Surface modification of bamboo fibers using chitosan and functionalization with AuNPs

In this work, a new surface modification of the bamboo substrate with chitosan was studied, followed by subsequent treatment with gold nanoparticles (AuNP) by the exhaustion method, aiming at obtaining a technical textile with ultraviolet (UV) protection. The treatment with chitosan in the bamboo substrate induced an increase in the AuNP adsorption due to the electrostatic interactions between the chitosan amino groups and the citrate ion that surrounds the AuNP. The nanoparticles were obtained by the chemical reduction method, with some adaptations, using sodium citrate as a reducing agent/stabilizer and chlorouronic acid as precursor. The AuNP were characterized by transmission electron microscopy (TEM) and reflection, showing an average size of 35 nm. The presence of AuNP on the fiber surface was confirmed by SEM and XRD, with crystallographic peaks characteristic of gold. The UV protection factor was tested on the material, demonstrating excellent results.info:eu-repo/semantics/publishedVersio

Dog wool microparticles/polyurethane composite for thermal insulation

A polyurethane (PU)-based eco-composite foam was prepared using dog wool fibers as a filler. Fibers were acquired from pet shops and alkaline treated prior to use. The influence of their incorporation on the PU foams’ morphological, thermal, and mechanical properties was investigated. The random and disorganized presence of the microfibers along the foam influence their mechanical performance. Tensile and compression strengths were improved with the increased amount of dog wool microparticles on the eco-composites. The same occurred with the foams’ hydration capacity. The thermal capacity was also slightly enhanced with the incorporation of the fillers. The fillers also increased the thermal stability of the foams, reducing their dilatation with heating. The best structural stability was obtained using up to 120 °C with a maximum of 15% of filler. In the end, the dog wool waste was rationally valorized as a filler in PU foams, demonstrating its potential for insulation applications, with a low cost and minimal environmental impact.Authors acknowledge the Fundação de Apoio a Pesquisa do Estado do Rio Grande do Norte (FAPERN) for financing this work. They thank the pet shops from Natal city for donating the dog wool fibers used in the experiments. H.P. Felgueiras and A. Zille also acknowledge project UID/CTM/00264/2019 of Centre for Textile Science and Technology (2C2T), funded by national funds through FCT/MCTES

Multifunctional chitosan/gold nanoparticles coatings for biomedical textiles

Gold nanoparticles (AuNPs), chemically synthesized by citrate reduction, were for the first time immobilized onto chitosan‐treated soybean knitted fabric via exhaustion method. AuNPs were successfully produced in the form of highly spherical, moderated polydisperse, stable structures. Their average size was estimated at ≈35 nm. Successful immobilization of chitosan and AuNPs were confirmed by alterations in the fabric’s spectrophotometric reflectance spectrum and by detection of nitrogen and gold, non‐conjugated C=O stretching vibrations of carbonyl functional groups and residual N‐acetyl groups characteristic bands by X‐ray photoelectron spectroscopy (XPS) and Fourier‐Transform Infrared Spectroscopy (FTIR) analysis. XPS analysis confirms the strong binding of AuNPs on the chitosan matrix. The fabrics’ thermal stability increased with the introduction of both chitosan and AuNPs. Coated fabrics revealed an ultraviolet protection factor (UPF) of +50, which established their effectiveness in ultraviolet (UV) radiation shielding. They were also found to resist up to 5 washing cycles with low loss of immobilized AuNPs. Compared with AuNPs or chitosan alone, the combined functionalized coating on soy fabrics demonstrated an improved antimicrobial effect by reducing Staphylococcus aureus adhesion (99.94%) and Escherichia coli (96.26%). Overall, the engineered fabrics were confirmed as multifunctional, displaying attractive optical properties, UV‐light protection and important antimicrobial features, that increase their interest for potential biomedical applications.: This research was funded by FEDER funds through the Operational Competitiveness Program – COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT) under the project POCI‐ 01‐0145‐FEDER‐007136 and UID/CTM/00264/2019. A. Zille also acknowledges financial support of the FCT through an Investigator FCT Research contract (IF/00071/2015) and the project PTDC/CTM‐TEX/28295/2017 financed by FCT, FEDER and POCI. This work was funded by FEDER funds through the Operational Competitiveness Program – COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT)—under the project POCI‐01‐0145‐FEDER‐007136 and UID/CTM/00264/2019. A. Zille also acknowledges financial support of the FCT through an Investigator FCT Research contract (IF/00071/2015) and the project PTDC/CTM‐ TEX/28295/2017 financed by FCT, FEDER and POCI

Characterization of a natural surfactant from an essential oil from neem (Azadirachta indica A. Juss) for textile industry applications

Surfactants are multipurpose active compounds and are ubiquitously present in detergents. Detergent demand spiked due to the current COVID-19 pandemic, further alerting to the need to replace petrochemical synthetic surfactants with natural and renewable surfactants to mitigate further environmental damage. The neem tree (Azadirachta indica A. Juss) is a fast-growing tree that provides a multitude of commodities, namely neem oil. Neem oil possesses insecticidal and medicinal activity. This work reports the extraction and characterization of a surfactant from neem oil (SNO), displaying a yield of approximately 100%. SNO exhibited suitable detergent characteristics with a high potential to be used as a cleansing agent for textile applications, such as high pH value (10.1), suitable foaming of 1.5 cm and a critical micelle concentration of nearly 0.12 g mL−1. In addition, SNO showed a moderate bactericidal activity against Escherichia coli and bacteriostatic activity against Staphylococcus aureus, both common nosocomial pathogens. Therefore, SNO has a good potential to be used in medical textile applications due to its detergent and bactericidal properties. Finally, an economical overview of the SNO production process was assessed, underscoring its viability.This work was supported by the Brazilian Coordenac¸~ao de Aperfei¸oamento de Pessoal de N ıvel Superior and by the Portuguese Fundac¸~ao para Cieˆncia e a Tecnologia, Fundo Europeu de Desenvolvimento Regional and Programa Operacional Competitividade e Internacionalizac¸~ao in the frame of the Portugal 2020 program for the project PLASMAMED PTDC/CTM-TEX/28295/2017

Cellulose nanowhisker obtained from cotton rejected by textile industry

This study aimed to characterize cellulose nanowhiskers (NWs) extracted from discarded cotton fibers. The nanocellulose was characterized by dynamic light scattering, zeta potential, Scanning Transmission Electron Microscopy (STEM), Atomic force microscopy (AFM) and X-ray powder diffraction (XRD). The nanocrystals are characterized by a rod-like morphology with sizes between 100 nm and 300 nm. The acidic hydrolyses applied to the extract nanocrystals increased the crystallinity index from 72 to 86%. The average length and diameter obtained were 98.1±4.7 and 8.0±3.4 nm, respectively. The aspect ratio of the fibers, around 12.3, was lower than the values usually reported in the literature. The dynamic light scattering results were in accordance with the nano crystal dimensions showing an average size of 235 nm. Cellulose NWs obtained from cotton rejected by textile industry due to their abundance, low cost, high crystallinity, strength, low weight and biodegradability, are the ideal candidates for the processing of polymer nanocomposites

Brazilian consortium for the study on renal diseases associated with COVID-19 : a multicentric effort to understand SARS-CoV-2-related nephropathy

