188 research outputs found

    Ultrafast QND measurements based on diamond-shape artificial atom

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    We propose a Quantum Non Demolition (QND) read-out scheme for a superconducting artificial atom coupled to a resonator in a circuit QED architecture, for which we estimate a very high measurement fidelity without Purcell effect limitations. The device consists of two transmons coupled by a large inductance, giving rise to a diamond-shape artificial atom with a logical qubit and an ancilla qubit interacting through a cross-Kerr like term. The ancilla is strongly coupled to a transmission line resonator. Depending on the qubit state, the ancilla is resonantly or dispersively coupled to the resonator, leading to a large contrast in the transmitted microwave signal amplitude. This original method can be implemented with state of the art Josephson parametric amplifier, leading to QND measurements in a few tens of nanoseconds with fidelity as large as 99.9 %.Comment: 5 pages, 4 figure

    Kerr non-linearity in a superconducting Josephson metamaterial

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    We present a detailed experimental and theoretical analysis of the dispersion and non-linear Kerr frequency shifts of plasma modes in a one-dimensional Josephson junction chain containing 500 SQUIDs in the regime of weak nonlinearity. The measured low-power dispersion curve agrees perfectly with the theoretical model if we take into account the Kerr renormalisation of the bare frequencies and the long-range nature of the island charge screening by a remote ground plane. We measured the self- and cross-Kerr shifts for the frequencies of the eight lowest modes in the chain. We compare the measured Kerr coefficients with theory and find good agreement

    Novel Report of Expression and Function of CD97 in Malignant Gliomas: Correlation With Wilms Tumor 1 Expression and Glioma Cell Invasiveness Laboratory investigation

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    Object. The Wilms tumor 1 (WT1) protein—a developmentally regulated transcription factor—is aberrantly expressed in gliomas and promotes their malignant phenotype. However, little is known about the molecular allies that help it mediate its oncogenic functions in glioma cells. Methods. The authors used short interfering RNA (siRNA) to suppress WT1 expression in glioblastoma (GBM) cells and evaluated the effect of this on GBM cell invasiveness. Gene expression analysis was then used to identify the candidate genes that were altered as a result of WT1 silencing. One candidate target, CD97, was then selected for further investigation into its role by suppressing its expression using siRNA silencing, followed by proliferation and invasion assays. Results. WT1 levels were reliably and reproducibly suppressed by siRNA application. This resulted in a significant decrease in cellular invasiveness. Microarray analyses identified the gene products that were consistently downregulated (27) and upregulated (11) with WT1 silencing. Of these, CD97 expression was consistently suppressed across the 3 different GBM cell lines studied and was found on further investigation to significantly impact GBM cell invasiveness. Conclusions. Although CD97 expression in gliomas has not been described previously, we conclude that the possible upregulation of CD97 mediated by WT1 promotes cellular invasiveness—one of the most characteristic and challenging aspects of glial tumor cells. Further studies are needed to clarify the nature of this regulation and its impact, as CD97 could represent a novel target for antiglioma therapies

    Novel Report of Expression and Function of CD97 in Malignant Gliomas: Correlation With Wilms Tumor 1 Expression and Glioma Cell Invasiveness Laboratory investigation

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    Object. The Wilms tumor 1 (WT1) protein—a developmentally regulated transcription factor—is aberrantly expressed in gliomas and promotes their malignant phenotype. However, little is known about the molecular allies that help it mediate its oncogenic functions in glioma cells. Methods. The authors used short interfering RNA (siRNA) to suppress WT1 expression in glioblastoma (GBM) cells and evaluated the effect of this on GBM cell invasiveness. Gene expression analysis was then used to identify the candidate genes that were altered as a result of WT1 silencing. One candidate target, CD97, was then selected for further investigation into its role by suppressing its expression using siRNA silencing, followed by proliferation and invasion assays. Results. WT1 levels were reliably and reproducibly suppressed by siRNA application. This resulted in a significant decrease in cellular invasiveness. Microarray analyses identified the gene products that were consistently downregulated (27) and upregulated (11) with WT1 silencing. Of these, CD97 expression was consistently suppressed across the 3 different GBM cell lines studied and was found on further investigation to significantly impact GBM cell invasiveness. Conclusions. Although CD97 expression in gliomas has not been described previously, we conclude that the possible upregulation of CD97 mediated by WT1 promotes cellular invasiveness—one of the most characteristic and challenging aspects of glial tumor cells. Further studies are needed to clarify the nature of this regulation and its impact, as CD97 could represent a novel target for antiglioma therapies

    Robust Adaptive Control of the Mold Level in the Continuous Casting Process Using Multiple Models

