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Magnesium (Mg) and its alloys have shown attractive biocompatibility and mechanical strength for medical applications, but low corrosion resistance of Mg in physiological environment limits its broad clinical translation. Hydroxyapatite (HA) nanoparticles (nHA) are promising coating materials for decreasing degradation rates and prolonging mechanical strength of Mg-based implants while enhancing bone healing due to their osteoconductivity and osteoinductivity. Conformal HA coatings with nano-to-submicron structures, namely nHA and mHA coatings, were deposited successfully on Mg plates and rods using a transonic particle acceleration (TPA) process under two different conditions, characterized, and investigated for their effects on Mg degradation in vitro. The nHA and mHA coatings enhanced corrosion resistance of Mg and retained 86-90% of ultimate compressive strength after in vitro immersion in rSBF for 6 weeks, much greater than non-coated Mg that only retained 66% of strength. Mg-based rods with or without coatings showed slower degradation than the respective Mg-based plates in rSBF after 6 weeks, likely because of the greater surface-to-volume ratio of Mg plates than Mg rods. This indicates that Mg-based plate and screw devices may undergo different degradation even when they have the same coatings and are implanted at the same or similar anatomical locations. Therefore, in addition to locations of implantation, the geometry, dimension, surface area, volume, and mass of Mg-based implants and devices should be carefully considered in their design and processing to ensure that they not only provide adequate structural and mechanical stability for bone fixation, but also support the functions of bone cells, as clinically required for craniomaxillofacial (CMF) and orthopedic implants. When the nHA and mHA coated Mg and non-coated Mg plates were cultured with bone marrow derived mesenchymal stem cells (BMSCs) using the in vitro direct culture method, greater cell adhesion densities were observed under indirect contact conditions than that under direct contact conditions for the nHA and mHA coated Mg. In comparison with non-coated Mg, the nHA and mHA coated Mg reduced BMSC adhesion densities directly on the surface, but increased the average BMSC adhesion densities under indirect contact. Further long-term studies in vitro and in vivo are necessary to elucidate the effects of nHA and mHA coatings on cell functions and tissue healing.

In this paper, the authors generalize the fractional curvature of plane curves introduced by Rubio et al. in 2023, to regular curves in the Euclidean space R 3 , and study the geometric properties of the curve using Caputo's fractional derivative. Furthermore, we introduce a new definition of fractional curvature and fractional mean curvature of a regular surface, using fractional principal curvatures; and prove that such concepts are invariant under isometries; i.e., they belong to the intrinsic geometry of the regular surface. Also, a geometric interpretation is given to Caputo's fractional derivative of algebraic polynomials. [ABSTRACT FROM AUTHOR]

GoalThe aim of this study was to investigate gene expression levels of proteins involved in sphingosine-1-phosphate (S1P) metabolism and signaling in a pediatric inflammatory bowel disease (IBD) patient population.BackgroundIBD is a debilitating disease affecting 0.4% of the US population. The incidence of IBD in childhood is rising. Identifying effective targeted therapies that can be used safely in young patients and developing tools for selecting specific candidates for targeted therapies are important goals. Clinical IBD trials now underway target S1PR1, a receptor for the pro-inflammatory sphingolipid S1P. However, circulating and tissue sphingolipid levels and S1P-related gene expression have not been characterized in pediatric IBD.MethodsPediatric IBD patients and controls were recruited in a four-site study. Patients received a clinical score using PUCAI or PCDAI evaluation. Colon biopsies were collected during endoscopy. Gene expression was measured by qRT-PCR. Plasma and gut tissue sphingolipids were measured by LC-MS/MS.ResultsGenes of S1P synthesis (SPHK1, SPHK2), degradation (SGPL1), and signaling (S1PR1, S1PR2, and S1PR4) were significantly upregulated in colon biopsies of IBD patients with moderate/severe symptoms compared with controls or patients in remission. Tissue ceramide, dihydroceramide, and ceramide-1-phosphate (C1P) levels were significantly elevated in IBD patients compared with controls.ConclusionsA signature of elevated S1P-related gene expression in colon tissues of pediatric IBD patients correlates with active disease and normalizes in remission. Biopsied gut tissue from symptomatic IBD patients contains high levels of pro-apoptotic and pro-inflammatory sphingolipids. A combined analysis of gut tissue sphingolipid profiles with this S1P-related gene signature may be useful for monitoring response to conventional therapy.

Drawing on longitudinal data of state K–12 education policymaker demographics, we examine education policymaking body diversity over time, and across states and institutional structures. Though dominated by white businessmen, females and professional educators increased their presence at the education policymaking table. There was little movement in representation of policymakers of color. Institutional structures such as election type and professionalism were related to greater representation of females and persons of color in state education policymaking bodies. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the postnatal outcome of children with antenatal colonic hyperechogenicity, currently considered as a sign of lysinuria‐cystinuria, but which may also be a sign of other disorders with a more severe prognosis. Method: We carried out a French multi‐centric retrospective study via 15 Multidisciplinary Center for Prenatal Diagnosis from January 2011 to January 2021. We included pregnancies for which fetal colonic hyperechogenicity had been demonstrated. We collected the investigations performed during pregnancy and at birth as well as the main clinical features of the mother and the child. We then established the prevalence of pathologies such as lysinuria‐cystinuria (LC), hypotonia‐cystinuria syndrome (HC), or lysinuric protein intolerance (LPI). Results: Among the 33 cases of colonic hyperechogenicity collected, and after exclusion of those lost to follow‐up, we identified 63% of children with lysinuria‐cystinuria, 8% with lysinuric rotein intolerance, and 4% with hypotonia‐cystinuria syndrome. Conclusion: Management of prenatal hyperechoic colon should include a specialized consultation with a clinical geneticist to discuss further investigations, which could include invasive amniotic fluid sampling for molecular diagnosis. A better understanding of diagnoses and prognosis should improve medical counseling and guide parental decision making. Key points: What's already known about this topic ? Currently, colonic hyperechogenicity is a sign of lysinuria‐cystinuria, but it can also be a sign of other disorders with a more severe prognosis. What does this study add? In this retrospective study, among fetuses with hyperechoic colon, we identified 63% of children with lysinuria‐cystinuria, 8% with lysinuric protein intolerance, and 4% with hypotonia‐cystinuria syndrome. These data are likely to modify the management of patients in whom a hyperechogenic fetal colon is identified. [ABSTRACT FROM AUTHOR]