Search

Microbiologically influenced corrosion (MIC) is a phenomenon of increasing concern that affects various materials and sectors of society. MIC describes the effects, often negative, that a material can experience due to the presence of microorganisms. Unfortunately, although several research groups and industrial actors worldwide have already addressed MIC, discussions are fragmented, while information sharing and willingness to reach out to other disciplines are limited. A truly interdisciplinary approach, which would be logical for this material/biology/chemistry-related challenge, is rarely taken. In this review, we highlight critical non-biological aspects of MIC that can sometimes be overlooked by microbiologists working on MIC but are highly relevant for an overall understanding of this phenomenon. Here, we identify gaps, methods, and approaches to help solve MIC-related challenges, with an emphasis on the MIC of metals. We also discuss the application of existing tools and approaches for managing MIC and propose ideas to promote an improved understanding of MIC. Furthermore, we highlight areas where the insights and expertise of microbiologists are needed to help progress this field. [ABSTRACT FROM AUTHOR]

This paper proposes a new methodology, Power Block Geometry (PBG), for the presentation of power electronics topologies that process ac voltage. PBG's strategy uses formal methods based on a geometrical representation with particular rules and defines a universe with axioms and conjectures to establish a formation law. It allows power electronics configurations observed in the technical literature to be obtained by just following PBG's proposed rules, taking a systematic approach and using the familiar concept of connection blocks. Such an approach provides the formal outline needed for a comprehensive didactic presentation.

Liquid-liquid equilibrium data were measured and analyzed for two ternary systems (biodiesel + methanol + glycerol and methyl palmitate + methanol + glycerol). Biodiesel, produced by the conventional chemical route at 60 °C for 60 min, using methanol and soybean oil at a molar rate of 10:1 and potassium hydroxide concentration (KOH) of 1 wt% exhibited thermal decomposition at temperatures between 100 and 250 ºC, reaching mass loss of approximately 98.8%, confirming soybean oil conversion into biodiesel by gas chromatography and thermogravimetry. Tie line composition quality was verified using Othmer-Tobias and Hand correlation equations. The distribution and selectivity coefficients were calculated for the immiscibility regions. The experimental tie line data exhibited good correlation in the UNIQUAC and NRTL thermodynamic models. The biodiesel system displayed deviations of 0.66 and 0.53% for the UNIQUAC and NRTL models, respectively. In addition, the methyl palmitate system showed a 1.23 and 0.48% deviation for the UNIQUAC and NRTL model, respectively. The individual behavior of the main biodiesel esters, based on the UNIQUAC model parameters, demonstrated that the type of fatty acid does not interfere in model correlation, likely due to the similarity between their composition and properties. [ABSTRACT FROM AUTHOR]

The sound generated by axial flow fans has become increasingly important in several industrial areas. These devices represent considerable noise sources that must be considered from the design stage. The scope of this research work is to present an axial fan design methodology based on the theory of the wing lift and to compare the aerodynamic and aeroacoustics behavior with the free vortex and the non-free vortex conditions. The effect of forward circumferential sweep on the rotor blades is analyzed in both conditions, which consists of a displacement in the tangential direction in the direction of rotor rotation. A cubic polynomial function is proposed for the construction of the blade geometry with circumferential sweep. It defines the center line of the blade and it is taken at 50% of the leading edge of each blade profile. The methodology for analyzing aeroacoustics behavior in fans is based on the integration of Computational Aeroacoustics and Computational Fluid Dynamics in order to analyze aerodynamic behavior, sound power level and sound pressure level at the preliminary design stage. It was verified that although both rotors present a similar aerodynamic behavior (the NFV rotor has a slightly lower performance), according to the analysis of local sound sources, the NFV rotor presents a slight decrease in the sound sources. It was also verified that the NFV rotor presents 2.2 dB less in sound pressure level than the FV rotor. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The draft tube is one of the main components that integrate a turbine, since it has the function of recovering the residual kinetic energy after the runner by the pressure energy. The search for a draft tube design that increases the efficiency of the turbine is always an engineering challenge. The hydromechanics components geometry optimization can be accomplished through the integration of optimization methods and CFD tools. In this work, the geometric optimization of a double diffuser draft tube of a Bulb turbine applied to ultra-low heads is presented, with the objectives of maximizing the pressure recovery coefficient, Cp, and increasing the hydraulic efficiency of the turbine, ηh. These improvements would make it possible to reduce the longitudinal length of the draft tube, thereby, making an easier insertion of this kind of turbines in water transport systems, with pressures around 3 [mH2O]. The optimization methodology was performed in the meridional plane, using twelve geometric variables in the draft tube through the integration of optimization methods and computational fluid dynamics. The optimized geometry obtained showed an increase in the Cp value of 0.71516, from the original geometry, to 0.83080. The results were extended to the 3D flow analysis, where the optimized turbine showed efficiency gains of 82% to 84%, when compared to the original turbine considering that its total length was reduced and its geometry simplified, resulting in a more compact and versatile equipment. The study also concluded that the applied methodology can be extended to other similar optimization problems in the design of hydraulic machines. [ABSTRACT FROM AUTHOR]

