Exploring Simple Particle-Based Signal Amplification Strategies in a Heterogeneous Sandwich Immunoassay with Optical Detection.

Heterogeneous sandwich immunoassays are widely used for biomarker detection in bioanalysis and medical diagnostics. The high analyte sensitivity of the current "gold standard" enzyme-linked immunosorbent assay (ELISA) originates from the signal-generating enzymatic amplification step, yielding a high number of optically detectable reporter molecules. For future point-of-care testing (POCT) and point-of-need applications, there is an increasing interest in more simple detection strategies that circumvent time-consuming and temperature-dependent enzymatic reactions. A common concept to aim for detection limits comparable to those of enzymatic amplification reactions is the usage of polymer nanoparticles (NP) stained with a large number of chromophores. We explored different simple NP-based signal amplification strategies for heterogeneous sandwich immunoassays that rely on an extraction-triggered release step of different types of optically detectable reporters. Therefore, streptavidin-functionalized polystyrene particles (PSP) are utilized as carriers for (i) the fluorescent dye coumarin 153 (C153) and (ii) hemin (hem) molecules catalyzing the luminol reaction enabling chemiluminescence (CL) detection. Additionally, (iii) NP labeling with hemin-based microperoxidase MP11 was assessed. For each amplification approach, the PSP was first systematically optimized regarding size, loading concentration, and surface chemistry. Then, for an immunoassay for the inflammation marker C-reactive protein (CRP), the analyte sensitivity achievable with optimized PSP systems was compared with the established ELISA concept for photometric and CL detection. Careful optimization led to a limit of detection (LOD) of 0.1 ng/mL for MP11-labeled PSP and CL detection, performing similarly well to a photometric ELISA (0.13 ng/mL), which demonstrates the huge potential of our novel assay concept.

[Isokinetic strength testing with different biomechanical demands on core strength: a comparison of military competitive athletes and soldiers with high occupational physical strain]. / Isokinetische Krafttestung bei unterschiedlichen biomechanischen Anforderungen an die Rumpfkraft ­ Vergleich von militärischen Leistungssportlern und Soldaten mit dienstlich bedingt hoher körperlicher Beanspruchung.

It is known that anthropometric data (weight, height, BMI, waist circumference and WHtR) and male gender are positively correlated with greater core strength, while age is negatively correlated. For competitive athletes with no significant differences in the anthropometric data stated above, there have hardly been any studies in which isometric core strength in a seated position is quantitatively compared among athletes in different sports. This study aimed to analyse different sports in well-trained athletes using military competitive sports as an example with regard to possible differences in core strength. For this purpose, Parachuting (n=28), Military Pentathlon (n=34) and Ski Platoon (n=38) groups were compared with regard to isokinetic core strength using dynamometry in seated position. In addition to the comparison of anthropometry and isokinetic results with descriptive statistics, ANOVA and Welch-ANOVA were used to compare the means of absolute and weight-adjusted core strength. It was shown that the Ski Platoon group had significantly higher flexion peak torque values than the Military Pentathlon and Parachuting groups. Even when adjusted for weight, the values were significantly higher than those measured in the Military Pentathlon group but not significantly higher than those in the Parachuting group. For extension peak torque, it was found that the Military Pentathlon group had significantly lower values than the Ski Platoon group and, in the weight-adjusted analysis, significantly lower values than the Parachuters. Using the example of competitive military sports, this study was able to show that there are significant differences in isokinetic core strength even among professional competitive athletes.This knowledge should be used to carry out detailed quantitative analyses of core strength, even in well-trained professional athletes, to find applications for prevention or to coordinate compensating exercises.

Origami single-end capacitive sensing for continuous shape estimation of morphing structures.

In this work, we propose a novel single-end morphing capacitive sensing method for shape tracking, FxC, by combining Folding origami structures and Capacitive sensing to detect the morphing structural motions using state-of-the-art sensing circuits and deep learning. It was observed through embedding areas of origami structures with conductive materials as single-end capacitive sensing patches, that the sensor signals change coherently with the motion of the structure. Different from other origami capacitors where the origami structures are used in adjusting the thickness of the dielectric layer of double-plate capacitors, FxC uses only a single conductive plate per channel, and the origami structure directly changes the geometry of the conductive plate. We examined the operation principle of morphing single-end capacitors through 3D geometry simulation combined with physics theoretical deduction, which deduced similar behavior as observed in experimentation. Then a software pipeline was developed to use the sensor signals to reconstruct the dynamic structural geometry through data-driven deep neural network regression of geometric primitives extracted from vision tracking. We created multiple folding patterns to validate our approach, based on folding patterns including Accordion, Chevron, Sunray and V-Fold patterns with different layouts of capacitive sensors using paper-based and textile-based materials. Experimentation results show that the geometry primitives predicted from the capacitive signals have a strong correlation with the visual ground truth with R-squared value of up to 95% and tracking error of 6.5 mm for patches. The simulation and machine learning constitute two-way information exchange between the sensing signals and structural geometry. By embedding part of the origami surface with morphing single-end capacitive sensors, FxC presents a unique solution that leverages both the mechanical properties of origami and sensing properties of capacitive sensing.

Embedding textile capacitive sensing into smart wearables as a versatile solution for human motion capturing.

This work presents a novel and versatile approach to employ textile capacitive sensing as an effective solution for capturing human body movement through fashionable and everyday-life garments. Conductive textile patches are utilized for sensing the movement, working without the need for strain or direct body contact, wherefore the patches can sense only from their deformation within the garment. This principle allows the sensing area to be decoupled from the wearer's body for improved wearing comfort and more pleasant integration. We demonstrate our technology based on multiple prototypes which have been developed by an interdisciplinary team of electrical engineers, computer scientists, digital artists, and smart fashion designers through several iterations to seamlessly incorporate the technology of capacitive sensing with corresponding design considerations into textile materials. The resulting accumulation of textile capacitive sensing wearables showcases the versatile application possibilities of our technology from single-joint angle measurements towards multi-joint body part tracking.