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Collapsing glomerulopathy (CG) is a clinicopathologic entity characterized by segmentar or global collapse of the glomerulus and hypertrophy and hyperplasia of podocytes. The Columbia classification of 2004 classified CG as a histological subtype of focal segmental glomerulosclerosis (FSGS). A growing number of studies have demonstrated a high prevalence of CG in many countries, especially among populations with a higher proportion of people with African descent. The present study is a narrative review of articles extracted from PubMed, Medline, and Scielo databases from September 1, 2020 to December 31, 2021. We have focused on populational studies (specially cross-sectional and cohort articles). CG is defined as a podocytopathy with a distinct pathogenesis characterized by strong podocyte proliferative activity. The most significant risk factors for CG include APOL1 gene mutations and infections with human immunodeficiency virus and severe acute respiratory syndrome coronavirus 2. CG typically presents with more severe symptoms and greater renal damage. The prognosis is notably worse than that of other FSGS subtypes.

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., The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Brazilian Coordenacao de Aperfeioamento de Pessoal de Nivel Superior and by the Portuguese Fundacao para Ciencia e a Tecnologia, Fundo Europeu de Desenvolvimento Regional and Programa Operacional Competitividade e Internacionalizacao in the frame of the Portugal 2020 program for the project PLASMAMED PTDC/CTM-TEX/28295/2017.

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&rsquo, 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&rsquo, 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 &deg, 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.

Lanthanum (La) doped zinc oxide (ZnO) nanomaterials (LaxZn1-xO, x = 0.0, 0.03, 0.05, 0.07 M) were synthesized via co-precipitation method using zinc acetate, lanthanum nitrate as precursors, octylamine as capping and reducing agent. The structures, morphologies, optical activity and antibacterial properties of LaxZn1-xO were investigated by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, High resolution scanning electron microscopy (HR-SEM), Energy dispersive X-ray (EDX), UV–Visible, Photoluminescence (PL) spectroscopy. The antibacterial activities of LaxZn1-xO were tested by modified disc diffusion method. The XRD results showed that the La3+ ions were successfully incorporated into the ZnO host, and the products were well-crystalline. The average size of undoped and doped La-doped ZnO was found to be in the ranges from 15.64 to 10.18 nm. In addition, the sphere-like nanoparticles morphology of LaxZn1-xO was confirmed by HR-SEM images. The band gap of La-doped ZnO nanoparticles were varied with the La3+ ions doping concentration. In addition, increasing the doping concentration of La3+ ions in ZnO increases the defects in ZnO lattice and hence resulting red-shift in UV emission, which indicate the presence of narrow band-gap in doped nanoparticles.

With the help of microwave-assisted technique, zirconia (ZrO 2 ) nanocrystalline powder was synthesized using a structure directing agent which could be controlled by the nucleation and particle growth. The various characterizations, namely, phase, surface morphology, surface area analysis and optical property were carried out by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET) and UV–visible spectroscopy. From XRD analysis, it was found that the synthesized materials reveal the tetragonal crystalline phase. The average particle size of ZrO 2 was found 14.7 nm by TEM. Specific surface area, pore volume and the pore size for ZrO 2 are 220 m 2 /g, 0.02 cm 3 /g and 10.7 nm investigated by BET, respectively. UV–vis DRS spectra of the prepared material confirmed that the Zr atoms are exclusively incorporated within silica framework. Besides, the maximum absorption peaks were observed at 215 nm and 217 nm for as-synthesized and calcined samples, respectively.

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 &asymp, 35 nm. Successful immobilization of chitosan and AuNPs were confirmed by alterations in the fabric&rsquo, 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&rsquo, 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.

Nanocrystalline TiO2 powders have been selectively prepared by the simple combustion reaction method using urea as a fuel. The crystalline powder was obtained using a silica basin heated directly on a hot plate at 500 °C until self-ignition occurred. After combustion process, the calcined products were obtained by heating the as-prepared powders for 1 h in air atmosphere at various sintering temperatures [500–900 °C]. The obtained nanopowder materials were systematically characterized by X-day diffraction (XRD), micro-Raman, UV–visible absorption (UV–vis), and Fourier transform infrared (FT-IR) spectroscopics. Powder XRD pattern shows the good agreement rutile phase structured TiO2 and the sharp diffraction peaks indicates good for crystallinity. The size of a symmetry of the nanoparticles have been measured with aid of a scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), and Brunauer, Emmett and Teller (BET) surface studies. The crystallinity of the powders was found to increase with respect to calcination temperatures. The average specific surface area of the particle was probed using gas adsorption–desorption measurements. Raman spectroscopy experiment was performed to ascertain the nature of TiO2 powder quality. UV–vis absorption spectra results showed the changes in the absorption edges of TiO2 report to increasing the calcinations temperatures.

