979 resultados para Non-aromatic B-ring flavanone
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The degree of gene hypermethylation in non-neoplastic colonic mucosa (NNCM) is a potentially important event in the development of colorectal cancer (CRC), particularly for the subgroup with a CpG island methylator phenotype (CIMP). In this study, we aimed to use an unbiased and high-throughput approach to evaluate the topography of DNA methylation in the non-neoplastic colonic mucosa (NNCM) surrounding colorectal cancer (CRC). A total of 61 tissue samples comprising 53 NNCM and 8 tumor samples were obtained from hemicolectomy specimens of two CRC patients (Cases 1 and 2). NNCM was stripped from the underlying colonic wall and samples taken at varying distances from the tumor. The level of DNA methylation in NNCM and tumor tissues was assessed at 1,505 CpG sites in 807 cancer-related genes using Illumina GoldenGate® methylation arrays. Case 1 tumor showed significantly higher levels of methylation compared to surrounding NNCM samples (P?
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To compare the rejection rates of non-small cell lung cancer (NSCLC) samples obtained by differing sampling methods for testing by Sanger sequencing for epidermal growth factor receptor (EGFR) mutations. To assess the association between unsatisfactory outcomes and the quantity of DNA extracted from cytological versus histological samples.
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Although the antimicrobial activity of atmospheric pressure non-thermal plasmas, including its capacity to eradicate microbial biofilms, has been gaining an ever increasing interest for different medical applications, its potential utilisation in the control of biofouling and biodeterioration has, to date, received no attention. In this study, the ability of atmospheric pressure plasma to eradicate biofilms of four biofouling bacterial species, frequently encountered in marine environments, was investigated. Biofilms were grown on both polystyrene and stainless steel surfaces before being exposed to the plasma source. Viability and biomass of biofilms were evaluated using colony count method and differential Live/Dead fluorescence staining followed by confocal laser scanning microscopy. Rapid and complete eradication of all biofilms under study was achieved after plasma exposures ranging from 60 to 120 s. Confocal microscopy examination showed that plasma treatment has mediated not only cell killing but also varying degrees of physical removal of biofilms. Further investigation and tailored development of atmospheric pressure non-thermal plasma sources for this particular application could provide an additional powerful and effective weapon in the current anti-biofouling armamentarium.
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Background:Mechanical ventilation is a critical component of paediatric intensive care therapy. It is indicated when the patient’s spontaneous ventilation is inadequate to sustain life. Weaning is the gradual reduction of ventilatory support and the transfer of respiratory control back to the patient. Weaning may represent a large proportion of the ventilatory period. Prolonged ventilation is associated with significant morbidity, hospital cost, psychosocial and physical risks to the child and even death. Timely and effective weaning may reduce the duration of mechanical ventilation and may reduce the morbidity and mortality associated with prolonged ventilation. However, no consensus has been reached on criteria that can be used to identify when patients are ready to wean or the best way to achieve it.Objectives:To assess the effects of weaning by protocol on invasively ventilated critically ill children. To compare the total duration of invasive mechanical ventilation of critically ill children who are weaned using protocols versus those weaned through usual (non-protocolized) practice. To ascertain any differences between protocolized weaning and usual care in terms of mortality, adverse events, intensive care unit length of stay and quality of life.Search methods:We searched the Cochrane Central Register of Controlled Trials (CENTRAL; The Cochrane Library, Issue 10, 2012), MEDLINE (1966 to October 2012), EMBASE (1988 to October 2012), CINAHL (1982 to October 2012), ISI Web of Science and LILACS. We identified unpublished data in the Web of Science (1990 to October 2012), ISI Conference Proceedings (1990 to October 2012) and Cambridge Scientific Abstracts (earliest to October 2012). We contacted first authors of studies included in the review to obtain further information on unpublished studies or work in progress. We searched reference lists of all identified studies and review papers for further relevant studies. We applied no language or publication restrictions.Selection criteriaWe included randomized controlled trials comparing protocolized weaning (professional-led or computer-driven) versus non-protocolized weaning practice conducted in children older than 28 days and younger than 18 years.Data collection and analysis:Two review authors independently scanned titles and abstracts identified by electronic searching. Three review authors retrieved and evaluated full-text versions of potentially relevant studies, independently extracted data and assessed risk of bias.Main results:We included three trials at low risk of bias with 321 children in the analysis. Protocolized weaning significantly reduced total ventilation time in the largest trial (260 children) by a mean of 32 hours (95% confidence interval (CI) 8 to 56; P = 0.01). Two other trials (30 and 31 children, respectively) reported non-significant reductions with a mean difference of -88 hours (95% CI -228 to 52; P = 0.2) and -24 hours (95% CI -10 to 58; P = 0.06). Protocolized weaning significantly reduced weaning time in these two smaller trials for a mean reduction of 106 hours (95% CI 28 to 184; P = 0.007) and 21 hours (95% CI 9 to 32; P < 0.001). These studies reported no significant effects for duration of mechanical ventilation before weaning, paediatric intensive care unit (PICU) and hospital length of stay, PICU mortality or adverse events.Authors' conclusions:Limited evidence suggests that weaning protocols reduce the duration of mechanical ventilation, but evidence is inadequate to show whether the achievement of shorter ventilation by protocolized weaning causes children benefit or harm.
