•Pure aluminum was reinforced with graphene-platelets by using mechanical milling.•The composites were studied after sintering condition.•Milling time and graphene-platelet enhance the mechanical ...behavior of the composites.
Graphene can be considered as an ideal reinforcement for the production of composites due to its outstanding mechanical properties. These characteristics offer an increased opportunity for their study in the production of metal matrix composites (MMCs). In this research, the studied composites were produced by mechanical alloying (MA). The employed milling times were of 1, 3 and 5h. GNPs were added in 0.25, 0.50 and 1.0wt% into an aluminum powder matrix. Milled powders were cold consolidated and subsequently sintered. Composites were microstructurally characterized with Raman spectroscopy and electron microscopy and X-ray diffraction. The hardness behavior in composites was evaluated with a Vickers micro-hardness test. A homogeneous dispersion of graphene during MA and the proper selection of sintering conditions were considered to produce optimized composites. The obtained results with electron microscopy indicate a homogeneous dispersion of GNPs into the aluminum matrix. Analyses showed GNPs edges where the structure of the graphene layers conserved after MA is observed.
Deep second and third degree burns treatment requires fibroblasts, keratinocytes and other skin cells in order to grow new dermis and epidermis. Cells can proliferate, secrete growth factors and ...extracellular matrix required to repair the damaged tissue. Radiosterilized human amnion and radiosterilized pig skin have been used as natural origin skin dressings for burned patients. Adipose-derived mesenchymal stem cells can differentiate into fibroblasts and keratinocytes and improve wound-healing progress. These cells can stimulate vascular tissue formation, release growth factors, synthetize new extracellular matrix and immunoregulate other cells. In this study, we developed mesenchymal stem cells-cellularized skin substitutes based from radiosterilized human amnion or pig skin. Third-degree burns were induced in mice animal models to evaluate the effect of cellularized skin substitutes on burn wound healing. Mesenchymal phenotype was immunophenotypically confirmed by flow cytometry and cell viability was close to 100%. Skin recovery was evaluated in burned mice after seven and fourteen days post-coverage with cellularized and non-cellularized sustitutes. Histological techniques and immunofluorescence were used to evaluate re-epithelization and type I collagen deposition. We determined that cellularized-human amnion or cellularized-pig skin in combination with mesenchymal stem cells improve extracellular matrix deposition. Both cellularized constructs increase detection of type I collagen in newly formed mouse skin and can be potentially used as skin coverage for further clinical treatment of burned patients.
According to WHO statistics, breast cancer (BC) disease represents about 2.3 million diagnosed and 685,000 deaths globally. Regarding histological classification of BC, the Estrogen (ER) and ...Progesterone (PR) receptors negative-expression cancer, named Triple-Negative BC (TNBC), represents the most aggressive type of this disease, making it a challenge for drug discovery. In this context, our research group, applying a well-established Virtual Screening (VS) protocol, in addition to docking and molecular dynamics simulations studies, yielded two ligands identified as 6 and 37 which were chemically synthesized and evaluated on MCF-7 and MDA-MB-231 cancer cell lines. Strikingly, 37 assayed on MDA-MB-231 (a TNBC cell model) depicted an outstanding value of 18.66 μM much lower than 65.67 μM yielded by Gossypol Bcl-2 inhibitor whose main disadvantage is to produce multiple toxic effects. Highlighted above, enforce the premise of the computational tools to find new therapeutic options against the most aggressive forms of breast cancer, as the results herein showed.
Advances in cryo-electron microscopy (cryo-EM) have made it possible to obtain structures of large biological macromolecules at near-atomic resolution. This “resolution revolution” has encouraged the ...use and development of modeling tools able to produce high-quality atomic models from cryo-EM density maps. Unfortunately, many practical problems appear when combining different packages in the same processing workflow, which make difficult the use of these tools by non-experts and, therefore, reduce their utility. We present here a major extension of the image processing framework Scipion that provides inter-package integration in the model building area and full tracking of the complete workflow, from image processing to structure validation.
In this paper, we refine the colonisation timeframe of pine marten (Martes martes) and Algerian hedgehog (Atelerix algirus) to the Balearic Islands synthesising their occurrence records and providing ...an accurate chronology through new directly 14C dated archaeological bone samples. The new dates are significantly earlier than previously reported finds; therefore, both cases currently represent the earliest records for the human‐mediated translocation of these species in Europe. These new data not only provide further accurate resolution for previous historical translocation hypothesis but also expand the geographical scope throughout the archipelago. The sequence and timing of introduction events are embedded in different historical timeframes. The time of arrival of the pine marten is now established in the early Roman period, a period that supported a huge wave of introduced alien species into the Balearics. For the Algerian hedgehog, the new records further support the hypothesis that the Almohads were responsible for its introduction to these islands. Both examples illustrate how important it is to connect past translocation records to tighter radiometric chronologies through direct dating on bones of the implicated species.
A refined colonisation timeframe of pine marten (Martes martes) and Algerian hedgehog (Atelerix algirus) to the Balearic Islands is provided through new directly carbon‐dated archaeological bone samples. The new dates represent the earliest records for human‐mediated translocation of these species in Europe. The sequence and timing of introduction events are embedded in different historical timeframes: The pine marten was established in the early Roman period, and the Algerian hedgehog was introduced in medieval times as a consequence of the Almohad conquest of the islands.
This paper aims to bridge the gap between neurophysiology and automatic control methodologies by redefining the Wilson-Cowan (WC) model as a control-oriented linear parameter-varying (LPV) system. A ...novel approach is presented that allows for the application of a control strategy to modulate and track neural activity.
