3,398 research outputs found
Tissue-nonspecific alkaline phosphatase promotes axonal growth of hippocampal neurons
Axonal growth is essential for establishing neuronal circuits during brain development and for regenerative processes in the adult brain. Unfortunately, the extracellular signals controlling axonal growth are poorly understood. Here we report that a reduction in extracellular ATP levels by tissue-nonspecific alkaline phosphatase (TNAP) is essential for the development of neuritic processes by cultured hippocampal neurons. Selective blockade of TNAP activity with levamisole or specific TNAP knockdown with short hairpin RNA interference inhibited the growth and branching of principal axons, whereas addition of alkaline phosphatase (ALP) promoted axonal growth. Neither activation nor inhibition of adenosine receptors affected the axonal growth, excluding the contribution of extracellular adenosine as a potential hydrolysis product of extracellular ATP to the TNAP-mediated effects. TNAP was colocalized at axonal growth cones with ionotropic ATP receptors (P2X7 receptor), whose activation inhibited axonal growth. Additional analyses suggested a close functional interrelation of TNAP and P2X7 receptors whereby TNAP prevents P2X7 receptor activation by hydrolyzing ATP in the immediate environment of the receptor. Furthermore inhibition of P2X7 receptor reduced TNAP expression, whereas addition of ALP enhanced P2X7 receptor expression. Our results demonstrate that TNAP, regulating both ligand availability and protein expression of P2X7 receptor, is essential for axonal development
The Dirichlet Obstruction in AdS/CFT
The obstruction for a perturbative reconstruction of the five-dimensional
bulk metric starting from the four-dimensional metric at the boundary,that is,
the Dirichlet problem, is computed in dimensions and some
comments are made on its general structure and, in particular, on its
relationship with the conformal anomaly, which we compute in dimension .Comment: 13 pages, references added (this paper supersedes hep-th/0206140, "A
Note on the Bach Tensor in AdS/CFT", which has been withdrawn
Experimental measurement of the quality factor of a Fabry-P\'erot open-cavity axion haloscope
The axion is a hypothetical boson arising from the most natural solution to
the problem of charge and parity symmetry in the strong nuclear force.
Moreover, this pseudoscalar emerges as a dark matter candidate in a parameter
space extending several decades in mass. The Dark-photons \& Axion-Like
particles Interferometer (DALI) is a proposal to search for axion dark matter
in a range that remains under-examined. Currently in a design and prototyping
phase, this haloscope is a multilayer Fabry-P\'erot interferometer. A
proof-of-principle experiment is performed to observe the resonance in a
prototype. The test unveils a quality factor per open cavity of a few hundred
over a bandwidth of the order of dozens of megahertz. The result elucidates a
physics potential to find the, so far elusive, axion, in a sector which can
simultaneously solve the symmetry problem in the strong interaction and the
enigma of dark matter.Comment: 5 pages, 6 figure
Influence of Bitartrate Ion Concentration in the Copper Electrodeposition Onto a Polycrystalline Gold Electrode
In the present work, the influence of the concentration of bitartrate ions (HT) on the copper electrodeposition process was analyzed. The study was carried out from an aqueous solution containing 0.001 M of CuX (where X = (NO3–)2 ,(Cl–)2, SO42–) and x M KHT (where x = 0.005 M, 0.01 M, and 0.015 M). From voltammetric and chronoamperometric studies, the results indicate that copper electrodeposition is a diffusion-controlled process. The current density transients were well described through a kinetic mechanism involving capacitive and faradaic contributions. The diffusion coefficient values of Cu1+ and Cu2+ result to be similar at the different concentration values of potassium bitartrate used in this work.
