Nanozymes are nanomaterials exhibiting intrinsic enzyme-like characteristics that have increasingly attracted attention, owing to their high catalytic activity, low cost and high stability. This ...combination of properties has enabled a broad spectrum of applications, ranging from biological detection assays to disease diagnosis and biomedicine development. Since the intrinsic peroxidase activity of Fe
O
nanoparticles (NPs) was first reported in 2007, >40 types of nanozymes have been reported that possess peroxidase-, oxidase-, haloperoxidase- or superoxide dismutase-like catalytic activities. Given the complex interdependence of the physicochemical properties and catalytic characteristics of nanozymes, it is important to establish a standard by which the catalytic activities and kinetics of various nanozymes can be quantitatively compared and that will benefit the development of nanozyme-based detection and diagnostic technologies. Here, we first present a protocol for measuring and defining the catalytic activity units and kinetics for peroxidase nanozymes, the most widely used type of nanozyme. In addition, we describe the detailed experimental procedures for a typical nanozyme strip-based biological detection test and demonstrate that nanozyme-based detection is repeatable and reliable when guided by the presented nanozyme catalytic standard. The catalytic activity and kinetics assays for a nanozyme can be performed within 4 h.
A new recursive one-step state prediction procedure is derived for a networked dynamic system. Under the coordination of a collaboration unit that provides optimal update gains for each individual ...subsystem utilizing merely system parameters, this predictor estimates plant's local states based only on local system output measurements. This estimator can be easily realized in a distributed way, and can also be simply scaled to systems with a large amount of subsystems, provided it has enough communication and storage capacities. It is proved that when prediction error variances are adopted in performance comparisons, the optimal gain matrix is usually unique. Recursive and explicit expressions are derived for both this optimal gain matrix and the covariance matrix of the corresponding prediction errors. The optimal gain matrix for every subsystem in this distributed recursive predictor has been shown to be equal to that of the well known Kalman filter utilizing only local system output measurements, which makes it possible to robustify this state predictor using a sensitivity penalization approach. Numerical simulation results illustrate that prediction accuracy of the suggested procedure may sometimes be as good as that of the lumped Kalman filter.
The study focuses on how online education is used in the sphere of sports from 2001 to 2022. Especially in the era of COVID-19 popularity, the deepening cross-fertilization between the field of ...sports and other fields, coupled with the fact that scholars have not yet analyzed and organized the areas in which online education is combined with sports, and what opportunities there will be for the development of online education in the field of sports. In this article, it summarizes the past two decades of research with bibliometric and scientometric research methods, quantitatively exploring the development paths, research hotspots, and evolutionary trends in the field under the online medium, and systematically integrates the field through knowledge mapping to suggest and indicate the development process for the combination of the sports field and online education. The information of authors, keywords, and the number of national publications are used to determine that online education will continue to be studied in the field of sports with high explosive keywords such as children, online education, and COVID-19. This will provide suggestions and directions for the development of the sports field and online education.
A recursive state estimation procedure is derived for a linear time varying system with both parametric uncertainties and stochastic measurement droppings. This estimator has a similar form as that ...of Kalman filter with intermittent observations, but its parameters should be adjusted when a plant output measurement arrives. A new recursive form is derived for the pseudo-covariance matrix of estimation errors. Based on a Riemannian metric for positive definite matrices, some necessary and sufficient conditions have been obtained for the strict contractiveness of this recursion. It has also been proved that under some controllability and observability conditions, as well as some weak requirements on measurement arrival probability, the update gain of this recursive robust state estimator and the mean of its squared estimation errors converge in probability one respectively to a corresponding stationary distribution. Numerical simulation results show that estimation accuracy of the suggested procedure is more robust against parametric modelling errors than Kalman filter.
Immunotherapy aiming at suppressing tumor development by relying on modifying or strengthening the immune system prevails among cancer treatments and points out a new direction for cancer therapy. B7 ...homolog 3 protein (B7-H3, also known as CD276), a newly identified immunoregulatory protein member of the B7 family, is an attractive and promising target for cancer immunotherapy because it is overexpressed in tumor tissues while showing limited expression in normal tissues and participating in tumor microenvironment (TME) shaping and development. Thus far, numerous B7-H3-based immunotherapy strategies have demonstrated potent antitumor activity and acceptable safety profiles in preclinical models. Herein, we present the expression and biological function of B7-H3 in distinct cancer and normal cells, as well as B7-H3-mediated signal pathways in cancer cells and B7-H3-based tumor immunotherapy strategies. This review provides a comprehensive overview that encompasses B7-H3's role in TME to its potential as a target in cancer immunotherapy.
Formic acid (HCOOH) is one of the most promising chemical fuels that can be produced through CO2 electroreduction. However, most of the catalysts for CO2 electroreduction to HCOOH in aqueous solution ...often suffer from low current density and limited production rate. Herein, we provide a bismuth/cerium oxide (Bi/CeOx) catalyst, which exhibits not only high current density (149 mA cm−2), but also unprecedented production rate (2600 μmol h−1 cm−2) with high Faradaic efficiency (FE, 92 %) for HCOOH generation in aqueous media. Furthermore, Bi/CeOx also shows favorable stability over 34 h. We hope this work could offer an attractive and promising strategy to develop efficient catalysts for CO2 electroreduction with superior activity and desirable stability.
