3,303 research outputs found
Running Scaling Dimensions in Holographic Renormalization Group Flows
Holographic renormalization group flows can be interpreted in terms of
effective field theory. Based on such an interpretation, a formula for the
running scaling dimensions of gauge-invariant operators along such flows is
proposed. The formula is checked for some simple examples from the AdS/CFT
correspondence, but can be applied also in non-AdS/non-CFT cases.Comment: 14 pages, 2 figure
First-trimester or second-trimester screening, or both, for Down's syndrome
BACKGROUND: It is uncertain how best to screen pregnant women for the presence of fetal Down's syndrome: to perform first-trimester screening, to perform second-trimester screening, or to use strategies incorporating measurements in both trimesters.METHODS: Women with singleton pregnancies underwent first-trimester combined screening (measurement of nuchal translucency, pregnancy-associated plasma protein A [PAPP-A], and the free beta subunit of human chorionic gonadotropin at 10 weeks 3 days through 13 weeks 6 days of gestation) and second-trimester quadruple screening (measurement of alpha-fetoprotein, total human chorionic gonadotropin, unconjugated estriol, and inhibin A at 15 through 18 weeks of gestation). We compared the results of stepwise sequential screening (risk results provided after each test), fully integrated screening (single risk result provided), and serum integrated screening (identical to fully integrated screening, but without nuchal translucency).RESULTS: First-trimester screening was performed in 38,167 patients; 117 had a fetus with Down's syndrome. At a 5 percent false positive rate, the rates of detection of Down's syndrome were as follows: with first-trimester combined screening, 87 percent, 85 percent, and 82 percent for measurements performed at 11, 12, and 13 weeks, respectively; with second-trimester quadruple screening, 81 percent; with stepwise sequential screening, 95 percent; with serum integrated screening, 88 percent; and with fully integrated screening with first-trimester measurements performed at 11 weeks, 96 percent. Paired comparisons found significant differences between the tests, except for the comparison between serum integrated screening and combined screening.CONCLUSIONS: First-trimester combined screening at 11 weeks of gestation is better than second-trimester quadruple screening but at 13 weeks has results similar to second-trimester quadruple screening. Both stepwise sequential screening and fully integrated screening have high rates of detection of Down's syndrome, with low false positive rates
8-Oxo-7,8-dihydro-2'-deoxyguanosine and other lesions along the coding strand of the exon 5 of the tumour suppressor gene P53 in a breast cancer case-control study.
The next-generation sequencing studies of breast cancer have reported that the tumour suppressor P53 (TP53) gene is mutated in more than 40% of the tumours. We studied the levels of oxidative lesions, including 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), along the coding strand of the exon 5 in breast cancer patients as well as in a reactive oxygen species (ROS)-attacked breast cancer cell line using the ligation-mediated polymerase chain reaction technique. We detected a significant ‘in vitro’ generation of 8-oxodG between the codons 163 and 175, corresponding to a TP53 region with high mutation prevalence, after treatment with xanthine plus xanthine oxidase, a ROS-generating system. Then, we evaluated the occurrence of oxidative lesions in the DNA-binding domain of the TP53 in the core needle biopsies of 113 of women undergoing breast investigation for diagnostic purpose. An increment of oxidative damage at the −G− residues into the codons 163 and 175 was found in the cancer cases as compared to the controls. We found significant associations with the pathological stage and the histological grade of tumours. As the major news of this study, this largest analysis of genomic footprinting of oxidative lesions at the TP53 sequence level to date provided a first roadmap describing the signatures of oxidative lesions in human breast cancer. Our results provide evidence that the generation of oxidative lesions at single nucleotide resolution is not an event highly stochastic, but causes a characteristic pattern of DNA lesions at the site of mutations in the TP53, suggesting causal relationship between oxidative DNA adducts and breast cancer
Oxidation of HMGB1 Causes Attenuation of Its Pro-Inflammatory Activity and Occurs during Liver Ischemia and Reperfusion
High mobility group box 1 (HMGB1) is a nuclear transcription factor. Once HMGB1 is released by damaged cells or activated immune cells, it acts as danger molecule and triggers the inflammatory signaling cascade. Currently, evidence is accumulating that posttranslational modifications such as oxidation may modulate the pro-inflammatory potential of danger signals. We hypothesized that oxidation of HMGB1 may reduce its pro-inflammatory potential and could take place during prolonged ischemia and upon reperfusion
Potential for Energy Production from Farm Wastes Using Anaerobic Digestion in the UK: An Economic Comparison of Different Size Plants
© 2017 by the authors. Anaerobic digestion (AD) plants enable renewable fuel, heat, and electricity production, with their efficiency and capital cost strongly dependent on their installed capacity. In this work, the technical and economic feasibility of different scale AD combined heat and power (CHP) plants was analyzed. Process configurations involving the use of waste produced in different farms as feedstock for a centralized AD plant were assessed too. The results show that the levelized cost of electricity are lower for large-scale plants due to the use of more efficient conversion devices and their lower capital cost per unit of electricity produced. The levelized cost of electricity was estimated to be 4.3 p/kWhe for AD plants processing the waste of 125 dairy cow sized herds compared to 1.9 p/kWhe for AD plants processing waste of 1000 dairy cow sized herds. The techno-economic feasibility of the installation of CO2 capture units in centralized AD-CHP plants was also undertaken. The conducted research demonstrated that negative CO2 emission AD power generation plants could be economically viable with currently paid feed-in tariffs in the UK.The authors would like to acknowledge the funding received from the Research Councils UK
