13,423 research outputs found
Reduced lysosomal acid lipase activity: A new marker of liver disease severity across the clinical continuum of non-alcoholic fatty liver disease?
Lysosomal acid lipase (LAL) plays a key role in intracellular lipid metabolism. Reduced LAL activity promotes increased multi-organ lysosomal cholesterol ester storage, as observed in two recessive autosomal genetic diseases, Wolman disease and Cholesterol ester storage disease. Severe liver steatosis and accelerated liver fibrosis are common features in patients with genetic LAL deficiency. By contrast, few reliable data are available on the modulation of LAL activity in vivo and on the epigenetic and metabolic factors capable of regulating its activity in subjects without homozygous mutations of the Lipase A gene. In the last few years, a less severe and non-genetic reduction of LAL activity was reported in children and adults with non-alcoholic fatty liver disease (NAFLD), suggesting a possible role of LAL reduction in the pathogenesis and progression of the disease. Patients with NAFLD show a significant, progressive reduction of LAL activity from simple steatosis to non-alcoholic steatohepatitis and cryptogenic cirrhosis. Among cirrhosis of different etiologies, those with cryptogenic cirrhosis show the most significant reductions of LAL activity. These findings suggest that the modulation of LAL activity may become a possible new therapeutic target for patients with more advanced forms of NAFLD. Moreover, the measurement of LAL activity may represent a possible new marker of disease severity in this clinical setting
Detection of delta Scuti-like pulsation in H254, a pre-main sequence F-type star in IC 348
We present time series observations of intermediate mass PMS stars belonging
to the young star cluster IC 348. The new data reveal that a young member of
the cluster, H254, undergoes periodic light variations with delta Scuti-like
characteristics. This occurrence provides an unambiguous evidence confirming
the prediction that intermediate-mass pre-main sequence (PMS) stars should
experience this transient instability during their approach to the
main-sequence. On the basis of the measured frequency f=7.406 c/d, we are able
to constrain the intrinsic stellar parameters of H254 by means of linear, non
adiabatic, radial pulsation models. The range of the resulting luminosity and
effective temperature permitted by the models is narrower than the
observational values. In particular, the pulsation analysis allows to derive an
independent estimate of the distance to IC 348 of about 320 pc. Further
observations could either confirm the monoperiodic nature of H254 or reveal the
presence of other frequencies.Comment: 7 pages, including 7 postscript figures, accepted for publication on
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An evaluation resource for geographic information retrieval
In this paper we present an evaluation resource for geographic information retrieval developed within the Cross Language Evaluation
Forum (CLEF). The GeoCLEF track is dedicated to the evaluation of geographic information retrieval systems. The resource
encompasses more than 600,000 documents, 75 topics so far, and more than 100,000 relevance judgments for these topics. Geographic
information retrieval requires an evaluation resource which represents realistic information needs and which is geographically
challenging. Some experimental results and analysis are reported
A salvage surgical solution for recurrent lymphangioma of the prepuce
Treatment of lymphangioma, circumscriptum of the prepuce is often technically demanding. Many different medical and surgical approaches have been described over the years, none of which has proved completely successful. We describe a case in which skin deficiency was a problem after prior multiple excisions of lymphangiomatous tissue. We decided to bury the degloved shaft in the scrotum. After 6 months the penis was raised and reconstructed using scrotal skin; this achieved satisfactory skin coverage. In such cases piliferous follicles can easily be dealt with at a later stage by cosmetic treatment.We believe this technical, approach may be a valid alternative to conventional procedures (i.e. grafts and flaps) especially when extensive resection makes skin coverage particularly difficult. (C) 2004 The British Association of Plastic Surgeons. Published by Elsevier Ltd. All rights reserved
Considering the Value of 3D Cultures for Enhancing the Understanding of Adhesion, Proliferation, and Osteogenesis on Titanium Dental Implants
Background: Individuals with pathologic conditions and restorative deficiencies might benefit from a combinatorial approach encompassing stem cells and dental implants; however, due to the various surface textures and coatings, the influence of titanium dental implants on cells exhibits extensive, wide variations. Three-dimensional (3D) cultures of stem cells on whole dental implants are superior in testing implant properties and were used to examine their capabilities thoroughly. Materials and methods: The surface micro-topography of five titanium dental implants manufactured by sandblasting with titanium, aluminum, corundum, or laser sintered and laser machined was compared in this study. After characterization, including particle size distribution and roughness, the adhesion, proliferation, and viability of adipose-derived stem cells (ADSCs) cultured on the whole-body implants were tested at three time points (one to seven days). Finally, the capacity of the implant to induce ADSCs’ spontaneous osteoblastic differentiation was examined at the same time points, assessing the gene expression of collagen type 1 (coll-I), osteonectin (osn), alkaline phosphatase (alp), and osteocalcin (osc). Results: Laser-treated (Laser Mach and Laser Sint) implants exhibited the highest adhesion degree; however, limited proliferation was observed, except for Laser Sint implants, while viability differences were seen throughout the three time points, except for Ti Blast implants. Sandblasted surfaces (Al Blast, Cor Blast, and Ti Blast) outpaced the laser-treated ones, inducing higher amounts of coll-I, osn, and alp, but not osc. Among the sandblasted surfaces, Ti Blast showed moderate roughness and the highest superficial texture density, favoring the most significant spontaneous differentiation relative to all the other implant surfaces. Conclusions: The results indicate that 3D cultures of stem cells on whole-body titanium dental implants is a practical and physiologically appropriate way to test the biological characteristics of the implants, revealing peculiar differences in ADSCs’ adhesion, proliferation, and activity toward osteogenic commitment in the absence of specific osteoinductive cues. In addition, the 3D method would allow researchers to test various implant surfaces more thoroughly. Integrating with preconditioned stem cells would inspire a more substantial combinatorial approach to promote a quicker recovery for patients with restorative impairments
Modified Debye-Huckel Electron Shielding and Penetration Factor
Screened potential, modified by non standard electron cloud distributions
responsible for the shielding effect on fusion of reacting nuclei in
astrophysical plasmas, is derived. The case of clouds with depleted tails in
space coordinates is discussed. The modified screened potential is obtained
both from statistical mechanics arguments based on fluctuations of the inverse
of the Debye-Huckel radius and from the solution of a Bernoulli equation used
in generalized statistical mechanics. Plots and tables useful in evaluating
penetration probability at any energy are provided.Comment: 9 pages, 3 figures, 3 table
Optimal charging of electric vehicles in microgrids through discrete event optimization
In this paper, a discrete event approach is proposed for the optimal charging of electrical vehicles in microgrids. In particular, the considered system is characterized by renewable energy sources (RES), non-renewable energy sources, electrical storage, a connection to the external grid and a charging station for electric vehicles (EVs). The decision variables are relevant to the schedule of production plants, storage systems and EVs' charging. The objective function to be minimized is related to the cost of purchasing energy from the external grid, the use of nonrenewable energy sources and tardiness of customer's service. The proposed approach is applied to a real case study and it is shown that it allows to considerably reduce the dimension of the problem (and thus the computational time required) as compared to a discrete-time approach
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