•A UHPLC-MS/MS method is developed and validated for multi-components in star anise.•An exogenous internal standard is used for matrix correction and analyte quantitation.•Three curative flavonoids ...and a toxic anisatin are analyzed in commercial products.•It can be used for the quality control & adulteration detection of star anise samples.
Chinese star anise is an anise-scented star-shaped fruit of the evergreen Illicium verum tree. It is generally used as a spice and folk medicine for treating digestive illness. Chinese star anise may be adulterated with Japanese star anise (fruit of Illicium anisatum tree with similar morphology to the former), containing high content of toxic anisatin leading to severe physical disorders. In this work, a UHPLC-MS/MS method has been developed to determine three quality markers (quercetin, kaempferol, and luteolin) and toxicity marker (anisatin) of star anise using quercetin-d3, an exogenous heavy isotopic compound, as internal standard. Chromatographic separation of quality and toxicity marker compounds was achieved using a T3 column within two minutes. The method was successfully developed, validated, and used to quantify the multiple marker compounds in both botanical reference materials and star anise samples. This method can be used for quality control and assessment of Chinese star anise products.
In this research, drought in Coke County, Texas is analyzed using Normalized Difference Vegetation Index (NDVI) derived from remotely sensed Landsat data. Shrub, crop, and evergreen are focused to ...analyze their response to a drought event. The study reveals that pre-drought NDVI in 2009 is found to be higher than post-drought NDVI in 2011. The dominant vegetation, shrub, is most affected by drought, and the crop is least affected by drought. The study of dominant vegetation type can be used to monitor and study the severity and status of local drought.
Ants are the standout group among eusocial insects in terms of their exceptional species richness and ecological dominance. The phylogenetic relationships among the group remain elusive. ...Mitochondrial genome sequences, as a kind of molecular marker, have been widely utilized in the phylogenetic analysis of insects. However, the number of ant mitogenomes published is still very limited. In this study, we utilized next-generation sequencing to determine the complete mitogenome of Pachycondyla annamita (Formicidae, Ponerinae). This is the first mitogenome from the genus Pachycondyla. Two gene rearrangements were identified in the mitogenome, the transposition of trnQ and trnM and the transposition of trnV and rrnS. The secondary structures of tRNAs were predicted. The tRNA genes trnR and trnS1 lacked the dihydrouridine (DHU) arm, and the trnE lacked the TΨC (T) arm. Phylogenetic analyses of the mitochondrial protein-coding genes under maximum likelihood (ML) and Bayesian inference (BI) criteria resulted in conflicting hypotheses. BI analysis using amino acid data with the site-heterogeneous mixture model produced a tree topology congruent with previous studies. The Formicidae was subdivided into two main clades, namely the “poneroid” clade and the “formicoid” clade. A sister group relationship between Myrmicinae and Formicinae was recovered within the “formicoid” clade.
Wearable epidermal patch can seamlessly monitor biological signals in real-time. Here, we report a liquid metal-polymer conductor-based wireless epidermal patch. The epidermal patch is made of a new ...conductive material called liquid metal-polymer conductors (LMPC). LMPC is made by casting and peeling off polymers from patterned liquid metal particles. Our printable conductors present good stretchability, repeatability, and biocompatibility. We fabricate LMPC-based antenna and wire, which achieves wireless signal communication and power supply. To demonstrate the capability of our LMPC-based antenna and wire, we fabricate an epidermal patch to analyze metabolites, electrolytes, and urea in sweat. When a portable device is close to the epidermal sensor, the device can power and read the sensor through LMPC-based antenna. The epidermal patch exhibited good analytical performance for sweat analysis with a low limit of detection, fast response time, and multiplex detection capabilities. This epidermal patch opens the possibility for a broad range of non-invasive diagnostic tools that can be used for health monitoring in the general population.
•Liquid metal-polymer conductor-based antenna and wire have good conductivity, stretchability, and biocompatibility.•The epidermal patch works in a battery-free manner which overcomes the limits imposed by battery life.•Four potentiometric ion-selective electrodes for detecting metabolites and electrolytes are integrated into this patch.•The epidermal patch exhibits good analytical performance for sweat analysis.
Herein, to improve the electrical characteristics, ZnO linear resistors mixed with MgO, TiO2, Al2O3, and various concentrations of Sc2O3 (with 0, 0.35, 0.7, and 1.05 wt %) were obtained using the ...conventional solid-state sintering technique, while the influences of Sc2O3 doping on the micro-morphology and electrical characteristics was investigated in detail. The crystalline phases and microstructure were investigated by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The dielectric properties and electrical characteristics were evaluated using a precision inductance-capacitance-resistance meter and a high-voltage source meter. Results from SEM micrographs, XRD patterns, and EDS mappings illustrated that the doping of Sc2O3 hinders the growth of ZnO grains. Electric field-current density and resistivity-frequency measurements illustrated that the doping of Sc2O3 improves the linear performance of ZnO linear resistors and increases its grain resistivity and grain boundary resistivity. With Sc2O3 doping, the dielectric properties of the samples are significantly affected, while the resistance-temperature features reveal the negative temperature constant function. By appropriate Sc2O3 doping, the ZnO linear resistors exhibited excellent performance with grain boundary barrier height φb of 0.0106 eV, nonlinear coefficient α of 1.03, and resistance temperature constant αT of −2.88 × 10−3. It is beneficial to investigate the influence of Sc2O3 doping on the micro-morphology and electrical performances in detail for the preparation of zinc oxide linear resistors with superior performance.
