Numerical and Experimental Investigation of Near-Field Mixing in Parallel Dual Round Jets

Parallel underexpanded round jets system has been widely used in engineering applications, and the flow field structures are very complex because of the jets interaction. In this paper, we studied the near-field mixing phenomenon in parallel dual underexpanded jets numerically by solving the Reynolds-Averaged Navier-Stokes Equations. The numerical results agree well with experimental data acquired by particle image velocimetry. Similar to plane jets, to some degree, two round jets are deflected towards the dual nozzle symmetry plane; the flow field can also be divided into three regions. Meanwhile, attempts have been made to predict merge point and combine point locations on certain cross profile of computational domain by correlating them with jet spacing and jet pressure ratio. The jet spacing plays an important role in jets interaction, and jet interaction decreases with the increase in jet spacing. The jets interaction in terms of merge (combine) point and pressure varies significantly while the jet spacing differs. Additionally, as pressure ratio increases, the effect of jet interaction decreases, and the merge (combine) point location moves downstream

Investigation of bio-aerosol dispersion in a tunnel-ventilated poultry house

Bio-aerosol concentrations in poultry houses must be controlled to provide adequate air quality for both birds and workers. High concentrations of airborne bio-aerosols would affect the environmental sustainability of the production and create environmental hazards to the surroundings via the ventilation systems. Previous studies demonstrate that several factors including the age of the birds, the housing configuration, the humidity and temperature would strongly affect the indoor concentration of bio-aerosols. However, limited studies are performed in the literature to investigate the bio-aerosol dispersion pattern inside poultry buildings. In order to fill a gap of the understanding of the bio-aerosol dispersion behavior, experimental measurements of the indoor bio-aerosol distribution are performed in a tunnel-ventilated poultry house in this paper. Meanwhile a three-dimensional computational fluid dynamics (CFD) model is built and validated to further investigate the effect of flow pattern, turbulence and vortex on the dispersion and deposition of the bio-aerosols. Furthermore, bio-aerosols with various diameters are also examined in the CFD model. It is found that higher concentrations of bio-aerosols are detected at the rear part of the house and strong turbulent flow resulting from the ventilation inlets enhances the diffusion and dispersion of bio-aerosols. Local vortex or disturbed flow is responsible for higher local concentration due to the re-suspension of settled bio-aerosols, which suggests that careful attentions should be paid to these locations during cleaning and disinfection. Results from present study contribute to the optimization of design and operation of the poultry houses from the standing point of reducing airborne bio-aerosol concentrations

Polysaccharides and polyphenols in sea buckthorn leaf tea have synergistic impact on studied colonic strains in vitro and bacteria in vivo

Present research on prebiotics focuses on either polysaccharides or polyphenols. This study compared the individual and combined impact of polysaccharide, quercetin, and gallic acid (GA) treatment on three human faecal strains. In vitro pure culturing and correlation analysis confirmed that the growth of both beneficial microbe B. longum subsp. longum (0.695, 0.205: R2, slope, respectively) and pathogenic C. perfringens (0.712, 0.085: R2, slope, respectively) increased due to polysaccharide treatment, and only GA treatment would inhibit C. perfringens (0.789, –0.165: R2, slope, respectively) growth. In vivo studies also revealed that genome copies of Bifidobacterium increased and C. perfringens decreased in the faeces, when a blend of the three nutrients rather than single polysaccharide or polyphenols were fed to rats. These data suggested that combined prebiotic treatment improved human faecal strain composition better than single treatment

Functional connectivity of the right inferior frontal gyrus and orbitofrontal cortex in depression

The orbitofrontal cortex extends into the laterally adjacent inferior frontal gyrus. We analyzed how voxel-level functional connectivity of the inferior frontal gyrus and orbitofrontal cortex is related to depression in 282 people with major depressive disorder (125 were unmedicated) and 254 controls, using FDR correction P < 0.05 for pairs of voxels. In the unmedicated group, higher functional connectivity was found of the right inferior frontal gyrus with voxels in the lateral and medial orbitofrontal cortex, cingulate cortex, temporal lobe, angular gyrus, precuneus, hippocampus and frontal gyri. In medicated patients, these functional connectivities were lower and toward those in controls. Functional connectivities between the lateral orbitofrontal cortex and the precuneus, posterior cingulate cortex, inferior frontal gyrus, ventromedial prefrontal cortex and the angular and middle frontal gyri were higher in unmedicated patients, and closer to controls in medicated patients. Medial orbitofrontal cortex voxels had lower functional connectivity with temporal cortex areas, the parahippocampal gyrus and fusiform gyrus, and medication did not result in these being closer to controls. These findings are consistent with the hypothesis that the orbitofrontal cortex is involved in depression, and can influence mood and behavior via the right inferior frontal gyrus, which projects to premotor cortical areas

MicroRNA-1 acts as a tumor suppressor microRNA by inhibiting angiogenesis-related growth factors in human gastric cancer

Background We recently reported that miR-1 was one of the most significantly downregulated microRNAs in gastric cancer (GC) patients from The Cancer Genome Atlas microRNA sequencing data. Here we aim to elucidate the role of miR-1 in gastric carcinogenesis. Methods We measured miR-1 expression in human GC cell lines and 90 paired primary GC samples, and analyzed the association of its status with clinicopathological features. The effect of miR-1 on GC cells was evaluated by proliferation and migration assay. To identify the target genes of miR-1, bioinformatic analysis and protein array analysis were performed. Moreover, the regulation mechanism of miR-1 with regard to these predicted targets was investigated by quantitative PCR (qPCR), Western blot, ELISA, and endothelial cell tube formation. The putative binding site of miR-1 on target genes was assessed by a reporter assay. Results Expression of miR-1 was obviously decreased in GC cell lines and primary tissues. Patients with low miR-1 expression had significantly shorter overall survival compared with those with high miR-1 expression (P = 0.0027). Overexpression of miR-1 in GC cells inhibited proliferation, migration, and tube formation of endothelial cells by suppressing expression of vascular endothelial growth factor A (VEGF-A) and endothelin 1 (EDN1). Conversely, inhibition of miR-1 with use of antago-miR-1 caused an increase in expression of VEGF-A and EDN1 in nonmalignant GC cells or low-malignancy GC cells. Conclusions MiR-1 acts as a tumor suppressor by inhibiting angiogenesis-related growth factors in human gastric cancer. Downregulated miR-1 not only promotes cellular proliferation and migration of GC cells, but may activates proangiogenesis signaling and stimulates the proliferation and migration of endothelial cells, indicating the possibility of new strategies for GC therapy