In addition to spintronics another motivation for exploring ferromagnetic two-dimensional materials is for biomedical applications such as magnetic labeling and hyperthermia treatment of tumors. ...Unfortunately, the widely studied Mn-containing monolayer is not biocompatible, although it is ferromagnetic. Here using first principles calculations combined with Monte Carlo simulations based on the Ising model, we systematically study a class of 2D ferromagnetic monolayers CrX3 (X = Cl, Br, I). The feasibility of exfoliation from their layered bulk phase is confirmed by the small cleavage energy and high in-plane stiffness. Spin-polarized calculations, combined with self-consistently determined Hubbard U that accounts for strong correlation energy, demonstrate that CrX3 (X = Cl, Br, I) monolayers are ferromagnetic and that Cr is trivalent and carries a magnetic moment of 3 μ(B); the resulting Cr(3+) ions are biocompatible. The corresponding Curie temperatures for CrCl3, CrBr3 and CrI3 are found to be 66, 86, and 107 K, respectively, which can be increased to 323, 314, and 293 K by hole doping. The biocompatibility and ferromagnetism render these Cr-containing trihalide monolayers unique for applications.
As a new kind of artificial material developed in recent decades, metamaterials exhibit novel performance and the promising application potentials in the field of practical engineering compared with ...the natural materials. Acoustic metamaterials and phononic crystals have some extraordinary physical properties, effective negative parameters, band gaps, negative refraction, etc., extending the acoustic properties of existing materials. The special physical properties have attracted the attention of researchers, and great progress has been made in engineering applications. This article summarizes the research on acoustic metamaterials and phononic crystals in recent decades, briefly introduces some representative studies, including equivalent acoustic parameters and extraordinary characteristics of metamaterials, explains acoustic metamaterial design methods, and summarizes the technical bottlenecks and application prospects.
Different from the isotropic Dirac cones existing in other two-dimensional (2D) materials, anisotropic Dirac cones have the merit of anisotropic carrier mobility for applications in ...direction-dependent quantum devices. Motivated by the recent experimental finding of an anisotropic Dirac cone in borophene, here we report a new 2D anisotropic Dirac cone material, B2S monolayer, identified by using a global structure search method and first-principles calculation combined with a tight-binding model. The B2S monolayer is found to be stable mechanically, thermally, and dynamically and exhibits an anisotropic Dirac cone exactly at the Fermi level, showing a Fermi velocity of 106 m/s in the same order of magnitude as that of graphene. Moreover, B2S monolayer is the first anisotropy Dirac cone material with a pristine honeycomb structure stabilized by S in free-standing conditions where each atom has four valence electrons on average being isoelectronic to C. This study would expand the Dirac cone material family with new features.
Automatic optical-to-SAR image registration is considered as a challenging problem because of the inconsistency of radiometric and geometric properties. Feature-based methods have proven to be ...effective; however, common features are difficult to extract and match, and the robustness of those methods strongly depends on feature extraction results. In this paper, a new method based on iterative line extraction and Voronoi integrated spectral point matching is developed. The core idea consists of three aspects: 1) An iterative procedure that combines line segment extraction and line intersections matching is proposed to avoid registration failure caused by poor feature extraction. 2) A multilevel strategy of coarse-to-fine registration is presented. The coarse registration aims to preserve main linear structures while reducing data redundancy, thus providing robust feature matching results for fine registration. 3) Voronoi diagram is introduced into spectral point matching to further enhance the matching accuracy between two sets of line intersection. Experimental results show that the proposed method improves the matching performance. Compared with previous methods, the proposed algorithm can effectively and robustly generate sufficient reliable point pairs and provide accurate registration.
As a common polycyclic aromatic hydrocarbon compound, benzoapyrene (BaP) is readily produced in processing of oil and fatty foods. It is not only a strong carcinogen but also a substance with ...strong immunotoxicity and reproduction toxicity. Autophagy and pyroptosis are two types of programmed cell death. Whether or not BaP damages body tissues via autophagy or pyroptosis remains unknown. The present study investigated the effects of BaP on autophagy and pyroptosis in HL-7702 cells. The results showed that BaP induced cell death in HL-7702 cells enhanced the intracellular levels of ROS and arrested the cell cycle at the S phase. Additionally, BaP resulted in cell death through autophagy and pyroptosis. Compared with the BaP group, the autophagy inhibitor 3-MA significantly (p < 0.01) inhibited the release of LDH by 70.53% ± 0.46 and NO by 50.36% ± 0.80, the increase of electrical conductivity by 12.08% ± 0.55, and the expressions of pyroptotic marker proteins (Caspase-1, Cox-2, IL-1β, IL-18). The pyroptosis inhibitor Ac-YVAD-CM also notably (p < 0.01) blocked BaP-induced autophagic cell death characterized by the increase of autophagic vacuoles and overexpression of Beclin-1 and LC3-II. In conclusion, BaP led to injury by inducing autophagy and pyroptosis simultaneously, the two of which coexisted and promoted each other in HL-7702 cells.
