Influence of material type and surface benzalkonium chloride preconditioning on biofilm formation and activity

This study investigates the potential of benzalkonium chloride (BC), a cationic surfactant, on the prevention of biofilm formation on stainless steel ASI 316 and silicone rubber, two distinct surfaces currently used on food processing facilities. The surfaces were preconditioned with several concentration of BC for 30 min. Treated surfaces were characterized by the sessile drop method, demonstrating that surfactant pre-treatment increased the hydrophobicity of the surfaces, this increase being a function of BC concentration increase applied for preconditioning. In order to ascertain the preventive effect in biofilm formation, the treated surfaces where inserted in a chemostat continuously inoculated with P. fluorescens in the exponential phase of growth, being the biofilm allowed to grow for 6 days. The results showed that BC preconditioning did not prevent or impair biofilm formation. In fact, biofilms developed on the treated surfaces presented higher biomass and respiratory activity than the ones formed on the untreated surfaces, this phenomenon being more evident for silicone than for stainless steel and for surfaces treated with higher BC concentrations. Scanning electron microscopy and biochemical analysis reveal that the difference of surface type and surface preconditioning, by itself, gave rise to the formation of structural and biochemical distinct biofilms. The overall results suggest that preconditioning of stainless steel and silicone rubber surfaces with BC allowed the formation of biofilms with more recalcitrant properties than the ones found on untreated surfaces

Blood Vessels Under the Microscope

This paper looks at blood vessels. All humans and animals have blood vessels, including your pet rabbit or dog, a whale or a giraffe! We need blood vessels to stay alive. This paper answers many questions, including what blood vessels are used for and why we need them. It looks at how and why blood vessels grow and what they look like. It also explores what happens when things go wrong with blood vessels and if blood vessels are ever bad for us. So, if you want to know how many miles of blood vessels there are in your body, learn about problems astronauts have in space, see real blood vessels through a microscope, or learn how to keep your blood vessels healthy, you are reading the right article

Brazilian Adolescents Infected by HIV: Epidemiologic Characteristics and Adherence to Treatment

Over the last 3 decades since the first AIDS cases appeared, we have witnessed great progress in therapeutic methodologies that have transformed the evolution of the disease from debilitating and fatal, into chronic and controllable. HIV-infected children are arriving at adolescence and bringing specific challenges, not only to themselves, but also to their families and caregivers. This retrospective study sets forth epidemiological and treatment characteristics of 46 HIV-infected adolescents followed in a specialized university service relating said characteristics to therapy adherence assessed through a combination of three indirect methods. Therapy adherence did not reveal any association with either epidemiologic characteristics regarding age, sex, school level, household composition, age at diagnosis, mode of infection, knowledge of diagnosis, treatment time, or initial antiretroviral scheme. Patients with good therapy adherence presented lower viral load and used a smaller number of antiretroviral schemes

Automated design of microwave discrete tuning differential capacitance circuits in Si-integrated technologies

A genetic algorithm used to design radio-frequency binary-weighted differential switched capacitor arrays (RFDSCAs) is presented in this article. The algorithm provides a set of circuits all having the same maximum performance. This article also describes the design, implementation, and measurements results of a 0.25 lm BiCMOS 3-bit RFDSCA. The experimental results show that the circuit presents the expected performance up to 40 GHz. The similarity between the evolutionary solutions, circuit simulations, and measured results indicates that the genetic synthesis method is a very useful tool for designing optimum performance RFDSCAs

Enzyme-assisted release of antioxidant peptides from porphyra dioica conchocelis

peer-reviewedThe conchocelis life cycle stage of P. dioica represents an unexplored source of bioactive compounds. The aim of this study was to generate and characterise, for the first time, hydrolysates of conchocelis using a specific combination of proteases (Prolyve® and Flavourzyme®). Hydrolysate molecular mass distribution and free amino acid contents were assessed, and the antioxidant activity was determined using a range of in vitro assays. The protein content and the total amino acid profiles of conchocelis were also studied. Conchocelis contained ~25% of protein (dry weight basis) and had a complete profile of essential amino acids. Direct sequential enzymatic treatment modified the profile of the generated compounds, increasing the amount of low molecular weight peptides (<1 kDa). There was a significant improvement in the antioxidant activity of the hydrolysates compared with the control (up to 2.5-fold), indicating their potential as a novel source of antioxidant ingredients

