1,434 research outputs found
Evaluation of the Structure-Activity Relationship of Hemoproteins through Physicochemical Studies: Hemoglobins as a Prototype of Biosensor
In the present work, we have studied a group of prerequisites in terms of “structure-function relationship” of hemoproteins, especially hemoglobins, emphasizing the role of the heme and its chemical environment in the biochemical and physicochemical properties of the biomolecule. We have discussed the ferrous center and its properties as coordination center; the macrocyclic ligands, especially the porphyrins; the esterochemical and electronic properties of the iron-porphyrins (heme groups); and the interaction between heme groups and globins, which is related to several redox and oligomeric properties of hemoprotein systems and its potential applications with respect to novel materials. One of the main uses of hemoglobins in new materials is also discussed, which is its employment as a biosensor. Therefore, we have discussed the development of novel biosensors based on hemoglobins and their physico-chemical properties as well as on the main molecules of biological relevance that have been detected by these biosensors, such as hydrogen peroxide (H2O2), nitric oxide (NO), and cholesterol, among others. Indeed, several important biomolecules and biological processes can be detected and/or evaluated by devices that present hemoglobins as leading chemical components. Different apparatus are covered with respect to distinct characteristics, such as chemical stability, sensitivity, selectivity, reproducibility, durability, optimum conditions of measurements, etc. and their respective characteristics are analyzed
Propolis microencapsulation by double emulsion solvent evaporation approach: Comparison of different polymeric matrices and extract to polymer ratio
Propolis, a heterogeneous matrix produced by honeybees, is an antioxidant amongst other valuable biological properties. Nevertheless, the practical application of propolis, especially for the food industry, is still limited due to its relative high hydrophilicity and strong/unpleasant taste and aroma. Accordingly, microencapsulation arises a potential alternative approach to protect propolis compounds while allowing to mask its unpleasant sensory properties. The purpose of this study was to microencapsulate propolis extracts in lipophilic polymer-carriers using alternative propolis extract to polymer ratios – 1/4, 1/2 and 3/4 – by double emulsion solvent evaporation approach. The product yield was higher than the previously reported in the literature (80.3 ± 3.7% versus 68%). The encapsulation efficiencies (considering the encapsulated antioxidants and phenolic compounds) were independent from the propolis extract to polymer ratio, for the studied lipophilic polymer-carriers. The results of this work provide promising approaches for the manufacture of propolis extracts-loaded microparticles for further incorporation in functional matrices.info:eu-repo/semantics/publishedVersio
Antibodies Against M-Type Phospholipase A2 Receptor (PLA2R) in Patients with Primary Membranous Nephropathy and Lupus Nephritis Class V: A Review
Membranous nephropathy (MN) is a very common disease of male adults with nephrotic syndrome. The disease can be primary, when the cause is not known, or secondary associated with infections, drugs, neoplasias and autoimmune systemic diseases, such as systemic lupus erythematosus (SLE). The primary form accounts for 70–80% of the cases. SLE is a common cause of secondary MN affecting young women. The differential diagnosis from primary and lupus MN by clinical and morphological findings can be difficult. The search for autoantibodies against podocyte antigen M-type phospholipase A2 receptor (PLA2R) has demonstrated high positivity in the serum and renal biopsies in the primary MN and negativity in lupus MN (WHO class V). There is a large literature on the role of anti-PLA2R antibody in the diagnosis and follow-up of patients with membranous nephropathy. The aim of this review is to summarize the literature data on the etiopathogenesis of MN and the value of anti-PLA2R antibody screening for the diagnosis and management of patients
Analise dos aspetos psicológicos na formação das Lovemarks
