Peer Observation to Improve Teacher Self-Efficacy

This qualitative descriptive study explored teachers’ perceptions of a peer observation structure, collegial visits (CVs), and CVs’ connection to teacher self-efficacy (TSE). The research question was: How do teachers perceive CVs, particularly with respect to their influence on TSE? Semi-structured interviews and a focus group were utilized to collect data from 13 K–12 educators from urban and suburban public school districts in the United States. The theoretical foundation included Bandura’s social cognitive theory and the triadic reciprocal causation model. Thematic analysis was used to analyze the data, and four themes emerged: (1) cultural drivers and effects of CVs; (2) impact of formal and informal learning experiences on teachers; (3) teachers’ positive shift in (a) opinions and (b) emotions regarding CVs; and (4) teachers’ increased TSE throughout CV implementation. Conclusions highlighted that CVs were an effective vehicle for professional learning. The results provide qualitative evidence demonstrating that CVs foster educators’ TSE beliefs

One-dimensional Models for Cell Feeding in Micro-channels.

Lab-on-Chip technology is an emerging tool to obtain, culture and study different kinds of tissue models. In particular, concerning cardiac microtissues, it could be exploited to investigate cellular behavior in response to biomimetic stimulation (e.g., electrical and/or mechanical actuations).Cell culture in microfluidic chip, usually last several days. During this period of time, cells need feeding to stay alive, proliferate and organize. Different configurations and sizes of microchip features can cause non-uniform distribution of nutrients and wastes on chip, which must be taken into account in studying the response of cells to electrical and/or mechanical stimulations. A simple one-dimensional model of diffusion was used to simulate the concentration of a nutrient and a waste in a previously developed microfluidic chip. For quasi-steady processes, analytical solutions were obtained and analyzed

LivHeart: A Multi Organ-on-Chip Platform to Study Off-Target Cardiotoxicity of Drugs Upon Liver Metabolism

The drug discovery and development process is still long, costly, and highly risky. The principal attrition factor is undetected toxicity, with hepatic and cardiac toxicities playing a critical role and being the main responsible of safety-related drug withdrawals from the market. Multi Organs-on-Chip (MOoC) represent a disruptive solution to study drug-related effects on several organs simultaneously and to efficiently predict drug toxicity in preclinical trials. Specifically focusing on drug safety, different technological features are applied here to develop versatile MOoC platforms encompassing two culture chambers for generating and controlling the type of communication between a metabolically competent liver model and a functional 3D heart model. The administration of the drug Terfenadine, a cardiotoxic compound liver-metabolized into the noncardiotoxic Fexofenadine, proved that liver metabolism and a fine control over drug diffusion are fundamental to elicit a physio-pathological cardiac response. From these results, an optimized LivHeart platform is developed to house a liver model and a cardiac construct that can be mechanically trained to achieve a beating microtissue, whose electrophysiology can be directly recorded in vitro. The platform is proved able to predict off-target cardiotoxicity of Terfenadine after liver metabolism both in terms of cell viability and functionality

PERFORMANCES OF A SMALL HYPERSONIC AIRPLANE (HYPLANE)

In the present work a preliminary performance study regarding a small hypersonic airplane named HyPlane is presented. It is designed for long duration sub-orbital space tourism missions, in the frame of the Space Renaissance (SR) Italia Space Tourism Program. The vehicle is also consistent with a point-to-point medium range hypersonic trip, within the “urgent business travel” market segment. The design of such a hypersonic airplane is based on the concept of integrating available technologies developed for aeronautical and space atmospheric re-entry systems. The vehicle, characterized by high aerodynamic efficiency and low wing loading, is able to provide aerodynamic stability and manoeuvrability along the flight path and to produce a reduced sonic boom during cruise and supersonic descent approach, ensuring a very limited environmental impact. HyPlane, powered by Turbine Based Combined Cycle (TBCC) engines plus a throtteable Rocket, is able to perform Horizontal Takeoff and Horizontal Landing (HTHL) on runways. Aerodynamic and propulsive performances for the different flight regimes encountered during the missions are studied. Aerodynamic heating effects are analyzed, in order to identify suitable structures and materials design to sustain the hypersonic flight conditions. Different flight paths are also investigated, including hypersonic cruise and sub-orbital parabolic trajectories, which provide Space tourists with the opportunity of long duration missions, offering short and repeated periods of low-gravity, in the high stratosphere where a large view of the Earth is ensured

Regulation of miR-483-3p by the O-linked N-acetylglucosamine transferase links chemosensitivity to glucose metabolism in liver cancer cells

