2,474 research outputs found
Design, construction and validation of an instrumented particle for the lagrangian characterization of flows. Application to gravity wave turbulence
The design and application of an instrumented particle for the lagrangian
characterization of turbulent free surface flows is presented in this study.
This instrumented particle constitutes a local measurement device capable of
measuring both its instantaneous 3D translational acceleration and angular
velocity components, as well as recording them on an embarked removeable memory
card. A lithium ion polymer battery provides the instrumented particle with up
to 8 hours of autonomous operation. Entirely composed of commercial off the
shelf electronic components, it features accelerometer and gyroscope sensors
with a resolution of 16 bits for each individual axis, and maximum data
acquisition rates of 1 and 8 kHz, respectively, as well as several user
programmable dynamic ranges. Its ABS 3D printed body takes the form of a 36 mm
diameter hollow sphere, and has a total mass of (19.6 0.5) g. Controlled
experiments, carried out to calibrate and validate its performance showed good
agreement when compared to reference techniques. In order to assess the
practicality of the instrumented particle, we apply it to the statistical
characterization of floater dynamics in experiments of surface wave turbulence.
In this feasibility study, we focused our attention on the distribution of
acceleration and angular velocity fluctuations as a function of the forcing
intensity. The IP's motion is also simultaneously registered by a 3D particle
tracking velocimetry (PTV) system, for the purposes of comparison. Beyond the
results particular to this study case, it constitutes a proof of both the
feasibility and potentiality of the IP as a tool for the experimental
characterization of particle dynamics in such flows
Vitamin B12 deficiency is associated with geographical latitude and solar radiation in the older population
Artículo de publicación SCOPUSVitamin B12 and folic acid deficiency are common in the older and are associated with several conditions including anaemia, cardiovascular disease, cognitive impairment and cancer. Evidence from in vitro studies suggests that solar radiation can degrade both vitamins in the skin. Chile is the longest country in the world running perfectly North–South making it an ideal place to study potential associations of latitude and solar radiation on vitamin B12 and folic acid deficiency.
Objectives
The objective was to examine the association between vitamin B12 and folic acid deficiencies and latitude.
Methods
Plasma samples were collected from Chileans aged 65+ years (n = 1013) living across the whole country and assayed for vitamin B12 and folic acid concentrations as part of the Chilean Health Survey 2009–2010, which is a national representative sample study.
Results
Overall, the prevalence of vitamin B12 deficiency was 11.3%, with the prevalence in the North of the country being significantly greater than in the Central and South zones (19.1%,10.5%, and 5.7%, respectively; P < 0.001). The prevalence of folic acid deficiency in the whole cohort was 0.7% with no difference between the 3 geographical zones. Using logistic regression analyses, vitamin B12 deficiency was significantly associated with geographical latitude (OR 0.910 [95% confidence intervals 0.890–0.940], P < 0.001) and solar radiation (OR 1.203 [95% confidence intervals 1.119–1.294], P < <0.001). These associations persisted after adjustments for confounders (OR 0.930, P < 0.001 and 1.198, P = 0.002, respectively).International Society of Nephrology/Kidney Research UK Long-Term Fellowship and by grant support from Becas Chil
PHF2 regulates homology-directed DNA repair by controlling the resection of DNA double strand breaks
Post-translational histone modifications and chromatin remodelling play a critical role controlling the integrity of the genome. Here, we identify histone lysine demethylase PHF2 as a novel regulator of the DNA damage response by regulating DNA damage-induced focus formation of 53BP1 and BRCA1, critical factors in the pathway choice for DNA double strand break repair. PHF2 knockdown leads to impaired BRCA1 focus formation and delays the resolution of 53BP1 foci. Moreover, irradiation-induced RPA phosphorylation and focus formation, as well as localization of CtIP, required for DNA end resection, to sites of DNA lesions are affected by depletion of PHF2. These results are indicative of a defective resection of double strand breaks and thereby an impaired homologous recombination upon PHF2 depletion. In accordance with these data, Rad51 focus formation and homology-directed double strand break repair is inhibited in cells depleted for PHF2. Importantly, we demonstrate that PHF2 knockdown decreases CtIP and BRCA1 protein and mRNA levels, an effect that is dependent on the demethylase activity of PHF2. Furthermore, PHF2-depleted cells display genome instability and are mildly sensitive to the inhibition of PARP. Together these results demonstrate that PHF2 promotes DNA repair by homologous recombination by controlling CtIP-dependent resection of double strand breaks.España Ministerio de Ciencia e Innovacion SAF2016-80626-REspaña, Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) [PIFUN16/18
Evaluation of Hemodynamic Autonomic Control in an Animal Model of Acute Heart Failure Induced by High Dose of Halothane
Acute animal models of cardiac failure are necessary to study new therapeutic options and should be thoroughly characterized from the hemodynamic point of view, including the response of the autonomic nervous system. Thus, the aim of this work was to characterize the pathophysiological adaptation of the autonomic nervous system to acute cardiac failure induced by high doses of halothane (4%). In six sheep, electrocardiogram, aortic pressure and flow were obtained and calculation of systemic vascular resistances was done. Variability analyses in the time and frequency domains were also performed. In the time domain, after heart failure induction using halothane 4%, a significant decrease of both aortic blood flow variability (from 0. 13 ± 0. 05 to 0. 09 ± 0. 02 L min -1, p < 0. 05) and the broad band spectra (from 1. 80 ± 0. 66 to 1. 25 ± 0. 57 L 2 min -2, p < 0. 005) was observed. Both mean RR (472 ± 44 to 567 ± 68 ms, p < 0. 01), and low frequency band of RR intervals (from 6. 2 ± 0. 9 to 7. 7 ± 1. 5 ms 2, p < 0. 05), showed a significant increase, and no change in systemic vascular resistance (from 54. 9 ± 29. 5 to 50. 3 ± 38. 4 mmHg min L -1), all of them after heart failure induction. We conclude that in this model of heart failure the autonomic nervous system activity is still functioning, the combination of increased mean and RR low frequency band, with no change in systemic vascular resistance suggest an increase in the sympathetic control (due to maintained SVR), in an attempt to compensate the depression in the cardiac activity and hemodynamic alterations after severe myocardial depression induced by halothane.Fil: Camus, Juan M.. Universidad de Mendoza. Facultad de Ingeniería; ArgentinaFil: Ramírez, Agustín José. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Risk, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Palacios, Pablo J.. Universidad Favaloro; ArgentinaFil: de Forteza, Eduardo. Universidad Favaloro; ArgentinaFil: Cabrera Fischer, Edmundo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; Argentin
Enhancing visible-light photocatalysis via endohedral functionalization of single-walled carbon nanotubes with organic dyes
The encapsulation of an organic dye, 10-phenylphenothiazine (PTH), in the inner cavity of single-walled carbon nanotubes (SWNTs) as a breaking heterogenization strategy is presented. The PTH@oSWNT material was microscopically and spectroscopically characterized, showing intense photoemission when illuminated with visible light at the nanoscale. Thus, PTH@oSWNT was employed as a heterogeneous photocatalyst in single electron transfer dehalogenation reactions under visible light irradiation. The material showed an enhanced photocatalytic activity, achieving turnover numbers as high as 3200, with complete recyclability and stability for more than eight cycles. Computational calculations confirm that electronic communication between both partners is established because, upon illumination, an electron of the excited PTH is transferred from the πsystem of the molecule to the delocalized π-cloud of the SWNT, thus justifying the enhanced photocatalytic activityFinancial support was provided by the European Research Council (ERC-CoG, contract number: 647550), the Spanish Government (RTI2018-095038-B-I00, PID2019-110091GB-I00), and the “Comunidad de Madrid” and European Structural Funds (S2018/NMT-4367). M.B. wishes to thank the Spanish Government for a Juan de la Cierva contract (IJC2019-042157-I). A.M.-S. acknowledges support by the Comunidad Autónoma de Madrid under grant 2016-T2/IND166
Risk of Dengue Incidence in Children and Adolescents in Zulia, Venezuela, using a Negative Binomial Generalized Linear Mixed Model
Introduction: Dengue is the most important arboviral disease. Its incidence has increased 30-fold over the last 50 years, causing global concerns. Studies have showed children to be the most vulnerable.
Methods: Observational study using dengue cases from Zulia state, Venezuela, modelling through a Negative Binomial Generalized Linear Mixed Model (GLMM) accounting for heterogeneity in the variance via a hierarchical Bayesian framework, was done. We assessed risk factors such as age and sex. The Bayesian framework enabled the estimation of Relative Risk (RR) and a Binomial regression was run using the WinBUGS software.
