23 research outputs found

    Chemical Functionalization of Cellulosic Materials — Main Reactions and Applications in the Contaminants Removal of Aqueous Medium

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    The cellulose is the most abundant biopolymer in the world and presents a higher chemical variability for presence of several hydroxyl groups. These hydroxyl groups allow surface modification of biomaterials, with insertion of several chemical groups which change cellulose characteristics. This natural biopolymer and its derivatives have been used a lot as adsorbent, from several contaminants of aqueous medium due to biocompatibility, chemical degradability, and variability. Therefore, this chapter has the objective to review the literature about several cellulose surfaces or cellulosic material (incorporation of carboxymethyl, phosphorus, carboxyl, amines, and sulfur), presenting the main characteristics of reactions and showing its adsorption in application of aqueous medium (metals, dyes, and drugs), locating the main interactions between biomaterial/contaminant

    Will ultrathin CIGS solar cells overtake the champion thin-film cells? Updated SCAPS baseline models reveal main differences between ultrathin and standard CIGS

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    Cu(In,Ga)Se2 (CIGS) solar cells are amongst the best performing thin-film technologies, with the latest performance gains being mainly due to recent years improvements obtained with post-deposition treatments (PDT). Moreover, thinning of the absorber layer down to sub-micrometre values (ultrathin absorbers) is of extreme importance for CIGS to be even more cost-effective and sustainable. However, electrical and optical limitations, such as rear interface recombination and insufficient light absorption, prevent the widespread implementation of ultrathin CIGS devices. The recent electrical CIGS simulation baseline models have failed to keep up with the experimental developments. Here an updated and experimentally based baseline model for electrical simulations in the Solar Cell Capacitor Simulator (SCAPS) software is presented and discussed with the incorporation of the PDT effects and increased optical accuracy with the support from Finite-Difference Time-Domain (FDTD) simulation results. Furthermore, a champion solar cell with an equivalent architecture validates the developed thin-film model. The baseline model is also applied to ultrathin CIGS solar cell devices, validated with the ultrathin champion cell. Ultimately, these ultrathin models pave the way for an ultrathin baseline model. Simulations results reveal that addressing these absorbers' inherent limitations makes it possible to achieve an ultrathin solar cell with at least 21.0% power conversion efficiency, with open-circuit voltage values even higher than the recent thin-film champion cells.This work was supported by the Fundação para a Ciência e Tecno-logia (FCT) grant numbers DFA/BD/7073/2020, DFA/BD/4564/2020, SFRH/BD/146776/2019, IF/00133/2015, UIDB/50025/2020, UIDP/50025/2020, UIDB/04730/2020, and UIDP/04730/2020. The authors want to acknowledge the funding from the project NovaCell (PTDC/ CTM-CTM/28075/2017). The authors also acknowledge the financial support of the project Baterias 2030, with the reference POCI-01-0247-FEDER-046109, co-funded by Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDFinfo:eu-repo/semantics/submittedVersio

    Influência da aplicação de águas residuárias de suinocultura na capacidade de infiltração de um solo Podzólico Vermelho-Amarelo Influence of swine wastewater application on the infiltration capacity of a Yellow-Red Podzol

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    Este trabalho foi conduzido na Área Experimental de Hidráulica, Irrigação e Drenagem do Departamento de Engenharia Agrícola da Universidade Federal de Viçosa, em Viçosa, MG, com o objetivo de se avaliar a influência de aplicações sucessivas de águas residuárias de suinocultura, com diferentes concentrações de sólidos totais sobre a capacidade de infiltração de um solo Podzólico Vermelho-Amarelo. O experimento foi conduzido em delineamento experimental inteiramente casualizado, com cinco tratamentos e três repetições, em que os tratamentos se constituíram da aplicação de água e de águas residuárias com concentrações de sólidos totais de 2,4, 7,0, 16,3 e 26,9 g L-1. Quinze infiltrômetros de anel foram instalados em uma área de 60 m², dividida em parcelas de dimensões 2 x 2 m, sendo que em cada uma delas foram conduzidos quatro testes de infiltração, com intervalo de 15 dias. Concluiu-se que o aumento da concentração de sólidos totais de águas residuárias de suinocultura provocou redução na capacidade de infiltração do solo, intensificada com aplicações sucessivas. A concentração de sólidos totais desse efluente foi mais importante na redução da capacidade de infiltração do solo que os níveis de razão de adsorção de sódio e de salinidade.<br>This work was carried out at the Experimental Area of Hydraulics, Irrigation and Drainage of the Agricultural Engineering Department, at the Federal University of Viçosa, Viçosa, Minas Gerais, Brazil. The aim was to evaluate the influence of successive applications of swine wastewater, with different concentrations of total solids, on the infiltration capacity of a Yellow Red Podzol. The experiment was conducted in a completely randomized design with five treatments and three replications. The treatments consisted of applying water and swine wastewater with 2.4, 7.0, 16.3 and 26.9 g L-1 of total solid concentrations. Fifteen ring infiltrometers were installed in an area of 60 m², which was divided in plots of 2 x 2 m dimensions. Four infiltration tests were performed at 15 day intervals in each plot. It was concluded that increasing the total solid concentration of swine wastewater caused a reduction of the soil infiltration capacity. In addition, it was observed that successive applications intensified this effect. The total solid concentration of wastewater was more important to reduce the soil infiltration capacity than the levels of sodium absorption ratio and salinity

