Kinetics of Aqueous Phase Dehydration of Xylose into Furfural Catalyzed by ZSM-5 Zeolite

ZSM-5 zeolite in H+ form with an average pore size of 1.2 nm was used for aqueous phase dehydration of xylose to furfural at low temperatures;, that is, from 413 to 493 K. The selectivity in furfural increased with the temperature to a value of 473 K. Beyond this temperature, condensation reactions were significant and facilitated by the intrinsic structure of ZSM-5. A reaction mechanism that included isomerization of xylose to lyxose, dehydration of lyxose and xylose to furfural, fragmentation of furfural to organic acids, oligomerization of furfural to bi- and tridimensional furilic species, and complete dehydration of organic acids to carbonaceous deposits was developed, and the associated kinetic parameters were estimated. The rate of furfural production was found to be more sensitive to temperature than the rates of side reactions, with an estimated activation energy of 32.1 kcal/mol. This value correlated well with data in the literature obtained by homogeneous catalytic dehydration.

Bimodules over nest algebras and Deddens'

We generalise Dedden's Theorem for nest algebras to nest algebra bimodules. We define an object which extends the Jacobson radical of a nest algebra, and characterose it generalising a theorem of Erdos.

La recuperación mutua en personas con trastornos psicológicos o diversidad funcional a través de la práctica creativa

En el presente artículo introducimos el concepto de “recuperación mutua” y proponemos las prácticas creativas como herramientas eficientesde recuperación de personas tanto con problemas de salud mental como con algún tipo de diversidad funcional. Frente al concepto clásico de “arte-terapia” nosotros proponemos el concepto de “práctica creativa” como más compatible con el modelo de “recuperación mutua”. Para ello, en primer lugar realizamos un breve repaso crítico a la relación del arte con la locura. Seguidamente, presentamos los conceptos hermanos de “recuperación” y “recuperación mutua” en el marco de lo que se ha venido a denominar las “health humanities”. Para finalizar, describimos dos prácticas creativas que en la actualidad están siendo evaluadas en España en el contexto de un proyecto de investigacióninternacional en recuperación mutua: Los seminarios creativos con personas con trastorno mental grave en el Museo de Arte Contemporáneo de Sevilla y el grupo de teatro con personas con diversidad funcional de la Asociación Síndrome de Down-Sevilla

Natural Exposure to Cutaneous Anthrax Gives Long-Lasting T Cell Immunity Encompassing Infection-Specific Epitopes

There has been a long history of defining T cell epitopes to track viral immunity and to design rational vaccines, yet few data of this type exist for bacterial infections. Bacillus anthracis, the causative agent of anthrax, is both an endemic pathogen in many regions and a potential biological warfare threat. T cell immunity in naturally infected anthrax patients has not previously been characterized, which is surprising given concern about the ability of anthrax toxins to subvert or ablate adaptive immunity. We investigated CD4 T cell responses in patients from the Kayseri region of Turkey who were previously infected with cutaneous anthrax. Responses to B. anthracis protective Ag and lethal factor (LF) were investigated at the protein, domain, and epitope level. Several years after antibiotic-treated anthrax infection, strong T cell memory was detectable, with no evidence of the expected impairment in specific immunity. Although serological responses to existing anthrax vaccines focus primarily on protective Ag, the major target of T cell immunity in infected individuals and anthrax-vaccinated donors was LF, notably domain IV. Some of these anthrax epitopes showed broad binding to several HLA class alleles, but others were more constrained in their HLA binding patterns. Of specific CD4 T cell epitopes targeted within LF domain IV, one is preferentially seen in the context of bacterial infection, as opposed to vaccination, suggesting that studies of this type will be important in understanding how the human immune system confronts serious bacterial infection.

