43 research outputs found

    Quantum Instruction Set Design for Performance

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    A quantum instruction set is where quantum hardware and software meet. We develop new characterization and compilation techniques for non-Clifford gates to accurately evaluate different quantum instruction set designs. We specifically apply them to our fluxonium processor that supports mainstream instruction iSWAP\mathrm{iSWAP} by calibrating and characterizing its square root SQiSW\mathrm{SQiSW}. We measure a gate fidelity of up to 99.72%99.72\% with an average of 99.31%99.31\% and realize Haar random two-qubit gates using SQiSW\mathrm{SQiSW} with an average fidelity of 96.38%96.38\%. This is an average error reduction of 41%41\% for the former and a 50%50\% reduction for the latter compared to using iSWAP\mathrm{iSWAP} on the same processor. This shows designing the quantum instruction set consisting of SQiSW\mathrm{SQiSW} and single-qubit gates on such platforms leads to a performance boost at almost no cost.Comment: 2 figures in main text and 21 figures in Supplementary Materials. This manuscript subsumes version 1 with significant improvements such as experimental demonstration and materials presentatio

    Killer immunoglobulin-like receptor polymorphism in a Chinese HIV-1 infection cohort

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    Genetic and functional studies have demonstrated that KIR gene polymorphism, including different haplotypes, allelic polymorphisms and different expression levels of KIRs, may all play a part in the association with HIV-1 infection outcome. Currently, there are very few studies focusing on the association between KIR and HIV in the Chinese population. In this project, we started to look at the polymorphism of KIRs in a unique chronic HIV-1 infected cohort (SM cohort), evaluating the impact of KIR and KIR-HLA interactions in terms of HIV-1 infection progression. The SM cohort is unique because the major factors such as viral strain, transmission route and timing of infection, which could affect the natural history of HIV-1, have been narrowly controlled. Through comparison with a healthy control population, some genetic associations were identified. The frequency of KIR2DL3 was lower in the “slow progressors” group; the compound genotype of KIR3DS1+ Bw4 homozygotes was significantly lower in the “slow progressors” group; additionally, group B genotypes (multiple activating genes) were shown to be likely to mount a greater immune pressure on HIV-1. In terms of KIR footprints, several amino acid positions were identified for which the substitution of an amino acid may be ascribed to the immune response from KIR-modulated NK cells rather than from HLA restricted CTL immune pressure. In Chapter 4, we report a novel method to sequence the entire locus of KIR3DL1/S1. Two specific pairs of primers have been successfully designed and tested to amplify KIR3DL1 and KIR3DS1 exclusively. Using this novel sequencing method, we showed the polymorphism of this locus at a 6-digit level. 8 new KIR3DS1 alleles, 12 new KIR3DL1 alleles, 1 new KIR3DL1 gene and 1 new KIR3DS1 gene have been identified in this study. In Chapter 5, we used a valuable acute HIV-1 infection cohort to further study associations between KIRs and the clinical outcomes. It was interesting to find that the frequency of KIR3DS1 was significantly lower in the slow progressors group (31%) than in the acute group (40.7%), which implies that KIR3DS1 plays a role in HIV-1 disease progression. There are two other trends demonstrated in this study. One trend was that positive KIR2DL2 and/or KIR2DS2 (they are in strong linkage disequilibrium with each other) were associated with a higher set point viral load (at 3 month) (p=0.06). Another trend was that KIR3DS1 might have an association with disease progression (p=0.057). Overall, in this study, the role of KIRs and KIR/HLA interactions were evaluated in acute and chronic HIV-1 infection, which has provided important information for further study.</p

    Achieving single domain relaxor-PT crystals by high temperature poling

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    Single domain relaxor-PT crystals are important from both fundamental and application viewpoints. Compared to domain engineered relaxor-PT crystals, however, single domain crystals are prone to cracking during poling. In this paper, based on the analysis of the cracking phenomenon in [001] poled tetragonal 0.25Pb(In0.5Nb0.5)O3-0.37Pb(Mg 1/3Nb2/3)O3-0.38PbTiO3 (PIN-PMN-PT) crystals, the non-180°ferroelastic domain switching was thought to be the dominant factor for cracking during the poling process. A high temperature poling technique, by which the domain switching can be greatly avoided, was proposed to achieve the single domain relaxor-PT crystals. By this poling approach, a quasi-single domain crystal was obtained without cracks. In addition, compared to room temperature poling, the high temperature poled PIN-PMN-PT crystals showed improved electromechanical properties, i.e., a low dielectric loss, a low strain-electric field hysteresis and a high mechanical quality factor, demonstrating a beneficial poling approach. This journal is the Partner Organisations 2014

    Killer Immunoglobulin-like Receptor Polymorphism in A Chinese HIV-1 Infection Cohort

