190 research outputs found
Supercaloric functions for the parabolic -Laplace equation in the fast diffusion case
We study a generalized class of supersolutions, so-called -supercaloric
functions, to the parabolic -Laplace equation. This class of functions is
defined as lower semicontinuous functions that are finite in a dense set and
satisfy the parabolic comparison principle. Their properties are relatively
well understood for , but little is known in the fast diffusion case
. Every bounded -supercaloric function belongs to the natural Sobolev
space and is a weak supersolution to the parabolic -Laplace equation for the
entire range . Our main result shows that unbounded
-supercaloric functions are divided into two mutually exclusive classes with
sharp local integrability estimates for the function and its weak gradient in
the supercritical case . The Barenblatt solution and the
infinite point source solution show that both alternatives occur. Barenblatt
solutions do not exist in the subcritical case and the
theory is not yet well understood
Amelioration of bleomycin-induced lung fibrosis in hamsters by dietary supplementation with taurine and niacin: biochemical mechanisms.
Interstitial pulmonary fibrosis induced by intratracheal instillation of bleomycin (BL) involves an excess production of reactive oxygen species, unavailability of adequate levels of NAD and ATP to repair the injured pulmonary epithelium, and an overexuberant lung collagen reactivity followed by deposition of highly cross-linked mature collagen fibrils resistant to enzymatic degradation. In the present study, we have demonstrated that dietary supplementation with taurine and niacin offered almost complete protection against the lung fibrosis in a multidose BL hamster model. The mechanisms for the protective effect of taurine and niacin are multifaceted. These include the ability of taurine to scavenge HOCl and stabilize the biomembrane; niacin's ability to replenish the BL-induced depletion of NAD and ATP; and the combined effect of taurine and niacin to suppress all aspects of BL-induced increases in the lung collagen reactivity, a hallmark of interstitial pulmonary fibrosis. It was concluded from the data presented at this Conference that the combined treatment with taurine and niacin, which offers a multipronged approach, will have great therapeutic potential in the intervention of the development of chemically induced interstitial lung fibrosis in animals and humans
Retroperitoneal necrotizing fasciitis presenting with peritonism in a 33-year-old Nepalese man: a case report
Biophysical Characterization of the Strong Stabilization of the RNA Triplex poly(U)β’poly(A)*poly(U) by 9-O-(Ο-amino) Alkyl Ether Berberine Analogs
Background: Binding of two 9-O-(v-amino) alkyl ether berberine analogs BC1 and BC2 to the RNA triplex poly(U)Npoly(A)*poly(U) was studied by various biophysical techniques. Methodology/Principal Findings: Berberine analogs bind to the RNA triplex non-cooperatively. The affinity of binding was remarkably high by about 5 and 15 times, respectively, for BC1 and BC2 compared to berberine. The site size for the binding was around 4.3 for all. Based on ferrocyanide quenching, fluorescence polarization, quantum yield values and viscosity results a strong intercalative binding of BC1 and BC2 to the RNA triplex has been demonstrated. BC1 and BC2 stabilized the Hoogsteen base paired third strand by about 18.1 and 20.5uC compared to a 17.5uC stabilization by berberine. The binding was entropy driven compared to the enthalpy driven binding of berbeine, most likely due to additional contacts within the grooves of the triplex and disruption of the water structure by the alkyl side chain. Conclusions/Significance: Remarkably higher binding affinity and stabilization effect of the RNA triplex by the amino alkyl berberine analogs was achieved compared to berberine. The length of the alkyl side chain influence in the triplex stabilization phenomena
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