Amanahyphes saguassu Salles and Molineri, 2006 is firstly recorded from state of Pará. Specimens from Parápresented wings with more curved anal veins than those from state of Amazonas, illustrated in the original description,showing variability among populations of this species. Amanahyphes saguassu is similar to Leptohyphodes inanis (Pictet,1843), sharing both nymph and adult characteristics.

Background: Vascular complications are still common in the catheterization laboratory setting. However, no risk scores for their prediction have been described. With a view to bridging this gap, the present study sought to develop and validate a score for prediction of vascular complications associated with arterial access in patients undergoing interventional cardiology procedures. Methods: This prospective multicenter cohort study included adult patients who underwent cardiac catheterization via the femoral or radial route. The outcomes of interest were: access site hematoma; major and minor bleeding; and retroperitoneal hemorrhage, pseudoaneurysm, or arteriovenous fistula requiring surgical repair. Past medical history as well as pre-procedural, intra-procedural, and post-procedural variables were collected. Patients were randomly allocated to the derivation or validation cohorts at a 2:1 ratio. The following equation constituted the score: (>6F introducer sheath×4.0)+(percutaneous coronary intervention×2.5)+(history of vascular complication after prior interventional cardiology procedure×2.0)+(prior use of warfarin or phenprocoumon×2.0)+(female sex×1.5)+(age⩾60 years×1.5). The maximum score is 13.5 points. Results: A score dichotomized at ⩾3 (best cutoff for balancing sensitivity and specificity) was moderately accurate (sensitivity=0.66 (95% confidence interval: 0.59–0.73); specificity=0.59 (95% confidence interval: 0.56–0.61)). Patients with a score ⩾3 were at increased risk of complications (odds ratio: 2.95; 95% confidence interval: 2.22–3.91). Conclusions: This study yielded a score that is capable of predicting vascular complications and easily applied in daily practice by providers working in the catheterization laboratory setting. [ABSTRACT FROM AUTHOR]

Morphological and structural features of the sperm of the Triatoma brasiliensis Neiva, 1911 ( Hemiptera: Reduviidae) species complex were examined in this first study investigating the sperm of Heteroptera and the genus Triatoma. Males were dissected and their seminal vesicles removed. For measurement, seminal vesicles were squashed on glass slides, spread, fixed and observed under a photomicroscope. The images were analysed and measures of sperm were made. Data were analysed using one-way analysis of variance and Tukey's test to detect differentiation among taxa. Furthermore, seminal vesicles were prepared for studies of transmission electron microscopy. All taxa studied showed polymorphic (short and long) sperm. The sperm of Triatoma brasiliensis macromelasoma was significantly longer (in total length) than that of the other four members of the complex, which supports the hypothesis of hybrid speciation of this member of the complex as an increase in the size of typical hybrids under heterosis was previously shown. The sperm cells of the five taxa have similar ultrastructural morphology. The ultrastructural features observed confirm the hypothesis, raised by previous studies, that they are synapomorphic to the suborder Heteroptera. [ABSTRACT FROM AUTHOR]

