Evaluation of Eddy Viscosity Models in Predicting Free- Stream Turbulence Penetration

Turbulence schemes have long been developed and examined for their accuracy and stability in a variety of environments. While many industrial flows are highly turbulent, models have rarely been tested to explore whether their accuracy withstands such augmented free-stream turbulence intensity or declines to an erroneous solution. In the present study, the turbulence intensity of an air flow stream, moving parallel to a flat plate is augmented by the means of locating a grid screen at a point at which Rex=2.5×105 and the effect on the flow and the near-wall boundary is studied. At this cross section, the turbulence intensity is augmented from 0.4% to 6.6% to flow downstream. Wind tunnel measurements provide reference bases to validate the numerical results for velocity fluctuations in the main stream and at the near-wall. Numerically, four of the most popular turbulence models are examined, namely the oneequation Spalart-Almaras, the two equation Standard k , the two equation Shear Stress Transport and the anisotropy multi equation Reynolds Stress Models (RSM). The resulting solutions for the domain are compared to experimental measurements and then the results are discussed. The conclusion is made that, despite the accuracy that these turbulence models are believed to have, even for some difficult flow field, they fail to handle high intensity turbulence flows. Turbulence models provide a better approach in experiments when the turbulence intensity is at about 2% and/or when the Reynolds number is high

Bioactivation of 3D Cell-Imprinted Polydimethylsiloxane Surfaces by Bone Protein Nanocoating for Bone Tissue Engineering

Physical and chemical parameters that mimic the physiological niche of the human body have an influence on stem cell fate by creating directional signals to cells. Micro/nano cell-patterned polydimethylsiloxane (PDMS) substrates, due to their ability to mimic the physiological niche, have been widely used in surface modification. Integration of other factors such as the biochemical coating on the surface can achieve more similar microenvironmental conditions and promote stem cell differentiation to the target cell line. Herein, we investigated the effect of physical topography, chemical functionalization by acid bone lysate (ABL) nanocoating, and the combined functionalization of the bone proteins' nanocoated surface and the topographically modified surface. We prepared four distinguishing surfaces: plain PDMS, physically modified PDMS by 3D cell topography patterning, chemically modified PDMS with bone protein nanocoating, and chemically modified nano 3D cell-imprinted PDMS by bone proteins (ABL). Characterization of extracted ABL was carried out by Bradford staining and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis, followed by the MTT assay for evaluation of cell viability on ABL-coated PDMS. Moreover, field emission scanning electron microscopy and profilometry were used for the determination of optimal coating thickness, and the appropriate coating concentration was identified and used in the study. The binding and retention of ABL to PDMS were confirmed by Fourier transform infrared spectroscopy and bicinchoninic acid assay. Sessile drop static water contact angle measurements on substrates showed that the combined chemical functionalization and nano 3D cell-imprinting on the PDMS surface improved surface wettability by 66% compared to plain PDMS. The results of ALP measurement, alizarin red S staining, immunofluorescence staining, and real-time PCR showed that the nano 3D cell-imprinted PDMS surface functionalized by extracted bone proteins, ABL, is able to guide the fate of adipose derived stem cellss toward osteogenic differentiation. Eventually, chemical modification of the cell-imprinted PDMS substrate by bone protein extraction not only improved the cell adhesion and proliferation but also contributed to the topographical effect itself and caused a significant synergistic influence on the process of osteogenic differentiation

Biological Evaluation of a Novel Tissue Engineering Scaffold of Layered Double Hydroxides (LDHs)

