Scalar Transfer across a Turbulent/non-turbulent Interface in a Planar Jet

This fluid dynamics video is an entry for the Gallery of Fluid Motion of the 66th Annual Meeting of the APS-DFD. In this video, the scalar transfer across the turbulent/non-turbulent (T/NT) interface in a planar jet is investigated by using a direct numerical simulation. Visualization of the scalar flux across the T/NT interface shows that the diffusive species premixed in the ambient flow is transferred into the turbulent region mainly across the leading edge (Here, the leading edge is the T/NT interface across which the turbulent fluid turns into the non-turbulent fluid in the streamwise direction).Comment: The fluid dynamics video for an entry for the Gallery of Fluid Motion of the 66th Annual Meeting of the APS-DFD is include

Analysis and Application of Decaying Turbulence with Initial Fractal Geometry

In this paper, we address high‐Schmidt‐number (Sc) scalar turbulent mixing that results from grid‐generated turbulence using the initial fractal geometry of the velocity profile. More specifically, as was proposed in our recent study, we adopt an initial flow field generated by a fractal grid and apply it to a water channel experiment based on a high‐Sc‐number scalar‐mixing layer in order to create grid‐generated turbulence, and thus solve our current research problem. The high‐Sc‐number scalar and velocity fields of the grid‐generated turbulence are then measured using planar laser‐induced fluorescence (PLIF) and particle image velocimetry (PIV), respectively. By means of fractal analysis, this study specifically addresses the turbulent mixing phenomena in which the fractal dimension of the mixing interface of an observed high‐Sc‐number scalar field is calculated. Additionally, we discuss the efficiency of using fractal grids as devices for enhancing high‐Sc‐number scalar turbulent mixing by observing turbulent intensities and dissipation by PIV

Modulation of Hepatocarcinoma Cell Morphology and Activity by Parylene-C Coating on PDMS

BACKGROUND: The ability to understand and locally control the morphogenesis of mammalian cells is a fundamental objective of cell and developmental biology as well as tissue engineering research. We present parylene-C (ParC) deposited on polydimethylsiloxane (PDMS) as a new substratum for in vitro advanced cell culture in the case of Human Hepatocarcinoma (HepG2) cells. PRINCIPAL FINDINGS: Our findings establish that the intrinsic properties of ParC-coated PDMS (ParC/PDMS) influence and modulate initial extracellular matrix (ECM; here, type-I collagen) surface architecture, as compared to non-coated PDMS substratum. Morphological changes induced by the presence of ParC on PDMS were shown to directly affect liver cell metabolic activity and the expression of transmembrane receptors implicated in cell adhesion and cell-cell interaction. These changes were characterized by atomic force microscopy (AFM), which elucidated differences in HepG2 cell adhesion, spreading, and reorganization into two- or three-dimensional structures by neosynthesis of ECM components. Local modulation of cell aggregation was successfully performed using ParC/PDMS micropatterns constructed by simple microfabrication. CONCLUSION/SIGNIFICANCE: We demonstrated for the first time the modulation of HepG2 cells' behavior in relation to the intrinsic physical properties of PDMS and ParC, enabling the local modulation of cell spreading in a 2D or 3D manner by simple microfabrication techniques. This work will provide promising insights into the development of cell-based platforms that have many applications in the field of in vitro liver tissue engineering, pharmacology and therapeutics

AJK2011-21015 CHARACTERISTICS OF THE SCALAR FIELD IN A TURBULENT LIQUID JET AND A FUNDAMENTAL STUDY ON THE MICRO SCALE CONCENTRATION MEASUREMENTS BY THE OPTICAL FIBER LIF METHOD

ABSTRACT In this study, the characteristics of the scalar field in an axisymmetric turbulent water jet are investigated experimentally. In the experiments, the axial velocity, the concentration of the dye solution and the temperature of the fluid are measured by the hot-film probe, the fiber sensor and the cold-firm probe, respectively. In particular, the difference of statistics between scalars (concentration and temperature) with the different molecular diffusion coefficients is discussed. The Schmidt number of the diffusing matter is 3,800, and the Prandtl number of temperature is 7. As regarding the mean values, the r.m.s values and distribution of PDF, we cannot find any difference between the concentration field and temperature field. However, in the spectrum, it is found that the temperature spectrum shows the -5/3 law almost in the same range as the velocity spectrum, on the other hand, the concentration spectrum shows the -5/3 law in the wider range than the velocity spectrum. This means that the shape of spectrum depends on the diffusion coefficient. In order to make the higher resolution measurement of concentration, a new optical probe based on the LIF method is designed. This probe consists of the two optical fibers, the tip of which is processed like the shape of a lens. By the effect of lens, the laser beam can be focused on the narrower area in comparison with the past LIF measurements. In the present design, the width of focus of laser beam is set to 0.6 micrometers, and the focal length is set to 7.3mm. It is shown that this probe has the resolution less than the Batchelor scale at in the condition of present jet diffusion field (d=4mm, Re=20,000). Further, a new system to adjust the position of the optic fiber probe exquisitely is developed. INTRODUCTION There are many practical problems in the industrial and natural flow fields that the diffusing matter are mixed. In this study, we pay a special attention to the diffusion fields of scalars (concentration and temperature) in the turbulent liquid jet. In the liquid phase, it is usually known that the Schmidt number of the diffusing matter (or the Prandtl number in case of temperature) is larger than 1, so that the scalar fields have been crucially influenced by the velocity field. In this case, it is useful to investigate the relations between the velocity and scalar statistics to understand the mixing process of the scalar in the turbulent liquid flows. With regard to the measurements of high Schmidt number matter, the concentrations of the fluorescent dye or the kalium chloride have been often measured by Laser-Induced Fluorescence (LIF) method or the electrode method. However seeing the past reports, in case of the flows with the mean shear, there are still large scattering of the data for the scalar statistics, and so the reliable turbulent statistics are keenly required. On the other hand, the similarity theory of turbulent scalar field shows that for the scalar field of high Schmidt number and high Reynolds number, there exist the statistical universal ranges called the "viscous convective subrange" and the "viscous diffusive subrange" in the space smaller than the Kolmogorov scale (which is the smallest velocity fluctuatio

