Limited Lifetime Research Articles

Phototherapy for atopic dermatitis: A survey of European practice.

Phototherapy is used to treat atopic dermatitis (AD). Evidence for its efficacy, impact on quality of life, cost-effectiveness and short- and long-term safety with real-life usage is weak. We established a taskforce to examine how phototherapy is currently being used as a treatment for AD across the United Kingdom and Europe to inform our understanding and guide future research into management of patients with AD using UV-based phototherapies. An anonymous electronic multiple-response survey exploring phototherapy prescribing practices and experience of phototherapy modalities was developed by the study authors and sent to members of phototherapy networks from the United Kingdom and Europe. Responses were received between February and July 2021. About 144 respondents from 27 European countries completed the survey. NBUVB was the most widely used [n = 138 (96%)]. Home-based NBUVB was available in 8/27 countries (25/144 respondents, 17%). Oral psoralen-UVA (PUVA) was more widely available than bath PUVA (n = 106, 74% vs. n = 60, 42%) and used mainly in adult patients. 49/144 (34%) of respondents had access to UVA1. Phototherapy would be considered instead of systemic treatment in 96% of adults and 82% of children for NBUVB, versus 40% of adults and 3% of children for PUVA. Starting doses, standard dosing increments, length of treatment courses, lifetime limits for treatments and thresholds for performing annual skin assessments varied between responders. NBUVB was the most widely used phototherapy for AD in adult and paediatric patients, while PUVA and UVA1 were less used. Prescribing practices varied considerably, highlighting the lack of consensus practice in many different aspects of phototherapy for the treatment of AD in children and adults. This indicates that further studies are required to determine optimal phototherapeutic regimens for AD and informs our understanding of parameters that should be included in future high-quality randomized controlled trials (RCT) of phototherapy.

Unraveling Degradation Processes and Strategies for Enhancing Reliability in Organic Light-Emitting Diodes

Organic light-emitting diodes (OLEDs) have emerged as a promising technology for various applications owing to their advantages, including low-cost fabrication, flexibility, and compatibility. However, a limited lifetime hinders the practical application of OLEDs in electronic devices. OLEDs are prone to degradation effects during operation, resulting in a decrease in device lifetime and performance. This review article aims to provide an exciting overview of OLED degradation effects, highlighting the various degradation mechanisms. Subsequently, an in-depth exploration of OLEDs degradation mechanisms and failure modes is presented. Internal and external processes of degradation, as well as the reactions and impacts of some compounds on OLED performance, are then elucidated. To overcome degradation challenges, the review emphasizes the importance of utilizing state-of-the-art analytical techniques and the role of these techniques in enhancing the performance and reliability of OLEDs. Furthermore, the review addresses the critical challenges of lifetime and device stability, which are crucial for the commercialization of OLEDs. This study also explores strategies to improve OLEDs’ lifetime and stability, such as using barrier layers and encapsulation techniques. Overall, this article aims to contribute to the advancement of OLED technology and its successful integration into diverse electronic applications.

Toward Commercialization of Mechanical Energy Harvester: Reusable Triboelectric Nanogenerator Based on Closed-Loop Mass Production of Recyclable Thermoplastic Fluoropolymer with Microstructures

Triboelectric nanogenerators (TENGs) have been considered a promising energy harvester. However, the wear-induced limited lifetime of the surface structure on fluoropolymeric contact layers of the TENG has been a critical issue in its commercialization because surface structures on soft engineering materials play a key role in enhancing the generation of electricity in TENGs. After the surface structure on the polymeric contact layer is worn out, the layer is required to be replaced with a new one with intact surface structures to reenhance the degraded output performance of the TENG. Herein, injection molding-assisted mass production is applied to manufacture micro/nanoscale surface-structured perfluoroalkoxy alkane (PFA) contact layers, which exhibit easily replaceable but fully recyclable characteristics. The optimized production time is shorter than 1 min, and the unit cost under $1 of manufacturing surface-structured PFA contact layers is achieved. TENG with the fabricated PFA contact layer can generate over 620 V of voltage and up to 12.4 mW of power from solid-solid contact and separation when the contact area is 5 cm × 5 cm and the contact frequency is 10 Hz. The manufactured PFA contact layer can be facilely replaced with a new one before the end of its lifetime to maintain the electrical output of the TENG, and the postused one can be fully recycled via reprocessing as the material for injection molding. Consequently, a tile-floor-based TENG is proposed as a proof-of-concept demonstration to show environmentally friendly and closed-loop production of TENGs.