Introduction Individuals carrying an inherited mutation for hereditary cancer syndromes usually have a longterm risk management process, requiring a responsive healthcare system. Most studies about their perceived quality of the services used patient-reported outcome measures through quantitative studies. Although valuable, they did not provide an in-depth understanding of individuals' experiences and perspectives about the healthcare system. Thus, this study aimed to describe the individuals' experiences of care and to identify their perceived psychosocial needs and preferences to improve healthcare responsiveness. Methods This is a qualitative study entailing 13 interviews with Portuguese adults. Participants had one of the following hereditary cancer syndromes: Hereditary Breast and Ovarian Cancer Syndrome, Lynch Syndrome, Hereditary Diffuse Gastric Cancer Syndrome, or Familial Adenomatous Polyposis. The protocol interview was developed in collaboration with individuals with hereditary cancer syndromes and healthcare professionals. Most participants were male (n = 7; 53.8%), ranging in age from 22 to 53 years old. Interviews were analyzed using thematic analysis. Results Four main themes emerged from the individuals' interviews: (1) quality of clinical information; (2) clinical relationship; (3) psychological support, and (4) healthcare organization processes. For each theme, participants described their needs, preferences, positive and negative aspects of each dimension of care, and provided suggestions about possible improvements to the healthcare services. Discussions To the best of our knowledge, we conducted the first study about the psychosocial needs and preferences of individuals with several hereditary cancer syndromes from the moment they decided to undergo genetic testing until the long-term management phase risk. Conclusions According to our results, individuals appreciated being informed about their clinical condition and available preventive approaches, and involved in a humanized, accessible, and responsive healthcare. This first-hand knowledge of mutation carriers' experiences is particularly valuable to healthcare professionals and settings become more responsive to these individuals that need clinical surveillance during their entire lives. Lessons learned The psychosocial needs and preferences that mattered most to mutation carriers also include their families and are not limited to their clinical condition but also to their personal identity. Individuals have different needs along with all the specific phases of the adaptation trajectory of carrying an inherited mutation that increases the risk for cancer. Limitations Although data saturation was reached, our study participants' experiences may represent little diversity because they are mainly associated with one healthcare center. Another limitation is the retrospective nature of the data collected, given some participants had undergone their genetic testing or surgery a long time ago. Suggestions for future research Our findings suggested the need for more research within identity concerns among the mutation carriers for a better understanding of their identity preferences with its associated implications in terms of clinical communication and healthcare services organization. In addition, we made several practice implications that may contribute to the healthcare services to become more responsive to the mutation carriers' psychosocial needs and preferences. [ABSTRACT FROM AUTHOR]

Peptide-based scaffolds are a frontier research area in materials science with widespread impact in biomedical engineering. In this paper, we describe a hybrid material formulated through the conjugation of electrospun polycaprolactone (PCL) fibers and micro/nanotubes of l,l-diphenylalanine (FF-MNTs). Morphology and crystallinity of the composite matrices are investigated using a wide range of analytical techniques including electron microscopy, thermal analyses, X-ray diffraction and micro-tomography. Peptide assemblies are found to produce deep modifications on the microstructure of PCL fibers, impacting average diameters, crystallinity degree and porous size in the polymer network. These changes are correlated with mechanical properties of the resulting scaffolds, whose strength is found to exhibit a brittle-to-ductile transition upon increasing the amount of FF-MNTs and lead to enhanced Young's moduli of polymer fibers. The PCL/FF-MNTs composites were tested for the drug delivery application of a lipophilic drug, benzocaine. In vitro permeation studies have shown that these polymer/peptide hybrids are able to produce a steady release of benzocaine over periods of up to ∼13 hours, much higher than commercially available gel formulations. Enzymatic tests have shown a significant increment in biodegradation rates in PCL/FF-MNTs hybrids containing higher peptide amounts, which exhibited almost 100% weight loss against only 10% found in pure PCL. Our findings indicate that using PCL/FF-MNTs materials is a simple route towards achieving enhanced mechanical strength of PCL networks that have the ability to promote controlled drug delivery from a completely biodegradable matrix. [ABSTRACT FROM AUTHOR]

Single-phase to three-phase conversion using power electronics converters is a well-known technology, especially when the configurations and control strategies already established in the technical literature are considered. Regarding the configurations conceived over the years, it can be observed two main tendencies: 1) configurations with a reduced number of components; and 2) configurations with an increased number of components. The search for topologies with a reduced number of components was the trend over a long period of time. This can be, in part, explained by the high cost of the power switch when compared to the capacitor used in the dc-link bus. Then, the converter leg was sometimes substituted for the midpoint capacitor. However, as far as the price of the semiconductor was going down, such tendency has been changed, and now the configurations with an increased number of components do appear as an interesting option, especially in terms of reliability, efficiency, and distortions improvement. A comprehensive review of the two possibilities (reduced and increased number of components) has been considered in this paper. Also, the single-phase to three-phase ac-ac direct conversion configurations and those which aim to reduce the dc-link voltage fluctuation have been included. The goal of this paper is to provide a complete range on the status of single-phase to three-phase power conversion technologies to professionals and researchers interested in this topic. [ABSTRACT FROM AUTHOR]

