845 research outputs found
Well-posedness of the Kolmogorov two-equation model of turbulence in optimal Sobolev spaces
In this paper, we study the well-posedness of the Kolmogorov two-equation model of turbulence in a periodic domain Td, for space dimensions d = 2,3. We admit the average turbulent kinetic energy k to vanish in part of the domain, i.e. we consider the case k ≥ 0; in this situation, the parabolic structure of the equations becomes degenerate.
For this system, we prove a local well-posedness result in Sobolev spaces Hs, for any s > 1+d/2. We expect this regularity to be optimal, due to the degeneracy of the system when k ≈ 0. We also prove a continuation criterion and provide a lower bound for the lifespan of the solutions. The proof of the results is based on Littlewood- Paley analysis and paradifferential calculus on the torus, together with a precise commutator decomposition of the non-linear terms involved in the computations
Climatoséquence de la région méridionale de l'île de Ténérife (îles Canaries) : 2ème partie. Caractéristiques minéralogiques, interprétation et classification
Peer reviewe
Séquence climatique des sols anciens de la région septentrionale de Ténérife (Iles Canaries) : 2ème partie. Caractéristiques minéralogiques et micromorphologiques
Séquence climatique des sols récents de la région septentrionale de Ténérife (îles Canaries) : 2ème partie. Caractéristiques minéralogiques : interprétation et classification
Séquence climatique des sols anciens de la région septentrionale de Ténérife (îles Canaries) : 1ère partie. Caractéristiques morphologiques et physico-chimiques
Observations sur la présence de sols ferrallitiques dérivés de matériaux volcaniques aux Iles Canaries
Séquence climatique des sols anciens de la région septentrionale de Ténérife (îles Canaries) : 3ème partie. Typologie, pédogenèse et classification
Andosoles canarios : 4. Intergrados andosol-tierra parda oligotrofica : caracteristicas mineralogicas, interpretacion y clasificacion
Influence of the Lubrication Conditions on the Surface Finish of Turned Aeronautical Aluminium Alloys. A preliminary Study
Nowadays, one of the main objectives that affects the development of any new product is the respect for the environment. Until the late 80's, the development and manufacture of the most of the product were aimed to achieve maximum quality in time and costs with environmental issues relegated to secondary importance. On the other hand, in the 90's, the pressure from factors such as markets, financial and legislative factors, led to environmental considerations being taken into account. In this context, the current aeronautical industry strategies are based on the search for economic, environmental and energy efficiency considerations for all the processes involved in the aircraft manufacturing
Proteomic identification and characterization of hepatic glyoxalase 1 dysregulation in non-alcoholic fatty liver disease
Background: Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. However, its
molecular pathogenesis is incompletely characterized and clinical biomarkers remain scarce. The aims of these
experiments were to identify and characterize liver protein alterations in an animal model of early, diet-related,
liver injury and to assess novel candidate biomarkers in NAFLD patients.
Methods: Liver membrane and cytosolic protein fractions from high fat fed apolipoprotein E knockout (ApoE−/−)
animals were analyzed by quantitative proteomics, utilizing isobaric tags for relative and absolute quantitation
(iTRAQ) combined with nano-liquid chromatography and tandem mass spectrometry (nLC-MS/MS). Differential
protein expression was confirmed independently by immunoblotting and immunohistochemistry in both murine
tissue and biopsies from paediatric NAFLD patients. Candidate biomarkers were analyzed by enzyme-linked
immunosorbent assay in serum from adult NAFLD patients.
Results: Through proteomic profiling, we identified decreased expression of hepatic glyoxalase 1 (GLO1) in a
murine model. GLO1 protein expression was also found altered in tissue biopsies from paediatric NAFLD patients. In
vitro experiments demonstrated that, in response to lipid loading in hepatocytes, GLO1 is first hyperacetylated then
ubiquitinated and degraded, leading to an increase in reactive methylglyoxal. In a cohort of 59 biopsy-confirmed adult
NAFLD patients, increased serum levels of the primary methylglyoxal-derived advanced glycation endproduct,
hydroimidazolone (MG-H1) were significantly correlated with body mass index (r = 0.520, p < 0.0001).
Conclusion: Collectively these results demonstrate the dysregulation of GLO1 in NAFLD and implicate the
acetylation-ubquitination degradation pathway as the functional mechanism. Further investigation of the role
of GLO1 in the molecular pathogenesis of NAFLD is warranted.
Keywords: Non-alcoholic fatty liver disease, Glyoxalase, Methylglyoxal, Proteomics, iTRA
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