Phenomenological theory of the giant magnetoimpedance of composite wires

Composite wires with a three-layered structure are known to show a particularly large magnetoimpedance effect. The wires consist of a highly conductive core, an insulating layer and an outer ferromagnetic shell. In order to understand the origin of the effect a theory based on a coupling of the Maxwell equations to the Landau-Lifschitz-Gilbert equation is suggested. The theory is phenomenological in the sense that it does not account for a domain structure. However, theoretical results nicely reproduce those obtained in various measurements. Furthermore, an upper limit of the magnetoimpedance ratio for a given combination of materials can be determined.Comment: 4 pages, figure

Crystal structure and electronic structure of quaternary semiconductors Cu2_2ZnTiSe4_4 and Cu2_2ZnTiS4_4 for solar cell absorber

We design two new I2-II-IV-VI4 quaternary semiconductors Cu$_2$ZnTiSe$_4$ and Cu$_2$ZnTiS$_4$, and systematically study the crystal and electronic structure by employing first-principles electronic structure calculations. Among the considered crystal structures, it is confirmed that the band gaps of Cu$_2$ZnTiSe$_4$ and Cu$_2$ZnTiS$_4$ originate from the full occupied Cu 3$d$ valence band and unoccupied Ti 3$d$ conducting band, and kesterite structure should be the ground state. Furthermore, our calculations indicate that Cu$_2$ZnTiSe$_4$ and Cu$_2$ZnTiS$_4$ have comparable band gaps with Cu$_2$ZnTSe$_4$ and Cu$_2$ZnTS$_4$, but almost twice larger absorption coefficient $\alpha(\omega)$. Thus, the materials are expected to be candidate materials for solar cell absorber.Comment: 4 pages, 4 figure

GENET: Unleashing the Power of Side Information for Recommendation via Hypergraph Pre-training

Recommendation with side information has drawn significant research interest due to its potential to mitigate user feedback sparsity. However, existing models struggle with generalization across diverse domains and types of side information. In particular, three challenges have not been addressed, and they are (1) the diverse formats of side information, including text sequences. (2) The diverse semantics of side information that describes items and users from multi-level in a context different from recommendation systems. (3) The diverse correlations in side information to measure similarity over multiple objects beyond pairwise relations. In this paper, we introduce GENET (Generalized hypErgraph pretraiNing on sidE informaTion), which pre-trains user and item representations on feedback-irrelevant side information and fine-tunes the representations on user feedback data. GENET leverages pre-training as a means to prevent side information from overshadowing critical ID features and feedback signals. It employs a hypergraph framework to accommodate various types of diverse side information. During pre-training, GENET integrates tasks for hyperlink prediction and self-supervised contrast to capture fine-grained semantics at both local and global levels. Additionally, it introduces a unique strategy to enhance pre-training robustness by perturbing positive samples while maintaining high-order relations. Extensive experiments demonstrate that GENET exhibits strong generalization capabilities, outperforming the SOTA method by up to 38% in TOP-N recommendation and Sequential recommendation tasks on various datasets with different side information

First-principles investigation of effect of pressure on BaFe2_2As2_2

On experimental side, BaFe$_2$As$_2$ without doping has been made superconducting by applying appropriate pressure (2-6 GPa). Here, we use a full-potential linearized augmented plane wave method within the density-functional theory to investigate the effect of pressure on its crystal structure, magnetic order, and electronic structure. Our calculations show that the striped antiferromagnetic order observed in experiment is stable against pressure up to 13 GPa. Calculated antiferromagnetic lattice parameters are in good agreements with experimental data, while calculations with nonmagnetic state underestimate Fe-As bond length and c-axis lattice constant. The effects of pressure on crystal structure and electronic structure are investigated for both the antiferromagnetic state and the nonmagnetic one. We find that the compressibility of the antiferromagnetic state is quite isotropic up to about 6.4 GPa. With increasing pressure, the FeAs$_4$ tetrahedra is hardly distorted. We observe a transition of Fermi surface topology in the striped antiferromagnetic state when the compression of volume is beyond 8% (or pressure 6 GPa), which corresponds to a large change of $c/a$ ratio. These first-principles results should be useful to understanding the antiferromagnetism and electronic states in the FeAs-based materials, and may have some useful implications to the superconductivity.Comment: 7 pages, 5 figure

Dual hepatocyte-targeting fluorescent probe with high sensitivity to tumorous pH: Precise detection of hepatocellular carcinoma cells

