406 resultados para 1227
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To examine the relationship between short-wavelength-sensitive (SWS) resolution acuity and epidemiologically defined stages of early age-related maculopathy (ARM).
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Results of recent studies have indicated that bone marrow cells can differentiate into various cells of ectodermal, mesodermal, and endodermal origins when transplanted into the body. However, the problems associated with those experiments such as the long latent period, rareness of the event, and difficulty in controlling the processes have hampered detailed mechanistic studies. In the present study, we examined the potency of mouse bone marrow cells to differentiate into cells comprising skin tissues using a skin reconstitution assay. Bone marrow cells from adult green fluorescent protein (GFP)-transgenic mice were transplanted in a mixture of embryonic mouse skin cells (17.5 days post-coitus) onto skin defects made on the backs of nude mice. Within 3 weeks, fully differentiated skin with hair was reconstituted. GFP-positive cells were found in the epidermis, hair follicles, sebaceous glands, and dermis. The localization and morphology of the cells, results of immunohistochemistry, and results of specific staining confirmed that the bone marrow cells had differentiated into epidermal keratinocytes, sebaceous gland cells, follicular epithelial cells, dendritic cells, and endothelial cells under the present conditions. These results indicate that this system is suitable for molecular and cellular mechanistic studies on differentiation of stem cells to various epidermal and dermal cells.
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This paper brings together and analyzes recent work based on the interpretation of the electrochemical measurements made on a modified micro-abrasion-corrosion tester used in several research programmes. These programmes investigated the role of abradant size, test solution pH in abrasion-corrosion of biomaterials, the abrasion-corrosion performance of sintered and thermally sprayed tungsten carbide surfaces under downhole drilling environments and the abrasion-corrosion of UNS S32205 duplex stainless steel. Various abrasion tests were conducted under two-body grooving, three-body rolling and mixed grooving-rolling abrasion conditions, with and without abrasives, on cast F75 cobalt-chromium-molybdenum (CoCrMo) alloy in simulated body fluids, 2205 in chloride containing solutions as well as sprayed and sintered tungsten carbide surfaces in simulated downhole fluids. Pre- and post-test inspections based on optical and scanning electron microscopy analysis are used to help interpret the electrochemical response and current noise measurements made in situ during micro-abrasion-corrosion tests. The complex wear and corrosion mechanisms and their dependence on the microstructure and surface composition as a function of the pH, abrasive concentration, size and type are detailed and linked to the electrochemical signals. The electrochemical versus mechanical processes are plotted for different test parameters and this new approach is used to interpret tribo-corrosion test data to give greater insights into different tribo-corrosion systems. Thus new approaches to interpreting in-situ electrochemical responses to surfaces under different abrasive wear rates, different abrasives and liquid environments (pH and NaCl levels) are made. This representation is directly related to the mechano-electrochemical processes on the surface and avoids quantification of numerous synergistic, antagonistic and additive terms associated with repeat experiments. (C) 2010 Elsevier Ltd. All rights reserved.
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A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team. Since then, a new body of highly relevant information has been generated from the Mars Reconnaissance Orbiter (launched in 2005) and Phoenix (2007) and data from Mars Express and the twin Mars Exploration Rovers (all 2003). Results have also been gleaned from the Mars Science Laboratory (launched in 2011). In addition to Mars data, there is a considerable body of new data regarding the known environmental limits to life on Earth—including the potential for terrestrial microbial life to survive and replicate under martian environmental conditions. The SR-SAG2 analysis has included an examination of new Mars models relevant to natural environmental variation in water activity and temperature; a review and reconsideration of the current parameters used to define Special Regions; and updated maps and descriptions of the martian environments recommended for treatment as “Uncertain” or “Special” as natural features or those potentially formed by the influence of future landed spacecraft. Significant changes in our knowledge of the capabilities of terrestrial organisms and the existence of possibly habitable martian environments have led to a new appreciation of where Mars Special Regions may be identified and protected. The SR-SAG also considered the impact of Special Regions on potential future human missions to Mars, both as locations of potential resources and as places that should not be inadvertently contaminated by human activity. Key Words: Martian environments—Mars astrobiology—Extreme environment microbiology—Planetary protection—Exploration resources. Astrobiology 14, 887–968.
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Herein, we present a facile method for the formation of monodispersed metal nanoparticles (NPs) at room temperature from M(III)Cl3 (with M = Au, Ru, Mn, Fe or V) in different media based on N,N-dimethylformamide (DMF) or water solutions containing a protic ionic liquid (PIL), namely the octylammonium formate (denoted OAF) or the bis(2-ethyl-hexyl)ammonium formate (denoted BEHAF). These two PILs present different structures and redox-active structuring properties that influence their interactions with selected molecular compounds (DMF or water), as well as the shape and the size of formed metal NPs in these solutions. Herein, the physical properties, such as the thermal, transport and micellar properties, of investigated PIL solutions were firstly investigated in order to understand the relation between PILs structure and their properties in solutions with DMF or water. The formation of metal NPs in these solutions was then characterized by using UV–vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and dynamic light scattering (DLS) measurements. From our investigations, it appears that the PILs structure and their aggregation pathways in selected solvents affect strongly the formation, growths, the shape and the size of metal NPs. In fact by using this approach, the shape-/size-controlled metal NPs can be generated under mild condition. This approach suggests also a wealth of potential for these designer nanomaterials within the biomedical, materials, and catalysis communities by using designer and safer media based on PILs.
