다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

A fast-Fourier-transform method of topography and interferometry is proposed. By computer processing of a noncontour type of fringe pattern, automatic discrimination is achieved between elevation and depression of the object or wave-front form, which has not been possible by the fringe-contour-generation techniques. The method has advantages over moire topography and conventional fringe-contour interferometry in both accuracy and sensitivity. Unlike fringe-scanning techniques, the method is easy to apply because it uses no moving components.

Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry

We review the recent developments in the area of optical fiber grating sensors, including quasi-distributed strain sensing using Bragg gratings, systems based on chirped gratings, intragrating sensing concepts, long period-based grating sensors, fiber grating laser-based systems, and interferometric sensor systems based on grating reflectors.

Fiber grating sensors

The PASCAL Visual Object Classes Challenge

We propose a tomographic reconstruction method for three-dimensional refractive index mapping of full-rotating cells in a microfluidic channel. Rolling angle recovery is achieved by exploiting the morphometric features of cells.

Tomographic phase microscopy of rolling cells in microfluidic flow

https://zenodo.org/record/7376933/files/1-s2.0-S2214180422000654-main.pdf

A Pin-Based Pyro-Electrohydrodynamic Jet Sensor for Tuning the Accumulation of Biomolecules Down to Sub-Picogram Level Detection

We report Schlieren imaging of inverted domains in congruent LiNbO/sub 3/. High contrast imaging is possible by taking advantage of the residual refractive index discontinuity at domain boundaries which is present even after prolonged thermal annealing.

/pdf/schlieren-imaging-of-inverted-domains-in-congruent-lithium-lz8l0dgzjr.pdf

Schlieren imaging of inverted domains in congruent lithium niobate

In biology and biomedical research fields one of the main topic is the understanding of morphology and mechanics of cells and microorganisms. Biological samples present low amplitude contrast that limits the information that can be retrieved through optical bright-field microscope measurements. Optical transparency is overcame for fixed specimen by means of staining techniques but such well-established methods present the issue to be invasive and not applicable on live cells. Study of microorganism in their natural environment without perturbing their equilibrium is challenging in biology. The main effect on light propagating in such objects is in phase, indeed it is altered respect to the phase of the beam propagating in the surrounding medium. This is known as phase-retardation or phase-shift. Objects are visible by Phase Contrast Imaging (PCI) due to interferometric processes able to transform tiny phase variation in amplitude modulation so that any small differences in the beam optical path can be visualized. Digital Holography (DH) in microscopy present as a powerful tool to overcome all these issues. The main characteristic is the possibility to discern between intensity and phase information performing quantitative mapping of the Optical Path Length. Up to now, DH has been considered as an innovative and alternative approach in microscopy and it’s a good candidate for complete specimen analysis in the framework of no invasive microscopy. In this paper, the flexibility of DH is employed to analyze in a completely and no-invasive way the cell mechanics of live and unstained cell subjected to appropriate stimuli. The potentialities of DH are employed to measure all the parameters useful to understand the deformations induced by external and controlled stress in living cells.

Cell mechanics investigation by digital holographic microscopy

Azopolymer materials belong to family special materials, which are subject to photo-isomerization when illuminated by appropriate light wavelength. Optical characterization of azopolymer materials is interesting because they can be patterned when illuminated by coherent polarized light with potentially interesting applications in the biotechnology, photonic elements, molding templates, etch masks and micro-nanochannels. The interference lithography is an excellent tool to trigger the isomerization reaction on the material. During this work, switchable patterns were fabricated by means of a well established holographic set-up: surface relief gratings (SRGs) were realized with Lloyd’s mirror system. Moreover, optical characterization of the material was performed, starting from a commercial one and using a new way to analyse SRGs by means of Digital Holography Microscopy, to determine relevant parameters for the realization of the patterns with different shape and size. Some preliminary results of the influence of such patterns on the cell behavior were shown.

Pietro Ferraro

Papers

Tomographic phase microscopy of rolling cells in microfluidic flow

A Pin-Based Pyro-Electrohydrodynamic Jet Sensor for Tuning the Accumulation of Biomolecules Down to Sub-Picogram Level Detection

Schlieren imaging of inverted domains in congruent lithium niobate

Cell mechanics investigation by digital holographic microscopy

Imaging and characterization of surface relief gratings on azopolymer by digital holographic microscopy