This paper aims to be a theoretical contribution to the understanding of underlying psychological processes of Kevin Roberts’ lovemarks concept that, in the marketing field, replaces brands, as we know it. The first section provides a brief story of branding evolution from a marketing and consumer psychology perspective. In the second section, Roberts’ lovemarks theory is explained, along with its components, the love/respect axis and mystery, sensuality and intimacy characteristics are analyzed. In addition, other branding literature authors and several successful applied cases are presented to support the theory. The third section is about the identification and analysis of the psychological aspects and processes that are relevant in lovemarks formation: perception, memory, individual and social motivation, and emotion. The fourth and last section is about the conclusions and implications in a consumer-brand relationship.El presente trabajo es una reflexión teórica que busca contribuir al entendimiento de los procesos psicológicos subyacentes en la teoría de Kevin Roberts sobre lovemarks que, dentro de la mercadotecnia, ha buscado reemplazar la idea tradicional que se tiene sobre las marcas. La primera parte proporciona una introducción sobre la evolución de las marcas desde una perspectiva psicológica y de mercadeo. La segunda parte explica la teoría de lovemarks y sus componentes: el eje amor/respeto, las características de misterio, sensualidad e intimidad. Adicionalmente, se soporta esta teoría a través de literatura complementaria y casos de éxito. La tercera parte, corresponde a la identificación y análisis de los procesos psicológicos que explican la formación de un lovemark: percepción, memoria, motivación individual y social y emoción. La cuarta y última parte contiene las conclusiones e implicaciones en la formación de la relación marca-consumidor.O presente trabalho é uma reflexão teórica que procura contribuir ao entendimento dos processos psicológicos subjacentes na teoria de Kevin Roberts acerca das lovemarks que, ao interior da mercadologia, tem procurado substituir a ideia tradicional que se tem ao respeito das marcas. A primeira parte proporciona uma introdução ao respeito da evolução das marcas desde uma perspectiva psicológica e de mercado. A segunda parte exprime a teoria das lovemarks e os seus componentes: o eixo amor/respeito, as características de mistério, sensualidade e intimidade. Adicionalmente, esta teoria é suportada pela literatura complementaria e casos de sucesso. A terceira parte corresponde à identificação e analise dos processos psicológicos que exprimem a formação de uma lovemark: percepção, memoria, motivação individual e social e emoção. A quarta e última parte contem as conclusões e as implicações na formação da relação marca-consumidor
Impacts of climate change on the biogeography of three amnesic shellfish toxin producing diatom species
Harmful algal blooms (HABs) are considered one of the main risks for marine ecosystems and human health worldwide. Climate change is projected to induce significant changes in species geographic distribution, and, in this sense, it is paramount to accurately predict how it will affect toxin-producing microalgae. In this context, the present study was intended to project the potential biogeographical changes in habitat suitability and occurrence distribution of three key amnesic shellfish toxin (AST)-producing diatom species (i.e., Pseudo-nitzschia australis, P. seriata, and P. fraudulenta) under four different climate change scenarios (i.e., RCP-2.6, 4.5, 6.0, and 8.5) up to 2050 and 2100. For this purpose, we applied species distribution models (SDMs) using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry) in a MaxEnt framework. Overall, considerable contraction and potential extirpation were projected for all species at lower latitudes together with projected poleward expansions into higher latitudes, mainly in the northern hemisphere. The present study aims to contribute to the knowledge on the impacts of climate change on the biogeography of toxin-producing miinfo:eu-repo/semantics/publishedVersio
Btk Mutations Selectively Regulate Btk Expression And Upregulate Monocyte Xbp1 Mrna In Xla Patients.
