Novel migrating mouse neural crest cell assay system utilizing P0-Cre/EGFP fluorescent time-lapse imaging

<p>Abstract</p> <p>Background</p> <p>Neural crest cells (NCCs) are embryonic, multipotent stem cells. Their long-range and precision-guided migration is one of their most striking characteristics. We previously reported that <it>P0-Cre/CAG-CAT-lacZ </it>double-transgenic mice showed significant lacZ expression in tissues derived from NCCs.</p> <p>Results</p> <p>In this study, by embedding a <it>P0-Cre/CAG-CAT-EGFP </it>embryo at E9.5 in collagen gel inside a culture glass slide, we were able to keep the embryo developing <it>ex vivo </it>for more than 24 hours; this development was with enough NCC fluorescent signal intensity to enable single-cell resolution analysis, with the accompanying NCC migration potential intact and with the appropriate NCC response to the extracellular signal maintained. By implantation of beads with absorbed platelet-derived growth factor-AA (PDGF-AA), we demonstrated that PDGF-AA acts as an NCC-attractant in embryos.</p> <p>We also performed assays with NCCs isolated from <it>P0-Cre/CAG-CAT-EGFP </it>embryos on culture plates. The neuromediator 5-hydroxytryptamine (5-HT) has been known to regulate NCC migration. We newly demonstrated that dopamine, in addition to 5-HT, stimulated NCC migration <it>in vitro</it>. Two NCC populations, with different axial levels of origins, showed unique distribution patterns regarding migration velocity and different dose-response patterns to both 5-HT and dopamine.</p> <p>Conclusions</p> <p>Although avian species predominated over the other species in the NCC study, our novel system should enable us to use mice to assay many different aspects of NCCs in embryos or on culture plates, such as migration, division, differentiation, and apoptosis.</p

Durability Analysis of the REIMEI Satellite Li-ion Batteries after more than 14 Years of Operation in Space

The satellite REIMEI was launched in August 2005, this is one of the first satellites to use Li-ion batteries. REIMEI is a small scientific satellite designed for carrying out aurora observations using three different cameras. The main scientific mission of the satellite ended in 2013. More than 14 years have passed, and the batteries have experienced over 78,100 charge/discharge cycles. REIMEI remains in operation with a new mission dedicated to analyzing its Li-ion battery. In this work, we present a durability analysis for the REIMEI battery based on telemetry data

トクシマ ケンナイ ノ カンゴ ショクイン コウド ジンザイ イクセイ ケンシュウ スイシン ジギョウ ニオケル トクテイ コウイ ニ カカル ジッタイ チョウサ

The purpose of this survey was to determine nurse administrators and hospital directors’ perspectives about nurses’ abilities in performing specific medical practices in hospitals in Tokushima Prefecture. The nurse administrators and hospital directors of all hospitals （１１３ hospitals） in Tokushima Prefecture were invited to respond to a survey questionnaire by mail posted during the period between February and March of ２０１５. Responses were received from ４６ nurse administrators （response rate, ４１％） and ３８ hospital directors （response rate, ３４％）. The obtained data were analyzed using descriptive statistics and the narrative descriptions summarized. Majority of responses from nurse administrators and hospital directors were accepting that nurses have responsibilities for administering medicines such as tranquilizers, anti-anxiety and anticonvulsant drugs. This result was not affected by the size of the hospital, in which fifty four percent （５４％） of respondents were from hospitals with less than １００ beds. In Japan, only hospitals with １００ beds or more may have procedures involving highly invasive treatments. Because of this, many of the respondents answered “not applicable” to statements in the questionnaire which were related to invasive treatments. Recruitment of nurses, strategies to cope with accidents and education curriculum were important concerns of nurse administrators and hospital directors which remain to be answered in future investigations

Microstructure-resolved degradation simulation of lithium-ion batteries in space applications

In-orbit satellite REIMEI, developed by the Japan Aerospace Exploration Agency, has been relying on off-the-shelf Li-ion batteries since its launch in 2005. The performance and durability of Li-ion batteries is impacted by various degradation mechanisms, one of which is the growth of the solid-electrolyte interphase (SEI). In this article, we analyse the REIMEI battery and parameterize a full-cell model with electrochemical cycling data, computer tomography images, and capacity fading experiments using image processing and surrogate optimization. We integrate a recent model for SEI growth into a full-cell model and simulate the degradation of batteries during cycling. To validate our model, we use experimental and in-flight data of the satellite batteries. Our combination of SEI growth model and microstructure-resolved 3D simulation shows, for the first time, experimentally observed inhomogeneities in the SEI thickness throughout the negative electrode for the degraded cell

Time-resolved serial femtosecond crystallography reveals early structural changes in channelrhodopsin

X線自由電子レーザーを用いて、光照射によるチャネルロドプシンの構造変化の過程を捉えることに成功. 京都大学プレスリリース. 2021-03-26.Channelrhodopsins (ChRs) are microbial light-gated ion channels utilized in optogenetics to control neural activity with light . Light absorption causes retinal chromophore isomerization and subsequent protein conformational changes visualized as optically distinguished intermediates, coupled with channel opening and closing. However, the detailed molecular events underlying channel gating remain unknown. We performed time-resolved serial femtosecond crystallographic analyses of ChR by using an X-ray free electron laser, which revealed conformational changes following photoactivation. The isomerized retinal adopts a twisted conformation and shifts toward the putative internal proton donor residues, consequently inducing an outward shift of TM3, as well as a local deformation in TM7. These early conformational changes in the pore-forming helices should be the triggers that lead to opening of the ion conducting pore