Search Results (62)

Tin contamination on extreme ultraviolet (EUV) collector mirrors significantly degrades mirror reflectivity. Hydrogen-based plasma cleaning is currently the standard method for removing the tin layer. However, to prevent substrate damage from over-cleaning, real-time monitoring of the tin layer thickness is critical. It has been established that the secondary electron yield (SEY) induced by high-energy primary electron bombardment correlates with the tin layer thickness. Thus, SEY can serve as a thickness indicator to determine the optimal cleaning endpoint. In this study, the evolution of secondary electrons during the cleaning process is simulated using a Particle-in-Cell (PIC) model combined with the Monte Carlo method, and the relationship between SEY and tin layer thickness is established. The simulation results indicate that under the specified conditions, H³⁺ is the dominant ionic species generated. Primary electrons account for nearly 24% of the incident particles, with an average energy of approximately 47 eV. Most secondary electrons possess energies below 30 eV, and their yield increases monotonically with the tin layer thickness, ranging from 0.60 to 1.05. These findings provide a novel approach for in situ detection of tin contamination layer evolution on EUV collector mirrors. Full article

Background: Dermal interstitial fluid (ISF) contains both plasma-derived biomarkers and biomarkers unique to ISF, making it a promising biofluid for painless, scalable, and decentralized liquid biopsy and continuous health monitoring. However, efficient ISF collection remains challenging due to the small accessible fluid volume in the dermis, slow physiological turnover, and stratum corneum. Methods: This review reframes dermal ISF sampling as a pressure gradient engineering problem using Darcy’s law. We examine how vacuum-assisted microneedle platforms can effectively drive ISF through the dermal extracellular matrix in a minimally invasive manner. We compare the two architectures: micropore-based and hollow microneedle approaches. Results: In the micropore approach, a vacuum chamber is placed over the transient micropores left by withdrawn microneedles, supporting off-device, multi-omic downstream analyses of the collected ISF. The hollow microneedle approach retains the microneedles in the skin and applies vacuum through internal lumens, allowing integration of the vacuum source, microneedles, and biosensors into a single wearable platform for in situ biomarker detection. Comparative studies across these architectures identify the vacuum seal between the device and the skin as the major engineering bottleneck shared by both architectures. Conclusions: Vacuum-assisted microneedle platforms provide a practical route for generating pressure gradient-driven ISF transport while preserving minimally invasive skin access. Future development should prioritize device–skin vacuum seal robustness, reproducible ISF recovery across users and skin sites, integrated vacuum sources, scalable fabrication, and usability in clinical or at-home settings. Full article

To address prevalent industrial challenges, including the high cost of fabricating microstructures via photolithography and 3D printing, impurity residues easily generated by conventional physical/chemical pore-forming techniques, and the limited sensitivity of regular capacitive sensors, this paper innovatively proposes an integrated low-temperature in situ gas foaming strategy using ammonium bicarbonate for the fabrication of porous TPU-based ionic gels. Relying on the complete gaseous decomposition property of ammonium bicarbonate upon heating, a three-dimensionally interconnected continuous porous network is spontaneously constructed inside the polymer matrix. Thermoplastic polyurethane (TPU) is selected as the continuous polymer phase, and [EMIM][TFSI] imidazolium ionic liquid is blended as the ion source to synthesize composite ionic gel substrates. A PDMS composite slurry filled with graphene is employed to prepare flexible substrates, followed by low-temperature oxygen plasma surface modification to introduce polar functional groups such as hydroxyl and carboxyl onto electrode surfaces. A standard sandwich-structured ionic pressure sensor with the configuration of “top modified electrode—porous ionic gel dielectric layer—bottom modified electrode” is finally assembled. The porous framework and modified electrodes constitute a dual synergistic enhancement system: the porous structure markedly reduces the equivalent elastic modulus of the gel and improves its compressive deformation capacity; polar-modified electrodes optimize the interfacial compatibility between electrodes and gels, shorten ion migration paths and lower interfacial contact resistance. Systematic calibration of multiple batches of parallel samples reveals that the as-fabricated sensor achieves a high sensitivity of 25.3 kPa⁻¹ across the full measuring range from 0 to 1000 kPa with a linear fitting coefficient R² = 0.992. The loading response time and unloading recovery time of the device are 60 ms and 80 ms respectively, with a performance degradation of less than 3% after 1000 consecutive loading–unloading cycles, featuring low hysteresis error and excellent signal repeatability. Multi-scenario in vivo wearable tests on human subjects verify that the device can precisely capture subtle fluctuations of radial artery pulse and periodic laryngeal deformation during swallowing, distinguish characteristic waveform patterns of various English words according to differences in vocal cord vibration, and accurately detect bending motions when attached to finger joints. The entire fabrication process adopts common chemical raw materials and standard laboratory equipment without expensive micro-nano processing facilities, featuring convenient raw material procurement and high process fault tolerance, which enables large-area coating-based mass production. This work delivers a novel technical route for the low-cost large-scale production of high-performance ionic flexible sensors and bears significant industrialization reference value for applications in wearable medical monitoring, bionic robotic electronic skin, flexible human–machine interactive touch panels and other related fields. Full article