Kidney involvement appears to be frequent in coronavirus disease 2019 (COVID-19). Despite this, information concerning renal involvement in COVID-19 is still scarce. Several mechanisms appear to be involved in the complex relationship between the virus and the kidney. Also, different morphological patterns have been described in the kidneys of patients with COVID-19. For some authors, however, this association may be just a coincidence. To investigate this issue, we propose assessing renal morphology associated with COVID-19 at the renal pathology reference center of federal university hospitals in Brazil. Data will come from a consortium involving 17 federal university hospitals belonging to Empresa Brasileira de Serviços Hospitalares (EBSERH) network, as well as some state hospitals and an autopsy center. All biopsies will be sent to the referral center for renal pathology of the EBSERH network. The data will include patients who had coronavirus disease, both alive and deceased, with or without pre-existing kidney disease. Kidney biopsies will be analyzed by light, fluorescence, and electron microscopy. Furthermore, immunohistochemical (IHC) staining for various inflammatory cells (i.e., cells expressing CD3, CD20, CD4, CD8, CD138, CD68, and CD57) as well as angiotensin-converting enzyme 2 (ACE2) will be performed on paraffinized tissue sections. In addition to ultrastructural assays, in situ hybridization (ISH), IHC and reverse transcription-polymerase chain reaction (RT-PCR) will be used to detect Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) in renal tissue. For the patients diagnosed with Collapsing Glomerulopathy, peripheral blood will be collected for apolipoprotein L-1 (APOL1) genotyping. For patients with thrombotic microangiopathy, thrombospondin type 1 motif, member 13 (ADAMTS13), antiphospholipid, and complement panel will be performed. The setting of this study is Brazil, which is second behind the United States in highest confirmed cases and deaths. With this complete approach, we hope to help define the spectrum and impact, whether immediate or long-term, of kidney injury caused by SARS-CoV-2

INFLUENCIA DO RETARDANTE DE CHAMA EM COMPÓSITO DE PALF E POLIÉSTER NÃO-SATURADO

A resistência e flamabilidade ao fogo dos materiais compósitos vêm sendo pesquisado com maior frequência e existe um campo bastante amplo para ser explorado com relação aos tipos, concentrações e combinações químicas dos agentes retardantes de chama. O retardante de chama tem o propósito de aumentar a resistência do material à ignição e, ao mesmo tempo, reduzir a velocidade de propagação da chama, podendo atuar durante ou após a ignição do produto. O hidróxido de alumínio é o agente retardante de chama mais utilizado no mercado, por ter baixo custo, agir como supressor de fumaça e não liberar gases tóxicos ou substâncias corrosivas durante a queima

ESTUDO DA ESTABILIDADE TÉRMICA DE FIBRA QUERATINA (KF) DE PENAS DE FRANGO PARA OBTENÇÃO DE CARBONO (CF)

A fibra de queratina de penas de frango foi submetida à análise térmica (TG) em sua forma natural e carbonizada, aumentando assim a expansão do reaproveitamento de materiais desperdiçados no Brasil. A partir das curvas obtidas por TG/DTG da pena natural (KF) e tratadas (KFNaOH, SCFC e SCFD) buscou-se um melhor ciclo de carbonização (pirólise) para esse tipo de precursor. O trabalho também trata como um dos focos, o estudo comparativo do comportamento térmico desses materiais. Uma parte da KF foi tratada com hidróxido de sódio (NaOH), e observou-se pelo o resultado TG/DTG que a resistência térmica do material não foi influenciada. Outra parte de KF foi semicarbonizada (220°C) sem controle do ambiente térmico e taxas de aquecimento e resfriamento, apresentando colorações diferentes, mais clara (SCFC) e mais escura (SCFD). Foi constatado nas curvas de TG/DTG, que esse tratamento de carbonização não é ideal para a obtenção de carbono. Também foi verificado nas curvas de TG/DTG que na CF houve um aumento da estabilidade térmica comparada a todas as outras amostras. Essa pesquisa é uma inovação no que diz respeito à preparação e avaliação de fibras de penas de frango na obtenção de fibras sintetizadas, que atualmente são, em larga escala, derivados do petróleo, lembrando-se da diminuição das reservas de petróleo e da poluição que os mesmos geram ao meio ambiente

Coordenação de cuidados primários para o paciente com doença renal crônica em diálise: revisitando papéis

