Pulsed Electromagnetic Field Stimulation in Osteogenesis and Chondrogenesis: Signaling Pathways and Therapeutic Implications

Mesenchymal stem cells (MSCs) are the main cell players in tissue repair and thanks to their self-renewal and multi-lineage differentiation capabilities, they gained significant attention as cell source for tissue engineering (TE) approaches aimed at restoring bone and cartilage defects. Despite significant progress, their therapeutic application remains debated: the TE construct often fails to completely restore the biomechanical properties of the native tissue, leading to poor clinical outcomes in the long term. Pulsed electromagnetic fields (PEMFs) are currently used as a safe and non-invasive treatment to enhance bone healing and to provide joint protection. PEMFs enhance both osteogenic and chondrogenic differentiation of MSCs. Here, we provide extensive review of the signaling pathways modulated by PEMFs during MSCs osteogenic and chondrogenic differentiation. Particular attention has been given to the PEMF-mediated activation of the adenosine signaling and their regulation of the inflammatory response as key player in TE approaches. Overall, the application of PEMFs in tissue repair is foreseen: (1) in vitro: to improve the functional and mechanical properties of the engineered construct; (2) in vivo: (i) to favor graft integration, (ii) to control the local inflammatory response, and (iii) to foster tissue repair from both implanted and resident MSCs cells.     

Acute Promyelocytic Leukemia in Children: A Model of Precision Medicine and Chemotherapy-Free Therapy

Acute promyelocytic leukemia (APL) represents a paradigm of precision medicine. Indeed, in the last decades, the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) completely revolutionized the therapeutic approach to this previously highly fatal disorder. This entirely chemotherapy-free treatment, which provided excellent survival rates, has been initially validated in adults and, recently, translated in the pediatric setting. This review summarizes currently available data on the use of ATRA and ATO combination in pediatric APL, providing a particular focus on peculiar issues and challenges, such as the occurrence of pseudotumor cerebri and death during induction (early death), as well as the advantage offered by the ATO/ATRA combination in sparing long-term sequelae.     

Effects of gastrointestinal digestion models in vitro on phenolic compounds and antioxidant activity of juçara (Euterpe edulis)

This study evaluated the effects of different gastrointestinal digestion models in vitro on the bioaccessibility of phenolics and antioxidant activity in juçara frozen pulp. In the sequence, method 3 was applied to juçara fruit in three different stages of maturation (vitrin – reddish fruits, mature – purple fruits, tuíra – deep purple fruits). In the method applied, the final pH adopted was 5.0, in order to avoid interference in the assay used to determine the antioxidant activity, and BHT was used to prevent excessive oxidation in the system. In this method, higher values for antioxidant activity were obtained (3574.95–3719.10 μmol L^?1 Trolox 100 g^?1 pulp) compared with the other two methods tested (1969.14–3034.74 μmol L^?1 Trolox 100 g^?1 pulp). In relation to juçara fruit, the mature stage was found to be ideal for processing, showing generally higher values of the bioaccessibility for phenolics and antioxidant activity compared to other maturation stages.     

Highly Stretchable Polymer Composite with Strain-Enhanced Electromagnetic Interference Shielding Effectiveness

Polymer composites with electrically conductive fillers have been developed as mechanically flexible, easily processable electromagnetic interference (EMI) shielding materials. Although there are a few elastomeric composites with nanostructured silvers and carbon nanotubes showing moderate stretchability, their EMI shielding effectiveness (SE) deteriorates consistently with stretching. Here, a highly stretchable polymer composite embedded with a three-dimensional (3D) liquid-metal (LM) network exhibiting substantial increases of EMI SE when stretched is reported, which matches the EMI SE of metallic plates over an exceptionally broad frequency range of 2.65–40 GHz. The electrical conductivities achieved in the 3D LM composite are among the state-of-the-art in stretchable conductors under large mechanical deformations. With skin-like elastic compliance and toughness, the material provides a route to meet the demands for emerging soft and human-friendly electronics.     

Assessment of heavy metal levels in Almendares River sediments--Havana City, Cuba

The Almendares River watershed covers a large portion of Havana, Cuba and is centrally important to both recreational and other activities in the region. In order to assess current water quality conditions prior to planned remediation efforts, the spatial distribution of six heavy metals and other compounds were determined in river sediments at fifteen sampling stations in the watershed. Metal concentrations in sediments ranged from 86.1 to 708.8 for Zn, 39.3 to 189.0 for Pb, 71.6 to 420.8 for Cu, 84.4 to 209.7 Cr, 1.5 to 23.4 for Co, and 1.0 to 4.3 for Cd microg/g dry weight sediment. Calculated enrichment factors (EF; measured metal versus background mineral conditions) were almost always greater than 1.0, suggesting significant anthropogenic impact on metal levels in the river. The highest EF values were seen immediately below Cotorro (EF>10 for Pb, Cu, and Cd), a suburban town that has an active secondary smelter, and below the largest municipal landfill in Havana (EF>10 for Pb, Cu, Cd, and Zn). Further, three sampling stations had multiple metals at concentrations higher than probable effects concentrations (PEC), implying possible local ecotoxicological impacts. Finally, sequential extractions of the sediments indicated that heavy metals were largely associated with the organic fraction, and it was estimated that up to 62% of metals in the sediments would be susceptible to release back into the water column if hydraulic or other changes occurred in the river. These data are being used to prioritize decisions related to the remediation of the river system.     

Montmorillonite reinforced type A gelatin nanocomposites

This study investigates the structural, morphological, thermal, and mechanical properties of type A gelatin/montmorillonite (MMT) films as a function of MMT concentration. The variations of the X‐ray diffraction pattern suggest that the structure of the nanocomposites turns from intercalated to exfoliated on increasing clay loading up to 20 wt %. Simultaneously, gelatin interaction with clay negative sheets during gelling provokes a reduction of the triple helix content of the composite films, in agreement with the reduction of the relative intensity of the 1.1 nm diffraction reflection of gelatin and of the values of denaturation enthalpy. On the other hand, the increase of the denaturation and decomposition temperatures, the significant rise of the Young's modulus, as well as the swelling decrease observed as clay content increases, demonstrate a relevant stabilizing effect of MMT on gelatin. The reinforcement action of MMT allows to utilize a relatively low concentration of the crosslinking agent genipin to further stabilize the films. The synergic action of clay and genipin prevents dissolution of the nanocomposites in aqueous solution and enhances their mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40301.     

Changes in bioactive compounds and antioxidant activity during convective drying of murta (Ugni molinae T.) berries

Murta (Ugni molinae T.) berries were air‐dried at five temperatures (40, 50, 60, 70 and 80 °C), and the changes in β‐carotene, phenolic acids, total phenolic and flavonoid contents and antioxidant capacities (DPPH and ORAC) were investigated. The berries showed a high content of β‐carotene, which decreased during drying temperature between 40 °C and 80 °C. Free and bound phenolic acids were also determined, showing gallic acid to be the prevalent phenolic acid. Total phenolic and flavonoid contents in the dried berries showed a higher decrease at lower temperature due to longer drying time. The radical‐scavenging activity also showed higher antioxidant activity at higher drying temperatures (70–80 °C) than at lower drying temperatures (40–50 °C). Total phenolic content (TPC) and flavonoids showed good correlation with antioxidant capacity. Murta berries proved to be an excellent source of antioxidants and bioactive compounds and are therefore a potential ingredient for new functional food products.     

Viral diffusion of technology products: a comprehensive stage framework

Information Systems and e-Business Management - The level of viral diffusion expected after a technology product or service is launched is important for determining the marketing budget,...