Efficacy of atmospheric pressure dielectric barrier discharge for inactivating airborne pathogens

Atmospheric pressure plasmas have gained attention in recent years for several environmental applications. This technology could potentially be used to deactivate airborne microorganisms, surface-bound microorganisms, and biofilms. In this work, the authors explore the efficacy of the atmospheric pressure dielectric barrier discharge (DBD) to inactivate airborne Staphylococcus epidermidis and Aspergillus niger that are opportunistic pathogens associated with nosocomial infections. This technology uses air as the source of gas and does not require any process gas such as helium, argon, nitrogen, or hydrogen. The effect of DBD was studied on aerosolized S. epidermidis and aerosolized A. niger spores via scanning electron microscopy (SEM). The morphology observed on the SEM micrographs showed deformations in the cellular structure of both microor- ganisms. Cell structure damage upon interaction with the DBD suggests leakage of vital cellular materials, which is a key mechanism for microbial inactivation. The chemical structure of the cell surface of S. epidermidis was also analyzed by near edge x-ray absorption fine structure spectros- copy before and after DBD exposure. Results from surface analysis revealed that reactive oxygen species from the DBD discharge contributed to alterations on the chemistry of the cell membrane/ cell wall of S. epidermidis

Antiapoptotic effects of cannabidiol in an experimental model of cognitive decline induced by brain iron overload

Iron accumulation in the brain has been recognized as a common feature of both normal aging and neurodegenerative diseases. Cognitive dysfunction has been associated to iron excess in brain regions in humans. We have previously described that iron overload leads to severe memory deficits, including spatial, recognition, and emotional memory impairments in adult rats. In the present study we investigated the effects of neonatal iron overload on proteins involved in apoptotic pathways, such as Caspase 8, Caspase 9, Caspase 3, Cytochrome c, APAF1, and PARP in the hippocampus of adult rats, in an attempt to establish a causative role of iron excess on cell death in the nervous system, leading to memory dysfunction. Cannabidiol (CBD), the main non-psychotropic component of Cannabis sativa, was examined as a potential drug to reverse iron-induced effects on the parameters analyzed. Male rats received vehicle or iron carbonyl (30 mg/kg) from the 12th to the 14th postnatal days and were treated with vehicle or CBD (10 mg/kg) for 14 days in adulthood. Iron increased Caspase 9, Cytochrome c, APAF1, Caspase 3 and cleaved PARP, without affecting cleaved Caspase 8 levels. CBD reversed iron-induced effects, recovering apoptotic proteins Caspase 9, APAF1, Caspase 3 and cleaved PARP to the levels found in controls. These results suggest that iron can trigger cell death pathways by inducing intrinsic apoptotic proteins. The reversal of iron-induced effects by CBD indicates that it has neuroprotective potential through its anti-apoptotic action

Impact of Nanocomposite Combustion Aerosols on A549 Cells and a 3D Airway Model

The use of nanomaterials incorporated into plastic products is increasing steadily. By using nano-scaled filling materials, thermoplastics, such as polyethylene (PE), take advantage of the unique properties of nanomaterials (NM). The life cycle of these so-called nanocomposites (NC) usually ends with energetic recovery. However, the toxicity of these aerosols, which may consist of released NM as well as combustion-generated volatile compounds, is not fully understood. Within this study, model nanocomposites consisting of a PE matrix and nano-scaled filling material (TiO$_{2}$, CuO, carbon nano tubes (CNT)) were produced and subsequently incinerated using a lab-scale model burner. The combustion-generated aerosols were characterized with regard to particle release as well as compound composition. Subsequently, A549 cells and a reconstituted 3D lung cell culture model (MucilAir™, Epithelix) were exposed for 4 h to the respective aerosols. This approach enabled the parallel application of a complete aerosol, an aerosol under conditions of enhanced particle deposition using high voltage, and a filtered aerosol resulting in the sole gaseous phase. After 20 h post-incubation, cytotoxicity, inflammatory response (IL-8), transcriptional toxicity profiling, and genotoxicity were determined. Only the exposure toward combustion aerosols originated from PE-based materials induced cytotoxicity, genotoxicity, and transcriptional alterations in both cell models. In contrast, an inflammatory response in A549 cells was more evident after exposure toward aerosols of nano-scaled filler combustion, whereas the thermal decomposition of PE-based materials revealed an impaired IL-8 secretion. MucilAir™ tissue showed a pronounced inflammatory response after exposure to either combustion aerosols, except for nanocomposite combustion. In conclusion, this study supports the present knowledge on the release of nanomaterials after incineration of nano-enabled thermoplastics. Since in the case of PE-based combustion aerosols no major differences were evident between exposure to the complete aerosol and to the gaseous phase, adverse cellular effects could be deduced to the volatile organic compounds that are generated during incomplete combustion of NC

Performance and carcass characteristics of lambs fed diets with fat and vitamin E

Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)This experiment aimed to determine the influence of diets with inclusion of protected fat and vitamin E on performance, yield and carcass characteristics of feedlot lambs with different weights. Thirty-two non-castrated Santa Ines lambs were fed diets with a ratio of 40% forage and 60% concentrate ad libitum, with presence or absence of protected fat and/or vitamin E, in a total of four diets. Two weights of early containment were also considered: between 20 and 25 kg and between 30 and 35 kg. All animals were slaughtered at 84 days of confinement. Animals fed diets without addition of protected fat, regardless of the use of vitamin E, had the highest intakes of dry matter, crude protein, neutral detergent fiber and ash, and decreased intake of ether extract. The variables investigated did not affect daily weight gain and total gain. Feed conversion was better for the lighter confined animals not fed protected fat. The heavier feedlot lambs fed diets with vitamin E showed higher cold carcass. The warm carcass for the lighter animals confined fed with vitamin E, and the heavier ones, fed with protected fat and vitamin E, showed the best yields of cold carcass. Objective measures of the carcass cold had the highest mean for heavier feedlot lambs. The addition of fat in the diet reduces the intake of dry matter and increases the ether extract. Although the inclusion of vitamin has no effect on intake of nutrients, it protects the carcasses from losses during cooling, and weight differences at containment directly reflect the measures of the carcasses

CONSTRUÇÃO CIVIL SUSTENTÁVEL: O CENÁRIO NA REGIÃO METROPOLITANA DE CUIABÁ-MT A PARTIR DA PERCEPÇÃO DE ARQUITETOS E ENGENHEIROS LOCAIS: SUSTAINABLE CONSTRUCTION: THE SCENERY IN THE METROPOLITAN REGION OF CUIABÁ-MT FROM THE PERCEPTION OF LOCAL ARCHITECTS AND ENGINEERS

Sustainable constructions are characterized by ensuring efficiency in the allocation of resources and respect for environmental preservation, that is, the responsible management of the built environment based on ecological principles. The present study aims to identify the obstacles to the execution of sustainable projects in the metropolitan region of Cuiabá-MT. Specifically, it seeks to identify the level of knowledge and interest of architects and engineers about sustainable certifications, the adoption of such concepts in their projects and, finally, the perception of sustainability as a differential for competitive advantage. For the development of the research, a desk research was carried out on the chosen theme. Then, data collection was carried out through the application of electronic questionnaires sent to architecture and engineering professionals in Mato Grosso. The results reveal significant female participation in a previously male predominant market; in addition, the diversification of respondents in terms of career time enabled diferente points of view. The research made possible to observe that despite the professionals' interest in sustainability, it doesn’t seem to be presente in professionals’ daily projects.Los edificios sostenibles se caracterizan por garantizar la eficiencia en la asignación de recursos y el respeto a la preservación del medio ambiente, es decir, una gestión responsable del entorno construido basada en principios ecológicos. El presente estudio tiene como objetivo identificar los factores que dificultan la ejecución de proyectos sostenibles en la región metropolitana de Cuiabá-MT. En concreto, se pretende identificar el nivel de conocimiento e interés de arquitectos e ingenieros sobre las certificaciones sostenibles, la adopción de dichos conceptos en sus proyectos y, por último, la percepción de la sostenibilidad como un diferencial de ventaja competitiva. Para el desarrollo de la investigación, se llevó a cabo una investigación documental sobre el tema elegido. A continuación, se recogieron datos mediante la aplicación de cuestionarios electrónicos enviados a profesionales de la arquitectura y la ingeniería de Mato Grosso. Los resultados revelan una importante participación femenina en un mercado que, hasta entonces, era predominantemente masculino; además, la diversificación de los encuestados en términos de tiempo de carrera permitió obtener puntos de vista muy variados. Con la encuesta se pudo observar que, a pesar del interés de los profesionales por el tema de la sostenibilidad, el discurso sigue difiriendo de la práctica.As construções sustentáveis são caracterizadas por assegurar eficiência na alocação dos recursos e respeito à preservação ambiental, ou seja, o gerenciamento responsável do ambiente construído possuindo como base os princípios ecológicos.  O presente estudo visa identificar os fatores entraves para a execução de projetos sustentáveis na região metropolitana de Cuiabá-MT. Especificamente busca-se identificar o nível de conhecimento e interesse dos arquitetos e engenheiros acerca das certificações sustentáveis, a adoção de tais conceitos em seus projetos e por fim, a percepção da sustentabilidade como diferencial para vantagem competitiva. Para o desenvolvimento da pesquisa foi realizada um desk research acerca da temática escolhida. Em seguida, foi realizada a coleta de dados através da aplicação de questionários eletrônicos enviados aos profissionais da arquitetura e engenharia de Mato Grosso. Os resultados revelam uma participação feminina significativa num mercado até então predominantemente masculino; além disso, a diversificação dos respondentes em termos de tempo de carreira possibilitou pontos de vistas abrangentes. Com a pesquisa foi possível observar que apesar do interesse dos profissionais pela temática sustentabilidade, o discurso ainda difere da prática

The carbonyl-lock mechanism underlying non-aromatic fluorescence in biological matter

