514 research outputs found
New cosmological solutions and stability analysis in full extended thermodynamics
The Einstein's field equations of FRW universes filled with a dissipative
fluid described by full theory of causal transport equations are analyzed. New
exact solutions are found using a non-local transformations on the nonlinear
differential equation for the Hubble factor. The stability of the de Sitter and
asymptotically friedmannian solutions are analyzed using Lyapunov function
method.Comment: 13 pages, LaTeX 2.09. To be published in International Journal of
Modern Physics
Geometric realizations of birational transformations via -actions
In this paper we study varieties admitting torus actions as geometric
realizations of birational transformations. We present an explicit construction
of these geometric realizations for a particular class of birational
transformations, and study some of their geometric properties, such as their
Mori, Nef and Movable cones
Chow quotients of -actions
Given an action of the one-dimensional torus on a projective variety, the
associated Chow quotient arises as a natural parameter space of invariant
-cycles, which dominates the GIT quotients of the variety. In this paper we
explore the relation between the Chow and the GIT quotients of a variety,
showing how to construct explicitly the former upon the latter via successive
blowups under suitable assumptions. We also discuss conditions for the
smoothness of the Chow quotient, and present some examples in which it is
singular.Comment: 29 pages, 4 figure
Ultrasonic-assisted extraction and natural deep eutectic solvents combination: A green strategy to improve the recovery of phenolic compounds from Lavandula Pedunculata subsp. Lusitanica (Chaytor) Franco
The present study aimed at evaluating the effectiveness of different natural deep eutectic solvents (NADES) on the extraction of phenolic compounds from Lavandula pedunculata subsp.
lusitanica (Chaytor) Franco, on the antioxidant activity, and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and tyrosinase (Tyr) inhibitory capacities. Ten different NADES were used
in this research and compared with conventional solvents. Ultrasound-assisted extraction (UAE)
for 60 min proved to be the best extraction condition, and proline:lactic acid (1:1) and choline
chloride:urea (1:2) extracts showed the highest total phenolic contents (56.00 ± 0.77 mgGAE/gdw)
and antioxidant activity [64.35 ± 1.74 mgTE/gdw and 72.13 ± 0.97 mgTE/gdw in 2.2-diphenyl-1-
picrylhydrazyl (DPPH) and 2.20
-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) methods,
respectively]. These extracts also exhibited enzymes inhibitory capacity particularly against Tyr and
AChE. Even so, organic acid-based NADES showed to be the best extractants producing extracts
with considerable ability to inhibit enzymes. Twenty-four phenolic compounds were identified
by HPLC-HRMS, being rosmarinic acid, ferulic acid and salvianolic acid B the major compounds.
The results confirmed that the combination of UAE and NADES provide an excellent alternative to
organic solvents for sustainable and green extraction, and have huge potential for use in industrial
applications involving the extraction of bioactive compounds from plants.Grant SFRH/BD/145243/2019, UIDB/05183/2020info:eu-repo/semantics/publishedVersio
Synergistic warm inflation
We consider an alternative warm inflationary scenario in which scalar
fields coupled to a dissipative matter fluid cooperate to produce power--law
inflation. The scalar fields are driven by an exponential potential and the
bulk dissipative pressure coefficient is linear in the expansion rate. We find
that the entropy of the fluid attains its asymptotic value in a characteristic
time proportional to the square of the number of fields. This scenario remains
nearly isothermal along the inflationary stage. The perturbations in energy
density and entropy are studied in the long--wavelength regime and seen to grow
roughly as the square of the scale factor. They are shown to be compatible with
COBE measurements of the fluctuations in temperature of the CMB.Comment: 13 pages, Revtex 3 To be published in Physical Review
High rank torus actions on contact manifolds
We prove LeBrun--Salamon conjecture in the following situation: if is a
contact Fano manifold of dimension whose group of automorphisms is
reductive of rank then is the adjoint variety of a
simple group. The rank assumption is fulfilled not only by the three series of
classical linear groups but also by almost all the exceptional ones.Comment: Minor changes committe
Dissipative cosmological solutions
The exact general solution to the Einstein equations in a homogeneous
Universe with a full causal viscous fluid source for the bulk viscosity index
is found. We have investigated the asymptotic stability of Friedmann
and de Sitter solutions, the former is stable for and the latter for
. The comparison with results of the truncated theory is made. For
, it was found that families of solutions with extrema no longer remain
in the full case, and they are replaced by asymptotically Minkowski evolutions.
These solutions are monotonic.Comment: 17 pages, LaTeX 2.09, 1 figure. To be published in Classical and
Quantum Gravit
Efficacy of Manual Therapy on Facilitatory Nociception and Endogenous Pain Modulation in Older Adults with Knee Osteoarthritis: A Case Series.
