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Featured Application: In-line implementation of microwave nondestructive testing and evaluation (MNDT&E) based on continuous wave radar operating in monostatic mode. A free-space microwave nondestructive testing and evaluation module is developed for the low-power, non-ionizing, contactless, and real-time characterization of doped composite thin-film materials in an industrial context. The instrumentation proposed is built up with a handled vector network analyzer interfaced with corrugated horn antennas to measure the near-field complex reflection S11 of planar prepreg composite materials in a roll-to-roll in-line production line. Dedicated modeling and calibrations routines are developed to extract the microwave conductivity from the measured microwave signal. Practical extraction of the radiofrequency (RF) conductivity of thin film prepreg composite materials doped with nano-powders is exemplary shown at the test frequency of 10 GHz. [ABSTRACT FROM AUTHOR]

Background: A population of >6 million people worldwide at high risk of Alzheimer's disease (AD) are those with Down Syndrome (DS, caused by trisomy 21 (T21)), 70% of whom develop dementia during lifetime, caused by an extra copy of β‐amyloid‐(Aβ)‐precursor‐protein gene (APP). This is in contrast to non‐DS patients who inherit just the duplication of the APP gene (DupAPP), who develop EOAD with 100% penetrance, raising hypotheses of potential other AD‐suppressing genes on chromosome 21. Method: Cerebral organoids were grown in vitro from isogenic T21 and normal induced‐pluripotent‐stem‐cells (iPSCs), as well as a DupAPP patient. Trisomy of chromosome‐21 gene BACE2 was corrected to disomy by CRISPR/Cas9 editing. Organoids were analysed histologically and organoid pools profiled for β‐amyloid secretion by immunoprecipitation‐mass spectrometry (IP‐MS). Tissue‐quantity‐independent peptide ratios were compared between organoid conditioned media (CM) and cerebrospinal fluid (CSF) from DS and age‐matched euploid individuals. Result: We found that T21, but not DupAPP, organoids secrete increased proportions of putative BACE2‐θ‐secretase (Aβ1‐19) and BACE2‐Aβ‐degrading protease (AβDP or Aβ‐clearance) products (Aβ1‐20 and Aβ1‐34) compared to isogenic normal controls. Increased ratios of BACE2‐related to BACE2‐unrelated anti‐amyloidogenic cleavages were reproduced in CSF of people with DS, mirroring organoid secretions. Finally, CRISPR/SpCas9‐HF1‐reduction of BACE2 (3 to 2 copies) in T21‐iPSC significantly decreased AβDP/amyloidogenic ratio and triggered early and accelerated AD‐like pathology in T21 organoids. The pathology consisted of insoluble amyloid plaque‐like deposits, fibrillar aggregates, pathologically altered Tau, and premature neuronal loss, and was preventable by an early application of a combination of β‐secretase and γ‐secretase inhibitors. Conclusion: Our combined data demonstrate the role of BACE2 as a genetic‐dose‐dependent AD‐suppressor in human brain, and organoid technology as a potential assay for screening for other protective genes and disease‐preventive drugs. [ABSTRACT FROM AUTHOR]

An electrochemical quartz crystal microbalance (EC-QCM) is a versatile gravimetric technique that allows for parallel characterization of mass deposition and electrochemical properties. Despite its broad applicability, simultaneous characterization of two electrodes remains challenging due to practical difficulties posed by the dampening from fixture parasitics and the dissipative medium. In this study, we present a dual electrochemical QCM (dual EC-QCM) that is employed in a three-electrode configuration to enable consequent monitoring of mass deposition and viscous loading on two crystals, the working electrode (WE) and the counter electrode (CE). A novel correction approach, along with a three standard complex impedance calibration, is employed to overcome the effect of dampening while keeping high spectral sensitivity. Separation of viscous loading and rigid mass deposition is achieved by robust characterization of the complex impedance at the resonance frequency. Validation of the presented system is done by cyclic voltammetry characterization of Ag underpotential deposition on gold. The results indicate mass deposition of 412.2 ng for the WE and 345.6 ng for the CE, reflecting a difference of the initially-present Ag adhered to the surface. We also performed higher harmonic measurements that further corroborate the sensitivity and reproducibility of the dual EC-QCM. The demonstrated approach is especially intriguing for electrochemical energy storage applications where mass detection with multiple electrodes is desired. [ABSTRACT FROM AUTHOR]

This paper reports the development of a new composite material as a matching medium for medical microwave diagnostic systems, where maximizing the microwave energy that penetrates the interrogated tissue is critical for improving the quality of the diagnostic images. The proposed material has several advantages over what is commonly used in microwave diagnostic systems: it is semi-flexible and rigid, and it can maximize microwave energy coupling by matching the tissue's dielectric constant without introducing high loss. The developed matching medium is a mirocomposite of barium titanate filler in polydimethylsiloxane (PDMS) in different weight-based mixing ratios. Dielectric properties of the material are measured using a Keysight open-ended coaxial slim probe from 0.5 to 10 GHz. To avoid systematic errors, a full dielectric properties calibration is performed before measurements of sample materials. Furthermore, the repeatability of the measurements and the homogeneity of the sample of interest are considered. Finally, to evaluate the proposed matching medium, its impact on a printed monopole antenna is studied. We demonstrate that the permittivity of the investigated mixtures can be increased in a controlled manner to reach values that have been previously shown to be optimal for medical microwave imaging (MWI) such as stroke and breast cancer diagnostic applications. As a result, the material is a good candidate for supporting antenna arrays designed for portable MWI scanners in applications such as stroke detection. [ABSTRACT FROM AUTHOR]

Development of future battery generations and quality control of current lithium-ion battery (LIB) systems require reliable techniques for the characterization of the complex dynamic processes in batteries. Electrochemical impedance spectroscopy (EIS) is an established tool for the electrochemical characterization of LIBs and the related ageing processes. Nevertheless, ensuring a reliable interpretation and validation of the impedance data remains challenging. Here we show how EIS complemented by microscopy data can be successfully used to follow battery ageing. We connect data from both methods in an electrochemical finite element model (FEM) to extract changes of intrinsic battery parameters, such as double layer capacitance, film resistance, exchange current density, and particle radii. Ageing mechanisms induced by cycling and temperature are investigated by EIS on commercial cells. Postmortem analysis of the anode and cathode electrodes is carried out to determine their initial micrometric and nanometric structure and to independently investigate morphological and electrical changes induced by ageing. While the obtained initial structural dimensions reduce drastically the number of adjustable parameters in the FEM model, which enables us to follow battery ageing processes noninvasively through the EIS spectra, the microscopy results of the aged cells prove independently the validity of the here presented approach. • Combination of EIS, microscopy and FEM to assess ageing in commercial LIBs. • FEM analyses of the EIS spectra gives direct access to physical and chemical parameters. • The approach allows for unambiguous extraction of ageing related parameters. • Microscopy reveals conductive subsurface features related with electrode degradation. • Non-invasive EIS measurements are confirmed independently by microscopy. [ABSTRACT FROM AUTHOR]

Down Syndrome (DS) is a complex chromosomal disorder, with neurological issues, featuring among the symptoms. Primary neuronal cells and tissues are extremely useful, but limited both in supply and experimental manipulability. To better understand the cellular, molecular and pathological mechanisms involved in DS neurodevelopment and neurodegeneration, a range of different cellular models have been developed over the years including human: mouse hybrid cells, transchromosomic mouse embryonic stem cells (ESCs) and human ESC and induced pluripotent stem cells derived from different sources. All of these model systems have provided useful information in the study of DS. Furthermore, different technologies to genetically modify or correct trisomy of either single genes or the whole chromosome have been developed using these cellular models. New techniques and protocols to allow better modeling of cellular mechanisms and disease processes are being developed and the use of cerebral organoids offers great promise for future research into the neural phenotypes seen in DS., (© 2020 Elsevier B.V. All rights reserved.)