Patología neurovascular aguda: ¿Existe solución mediante técnicas intervencionistas?

Acute neurovascular pathology is a group of life-threatening diseases with a severe disability in patients who survive from the initial event.Although clinically often cannot differentiate the underlying cause, through the introduction and development of advanced imaging techniques, we can safely identify the type of event (ischemic or hemorrhagic) and select which type of treatment is appropriate.For years the interventional neuroradiology has managed the treatment of this group of diseases using minimally invasive techniques. In ischemic stroke events the treatment is performed by using trievers thrombectomy devices, called stentrievers, in aneurysms different materials such as coils, stents, or balloons are used, and for arteriovenous malformations the most used liquid embolic agent is Onyx.With these interventional technological advances, it has been possible to treat successfully and safely to 90% of patients suffering neurovascular diseases.La patología neurovascular aguda constituye un grupo de enfermedades potencialmente letales que condicionan una severa discapacidad en los pacientes que consiguen sobrevivir el evento inicial.Aunque clínicamente en muchas ocasiones no podemos diferenciar la causa subyacente, mediante la introducción y desarrollo de las ténicas de imagen avanzadas podemos filiar, con seguridad, el tipo de evento (isquémico o hemorrágico) así como seleccionar qué tipo de tratamiento es el apropiado.Desde hace unos años la neurorradiología intervencionista ha conseguido el tratamiento de este grupo de patologías mediante técnicas mínimamente invasivas. En el ictus isqúemico el tratamiento se realiza mediante dispositivos de trombectomía o stentrievers. Para los aneurismas se utilizan distintos materiales como coils, stents, o balones, y para las malformaciones arteriovenosas el agente líquido embolizante más utilizado es el Onyx.Con estos avances tecnológicos intervencionistas, se ha conseguido tratar de forma satisfactoria y segura a un 90% de los pacientes que sufren patología neurovascular

Hydrazones as Singular Reagents in Asymmetric Organocatalysis

This Minireview summarizes strategies and developments regarding the use of hydrazones as reagents in asymmetric organocatalysis, their distinct roles in nucleophile–electrophile, cycloaddition, and cyclization reactions. The key structural elements governing the reactivity of these reagents in a preferred pathway will be discussed, as well as their different interactions with organocatalysts, leading to diverse activation modes. Along these studies, the synthetic equivalence of N-monoalkyl, N,N-dialkyl, and N-acyl hydrazones with several synthons is also highlighted. Emphasis is also put on the mechanistic studies performed to understand the observed reactivities. Finally, the functional group transformations performed from the available products has also been analyzed, highlighting the synthetic value of these methodologies, which served to access numerous families of valuable multifunctional compounds and nitrogen-containing heterocycles.Ministerio de Economía y Competitividad CTQ2013-48164-C2-1-P, CTQ201348164-C2-2-PEuropean FEDER fundsJunta de Andalucía 2012/FQM 107

Solvent-free synthesis of quaternary α-hydroxy α-trifluoromethyl diazenes: the key step of a nucleophilic formylation strategy

An efficient, scalable and operationally simple one-pot, 2-step strategy for the nucleophilic formylation of trifluoromethyl ketones is presented. The key step is an unprecedented diaza-carbonyl-ene reaction of formaldehyde tert-butyl hydrazone and trifluoromethyl ketones under solvent-free conditions. This reaction proved to be very fast, clean and high-yielding, affording densely functionalised α-hydroxy α-trifluoromethyl diazenes. The ensuing diazene-to-aldehyde transformation, avoiding protection/deprotection reactions and chromatographic purifications, and subsequent derivatizations in a one-pot fashion provide a direct entry to a variety of useful trifluoromethylated building blocks.We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).This work was supported by the Ministerio de Economía y Competitividad of Spain (CTQ2013-48164-C2-1-P, CTQ2013-48164-C2-2-P, and predoctoral fellowship to E. M.), European FEDER funds and the Junta de Andalucía (Grant 2012/FQM 1078). D. M. acknowledges Universidad de Sevilla for a postdoctoral contract.Peer reviewe

Estudio químico y morfológico de Ramalina polymorpha grex en España

La variabilidad morfológica que presenta Ramalina polymorpha grex, unida a la transición de caracteres entre algunos de los taxones del grupo, hace a veces dificultosa su determinación. Un amplio estudio químico y morfológico del grupo apoyado en su distribución y ecología, nos sugiere la presencia de dos taxones claramente diferenciables: Ramalina polymorpha (Ach.) Ach. y Ramalina capi tata (Ach.) Nyl., incluyendo en ésta última el resto de las variaciones morfológicas encontradas en la Península Ibérica, que se tratan como variedades.The identification of members of the Ramalina polymorpha grex is often complicated by the considerable morphological variation and intergradation of the characters within the group. Based on a broad chemical and morphological study of this group and its ecology and distribution, we recognize two distinct taxa: Ramalina polymorpha (Ach.) Ach.and Ramalina capacita (Ach.) Nyl., the latter including the rest of the morphological variations encountered on the Iberian Peninsula, wich are treated here as varietie