The limited current density, production rate as well as selectivity hinder the improvement of HCOOH production from CO2 electroreduction. Here, bismuth/cerium oxide (Bi/CeOx) displays outstanding performances for CO2 electroreduction to HCOOH, which not only shows excellent selectivity, but also achieves a high current density (149 mA cm−2) and especially the maximum HCOOH production rate (2600 μmol h−1 cm−2) ever reported.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Rational design of non‐noble metal catalysts with robust and durable electrocatalytic activity for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction ...(HER) is extremely important for renewable energy conversion and storage, regenerative fuel cells, rechargeable metal–air batteries, water splitting etc. In this work, a unique hybrid material consisting of Fe3C and Co nanoparticles encapsulated in a nanoporous hierarchical structure of N‐doped carbon (Fe3C‐Co/NC) is fabricated for the first time via a facile template‐removal method. Such an ingenious structure shows great features: the marriage of 1D carbon nanotubes and 2D carbon nanosheets, abundant active sites resulting from various active species of Fe3C, Co, and NC, mesoporous carbon structure, and intimate integration among Fe3C, Co, and NC. As a multifunctional electrocatalyst, the Fe3C‐Co/NC hybrid exhibits excellent performance for ORR, OER, and HER, outperforming most of reported triple functional electrocatalysts. This study provides a new perspective to construct multifunctional catalysts with well‐designed structure and superior performance for clean energy conversion technologies.
A hybrid material of Fe3C‐Co/NC is synthesized through a facile template‐removal method, where Fe3C and Co nanoparticles are encapsulated in a nanoporous N‐doped hierarchical structure integrating 1D carbon nanotubes and 2D carbon nanosheets. As a multifunctional electrocatalyst, such a hybrid exhibits superior catalytic performances for oxygen reduction reaction, oxygen evolution reaction and hydrogen evolution reaction simultaneously.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The world of small noncoding RNAs (sncRNAs) is ever-expanding, from small interfering RNA, microRNA and Piwi-interacting RNA to the recently emerging non-canonical sncRNAs derived from longer ...structured RNAs (for example, transfer, ribosomal, Y, small nucleolar, small nuclear and vault RNAs), showing distinct biogenesis and functional principles. Here we discuss recent tools for sncRNA identification, caveats in sncRNA expression analysis and emerging methods for direct sequencing of sncRNAs and systematic mapping of RNA modifications that are integral to their function.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The Savonius vertical axis wind turbine is simple in structure, has good starting characteristics, relatively low operating speeds, and an ability to accept wind from any direction, although it has a ...lower efficiency than some other vertical axis wind turbines. So far a number of experimental investigations have been carried out to study the performance of the Savonius rotor; however, there is a lack of detailed descriptions of the flow field for different types of Savonius rotors. The aim of this paper is to numerically explore the non-linear two-dimensional unsteady flow over a conventional Savonius-type rotor and a Bach-type rotor, and develop a simulation method for predicting their aerodynamic performance. The simulations are performed using Star-CCM+. The motion of the blades is solved by using a moving mesh. A comparative study of the two types of rotors was carried out, and numerical simulation results were compared with experimental data. The Bach-type rotor is demonstrated to have better performance for torque and power coefficient than the conventional Savonius-type rotor. A discussion of the causes of these differences is presented that is based on a detailed study of the respective flow field characteristics, including the behavior of moment coefficients, velocity vectors and pressure distribution. A simulation method for further study of new blades shapes is suggested.
► We explore the non-linear two-dimensional unsteady potential flow over a Savonius rotor. ► A simulation method for predicting the aerodynamic performance of the Savonius rotor has been developed. ► A comparative study of the conventional Savonius-type rotor versus the Bach-type rotor was carried out. ► Pressure distribution and detailed velocity fields were analyzed, respectively. ► We were able to shed additional light on the flow physics of power generation Savonius turbines.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract
Developing robust nonprecious electrocatalysts towards hydrogen/oxygen evolution reactions is crucial for widespread use of electrochemical water splitting in hydrogen production. Here, we ...report that intermetallic Co
3
Mo spontaneously separated from hierarchical nanoporous copper skeleton shows genuine potential as highly efficient electrocatalysts for alkaline hydrogen/oxygen evolution reactions in virtue of in-situ hydroxylation and electro-oxidation, respectively. The hydroxylated intermetallic Co
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Mo has an optimal hydrogen-binding energy to facilitate adsorption/desorption of hydrogen intermediates for hydrogen molecules. Associated with high electron/ion transport of bicontinuous nanoporous skeleton, nanoporous copper supported Co
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Mo electrodes exhibit impressive hydrogen evolution reaction catalysis, with negligible onset overpotential and low Tafel slope (~40 mV dec
−1
) in 1 M KOH, realizing current density of −400 mA cm
−2
at overpotential of as low as 96 mV. When coupled to its electro-oxidized derivative that mediates efficiently oxygen evolution reaction, their alkaline electrolyzer operates with a superior overall water-splitting output, outperforming the one assembled with noble-metal-based catalysts.
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