Experiments in micro-patterned model membranes support the narrow escape theory

The narrow escape theory (NET) predicts the escape time distribution of Brownian particles confined to a domain with reflecting borders except for one small window. Applications include molecular activation events in cell biology and biophysics. Specifically, the mean first passage time bar{tau } can be analytically calculated from the size of the domain, the escape window, and the diffusion coefficient of the particles. In this study, we systematically tested the NET in a disc by variation of the escape opening. Our model system consisted of micro-patterned lipid bilayers. For the measurement of bar{tau }, we imaged diffusing fluorescently-labeled lipids using single-molecule fluorescence microscopy. We overcame the lifetime limitation of fluorescent probes by re-scaling the measured time with the fraction of escaped particles. Experiments were complemented by matching stochastic numerical simulations. To conclude, we confirmed the NET prediction in vitro and in silico for the disc geometry in the limit of small escape openings, and we provide a straightforward solution to determine bar{tau } from incomplete experimental traces.

Design and Analysis of High Power Density On-Board Charger with Active Power Decoupling Circuit for Electric Vehicles

This article presents a design method for the active power decoupling (APD) circuit of a PFC converter for high power density on-board chargers (OBCs) utilized in electric vehicles (EVs). The utilization of electrolytic capacitors to mitigate power ripple at the input is a common practice in PFC converters. However, these electrolytic capacitors are associated with issues such as limited lifetime and low current ratings, resulting in a significant portion of the OBC’s volume being occupied by them. To address these challenges and achieve power density, the relationship between the power of the APD circuit and DC-link voltage is derived, and a design method for the APD circuit for high power density is proposed. The feasibility of this design approach is validated through the PFC converter prototype designed for 6.6 kW OBC. Consequently, a substantial volume reduction of 19.7% is realized when compared to the utilization of the electrolytic capacitor approach, and a reduction of 36.2% is achieved in comparison to the conventional APD design method. This reduction in volume proves advantageous for fulfilling the requisites of high power density OBCs.

Diffusion limited aggregation, resetting and large deviations of Brownian motion

Models of fractal growth commonly consider particles diffusing in a medium and that stick irreversibly to the forming aggregate when making contact for the first time. As shown by the well-known diffusion limited aggregation (DLA) model and its generalisations, the fractal dimension is sensitive to the nature of the stochastic motion of the particles. Here, we study the structures formed by finite-lived Brownian particles, i.e. particles constrained to find the aggregate within a prescribed time, and which are removed otherwise. This motion can be modelled by diffusion with stochastic resetting, a class of processes which has been widely studied in recent years. In the short lifetime limit, a very small fraction of the particles manage to reach the aggregate. Hence, growth is controlled by atypical Brownian trajectories, that move nearly in straight line according to a large deviation principle. In d dimensions, the resulting fractal dimension of the aggregate decreases from the DLA value and tends to 1, instead of increasing to d as expected from ballistic aggregation. In the zero lifetime limit one recovers the non-trivial model of ‘aggregation by the tips’ proposed long ago by R. Jullien [J. Phys. A: Math. Gen. 19, 2129 (1986)].

Size exclusion chromatography for screening yeastolate used in cell culture media.

Yeastolate is often used as a media supplement in industrial mammalian cell culture or as a major media component for microbial fermentations. Yeastolate variability can significantly affect process performance, but analysis is technically challenging because of its compositional complexity. However, what may be adequate for manufacturing purposes is a fast, inexpensive screening method to identify molecular variance and provide sufficient information for quality control purposes, without characterizing all the molecular components. Here we used Size Exclusion Chromatography (SEC) and chemometrics as a relatively fast screening method for identifying lot-to-lot variance (with Principal Component Analysis, PCA) and investigated if Partial Least Squares, PLS, predictive models which correlated SEC data with process titer could be obtained. SEC provided a relatively fast measure of gross molecular size hydrolysate variability with minimal sample preparation and relatively simple data analysis. The sample set comprised of 18 samples from 12 unique source lots of an ultra-filtered yeastolate (10kDa molecular weight cut-off) used in a mammalian cell culture process. SEC showed significant lot-to-lot variation, at 214 and 280nm detection, with the most significant variation, that correlated with process performance, occurring at a retention time of ∼6min. PCA and PLS regression correlation models provided fast identification of yeastolate variance and its process impact. The primary drawback is the limited column lifetime (<300 injections) caused by the complex nature of yeastolate and the presence of zinc. This limited long term reproducibility because these age-related, non-linear changes in chromatogram peak positions and shapes were very significant.

