Improvement in Efficiency of Wireless Power Transfer of Magnetic Resonant Coupling Using Magnetoplated Wire

Wireless power transfer is expected in the use of an electric vehicle and a chip card. However, it requires a high efficiency and takes a long distance. In this paper, we propose the use of a magnetoplated wire (MPW), which is a copper wire (COW) whose circumference is plated with a magnetic thin film to improve transmission efficiency. The MPW can reduce resistances due to the proximity effect comparison with the COW. The inner diameter of COW and MPW coils is d(i) = 37 mm and their number of turns is n = 10. As a result, the resistances of the COW and MPW at the frequency f = 12 MHz are 6.8 and 4.1 Omega, respectively, which show a reduction of 40%. The quality factors of the COW and MPW at the frequency f = 12 MHz are 83 and 138, respectively, which show an increase of 66%. The efficiencies of the COW and MPW at a transmission distance of 10 mm are 69.8% and 77.7%, respectively, which show an increase of 7.9%.ArticleIEEE TRANSACTIONS ON MAGNETICS. 47(10):4445-4448 (2011)journal articl

Selective vulnerability of human-induced pluripotent stem cells to dihydroorotate dehydrogenase inhibition during mesenchymal stem/stromal cell purification

間葉系幹細胞から未分化iPS細胞を選択除去する方法を開発: iPS細胞由来間葉系幹細胞の再生医療利用に期待. 京都大学プレスリリース. 2023-03-01.The use of induced mesenchymal stem/stromal cells (iMSCs) derived from human induced pluripotent stem cells (hiPSCs) in regenerative medicine involves the risk of teratoma formation due to hiPSCs contamination in iMSCs. Therefore, eradicating the remaining undifferentiated hiPSCs is crucial for the effectiveness of the strategy. The present study demonstrates the Brequinar (BRQ)-induced inhibition of dihydroorotate dehydrogenase (DHODH), a key enzyme in de novo pyrimidine biosynthesis, selectively induces apoptosis, cell cycle arrest, and differentiation; furthermore, it promotes transcriptional changes and prevents the growth of 3-dimensional hiPSC aggregates. Contrastingly, BRQ-treated iMSCs showed no changes in survival, differentiation potential, or gene expression. The results suggest that BRQ is a potential agent for the effective purification of iMSCs from a mixed population of iMSCs and hiPSCs, which is a crucial step in successful iMSC-based therapy

Generation of a human SOX10 knock-in reporter iPSC line for visualization of neural crest cell differentiation

SOX10 (SRY-box transcription factor 10) is not only a definitive molecular marker of neural crest cells (NCCs) but also an essential transcription factor for the differentiation of NCCs in vertebrate embryogenesis. Here, we report the establishment of a human SOX10 knock-in reporter iPSC line (SOX10-tdT) by CRISPR/Cas9-mediated homologous recombination, in which the expression of SOX10 can be monitored as tdTomato fluorescence. This iPSC line can provide a useful tool to model the differentiation process of human NCCs in vitro

Conditional deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, increasing volume of remodeling bone in mice

Bone undergoes remodeling consisting of osteoclastic bone resorption followed by osteoblastic bone formation throughout life. Although the effects of bone morphogenetic protein (BMP) signals on osteoblasts have been studied extensively, the function of BMP signals in osteoclasts has not been fully elucidated. To delineate the function of BMP signals in osteoclasts during bone remodeling, we deleted BMP receptor type IA ( Bmpr1a ) in an osteoclast‐specific manner using a knock‐in Cre mouse line to the cathepsin K locus ( Ctsk Cre/+ ;Bmpr1a flox/flox , designated as Bmpr1a ΔOc/ΔOc ). Cre was specifically expressed in multinucleated osteoclasts in vivo. Cre‐dependent deletion of the Bmpr1a gene occurred at 4 days after cultivation of bone marrow macrophages obtained from Bmpr1a ΔOc/ΔOc with RANKL. These results suggested that Bmpr1a was deleted after formation of osteoclasts in Bmpr1a ΔOc/ΔOc mice. Expression of bone‐resorption markers increased, thus suggesting that BMPRIA signaling negatively regulates osteoclast differentiation. Trabeculae in tibia and femurs were thickened in 3.5‐, 8‐, and 12‐week‐old Bmpr1a ΔOc/ΔOc mice. Bone histomorphometry revealed increased bone volume associated with increased osteoblastic bone‐formation rates (BFR) in the remodeling bone of the secondary spongiosa in Bmpr1a ΔOc/ΔOc tibias at 8 weeks of age. For comparison, we also induced an osteoblast‐specific deletion of Bmpr1a using Col1a1‐Cre. The resulting mice showed increased bone volume with marked decreases in BFR in tibias at 8 weeks of age. These results indicate that deletion of Bmpr1a in differentiated osteoclasts increases osteoblastic bone formation, thus suggesting that BMPR1A signaling in osteoclasts regulates coupling to osteoblasts by reducing bone‐formation activity during bone remodeling. © 2011 American Society for Bone and Mineral ResearchPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/1/477_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/87086/2/jbmr_477_sm_SupplData.pd

Preventive Effect of Pine Bark Extract (Flavangenol) on Metabolic Disease in Western Diet-Loaded Tsumura Suzuki Obese Diabetes Mice