    Unveiling the role of osteosarcoma-derived secretome in premetastatic lung remodelling

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    Abstract Background Lung metastasis is the most adverse clinical factor and remains the leading cause of osteosarcoma-related death. Deciphering the mechanisms driving metastatic spread is crucial for finding open therapeutic windows for successful organ-specific interventions that may halt or prevent lung metastasis. Methods We employed a mouse premetastatic lung-based multi-omics integrative approach combined with clinical features to uncover the specific changes that precede lung metastasis formation and identify novel molecular targets and biomarker of clinical utility that enable the design of novel therapeutic strategies. Results We found that osteosarcoma-bearing mice or those preconditioned with the osteosarcoma cell secretome harbour profound lung structural alterations with airway damage, inflammation, neutrophil infiltration, and extracellular matrix remodelling with increased deposition of fibronectin and collagens by resident stromal activated fibroblasts, favouring the adhesion of disseminated tumour cells. Systemic-induced microenvironmental changes, supported by transcriptomic and histological data, promoted and accelerated lung metastasis formation. Comparative proteome profiling of the cell secretome and mouse plasma identified a large number of proteins involved in extracellular-matrix organization, cell-matrix adhesion, neutrophil degranulation, and cytokine-mediated signalling, consistent with the observed lung microenvironmental changes. Moreover, we identified EFEMP1, an extracellular matrix glycoprotein exclusively secreted by metastatic cells, in the plasma of mice bearing a primary tumour and in biopsy specimens from osteosarcoma patients with poorer overall survival. Depletion of EFEMP1 from the secretome prevents the formation of lung metastasis. Conclusions Integration of our data uncovers neutrophil infiltration and the functional contribution of stromal-activated fibroblasts in ECM remodelling for tumour cell attachment as early pro-metastatic events, which may hold therapeutic potential in preventing or slowing the metastatic spread. Moreover, we identified EFEMP1, a secreted glycoprotein, as a metastatic driver and a potential candidate prognostic biomarker for lung metastasis in osteosarcoma patients. Graphical abstract Osteosarcoma-derived secreted factors systemically reprogrammed the lung microenvironment and fostered a growth-permissive niche for incoming disseminated cells to survive and outgrow into overt metastasis. Daily administration of osteosarcoma cell secretome mimics the systemic release of tumour-secreted factors of a growing tumour in mice during PMN formation; Transcriptomic and histological analysis of premetastatic lungs revealed inflammatory-induced stromal fibroblast activation, neutrophil infiltration, and ECM remodelling as early onset pro-metastatic events; Proteome profiling identified EFEMP1, an extracellular secreted glycoprotein, as a potential predictive biomarker for lung metastasis and poor prognosis in osteosarcoma patients. Osteosarcoma patients with EFEMP1 expressing biopsies have a poorer overall survival

    Effect of dietary levels of methionine + cystine on performance of broiler breeders Efeito dos níveis dietéticos de metionina + cistina no desempenho de matrizes pesadas

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    The objective of this experiment was to evaluate levels of methionine + cystine levels for broiler breeders from 40 to 60 weeks of age. It was used 288 Cobb broiler breeders, distributed in a randomized experimental design with six levels of methionine+ cystine in the diets (0.39; 0.47; 0.55; 0.63; 0.71 and 0.79%), eight repetitions and six breeders per experimental unit. The diets were isocaloric and isoprotein (2,850 kcal ME/kg and 12.58% CP) and oferred at a fixed amount (155 g) per bird. For the entire studied period, by using polynomial analysis, it was observed a quadratic effect of methionine + cystine levels on the percentage of egg production, on number of eggs per hen housed, on number of eggs per hen and egg weight. There was also a linear effect on shell weight when it was calculated in relation to egg weight. The total methionine + cystine requirement for broiler breeders was calculated at 0.521% for percentage of egg production and number of eggs per hen, which corresponds to a daily intake of 808 mg of methionine + cystine/day. The digestible methionine + cystine requirement for broiler breeders was estimated at 727 mg for laying percentage and number of eggs per hen.<br>Com o objetivo de avaliar níveis de metionina + cistina para matrizes pesadas de 40 a 60 semanas de idade, conduziu-se um experimento com 288 matrizes da linhagem Cobb-500, distribuídas em delineamento inteiramente casualizado, com seis níveis de metionina + cistina nas dietas (0,39; 0,47; 0,55; 0,63; 0,71 e 0,79%), oito repetições e seis matrizes por unidade experimental. As rações foram isocalóricas e isoproteicas (2.850 kcal EM/kg e 12,58% PB) e fornecidas em quantidade fixa (155 g) por ave. No período total estudado, por meio de análise polinomial, foi observado efeito quadrático dos níveis de metionina + cistina sobre o percentual de produção de ovos, o número de ovos por ave alojada, o número de ovos por ave e o peso dos ovos. Houve também efeito linear sobre o peso da casca quando calculado em relação ao peso dos ovos. A exigência de metionina + cistina total para matrizes pesadas foi estimada em 0,521% para percentual de produção de ovos e número de ovos por ave, o que corresponde a uma ingestão diária de 808 mg de metionina + cistina total. A exigência de metionina + cistina digestível para matrizes pesadas é de 727 mg para percentual de postura e número de ovos por ave
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