全文获取类型
收费全文 | 1146篇 |
免费 | 156篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 59篇 |
妇产科学 | 11篇 |
基础医学 | 208篇 |
口腔科学 | 47篇 |
临床医学 | 113篇 |
内科学 | 257篇 |
皮肤病学 | 32篇 |
神经病学 | 28篇 |
特种医学 | 243篇 |
外科学 | 76篇 |
综合类 | 39篇 |
预防医学 | 94篇 |
眼科学 | 4篇 |
药学 | 49篇 |
肿瘤学 | 64篇 |
出版年
2022年 | 6篇 |
2021年 | 6篇 |
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 15篇 |
2015年 | 11篇 |
2014年 | 26篇 |
2013年 | 23篇 |
2012年 | 23篇 |
2011年 | 28篇 |
2010年 | 30篇 |
2009年 | 37篇 |
2008年 | 30篇 |
2007年 | 27篇 |
2006年 | 31篇 |
2005年 | 35篇 |
2004年 | 31篇 |
2003年 | 31篇 |
2002年 | 20篇 |
2001年 | 29篇 |
2000年 | 31篇 |
1999年 | 22篇 |
1998年 | 54篇 |
1997年 | 55篇 |
1996年 | 57篇 |
1995年 | 52篇 |
1994年 | 27篇 |
1993年 | 40篇 |
1992年 | 45篇 |
1991年 | 28篇 |
1990年 | 19篇 |
1989年 | 34篇 |
1988年 | 35篇 |
1987年 | 53篇 |
1986年 | 30篇 |
1985年 | 21篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 24篇 |
1980年 | 25篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 11篇 |
1976年 | 25篇 |
1975年 | 11篇 |
1972年 | 7篇 |
1967年 | 6篇 |
1965年 | 5篇 |
排序方式: 共有1326条查询结果,搜索用时 15 毫秒
11.
12.
P55, an immunogenic but nonprotective 55-kilodalton Borrelia burgdorferi protein in murine Lyme disease. 下载免费PDF全文
Immunization of C3H mice with P55 (previously called S1), a 55-kDa Borrelia burgdorferi antigen that is immunogenic after infection, elicited a strong antibody response but did not protect mice against B. burgdorferi challenge. Mice immunized with a P55 fusion protein in complete Freund's adjuvant developed anti-P55 antibodies, detectable at a titer of 1:10,000 by immunoblotting. To determine, if a protective response had been elicited, P55-vaccinated mice were fed upon by ticks infected with B. burgdorferi. The frequency of B. burgdorferi infection was similar in P55-immunized and control mice, and spirochetes were not destroyed within ticks that fed on P55-vaccinated mice. P55 is an immunogenic antigen that does not induce a protective response in the vertebrate or invertebrate host. 相似文献
13.
Laura Telford Scott H. Seidman Gary D. Paige 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1998,118(1):115-125
Natural head movements include angular and linear components of motion. Two classes of vestibulo-ocular reflex (VOR), mediated
by the semicircular canals and otoliths (the angular and linear VOR, or AVOR and LVOR, respectively), compensate for head
movements and help maintain binocular fixation on targets in space. In this study, AVOR/LVOR interactions were quantified
during complex head motion over a broad range of fixation distances at a fixed stimulus frequency of 4.0 Hz. Binocular eye
movements were recorded (search-coil technique) in squirrel monkeys while fixation distance (assessed by vergence) was varied
using brief presentations of earth-fixed targets at various distances. Stimuli consisted of rotations around an earth-vertical
axis and therefore always activated the AVOR. Horizontal and vertical AVORs were assessed when the head was centered over
the axis of rotation and oriented upright (UP) and right-side-down (RD), respectively. AVOR gains increased slightly with
increasing vergence in darkness, as expected given the small anterior position of the eyes in the head. Combined AVOR/LVOR
responses were recorded when subjects were displaced eccentrically from the rotation axis. Eccentric rotations activated the
AVOR just as when the head was centered, but added a translational stimulus which generated an LVOR component in response
to interaural (IA) or dorsoventral (DV) tangential accelerations, depending on whether the head was UP or RD, respectively.