Repertoire of HLA-DR1-restricted CD4 T cell responses to capsular Caf1 antigen of Y. pestis HLA-transgenic mice

Yersinia pestis is the causative agent of plague, a rapidly fatal infectious disease that has not been eradicated worldwide. The capsular Caf1 protein of Y. pestis is a protective antigen under development as a recombinant vaccine. However, little is known about the specificity of human T cell responses for Caf1. We characterized CD4 T cell epitopes of Caf1 in 'humanized'-HLA-DR1 transgenic mice lacking endogenous MHC class II molecules. Mice were immunized with Caf1 or each of a complete set of overlapping synthetic peptides, and CD4 T cell immunity was measured with respect to proliferative and IFNgamma T cell responses and recognition by a panel of T cell hybridomas, as well as direct determination of binding affinities of Caf1 peptides to purified HLA-DR molecules. Although a number of DR1-restricted epitopes were identified following Caf1 immunization, the response was biased towards a single immunodominant epitope near the C-terminus of Caf1. In addition, potential promiscuous epitopes, including the immunodominant epitope, were identified by their ability to bind multiple common HLA alleles, with implications for the generation of multivalent vaccines against plague for use in humans.

Rhodopsin and the Others: A Historical Perspective on Structural Studies of G Protein-Coupled Receptors

The role of rhodopsin as a structural prototype for the study of the whole superfamily of G protein-coupled receptors (GPCRs) is reviewed in an historical perspective. Discovered at the end of the nineteenth century, fully sequenced since the early 1980s, and with direct three-dimensional information available since the 1990s, rhodopsin has served as a platform to gather indirect information on the structure of the other superfamily members. Recent breakthroughs have elicited the solution of the structures of additional receptors, namely the beta 1- and beta 2-adrenergic receptors and the A(2A) adenosine receptor, now providing an opportunity to gauge the accuracy of homology modeling and molecular docking techniques and to perfect the computational protocol. Notably, in coordination with the solution of the structure of the A(2A) adenosine receptor, the first "critical assessment of GPCR structural modeling and docking" has been organized, the results of which highlighted that the construction of accurate models, although challenging, is certainly achievable. The docking of the ligands and the scoring of the poses clearly emerged as the most difficult components. A further goal in the field is certainly to derive the structure of receptors in their signaling state, possibly in complex with agonists. These advances, coupled with the introduction of more sophisticated modeling algorithms and the increase in computer power, raise the expectation for a substantial boost of the robustness and accuracy of computer-aided drug discovery techniques in the coming years.

Ligand and structure-based methodologies for the prediction of the activity of G protein-coupled receptor ligands

Accurate in silico models for the quantitative prediction of the activity of G protein-coupled receptor (GPCR) ligands would greatly facilitate the process of drug discovery and development. Several methodologies have been developed based on the properties of the ligands, the direct study of the receptor-ligand interactions, or a combination of both approaches. Ligand-based three-dimensional quantitative structure-activity relationships (3D-QSAR) techniques, not requiring knowledge of the receptor structure, have been historically the first to be applied to the prediction of the activity of GPCR ligands. They are generally endowed with robustness and good ranking ability; however they are highly dependent on training sets. Structure-based techniques generally do not provide the level of accuracy necessary to yield meaningful rankings when applied to GPCR homology models. However, they are essentially independent from training sets and have a sufficient level of accuracy to allow an effective discrimination between binders and nonbinders, thus qualifying as viable lead discovery tools. The combination of ligand and structure-based methodologies in the form of receptor-based 3D-QSAR and ligand and structure-based consensus models results in robust and accurate quantitative predictions. The contribution of the structure-based component to these combined approaches is expected to become more substantial and effective in the future, as more sophisticated scoring functions are developed and more detailed structural information on GPCRs is gathered.

