26 research outputs found
Perfis proteicos e desempenho fisiológico de sementes de café submetidas a diferentes métodos de processamento e secagem.
O objetivo deste trabalho foi avaliar os perfis proteicos e o desempenho fisiolĂłgico de sementes de cafĂ© submetidas a diferentes mĂ©todos de processamento e secagem. Foram avaliados os processamentos por via seca e Ășmida, e as secagens natural, em terreiro, e artificial a 60ÂșC, ou a 60ÂșC atĂ© 30% de umidade e 40ÂșC atĂ© teor final de 11% (base Ășmida). ApĂłs serem processadas e secadas, as sementes foram avaliadas quanto ao desempenho fisiolĂłgico e submetidas a anĂĄlises bioquĂmicas, por meio da eletroforese de proteĂnas resistentes ao calor LEA (?late embryogenesis abundant?) e das enzimas superĂłxido dismutase, catalase, peroxidase, esterase, polifenoloxidase, isocitrato desidrogenase, ĂĄlcool desidrogenase e malato desidrogenase. O perfil proteico de sementes de cafĂ© Ă© afetado pelo mĂ©todo de processamento e de secagem. Os cafĂ©s processados por via Ășmida apresentam maior tolerĂąncia Ă secagem ? revelada pela maior atividade de enzimas antioxidativas e pelo melhor desempenho fisiolĂłgico ? do que os processados por via seca. A atividade de proteĂnas resistentes ao calor e de enzimas antioxidantes Ă© variĂĄvel promissora para diferenciar a qualidade dos cafĂ©s submetidos a diferentes manejos pĂłs‑colheita
Y Engineering a 3D in vitro model of human skeletal muscle at the single fiber scale
The reproduction of reliable in vitro models of human skeletal muscle is made harder by the intrinsic 3D structural complexity of this tissue. Here we coupled engineered hydrogel with 3D structural cues and specific mechanical properties to derive human 3D muscle constructs (âmyobundlesâ) at the scale of single fibers, by using primary myoblasts or myoblasts derived from embryonic stem cells. To this aim, cell culture was performed in confined, laminin-coated micrometric channels obtained inside a 3D hydrogel characterized by the optimal stiffness for skeletal muscle myogenesis. Primary myoblasts cultured in our 3D culture system were able to undergo myotube differentiation and maturation, as demonstrated by the proper expression and localization of key components of the sarcomere and sarcolemma. Such approach allowed the generation of human myobundles of ~10 mm in length and ~120 ÎŒm in diameter, showing spontaneous contraction 7 days after cell seeding. Transcriptome analyses showed higher similarity between 3D myobundles and skeletal signature, compared to that found between 2D myotubes and skeletal muscle, mainly resulting from expression in 3D myobundles of categories of genes involved in skeletal muscle maturation, including extracellular matrix organization. Moreover, imaging analyses confirmed that structured 3D culture system was conducive to differentiation/maturation also when using myoblasts derived from embryonic stem cells. In conclusion, our structured 3D model is a promising tool for modelling human skeletal muscle in healthy and diseases conditions
Intravital three-dimensional bioprinting
Fabrication of three-dimensional (3D) structures and functional tissues directly in live animals would enable minimally invasive surgical techniques for organ repair or reconstruction. Here, we show that 3D cell-laden photosensitive polymer hydrogels can be bioprinted across and within tissues of live mice, using bio-orthogonal two-photon cycloaddition and crosslinking of the polymers at wavelengths longer than 850 nm. Such intravital 3D bioprinting\u2014which does not create by-products and takes advantage of commonly available multiphoton microscopes for the accurate positioning and orientation of the bioprinted structures into specific anatomical sites\u2014enables the fabrication of complex structures inside tissues of live mice, including the dermis, skeletal muscle and brain. We also show that intravital 3D bioprinting of donor-muscle-derived stem cells under the epimysium of hindlimb muscle in mice leads to the de novo formation of myofibres in the mice. Intravital 3D bioprinting could serve as an in vivo alternative to conventional bioprinting
Intravital three-dimensional bioprinting
Fabrication of three-dimensional (3D) structures and functional tissues directly in live animals would enable minimally invasive surgical techniques for organ repair or reconstruction. Here, we show that 3D cell-laden photosensitive polymer hydrogels can be bioprinted across and within tissues of live mice, using bio-orthogonal two-photon cycloaddition and crosslinking of the polymers at wavelengths longer than 850ânm. Such intravital 3D bioprintingâwhich does not create by-products and takes advantage of commonly available multiphoton microscopes for the accurate positioning and orientation of the bioprinted structures into specific anatomical sitesâenables the fabrication of complex structures inside tissues of live mice, including the dermis, skeletal muscle and brain. We also show that intravital 3D bioprinting of donor-muscle-derived stem cells under the epimysium of hindlimb muscle in mice leads to the de novo formation of myofibres in the mice. Intravital 3D bioprinting could serve as an in vivo alternative to conventional bioprinting
Post-harvest effects on beverage quality and physiological performance of coffee beans.
During coffee drying, different temperatures applied to the beans with varied humidity content levels can interfere in the membranes integrity, germination, organic acid and carbohydrate content resulting in coffees with distinct flavors. The quality control of the beans will be much more effective the earlier the alterations provoked in the postharvest are detected. This work has an objective to study alternative methods for the dehydration o f the coffee beans using ultra-drying followed by slow drying and its impact on the sensorial quality, chemical composition and physiology. For that purpose, coffee lots were processed by the methods, dry (natural coffee) and wet (fully washed coffee); and sun-dried and machine-dried at a constant 60°C temperature and alternating 60/40°C. The sensory quality of the samples was assessed by the Specialty Coffee Association of America (SCAA) analysis protocol. The sugar, total titratable acidity and the phenolic compound content was also analyzed. The physiological alterations of the coffee beans were analyzed by germination tests, emergence speed index, electrical conductivity and potassium leaching. The temperature of the drying air significantly altered the sensorial quality of the coffee beans. The processing way associated to drying methods causes many physiological alterations with the highest damage observed in the natural coffees. For the first time, we are showing that drying with heated air at 60/40ÂșC is promising for the fully washed coffee beans, which are more tolerant to dehydration than the natural coffee beans. Conversely, the natural coffee beans were much more sensitive to drying regardless the temperature, with very low performance in the physiological analyses. The drying at the constant 60ÂșC temperature is inappropriate for the natural coffee as well as for the fully washed coffee beans. In addition, the physiological tests used were shown effective for the early evaluation of coffee beans quality
A Combined Electrochemical-Microfluidic Strategy for the Microscale-Sized Selective Modification of Transparent Conductive Oxides
Surface chemical functionalization of transparent conductive oxides (TCOs) is helpful for a wide range of technological applications, ranging from solar cells to biomedical devices, as it allows to tune the electrical, optical, and morphological properties of TCOs toward the desired goal. The electrochemical grafting technique is a surface modification methodology affording robust coatings with tuneable properties and has the potential to be exploited for modifying TCO surfaces. However, due to technical limitations, like the use of a 3-electrode cell and the need for low pH-solutions, this approach has not been recurrently applied. Here a novel electrochemical-microfluidic combined methodology is used where the use of a microchannel drives the spatially controlled covalent grafting of reagents on a TCO surface. To corroborate the validity of this approach in producing more complex chemical structures localized on selected microscale-sized areas, where a first electrochemical grafting step takes place, an electrochemical glucose biosensor is realized through a layer-by-layer approach that shows a remarkable limit of detection in the micromolar concentration range. The sensing mechanism is based on an efficient electron transfer from glucose to the functionalized TCO surface. Biosensor performance is conveniently tuned by acting on the number of enzymatic units loaded onto the biosensor-tree
Surface Functionalization of Fluorine-Doped Tin Oxide Samples through Electrochemical Grafting
Transparent
conductive oxides are emerging materials in several
fields, such as photovoltaics, photoelectrochemistry, and optical
biosensing. Their high chemical inertia, which ensured long-term stability
on one side, makes challenging the surface modification of transparent
conductive oxides; long-term robust modification, high yields, and
selective surface modifications are essential prerequisite for any
further developments. In this work, we aim at inducing chemical functionality
on fluorine-doped tin oxide surfaces (one of the most inexpensive
transparent conductive oxide) by means of electrochemical grafting
of aryl diazonium cations. The grafted layers are fully characterized
by photoemission spectroscopy, cyclic voltammetry, and atomic force
microscopy showing linear correlation between surface coverage and
degree of modification. The electrochemical barrier effect of modified
surfaces was studied at different pH to characterize the chemical
nature of the coating. We showed immuno recognition of biotin complex
built onto grafted fluorine-doped tin oxides, which opens the perspective
of integrating FTO samples with biological-based devices