When the head was eccentric and facing nose-out, the AVOR and LVOR produced ocular responses in the same plane and direction
(coplanar and synergistic), and response magnitudes increased with increasing vergence. With the head facing nose-in, AVOR
and LVOR response components were oppositely directed (coplanar and antagonistic). The AVOR dominated the response when fixation
distance was far, and phase was compensatory for head rotation. As fixation distance decreased toward the rotation axis, responses
declined to near zero, and when fixation distance approached even closer, the LVOR component dominated and response phase
inverted. The same pattern was observed for both horizontal (head UP) and vertical (head RD) responses. The LVOR was recorded
directly by rotating subjects eccentrically but in the nose-up (NU) orientation. The AVOR then generated torsional responses
to head roll, coexistent with either horizontal or vertical LVOR responses to tangential acceleration when the subject was
oriented head-out or right-side-out, respectively. Only the LVOR response components were modulated by vergence. A vectorial
analysis of AVOR, LVOR, and combined responses supports the conclusion that AVOR and LVOR response components combine linearly
during complex head motion.
Received: 27 February 1997 / Accepted: 18 June 1997 相似文献
14.
The intercellular adhesion molecule (ICAM) family of proteins 总被引:8,自引:0,他引:8
Macromolecular adhesive associations between cells are important for transmitting spatial and temporal information that is
critical for immune system function. One such group of proteins, the intercellular adhesion molecules (ICAMs), has grown as
newly identified members are revealed. In addition, the functions of the ICAMs, in general, have begun to be better understood,
including intracellular signaling events. This information has led to the design of novel therapeutic agents that may prove
effective in a variety of disease states. 相似文献
15.
Partial destruction of Borrelia burgdorferi within ticks that engorged on OspE- or OspF-immunized mice. 总被引:9,自引:8,他引:9 下载免费PDF全文
T P Nguyen T T Lam S W Barthold S R Telford rd R A Flavell E Fikrig 《Infection and immunity》1994,62(5):2079-2084
We determined whether Borrelia burgdorferi outer surface proteins (Osps) E and F could elicit immune responses useful for a Lyme disease vaccine. Thirty days after challenge with B. burgdorferi, mice produced antibodies to OspE but not OspF, whereas antibodies to OspF were present in sera of mice obtained 90 days after infection. Examination of sera from patients with Lyme disease revealed antibodies to OspF in a small number (14%) of early-stage disease patients but in a majority (58%) of patients with late-stage disease, while antibodies to OspE were rarely detected in patients. Mice immunized with recombinant OspE or OspF produced high titers of antibodies to OspE or OspF, respectively. OspF-immunized mice were partially protected from both intradermal syringe challenge and tick-mediated transmission of B. burgdorferi while vaccination with OspE did not confer immunity. B. burgdorferi organisms were, however, substantially destroyed within ticks that engorged on either OspE- (75% reduction in the number of spirochetes within the ticks, compared with controls) or OspF (90% reduction in the number of spirochetes within the ticks)-immunized mice. 相似文献
16.
17.
Terminal deletion (14)(q32.3): a new case. 总被引:2,自引:1,他引:2
N Telford D A Thomson M J Griffiths S Ilett J L Watt 《Journal of medical genetics》1990,27(4):261-263
A mildly dysmorphic, 2 year old girl with mental retardation was found to have a small de novo terminal deletion of the long arm of chromosome 14, del(14)(q32.3). She was found to have features in common with two previous terminal deletion cases and particularly with the well documented ring 14 syndrome, although seizures, a characteristic feature of ring 14, were notably absent. 相似文献
18.
Lone star tick-infecting borreliae are most closely related to the agent of bovine borreliosis 下载免费PDF全文
Although Borrelia theileri, the agent of bovine borreliosis, was described at the turn of the century (in 1903), its relationship with borreliae causing Lyme disease or relapsing fever remains undescribed. We tested the previously published hypothesis that spirochetes infecting Lone Star ticks (Amblyomma americanum) may comprise B. theileri by analyzing the 16S ribosomal DNAs (rDNAs) and flagellin genes of these spirochetes. B. theileri, the Amblyomma agent, and B. miyamotoi formed a natural group or clade distinct from but most closely related to that of the relapsing fever spirochetes. B. theileri and the Amblyomma agent were 97 and 98% similar at the nucleotide level within the analyzed portions of the 16S rDNA and the flagellin gene respectively, suggesting a recent divergence. The agent of bovine borreliosis might be explored as a surrogate antigen for the as-yet-uncultivatable Amblyomma agent in studies designed to explore the etiology of a Lyme disease-like infection associated with Lone Star ticks. 相似文献
19.
20.