123 research outputs found
Uniaxial Tensile Properties of AS4 3D Woven Composites with Four Different Resin Systems: Experimental Results and Analysis: Property Computations
As a part of the NASA Composite Technology for Exploration project, eight different AS4 3D orthogonal woven composite panels were manufactured and were subjected to mechanical testing including uniaxial tension along the weaves' warp direction. Each set, with four different resin systems (KCR-IR6070, EP2400, RTM6, and RS-50), included weave architectures designed using 12K and 6K AS4 carbon fiber yarns. For the tension testing conducted at Room Temperature Ambient (RTA) conditions, the elastic modulus and strength of these eight panels (as-processed and thermally-cycled) were measured and compared while the potential evolution of micro-cracking before and after thermal cycling were monitored via optical microscopy and X-Ray Computed Tomography. The data set also included test results of the as-processed materials at Elevated Temperature Wet (ETW) conditions. In the second part of this study, efforts were made to compute elastic constants for AS4 6K/RTM6 and AS4 12K/RTM6 materials by implementing a finite element approach and the Multiscale Generalized Method of Cells (MSGMC) technique developed at NASA Glenn Research Center. Digimat-FE was used to model the weave architectures, assign properties, calculate yarn properties, create the finite element mesh, and compute the elastic properties by applying periodic boundary conditions to finite element models of each repeating unit cell. The required input data for MSGMC was generated using Matlab from Digimat exported weave information. Experimental and computational results were compared, and the differences and limitations in correlating to the test data were briefly discussed
RNAi‑mediated knockdown of E2F2 inhibits tumorigenicity of \ud human glioblastoma cells
In a previous genome‑wide expression profiling study, \ud
we identified E2F2 as a hyperexpressed gene in stem‑like cells \ud
of distinct glioblastoma multiforme (GBM) specimens. Since \ud
the encoded E2F2 transcription factor has been implicated in \ud
both tumor suppression and tumor development, we conducted a \ud
functional study to investigate the pertinence of E2F2 to human \ud
gliomagenesis. E2F2 expression was knocked down by trans‑\ud
fecting U87MG cells with plasmids carrying a specific silencing \ud
shRNA. Upon E2F2 silencing, in vitro cell proliferation was \ud
significantly reduced, as indicated by a time‑course analysis of \ud
viable tumor cells. Anchorage‑independent cell growth was also \ud
significantly inhibited after E2F2 silencing, based on cell colony \ud
formation in soft agar. Subcutaneous and orthotopic xenograft \ud
models of GBM in nude mice also indicated inhibition of tumor \ud
development in vivo, following E2F2 silencing. As expression \ud
of the E2F2 gene is associated with glioblastoma stem cells \ud
and is involved in the transformation of human astrocytes, the \ud
present findings suggest that E2F2 is involved in gliomagenesis \ud
and could be explored as a potential therapeutic target in malig‑\ud
nant gliomas.This study was supported by grants from the National Institute of Science and Technology‑Stem Cells in Human Genetic Diseases, the National Council for Scientific and Technological Development (CNPq), the Coordination for the Improvement of Higher Education Personnel (CAPES), and the São Paulo Research Foundation (FAPESP). Dr Adriana M. Nakahata and Dr Daniela E. Suzuki were recipients of fellowships from CAPES and CNPq, respectively. Miss Carolina O. Rodini and Miss Mayara L. Fiuza received fellowships from FAPESP
'Mobile Only' Users Powered by Fixed-Mobile Substitution
In a context of partial fixed-mobile substitution, we analyze fixed-mobile bundling and mobile-to-fixed off-loading in a duopoly model in which consumers buy one or two products. A joint purchase discount mitigates fixed-mobile substitutability and consequently reduces mobile-only and fixed-only consumers. Practises like introducing a small discount, applied on a bundle of multiple service or mobile-to-fixed offloading by both operators are analysed. We find that such practises do not have negative impacts on the profits of whole market and lead to both consumers' surplus and welfare gains. The investment incentives in fixed network are positive and can be boosted by FM bundling without considering regulatory intervention and before taking into account of fixed costs. The investment incentives in mobile network are more likely a situation of prisoners' dilemma where operators should invest as long as there are mobile-only consumers
The functional assessment Berg Balance Scale is better capable of estimating fall risk in the elderly than the posturographic Balance Stability System
Strong Interaction Physics at the Luminosity Frontier with 22 GeV Electrons at Jefferson Lab
This document presents the initial scientific case for upgrading the
Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab)
to 22 GeV. It is the result of a community effort, incorporating insights from
a series of workshops conducted between March 2022 and April 2023. With a track
record of over 25 years in delivering the world's most intense and precise
multi-GeV electron beams, CEBAF's potential for a higher energy upgrade
presents a unique opportunity for an innovative nuclear physics program, which
seamlessly integrates a rich historical background with a promising future. The
proposed physics program encompass a diverse range of investigations centered
around the nonperturbative dynamics inherent in hadron structure and the
exploration of strongly interacting systems. It builds upon the exceptional
capabilities of CEBAF in high-luminosity operations, the availability of
existing or planned Hall equipment, and recent advancements in accelerator
technology. The proposed program cover various scientific topics, including
Hadron Spectroscopy, Partonic Structure and Spin, Hadronization and Transverse
Momentum, Spatial Structure, Mechanical Properties, Form Factors and Emergent
Hadron Mass, Hadron-Quark Transition, and Nuclear Dynamics at Extreme
Conditions, as well as QCD Confinement and Fundamental Symmetries. Each topic
highlights the key measurements achievable at a 22 GeV CEBAF accelerator.
Furthermore, this document outlines the significant physics outcomes and unique
aspects of these programs that distinguish them from other existing or planned
facilities. In summary, this document provides an exciting rationale for the
energy upgrade of CEBAF to 22 GeV, outlining the transformative scientific
potential that lies within reach, and the remarkable opportunities it offers
for advancing our understanding of hadron physics and related fundamental
phenomena.Comment: Updates to the list of authors; Preprint number changed from theory
to experiment; Updates to sections 4 and 6, including additional figure
The case for an EIC theory alliance : theoretical challenges of the EIC
We outline the physics opportunities provided by the Electron Ion Collider (EIC). These include the study of the parton structure of the nucleon and nuclei, the onset of gluon saturation, the production of jets and heavy flavor, hadron spectroscopy and tests of fundamental symmetries. We review the present status and future challenges in EIC theory that have to be addressed in order to realize this ambitious and impactful physics program, including how to engage a diverse and inclusive workforce. In order to address these many-fold challenges, we propose a coordinated effort involving theory groups with differing expertise is needed. We discuss the scientific goals and scope of such an EIC Theory Alliance
Desempenho e hematologia de tilápias-do-nilo alimentadas com Saccharomyces cerevisiae e vacinadas contra Streptococcus agalactiae
O objetivo deste trabalho foi avaliar a inter-relação entre a suplementação alimentar com parede celular de Saccharomyces cerevisae e a vacinação contra Streptococcus agalactiae e seu efeito sobre o desempenho produtivo e as variáveis hematológicas de tilápia-do-nilo (Oreochromis niloticus). Oitenta e quatro tilápias-do-nilo foram distribuídas em 12 caixas de fibra (n=7), em arranjo fatorial 2x2x3, correspondente a dois níveis de suplementação com parede celular de levedura, dois tipos de inoculação e três tempos de avaliação. Os peixes foram alimentados durante 77 dias. A vacinação dos peixes foi realizada 60 dias após o início da alimentação. Quinze dias após a vacinação, todos os peixes foram submetidos ao desafio com cepa viva de S. agalactiae, e 6, 24 e 48 horas após o desafio, o sangue foi colhido da veia caudal para avaliações. Peixes alimentados com ração suplementada apresentam maior ganho de peso e taxa de crescimento específico, e a interação entre os efeitos da dieta e da vacinação resulta em maiores taxas de hematócrito, hemoglobina e leucócitos
Relevant aspects of golden retriever muscular dystrophy for the study of Duchenne muscular dystrophy in humans
ABSTRACT: Golden Retriever muscular dystrophy (GRMD) is the most representative model for studying Duchenne muscular dystrophy (DMD) in humans, owing its phenotypic expression. DMD is a recessive disorder linked to the X chromosome in which the loss of dystrophin induces progressive weakness and degeneration of the skeletal and cardiac muscles, which lead to replacement by connective and adipose tissues. Onset of clinical signs occurs between 2 and 5 years of age, and many patients die from heart or respiratory failure. The main studies concerning dystrophic Golden Retrievers (DGR) sought to elucidate the pathophysiology of the disease and its clinical implications to develop therapies and alternative treatments to improve the quality of life and increase longevity of DMD patients. This review presents an overview of relevant contributions of the DGR model for elucidating DMD in humans
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