Digital holography as 3D tracking tool for assessing acoustophoretic particle manipulation

The integration of digital holography (DH) imaging and the acoustic manipulation of micro-particles in a microfluidic environment is investigated. The ability of DH to provide efficient 3D tracking of particles inside a microfluidic channel is exploited to measure the position of multiple objects moving under the effect of stationary ultrasound pressure fields. The axial displacement provides a direct verification of the numerically computed positions of the standing wave’s node, while the particle’s transversal movement highlights the presence of nodes in the planar direction. Moreover, DH is used to follow the aggregation dynamics of trapped spheres in such nodes by using aggregation rate metrics

Mid-infrared tunable two-dimensional Talbot array illuminator

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Visible reconstruction by a circular holographic display from digital holograms recorded under infrared illumination

Cataloged from PDF version of article.A circular holographic display that consists of phase-only spatial light modulators is used to reconstruct images in visible light from digital holograms recorded under infrared (10.6 μm) illumination. The reconstruction yields a holographic digital video display of a three-dimensional ghostlike image of an object floating in space where observers can move and rotate around it. © 2012 Optical Society of Americ

Rapid prototyping of plastic lab-on-a-chip by femtosecond laser micromachining and removable insert microinjection molding

We have introduced a new hybrid fabrication method for lab-on-a-chip devices through the combination of femtosecond laser micromachining and removable insert micro-injection molding. This method is particularly suited for the fast prototyping of new devices, while maintaining a competitive low cost. To demonstrate the effectiveness of our approach, we designed, fabricated, and tested a completely integrated flow cytometer coupled to a portable media device. The system operation was tested with fluorescent plastic micro-bead solutions ranging from 100 beads/?L to 500 beads/?L. We demonstrated that this hybrid lab-on-a-chip fabrication technology is suitable for producing low-cost and portable biological microsystems and for effectively bridging the gap between new device concepts and their mass production

Optical reconstruction of digital holograms recorded at 10.6 μm: Route for 3D imaging at long infrared wavelengths

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Tunable two-dimensional hexagonal phase array in domain-engineered z-cut lithium niobate crystal

An optical phase array with tunable phase step is demonstrated. The phase array consists of a 2-dimensional hexagonal lattice of inverted ferroelectric domains fabricated on a z-cut lithium niobate substrate. The electro-optically tunable phase step is obtained by the application of an external electric field along the z axis of the crystal via transparent electrodes. Theoretical analysis and experimental results are presented showing that a tunable and flexible adaptive optical illuminator device can be realized by combining the electro-optic tunability with the Talbot effect. Generation of a multiplicity of light pattern is shown

An Implantable Vascularized Protein Gel Construct That Supports Human Fetal Hepatoblast Survival and Infection by Hepatitis C Virus in Mice

Widely accessible small animal models suitable for the study of hepatitis C virus (HCV) in vivo are lacking, primarily because rodent hepatocytes cannot be productively infected and because human hepatocytes are not easily engrafted in immunodeficient mice.We report here on a novel approach for human hepatocyte engraftment that involves subcutaneous implantation of primary human fetal hepatoblasts (HFH) within a vascularized rat collagen type I/human fibronectin (rCI/hFN) gel containing Bcl-2-transduced human umbilical vein endothelial cells (Bcl-2-HUVEC) in severe combined immunodeficient X beige (SCID/bg) mice. Maturing hepatic epithelial cells in HFH/Bcl-2-HUVEC co-implants displayed endocytotic activity at the basolateral surface, canalicular microvilli and apical tight junctions between adjacent cells assessed by transmission electron microscopy. Some primary HFH, but not Huh-7.5 hepatoma cells, appeared to differentiate towards a cholangiocyte lineage within the gels, based on histological appearance and cytokeratin 7 (CK7) mRNA and protein expression. Levels of human albumin and hepatic nuclear factor 4alpha (HNF4alpha) mRNA expression in gel implants and plasma human albumin levels in mice engrafted with HFH and Bcl-2-HUVEC were somewhat enhanced by including murine liver-like basement membrane (mLBM) components and/or hepatocyte growth factor (HGF)-HUVEC within the gel matrix. Following ex vivo viral adsorption, both HFH/Bcl-2-HUVEC and Huh-7.5/Bcl-2-HUVEC co-implants sustained HCV Jc1 infection for at least 2 weeks in vivo, based on qRT-PCR and immunoelectron microscopic (IEM) analyses of gel tissue.The system described here thus provides the basis for a simple and robust small animal model of HFH engraftment that is applicable to the study of HCV infections in vivo

The lived experience of caregivers of persons with heart failure: A phenomenological study

Heart failure (HF) patients need to follow a strict pharmacological and nonpharmacological regimen in order to counteract the burden of the disease, and informal caregivers are an important resource for HF patients in managing and coping with their disease. Few studies have examined the lived experience of these caregivers with a rigorous phenomenological approach, and none have been conducted in Italy

Resolution gain in space-time digital holography by self-assembling of the object frequencies

Space-time digital holography (STDH) exploits the object motion to record the hologram in a hybrid ST domain. This representation adds new capabilities to conventional DH, e.g., unlimited field of view and variable phase shifting. This is the best candidate for imaging biological samples flowing in microfluidic channels. Here, we show that STDH is able to improve the spatial resolution as well. Different from other super-resolution approaches, stitching between holograms or their spectra is no longer required. Moreover, we introduce a new oblique STDH modality to record and process hybrid ST representations. This allows improving resolution in 2D with one single object scan, paving the way to the use of STDH for super-resolution imaging onboard microfluidic devices

Media 1: Spatio-temporal scanning modality for synthesizing interferograms and digital holograms

Originally published in Optics Express on 22 September 2014 (oe-22-19-22328