Materials used for wound care have evolved from simple covers to functional wound dressings with bioactive properties. Electrospun nanofibers show great similarity to the natural fibrillar structure ...of skin extracellular matrix (ECM); therefore, by mimic, the morphology of ECM, nanofibers show high potential for facilitating the healing of skin injuries. Besides morphology, scaffold composition is another important parameter in the production of bioactive wound dressings. Collagen type I is the main structural protein of skin ECM is biocompatible, biodegradable, and its extraction from animal sources is relatively simple. The fabrication of electrospun wound dressings based on collagen and its blends have been studied for skin tissue engineering applications. This review focus on the new advances of collagen electrospun materials for skin wound treatment. It summarizes the recent research on pristine collagen, collagen blends, and collagen surface modifications on nanofibers mats. Finally, the strategies for three‐dimensional nanofibers production will also be discussed.
Homem, 52 anos, portador de neoplasia prostática (Gleason 3 +3) deu entrada no pronto-socorro com quadro de lesão renal aguda, anemia normocrômica e normocítica e relato de fratura patológica. ...Encaminhado para o Hospital Geral, foi iniciado investigação do quadro. Alguns achados em exames laboratoriais como inversão da relação albumina-globulina e lesões líticas em exame de imagem fizeram os médicos a levantarem um importante diagnóstico diferencial, no contexto de metástase ósseas e neoplasias: o mieloma múltiplo. Diante disso, foi indicado aspirado de medula óssea e imunofetipagem que surpreendentemente teve como resultado principal a presença de 12% de células plasmócitarias com caraterísticas anômalas e clonalidade intracelular para cadeia leve Kappa. Fechado diagnóstico de mieloma, o tratamento inicial foi estabelecido com dexametasona, ciclofosfamida e pamidronato com melhora progressiva dos parâmetros laboratoriais e clínicos sendo encaminhado para acompanhamento ambulatorial em cidade de origem com onco-hematologista e urologista. A neoplasia prostática é uma entidade na qual o osso é um dos principais sítios de metástase assim como o mieloma pode atingir diretamente essa estrutura. Ambas são comuns ao sexo masculino e em pacientes de idade mais avançada, sempre devendo ser levantadas como hipótese diagnóstica em pacientes com anemia, fratura patológica e idade maior que 50 anos. O Mieloma múltiplo (MM) tem na sua fisiopatologia a proliferação clonal de plasmócitos na medula óssea, resultando em produção de imunoglobulinas monoclonais e disfunção orgânica, afetando principalmente esses três tecidos: osso/cartilagem, rim e hematopoiese. Como consequência se têm a hipercalcemia, pancitopenia e a nefropatia por cadeias leves, típica da doença. A presença de dados sugestivos favoreceu, portanto, essa alternativa diagnóstica. A biópsia da médula, nesse contexto, foi fundamental para selar o diagnóstico de MM pois a presença de pelo menos 10% de plasmócitos no anatomopatológico associado as alterações clínicas do paciente confirmaram a hipótese. É uma realidade da prática que o quadro de dor óssea e fratura patológica associada a neoplasia de próstata traz como principal hipótese a metástase óssea. No entanto, devido a semelhantes aspectos clínicos, laboratoriais e de imagem, e a possibilidade de sincronismo com o mieloma, acrescentam desafios para ao diagnóstico. Com o envelhecimento populacional, o tema tornar-se, portanto, relevante para a prática clínica. Mesmo limitado a apenas um relato de caso, o presente estudo pode elevar o índice de suspeita clínica principalmente no sexo masculino, de associação comum, cujo diagnóstico precoce é fundamental para um bom prognóstico.
