Development and characterisation of microporous biomimetic scaffolds loaded with magnetic nanoparticles as bone repairing material

Fine-tuning of the scaffolds structural features for bone tissue engineering can be an efficient approach to regulate the specific response of the osteoblasts. Here, we loaded magnetic nanoparticles aka superparamagnetic iron oxide nanoparticles (SPIONs) into 3D composite scaffolds based on biological macromolecules (chitosan, collagen, hyaluronic acid) and calcium phosphates for potential applications in bone regeneration, using a biomimetic approach. We assessed the effects of organic (chitosan/collagen/hyaluronic acid) and inorganic (calcium phosphates, SPIONs) phase over the final features of the magnetic scaffolds (MS). Mechanical properties, magnetic susceptibility and biological fluids retention are strongly dependent on the final composition of MS and within the recommended range for application in bone regeneration. The MS architecture/pore size can be made bespoken through changes of the final organic/inorganic ratio. The scaffolds undertake mild degradation as the presence of inorganic components hinders the enzyme catalytic activity. In vitro studies indicated that osteoblasts (SaOS-2) on MS9 had similar cell behaviour activity in comparison with the TCP control. In vivo data showed an evident development of integration and resorption of the MS composites with low inflammation activity. Current findings suggest that the combination of SPIONs into 3D composite scaffolds can be a promising toolkit for bone regeneration.     

Hydraulic reactivity and cement formation of baghdadite

In this study, the hydraulic reactivity and cement formation of baghdadite (Ca₃ZrSi₂O₉) was investigated. The material was synthesized by sintering a mixture of CaCO₃, SiO₂, and ZrO₂ and then mechanically activated using a planetary mill. This leads to a decrease in particle and crystallite size and a partial amorphization of baghdadite as shown by X-ray powder diffraction (XRD) and laser diffraction measurements. Baghdadite cements were formed by the addition of water at a powder to liquid ratio of 2.0 g/ml. Maximum compressive strengths were found to be ~2 MPa after 3-day setting for a 24-h ground material. Inductively coupled plasma mass spectrometry (ICP-MS) measurements showed an incongruent dissolution profile of set cements with a preferred dissolution of calcium and only marginal release of zirconium ions. Cement formation occurs under alkaline conditions, whereas the unground raw powder leads to a pH of 11.9 during setting, while prolonged grinding increased pH values to approximately 12.3.     

Advances in Lupus Nephritis Pathogenesis: From Bench to Bedside

Systemic lupus erythematosus (SLE) is the prototype of autoimmune disorders caused by a loss of tolerance to endogenous nuclear antigens triggering an aberrant autoimmune response targeting various tissues. Lupus nephritis (LN), a major cause of morbidity and mortality in patients with SLE, affects up to 60% of patients. The recent insights into the genetic and molecular basis of SLE and LN paved the way for newer therapies to be developed for these patients. Apart from the traditional B-cell-centered view of this disease pathogenesis, acknowledging that multiple extrarenal and intrarenal pathways contribute to kidney-specific autoimmunity and injury may help refine the individual therapeutic and prognostic characterization of such patients. Accordingly, the formerly induction-maintenance treatment strategy was recently challenged with the exciting results obtained from the trials that evaluated add-on therapy with voclosporin, belimumab, or Obinutuzumab. The scope of this review is to provide an insight into the current knowledge of LN pathogenesis and future therapeutic strategies.     

Review of the environmental policy instruments in the standardization of H2 for the decarbonization of Mexico

The objective of this work is to review the environmental and ecological policy instruments that Mexican legislation for existence of an Official Mexican Hydrogen Standard according to the premises motivates decarbonization. There is a worldwide interest in hydrogen (H₂) and its incorporation into legal systems. In Mexico there are large legal gaps that question the legality of H₂, because it is not recognized in a federal law and is only considered in technical standards of voluntary application. Also, Mexico has forest, agricultural, and livestock waste that, if properly used, can cover the energy demand of communities. The main findings of this study refer to the fact that, according to international standards for the management of H₂ and taking into account the regulatory limitations in Mexico, it is possible to promote, an Official Mexican Standard exclusively aimed at establishing the minimum requirements for the design, construction, operation and maintenance of H₂ storage, considering the areas of the opportunity offered by foreign experiences, according to the Mexican context. It is concluded that the parameters of legality exist in the instruments of environmental policy, to support the existence of an Official Mexican Standard of H₂.     

