Broadband 2D phase-gradient metasurface for linearly-polarized waves by suppressing Lorentz resonance of meta-atoms.

Metasurfaces have exhibited versatile capacities of controlling electromagnetic (EM) waves due to the high degree of freedom of designing artificially engineered meta-atoms. For circular polarization (CP), broadband phase gradient metasurfaces (PGMs) can be realized based on P-B geometric phase by rotating meta-atoms; while for linear polarization (LP), realization of broadband phase gradients has to resort to P-B geometric phase during polarization conversion and polarization purity has to be sacrificed for broadband properties. It is still challenging to obtain broadband PGMs for LP waves without polarization conversion. In this paper, we propose the design of 2D PGMs by combining the inherently wideband geometric phases and non-resonant phases of meta-atom, under the philosophy of suppressing Lorentz resonances that usually bring about abrupt phase changes. To this end, an anisotropic meta-atom is devised which can suppress abrupt Lorentz resonances in 2D for both x- and y-polarized waves. For y-polarized waves, the central straight wire is in perpendicular to electric vector Ein of incident waves, Lorentz resonance cannot be excited although the electrical length approaches or even exceeds half a wavelength. For x-polarized waves, the central straight wire is in parallel with Ein, a split gap is opened on the center of the straight wire so as to avoid Lorentz resonance. In this way, the abrupt Lorentz resonances are suppressed in 2D and the wideband geometric phase and the gradual non-resonant phase are left for broadband PGM design. As a proof of concept, a 2D PGM prototype for LP waves was designed, fabricated and measured in microwave regime. Both simulated and measured results show that the PGM can achieve broadband beam deflection for reflected waves for both x- and y-polarized waves in broadband, without changing the LP state. This work provides a broadband route to 2D PGMs for LP waves and can be readily extended to higher frequencies such as terahertz and infrared regimes.

Synthesis and anti-inflammatory activity of paeonol analogues in the murine model of complete Freund's adjuvant induced arthritis.

A new series of paeonol alkyl ether analogues were synthesized and confirmed with IR, 1H NMR, 13C NMR and HRMS spectra. They have shown anti-inflammatory activities by scavenging mediator of free radicals and inhibiting lipid mediator of inflammation on complete Freund's adjuvant (CFA) induced arthritis in mice. The in vitro and in vivo scavenging ability of free radicals was determined by using chemical analysis and commercial assay kits, respectively. The in vivo inhibiting lipid mediator of inflammation was examined by ELISA. Our results indicated that the substitution of the hydrogen in hydroxyl group at C2 position of paeonol 1 by short carbon chain, in the presence or absence of bromo atom at C5 position, decreased its scavenging ability on radicals (3a or 4a vs 1), while the long alkyl substitution (Cn>14) increased the activity. Compared with 3a or 4a, scavenging abilities of 3a-h or 4a-h gradually increased following the length elongation of alkyl carbon chain. Compounds 3h and 4h showed great scavenging ability on OH, O2-, DPPH, ATBS+ and MDA, and good promotion on T-AOC and SOD. The results of the in vivo inhibiting lipid mediator of inflammation also demonstrated that 3h, 4h exhibited substantial inhibition on enzyme activity of COX-2, PGE2. Therefore, 3h and 4h have great potential to be the novel anti-inflammatory drug candidates for the therapy of arthritis.

Image detection of aortic dissection complications based on multi-scale feature fusion.

Background: Aortic dissection refers to the true and false two-lumen separation of the aortic wall, in which the blood in the aortic lumen enters the aortic mesomembrane from the tear of the aortic intima to separate the mesomembrane and expand along the long axis of the aorta. Purpose: In view of the problems of individual differences, complex complications and many small targets in clinical aortic dissection detection, this paper proposes a convolution neural network MFF-FPN (Multi-scale Feature Fusion based Feature Pyramid Network) for the detection of aortic dissection complications. Methods: The proposed model uses Resnet50 as the backbone for feature extraction and builds a pyramid structure to fuse low-level and high-level feature information. We add an attention mechanism to the backbone network, which can establish inter-dependencies between feature graph channels and enhance the representation quality of CNN. Results: The proposed method has a mean average precision (MAP) of 99.40% in the task of multi object detection for aortic dissection and complications, which is higher than the accuracy of 96.3% on SSD model and 99.05% on YoloV7 model. It greatly improves the accuracy of small target detection such as cysts, making it more suitable for clinical focus detection. Conclusions: The proposed deep learning model achieves feature reuse and focuses on local important information. By adding only a small number of model parameters, we are able to greatly improve the detection accuracy, which is effective in detecting small target lesions commonly found in clinical settings, and also performs well on other medical and natural datasets.

