23 research outputs found

    Recovery of the Phosphorus from the Nitric Acid Extract of Powder Collected in a Bag Filter during the Recycling of Used Fluorescence Tubes

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    During the recovery of phosphorus from the powder collected in a bag filter during the recycling of used fluorescence tubes (bag-powder), the batch method with aqueous HNO3 was used to examine the elution behavior of aqueous phosphate contained in the bag-powder. The main components of the bag-powder included Ca2+, PO4 3- and Y3+ along with Si4+, Sr2+ and lanthanide cations such as La3+ and Ce4+. Therefore, it seemed possible that, with the selective dissolution of Ca2+ and PO4 3- from the bag-powder, these lanthanide cations in the residue could be enriched. With the batch method, most of the phosphate in the bag-powder was dissolved within 0.2 min using 1.0 mol/L HNO3. The dissolution behavior of calcium cation was similar to that of the phosphate. In contrast, the dissolution of yttrium, the content of which was the highest among the lanthanide cations in the bag-powder, was increased with the dissolution times, reaching complete dissolution after 24 h. The Sr2+, La3+ and Si4+ in the bag-powder, however, did not dissolve under the same conditions. Although Ca2+, PO4 3- and Y3+ were the main components in the nitric acid extract, Y3+ was separated as YPO4 at pH = 4.0, while Ca2+ and PO4 3- were separated as calcium phosphates at pH= 7.0. These results revealed that the separation of calcium phosphates, YPO4 and some residue was possible, and resulted in the enrichment of lanthanide cations along with the recovery of phosphorus from the bag-powder. Using the present technique, 91% of the P in the bag-powder was recovered

    PLC-based LP11 mode rotator for mode-division multiplexing transmission

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    A PLC-based LP11 mode rotator is proposed. The proposed mode rotator is composed of a waveguide with a trench that provides asymmetry of the waveguide. Numerical simulations show that converting LP11a (LP11b) mode to LP11b (LP11a) mode can be achieved with high conversion efficiency (more than 90%) and little polarization dependence over a wide wavelength range from 1450 nm to 1650 nm. In addition, we fabricate the proposed LP11 mode rotator using silica-based PLC. It is confirmed that the fabricated mode rotator can convert LP11a mode to LP11b mode over a wide wavelength range. (C) 2014 Optical Society of Americ

    Efficient long-term survival of cell grafts after myocardial infarction with thick viable cardiac tissue entirely from pluripotent stem cells

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    心臓組織シートを、細胞が生きた状態で簡便に積層化する方法の開発. 京都大学プレスリリース. 2015-11-27.Poor engraftment of cells after transplantation to the heart is a common and unresolved problem in the cardiac cell therapies. We previously generated cardiovascular cell sheets entirely from pluripotent stem cells with cardiomyocytes, endothelial cells and vascular mural cells. Though sheet transplantation showed a better engraftment and improved cardiac function after myocardial infarction, stacking limitation (up to 3 sheets) by hypoxia hampered larger structure formation and long-term survival of the grafts. Here we report an efficient method to overcome the stacking limitation. Insertion of gelatin hydrogel microspheres (GHMs) between each cardiovascular cell sheet broke the viable limitation via appropriate spacing and fluid impregnation with GHMs. Fifteen sheets with GHMs (15-GHM construct; >1mm thickness) were stacked within several hours and viable after 1 week in vitro. Transplantation of 5-GHM constructs (≈2×106 of total cells) to a rat myocardial infarction model showed rapid and sustained functional improvements. The grafts were efficiently engrafted as multiple layered cardiovascular cells accompanied by functional capillary networks. Large engrafted cardiac tissues (0.8mm thickness with 40 cell layers) successfully survived 3 months after TX. We developed an efficient method to generate thicker viable tissue structures and achieve long-term survival of the cell graft to the heart

    Efficient and robust differentiation of endothelial cells from human induced pluripotent stem cells via lineage control with VEGF and cyclic AMP.

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    Blood vessels are essential components for many tissues and organs. Thus, efficient induction of endothelial cells (ECs) from human pluripotent stem cells is a key method for generating higher tissue structures entirely from stem cells. We previously established an EC differentiation system with mouse pluripotent stem cells to show that vascular endothelial growth factor (VEGF) is essential to induce ECs and that cyclic adenosine monophosphate (cAMP) synergistically enhances VEGF effects. Here we report an efficient and robust EC differentiation method from human pluripotent stem cell lines based on a 2D monolayer, serum-free culture. We controlled the direction of differentiation from mesoderm to ECs using stage-specific stimulation with VEGF and cAMP combined with the elimination of non-responder cells at early EC stage. This "stimulation-elimination" method robustly achieved very high efficiency (>99%) and yield (>10 ECs from 1 hiPSC input) of EC differentiation, with no purification of ECs after differentiation. We believe this method will be a valuable technological basis broadly for regenerative medicine and 3D tissue engineering

    Time course of endothelial cell and pre-endothelial cell marker.

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    <p>(a) Representative expression time course of VE-cadherin (VECad) and CD31 under stimulation method (VEGF+cAMP) or vehicle without VEGF and cAMP by FACS. (b) Time course of VE-Cadherin-positive cell ratio in two groups. (c) Yield of VE-Cadherin positive endothelial cells per 1cm<sup>2</sup> in two groups. (d) Time course of total cell counts in two groups. (e) Representative expression time course of VEGF receptor 2 (VEGFR2) and VE-cadherin in stimulation method (VEGF+cAMP) or vehicle without cAMP and VEGF. Arrows: non-responder cells to VEGF and cAMP stimulation.</p
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