In some practical problems, for instance, the suppression of vibration in mechanical systems, the state-derivative signals are easier to obtain than the state signals. Using Linear Matrix Inequalities (LMIs), and applying the reciprocal projection lemma in a Parameter-dependent Lyapunov Function (PDLF), this article proposes a method for the design of state-derivative feedback applied to uncertain linear systems. The control design aims the system stabilisation without and with decay rate restriction. When considering only the system stability, the proposed methodology becomes practically equivalent to the Common Quadratic Lyapunov Function (CQLF) technique. Otherwise, when the decay rate is taken in account, the proposed methodology is shown to be less conservative. Numerical examples illustrate its efficiency. [ABSTRACT FROM AUTHOR]

We study the effect of the soft confinement by fluid lipid bilayers on the spatial organisation of DNA molecules in a DNA-zwitterionic lipid hydrated lamellar complex. The confinement is increased by dehydrating the complex in a controlled way, which leads to a decrease of the water channel thickness separating the periodically stacked bilayers. Using grazing-incidence small-angle X-ray scattering on an oriented thin film, we probe in situ as dehydration proceeds the structure of the DNA-lipid complex. A structural phase transition is evidenced, where an apparently disordered phase of DNA rods embedded within the one-dimensionally ordered lipid lamellar phase observed at high hydration is replaced by a 2D hexagonal structure of DNA molecules intercalated between the lipid bilayers. [ABSTRACT FROM AUTHOR]

The overall heat transfer coefficient as a function of rotation speed (5-20 rpm) was calculated for cans containing a 2% NaCI and 1.5% sucrose aqueous solution during end-over-end heat sterilisation at 120°C. The values obtained for the overall heat transfer coefficient, U (W/m²°C), were: 544.4±85.3 at 5 rpm, 710.7±24.5 at 10 rpm, 760.5±17.7 at 15 rpm and 941.6±22.1 at 20 rpm. A correlation was developed in terms of Nusselt, rotational Reynolds and Prandtl numbers to predict U (Nu = 1.866 Re0.379 Pr0.38). The characteristic dimension in Nu and Re was the diameter of the can. This correlation (R² = 0.88) was valid for Re within the range of 3,012-14,820 and Pr within 2.02-2.63 values. [ABSTRACT FROM AUTHOR]

Aims: To investigate the coagulase gene polymorphism of Staphylococcus aureus isolated from mastitic goat's milk. Methods and Results: A typing procedure based on coagulase gene polymorphism was used to discriminate S. aureus isolated from goat mastitis. Thirty-six strains collected from goats belonging to herds from northern Ceara State and Serrana region of Rio de Janeiro State were analysed. Based on restriction fragment length polymorphism of 3′ end coagulase gene, the goat strains were grouped into 11 types. In northern Ceara herds, the predominant type was found in 60% of the strains, while in the Serrana region herds the two most common accounting for 62·5% of the strains. Conclusions: The analysis of the coa gene proved to be useful for typing S. aureus from goat mastitis. Although the results showed that goats from the studied regions were infected by S. aureus strains harbouring more than one coagulase genotype, only one or two types predominated. Significance and Impact of the Study: The identification of the prevalent strains within a herd or region is a necessity. The important virulence factors could be identified in such strains and this information can then be used as a specific base to develop S. aureus mastitis control measures. [ABSTRACT FROM AUTHOR]

The use of heart rate (HR) monitors for horse training assessment under field conditions has been expanded because its use facilitates the understanding of horse fitness levels. Work has been carried out to determine the HR, velocity (V) and exercise time for pull and helper horses submitted to the Vaquejada simulation test (VST). The test was used on 70 Quarter Horses that had trained and competed for more than 6 months. The VST consists of two horses, a puller and a helper, and a bull, all running on a soft sand track. A race cycle consists of three runs with the bull. Pull horses run one cycle and helper horses run two cycles. A Polar V800-GPS HR monitor for equines was used to measure several parameters: time, V and HR. The results were analysed by ANOVA and a Tukey test with P set at 5%. It was shown that pull horses developed an HRmax of ∼200 bpm and an HRmin ∼110 bpm, both higher than the helper horses (P<0.05). However, the HRmed of pull horses (∼150 bpm) and helper horses (∼139 bpm) in C-2 trials were not substantially different from one another (P>0.05). Additionally, both groups of horses had similar maximum (∼8.90 m/s) and average (∼1.87 m/s) velocities (P>0.05). In analysing the distribution of HR among five rate categories, we determined that pull horses presented a higher percentage of their HR above 170 bpm in comparison to helper horses (P<0.05). It was concluded that, based on VST results, pull and helper horses presented different HRmax, HRmed and HRmin values, even when V and duration were similar, and that pull horses perform more intensive work than helper horses. [ABSTRACT FROM AUTHOR]

Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the Michaelis-Menten model (Vmax = 111.11 mg L-1 h-1 and Km = 448.3 mg L-1). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.

