191 research outputs found

    (2E,6E)-2,6-Bis(4-ethoxy­benzyl­idene)cyclo­hexa­none

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    The title compound, C24H26O3, was prepared by the condensation reaction of 4-ethoxy­benzaldehyde with cyclo­hexa­none. The mol­ecule has crystallographic mirror symmetry and exhibits a butterfly-shaped geometry, with a dihedral angle of 5.46 (1)° between the two benzene rings. Weak inter­molecular C—H⋯π inter­actions help stabilize the crystal structure

    Schlieren Techniques for Observations of Long Positive Sparks: Review and Application

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    Understanding the mechanism of positive leader discharge is important in lightning protection engineering and the external insulation design in high voltage power transmission systems. During the propagation of a positive leader, some processes without light-emitting, for example, the insulation recovery process after the breakdown, cannot be observed by optical photography techniques. With the combination of the digital high-speed imaging system, the conventional Schlieren techniques offer new vistas in the long air gap discharge observation. The important features of high spatial resolution, high sensitivity, and easy arrangement make Schlieren techniques powerful and effective tools for characterising the discharge processes without light-emitting. This work presents a brief review of current Schlieren techniques and discusses the design of the Schlieren optics system for long spark observations. Several interesting phenomena discovered at different phases of long sparks with high-speed Schlieren techniques are also presented

    Evolution of the edge states and corner states in a multilayer honeycomb valley-Hall topological metamaterial

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    The valley-Hall effect provides topological protection to a broad class of defects in valley-Hall photonic topological metamaterials. Unveiling precisely how such protection is achieved and its implications in practical implementations is paramount to move from fundamental science to applications. To this end, we investigate a honeycomb valley-Hall topological metamaterial and monitor the evolution of the topological valley-Hall edge states and higher-order corner states under different perturbation δR. The evolutions of the edge states of the armchair and zigzag interfaces are demonstrated, respectively. By adjusting the geometric parameters and introducing disturbances to break the inversion symmetry, we achieve the edge states with different modes including the conventional crossed edge state and the specific gapped edge state. It is found that the edge states of topological valley kinking will gradually separate with the increase of δR, and finally a complete gap between the edge states appears. The gap has rarely been reported previously in topological materials fabricated by printed circuit board technology. In addition, the higher-order topological corner states can also be observed in the proposed topological metamaterial. The higher-order topological phase is theoretically characterized by nontrivial bulk polarization and the Wannier centers. Our results show that the corner state localization becomes stronger with the increase of δR. It is expected that our results will provide a platform for the realization of optical topological insulators

    Changes in and the association of retinal blood perfusion and retinal nerves in diabetic patients without retinopathy

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    ObjectiveTo explore intraretinal blood flow perfusion and nerve changes, as well as the correlation between them, in diabetic patients without diabetic retinopathy (NDR).MethodEighty-six NDR patients (86 eyes) who attended the ophthalmology clinic between December 2019 and December 2021 were included. Sixty-four eyes of 64 healthy examined controls in the same period were selected as the control group. The patients underwent routine ophthalmological examination, optical coherence tomography (OCT) and OCT angiography.ResultsThe average thickness, minimum thickness and thickness of each quadrant except for the superior temporal quadrant of the ganglion cell-inner plexiform layer (GCIPL) in the macular area of the affected eyes in the NDR group were lower than that of the tested eyes in the control group (P < 0.05). The average retinal nerve fibre layer (RNFL) thickness of the NDR group and the superior, inferior and nasal quadrants around the optic disc of the affected eyes in the NDR group were lower compared with the tested eyes in the control group (P < 0.001, P = 0.003, P = 0.001, P = 0.009). The mean vessel length density in the parafoveal and perifoveal areas in the NDR group was positively associated with the mean GCIPL thickness in the macular area (ρ = 0.265, ρ = 0.257 and P < 0.001). No blood flow perfusion parameters in the NDR group were correlated with the RNFL thickness of the corresponding quadrant around the optic disc (P > 0.05).ConclusionIn diabetic patients without diabetic retinopathy, the superficial retinal vessel density in the macular area positively correlated with GCIPL thickness, and the superficial retinal vessel density around the optic disc was not correlated with RNFL thickness

    Optimization design of Ti0.5Al0.5N/Ti0.25Al0.75N/AlN solar selective costing

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    AbstractA new solar selective coating was designed in our paper. Ti0.5Al0.5N and Ti0.25Al0.75N coatings were chosen as absorber layers, and AlN coating was chosen as anti-reflection layer. The optical constants of these coatings were studied by spectroscopic ellipsometric. The Ti0.5Al0.5N coating exhibits metallic character. But, the Ti0.25Al0.75N coating exhibits semiconducting property. The AlN coating is expected as a dielectric layer. The solar selective coating was optimized by using a computer program named TFCalc and verified by experimental results. The absorptance and emittance of the optimized solar selective coating were 0.945 and 0.04 (82°C), respectively

    Xue-Jie-San restricts ferroptosis in Crohn’s disease via inhibiting FGL1/NF-κB/STAT3 positive feedback loop

