Phosphorus atomic chains, the narrowest nanostructures of black phosphorus （BP）, are highly relevant to the in-depth development of BP-based one-dimensional （1D） nano-electronics components. In this ...study, we report a top-down route for the preparation of phosphorus atomic chains via electron beam sculpturing inside a transmission electron microscope （TEM）. The growth and dynamics （i.e., rupture and edge migration） of 1D phosphorus chains are experimentally captured for the first time. Furthermore, the dynamic behavior and associated energetics of the as-formed phosphorus chains are further investigated by density functional theory （DFT） calculations. It is hoped that these 1D BP structures will serve as a novel platform and inspire further exploration of the versatile properties of BP.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Cardiomyopathy is often fatal in Friedreich ataxia (FA). However, FA hearts maintain adequate function until advanced disease stages, suggesting initial adaptation to the loss of frataxin (FXN). ...Conditional cardiac knockout mouse models of FXN show transcriptional and metabolic profiles of the mitochondrial integrated stress response (ISRmt), which could play an adaptive role. However, the ISRmt has not been investigated in models with disease-relevant, partial decrease in FXN. We characterized the heart transcriptomes and metabolomes of three mouse models with varying degrees of FXN depletion: YG8-800, KIKO-700 and FXNG127V. Few metabolites were changed in YG8-800 mice, which did not provide a signature of cardiomyopathy or ISRmt; several metabolites were altered in FXNG127V and KIKO-700 hearts. Transcriptional changes were found in all models, but differentially expressed genes consistent with cardiomyopathy and ISRmt were only identified in FXNG127V hearts. However, these changes were surprisingly mild even at advanced age (18 months), despite a severe decrease in FXN levels to 1% of those of wild type. These findings indicate that the mouse heart has low reliance on FXN, highlighting the difficulty in modeling genetically relevant FA cardiomyopathy.
BackgroundGamma-delta (γδ) T cells are depleted during cancer progression resulting in the progressive loss of anti-cancer activity. Elevated numbers of γδ T cells are associated with greater ...survival outcomes in both hematopoietic and solid malignancies. Induced pluripotent stem cell (iPSC) derived γδ T cells could address the therapeutic challenges of multiple allogeneic γδ T cell infusions as iPSCs possess nearly unlimited self-renewal and multi-lineage differentiation potential. These can be genetically modified, selected, and propagated to provide a source of potentially ‘off-the-shelf’ immune cells.MethodsPrecursor cells obtained from healthy volunteer donors were reprogrammed into iPSCs using non-integrating Yamanaka factors. A feeder-free multi-step strategy was used to differentiate iPSCs, leading to the generation of Vδ1+ γδ T cells. Characterization of the Vδ1+ T cell product included multiplex genomic PCR assays and Sanger sequencing to examine the rearrangement of the TCRγ and TCRδ gene loci, and G-band karyotype analysis. Pluripotent markers (Tra-1–60, OCT3/4 & SSEA4), HPC markers (CD34, CD43), γδ T cell surface markers (CD3, γδ TCR, CD4, CD8, CD16, CD56), effector memory markers (CD45RA, CD27), natural cytotoxicity receptors (NKG2D) were identified using multiparameter flow cytometry. T cell function was determined by flow cytometric cytotoxicity assays against K562, OLM13, U87MG, OVSAHO, OVCAR-3, KURAMUCHI targets at increasing Effector to Target (E:T) ratios. Th1/2/17 cytokine release was determined following PMA/ionomycin stimulation and LEGENDplex™ bead-based immunoassays.ResultsWe generated Vδ1T-iPSC lines (iVδ1T) identified as Vγ5-to-Jγ1/2 and Vδ1-to-Jδ1 recombination. One iPSC line showed normal karyotype with 99% cells expressing OCT3/4 & SSEA4. The differentiation process generated 70+ million iVδ1T cells from 3 million iPSCs expressing γδ T cell markers CD45, CD3, Vδ1-TCR, CD16, CD56, NKG2D, CD45RA, and CD27. Cytokine release following PMA/ionomycin stimulation showed increases of at least 50x for Granzyme A, 300x for IFN-γ, 1400x for TNF-α, ~10 to 20x for Granzyme B, ~5 to 10x for Perforin, ~6x for Granulysin. IL-6 was not detected either before or after stimulation, and IL17A was at low concentration. At a 16:1 E:T ratio, preliminary data shows that Vδ1+ γδ T cells killed K562 (CML) 95.7%; MOLM13 (AML) 60.3%; U87MG (glioblastoma) 70.3%; and ovarian cancer lines OVSAHO 57.1%, OVCAR-3 69.6%, and KURAMUCHI 55.1%.ConclusionsWe generated Vδ1+ iPSC derived γδ T cells with effector cytokine phenotype and low risk for cytokine release syndrome. Robust cytotoxic activity was seen across a variety of cancer cell lines, potentially providing an off-the-shelf platform for allogeneic cell therapy.