•With Sc2O3 doping, the ZnO grain size d is decreasing.•Sc2O3 as a donor additive, enhances the linear characteristics of ZnO linear resistors.•With Sc2O3 doping, the εr and tanδ of the ZnO linear resistors decrease.
Organic magnesium storage materials are intriguing as cathode materials for rechargeable magnesium batteries (RMBs) because of their flexible structure and the potential of fast Mg-ion diffusion ...kinetics. However, the dissolution of these materials in the electrolytes of the RMBs limits their application. Herein, the pentacenetetrone (PT) and its polymer poly(pentacenetetrone sulfide) (PPTS) are developed as cathode materials for RMBs. Given the benefit of its insoluble property in the Mg-ion electrolyte, the as-prepared PPTS cathode exhibits significantly enhanced reversible capacity, coulombic efficiency, and rate performance compared to PT. For instance, the high capacities of 241 mAh g–1 (100 mA g–1) and 131 mAh g–1 (2 A g–1) are obtained for the PPTS cathode, demonstrating a competitive rate performance of PPTS compared to previously reported organic cathodes of RMBs. In contrast, the soluble PT cathode exhibits much lower capacities of 163 mAh g–1 (100 mAh g–1) and 31 mAh g–1 (2 A g–1).
Frequency agile radar (FAR) is known to have excellent electronic counter-countermeasures performance and the potential to realize spectrum sharing in dense electromagnetic environments. Many ...compressed sensing (CS) based algorithms have been developed for joint range and Doppler estimation in FAR. This paper considers theoretical analysis of FAR via CS algorithms. In particular, we analyze the properties of the sensing matrix, which is a highly structured random matrix. We then derive bounds on the number of recoverable targets. Numerical simulations and field experiments validate the theoretical findings and demonstrate the effectiveness of CS approaches to FAR.
In this paper, we propose an effective online portfolio selection strategy by integrating expert opinions, which are obtained based on mean reversion and trading volume. Existing studies have found ...that mean reversion and high volume premium exist in the stock market in the short term. Some online portfolio strategies have been proposed that rely upon mean reversion, but it is rare to consider both mean reversion and high volume premium, which is what we will do in this paper. First, a portfolio based on mean reversion and high volume premium is constructed using recent window data. Second, a pool of portfolios, also known as a pool of expert strategies or expert opinions, is established by changing the window size. Finally, the online gradient update algorithm is adopted to integrate a pool of expert strategies, and the MRvol strategy in this paper is proposed. Theoretically, we prove that the regret of MRvol is bounded. Empirically, we use the actual stock price and trading volume data from different markets to test the performance of MRvol. The results show that MRvol performs better than other online strategies in terms of final cumulative wealth and risk-adjusted return metrics in most cases, among which the annualized percentage yield on all datasets is 16%–37%, and the average values of Sharpe ratio, Calmar ratio and Information ratio are 1.113, 0.9216 and 0.0299, respectively. Additionally, MRvol has linear computational time complexity, and the running time of test results is all less than 1 s. Furthermore, it maintains strong robustness under different parameters and can bear reasonable transaction costs.
•Mean reversion and high volume premium phenomena are used to design expert advice.•Online gradient update algorithm is applied to establish portfolio strategy MRvol.•It is proved that the MRvol strategy has a theoretical regret bound.•Extensive experiments show that MRvol performs well in multiple evaluation metrics.
Despite the recent advancement in the in‐practical active materials (e.g., silicon, sulfur) in the rechargeable lithium‐ion energy storage systems, daunting challenges still remain for these ...high‐capacity electrode material candidates to overcome the severe volume changes associated with the repeated lithiation/delithiation process. Herein, developing a room‐temperature covalently cross‐linked polyacrylamide (c‐PAM) binder with high stretchability and abundant polar groups targeting the construction of high‐performance Si and sulfur electrodes is focused on. The robust 3D c‐PAM binder network enables not only significant enhancement of the strain resistance for working electrodes but also strong affinity to bonding with nano‐Si surface as well as effective capture of the soluble Li2Sn intermediates, thereby giving rise to remarkably improved cycling performances in both types of electrodes. This rational design of such an effective and multifunctional binder offers a pathway toward advanced energy storage implementations.
A covalently cross‐linked polyacrylamide hydrogel with high stretchability and abundant polar groups is utilized as binder material for fabricating high‐strength silicon and sulfur electrodes. Such a multifunctional binder can provide strong affinity to bonding with the nanosilicon surface and trap the soluble polysulfide intermediates, resulting in remarkably improved electrochemical performance of both the silicon anodes and sulfur cathodes.
Diseases induced by bacterial and viral infections are common occurrences in our daily life, and the main prevention and treatment strategies are vaccination and taking antibacterial/antiviral drugs. ...However, vaccines can only be used for specific viral infections, and the abuse of antibacterial/antiviral drugs will create multi-drug-resistant bacteria and viruses. Therefore, it is necessary to develop more targeted prevention and treatment methods against bacteria and viruses. Proteins on the surface of bacteria and viruses can specifically bind to sugar, so glycopolymers can be used as potential antibacterial and antiviral drugs. In this review, the research of glycopolymers for bacterial/viral detection/inhibition and antibacterial/antiviral applications in recent years are summarized.
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