A non-contact measuring system for in-situ surface characterization based on laser confocal microscopy

The characterization of surface topographic features on a component is typically quantified using two-dimensional roughness descriptors which are captured by off-line desktop instruments. Ideally any measurement system should be integrated into the manufacturing process to provide in-situ measurement and real-time feedback. A non-contact in-situ surface topography measuring system is proposed in this paper. The proposed system utilizes a laser confocal sensor in both lateral and vertical scanning modes to measure the height of the target features. The roughness parameters are calculated in the developed data processing software according to ISO 4287. To reduce the inherent disadvantage of confocal microscopy, e.g. scattering noise at steep angles and background noise from specular reflection from the optical elements, the developed system has been calibrated and a linear correction factor has been applied in this study. A particular challenge identified for this work is the in-situ measurement of features generated by a robotized surface finishing system. The proposed system was integrated onto a robotic arm with the measuring distance and angle adjusted during measurement based on a CAD model of the component in question. Experimental data confirms the capability of this system to measure the surface roughness within the Ra range of 0.2 – 7 μm (bandwidth λc/λs of 300), with a relative accuracy of 5%

A practical review on the measurement tools for cellular adhesion force

Cell cell and cell matrix adhesions are fundamental in all multicellular organisms. They play a key role in cellular growth, differentiation, pattern formation and migration. Cell-cell adhesion is substantial in the immune response, pathogen host interactions, and tumor development. The success of tissue engineering and stem cell implantations strongly depends on the fine control of live cell adhesion on the surface of natural or biomimetic scaffolds. Therefore, the quantitative and precise measurement of the adhesion strength of living cells is critical, not only in basic research but in modern technologies, too. Several techniques have been developed or are under development to quantify cell adhesion. All of them have their pros and cons, which has to be carefully considered before the experiments and interpretation of the recorded data. Current review provides a guide to choose the appropriate technique to answer a specific biological question or to complete a biomedical test by measuring cell adhesion

A general perspective of the characterization and quantification of nanoparticles: Imaging, spectroscopic, and separation techniques

This article gives an overview of the different techniques used to identify, characterize, and quantify engineered nanoparticles (ENPs). The state-of-the-art of the field is summarized, and the different characterization techniques have been grouped according to the information they can provide. In addition, some selected applications are highlighted for each technique. The classification of the techniques has been carried out according to the main physical and chemical properties of the nanoparticles such as morphology, size, polydispersity characteristics, structural information, and elemental composition. Microscopy techniques including optical, electron and X-ray microscopy, and separation techniques with and without hyphenated detection systems are discussed. For each of these groups, a brief description of the techniques, specific features, and concepts, as well as several examples, are described.Junta de Andalucía FQM-5974CEI-Biotic Granada CEI2013- MP-1

Doctor of Philosophy

dissertationSmall molecule partitioning between aqueous and lipid-like phases is of importance in pharmaceutics, biology, and environmental chemistry. Measuring small-molecule partitioning has remained a challenge, however, due to the scale of current measurement techniques such as chromatographic columns and shake flasks, which require large sample volumes, long equilibration times, and ex-situ quantification steps. In the work presented in this dissertation, confocal Raman microscopy is applied to analyze, in-situ, the structure of lipid-like phases within single chromatographic support particles and their application to measuring small-molecule partitioning. The 2μm â€" 10μm diameter size of a single support particle is well-matched to the size of the confocal probe (~0.6μm diameter, 1 fL) of a 100X confocal microscope. The large (~300m2/g) surface area within the porous particle concentrates surface-associated molecular populations, providing a large enough ‘concentration’ within the particle to measure partitioning despite the small cross-sections for Raman scattering. This dissertation covers the evolution of confocal Raman microscopy measurements within individual porous particles from measuring partitioning of pyrene into surface bound C18 alkyl chains, detecting octanol-water partitioning of naphthoic acid in reverse-phase chromatographic particles, and characterizing the structure of withinparticle hybrid-phospholipid bilayers. This evolution represents a progression toward more biologically-relevant substrates for measuring small-molecule lipophilicity

J Fluorescence

The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requirements on fluorescence standards for the characterization and performance validation of fluorescence instruments, to enhance the comparability of fluorescence data, and to enable quantitative fluorescence analysis are discussed. Special emphasis is dedicated to spectral fluorescence standards and fluorescence intensity standards

Accelerated Growth Plate Mineralization and Foreshortened Proximal Limb Bones in Fetuin-A Knockout Mice

PMCID: PMC3473050This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited