The advent of the genome facilitated by the advances in micro- and nanotechnology has revolutionized our understanding of living systems. DNA microarrays, catalytic RNA arrays, and protein arrays are ...all a consequence of innovations in engineering at the micro- and nanoscales. Here, we extend this paradigm to the fabrication of live mammalian cell arrays that can be used to investigate the state of the cell at the level of an integrated system. Specifically, we describe an electro-optical system that utilizes physical properties of mammalian cells (charge, dielectric permittivity) rather than receptor-mediated adhesion to rapidly pattern and manipulate cells in a microarray format. The platform we describe is an electro-optical method that employs two complementary methods of cell manipulation: (1) electrophoretic arraying of cells in a dc field due to their intrinsic negative surface charge and (2) remote optical manipulation of individual cells by vertical-cavity surface emitting laser driven infrared optical tweezers. The platform is optically transparent and thus enables monitoring of fluorescent reporters of cellular events (e.g., expression of green fluorescent protein) and allows remote optical manipulation of arrayed cells without risk of breaching the aseptic environment. In addition to the experimental manipulation of mammalian cells, we also present a theoretical framework to establish the limitations of the platform we describe. The ability to probe dynamic cellular events in parallel may offer insights into unforeseen biological mechanisms of cellular function and find applications in drug discovery, functional genomics, and tissue engineering.
The experimental investigations were carried out in order to have detailed information on the flow structure around perforated cylinders using high-image density Particle Image Velocimetry technique ...in shallow water flow. The depth-averaged free-stream velocity was kept constant as U∞=100mm/s corresponding to the Reynolds number of Re=10000 based on the perforated cylinder diameter. In order to analyze the effect of porosity, β on the flow structure, the porosities in the range of 0.1≤β≤0.8 with an increment of 0.1 were used and the results were compared with the bare cylinder case by means of velocity and vorticity contours, turbulent kinetic energy, Reynolds shear stress and streamline topologies. It was concluded that the porosity, β had a substantial effect on the control of large-scale vortical structures downstream of the cylinder in which the shear layers were elongated, fluctuations were significantly attenuated and formation of Karman Vortex Street was successfully prevented by the use of perforated cylinders.
•This study reveals the effect of the shroud diameter and porosity on the vortex shedding mechanism of cylinder.•Flow structures in the gap between the cylinder and the shroud are investigated using ...PIV technique.•Penetrating flow through the shroud causes different wake flow regimes.•Drag coefficient of the cylinder is sensitive to shroud diameter and porosity.
In the present study, flow characteristics were investigated experimentally using particle image velocimetry technique (PIV) in a gap between a solid cylinder and a shroud to reveal the effect of shroud diameter (Ds) and porosity (β) on the vortex shedding mechanism of the cylinder. Porosity (varied from β = 0.3 to 0.7) and diameter ratio (D/Ds = 0.4, 0.5 and 0.6) were main parameters examined at a Reynolds number of Re = 5000. For the porosity values of β ≤ 0.5, it is observed that vortex formation of the cylinder occurs only in the gap and shroud produces its own wake flow patterns. Penetrating flow through the shroud extends the shear layers on the both sides of the shroud through the downstream direction and prevents the interaction of shear layers in the near wake region. The diameter ratio and the porosity are impactful on the wake flow patterns in outer region of the shroud since they are determinant of the penetrating flow rate. Force measurements were also performed in the air tunnel in order to reveal the effect of shroud on the drag coefficient of cylinder. It is found that the drag coefficient of the cylinders are reduced significantly by shrouds when compared with that obtained from the bare cylinder case. However, the drag coefficient of the cylinder together with the shroud is higher than the bare cylinder for all cases since the shrouds enlarge the area exposed to the flow.
Aim
Radial artery spasm is common during transradial procedures and is the most common cause of procedural failure. The objectives of this study were to assess whether the routine administration of ...sedation at the beginning of transradial coronary angiography with the use of hydrophilic-coated and smaller sheaths/catheters would reduce the incidence of radial artery spasm.
Patients and methods
Patients undergoing transradial coronary angiography were prospectively randomized to receive midazolam during the procedure or no sedative treatment. The primary endpoint was angiographically confirmed radial artery spasm. Stenosis of the radial artery was measured with a computer-assisted quantification method.
Results
In all, 150 patients were randomized into a treatment group and a control group. Spasm occurred in 15 patients of the treatment group (20 %) versus 16 in the control group (21.3 %). There were no differences between the two groups regarding the incidence of spasm and the distribution of spasm severity (
p
> 0.05). No significant differences were observed between the two groups in terms of 30-day mortality or repeat hospitalization for any cause (
p
> 0.05).
Conclusion
Routine use of midazolam could not reduce the occurrence of radial artery spasm during transradial coronary angiography.
In this study, Silicon (Si) and glass substrates were coated with Zinc sulfide (ZnS) using Thermionic Vacuum Arc (TVA) technique for the first time. With this technique, the coating time of the ...samples is very short and film thickness can be controlled during the coating process. Moreover, TVA provides many advantages to deposited thin films than other techniques such as compactness, low roughness, nanostructures, homogeneities as compared to other deposition techniques. This paper presents a different technique for deposition of high-quality ZnS thin films. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscopy (AFM) were used to characterize the coated silicon and glass surface morphologies. Additionally, transmittances, thickness and refractive indices of coated glass samples with ZnS were measured by ultraviolet–visible spectrophotometer and interferometer to characterize their optical properties.
In this study, magnesium thin films were deposited on glass substrate by the Thermionic Vacuum Arc (TVA) technique for the first time. We present a different technique for deposition of high-quality ...magnesium thin films. By means of this technique, the production of films is achieved by condensing the plasma of anode material generated using Thermionic Vacuum Arc (TVA) under high vacuum conditions onto the surface to be coated. The crystal orientation and morphology of the deposited films were investigated by using XRD, EDX, SEM and AFM. The aim of this study is to search the use of TVA technique to coat magnesium thin films and to determine some of the physical properties of the films generated. Furthermore, this study will contribute to the scientific studies which search the thin films of magnesium or the compounds containing magnesium. In future, this study will be preliminary work to entirely produce magnesium diboride (MgB
2) superconductor thin film with the TVA technique.
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