全文获取类型
收费全文 | 8238篇 |
免费 | 573篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 425篇 |
妇产科学 | 248篇 |
基础医学 | 876篇 |
口腔科学 | 215篇 |
临床医学 | 690篇 |
内科学 | 1450篇 |
皮肤病学 | 89篇 |
神经病学 | 479篇 |
特种医学 | 898篇 |
外科学 | 1381篇 |
综合类 | 114篇 |
一般理论 | 7篇 |
预防医学 | 598篇 |
眼科学 | 587篇 |
药学 | 240篇 |
中国医学 | 3篇 |
肿瘤学 | 466篇 |
出版年
2021年 | 84篇 |
2018年 | 115篇 |
2017年 | 80篇 |
2016年 | 86篇 |
2015年 | 106篇 |
2014年 | 123篇 |
2013年 | 222篇 |
2012年 | 257篇 |
2011年 | 302篇 |
2010年 | 226篇 |
2009年 | 186篇 |
2008年 | 322篇 |
2007年 | 275篇 |
2006年 | 280篇 |
2005年 | 242篇 |
2004年 | 248篇 |
2003年 | 242篇 |
2002年 | 226篇 |
2001年 | 216篇 |
2000年 | 209篇 |
1999年 | 230篇 |
1998年 | 203篇 |
1997年 | 180篇 |
1996年 | 178篇 |
1995年 | 149篇 |
1994年 | 127篇 |
1993年 | 134篇 |
1992年 | 179篇 |
1991年 | 189篇 |
1990年 | 196篇 |
1989年 | 255篇 |
1988年 | 212篇 |
1987年 | 229篇 |
1986年 | 207篇 |
1985年 | 209篇 |
1984年 | 179篇 |
1983年 | 161篇 |
1982年 | 96篇 |
1981年 | 72篇 |
1980年 | 103篇 |
1979年 | 122篇 |
1978年 | 113篇 |
1977年 | 94篇 |
1976年 | 109篇 |
1975年 | 91篇 |
1974年 | 92篇 |
1973年 | 92篇 |
1972年 | 67篇 |
1971年 | 75篇 |
1970年 | 59篇 |
排序方式: 共有8836条查询结果,搜索用时 0 毫秒
71.
Ocular colobomata, cardiac defect, and other anomalies: a study of seven cases including two sibs. 下载免费PDF全文
An association of ocular colobomata and congenital heart disease was observed in seven patients. Two of these were maternal half sisters whose mother also had ocular colobomata. All the patients had normal karyotypes. There was a high incidence of other associated abnormalities involving the central nervous, skeletal, and urogenital systems. Discovery of an ocular coloboma should alert the clinician to search for other abnormalities. 相似文献
72.
73.
74.
75.
The manifestation of diurnal periodicity and the extent of its control by the photoperiod was assessed in three predation defense reactions which constitute either components or outcomes of a predator-prey interaction sequence. Two-hundred White Leghorn chicks were reared from hatching for one week in either 24L or 12L and then tested at one of two clock hours previously demonstrated to define peak and trough response for one of the components. Putative evidence was found for an endogenous source of the periodicity manifested in all reactions. Maintenance schedule did not entrain the periodicity, but simple room entry and handling elicited anti-predator reactions, the extent of which varied as a function of clock hour. A general model of predation defense behavior was proposed. 相似文献
76.
77.
78.
79.
Antiphospholipid antibodies and the outcome of pregnancy after the first in-vitro fertilization and embryo transfer cycle 总被引:1,自引:1,他引:1
Balasch J; Creus M; Fabregues F; Civico S; Reverter JC; Carmona F; Tassies D; Vanrell JA 《Human reproduction (Oxford, England)》1998,13(5):1180-1183
Increased antiphospholipid antibody prevalence has been demonstrated by a
number of recent studies in in-vitro fertilization (IVF) patients but the
potential effects of antiphospholipid antibodies on the different
components of the reproductive process and the consideration of whether to
test IVF patients for antiphospholipid antibodies are controversial. The
present study was undertaken to investigate the possible association
between the presence of circulating antiphospholipid antibodies (namely the
lupus anticoagulant and anticardiolipin antibodies), among a series of 21
consecutive IVF patients having a clinical spontaneous abortion after their
first embryo transfer. As a control group (n=42), the nearest IVF cycle
resulting in an ongoing pregnancy before and after each miscarried IVF
cycle (i.e. the closest cycles in temporal relationship to the index cycle)
was used. One patient (4.8%) in the study group and two women (4.8%) among
controls were seropositive for antiphospholipid antibodies. These low and
similar seropositivity rates found in the two groups studied lead us to
conclude that antiphospholipid antibodies testing in IVF patients should be
considered only in those women having repeated failures of
implantation/clinical abortion after embryo transfer but not in an
infertile general population reaching an IVF programme.
相似文献
80.
Huisman JA; Paulussen RJ; Geurts TB; Odink J; Rekers H 《Human reproduction (Oxford, England)》1997,12(1):34-38
The objective was to demonstrate bioequivalence between s.c. and i.m.
administration of Humegon (FSH/LH ratio 1:1) and Normegon (FSH/LH ratio
3:1). In two randomized, single-centre, cross-over studies, 18 healthy
volunteers on each formulation were assigned to one of the two
administration sequences. Subjects were given single doses of one of the
above gonadotrophins after endogenous gonadotrophin production had first
been suppressed using high-dose oral contraceptive. Subsequently, rate
(Cmax, tmax) and extent (AUC) of absorption of follicle stimulating hormone
(FSH) and luteinizing hormone (LH) were determined for 14 days. For Cmax
and AUC, analysis of variance (ANOVA) was performed on log-transformed data
and for tmax ANOVA was performed on ranks. Intramuscular and s.c.
injections of Humegon were bioequivalent with respect to the main
pharmacokinetic parameters, being AUC and Cmax of FSH absorption.
Intramuscular and s.c. injections of Normegon were bioequivalent with
respect to the AUC of FSH and not bioequivalent with respect to the Cmax of
FSH. For tmax of FSH as well as for most LH variables of both preparations,
bioequivalence could not be proven due to the high intra- and
interindividual variability and/or concentrations being close to the
detection limit. Thus, the main pharmacokinetic FSH variables after i.m.
and s.c. administration of Humegon and Normegon were bioequivalent.
相似文献