Dhvar5 antimicrobial peptide (AMP) chemoselective covalent immobilization results on higher antiadherence effect than simple physical adsorption

Bacterial colonization and subsequent biofilm formation is still one of the major problems associated with medical devices. Antimicrobial peptides (AMP) immobilization onto biomaterials surface is a promising strategy to avoid bacterial colonization. However, a correct peptide orientation and exposure from the surface is essential to maintain AMP antimicrobial activity. This work aims to evaluate the effect of the immobilization on antibacterial activity of Dhvar5 (LLLFLLKKRKKRKY), an AMP with a head-to-tail amphipathicity. Dhvar5 was linked to thin chitosan coatings in i) a controlled orientation and exposure, testing covalent immobilization of its N- or C-terminus and using spacers with different lengths and flexibilities or in ii) a random orientation by physical adsorption. Chitosan coating was chosen due to its antimicrobial properties and readiness to be functionalized. Surface characterization demonstrated the chemoselective immobilization of the peptide with different spacers in a similar concentration (∼2 ng/cm2). Efficacy assays demonstrated that covalent immobilization of Dhvar5 exposing its cationic end, improves the chitosan coating antimicrobial effect by decreasing Methicillin-resistant Staphylococcus aureus (MRSA) colonization. This effect was enhanced when longer spacers were used independently of their flexibility. In opposite, immobilized Dhvar5 exposing its hydrophobic end has no effect on bacterial adhesion to chitosan, and when adsorbed in a random orientation even induces bacterial adhesion to chitosan coating.This work was financed by FEDER funds through the Programa Operacional Factores de Competitividade (COMPETE) and by Portuguese funds through FCT (Fundacao para a Ciencia e a Tecnologia) in the framework of the projects: PTDC/CTM/101484/2008; PEst-C/SAU/LA0002/2013; Pest-C/QUI/UI0081/2013. Fabiola Costa acknowledges FCT for the PhD grant SFRH/BD/72471/2010

Numerical modelling of the dynamic response of liquefiable deposits in the presence of small scale buildings

The impact of liquefaction in building performance during earthquakes is an aspect that has been recently receiving more attention by the technical and scientific communities, in an attempt to reduce the vulnerability of structures located in loose sandy saturated deposits. Currently, the design of buildings in liquefiable layers is performed based on empirical rules, where the liquefaction potential and the ground settlements are usually assessed free-field conditions, i.e., neglecting the presence of the surface structures. Even in the probabilistic approaches that tend to incorporate Earthquake Liquefaction Induced Damages (ELID) from some case-histories that include buildings at the surface, have never incorporated foundations characteristics and loading conditions. However, recent advances in numerical modelling allow performing a more rigorous assessment of the effects induced by liquefaction, namely the settlements that are expected to occur in the spread footings of structures, one of the most common foundation system implemented in small-to-mid-rise constructions in Europe. Therefore, the present paper focuses research on the assessment of the settlements due to earthquake-induced liquefaction that is being conducted within the European Project LIQUEFACT

Geodynamics of very high speed transport systems

This work reveals the existence of a new dynamic load amplification mechanism due to ground surface loads. It is caused by the interaction between a moving vehicle's axle configuration and the vibration characteristics of the underlying soil-guideway system. It is more dominant than the traditionally considered ‘critical velocity’ dynamic amplification mechanism of the guideway-ground structure, and is of relevance to very high speed transport systems such as high speed rail. To demonstrate the new amplification mechanism, first a numerical model is developed, capable of simulating ground-wave propagation in the presence of a series of discrete high speed loads moving on a soil-guideway system. The model couples analytical equations for the transportation system guideway with the thin-layer element method for ground simulation. As a practical example, it is validated using high speed railroad field data and then used to analyse the response of a generalised single moving load at high speed. Next the effect of multiple discrete vehicle-guideway contact points is studied and it is shown that dynamic amplification is highly sensitive to load spacing when the speed is greater than the critical velocity. In particular, large resonant effects occur when the axle/magnet loading frequency and the propagating wave vibration frequency of the soil-guideway structure are equivalent. As an example, it is shown that for an individual case, although critical velocity might increase displacements by 50–100%, for the same scenario, axle configuration can increase displacements by 400%. It is also shown that resonance is sensitive to the total number of loading points and the individual frequencies excited by various spacings. The findings are important for current (e.g. high speed railway) and potential future (e.g. hyperloop) transport systems required to operate at speeds either close-to, or greater than the critical velocity of their supporting guideway-soil structure. In such situations, it is important to design the vehicle and supporting structure(s) as a combined system, rather than in isolation

Genetic algorithm in chemistry.