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The effect of glycosylation on susceptibility of skin collagen to collagenase digestion was studied in a skin sample obtained at autopsy from the interscapular region of a 24 year old white male who had died of an acute illness and who had no history of diabetes. Homogeneous suspensions of insoluble collagen were prepared, and were incubated in 50 mmol l-1 dextrose at pH 7.35 and 37 degrees C for 7 days. Non-enzymatic glycosylation measured by the weak acid hydrolysis/thiobarbituric acid method increased from 13.1 +/- 1.0 (n = 5) to 45.2 +/- 5.5 (n = 8) nmol fructose per 10 mg collagen (P less than 0.001). Digestion of collagen using clostridial collagenase was monitored by measuring (a) hydroxyproline content and (b) absorption at 206 nm of the supernatant after centrifugation to remove substrate. The rate of digestion was similar in glycosylated and control collagen. We conclude that the ketoamine link formed in non-enzymatic glycosylation does not increase the resistance of collagen to enzymatic digestion. The possibility remains that subsequent rearrangement of this link could be important in this respect.
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We investigate the backflow of information in a system with a second-order structural phase transition, namely, a quasi-one-dimensional Coulomb crystal. Using standard Ramsey interferometry which couples a target ion (the system) to the rest of the chain (a phononic environment), we study the non-Markovian character of the resulting open system dynamics. We study two different time scales and show that the backflow of information pinpoints both the phase transition and different dynamical features of the chain as it approaches criticality. We also establish an exact link between the backflow of information and the Ramsey fringe visibility.
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Failure to efficiently induce apoptosis contributes to cisplatin resistance in non-small-cell lung cancer (NSCLC). Although BCL-2-associated X protein (BAX) and BCL-2 antagonist killer (BAK) are critical regulators of the mitochondrial apoptosis pathway, their requirement has not been robustly established in relation to cisplatin. Here, we show that cisplatin can efficiently bypass mitochondrial apoptosis block caused by loss of BAX and BAK, via activation of the extrinsic death receptor pathway in some model cell lines. Apoptosis resistance following cisplatin can only be observed when both extrinsic and intrinsic pathways are blocked, consistent with redundancy between mitochondrial and death receptor pathways in cisplatin-induced apoptosis. In H460 NSCLC cells, caspase-8 cleavage was shown to be induced by cisplatin and is dependent on death receptor 4, death receptor 5, Fas-associated protein with death domain, acid sphingomyelinase and ceramide synthesis. In contrast, cisplatin-resistant cells fail to activate caspase-8 via this pathway despite conserving sensitivity to death ligand-driven activation. Accordingly, caspase-8 activation block acquired during cisplatin resistance, can be bypassed by death receptor agonism. © 2012 Macmillan Publishers Limited
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In this paper, we introduce an application of matrix factorization to produce corpus-derived, distributional
models of semantics that demonstrate cognitive plausibility. We find that word representations
learned by Non-Negative Sparse Embedding (NNSE), a variant of matrix factorization, are sparse,
effective, and highly interpretable. To the best of our knowledge, this is the first approach which
yields semantic representation of words satisfying these three desirable properties. Though extensive
experimental evaluations on multiple real-world tasks and datasets, we demonstrate the superiority
of semantic models learned by NNSE over other state-of-the-art baselines.
