963 resultados para Triple helix
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En el presente estudio se han analizado las posibilidades de reducción del impacto ambiental que genera el consumo de energía en el Monasterio budista Sakya Tashi Ling del Parque del Garraf, mediante la mejora de la eficiencia energética de los edificios y la producción de la energía consumida a partir de fuentes de energía renovables. Se ha realizado un inventario exhaustivo de los flujos energéticos de entrada del Monasterio: electricidad y combustibles fósiles, y el análisis de estos datos ha permitido observar que la mayor parte del consumo energético del Monasterio tiene como uso final la iluminación. El consumo total de energía se ha cuantificado en 138 kWh/m2/año y la emisiones de CO2 en 177 kg CO2/m2/año. A partir de estos datos se ha estudiado la posibilidad de reducir el consumo y abastecer la demanda energética del Monasterio a través de fuentes de energía renovable como las placas solares fotovoltaicas o las calderas de biomasa. Para alcanzar este objetivo se han propuesto tres escenarios posibles con costes económicos y resultados muy distintos. A diferencia de los escenarios “Edificio Energía Plus” y “Edificio Energía 0”, el tercer escenario propuesto, que trataba de alcanzar el triple objetivo del Plan 20/20/20 (producir a partir de fuentes renovables el 20% de la energía consumida, aumentar en una 20% la eficiencia energética y reducir en un 20% las emisiones de CO2 derivadas del uso de la energía) ha resultado ser muy viable económicamente: la inversión necesaria se amortizaría en tan sólo 5 años.
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Tobacco consumption is a global epidemic responsible for a vast burden of disease. With pharmacological properties sought-after by consumers and responsible for addiction issues, nicotine is the main reason of this phenomenon. Accordingly, smokeless tobacco products are of growing popularity in sport owing to potential performance enhancing properties and absence of adverse effects on the respiratory system. Nevertheless, nicotine does not appear on the 2011 World Anti-Doping Agency (WADA) Prohibited List or Monitoring Program by lack of a comprehensive large-scale prevalence survey. Thus, this work describes a one-year monitoring study on urine specimens from professional athletes of different disciplines covering 2010 and 2011. A method for the detection and quantification of nicotine, its major metabolites (cotinine, trans-3-hydroxycotinine, nicotine-N'-oxide and cotinine-N-oxide) and minor tobacco alkaloids (anabasine, anatabine and nornicotine) was developed, relying on ultra-high pressure liquid chromatography coupled to triple quadrupole mass spectrometry (UHPLC-TQ-MS/MS). A simple and fast dilute-and-shoot sample treatment was performed, followed by hydrophilic interaction chromatography-tandem mass spectrometry (HILIC-MS/MS) operated in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM) data acquisition. After method validation, assessing the prevalence of nicotine consumption in sport involved analysis of 2185 urine samples, accounting for 43 different sports. Concentrations distribution of major nicotine metabolites, minor nicotine metabolites and tobacco alkaloids ranged from 10 (LLOQ) to 32,223, 6670 and 538 ng/mL, respectively. Compounds of interest were detected in trace levels in 23.0% of urine specimens, with concentration levels corresponding to an exposure within the last three days for 18.3% of samples. Likewise, hypothesizing conservative concentration limits for active nicotine consumption prior and/or during sport practice (50 ng/mL for nicotine, cotinine and trans-3-hydroxycotinine and 25 ng/mL for nicotine-N'-oxide, cotinine-N-oxide, anabasine, anatabine and nornicotine) revealed a prevalence of 15.3% amongst athletes. While this number may appear lower than the worldwide smoking prevalence of around 25%, focusing the study on selected sports highlighted more alarming findings. Indeed, active nicotine consumption in ice hockey, skiing, biathlon, bobsleigh, skating, football, basketball, volleyball, rugby, American football, wrestling and gymnastics was found to range between 19.0 and 55.6%. Therefore, considering the adverse effects of smoking on the respiratory tract and numerous health threats detrimental to sport practice at top level, likelihood of smokeless tobacco consumption for performance enhancement is greatly supported.
