全文获取类型
收费全文 | 548篇 |
免费 | 79篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 44篇 |
妇产科学 | 14篇 |
基础医学 | 102篇 |
口腔科学 | 11篇 |
临床医学 | 60篇 |
内科学 | 135篇 |
皮肤病学 | 34篇 |
神经病学 | 17篇 |
特种医学 | 83篇 |
外科学 | 38篇 |
综合类 | 21篇 |
预防医学 | 12篇 |
眼科学 | 7篇 |
药学 | 21篇 |
中国医学 | 1篇 |
肿瘤学 | 24篇 |
出版年
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 16篇 |
2013年 | 27篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 25篇 |
2009年 | 26篇 |
2008年 | 15篇 |
2007年 | 12篇 |
2006年 | 16篇 |
2005年 | 16篇 |
2004年 | 7篇 |
2003年 | 13篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 8篇 |
1998年 | 20篇 |
1997年 | 42篇 |
1996年 | 32篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 21篇 |
1992年 | 14篇 |
1991年 | 5篇 |
1990年 | 17篇 |
1989年 | 26篇 |
1988年 | 19篇 |
1987年 | 11篇 |
1986年 | 18篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 11篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1956年 | 1篇 |
1955年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有627条查询结果,搜索用时 31 毫秒
11.
12.
Production of rheumatoid factor in adoptively immune guinea-pigs after challenge with Treponema pallidum.
下载免费PDF全文
![点击此处可从《Immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Guinea-pigs of inbred strains 2 and C4D were infused with various concentrations (1 x 10(8) to 4 x 10(8) of syngeneic nylon wool-purified Treponema pallidum-immune T lymphocytes (TPI-T) and challenged 24 hr later with virulent T. pallidum (10(8) organisms). The degree of protection depended on the number of infused T cells and was associated with an accelerated production of IgM rheumatoid factor (RF). Fully protected animals (4 x 10(8) TPI-T) did not produce treponemal antibodies or circulating immune complexes (CIC) but produced IgM RF detectable 10 days after infection. Partially protected animals (< or = 2 x 10(8) TPI-T) produced, 30 days post-infection, relatively low levels of treponemal antibodies but high levels of CIC and RF. Control animals infused with 2 x 10(8) TPI-T lymphocytes but not infected with T. pallidum, when monitored for a period of 6 weeks, did not produce treponemal antibodies, CIC, or RF, excluding the possibility that IgM RF could be generated by the donor's B cells contaminating (circa 3%) the TPI-T lymphocytes. Moreover, unprotected syngeneic control animals infused, prior to infection, with T. phagedenis biotype Reiter-immune T cells or with T. pallidum-free testicular inflammatory fluid-immune T cells responded with increasing levels of treponemal antibodies; only a few animals produced RF and CIC 5 months after infection similarly to control guinea-pigs infected only. The production of RF in partially protected animals responding to infection with treponemal antibodies and CIC was apparently associated with the presence of the CIC; but the mechanism of RF production in fully protected animals in which no antibodies or CIC were detected is currently unknown. 相似文献
13.
Whole-blood hemagglutination inhibition test for venereal disease research laboratory (VDRL) antibodies
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nontreponemal antibody tests such as the Venereal Disease Research Laboratory (VDRL) test are carried out on serum and widely used as screening tests for syphilis. The aim of the present study was to develop a screening test for syphilis making use of whole blood and VDRL liposomes. Antibody to human red blood cells was conjugated to VDRL liposomes and reacted with a diluted sample of patient whole blood. A total of 951 samples were tested by the new test and the VDRL tube test. All 49 VDRL samples positive by the VDRL test showed inhibition of hemagglutination in the whole-blood test (sensitivity, 100%). Of 902 samples with negative results by the VDRL test, 901 caused hemagglutination when tested with the liposomes (specificity, 99.9%). The hemagglutination inhibition method tests for syphilis in a simple one-step procedure in which whole blood is added to a tube containing liposomes. The new test has potential for point-of-care testing in developing countries. 相似文献
14.