Environmental concerns have been changing the way of looking for solutions to problems. The hydrosphere, together with its biosphere, has been feeling the impact of many pollutants, used for instance in the marine industry for economic reasons or lack of knowledge of their effects. In particular biocides, applied as coatings in paints, are released into the waters becoming toxic and persistent extending their action to an area far beyond the initial coated surface they should protect. In order to minimize these side effects, two biocides, Irgarol (I) and Econea (E), were covalently attached to polyurethane (PU) and foul-release silicone based (PDMS) marine paints through an isocyanate linker. Their antifouling bioactivity was better in PDMS coatings, both for single (Econea) and combined biocides (E/I ratio = 1.5) with contents lower than 0.6 wt%. The treated samples remained almost clean after more than one year immersion in the Portuguese shore of the Atlantic Ocean, and after about 24 weeks under the tropical conditions of Singapore (Fouling rate < 1%). Complementary biofilm adhesion susceptibility tests against Pseudoalteromonas tunicata D2 showed adhesion reduction higher than 90% for PU formulations containing single biocides and close to 100% for PDMS with combined biocides. The eco-toxicity assessment evidenced a low environmental impact, in accordance with the European standards. In addition, shipping field trial tests showed the best antifouling performance for the Econea-based PDMS formulations (E = 0.6 wt%), which remained clean for about nine months in open seawaters, proving the efficacy of this non-release strategy, when applied under dynamic conditions., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Vascular complications are still common in the catheterization laboratory setting. However, no risk scores for their prediction have been described. With a view to bridging this gap, the present study sought to develop and validate a score for prediction of vascular complications associated with arterial access in patients undergoing interventional cardiology procedures., Methods: This prospective multicenter cohort study included adult patients who underwent cardiac catheterization via the femoral or radial route. The outcomes of interest were: access site hematoma; major and minor bleeding; and retroperitoneal hemorrhage, pseudoaneurysm, or arteriovenous fistula requiring surgical repair. Past medical history as well as pre-procedural, intra-procedural, and post-procedural variables were collected. Patients were randomly allocated to the derivation or validation cohorts at a 2:1 ratio. The following equation constituted the score: (>6F introducer sheath×4.0)+(percutaneous coronary intervention×2.5)+(history of vascular complication after prior interventional cardiology procedure×2.0)+(prior use of warfarin or phenprocoumon×2.0)+(female sex×1.5)+(age⩾60 years×1.5). The maximum score is 13.5 points., Results: A score dichotomized at ⩾3 (best cutoff for balancing sensitivity and specificity) was moderately accurate (sensitivity=0.66 (95% confidence interval: 0.59-0.73); specificity=0.59 (95% confidence interval: 0.56-0.61)). Patients with a score ⩾3 were at increased risk of complications (odds ratio: 2.95; 95% confidence interval: 2.22-3.91)., Conclusions: This study yielded a score that is capable of predicting vascular complications and easily applied in daily practice by providers working in the catheterization laboratory setting.

This study evaluated the abundance and spatial-temporal distribution of the shrimp Xiphopenaeus kroyeri in the coastal region of Macaé, state of Rio de Janeiro, southeastern Brazil. Monthly samples were obtained from March 2008 to February 2010 in six stations located in Inner (5, 10 and 15m depth) and Outer (25, 35 and 45m depth) areas. It was used a commercial fishery boat equipped with an otter-trawl net (3.5 m mouth width, mesh size 20mm and 15mm in the cod end). Water samples were taken for determination of temperature and salinity, and sediment samples for determination of texture and organic matter content. A total of 7146 shrimps were sampled. About 95% of all shrimps were caught in the shallow area, i.e., depths <20m. Greatest abundances were recorded in winter and spring. No significant correlation was observed between sediment (phi) and abundance. The distribution of X. kroyeri in the studied area was closely related to seasonal cold waterfront of the South Atlantic Central Water (SACW) and temperature was the main factor affecting the species abundance.