82 research outputs found
Scalable Method for Eliminating Residual Interaction between Superconducting Qubits
Unwanted interaction is a quantum-mechanical crosstalk phenomenon which
correlates qubit dynamics and is ubiquitous in superconducting qubit systems.
It adversely affects the quality of quantum operations and can be detrimental
in scalable quantum information processing. Here we propose and experimentally
demonstrate a practically extensible approach for complete cancellation of
residual interaction between fixed-frequency transmon qubits, which are
known for long coherence and simple control. We apply to the intermediate
coupler that connects the qubits a weak microwave drive at a properly chosen
frequency in order to noninvasively induce an ac Stark shift for
cancellation. We verify the cancellation performance by measuring vanishing
two-qubit entangling phases and correlations. In addition, we implement a
randomized benchmarking experiment to extract the idling gate fidelity which
shows good agreement with the coherence limit, demonstrating the effectiveness
of cancellation. Our method allows independent addressability of each
qubit-qubit connection, and is applicable to both nontunable and tunable
couplers, promising better compatibility with future large-scale quantum
processors.Comment: Main text: 6 pages, 4 figures; Supplement: 7 pages, 6 figure
Risk factors of oncogenic HPV infection in HIV-positive men with anal condyloma acuminata in Shenzhen, Southeast China: a retrospective cohort study
BackgroundHuman immunodeficiency virus (HIV)-positive patients with anal condyloma acuminata (CA) present an increased risk of anal cancer progression associated with oncogenic human papillomavirus (HPV) infection. It is essential to explore determinants of anal infection by oncogenic HPV among HIV-positive patients with CA.MethodsA retrospective cohort study was performed in HIV-positive patients with CA between January 2019 to October 2021 in Shenzhen, Southeast China. Exfoliated cells were collected from CA lesions and the anal canal of HPV genotypes detected by fluorescence PCR. Unconditional logistic regression analysis was used to probe associations of independent variables with oncogenic HPV infection.ResultsAmong HIV-positive patients with CA, the most prevalent oncogenic genotypes were HPV52 (29.43%), HPV16 (28.93%), HPV59 (19.20%), and HPV18 (15.96%). Risk of oncogenic HPV infection increased with age at enrollment (COR: 1.04, 95% CI: 1.01–1.07, p = 0.022). In the multivariable analysis, age ≥ 35 years (AOR: 2.56, 95% CI: 1.20–5.70, p = 0.02) and history of syphilis (AOR: 3.46, 95% CI: 1.90–6.79, p < 0.01) were independent risk factors statistically associated with oncogenic HPV infection. History of syphilis (AOR: 1.72, 95% CI: 1.08–2.73, p < 0.02) was also an independent risk factor statistically associated with HPV16 or HPV18 infection.ConclusionIn clinical practice, HIV-positive CA patients aged ≥35 years or with a history of syphilis should carry out HR-HPV testing and even anal cancer-related examinations to prevent the occurrence of anal cancer
Broad and colossal edge supercurrent in Dirac semimetal Cd<sub>3</sub>As<sub>2</sub> Josephson junctions
Multi-Level Variational Spectroscopy using a Programmable Quantum Simulator
Energy spectroscopy is a powerful tool with diverse applications across
various disciplines. The advent of programmable digital quantum simulators
opens new possibilities for conducting spectroscopy on various models using a
single device. Variational quantum-classical algorithms have emerged as a
promising approach for achieving such tasks on near-term quantum simulators,
despite facing significant quantum and classical resource overheads. Here, we
experimentally demonstrate multi-level variational spectroscopy for fundamental
many-body Hamiltonians using a superconducting programmable digital quantum
simulator. By exploiting symmetries, we effectively reduce circuit depth and
optimization parameters allowing us to go beyond the ground state. Combined
with the subspace search method, we achieve full spectroscopy for a 4-qubit
Heisenberg spin chain, yielding an average deviation of 0.13 between
experimental and theoretical energies, assuming unity coupling strength. Our
method, when extended to 8-qubit Heisenberg and transverse-field Ising
Hamiltonians, successfully determines the three lowest energy levels. In
achieving the above, we introduce a circuit-agnostic waveform compilation
method that enhances the robustness of our simulator against signal crosstalk.