Variaciones intratalinas de las sustancias liquénicas con la edad en Lasallia pustulata (L.) Mérat

Utilizando la cromatografía líquida de alta resolución, se estudia la distribución de sustancias I iquénicas a través del talo de Lasallia pustulata (L.) Mérat y la variación de la concentración de dichas sustancias a lo largo de la vida del liquen. Los ácidos lecanórico y girofórico se acumulan más, por unidad de peso seco, en la periferia del talo y se presentan en mayor proporción en los talos más jóvenes.The distribution of lichen substances within the tallus ofLusalliapustulam (L.) Mérat, and the variation in concentration of these substances with thallus age was studied using high performance liquid chromatography. Lecanoric and gyrophoric acids were presents in greatest quantity per unit weigh at the thallus periphery and also in the youngest thalli studied

Scaling laws of strategic behaviour and size heterogeneity in agent dynamics

The dynamics of many socioeconomic systems is determined by the decision making process of agents. The decision process depends on agent's characteristics, such as preferences, risk aversion, behavioral biases, etc.. In addition, in some systems the size of agents can be highly heterogeneous leading to very different impacts of agents on the system dynamics. The large size of some agents poses challenging problems to agents who want to control their impact, either by forcing the system in a given direction or by hiding their intentionality. Here we consider the financial market as a model system, and we study empirically how agents strategically adjust the properties of large orders in order to meet their preference and minimize their impact. We quantify this strategic behavior by detecting scaling relations of allometric nature between the variables characterizing the trading activity of different institutions. We observe power law distributions in the investment time horizon, in the number of transactions needed to execute a large order and in the traded value exchanged by large institutions and we show that heterogeneity of agents is a key ingredient for the emergence of some aggregate properties characterizing this complex system.Comment: 6 pages, 3 figure

Química y distribución de Umbilicaria freyi, U. grisea y U. hirsuta en la Peninsula Ibérica.

Se realiza un estudio químico comparado de Umbilicaria freyi Codogno & al., una nueva especie descrita recientemente, y de sus especies afines U. hirsuta (Sw.) Ach. y U.grisea Hoffm. Se aportan nuevos datos sobre la distribución y ecología de estos tres táxones en la Península Ibérica.Chemistry and distribution of Umbilicaria freyi, U. grisea and U. hirsuta on the Iberian península: This paper reports a comparative chemical study of Umbilicaria freyi Codogno & al., a species recently described, and the related species U. hirsuta (Sw.) Ach. and U. grisea Hoffm. New data about the distribution and ecology of these three taxa on the Iberian peninsula are presented

Specialization of strategies and herding behavior of trading firms in a financial market

The understanding of complex social or economic systems is an important scientific challenge. Here we present a comprehensive study of the Spanish Stock Exchange showing that most financial firms trading in that market are characterized by a resulting strategy and can be classified in groups of firms with different specialization. Few large firms overally act as trending firms whereas many heterogeneous firm act as reversing firms. The herding properties of these two groups are markedly different and consistently observed over a four-year period of trading.Comment: 8 pages, 5 figure

Hydrazones as Singular Reagents in Asymmetric Organocatalysis

This Minireview summarizes strategies and developments regarding the use of hydrazones as reagents in asymmetric organocatalysis, their distinct roles in nucleophile–electrophile, cycloaddition, and cyclization reactions. The key structural elements governing the reactivity of these reagents in a preferred pathway will be discussed, as well as their different interactions with organocatalysts, leading to diverse activation modes. Along these studies, the synthetic equivalence of N-monoalkyl, N,N-dialkyl, and N-acyl hydrazones with several synthons is also highlighted. Emphasis is also put on the mechanistic studies performed to understand the observed reactivities. Finally, the functional group transformations performed from the available products has also been analyzed, highlighting the synthetic value of these methodologies, which served to access numerous families of valuable multifunctional compounds and nitrogen-containing heterocycles.Peer Reviewe

Study of the Molecular Weight Influence on the Formation of the ß-polymorph in Metallocenic Isotactic Polypropylene

Isotactic polypropylene, iPP, is one of the most important thermoplastic polymers due to its low manufacturing cost and rather versatile properties. iPP exhibits a very interesting polymorphic behavior depending on the polymerization procedure, thermal history and use of different nucleating agents. Recently, studies on different aspects of the iPP β-polymorph have been published [1, 2]. This paper completes these previous works by analyzing the formation of the β-polymorph starting from samples of metallocenic iPP of different molecular weight. We also consider the effect of the cooling rate in the appearance of β-polymorph in the iPP samples that were studied