970 research outputs found

    Laser microdissection of cellular compartments for expression analyses in cancer models

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    金沢大学新学術創成研究機構ナノ生命科学研究所Cancer tissues are composed of various cell types including cancer cells, cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs) and endothelial cells. These surrounding stromal cells form the tumor microenvironment, partly through the inflammatory response, which plays an important role in the development and malignant progression of cancer. It is therefore important to examine the expression profiles and protein modifications of each cellular component independently to decipher the interaction between the tumor cells and the microenvironment. We herein describe a protocol for laser microdissection, which allows for the individual cellular compartments to be collected separately. This will allow us to perform real-time RT-PCRs and microarray analyses of specific cell types in tumor tissues. © 2018, Springer Science+Business Media, LLC.Embargo Period 12 month

    Tempcore Process Simulator to Analyze Microstructural Evolution of Quenched and Tempered Rebar

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    Featured Application Proposed process simulator can be widely applied to parameter design of industrial Tempcore process with reduced cost and time. Abstract Tempcore process simulator (TPS) has been developed in this study to analyze the microstructural evolution of quenched and tempered rebar. There has been an increasing need to relate the complex microstructures to the resulting properties of quenched and tempered rebar. However, information on such relationships typically requires precise thermal histories imposed on the workpiece. Therefore, TPS, capable of simulating the Tempcore process, has been developed to produce high-fidelity data. TPS mainly consists of a vacuum induction furnace, pilot rolling mill, box furnace, and cooling unit to simulate shop floor operations. A series of experimental tests were successfully carried out with various parameters, such as reheating temperature, water flow, water pressure, and cooling time. The effects of chemical compositions and cooling time on the microstructural evolution and mechanical properties of quenched and tempered rebar have been analyzed to validate the performance of TPS. The results show that TPS can simulate the Tempcore process with a high degree of fidelity and reliability.11Ysciescopu

    Characterizing the Efficiency of Perovskite Solar Cells and Light-Emitting Diodes

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    Metal halide perovskites (MHPs) are being widely studied as a light-absorber for high-efficiency solar cells. With efforts being made throughout the globe, the power conversion efficiency of MHP solar cells has recently soared up to 25.2%. MHPs are now being spotlighted as a next-generation light-emitter as well. Their high color purity and solution-processability are of particular interest for display applications, which in general benefit from wide color gamut and low-cost high-resolution subpixel patterning. For this reason, research activities on perovskite light-emitting diodes (LEDs) are rapidly growing, and their external quantum efficiencies have been dramatically improved to over 20%. As more and more research groups with different backgrounds are working on these perovskite optoelectronic devices, the demand is growing for standard methods for accurate efficiency measurement that can be agreed upon across the disciplines and, at the same time, can be realized easily in the lab environment with due diligence. Herein, optoelectronic characterization methods are revisited from the viewpoint of MHP solar cells and LEDs. General efficiency measurement practices are first reviewed, common sources of errors are introduced, and guidelines for avoiding or minimizing those errors are then suggested to help researchers in fields develop the best measurement practice.

    NF-κB/STAT3/PI3K signaling crosstalk in iMycEμ B lymphoma

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    <p>Abstract</p> <p>Background</p> <p>Myc is a well known driver of lymphomagenesis, and Myc-activating chromosomal translocation is the recognized hallmark of Burkitt lymphoma, an aggressive form of non-Hodgkin's lymphoma. We developed a model that mimics this translocation event by inserting a mouse <it>Myc </it>cDNA gene into the immunoglobulin heavy chain locus, just upstream of the intronic Eμ enhancer. These mice, designated iMyc<sup>Eμ</sup>, readily develop B-cell lymphoma. To study the mechanism of Myc-induced lymphoma, we analyzed signaling pathways in lymphoblastic B-cell lymphomas (LBLs) from iMyc<sup>Eμ </sup>mice, and an LBL-derived cell line, iMyc<sup>Eμ</sup>-1.</p> <p>Results</p> <p>Nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) were constitutively activated in iMyc<sup>Eμ </sup>mice, not only in LBLs but also in the splenic B-lymphocytes of young animals months before tumors developed. Moreover, inhibition of either transcription factor in iMyc<sup>Eμ</sup>-1 cells suppressed growth and caused apoptosis, and the abrogation of NF-κB activity reduced DNA binding by both STAT3 and Myc, as well as Myc expression. Inhibition of STAT3 signaling eliminated the activity of both NF-κB and Myc, and resulted in a corresponding decrease in the level of Myc. Thus, in iMyc<sup>Eμ</sup>-1 cells NF-κB and STAT3 are co-dependent and can both regulate Myc. Consistent with this, NF-κB and phosphorylated STAT3 were physically associated with one another. In addition, LBLs and iMyc<sup>Eμ</sup>-1 cells also showed constitutive AKT phosphorylation. Blocking AKT activation by inhibiting PI3K reduced iMyc<sup>Eμ</sup>-1 cell proliferation and caused apoptosis, via downregulation of NF-κB and STAT3 activity and a reduction of Myc levels. Co-treatment with NF-κB, STAT3 or/and PI3K inhibitors led to additive inhibition of iMyc<sup>Eμ</sup>-1 cell proliferation, suggesting that these signaling pathways converge.</p> <p>Conclusions</p> <p>Our findings support the notion that constitutive activation of NF-κB and STAT3 depends on upstream signaling through PI3K, and that this activation is important for cell survival and proliferation, as well as for maintaining the level of Myc. Together, these data implicate crosstalk among NF-κB, STAT3 and PI3K in the development of iMyc<sup>Eμ </sup>B-cell lymphomas.</p

    Efficient Perovskite Light-Emitting Diodes Using Polycrystalline Core-Shell-Mimicked Nanograins

