Enhancing the antimicrobial efficacy of polyester fabric impregnated with silver nanoparticles using DBD plasma treatment

The functionalization of polyester fabric (PES) with antimicrobial agents presents huge number of potential applications in advanced products. However, the lack of functional groups and the high PES hydrophobicity make the functionalization processes costly, prolonged and requires the use of polluting chemical compounds. In this work, dielectric barrier discharge (DBD) plasma treatment, an affordable and environmental-friendly method, was used to introduce new chemical groups, increase the surface energy and roughness of PES in order to improve the adhesion of silver nanoparticles (AgNPs) in its surface. The PES functionalization was evaluated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and antimicrobial efficacy against Staphylococcus aureus and Escherichia coli. Despite some additional oxidation, the DBD plasma- treated PES showed superior adhesion of AgNPs and excellent antimicrobial efficacy even after 10 washing cycles (WC)

Improvement of the female mouse computational model developed at CDTN

Small animals, such as mice, have been used in experiments involving ionizing radiation. New preclinical experimental methods often include extensive imaging (MicroCT and/or PET/SPECT) that can result in absorbed dose values considerably high. In addition, assays with theranosticsradiopharmaceuticals administered in small animals have been used to determine the main potential adverse effects and the therapeutic efficacy. For all these mentioned cases, the precise quantification of absorbed doses and the determination of energy deposition patterns are of fundamental importance to qualify or exclude potential radiobiological effects that may interfere with in vivo experiment results. Thus, the development and improvement of mouse phantoms is essential for good small animal dosimetry. In 2021, our group segmented and implemented a female C57BL mouse phantom, called FM_BRA, in the MCNP. The objective of this work was to review the segmentation of the FM_BRA computational model and to identify and segment new organs for an improved version of this phantom. Three different researchers segmented different organs of the model. The masses of the segmented organs were compared with those of the first version. Information on mass or volume of organs from different mouse strains, and more specifically from the C57BL strain, was also obtained from the literature for comparison and to aid in segmentation. The mice image representing a female mouse of the C57BL strain weighing 26 g were kindly provided by the Turku Center for Disease and were manually segmented. The software GIMP® 2.10 was used to select and segment each organ/tissue. The IMAIOS-VET Anatomy website was used as an anatomical basis for the identification of organs/tissues. The IMAGEJ® software was applied to assemble the segmented images into a 3D stack and to convert the segmented images into binary files. The volumes of the segmented organs were measured with a C++ in house program. Corresponding human tissue densities provided in ICRP 110 were used to calculate organ mass from the calculated volumes. Data were compared with literature reports. The number of segmented organs increased from 20 in the old model to 33 in the new models. The masses of the organs segmented in this work, by the different researchers, showed agreement in most cases. However, organs such as the small intestines, bones and trachea still deserve a new round of reviewing

Development of a plasma activated multifunctional polyester fabric using zinc oxide nanoparticles and citronella oil microcapsules

There is a high demand for the development of textiles possessing multifunctional properties for outdoor, protective and health care applications. The coating of polyester (PES) textiles with metal nanoparticles and essential oils may act in a synergistic mode to obtain materials with improved antimicrobial and UV-protection properties. However, the lack of functional groups onto PES structure makes the adhesion of particles a difficult task. In this work, PES fabric was activated by dielectric barrier discharge (DBD) plasma treatment, and functionalized with zinc oxide nanoparticles (ZnO NPs) and poly (methyl methacrylate) (PMMA)-citronella microcapsules by dip-coating

Sustainable and multifunctional natural fiber-based electric wire sheaths for smart textiles

Envisioning the development of sustainable products for improvement of daily life quality, a cable-like composite using natural fibers was developed to be potentially used in smart textiles. Natural fibers such as jute and hemp were used along with Bekinox®VN yarn. Bekinox®VN is a stainless steel conductive yarn often used in intelligent textiles within a wide range of applications such as antistatic, power and signal transfer, thermal conductivity or even as a heat resistant sewing yarn. Furthermore, applying a chitosan coating on the surface of the sheath will confer antibacterial properties, thus preventing the colonization and proliferation of bacteria, as well as natural fiber degradation. The chitosan coating was applied by a pad dry method. Tests were performed to evaluate the mechanical, electrical and antimicrobial properties. The results displayed that the best tensile strength was obtained for hemp fabric followed by cable composite. The antimicrobial properties were improved with the coating of chitosan and demonstrating excellent results against Gram-positive and Gram-negative bacteria. Although chitosan reduces the mechanical strength of the sheath, it confers antibacterial activity, which not only will preserve the fiber in the structure but will also protect human skin against possible cross-contaminations.This work was funded by ERDF through the COP and FCT projects: UID/CTM/00264/2021, PLASMAMED PTDC/CTM TEX/28295/2017, ARCHKNIT POCI-01-0247-FEDER-039733, FATORST+ POCI-01-0247-ERDF-047124, MEDCOR PTDC/CTM-TEX/1213/2020, 4NoPressure POCI-01-0247-FEDER-039869 financed by FEDER through POCI under the “Portugal 2020” programme. RDVF and AIR also acknowledge Ph.D. scholarships SFRH/BD/145269/2019 and SFRH/BD/137668/2018, respectively

Sustainable and multifunctional natural fiber-based electric wire sheaths for smart textiles