Relationships Between Meteorological Factors and Mongolian Gerbils and Its Flea Burdens - Xilingol League, Inner Mongolia Autonomous Region, China, 2012-2021.

Introduction: Plague is a significant global infectious disease, its spread is linked to host and flea populations. Meteorological conditions can impact flea populations and host densities, hence influencing plague outbreaks. Investigating the connection between meteorological factors, flea populations, and rodent densities in Inner Mongolia's natural plague foci can aid in predicting and managing plague outbreaks. Methods: Monthly data on flea index, rodent density, meteorological factors, and normalized difference vegetation index (NDVI) were collected for the study area. Generalized additive modeling (GAM) was used to analyze the non-linear and lag effects of meteorological factors on flea index and rodent density. Structural equation modeling (SEM) was employed to investigate the relationships among meteorological factors, NDVI, flea index, and rodent density. Results: GAM analysis revealed that temperature, precipitation, relative humidity, and NDVI had significant linear, non-linear, and time-lagged impacts on the density of Mongolian gerbils and the flea index. SEM analysis indicated that meteorological factors could directly influence the density and flea index of Mongolian gerbils, or indirectly impact NDVI, subsequently influencing gerbil density and the flea index. Conclusions: Meteorological factors primarily influence gerbil density and flea index indirectly by affecting NDVI and the relationship between flea index and gerbil density. This study offers additional support for the significance of meteorological factors and NDVI in influencing the vector-rodent system, offering valuable insights for predicting and managing plague outbreaks.

Comparative transcriptomic and metabolomic analyses reveal differences in flavonoid biosynthesis between PCNA and PCA persimmon fruit.

The fruit of the persimmon (Diospyros kaki.) has high economic and nutritional value and is rich in flavonoids. Flavonoids are essential secondary metabolisms in plants. The association between persimmon astringency and changes in the proanthocyanidins (a flavonoid subclass) content is well-known. However, information on the relationships between different astringency types and other flavonoid subclasses and biosynthetic genes is more limited. In this study, an initial correlation analysis between total flavonoids and fruit astringency type, and KEGG analysis of metabolites showed that flavonoid-related pathways were linked to differences between mature pollination-constant non-astringent (PCNA) varieties ('Jiro' and 'Yohou') and pollination-constant astringent (PCA) fruit varieties ('Zhongshi5' and 'Huojing'). Based on these findings, variations in the expression of genes and metabolites associated with flavonoid biosynthesis were investigated between typical PCNA ('Jiro') and PCA ('Huojing') persimmons during fruit development. The flavonoid concentration in 'Huojing' fruit was significantly higher than that of 'Jiro' fruit, especially, in levels of proanthocyanin precursor epicatechin and anthocyanin cyanidin derivatives. Combined WGCNA and KEGG analyses showed that genes such as PAL, C4H, CHI, CHS, F3H, F3'5'H, FLS, DFR, ANR, ANS, and UF3GT in the phenylpropanoid and flavonoid biosynthesis pathways may be significant factors impacting the proanthocyanin precursor and anthocyanin contents. Moreover, interactions between the R2R3MYB (evm.TU.contig7272.598) and WD40 (evm.TU.contig3208.5) transcription factors were found to be associated with the above structural genes. These findings provide essential information on flavonoid biosynthesis and its regulation in the persimmon and lay a foundation for further investigation into how astringency types affect flavor components in PCNA and PCA persimmons.

