A Definition of Vortex Vector and Vortex

Vortex is ubiquitous in nature. However, there is not a consensus on the vortex definition in fluid dynamics. Lack of mathematical definition has caused considerable confusions in visualizing and understanding the coherent vortical structures in turbulence. According to previous study, it is realized that vortex is not the vorticity tube and vorticity should be decomposed into a rotational part which is the vortex vector and a non-rotational part which is the shear. In this paper, several new concepts such as fluid rotation of local point, the direction of fluid rotation axis and the strength of fluid rotation are proposed by investigating the kinematics of fluid element in the 2D and 3D flows. A definition of a new vector quantity called vortex vector is proposed to describe the local fluid rotation. The direction of the vortex vector is defined as the direction of local fluid rotation axis. The velocity components in the plane orthogonal to the vortex vector have zero derivatives along the vortex vector direction. The magnitude of the vortex vector is defined as the rotational part of vorticity in the direction of the vortex vector, which is the twice of the minimum angular velocity of fluid around the point among all azimuth in the plane perpendicular to vortex vector. According to the definition of the vortex vector, vortex is defined as a connected flow region where the magnitude of the vortex vector at each point is larger than zero. The new definition for the vortex vector and vortex follows three principles: 1. Local in quantity, 2. Galilean invariant, 3. Unique. The definitions are carefully checked by DNS and LES examples which clearly show that the new defined vortex vector and vortex can fully represent the complex structures of vortices in turbulence.Comment: 26 pages, 15figure

Effect of Low-Stress Fatigue on the Off-Crack-Plane Fracture Energy in Engineered Cementitious Composites

This paper presented an experimental study on the flexural properties of engineered cementitious composites (ECCs). The bending fatigue damage, residual deformation, and damage characteristics were investigated after a certain number of low stress levels in fatigue load. The composite fracture energy and fiber-bridging fracture energy were calculated by the J integral. It is observed that the number of cracks increased with the increment of stress levels, and most of the cracks were formed during the earlier stage of the dynamic test. The deformation capability decreased with the increment of stress levels while the reduction of the ultimate load was minor after the dynamic load. Furthermore, the strain-hardening phenomenon of the specimen enhanced initially and then weakened with the increment of stress levels. The residual equivalent yield strength became smaller with the increase of stress levels. Meanwhile, the trend was mild at low stress levels and then became steep at high stress levels

First Principles Calculation and Analysis of Adsorption of Choline Deep with Zinc Oxide

This is an article in the field of metallurgical engineering. In order to better realize the leaching of zinc oxide from zinc-containing dust, Materials Studio software based on density functional theory was used to simulate and optimize the crystal structure of zinc oxide and the structure of three kinds of choline deep eutectic solvents, and the mutual adsorption model of the two was calculated. The calculated results show that the ZnO(001) plane is a complete cleavage plane, and the highest occupied state near the Fermi level shifts to the left, and the peak of the highest occupies state increases, and the p orbital of O and the d orbital of Zn are more active, which are the active sites of the ZnO(001) plane. Optimization of three choline hyper eutectic solvent shows that choline chloride forms multiple intermolecular hydrogen bonds with three different hydrogen bond donors centered on chlorine atom. The adsorption model of deep eutectic solvents and zinc oxide was calculated using Forcite module. The results shows that the interaction strength of zinc oxide with three choline deep eutectic solvent is Chcl-MA >Chcl-Urea>Chcl-Eg. The radial distribution function shows that malonic acid makes it easier for Cl in choline chloride to chemisorb with Zn. In the three kinds of hydrogen bond donors, the activity of oxygen atomic functional groups forming chemical bonds with Zn is C=O, N-O and C-O, indicating that C=O in malonic acid makes the combination of Chcl-MA and ZnO more stable. Results show that the leaching temperature of Chcl-MA is 70 ℃ and the liquid-solid ratio is 10∶1. Under the condition of leaching time of 1 h for 60 min, single mineral zinc oxide can be almost completely leached, and the leaching effect is far greater than that of Chcl-Urea and Chcl-Eg, thus proving the accuracy of molecular simulation and providing theoretical guidance for the leaching of zinc-containing dust in choline deep eutectic solvent

A comprehensive study on the impact of Ligustrum vicaryi L. fruit polysaccharide on myocardial fibrosis through animal experiments, network pharmacology and molecular docking

BackgroundMyocardial fibrosis (MF) is a prevalent pathological condition associated with various heart diseases, such as heart failure and arrhythmias, which disrupt electrical signals and reduce pumping efficiency. This research explored the therapeutic effects and potential mechanisms of Ligustrum vicaryi L. fruit polysaccharide (LVFP) on MF.MethodsIn vivo experiments, including fibrosis markers assay, echocardiography, HE staining, Sirius red staining, and Masson's trichrome staining, were performed to evaluate the therapeutic efficacy of LVFP in treating isoproterenol (ISO)-induced MF. We utilized the PharmMapper database to identify targets of LVFP, aiming to explore potential targets. Additionally, we obtained MF-related targets from the GeneCards database. We utilized Venny, a bioinformatics tool, to identify the intersection between the targets of LVFP and those related to MF. We utilized the STRING database to construct a protein interaction network for the overlapping targets and identified key targets for LVFP in treating MF through cytoHubba analysis. We conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the intersection targets. We also examined the interaction between LVFP and the key targets using molecular docking techniques.ResultsLVFP significantly inhibited fibrosis biomarker such as hydroxyproline (HYP) and decreased myocardial fibrosis level as shown by heart weight to tibia length (HW/TL) measurement when compared to ISO-treated mice. Additionally, it increased ejection fraction (EF) and fractional shortening (FS) levels. LVFP showed decreased collagen levels compared to the ISO-treated mice by histological quantification of cardiac fibrosis. Based on the monosaccharide structures of LVFP, 413 targets were identified, with 67 associated with MF. Analysis indicated that the 9 hub genes (AKT1, HSP90AA1, SRC, GSK3β, VEGFR2, RHOA, ENO1, PKM, and IL-2) play roles in MF treatment by participating in signaling pathways related to prostate cancer, lipid and atherosclerosis, and insulin resistance. Molecular docking results showed that LVFP exhibited strong binding potential to VEGFR2 (−8.65 kcal/mol), AKT1 (−7.36 kcal/mol) and GSK3β (−7.68 kcal/mol).ConclusionLVFP shows promise as a therapeutic agent for MF, primarily through the regulation of various signaling pathways and targets. These findings provide novel insights for the treatment of MF utilizing LVFP

Synthesis and Characterization of Single-Crystalline SnO₂Nanowires

Tin oxide (SnO2) nanowires were synthesized on oxidized silicon substrates by thermal evaporation of tin grains at 900°C in Ar flow at ambient pressure. Structural characterization using X-ray diffraction and transmission electron microscopy shows that SnO2nanowires have a single crystal tetragonal structure. Scanning electron microscopy observation demonstrates that SnO2nanowires are 30–200 nm in diameter and several tens of micrometers in length. The surface vibration mode resulting from the nanosize effect at 565.1 cm−1was found from the Fourier transform infrared spectrum. The formation of SnO2nanowires follows a vapour-solid (VS) growth mechanism. The gas sensing measurements indicate that SnO2nanowire gas sensor obtains peak sensitivity at a low operating temperature of 150°C and shows reversible response to H2gas (100–1000 ppm) at an operating temperature of RT-300°C.</jats:p

Predictive value of PD-L1 and TMB for short-term efficacy prognosis in non-small cell lung cancer and construction of prediction models

ObjectiveTo investigate the correlation between programmed death ligand 1(PD-L1), tumor mutation burden (TMB) and the short-term efficacy and clinical characteristics of anti-PD-1 immune checkpoint inhibitor combination chemotherapy in NSCLC patients. The efficacy of the prediction model was evaluated.MethodsA total of 220 NSCLC patients receiving first-line treatment with anti-PD-1 immune checkpoint inhibitor combined with chemotherapy were retrospectively collected. The primary endpoint was short-term efficacy ORR. The correlation between short-term efficacy, PD-L1, TMB, and clinical characteristics using χ2 test or t-test was evaluated. Screen the independent prognostic factors using univariate and multivariate logistic regression analyses, and construct a nomogram prediction model using the “rms” package in R software. Using receiver operating characteristic (ROC) curve analysis to evaluate the independent Prognostic factors and the prediction model. Using decision curve analysis (DCA) to verify the superiority of the prediction model.ResultsThe mean values of PD-L1, TMB, neutrophils, lymphocytes, neutrophil-to-lymphocyte ratio, and albumin were the highest in the ORR group, PD-L1 expression and TMB correlated with epidermal growth factor receptor expression. Multivariate analyses showed that PD-L1, TMB, and neutrophil were independent prognostic factors for ORR. The area under the ROC curve (AUC) values of the ROC constructed based on these three indicators were 0.7104, 0.7139, and 0.7131, respectively. The AUC value under the ROC of the nomogram model was 0.813. The DCA of the model showed that all three indicators used together to build the prediction model of the net return were higher than those of the single indicator prediction model.ConclusionPD-L1, TMB, and neutrophils are independent prognostic factors for short-term efficacy. The nomogram prediction model constructed using these three indicators can further improve predictive efficacy of ICIs in patients with NSCLC

Insulin resistance has closer correlation with the occurrence of metabolic dysfunction associated steatotic liver disease diagnosed by liver biopsy

ObjectiveTo explore any correlation between serum urate (SU) level or insulin resistance (IR) and metabolic dysfunction associated steatotic liver disease (MASLD) in patients with metabolic syndrome (MS).MethodsData from all MASLD patients, diagnosed by liver biopsy, were enrolled and divided into MASLD alone group and MASLD with MS group. They were subdivided into hyperuricemia group and normal SU group to find correlation between SU/IR and MASLD in patients with MS and independent risk factors for MASLD.ResultsData from 539 MASLD patients were analyzed. Body mass index (BMI) (p = 0.000), waist circumference (WC) (p = 0.004), and low-density lipoprotein (LDL) (p = 0.000) were dramatically higher in MASLD with MS group than those with MASLD alone; MASLD with MS patients had significantly more family history of diabetes (p = 0.000) and hypertension (p = 0.000) than patients with MASLD alone. Height (p = 0.000), weight (p = 0.000), BMI (p = 0.000) and WC (p = 0.001), and LDL (p = 0.007) were dramatically higher in hyperuricemia patients than those with normal SU. SU was inversely associated with age (p = 0.000) and high-density lipoprotein (HDL) (p = 0.003), and positively correlated with weight (p = 0.000), BMI (p = 0.000) and WC (p = 0.000), TG (p = 0.000), and LDL (p = 0.000). Logistic Regression analysis showed that age (p = 0.031), TG (p = 0.002), LDL (p = 0.010), HbA1c (p = 0.026), and family history of hypertension (p = 0.000) may be independent risk factors for MASLD in patient with MS.ConclusionInsulin resistance (IR) in MASLD patients with MS, but not higher SU levels, has closer correlation with the occurrence of MASLD in patients with family history of hypertension and diabetes having higher BMI, LDL, HbA1c