Bone Tissue Engineering (BTE) Composed of Three Main Parts: Scaffold, Cells and Signaling Factors. Several Materials and Composites Are Suggested as a Scaffold for BTE. Biocompatibility is One of the Most Important Property of a BTE Scaffold. in This Work Synthesis of a Novel Nanocomposite Including Layered Double Hydroxides (LDH) and Gelatin is Carried Out and its Biological Properties Were Studied. the Co-Precipitation (PH=11) Method Was Used to Prepare the LDH Powder, using Calcium Nitrate, Magesium Nitrate and Aluminum Nitrate Salts as Starting Materials. the Resulted Precipitates Were Dried. X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) Analyses Were Used to Characterize the Synthesized Powders. the Results Demonstrated the Presence of Nanocrystals of Ca-LDH and Mg-LDH as Hexagonal and Layered Morphology. the Obtained Powders Were Composed to Gelatin Via Solvent Casting Method Then Freez Dried. the Scaffold Was Prepared Via Membrane Lamination Method from the Resulted Layers that Linked Together with Gelatin as Binder. in Order to Investigate the Scaffold Cytotoxicity MTT Assay Was Done with a Osteosarcoma Cell Line. No Toxic Response Was Observed in Specimens. as a Major Result, It Was Demonstrated that the Specimen Showed a Significant Cellular Response. Then Osteosarcoma Cells Were Cultured for 7-Day and 14-Day Extract of Powders. the Composites Osteoconductivity Was Investigate with Cells Alkaline Phosphatase Extraction. the Results Demonstrated that the Ca-LDH/gelatin Composite Scaffold Has a Good Potential for Bone Tissue Engineering Applications and Mg-LDH Specimen Has a Better Osteconductivity. © (2012) Trans Tech Publications

Targeting delivery of lipocalin 2-engineered mesenchymal stem cells to colon cancer in order to inhibit liver metastasis in nude mice

One of the major obstacles in cancer therapy is the lack of anticancer agent specificity to tumor tissues. The strategy of cell-based therapy is a promising therapeutic option for cancer treatment. The specific tumor-oriented migration of mesenchymal stem cells (MSCs) makes them a useful vehicle to deliver anticancer agents. In this study, we genetically manipulated bone marrow-derived mesenchymal stem cells with their lipocalin 2 (Lcn2) in order to inhibit liver metastasis of colon cancer in nude mice. Lcn2 was successfully overexpressed in transfected MSCs. The PCR results of SRY gene confirmed the presence of MSCs in cancer liver tissue. This study showed that Lcn2-engineered MSCs (MSC-Lcn2) not only inhibited liver metastasis of colon cancer but also downregulated the expression of vascular endothelial growth factor (VEGF) in the liver. Overall, MSCs by innate tropism toward cancer cells can deliver the therapeutic agent, Lcn2, and inhibit cancer metastasis. Hence, it could be a new modality for efficient targeted delivery of anticancer agent to liver metastasis. © 2015, International Society of Oncology and BioMarkers (ISOBM)

Neutrophil Gelatinase-Associated Lipocalin induces the expression of heme oxygenase-1 and superoxide dismutase 1, 2

Lipocalin-2 (Lcn2, NGAL) is a member of the lipocalin super family with diverse function such as the induction of apoptosis, the suppression of bacterial growth, and modulation of inflammatory response. Much interest has recently been focused on the physiological/pathological role of the lipocalin-2 that is considered to be a novel protective factor against oxidative stress. However, its precise biological roles in this protection are not fully understood. In this report we intended to test the effect of lipocalin-2 on the expression of heme oxygenase (1, 2) and superoxide dismutase (1, 2) which are two strong antioxidants. NGAL was cloned to pcDNA3.1 plasmid by using genetic engineering method. The recombinant vector was transfected to CHO and HEK293T to establish stable cell expressing NGAL and the expression of HO-1, 2 and SOD1, 2 were compared with appropriate controls byRT-PCR and western blot. On the other hand, expression of NGAL was suppressed by siRNA transfection in order to study the effect of lipocalin-2 on mentioned genes/proteins. The results showed that the expression of HO-1 and SOD 1, 2 enzymes were higher in cells expressing recombinant lipocalin-2 compared with the control cells. Although the expression of HO-1 was lower in NGAL silencing cells, the expression of SOD1 and SOD2 were higher. Our data suggest that NGAL is a potent inducer of HO-1 and somewhat SOD1 and SOD2 and it appears that part of antioxidant property of NGAL could be attributed to the induction of HO-1and SOD 1, 2. © Cell Stress Society International 2009

Genetics of immunoglobulin-A vasculitis (Henoch-Schönlein purpura): An updated review