This study represents an exploratory characterization and comparison of electron-beam melted (EBM) or rapid manufacturing (RM) of Ti–6Al–4V components (from nominal 30 μm diameter powder) with ...wrought products. Acicular α and associated β microstructures observed by optical metallography and electron microscopy (SEM and TEM) are compared along with corresponding tensile test and hardness data; including the initial powder particles where the Vickers microindentation hardness averaged 5.0 GPa in comparison with the fully dense, EB manufactured product with an average microindentation hardness ranging from 3.6 to 3.9 GPa. This compared with wrought products where the Vickers microindentation hardness averaged 4.0 GPa. Values of UTS for the EBM samples averaged 1.18 GPa for elongations ranging from 16 to 25%. Biomaterials/biomedical applications of EBM prototypes in direct prosthesis or implant manufacturing from CT or MRI data are discussed in the context of this work, especially prospects for tailoring physical properties through EB control to achieve customized and optimized implant and prosthetic products direct from CT-scans.
Water Catalysis of a Radical-Molecule Gas-Phase Reaction Vöhringer-Martinez, E; Hansmann, B; Hernandez, H ...
Science (American Association for the Advancement of Science),
01/2007, Letnik:
315, Številka:
5811
Journal Article
Recenzirano
There has been considerable speculation about the role of water and water complexes in chemical gas-phase reactions, including the conjecture that water may act as a molecular catalyst through its ...ability to form hydrogen bonds. Here, we present kinetic studies in which the effect of water on the rate of the reaction between hydroxyl radicals and acetaldehyde has been measured directly in Laval nozzle expansions at low temperatures. An increasing enhancement of the reaction rate by added water was found with decreasing temperatures between 300 and 60 kelvin. Quantum chemical calculations and statistical rate theory support our conclusions that this observation is due to the reduction of an intrinsic reaction barrier caused by specific water aggregation. The results suggest that even single water molecules can act as catalysts in radical-molecule reactions.
The relationship between brain diffusion microstructural changes and disability in multiple sclerosis (MS) remains poorly understood. We aimed to explore the predictive value of microstructural ...properties in white (WM) and grey matter (GM), and identify areas associated with mid-term disability in MS patients. We studied 185 patients (71% female; 86% RRMS) with the Expanded Disability Status Scale (EDSS), timed 25-foot walk (T25FW), nine-hole peg test (9HPT), and Symbol Digit Modalities Test (SDMT) at two time-points. We used Lasso regression to analyse the predictive value of baseline WM fractional anisotropy and GM mean diffusivity, and to identify areas related to each outcome at 4.1 years follow-up. Motor performance was associated with WM (T25FW: RMSE = 0.524, R
= 0.304; 9HPT dominant hand: RMSE = 0.662, R
= 0.062; 9HPT non-dominant hand: RMSE = 0.649, R
= 0.139), and SDMT with GM diffusion metrics (RMSE = 0.772, R
= 0.186). Cingulum, longitudinal fasciculus, optic radiation, forceps minor and frontal aslant were the WM tracts most closely linked to motor dysfunction, and temporal and frontal cortex were relevant for cognition. Regional specificity related to clinical outcomes provide valuable information that can be used to develop more accurate predictive models that could improve therapeutic strategies.
Fat waste discarded from butcheries was used as a cosubstrate in the anaerobic codigestion of sewage sludge (SS). The process was evaluated under mesophilic and thermophilic conditions. The ...codigestion was successfully attained despite some inhibitory stages initially present that had their origin in the accumulation of volatile fatty acids (VFA) and adsorption of long-chain fatty acids (LCFA). The addition of a fat waste improved digestion stability and increased biogas yields thanks to the higher organic loading rate (OLR) applied to the reactors. However, thermophilic digestion was characterized by an effluent of poor quality and high VFA content. Results from spectroscopic analysis suggested the adsorption of lipid components onto the anaerobic biomass, thus disturbing the complete degradation of substrate during the treatment. The formation of fatty aggregates in the thermophilic reactor prevented process failure by avoiding the exposure of biomass to the toxic effect of high LCFA concentrations.
Chronic illnesses like obesity, type 2 diabetes (T2D) and cardiovascular diseases, are worldwide major causes of morbidity and mortality. These pathological conditions involve interactions between ...environmental, genetic, and epigenetic factors. Recent advances in nutriepigenomics are contributing to clarify the role of some nutritional factors, including dietary fatty acids in gene expression regulation. This systematic review assesses currently available information concerning the role of the different fatty acids on epigenetic mechanisms that affect the development of chronic diseases or induce protective effects on metabolic alterations.