Improving the electrocatalytic hydrogen evolution reaction through a magnetic field and hydrogen peroxide production co-assisted Ni/Fe3O4@poly(3,4-ethylene-dioxythiophene)/Ni electrode

The production of high-purity hydrogen using surplus electrical energy and abundant water resources has immense potential in mitigating the fossil energy crisis, as hydrogen fuel holds clean, pollution-free, and high-energy characteristics. However, the practical application of large-scale hydrogen production from water faces challenges such as high overpotentials, sluggish dynamics, and limited electrocatalytic lifetime associated with the hydrogen evolution reaction (HER). Here, we fabricated the sandwich structure of a Ni/Fe3O4@poly(3,4-ethylene-dioxythiophene)/Ni (Ni/Fe3O4@PEDOT/Ni) electrode and employed a strong magnet to obtain a magnetic electrode capable of achieving high-activity and durability for HER. Electrochemical analysis reveals that the activated magnetic electrode displays a significantly reduced overpotential and an extended electrocatalytic lifetime of 10 days. Notably, its stability is higher than that of non-magnetic Ni/Fe3O4/Ni and Ni/Fe3O4@PEDOT/Ni electrodes, primarily due to the support from magnetic force and the protective PEDOT layer. Moreover, the minute atomized droplets can form the H2O2 species in a moist environment, facilitating the formation of the NiO layer on the Ni surface, which plays a vital role in boosting catalytic activity. In conclusion, our magnetic electrode strategy, combined with the emergence of the NiO layer, offers valuable insights for the development of advanced HER electrodes.

High-resolution nanoscale NMR for arbitrary magnetic fields

Nitrogen vacancy (NV) centers are a major platform for the detection of nuclear magnetic resonance (NMR) signals at the nanoscale. To overcome the intrinsic electron spin lifetime limit in spectral resolution, a heterodyne detection approach is widely used. However, application of this technique at high magnetic fields is yet an unsolved problem. Here, we introduce a heterodyne detection method utilizing a series of phase coherent electron nuclear double resonance sensing blocks, thus eliminating the numerous Rabi microwave pulses required in the detection. Our detection protocol can be extended to high magnetic fields, allowing chemical shift resolution in NMR experiments. We demonstrate this principle on a weakly coupled 13C nuclear spin in the bath surrounding single NV centers, and compare the results to existing heterodyne protocols. Additionally, we identify the combination of NV-spin-initialization infidelity and strong sensor-target-coupling as linewidth-limiting decoherence source, paving the way towards high-field heterodyne NMR protocols with chemical resolution.

Towards the Structural Health Monitoring of Bridges Using Wireless Sensor Networks: A Systematic Study.

To perform a comprehensive assessment of important infrastructures (like bridges), the process of structural health monitoring (SHM) is employed. The development and implementation of SHM systems are generally based on wireless sensor networks (WSN) platforms. However, most of the WSN platforms are battery-powered, and therefore, have a limited battery lifetime. The power constraint is generally addressed by applying energy harvesting (EH) technologies. As a result, there exists a plethora of WSN platforms and EH techniques. The employment of a particular platform and technique are important factors during the development and implementation of SHM systems and depend upon various operating conditions. Therefore, there is a need to perform a systematic literature review (SLR) for WSN platforms and EH techniques in the context of SHM for bridges. Although state-of-the-art review articles present multiple angles of the field, there is a lack of an SLR presenting an in-depth comparative study of different WSN platforms and EH techniques. Moreover, a systematic analysis is also needed for the exploration of other design considerations such as inspection scale (global/local), response type (static/dynamic), and types of sensors. As a result, this SLR selects 46 articles (during 2007-2023), related to EH techniques and WSN platforms in SHM for bridges. The selected articles are classified into three groups: WSN platforms, energy harvesting techniques, and a combination of both. Subsequently, a comparative analysis of WSN platforms and EH techniques is made. Furthermore, the selected articles (total = 46) are also explored in terms of sensor type, inspection scale, and response type. As a result, 17 different sensor types are identified. This research is significant as it may facilitate the various stakeholders of the domain during the selection of appropriate WSN platforms, EH techniques, and related design issues.

Are NH3 and CO2 Ice Present on Miranda?

Published near-IR spectra of the four largest classical Uranian satellites display the presence of discrete deposits of CO2 ice, along with subtle absorption features around 2.2 μm. The two innermost satellites, Miranda and Ariel, also possess surfaces heavily modified by past endogenic activity. Previous observations of the smallest satellite, Miranda, have not detected the presence of CO2 ice, and a report of an absorption feature at 2.2 μm has not been confirmed. An absorption feature at 2.2 μm could result from exposed or emplaced NH3- or NH4-bearing species, which have a limited lifetime on Miranda’s surface, and therefore may imply that Miranda’s internal activity was relatively recent. In this work, we analyzed near-IR spectra of Miranda to determine whether CO2 ice and the 2.2 μm feature are present. We measured the band area and depth of the CO2 ice triplet (1.966, 2.012, and 2.070 μm), a weak 2.13 μm band attributed to CO2 ice mixed with H2O ice, and the 2.2 μm band. We confirmed a prior detection of a 2.2 μm band on Miranda, but we found no evidence for CO2 ice, either as discrete deposits or mixed with H2O ice. We compared a high signal-to-noise-ratio spectrum of Miranda to synthetic and laboratory spectra of various candidate compounds to shed light on what species may be responsible for the 2.2 μm band. We conclude that the 2.2 μm absorption is best matched by a combination of NH3 ice with NH3 hydrates or NH3–H2O mixtures. NH4-bearing salts like NH4Cl are also promising candidates that warrant further investigation.

FABRICATION OF PORTABLE TRIBOELECTRIC NANOGENERATOR BASED ON NATURAL LEAVES

Recently, green triboelectric nanogenerators (TENG) have emerged as an alternative adequate power supply to solid-state chemical batteries to overcome certain drawbacks, including toxic materials, limited lifetime, or recharged requirement. In this paper, we demonstrated the fabrication of the natural and common leaf-based triboelectric nanogenerator (NF-TENG), which uses jackfruit, banana, and bamboo leaves as positive triboelectric layers. Among some fabricated NF-TENGs, the bamboo leaf-based TENG presents novel output characteristics, including the maximum output power density of 7 mW.m−2, the short-circuit current of 6 μA under the excitation power and the frequency supplied to the mechanical oscillatorof 33.6 mW and 30 Hz. This NF-TENG can light up 18 green commercial LEDs simultaneously, which promises to be a novel solution for powering low-power electronic devices using different vibration energy sources.

Rational design and experimental evaluation of peptide ligands for the purification of adeno-associated viruses via affinity chromatography.

Adeno-associated viruses (AAVs) have acquired a central role in modern medicine as delivery agents for gene therapies targeting rare diseases. While new AAVs with improved tissue targeting, potency, and safety are being introduced, their biomanufacturing technology is lagging. In particular, the AAV purification pipeline hinges on protein ligands for the affinity-based capture step. While featuring excellent AAV binding capacity and selectivity, these ligands require strong acid (pH <3) elution conditions, which can compromise the product's activity and stability. Additionally, their high cost and limited lifetime has a significant impact on the price tag of AAV-based therapies. Seeking to introduce a more robust and affordable affinity technology, this study introduces a cohort of peptide ligands that (i) mimic the biorecognition activity of the AAV receptor (AAVR) and anti-AAV antibody A20, (ii) enable product elution under near-physiological conditions (pH 6.0), and (iii) grant extended reusability by withstanding multiple regenerations. A20-mimetic CYIHFSGYTNYNPSLKSC and AAVR-mimetic CVIDGSQSTDDDKIC demonstrated excellent capture of serotypes belonging to distinct clones/clades - namely, AAV1, AAV2, AAV5, AAV6, AAV8, and AAV9. This corroborates the in silico models documenting their ability to target regions of the viral capsid that are conserved across all serotypes. CVIDGSQSTDDDKIC-Toyopearl resin features binding capacity (≈1014 vp mL-1 ) and product yields (≈60%-80%) on par with commercial adsorbents, and purifies AAV2 from HEK293 and Sf9 cell lysates with high recovery (up to 78%), reduction of host cell proteins (up to 700-fold), and high transduction activity (up to 65%).