Single-wall and multiwall carbon nanotubes at high temperature are irradiated with the focused electron beam in an electron microscope. Nanotubes can be tailored with monolayer precision, and new ...morphologies of nanotubes are created. Atoms from layers of multiwall tubes can be removed and the tubes can be bent by a predefined angle. Bundles of single-wall tubes are transformed locally to multiwall tubes with coherent transition between the two modifications.
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IJS, KILJ, NUK, PNG, UL, UM
•A simple and efficient approach to acquire the charge distribution in TEM•Direct inspection of charge and fast response to charge variations•Mapping charge density in quantitative way with a high ...sensitivity
Mapping the charge distribution in nano scale systems still is a difficult task, but is important to provide fundamental insights into the properties of materials. We demonstrate how in-line holography in transmission electron microscopy can be used to extract the charge distribution in the nanowire in a quantitative way. This technique can realize a fast acquisition of delicate charge variations. By taking advantage of the possibilities of in-situ electron microscopy, variations of the external field can be used to modulate the charge distribution. Because of the fast response to charge variations, this method provides an efficient probing tool for detecting dynamic charge redistribution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPUK, ZRSKP
Power level control is one of the critical functions in the instrument and control system of nuclear power plants (NPPs). In most power level control systems of NPPs, the power level or average ...neutron flux in reactor cores provided by out-of-core neutron sensors are usually measured as feedback of power control systems, while, as critical measuring devices, there is a risk of damage to out-of-core neutron sensors. For improving the operation reliability of NPPs under the neutron sensors’ failure, a power control system based on power observer is developed in this work. The simulation based on NPP simulator shows the power control system based on the observer is effective when neutron sensors fail.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
A highly active heterogeneous palladium catalyst was prepared from coated mesoporous materials which contain a layer of readily available PEG with a labile coordinating ability for palladium. The ...aqueous suspension of the catalyst may be reused several times by simple extraction of the aqueous reaction mixture with ether to remove the product.
The rational design of catalytic materials from the reaction characteristics is expected to be a useful strategy to create highly efficient catalysts. Herein, according to a well‐established reaction ...pathway of epoxide hydration catalyzed a dual‐molecular system of Co3+/salen in which a high concentration of active sites is favorable to enhance the activity, we provide an alternative way to prepare a highly efficient heterogeneous catalyst with a high concentration of Co3+/salen from the polymerization of vinyl‐functionalized salen monomers followed by the loading of Co3+ species (Co3+/POL‐salen). Co3+/POL‐salen has a hierarchical porosity and an extraordinary hydrothermal stability. Importantly, catalytic tests in epoxide hydration demonstrate that Co3+/POL‐salen affords excellent high activities, which are even better than those of the homogeneous version. This phenomenon is related to the very high concentration of Co3+/salen in the catalyst. In addition, this catalyst can be recycled readily because of its excellent hydrothermal stability.
Rational design: A porous organic polymer with a very high salen concentration is rationally synthesized from the self‐polymerization of a salen‐based monomer. After the loading of Co3+, the heterogeneous catalyst shows even better properties than the homogeneous version in the catalytic hydration of epoxides because of the enrichment of activated reactants.
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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