Active Elements Research Articles

Aggregation-induced emissive nanoarchitectures for luminescent solar concentrators.

Aggregation-induced emission (AIE), the phenomenon by which selected luminophores undergo the enhancement of emission intensity upon aggregation, has demonstrated potential in materials and biomaterials science, and in particular in those branches for which spectral management in the solid state is of fundamental importance. Its development in the area of luminescent spectral conversion devices like luminescent solar concentrators (LSCs) is instead still in its infancy. This account aims at summarizing relevant contributions made in this field so far, with a special emphasis on the design of molecular and macromolecular architectures capable of extending their spectral breadth to the deep-red (DR) and the near-infrared (NIR) wavelengths. Because of the many prospective advantages characterizing these spectral regions in terms of photon flux density and human-eye perception, it is anticipated that further development in the design, synthesis and engineering of advanced molecular and macromolecular DR/NIR-active AIE luminophores will enable faster and easier integration of LSCs into the built environment as highly transparent, active elements for unobtrusive light-to-electricity conversion.

Revolutionizing sample preparation: a novel autonomous microfluidic platform for serial dilution.

Dilution is a standard fluid operation widely employed in the sample preparation process of many bio(chemical) assays. It serves multiple essential functions such as sample mixing with certain reagents at specific dilution ratios, reducing sample matrix effects, bringing target analytes within the linear assay detection range, among many others. Traditionally, sample processing is performed in laboratory settings through manual or automated pipetting. When working in resource-limited settings, however, neither trained personnel nor proper laboratory equipment are available limiting the accessibility to high-quality diagnostic tests. In this work, we present a novel standalone and fully automated microfluidic platform for the stepwise preparation of serial dilutions without the need for any active elements. Stepwise dilution is achieved using the coordinated burst action of hydrophobic burst valves to first isolate a precisely metered volume from an applied sample drop and subsequently merge it with a prefilled diluent liquid. Downstream, expansion chambers are used to mix both reagents into a homogeneous solution. The dilution module was characterized to generate accurate and reproducible (CV < 7%) dilutions for targeted dilution factors of 2, 5 and 10×, respectively. Three dilution modules were coupled in series to generate three-fold logarithmic (log5 or log10) dilutions, with excellent linearity (R2 > 0.99). Its compatibility with whole blood was furthermore illustrated, proving its applicability for automating and downscaling bioassays with complex biological matrices. Finally, autonomous on-chip serial dilution was demonstrated by incorporating the self-powered (i)SIMPLE technology as a passive driving source for liquid manipulation. We believe that the simplicity and modularity of the presented autonomous dilution platform are of interest to many point-of-care applications in which sample dilution and reagent mixing are of importance.

Исследование влияния конструкции антипараллельной пары диодов с барьером Шоттки на потери преобразования гармонического смесителя 3-мм диапазона

This paper presents the design and principle of operation of a passive harmonic mixer in the 3-mm range (75-110 GHz), the active element of which is an antiparallel pair of Schottky barrier diodes (SBD). A theoretical analysis of the mixer operation was carried out. A technique for measuring conversion losses using a vector network analyzer is presented. The experimental results of a study of the dependence of the conversion losses of a harmonic mixer on the design of an antiparallel pair of DBSs are presented. The variable parameters of the antiparallel pair of diodes were the distance between the anode leads, the length of the anode lead and the diameter of the Schottky barrier contact. The dynamic range of the mixer is investigated.

Matrix effects on the magnetic properties of a molecular spin triangle embedded in a polymeric film.

Molecular triangles with competing Heisenberg interactions and significant Dzyaloshinskii-Moriya interactions (DMI) exhibit high environmental sensitivity, making them potential candidates for active elements for quantum sensing. Additionally, these triangles exhibit magnetoelectric coupling, allowing their properties to be controlled using electric fields. However, the manipulation and deposition of such complexes pose significant challenges. This work explores a solution by embedding iron-based molecular triangles in a polymer matrix, a strategy that offers various deposition methods. We investigate how the host matrix alters the magnetic properties of the molecular triangle, with specific focus on the magnetic anisotropy, aiming to advance its practical applications as quantum sensors.

Microstructural optimization of active element and reinforcement proportion of Si3N4/42CrMo joints

Micron-TiN particles and Ti powder were introduced into the AgCu powder filler to design a particle-reinforced composite filler. This TiN particle (TiNp) modified brazing material was adopted to reliably braze Si3N4 ceramics onto 42CrMo steel. The ratio of active element Ti and TiNp reinforcement was optimized according to the joints’ microstructuret. The reaction layer’s thickness close to the Si3N4 increased by decreasing the TiNp content or increasing the Ti content according to the microstructural observation. In addition, higher Ti content would result in more Cu-Ti intermetallics precipitation in the joint and Ti2N could be detected instead of TiNp when 10 wt.% of Ti was used.

Development of Ankle-Foot Orthosis Using Servo Motor with On-Off Control System for Drop-Foot

This research addresses the imperative need for a lightweight, compact, and efficient design of an Active Ankle-Foot Orthosis (AFO), with the potential for everyday use and enhancement of gait cycles in individuals with drop-foot. The proposed AFO employs a servo motor to generate ankle moments based on gait phase detection, ensuring low power consumption and a structurally lightweight configuration. The study encompasses a kinematic analysis of the gait mechanism utilizing a graphical method, facilitating the determination of the requisite force for the motor actuator. Additionally, a finite element approach is employed to assess the strength of linkages. The connecting mechanism utilizes Poly (methyl methacrylate) or PMMA board due to its lightweight nature and ease of fabrication. Based on the simulation result, the minimum safety factor of link bars was 1.8. While, based on the kinematic analysis, the minimum required torque that should be provided by the servo motor is 3.838 Nm. The servo motor serves as the active element within the AFO, and an on-off control system, driven by a rotary encoder detecting gait phases, governs the AFO's movement. Ankle joint angle readings obtained through AFO implementation exhibit values within the range of normal individuals. The entire control system operates with remarkably low power consumption, registering at 0.06 W over one running cycle. Based on these analyses, a prototype has been developed for further evaluation in patient trials, underscoring the potential efficacy and practicality of the proposed active AFO design.

Reactive extrusion additive manufacturing of a short carbon fiber thermosetting composite via active mixing

Reactive extrusion additive manufacturing (REAM) is a recently developed process that utilizes reactive thermoset resin-hardener systems that are mixed inside a shearing element, deposited layer by layer to form a structure, and cured in-situ without external energy. An externally powered active mixing element was developed and used to demonstrate REAM with a highly viscous resin that was filled with 10 wt% chopped carbon fibers. This was achieved by adding fumed silica and increasing the temperature of the fiber-resin mixture to enable effective in-situ mixing while maintaining shape retention upon deposition. Tensile properties of fiber-reinforced and reference REAM parts were measured and explained using their fiber alignment and length distribution. Finally, a mechanics model was utilized to determine the optimal fiber content for strength and stiffness, considering the degradation of fiber length at higher volume fractions due to the mixing.

Impact of green technology on content of bioactive components in eggplant

Background: Green manure fertilizers play a great role in increasing fertility, soil quality and nutrient supply of crops. Additionally, biofertilizers with various strains of fungi increase the availability of biologically active elements for plants. The combined use of green manure and biological fertilizers is of great interest for increasing the content of bioactive components and the functional activity of food.Objective: The main goal of the research was to evaluate the effectiveness of the combined use of various green manure plants and biological fertilizers on the content of bioactive components (total sugars, dry matter, ascorbic acid, B vitamins and macro and micronutrients) in eggplants in the context of increasing food functionality. Methods: Plants from the Fabaceae L. family (beans, peas, and soybeans) were used as green manure. The experiment was set up by a block-randomized method in 4 replications. Biofertilizers were applied at the beginning of intensive growth and at the beginning of the fruiting stage. Soil analysis and content of macro- and micronutrients (Potassium, Calcium, Magnesium, Phosphate, and Iron) in eggplant fruits were done with a spectrophotometry system. Results: Green manure crops and their combination with biofertilizers contributed to an increase in content of vitamin C, Vitamin B1, macro-micronutrients (calcium, potassium, phosphorus, magnesium, and Iron) in all treatment options. The higher yield was recorded in variants with the use of Organit N’ and ‘Organit P’.Conclusion: The concurrent application of green manure and biofertilizers leads to an enhancement of the functional properties of eggplant fruits. This improvement is attributed to the enhanced soil quality and increased levels of nutrients and bioactive compounds, including vitamins C and B1.The positive effect of the applied technology on the eggplant fruits’ qualitative particularities, productivity and functionality creates a basis for recommending the use of tested fertilizers to producers and will serve as a starting point for evaluating the proposed green technology on other crops.Keywords: soya, bean, pea, vitamin C, vitamin B 1

NANOSTRUCTURED POROUS SILICA GLASS AS PROMISING MATERIAL FOR SENSORS (Review)

The work is devoted to the study of additional possibilities of using slotted silicate glasses in sensors. These substances are promising because they are chemically stable, mechanically durable and have a very wide inner surface. But due to the very large energy gap, they can glow only in the far ultraviolet range, and, moreover, the intrinsic electrical resistance of standard-sized samples turns out to be quite large. This hinders the direct use of slotted glass in the development of both luminescent and resistive type sensors. However, due to the peculiarities of their structure, these glasses can be used as a matrix for the formation of ensembles of nanoparticles of suitable substances, which are able to form a conductive phase inside the porous sample, which will significantly reduce its resistance, or glow in the visible part of the spectrum, while changing the parameters of its luminescence when the properties change the environment The properties of slotted silicate glasses are systematized and methods of formation of ensembles of nanoparticles of substances suitable for use as an active element of some transmitters are described.

Active moss biomonitoring of airborne potentially toxic elements in recreational areas of Moscow.

Active biomonitoring using the moss bag technique was applied to examine the atmospheric deposition of potentially toxic and other elements in recreational areas of Moscow. Moss bags with Sphagnum girgensohnii were placed in the territory of seven parks (Losiny Ostrov, Victory Park, Ostankino, Sokolniki, Izmailovo, Kuzminki-Lyublino, Tsaritsyno) at three locations in each park from June to September 2018. The content of 32 chemical elements: Na, Mg, Al, Cl, K, Ca, Sc, V, Mn, Fe, Co, Zn, As, Br, Rb, Sr, Mo, Sb, Cs, Ba, La, Sm, Tb, Hf, Ta, W, Au, Th, U, Cu, Pb, and Cd in moss samples was determined by instrumental neutron activation analysis and atomic absorption spectrometry. After a 3-month exposure period, high uptake of Sb, U, Th, Sm, La, Mo, Zn, Co, Fe, V, Sc, etc. was observed in some of the moss samples. The physiologically active elements Cl and K and alkaline elements Rb and Cs were depleted from the moss tissue during the exposure. The high accumulation of Zn, Pb, Cu, Co, V, and Sb in moss samples evidenced an anthropogenic impact on the parks, mainly associated with road traffic. To determine the level of pollution, a set of environmental indices was calculated: contamination factor (CF), enrichment factor (EF), total pollution index (TPI), and relative accumulation factor (RAF). The highest RAF values were obtained for Sb on the territory of all parks. According to EF, the samples were enriched in Al, Fe, U, Pb, Cd, Au, Sb, Th, and Ta. High CF values were obtained for sites in Losiny Ostrov, Izmailovo, Tsaritsyno, and Kuzminki-Lyublino located close to roads. According to TPI, the level of air pollution on the territory of the abovementioned parks varied from moderate to high. To identify the major sources of pollution, correlation analysis and principal component analysis were applied.

MYB3R-mediated and cell cycle-dependent transcriptional regulation of a tobacco ortholog of SCARECROW-LIKE28 in synchronized cultures of BY-2 cells.

Although it is well known that hierarchical transcriptional networks are essential for various aspects of plant development and environmental response, little has been investigated about whether and how they also regulate the plant cell cycle. Recent studies on cell cycle regulation in Arabidopsis thaliana identified SCARECROW-LIKE28 (SCL28), a GRAS-type transcription factor, that constitutes a hierarchical transcriptional pathway comprised of MYB3R, SCL28 and SIAMESE-RELATED (SMR). In this pathway, MYB3R family proteins regulate the G2/M-specific transcription of the SCL28 gene, of which products, in turn, positively regulate the transcription of SMR genes encoding a group of plant-specific inhibitor proteins of cyclin-dependent kinases. However, this pathway with a role in cell cycle inhibition is solely demonstrated in A. thaliana, thus leaving open the question of whether and to what extent this pathway is evolutionarily conserved in plants. In this study, we conducted differential display RT-PCR on synchronized Nicotiana tabacum (tobacco) BY-2 cells and identified several M-phase-specific cDNA clones, one of which turned out to be a tobacco ortholog of SCL28 and was designated NtSCL28. We showed that NtSCL28 is expressed specifically during G2/M and early G1 in the synchronized cultures of BY-2 cells. NtSCL28 contains MYB3R-binding promoter elements, so-called mitosis-specific activator elements, and is upregulated by a hyperactive form of NtmybA2, one of the MYB3R proteins from tobacco. Our study indicated that a part of the hierarchical pathway identified in A. thaliana is equally operating in tobacco cells, suggesting the conservation of this pathway across different families in evolution of angiosperm.

Software Defined Radio for GNSS Radio Frequency Interference Localization.

The use of radio direction finding techniques in order to identify and reject harmful interference has been a topic of discussion both past and present for signals in the GNSS bands. Advances in commercial off-the-shelf radio hardware have led to the development of new low-cost, compact, phase coherent receiver platforms such as the KrakenSDR from KrakenRF whose testing and characterization will be the primary focus of this paper. Although not specifically designed for GNSSs, the capabilities of this platform are well aligned with the needs of GNSSs. Testing results from both benchtop and in the field will be displayed which verify the KrakenSDR's phase coherence and angle of arrival estimates to array dependent resolution bounds. Additionally, other outputs from the KrakenSDR such as received signal strength indicators and the angle of arrival confidence values show strong connections to angle of arrival estimate quality. Within this work the testing that will be primarily presented is at 900 MHz, with results presented from a government-sponsored event where the Kraken was tested at 1575.42 MHz. Finally, a discussion of calibration of active antenna arrays for angle of arrival is included as the introduction of active antenna elements used in GNSS signal collection can influence angle of arrival estimation.

New Materials for Memory Applications by Atomic Layer Deposition

The architectures of integrated logic and memory devices have shifted from 2D to 3D layouts, enabling a continued scaling of device densities. Atomic layer deposition (ALD) allows the conformal deposition of thin films with sub-nm thickness control on high aspect ratio 3D structures. ALD has become the technique of choice for the synthesis of an increasing number of materials in advanced logic and memory devices. In the first part of this presentation, we briefly review some of the key ALD processes which enable the fabrication of state-of-the-art 3D-NAND and 2D-DRAM. Next, we present the ALD of emerging ferroelectric HfZrO developed at ASM in industrial scale ALD reactors. HfO2 has been established as the preferred gate oxide material for logic devices for almost two decades. The recent discovery of ferroelectricity in HfO2 has opened new applications for HfO2-based materials as active memory elements in DRAM and 3D-NAND. We show that ALD La:HfZrO can achieve high polarization field (2Pr > 60 uC/cm2) and high endurance (> 107 cycle) by applying interface engineering schemes and optimizing deposition processes and film composition (i.e. Hf/Zr ratio, dopant concentration).

Printable 2D Materials for Thin Film Batteries and Supercapacitors

Two-dimensional transition metal oxide (TMO) nanosheets are the oxide equivalents of the well-known 2D graphene phase. Compared with graphene, a much wider range of compositions, structures and properties can be realized from TMOs. 2D metal oxides typically have thicknesses of 0.45-2.5 nm, and lateral dimensions between 50 nm and tens of micrometers. Interestingly, although they are oxides, they are very flexible and bendable owing to their thinness. So far, several dozen nanosheet phases have been reported in literature, but many more compositions are possible.Dispersions of TMO nanosheets can be made following one of several solution-phase strategies. Often, they are prepared by chemical delamination of isomorphous layered metal oxide parent phases. In a few cases, the 2D TMO phase can be grown directly bottom-up from an aqueous chemical solution. Either way, the resulting colloidal solutions of 2D single crystal nanosheets can serve in subsequent process step as the basis of a chemical ink suitable for ink jet printing on arbitrary substrates like paper, silicon or flexible polymers. Redox-active nanosheets may also be used as active electrode elements for micro-supercapacitors and flexible thin film batteries.For example, 2D MnO2 nanosheets that are isomorphous to the layered δ-MnO2 (birnessite) phase exhibit high pseudocapacance owing to their beneficial redox properties, relatively high in-plane conductivity and very large specific surface area. Ink-jet printed 2D MnO2 based thin film microsupercapacitors were realized that showed comparable performance with other state of the art systems. However, undoped MnO2 nanosheets exhibit relatively low sheet conductivity. Substitutional doping of 3d metal ions (Co, Fe and Ni) into MnO2 nanosheets improved the volumetric energy density to 1.13 mWh cm−3 at a power density of 0.11 W cm−3. The dopants introduced new electronic states near the Fermi level which enhanced the electronic conductivity within the nanosheets and contributed to the further formation of redox-active 3d surface states. Among these, Fe-doped MnO2 exhibited a significant increase in the carrier density and conductivity, while doping with Ni or Co had a much more limited effect on conductivity. These Fe-doped MnO2 nanosheet-based microsupercapacitors show long cycle life and bendability without performance loss on flexible plastic substrates [1].Following a similar inkjet printing approach, thin film cathodes for Li ion batteries were made using V2O5 nanosheets as charge-storage medium. In this case the conductivity of the electrode was improved by addition of highly conductive 2D MXene (Ti3C2) platelets derived from the parent MAX phase Ti3AlC2. Using LiPF6 in EC/DMC as electrolyte, the hybrid V2O5-MXene electrodes showed a high capacity of 321 mAh g-1 at 1C, 112 mAh g-1 at 10.5C and 92% capacity retention after ~700 cycles [2].As third example, an all inkjet-printed MXene/graphene oxide (GO)/MXene thin film supercapacitor with GO as solid electrolyte phase will be discussed. Here, free water molecules trapped between GO layers enabled proton transport through the electrolyte. The as-made capacitor showed high areal capacitance, good cyclability and power densities comparable with state of the art printed supercapacitors. The specific capacitance could be increased further by addition of liquid electrolyte [3].[1] Y. Wang, Y.-Z. Zhang, Y.-Q. Gao, G. Sheng, J.E. ten Elshof, Nano Energy 68 (2020) 104306.[2] Y. Wang, T. Lubbers, R. Xia, Y.-Z. Zhang, M. Mehrali, M. Huijben, J.E. ten Elshof, J. Electrochem. Soc. 168 (2021) 020507[3] Y. Wang, M. Mehrali, Y.-Z. Zhang, M.A. Timmerman, B.A. Boukamp, P.-Y. Xu, J.E. ten Elshof, Energy Storage Mater. 36 (2021) 318-325.

Carbon Dioxide Reduction on Alloyed Galinstan

Solar powered electrochemical CO₂ reduction to disposable products is presently being developed as one of negative carbon emission technologies1. State-of-the-art electrocatalysts are mainly developed for the CO2 reduction to hydrogen rich products or chemical feedstock materials while for the above-mentioned application solid carbon-rich products are desired (best pure carbon). Even though the formation of solid products is sometimes observed on catalysts (coking effect), this usually leads to an undesirable irreversible deactivation of their solid interfaces.Thus, the development of next generation CO2 electrocatalysts is demanded based on liquid metal alloys such as galinstan (GaInSn). The advantage of using liquid phase electrodes is to eliminate coking and coarsening limitations that are associated with solid catalysts. For example, it has been reported that ceria-supported liquid galinstan can electrochemically produce carbonaceous materials from CO2 gas2. This shows, that doping with additional active elements can change the CO2 reduction activity of GaInSn in the direction of other desired products.Our work investigates the activity of galinstan for the electroreduction of CO2 depending on alloying with additional metals (such as Ce, Ag, Pb). While pure GaInSn shows a predominant activity for the formation of C1 products (CO, HCOOH) in DMF/H2O electrolyte, we are mainly interested in the formation of solid carbon or oxalate. Therefore, our investigations aim at finding suitable modifications of GaInSn that achieve high selectivity for these products. Electrochemical analysis coupled with in-line gas chromatography and in-line mass spectroscopy are used to characterize the reactivity. Furthermore, the influence of the water content of the organic electrolyte on the product selectivity will be investigated. In particular, to suppress the observed low hydrogen evolution as a by-product even more efficiently. May, M. M.; Rehfeld, K., Negative Emissions as the New Frontier of Photoelectrochemical CO2 Reduction. Advanced Energy Materials 2022, 2103801.Esrafilzadeh, D.; Zavabeti, A.; Jalili, R.; Atkin, P.; Choi, J.; Carey, B. J.; Brkljača, R.; O’Mullane, A. P.; Dickey, M. D.; Officer, D. L.; MacFarlane, D. R.; Daeneke, T.; Kalantar-Zadeh, K., Room Temperature CO2 Reduction to Solid Carbon Species on Liquid Metals Featuring Atomically Thin Ceria Interfaces. Nature Communications 2019, 10 (1), 865. Figure 1

Temperature Dependent EXAFS to Address Functional Mechanisms in Battery Materials

Increasing the contribution of renewable energy sources is necessary to meet the fast increase of global energy needs and match the CO2 reduction targets. In order to address these challenges, intensive research efforts are ongoing both in energy harvesting and storage technologies such as solar panels, fuel cells, supercapacitors and batteries. The latter are required to match the energy demand and supply; in fact, batteries are by far the most ubiquitous energy storage technology currently employed.Synchrotron x-ray spectroscopies have played a key role in the continuous development and breakthroughs in battery science, thanks to their capability to provide accurate information on electronic structure of the redox active element, local structure, and morphological information. In particular, X-ray absorption spectroscopy (XAS) is more and more employed for addressing battery materials [1]. Generally, XAS studies on battery materials are performed at a single temperature as a function of charge, to access information on the electrochemical behavior and charge transfer mechanism during the intercalation or deintercalation process. However, the fact that the charging/discharging process is expected to have direct influence on the bond length characteristics, strength and disorder, it is important to perform temperature dependence measurements to find a realistic correlation between the local structure and the battery characteristics. Indeed, temperature-dependent studies quantitatively allow to discriminate in between static and dynamic disorder, and to have direct access to the local force constant between the atom pairs. Here the interest of performing temperature dependent extended X-ray absorption fine structure (EXAFS) studies is highlighted by exploiting several examples. In Li and Mn-rich NMC cathodes temperature-dependent EXAFS investigation revealed the evolution of the lattice rigidity which directly affects the reversible anionic redox contribution [2-3]. Similar studies on Ti based MXene-type [4], NaxCoO2 [5], and V2O5 [6] electrode materials underline the importance of the local atomic correlations as limiting factor in the ion diffusion in battery materials.

Matrix metalloproteinase 9: A Representative Diagnostic Biomarker for Mesial Temporal Lobe Epilepsy with Hippocampal Sclerosis

Matrix metalloproteinase 9 is a proteolytic enzyme which is recently one of the more often studied biomarkers. Its possible use as a biomarker of neuronal damage in stroke, heart diseases, tumors, multiple sclerosis, and epilepsy is being widely indicated. In epilepsy, MMP-9 is suggested to play a role in epileptic focus formation and in the stimulation ofseizures. The increase of MMP- 9 activity in the epileptic focus was observed both in animal models and in clinical studies. MMP-9 contributes to formation of epileptic focus,for example, by remodeling ofsynapses. Its proteolytic action on the elements of blood-brain barrier and activation of chemotactic processes facilitates accumulation of inflammatory cells and induces seizures. Also, modification of glutamatergic transmission by MMP-9 is associated with seizures.

Production of Nitrogen‐Alloyed Stainless Steels in Argon Oxygen Decarburization Converter: Kinetics and Modeling of Nitrogenation and Denitrogenation

The study aims to comprehend the behavior of nitrogen in the argon oxygen decarburization (AOD) process during the production of nitrogen‐alloyed stainless steels, where the precise adjustment of nitrogen content plays a crucial role in enhancing productivity. Furthermore, the objective is to investigate the rate of change in nitrogen content when blowing a mixture of nitrogen and argon, instead of using pure nitrogen or argon alone. Hence, both nitrogenation and denitrogenation cases are examined, and kinetic models are developed. While solution thermodynamics can predict the final nitrogen content, the kinetics are influenced by the gas flow rate, steel temperature and composition, and levels of the surface active elements in the steel. By integrating a previously developed thermodynamic equilibrium equation with the kinetic models, nitrogen contents in the range of 0.150–0.400% can be reliably predicted. Consequently, the equations can be applied to predict nitrogen content during both the nitrogenation and denitrogenation stages in the reduction and desulfurization phases of the AOD process.

Tailored support for preparing employees with cancer to return to work: Recognition and gaining new insights in an open atmosphere.

A considerable number of cancer survivors face difficulties in returning to work (RTW). More insight is needed on how to support employees shortly after cancer treatment and help them make the transition back to work. To gain an in-depth understanding of how and under what circumstances a Cancer & Work Support (CWS) program, which assists sick-listed employees with cancer in preparing their RTW, works. A qualitative design was used, inspired by Grounded Theory and Realist Evaluation components. Semi-structured interviews were conducted with RTW professionals (N = 8) and employees with cancer (N = 14). Interview themes covered experiences with CWS, active elements, and impeding and facilitating factors. Interviews were transcribed and analyzed by multiple researchers for contextual factors, active mechanisms, and the outcomes experienced. Respondents experienced the support as human centered, identifying two characteristics: 'Involvement' ('how' the support was offered), and 'Approach' ('what' was offered). Four themes were perceived as important active elements: 1) open connection and communication, 2) recognition and attention, 3) guiding awareness and reflection, and 4) providing strategies for coping with the situation. Variation in the experiences and RTW outcomes, appeared to be related to the personal, medical and environmental context. Both professionals and employees really appreciated the CWS because it contributed to RTW after cancer. This research shows that not only 'what' RTW professionals do, but also 'how' they do it, is important for meaningful RTW support. A good relationship in an open and understanding atmosphere can contribute to the receptiveness (of employees) for cancer support.

Design of a memristor-based neuron for spiking neural networks

The primary objective of neuromorphic system design is to surpass limitations in energy efficiency and scaling of classical von Neumann computing systems, through the emulation of animals’ nervous systems. This is achieved by conducting calculations in memory and encoding information in impulse signals, ultimately leading to enhanced adaptability. Adhering to these principles allows for improved energy efficiency and computational speed when solving machine learning problems, encompassing biomedical applications, embedded systems, and cyber-physical systems. Functional blocks modeling the main elements of the central nervous system, namely neurons and synapses, offer an advantage in implementing learning on a chip. The use of memristive electronic components, capable of altering their resistance based on the charge flowing through them, opens new doors for hardware implementation of neuromorphic systems. These devices offer advantages over conventional transistor electronics with respect to power consumption, component density, and performance. To achieve optimal results, the architecture of neuromorphic systems should be optimized at the device level. Memristive components are utilized to create neurons and synapses. This thesis is specifically focused on producing memristive neuron-like spike signal generators. Previously, memristive neurons were crafted using a locally active element comprised of vanadium dioxide VO2, which incorporated a negative differential resistance section of the IV-curve. One of the recent advancements in this field is a spiking neuron with frequency adaptation [1]. Its drawbacks, however, involve separating the memristive and locally active elements physically, resulting in higher energy consumption and decreased integration quality. In [2], models of memristive neurons with minimal complexity are introduced, which incorporate the Leaky Integrate-and-Fire principle. However, the circuits presented require the application of negative voltage pulses to a DC battery to reset the memristor to its initial high-resistance state. This limitation restricts its sphere of application in neuromorphic systems. This paper proposes a model of a neuron that overcomes these limitations by using the negative differential resistance of the memristor to generate spikes, along with integrating supplementary circuit components to sustain the resistive switching cycles of the memristor. The neuron model under consideration is implemented using the NI Multisim 14.2 SPICE environment and has been verified in the NI LabVIEW 2022 tool environment. The equations of the modified model of the generalized mean metastable switch of the memristor with self-directed channel [3] represent the current in the memristor branch of the neuron equivalent circuit. The simplicity of the equivalent circuitry of the neuron is attained by merging all the nonlinear features necessary for spike generation into one memristor model. The experimental phase of the study employed obtainable memristors from Knowm Corporation and the laboratory prototyping platform NI ELVIS III. The investigation of the proposed neuron model was accomplished through the application of sinusoidal and rectangular input signals. The refractory time of the neuron model was calculated. The chosen stack of computer simulation and semi-natural modeling technologies is applied within the research-driven design concept of electronic devices. This approach considers the importance of refining the properties and identification of the design object or its components during the development cycle.