The miR-483-3p is upregulated in several tumors, including liver tumors, where it inhibits TP53-dependent apoptosis by targeting the pro-apoptotic gene BBC3/PUMA. The transcriptional regulation of the miR-483-3p could be driven by the β-catenin/USF1 complex, independently from its host gene IGF2, and we previously demonstrated that in HepG2 hepatoblastoma cells carrying wild-type TP53 the upregulation of the miR-483-3p overcomes the antitumoral effects of the tumor-suppressor miR-145-5p by a mechanism involving cellular glucose availability. Here we demonstrate that in HepG2 cells, the molecular link between glucose concentration and miR-483-3p expression entails the O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT), which stabilizes the transcriptional complex at the miR-483 promoter. HepG2 cells showed reduced miR-483-3p expression and increased susceptibility to 5-fluorouracil (5-FU)-induced apoptosis in presence of the inhibitor of glycolysis 2-deoxy-D-glucose (2-DG). However, in vivo experiments showed that HepG2 cells with higher miR-483-3p expression were selected during tumor progression regardless of 5-FU treatment. Furthermore, treatment with 2-DG alone did not significantly reduce HepG2 xenograft load in immunodeficient mice. In conclusion, we show that in HepG2 cells glucose uptake increases the expression of the oncogenic miR-483-3p through the OGT pathway. This suggests that depletion of the miR-483-3p may be a valuable therapeutic approach in liver cancer patients, but the use of inhibitors of glycolysis to achieve this purpose could accelerate the selection of resistant neoplastic cell clones

Enhancing all-in-one bioreactors by combining interstitial perfusion, electrical stimulation, on-line monitoring and testing within a single chamber for cardiac constructs

Tissue engineering strategies have been extensively exploited to generate functional cardiac patches. To maintain cardiac functionality in vitro, bioreactors have been designed to provide perfusion and electrical stimulation, alone or combined. However, due to several design limitations the integration of optical systems to assess cardiac maturation level is still missing within these platforms. Here we present a bioreactor culture chamber that provides 3D cardiac constructs with a bidirectional interstitial perfusion and biomimetic electrical stimulation, allowing direct cellular optical monitoring and contractility test. The chamber design was optimized through finite element models to house an innovative scaffold anchoring system to hold and to release it for the evaluation of tissue maturation and functionality by contractility tests. Neonatal rat cardiac fibroblasts subjected to a combined perfusion and electrical stimulation showed positive cell viability over time. Neonatal rat cardiomyocytes were successfully monitored for the entire culture period to assess their functionality. The combination of perfusion and electrical stimulation enhanced patch maturation, as evidenced by the higher contractility, the enhanced beating properties and the increased level of cardiac protein expression. This new multifunctional bioreactor provides a relevant biomimetic environment allowing for independently culturing, real-time monitoring and testing up to 18 separated patches

UCbase & miRfunc: a database of ultraconserved sequences and microRNA function

Four hundred and eighty-one ultraconserved sequences (UCRs) longer than 200 bases were discovered in the genomes of human, mouse and rat. These are DNA sequences showing 100% identity among the three species. UCRs are frequently located at genomic regions involved in cancer, differentially expressed in human leukemias and carcinomas and in some instances regulated by microRNAs (miRNAs). Here we present UCbase & miRfunc, the first database which provides ultraconserved sequences data and shows miRNA function. Also, it links UCRs and miRNAs with the related human disorders and genomic properties. The current release contains over 2000 sequences from three species (human, mouse and rat). As a web application, UCbase & miRfunc is platform independent and it is accessible at http://microrna.osu.edu/.UCbase4

A method to generate perfusable physiologic-like vascular channels within a liver-on-chip model

Data availability: The data that support the findings of this study are available from the corresponding author upon reasonable request.Supplementary Material: Further data on collagen–fibrin gel characterization, immunofluorescent staining of peculiar endothelial markers, rocker platform setup, and an upgraded version of the current ECM-mediated-contact platform are presented in the supplementary material available online at: https://pubs.aip.org/bmf/article-supplement/2925768/zip/064103_1_5.0170606.suppl_material/ (zip file).Copyright © 2023 Author(s). The human vasculature is essential in organs and tissues for the transport of nutrients, metabolic waste products, and the maintenance of homeostasis. The integration of vessels in in vitro organs-on-chip may, therefore, improve the similarity to the native organ microenvironment, ensuring proper physiological functions and reducing the gap between experimental research and clinical outcomes. This gap is particularly evident in drug testing and the use of vascularized models may provide more realistic insights into human responses to drugs in the pre-clinical phases of the drug development pipeline. In this context, different vascularized liver models have been developed to recapitulate the architecture of the hepatic sinusoid, exploiting either porous membranes or bioprinting techniques. In this work, we developed a method to generate perfusable vascular channels with a circular cross section within organs-on-chip without any interposing material between the parenchyma and the surrounding environment. Through this technique, vascularized liver sinusoid-on-chip systems with and without the inclusion of the space of Disse were designed and developed. The recapitulation of the Disse layer, therefore, a gap between hepatocytes and endothelial cells physiologically present in the native liver milieu, seems to enhance hepatic functionality (e.g., albumin production) compared to when hepatocytes are in close contact with endothelial cells. These findings pave the way to numerous further uses of microfluidic technologies coupled with vascularized tissue models (e.g., immune system perfusion) as well as the integration within multiorgan-on-chip settings.This work was partially financed by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No 800924 (International Cancer Research Fellowships-2 [iCARE-2])