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    Genetic and functional studies have demonstrated that KIR gene polymorphism, including different haplotypes, allelic polymorphisms and different expression levels of KIRs, may all play a part in the association with HIV-1 infection outcome. Currently, there are very few studies focusing on the association between KIR and HIV in the Chinese population. In this project, we started to look at the polymorphism of KIRs in a unique chronic HIV-1 infected cohort (SM cohort), evaluating the impact of KIR and KIR-HLA interactions in terms of HIV-1 infection progression. The SM cohort is unique because the major factors such as viral strain, transmission route and timing of infection, which could affect the natural history of HIV-1, have been narrowly controlled. Through comparison with a healthy control population, some genetic associations were identified. The frequency of KIR2DL3 was lower in the “slow progressors” group; the compound genotype of KIR3DS1+ Bw4 homozygotes was significantly lower in the “slow progressors” group; additionally, group B genotypes (multiple activating genes) were shown to be likely to mount a greater immune pressure on HIV-1. In terms of KIR footprints, several amino acid positions were identified for which the substitution of an amino acid may be ascribed to the immune response from KIR-modulated NK cells rather than from HLA restricted CTL immune pressure. In Chapter 4, we report a novel method to sequence the entire locus of KIR3DL1/S1. Two specific pairs of primers have been successfully designed and tested to amplify KIR3DL1 and KIR3DS1 exclusively. Using this novel sequencing method, we showed the polymorphism of this locus at a 6-digit level. 8 new KIR3DS1 alleles, 12 new KIR3DL1 alleles, 1 new KIR3DL1 gene and 1 new KIR3DS1 gene have been identified in this study. In Chapter 5, we used a valuable acute HIV-1 infection cohort to further study associations between KIRs and the clinical outcomes. It was interesting to find that the frequency of KIR3DS1 was significantly lower in the slow progressors group (31%) than in the acute group (40.7%), which implies that KIR3DS1 plays a role in HIV-1 disease progression. There are two other trends demonstrated in this study. One trend was that positive KIR2DL2 and/or KIR2DS2 (they are in strong linkage disequilibrium with each other) were associated with a higher set point viral load (at 3 month) (p=0.06). Another trend was that KIR3DS1 might have an association with disease progression (p=0.057). Overall, in this study, the role of KIRs and KIR/HLA interactions were evaluated in acute and chronic HIV-1 infection, which has provided important information for further study.This thesis is not currently available on ORA

    An efficient way to enhance output strain for shear mode Pb(In1/2Nb1/2)O-3-Pb(Mg1/3Nb2/3)O-3-PbTiO3 crystals: Applying uniaxial stress perpendicular to polar direction

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    The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with 1T and 2R domain configurations, respectively, were investigated under uniaxial stress perpendicular to polar direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both 1T and 2R crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to polar direction, resulting in a harder polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain

    Double pentavalent (Sb5+, Nb5+) and trivalent (Sm3+, Y3+) co-doped Ti0.9Zr0.1O2 colossal dielectric permittivity multilayer ceramics for the miniaturization of the next-generation electronics

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    Materials with colossal dielectric permittivity (CP) are in the focus of interest for the development of miniaturization and integration of electronic components. Despite the extensive study of these new classes of co-doped TiO2 CP materials, the preparation of multilayer ceramics using this kind of CP materials is still challenging work. Here, we synthesize a series of (Sb5+, Nb5+) and (Sm3+, Y3+) co-doped Ti0.9Zr0.1O2 ceramics (SNSYTZO) through the conventional solid-state reaction method. XRD spectrum identifies that ceramics under x = 0.04 show a perfect rutile phase with the tetragonal crystal structure; however, minor brookite orthorhombic crystal structure appears when x > 0.04. FESEM images show the prepared ceramics have excellent densification and low porosity. Dielectric, modulus, and impedance spectrum are systematically explored the underlying CP mechanism and compared with each other to find the optimal materials composition to prepare further multilayer ceramics, which is fabricated by the industrial tape casting method. FESEM, together with surface element mapping, indicates that all doping elements are homogeneously distributed. Also, we investigate the dielectric response without/with DC bias. This work sheds light on a promising feasible route to prepare the miniaturization of the next-generation electronics via a large scale industrial tape casting method

    Multiplex Tests for Respiratory Tract Infections: The Direct Utility of the FilmArray Respiratory Panel in Emergency Department

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    BACKGROUND. The FilmArray Respiratory Panel with multiplex targets for respiratory pathogens has been widely used and verified in clinical trials in special test settings. However, it is necessary to evaluate the panel’s performance at the point of care directly, in nonspecific test settings. METHODS. Patients with respiratory tract infections were enrolled from among emergency department visitors, and all steps, including the collection of specimens and testing, were performed by our clinicians. Results. Among 270 patients, 196 (72.6%) patients were found to have one or more pathogens. For signal pathogen detection, influenza A virus had the highest rate of detection; 45 (16.7%) of the patients had two or more respiratory pathogens codetected, and most of the multiplex pathogens were rhinovirus/enterovirus codetected with Bordetella pertussis (17.8%). The information provided by the FilmArray had an impact on the prescription of antimicrobials, and there were differences in the rates of antibiotic prescriptions and anti-influenza prescriptions among patients. COCLUSIONS. Use of the FilmArray by clinical staff was successfully implemented in the emergency department for the first time in China. The FilmArray has the potential for point-of-care testing in nonspecific settings

    Piezoelectric activity in Perovskite ferroelectric crystals

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