Revealing hidden symmetries and gauge invariance of the massive Carroll-Field-Jackiw model

In this paper we have analyzed the improved version of the Gauge Unfixing (GU) formalism of the massive Carroll-Field-Jackiw model, which breaks both the Lorentz and gauge invariances, to disclose hidden symmetries to obtain gauge invariance, the key stone of the Standard Model. In this process, as usual, we have converted this second-class system into a first-class one and we have obtained two gauge invariant models. We have verified that the Poisson brackets involving the gauge invariant variables, obtained through the GU formalism, coincide with the Dirac brackets between the original second-class variables of the phase space. Finally, we have obtained two gauge invariant Lagrangians where one of them represents the Stueckelberg form.Comment: revised version. To appear in Europhysics Letter

SPATIAL AND TEMPORALVARIATION OF DISSOLVED INORGANIC NUTRIENTS, AND CHLOROPHYLL-α IN A TROPICAL ESTUARY IN NORTHEASTERN BRAZIL: DYNAMICS OF NUTRIENT REMOVAL

Monthly sampling campaigns were carried out between February 2010 and January 2011 to evaluate the spatial and temporal distribution of nutrients (ammonium, nitrite, nitrate, dissolved organic nitrogen, phosphate, dissolved organic phosphorus and silicate) and chlorophyll-α along a salinity gradient in the tropical Cachoeira River estuary, subject to the untreated effluents of a sewage treatment plant (STP). During the study period the lowest and highest river discharge occurred in February and April 2010, respectively. High river outflow promoted increased concentrations of inorganic nitrogen and silicate but did not affect the concentration of phosphate. Based on the chlorophyll-α concentration the estuary may be classified as eutrophic / hypereutrophic in its inner portion and mesotrophic in the lower region. The inner portion is more affected by the nutrient load carried out by the river and STP, while dilution by seawater contributed to the reduction of the nutrient concentrations in the lower reaches of the estuary. The results indicate that nutrient uptake by the phytoplankton is the most effective dissolved inorganic nutrient removal processes, especially for phosphate. Mixing diagrams suggest that the coupling of nitrification and denitrification processes is also responsible for the elimination of nitrogen from this ecosystem.Campanhas de amostragens mensais foram realizadas entre fevereiro de 2010 e janeiro de 2011 para avaliar a distribuição espacial e temporal de nutrientes (amônia, nitrito, nitrato, nitrogênio orgânico dissolvido, fosfato, fósforo orgânico dissolvido e silicato) e clorofila-α, ao longo do gradiente de salinidade no estuário tropical do Rio Cachoeira. Este estuário é sujeito aos efluentes de esgotos não tratados de uma estação de tratamento de esgoto (ETE). No período estudado a maior e menor vazão do rio ocorreram em fevereiro e abril de 2010, respectivamente. A alta vazão do rio promoveu aumento das concentrações de nitrogênio inorgânico e silicato, mas não afetou as concentrações de fosfato. Baseado nas concentrações de clorofila-α, o estuário pode ser classificado como eutrófico/hipereutrófico na porção interna e mesotrófico na região externa. A porção interna é mais afetada pela carga de nutrientes do rio e da ETE, enquanto a diluição pela água marinha contribuiu para diminuir as concentrações de nutrientes na porção externa. Os resultados indicam que a absorção de nutrientes pelo fitoplâncton é o processo mais eficiente na remoção desses nutrientes, especialmente do fosfato. No entanto, os diagramas de mistura sugerem que a nitrificação e denitrificação acopladas no rio também são responsáveis pela eliminação do nitrogênio do ecossistema

Silk fibroin nanoparticles for drug delivery purposes : stabilization, incorporation and release design

Silk Fibroin (SF) has been extensively studied for various applications due to its impressive mechanical properties and biocompatibility. Recently, SF based-particles have been proposed as controlled drug delivery systems. A new and efficient method was developed to prepare SF nanoparticles (SF-NPs) by high pressure homogenization (HPH) emulsification, in oil-in-water emulsions (o/w). During the NPs production by HPH emulsification process, the secondary SF structure changed from random-coil conformation to a more stable structure, -sheets. To improve even more the NPs stability over time the effect of various surfactants was studied, namely poloxamer 407, transcutol, tween 80 and sodium dodecyl sulfate, in which SF nanoemulsions with 1% of transcutol demonstrated lower diameters and better polydispersity values during the 4 weeks of evaluation. The drug incorporation efficiency and release of SF-NPs was assessed using orange IV dye as model-drug. The influence of a human protease (human neutrophil elastase) on orange IV release profile was also evaluated. The encapsulation of orange IV effectively stabilized the size and size distribution of the SF-NPs over time, being evident the conformational change to -sheets. SF-NPs encapsulated with orange IV had a formation and encapsulation efficiency of 67% and 91%, respectively, with a controlled release over time. The stability and release profile induced by the SF-NPs enhances its potential for various applications, including biomedical

