全文获取类型
收费全文 | 1424045篇 |
免费 | 117520篇 |
国内免费 | 6594篇 |
专业分类
耳鼻咽喉 | 17723篇 |
儿科学 | 45137篇 |
妇产科学 | 38042篇 |
基础医学 | 194322篇 |
口腔科学 | 37847篇 |
临床医学 | 130001篇 |
内科学 | 295336篇 |
皮肤病学 | 32933篇 |
神经病学 | 119271篇 |
特种医学 | 58653篇 |
外国民族医学 | 277篇 |
外科学 | 223643篇 |
综合类 | 32543篇 |
现状与发展 | 2篇 |
一般理论 | 539篇 |
预防医学 | 113954篇 |
眼科学 | 29870篇 |
药学 | 99319篇 |
5篇 | |
中国医学 | 2319篇 |
肿瘤学 | 76423篇 |
出版年
2018年 | 15502篇 |
2017年 | 12142篇 |
2016年 | 14455篇 |
2015年 | 16200篇 |
2014年 | 22802篇 |
2013年 | 33755篇 |
2012年 | 42614篇 |
2011年 | 45618篇 |
2010年 | 28279篇 |
2009年 | 27442篇 |
2008年 | 42355篇 |
2007年 | 45149篇 |
2006年 | 46056篇 |
2005年 | 44339篇 |
2004年 | 42432篇 |
2003年 | 40979篇 |
2002年 | 38680篇 |
2001年 | 66753篇 |
2000年 | 68408篇 |
1999年 | 57373篇 |
1998年 | 17763篇 |
1997年 | 15759篇 |
1996年 | 16643篇 |
1995年 | 16798篇 |
1994年 | 15575篇 |
1993年 | 14636篇 |
1992年 | 47461篇 |
1991年 | 46080篇 |
1990年 | 44246篇 |
1989年 | 42068篇 |
1988年 | 38982篇 |
1987年 | 38320篇 |
1986年 | 36058篇 |
1985年 | 34853篇 |
1984年 | 26622篇 |
1983年 | 22323篇 |
1982年 | 14126篇 |
1981年 | 12688篇 |
1980年 | 11919篇 |
1979年 | 23634篇 |
1978年 | 17201篇 |
1977年 | 14492篇 |
1976年 | 13262篇 |
1975年 | 13784篇 |
1974年 | 16147篇 |
1973年 | 15463篇 |
1972年 | 14212篇 |
1971年 | 13075篇 |
1970年 | 11908篇 |
1969年 | 11143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
M L Chindia S W Guthua D L Mwaniki 《International journal of oral and maxillofacial surgery》1991,20(2):73-74
A case of an ameloblastoma diagnosed about 3 1/2 years after removal of an impacted mandibular 3rd molar is presented. The pre-operative radiographs, though poor in quality, showed an ill-defined radiolucency in relation to the tooth. This feature was not apparent to the examiners at the time of first presentation. Despite unfavourable working conditions in developing countries, a high level of suspicion should be maintained to avoid serious sequelae at a later stage. 相似文献
992.
993.
Gordon J. Christensen D.D.S. M.S.D. Ph.D. Rella P. Christensen Ph.D. † 《Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.]》1991,3(5):174-179
One hundred and sixty-five Cerinate porcelain veneers were placed by 11 private practice clinicians from diverse locations throughout the USA. The veneers were evaluated over a 3-year service period using Kodachrome photographs and grading of clinical characteristics by evaluators. The following factors were evaluated: (1) esthetics; (2) margin fit; (3) margin discoloration; (4) breakage; (5) gingival irritation; (6) patient acceptance; and (7) caries. Specific characteristics and their evaluations over three years were: (1) Esthetics started out excellent and remained that way; (2) Margin fit was acceptable at the beginning of the study and was actually perceived to improve, perhaps related to cement at the margins wearing and smoothing; (3) Margin discoloration started very low and became slightly worse; (4) Breakage was present during each of the 3 years, and 13 percent of veneers had some breakage after 3 years. Changes in clinical procedures are suggested in this paper to diminish this problem; (5) Gingival irritation was minimal throughout the study; (6) Patient acceptance was excellent at the beginning of the study and improved; and (7) Dental caries involvement was minimal, with only one veneered tooth showing caries involvement. Over the 3-year period, the veneers provided excellent service overall. 相似文献
994.
Daptomycin (LY146032) caused a calcium-dependent dissipation of the membrane potential (delta psi) in Staphylococcus aureus without noticeably affecting the chemical gradient (delta pH) across the membrane. The effect of daptomycin on membrane energization may account for many of the inhibitory effects on macromolecular biosyntheses and membrane function reported for this antibiotic. Our evidence indicates that the bactericidal activity of daptomycin is dependent on an available delta psi. 相似文献
995.
996.
997.
In this new radioimmunoassay system for determination of amatoxins in urine and plasma, a novel chemical approach is used for antigen and 125I-tracer production, based on a detoxified alpha-amanitin derivative (aldoamanitin). Total assay time, including data processing, is less than 100 min. The lowest detectable concentration is 1 microgram/L for urine, 0.1 microgram/L for plasma. In the clinically significant range, within-run CVs are less than 8%. This new 125I-based assay is a significant improvement over existing 3H technology in terms of speed, precision, and freedom from interference. 相似文献
998.
Clinical pharmacologists for the future in the United Kingdom 总被引:1,自引:0,他引:1
D G McDevitt 《Clinical pharmacology and therapeutics》1986,39(4):459-461
999.
D J Brooks J S Gibbs P Sharp S Herold D R Turton S K Luthra E M Kohner S R Bloom T Jones 《Journal of cerebral blood flow and metabolism》1986,6(2):240-244
Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB. 相似文献
1000.
Neurosyphilis today is a rare problem. We describe a man who presented with organic brain syndrome, psychosis and incontinence, and diagnosis was neurosyphilis with resultant bladder dysfunction. Urodynamic studies defined the voiding dysfunction as detrusor areflexia with a positive bethanechol test. This case reminds us of the necessity of obtaining a test for venereal disease to rule out neurosyphilis in patients with idiopathic voiding dysfunction. 相似文献