Single atom nanozymes are the artificial enzymes with enzyme-like activity, which have attracted a great deal attention in recent years due to their unique merits such as remarkable stability, ...excellent atom utilization and low cost. Herein, a convenient and sensitive colorimetric strategy was developed for the sensing of galactose based on Fe–N–C single-atom nanozyme (Fe-SAzyme). The Fe-SAzyme was prepared through “isolation-pyrolysis” method that exhibited intrinsic peroxidase mimicking activity, which can quickly catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to produce blue-colored oxTMB in the presence of hydrogen peroxide (H2O2). Galactose can be oxidized by galactose oxidase (Gal Ox) to generate H2O2, and Fe-SAzyme can be utilized for quantitative colorimetric detection of galactose. A good linearity between absorbance and the galactose concentration in the range of 50–500 μM was obtained with a detection limit of (LOD) 10 μM. The Fe-SAzyme based colorimetric strategy offered a rapid, convenient and economic way for galactose quantification detection, which could be used as an alternative method for galactosemia diagnosis.
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•The Fe-SAzyme was synthesized by low-cost precursors and simple procedure.•The Fe-SAzyme displayed high stability and excellent peroxidase-like activity.•A convenient and economic colorimetric detection method for H2O2 and galactose has been successfully established.•This proposed strategy exhibited satisfactory performance for galactose assay in human serum samples.
ALT value is often used to reflect the hepatic inflammation and injury in NAFLD patients, but many studies proved that ALT values were normal in many NAFLD patients. The aim of this study was to ...identify the summarized proportion of NAFLD patients with normal ALT value in the overall NAFLD patients.
Electronic databases PubMed, EMBASE, Ovid, and the Cochrane Library were searched for potential studies published from January 1, 2000 to September 30, 2019. Studies that have reported the number of NAFLD or NASH patients with normal and abnormal ALT value were included and analyzed. Abstracts, reviews, case reports, and letters were excluded.
A total of 11 studies with 4084 patients were included for assessing the summarized proportion of NAFLD patients with normal ALT in overall NAFLD patients. As the results shown, the summarized proportion of NAFLD patients with normal ALT value in overall NAFLD patients was 25% (95%CI: 20-31%) which was calculated by the random-effects model. The summarized proportion of NASH patients with normal ALT value in overall NASH patients was 19% (95%CI: 13-27%). Subgroup analysis includes region, study type, diagnostic method, and group size were conducted to investigate the resource of heterogeneity in the summarized proportion of NAFLD and NASH patients with normal ALT value.
25% NAFLD patients and 19% NASH patients possess the normal ALT value in the clinical manifestation. The value of ALT in the clinical diagnosis of NAFLD and NASH remains need be further testified.
The research on high-precision and all-scenario localization using the millimeter-wave (mmWave) band is of great urgency. Due to the characteristics of mmWave, blockages make the localization task ...more complex. This paper proposes a cooperative localization system among user equipment (UEs) assisted by reconfigurable intelligent surfaces (RISs), which considers device-to-device (D2D) communication. RISs are used as anchor points, and position estimation is achieved through signal exchanges between UEs. Firstly, we establish a localization model based on this system and derive the UEs’ positioning error bound (PEB) as a performance metric. Then, a UE-RIS joint beamforming design is proposed to optimize channel state information (CSI) with the objective of achieving the minimum PEB. Finally, simulation analysis demonstrates the advantages of the proposed scheme over RIS-assisted base station positioning, achieving centimeter-level accuracy with a 10 dBm lower transmission power.