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As many as one-third of U.S. hotels have been converted from one brand to another in recent years, a process that frequently improves the hotel’s financial performance—although that is not always the case. Using data collected between 1994 and 2012 from PKF Hospitality Research, an analysis of brand conversions by 260 hotels shows that hotels moving downscale generally improved their occupancy, and thus their top-line revenue and profit ratios, compared to a control group of 2,750 hotels that did not change brands. However, hotels that moved upscale did not see notable changes in revenue or profit, nor did hotels that moved across their tier, especially when they stayed within their brand family. Two factors seem to drive the financial results for converted hotels—the relative strength of the brand and the fit between the brand and the property.
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The occurrence of seven pharmaceuticals and two metabolites belonging to non-steroidal anti-inflammatory drugs and analgesics therapeutic classes was studied in seawaters. A total of 101 samples covering fourteen beaches and five cities were evaluated in order to assess the spatial distribution of pharmaceuticals among north Portuguese coast. Seawaters were selected in order to embrace different bathing water quality (excellent, good and sufficient). Acetaminophen, ketoprofen and the metabolite hydroxyibuprofen were detected in all the seawater samples at maximum concentrations of 584, 89.7 and 287 ng L− 1, respectively. Carboxyibuprofen had the highest seawater concentration (1227 ng L− 1). The temporal distribution of the selected pharmaceuticals during the bathing season showed that, in general, higher concentrations were detected in August and September. The environmental risk posed by the pharmaceuticals detected in seawaters towards different trophic levels (fish, daphnids and algae) was also assessed. Only diclofenac showed hazard quotients above one for fish, representing a potential risk for aquatic organisms. These results were observed in seawaters classified as excellent bathing water. Additional data is needed in order to support the identification and prioritization of risks posed by pharmaceuticals in marine environment.
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Chlamydiales possess a minimal but functional peptidoglycan precursor biosynthetic and remodeling pathway involved in the assembly of the division septum by an atypical cytokinetic machine and cryptic or modified peptidoglycan-like structure (PGLS). How this reduced cytokinetic machine collectively coordinates the invagination of the envelope has not yet been explored in Chlamydiales. In other Gram-negative bacteria, peptidoglycan provides anchor points that connect the outer membrane to the peptidoglycan during constriction using the Pal-Tol complex. Purifying PGLS and associated proteins from the chlamydial pathogen Waddlia chondrophila, we unearthed the Pal protein as a peptidoglycan-binding protein that localizes to the chlamydial division septum along with other components of the Pal-Tol complex. Together, our PGLS characterization and peptidoglycan-binding assays support the notion that diaminopimelic acid is an important determinant recruiting Pal to the division plane to coordinate the invagination of all envelope layers with the conserved Pal-Tol complex, even during osmotically protected intracellular growth.
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Collectionneur : Gaignières, Roger de (1642-1715)
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1887/07/28 (Numéro 1227).
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Titre uniforme : [Leçons de ténèbres à une et deux voix. No 2]
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Contient : Chartes de l'abbaye de Montiéramey ; Extraits du nécrologe de la même abbaye ; Charte de Marie, duchesse de Bar, pour Montiéramey ; Vente faite au chapitre de Troyes par Jean de Vellery ; Extraits du cartulaire de Longuay (1170-1276), par Camuzat ; Titres de la commanderie du Temple de Troyes ; Chartes de Montiéramey ; Chartes du prieuré du Saint-Sépulcre ; Inventaire des titres de la maison de Brienne ; Notes sur Larrivour ; Pièces relatives à la maison de Brienne et de Luxembourg, rangées par ordre chronologique ; Testament de Robert de Colaverdey ; Testament d'Ysabeau de Flamericourt, veuve du précédent ; Pièces relatives à Jean et Pierre de Foicy ; Extrait d'un registre de l'évêque de Troyes ; Épitaphes de Troyes ; Extrait d'un registre de l'évêque de Troyes ; Chartes de l'abbaye de Trois-Fontaines ; Actes relatifs à la maison de Brienne-Luxembourg ; Union de la Maison-Dieu du Chêne à l'abbaye de Saint-Rémi de Reims ; Actes relatifs à la maison de Brienne ; Actes concernant les salines de Vic ; Arrêt du Parlement touchant la possession du comté de Roucy ; Arrêt du Parlement en faveur de l'Hôtel-Dieu de Corbeil contre Claude de Châtillon ; Donation du comté d'Eu au comte de Saint-Pol ; Renonciation par Ogier, sire de Gigny, à la dîme du « Meis Thiecelin », en faveur de l'église de Troyes ; Arrêt du Parlement de Paris concernant la maison de Salignac ; Fondation du monastère de Saint-Pierremont ; Chartes de l'abbaye de Trois-Fontaines ; Lettres de l'empereur Maximilien confirmant à François de Bourbon, comte de Saint-Pol, le comté de Roucy ; Note d'un missel de Jean de Saarebruck ; Donation faite par Jeanne de France, comtesse de Roussillon, à Jean d'Anneville ; Acquisition par Charles V des villes de Mouzon et Beaumont ; Testament de Jeanne de Champagne, reine de France ; Fragment d'une requête adressée au roi par les héritiers du sr de Couasnay ; Fondation de l'église de Notre-Dame de Rosnay par le comte Isembard ; Aveu rendu au roi par Claude de Dinteville ; Diplôme du roi Eudes pour Montiéramey ; Chartes de Montiérender