Metanephrine (MN) and normetanephrine (NMN) are critical biomarkers for neuroendocrine tumors (pheochromocytoma and paraganglioma). Following our previous development of a molecularly imprinted solid-phase extraction (MISPE) sorbent for urine analysis, this study evaluated MISPE coupled with HILIC-MS/MS for determining metanephrines in human plasma. Unlike conventional phases, the novel polymer selectively binds analytes as in situ-generated anions via quaternary alkylammonium groups in hydroxide form, ensuring accurate extraction from just 25 µL of plasma. Validated per U.S. FDA guidelines, the assay showed good intra- and interday precision (CV < 10.8%), accuracy (bias < −10.6%) and excellent linearity (R² > 0.99) across pathological ranges (184.3–877.8 ng/L for MN; 174.8–923.0 ng/L for NMN), with low relative standard errors (<6.9%). Excellent selectivity was demonstrated in the presence of structurally close analogs (catecholamines, DOPA and its derivatives). Compared with commercial WCX, the sorbent yielded cleaner extracts, significantly reducing the phospholipid interference. Although lower limits of quantification (92.2 ng/L MN; 87.4 ng/L NMN) slightly exceeded healthy upper thresholds, the method has potential for use in specific clinical scenarios with pronounced biomarker elevations: diagnosis of pheochromocytoma/paraganglioma, monitoring post-treatment metanephrine decline, and tracking tumor-induced hypertensive crises in emergencies. This accessible protocol forms a solid foundation for advanced diagnostics. Full article

Laser-induced breakdown spectroscopy (LIBS) offers rapid, in situ, and multi-element detection, and therefore shows strong potential for quality monitoring of metal powders in additive manufacturing. However, direct LIBS analysis of flowing metal powders is often affected by particle splashing, unstable laser–particle coupling, and plasma fluctuations, which reduce signal repeatability and detection reliability. To address these issues, this study developed an integrated measurement and classification framework for identifying cross-contamination in additive-manufacturing metal powders. A stable powder particle stream was generated through vibratory feeding and particle-flow focusing, while a hollow quartz tube with a side opening was introduced to provide cylindrical spatial confinement, thereby improving the stability of laser–particle interaction and enabling in situ spectral acquisition without pellet preparation. TC4 powder was used as the base material and AlSi10Mg powder as the contaminant, and samples with contamination levels of 0, 0.5, 1, 2, and 5 wt.% were prepared. Two independent batches of single-shot LIBS spectra were collected. To reduce the influence of strong spectral fluctuations, outlier spectra were removed using full-spectrum total-intensity quantile filtering, followed by asymmetric least-squares baseline correction and standard normal variate transformation. PCA combined with multiple machine-learning models was then applied for contamination identification. The results showed that LIBS spectra at different contamination levels exhibited distinguishable distributions in principal-component space, and the spectral differences between clean and contaminated powders became more pronounced with increasing contamination level. In binary classification, several models achieved high classification accuracy at medium and high contamination levels, while PCA-SVM-RBF showed the best performance at low concentrations. In five-class cross-validation, the 5 wt.% class exhibited the clearest decision boundary, whereas confusion remained among low and adjacent contamination levels, indicating that contamination-induced spectral responses followed a more continuous transition. These results demonstrate that the proposed spatially confined particle-flow LIBS framework combined with machine-learning classification can effectively achieve rapid identification of cross-contamination in additive-manufacturing metal powders and provides a feasible technical route for online powder quality monitoring. Full article