(RCUK) and particularly the Engineering and Physical Sciences Research Council (EPSRC) under Grant Number:
EP/K011820/1 (Centre for Sustainable Energy Use in Food Chains-CSEF) and EP/M007359/1 (Recovery and
re-use of energy, water and nutrients from waste in the food chain-Redivivus)
Transport in holographic superfluids
We construct a slowly varying space-time dependent holographic superfluid and
compute its transport coefficients. Our solution is presented as a series
expansion in inverse powers of the charge of the order parameter. We find that
the shear viscosity associated with the motion of the condensate vanishes. The
diffusion coefficient of the superfluid is continuous across the phase
transition while its third bulk viscosity is found to diverge at the critical
temperature. As was previously shown, the ratio of the shear viscosity of the
normal component to the entropy density is 1/(4 pi). As a consequence of our
analysis we obtain an analytic expression for the backreacted metric near the
phase transition for a particular type of holographic superfluid.Comment: 45 pages + appendice
Cysteine oxidation targets peroxiredoxins 1 and 2 for exosomal release through a novel mechanism of redox-dependent secretion
Non-classical protein secretion is of major importance as a number of cytokines and inflammatory mediators are secreted via this route. Current evidence indicates that there are several mechanistically distinct methods of non-classical secretion. We have recently shown that peroxiredoxin (Prdx) 1 and Prdx2 are released by various cells upon exposure to inflammatory stimuli such as LPS or TNF-α. The released Prdx then acts to induce production of inflammatory cytokines. However, Prdx1 and 2 do not have signal peptides and therefore must be secreted by alternative mechanisms as has been postulated for the inflammatory mediators IL-1β and HMGB1. We show here that circulating Prdx1 and 2 are present exclusively as disulphide-linked homodimers. Inflammatory stimuli also induce in vitro release of Prdx1 and 2 as disulfide-linked homodimers. Mutation of cysteines Cys51 or Cys172 (but not Cys70) in Prdx2, and Cys52 or Cys173 (but not Cys71 or Cys83) in Prdx1 prevented dimer formation and this was associated with inhibition of their TNF-α-induced release. Thus, the presence and oxidation of key cysteine residues in these proteins are a prerequisite for their secretion in response to TNF-α and this release can be induced with an oxidant. In contrast, the secretion of the nuclear-associated danger signal HMGB1 is independent of cysteine oxidation, as shown by experiments with a cysteine-free HMGB1 mutant. Release of Prdx1 and 2 is not prevented by inhibitors of the classical secretory pathway; instead, both Prdx1 and 2 are released in exosomes from both HEK cells and monocytic cells. Serum Prdx1 and 2 are also associated with the exosomes. These results describe a novel pathway of protein secretion mediated by cysteine oxidation that underlines the importance of redox-dependent signalling mechanisms in inflammation
Spatio-temporal Models of Lymphangiogenesis in Wound Healing
Several studies suggest that one possible cause of impaired wound healing is
failed or insufficient lymphangiogenesis, that is the formation of new
lymphatic capillaries. Although many mathematical models have been developed to
describe the formation of blood capillaries (angiogenesis), very few have been
proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a
markedly different process from angiogenesis, occurring at different times and
in response to different chemical stimuli. Two main hypotheses have been
proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the
edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic
endothelial cells first pool in the wound region following the lymph flow and
then, once sufficiently populated, start to form a network. Here we present two
PDE models describing lymphangiogenesis according to these two different
hypotheses. Further, we include the effect of advection due to interstitial
flow and lymph flow coming from open capillaries. The variables represent
different cell densities and growth factor concentrations, and where possible
the parameters are estimated from biological data. The models are then solved
numerically and the results are compared with the available biological
literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total
Impact of treatment with dimethyl fumarate on sleep quality in patients with relapsing-remitting multiple sclerosis: A multicentre Italian wearable tracker study
BackgroundSleep disorders are common in patients with multiple sclerosis and have a bidirectional interplay with fatigue and depression. ObjectiveTo evaluate the effect of treatment with oral dimethyl fumarate on the quality of sleep in relapsing-remitting multiple sclerosis. MethodsThis was a multicentre observational study with 223 relapsing-remitting multiple sclerosis subjects starting treatment with dimethyl fumarate (n=177) or beta interferon (n=46). All patients underwent subjective (Pittsburgh Sleep Quality Index) and objective (wearable tracker) measurements of quality of sleep. Fatigue, depression, and quality of life were also investigated and physical activity was monitored. ResultsPatients treated with dimethyl fumarate had significant improvement in the quality of sleep as measured with the Pittsburgh Sleep Quality Index (p<0.001). At all-time points, no significant changes in Pittsburgh Sleep Quality Index score were observed in the interferon group. Total and deep sleep measured by wearable tracker decreased at week 12 with both treatments, then remained stable for the total study duration. Depression significantly improved in patients treated with dimethyl fumarate. No significant changes were observed in mobility, fatigue and quality of life. ConclusionIn patients with relapsing-remitting multiple sclerosis, the treatment with dimethyl fumarate was associated with improvements in patient-reported quality of sleep. Further randomised clinical trials are needed to confirm the benefits of long-term treatment with dimethyl fumarate
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