Jing Wang

Last Name

Wang

First Name

Jing

ORCID

0000-0003-2078-137X

Organisational unit

03887 - Wang, Jing / Wang, Jing

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Publications 1 - 10 of 164

Carbon nanotubes released from an epoxy-based nanocomposite: quantification and particle toxicity
Schlagenhauf, Lukas; Buerki-Thurnherr, Tina; Kuo, Yu-Ying; et al. (2015)
Environmental Science & Technology
Studies combining both the quantification of free nanoparticle release and the toxicological investigations of the released particles from actual nanoproducts in a real-life exposure scenario are urgently needed, yet very rare. Here, a new measurement method was established to quantify the amount of free-standing and protruding multiwalled carbon nanotubes (MWCNTs) in the respirable fraction of particles abraded from a MWCNT–epoxy nanocomposite. The quantification approach involves the prelabeling of MWCNTs with lead ions, nanocomposite production, abrasion and collection of the inhalable particle fraction, and quantification of free-standing and protruding MWCNTs by measuring the concentration of released lead ions. In vitro toxicity studies for genotoxicity, reactive oxygen species formation, and cell viability were performed using A549 human alveolar epithelial cells and THP-1 monocyte-derived macrophages. The quantification experiment revealed that in the respirable fraction of the abraded particles, approximately 4000 ppm of the MWCNTs were released as exposed MWCNTs (which could contact lung cells upon inhalation) and approximately 40 ppm as free-standing MWCNTs in the worst-case scenario. The release of exposed MWCNTs was lower for nanocomposites containing agglomerated MWCNTs. The toxicity tests revealed that the abraded particles did not induce any acute cytotoxic effects.
Modeling city-wide intra-urban variations of ultrafine particles via low-to-middle cost sensors: Comparisons between land use regression and machine learning approaches
Abdillah, Sultan F.I.; Wang, Ya-Fen; You, Sheng-Jie; et al. (2025)
Journal of Environmental Chemical Engineering
Accurate exposure assessment for pollutants such as black carbon (BC) and ultrafine particles (UFPs) remains challenging in cities lacking dense monitoring networks. This study develops city-wide prediction models for BC, UFPs, PM₁₀, and PM_2.5 in Zurich city, Switzerland based on the results of a small-scale monitoring campaign using low-to-middle cost sensors. Two conventional land use regression (LUR) methods including LM-LUR & generalized additive models (GAM), and two non-linear machine learning (ML) methods including random forest (RF) & XGBoost were used in models training. In total, 16 high-resolution (50 m × 50 m grid) models were developed and externally validated. The study further examined the spatial extrapolation of predictions from a small-scale modeling domain covering a 500 m² sampling area to a city-wide prediction domain of 87.88 km². Among the four modeling approaches, RF demonstrated the most robust and consistent performance, with a repeated leave-one-out cross-validation (LOOCV) R² ranging from 0.74 to 0.87 and externally validated prediction errors within 2.46 % – 39 % across pollutants. While non-linear models outperformed conventional LUR approaches, LM-LUR and GAM exhibited inconsistent performances when applied to the larger prediction domain. Despite the limitations of a small-scale monitoring campaign in representing temporal variation, the intra-urban spatial variability captured by the integrated campaign and ML modeling approach provide valuable insights into future air pollution exposure and health studies in under-monitored regions.
Flexible and ultrathin waterproof conductive cellular membranes based on conformally gold-coated PVDF nanofibers and their potential as gas diffusion electrode
Yu, Ranxue; Senocrate, Alessandro; Bernasconi, Francesco; et al. (2023)
Materials & Design
Nanofiber membranes (NFMs) coated with noble metals are intensively researched for various applications such as wearable electronics, environmental sensors, and point of care diagnostics. To achieve the desired functionality while minimizing costs, a combination of facile coating methods and accurate microstructural designs is required, but remains elusive. Herein, novel conductive and porous membranes are designed based on a facile and scalable approach to fabricating conformally coated gold layers on electrospun PVDF fibers (Au-PVDF-NFMs) via electroless plating. The deposition of a conformal and fully interconnected gold layer with an average thickness of circa 38 nm on the surface of nanofibers is confirmed by systematic characterizations. The high-conjunction gold layers endows a high electrical conductivity to the membranes, yielding a low sheet resistance of 1.2 Ω/sq. In addition, the membranes show integrated functionalities such as hydrophobicity and gas permeability. Notably, the NFMs also show excellent mechanical durability under both stretching and bending, with negligible conductivity losses after 1000 test cycles. Thanks to these properties, the Au-PVDF-NFMs demonstrates practical suitability as gas diffusion electrodes (GDEs) for electrochemical CO₂ reduction. The Au-PVDF-NFMs exhibit a substantial Faradaic efficiency towards CO, as high as ∼ 85 % at −0.7 V vs reversible hydrogen electrode (RHE), and are able to reach current densities of 100 mA cm⁻² at −0.95 V versus RHE.
Towards an active droplet-based microfluidic platform for programmable fluid handling
