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

The thickness of thin liquid films is of great interest to industrial processes and life science. However, there are not appropriate quantitative experimental tools for an adequate study of film evolution in case of not-ideal conditions. Here, we show the application of a holographic system for the evaluation of the 3D topography and thickness of evolving protein films. We use a custom holographic microscope that combines quantitative phase imaging with materials engineering. This technique offers an unprecedented level of details and we anticipate that it will promote a deeper understanding of the underlying physics of thin film dynamics.

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Fast and Accurate Thickness Mapping of Thin Liquid Films

Induced dehydration as a method to enhance phase-contrast observation of plant cells intracellular dynamics

Tomographic phase microscopy in cytometry environment is feasible at single cell level and without the a-priori knowledge of the cell orientation. In the present paper we demonstrate different strategies for recovery the rotation angles of single cells and clusters when rotating into microfluidic channels, thus realistically opening to the implementation of marker-free cytofluorimeter for three-dimensional imaging of biological fluids. The pioneering developed strategies allows to measure quantitatively the inner distribution of the refractive indexes inside the cell volume avoiding the use of chemical and fluorescent tags. The imaging apparatus is based on label-free Digital Holography in microscopy setup designed in transmission geometry to image 700x700μm Field of View with lateral resolution of 0.5μm. Digital Holography is perfectly suited for imaging in microchannels as it allows the numerical refocusing of sample into a three-dimensional volume. In the present paper, such imaging arrangement is combined with a high-precision pumping system connected to a microfluidic channel that allow the complete rotation of the flowing cells into the Field of View. High-speed 25Megapixel camera acquires holographic set measurements of all rotating cells that are numerically processed to obtain quantitative two-dimensional phase-contrast maps at different view angles. Accurate numerical algorithms allow to tag each phasecontrast maps with the rotation angle in the microchannel. The couples made of phase-contrast map and measured angle are given as input at tomography algorithms to obtain the refractive index distribution into the cell volume. The approach in principles works properly for any kind of biological matter subjected to rotation as already demonstrated in case of nuclei of plant cells during dehydration. Furthermore, the same approach allows to show the three-dimensional distribution of internalized nano-particles as in case of nano-graphene oxide. The most important achievement and innovation of such strategy is the high-throughput phase-contrast tomography at single cell level that opens to new diagnostic tool thanks to the possibility to have statistically relevant measurement on cell population and also for the possibility to use artificial intelligence architecture for cell identification and classification.

Tomographic phase microscopy at single cell scale without a-priori knowledge of cell orientations: smart strategies for rotation angles recovery

In this work, we have devised different ways to interrogate a single-mode FBGFP sensor, based on both the PDH lock and a polarization-spectroscopy scheme, which extends the idea of Hansch et al. and exploits the internal fiber birefringence and the additional birefringence induced by the grating-inscription process.

Fiber Bragg-grating (FBG) resonators for high-sensitivity multi-parameter sensing

A numerical method to easily obtain a quantitative phase map of objects flowing in micro-fluidic devices using a digital holographic microscope is shown. The presented technique is called digital self-referencing because the retrieved wavefront is folded in order to subtract the area outside the micro-fluidic channel from the area where the sample is.

Pietro Ferraro

Papers

Fast and Accurate Thickness Mapping of Thin Liquid Films

Induced dehydration as a method to enhance phase-contrast observation of plant cells intracellular dynamics

Tomographic phase microscopy at single cell scale without a-priori knowledge of cell orientations: smart strategies for rotation angles recovery

Fiber Bragg-grating (FBG) resonators for high-sensitivity multi-parameter sensing

Digital holographic self-referencing quantitative phase microscopy