Morphological Expression of KIT Positive Interstitial Cells of Cajal in Human Bladder

PURPOSE: We investigated the 3-dimensional morphological arrangement of KIT positive interstitial cells of Cajal in the human bladder and explored their structural interactions with neighboring cells.MATERIALS AND METHODS: Human bladder biopsy samples were prepared for immunohistochemistry/confocal or transmission electron microscopy.RESULTS: Whole mount, flat sheet preparations labeled with anti-KIT (Merck, Darmstadt, Germany) contained several immunopositive interstitial cell of Cajal populations. A network of stellate interstitial cells of Cajal in the lamina propria made structural connections with a cholinergic nerve plexus. Vimentin positive cells of several morphologies were present in the lamina propria, presumably including fibroblasts, interstitial cells of Cajal and other cells of mesenchymal origin. Microvessels were abundant in this region and branched, elongated KIT positive interstitial cells of Cajal were found discretely along the vessel axis with each perivascular interstitial cell of Cajal associated with at least 6 vascular smooth muscle cells. Detrusor interstitial cells of Cajal were spindle-shaped, branched cells tracking the smooth muscle bundles, closely associated with smooth muscle cells and vesicular acetylcholine transferase nerves. Rounded, nonbranched KIT positive cells were more numerous in the lamina propria than in the detrusor and were immunopositive for anti-mast cell tryptase. Transmission electron microscopy revealed cells with the ultrastructural characteristics of interstitial cells of Cajal throughout the human bladder wall.CONCLUSIONS: The human bladder contains a network of KIT positive interstitial cells of Cajal in the lamina propria, which make frequent connections with a cholinergic nerve plexus. Novel perivascular interstitial cells of Cajal were discovered close to vascular smooth muscle cells, suggesting interstitial cells of Cajal-vascular coupling in the bladder. KIT positive detrusor interstitial cells of Cajal tracked smooth muscle bundles and were associated with nerves, perhaps showing a functional tri-unit controlling bladder contractility.

Identifying early signs of aggression: psychometric properties of the cardiff infant contentiousness scale

Our aim was to develop an age-appropriate measure of early manifestations of aggression. We constructed a questionnaire about normative developmental milestones into which a set of items measuring infants’ use of physical force against people and expressed anger were included. These items comprise the Cardiff Infant Contentiousness Scale (CICS). Evidence for the reliability and validity of the CICS is provided from analyses of a sample of N5310 British infants, assessed at a mean age of 6 months as part of a larger longitudinal study of the development of aggression. The informants’ CICS ratings demonstrated reasonable levels of internal consistency and interrater agreement. Informants’ ratings were validated by observations of infants’ distress in response to restraint in a car seat. Longitudinal analyses revealed that contentiousness was stable over time and that contentiousness at 6 months predicted infants’ later use of force with peers. When used in the company of other methods, the simple four-item CICS scale could serve as a useful screen for early manifestations of aggressiveness in human infants.

Decadence in the Forest: Smyth's Der Wald in its Critical Context

Ethel Smyth’s opera, Der Wald, met with mixed reactions at its premiere in Berlin in 1902. Many factors contributed to this, not least, as Smyth herself observed, anti-British sentiment in Germany following the second Boer War. One might have expected that the reception of the opera at its British premiere on 18 July at Covent Garden might have been more positive, but even here critical opinion was divided. Even positive reviews were not free from gender discrimination, and other reviews condemned the opera for being too German or Wagnerian. What was meant by ‘Wagnerian’? This article answers the question in three ways. Firstly, I argue that ‘Wagnerian’ meant not a leitmotif-filled, through-composed work (as distinct from a number opera), but simply a lyrical drama; for British audiences the model for this was Tannhäuser or Lohengrin, not the Ring or Tristan. Secondly, taking this definition on board, I analyse the musical language of the opera, in particular the key structure. The central duet sung by the doomed lovers, Heinrich and Röschen, is in F major, almost the furthest possible distance from the home key of the opera (E major), which characterizes the forest and ‘nature’ in general; by contrast, the next scene, where the Kundry-like Iolanthe attempts to seduce Heinrich (a crucial reversal of the more conventional power relations of the love duet), sees a return to the home key. Thirdly, I set the hermeneutical implications of this reversal in the context of the decadent movement, with which late nineteenth-century Wagnerism was associated, and which, following the conviction of Oscar Wilde in 1895, was discredited. Der Wald thus failed because of its ‘guilt by association’ with an aesthetic that had fallen into disrepute.