Cao, Xiaobao; Buryska, Tomas; Yang, Tianjin; et al. (2023)
Lab on a Chip
Droplet-based microfluidic systems have emerged as powerful alternatives to conventional high throughput screening platforms, due to their operational flexibility, high-throughput nature and ability to efficiently process small fluid volumes. However, the challenges associated with performing bespoke operations on user-defined droplets often limit their utility in screening applications that involve complex workflows. To this end, the marriage of droplet- and valve-based microfluidic technologies offers the prospect of balancing the controllability of droplet manipulations and analytical throughput. In this spirit, we present a microfluidic platform that combines the capabilities of integrated microvalve technology with droplet-based sample compartmentalization to realize a highly adaptable programmable fluid handling functionality. The microfluidic device consists of a programmable formulator linked to an automated droplet generation device and storage array. The formulator leverages multiple inputs coupled to a mixing ring to produce combinatorial solution mixtures, with a peristaltic pump enabling titration of reagents into the ring with picoliter resolution. The platform allows for the execution of user-defined reaction protocols within an array of storage chambers by consecutively merging programmable sequences of pL-volume droplets containing specified reagents. The precision in formulating solutions with small differences in concentration is perfectly suited for the accurate estimation of kinetic parameters. The utility of our platform is showcased through the performance of enzymatic kinetic measurements of beta-galactosidase and horseradish peroxidase with fluorogenic substrates. The presented platform provides for a range of automated manipulations and paves the way for a more diverse range of droplet-based biological experiments.
Modeling the flows of engineered nanomaterials during waste handling
Mueller, Nicole C.; Buha, Jelena; Wang, Jing; et al. (2013)
Environmental Science: Processes & Impacts
Recent Development of Optofluidics for Imaging and Sensing Applications
Tang, Jiukai; Qiu, Guangyu; Wang, Jing (2022)
Chemosensors
Optofluidics represents the interaction of light and fluids on a chip that integrates microfluidics and optics, which provides a promising optical platform for manipulating and analyzing fluid samples. Recent years have witnessed a substantial growth in optofluidic devices, including the integration of optical and fluidic control units, the incorporation of diverse photonic nanostructures, and new applications. All these advancements have enabled the implementation of optofluidics with improved performance. In this review, the recent advances of fabrication techniques and cutting-edge applications of optofluidic devices are presented, with a special focus on the developments of imaging and sensing. Specifically, the optofluidic based imaging techniques and applications are summarized, including the high-throughput cytometry, biochemical analysis, and optofluidic nanoparticle manipulation. The optofluidic sensing section is categorized according to the modulation approaches and the transduction mechanisms, represented by absorption, reflection/refraction, scattering, and plasmonics. Perspectives on future developments and promising avenues in the fields of optofluidics are also provided.
Protection Level and Reusability of a Modified Full-Face Snorkel Mask as Alternative Personal Protective Equipment for Healthcare Workers during the COVID-19 Pandemic
Schmitt, Jean; Jones, Lewis; Aeby, Elise A.; et al. (2021)
Chemical Research in Toxicology
The worldwide outbreak of COVID-19 has drastically increased pressure on medical resources and highlighted the need for rapidly available, large-scale, and low-cost personal protective equipment (PPE). In this work, an alternative full-face mask is adapted from a modified snorkel mask to be used as PPE with two medical-grade filters and a 3D-printed adapter. Since the mask covers the eyes, mouth, and nose, it acts as a full-face shield, providing additional protection to healthcare workers. The SARS-CoV-2 has a size between 60 nm and 140 nm, and airborne viral particles can be carried by larger droplets with sizes up to several millimeters. The minimum filtration efficiency of mechanical and electrostatic filters is usually reached between 30 nm and 300 nm. The filtration efficiency of different medical filters is measured for particles below 300 nm to cover the size of the SARS-CoV-2 and small virus-laden droplets, and determine the minimum efficiency. The filtration performance of the adapted full-face mask is characterized using NaCl particles below 500 nm and different fitting scenarios to determine the minimum protection efficiency. The mask is compared to a commercial respirator and characterized according to the EN 149 standard, demonstrating that the protection fulfills the requirements for the FFP2 level (filtering face-piece 2, stopping at least 94% of airborne particles). The device shows a good resistance to several cycles of decontamination (autoclaving and ethanol immersion), is easy to be produced locally at low cost, and helps to address the shortage in FFP2 masks and face shields by providing adequate protection to healthcare workers against particles <500 nm in size. © 2020 American Chemical Society.
Air path of antimicrobial resistance related genes from layer farms: Emission inventory, atmospheric transport, and human exposure
