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排序方式: 共有128条查询结果,搜索用时 15 毫秒
81.
Principal component models for sparse functional data 总被引:5,自引:0,他引:5
82.
83.
In anti-neutrophil cytoplasmic autoantibody-associated vasculitides (AAV), several observations support a key role of T-helper
cells (CD4+ T cells) in disease pathophysiology. An expanded population of effector memory CD4+ T cells in AAV patients may contribute to tissue injury and disease progression. In addition, functional impairment of regulatory
T cells (TRegs) is reported in AAV patients. A fraction of TRegs have the capacity to differentiate into Th17 cells in the context of a proinflammatory environment. Therefore, nonfunctionality
of TRegs described in AAV patients may be caused by their conversion into IL-17-producing cells that may contribute to granulomatous
vasculitis. Further investigations directed at the plasticity of TRegs in AAV patients are warranted. 相似文献
84.
Cees GM Kallenberg Arjan Vissink Frans GM Kroese Wayel H Abdulahad Hendrika Bootsma 《Arthritis research & therapy》2011,13(1):205
In vitro and in vivo experimental data have pointed to new immunopathogenic mechanisms in primary Sj?gren's syndrome (pSS). The availability of
targeted treatment modalities has opened new ways to selectively target these mechanistic pathways in vivo. This has taught us that the role of proinflammatory cytokines, in particular TNFα, is not crucial in the immunopathogenesis
of pSS. B cells appear to play a major role, as depletion of B cells leads to restoration of salivary flow and is efficacious
for treatment of extraglandular manifestations and mucosa-associated lymphoid tissue lymphoma. B cells also orchestrate T-cell
infiltration and ductal epithelial dearrangement in the salivary glands. Gene profiling of salivary gland tissue in relation
to B-cell depletion confirms that the axis of IFNα, B-cell activating factor, B-cell activation, proliferation and survival
constitutes a major pathogenic route in pSS. 相似文献
85.
We developed a new and simple method to collect sections of a whole brown rice kernel for investigation of histological properties. A single kernel of rice was dehydrated through a graded ethanol series, transferred to xylene, and embedded in paraffin. During sectioning of the blocks using a rotary microtome, we used a special adhesive tape to collect and place the sections on slides so they remained flat. The use of the adhesive tape technique combined with autofluorescence characteristics allowed us to visualize cell walls throughout an entire longitudinal or transverse section of a whole rice kernel. We obtained scanning electron microscopy images of the sections to determine section quality. 相似文献
86.
Céline Colinon Dominique Jocktane Elisabeth Brothier Gian Maria Rossolini Benoit Cournoyer Sylvie Nazaret 《Environmental microbiology》2010,12(3):716-729
Faecal carriage of Pseudomonas aeruginosa was investigated by selective plating and PCR identification test, among healthy captive snakes from zoological and private collections from France as well as from wild snakes from Guinea. P. aeruginosa faecal carriage among captive snakes was high (72 out of 83 individuals), but low among wild specimen (3 out of 23 individuals). Genetic diversity analyses of the isolates, based on SpeI‐PFGE profiles, evidenced five dominant clones or clonal complexes spreading among snakes within a site and between sites and persisting over time. Similar clones or clonal complexes were detected from mouth swabs of the owners and from water and preys used to feed the snakes, evidencing various sources of snake colonization and the first cases of P. aeruginosa cross‐contamination between snakes and owners. These observations led to the conclusion that P. aeruginosa behaves as an opportunistic species within snakes in captivity and that colonization and dissemination occurs consecutively to processes similar to those identified within the hospital. Antibiotic susceptibility testing showed that most isolates had a wild‐type resistance profile except for one persistent clone isolated from both snakes and preys that harboured multiple antimicrobial resistance genes mediated by an integron carrying the qacH, aadB, aadA2 and cmlA10 cassettes, and a tetA(C)‐carrying transposon. Biocides or antibiotics used in the zoological garden could have led to the acquisition of this integron. 相似文献
87.
Background
Poorly preserved biological tissues have become an important source of DNA for a wide range of zoological studies. Measuring the quality of DNA obtained from these samples is often desired; however, there are no widely used techniques available for quantifying damage in highly degraded DNA samples. We present a general method that can be used to determine the frequency of polymerase blocking DNA damage in specific gene-regions in such samples. The approach uses quantitative PCR to measure the amount of DNA present at several fragment sizes within a sample. According to a model of random degradation the amount of available template will decline exponentially with increasing fragment size in damaged samples, and the frequency of DNA damage (λ) can be estimated by determining the rate of decline.Results
The method is illustrated through the analysis of DNA extracted from sea lion faecal samples. Faeces contain a complex mixture of DNA from several sources and different components are expected to be differentially degraded. We estimated the frequency of DNA damage in both predator and prey DNA within individual faecal samples. The distribution of fragment lengths for each target fit well with the assumption of a random degradation process and, in keeping with our expectations, the estimated frequency of damage was always less in predator DNA than in prey DNA within the same sample (mean λpredator = 0.0106 per nucleotide; mean λprey = 0.0176 per nucleotide). This study is the first to explicitly define the amount of template damage in any DNA extracted from faeces and the first to quantify the amount of predator and prey DNA present within individual faecal samples.Conclusion
We present an approach for characterizing mixed, highly degraded PCR templates such as those often encountered in ecological studies using non-invasive samples as a source of DNA, wildlife forensics investigations and ancient DNA research. This method will allow researchers to measure template quality in order to evaluate alternate sources of DNA, different methods of sample preservation and different DNA extraction protocols. The technique could also be applied to study the process of DNA decay. 相似文献88.
Roberto Mariotti Nicolò GM Cultrera Concepcion Muñoz Díez Luciana Baldoni Andrea Rubini 《BMC plant biology》2010,10(1):211
Background
The cultivated olive (Olea europaea L.) is the most agriculturally important species of the Oleaceae family. Although many studies have been performed on plastid polymorphisms to evaluate taxonomy, phylogeny and phylogeography of Olea subspecies, only few polymorphic regions discriminating among the agronomically and economically important olive cultivars have been identified. The objective of this study was to sequence the entire plastome of olive and analyze many potential polymorphic regions to develop new inter-cultivar genetic markers. 相似文献89.
Harriëtte Riese Tanja GM Vrijkotte Piet Meijer Cees Kluft Eco JC de Geus 《BMC cardiovascular disorders》2002,2(1):9-12
Background
Serum C-reactive protein (CRP) has been identified in prospective epidemiological research as an independent risk marker for cardiovascular disease. In this paper, short-term biological variation of CRP is documented and a strategy to test the reliability of a single CRP sample is proposed. 相似文献90.
Arvind K Awasthi GM Nagaraja GV Naik Sriramana Kanginakudru K Thangavelu Javaregowda Nagaraju 《BMC genetics》2004,5(1):1