Heavy metal contamination of foods remains a persistent global challenge for food safety and public health, driven by industrialization, mining activities, intensive agriculture, and ongoing environmental degradation. This scoping review synthesizes peer-reviewed literature on the occurrence of priority toxic metals—arsenic, cadmium, lead, mercury, and nickel—in food matrices, with emphasis on contamination pathways, analytical detection strategies, and documented human health effects. The reviewed studies reveal widespread accumulation of heavy metals in staple foods, including cereals, vegetables, seafood, and processed products, with concentrations frequently approaching or exceeding international regulatory limits, particularly in regions exposed to strong anthropogenic pressure. Conventional laboratory-based techniques, such as atomic absorption spectrometry and inductively coupled plasma methods, remain the reference standards for quantitative determination and regulatory compliance; however, their application to large-scale or continuous monitoring is often constrained by cost, infrastructure, and operational complexity. Consequently, increasing attention has been directed toward emerging detection approaches, including portable X-Ray fluorescence, Raman/SERS spectroscopy, electrochemical biosensors, electronic tongues, and in situ magnetic measurements, as complementary tools for rapid screening and field-based surveillance. Among these, environmental magnetism and in situ magnetic techniques stand out as non-destructive, low-cost proxies capable of identifying metal-associated particulate contamination linked to food production systems. Chronic dietary exposure to heavy metals is consistently associated with neurotoxicity, nephrotoxicity, carcinogenicity, and oxidative stress, underscoring the need for integrated, multi-tiered monitoring frameworks to support early detection, risk assessment, and prevention. Full article

This study investigates how torch standoff distance influences the microstructure, surface topography, and progressive-load scratch response of air plasma-sprayed 8YSZ and rare-earth co-doped GdYbYSZ thermal barrier coatings on an St-52 grade carbon steel substrate. Three nozzle-to-substrate spraying distances were examined: 80, 100, and 120 mm. X-ray diffraction revealed that the 8YSZ coatings possessed a predominantly tetragonal (t′) structure, with minor monoclinic fractions detected in the coatings obtained with the 80 mm and 100 mm distance parameters. The GdYbYSZ coatings, in contrast, exhibited a single-phase cubic defect-fluorite structure; their diffraction peaks appeared at lower 2θ angles relative to undoped cubic ZrO₂, consistent with lattice expansion caused by the substitution of Zr⁴⁺ by the larger Gd³⁺ and Yb³⁺ cations. Surface topography was quantified by non-contact laser profilometry, providing areal (Sa) and profile (Ra) roughness parameters for the as-sprayed condition as well as three-dimensional scratch-damage morphology after testing. Progressive-load scratch tests were performed using a Rockwell diamond indenter over a 2 mm track with the normal load ramped from 0.03 N to 30 N. Penetration depth, residual depth, tangential force, and acoustic emission were recorded continuously to identify critical damage transitions. Across all spraying distances, 8YSZ exhibited systematically shallower scratch grooves than GdYbYSZ; end-of-track maximum groove depths remained below 37 µm for 8YSZ, whereas GdYbYSZ reached up to 72 µm under identical loading conditions. The novelty of this study lies in combining torch standoff distance as a processing variable with multi-channel progressive-load scratch diagnostics, including in situ acoustic emission, depth profiling, and friction monitoring, to comparatively assess the scratch wear performance of 8YSZ and rare-earth co-doped zirconia TBCs for the first time. Full article

Chronic lymphocytic leukemia (CLL) is a heterogenous disease, with varied clinical outcomes. Multiplex assays used to measure soluble immune checkpoints offer a less laborious method of monitoring patients with CLL, but none of these panels have been validated. The aim of the study was to assess soluble immune checkpoint profiles in patients with CLL and to correlate these with independent prognostic markers such as β2-microglobulin (B2M), Rai stage, fluorescence in situ hybridization (FISH) status, and the International Prognostic Index for Chronic Lymphocytic Leukemia (CLL-IPI). We measured plasma levels of soluble interleukin-2 receptor alpha (sCD25), T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), galectin-9, programmed cell death 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) using cytometric bead array-based assays. We further measured plasma levels of B2M using an enzyme-linked immunosorbent assay (ELISA) kit. Soluble immune checkpoints were correlated with prognostic markers. The plasma levels of sCD25, TIM-3, galectin-9, PD-1, and PD-L1 were significantly increased in patients with CLL compared to the control group, p < 0.0001. Galectin-9 plasma levels were directly associated with B2M levels (β = 0.65, p = 0.012). Our findings suggest that galectin-9 may provide valuable prognostic significance for patients with CLL. Full article