Gao, Min; Zhang, Xiaole; Yang, Yue; et al. (2022)
Journal of Hazardous Materials
Animal husbandry is a significant contributor to increased environmental antimicrobial resistance (AMR), but little is known regarding the dissemination of AMR from animal farms via airborne transmission. Here, we connected the air path of AMR related genes tailored to layer poultry farms from source of escape to end of sedimentation. The emission inventories of 8 AMR related genes from all 163-layer poultry farms around Beijing city were quantified. We developed the atmospheric transport model with a gene degradation module to estimate the spatiotemporal distribution of airborne AMR, and also assessed their corresponding regional exposure and sedimentation. Total emissions of 16 S rDNA and AMR related genes from layer houses ranged from 1015 to 1016 copies year−1. Those layer-sourced genes contributed 1–14.6% of antimicrobial resistant genes, 4.9% of Staphylococcus spp. and 2.2% of CintI1 to the corresponding annual genetic burden of Beijing's urban air. The average exposure of the Beijing residents to layer-sourced airborne 16 S rDNA was 1.39 × 104 copies year−1 person−1, approximately 87% of them would be deposited in the upper respiratory tract. The findings highlight that air medium represents an important dissemination pathway of animal-sourced genes to AMR burden in humans and environment.
A portable and smartphone-based plasmonic system for on-site measurement of airborne redox-active compounds by light-initiated redox reaction
Yu, Ranxue; Qiu, Guangyu; Zhao, Yi-Bo; et al. (2022)
Sensors and Actuators B: Chemical
The determination of airborne redox-active compounds (ARC) is essential for monitoring adverse environmental changes and understanding the potential impact on human health. With the exception of relying on the common total organic carbon (TOC) analyzer and dithiothreitol (DTT) assay, there is currently no easy-to-use method for quantitative assessment. Herein, a compatible and easy-to-use colorimetric sensing strategy was developed for on-site ARC quantification. This approach integrated a plasmonic sensing system, where the ARC-induced gold nanoparticles (AuNPs) reduction, localized surface plasmon resonance (LSPR), and the light-mediated photochemistry collaborated to achieve a limit of detection (LOD) at 0.026 μg∙mm-2 on the filters. Distinguished from the abovementioned methods, the ARC content can be directly determined by in-situ monitoring the colorimetric reaction on the sampling quartz filters (QF) without additional sample pre-treatment. Apart from utilizing the standard benchtop photodetector (e.g., UV-VIS spectrophotometer), the colorimetric images of AuNP@QF samples could also be imaged by a smartphone camera in a sealed box and analyzed through a smartphone-based application to read the RGB (Red, Green, Blue) values for ARC quantification. The good correlation between the results using the spectrophotometer and smartphone validate the applicability of the AuNP sensor. The smartphone-based method was then deployed to test real-world aerosols collected from Zurich, Bern and Rigi and the results of ARC exhibited a positive correlation with that of PM10. With the advantages of low-cost, easy-operation and no need for pre-treatment, this smartphone-based plasmonic system holds great potential for rapid and portable ARC detection and corresponding air quality assessment.
Quantitative modeling of the impact of facemasks and associated leakage on the airborne transmission of SARS-CoV-2
Schmitt, Jean; Wang, Jing (2021)
Scientific Reports
The ongoing worldwide outbreak of COVID-19 has set personal protective equipment in the spotlight. A significant number of countries impose the use of facemasks in public spaces and encourage it in the private sphere. Even in countries where relatively high vaccination rates are achieved at present, breakthrough infections have been frequently reported and usage of facemasks in certain settings has been recommended again. Alternative solutions, including community masks fabricated using various materials, such as cotton or jersey, have emerged alongside facemasks following long-established standards (e.g., EN 149, EN 14683). In the present work, we present a computational model to calculate the ability of different types of facemasks to reduce the exposure to virus-laden respiratory particles, with a focus on the relative importance of the filtration properties and the fitting on the wearer’s face. The model considers the facemask and the associated leakage, the transport of respiratory particles and their accumulation around the emitter, as well as the fraction of the inhaled particles deposited in the respiratory system. Different levels of leakages are considered to represent the diversity of fittings likely to be found among a population of non-trained users. The leakage prevails over the filtration performance of a facemask in determining the exposure level, and the ability of a face protection to limit leakages needs to be taken into account to accurately estimate the provided protection. Filtering facepieces (FFP) provide a better protection efficiency than surgical and community masks due to their higher filtration efficiency and their ability to provide a better fit and thus reduce the leakages. However, an improperly-fitted FFP mask loses a critical fraction of its protection efficiency, which may drop below the protection level provided by properly-worn surgical and community masks.

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