Immunoglobulin-A vasculitis (IgAV) is classically a childhood small-sized blood vessel vasculitis with predominant involvement of the skin. Gastrointestinal and joint manifestations are common in patients diagnosed with this condition. Nephritis, which is more severe in adults, constitutes the most feared complication of this vasculitis. The molecular bases underlying the origin of IgAV have not been completely elucidated. Nevertheless, several pieces of evidence support the claim that genes play a crucial role in the pathogenesis of this disease. The human leukocyte antigen (HLA) region is, until now, the main genetic factor associated with IgAV pathogenesis. Besides a strong association with HLA class II alleles, specifically HLA-DRB1 alleles, HLA class I alleles also seem to influence on the predisposition of this disease. Other gene polymorphisms located outside the HLA region, including those coding cytokines, chemokines, adhesion molecules as well as those related to T-cells, aberrant glycosylation of IgA1, nitric oxide production, neoangiogenesis, renin-angiotensin system and lipid, Pyrin and homocysteine metabolism, may be implicated not only in the predisposition to IgAV but also in its severity. An update of the current knowledge of the genetic component associated with the pathogenesis of IgAV is detailed in this review.Acknowledgements: RL-Mis supported by the Miguel Servet I programme of the Spanish Ministry of Economy and Competitiveness through the grant CP16/ 00033. FG is recipient of a Sara Borrell postdoctoral fellowship from the “Instituto Carlos III de Salud” at the Spanish Ministry of Health (Spain) (CD15/00095). SR-M is supported by funds from the RETICS Program (RIER) (RD16/0012/0009). FDC is supported by the Ramón y Cajal programme of the Spanish Ministry of Economy and Competitiveness through the grant RYC-2014-16458

Mutations in Thalassemia Carrier Couples: The Importance of Prenatal Diagnostic Tests

Background: Thalassemia carrier couples play an important role in increasing thalassemia patients. The study of thalassemia genotypes in carrier couples is also effective in improving genetic counseling for them. The aim of this study was to investigate the prevalence of thalassemia mutations and genotypes in couples. Methods: This cross-sectional study was performed on 241 couples who were suspected of thalassemia from April 2018 to March 2020 in Lorestan province. Statistical analysis of data was performed using SPSS software 16.0 (SPSS Inc., Chicago, IL, USA). Online tools such as www.ithanet.eu/db/ithagenes and http://globin.bx.psu.edu/hbvar/menu.html were also used to match patients' mutations with known cases. Results: IVSII-1 (G>A), CD36-37 (-T), IVSI-110 (G>A), —Med, and alpha(3.7 )were the most common mutations in the beta and alpha genes, respectively. IVSII-1 (G>A) 130/13 (26.1), CD36-37 (-T) beta 0/beta (21.1), and IVSI-110 (G>A) beta 0/beta (10.3) genotypes were the most common in women. The frequency of these genotypes in men were 24.8, 28.6, and 12.8, respectively. Among alpha thalassemia carriers, the alpha(3.7)alpha/alpha alpha genotype had the highest frequency among women (3.7) and men (5.3). Alpha and beta-thalassemia were 15 and 13 times higher in related women and 18 and 9 times higher in related men than non-related ones, respectively. This difference was statistically significant (p < 0.001). In addition, 12.8 of fetuses were thalassemia major, 31.9 beta thalassemia minor, and 10.3 normal. Conclusions: Thalassemia screening in related couples plays an important role in reducing thalassemia major infants

Immune reactions of the lesser mulberry pyralid, Glyphodes pyloalis Walker (Lepidoptera: Pyralidae) to the entomopathogenic fungus, Beauveria bassiana (Bals.-Criv.) Vuill and two developmental hormones

Effects of Beauveria bassiana (Bals.-Criv.) spores on immune functions of Glyphodes pyloalis Walker larvae were studied. Total and differential hemocyte counts revealed that infection by B. bassiana caused a dramatic change in hemocyte number. In vivo and in vitro studies demonstrated that increase in time exposure to fungal pathogen resulted in elevated phagocytic activity. Nodules were formed in response to spore injection and their numbers were maximal 6 h post injection. The phenoloxidase (PO) activity in treated larvae changed significantly 3 and 6 h after spore injection compared with the control larvae. The reduction in PO activity was observed 12 and 24 h post injection. Effect of two developmental hormones, juvenile hormone (JH) and ecdysone on cellular immune response of G. pyloalis were also evaluated. Larval treatment with JH prior to B. bassiana spore injection reduced nodulation while ecdysone enhanced it. These results demonstrated that ecdysone and JH play an important regulatory role in the immune response in the studied insect