Background: manual therapy (MT) has been shown to have positive effects in patients with osteoarthritis (OA)-related pain, and its use in clinical settings is recommended. However, the mechanisms of action for how these positive effects occur are not yet well understood. The aim of the present study was to investigate the influence of MT treatment on facilitatory nociception and endogenous pain modulation in patients with knee OA related pain. Methods: Twenty-eight patients with knee OA were included in this study. Pain intensity using the numerical pain rating scale (NPRS), temporal summation (TS), conditioned pain modulation (CPM), and local (knee) and distant (elbow) hyperalgesia through the pressure pain threshold (PPT), were assessed to evaluate the pain modulatory system. Patients underwent four sessions of MT treatments within 3 weeks and were evaluated at the baseline, after the first session and after the fourth session. Results: the MT treatment reduced knee pain after the first session (p = 0.03) and after the fourth session (p = 0.04). TS decreased significantly after the fourth session of MT (p = 0.02), while a significant increase in the CPM assessment was detected after the fourth session (p = 0.05). No significant changes in the PPT over the knee and elbow were found in the follow-ups. Conclusions: The results from our study suggest that MT might be an effective and safe method for improving pain and for decreasing temporal summation.post-print502 K
Pharmacokinetics and bioavailability of fosfomycin in broiler chicken
La pharmacocinétique et biodisponibilité de deux formulations de fosfomycine (fosfomycine disodique et fosfomycine calcique) ont été étudiées chez le poulet de chair. Les concentrations plasmatiques de fosfomycine ont été mesurées par chromatographie liquide haute performance (HPLC) couplée à une spectrométrie de masse en tandem (HPLC – SM/SM). Après administration d’un bolus intraveineux, la demi-vie d’élimination chez le poulet de chair est environ 1,4 h et le volume de distribution 231 ml/kg. Après absorption de fosfomycine par voie orale les valeurs de Cmax, Tmax, AUC(0-24) et biodisponibilité (F) sont respectivement 29,8 µg/ml, 2,0 h, 125 µg.h/ml et 39,3 %. Après l’administration par voie intramusculaire, les valeurs obtenues sont 20,7 µg/ml, 0,8 h, 65,1 µg.h/ml et 82 % pour la Cmax, Tmax, AUC(0-24) et biodisponibilité (F) respectivement. En considérant une CIM90= 8 µg/ml pour la fosfomycine sur des souches de E.coli chez le poulet de chair, les rapports AUC0-24/CMI90 calculés pour la fosfomycine administrée par voie orale et intramusculaire sont de 15,6 et 8,1 ce qui suggère une efficacité thérapeutique insuffisante in vivo lors d'une administration unique. Pour cette raison, il a été récemment proposé d’utiliser sur des souches sensibles de E.coli, une dose orale de charge de 40 mg/kg de fosfomycine disodique administrée dans l'eau de boisson, suivie d'une nouvelle administration de 40 mg/kg 8 h plus tard (soit 80 mg/kg par jour).The pharmacokinetics and the bioavailability of fosfomycin salts (sodium fosfomycin and calcium fosfomycin) were studied in broiler chickens after intravenous, intramuscular and oral administration. Plasma concentrations were measured by high performance liquid ms/ms. After IV administration the area under the fosfomycin concentration: time curve in plasma was AUC(0-24) of 318 µg.h/ml and the volume of distribution (Vd) of 231 ml/kg. The elimination was rapid with a plasma clearance of 115 ml/kg/hr and a T1/2 of 1.4 h. Peak plasmatic concentration (Cmax), Tmax, AUC(0-24) and bioavailability for the oral administration (40 mg/kg) were 29.8 µg/ml, 2.0 h, 125 µg.h/ml and 39.3% respectively. Peak plasmatic concentration (Cmax), Tmax, AUC(0-24) and bioavailability for the IM administration (10 mg/kg) were 20.7 µg/ml, 0.8 h, 65.1 µg.h/ml and 82% respectively. Considering a minimum inhibitory concentration (MIC90) of 8 µg/ml for fosfomycin on E.coli in broilers, the ratios AUC0-24/CMI90 estimated for fosfomycin after oral and IM administrations were 15.6 and 8.1 respectively. This suggests an insufficient therapeutic efficacy in vivo when administered in a unique dose. For this reason, a loading dose of 40 mg/kg via drinking water has been recently proposed for disodium fosfomycin versus E. coli strains, followed by ad libitum administration of 40 mg/kg 8h later (i.e. 80 mg/kg per day).Fil: Soraci, Alejandro Luis. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Pérez, Denisa Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia; ArgentinaFil: Tapia, Maria Ofelia. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Martinez, Guadalupe. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia; ArgentinaFil: Dieguez, Susana Nelly. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Departamento de Fisiopatologia; ArgentinaFil: Buronfosse Roque Florence. Centre de Pharmacovigilance, Vetagro-Sup, Campus Vètèrinaire de Lyon, Marcy L’Etoile,; FranciaFil: Harkes, Roberto. Laboratorio Bedson S.A.; ArgentinaFil: Colusi, A.. Laboratorio Bedson S.A.; ArgentinaFil: Romano Omar. Laboratorio Bedson S.A.; Argentin
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