Synergy between the genes for butyrylcholinesterase K variant and apolipoprotein E4 in late-onset confirmed Alzheimer's disease 总被引:5,自引:2,他引:5
The allelic frequency of the gene for the K variant of
butyrylcholinesterase (BCHE-K) was 0.17 in 74 subjects with late-onset (age
> 65 years) histopathologically diagnosed Alzheimer's disease (AD),
which was higher than the frequencies in 104 elderly control subjects
(0.09), in 14 early-onset cases of confirmed AD (0.07) and in 29 confirmed
cases of other dementia (0.10). The association of BCHE-K with late-onset
AD was limited to carriers of the epsilon 4 allele of the apolipoprotein E
gene (APOE), among whom the presence of BCHE-K gave an odds ratio of
confirmed late-onset AD of 6.9 (95% C.I. 1.65-29) in subjects > 65 years
and of 12.8 (1.9-86) in subjects > 75 years. In APOE epsilon 4 carriers
over 75 years, only 1/22 controls, compared with 10/24 confirmed late-onset
AD cases, had BCHE-K. We suggest that BCHE-K, or a nearby gene on
chromosome 3, acts in synergy with APOE epsilon 4 as a susceptibility gene
for late-onset AD.
相似文献
15.
Analysis of western blotting (immunoblotting) technique in diagnosis of congenital syphilis. 总被引:7,自引:1,他引:7
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The diagnosis of congenital syphilis in apparently healthy infants continues to be problematic. Immunoglobulin M antibodies specific for a subset of Treponema pallidum antigens have been detected by Western blotting (immunoblotting). In the present study we investigated the sensitivity and specificity of this method. We tested 26 infants aged 0 to 4 months who fulfilled the accepted criteria for the diagnosis of congenital syphilis. There were 14 symptomatic infants. Sera from 13 of these infants were positive for the 47-kDa treponemal antigen (92% sensitivity). The remaining 12 infants were clinically asymptomatic when tested at birth but subsequently displayed features consistent with the disease. Reactive blots (antibodies to the 47- and/or the 15-kDa antigens) were noted in 10 of the 12 infants (83% sensitivity). Thirty infants whose mothers had syphilis were monitored and shown to be uninfected. Nonreactive blots were seen in sera from 27 infants, while sera from 3 older infants had false-positive tests (90% specificity). The Western blotting technique is sensitive (even in the diagnosis of clinically inapparent cases) and, in the absence of immunoglobulin M rheumatoid factor, is a useful confirmatory test for congenital syphilis. 相似文献
16.
17.
DL?MagerEmail author AD?Haffajee PM?Devlin CM?Norris MR?Posner JM?Goodson 《Journal of translational medicine》2005,3(1):27
Background
The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls. 相似文献18.
Aberrant secondary antibody responses to sheep erythrocytes in rabbits with experimental syphilis.
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Rabbits infected with Treponema pallidum have strikingly depressed in vivo immunoglobulin G responses to sheep erythrocytes. To gain further insight into the nature of this suppression, the immune responses of splenic and peripheral blood lymphocytes from infected rabbits to sheep erythrocytes were studied in vitro. Spleen cells from rabbits that had been sensitized with sheep erythrocytes during active syphilis had greatly decreased immunoglobulin M and G responses after in vitro incubation with sheep erythrocytes, when compared to the results obtained with cells from sensitized uninfected animals. Suppressor cells could be demonstrated in peripheral blood lymphocytes of control rabbits 6 months after sensitization with sheep erythrocytes; these cells could be removed by nylon wool filtration. When primary sensitization with sheep erythrocytes was carried out during active syphilis, these suppressor cells were not detectable in peripheral blood lymphocytes 6 to 9 months later. These findings provide further evidence that induction of immune responses may be abnormal early in treponemal infection and may help to explain the failure of the host to produce antibodies which eradicate the organism during the first 2 to 3 months of infection. 相似文献
19.
Ionizing radiation is a carcinogen that induces oxidative DNA damage. 8-
Hydroxy-2'-deoxyguanosine (8-OHdG) is a relatively abundant, mutagenic
lesion that is widely regarded as a reliable index of oxidative DNA damage.
The purpose of this study was to examine the effects of X- radiation on
levels of 8-OHdG in the context of an experimental model for breast cancer
in which chronic radiation exposure has been shown to be carcinogenic in
Sprague-Dawley rats. A secondary objective of this study was to determine
if the use of phenol during DNA isolation affected the concentration of
8-OHdG subsequently measured. Our results indicate that a profoundly
carcinogenic dose of radiation induced a small but significant increase in
8-OHdG concentration in mammary gland DNA, and that the use of a
phenol-based versus a salt-based method of DNA isolation had no significant
impact on the levels of 8-OHdG detected in either control or irradiated
tissue.
相似文献
20.