1,633 research outputs found

    Bell Inequalities Classifying Bi-separable Three-qubit States

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    We present a set of Bell inequalities that gives rise to a finer classification of the entanglement for tripartite systems. These inequalities distinguish three possible bi-separable entanglements for three-qubit states. The three Bell operators we employed constitute an external sphere of the separable cube.Comment: 8 page

    Photocurrent measurements of supercollision cooling in graphene

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    The cooling of hot electrons in graphene is the critical process underlying the operation of exciting new graphene-based optoelectronic and plasmonic devices, but the nature of this cooling is controversial. We extract the hot electron cooling rate near the Fermi level by using graphene as novel photothermal thermometer that measures the electron temperature (T(t)T(t)) as it cools dynamically. We find the photocurrent generated from graphene pnp-n junctions is well described by the energy dissipation rate CdT/dt=A(T3Tl3)C dT/dt=-A(T^3-T_l^3), where the heat capacity is C=αTC=\alpha T and TlT_l is the base lattice temperature. These results are in disagreement with predictions of electron-phonon emission in a disorder-free graphene system, but in excellent quantitative agreement with recent predictions of a disorder-enhanced supercollision (SC) cooling mechanism. We find that the SC model provides a complete and unified picture of energy loss near the Fermi level over the wide range of electronic (15 to \sim3000 K) and lattice (10 to 295 K) temperatures investigated.Comment: 7pages, 5 figure

    Optical amplification in hollow-core negative-curvature fibers doped with perovskite CsPbBr3 nanocrystals

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    We report a hollow-core negative-curvature fiber (HC-NCF) optical signal amplifier fabricated by the filling of the air microchannels of the fiber with all-inorganic CsPbBr3 perovskite nanocrystals (PNCs). The optimum fabrication conditions were found to enhance the optical gain, up to +3 dB in the best device. Experimental results were approximately reproduced by a gain assisted mechanism based on the nonlinear optical properties of the PNCs, indicating that signal regeneration can be achieved under low pump powers, much below the threshold of stimulated emission. The results can pave the road for new functionalities of the HC-NCF with PNCs, such as optical amplification, nonlinear frequency conversion and gas sensors

    CAR T cells targeting BAFF-R can overcome CD19 antigen loss in B cell malignancies

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    CAR T cells targeting CD19 provide promising options for treatment of B cell malignancies. However, tumor relapse from antigen loss can limit efficacy. We developed humanized, second-generation CAR T cells against another B cell–specific marker, B cell activating factor receptor (BAFF-R), which demonstrated cytotoxicity against human lymphoma and acute lymphoblastic leukemia (ALL) lines. Adoptively transferred BAFF-R-CAR T cells eradicated 10-day preestablished tumor xenografts after a single treatment and retained efficacy against xenografts deficient in CD19 expression, including CD19-negative variants within a background of CD19-positive lymphoma cells. Four relapsed, primary ALLs with CD19 antigen loss obtained after CD19-directed therapy retained BAFF-R expression and activated BAFF-R-CAR, but not CD19-CAR, T cells. BAFF-R-CAR, but not CD19-CAR, T cells also demonstrated antitumor effects against an additional CD19 antigen loss primary patient–derived xenograft (PDX) in vivo. BAFF-R is amenable to CAR T cell therapy, and its targeting may prevent emergence of CD19 antigen loss variants

    Plasmon-phonon coupling in large-area graphene dot and antidot arrays

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    Nanostructured graphene on SiO2 substrates pave the way for enhanced light-matter interactions and explorations of strong plasmon-phonon hybridization in the mid-infrared regime. Unprecedented large-area graphene nanodot and antidot optical arrays are fabricated by nanosphere lithography, with structural control down to the sub-100 nanometer regime. The interaction between graphene plasmon modes and the substrate phonons is experimentally demonstrated and structural control is used to map out the hybridization of plasmons and phonons, showing coupling energies of the order 20 meV. Our findings are further supported by theoretical calculations and numerical simulations.Comment: 7 pages including 6 figures. Supporting information is available upon request to author