Near-optimal replacement policies for shared caches in multicore processors

The Journal of Supercomputing - An optimal replacement policy that minimizes the miss rate in a private cache was proposed several decades ago. It requires knowing the future access sequence the...     

Preservative Effect of a Previous High-Pressure Treatment on the Chemical Changes Related to Quality Loss in Frozen Hake (<Emphasis Type="Italic">Merluccius merluccius</Emphasis>)

The objective of this study was the quality loss inhibition of hake (Merluccius merluccius) during the frozen storage. For it, the effect of a previous high-pressure (HP) treatment (150–450 MPa for 2 min) was analysed throughout a 5-month storage at ? 10 °C. Quality changes were monitored by complementary chemical analyses. Inhibition (p < 0.05) of dimethylamine (DMA), free fatty acid (FFA), formaldehyde (FA), trimethylamine, total volatile amine and fluorescent compound (tertiary lipid oxidation compound) formation was concluded by previous pressure treatment according to the one-way ANOVA analysis. On the contrary, no effect (p > 0.05) on the K value, polyene index and formation of peroxides and thiobarbituric acid reactive substances was achieved. Additionally, a multifactor ANOVA test (pressure and frozen storage time effects; i.e. comparison among HP treatments) showed an inhibitory effect (p < 0.015) on DMA and FFA formation, this effect increasing with pressure level applied. This inhibitory effect on the formation of such molecules related to quality loss can be explained on the basis of the damage caused to different kinds of enzymes such as trimethylamine oxide demethylase, lipases and phospholipases, so that their activity during the subsequent frozen storage would decrease. The work here presented provides for the first time information concerning the employment of HP technology to inhibit the DMA, FA and FFA formation during the frozen storage of hake. Further research focussed on commercial frozen conditions (? 18 °C) and including sensory and nutritional aspects is foreseen.     

Numerical Simulation of Water Flow from the Coal Seam Floor in a Deep Longwall Mine in China

The study of groundwater flow from the coal seam floor is critical to safe mining operations in China. We developed a numerical simulation model to describe flood water pathways during mining, using the field conditions present at the no. 4196 west work face in the Panxi longwall coal mine, Shandong Province, China, Groundwater flow analysis revealed unusual values for the failure depth of the coal seam floor. The high ground stress and underground pressure, excavation length, width of working face, poor mechanical properties of aquitards, and expansion of fractures by groundwater infiltration all contribute to groundwater flow into the mine. The modeling results predict the time and longwall locations associated with the maximum likelihood of flood occurrence. Such results can be used by decision makers to improve mine design and safety.     

Recovering Bioactive Compounds from Olive Oil Filter Cake by Advanced Extraction Techniques

The potential of by-products generated during extra-virgin olive oil (EVOO) filtration as a natural source of phenolic compounds (with demonstrated bioactivity) has been evaluated using pressurized liquid extraction (PLE) and considering mixtures of two GRAS (generally recognized as safe) solvents (ethanol and water) at temperatures ranging from 40 to 175 °C. The extracts were characterized by high-performance liquid chromatography (HPLC) coupled to diode array detection (DAD) and electrospray time-of-flight mass spectrometry (HPLC-DAD-ESI-TOF/MS) to determine the phenolic-composition of the filter cake. The best isolation procedure to extract the phenolic fraction from the filter cake was accomplished using ethanol and water (50:50, v/v) at 120 °C. The main phenolic compounds identified in the samples were characterized as phenolic alcohols or derivatives (hydroxytyrosol and its oxidation product), secoiridoids (decarboxymethylated and hydroxylated forms of oleuropein and ligstroside aglycones), flavones (luteolin and apigenin) and elenolic acid derivatives. The PLE extraction process can be applied to produce enriched extracts with applications as bioactive food ingredients, as well as nutraceuticals.