A new dual hepatocyte-targeting fluorescent probe HPL-1, which can precisely distinguish tumorous pH from physiological pH, was developed. The OFF-ON switch of HPL-1 can be triggered via pH-induced structural change of the lactam group of the rhodamine moiety from closed-ring to open-ring. Our results showed that the phosphate group of HPL-1 is beneficial to its accumulation in liver cells, and combination of the phosphate and galactose units could synergistically increase the hepatocyte-targeting capacity. HPL-1 could selectively distinguish hepatoma cells from other tissue cells, and precisely distinguish cancerous liver cells from normal liver cells. Compared with other reported probes, HPL-1 not only enable a simple and convenient detection method, but also has good hepatocyte-targeting capacity and precise recognition capacity of tumors under weak acid micro-environment, which opens new avenues for precise diagnosis and treatment of hepatocellular carcinoma

Novel compounds in fruits of coriander (Coşkuner & Karababa) with anti-inflammatory activity

© 2020 Coriander, Coriandrum Sativum L., is one of the commonest food and medicinal plants in many countries, but its chemical ingredients and pivotal role in anti-inflammatory activity have not been fully explored. The present study aimed to identify new compounds in the fruits of coriander and explore their anti-inflammatory activity. The compounds were isolated by chromatographic seperations and identified using spectroscopic and spectrometric methods. RAW264.7 macrophage cells were used to detect the anti-inflammatory activity of the compounds via Griess assay, western blotting, ELISA, and flow cytometry methods. The study resulted in the discovery of four new compounds, which were identified as: 4α-(furo[2,3-d]pyrimidin-6′-ylmethyl)-9α-propylnonolactone (1), 4-(formyloxy)-4-(6′-methylcyclohex-1-en-1-yl)butanoate(2), (7α,8α)-3α-hydroxyl-12,13α-dimethyl-5(6)-en-bicyclo[5,3,0]caprolactone (3), 7-methoxy-4-methyl-5,6-dihydro-7H-(2-hydroxypropan-2-yl)furo[2,3-f] coumarin (4). Compound 3 showed the highest anti-inflammatory activity with IC50 of 6.25 μM for an inhibitory effect on nitrite oxide (NO) level. In addition, compound 3 decreased the lipopolysaccharides-stimulated generations of ROS and the inflammatory cytokines (IL-6 and TNF-α). Mechanism exploration indicated that compound 3 suppressed inflammatory mediators’ expression, like iNOS and COX-2. Furthermore, the NF-κB and MAPK pathways were involved in the anti-inflammatory process of compound 3

Microwave-Assisted Synthesis of Co/CoOx Supported on Earth-Abundant Coal-Derived Carbon for Electrocatalysis of Oxygen Evolution

The evident demand for hydrogen as the ultimate energy fuel for posterity calls for the development of low-cost, efficient and stable electrocatalysts for water splitting. Herein, we report the synthesis of Co/CoOx supported on coal-derived N-doped carbon via a simple microwave-assisted method and demonstrate its application as an efficient catalyst for the oxygen evolution reaction (OER). With the optimal amount of cobalt introduced into the N-doped coal-derived, the developed catalyst achieved overpotentials of 0.370 and 0.429 V during water oxidation at current densities of 1 mA cm(-2) and 10 mA cm(-2), respectively. There was no noticeable loss in the activity of the catalyst during continuous galvanostatic polarization at a current density of 10 mA cm(-2) for a test period of 66 h. The synergistic interaction of the Co/CoOx moieties with the pyridinic and pyrollic nitrogen functional groups in the N-doped carbon, as well with the other heteroatoms species in the pristine coal favored enhancement of the OER electrocatalytic performance. (C) The Author(s) 2019. Published by ECS

Research progress on and molecular mechanism of vacuum sealing drainage in the treatment of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are common chronic wounds and a common complication of diabetes. The foot is the main site of diabetic ulcers, which involve small and medium-sized arteries, peripheral nerves, and microcirculation, among others. DFUs are prone to coinfections and affect many diabetic patients. In recent years, interdisciplinary research combining medicine and material science has been increasing and has achieved significant clinical therapeutic effects, and the application of vacuum sealing drainage (VSD) in the treatment of DFUs is a typical representative of this progress, but the mechanism of action remains unclear. In this review, we integrated bioinformatics and literature and found that ferroptosis is an important signaling pathway through which VSD promotes the healing of DFUs and that System Xc-GSH-GPX4 and NAD(P)H-CoQ10-FSP1 are important axes in this signaling pathway, and we speculate that VSD is most likely to inhibit ferroptosis to promote DFU healing through the above axes. In addition, we found that some classical pathways, such as the TNF, NF-κB, and Wnt/β-catenin pathways, are also involved in the VSD-mediated promotion of DFU healing. We also compiled and reviewed the progress from clinical studies on VSD, and this information provides a reference for the study of VSD in the treatment of DFUs