A targeted search was conducted in the PubMed/Medline databases using the keywords "fatty acids and epigenetic". The data were analyzed according to the PRISMA-P guidelines.
Consumption fatty acids like n-3 PUFA: EPA and DHA, and MUFA: oleic and palmitoleic acid was associated with an improvement of metabolic alterations. On the other hand, fatty acids that have been associated with the presence or development of obesity, T2D, pro-inflammatory profile, atherosclerosis and IR were n-6 PUFA, saturated fatty acids (stearic and palmitic), and trans fatty acids (elaidic), have been also linked with epigenetic changes.
Fatty acids can regulate gene expression by modifying epigenetic mechanisms and consequently result in positive or negative impacts on metabolic outcomes.
ABSTRACT
Dark matter annihilation signals coming from Galactic subhaloes may account for a small fraction of unassociated point sources detected in the second Fermi‐LAT Catalogue (2FGL). To ...investigate this possibility, we present sibyl, a Random Forest classifier that offers predictions on class memberships for unassociated Fermi‐LAT sources at high Galactic latitudes using gamma‐ray features extracted from the 2FGL. sibyl generates a large ensemble of classification trees that are trained to vote on whether a particular object is an active galactic nucleus (AGN) or a pulsar. After training on a list of 908 identified/associated 2FGL sources, sibyl reaches individual accuracy rates of up to 97.7 per cent for AGNs and 96.5 per cent for pulsars. Predictions for the 269 unassociated 2FGL sources at |b|≥ 10° suggest that 216 are potential AGNs and 16 are potential pulsars (with majority votes greater than 70 per cent). The remaining 37 objects are inconclusive, but none is an extreme outlier. These results could guide future quests for dark matter Galactic subhaloes.
The microstructure and mechanical behavior of simple product geometries produced by layered manufacturing using the electron beam melting (EBM) process and the selective laser melting (SLM) process ...are compared with those characteristic of conventional wrought and cast products of Ti–6Al–4V. Microstructures are characterized utilizing optical metallography (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and included
α
(hcp),
β
(bcc) and
α
′
(hcp) martensite phase regimes which give rise to hardness variations ranging from HRC 37 to 57 and tensile strengths ranging from 0.9 to 1.45 GPa. The advantages and disadvantages of layered manufacturing utilizing initial powders in custom building of biomedical components by EBM and SLM in contrast to conventional manufacturing from Ti–6Al–4V wrought bar stock are discussed.
Periodontitis is a chronic multifactorial inflammatory disease linked to oral microbiota dysbiosis. This disease progresses to infection that stimulates a host immune/inflammatory response, with ...progressive destruction of the tooth-supporting structures.
This systematic review aims to present a robust critical evaluation of the evidence of salivary protein profiles for identifying oral diseases using proteomic approaches and summarize the use of these approaches to diagnose chronic periodontitis.
A systematic literature search was conducted from January 1st, 2010, to December 1st, 2022, based on PICO criteria following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and by searching the three databases Science Direct, Scopus, and Springer Link.
According to the inclusion criteria, eight studies were identified to analyze the proteins identified by proteomics.
The protein family S100 was identified as the most abundant in patients with chronic periodontitis. In this family, an increased abundance of S100A8 and S100A9 from individuals with the active disease was observed, which strongly relates to the inflammatory response. Moreover, the ratio S100A8/S100A9 and the metalloproteinase-8 in saliva could differentiate distinct periodontitis groups. The changes in protein profile after non-surgical periodontal therapy improved the health of the buccal area. The results of this systematic review identified a set of proteins that could be used as a complementary tool for periodontitis diagnosis using salivary proteins.
Biomarkers in saliva can be used to monitor an early stage of periodontitis and the progression of the disease following therapy.
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