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L'objectiu és revelar la potència pedagògica de l'obra d'Ouaknin (segle XX): 1991-2000. En conseqüència, la hipòtesi conjectura que un seguiment atent dels textos ouakninians pot derivar vers una pedagogia lectora. El mètode, conreat per la filosofia i adient al fenomen lector, és l'hermenèutica de Gadamer. Bàsicament, tres autories influencien el nostre rabí quant a lectura: Arendt (acció), Ricoeur (triple mimesi) i Levinas (fecunditat). Aquesta pedagogia lectora, espaciotemporalitat que facilita una antropologia on l'humà avé qüestionament (quoibilité), situa les modalitats lectores (intencional i vivencial), vehicula els protagonistes (deixeble, mestre i text) i mostra els moviments concomitants (carícia, bibliofarmacologia i ètica)
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L'objectiu del projecte era la creació d’una eina de tipus intranet que permetés al personal docent de la Facultat enregistrar i documentar les feines d’innovació docent, així com desenvolupar els processos associats per a la seva gestió. La utilitat que es volia donar a aquest registre és triple: 1) permetre compartir entre els professors les experiències, tant positives com negatives, d’innovació i millora de la docència i 2) permetre a la Facultat detectar iniciatives interessants, per promoure-les i estendre-les, així com eventualment reconèixer la feina dels professors que innoven i 3) permetre a la Facultat mostrar a entitats externes la feina de renovació que els seus professors duen a terme.
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Background: Hepatitis C virus (HCV) nonstructural protein 2 (NS2) plays essential roles in particle assembly and polyprotein processing. It harbors an N-terminal membrane domain comprising three putative transmembrane s egments ( amino acids [aa] 1-93) a nd a C-terminal cysteine protease domain (aa 94-217). Given that the latter has been predicted to be membrane-associated, we aimed to identify molecular determinants for membrane association of the NS2 protease domain. Methods: A comprehensive panel of NS2 deletion constructs was analyzed by fluorescence microscopy, selective membrane extraction, and m embrane flotation assays. Candidate aa r esidues involved in membrane association were substituted by site-directed mutagenesis. Results: The NS2 protease domain alone was found to associate with membranes. Two N-terminal α-helices comprising aa 102-114 and aa 123-136 were found to m ediate this a ssociation, w ith c onserved hydrophobic and positively charged aa residues representing the key determinants. I nterestingly, m utagenesis analyses r evealed that electrostatic interactions involving a positively charged aa residue in α-helix aa 123-136 are required for membrane association. Mono- and bicistronic (i.e. NS2 c leavage-independent) HCV constructs were prepared to i nvestigate the effect o f these substitutions on RNA replication and infectious viral particle formation. Conclusions: T he NS2 protease d omain itself harbors m olecular determinants for membrane association within α-helices aa 102-114 and aa 1 23-136 which may contribute to p roper p ositioning of t he active site. These results provide new insights i nto the membrane topology and t he p oorly understood f unction of t his essential viral protease.
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Sentinel lymph node dissection (SLND) identifies melanoma patients with metastatic disease who would benefit from radical lymph node dissection (RLND). Rarely, patients with melanoma have an underlying lymphoproliferative disease, and melanoma metastases might develop as collision tumours in the sentinel lymph node (SLN). The aim of this study was to measure the incidence and examine the effect of collision tumours on the accuracy of SLND and on the validity of staging in this setting. Between 1998 and 2012, 750 consecutive SLNDs were performed in melanoma patients using the triple technique (lymphoscintigraphy, gamma probe and blue dye). The validity of SLND in collision tumours was analysed. False negativity was reflected by the disease-free survival. The literature was reviewed on collision tumours in melanoma. Collision tumours of melanoma and chronic lymphocytic leukaemia (CLL) were found in two SLN and in one RLND (0.4%). Subsequent RLNDs of SLND-positive cases were negative for melanoma. The patient with negative SLND developed relapse after 28 months with an inguinal lymph node metastasis of melanoma; RLND showed collision tumours. The literature review identified 12 cases of collision tumours. CLL was associated with increased melanoma incidence and reduced overall survival. This is, to our knowledge, the first assessment of the clinical value of SLND when collision tumours of melanoma and CLL are found. In this small series of three patients with both malignancies present in the same lymph node basin, lymphocytic infiltration of the CLL did not alter radioisotope uptake into the SLN. No false-negative result was observed. Our data suggest the validity of SLND in collision tumours, but given the rarity of the problem, further studies are necessary to confirm this reliability.
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Cell elongation during seedling development is antagonistically regulated by light and gibberellins (GAs). Light induces photomorphogenesis, leading to inhibition of hypocotyl growth, whereas GAs promote etiolated growth, characterized by increased hypocotyl elongation. The mechanism underlying this antagonistic interaction remains unclear. Here we report on the central role of the Arabidopsis thaliana nuclear transcription factor PIF4 (encoded by PHYTOCHROME INTERACTING FACTOR 4) in the positive control of genes mediating cell elongation and show that this factor is negatively regulated by the light photoreceptor phyB (ref. 4) and by DELLA proteins that have a key repressor function in GA signalling. Our results demonstrate that PIF4 is destabilized by phyB in the light and that DELLAs block PIF4 transcriptional activity by binding the DNA-recognition domain of this factor. We show that GAs abrogate such repression by promoting DELLA destabilization, and therefore cause a concomitant accumulation of free PIF4 in the nucleus. Consistent with this model, intermediate hypocotyl lengths were observed in transgenic plants over-accumulating both DELLAs and PIF4. Destabilization of this factor by phyB, together with its inactivation by DELLAs, constitutes a protein interaction framework that explains how plants integrate both light and GA signals to optimize growth and development in response to changing environments.