Envisioning the development of sustainable products for improvement of daily life quality, a cable-like composite using natural fibers was developed to be potentially used in smart textiles. Natural fibers such as jute and hemp were used along with Bekinox®VN yarn. Bekinox®VN is a stainless steel conductive yarn often used in intelligent textiles within a wide range of applications such as antistatic, power and signal transfer, thermal conductivity or even as a heat resistant sewing yarn. Furthermore, applying a chitosan coating on the surface of the sheath will confer antibacterial properties, thus preventing the colonization and proliferation of bacteria, as well as natural fiber degradation. The chitosan coating was applied by a pad dry method. Tests were performed to evaluate the mechanical, electrical and antimicrobial properties. The results displayed that the best tensile strength was obtained for hemp fabric followed by cable composite. The antimicrobial properties were improved with the coating of chitosan and demonstrating excellent results against Gram-positive and Gram-negative bacteria. Although chitosan reduces the mechanical strength of the sheath, it confers antibacterial activity, which not only will preserve the fiber in the structure but will also protect human skin against possible cross-contaminations.This work was funded by ERDF through the COP and FCT projects: UID/CTM/00264/2021, PLASMAMED PTDC/CTM TEX/28295/2017, ARCHKNIT POCI-01-0247-FEDER-039733, FATORST+ POCI-01-0247-ERDF-047124, MEDCOR PTDC/CTM-TEX/1213/2020, 4NoPressure POCI-01-0247-FEDER-039869 financed by FEDER through POCI under the “Portugal 2020” programme. RDVF and AIR also acknowledge Ph.D. scholarships SFRH/BD/145269/2019 and SFRH/BD/137668/2018, respectively

Development of alternative methodology for normalization of the small animals PET scanner of LIM/CDTN

Normalization is a step taken to correct variations in count rates between detection channels of small animals PET scanners. In general, in laboratory practice, normalization is performed using a commercial source of germanium 68. Given the half-life of the Ge-68 isotope, the normalization source must be replaced every two years at most, which generates a significant spent for the Laboratory. The objective of this work was to develop and test an alternative rechargeable source to be used on normalization routine. The results indicated that the rechargeable source (18F-FDG) can be used to replace the commercial source

Imidazolium salt and dielectric barrier discharge plasma treatment to enhance the conductivity of fabrics impregnated with pedot:PSS

Conductive textiles are a class of materials with a growing interest due to their potential applications in medical, healthcare, comfort, protective clothing, and sportswear sectors. They can be used for the development of smart textiles able to answer to different external stimuli such as thermal, mechanical, chemical, electrical, magnetic, and optical. The complex poly (3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) is the most explored polymer to prepare conductive textiles. Dopants can be introduced to add or remove electrons from the backbone of PEDOT:PSS, resulting in increased conductivity. Salts such as 1-butyl-3-methylimidazolium octyl sulphate (IZ) may promote ionic interactions with PEDOT:PSS, stimulating a microstructure reorganization. Moreover, the dielectric barrier discharge (DBD) plasma treatment has been shown to improve the adhesion of coatings by modifying the surface roughness, surface chemistry, and hydrophilicity of the fabrics. In this work, untreated and DBD plasma-treated polyester (PES) fabrics were impregnated with PEDOT:PSS with and without the addition of imidazolium salt (0.2M) as a dopant. Using the IZ, it was possible to adapt the textile materials into resistors, where the applied current converted electrical energy into heat. The developed textiles can be used to produce heating garments

Uso de CPAP para apnéia obstrutiva do sono comparadas ao tratamento conservador / CPAP use for obstructive sleep apnea compared to conservative treatment

Introdução: A apneia obstrutiva do sono (AOS) tornou-se um grande problema de saúde pública, por ser um distúrbio do sono, que resulta em ronco e riscos nocivos para a saúde. A baixa adesão ao tratamento conservador tem dado espaço para a criação de novos dispositivos. Objetivo: comparar custos, funcionalidade, durabilidade e eficiência de tecnologias assistivas aliadas ao tratamento conservador da AOS. Método: A pesquisa exploratória e descritiva foi realizada nas bases National Library of Medicine (PubMed), Web of Science, Scopus, Biblioteca Virtual em Saúde (BVS) e IEEEXplore. Como descritores e palavras-chaves, com o operador booleano “AND” ou “OR”, foram pesquisados os termos “spleep apnea” and “assistive technology” or “self-help devices” or “devices”. Resultados: A pressão positiva contínua nas vias aéreas (CPAP) representa o método padrão-ouro, porém, possui baixa aceitabilidade pelos pacientes com AOS devido a limitação da funcionalidade. O aparelho de avanço mandibular (MAA) é  reconhecido como uma opção de terapia de primeira linha para a AOS leve a moderada apresentando variedade em relação à custo, benefício e durabilidade. O  uso de terapia oral com aparelho (OAT) a longo prazo foi associado a alterações dentárias. Conclusão: Constatou-se a variedade de dispositivos para AOS, ressaltando a necessidade de avaliação da realidade do paciente, sendo de suma importância avaliar o custo-benefício, os sintomas e principalmente, prestar orientações assertivas para a melhor escolha dos dispositivos, sendo o dispositivo de avanço mandibular (MAD), o que apresentou melhor adesão. Ressalta-se a necessidade de novos estudos para melhores intervenções, pois protótipos não substituem tratamentos comprovados

Estudos Artísticos

O 18º número da revista croma apresenta 15 artigos que prosseguem os objetivos editoriais desta revista. Trata-se de desafiar os autores ou criadores apresentar a obra de outros artistas preferencialmente originários dos países de expressão portuguesa ou espanhola.info:eu-repo/semantics/publishedVersio

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE