A fundamental assumption in statistical physics is that generic closed quantum many-body systems thermalize under their own dynamics. Recently, the emergence of many-body localized systems has ...questioned this concept and challenged our understanding of the connection between statistical physics and quantum mechanics. Here we report on the observation of a many-body localization transition between thermal and localized phases for bosons in a two-dimensional disordered optical lattice. With our single-site–resolved measurements, we track the relaxation dynamics of an initially prepared out-of-equilibrium density pattern and find strong evidence for a diverging length scale when approaching the localization transition. Our experiments represent a demonstration and in-depth characterization of many-body localization in a regime not accessible with state-of-the-art simulations on classical computers.
Coherent many-body quantum dynamics lies at the heart of quantum simulation and quantum computation. Both require coherent evolution in the exponentially large Hilbert space of an interacting ...many-body system. To date, trapped ions have defined the state of the art in terms of achievable coherence times in interacting spin chains. Here, we establish an alternative platform by reporting on the observation of coherent, fully interaction-driven quantum revivals of the magnetization in Rydberg-dressed Ising spin chains of atoms trapped in an optical lattice. We identify partial many-body revivals at up to about ten times the characteristic time scale set by the interactions. At the same time, single-site-resolved correlation measurements link the magnetization dynamics with interspin correlations appearing at different distances during the evolution. These results mark an enabling step towards the implementation of Rydberg-atom-based quantum annealers, quantum simulations of higher-dimensional complex magnetic Hamiltonians, and itinerant long-range interacting quantum matter.
Monitoring the status of the facilities and detecting any faults are considered an important technology in a smart factory. Although the faults of machine can be analyzed in real time using collected ...data, it requires a large amount of computing resources to handle the massive data. A cloud server can be used to analyze the collected data, but it is more efficient to adopt the edge computing concept that employs edge devices located close to the facilities. Edge devices can improve data processing and analysis speed and reduce network costs. In this paper, an edge device capable of collecting, processing, storing and analyzing data is constructed by using a single-board computer and a sensor. And, a fault detection model for machine is developed based on the long short-term memory (LSTM) recurrent neural networks. The proposed system called LiReD was implemented for an industrial robot manipulator and the LSTM-based fault detection model showed the best performance among six fault detection models.
For incompletely reduced graphene oxides (RGOs), an effect of oxygen functional groups such as carboxyl, phenol, carbonyl, and quinone on electrochemical capacitive behavior was studied. To prepare ...RGO thin-film electrodes, a simple fabrication process by (i) dropping and evaporating the graphene oxide (GO) solution, (ii) irradiating pulsed light, and (iii) heat-treating at 200 ∼ 360°C was applied. It was notable that the pulsed light irradiation was effective to prevent the disfiguring of deposited GO thin-film during the thermal reduction. From XRD analyses, interlayer distances of the RGOs were gradually decreased from 0.379 to 0.354nm. As increasing the thermal reduction temperature from 200 to 360°C, XPS O 1s spectra analyses showed that the atomic percentages of carboxyl and phenol of the RGOs were sustained as 5.40±0.36 and 4.77±0.41 at% respectively. Meanwhile, those of carbonyl and quinone of the RGOs were gradually declined from 3.10 to 1.81 and from 1.32 to 0.65 at% with different thermal reduction temperature respectively. For all RGO thin-film electrodes, the specific capacitance from the CV measurement in 6M KOH was sustained as ca. 220 F g−1 at the scan of 5mV s−1. However, in 1M H2SO4, the specific capacitance was gradually decreased from 171 to 136 F g−1. After 100,000 cycles in 6M KOH, 1M H2SO4, and 0.5M Na2SO4, the RGO (200°C) electrodes showed ca. 92, 54, and 104% of the initial capacitances respectively. The atomic percentages of the oxygen functional groups involved in the pseudocapacitive Faradaic reaction were decreased after the cycle test. Especially in 1M H2SO4, quinone group was decreased to ca. 48% of initial atomic percentage, which seems to be a main reason for the drastic reduction of capacitance. The specific pseudocapacitance per unit atomic percentage for either carboxyl or phenol group in 6M KOH was obtained as 12.59 F g−1 at%−1. For carbonyl group in 1M H2SO4, it was a slightly deviated value as 13.55 F g−1 at%−1. For quinone group in 1M H2SO4, it was 27.09 F g−1at%−1.
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•Maple leaf-derived biochars were prepared at the different pyrolytic temperature.•Biochar produced at 750 °C showed BET surface area of 191.1 m2/g.•Selected biochar presented maximum ...adsorption capacity of 361 mg/g.•Adsorption of tetracycline followed pseudo-second-order and Freundlich models.
The present study evaluates the physicochemical properties of maple leaf-derived biochars (M-BCs) produced at different pyrolytic temperatures (i.e., 350, 550, and 750 °C) and their adsorptive properties for tetracycline onto M-BCs. The increase in pyrolysis temperature to produce M-BCs led to a significant increase in the biochar’s hydrophobicity, surface area, and calcite (CaCO3) crystallization. The M-BC750 produced without functionalization or activation possessed a high calcite composition and a hydrophobic nature with lower O/C and H/C, hydroxyl groups (–OH) on the surface, and functional groups (i.e., O-containing) as H-bond acceptors. Among M-BCs, the M-BC750 present a highest TC adsorption capacity owing to possible mechanisms such as metal complexation, H-bonding, and hydrophobic interactions. The isotherm and kinetic models for TC adsorption followed the Freundlich models and pseudo-second-order models, respectively. M-BCs produced from the waste fallen maple leaves could be applied as low-cost environmental adsorbents for TC removal.