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Combustion-derived and manufactured nanoparticles (NPs) are known to provoke oxidative stress and inflammatory responses in human lung cells; therefore, they play an important role during the development of adverse health effects. As the lungs are composed of more than 40 different cell types, it is of particular interest to perform toxicological studies with co-cultures systems, rather than with monocultures of only one cell type, to gain a better understanding of complex cellular reactions upon exposure to toxic substances. Monocultures of A549 human epithelial lung cells, human monocyte-derived macrophages and monocyte-derived dendritic cells (MDDCs) as well as triple cell co-cultures consisting of all three cell types were exposed to combustion-derived NPs (diesel exhaust particles) and to manufactured NPs (titanium dioxide and single-walled carbon nanotubes). The penetration of particles into cells was analysed by transmission electron microscopy. The amount of intracellular reactive oxygen species (ROS), the total antioxidant capacity (TAC) and the production of tumour necrosis factor (TNF)-a and interleukin (IL)-8 were quantified. The results of the monocultures were summed with an adjustment for the number of each single cell type in the triple cell co-culture. All three particle types were found in all cell and culture types. The production of ROS was induced by all particle types in all cell cultures except in monocultures of MDDCs. The TAC and the (pro-)inflammatory reactions were not statistically significantly increased by particle exposure in any of the cell cultures. Interestingly, in the triple cell co-cultures, the TAC and IL-8 concentrations were lower and the TNF-a concentrations were higher than the expected values calculated from the monocultures. The interplay of different lung cell types seems to substantially modulate the oxidative stress and the inflammatory responses after NP exposure. [Authors]
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Several members of the FXYD protein family are tissue-specific regulators of Na,K-ATPase that produce distinct effects on its apparent K(+) and Na(+) affinity. Little is known about the interaction sites between the Na,K-ATPase alpha subunit and FXYD proteins that mediate the efficient association and/or the functional effects of FXYD proteins. In this study, we have analyzed the role of the transmembrane segment TM9 of the Na,K-ATPase alpha subunit in the structural and functional interaction with FXYD2, FXYD4, and FXYD7. Mutational analysis combined with expression in Xenopus oocytes reveals that Phe(956), Glu(960), Leu(964), and Phe(967) in TM9 of the Na,K-ATPase alpha subunit represent one face interacting with the three FXYD proteins. Leu(964) and Phe(967) contribute to the efficient association of FXYD proteins with the Na,K-ATPase alpha subunit, whereas Phe(956) and Glu(960) are essential for the transmission of the functional effect of FXYD proteins on the apparent K(+) affinity of Na,K-ATPase. The relative contribution of Phe(956) and Glu(960) to the K(+) effect differs for different FXYD proteins, probably reflecting the intrinsic differences of FXYD proteins on the apparent K(+) affinity of Na,K-ATPase. In contrast to the effect on the apparent K(+) affinity, Phe(956) and Glu(960) are not involved in the effect of FXYD2 and FXYD4 on the apparent Na(+) affinity of Na,K-ATPase. The mutational analysis is in good agreement with a docking model of the Na,K-ATPase/FXYD7 complex, which also predicts the importance of Phe(956), Glu(960), Leu(964), and Phe(967) in subunit interaction. In conclusion, by using mutational analysis and modeling, we show that TM9 of the Na,K-ATPase alpha subunit exposes one face of the helix that interacts with FXYD proteins and contributes to the stable interaction with FXYD proteins, as well as mediating the effect of FXYD proteins on the apparent K(+) affinity of Na,K-ATPase.
