A novel heteroditopic terpyridine-pincer ligand as building block for mono- and heterometallic Pd(II) and Ru(II) complexes

A palladium-catalyzed Stille coupling reaction was employed as a versatile method for the synthesis of a novel terpyridine-pincer (3, TPBr) bridging ligand, 4'-{4-BrC6H2(CH2NMe2)(2)-3,5}-2,2':6',2 ''-terpyridine. Mononuclear species [PdX(TP)] (X = Br, Cl), [Ru(TPBr)(tpy)](PF6)(2), and [Ru(TPBr)(2)](PF6)(2), synthesized by selective metalation of the NCNBr-pincer moiety or complexation of the terpyridine of the bifunctional ligand TPBr, were used as building blocks for the preparation of heterodi- and trimetallic complexes [Ru(TPPdCl)(tpy)](PF6)(2) (7) and [Ru(TPPdCl)(2)]-(PF6)(2) (8). The molecular structures in the solid state of [PdBr(TP)] (4a) and [Ru(TPBr)(2)](PF6)(2) (6) have been determined by single-crystal X-ray analysis. Electrochemical behavior and photophysical properties of the mono-and heterometallic complexes are described. All the above di- and trimetallic Ru complexes exhibit absorption bands attributable to (MLCT)-M-1 (Ru -> tpy) transitions. For the heteroleptic complexes, the transitions involving the unsubstituted tpy ligand are at a lower energy than the tpy moiety of the TPBr ligand. The absorption bands observed in the electronic spectra for TPBr and [PdCl(TP)] have been assigned with the aid of TD-DFT calculations. All complexes display weak emission both at room temperature and in a butyronitrile glass at 77 K. The considerable red shift of the emission maxima relative to the signal of the reference compound [Ru(tpy)(2)](2+) indicates stabilization of the luminescent (MLCT)-M-3 state. For the mono- and heterometallic complexes, electrochemical and spectroscopic studies (electronic absorption and emission spectra and luminescence lifetimes recorded at room temperature and 77 K in nitrile solvents), together with the information gained from IR spectroelectrochemical studies of the dimetallic complex [Ru(TPPdSCN)(tpy)](PF6)(2), are indicative of charge redistribution through the bridging ligand TPBr. The results are in line with a weak coupling between the {Ru(tpy)(2)} chromophoric unit and the (non)metalated NCN-pincer moiety

Hybrid Session Verification through Endpoint API Generation

© Springer-Verlag Berlin Heidelberg 2016.This paper proposes a new hybrid session verification methodology for applying session types directly to mainstream languages, based on generating protocol-specific endpoint APIs from multiparty session types. The API generation promotes static type checking of the behavioural aspect of the source protocol by mapping the state space of an endpoint in the protocol to a family of channel types in the target language. This is supplemented by very light run-time checks in the generated API that enforce a linear usage discipline on instances of the channel types. The resulting hybrid verification guarantees the absence of protocol violation errors during the execution of the session. We implement our methodology for Java as an extension to the Scribble framework, and use it to specify and implement compliant clients and servers for real-world protocols such as HTTP and SMTP

On Asynchronous Session Semantics

This paper studies a behavioural theory of the π-calculus with session types under the fundamental principles of the practice of distributed computing — asynchronous communication which is order-preserving inside each connection (session), augmented with asynchronous inspection of events (message arrivals). A new theory of bisimulations is introduced, distinct from either standard asynchronous or synchronous bisimilarity, accurately capturing the semantic nature of session-based asynchronously communicating processes augmented with event primitives. The bisimilarity coincides with the reduction-closed barbed congruence. We examine its properties and compare them with existing semantics. Using the behavioural theory, we verify that the program transformation of multithreaded into event-driven session based processes, using Lauer-Needham duality, is type and semantic preserving

Acetate intolerance is mediated by enhanced synthesis of nitric oxide by endothelial cells.

The clinical picture of acetate intolerance strictly mimics the nitric oxide (NO) effect, including smooth muscle relaxation and extreme vasodilation. Because acetate induces production of cAMP, which is a powerful stimulus of NO synthase (NOS), we evaluated the effect of different dialysate solutions with and without acetate on NOS activity in endothelial cells (EC). NOS activity of EC, evaluated as H3-citrulline produced from H3-arginine, was modulated by the dialysate composition (e.g., 38 mmol/L acetate produced an increase of 3.2 +/- 0.39-fold compared with basal values (P < 0.0005), and the small amount of acetate (4 mmol/L) in 35 mmol/L bicarbonate solution increased the NOS activity by 2 +/- 0.49-fold (P < 0.05). Conversely, the acetate-free solution produced no effect on NOS activity. The mRNA encoding for inducible NOS was highly expressed in EC incubated with acetate buffer and also with acetate in bicarbonate dialysis buffer. The EC proliferative index was depressed by acetate (P < 0.0005), and tumor necrosis factor synthesis was increased (P < 0.0005) compared with acetate-free buffer. This study suggests that dialytic "acetate intolerance" can be induced by the activation, through cAMP and tumor necrosis factor release, of NOS. The small amount of acetate in bicarbonate dialysate, although capable of inducing in vitro NOS activation, is likely to be rapidly metabolized, whereas the large amounts of this anion in acetate fluids overwhelm metabolism by the liver. Acetate-free dialysate is the only solution that provides an acceptable level of biocompatibility both in vivo and in vitro

