Synthesis and characterization of viscosity-dependent fluorophores for bioanalytical use

Organic synthesis and complete stereochemical and spectroscopic characterization of novel fluorophores acting as viscosity sensors were carried out. Three classes of molecular rotors were thoroughly investigated: stilbene, coumarin and boron-diindomethene (BDI) derivatives

Sviluppo di un modello non lineare di danneggiamento a taglio per laminati compositi

Questa tesi illustra le attività di studio, sviluppo e prova, in ambito numerico, di un modello non lineare di danneggiamento a taglio per laminati compositi. Per simulare la parte non lineare del comportamento costitutivo tensione-deformazione il modello sfrutta una curva esponenziale, mentre viene usato un legame costitutivo lineare per il danneggiamento a taglio fino a completa rottura del materiale. Il modello è stato implementato in un codice di danneggiamento progressivo, già esistente, e utilizzato (mediante routine utente) in abbinamento con un software FEM commerciale. E’ stata quindi predisposta una vasta campagna di test-case per verificarne il corretto funzionamento numerico e per poi effettuare un confronto con i risultati di un modello di danneggiamento a taglio di letteratura. Sono state effettuate, preliminarmente, prove numeriche di indentazione quasi-statica per verificare la capacità del modello di simulare l’indentazione residua. Il modello è stato poi utilizzato per simulare una prova d’impatto a bassa velocità confrontando i risultati ottenuti con i dati sperimentali, valutando l’entità del danneggiamento intralaminare, mettendo a confronto le zone delaminate e rilevando l’indentazione residua. Parallelamente è stata portata avanti una campagna di analisi numeriche preliminari su un pannello irrigidito in composito, con alcuni difetti pre-esistenti, sottoposto a compressione. Tali analisi rappresentano un primo passo per la valutazione del codice sviluppato nell’ambito di analisi di tipo Compression After Impact per il pannello irrigidito caratterizzato da danneggiamenti da impatto

City Rights in an Era of Preemption: A State-by-State Analysis

In a new report, NLC finds that states limit city power through preemption in a number of policy areas, ranging from labor protections to taxing authority.Preemption is the use of state law to nullify a municipal ordinance or authority. In some cases, preemption can lead to improved policy statewide. However, preemption that prevents cities from expanding rights, building stronger economies, and promoting innovation can be counterproductive when decision-making is divorced from the core wants and needs of community members

Control of Q-factor in nanobeam cavities on substrate

In this paper, we demonstrate how to efficiently control the quality factor of silicon nitride nanobeam cavities, grown on a silica substrate and embedded in an upper cladding, by engineering the nanobeam cross-section and the shape of the periodic holes. We propose optimized configurations that are able to overcome the decreasing of the Q-factor when the nanobeam is embedded in an asymmetric medium. More precisely, we show that the maximum achievable quality factor can be designed and tuned in asymmetric configurations where the upper cladding is particularly different from the substrate one. These optimized configurations exhibit high-Q factor and small mode volume over a wide range of the upper cladding refractive index paving the way for the realization of innovative optical sensors and for the compensation of fabrication tolerances in embedded optical nanobeam cavities.Postprin

Pepducins as a potential treatment strategy for asthma and COPD.

Current therapies to treat asthma and other airway diseases primarily include anti-inflammatory agents and bronchodilators. Anti-inflammatory agents target trafficking and resident immunocytes and structural cells, while bronchodilators act to prevent or reverse shortening of airway smooth muscle (ASM), the pivotal tissue regulating bronchomotor tone. Advances in our understanding of the biology of G protein-coupled receptors (GPCRs) and biased agonism offers unique opportunities to modulate GPCR function that include the use of pepducins and allosteric modulators. Recent evidence suggests that small molecule inhibitors of Gα q as well as pepducins targeting G q -coupled receptors can broadly inhibit contractile agonist-induced ASM function. Given these advances, new therapeutic approaches can be leveraged to diminish the global rise in morbidity and mortality associated with asthma and chronic obstructive pulmonary disease

