3,200 research outputs found

    ELLIPTIC ESTIMATES INDEPENDENT OF DOMAIN EXPANSION

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    In this paper, we consider elliptic estimates for a system with mooth variable coeffcients on a domain ­ ½ Rn; n ¸ 2 containing the origin. e first show the invariance of the estimates under a domain expansion de¯ned y the scale that y = Rx, x; y 2 Rn with parameter R > 1, provided that the oeffcients are in a homogeneous Sobolev space. Then we apply these invariant stimates to the global existence of unique strong solutions to a parabolic ystem de¯ned on an unbounded domain

    Remarks on the relativistic Hartree equations

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    We study the global well-posedness (GWP) and small data scattering of radial solutions of the relativistic Hartree type equations with nonlocal nonlinearity F(u) = ¸(j ¢ j¡° ¤ juj2)u, ¸ 2 R n f0g, 0 < ° < n, n ¸ 3. We establish a weighted L2 Strichartz estimate applicable to non-radial functions and some fractional integral estimates for radial functions

    AAD-2004, a potent spin trapping molecule and microsomal prostaglandin E synthase-1 inhibitor, shows safety and efficacy in a mouse model of ALS

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    While free radicals and inflammation constitute major routes of neuronal injury occurring in neurodegenerative diseases, neither antioxidants nor nonsteroidal anti-inflammatory drugs (NSAIDs) have shown significant efficacy in human clinical trials. To explore the possibility that concurrent blockade of free radicals and PGE2-mediated inflammation might constitute a safe and effective therapeutic approach to certain neurodegenerative diseases, we have developed 2-hydroxy-5-[2-(4-trifluoromethylphenyl)-ethylaminobezoic acid (AAD-2004) as a derivative of aspirin. AAD-2004 completely removed free radicals at 50 nM as a potent spin trapping molecule and inhibited microsomal prostaglandin E synthase-1 (mPGES-1) with an IC50 of 230 nM. Oral administration of AAD-2004 blocked free radical formation, PGE2 formation, and microglial activation in the spinal motor neurons of SOD1G93A mice. As a consequence, AAD-2004 reduced autophagosome formation, axonopathy, and motor neuron degeneration, improving motor function and increasing life span. In these assays, AAD-2004 was superior to ibuprofen or riluzole. Gastric bleeding was not induced by AAD-2004 even at a dose 400-fold higher than that required to obtain maximal therapeutic efficacy in SOD1G93A mice. Targeting both mPGES-1 and free radicals may be a promising approach to reduce neurodegeneration in ALS and possibly other neurodegenerative diseases

    Effect of growth interruption on optical properties of In-rich InGaN/GaN single quantum well structures

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    In-rich InGaN/GaN single quantum well (SQW) structures with and without growth interruption (GI) were successfully grown on sapphire substrates by metal-organic chemical vapor deposition. The optical properties were systematically investigated by photoluminescence (PL), selectively excited PL, PL excitation (PLE), and cathodoluminescence (CL) techniques. The integrated PL intensity of the main In-rich InGaN emissions for the sample grown without GI decreased only by a factor of 15.5 when the temperature increased from 11 to 300 K, while that of the sample with GI decreased by about 1040, showing very good quantum efficiency for the sample without GI. The In-rich InGaN SQW emissions have been verified by selectively excited PL spectra and by the different PLE absorption edges. CL observations showed that the epilayer of the sample without GI agglomerated together to form clusters due to the large lattice and thermal mismatches with GaN, which confine the carriers in the clusters and ensure the relatively high quantum efficiency of the sample. The sample with GI showed relatively smooth surface with cluster structures jointed together, which gives two-dimensional QW environment in its energy band structure, and its optical emission is more sensitive to temperatures than that of the sample grown without GI.open7

    Carotid Endarterectomy for Symptomatic Complete Occlusion of the Internal Carotid Artery

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    We described 9 consecutive patients who underwent operative carotid artery exploration with attempted carotid endarterectomy (CEA) for symptomatic internal carotid artery (ICA) occlusion. Indications for this surgery based on vascular imaging included segmental occlusion of the proximal ICA and also extensive occlusion of the distal ICA in selected patients in whom color-flow duplex ultrasound showed a poorly echogenic or anechoic thrombus with a flow void, suggestive of an acute thrombus. CEA was performed successfully to restore blood flow in all 9 patients:CEA in 5 and CEA with Fogarty thrombectomy in 4. Postoperative magnetic resonance (MR) angiography confirmed that revascularization had been successful in all 9 patients, and MR imaging displayed improved perfusion in 4 patients. Despite the lack of a generalized efficacy of surgical revascularization for symptomatic ICA occlusion, our study demonstrated that preoperative vascular imaging allows the selection of patients who may benefit from CEA

    The antifungal activity and membrane-disruptive action of dioscin extracted from Dioscorea nipponica

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    AbstractDioscin is a kind of steroidal saponin isolated from the root bark of wild yam Dioscorea nipponica. We investigated the antifungal effect of dioscin against different fungal strains and its antifungal mechanism(s) in Candida albicans cells. Using the propidium iodide assay and calcein-leakage measurement, we confirmed that dioscin caused fungal membrane damage. Furthermore, we evaluated the ability of dioscin to disrupt the plasma membrane potential, using 3,3′-dipropylthiadicarbocyanine iodide [DiSC3(5)] and bis-(1,3-dibarbituric acid)-trimethine oxanol [DiBAC4(3)]. Cells stained with the dyes had a significant increase in fluorescent intensity after exposure to dioscin, indicating that dioscin has an effect on the membrane potential. To visualize the effect of dioscin on the cell membrane, we synthesized rhodamine-labeled giant unilamellar vesicles (GUVs) mimicking the outer leaflet of the plasma membrane of C. albicans. As seen in the result, the membrane disruptive action of dioscin caused morphological change and rhodamine leakage of the GUVs. In three-dimensional contour-plot analysis using flow cytometry, we observed a decrease in cell size, which is in agreement with our result from the GUV assay. These results suggest that dioscin exerts a considerable antifungal activity by disrupting the structure in membrane after invading into the fungal membrane, resulting in fungal cell death

    (E)-2,2′-[3-(2-Nitro­phen­yl)prop-2-ene-1,1-di­yl]bis­(3-hy­droxy-5,5-dimethyl­cyclo­hex-2-en-1-one)

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    In the title compound, C25H29NO6, each of the cyclo­hexenone rings adopts a half-chair conformation. Each of the pairs of hy­droxy and carbonyl O atoms are oriented to allow for the formation of intra­molecular O—H⋯O hydrogen bonds, which are typical of xanthene derivatives. The nitro group is rotationally disordered over two orientations in a 0.544 (6):0.456 (6) ratio. In the crystal, weak inter­molecualr C—H⋯O hydrogen bonds link mol­ecules into layers parallel to the ab plane
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