Metal–Organic Framework Supercapacitors: Challenges and Opportunities

AbstractSupercapacitors offer superior energy storage capabilities than traditional capacitors, making them useful for applications such as electric vehicles and rapid large‐scale energy storage. The energy storage performance of these devices relies on electrical double‐layer capacitance and/or pseudocapacitance from rapid reversible redox reactions. Metal–organic frameworks (MOFs) have recently emerged as a new class of electrode materials with promising supercapacitor performances and capacitances that exceed those of traditional materials. However, the comparison of the supercapacitor performance of a porous carbon and a state‐of‐the‐art MOF highlights a number of challenges for MOF supercapacitors, including low potential windows, limited cycle lifetimes, and poor rate performances. It is proposed that the well‐defined and tuneable chemical structures of MOFs present a number of avenues for improving supercapacitor performance. Recent experimental and theoretical work on charging mechanisms in MOF‐based supercapacitors is also discussed, and it is found that there is a need for more studies that elucidate the charge storage and degradation mechanisms. Ultimately, a deeper understanding will lead to design principles for realizing improved supercapacitor energy storage devices.

Immobilization of Enzyme Electrochemical Biosensors and Their Application to Food Bioprocess Monitoring.

Electrochemical biosensors based on immobilized enzymes are among the most popular and commercially successful biosensors. The literature in this field suggests that modification of electrodes with nanomaterials is an excellent method for enzyme immobilization, which can greatly improve the stability and sensitivity of the sensor. However, the poor stability, weak reproducibility, and limited lifetime of the enzyme itself still limit the requirements for the development of enzyme electrochemical biosensors for food production process monitoring. Therefore, constructing sensing technologies based on enzyme electrochemical biosensors remains a great challenge. This article outlines the construction principles of four generations of enzyme electrochemical biosensors and discusses the applications of single-enzyme systems, multi-enzyme systems, and nano-enzyme systems developed based on these principles. The article further describes methods to improve enzyme immobilization by combining different types of nanomaterials such as metals and their oxides, graphene-related materials, metal-organic frameworks, carbon nanotubes, and conducting polymers. In addition, the article highlights the challenges and future trends of enzyme electrochemical biosensors, providing theoretical support and future perspectives for further research and development of high-performance enzyme chemical biosensors.

SUMMER：A small modular lead-bismuth-cooled fast reactor for mobile energy supply

The pursuit of small modular reactors (SMRs) has become a trend in this century due to their potential to expand the use of clean and reliable nuclear energy to a broader range of customers and applications. One promising candidate is the lead-based fast reactor. A mobile energy supply unit based on a lead-bismuth-cooled, pool-type, small modular fast reactor named SUstainable Modular Mobile Enhanced Reactor (SUMMER) is being developed by the University of Science and Technology of China (USTC) and China Nuclear Power Technology Research Institute. SUMMER is intended to provide stable energy supply in the field or remote regions, which are potential application scenarios for SMRs. Key features of SUMMER include a long lifetime of over a decade, mobility (transportable by truck or train), and inherent safety. In this paper, the reactor design is completed under the constraints of fulfilling these features, such as the limitation of size and lifetime. Neutronic and thermal-hydraulic analyses are implemented, as well as safety analyses of the reactor under several typical accidents. The results show that the design meets all these criteria and that the reactor has an adequate safety margin under both steady-state and transient conditions.

