3D micro-CT and O-PTIR spectroscopy bring new understanding of the influence of filler content in dental resin composites.

Background: Dental resin composites' performance is intricately linked to their polymerisation shrinkage characteristics. This study compares polymerisation shrinkage using advanced 3D micro-computed tomography (micro-CT) and traditional 2D linear assessments. It delves into the crucial role of filler content on shrinkage and the degree of conversion in dental resin composites, providing valuable insights for the field.

Using Compound Neural Action Potentials for Functional Validation of a High-Density Intraneural Interface: A Preliminary Study.

Compound nerve action potentials (CNAPs) were used as a metric to assess the stimulation performance of a novel high-density, transverse, intrafascicular electrode in rat models. We show characteristic CNAPs recorded from distally implanted cuff electrodes. Evaluation of the CNAPs as a function of stimulus current and calculation of recruitment plots were used to obtain a qualitative approximation of the neural interface's placement and orientation inside the nerve.

OCTAVVS: A Graphical Toolbox for High-Throughput Preprocessing and Analysis of Vibrational Spectroscopy Imaging Data.

Modern vibrational spectroscopy techniques enable the rapid collection of thousands of spectra in a single hyperspectral image, allowing researchers to study spatially heterogeneous samples at micrometer resolution. A number of algorithms have been developed to correct for effects such as atmospheric absorption, light scattering by cellular structures and varying baseline levels. After preprocessing, spectra are commonly decomposed and clustered to reveal informative patterns and subtle spectral changes.

Fully integrated biochip platforms for advanced healthcare.

Recent advances in microelectronics and biosensors are enabling developments of innovative biochips for advanced healthcare by providing fully integrated platforms for continuous monitoring of a large set of human disease biomarkers. Continuous monitoring of several human metabolites can be addressed by using fully integrated and minimally invasive devices located in the sub-cutis, typically in the peritoneal region. This extends the techniques of continuous monitoring of glucose currently being pursued with diabetic patients.

Primary motor cortex and cerebellum are coupled with the kinematics of observed hand movements.

To find out in which detail the kinematics of observed movements is represented in the viewer's brain, we searched for brain areas displaying coherent magnetoencephalographic (MEG) activity with observed repetitive hand movements. Whole-scalp MEG signals were recorded from 10 right-handed young adults who observed repetitive 3-Hz right-hand flexion-extension movements performed by the experimenter. The coherence between the subject's MEG signals and the experimenter's index-finger acceleration was computed to index the level of actor-observer coupling.

The pace of prosodic phrasing couples the listener's cortex to the reader's voice.

We studied online coupling between a reader's voice and a listener's cortical activity using a novel, ecologically valid continuous listening paradigm. Whole-scalp magnetoencephalographic (MEG) signals were recorded from 10 right-handed, native French-speaking listeners in four conditions: a female (Exp1f) and a male (Exp1m) reading the same text in French; a male reading a text in Finnish (Exp 2), a language incomprehensible for the subjects, and a male humming Exp1 text (Exp 3). The fundamental frequency (f0) of the reader's voice was recorded with an accelerometer attached to the throat, and coherence was computed between f0 time-course and listener's MEG.

Development of cost-effective biocompatible packaging for microelectronic devices.

A cost-effective, miniaturized and biocompatible packaging method for medical devices is proposed, resulting in a small, soft and comfortable implantable package. Towards this end, the barrier materials and fabrication process for the individual die encapsulation are largely explored. We demonstrate that various common clean room materials are good candidates for preventing metal leaching into body.

Ultra-Thin Chip Package (UTCP) and stretchable circuit technologies for wearable ECG system.

A comfortable, wearable wireless ECG monitoring system is proposed. The device is realized using the combination of two proprietary advanced technologies for electronic packaging and interconnection : the UTCP (Ultra-Thin Chip Package) technology and the SMI (Stretchable Mould Interconnect) technology for elastic and stretchable circuits. Introduction of these technologies results in small fully functional devices, exhibiting a significant increase in user comfort compared to devices fabricated with more conventional packaging and interconnection technologies.

Hydrogel optimization towards fibroblast-friendly biomimetic coatings for implantable devices.

In this paper we present our investigations related to the optimization of hydrogels for the coating/packaging of biomedical devices. In order for hydrogels to be a viable interface/packaging material, a number of conditions must be met. We outline the tailoring of the mechanical properties of a HEMA based hydrogel by exploiting the influence of individual hydrogel components to achieve these requirements.

2-Scale topography dry electrode for biopotential measurements.

The design and fabrication of a novel 2-scale topography dry electrode using macro and micro needles is presented. The macro needles enable biopotential measurements on hairy skin, the function of the micro needles is to decrease the electrode impedance even further by penetrating the outer skin layer. Also, a fast and reliable impedance characterization protocol is described.

Tuning electrode impedance for the electrical recording of biopotentials.

Tuning the electrode impedance through the DC biasing of iridium oxide is presented. Impedance reduction of up to two orders of magnitude was reproducibly observed in 20 microm diameter microelectrodes at a biasing of 1V.

Within-canopy and ozone fumigation effects on delta13C and Delta18O in adult beech (Fagus sylvatica) trees: relation to meteorological and gas exchange parameters.

In this study, the effects of different light intensities either in direct sunlight or in the shade crown of adult beech (Fagus sylvatica L.) trees on delta13C and Delta18O were determined under ambient (1 x O3) and twice-ambient (2 x O3) atmospheric ozone concentrations during two consecutive years (2003 and 2004). We analysed the isotopic composition in leaf bulk, leaf cellulose, phloem and xylem material and related the results to (a) meteorological data (air temperature, T and relative humidity, RH), (b) leaf gas exchange measurements (stomatal conductance, g(s); transpiration rate, E; and maximum photosynthetic activity, A(max)) and (c) the outcome of a steady-state evaporative enrichment model.