Our study highlights symmetry-assisted resource efficiency in variational
quantum algorithms and lays the foundation for practical spectroscopy on
near-term quantum simulators, with potential applications in quantum chemistry
and condensed matter physics
Stress-Induced Epinephrine Enhances Lactate Dehydrogenase A and Promotes Breast Cancer Stem-Like Cells
Chronic stress triggers activation of the sympathetic nervous system and drives malignancy. Using an immunodeficient murine system, we showed that chronic stress–induced epinephrine promoted breast cancer stem-like properties via lactate dehydrogenase A–dependent (LDHA-dependent) metabolic rewiring. Chronic stress–induced epinephrine activated LDHA to generate lactate, and the adjusted pH directed USP28-mediated deubiquitination and stabilization of MYC. The SLUG promoter was then activated by MYC, which promoted development of breast cancer stem-like traits. Using a drug screen that targeted LDHA, we found that a chronic stress–induced cancer stem-like phenotype could be reversed by vitamin C. These findings demonstrated the critical importance of psychological factors in promoting stem-like properties in breast cancer cells. Thus, the LDHA-lowering agent vitamin C can be a potential approach for combating stress-associated breast cancer
Coke production scheduling problem: A parallel machine scheduling with batch preprocessings and location-dependent processing times
International audienceIn this paper, an integer programming model is developed for a newly addressed coke production scheduling problem, in which two typical characteristics are considered: (i) The transportation of raw coal by a vehicle causes a batch preprocessing; (ii) The heating of raw coal by closely located coke ovens may extend the processing times of cokes, under the temperature influence. To the best of our knowledge, such a geographically location-dependent processing time has not been studied. The purpose is to minimize the completion time of the last coke among all ovens, i.e., the makespan. Therefore, the problem of interest can be viewed as a parallel machine makespan minimization scheduling problem, featured with batch preprocessings and location-dependent processing times. For this NP-hard problem, a problem-specific genetic algorithm and a fast heuristic are devised to enhance the computational efficiency. Experimental results on 330 randomly generated instances show the effectiveness and efficiency of the proposed solution methods
Relationship between granulocyte–macrophage colony-stimulating factor, embryo quality, and pregnancy outcomes in women of different ages in fresh transfer cycles: a retrospective study
This study aimed to explore the effects of low-concentration (0.6 ng/mL) granulocyte–macrophage colony-stimulating factor (GM-CSF) supplementation on human embryo quality and pregnancy outcomes in patients with fresh transfer cycles. The data were retrospectively collected from 719 hyperstimulation cycles of 631 patients divided into two groups: GM-CSF supplementation (0.6 ng/mL, n = 399) and control (n = 320). The embryo quality and pregnancy outcomes were compared. GM-CSF addition significantly increased the available embryo rate (52.0 vs. 48.1%, p 38 years, it significantly enhanced cleavage (99.4 vs. 97.8%, p 38 years.IMPACT STATEMENT What is already known on this subject? Granulocyte–macrophage colony-stimulating factor (GM-CSF) has a beneficial effect on the development of human embryos in assisted reproductive technology. What do the results of this study add? Adding 0.6 ng/mL GM-CSF significantly increased the available embryo rate. In patients over 38 years of age, it statistically significantly enhanced the cleavage rate (99.4 vs. 97.8%, p < .05) and blastocyst formation rate (45.7 vs. 34.9%, p < .05). What are the implications of these findings for clinical practice and/or further research? GM-CSF benefits embryos with poorer development potential and a randomised clinical trial with a larger sample size should be performed
- …