4,403 research outputs found

    Comparison of retinal nerve fiber layer thinning and retinal ganglion cell loss after optic nerve transection in adult albino rats

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    We compared the time-course and magnitude of retinal nerve fiber layer (RNFL) thinning with that of retinal ganglion cell (RGC) loss after intraorbital optic nerve transection (IONT) in adult rats

    Validation of a method to estimate direct normal irradiance of UVA and PAR bands from global horizontal measurements for cloudless sky conditions in Valencia, Spain, by a measurement campaign

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    A method is proposed to provide measurement of direct normal solar irradiance of bands with wavelength ranges (315-400 nm, 400-700 nm) from measurements of global horizontal band irradiance for cloudless sky conditions in Valencia. Global and normal direct irradiance data for every air mass were obtained by applying the SMART2 model to the atmosphere of Valencia. The direct normal to global irradiance ratio was parameterized versus the relative optical air mass. A measurement campaign of global horizontal and diffuse irradiance of UVA and PAR bands was carried out in Valencia, after which, the inferred direct normal irradiance was compared with those provided by the method. The result of the comparison shows that the method is acceptably accurate. The proposed model tends to underestimate the direct normal irradiance of the UVA band by 6%, although for values below 25 W/m2 the model overestimates the direct irradiance by 6%, while for values above 25 W/m2 the model underestimates it by 10%. The other two error estimators used ranging from 11% to 15% are similar in the defined interval measurements in relation to the whole UVA band. Regarding the PAR band, the model overestimates the direct normal irradiance of the PAR band by only 2.2%. With this, the results of the PAR band are more conclusive, as it has been found that for direct normal irradiance values higher than 280 W/m2 the MBE error is almost zero and the other two estimator errors are small, about 5%. © 2010 Springer-Verlag.This work was supported by the Spanish Government through MEC grant MAT2009-14625-C03-03, and is a part of the activities of the Grup d'Optoelectronica i Semiconductors of the Polytechnic University of Valencia. The translation of this paper was funded by the Universidad Politecnica de Valencia, Spain.Serrano Jareño, MA.; BoscĂĄ Berga, JV. (2011). Validation of a method to estimate direct normal irradiance of UVA and PAR bands from global horizontal measurements for cloudless sky conditions in Valencia, Spain, by a measurement campaign. Theoretical and Applied Climatology. 103(1):95-101. https://doi.org/10.1007/s00704-010-0284-9S951011031Barth J, Cadet J, CĂ©sarini JP, Fitzpatrick TB, McKinlay A, Mutzhas M, Pathak M, Peak M, Sliney D, Urbach F (1999) TC 6-26 report: Standardization of the terms UV-A1, UV-A2 and UV-B, CIE 134-1999 ISBN 3-900-734-94-1Batlles FJ, Olmo FJ, Alados-Arboledas L (1995) On shadowband correction methods for diffuse irradiance measurements. Solar Energy 54(5):105–114Drummond AJ (1956) On the measurement of sky radiation. Arch 602 Meteor Geophys Bioklim B 7:413–436Gueymard C (1995) SMARTS2: a simple model of the atmospheric radiative transfer of sunshine: algorithms and performance assessment. FSEC-PF-270-95, Florida Solar Energy CenterGueymard C (2003) SMARTS2 code, versiĂłn 2.9.2. User’s Manual, Solar Consulting Services Bailey CO. Available from http://rredc.nrel.gov/solar/models/SMARTS/smarts_index.htmlGueymard C (2004) The sun’s total and spectral irradiance for solar energy applications and solar radiation models. Solar Energy 76:423–453HĂ€der DP, Lebert M, Marangoni R, Colombetti G (1999) ELDONET-European light dosimeter network hardware and software. J Photochem Photobiol B: Biol 52:51–58HĂ€der DP, Lebert M, Colombetti G, Figueroa F (2001) European light dosimeter network (ELDONET). Helgol Mar Res 55:35–44Iqbal M (1983) An introduction to solar radiation. Academic, TorontoKudish AI, Evseev EG (2008) The assessment of four different correction models applied to the diffuse radiation measured with a shadow ring using global and normal beam radiation measurements for Beer Sheva, Israel. Solar Energy 82(2):144–156LeBaron BA, Michalsky JJ, Perez R (1990) A simple procedure for correcting shadowband data for all sky conditions. Solar Energy 44:249–256MarĂ­n FernĂĄndez MJ (2007) Estudio de la irradiancia solar ultravioleta y eritemĂĄtica en la Comunidad Valenciana. Doctoral Thesis University of Valencia (Spain)Perez R, Ineichen P, Seals R, Michalsky JJ, Stewart R (1990) Modelling daylight availability and irradiance components from direct and global irradiance. Sol Energy 44:271–289Pinazo JM, Cañada J, Bosca JV (1995) A new method to determine Ångström's turbidity coefficient: its application for Valencia. Solar Energy 54:219–226Serrano MA, BoscĂĄ JV, Cañada J (2008) The determination of a band factor to express irradiance of UV and PAR wavelength ranges in a clean and dry atmosphere at Valencia (Spain). Int J Ambient Energy 29(4):171–180Utrillas MP, BoscĂ  JV, Martinez-Lozano JA, Cañada J, Tena F, Pinazo JM (1998) A comparative study of Spectral2, and Smarts2 parameterised models based on spectral irradiance measurements at Valencia, Spain. Solar Energy 63:161–171Utrillas MP, MarĂ­n MJ, Esteve AR, Tena F, Cañada J, EstellĂ©s V, MartĂ­nez Lozano JA (2007) Diffuse UV erythemal radiation experimental values. J Geophy Res 112:387–39