Mutations in the Bruton agammaglobulinemia tyrosine kinase (BTK) gene are responsible for X-linked agammaglobulinemia (XLA). Unfolded or misfolded proteins can trigger stress pathways in the endoplasmic reticulum (ER), known as unfolded protein response (UPR). The aim was to clarify the involvement of UPR in XLA pathophysiology. By reverse transcription-quantitative PCR, we evaluated the expression of BTK and 12 UPR-related genes in eight patients. Moreover, we assessed the BTK protein expression and pattern in the patients' monocytes by flow cytometry and fluorescence immunocytochemistry. We found a reduced BTK expression in patients with stop codon mutations (P < 0.02). However, missense mutations did not affect BTK expression. Flow cytometry showed a reduction of BTK in patients which was corroborated by an absent or nonfunctional protein synthesis revealed by immunocytochemistry. In contrast with the other UPR-related genes, X-box binding protein 1 (XBP1) was markedly upregulated in the patients (P < 0.01), suggesting Toll-like receptor (TLR) activation since BTK directly interacts with TLRs as a negative regulator and XBP1 can be activated in direct response to TLR ligation. Different BTK mutations can be identified by the BTK expression. Inasmuch as UPR-related genes were downregulated or unaltered in patients, we speculate the involvement of the TLRs-XBP1 axis in the XLA pathophysiology. Such data could be the basis for further studies of this novel pathomechanism concerning XLA.3171-18
An Overview of the Circular Economy among SMEs in the Basque Country: A Multiple Case Study.
Purpose: This research analyzes the maturity of environmental management as well as the degreeof to which the Circular Economy has been implemented in Basque SMEs.Design/methodology/approach:A total of 17 case studies were carried out in industrialSMEs companies in the Basque Country.Findings:The main results show that companies are limited to complying with the law and inmany cases are worried about the image of the company, although they are not committed toenvironmental issues. There is still a lot to do in SMEs, as they are the companies that face thebiggest challenges due to a lack of resources.Originality/value: Circular Economy aims to change a linear economy into promotingsustainability of the economy while also engaging in sustainable environmental protection. Thisresearch has focused on small and medium enterprises as they represent a 99% of companies inEurope and they are the ones that have the most difficulty reaching a stage of environmentalexcellence due to their limited resources
Evaluation of FT-Raman and FTIR-ATR spectroscopy for the quality evaluation of Lavandula spp. Honey
Monofloral Lavandula spp. honey is very appreciated by consumers due to its characteristic and pleasant aroma and flavor. Given the economic importance of this type of honey, it is important to develop a rapid and non-expensive methodology that allows certifying its quality. In this context, this study aimed to compare the applicability and accuracy of FTIR-ATR and FT-Raman techniques for the quality evaluation of Lavandula spp. honey. Calibration models, with PLS regression models, were obtained for both methodologies concerning the following parameters: total acidity, reducing sugars, hidroximetilfurfural (HMF), electrical conductivity, ash, proline content, diastase activity, apparent sucrose, total flavonoids, and total phenolic contents. The calibration models had high regression coefficients, r2 (FTIR-ATR: 0.965–0.996; FT-Raman: 0.983–0.999), high ratios of performance to deviation, RPD (FTIR-ATR: 5.4–15.7; FT-Raman: 7.6–53.7), and low root mean square errors (RMSEs; FTIR-ATR: 0.005–3.0; FT-Raman: 0.004–1.02). These results corroborate the potentiality of FTIR-ATR and FT-Raman for quality evaluation and evaluation of the chemical properties of Lavandula spp. honey even though FT-Raman technique provided more accurate models.Centro de Estudos Florestais is a
research unit funded by FCT (UIDB/00239/2020). Financial
support is acknowledged to CIMO Research Centre, a
research unit funded by FCT (project Ref.a UIDB/00690/2020) and supported by Polytechnic Institute of Bragança.
Financial support for publication is acknowledged to
CERNAS Research Centre, a research unit funded by FCT
(project Ref.a UIDB/00681/2020) and supported by
Polytechnic Institute of Viseu. The Open Access Article
Processing Charges was funded by CERNAS Project (project
Ref.a UIDB/00681/2020). This research was funded by the Forest
Research Centre, a research unit funded by Fundação
para a Ciência e a Tecnologia I. P. (FCT), Portugal (UIDB/
00239/2020), and CIMO Research Centre, a research unit
funded by FCT (FCT), Portugal (UIDB/00690/2020) and supported
by Polytechnic Institute of Bragança.info:eu-repo/semantics/publishedVersio
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