476 research outputs found
Synthesis and cytotoxic activity of 3-[2-(1H-Indol-3-yl)-1,3-thiazol-4-yl]-1H-pyrrolo[3,2-c]pyridine hydrobromides, analogues of the marine alkaloid nortopsentin
A new series of thiazole nortopsentin analogues with a 5-azaindole moiety was conveniently synthesized in good to excellent yields by an Hantzsch reaction between thioamides and \u3b1-bromoacetyl compounds. The cytotoxic activity of the new derivatives was tested against different human tumor cell lines of the NCI full panel. All tested compounds were active against all of the investigated cell lines showing GI50 values from micro to submicromolar levels. Some of the new analogues exhibited good selectivities against different NCI sub-panels
Turbulent anisotropic transport in a model cloud interface
Small-scale turbulence in cumuli can make a significant contribution to the droplet growth by coalescence (Grabowski & Wang, ARFM 2013, Wang & Grabowski Atm.Sci.Lett. 2009), with a consequent significant impact of the onset of warm rain. We study the transport of energy and water vapour at the interface between two turbulent regions with a different kinetic energy and vapour concentration in a stratified environment through direct numerical simulations by applying the Boussinesq approximation. This configuration (Iovieno et al. JoT 2014, Gallana et al. JoP:CS 2015) mimics the inhomogeneity observed at the edge of a cloud between a more energetic cloud and the calmer drier ambient. Both stable and unstable stratifications are considered. In presence of a stable stratification we show the onset of two intermittent layers which confine a low kinetic energy sublayer, which acts as a barrier and blocks entrainment. On the opposite situation, a fast growth of an
intermittent mixing layer enhances the entrainment till the bouyancy forces overcome inertial forces. We consider also the motion of droplets subject to the Stokes drag, gravitational acceleration and condensational growth. Their motion is coupled with the advection-diffusion of vapour in the air by using Mason’s model (Villancourt et al., J.Atm.Sci. 2000, Devenish et al. QJRMS 2012, Kumar et al. TCFD 2013). Unlikely most simulations, which use the "ghost collision approximation" (e.g. Ayala et al. 2008), we assume coalescence of the droplets. By means of this formulation, we will verigy our ansatz that the concentration of fluid elements across the cloud interface (shearless mixing layer) can ehnance collision rate and coalescence. We will show how the flow inhomogeneity
influences the droplet growth and their spatial distribution. Collision kernels and the spectral density function of particle size will be also given
Reseña del libro de Daniel Del Percio, La historia y un instante
Daniel Del Percio en su primera novela, La historia y un instante, nos invita a emprender un viaje por una ucronĂa que inicia con la modificaciĂłn de un hecho histĂłrico: un desenlace diferente de la Guerra de Malvinas. Desde una estĂ©tica de extrañamiento del presente y por medio del despliegue de estrategias creativas logra interpelar al lector enfrentándolo a reflexionar sobre diversas cuestiones que refieren a la identidad, la memoria, la polĂtica, la toma de decisiones y sus efectos. Estrategias que le permiten al autor reinventar las narrativas establecidas como asĂ tambiĂ©n narrar con imágenes sincronicidades que rozan los bordes de la imaginaciĂłn y de los discursos histĂłricos. El libro hace un especial llamado al lector a adquirir una posiciĂłn activa a travĂ©s de los sentidos y de la necesidad de pensar crĂticamente nuevos escenarios. Esto es posible, en primer lugar, gracias a la elecciĂłn de una trama no lineal es decir una trama compuesta por instantes que transcurren en mĂşltiples temporalidades, en segundo lugar, al desarrollo de historias dentro de historias lo que se conoce como microrrelatos y, en tercer lugar, a la posibilidad de acceder al mundo interno de cada uno de los interesantes personajes (reales y ficcionales)
Recent Developments in the Inhibition of Bacterial Adhesion as Promising Anti-Virulence Strategy
Infectious diseases caused by antimicrobial-resistant strains have become a serious threat to global health, with a high social and economic impact. Multi-resistant bacteria exhibit various mechanisms at both the cellular and microbial community levels. Among the different strategies proposed to fight antibiotic resistance, we reckon that the inhibition of bacterial adhesion to host surfaces represents one of the most valid approaches, since it hampers bacterial virulence without affecting cell viability. Many different structures and biomolecules involved in the adhesion of Gram-positive and Gram-negative pathogens can be considered valuable targets for the development of promising tools to enrich our arsenal against pathogens
Bud extracts from Tilia tomentosa Moench inhibit hippocampal neuronal firing through GABAA and benzodiazepine receptors activation
Leptin counteracts the hypoxia-induced inhibition of spontaneously firing hippocampal neurons: a microelectrode array study.