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    Crohn’s disease (CD) is an incurable inflammatory bowel disease due to unclear etiology and pathogenesis. Accumulating evidences have shown the harmful role of ferroptosis in CD onset and development. Additionally, fibrinogen-like protein 1 (FGL1) has been verified to be a potential therapeutic target of CD. Xue-Jie-San (XJS) is an effective prescription for treating CD. However, its therapeutic mechanism has not been fully elucidated. This study aimed to determine whether XJS alleviating CD via regulating ferroptosis and FGL1 expression. A colitis rat model was induced by 2,4,6-trinitrobenzene sulfonic acid and treated with XJS. The disease activity indices of the colitis rats were scored. Histopathological damage was assessed using HE staining. ELISA was performed to examine inflammatory cytokines. Transmission electron microscopy was utilized to observe ultrastructure changes in intestinal epithelial cells (IECs). Iron load was evaluated by examining iron concentrations, the expressions of FPN, FTH and FTL. Lipid peroxidation was investigated through detecting the levels of ROS, 4-HNE, MDA and PTGS2. Furthermore, the SLC7A11/GSH/GPX4 antioxidant system and FGL1/NF-κB/STAT3 signaling pathway were examined. The results showed that colitis was dramatically ameliorated in the XJS-treated rats as evidenced by relief of clinical symptoms and histopathological damages, downregulation of pro-inflammatory cytokines IL-6, IL-17 and TNF-α, and upregulation of anti-inflammatory cytokine IL-10. Furthermore, XJS administration led to ferroptosis inhibition in IECs by reducing iron overload and lipid peroxidation. Mechanistically, XJS enhanced the SLC7A11/GSH/GPX4 antioxidant system negatively regulated by the FGL1/NF-κB/STAT3 positive feedback loop. In conclusion, XJS might restrain ferroptosis in IECs to ameliorate experimental colitis by inhibition of FGL1/NF-κB/STAT3 positive feedback loop

    The More Similar, the Healthier: The Effect of Perceived Parent-Child Facial Resemblance on Parental Physical Health

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    Parent-child facial resemblance (PCFR) is one of the direct cues used to assess the genetic relationship between two individuals. Due to the inner fertilization of humans, fathers are liable to suffer from paternal uncertainty. When a father perceives low father-child facial resemblance, he would become anxious, which is detrimental to his immune system and physical health. For a mother, however, she can assure her genetic relationship to her children and does not need any external cues to verify her maternity. Thus, the mother-child facial resemblance does not influence the mothers’ physical health. To test these hypotheses, we examined the moderating effect of parental gender and the mediating effect of trait anxiety on the relationship between PCFR and physical health of parents. The results showed that fathers’ PCFR positively predicted their physical health, whereas the mothers’ PCFR failed to show any predicting effect on mothers’ physical health. Furthermore, trait anxiety mediated the relationship between fathers’ PCFR and their physical health. The implications for paternal uncertainty, gender difference, and public policy were discussed

    Differences in soil physicochemical properties and rhizosphere microbial communities of flue-cured tobacco at different transplantation stages and locations

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    Rhizosphere microbiota play an important role in regulating soil physical and chemical properties and improving crop production performance. This study analyzed the relationship between the diversity of rhizosphere microbiota and the yield and quality of flue-cured tobacco at different transplant times (D30 group, D60 group and D90 group) and in different regions [Linxiang Boshang (BS) and Linxiang ZhangDuo (ZD)] by high-throughput sequencing technology. The results showed that there were significant differences in the physicochemical properties and rhizosphere microbiota of flue-cured tobacco rhizosphere soil at different transplanting times, and that the relative abundance of Bacillus in the rhizosphere microbiota of the D60 group was significantly increased. RDA and Pearson correlation analysis showed that Bacillus, Streptomyces and Sphingomonas were significantly correlated with soil physical and chemical properties. PIGRUSt2 function prediction results showed that compared with the D30 group, the D60 group had significantly increased metabolic pathways such as the superpathway of pyrimidine deoxyribonucleoside salvage, allantoin degradation to glyoxylate III and pyrimidine deoxyribonucleotides de novo biosynthesis III metabolic pathways. The D90 group had significantly increased metabolic pathways such as ubiquitol-8 biosynthesis (prokaryotic), ubiquitol-7 biosynthesis (prokaryotic) and ubiquitol-10 biosynthesis (prokaryotic) compared with the D60 group. In addition, the yield and quality of flue-cured tobacco in the BS region were significantly higher than those in the ZD region, and the relative abundance of Firmicutes and Bacillus in the rhizosphere microbiota of flue-cured tobacco in the BS region at the D60 transplant stage was significantly higher than that in the ZD region. In addition, the results of the hierarchical sample metabolic pathway abundance map showed that the PWY-6572 metabolic pathway was mainly realized by Paenibacillus, and that the relative abundance of flue-cured tobacco rhizosphere microbiota (Paenibacillus) participating in PWY-6572 in the D60 transplant period in the BS region was significantly higher than that in the ZD region. In conclusion, different transplanting periods of flue-cured tobacco have important effects on soil physical and chemical properties and rhizosphere microbial communities. There were significant differences in the rhizosphere microbiota and function of flue-cured tobacco in different regions, which may affect the performance and quality of this type of tobacco
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