Polyoxometalates as promoters of laccase-assisted reactions

A synergistic effect of polyoxometalate and laccase benzenediol:oxygen oxidoreductase, EC 1.10.3.2 has been observed in the aerobic oxidation of a hydrazonaphthalene type colorant. The considerable increase in the decolorization rate of Solophenyl Blue GL dye with the new catalytic system composed by laccase and heptamolybdopentovanadophosphate heteropolyanion, when compared with the treatment with enzyme or heteropolyanion alone, was tentatively explained by the redox mediation action of the heteropolyanion

Do genes and environment meet to regulate cerebrospinal fluid dynamics? Relevance for schizophrenia

Schizophrenia is a neurodevelopment disorder in which the interplay of genes and environment contributes to disease onset and establishment. The most consistent pathological feature in schizophrenic patients is an enlargement of the brain ventricles. Yet, so far, no study has related this finding with dysfunction of the choroid plexus (CP), the epithelial cell monolayer located within the brain ventricles that is responsible for the production of most of the cerebrospinal fluid (CSF). Enlarged brain ventricles are already present at the time of disease onset (young adulthood) and, of notice, isolated mild ventriculomegaly detected in utero is associated with subsequent mild neurodevelopmental abnormalities similar to those observed in children at high risk of developing schizophrenia. Here we propose that altered CP/CSF dynamics during neurodevelopment may be considered a risk, causative and/or participating factor for development of schizophrenia.Nadine C. Santos and Fernanda Marques are recipients of postdoctoral fellowships by the Switchbox project (European Commission FP7 initiative grant HEALTH-F2-2010-259772) and the Fundação para a Ciência e Tecnologia (FCT, Portugal), respectively

Gauge Symmetry of the Chiral Schwinger model from an improved Gauge Unfixing formalism

In this paper, the Hamiltonian structure of the bosonized chiral Schwinger model (BCSM) is analyzed. From the consistency condition of the constraints obtained from the Dirac method, we can observe that this model presents, for certain values of the $\alpha$ parameter, two second-class constraints, which means that this system does not possess gauge invariance. However, we know that it is possible to disclose gauge symmetries in such a system by converting the original second-class system into a first-class one. This procedure can be done through the gauge unfixing (GU) formalism by acting with a projection operator directly on the original second-class Hamiltonian, without adding any extra degrees of freedom in the phase space. One of the constraints becomes the gauge symmetry generator of the theory and the other one is disregarded. At the end, we have a first-class Hamiltonian satisfying a first-class algebra. Here, our goal is to apply a new scheme of embedding second-class constrained systems based on the GU formalism, named improved GU formalism, in the BCSM. The original second-class variables are directly converted into gauge invariant variables, called GU variables. We have verified that the Poisson brackets involving the GU variables are equal to the Dirac brackets between the original second-class variables. Finally, we have found that our improved GU variables coincide with those obtained from an improved BFT method after a particular choice for the Wess-Zumino terms.Comment: 13 page

Descriptive?Acute Respiratory Distress Syndrome (ARDS) in adults with imported severe Plasmodium falciparum?malaria: A 10 year-study in a Portuguese tertiary care hospital

Acute respiratory distress syndrome (ARDS) is a severe complication of malaria that remains largely unstudied. We aim to describe the development of ARDS associated with severe P. falciparum malaria, its management and impact on clinical outcome.B910-DDDF-6BB2 | Lu?s Carlos Carvalho da Gra?aN/

Educational Game about Drugs for Visually Impaired People: A Comparison between Brazil and Portugal