This work is licensed under a Creative Commons Attribution 4.0 International License
OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level
Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu
Encapsulation of Lactobacillus fermentum K73 by Refractance Window drying
The purpose of this work was to model the survival of the microorganism and the kinetics of drying during the encapsulation of Lactobacillus fermentum K73 by Refractance Window drying. A whey culture medium with and without addition of maltodextrin were used as encapsulation matrices. The microorganism with the encapsulation matrices was dried at three water temperatures (333, 343 and 353 K) until reaching balanced moisture. Microorganism survival and thin layer drying kinetics were studied by using mathematical models. Results showed that modified Gompertz model and Midilli model described the survival of the microorganism and the drying kinetics, respectively. The most favorable process conditions found with the mathematical modelling were a drying time of 2460 s, at a temperature of 353 K. At these conditions, a product with 9.1 Log CFU/g and a final humidity of 10% [wet basis] using the culture medium as encapsulation matrix was obtained. The result shows that Refractance Window can be applied to encapsulate the microorganism probiotic with a proper survival of the microorganism
Polymerized-Type I Collagen Downregulates Inflammation and Improves Clinical Outcomes in Patients with Symptomatic Knee Osteoarthritis Following Arthroscopic Lavage: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial
Objectives. Polymerized-type I collagen (polymerized collagen) is a downmodulator of inflammation and cartilage regenerator biodrug. Aim. To evaluate the effect of intraarticular injections of polymerized collagen after arthroscopic lavage on inflammation and clinical improvement in patients with knee osteoarthritis (OA). Methods. Patients (n = 19) were treated with 6 intraarticular injections of 2 mL of polymerized collagen (n = 10) or 2 mL of placebo (n = 9) during 3 months. Followup was 3 months. The primary endpoints included Lequesne index, pain on a visual analogue scale (VAS), WOMAC, analgesic usage, the number of Tregs and proinflammatory/anti-inflammatory cytokine-expressing peripheral cells. Secondary outcomes were Likert score and drug evaluation. Clinical and immunological improvement was determined if the decrease in pain exceeds 20 mm on a VAS, 20% of clinical outcomes, and inflammatory parameters from baseline. Urinary levels of C-terminal crosslinking telopeptide of collagen type II (CTXII) and erythrocyte sedimentation rate (ESR) were determined. Results. Polymerized collagen was safe and well tolerated. Patients had a statistically significant improvement (P < 0.05) from baseline versus polymerized collagen and versus placebo at 6 months on Lequesne index, VAS, ESR, Tregs IL-1β, and IL-10 peripheral-expressing cells. Urinary levels of CTXII were decreased 44% in polymerized collagen versus placebo. No differences were found on incidence of adverse events between groups. Conclusion. Polymerized collagen is safe and effective on downregulation of inflammation in patients with knee OA
Forecasting confined spatiotemporal chaos with genetic algorithms
A technique to forecast spatiotemporal time series is presented. it uses a
Proper Ortogonal or Karhunen-Lo\`{e}ve Decomposition to encode large
spatiotemporal data sets in a few time-series, and Genetic Algorithms to
efficiently extract dynamical rules from the data. The method works very well
for confined systems displaying spatiotemporal chaos, as exemplified here by
forecasting the evolution of the onedimensional complex Ginzburg-Landau
equation in a finite domain.Comment: 4 pages, 5 figure
Asociación del locus BOLA-DRB3.2 con el virus de la leucosis bovina en el ganado criollo colombiano
The presence of the bovine leukemia virus (BLV) (pro-virus detection – Nested PCR), BoLA-DRB3.2* gen polymorphisms detection (Semi-nested PCR-RFLP) and the association between them (OR) were carried out in 330 DNA samples from eight creole breeds (Blanco Orejinegro, Caqueteño, Casanareño, Costeño con Cuernos, Chino Santandereano, Hartón del Valle, Romosinuano and Sanmartinero), two Colombian synthetic breeds (Lucerna y Velásquez) and two introduced ones (Brahmán y Holstein). A positive association was found between absence of BLV (resistant individuals) with alleles *21, *24 and *37; and the presence of BLV (susceptible individuals) with alleles *6 and *42. The cumulated allele frequency was 23.7% and 6% for the resistant and susceptible alleles respectively. For the Colombian creole cattle, 10% of genotyped individuals were classified as Resistant/ Resistant (RR), 2.5% as Susceptible/Susceptible (SS) and 57% as neutral homozygous (N/N). For the introduced breeds, 16% were RR and 8.3% SS. The results indicate that the Colombian creole cattle has VLB resistance genes. En 330 muestras de ADN de ocho razas bovinas criollas (Blanco Orejinegro, Caqueteño, Casanareño, Costeño con Cuernos, Chino Santandereano, Hartón del Valle, Romosinuano y Sanmartinero), dos razas sintéticas colombianas (Lucerna y Velásquez) y dos foráneas (Brahmán y Holstein) se evaluó la presencia del VLB (detección de provirus - PCR anidada), los polimorfismos del gen BoLA-DRB3.2* (PCR semianidada - RFLP) y la asociación entre ambos (OR). Se estimaron asociaciones entre la ausencia (resistentes) del VLB y los alelos *21, *24 y *37 y la presencia (susceptibles) del VLB y los alelos *6 y *42 en los ganados criollos. La frecuencia acumulada de los alelos resistentes fue de 23.7% contra 6% de los susceptibles. El 10% de los individuos fue genotipificado como Resistente/ Resistente, el 2.5% como Susceptible/Susceptible y el 57% fue de genotipo homocigoto neutral (N/N) en el ganado criollo colombiano. En los ganados controles el 16% fueron Resistente/Resistente y el 8.3% Susceptible/Susceptible. Los resultados indican que el ganado criollo colombiano posee genes de resistencia al VLB
- …