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    Abstract-In the continuous casting of steel, mold level control is fundamental for obtaining high productivity and high quality. Using conventional methods, it is difficult to achieve both stability and performance robustness because of different classes of disturbances and parameters uncertainties in the process. This paper presents a multi-model adaptive control architecture based on the so-called RMMAC methodology. With the help of precise definition of robust performance requirements, the number of models, estimators and controllers are merely derived. More importantly, the combination of robust non-adaptive mixed-µ synthesis and stochastic hypothesis testing concepts enables controller performances prediction as well as online monitoring process parameters which could be used by operators to take corrective actions. The generated signals are likewise useful for understanding the physical phenomena in the process

    Coherent frequency conversion in a superconducting artificial atom with two internal degrees of freedom

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    By adding a large inductance in a dc-SQUID phase qubit loop, one decouples the junctions' dynamics and creates a superconducting artificial atom with two internal degrees of freedom. In addition to the usual symmetric plasma mode ({\it s}-mode) which gives rise to the phase qubit, an anti-symmetric mode ({\it a}-mode) appears. These two modes can be described by two anharmonic oscillators with eigenstates ∣ns⟩\ket{n_{s}} and ∣na⟩\ket{n_{a}} for the {\it s} and {\it a}-mode, respectively. We show that a strong nonlinear coupling between the modes leads to a large energy splitting between states ∣0s,1a⟩\ket{0_{s},1_{a}} and ∣2s,0a⟩\ket{2_{s},0_{a}}. Finally, coherent frequency conversion is observed via free oscillations between the states ∣0s,1a⟩\ket{0_{s},1_{a}} and ∣2s,0a⟩\ket{2_{s},0_{a}}

    Epitaxial rhenium microwave resonators

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    International audienceWe have fabricated rhenium microwave resonators from epitaxial films. We have used thin films of different structural quality depending on their growth conditions. The resonators were coupled to a microwave transmission line which allows the measurement of their resonance frequencies and internal quality factors. From the resonance frequency at low temperature , the effective penetration depth and the London penetration depth of the rhenium film are extracted

    The phosphorylated prodrug FTY720 is a histone deacetylase inhibitor that reactivates ERα expression and enhances hormonal therapy for breast cancer

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    Estrogen receptor-α (ERα)-negative breast cancer is clinically aggressive and does not respond to conventional hormonal therapies. Strategies that lead to re-expression of ERα could sensitize ERα-negative breast cancers to selective ER modulators. FTY720 (fingolimod, Gilenya), a sphingosine analog, is the Food and Drug Administration (FDA)-approved prodrug for treatment of multiple sclerosis that also has anticancer actions that are not yet well understood. We found that FTY720 is phosphorylated in breast cancer cells by nuclear sphingosine kinase 2 and accumulates there. Nuclear FTY720-P is a potent inhibitor of class I histone deacetylases (HDACs) that enhances histone acetylations and regulates expression of a restricted set of genes independently of its known effects on canonical signaling through sphingosine-1-phosphate receptors. High-fat diet (HFD) and obesity, which is now endemic, increase breast cancer risk and have been associated with worse prognosis. HFD accelerated the onset of tumors with more advanced lesions and increased triple-negative spontaneous breast tumors and HDAC activity in MMTV-PyMT transgenic mice. Oral administration of clinically relevant doses of FTY720 suppressed development, progression and aggressiveness of spontaneous breast tumors in these mice, reduced HDAC activity and strikingly reversed HFD-induced loss of estrogen and progesterone receptors in advanced carcinoma. In ERα-negative human and murine breast cancer cells, FTY720 reactivated expression of silenced ERα and sensitized them to tamoxifen. Moreover, treatment with FTY720 also re-expressed ERα and increased therapeutic sensitivity of ERα-negative syngeneic breast tumors to tamoxifen in vivo more potently than a known HDAC inhibitor. Our work suggests that a multipronged attack with FTY720 is a novel combination approach for effective treatment of both conventional hormonal therapy-resistant breast cancer and triple-negative breast cancer

    Reduced Expression of Inflammatory Genes in Deceased Donor Kidneys Undergoing Pulsatile Pump Preservation

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    Background The use of expanded criteria donor kidneys (ECD) had been associated with worse outcomes. Whole gene expression of pre-implantation allograft biopsies from deceased donor kidneys (DDKs) was evaluated to compare the effect of pulsatile pump preservation (PPP) vs. cold storage preservation (CSP) on standard and ECD kidneys. Methodology/Principal Findings 99 pre-implantation DDK biopsies were studied using gene expression with GeneChips. Kidneys transplant recipients were followed post transplantation for 35.8 months (range = 24–62). The PPP group included 60 biopsies (cold ischemia time (CIT) = 1,367+/−509 minutes) and the CSP group included 39 biopsies (CIT = 1,022+/−485 minutes) (P Conclusions/Significance Inflammation was the most important up-regulated pattern associated with pre-implantation biopsies undergoing CSP even when the PPP group has a larger number of ECD kidneys. No significant difference was observed in delayed graft function incidence and graft function post-transplantation. These findings support the use of PPP in ECD donor kidneys
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