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Focal gamma irradiation was used to limit the intraocular extension of scar tissue which typically occurs after posterior perforating injury to the eye. Standard posterior perforating injuries were created in the right eye of forty-eight rabbits, half of which had the site of perforation focally irradiated using a Cobalt 60 ophthalmic plaque. Non-irradiated wounds healed with profuse formation of highly cellular and vascularised granulation tissue which invaded the vitreous to form contractile vitreo-retinal membranes. In irradiated eyes vitreo-retinal membrane formation was infrequent; the wounds showing only sparse granulation tissue with little or no extension into the vitreous cavity. Autoradiographic studies carried out in a second group of 40 animals showed that the episclera was the main source of the proliferating fibroblasts, and cell counts confirmed that the inflammatory and repair responses in irradiated wounds were both delayed and attenuated.
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Atmospheric pressure non-thermal plasma (APNTP) has been gaining increasing interest as a new alternative antibacterial approach. Although this approach has demonstrated promising antibacterial activity, its exact mechanism of action remains unclear. Mechanistic elucidation of the antimicrobial activity will facilitate development and rational optimisation of this approach for potential medical applications. In this study, the antibacterial efficacy of an in-house-built APNTP jet was evaluated alongside an investigation of the interactions between APNTP and major cellular components in order to identify the potential cellular targets involved in plasma-mediated bacterial destruction mechanisms. The investigated plasma jet exhibited excellent, rapid antibacterial activity against a selected panel of clinically significant bacterial species including Bacillus cereus, meticillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Pseudomonas aeruginosa, all of which were completely inactivated within 2 min of plasma exposure. Plasma-mediated damaging effects were observed, to varying degrees, on all of the investigated cellular components including DNA, a model protein enzyme, and lipid membrane integrity and permeability. The antibacterial efficacy of APNTP appears to involve a multiple-target mechanism, which potentially reduces the likelihood of emergence of microbial resistance towards this promising antimicrobial approach. However, cellular membrane damage and resulting permeability perturbation was found to be the most likely rate-determining step in this mechanism. Crown Copyright © 2013.
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We investigate the conditions under which the trace distance between two different states of a given open system increases in time due to the interaction with an environment, therefore signaling non-Markovianity. We find that the finite-time difference in trace distance is bounded by two sharply defined quantities that are strictly linked to the occurrence of system-environment correlations created throughout their interaction and affecting the subsequent evolution of the system. This allows us to shed light on the origin of non-Markovian behaviors in quantum dynamics. We best illustrate our findings by tackling two physically relevant examples: a non-Markovian dephasing mechanism that has been the focus of a recent experimental endeavor and the open-system dynamics experienced by a spin connected to a finite-size quantum spin chain.
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OBJECTIVE - To describe and compare the associations of serum lipoproteins and apolipoproteins with diabetic retinopathy. RESEARCH DESIGN AND METHODS - This was a cross-sectional study of 224 diabetic patients (85 type 1 and 139 type 2) froma diabetes clinic. Diabetic retinopathy was graded from fundus photographs according to the Airlie House Classification system and categorized into mild, moderate, and vision-threatening diabetic retinopathy (VTDR). Serum traditional lipids (total, LDL, non-HDL, and HDL cholesterol and triglycerides) and apolipoprotein AI (apoAI), apolipoprotein B (apoB), and the apoB-to-apoAI ratio were assessed. RESULTS - Diabetic retinopathy was present in 133 (59.4%) individuals. After adjustment for age, sex, diabetes duration, A1C, systolic blood pressure, and diabetes medications, the HDL cholesterol level was inversely associated with diabetic retinopathy (odds ratio 0.39 [95% CI 0.16-0.94], highest versus lowest quartile; P = 0.017). The ApoAI level was inversely associated with diabetic retinopathy (per SD increase, 0.76 [95% CI 0.59-0.98]), whereas apoB (per SD increase, 1.31 [1.02-1.68]) and the apoB-to-apoAI ratio (per SD increase, 1.48 [1.13-1.95]) were positively associated with diabetic retinopathy. Results were similar for mild to moderate diabetic retinopathy and VTDR. Traditional lipid levels improved the area under the receiver operating curve by 1.8%, whereas apolipoproteins improved the area by 8.2%. CONCLUSIONS - ApoAI and apoB and the apoB-to-apoAI ratio were significantly and independently associated with diabetic retinopathy and diabetic retinopathy severity and improved the ability to discriminate diabetic retinopathy by 8%. Serum apolipoprotein levels may therefore be stronger biomarkers of diabetic retinopathy than traditional lipid measures. © 2011 by the American Diabetes Association.