to make comparisons with other centres in New Zealand. Information was gathered about their ability to perform various activities of daily living by staff members who completed a structured precoded and pretested questionnaire for each resident or patient. Overall levels of dependency were also assessed as part of the questionnaire: 13% were assessed as requiring long stay hospital care, 48% had moderate or appreciable dependency, and the remainder had some dependency (23%) or none at all (16%). Almost one quarter (23%) of the 5213 residents in old people's homes were rated as apparently independent. Of people in religious and welfare residential homes, 38% were rated as independent whereas in commercial rest homes 12% of people were classified in this way. This high level of apparent independence in religious and welfare homes is the main aspect in which the Auckland long term care scene is distinct from other regions in the country. 相似文献
994.
BRIAN J. STOCKMAN CAROL A. BANNOW ROBERT M. MICELI MICHAEL E. DEGRAAF H. DAVID FISCHER CLARK W. SMITH 《Chemical biology & drug design》1995,45(1):11-16
Epitope libraries provide a method to identify peptide ligands for antibodies, receptors or other binding proteins. As such, they provide a powerful tool to rapidly identify lead ligands in the drug discovery process. In an attempt to correlate structural information with the results from peptide screening, we have used NMR spectroscopy of peptide/antibody complexes to demonstrate that core residues identified through a two-stage selection process undergo a larger structural change upon binding antibody than do positions in the peptide amenable to a variety of side chains. The model system used was the M2 monoclonal antibody/Flag? octapeptide epitope system. We have analyzed two peptides: Ac-Asp-Tyr-Lys-Leu-Gly-Asp-Asp-Leu-NH2 (peptide l), which contains several non-core positions randomized, and Ac-Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Leu-NH2 (peptide 2), which closely corresponds to the original Flag? sequence. Enrichment of the peptides with 15N facilitated the investigation by permitting spectral editing of the peptide resonances in the presence of antibody. For peptide 1 the absolute shifts for the free vs. Fab-bound peptide were found to be largest for the amide groups of Asp-1 and Asp-6, in agreement with classification of these residues as critical by the phage display library selection process. For peptide 2 the largest absolute shifts were observed for Asp-1 and Asp-4, with the other aspartic acid residues also showing significant but smaller changes. © Munksgaard 1995. 相似文献
995.
C. AZCONA L. CASTRO E. CRESPO M. JIMÉNEZ & L. SIERRASESÚMAGA 《Alimentary pharmacology & therapeutics》1996,10(4):577-586
Background : Malnutrition is very frequent in childhood cancer. Its main cause is inadequate intake for energy demands owing to lack of appetite. Megestrol acetate is a synthetic progestin that has been used for reversing anorexia in adult cancer.
Objectives : To assess megestrol acetate efficacy and side-effects in treating anorexia in childhood cancer.
Methods : Thirty-five children with solid tumours were receiving antitumour therapy. Nutritional assessment was by anthropometry. Megestrol acetate efficacy was assessed by evaluating grade of appetite, energy intake and well-being. Side-effects were evaluated by means of clinical history, physical examination, lipid profile, coagulation tests and cortisol rhythm.
Results : When compared to baseline all the anthropometric measurements increased ( P <0.05) from the first month of megestrol acetate therapy, as well as appetite and energy intake. No significant side-effects were found.
Conclusion : Megestrol acetate therapy is a powerful appetite stimulant which led to weight gain, composed of both fat mass and fat-free mass. Megestrol acetate is well tolerated, with few and mild side-effects. If megestrol acetate therapy is started at the onset of anorexia, the use of more expensive, invasive and complicated techniques of nutritional support may be avoided. 相似文献
Objectives : To assess megestrol acetate efficacy and side-effects in treating anorexia in childhood cancer.
Methods : Thirty-five children with solid tumours were receiving antitumour therapy. Nutritional assessment was by anthropometry. Megestrol acetate efficacy was assessed by evaluating grade of appetite, energy intake and well-being. Side-effects were evaluated by means of clinical history, physical examination, lipid profile, coagulation tests and cortisol rhythm.
Results : When compared to baseline all the anthropometric measurements increased ( P <0.05) from the first month of megestrol acetate therapy, as well as appetite and energy intake. No significant side-effects were found.
Conclusion : Megestrol acetate therapy is a powerful appetite stimulant which led to weight gain, composed of both fat mass and fat-free mass. Megestrol acetate is well tolerated, with few and mild side-effects. If megestrol acetate therapy is started at the onset of anorexia, the use of more expensive, invasive and complicated techniques of nutritional support may be avoided. 相似文献
996.
Harold T. Kyriazi George E. Carvell Joshua C. Brumberg Daniel J. Simons 《Brain research》1996,712(2):325
Extracellular single-unit recordings were made in somatosensory cortical barrels of fentanyl-sedated rats. Whiskers were deflected singly or in paired combinations. lontophoretically-applied (−)-baclofen disproportionately reduced weak responses, and phaclofen disproportionately increased them, resulting in more tightly focused or more broadly focused receptive fields, respectively. Both drugs had only minor effects on surround inhibition. In light of previous findings, we conclude that GABAA and GABAB mechanisms both act to enhance spatial contrast, but that the former plays a much greater role in enhancing temporal resolution. 相似文献
997.
G. Chalkiadakis M. Menton E. Wiest R. Schrage 《Archives of gynecology and obstetrics》1993,254(1-4):1243-1244
Ohne Zusammenfassung 相似文献
998.
999.
1000.
Dr. J. Tajti MD PhD ; Dr. K. Sas MD ; Dr. D. Szok MD ; Dr. E. Vörös MD ; Dr. L. Vécsei MD DSc 《Headache》1996,36(4):259-260
We report on a patient with clusterlike headache and multiple brain metastases of lung cancer. Initially, cluster headache was suggested clinically by characteristic symptoms without any focal central nervous system signs. However, magnetic resonance imaging demonstrated multiple brain metastases. It is possible that tumor necrosis factor may have played a role in initiating the clusterlike headache. 相似文献