Impact of cardiac support device combined with slow-release prostacyclin agonist in a canine ischemic cardiomyopathy model

BackgroundThe cardiac support device supports the heart and mechanically reduces left ventricular (LV) diastolic wall stress. Although it has been shown to halt LV remodeling in dilated cardiomyopathy, its therapeutic efficacy is limited by its lack of biological effects. In contrast, the slow-release synthetic prostacyclin agonist ONO-1301 enhances reversal of LV remodeling through biological mechanisms such as angiogenesis and attenuation of fibrosis. We therefore hypothesized that ONO-1301 plus a cardiac support device might be beneficial for the treatment of ischemic cardiomyopathy.MethodsTwenty-four dogs with induced anterior wall infarction were assigned randomly to 1 of 4 groups at 1 week postinfarction as follows: cardiac support device alone, cardiac support device plus ONO-1301 (hybrid therapy), ONO-1301 alone, or sham control.ResultsAt 8 weeks post-infarction, LV wall stress was reduced significantly in the hybrid therapy group compared with the other groups. Myocardial blood flow, measured by positron emission tomography, and vascular density were significantly higher in the hybrid therapy group compared with the cardiac support device alone and sham groups. The hybrid therapy group also showed the least interstitial fibrosis, the greatest recovery of LV systolic and diastolic functions, assessed by multidetector computed tomography and cardiac catheterization, and the lowest plasma N-terminal pro-B-type natriuretic peptide levels (P < .05).ConclusionsThe combination of a cardiac support device and the prostacyclin agonist ONO-1301 elicited a greater reversal of LV remodeling than either treatment alone, suggesting the potential of this hybrid therapy for the clinical treatment of ischemia-induced heart failure

超常磁性体を用いたMRリンフォグラフィーによる口腔癌患者のセンチネルリンパ節同定

The purpose of this study was to examine the feasibility of interstitial MR lymphography using Superparamagnetic Iron Oxide (SPIO) to detect sentinel lymph nodes (SLNs) in head and neck cancer. For two patients with cT2N0 squamous cell carcinoma of the tongue, the submucosal injection of SPIO as well as sentinel lymph node navigation surgery (SLNNS) was performed before undergoing surgical treatment. SPIO was used for MR lymphography and Tc-99m phytate for SPECT. We compared the images by both modalities. Berlin blue stain was also performed postoperatively if SLNs had the uptake of SPIO. The lymph nodes with MR signal attenuation and those with hot spots were probed to be anatomically identical. All the lymph nodes detected as a SLN by a gamma-probe contained the blue granules from SPIO. These data suggest that SPIO can be a novel tracer for performing SLNNS and SLN biopsy in oral cancer patients with cN0 neck.博士（医学）・甲622号・平成26年3月17

W(E_10) Symmetry, M-Theory and Painleve Equations

The Weyl group symmetry W(E_k) is studied from the points of view of the E-strings, Painleve equations and U-duality. We give a simple reformulation of the elliptic Painleve equation in such a way that the hidden symmetry W(E_10) is manifestly realized. This reformulation is based on the birational geometry of the del Pezzo surface and closely related to Seiberg-Witten curves describing the E-strings. The relation of the W(E_k) symmetry to the duality of M-theory on a torus is discussed on the level of string equations of motion.Comment: 14 pages, dedicated to the memory of Sung-Kil Yang, references adde

FGF2 Has Distinct Molecular Functions from GDNF in the Mouse Germline Niche

Both glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2) are bona fide self-renewal factors for spermatogonial stem cells, whereas retinoic acid (RA) induces spermatogonial differentiation. In this study, we investigated the functional differences between FGF2 and GDNF in the germline niche by providing these factors using a drug delivery system in vivo. Although both factors expanded the GFRA1+ subset of undifferentiated spermatogonia, the FGF2-expanded subset expressed RARG, which is indispensable for proper differentiation, 1.9-fold more frequently than the GDNF-expanded subset, demonstrating that FGF2 expands a differentiation-prone subset in the testis. Moreover, FGF2 acted on the germline niche to suppress RA metabolism and GDNF production, suggesting that FGF2 modifies germline niche functions to be more appropriate for spermatogonial differentiation. These results suggest that FGF2 contributes to induction of differentiation rather than maintenance of undifferentiated spermatogonia, indicating reconsideration of the role of FGF2 in the germline niche