DNA code analysis with fractional calculus

This paper addresses the DNA code analysis in the perspective of dynamics and fractional calculus. Several mathematical tools are selected to establish a quantitative method without distorting the alphabet represented by the sequence of DNA bases. The association of Gray code, Fourier transform and Fractional calculus leads to a categorical representation of species and chromosomes.N/

The bigger the better? Evaluation of the value of large multi-gene panels in Portuguese cardiomyopathy genetic testing

Introduction: Genetic testing of cardiomyopathies went through major changes in the last few years, from sequential Sanger sequencing of the most likely gene candidates, to multigene panels by NGS, with an ever increasing number of genes analyzed.info:eu-repo/semantics/publishedVersio

Monitorização do vale e pico sérico de vancomicina em recém-nascidos de termo: comparação entre as técnicas de cromatografia líquida de alta eficácia e imunoensaio por fluorescência polarizada

INTRODUCTION: Peak and trough serum concentrations of vancomycin were determined in term newborn infants with confirmed or suspected Staphylococcus sp sepsis by high performance liquid chromatography and flourescence polarization immunoassay. OBJECTIVE: To statistically compare the results of the high performance liquid chromatography and flourescence polarization immunoassay techniques for measuring serum vancomycin concentrations. METHODS: Eighteen peak and 20 trough serum samples were assayed for vancomycin concentrations using high performance liquid chromatography and flourescence polarization immunoassay from October 1995 to October 1997. RESULTS: The linear correlation coefficients for high performance liquid chromatography and flourescence polarization immunoassay were 0.27 (peak, P = 0.110) and 0.26 (trough, P = 0.1045) respectively, which were not statistically significant. CONCLUSION: There was wide variation in serum vancomycin concentrations determined by high performance liquid chromatography as compared with those determined by flourescence polarization immunoassay. There was no recognizable pattern in the variability; in an apparently random fashion, the high performance liquid chromatography measurement was sometimes substantially higher than the flourescence polarization immunoassay measurement, and at other times it was substantially lower.INTRODUÇÃO: Foi realizada monitorização dos níveis séricos de vancomicina em recém-nascidos de termo com sepse ou suspeita de sepse Staphylococcus sp., através da cromatografia líquida de alta eficácia (HPLC) e imunoensaio por fluorescência polarizada (FPIA). OBJETIVO: Verificar a existência de correlação estatística entre os resultados obtidos pelas duas técnicas. MÉTODO E CASUÍSTICA: Foram obtidas dezoito e vinte concentrações séricas de vancomicina no pico e vale respectivamente, em recém-nascidos de termo, no período de outubro de 1995 a outubro de 1997. RESULTADO: O coeficiente de correlação linear para pico sérico foi de 0,27, p=0,110 e para vale sérico 0,26, p= 0,1045 não sendo estatisticamente significativo, não sendo estatisticamente significativo. CONCLUSÃO: Apesar da pequena casuística, não houve correlação estatisticamente significante entre os resultados obtidos pelos duas técnicas

The VISIR+ Project – Helping Contextualize Math in an Engineering Course

[EN]The long-term goal of engineering education is to prepare students to work as engineers. Being a practical profession, laboratories play a crucial role in illustrating concepts and principles as well as improving technical skills. In the last decades the use of online resources (simulators and remote labs) has been growing, either as a complementary and/or as an alternative way of developing experimental competences. In the scope of the VISIR+ Project, this work presents the first results of a didactical implementation using simultaneously the remote laboratory VISIR (Virtual Instrument Systems in Reality), simulation and calculus in a Math Course at the Federal University of Santa Catarina (UFSC). The preliminary results indicate that the use of several resources increases students’ performance, boosting their learning and competence development