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.

Chitin is widely distributed in nature, being the main structural component of the exoskeleton of crustaceans and is non-toxic, biodegradable and biocompatible. These exoskeletons once discarded become an industrial waste creating environmental pollutant. In order to find an alternative use, the present work exploits the extraction of the chitosan from chitin that is present in the exoskeletons of shrimps Litopenaeus vannamei and crabs Ucides cordatus and transforms it into high valued products, which can help solving the environmental problem as well to provide extra income to the fishermen. One example is the manufacture of nanomembranes from chitosan for the application in medical textiles. Nanomembranes using electrospinning of chitosan solutions (7% and 5wt%) with 100:0 v/v (TFA/DCM) and 70:30 v/v (TFA/DCM) were produced. Morphological properties of chitin and chitosan were studied using SEM, DRX, and thermal properties through TG/DTG and molecular structure by FTIR analysis. TG/DTG showed thermal decomposition of chitosan samples. X-ray diffraction analysis indicated the semi-crystalline structure of chitosan, and highly crystalline structure for chitin. Morphologies of the nanomembranes were also observed from scanning electron micrographs. Results showed that the nanomembranes with 5% chitosan solutions with 70:30 v/v (TFA/DCM) showed facilitation in the formation of the nanomembranes. The nanomembranes of shrimp and crab with 5% 70:30 v/v (TFA/DCM) had higher breaking tension and breaking extension. With positive results obtained, the present work will help the authorities to organize the fishermen to have consciousness in the collection of exoskeleton waste as well as helping to have a better environment.

Because of the constant challenge to preserve the environment and the search for new materials, a comparative study was carried out using keratin fiber, a fibrous protein, found in the chicken feathers. Five different samples of the feather were analyzed by Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). First in their natural form Keratin Fiber (KF); the second treated with sodium hydroxide (KFNaOH); the third and fourth samples were semi carbonized at 220℃ in an oven without atmospheric control for 24 hours (samples obtained: Clear brown (SCFC) and Dark brown (SCFD)); and the fifth sample was carbonized by pyrolysis Carbonized Feathers (CF). The SEM result shows that the KF has a hollow structure, with knots and hooks. The KFNaOH structure presented rougher than that of the KF, but lost their hooks. The SCFC and SCFD presented brittle structures, but preserved the hollow structure of KF; however, it was only noticeable to a magnification of 3000 times. On the other hand, the CF, was shiny, black, and showed a higher amount of porosity with open micro-pores and micro-tubes, preserved the hollow structure of KF than any other samples studied, and also presented well-defined closed micro-tubes. From the XRD analysis of the KF, CF, KFNaOH, SCFC and SCFD, presented semi-crystalline structures, with the following indices of crystallinity, 20.09%, 18.93%, 17.97%, 15.02% and 14.31%, respectively. The CF presented smaller size crystallites, in between the micro- particulates, around 27 nm and the KFNaOH with larger size around 74 nm. From this study it was concluded that micro-porous carbon material from chicken feathers (KF) could be efficiently obtained through pyrolysis.

This study aimed to characterize cellulose nanowhiskers 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 nanowhiskers 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., (undefined)

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.

Graphene oxide (GO) nanosheets modified with zinc oxide nanocrystals were achieved by a green wet-chemical approach. As-obtained products were characterized by XRD, Raman spectra, XPS, HR-TEM, EDS, PL and Photocatalytic studies. XRD studies indicate that the GO nanosheet have the same crystal structure found in hexagonal form of ZnO . The enhanced Raman spectrum of 2D bands confirmed formation of single layer graphene oxides. The gradual photocatalytic reduction of the GO nanosheet in the GO : ZnO suspension of ethanol was studied by using X-ray photoelectron (XPS) spectroscopy. The nanoscale structures were observed and confirmed using high resolution transmission electron microscopy (HR-TEM). The evolution of the elemental composition, especially the various numbers of layers were determined from energy dispersive X-ray spectra (EDS). PL properties of GO : ZnO nanosheet were found to be dependent on the growth condition and the resultant morphology revealed that GO nanosheet were highly transparent in the visible region. The photocatalytic performance of GO : ZnO nanocomposites was performed under UV irradiation. Therefore, the ZnO nanocrystals in the GO : ZnO composite could be applied in gradual chemical reduction and consequently tuning the electrical conductivity of the graphene oxide nanosheet.