Results: During 2002-2008, there were 49,330 cases of dengue in Zulia state, Venezuela. Most of them (18.71%) in 2007. The model revealed that children aged from 5 to 14 y-old had 1.59-higher risk (95%CI 1.41-1.79) compared with those aged from 0-4 y-old. Those aged 25-44 years old and ≥45, have significantly less RR than the baseline category, RR 0.5228 (95%CI 0.46-0.59) and 0.3069 (95%CI 0.27-0.34).
Conclusions: The findings confirmed that groups most at risk were children aged 5 to 14 years. Modelling and predicting dengue epidemiology are still a need in multiple countries, especially those at risk of newer epidemics, as is the case of Zulia and Venezuela
Risk of Dengue Incidence in Children and Adolescents in Zulia, Venezuela, using a Negative Binomial Generalized Linear Mixed Model
Introduction: Dengue is the most important arboviral disease. Its incidence has increased 30-fold over the last 50 years, causing global concerns. Studies have showed children to be the most vulnerable.
Methods: Observational study using dengue cases from Zulia state, Venezuela, modelling through a Negative Binomial Generalized Linear Mixed Model (GLMM) accounting for heterogeneity in the variance via a hierarchical Bayesian framework, was done. We assessed risk factors such as age and sex. The Bayesian framework enabled the estimation of Relative Risk (RR) and a Binomial regression was run using the WinBUGS software.
Results: During 2002-2008, there were 49,330 cases of dengue in Zulia state, Venezuela. Most of them (18.71%) in 2007. The model revealed that children aged from 5 to 14 y-old had 1.59-higher risk (95%CI 1.41-1.79) compared with those aged from 0-4 y-old. Those aged 25-44 years old and ≥45, have significantly less RR than the baseline category, RR 0.5228 (95%CI 0.46-0.59) and 0.3069 (95%CI 0.27-0.34).
Conclusions: The findings confirmed that groups most at risk were children aged 5 to 14 years. Modelling and predicting dengue epidemiology are still a need in multiple countries, especially those at risk of newer epidemics, as is the case of Zulia and Venezuela
Noninvasive detection of microsatellite instability in patients with endometrial cancer
Endometrial cancer; Liquid biopsy; Uterine aspirateCàncer d'endometri; Biòpsia líquida; Aspirat uteríCáncer de endometrio; Biopsia líquida; Aspirado uterinoThe analysis of mismatch repair proteins in solid tissue is the standard of care (SoC) for the microsatellite instability (MSI) characterization in endometrial cancer (EC). Uterine aspirates (UAs) or circulating-DNA (cfDNA) samples capture the intratumor heterogeneity and provide a more comprehensive and dynamic molecular diagnosis. Thus, MSI analysis by droplet-digital PCR (ddPCR) in UAs and cfDNA can provide a reliable tool to characterize and follow-up the disease. The UAs, paraffin-embedded tumor tissue (FFPE) and longitudinal plasma samples from a cohort of 90 EC patients were analyzed using ddPCR panel and compared to the SoC. A high concordance (96.67%) was obtained between the analysis of MSI markers in UAs and the SoC. Three discordant cases were validated as unstable by ddPCR on FFPE samples. Besides, a good overall concordance (70.27%) was obtained when comparing the performance of the ddPCR assay on UAs and cfDNA in high-risk tumors. Importantly, our results also evidenced the value of MSI analysis to monitor the disease evolution. MSI evaluation in minimally invasive samples shows great accuracy and sensitivity and provides a valuable tool for the molecular characterization and follow-up of endometrial tumors, opening new opportunities for personalized management of EC.Centro de Investigación Biomédica en Red de Cáncer, Grant/Award Numbers: CB16/12/00295, CB16/12/00328; Fundación Científica Asociación Española Contra el Cáncer, Grant/Award Numbers: FC_AECC PROYE19036MOR, 2018-AECC, INVES20051COLA; Fundación Instituto de Investigación Sanitaria de Santiago de Compostela; Instituto de Salud Carlos III and FEDER, Grant/Award Numbers: CM19/00087, CP20/00119, PI20/00969, PI20/01566, PI21/00990; Spanish Ministry of Economy and Innovation, Grant/Award Number: PID2019-104644RB-I0
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