The WC model is redefined as a control-oriented LPV system in this study. The LPV modelling framework is leveraged to design an LPV controller, which is used to regulate and manipulate neural dynamics.
Promising outcomes, in understanding and controlling neural processes through the synergistic combination of control-oriented modelling and estimation, are obtained in this study. An LPV controller demonstrates to be effective in regulating neural activity.
The presented methodology effectively induces neural patterns, taking into account optogenetic actuation. The combination of control strategies with neurophysiology provides valuable insights into neural dynamics. The proposed approach opens up new possibilities for using control techniques to study and influence brain functions, which can have key implications in neuroscience and medicine. By means of a model-based controller which accounts for non-linearities, noise and uncertainty, neural signals can be induced on brain structures.
CsPbI3 perovskite nanocrystals (NCs) are promising building blocks for photovoltaics and optoelectronics. However, they exhibit an essential drawback in the form of phase stability: α-phase, with a ...∼1.80 eV bandgap, can easily experience a phase transition to a non-radiative orthorhombic δ-phase in an ambient environment. This leads to the need to carry out the CsPbI3-based device fabrication in an inert atmosphere, which is technologically inconvenient and expensive. One of the most successful approaches proposed to overcome this problem is synthesizing mixed halide CsPbBr3−xIx NCs to improve the stability of the α-phase perovskite structure. However, the formation of high-quality thin films of CsPbBr3−xIx NCs with high PLQY is challenging owing to the degradation of their optical properties after deposition on a substrate. This work presents spray coating to carry out a solid-state anion exchange in CsPbBr3 NCs thin films at ambient conditions with low-demanding reaction conditions. This constitutes a novel open-air and annealing-free technology to manufacture CsPbBr3−xIx NC thin films with high optical quality and record high photoluminescence quantum yields (PLQY) based on spray-driven halide (Br− to I−) anion exchange in a solid-state phase. Besides, tunable emission wavelengths between 520 and 670 nm can be obtained from CsPbBr3−xIx NC films using accurate tuning volumes of HI solution sprayed over the initial surface of CsPbBr3 film to provide the halide exchange. The optical quality of the halide-exchanged PNCs films remains practically identical to that of initial Br-containing layers, with a remarkable PLQY enhancement after anion exchange, from ∼61% for CsPbBr3 thin films emitting at 520 nm to ∼84% for mixed halide CsPbBr3−xIx film emitting at 640 nm. The huge potential of the system is confirmed by demonstrating a low-threshold amplified spontaneous emission.
Background: Axial spondyloarthritis (axSpA) affects spinal muscles, due to inflammation and structural damage. The mechanical properties of the muscles, such as tone or stiffness, could be altered in ...axSpA. The aim of this work is to analyze the mechanical properties of cervical and lumbar spine muscles in axSpA patients and their relationship with metrology measures, function, disease activity, structural damage and quality of life. Methods: axSpA patients and age/gender/BMI matched healthy controls were recruited. The muscle mechanical properties (MMPs), such as tone or frequency, stiffness, decrement (linear elastic properties), relaxation and creep (viscoelastic properties), of cervical (semispinalis capitis) and lumbar (erector spinae) muscles were bilaterally measured at rest using myotonometry. Additionally, conventional metrology, BASMI (metrology index), BASDAI (disease activity index), mSASSS (radiological structural damage index) and SF-12 (health-related quality of life questionnaire) were used in the axSpA group. Between-groups comparison, intra-group correlations and multivariable regression analyses were performed to achieve the study aims. Results: Thirty-four axSpA patients (mean age: 46.21 ± 8.53 y) and 34 healthy volunteers (mean age: 43.97 ± 8.49 y) were recruited. Both in cervical and lumbar spine, linear elastic parameters were significantly higher in axSpA patients in comparison with controls, while viscoelastic parameters were significantly lower. Lumbar muscle frequency, stiffness, relaxation, creep and cervical muscle elasticity were fair to strongly correlated (|0.346| < r < |0.774|) with age, functional status, activity of disease, structural damage and quality of life in axSpA patients. Furthermore, moderate to good fitted multivariate models (0.328 < R2 < 0.697) were obtained combining age, conventional metrology, activity of the disease and function for the estimation of cervical and lumbar MMPs. Conclusion: Mechanical properties of spinal muscles of axSpA patients differ from controls. Lumbar and cervical muscles exhibit greater linear elastic properties and lower viscoelastic properties, which are related with age, clinical and psychophysiological features of axSpA.
The combined effect of the cooling rate and microalloying has been studied from suction casted Cu50Zr50, Cu49.5Zr50Fe0.5 and Cu49Zr50Fe1 at. % rods of 2 mm and 4 mm diameter. For the 2 mm samples, ...∼1000 K/s cooling rate, the microstructure mostly consists of B2 CuZr austenite and it is basically the same for all compositions. However, 0.5 at. % Fe addition promotes the formation of stress-induced B19’ martensite upon wear testing thus improving the wear resistance of the alloy. For the 4 mm samples, ∼250 K/s cooling rate, a multiphase intermetallic is predominant and when microalloyed with 0.5 at. % Fe, a relatively large volume fraction of as-cast B33 CuZr martensite is formed thus resulting in a reduction of the wear resistance. At high cooling rate the wear mechanism is predominantly delamination wear while for low cooling rate the large continuous grooves are indicative of abrasive wear.
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•At high cooling rate (2 mm) the wear mechanism is predominantly delamination wear.•For low cooling rate the large continuous grooves are indicative of abrasive wear.•Microalloying with 0.5 at. % Fe is only useful for wear enhancement of 2 mm samples.•Wear resistance is enhanced through stress-induced martensitic transformation.•For 4 mm samples, large volume fraction of intermetallic phases are formed.
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