We propose a low-insertion-loss electro-optic modulator formed with LNOI bonded on a D-shaped SMF. The proposed modulator employs high-performance Mach-Zehnder interferometer (MZI) formed with ridge ...LNOI waveguides and driven by travelling-wave electrodes. The light from the fiber core is coupled into a thin strip LNOI waveguide and then launched into the MZI via a ridge LNOI waveguide with tapered slab height and vice versa. Such all-fiber configuration exempts the need of the butt-coupling with an SMF. The calculated results show that our proposed modulator is capable of achieving a low insertion loss of less than 1.5 dB, an EO modulation efficiency (
V
π
·L
) of 2.05 V·cm, and a 3-dB modulation bandwidth of larger than 80 GHz. Our all-fiber LNOI modulator is feasible in practice and opens a new door to realize high-speed fiber devices by the integration of an optical fiber and thin film LN.
In recent years, tin monosulfide (SnS), one kind of black phosphorus analogues, is of great interest owing to its unique properties, such as low cost, environmental compatibility, nontoxicity, ...earth‐abundance, etc., which merit it an ideal candidate for modern devices, such as batteries, sensors, and optoelectronics, among others. The controllable and precise synthesis of SnS‐based nanostructures with various crystal phases, sizes, and compositions holds great potential for high‐performance devices as crucial components. To further improve their performance for next‐generation devices, the nanoengineering of SnS‐based nanostructures has been extensively explored over the past decade. In this review, the latest research and progress on SnS‐based nanostructures, including 0D, 1D, 2D, and 3D pure SnS nanostructures, and SnS‐based loaded, sandwiched or encapsulated models are comprehensively presented, focusing on their synthetic approaches, fundamental properties, and fascinating applications such as batteries and solar cells, catalysis (photocatalysis and electrocatalysis), optoelectronics, sensors, ferroelectrics, thermoelectrics, nonlinear properties, and biomedical applications. Finally, the critical challenges and constructive perspectives are discussed for further improvement of the SnS‐based nanostructures in these burgeoning fields.
This review provides an overview of the controlled synthesis and versatile applications of SnS‐based nanostructures, and presents insights on the challenges and future opportunities in the research area. It is envisioned that the controllable manipulation techniques and unique properties of SnS‐based nanostructures can inspire more efforts toward the next‐generation nanodevices based on SnS‐related nanostructures.
Abrasive wear of the orifice cannot be avoided for a hopper which should be operated uninterruptedly for a long time in engineering applications. Consequently, the change of the orifice shape will ...lead to the variation of flow rate for the hopper. In this paper, the influence of orifice shape on the flow rate in ordinary flat-bottom hoppers is investigated both numerically and experimentally. The flow rate increases when the orifice is from sharp to smooth in both flat-bottom and conical-bottom hoppers. The data can be well fitted with a modified Beverloo's formula. The result is supported by the profile of kinetic pressure near the orifice. Moreover, the fluctuation of the instantaneous flow rate is reduced with smooth orifice. In addition, it is found that the diameter of the hopper D and the thickness of the bottom H do not influence the flow rate. This paper contributes to control the flow rate by optimizing the shape of orifice.
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•The first investigation of the influence of the orifice shape on the flow rates in a hopper•Both experimental and numerical studies are performed to explain this phenomenon.•The increasing of radius of the arc on the orifice reduces the empty annulus.
To exploit the plant byproducts from selenium (Se) biofortification and reduce environmental risk of inorganic Se fertilizer, pot experiment was conducted in this study. The effects of Se-enriched ...wheat (Triticum aestivum L.) straw (WS + Se) and pak choi (Brassica chinensis L.) (P + Se) amendment on organo-selenium speciation transformation in soil and its bioavailability was evaluated by pak choi uptake. The Se contents of the cultivated pak choi in treatments amended with the same amount of Se-enriched wheat straw and pak choi were 1.7 and 9.7 times in the shoots and 2.3 and 6.3 times in the roots compared with control treatment. Soil respiration rate was significantly increased after all organic material amendment in soil (p < 0.05), which accelerated the mineralization of organic materials and thus resulted in soluble Se (SOL-Se), exchangeable Se (EX-Se), and fulvic acid-bound Se (FA-Se) fraction increasing by 25.2–29.2%, 9–13.8%, and 4.92–8.28%, respectively. In addition, both Pearson correlation and cluster analysis showed that EX-Se and FA-Se were better indicators for soil Se availability in organic material amendment soils. The Marquardt–Levenberg Model well described the dynamic kinetics of FA-Se content after Se-enriched organic material amendment in soil mainly because of the mineralization of organic carbon and organo-selenium. The utilization of Se in P + Se treatment was significantly higher than those in WS + Se treatment because of the different mineralization rates and the amount of FA-Se in soil. Se-enriched organic materials amendment can not only increase the availability of selenium in soil but also avoid the waste of valuable Se source.
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•Se-enriched pak choi amendment resulted in better Se utilization efficiency than wheat straw.•Se-enriched organic material amendments elevated soil Se availability through increasing FA-Se fraction.•EX-Se and FA-Se fraction could better reflect Se availability in organic materials amended soils.•The dynamic kinetics of FA-Se could be well described by Marquardt–Levenberg Model.
Bismuth (Bi) has achieved remarkable progress due to its intriguing physicochemical properties, such as low toxicity, controllable stability, tunable bandgap, superior optical response, and strong ...diamagnetism. Bi-based hybrids have drawn increasing attention in recent years due to the integrated features of the Bi component and the synergistic effect on the separation and transfer of charges, holding great promises for versatile applications. In this Perspective, we systematically review the recent progress on the controlled synthesis of Bi-based heterostructures and their improved nanophotonic performances compared with those of mono-element Bi counterparts and present the existing challenges and future opportunities. It is anticipated that this Perspective can shed light on new designs of high-performance functional Bi-based heterostructures to meet the growing demand for next-generation nanophotonic systems.
is a traditional medicinal plant popularly used in China. This study intended to evaluate the antioxidant properties and the chemical components of the flavonoid-rich extracts from the flowers of
. ...The results showed that the flavonoid-rich extracts from the flowers of
had strong scavenging capacities on 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS), hydroxyls, superoxide anions, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent manner. Five flavonoids, dihydrokaempferol (
), apigenin-7-
-β-d-glucoside (
), apigenin-7-
-β-d-neohesperidoside (
), kaempferol-7-
-β-d-glucopyranoside (
), and kaempferol-3-
-β-d-glucopyranosyl-7-
-β-d-glucopyranoside (
), were isolated from the flavonoid-rich extracts of the flowers of
. High-performance liquid chromatography (HPLC) analysis revealed that compounds
and
were abundant in the
flower and in flavonoid-rich extracts. The main components of the flower of
are flavonoids. The high antioxidant activity of the flavonoid-rich extracts may be attributed to the high content of flavonoids. The five isolated flavonoids were the primary antioxidant ingredients, and may play important roles in the strong antioxidant activities of this flower. Based on the obtained results, the flower of
could be a potential source of natural antioxidants in food and pharmaceutical applications.
The occlusion of buildings in urban environments leads to the intermittent reception of satellite signals, which limits the utilization of observations. This subsequently results in a decline of the ...positioning and attitude accuracy of Global Navigation Satellite System (GNSS)/Inertial Navigation System (INS) integrated system (GNSS/INS). This study implements a smooth post-processing strategy based on a tightly coupled differential GNSS/INS. Specifically, this strategy used the INS-estimated position to reinitialize integer ambiguity. The GNSS raw observations were input into the Kalman filter to update the measurement. The Rauch-Tung-Striebel smoothing (RTSS) algorithm was used to process the observations of the entire period. This study analyzed the performance of loosely coupled and tightly coupled systems in an urban environment and the improvement of the RTSS algorithm on the navigation solution from the perspective of fully mining the observations. The experimental results of the simulation data and real data show that, compared with the traditional tightly coupled processing strategy which does not use INS-aided integer ambiguity resolution and RTSS algorithm, the strategy in this study sufficiently utilized INS observations and GNSS observations to effectively improve the accuracy of positioning and attitude and ensure the continuity of navigation results in an obstructed environment.
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