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    Making small nanograins in polycrystalline organic-inorganic halide perovskite (OIHP) films is critical to improving the luminescent efficiency in perovskite light-emitting diodes (PeLEDs). 3D polycrystalline OIHPs have fundamental limitations related to exciton binding energy and exciton diffusion length. At the same time, passivating the defects at the grain boundaries is also critical when the grain size becomes smaller. Molecular additives can be incorporated to shield the nanograins to suppress defects at grain boundaries; however, unevenly distributed molecular additives can cause imbalanced charge distribution and inefficient local defect passivation in polycrystalline OIHP films. Here, a kinetically controlled polycrystalline organic-shielded nanograin (OSN) film with a uniformly distributed organic semiconducting additive (2,2 ',2 ''-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole), TPBI) is developed mimicking core-shell nanoparticles. The OSN film causes improved photophysical and electroluminescent properties with improved light out-coupling by possessing a low refractive index. Finally, highly improved electroluminescent efficiencies of 21.81% ph el(-1) and 87.35 cd A(-1) are achieved with a half-sphere lens and four-time increased half-lifetime in polycrystalline PeLEDs. This strategy to make homogeneous, defect-healed polycrystalline core-shell-mimicked nanograin film with better optical out-coupling will provide a simple and efficient way to make highly efficient perovskite polycrystal films and their optoelectronics devices.

    Molecular and cytological features of the mouse B-cell lymphoma line iMyc(Eμ)-1

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    BACKGROUND: Myc-induced lymphoblastic B-cell lymphoma (LBL) in iMyc(Eμ )mice may provide a model system for the study of the mechanism by which human MYC facilitates the initiation and progression of B cell and plasma cell neoplasms in human beings. We have recently shown that gene-targeted iMyc(Eμ )mice that carry a His(6)-tagged mouse Myc cDNA, Myc(His), just 5' of the immunoglobulin heavy-chain enhancer, Eμ, are prone to B cell and plasma cell tumors. The predominant tumor (~50%) that arose in the iMyc(Eμ )mice on the mixed genetic background of segregating C57BL/6 and 129/SvJ alleles was LBL. The purpose of this study was to establish and characterize a cell line, designated iMyc(Eμ)-1, for the in-depth evaluation of LBL in vitro. METHODS: The morphological features and the surface marker expression profile of the iMyc(Eμ)-1 cells were evaluated using cytological methods and FACS, respectively. The cytogenetic make-up of the iMyc(Eμ)-1 cells was assessed by spectral karyotyping (SKY). The expression of the inserted Myc(His )gene was determined using RT-PCR and qPCR. Clonotypic immunoglobulin gene arrangements were detected by Southern blotting. The global gene expression program of the iMyc(Eμ)-1 cells and the expression of 768 "pathway" genes were determined with the help of the Mouse Lymphochip(© )and Superarray(© )cDNA micro- and macroarrays, respectively. Array results were verified, in part, by RT-PCR and qPCR. RESULTS: Consistent with their derivation from LBL, the iMyc(Eμ)-1 cells were found to be neoplastic IgM(high)IgD(low )lymphoblasts that expressed typical B-cell surface markers including CD40, CD54 (ICAM-1), CD80 (B7-1) and CD86 (B7-2). The iMyc(Eμ)-1 cells harbored a reciprocal T(9;11) and three non-reciprocal chromosomal translocations, over-expressed Myc(His )at the expense of normal Myc, and exhibited gene expression changes on Mouse Lymphochip(© )microarrays that were consistent with Myc(His)-driven B-cell neoplasia. Upon comparison to normal B cells using eight different Superarray(© )cDNA macroarrays, the iMyc(Eμ)-1 cells showed the highest number of changes on the NFκB array. CONCLUSION: The iMyc(Eμ)-1 cells may provide a uniquely useful model system to study the growth and survival requirements of Myc-driven mouse LBL in vitro

    Extracting regulatory modules from gene expression data by sequential pattern mining

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    Abstract Background Identifying a regulatory module (RM), a bi-set of co-regulated genes and co-regulating conditions (or samples), has been an important challenge in functional genomics and bioinformatics. Given a microarray gene-expression matrix, biclustering has been the most common method for extracting RMs. Among biclustering methods, order-preserving biclustering by a sequential pattern mining technique has native advantage over the conventional biclustering approaches since it preserves the order of genes (or conditions) according to the magnitude of the expression value. However, previous sequential pattern mining-based biclustering has several weak points in that they can easily be computationally intractable in the real-size of microarray data and sensitive to inherent noise in the expression value. Results In this paper, we propose a novel sequential pattern mining algorithm that is scalable in the size of microarray data and robust with respect to noise. When applied to the microarray data of yeast, the proposed algorithm successfully found long order-preserving patterns, which are biologically significant but cannot be found in randomly shuffled data. The resulting patterns are well enriched to known annotations and are consistent with known biological knowledge. Furthermore, RMs as well as inter-module relations were inferred from the biologically significant patterns. Conclusions Our approach for identifying RMs could be valuable for systematically revealing the mechanism of gene regulation at a genome-wide level.</p

    Antibiotic-induced Severe Neutropenia with Multidrug-Dependent Antineutrophil Antibodies Developed in A Child with Streptococcus pneumoniae Infection

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    Drug-induced neutropenia (DIN), particularly that in which antibiotic-dependent antineutrophil antibodies have been detected, is a rare disorder. We report the case of a child with pneumococcal pneumonia, who experienced severe neutropenia during various antibiotic treatments. We detected 4 kinds (cefotaxim, augmentin, vancomycin, and tobramycin) of antibiotic-dependent antineutrophil antibodies by using the mixed passive hemagglutination assay (MPHA) technique with this child
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