244 research outputs found

    Magnetoelectric properties of flexible BiFeO 3 /Ni tapes

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    We report ferroelectric (FE), ferromagnetic, and magnetoelectric (ME) properties of BiFeO 3 films directly deposited on flexible magnetic Ni tapes. Without use of metal-oxide and/or noble metal buffer layer between the BiFeO 3 and the Ni, both ferroelectric and magnetic properties of the film and the substrate are preserved. X-ray diffraction and transmission electron microscopy analyses confirm the formation of preferentially oriented (110) BiFeO 3 film on Ni tapes. The BiFeO 3 film has a saturation polarization and a piezoelectric d 33 coefficient of 69 μC/cm 2 and 52 pm/V, respectively. The BiFeO 3 /Ni tape shows a magnetoelectric coefficient of 3.5 mV/cm·Oe.Fil: Yan, L.. No especifíca;Fil: Zhuo, M.. No especifíca;Fil: Wang, Z.. Virginia Tech University; Estados UnidosFil: Yao, J.. Virginia Tech University; Estados UnidosFil: Haberkorn, Nestor Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Zhang, S.. No especifíca;Fil: Civale, L.. No especifíca;Fil: Li, J.. Virginia Tech University; Estados UnidosFil: Viehland, D.. Virginia Tech University; Estados UnidosFil: Jia, Q. X.. No especifíca

    The Intratubular and Intracrine Renin-Angiotensin System in the Proximal Tubules of the Kidney and Its Roles in Angiotensin II-Induced Hypertension

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    The kidney plays a fundamental role in the physiological regulation of basal blood pressure and the development of hypertension. Although the mechanisms underlying hypertension are very complex, the renin-angiotensin system (RAS) in the kidney, especially intratubular and intracellular RAS, undoubtedly plays a critical role in maintaining basal blood pressure homeostasis and the development of angiotensin II (ANG II)-dependent hypertension. In the proximal tubules, ANG II activates two G protein-coupled receptors, AT1 and AT2, to exert powerful effects to regulate proximal tubular sodium and fluid reabsorption by activating cell surface as well as intracellular AT1 receptors. Increased production and actions of ANG II in the proximal tubules may cause salt and fluid retention, impair the pressure-natriuresis response, and consequently increase blood pressure in hypertension. The objectives of this chapter are to critically review and discuss our current understanding of intratubular and intracellular RAS in the kidney, and their contributions to basal blood pressure homeostasis and the development of ANG II-dependent hypertension. The new knowledge will likely help uncover novel renal mechanisms of hypertension, and develop kidney- or proximal tubule-specific strategies or drugs to prevent and treat hypertension in humans

    FOXD1-ALDH1A3 signaling is a determinant for the self-renewal and tumorigenicity of mesenchymal glioma stem cells

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    Glioma stem-like cells (GSC) with tumor-initiating activity orchestrate the cellular hierarchy in glioblastoma and engender therapeutic resistance. Recent work has divided GSC into two subtypes with a mesenchymal (MES) GSC population as the more malignant subtype. In this study, we identify the FOXD1-ALDH1A3 signaling axis as a determinant of the MES GSC phenotype. The transcription factor FOXD1 is expressed predominantly in patient-derived cultures enriched with MES, but not with the proneural GSC subtype. shRNA-mediated attenuation of FOXD1 in MES GSC ablates their clonogenicity in vitro and in vivo. Mechanistically, FOXD1 regulates the transcriptional activity of ALDH1A3, an established functional marker for MES GSC. Indeed, the functional roles of FOXD1 and ALDH1A3 are likely evolutionally conserved, insofar as RNAi-mediated attenuation of their orthologous genes in Drosophila blocks formation of brain tumors engineered in that species. In clinical specimens of high-grade glioma, the levels of expression of both FOXD1 and ALDH1A3 are inversely correlated with patient prognosis. Finally, a novel small-molecule inhibitor of ALDH we developed, termed GA11, displays potent in vivo efficacy when administered systemically in a murine GSC-derived xenograft model of glioblastoma. Collectively, our findings define a FOXD1-ALDH1A3 pathway in controling the clonogenic and tumorigenic potential of MES GSC in glioblastoma tumors

    Flexible Communication Avoiding Matrix Multiplication on FPGA with High-Level Synthesis

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    Data movement is the dominating factor affecting performance and energy in modern computing systems. Consequently, many algorithms have been developed to minimize the number of I/O operations for common computing patterns. Matrix multiplication is no exception, and lower bounds have been proven and implemented both for shared and distributed memory systems. Reconfigurable hardware platforms are a lucrative target for I/O minimizing algorithms, as they offer full control of memory accesses to the programmer. While bounds developed in the context of fixed architectures still apply to these platforms, the spatially distributed nature of their computational and memory resources requires a decentralized approach to optimize algorithms for maximum hardware utilization. We present a model to optimize matrix multiplication for FPGA platforms, simultaneously targeting maximum performance and minimum off-chip data movement, within constraints set by the hardware. We map the model to a concrete architecture using a high-level synthesis tool, maintaining a high level of abstraction, allowing us to support arbitrary data types, and enables maintainability and portability across FPGA devices. Kernels generated from our architecture are shown to offer competitive performance in practice, scaling with both compute and memory resources. We offer our design as an open source project to encourage the open development of linear algebra and I/O minimizing algorithms on reconfigurable hardware platforms

    Atg7-Mediated Autophagy Is Involved in the Neural Crest Cell Generation in Chick Embryo