Energy harvesting in self-sustainable IoT devices and applications based on cross-layer architecture design: A survey

The Internet of Things (IoT) is envisioned to become a driving force in the evolution of fifth-generation (5G) mobile networks, autonomous continuous monitoring and control platforms, and low-power consumption devices. Conventionally, these devices are battery-operated. The battery lifespan degrades faster in the case of continuous monitoring devices. Limited battery lifetime motivates us to investigate an eco-friendly solution to solve the issue of limited battery life and frequent replacement. Energy harvesting (EH) is a key-enabling technique that provides a viable solution to the challenge at hand. EH minimizes battery dependence by collecting energy from ambient sources. Although several studies have been conducted on EH-IoT networks, a tutorial on a possible mapping between the use cases/application to the IoT devices and the IoT devices to EH power source still needs to be included. To address this gap, we classify IoT devices based on their applications. Based on the different interfacing sections of layer architecture design of IoT device, this paper tries to fill the gap between IoT applications and the self-sustainable IoT system design. Next, each interfacing section is categorized into layer architecture of IoT device to study layer-specific power requirements (or demand) versus EH sources (or supply). We have considered various applications like agriculture, healthcare, industry, city, security, transportation, and water management. Further, we discuss different energy sources to harness ambient energy and the method to store the harvested energy. Then, the widely used standards and the various steps taken for the interoperability and compatibility of EH-IoT are outlined to understand the elements of the EH interface. Finally, we point out future research issues requiring specific attention for deploying self-sustainable IoT-based delay-limited applications.

Differential aeration corrosion of silver in sulfate melts at 900 °C

The thermodynamic of the Ag/Ag2SO4 electrode, serving as reference for carrying electrochemical experiences of corrosion in sulfates at 900 °C, was investigated because of the observed limited operating lifetime. Its use led to the total degradation of the ∅1 mm Ag wire in ∼200 h. Half-immersion of Ag wires in sulfates mixes (selected for their acido-basicity) evidenced the homogeneous thinning of the immersed part of the wires and the precipitation of metallic Ag in the salt. The different steps governing the corrosion mechanism were proposed considering that the driving force was the differential aeration of the Ag wire.

Demonstrating Autonomy for Complex Space Missions: A Europa Lander Mission Autonomy Prototype

There is a desire for robotic spacecraft to perform exploration in unknown, dynamic environments. The Europa Lander Mission Concept is one such mission that needs to deal with an extremely limited lifetime and energy supply, manage intermittent communications with long blackouts, face numerous environmental dangers, and ultimately take place too far from Earth to rely on human control. No missions to date have operated with the required level of autonomy and under the same level of communication constraints, uncertainty, and mission concept complexity as this mission. As a result, the viability of the autonomy must be demonstrated before it will be trusted with mission-critical planning. In this paper, we present an autonomous software prototype that can demonstrate and test the ability of different planners and executives to carry out complex, science-centric missions with limited interventions from humans. The prototype uses a hierarchical utility model that is used to maximize both the amount of expected science return as well as the number of mission objectives imposed by the ground. We demonstrate how this system handles some of the autonomous tasks expected of complex space missions such as decision making, in-situ data acquisition and analysis, data prioritization, resource management, and failure response handling in both simulation and on actual hardware. Through several scenario-based experiments we show how different planners and executives can meet the challenges of the Europa Lander Mission Concept. We also demonstrate that this system can be used in concert with a hardware prototype for autonomy field tests.

Search for tri-nucleon decays of ^{76}Ge in GERDA

We search for tri-nucleon decays of ^{76}Ge in the dataset from the GERmanium Detector Array (GERDA) experiment. Decays that populate excited levels of the daughter nucleus above the threshold for particle emission lead to disintegration and are not considered. The ppp-, ppn-, and pnn-decays lead to ^{73}Cu, ^{73}Zn, and ^{73}Ga nuclei, respectively. These nuclei are unstable and eventually proceed by the beta decay of ^{73}Ga to ^{73}Ge (stable). We search for the ^{73}Ga decay exploiting the fact that it dominantly populates the 66.7 keV ^{73m}Ga state with half-life of 0.5 s. The nnn-decays of ^{76}Ge that proceed via ^{73m}Ge are also included in our analysis. We find no signal candidate and place a limit on the sum of the decay widths of the inclusive tri-nucleon decays that corresponds to a lower lifetime limit of 1.2times 10^{26} yr (90% credible interval). This result improves previous limits for tri-nucleon decays by one to three orders of magnitude.