Toroidal optical dipole traps for atomic Bose-Einstein condensates using Laguerre-Gaussian beams

We theoretically investigate the use of red-detuned Laguerre-Gaussian (LG) laser beams of varying azimuthal mode index for producing toroidal optical dipole traps in two-dimensional atomic Bose-Einstein condensates. Higher-order LG beams provide deeper potential wells and tighter confinement for a fixed toroid radius and laser power. Numerical simulations of the loading of the toroidal trap from a variety of initial conditions is also given.Comment: 12 pages, 5 figures, submitted to Phys. Rev.

Aestivation motifs explain hypertension and muscle mass loss in mice with psoriatic skin barrier defect

AIM: Recent evidence suggests that arterial hypertension could be alternatively explained as a physiological adaptation response to water shortage, termed aestivation, which relies on complex multi-organ metabolic adjustments to prevent dehydration. Here we tested the hypothesis that chronic water loss across diseased skin leads to similar adaptive water conservation responses as observed in experimental renal failure or high salt diet. METHODS: We studied mice with keratinocyte-specific overexpression of IL-17A which develop severe psoriasis-like skin disease. We measured transepidermal water loss and solute and water excretion in the urine. We quantified glomerular filtration rate (GFR) by intravital microscopy, and energy and nitrogen pathways by metabolomics. We measured skin blood flow and transepidermal water loss (TEWL) in conjunction with renal resistive indices and arterial blood pressure. RESULTS: Psoriatic animals lost large amounts of water across their defective cutaneous epithelial barrier. Metabolic adaptive water conservation included mobilization of nitrogen and energy from muscle to increase organic osmolyte production, solute-driven maximal anti-diuresis at normal GFR, increased metanephrine and angiotensin 2 levels, and cutaneous vasoconstriction to limit TEWL. Heat exposure led to cutaneous vasodilation and blood pressure normalization without parallel changes in renal resistive index, albeit at the expense of further increased TEWL. CONCLUSION: Severe cutaneous water loss predisposes psoriatic mice to lethal dehydration. In response to this dehydration stress, the mice activate aestivation-like water conservation motifs to maintain their body hydration status. The circulatory water conservation response explains their arterial hypertension. The nitrogen-dependency of the metabolic water conservation response explains their catabolic muscle wasting

VERSO UNA NUOVA ‘RURALITÀ’? UNA CLASSIFICAZIONE DELLE AREE RURALI COME SUPPORTO ALLE POLITICHE DI SVILUPPO REGIONALE

The present study is aimed at proposing a methodology for defining and profiling different typologies of rural areas. A quantitative exercise has been developed in Greece, an European country showing drastic economic changes in rural areas during the last decades. Results indicate that the optimal classification for rural areas in Greece can be derived through the combined use of the Degree of Handicap of EU Regulation 1257/99 and Degree of urbanism (using the standard OCSE criterion). This methodology constitutes an appropriate base to inform policy measures stimulating the socioeconomic performances of rural areas in Greece, that could be successfully extended to other European Countries

Solution structure of Ser14Gly-humanin, a potent rescue factor against neuronal cell death in Alzheimer's disease

The NMR solution study of Ser14Gly-humanin (S14G-HN), a 1000-fold more potent derivative of humanin (HN), is reported. HN is 24-residue peptide that selectively suppresses neuronal cell death caused by Alzheimer's disease (AD)-specific insults and offers hope for the development of a cure against AD. In aqueous solution the NMR data show that S14G-HN is a flexible peptide with turn-like structures in its conformational ensemble distributed over an extensive part of its sequence from Pro3 to Glu15. In the more lipophilic environment of 30% TFE, an α-helical structure spanning residues Phe6 to Thr13 is identified. Comparison of these findings to the NMR structure of the parent HN and to existing structure-function relationship literature data outlines the important for activity structural features for this class of neuroprotective peptides, and brings forth flexibility as an important characteristic that may facilitate interactions with functional counterparts of the neuroprotection pathway. © 2006 Elsevier Inc. All rights reserved

High-resolution NMR spectroscopy of the β-amyloid(1-28) fibril typical for Alzheimer's disease

Unlabeled samples of the β-amyloid peptide(1-28) fibrils typical of Alzheimer's disease could be used to obtain well-resolved one- and two-dimensional 1H NMR spectra (see picture). The technique applied was high-resolution magic-angle spinning on a 600 MHz NMR spectrometer. The results are in agreement with a parallel, in-register arrangement of the β-amyloid peptide in the fibril

Detection of interactions of the β-amyloid peptide with small molecules employing transferred NOEs

The interaction of pineal hormone melatonin, the histological dye thioflavin T, and the olive tree polyphenol oleuropein, with the 28 amino acid residue N-terminal fragment of the β-amyloid peptide (β-AP) of Alzheimer's disease, [β-AP(1-28)], was detected in solution through the observationof transferredNOEs (trNOEs) in1Dand2DNOEspectroscopy (NOESY) experiments. The trNOE method is applied for the first time in the detection of interactions of soluble β-AP(1-28) with small molecules and may provide a means of screening for the identification of possible inhibitors of the formation of neurotoxic β-AP assemblies. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd

Application of nuclear magnetic resonance spectroscopy combined with principal component analysis in detecting inborn errors of metabolism using blood spots: A metabonomic approach

NMR spectra of extracted blood spots were used to investigate the possibility for the development of a new method for mass screening concerning the diagnosis of inborn errors of metabolism (IEM). Blood spots were collected on filter papers from normal, phenylketonuric (PKU) and maple syrup urine disease (MSUD) subjects and their Carr-Purcell-Meiboom-Gill (CPMG) 1H NMR spectra were acquired. The spectra were reduced to a number of spectral descriptors and principal component analysis (PCA) was performed. The scores plot showed that PKU and MSUD samples were well discriminated from the main cluster of points. © 2004 Elsevier B.V. All rights reserved

Solution structure of humanin, a peptide against Alzheimer's disease-related neurotoxicity

Humanin is a newly identified 24-residue peptide that suppresses neuronal cell death caused by a wide spectrum of familial Alzheimer’s disease genes and the beta-amyloid peptide. In this study, NMR and circular dichroism Studies of synthetic humanin in aqueous and 30% 2,2,2-trifluoroethanol (TFE) solutions are reported. In aqueous Solution, humanin exists predominantly in an unstructured conformation in equilibrium with turn-like structures involving residues Gly5 to Leu10 and Glu15 to Leu18, providing indication of nascent helix. In the less polar environment of 30% TFE, humanin readily adopts helical structure with long-range order spanning residues Gly5 to Leu18. Comparative 3D modeling studies and topology predictions are in qualitative agreement with the experimental findings in both environments. Our studies reveal a flexible peptide in aqueous environment, which is free to interact with possible receptors that mediate its action, but may also acquire a helical conformation necessary for specific interactions and/or passage through membranes. (C) 2005 Elsevier Inc. All rights reserved