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    Autophagy plays a very important role in numerous physiological and pathological events. However, it still remains unclear whether Atg7-induced autophagy is involved in the regulation of neural crest cell production. In this study, we found the co-location of Atg7 and Pax7+ neural crest cells in early chick embryo development. Upregulation of Atg7 with unilateral transfection of full-length Atg7 increased Pax7+ and HNK-1+ cephalic and trunk neural crest cell numbers compared to either Control-GFP transfection or opposite neural tubes, suggesting that Atg7 over-expression in neural tubes could enhance the production of neural crest cells. BMP4 in situ hybridization and p-Smad1/5/8 immunofluorescent staining demonstrated that upregulation of Atg7 in neural tubes suppressed the BMP4/Smad signaling, which is considered to promote the delamination of neural crest cells. Interestingly, upregulation of Atg7 in neural tubes could significantly accelerate cell progression into the S phase, implying that Atg7 modulates cell cycle progression. However, β-catenin expression was not significantly altered. Finally, we demonstrated that upregulation of the Atg7 gene could activate autophagy as did Atg8. We have also observed that similar phenotypes, such as more HNK-1+ neural crest cells in the unilateral Atg8 transfection side of neural tubes, and the transfection with full-length Atg8-GFP certainly promote the numbers of BrdU+ neural crest cells in comparison to the GFP control. Taken together, we reveal that Atg7-induced autophagy is involved in regulating the production of neural crest cells in early chick embryos through the modification of the cell cycle

    Recombinant Human Endostatin Endostar Inhibits Tumor Growth and Metastasis in a Mouse Xenograft Model of Colon Cancer

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    To investigate the effects of recombinant human endostatin Endostar on metastasis and angiogenesis and lymphangiogenesis of colorectal cancer cells in a mouse xenograft model. Colon cancer cells SW620 were injected subcutaneously into the left hind flank of nude mice to establish mouse xenograft models. The mice were treated with normal saline or Endostar subcutaneously every other day. The growth and lymph node metastasis of tumor cells, angiogenesis and lymphangiogenesis in tumor tissue were detected. Apoptosis and cell cycle distribution were studied by flow cytometry. The expression of VEGF-A, -C, or -D in SW620 cells was determined by immunoblotting assays. Endostar inhibited tumor growth and the rate of lymph node metastasis (P < 0.01). The density of blood vessels in or around the tumor area was 12.27 ± 1.21 and 22.25 ± 2.69 per field in Endostar-treated mice and controls (P < 0.05), respectively. Endostar also decreased the density of lymphatic vessels in tumor tissues (7.84 ± 0.81 vs. 13.83 ± 1.08, P < 0.05). Endostar suppresses angiogenesis and lymphangiogenesis in the lymph nodes with metastases, simultaneously. The expression of VEGF-A, -C and -D in SW620 cells treated with Endostar was substantially lower than that of controls. Endostar inhibited growth and lymph node metastasis of colon cancer cells by inhibiting angiogenesis and lymphangiogenesis in a mouse xenograft model of colon cancer

    Expression of TRPC6 in Renal Cortex and Hippocampus of Mouse during Postnatal Development

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    TRPC6, a member of the TRPC family, attracts much attention from the public because of its relationship with the disease. In both the brain and kidney, TRPC6 serves a variety of functions. The aim of the present study was to observe the expression and effects of TRPC6 in renal cortex and hippocampus during early postnatal development of the mouse. In the present study, immunohistochemistry and Western blotting were used to detect the expression of TRPC6 in the mouse kidney and hippocampus of postnatal day 1, 3, 5, 7, 14, 21, 28 and 49 (P1, P3, P5, P7, P14, P21, P28 and P49). Results showed that the expression of TRPC6 was increased in the mouse hippocampus, and there was a significant increase between P7 and P14 during the postnatal development. Meanwhile, the expression of TRPC6 was also detected in glomerulus and tubules, and a decreased expression was found during postnatal maturation of mouse renal cortex. From these in vivo experiments, we concluded that the expression of TRPC6 was active in the developing mouse kidney cortex, and followed a loss of expression with the development of kidney. Meanwhile, an increased expression was found in the hippocampus with the development. Together, these data suggested that the developmental changes in TRPC6 expression might be required for proper postnatal kidney cortex development, and played a critical role in the hippocampus during development, which formed the basis for understanding the nephrogenesis and neurogenesis in mice and provided a practically useful knowledge to the clinical and related research

    REGγ is associated with multiple oncogenic pathways in human cancers

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    <p>Abstract</p> <p>Background</p> <p>Recent studies suggest a role of the proteasome activator, REGγ, in cancer progression. Since there are limited numbers of known REGγ targets, it is not known which cancers and pathways are associated with REGγ.</p> <p>Methods</p> <p>REGγ protein expressions in four different cancers were investigated by immunohistochemistry (IHC) analysis. Following NCBI Gene Expression Omnibus (GEO) database search, microarray platform validation, differential expressions of REGγ in corresponding cancers were statistically analyzed. Genes highly correlated with REGγ were defined based on Pearson's correlation coefficient. Functional links were estimated by Ingenuity Core analysis. Finally, validation was performed by RT-PCR analysis in established cancer cell lines and IHC in human colon cancer tissues</p> <p>Results</p> <p>Here, we demonstrate overexpression of REGγ in four different cancer types by micro-tissue array analysis. Using meta-analysis of publicly available microarray databases and biological studies, we verified elevated REGγ gene expression in the four types of cancers and identified genes significantly correlated with REGγ expression, including genes in p53, Myc pathways, and multiple other cancer-related pathways. The predicted correlations were largely consistent with quantitative RT-PCR analysis.</p> <p>Conclusions</p> <p>This study provides us novel insights in REGγ gene expression profiles and its link to multiple cancer-related pathways in cancers. Our results indicate potentially important pathogenic roles of REGγ in multiple cancer types and implicate REGγ as a putative cancer marker.</p
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