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Among the various determinants of treatment response, the achievement of sufficient blood levels is essential for curing malaria. For helping us at improving our current understanding of antimalarial drugs pharmacokinetics, efficacy and toxicity, we have developed a liquid chromatography-tandem mass spectrometry method (LC-MS/MS) requiring 200mul of plasma for the simultaneous determination of 14 antimalarial drugs and their metabolites which are the components of the current first-line combination treatments for malaria (artemether, artesunate, dihydroartemisinin, amodiaquine, N-desethyl-amodiaquine, lumefantrine, desbutyl-lumefantrine, piperaquine, pyronaridine, mefloquine, chloroquine, quinine, pyrimethamine and sulfadoxine). Plasma is purified by a combination of protein precipitation, evaporation and reconstitution in methanol/ammonium formate 20mM (pH 4.0) 1:1. Reverse-phase chromatographic separation of antimalarial drugs is obtained using a gradient elution of 20mM ammonium formate and acetonitrile both containing 0.5% formic acid, followed by rinsing and re-equilibration to the initial solvent composition up to 21min. Analyte quantification, using matrix-matched calibration samples, is performed by electro-spray ionization-triple quadrupole mass spectrometry by selected reaction monitoring detection in the positive mode. The method was validated according to FDA recommendations, including assessment of extraction yield, matrix effect variability, overall process efficiency, standard addition experiments as well as antimalarials short- and long-term stability in plasma. The reactivity of endoperoxide-containing antimalarials in the presence of hemolysis was tested both in vitro and on malaria patients samples. With this method, signal intensity of artemisinin decreased by about 20% in the presence of 0.2% hemolysed red-blood cells in plasma, whereas its derivatives were essentially not affected. The method is precise (inter-day CV%: 3.1-12.6%) and sensitive (lower limits of quantification 0.15-3.0 and 0.75-5ng/ml for basic/neutral antimalarials and artemisinin derivatives, respectively). This is the first broad-range LC-MS/MS assay covering the currently in-use antimalarials. It is an improvement over previous methods in terms of convenience (a single extraction procedure for 14 major antimalarials and metabolites reducing significantly the analytical time), sensitivity, selectivity and throughput. While its main limitation is investment costs for the equipment, plasma samples can be collected in the field and kept at 4 degrees C for up to 48h before storage at -80 degrees C. It is suited to detecting the presence of drug in subjects for screening purposes and quantifying drug exposure after treatment. It may contribute to filling the current knowledge gaps in the pharmacokinetics/pharmacodynamics relationships of antimalarials and better define the therapeutic dose ranges in different patient populations.
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A small proportion of the treated hypertensive population consistently has a blood pressure greater than 140/90 mm Hg despite a triple therapy including a diuretic, a calcium channel blocker, and a blocker of the renin-angiotensin system. According to guidelines, these patients have so-called resistant hypertension. The prevalence of this clinical condition is higher in tertiary than primary care centers and often is associated with chronic kidney disease, diabetes, obesity, and sleep apnea syndrome. Exclusion of pseudoresistant hypertension using ambulatory or home blood pressure monitoring is a crucial step in the investigation of patients with resistant hypertension. Thus, among the multiple factors to consider when investigating patients with resistant hypertension, ambulatory blood pressure monitoring should be performed very early. Among other factors to consider, physicians should investigate patient adherence to therapy, assess the adequacy of treatment, exclude interfering factors, and, finally, look for secondary forms of hypertension. Poor adherence to therapy accounts for 30% to 50% of cases of resistance to therapy depending on the methodology used to diagnose adherence problems. This review discusses the clinical factors implicated in the pathogenesis of resistant hypertension with a particular emphasis on pseudoresistance, drug adherence, and the use of ambulatory blood pressure monitoring for the diagnosis and management of resistant hypertension.
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Heart transplantation remains the best therapeutic option for the treatment of end-stage heart failure. However, good survival rates can be obtained only if patients are closely monitored, particularly for their immunosuppressive regimens. Currently, a triple-drug regimen usually based on calcineurin-inhibitors (cyclosporin A or tacrolimus), anti-proliferative agents and steroids is used in most recipients. New agents such as the mTOR inhibitors, a more recently developed class of immunosuppressive drugs, can also be used in some patients. The aim of this article is to review currently used immunosuppressive regimens after heart transplantation, and to propose some individualized options depending on specific patient characteristics and recent pharmacological developments in the field.