An amorphous hierarchical MnO2/acetylene black composite with boosted rate performance as an anode for lithium-ion batteries.

Amorphization is considered to be an effective way to enhance the electrochemical performances of electrode materials due to the existence of isotropy and numerous defects. Herein, an amorphous hierarchically structured MnO2/acetylene black (a-MnO2/AB) composite is successfully fabricated via a redox method and subsequent mechanical ball milling. The a-MnO2/AB composite is composed of approximately 300 nm flower-like amorphous MnO2 submicron spheres and acetylene black particles with a diameter of about 50 nm. The a-MnO2/AB electrode exhibits an initial coulombic efficiency of 73.2%, excellent rate capabilities of 318 mA h g-1 at 9.6 A g-1, and high specific capacity retention of 1300 mA h g-1 after 300 cycles at 1 A g-1. The amorphous structure can provide more channels for rapid lithium-ion transmission due to the disorder and defects, and the ion-diffusion coefficient (∼5 × 10-7 cm2 s-1) is higher than those of crystalline materials. Due to the strong interactions (Mn-O-C bonds) between MnO2 and AB as a result of the ball milling, the composite shows low charge transport resistance and small volume changes during the discharging/charging process. This work provides a facile route for the construction of amorphous hierarchically structured Mn-based oxides as anodes for lithium-ion batteries (LIBs).

Diosmetin exerts anti-oxidative, anti-inflammatory and anti-apoptotic effects to protect against endotoxin-induced acute hepatic failure in mice.

To investigate the effects and mechanism of diosmetin on acute hepatic failure (AHF), an AHF murine model was established through administration of lipopolysaccharides/D-galactosamine (LPS/D-GalN). In vitro, diosmetin scavenged free radicals. In vivo, diosmetin decreased mortality among mice, blocked the development of histopathological changes and hepatic damage, and suppressed levels of inflammatory mediators and cytokines. In addition, diosmetin prevented the expression of phosphorylated IKK, IκBα, and NF-κB p65 in the NF-κB signaling pathway, and JNK and p38 in the MAPK signaling pathway. Diosmetin also inhibited hepatocyte apoptosis. Thus, diosmetin exerts protective effects against endotoxin-induced acute hepatic failure in mice. The underlying mechanisms are antioxidation, NF-κB signaling inhibition, inflammatory mediator/cytokine attenuation, and hepatocyte apoptosis suppression. Diosmetin is thus a potential drug candidate for use in the treatment of acute hepatic failure.

The protective effect of coptisine on experimental atherosclerosis ApoE-/- mice is mediated by MAPK/NF-κB-dependent pathway.

Coptisine is one of main bioactive compounds extracted from the traditional Chinese herbal medicine Rhizoma Coptidis. It is reported that coptisine can attenuate obesity-related inflammation and oxidant damage in Syrian golden hamsters. Therefore，coptisine may exhibit beneficial effects for the treatment of atherosclerosis (AS) due to its hypolipidemic and anti-inflammation activities. The present study investigated the anti-atherosclerotic and anti-inflammatory properties of coptisine using apoE-/- mice as AS model. The atherosclerotic plaque area of aorta, serum lipid profile and the expression of inflammatory cytokines were determined. After coptisine treatment, the serum level of TC, TG and LDL-C decreased; the serum level of IL-6, IL-1ß and TNF-α were decreased; the mRNA levels of NF-κBp65, VCAM-1, ICAM-1, IL-6 and IL-1ß in both aorta and liver were down-regulated; the p-p38 and p-JNK1/2 protein expression level were decreased. Coptisine decreased atherosclerotic plaque area significantly through both anti-inflammation and lipid lowering effect. The anti-inflammatory effect of coptisine is achieved through inhibiting activation of MAPK signaling pathways and NF-κB nuclear translocation. Therefore，the combined anti-inflammation and lipid lowering effect of coptisine attributed the decreased atherosclerotic plaque area in coptisine treated apoE-/- mice. The results of this study will afford a novel application for coptisine in the treatment of atherosclerosis and other chronic inflammatory disease.