The colonial hydroid Podocoryna carnea grows adherent to surfaces progressing along them by a motile stolon tip. We here ask whether the stolon tip grows preferentially within grooves etched in silicon wafers. In a series of pilot experiments, we varied the dimensions of grooves and found that stolons did not utilize grooves with a width:depth of 5:5 μm or 10:10 μm, occasionally followed groove...

We used an in vitro system that eliminates competing guidance cues found in embryos to determine whether substratum topography alone provides important neurite guidance information. Dissociated embryonic Xenopus spinal cord neurons and rat hippocampal neurons were grown on quartz etched with a series of parallel grooves. Xenopus neurites grew parallel to grooves as shallow as 14 nm and as narro...

Based on the waveguide mode (WGM) method, coupling interaction of electromagnetic wave in a groove doublet configuration is studied. The formulation obtained by WGM method for a single groove [Prog. Electromagn. Res. 18, 1-17 (1998)] is extended to two grooves. By exploring the total scattered field of the configuration, coupling interaction ratios are defined to describe the interaction betwee...

OBJECTIVES The aims of this study were to conduct a morphometric analysis on the buccal furcation grooves in freshly extracted bifurcated maxillary first premolars (MFPs) and to correlate all anatomical measurements using microcomputed tomography. MATERIALS AND METHODS Twenty-three human MFPs with bifurcated canals were selected for this study. The specimens were analyzed with microcomputed t...

Electromagnetic scattering from a two-dimensional groove recessed in an arbitrarily thick conducting screen is studied. The groove may be empty or loaded with a lossy material which may or may not completely fill the cavity. For the partially loaded groove, the filling material is assumed electrically dense so that the standard impedance boundary condition is applicable at the top surface of th...

A "sheath" fluid passing through a microfluidic channel at low Reynolds number can be directed around another "core" stream and used to dictate the shape as well as the diameter of a core stream. Grooves in the top and bottom of a microfluidic channel were designed to direct the sheath fluid and shape the core fluid. By matching the viscosity and hydrophilicity of the sheath and core fluids, th...

Circular three-dimensional (3D) micropatterns with grooves and ridges of various sizes on the circumference of the structure were micromachined in polymethylmethacrylate, using proton beam micromachining. Fibroblasts were seeded in the center smooth nonpatterned surface of the circle. The circumference grooves could retard the outward spreading of cells after they became confluent in the centra...

Remarkably enhanced transmission of microwave radiation through a single subwavelength slit in a thick metallic substrate surrounded by just a pair of parallel deep and narrow grooves is recorded. By also patterning the output face of the metal slab with two grooves there is strong exit beam confinement. There are no gratings in this structure and, hence, the transmission mechanism is not relat...

Grooves on the surface of the plasmalemma(plasma membrane) of frozen-etched yeast cells have been shown by many investigators (1, 10, 12) . Necas et al. (13) showed interconnected grooves on the surface of frozen-etched Saccharomyces cerevisiae protoplasts, but such structures could not be so effectively demonstrated in frozen-etched protoplasts prefixed in glutaraldehyde . Structures comparabl...

In microwave and terahertz frequency band, a textured metal surface can support spoof surface plasmon polaritons (SSPPs). In this paper, we explore a SSPPs waveguide composed of a metal block with pyramidal grooves. Under the deep subwavelength condition, theoretical formulas for calculation of dispersion relations are derived based on the modal expansion method (MEM). Using the obtained formul...