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Da Bisanzio alla Santa Russia Résumé Ivan Foletti Le texte du premier volume de YIkonografija Bogomatri (Iconographie de la mère de Dieu), publié en 1914 à Saint Pétersbourg par Nikodim Kondakov et traduit dans le cadre de ce travail, soulève chez le lecteur contemporain de nombreuses questions quant au développement des études byzantines, entre la fin du XIXe et le début du XXe siècle. Il s'agit, avant tout, de comprendre les enjeux fondamentaux de la naissance de cette discipline, dans le cadre de l'Europe romantique et plus particulièrement de son acculturation à la réalité russe. En se concentrant sur le personnage de Nikodim Kondakov, considéré par ses contemporains comme le patriarche des études byzantines, ce travail propose d'articuler la réflexion autour de deux axes principaux. Il s'agit d'une part de la relation entre histoire de l'art et société : dans le contexte russe et plus largement dans celui de l'Europe, la recherche semble se développer en étroite relation avec les tendances politiques et sociales de ces années. C'est probablement la raison du choix pour Nikodim Kondakov de se dédier aux études de Byzance, dans les années où la Russie prépare sa guerre contre la Turquie (1877-1878), tandis que l'opinion publique est martelée avec un revival de l'ancienne idéologie de Moscou comme « troisième Rome » et héritière de Byzance. Un autre aspect significatif est la décision de ce même chercheur d'étudier les antiquités russes sous le règne de Alexandre III, le tzar « contre-réformateur », quand la Russie se replie sur elle même autour de trois mots d'ordre: Orthodoxie, autocratie, et nationalité. D'autre part, la réception de Kondakov en Occident, semble aussi dépendre de questions politiques. Son accueil très favorable en France et en Angleterre contraste avec une perception bien plus négative en Autriche et en Allemagne ; il s'agit là d'une position en étonnante harmonie avec les traités politiques - l'alliance franco-russe de 1891 et la triple entente de 1911 qui opposent les pays membres aux empires centraux. Le deuxième axe considéré est celui d'une analyse systématique de la naissance des études sur les images cultuelles russes, les icônes. Les pages dédiées à ce phénomène dans Γ Ikonograflja Bogomatri, mais également dans les autres ouvrages de Kondakov, posent clairement la question des raisons nationalistes et populistes de la redécouverte, autour de 1900, en Russie et en Europe de cette expression visuelle. Conclusion logique de la tradition historiographique du XIXe siècle - qui s'est préoccupé des icônes perçues comme documents historiques - cette nouvelle vague d'intérêt pose la question de l'icône commé"oeuvre d'art. C'est autour de ce débat, alimenté également par l'apparition des avant-gardes, que se situent les plus importants savants russes de ces années en opposant deux manières radicalement différentes de percevoir l'art : à l'approche positiviste s'oppose celle d'un renouveau d'Hegel. Ce débat sera brusquement interrompu par la révolution, suivie par les années staliniennes qui vont définitivement « discerner » laquelle des deux méthodes et approches est la « juste », en congelant de fait, pour des décennies, toute possibilité de discussion. Cette thèse souhaiterait donc ouvrir en Occident un débat pour l'instant marginal dans les études : celui de la naissance d'une histoire de l'art moderne en Russie, mais également de l'émergence d'une nouvelle Europe savante autour de 1900 où l'histoire de l'art byzantin s'affirme comme un domaine émergent.
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The RsmA family of RNA-binding proteins are global post-transcriptional regulators that mediate extensive changes in gene expression in bacteria. They bind to, and affect the translation rate of target mRNAs, a function that is further modulated by one or more, small, untranslated competitive regulatory RNAs. To gain new insights into the nature of this protein/RNA interaction, we used X-ray crystallography to solve the structure of the Yersinia enterocolitica RsmA homologue. RsmA consists of a dimeric beta barrel from which two alpha helices are projected. From structure-based alignments of the RsmA protein family from diverse bacteria, we identified key amino acid residues likely to be involved in RNA-binding. Site-specific mutagenesis revealed that arginine at position 44, located at the N terminus of the alpha helix is essential for biological activity in vivo and RNA-binding in vitro. Mutation of this site affects swarming motility, exoenzyme and secondary metabolite production in the human pathogen Pseudomonas aeruginosa, carbon metabolism in Escherichia coli, and hydrogen cyanide production in the plant beneficial strain Pseudomonas fluorescens CHA0. R44A mutants are also unable to interact with the small untranslated RNA, RsmZ. Thus, although possessing a motif similar to the KH domain of some eukaryotic RNA-binding proteins, RsmA differs substantially and incorporates a novel class of RNA-binding site.
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Aquest estudi permet conèixer les implicacions dels diferents subtipus de cáncer de mama: luminal A, luminal B, HER2+, triple negatiu en el desenvolupament y pronostic de la carcinomatosi leptomeníngea (CL). Es van identificar 38 pacients, major proporció: luminal B y HER2+, 53% va rebre quimioteràpia sistémica (QTS). La mitjana de supervivencia post CL: 2,6 messos. A l’anàlisis univariat: ECOG de 0-2 y tractament amb QT van ser variables pronòstiques i al multivariant nomès QTS. En conclussió el subtipus de cáncer de mama influiex en el temps d’aparició de la CL, no afectant la supervivencia desprès del diagnóstic.