369 resultados para Ramón Sender


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A partir de la resonancia que ha tenido en los medios de comunicación el 150 aniversario del nacimiento de Freud, se hace un breve recuento de los principales tópicos y confusiones que se difunden en torno al psicoanálisis, y se presenta una breve reflexión acerca de las dos principales críticas de que es objeto, las referidas a la falta de validez de su conocimiento y a la falta de eficacia de sus tratamientos.

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L’estudi dels materials ceràmics trobats als jaciments romans del Cementeri (Alcanar) i la Torreta (Ulldecona) ens permet emmarcar-ho en l’àmbit comarcal i efectuar una aproximació al desenvolupament de la romanització a la comarca del Montsià i a les terres veïnes del Baix Maestrat.

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El presente artículo trata de aportar una puesta al día de los problemas que presentan los pacientes afectados de anorexia y de bulimia nerviosa. Se expone la información que el odontólogo debe tener en cuenta respecto al conocimiento de la enfermedad, sus manifestaciones orales, los criterios diagnósticos y los enfoques preventivos y terapéuticos necesarios.

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Recent studies provided new data about late Roman imports (ARS, amphorae, lamps) in the coast of Hispania Tarraconensis. Concerning urban contexts (the ancient towns of Barcino, Tarraco and others) and rural settlements, the data allow us to identify the imports and the economic trends of the region from the 4th to the late 6th /early 7th centuries. We hope this paper to be an interpretative work of synthesis about the economic relationship between town and country in Catalonia and Northern Comunidad Valenciana in the Late Antiquity.

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A series of 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridines differently substituted at positions 1, 5, and 9 have been designed from the pyrano[3,2-c]quinoline derivative 1, a weak inhibitor of acetylcholinesterase (AChE) with predicted ability to bind to the AChE peripheral anionic site (PAS), at the entrance of the catalytic gorge. Fourteen novel benzonaphthyridines have been synthesized through synthetic sequences involving as the key step a multicomponent Povarov reaction between an aldehyde, an aniline and an enamine or an enamide as the activated alkene. The novel compounds have been tested against Electrophorus electricus AChE (EeAChE), human recombinant AChE (hAChE), and human serum butyrylcholinesterase (hBChE), and their brain penetration has been assessed using the PAMPA-BBB assay. Also, the mechanism of AChE inhibition of the most potent compounds has been thoroughly studied by kinetic studies, a propidium displacement assay, and molecular modelling. We have found that a seemingly small structural change such as a double O → NH bioisosteric replacement from the hit 1 to 16a results in a dramatic increase of EeAChE and hAChE inhibitory activities (>217- and >154-fold, respectively), and in a notable increase in hBChE inhibitory activity (> 11-fold), as well. An optimized binding at the PAS besides additional interactions with AChE midgorge residues seem to account for the high hAChE inhibitory potency of 16a (IC50 = 65 nM), which emerges as an interesting anti-Alzheimer lead compound with potent dual AChE and BChE inhibitory activities.

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The toxicity and environmental behavior of new pH-sensitive surfactants from lysine are presented. Three different chemical structures are studied: surfactants with one amino acid and one alkyl chain, surfactants with two amino acids on the polar head and one alkyl chain, and gemini surfactants. The pH sensitivity of these compounds can be tuned by modifying their chemical structures. Cytotoxicity has been evaluated using erythrocytes and fibroblast cells. The toxic effects against these cells depend on the hydrophobicity of the molecules as well as their cationic charge density. The effect of hydrophobicity and cationic charge density on toxicity is different for each type of cells. For erythrocytes, the toxicity increases as hydrophobicity and charge density increases. Nevertheless, for fibroblasts cationic charge density affects cytotoxicity in the opposite way: the higher charge density, the lower the toxicity. The effect of the pH on hemolysis has been evaluated in detail. The aquatic toxicity was established using Daphnia magna. All surfactants yielded EC50 values considerably higher than that reported for cationic surfactants based on quaternary ammonium groups. Finally, their biodegradability was evaluated using the CO2 headspace test (ISO 14593). These lysine derivatives showed high levels of biodegradation under aerobic conditions and can be classified as"readily biodegradable compounds".

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A series of 1,2,3,4-tetrahydrobenzo[h][1,6]naphthyridines differently substituted at positions 1, 5, and 9 have been designed from the pyrano[3,2-c]quinoline derivative 1, a weak inhibitor of acetylcholinesterase (AChE) with predicted ability to bind to the AChE peripheral anionic site (PAS), at the entrance of the catalytic gorge. Fourteen novel benzonaphthyridines have been synthesized through synthetic sequences involving as the key step a multicomponent Povarov reaction between an aldehyde, an aniline and an enamine or an enamide as the activated alkene. The novel compounds have been tested against Electrophorus electricus AChE (EeAChE), human recombinant AChE (hAChE), and human serum butyrylcholinesterase (hBChE), and their brain penetration has been assessed using the PAMPA-BBB assay. Also, the mechanism of AChE inhibition of the most potent compounds has been thoroughly studied by kinetic studies, a propidium displacement assay, and molecular modelling. We have found that a seemingly small structural change such as a double O → NH bioisosteric replacement from the hit 1 to 16a results in a dramatic increase of EeAChE and hAChE inhibitory activities (>217- and >154-fold, respectively), and in a notable increase in hBChE inhibitory activity (> 11-fold), as well. An optimized binding at the PAS besides additional interactions with AChE midgorge residues seem to account for the high hAChE inhibitory potency of 16a (IC50 = 65 nM), which emerges as an interesting anti-Alzheimer lead compound with potent dual AChE and BChE inhibitory activities.

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Els temps canvien, i amb el temps, els negocis. L'entorn social, cultural i econòmic ha canviat durant els darrers anys i s’han desenvolupat grans oportunitats i difícils problemes. Molts dels països desenvolupats han sofert altes taxes d’atur i els individus han vist disminuïdes les seves qualitats de vida. Noves i a la vegada antigues opcions han sorgit per fer front a tots aquests canvis, una d’aquestes, l’autoocupació. Els emprenedors estan de moda, i qualsevol canvi social, implica un canvi legislatiu. El legislador espanyol ha trigat temps en desenvolupar mecanismes per protegir i promocionar als emprenedors. En primer lloc, aquesta investigació tracta d’entendre perquè Espanya és un dels països amb pitjors condicions per emprendre un negoci. En segon lloc, es pretén inspeccionar la Llei 14/2013 de recolzament als emprenedors i la seva internacionalització, aprovada els darrers mesos de l’any 2013, per veure si dóna solucions al problema anterior. En tercer lloc, per poder aconseguir aquesta difícil tasca, la investigació compara la legislació espanyola amb les necessitats reals dels emprenedors i amb les bones mesures implementades per altres països europeus. No hi ha dubte de que l’emprenedoria és una realitat, ara hem d’observar si les bones condicions per emprendre a Espanya també són una realitat.