    Growth of Chlorella vulgaris and Nannochloris oculata in effluents of Tilapia farming for the production of fatty acids with potential in biofuels

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    The use of microalgae in wastewater treatment and its biotechnological exploitation for the production of biofuels is a potential environmental application. Some species of microalgae are notable due to their lipid composition and fatty acid profile suitable for biofuel production. During the present study, a factorial 23 experimental design was conducted, which assessed three factors: i) two species of microalgae (Chlorella vulgaris and Nannochloris oculata), ii) two types of culture media [wastewater of tilapia farming (WTF) and bold’s basal medium (BB)], and iii) two types of lighting (multi-LED lamps and white light). Microalgae were inoculated in photobioreactors in 6 L of medium (WTF or BBM) at an initial concentration of 1.0 × 106 cells ml-1 at 20 ± 2°C. The highest average cell density as well as the highest productivity of biomass observed in the treatments was C. vulgaris treatment in BBM and multi-LED lighting (8.83 × 107 cells ml-1 and 0.0854 g l-1 d-1, respectively). Although the majority of lipid productivity was obtained in the exponential phase of N. oculata cultivated in multi-LEDs in both treatments (BBM with 58% and WTF with 52%), cultivation of both species was generally maintained in WTF and were those that presented the major lipid productivity (2-18 mg l-1 d-1) in comparison with those cultivated in BBM. Palmitic, stearic, oleic, linoleic, linolenic and eicosanoic (C16–C20) fatty acids were present in both species of microalgae in concentrations between 26 and 74%. Based on the results of the present study, we conclude that cultivation of N. oculata and/or C. vulgaris in WTF illuminated with multi-LEDs is an economic and sustainable alternative for biodiesel production because it can represent up to 58% of lipids with a fatty acid profile optimal up to 74% of the total fatty acids.Key words: Chlorella vulgaris, Nannochloris oculata, production of fatty acids, wastewater of tilapia farming, production of biofuels

    Pharmacology of airways and vessels in lung slices in situ: role of endogenous dilator hormones

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    Small airway and vessels play a critical role in chronic airway and pulmonary vascular diseases, but their pharmacology has not been well characterised. We have studied airway and vascular responses in rat lung slices and separately in vitro using myography. In lung slices, under basal conditions, acetylcholine contracted airways, but had no vascular effect. The thromboxane mimetic, U46619 contracted both vessels and airways. In the presence of U46619, acetylcholine dilated vessels, but further contracted airways, an effect that was blocked by the nitric oxide synthase inhibitor L-N(G)-nitro-L-arginine or apamin plus charybdotoxin, which inhibit endothelial-derived hyperpolarising factor. Airway responses in lung slices were unaffected by L-N(G)nitro-L-arginine methyl ester, indomethacin or apamin plus charybdotoxin. By contrast, apamin plus charybdotoxin contracted bronchi studied in isolation. Our observations are the first to identify mechanisms of endothelium dependent dilations in precision cut lung slices and the potential for transverse hormonal communication between airways and vessels

    Contribution of cyanobacterial alkane production to the ocean hydrocarbon cycle.