Besides regulating energy balance and reducing body-weight, the adipokine leptin has been recently shown to be neuroprotective and antiapoptotic by promoting neuronal survival after excitotoxic and oxidative insults. Here, we investigated the firing properties of mouse hippocampal neurons and the effects of leptin pretreatment on hypoxic damage (2 hours, 3% O(2)). Experiments were carried out by means of the microelectrode array (MEA) technology, monitoring hippocampal neurons activity from 11 to 18 days in vitro (DIV). Under normoxic conditions, hippocampal neurons were spontaneously firing, either with prevailing isolated and randomly distributed spikes (11 DIV), or with patterns characterized by synchronized bursts (18 DIV). Exposure to hypoxia severely impaired the spontaneous activity of hippocampal neurons, reducing their firing frequency by 54% and 69%, at 11 and 18 DIV respectively, and synchronized their firing activity. Pretreatment with 50 nM leptin reduced the firing frequency of normoxic neurons and contrasted the hypoxia-induced depressive action, either by limiting the firing frequency reduction (at both ages) or by increasing it to 126% (in younger neurons). In order to find out whether leptin exerts its effect by activating large conductance Ca(2+)-activated K(+) channels (BK), as shown on rat hippocampal neurons, we applied the BK channel blocker paxilline (1 µM). Our data show that paxilline reversed the effects of leptin, both on normoxic and hypoxic neurons, suggesting that the adipokine counteracts hypoxia through BK channels activation in mouse hippocampal neurons
The effect of CdSe-ZnS quantum dots on calcium currents and catecholamine secretion in mouse chromaffin cells
Como as empresas integrantes da Carteira ISE avaliam o retorno do investimento social privado
O investimento social privado (ISP) Ă© um tema em ascensĂŁo, já considerado estratĂ©gico por muitas empresas da carteira ISE (ĂŤndice de Sustentabilidade Empresarial). Contudo, faz-se necessário um processo de avaliação de retorno do ISP a fim de garantir a manutenção ou ampliação dos recursos financeiros alocados, alĂ©m de ser um instrumento avaliado positivamente nas análises desenvolvidas pela BOVESPA (Bolsa de valores de SĂŁo Paulo). Face ao exposto, o objetivo geral deste estudo foi analisar como as empresas integrantes da carteira ISE avaliam o retorno das ações de ISP que desenvolvem. Com relação Ă metodologia utilizada, optou-se por dois tipos de pesquisas: a primeira, exploratĂłria em livros, artigos acadĂŞmicos e relatĂłrios de sustentabilidade, integrados ou socioambientais das empresas da carteira ISE. A segunda, por meio de pesquisa aplicada, qualitativa, explicativa com estudo de casos, onde se investigou como as empresas integrantes do ISE avaliam o retorno do ISP. Complementarmente, os resultados foram cruzados com as respostas fornecidas pelas empresas ao questionário do ISE - dimensĂŁo social. Como resultado, pode-se avaliar a prática de avaliação do ISE, bem como as estratĂ©gias adotadas pelas empresas e foi possĂvel comprovar que a gestĂŁo do ISP deixa transparecer o quanto o tema está alinhado Ă estratĂ©gia da empresa.
Early alteration of hippocampal neuronal firing induced by Abeta42 oligomers in Alzheimer’s Disease
- …