Objective: To validate the educational board game “Drugs: playing fair” for visually impaired people in Brazil and Portugal. Methods: Study of apparent validation carried out in two associations for visually impaired people in Fortaleza, Brazil, and in Porto, Portugal. Thirty-six visually impaired people, 18 from each country, participated in the study. An evaluation tool with 23 items on specifications, content and motivation of the game was applied. Results: The scores awarded in both countries were excellent, with means varying in Brazil from 9.0 to 9.6 and in Portugal, from 8.4 to 9.2. As for the categories and subcategories, the best means in Brazil were: content (9.5); theoretical and methodological consistency (9.6) and concepts/information (9.5). In Portugal, the best means were concepts/information (9.2) and curiosity (9.2). Only two items showed a significant difference: “it allows interaction” (p = 0.024) and “compatible degree of difficulty” (p = 0.012). Conclusion: The educational game on drugs was validated in Brazil and Portugal.info:eu-repo/semantics/publishedVersio

Prior exercise training does not prevent acute cardiac alterations after myocardial infarction in female rats

OBJECTIVE: This study aimed to investigate whether previous exercise training could prevent or attenuate acute cardiac alterations after myocardial infarction. METHODS: Female rats were submitted to swim training (1 h/day; 5 days/week) or allowed to remain sedentary for 8 weeks. Afterwards, they were randomly assigned to left coronary artery occlusion or sham surgery. After this procedure, the rats remained sedentary for one week until euthanasia. Cardiac structural and functional analyses were performed using Doppler echocardiography. The rats that had a moderate or large infarct size were included in the evaluations. The data (mean + SEM) were analyzed using a two-way ANOVA model followed byTukey's post-hoc test. RESULTS: After the surgery, no significant difference between the exercise and sedentary groups was observed in the left ventricular infarct sizes (34.58 + 3.04 vs. 37.59 + 3.07). In another group of rats evaluated with Evans blue 1 h after myocardial infarction, no siginificant difference in the area at risk was observed between the exercised and sedentary rats (49.73 + 1.52 vs. 45.48 + 3.49). The changes in the left ventricular fractional areas for the exercised and sedentary myocardial infarction groups (36 + 2% and 39 + 3%, respectively) were smaller than those for the exercise sham surgery (ES, 67+1%) and sedentary sham surgery (SS, 69 + 2%) groups. The E/A was higher in the sedentary myocardial infarction (4.4 + 0.3) and exercised myocardial infarction (5.5 + 0.3) rats than in the SS (2.4 + 0.1) and ES (2.2 + 0.1) rats. CONCLUSION: Previous swim training of female rats does not attenuate systolic and diastolic function alterations after myocardial infarction induced by left coronary artery occlusion, suggesting that cardioprotection cannot be provided by exercise training in this experimental model

Enzymatic synthesis of poly(catechin)-antibiotic conjugates : an antimicrobial approach for indwelling catheters

Biofilm formation in urinary indwelling catheters is one of the most critical issues that patients face. Catheters were coated with poly(catechin)-antibiotic conjugates with enhanced antimicrobial properties. Catechin was conjugated with two antibiotics, namely trimethoprim (TMP) and sulfamethoxazole (SMZ) via activation with N,N′-disuccinimidyl carbonate (DSC) and subsequent coupling to molecules containing α-amine moieties. Silicone and polyurethane catheters were functionalized in situ through laccase oxidation of catechin-antibiotic conjugates. Four antimicrobial coatings were produced, namely with poly(catechin), poly(catechin)- TMP, poly(catechin)-SMZ and poly(catechin)-TMP-SMZ. The bacterial adhesion reduction was tested on the functionalized devices using gram-negative and gram-positive strains. The most significant reduction in adhesion was observed with poly(catechin)-TMP (gram-negative −85 % and grampositive −87 %) and with poly(catechin)-TMP-SMZ (gramnegative −85 % and gram-positive −91 %). The cytotoxicity to mammalian cells was tested by indirect contact for 5 days and revealed that all the tested coatings supported more than 90 % of viable cells. A promising approach for the increase of the indwelling catheter lifespan was developed aiming to reduce catheter-associated chronic infections.The authors would like to acknowledge Pronefro (Portugal) and Degania (Israel) for supplying polyurethane and silicone catheters, respectively. The author Idalina Goncalves would like to acknowledge the NOVO project (FP7-HEALTH-2011.2.3.1-5) for funding. This work was partly supported by FEDER through POFC-COMPETE and by Portuguese funds from Fundacao para a Ciencia e a Tecnologia (FCT) through the project PEst-OE/BIA/UI4050/2014. The authors Carla Silva and Teresa Matama would like to acknowledge FCT for their scholarships SFRH/BPD/46515/2008 and SFRH/BPD/47555/2008