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    Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2-540 pg alkanes per mL per day, which translates into a global ocean yield of ∌ 308-771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities

    Identifying chemokines as therapeutic targets in renal disease: Lessons from antagonist studies and knockout mice

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    Chemokines, in concert with cytokines and adhesion molecules, play multiple roles in local and systemic immune responses. In the kidney, the temporal and spatial expression of chemokines correlates with local renal damage and accumulation of chemokine receptor-bearing leukocytes. Chemokines play important roles in leukocyte trafficking and blocking chemokines can effectively reduce renal leukocyte recruitment and subsequent renal damage. However, recent data indicate that blocking chemokine or chemokine receptor activity in renal disease may also exacerbate renal inflammation under certain conditions. An increasing amount of data indicates additional roles of chemokines in the regulation of innate and adaptive immune responses, which may adversively affect the outcome of interventional studies. This review summarizes available in vivo studies on the blockade of chemokines and chemokine receptors in kidney diseases, with a special focus on the therapeutic potential of anti-chemokine strategies, including potential side effects, in renal disease. Copyright (C) 2004 S. Karger AG, Basel

    Exploring Protein-Protein Interactions as Drug Targets for Anti-cancer Therapy with In Silico Workflows

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    We describe a computational protocol to aid the design of small molecule and peptide drugs that target protein-protein interactions, particularly for anti-cancer therapy. To achieve this goal, we explore multiple strategies, including finding binding hot spots, incorporating chemical similarity and bioactivity data, and sampling similar binding sites from homologous protein complexes. We demonstrate how to combine existing interdisciplinary resources with examples of semi-automated workflows. Finally, we discuss several major problems, including the occurrence of drug-resistant mutations, drug promiscuity, and the design of dual-effect inhibitors.Fil: Goncearenco, Alexander. National Institutes of Health; Estados UnidosFil: Li, Minghui. Soochow University; China. National Institutes of Health; Estados UnidosFil: Simonetti, Franco Lucio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; ArgentinaFil: Shoemaker, Benjamin A. National Institutes of Health; Estados UnidosFil: Panchenko, Anna R. National Institutes of Health; Estados Unido

    Rhesus TRIM5α disrupts the HIV-1 capsid at the inter-hexamer interfaces

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    TRIM proteins play important roles in the innate immune defense against retroviral infection, including human immunodeficiency virus type-1 (HIV-1). Rhesus macaque TRIM5α (TRIM5αrh) targets the HIV-1 capsid and blocks infection at an early post-entry stage, prior to reverse transcription. Studies have shown that binding of TRIM5α to the assembled capsid is essential for restriction and requires the coiled-coil and B30.2/SPRY domains, but the molecular mechanism of restriction is not fully understood. In this study, we investigated, by cryoEM combined with mutagenesis and chemical cross-linking, the direct interactions between HIV-1 capsid protein (CA) assemblies and purified TRIM5αrh containing coiled-coil and SPRY domains (CC-SPRYrh). Concentration-dependent binding of CC-SPRYrh to CA assemblies was observed, while under equivalent conditions the human protein did not bind. Importantly, CC-SPRYrh, but not its human counterpart, disrupted CA tubes in a non-random fashion, releasing fragments of protofilaments consisting of CA hexamers without dissociation into monomers. Furthermore, such structural destruction was prevented by inter-hexamer crosslinking using P207C/T216C mutant CA with disulfide bonds at the CTD-CTD trimer interface of capsid assemblies, but not by intra-hexamer crosslinking via A14C/E45C at the NTD-NTD interface. The same disruption effect by TRIM5αrh on the inter-hexamer interfaces also occurred with purified intact HIV-1 cores. These results provide insights concerning how TRIM5α disrupts the virion core and demonstrate that structural damage of the viral capsid by TRIM5α is likely one of the important components of the mechanism of TRIM5α-mediated HIV-1 restriction. © 2011 Zhao et al
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