152 research outputs found

    High coherence hybrid superconducting qubit

    Full text link
    We measure the coherence of a new superconducting qubit, the {\em low-impedance flux qubit}, finding T2∗∼T1∼1.5μT_2^* \sim T_1 \sim 1.5\mus. It is a three-junction flux qubit, but the ratio of junction critical currents is chosen to make the qubit's potential have a single well form. The low impedance of its large shunting capacitance protects it from decoherence. This qubit has a moderate anharmonicity, whose sign is reversed compared with all other popular qubit designs. The qubit is capacitively coupled to a high-Q resonator in a λ/2\lambda/2 configuration, which permits the qubit's state to be read out dispersively

    A simple all-microwave entangling gate for fixed-frequency superconducting qubits

    Full text link
    We demonstrate an all-microwave two-qubit gate on superconducting qubits which are fixed in frequency at optimal bias points. The gate requires no additional subcircuitry and is tunable via the amplitude of microwave irradiation on one qubit at the transition frequency of the other. We use the gate to generate entangled states with a maximal extracted concurrence of 0.88 and quantum process tomography reveals a gate fidelity of 81%

    Efficient measurement of quantum gate error by interleaved randomized benchmarking

    Full text link
    We describe a scalable experimental protocol for obtaining estimates of the error rate of individual quantum computational gates. This protocol, in which random Clifford gates are interleaved between a gate of interest, provides a bounded estimate of the average error of the gate under test so long as the average variation of the noise affecting the full set of Clifford gates is small. This technique takes into account both state preparation and measurement errors and is scalable in the number of qubits. We apply this protocol to a superconducting qubit system and find gate errors that compare favorably with the gate errors extracted via quantum process tomography.Comment: 5 pages, 2 figures, published versio

    Domain Specific Self-Efficacy Mediates the Impact of Pain Catastrophizing on Pain and Disability in Overweight and Obese Osteoarthritis Patients

    Get PDF
    This study examined whether self-efficacy mediated the relationship between pain catastrophizing and pain and disability. Participants were 192 individuals diagnosed with osteoarthritis (OA) of the knees who were overweight or obese. Multiple mediator analyses were conducted to simultaneously test self-efficacy for pain control, physical function, and emotional symptoms as mediators while controlling for demographic and medical status variables. Higher pain catastrophizing was associated with lower self-efficacy in all three domains (ps< .05). Self-efficacy for pain control fully mediated the relationship between pain catastrophizing and pain (Beta=.08, Sobel test Z=1.97, p<.05). The relationship between pain catastrophizing and physical disability was fully mediated by self-efficacy for physical function (Beta=.06, Sobel test Z=1.95, p=.05). Self-efficacy for emotional symptoms partially mediated the relationship between pain catastrophizing and psychological disability (Beta=. 12, Sobel test Z=2.92, p<.05). These results indicate that higher pain catastrophizing contributed to greater pain and disability via lower domain-specific self-efficacy. Efforts to reduce pain and improve functioning in OA patients should consider addressing pain catastrophizing and domain specific selfefficacy. Pain catastrophizing may be addressed through cognitive therapy techniques and selfefficacy may be enhanced through practice of relevant skills and personal accomplishments. Perspective- This paper found that higher pain catastrophizing contributed to great pain and disability via domain specific self-efficacy. These results suggest that treatment efforts to reduce pain and improve functioning in OA patients who are overweight or obese should consider addressing both pain catastrophizing and self-efficacy. Originally published Journal of Pain, Vol. 9, No. 10, Oct 200

    Circulating Serum Exosomal miRNAs As Potential Biomarkers for Esophageal Adenocarcinoma

    Get PDF
    Author version made available in accordance with publisher policy.Abstract Background The poor prognosis and rising incidence of esophageal adenocarcinoma highlight the need for improved detection methods. The potential for circulating microRNAs (miRNAs) as biomarkers in other cancers has been shown, but circulating miRNAs have not been well characterized in esophageal adenocarcinoma. We investigated whether circulating exosomal miRNAs have potential to discriminate individuals with esophageal adenocarcinoma from healthy controls and non-dysplastic Barrett’s esophagus. Methods Seven hundred fifty-eight miRNAs were profiled in serum circulating exosomes from a cohort of 19 healthy controls, 10 individuals with Barrett’s esophagus, and 18 individuals with locally advanced esophageal adenocarcinoma. MiRNA expression was assessed using all possible permutations of miRNA ratios per individual. Four hundred eight miRNA ratios were differentially expressed in individuals with cancer compared to controls and Barrett’s esophagus (Mann-Whitney U test, P<0.05). The 179/408 ratios discriminated esophageal adenocarcinoma from healthy controls and Barrett’s esophagus (linear regression, P0.7, P<0.05). A multi-biomarker panel (RNU6-1/miR- 16-5p, miR-25-3p/miR-320a, let-7e-5p/miR-15b-5p, miR- 30a-5p/miR-324-5p, miR-17-5p/miR-194-5p) demonstrated enhanced specificity and sensitivity (area under ROC=0.99, 95 % CI 0.96–1.0) over single miRNA ratios to distinguish esophageal adenocarcinoma from controls and Barrett’s esophagus. Conclusions This study highlights the potential for serum exosomal miRNAs as biomarkers for the detection of esophageal adenocarcinoma

    Retrogradely Transportable Lentivirus Tracers for Mapping Spinal Cord Locomotor Circuits

    Get PDF
    Retrograde tracing is a key facet of neuroanatomical studies involving long distance projection neurons. Previous groups have utilized a variety of tools ranging from classical chemical tracers to newer methods employing viruses for gene delivery. Here, we highlight the usage of a lentivirus that permits highly efficient retrograde transport (HiRet) from synaptic terminals within the cervical and lumbar enlargements of the spinal cord. By injecting HiRet, we can clearly identify supraspinal and propriospinal circuits innervating motor neuron pools relating to forelimb and hindlimb function. We observed robust labeling of propriospinal neurons, including high fidelity details of dendritic arbors and axon terminals seldom seen with chemical tracers. In addition, we examine changes in interneuronal circuits occurring after a thoracic contusion, highlighting populations that potentially contribute to spontaneous behavioral recovery in this lesion model. Our study demonstrates that the HiRet lentivirus is a unique tool for examining neuronal circuitry within the brain and spinal cord
    • …
    corecore