117 research outputs found
Experimental measurement of the quantum geometric tensor using coupled qubits in diamond
Geometry and topology are fundamental concepts, which underlie a wide range
of fascinating physical phenomena such as topological states of matter and
topological defects. In quantum mechanics, the geometry of quantum states is
fully captured by the quantum geometric tensor. Using a qubit formed by an NV
center in diamond, we perform the first experimental measurement of the
complete quantum geometric tensor. Our approach builds on a strong connection
between coherent Rabi oscillations upon parametric modulations and the quantum
geometry of the underlying states. We then apply our method to a system of two
interacting qubits, by exploiting the coupling between the NV center spin and a
neighboring C nuclear spin. Our results establish coherent dynamical
responses as a versatile probe for quantum geometry, and they pave the way for
the detection of novel topological phenomena in solid state
Two-photon-transition superadiabatic passage in an nitrogen-vacancy center in diamond
Reaching a given target quantum state with high fidelity and fast operation
speed close to the quantum limit represents an important goal in quantum
information science. Here, we experimentally demonstrate superadiabatic quantum
driving to achieve population transfer in a three-level solid-state spin
system. Starting from traditional stimulated Raman adiabatic passage (STIRAP),
our approach implements superadiabatic corrections to the STIRAP Hamiltonians
with several paradigmatic pulse shapes. It requires no need of intense
microwave pulses or long transfer times and shows enhanced robustness over
pulse imperfections. These results might provide a useful tool for quantum
information processing and coherent manipulations of quantum systems.Comment: 8 pages, 7 figure
A combination of pre-infusion serum ferritin, CRP and IL-6 predicts outcome in relapsed/refractory multiple myeloma patients treated with CAR-T cells
BackgroundChimeric antigen receptor - T (CAR-T) cell therapy has shown remarkable efficacy in patients with relapsed/refractory multiple myeloma (R/R MM). However, a subset of patients still experienced progression or relapse, and the predictors of prognosis are little known. We analyzed the inflammatory markers before CAR-T cell infusion, to clarify their correlation with survival and toxicity.MethodsThis study involved 109 R/R MM patients who received CAR-T therapy between June 2017 and July 2021. Inflammatory markers, including ferritin, c-reactive protein (CRP), and interleukin-6 (IL-6) before CAR-T cell infusion were detected and then categorized by quartiles. Adverse events and clinical outcomes were compared between patients with upper quartile of inflammatory markers and patients with lower three quartiles of inflammatory markers. An inflammatory prognostic index (InPI) based on these three inflammatory markers was developed in this study. Patients were divided into 3 groups according to the InPI score, progression-free survival (PFS) and overall survival (OS) were compared among the groups. In addition, we explored the correlation between cytokine release syndrome (CRS) and pre-infusion inflammatory markers.ResultsWe found that the pre-infusion high ferritin (hazard ratio [HR], 3.382; 95% confidence interval [CI], 1.667 to 6.863; P = .0007), high CRP (HR, 2.043; 95% CI, 1.019 to 4.097; P = .044), and high IL-6 (HR, 3.298; 95% CI, 1.598 to 6.808; P = .0013) were significantly associated with inferior OS. The formula of the InPI score was based on the HR value of these 3 variables. Three risk groups were formed: (good, 0 to 0.5 point; intermediate, 1 to 1.5 points; poor, 2 to 2.5 points). Median OS for patients with good, intermediate, and poor InPI was not reached, 24 months, and 4 months, respectively, and median PFS was 19.1 months, 12.3 months, and 2.9 months, respectively. In the cox proportional hazards model, poor InPI remained an independent prognostic factor for PFS and OS. Pre-infusion ferritin was negatively associated with CAR T-cell expansion normalized to baseline tumor burden. Spearman correlation analysis showed that pre-infusion ferritin and IL-6 levels positively correlated with the grade of CRS (P = .0369 and P = .0117, respectively). The incidence of severe CRS was higher in patients with high IL-6 compared with patients with low IL-6 (26% vs. 9%, P = .0405). Pre-infusion ferritin, CRP and IL-6 were positively correlated with each peak values within the first month after infusion.ConclusionsOur results suggest that patients with elevated inflammation markers before CAR-T cell infusion are more likely to have poor prognosis
A Distributed Randomized Gradient-Free Algorithm for the Non-Convex Economic Dispatch Problem
In this paper, a distributed randomized gradient-free algorithm (DRGF) is employed to solve the complex non-convex economic dispatch problem whose non-convex constraints include valve-point loading effects, prohibited operating zones, and multiple fuel options. The DRGF uses the Gauss approximation, smoothing parameters, and a random sequence to construct distributed randomized gradient-free oracles. By employing a consensus procedure, generation units can gather local information through local communication links and then process the economic dispatch data in a distributed iteration format. Based on the principle of projection optimization, a projection operator is adopted in the DRGF to deal with the discontinuous solution space. The effectiveness of the proposed approach in addressing the non-convex economic dispatch problem is demonstrated by simulations implemented on three standard test systems
The bounds estimate of sub-band operators for multi-band wavelets
Abstract A concept of the sub-band operator of multi-band wavelets is introduced, the theory of d-circular matrices is developed and the upper bound and the lower bound of the norm of the sub-band operator are obtained. Examples are provided to illustrate the results proposed in this paper
Solvable groups which do not possess characters of nontrivial prime power degree
National Natural Science Foundation of China [11171243, 11201385]; Natural Science Foundation of Fujian Province [2011J01022]; Fundamental Research Funds for the Central Universities [2010121003]; Science Foundation of Henan University of Technology [2011BS043]; Tianyuan Fund of Mathematics of China [11226046]In this paper, we consider solvable groups which do not possess characters of nontrivial prime power degree. In particular, for some of the minimal groups with this property, we characterize them and determine their structure
Mechanisms of Melatonin in Obesity: A Review
Obesity and its complications have become a prominent global public health problem that severely threatens human health. Melatonin, originally known as an effective antioxidant, is an endogenous hormone found throughout the body that serves various physiological functions. In recent decades, increasing attention has been paid to its unique function in regulating energy metabolism, especially in glucose and lipid metabolism. Accumulating evidence has established the relationship between melatonin and obesity; nevertheless, not all preclinical and clinical evidence indicates the anti-obesity effect of melatonin, which makes it remain to conclude the clinical effect of melatonin in the fight against obesity. In this review, we have summarized the current knowledge of melatonin in regulating obesity-related symptoms, with emphasis on its underlying mechanisms. The role of melatonin in regulating the lipid profile, adipose tissue, oxidative stress, and inflammation, as well as the interactions of melatonin with the circadian rhythm, gut microbiota, sleep disorder, as well as the α7nAChR, the opioidergic system, and exosomes, make melatonin a promising agent to open new avenues in the intervention of obesity
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