Integración de modelos para aplicaciones geográficas

Existe actualmente número muy grande de aplicaciones informáticas destinadas al procesamiento de información geográfica. Éstas se caracterizan por emplear bases de datos propietarias y no estandarizadas. Si bien son funcionalmente cada vez más completas (y complejas), es difícil concebir una aplicación que satisfaga las infinitas necesidades y preferencias de los analistas, modeladores y simuladores de información y procesos geográficos y ambientales, y menos aún que facilite el reuso o la documentación de las diferentes secuencias de procesamiento aplicadas en una tarea en particular. Por su parte, una tendencia generalmente aceptada es la de producir estándares y protocolos internacionales que apuntan a la integración de los sistemas, como lo es actualmente el OpenGIS en este campo de aplicación. En este trabajo se propone la creación de un banco de trabajo visual que brinde al usuario final la posibilidad de implementar modelos en los que se integran componentes interconectables en una red para la conformación de un sistema flexible y predecible. Estos componentes podrían ser implementados por diversos fabricantes y/o proveedores de software o encontrarse como servicios distribuidos físicamente sobre una red informática.El programa de modelación visual actúa como controlador de todo el sistema permitiendo al analista desarrollar, con una única herramienta, el modelo de su interés. Se presenta como ejemplo el modelo conceptual y la implementación de una aplicación que permite el renderizado de un DEM como superficie 3D, obtenido a partir de un archivo de curvas de nivel.Eje: Ingeniería de Software y Bases de Datos (ISBD)Red de Universidades con Carreras en Informática (RedUNCI

Integración de modelos para aplicaciones geográficas

Existe actualmente número muy grande de aplicaciones informáticas destinadas al procesamiento de información geográfica. Éstas se caracterizan por emplear bases de datos propietarias y no estandarizadas. Si bien son funcionalmente cada vez más completas (y complejas), es difícil concebir una aplicación que satisfaga las infinitas necesidades y preferencias de los analistas, modeladores y simuladores de información y procesos geográficos y ambientales, y menos aún que facilite el reuso o la documentación de las diferentes secuencias de procesamiento aplicadas en una tarea en particular. Por su parte, una tendencia generalmente aceptada es la de producir estándares y protocolos internacionales que apuntan a la integración de los sistemas, como lo es actualmente el OpenGIS en este campo de aplicación. En este trabajo se propone la creación de un banco de trabajo visual que brinde al usuario final la posibilidad de implementar modelos en los que se integran componentes interconectables en una red para la conformación de un sistema flexible y predecible. Estos componentes podrían ser implementados por diversos fabricantes y/o proveedores de software o encontrarse como servicios distribuidos físicamente sobre una red informática.El programa de modelación visual actúa como controlador de todo el sistema permitiendo al analista desarrollar, con una única herramienta, el modelo de su interés. Se presenta como ejemplo el modelo conceptual y la implementación de una aplicación que permite el renderizado de un DEM como superficie 3D, obtenido a partir de un archivo de curvas de nivel.Eje: Ingeniería de Software y Bases de Datos (ISBD)Red de Universidades con Carreras en Informática (RedUNCI

The Paths to Choreography Extraction

Choreographies are global descriptions of interactions among concurrent components, most notably used in the settings of verification (e.g., Multiparty Session Types) and synthesis of correct-by-construction software (Choreographic Programming). They require a top-down approach: programmers first write choreographies, and then use them to verify or synthesize their programs. However, most existing software does not come with choreographies yet, which prevents their application. To attack this problem, we propose a novel methodology (called choreography extraction) that, given a set of programs or protocol specifications, automatically constructs a choreography that describes their behavior. The key to our extraction is identifying a set of paths in a graph that represents the symbolic execution of the programs of interest. Our method improves on previous work in several directions: we can now deal with programs that are equipped with a state and internal computation capabilities; time complexity is dramatically better; we capture programs that are correct but not necessarily synchronizable, i.e., they work because they exploit asynchronous communication