Anaphylatoxin C3a Receptors in Asthma

The complement system forms the central core of innate immunity but also mediates a variety of inflammatory responses. Anaphylatoxin C3a, which is generated as a byproduct of complement activation, has long been known to activate mast cells, basophils and eosinophils and to cause smooth muscle contraction. However, the role of C3a in the pathogenesis of allergic asthma remains unclear. In this review, we examine the role of C3a in promoting asthma. Following allergen challenge, C3a is generated in the lung of subjects with asthma but not healthy subjects. Furthermore, deficiency in C3a generation or in G protein coupled receptor for C3a abrogates allergen-induced responses in murine models of pulmonary inflammation and airway hyperresponsiveness. In addition, inhibition of complement activation or administration of small molecule inhibitors of C3a receptor after sensitization but before allergen challenge inhibits airway responses. At a cellular level, C3a stimulates robust mast cell degranulation that is greatly enhanced following cell-cell contact with airway smooth muscle (ASM) cells. Therefore, C3a likely plays an important role in asthma primarily by regulating mast cell-ASM cell interaction. © 2005 Ali and Panettieri; licensee BioMed Central Ltd

Damage initialization techniques for non-sequential FE propagation analysis of delaminations in composite aerospace structures

The experimental effort required to develop, damage tolerant, aerospace composite structures could be significantly reduced if reliable numerical simulations were used to perform engineering studies of complex damaged structures. Finite element (FE) simulations of impact damaged structures typically follow a sequential approach that require large computational resources to reproduce complex damage scenarios. A numerical tool capable to reconstruct such scenarios using data from previous impact simulations or NDI could noticeably improve the simulation workflow for damaged composite structures. The paper proposes a method to inizialize the damage variables in numerical analyses aimed at assessing damage propagation, and that are potentially able to evaluate the residual strength of damaged structures. The approach is developed within FE software ABAQUS, and uses SDVINI subroutine to initialize damage variables defined by a user-material-subroutine (UMAT), that provides the constitutive models of the lamina and of the interlaminar layers. Albeit the proposed technique might deal with both inter-laminar and intra-laminar damage, the paper is focused on delaminations. A user defined traction-separation law is coded in an UMAT that endows ABAQUS cohesive elements with damage initialization capabilities. Then, results of test cases, of increasing complexity, are presented in order to assess the damage initialization procedure and verify the performances of its different operating modes. Two test-cases are based on plate-like specimens for which literature data exist: the first is relevant to a circular artificial delamination while the second presents multiple delaminations caused by an impact and measured via NDI techniques. The last test-case is a stiffened panel which incorporates the typical complexities of aerospace structures, but is still tractable with the sequential simulation approach whose results are used as a term of comparison

Biological cycle determination of <i>Capillaria bursata</i>

Comprobada la parasitosis por Capillaria bursata, los autores logran reproducir la enfermedad en pollos mantenidos libres de toda infestación, dándoles a ingerir lombrices recogidas en el gallinero del que procedían las aves originalmente necropsiadas demostrando así el ciclo indirecto de este nematode y el papel de Eisenia sp. como hospedador intermediario.After the verification of the parasitic infection caused by Capillaria bursata the authors reproduced the disease in parasites free chicken, feeding the birds with earth worm collected from the poultry yard, where were the birds come from and necropsied. The workers demonstrated by this way the roll of Elsenia sp. as intermediary host of this nematode and its indirect biological cycle.Facultad de Ciencias Veterinaria

Profile of aclidinium bromide in the treatment of chronic obstructive pulmonary disease

Bronchodilators provide the mainstay of pharmacologic therapy for chronic obstructive pulmonary disease (COPD), and anticholinergic bronchodilators, in particular, appear to be the most effective. There are currently two anticholinergic agents available in the US for the treatment of COPD (ipratropium bromide and tiotropium bromide), but several others are in various stages of development. Aclidinium bromide, a novel, long-acting, anticholinergic bronchodilator, is currently in Phase III trials for the management of COPD. Available evidence suggests that aclidinium is a safe and well tolerated drug with a relatively rapid onset and a sufficient duration of action to provide once-daily dosing. This article will provide a pharmacologic profile of aclidinium bromide and review the preclinical and clinical studies evaluating its safety and efficacy in the treatment of COPD