    Transcriptome Atlases of Mouse Brain Reveals Differential Expression Across Brain Regions and Genetic Backgrounds

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    Mouse models play a crucial role in the study of human behavioral traits and diseases. Variation of gene expression in brain may play a critical role in behavioral phenotypes, and thus it is of great importance to understand regulation of transcription in mouse brain. In this study, we analyzed the role of two important factors influencing steady-state transcriptional variation in mouse brain. First we considered the effect of assessing whole brain vs. discrete regions of the brain. Second, we investigated the genetic basis of strain effects on gene expression. We examined the transcriptome of three brain regions using Affymetrix expression arrays: whole brain, forebrain, and hindbrain in adult mice from two common inbred strains (C57BL/6J vs. NOD/ShiLtJ) with eight replicates for each brain region and strain combination. We observed significant differences between the transcriptomes of forebrain and hindbrain. In contrast, the transcriptomes of whole brain and forebrain were very similar. Using 4.3 million single-nucleotide polymorphisms identified through whole-genome sequencing of C57BL/6J and NOD/ShiLtJ strains, we investigated the relationship between strain effect in gene expression and DNA sequence similarity. We found that cis-regulatory effects play an important role in gene expression differences between strains and that the cis-regulatory elements are more often located in 5′ and/or 3′ transcript boundaries, with no apparent preference on either 5′ or 3′ ends

    Mesenchymal stem cell transplantation for diffuse alveolar hemorrhage in SLE

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    Background. A 19-year-old girl was diagnosed with systemic lupus erythematosus, based on findings of arthritis, malar rash, positive antinuclear antibody test and high levels of antibodies to double-stranded DNA. Two months after diagnosis, the patient presented with a sudden drop in blood hemoglobin level. Several days later, she developed bloody sputum, rapidly progressive dyspnea and hypoxemia. High-resolution CT showed diffuse alveolar infiltrates in both lung fields.Investigations. Physical examination, complete blood count, erythrocyte sedimentation rate, urinalysis, 24-h urine protein excretion, fecal occult blood test, d-dimer test, acid hemolysis test, activated partial thromboplastin time and prothrombin time, direct and indirect Coombs tests, bone marrow smear, arterial blood gas, sputum smear and culture, and high-resolution CT scan of the chest.Diagnosis. Diffuse alveolar hemorrhage associated with systemic lupus erythematosus.Management. The patient did not respond to pulsed intravenous methylprednisolone (two courses of 500 mg per day for 3 days) and intravenous immunoglobulin (20 g per day for 5 days). The patient was referred to a specialist treatment center for allogenic transplantation using umbilical-cord-derived mesenchymal stem cells. She underwent transplantation with an infusion of 8 - 10 7 mesenchymal stem cells. After showing dramatic improvements in her clinical condition, oxygenation level, radiographic and hematological status, the patient was discharged from hospital approximately 5 weeks after undergoing transplantation. © 2010 Macmillan Publishers Limited.postprin

    IsoDOT Detects Differential RNA-isoform Expression/Usage with respect to a Categorical or Continuous Covariate with High Sensitivity and Specificity

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    We have developed a statistical method named IsoDOT to assess differential isoform expression (DIE) and differential isoform usage (DIU) using RNA-seq data. Here isoform usage refers to relative isoform expression given the total expression of the corresponding gene. IsoDOT performs two tasks that cannot be accomplished by existing methods: to test DIE/DIU with respect to a continuous covariate, and to test DIE/DIU for one case versus one control. The latter task is not an uncommon situation in practice, e.g., comparing paternal and maternal allele of one individual or comparing tumor and normal sample of one cancer patient. Simulation studies demonstrate the high sensitivity and specificity of IsoDOT. We apply IsoDOT to study the effects of haloperidol treatment on mouse transcriptome and identify a group of genes whose isoform usages respond to haloperidol treatment
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