Accurately predicting the complex inhomogeneous heat transfer behavior in gas–solid fluidized beds is of fundamental importance. In this work, we constitute an enhanced filtered interphase heat ...transfer coefficient (IHTC) closure by systematically filtering the dataset from highly resolved three‐dimensional (3D) computational fluid dynamics–discrete element model simulations. Particularly, effects of several potential filtered variable markers on filtered IHTC predictions are examined by statistical analysis. We reveal the formulated filtered IHTC correction closure manifests a systematic dependence on filtered interphase temperature difference as an additional marker. The proposed closure shows good agreement with the filtered fine‐grid simulation data in an a priori analysis. Moreover, the difference of filtered IHTC corrections deduced from 3D Euler–Euler and Euler–Lagrange simulations is quantified. Finally, the comparative analysis between our proposed filtered IHTC formulation and those in literature is implemented. This work holds a potential to facilitate the development of thermal gas–solid flow modeling.
The nutritional components in oat and tartary buckwheat had been assessed to have cholesterollowering effects. However, The effect of oat and tartary buckwheat based-food (OF) on cholesterol-lowering ...and gut microbiota in hypercholesterole hamsters was still limited studied because they are usually consumed in whole gran as well as after being processed. In this study, normal diets, high fat diet (HFD) with/without OF were fed to hamsters for 30 days respectively and growth parameters, metabolic parameters, and gut microbiota were investigated, respectively. It was found that OF significantly decreased plasma total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-cholesterol), lowered liver TC, cholesterol ester (CE), and triglycerides (TG) concentrations, and increased fecal weight and bile acids (BA) concentrations, compared with HFD (p < 0.05). Moreover, the concentrations of acetate, propionate, butyrate and total short-chain fatty acids (SCFAs) were significantly increased in hamsters fed with OF, compared with HFD (p < 0.05). OF changed the overall structure of gut microbiota. The relative abundances of Erysipelotrichaceae, Ruminococcaceae, and Lachnospiraceae were decreased and the relative abundance of Eubacteriaceae was increased, compared with HFD. These results suggested that OF could reduce the concentrations of plasma lipid by inhibiting cholesterol absorption in liver and promoting excretions of fecal lipid and BA. And it also increased SCFAs and modulated the gut microbiota effectively to exert the hypocholesterolemic effects.
The genetic variability has obtained more and more attention in the process of diagnosis and treatment of tumors. Herein, we have described a multiple genotyping method based on magnetic enrichment- ...multiplex PCR （MEM-PCR） and microarray technology. Monodisperse magnetic beads were fabricated and modified with streptavidin. Four loci on two genes （M235T and A-6G loci on AGT gene, A1298C and C677T loci on MTHFR gene） were selected to study single nucleotide polymorphisms （SNP）. Target sequences of these SNP loci were amplified using Cy3-1abeled primers through multiplex PCR in one tube after the templates were enriched and purified by functional magnetic beads （MB）. Four pairs of NH2- labeled probes, corresponding to each locus, were fixed on CHO-modified glass slide by covalent binding. Hybridization between target sequences and probes was performed under suitable conditions. The spotting locations on microarray and the ratio of fluorescence intensity, produced by different loci, were used to distinguish the SNP genotypes. Finally, three of gastric cancer samples were collected and genotvping analysis for these four SNP loci was carried out successfully simultaneously by this method.
For a small fraction of hot CO2 molecules immersed in a liquid‐phase CO2 thermal bath, classical cavity molecular dynamics simulations show that forming collective vibrational strong coupling (VSC) ...between the C=O asymmetric stretch of CO2 molecules and a cavity mode accelerates hot‐molecule relaxation. This acceleration stems from the fact that polaritons can be transiently excited during the nonequilibrium process, which facilitates intermolecular vibrational energy transfer. The VSC effects on these rates 1) resonantly depend on the cavity mode detuning, 2) cooperatively depend on Rabi splitting, and 3) collectively scale with the number of hot molecules. For larger cavity volumes, the average VSC effect per molecule can remain meaningful for up to N≈104 molecules forming VSC. Moreover, the transiently excited lower polariton prefers to relax by transferring its energy to the tail of the molecular energy distribution rather than distributing it equally to all thermal molecules. As far as the parameter dependence is concerned, the vibrational relaxation data presented here appear analogous to VSC catalysis in Fabry–Pérot microcavities.
We performed cavity molecular dynamics simulations and showed that, under vibrational strong coupling conditions, vibrational relaxation and energy transfer from hot to thermal molecules can be accelerated relative to that outside a cavity due to polariton‐accelerated intermolecular vibrational energy transfer.
This study performs data‐driven modeling of mesoscale solids stress closures for filtered two‐fluid model (fTFM) in gas–particle flows via an artificial neural network (ANN) based machine learning ...method. The data used for developing the ANN‐based predictive data‐driven modeling framework is systematically filtered from fine‐grid simulations. The loss function optimization result reveals that coupling two loss functions promotes more accurate predictions of the mesoscale solids stresses than using a single loss function. Further comprehensive assessments of closure markers demonstrate a systematic dependence of the mesoscale solids stresses on the filtered particle velocity and its gradient as additional anisotropic markers, instead of using the conventional isotropic filtered rate of solid phase deformation as a closure marker. An optimal three‐marker mesoscale closure is thus proposed. Comparative analysis of the conventional filtered model and present three‐marker model shows that the data‐driven model can substantially enhance the prediction accuracy.
Branched-chain amino acid (BCAA) metabolism is potentially linked with development of pancreatic ductal adenocarcinoma (PDAC)
. BCAA transaminase 2 (BCAT2) was essential for the collateral lethality ...conferred by deletion of malic enzymes in PDAC and the BCAA-BCAT metabolic pathway contributed to non-small-cell lung carcinomas (NSCLCs) other than PDAC
. However, the underlying mechanism remains undefined. Here we reveal that BCAT2 is elevated in mouse models and in human PDAC. Furthermore, pancreatic tissue-specific knockout of Bcat2 impedes progression of pancreatic intraepithelial neoplasia (PanIN) in LSL-Kras
; Pdx1-Cre (KC) mice. Functionally, BCAT2 enhances BCAA uptake to sustain BCAA catabolism and mitochondrial respiration. Notably, BCAA enhances growth of pancreatic ductal organoids from KC mice in a dose-dependent manner, whereas addition of branched-chain α-keto acid (BCKA) and nucleobases rescues growth of KC organoids that is suppressed by BCAT2 inhibitor. Moreover, KRAS stabilizes BCAT2, which is mediated by spleen tyrosine kinase (SYK) and E3 ligase tripartite-motif-containing protein 21 (TRIM21). In addition, BCAT2 inhibitor ameliorates PanIN formation in KC mice. Of note, a lower-BCAA diet also impedes PDAC development in mouse models of PDAC. Thus, BCAT2-mediated BCAA catabolism is critical for development of PDAC harbouring KRAS mutations. Targeting BCAT2 or lowering dietary BCAA may have translational significance.
Abstract Superbubbles in the nuclear region of galaxies could be produced by active galactic nuclei (AGN) or nuclear starburst via different driving forces. We report analysis of the multiwavelength ...data of the kiloparsec-scale nuclear superbubble in NGC 3079 in order to probe the mechanisms driving the expansion of the superbubble. Based on the Chandra X-ray observations, we derive the hot-gas thermal pressure inside the bubble, which is about 1 order of magnitude higher than that of the warm ionized gas traced by optical lines. We derive a C ii -based star formation rate (SFR) of SFR ∼ 1.3 M ⊙ yr −1 from the nuclear region using the SOFIA/FIFI-LS observation. This SFR infers a radiation pressure toward the bubble shells much lower than the thermal pressure of the gases. The Very Large Array radio image infers that magnetic pressure at the northeast cap above the superbubble is less than the thermal pressure of the hot gas enclosed in the bubble but has a clearly larger extension. The magnetic field may thus still help to reconcile the expansion of the bubble. The observed thermal energy of the hot gas enclosed in the bubble requires an energy injection rate of ≳10 42 erg s −1 within the bubble’s dynamical age, which is probably larger than the power provided by the current nuclear starburst and the parsec-scale jet. If this is true, stronger past AGN activity may provide an alternative energy source to drive the observed bubble expansion.
2,5‐Furandicarboxylic acid was obtained from the electrooxidation of 5‐hydroxymethylfurfural (HMF) with non‐noble metal‐based catalysts. Moreover, combining the biomass oxidation with the hydrogen ...evolution reaction (HER) increased the energy conversion efficiency of an electrolyzer and also generated value‐added products at both electrodes. Here, the reaction pathway on the surface of a carbon‐coupled nickel nitride nanosheet (Ni3N@C) electrode was evaluated by surface‐selective vibrational spectroscopy using sum frequency generation (SFG) during the electrochemical oxidation. The Ni3N@C electrode shows catalytic activities for HMF oxidation and the HER. As the first in situ SFG study on transition‐metal nitride for the electrooxidation upgrade of HMF, this work not only demonstrates that the reaction pathway of electrochemical oxidation but also provides an opportunity for nonprecious metal nitrides to simultaneously upgrade biomass and produce H2 under ambient conditions.
To sum up: A carbon‐coupled nickel nitride nanosheet was employed as an efficient electrocatalyst for 5‐hydroxymethylfurfural (HMF) oxidation. In situ sum frequency generation (SFG) spectroscopy was used to explore the HMF electrooxidation process, and confirmed that the oxidation pathway proceeds via 5‐hydroxymethyl‐2‐furancarboxylic acid (HMFCA).
Metadata and data association rules are combined in this paper to create an aggregation framework for Meishan cultural digital resources. Meishan cultural digital resources are standardized through ...the use of metadata standards. The accuracy of metadata is evaluated in conjunction with trustworthiness. Metadata association rules are employed to evaluate the degree of association in Meishan cultural data. Enhance the efficiency of data association analysis by enhancing the Apriori algorithm. The algorithm is applied to the association analysis of Meishan culture data, and the degree of association between different digital resources and Meishan culture is determined by combining the data. The results show that the highest correlation with Meishan culture is the digital resources of documentaries and skills, with a correlation degree of 0.9, and the lowest correlation is the book resources, with a correlation degree of 0.65. The number of nodes in the period of 1-6 and the time consumed by each dataset is in the interval of (7000,1100).
PDF