Genetic algorithm is an optimization technique based on Darwin evolution theory. In last years its application in chemistry is increasing significantly due the special characteristics for optimization of complex systems. The basic principles and some further modifications implemented to improve its performance are presented, as well as a historical development. A numerical example of a function optimization is also shown to demonstrate how the algorithm works in an optimization process. Finally several chemistry applications realized until now is commented to serve as parameter to future applications in this field.22340541

A investigação criminal pelo Ministério Público, à luz da teoria de dos direitos fundamentais de Robert Alexy: estudo do HC 91.613-MG/STF

O presente trabalho se propõe a analisar a constitucionalidade do caráter subsidiário das investigações criminais realizadas pelo Ministério Público enquanto nova tendência de consolidação de jurisprudência do Supremo Tribunal Federal Brasileiro, vazada no HC 91.613/MG. Propõe-se, no presente trabalho, uma revisão da mencionada decisão pretoriana sob um olhar mais criterioso, especificamente sob a bandeira de um controle racional da decisão judicial, devendo-se utilizar para tanto os estudos do renomado doutrinador Robert Alexy sobre a matéria. Nossa pretensão não é propriamente pesquisar o que significa este caráter subsidiário das investigações, mas sim, investigar se a construção da decisão que levou a estabelecer esse modelo de investigação passa pelo crivo da racionalidade ou é mais um exemplo de mero decisionismo judicial, enquanto aspecto negativo do chamado “ativismo judicial”. Palavras-chave: investigação criminal; Ministério Público; subsidiariedade; racionalidade; ponderação; sopesamento; igualdade. CRIMINAL PROSECUTION OF PUBLIC MINISTRY AT THE LIGHT OF ROBERT ALEXY´S THEORY OF FUNDAMENTAL RIGHTS: THE CASE HC - 91 613 MG / STF ABSTRACT This paper aims to examine the constitutionality of the subsidiary nature of criminal investigations by prosecutors as new Brazilian Supreme Court jurisprudence consolidation trend, poured into the HC 91,613 / MG. It is proposed in this paper, a review of that decision under praetorian a more careful look, specifically under the banner of a rational control of the court decision, should be used for both studies the renowned theoretician Robert Alexy on the matter. Our intention is not really research what this means subsidiary nature of the investigations, but rather investigate whether the construction of the decision that led to establish this research model passes the test of rationality or is it more a case of mere judicial decisionism, while negative the so-called "judicial activism". KEY WORDS: Data de submissão: 17/11/2015 Data de aceitação: 18/02/201

Divergent mathematical treatments in utility theory

In this paper I study how divergent mathematical treatments affect mathematical modelling, with a special focus on utility theory. In particular I examine recent work on the ranking of information states and the discounting of future utilities, in order to show how, by replacing the standard analytical treatment of the models involved with one based on the framework of Nonstandard Analysis, diametrically opposite results are obtained. In both cases, the choice between the standard and nonstandard treatment amounts to a selection of set-theoretical parameters that cannot be made on purely empirical grounds. The analysis of this phenomenon gives rise to a simple logical account of the relativity of impossibility theorems in economic theory, which concludes the paper

Decision Making for Inconsistent Expert Judgments Using Negative Probabilities

In this paper we provide a simple random-variable example of inconsistent information, and analyze it using three different approaches: Bayesian, quantum-like, and negative probabilities. We then show that, at least for this particular example, both the Bayesian and the quantum-like approaches have less normative power than the negative probabilities one.Comment: 14 pages, revised version to appear in the Proceedings of the QI2013 (Quantum Interactions) conferenc

The Hydration Structure at Yttria-Stabilized Cubic Zirconia (110)-Water Interface with Sub-Angstrom Resolution

The interfacial hydration structure of yttria-stabilized cubic zirconia (110) surface in contact with water was determined with ~0.5 Å resolution by high-resolution X-ray reflectivity measurement. The terminal layer shows a reduced electron density compared to the following substrate lattice layers, which indicates there are additional defects generated by metal depletion as well as intrinsic oxygen vacancies, both of which are apparently filled by water species. Above this top surface layer, two additional adsorbed layers are observed forming a characteristic interfacial hydration structure. The first adsorbed layer shows abnormally high density as pure water and likely includes metal species, whereas the second layer consists of pure water. The observed interfacial hydration structure seems responsible for local equilibration of the defective surface in water and eventually regulating the long-term degradation processes. The multitude of water interactions with the zirconia surface results in the complex but highly ordered interfacial structure constituting the reaction front.ope

Fatty acids profile of pulp and nuts of brazilian fruits

Fruits and nuts from the North and Northeast regions of Brazil were collected to determine the fatty acid profile of their oils. The species studied were Brazil (Bertholletia excelsa H. B. K.), Mucaja (Couma rigida M.), Inaja (Maximiliana maripa D.), Jenipapo (Genipa Americana L.), and Buriti (Mauritia flexuosa L.) nuts. Fatty acid methyl esters were analyzed by gas chromatography with flame ionization detection (GC-FID). Brazil nut major fatty acid was 18:3n-3 (alpha-linolenic acid), and Buriti nut had approximately 23 times more 18: 3n-3 than the pulp. Mucaja nut presented high content of 12: 0 (lauric acid) and 16: 0 (palmitic acid), and Mucaja pulp showed significant levels of 18: 2n-6 (linoleic acid). Considering the PUFA (polyunsaturated fatty acid) sum values, almost all fruits and nuts analyzed presented very high levels of these compounds. Regarding n-6/n-3 ratio, only Brazil Nut, Buriti Nut, Inaja pulp, and Jenipapo pulp corresponded to the desired profile. These Brazilian fruits and nuts could be of potential interest due to their high nutritive value and lipid content.31495095