Challenging the basis of our chemical intuition, recent experimental evidence reveals the presence of a new type of intrinsic fluorescence in biomolecules that exists even in the absence of aromatic or electronically conjugated chemical compounds. The origin of this phenomenon has remained elusive so far. In the present study, we identify a mechanism underlying this new type of fluorescence in different biological aggregates. By employing non-adiabatic ab initio molecular dynamics simulations combined with a data-driven approach, we characterize the typical ultrafast non-radiative relaxation pathways active in non-fluorescent peptides. We show that the key vibrational mode for the non-radiative decay towards the ground state is the carbonyl elongation. Non-aromatic fluorescence appears to emerge from blocking this mode with strong local interactions such as hydrogen bonds. While we cannot rule out the existence of alternative non-aromatic fluorescence mechanisms in other systems, we demonstrate that this carbonyl-lock mechanism for trapping the excited state leads to the fluorescence yield increase observed experimentally, and set the stage for design principles to realize novel non-invasive biocompatible probes with applications in bioimaging, sensing, and biophotonics.Recent experimental evidence shows a new type of intrinsic fluorescence in biomolecules void of aromatic chemical compounds whose origin is unclear. Here, the authors use non-adiabatic AIMD simulations to show a potential carbonyl-lock mechanism originating this phenomenon

CIÊNCIA E SENSO COMUM: BOAVENTURA E AS CRÍTICAS A VISÃO BACHELARDIANA

Este trabalho se propõe a analisar as críticas de Santos acerca da relação ciência e senso comum de Gaston Bachelard. Nesse sentido, Santos argumenta que a construção epistemológica bachelardiana defende o rompimento da cultura científica com o senso comum. Dito isso, o senso comum acaba sendo diminuído em detrimento do conhecimento científico e este trazendo uma imagem inadequada tanto do senso comum, quanto da própria ciência. Logo, Santos acredita que estamos caminhando para uma nova relação entre ciência e senso comum, em que uma cultura faz parte da outra e ambas constroem uma nova proposta de conhecimento

O lúdico no ensino de biologia celular: possibilidades no ensino superior

peer reviewedConsidering the difficulties that some new students at the University present to understand abstract concepts, this work describes an extension course, in the area of Cell Biology, which was carried out with the objective of contributing to the effective learning of a group of undergraduate students at the University Federal University of Viçosa (MG). The work also reports the importance of the experience lived for the graduate students who taught the Course. In the Course, diversified recreational activities were used, chosen according to the theme that would be approached. The results showed that the process was very well accepted by the students, helping them to understand the contents, through a pleasant and accessible process, which enabled the construction of knowledge. For graduate students, the experience was unique and contributed to their professional training. Therefore, the results were significant for everyone involved.Considerando as dificuldades que alguns alunos recém-ingressos na Universidade apresentam para compreender conceitos abstratos, este trabalho descreve um curso de extensão, na área de Biologia Celular, que foi realizado com o objetivo de contribuir para a aprendizagem efetiva de um grupo de graduandos da Universidade Federal de Viçosa (MG). O trabalho relata também a importância da experiência vivenciada para os pós-graduandos que ministraram o mesmo. No Curso foram utilizadas atividades lúdicas diversificadas, escolhidas de acordo com o tema que seria abordado. Os resultados mostraram que as atividades desenvolvidas foram muito bem aceitas pelos graduandos, ajudando na compreensão dos conteúdos, através de um processo agradável e acessível, que viabilizou a construção dos saberes. Para os discentes da pós-graduação, a experiência foi única e contribuiu para a formação profissional dos mesmos. Portanto, os resultados obtidos foram significativos para todos os envolvidos.Considerando las dificultades que presentan algunos estudiantes nuevos de la Universidad para comprender conceptos abstractos, este trabajo describe un curso de extensión, en el área de Biología Celular, el cual se llevó a cabo con el objetivo de contribuir al aprendizaje efectivo de un grupo de estudiantes de pregrado. estudiantes de la Universidad Federal de Viçosa (MG). El trabajo también reporta la importancia de la experiencia vivida por los estudiantes graduados que impartieron el Curso. En el mismo se utilizaron actividades recreativas diversificadas, elegidas según la temática que se abordaría. Los resultados mostraron que el proceso fue muy bien acogido por los estudiantes, ayudándoles a comprender los contenidos, a través de un proceso ameno y accesible, que permitió la construcción de conocimientos. Para los estudiantes de posgrado, la experiencia fue única y contribuyó a su formación profesional. Por lo tanto, los resultados fueron significativos para todos los involucrados. Palabra

Hierarchical CO2-protective shell for highly efficient oxygen reduction reaction

The widespread application of intermediate-temperature solid oxide fuel cells is mainly being hurdled by the cathode's low efficiency on oxygen reduction reaction and poor resistance to carbon dioxide impurity. Here we report the fabrication of a hierarchical shell-covered porous cathode through infiltration followed by microwave plasma treatment. The hierarchical shell consists of a dense thin-film substrate with cones on the top of the substrate, leading to a three-dimensional (3D) heterostructured electrode. The shell allows the cathode working stably in CO2-containing air, and significantly improving the cathode's oxygen reduction reactivity with an area specific resistance of ∼0.13 Ωcm2 at 575°C. The method is also suitable for fabricating functional shell on the irregularly shaped substrate in various applications