It is known that the metabolic syndrome has a multi-factorial basis involving both genetic and environmental risk factors. In this study, Tsumura Suzuki Obese Diabetes (TSOD) mice, a mouse model of multi-factorial, hereditary, obese type II diabetes, were given a Western diet (WTD) as an environmental factor to prepare a disease model (TSOD-WTD) and to investigate the preventive effects of Pine bark extract (Flavangenol) against obesity and various features of metabolic disease appearing in this animal model. In contrast to control Tsumura Suzuki Non-obesity (TSNO) mice, TSOD mice were obese and suffered from other metabolic complications. WTD-fed TSOD mice developed additional features such as hyperinsulinemia, abnormal glucose/lipid metabolism and fatty liver. The treatment with Flavangenol had a suppressive effect on increase in body weight and accumulation of visceral and subcutaneous fat, and also showed preventive effects on symptoms related to insulin resistance, abnormal glucose/lipid metabolism and hypertension. Flavangenol also increased the plasma concentration of adiponectin and decreased the plasma concentration of TNF-α. We next investigated the effect of Flavangenol on absorption of meal-derived lipids. Flavangenol suppressed absorption of neutral fat in an olive-oil-loading test (in vivo) and showed an inhibitory effect on pancreatic lipase (in vitro). The above results suggest that Flavangenol has a preventive effect on severe metabolic disease due to multiple causes that involve both genetic and environmental risk factors. The mechanism of action might involve a partial suppressive effect of meal-derived lipids on absorption

Random walk and cell morphology dynamics in Naegleria gruberi

Amoeboid cell movement and migration are wide-spread across various cell types and species. Microscopy-based analysis of the model systems Dictyostelium and neutrophils over the years have uncovered generality in their overall cell movement pattern. Under no directional cues, the centroid movement can be quantitatively characterized by their persistence to move in a straight line and the frequency of re-orientation. Mathematically, the cells essentially behave as a persistent random walker with memory of two characteristic time-scale. Such quantitative characterization is important from a cellular-level ethology point of view as it has direct connotation to their exploratory and foraging strategies. Interestingly, outside the amoebozoa and metazoa, there are largely uncharacterized species in the excavate taxon Heterolobosea including amoeboflagellate Naegleria. While classical works have shown that these cells indeed show typical amoeboid locomotion on an attached surface, their quantitative features are so far unexplored. Here, we analyzed the cell movement of Naegleria gruberi by employing long-time phase contrast imaging that automatically tracks individual cells. We show that the cells move as a persistent random walker with two time-scales that are close to those known in Dictyostelium and neutrophils. Similarities were also found in the shape dynamics which are characterized by the appearance, splitting and annihilation of the curvature waves along the cell edge. Our analysis based on the Fourier descriptor and a neural network classifier point to importance of morphology features unique to Naegleria including complex protrusions and the transient bipolar dumbbell morphologies

Enhanced chondrogenic differentiation of iPS cell-derived mesenchymal stem/stromal cells via neural crest cell induction for hyaline cartilage repair

iPS細胞由来の間葉系幹細胞から高品質な軟骨を作製. 京都大学プレスリリース. 2023-06-08.Generation of high-quality cartilage from iPS cell-derived mesenchymal stem cells. 京都大学プレスリリース. 2023-06-15.Background: To date, there is no effective long-lasting treatment for cartilage tissue repair. Primary chondrocytes and mesenchymal stem/stromal cells are the most commonly used cell sources in regenerative medicine. However, both cell types have limitations, such as dedifferentiation, donor morbidity, and limited expansion. Here, we report a stepwise differentiation method to generate matrix-rich cartilage spheroids from induced pluripotent stem cell-derived mesenchymal stem/stromal cells (iMSCs) via the induction of neural crest cells under xeno-free conditions. Methods: The genes and signaling pathways regulating the chondrogenic susceptibility of iMSCs generated under different conditions were studied. Enhanced chondrogenic differentiation was achieved using a combination of growth factors and small-molecule inducers. Results: We demonstrated that the use of a thienoindazole derivative, TD-198946, synergistically improves chondrogenesis in iMSCs. The proposed strategy produced controlled-size spheroids and increased cartilage extracellular matrix production with no signs of dedifferentiation, fibrotic cartilage formation, or hypertrophy in vivo. Conclusion: These findings provide a novel cell source for stem cell-based cartilage repair. Furthermore, since chondrogenic spheroids have the potential to fuse within a few days, they can be used as building blocks for biofabrication of larger cartilage tissues using technologies such as the Kenzan Bioprinting method

Induction of functional xeno-free MSCs from human iPSCs via a neural crest cell lineage

iPS細胞から間葉系幹細胞の誘導方法を確立 --動物由来成分を含まず再生医療への利用に期待. 京都大学プレスリリース. 2022-09-15.A new method for inducing mesenchymal stem cells from iPS cells without using animal-derived components. 京都大学プレスリリース. 2022-09-27.Mesenchymal stem/stromal cells (MSCs) are adult multipotent stem cells. Here, we induced MSCs from human induced pluripotent stem cells (iPSCs) via a neural crest cell (NCC) lineage under xeno-free conditions and evaluated their in vivo functions. We modified a previous MSC induction method to work under xeno-free conditions. Bovine serum albumin-containing NCC induction medium and fetal bovine serum-containing MSC induction medium were replaced with xeno-free medium. Through our optimized method, iPSCs differentiated into MSCs with high efficiency. To evaluate their in vivo activities, we transplanted the xeno-free-induced MSCs (XF-iMSCs) into mouse models for bone and skeletal muscle regeneration and confirmed their regenerative potency. These XF-iMSCs mainly promoted the regeneration of surrounding host cells, suggesting that they secrete soluble factors into affected regions. We also found that the peroxidasin and IGF2 secreted by the XF-iMSCs partially contributed to myotube differentiation. These results suggest that XF-iMSCs are important for future applications in regenerative medicine