Emergency management agencies must address the challenges presented by frequent flooding events. Remote sensing imagery provides a means for timely monitoring of rapidly changing water bodies during ...flooding events; but manual analysis of remote sensing (RS) images however, is labor intensive and time consuming. Automated methods are effective, but the post-classification comparison method for flood inundation detection is subject to error accumulation, and the direct change detection method is limited by the accuracy of flood mapping and the difficulty of obtaining training samples. To overcome these challenges, a flood inundation detection network (Siam-DWENet) that achieves high-accuracy inundation detection is proposed. In Siam-DWENet, an innovative cross-task transfer learning strategy incorporates an attention mechanism and multi-scale pyramid structure based on Siamese architectures. This approach realizes a priori knowledge transfer-based flood inundation detection with a limited number of training samples. Comparative experiments on Siam-DWENet and other methods using two flooding SAR datasets to evaluate the accuracy of flood detection. The experimental results indicate that Siam-DWENet outperforms other change detection methods and makes the inundation area edge more accurate when dealing with complex backgrounds, achieving an average OA of 0.887 and F1 of 0.865 in flood inundation detection tasks.
•Dual-temporal SAR images change detection is import for flood rapid mapping.•We propose Siam-DWENet for flood inundation detection.•This method has potential application in different remote sensing images.
This paper investigates the feasibility of an iterative learning control (ILC) with variable sampling frequency for current control of power converters in frequency-wild power systems. The proposed ...solution is explained and demonstrated for the case of a shunt active filter in new-generation aircraft, where a variable-speed variable-frequency power system, typically between 360 and 900 Hz, is nowadays used. Due to the high supply frequency, such application is particularly demanding for both power and control devices, requiring control capabilities even for frequencies up to several kilohertz. Furthermore, variable supply frequency leads to variable frequency harmonics in the aircraft grid that are challenging to track and compensate. An original and effective solution based on an ILC approach, where both the number of samples per period and the sampling frequency are changed, is studied and implemented. Experimental results confirm the validity of the proposed strategy.
Food pantries play a critical role in combating food insecurity. The objective of the present work was to systematically review and synthesize scientific evidence regarding the effectiveness of food ...pantry-based interventions in the USA.
Keyword/reference search was conducted in PubMed, Web of Science, Scopus, Cochrane Library and CINAHL for peer-reviewed articles published until May 2018 that met the following criteria.
food pantry and/or food bank in the USA; study design: randomized controlled trial (RCT) or pre-post study; outcomes: diet-related outcomes (e.g. nutrition knowledge, food choice, food security, diet quality); study subjects: food pantry/bank clients.
Fourteen articles evaluating twelve distinct interventions identified from the keyword/reference search met the eligibility criteria and were included in the review. Five were RCT and the remaining seven were pre-post studies. All studies found that food pantry-based interventions were effective in improving participants' diet-related outcomes. In particular, the nutrition education interventions and the client-choice intervention enhanced participants' nutrition knowledge, cooking skills, food security status and fresh produce intake. The food display intervention helped pantry clients select healthier food items. The diabetes management intervention reduced participants' glycaemic level.
Food pantry-based interventions were found to be effective in improving participants' diet-related outcomes. Interventions were modest in scale and usually short in follow-up duration. Future studies are warranted to address the challenges of conducting interventions in food pantries, such as shortage in personnel and resources, to ensure intervention sustainability and long-term effectiveness.
Based on a recent experimental study on the Ni3C12S12 sheet J. Am. Chem. Soc. 2013, 135, 2462 and a theoretical study on the Mn3C12S12 sheet Nanoscale 2013, 5, 10404, by using density functional ...theory combined with a thermodynamic model, it is shown that when sulfur atoms are replaced by NH groups the resulting Mn3C12N12H12 sheet can exhibit strong ferromagnetism with a Curie temperature of 450 K. The enhanced ferromagnetism is due to two main factors: the reduced lattice constant and nitrogen is more effective in mediating magnetic couplings through p–d exchange interactions. Furthermore, it is also confirmed that the Mn3C12N12H12 sheet is kinetically and thermally stable, and displays half metallicity.
Attractive replacement: When sulfur atoms are replaced by NH groups in Mn3C12S12, the resulting Mn3C12N12H12 sheet exhibits strong ferromagnetism with a high Curie temperature (see figure). The enhanced ferromagnetism is due to the reduced lattice constant and nitrogen being more effective at mediating magnetic couplings through p–d exchange interactions.
We report a redox‐neutral formylation of aryl chlorides that proceeds through selective 2‐functionalization of 1,3‐dioxolane through nickel and photoredox catalysis. This scalable benchtop approach ...provides a distinct advantage over traditional reductive carbonylation in that no carbon monoxide, pressurized gas, or stoichiometric reductant is employed. The mild conditions give unprecedented scope from abundant and complex aryl chloride starting materials.
Born to be mild: Aromatic aldehydes are generated from abundant aryl chlorides through nickel‐photocatalyzed C−H functionalization of the inexpensive solvent 1,3‐dioxolane. The mild conditions and absence of pressurized carbon monoxide or stoichiometric reductant lead to broad functional‐group tolerance and scope.
PDF
![Benzo[a]pyrene Induces Auto...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0021-8561/small "Benzo[a]pyrene Induces Autophagic and Pyroptotic Death Simultaneously in HL-7702 Human Normal Liver Cells")