This paper proposes the cross-quantilogram to measure the quantile dependence between two time series. We apply it to test the hypothesis that one time series has no directional predictability to ...another time series. We establish the asymptotic distribution of the cross-quantilogram and the corresponding test statistic. The limiting distributions depend on nuisance parameters. To construct consistent confidence intervals we employ a stationary bootstrap procedure; we establish consistency of this bootstrap. Also, we consider a self-normalized approach, which yields an asymptotically pivotal statistic under the null hypothesis of no predictability. We provide simulation studies and two empirical applications. First, we use the cross-quantilogram to detect predictability from stock variance to excess stock return. Compared to existing tools used in the literature of stock return predictability, our method provides a more complete relationship between a predictor and stock return. Second, we investigate the systemic risk of individual financial institutions, such as JP Morgan Chase, Morgan Stanley and AIG.
Closed generic quantum many-body systems may fail to thermalize under certain conditions even after long times, a phenomenon called many-body localization (MBL). Numerous studies support the ...stability of the MBL phase in strongly disordered one-dimensional systems. However, the situation is much less clear when a small part of the system is ergodic, a scenario which also has important implications for the existence of many-body localization in higher dimensions. Here we address this question experimentally using a large-scale quantum simulator of ultracold bosons in a two-dimensional optical lattice. We prepare two-component mixtures of varying relative population and implement a disorder potential which is experienced only by one of the components. The second nondisordered “clean” component plays the role of a bath of adjustable size that is collisionally coupled to the “dirty” component. Our experiments show how the dynamics of the dirty component, which, when on its own, show strong evidence of localization, become affected by the coupling to the clean component. For a high clean population, the clean component appears to behave as an effective bath for the system which leads to its delocalization, while for a smaller clean population, the ability of the bath to destabilize the system becomes strongly reduced. Our results reveal how a finite-sized quantum system can bring another one towards thermalization, in a regime of complex interplay between disorder, tunneling, and intercomponent interactions. They provide a new benchmark for effective theories aiming to capture the complex physics of MBL in the weakly localized regime.
Smart contact lenses for continuous glucose monitoring (CGM) have great potential for huge clinical impact. To date, their development has been limited by challenges in accurate detection of glucose ...without hysteresis for tear glucose monitoring to track the blood glucose levels. Here, long‐term robust CGM in diabetic rabbits is demonstrated by using bimetallic nanocatalysts immobilized in nanoporous hydrogels in smart contact lenses. After redox reaction of glucose oxidase, the nanocatalysts facilitate rapid decomposition of hydrogen peroxide and nanoparticle‐mediated charge transfer with drastically improved diffusion via rapid swelling of nanoporous hydrogels. The ocular glucose sensors result in high sensitivity, fast response time, low detection limit, low hysteresis, and rapid sensor warming‐up time. In diabetic rabbits, smart contact lens can detect tear glucose levels consistent with blood glucose levels measured by a glucometer and a CGM device, reflecting rapid concentration changes without hysteresis. The CGM in a human demonstrates the feasibility of smart contact lenses for further clinical applications.
Smart contact lenses containing bimetallic nanocatalysts immobilized in nanoporous hydrogels are developed for long‐term and robust continuous glucose monitoring. The smart contact lenses can accurately monitor increasing and decreasing blood glucose levels with 92.2% acceptable data in diabetic and normal rabbits. Finally, the clinical feasibility and safety of smart contact lenses are evaluated on the eyes of a human patient.
In this paper, we propose a doubly robust method to estimate the heterogeneity of the average treatment effect with respect to observed covariates of interest. We consider a situation where a large ...number of covariates are needed for identifying the average treatment effect but the covariates of interest for analyzing heterogeneity are of much lower dimension. Our proposed estimator is doubly robust and avoids the curse of dimensionality. We propose a uniform confidence band that is easy to compute, and we illustrate its usefulness via Monte Carlo experiments and an application to the effects of smoking on birth weights.
Tumor metastasis remains the cause of 90% of cancer‐related deaths. Cancer stem cells (CSC) are thought to be responsible for the aggressive and metastatic nature of triple‐negative breast cancers ...(TNBC), and new therapeutic strategies are being devised to target them. Flubendazole (FLU) is a widely used anthelmintic agent that also exhibits anticancer activity in several cancer types. The aim of this study was to characterize the mechanism of action of FLU on breast cancer stem cell (BCSC)‐like properties and metastasis in TNBC. FLU treatment caused a significant induction of apoptosis, accompanied by G2/M phase accumulation, caspase‐3/‐7 activation and the dysregulation of STAT3 activation in TNBC cells. The latter phenomenon was associated with impairment of cancer stem‐like traits, concomitant with a reduction in the CD24low/CD44high, CD24high/CD49fhigh subpopulation, ALDH1 activity and mammosphere formation. The BCSC‐enriched populations exhibited enhanced metastasis with higher STAT3 activation, while FLU administration inhibited tumor growth, angiogenesis and lung and liver metastasis, coinciding with decreased MMP‐2 and MMP‐9 levels in circulating blood. FLU kills not only rapid proliferating tumor cells but also effectively eradicates BCSC‐like cells in vitro and in vivo. Our findings warrant further investigation of FLU as a treatment for metastatic TNBC.
What's new?
Triple‐negative breast cancers (TNBCs) with high levels of cancer stem‐like properties have aggressive metastatic phenotypes and are difficult to treat. Despite chemotherapy, many patients with TNBC die within five years of diagnosis. Here, the authors show that breast cancer cell populations enriched with cancer stem cells (CSCs) exhibit enhanced metastasis and increased STAT3 activation and that STAT3 activation can be inhibited in vitro following administration of the anthelmintic drug flubendazole. In mice with CSC‐enriched TNBC tumors, flubendazole inhibited tumor growth, angiogenesis and lung and liver metastasis. The data warrant additional study of the potential clinical value of flubendazole in TNBC.
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