全文获取类型
收费全文 | 90篇 |
免费 | 12篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 6篇 |
2011年 | 1篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 7篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1976年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有102条查询结果,搜索用时 15 毫秒
1.
2.
Endothelial cells (EC) were cocultured with allogeneic PBL, CD4+ T cells, or CD8+ T cells, and the degrees of EC activation induced examined by determining patterns of endothelial class I and class II MHC and intercellular adhesion molecule-1 (ICAM-1) expression. Coculture with PBL or CD8+ T cells uniformly increases class I MHC and ICAM-1 expression on all EC within a culture, but induces class II MHC expression on only a subpopulation(s) of EC. This heterogeneous EC response to coculture contrasts with the uniform class II expression on all EC induced by IFN-gamma in replicate wells. CD4+ T cells, when compared to equal numbers of unfractionated PBL or CD8+ T cells, are more effective at increasing class I MHC and ICAM-1 but are unable to induce class II MHC expression. The failure of CD4+ T cells to induce EC class II MHC Ag is not due to insufficient activation of the T cells, as PHA-activated CD4+ T cells also do not induce significant class II expression. In addition, conditioned media (CM) from CD4+ T cell/EC contain greater levels of immunoreactive IFN-gamma than do CM from PBL/EC cocultures. Rather, CD4+ T cells appear to actively inhibit the induction of EC class II Ag but not class I or ICAM-1 by IFN-gamma. Inhibition occurs at the time of induction, as CD4+ T cells are not capable of down-regulating previously induced class II Ag. CM from CD4+/EC (but not PBL/EC) cocultures also inhibits IFN-gamma induction of EC class II MHC expression. The inhibitory activity is generated during CD4+ T cell-EC cell contact, and is enhanced by PHA. The inhibitory activity(ies) of the CD4+/EC-CM is as yet unidentified, and is only minimally reversible by cocktails of neutralizing antibodies directed against TNF-alpha, TNF-beta (lymphotoxin), IFN-alpha and IFN-beta. In conclusion, CD4+ and CD8+ T cells are each effective activators of EC, but the patterns of activation produced by these subsets are quite distinct, largely due to generation of a soluble inhibitor(s) of class II MHC induction during coculture of CD4+ T cells with EC. 相似文献
3.
mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species 总被引:4,自引:0,他引:4
Reconstructions of the human-African great ape phylogeny by using
mitochondrial DNA (mtDNA) have been subject to considerable debate. One
confounding factor may be the lack of data on intraspecific variation. To
test this hypothesis, we examined the effect of intraspecific mtDNA
diversity on the phylogenetic reconstruction of another Plio- Pleistocene
radiation of higher primates, the fascicularis group of macaque (Macaca)
monkey species. Fifteen endonucleases were used to identify 10 haplotypes
of 40-47 restriction sites in M. mulatta, which were compared with similar
data for the other members of this species group. Interpopulational,
intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of
divergence time and branching order incorporating this variation were
substantially different from those based on single representatives of each
species. We conclude that intraspecific mtDNA diversity is substantial in
at least some primate species. Consequently, without prior information on
the extent of genetic diversity within a particular species, intraspecific
variation must be assessed and accounted for when reconstructing primate
phylogenies. Further, we question the reliability of hominoid mtDNA
phylogenies, based as they are on one or a few representatives of each
species, in an already depauperate superfamily of primates.
相似文献
4.
Doukas DJ 《Theoretical medicine》1992,73(1):5-14
The emergence of the ethics consultation as a means to resolve moral crises in clinical medicine has revealed the need for a worksheet that would facilitate intake and analysis. The author developed the "Bioethics Consultation Form" as an attempt to remedy this need. The form is arranged in an outline format and is a useful asset to ethics committee discussions and record keeping. The first section covers basic intake data concerning the patient's medical and personal information, advance directives, and values, as well as the values of the physician and family. After the intake section is completed with the above data, the ethics consultant then turns to the analysis section. This second section allows for (1) the discussion of conflicting values, (2) the identification of priorities, and (3) the elucidation of ethical norms relevant to the case. The Bioethics Consultation Form was adopted by the Patient Care Advisory Committee of the Franklin Square Hospital Center in Baltimore, Maryland in 1986. The methodology in the use of the form will be discussed. Further, the potential spectrum of consultative cases that can be analyzed using the form will be highlighted. 相似文献
5.