The number of patients on dialysis has increased significantly in recent years. These patients are, in general, carriers of multiple and complex chronic conditions, and the coordination of their care becomes a challenge. This article aims to summarize the results of the literature regarding the coordination of care for dialysis patients. This is an integrative review based on data published and available in the databases: LILACS, SciELO and PubMed. 16 articles published between 1992 and 2020 were identified. Based on the thematic analysis, five areas were highlighted: linkage of patients with primary health care (PHC) and with the family and community physician (FCF); professionals' perception of their roles and skills; patients' perception of the professionals' roles and skills; primary care delivered by nephrologists and FCF and; impact of PHC on mortality, hospitalization and quality of life. The results suggest that the nephrologist has assumed the role of care coordinator and main provider of primary care for dialysis patients. However, this does not mean that the care offered is adequate for the patient's needs, and the FCF should be increasingly involved with this care.O número de pessoas em diálise tem aumentado de maneira significativa nos últimos anos. Essas pessoas são, em geral, portadoras de condições crônicas múltiplas e complexas, e a coordenação do seu cuidado torna-se um desafio. O presente artigo objetiva sintetizar os resultados da literatura a respeito da coordenação do cuidado e dos cuidados primários ofertados ao paciente em diálise. Trata-se de uma revisão integrativa que teve como fontes de dados publicações disponíveis nas bases: LILACS, SciELO e PubMed. Foram identificados 16 artigos publicados entre 1992 e 2020. A partir da análise temática, evidenciaram-se cinco áreas: vínculo das pessoas em diálise com a Atenção Primária à Saúde (APS) e com o médico da família e comunidade (MFC); percepção dos profissionais quanto a seus papéis e habilidades; percepção das pessoas a respeito dos papéis e habilidades dos profissionais; cuidados primários (CP) prestados por nefrologistas e MFC; e impacto da APS na mortalidade, hospitalização e qualidade de vida. Os resultados sugerem que o nefrologista tem assumido o papel de coordenador do cuidado e de principal provedor de CP à pessoa em diálise. Todavia, isso não significa que os cuidados oferecidos sejam adequados às necessidades do paciente, devendo o MFC estar cada vez mais envolvido com esse cuidado, o que tem sido gradualmente observado nos últimos anos

Determination of the Biosorption of Cd(Ⅱ) by Coconut Fiber

Made available in DSpace on 2015-05-04T17:07:34Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) mirian_pereiraetal_IOC_2014.pdf: 279050 bytes, checksum: 56b80540ed54c2c0f81bacc18831da2f (MD5) Previous issue date: 2014Universidade Federal do Rio Grande do Norte. Centro Tecnológico. Engenharia Mecânica. Natal. RN, Brasil / University of Coimbra. Centre of Chemical Processes Engineering and Forest Products (CIEPQPF), Coimbra, Portugal / Universidade Federal do Rio Grande do Norte. Faculdade de Ciências da Saúde do Traíri. Santa Cruz, RN, Brasil.Universidade Federal do Rio Grande do Norte. Centro Tecnológico. Engenharia Mecânica. Natal. RN, Brasil .Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Ultraestrutura Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Ultraestrutura Celular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Ultraestrutura Celular. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio Grande do Norte. Departamento de Análises Clínicas. Natal, RN, Brasil.Universidade Federal do Rio Grande do Norte. Departamento de Engenharia Têxtil. Natal, RN, Brasil.University of Coimbra. Centre of Chemical Processes Engineering and Forest Products (CIEPQPF). Coimbra, Portugal.University of Coimbra. Centre of Chemical Processes Engineering and Forest Products (CIEPQPF). Coimbra, Portugal.Universidade Federal do Rio Grande do Norte. Centro Tecnológico. Engenharia Mecânica. Natal. RN, Brasil / Fundação Oswaldo Cruz. Laboratório de Ultraestrutura Celular. Rio de Janeiro, RJ, Brasil.The coconut fiber is produced in large quantities in Brazil, even though very small quantities are being used by some industries, mainly cordage mats and handicrafts. An alternative usage would be the use of these fibers in biosorption of heavy metals from aqueous solutions. This present study aimed to evaluate the potentiality of cadmium biosorption by coconut fiber. The coconut fibers were used at kinetic analysis, influence of pH and adsorption isotherms were also carried out. It can be concluded that there is great potential for the use of coconut fiber, and the optimum pH for adsorption was around 5.0. The adsorption kinetics is fast and equilibrium occurs within 120 min. The Langmuir isotherm was considered the most suitable to describe the experimental data