Sotirios G. Doukas Panagiotis G. Doukas Clarence T. Sasaki Dimitra Vageli 《Journal of cellular and molecular medicine》2020,24(18):10311-10321
Bile at strongly acidic pH exerts a carcinogenic effect on the hypopharynx, based upon recent pre‐clinical studies that support its role as an independent risk factor. We recently demonstrated in vitro that curcumin can prevent oncogenic profile of bile in human hypopharyngeal cells, by inhibiting NF‐κB. We hypothesize that topically applied curcumin to the hypopharynx can similarly block early oncogenic molecular events of bile, by inhibiting NF‐κB and consequently altering the expression of genes with oncogenic function. Using Mus musculus (C57Bl/6J), we topically applied curcumin (250 μmol/L; three times per day; 10 days) to the hypopharynx, 15 minutes before, 15 minutes after or in combination with bile acids (pH 3.0). Immunohistochemical analysis and qPCR revealed that topically applied curcumin either before, after or in combination with acidic bile exposure significantly suppressed its induced NF‐κB activation in regenerating epithelial cells, and overexpression of Rela, Bcl2, Egfr, Stat3, Wnt5a, Tnf, Il6, Ptgs2. Akt1 was particularly inhibited by curcumin when applied simultaneously with bile. We provide novel evidence into the preventive and therapeutic properties of topically applied curcumin in acidic bile‐induced early oncogenic molecular events in hypopharyngeal mucosa, by inhibiting NF‐κB, and shaping future translational development of effective targeted therapies using topical non‐pharmacologic inhibitors of NF‐κB. 相似文献
6.
Menounos P Zervas C Garinis G Doukas C Kolokithopoulos D Tegos C Patrinos GP 《Human heredity》2000,50(4):237-241
We report results from a systematic study to identify the molecular basis of glucose-6-phosphate dehydrogenase (G6PD) deficiency on a sample of 299 male subjects from the Hellenic population. Our stepwise approach involved partial biochemical characterization and quantitation of the enzyme's activity, MboII restriction endonuclease digestion to identify the G6PD Mediterranean variant, which represents the most frequent G6PD variant in our population and a nonradioactive polymerase chain reaction-single-strand conformation polymorphism methodology for the detection of the underlying molecular defect(s) in the rest of the non-Mediterranean G6PD-deficient individuals. Through this approach, six different G6PD variants were identified (G6PD Mediterranean, G6PD Hermoupolis, G6PD Cassano, G6PD Seattle, G6PD Ierapetra and G6PD Acrokorinthos), two of which were new (G6PD Hermoupolis, G6PD Acrokorinthos). In essence, this study underlines the remarkable genetic heterogeneity of the G6PD deficiency in the Hellenic population, while the finding of the double mutant, G6PD Hermoupolis, may help to outline the relationship and evolution of mutations in the human G6PD locus. 相似文献
7.
Ad N Cheng DC Martin J Berglin EE Chang BC Doukas G Gammie JS Nitta T Wolf RK Puskas JD 《Innovations (Philadelphia, Pa.)》2010,5(2):74-83
OBJECTIVE:: This purpose of this consensus conference was to determine whether surgical atrial fibrillation (AF) ablation during cardiac surgery improves clinical and resource outcomes compared with cardiac surgery alone in adults undergoing cardiac surgery for valve or coronary artery bypass grafting. METHODS:: Before the consensus conference, the consensus panel reviewed the best available evidence, whereby systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. Evidence-based statements were created, and consensus processes were used to determine the ensuing recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of recommendation. RESULTS:: The consensus panel agreed on the following statements in patients with AF undergoing cardiac surgery concomitant surgical ablation: CONCLUSIONS:: Given these evidence-based statements, the consensus panel stated that, in patients with persistent and permanent AF undergoing cardiac surgery, concomitant surgical ablation is recommended to increase incidence of sinus rhythm at short- and long-term follow-up (class 1, level A); to reduce the risk of stroke and thromboembolic events (class 2a, level B); to improve EF (class 2a, level A); and to exercise tolerance (class 2a, level A) and long-term survival (class 2a, level B). 相似文献
8.
Muma JB Lund A Siamudaala VM Munang'andu HM Munyeme M Matope G Nielsen K DJønne B Godfroid J Tryland M Skjerve E 《Journal of wildlife diseases》2010,46(4):1063-1069
One of the diseases of veterinary and public health importance affecting the Kafue lechwe (Kobus leche kafuensis) on the Kafue flats is brucellosis, for which only scant information is available. During the 2003 (October), 2004 (December), and 2008 (July-December) hunting seasons in the Kafue flats, we conducted a study to determine the seroprevalence of Brucella spp. in the Kafue lechwe and to evaluate serologic tests for detection of Brucella spp. antibodies in lechwe. The Rose Bengal Test (RBT), competitive enzyme-linked immunosorbent assay (cELISA), and fluorescence polarization assay (FPA) were used. A total of 121 Kafue lechwe were hunted for disease investigations in 2003, 2004, and 2008 in the Kafue Flat Game Management Area. Of these, 21.6%, (95% confidence interval [CI]: 14.2-29.1%) had detectable antibodies to Brucella spp. The Kafue lechwe in Lochnivar National Park had higher antibody results than those in Blue Lagoon National Park (odds ratio=3.0; 95% CI: 0.94-9.4). Infection levels were similar in females (21.6%) and males (21.7%). Results were similar among RBT, FPA, cELISA tests, suggesting that these could effectively be used in diagnosing brucellosis in the Kafue lechwe. Our study demonstrates the presence of Brucella infections in the Kafue lechwe in two national parks located in the Kafue flats and further highlights the suitability of serologic assays for testing the Kafue lechwe. Because the Kafue lechwe is the most hunted wildlife species in Zambia, hunters need to be informed of the public health risk of Brucella spp. infection. 相似文献
9.
Poornima Parameswaran Ella Sklan Courtney Wilkins Trever Burgon Melanie A. Samuel Rui Lu K. Mark Ansel Vigo Heissmeyer Shirit Einav William Jackson Tammy Doukas Suman Paranjape Charlotta Polacek Flavia Barreto dos Santos Roxana Jalili Farbod Babrzadeh Baback Gharizadeh Dirk Grimm Mark Kay Satoshi Koike Peter Sarnow Mostafa Ronaghi Shou-Wei Ding Eva Harris Marie Chow Michael S. Diamond Karla Kirkegaard Jeffrey S. Glenn Andrew Z. Fire 《PLoS pathogens》2010,6(2)
We have used multiplexed high-throughput sequencing to characterize changes in small RNA populations that occur during viral infection in animal cells. Small RNA-based mechanisms such as RNA interference (RNAi) have been shown in plant and invertebrate systems to play a key role in host responses to viral infection. Although homologs of the key RNAi effector pathways are present in mammalian cells, and can launch an RNAi-mediated degradation of experimentally targeted mRNAs, any role for such responses in mammalian host-virus interactions remains to be characterized. Six different viruses were examined in 41 experimentally susceptible and resistant host systems. We identified virus-derived small RNAs (vsRNAs) from all six viruses, with total abundance varying from “vanishingly rare” (less than 0.1% of cellular small RNA) to highly abundant (comparable to abundant micro-RNAs “miRNAs”). In addition to the appearance of vsRNAs during infection, we saw a number of specific changes in host miRNA profiles. For several infection models investigated in more detail, the RNAi and Interferon pathways modulated the abundance of vsRNAs. We also found evidence for populations of vsRNAs that exist as duplexed siRNAs with zero to three nucleotide 3′ overhangs. Using populations of cells carrying a Hepatitis C replicon, we observed strand-selective loading of siRNAs onto Argonaute complexes. These experiments define vsRNAs as one possible component of the interplay between animal viruses and their hosts. 相似文献
10.
Studies in polytunnels were conducted to investigate the effects of ultraviolet (UV)‐blocking films on naturally occurring insect pests and their arthropod natural enemies on a cucumber crop. Within tunnels clad with Antibotrytis (blocks light < 400 nm) and UVI/EVA (UV transmitting), 5.8 and 23.4 times more aphids, respectively, were recorded on traps compared with those on traps within tunnels clad with XL 385 (blocks light < 385 nm). When all plants within the UVI/EVA tunnels had become heavily infested with aphids, half of the plants in XL 385 tunnels were uninfested. More Coleoptera and thrips (approximately two times) were recorded under the UVI/EVA film than under the UV‐blocking films, but for other arthropod pests (e.g. whitefly, leafhoppers), clear conclusions could not be drawn as low numbers were recorded. Substantial numbers of chalcid parasitoids and syrphids were found under the UV‐blocking films, but further research is needed to evaluate fully the effect of such films on biological control of aphids. Higher syrphid numbers and more aphid mummies were recorded under the UVI/EVA film, probably because of the higher numbers of aphids present in tunnels clad with this film. The potential that UV‐blocking films have as an effective component of commercial Integrated Pest Management (IPM) systems, for protected horticultural crops, is discussed. 相似文献