Arsenic (As) in groundwater often fluctuates around the 10 µg/L health-based guideline, complicating compliance assessment and risk-based management. This study investigates the short-term temporal behavior of As and its implications for compliance at three supply wells in the Caplina aquifer (La Yarada Los Palos, Tacna, Peru), based on a one-year fortnightly time series. At each visit, in situ electrical conductivity (EC), total dissolved solids (TDS), pH, and temperature were measured, and total As was determined by inductively coupled plasma–mass spectrometry (ICP–MS). The dataset was evaluated using robust descriptive statistics, exceedance proportions with Wilson 95% confidence intervals, Spearman rank correlations, simple time-series diagnostics, and comparisons of deterministic monthly schemes against the fortnightly reference. Exceedances were widespread—100% at Point 1 and 91.7% at Points 2 and 3—yielding 94.4% at the network scale, with no consistent seasonal signal. Relative variability was low yet operationally decisive (coefficient of variation (CV) ≈ 7–10%; interquartile range ≈ 1.3–1.6 µg/L), and typical fortnightly oscillations of ~0.5–1.5 µg/L were sufficient to flip compliance labels under monthly sampling. Point-wise associations were generally weak, except for a moderate As–TDS correlation at Point 1, supporting an interpretation dominated by geogenic As under arid, alkaline, and saline conditions, modulated by redox processes, anion competition, and mixing/pumping dynamics. The findings support risk-based monitoring with a fortnightly baseline and adaptive escalation when predefined activation criteria and action thresholds are met, using EC/TDS, pH, and simple redox indicators as operational early warnings. To reduce exposure in such settings, priority should be given to source management, pre-oxidation of As(III) to As(V), and adsorption onto iron media (or membranes where appropriate), while future work should integrate high-frequency sensing, in situ or inline speciation, reactive-transport modeling, and locally trained risk mapping to strengthen contributions to Sustainable Development Goals 3 (Good Health and Well-Being) and 6 (Clean Water and Sanitation). Full article

The chemical identity of oxygen species plays a decisive role in determining the optical stability of halide perovskite QD films. Here, real-time in situ spectroscopic monitoring, together with steady-state and time-resolved photoluminescence measurements, is utilized to differentiate the effects of molecular oxygen and plasma-activated oxygen species on CsPbBr₃ QD films. The films maintain nearly unchanged emission intensity, spectral profile, and carrier lifetimes when stored in vacuum or exposed to molecular O₂ even under UV illumination, demonstrating that neutral O₂ exhibits minimal reactivity toward the [PbBr₆]⁴⁻ framework. In contrast, oxygen plasma generates highly reactive atomic and ionic oxygen species that induce rapid and spatially heterogeneous photoluminescence quenching. This degradation is attributed to Br⁻ extraction, Br-vacancy formation, and subsequent Pb–O bond generation, which collectively introduce deep trap states and enhance nonradiative recombination. These findings clearly indicate that reactive oxygen species rather than molecular O₂ are the dominant driver of oxygen-induced luminescence degradation, providing mechanistic insight and offering processing guidelines for the reliable integration of perovskite nanomaterials in optoelectronic devices. Full article

In applications involving repeated high-frequency mechanical impacts, such as cutting, machining, or percussive operations, understanding the surface fatigue performance of advanced ceramics is critical. This study investigated the surface fatigue resistance of duplex oxide–carbide ceramic composites fabricated via spark plasma sintering, complementing prior work on their sliding wear performance. The composites, featuring a hybrid oxide–carbide structure, were tested using a cyclic impact setup with a 10 mm ZrO₂ ball activated with 12 hammers fixed to a rotary disc delivering 500,000 impacts per test. Surface degradation was quantified through three-dimensional profilometry to determine the net material loss and scar depth, while fatigue mechanisms were analyzed using scanning electron microscopy coupled with energy-dispersive spectroscopy. In situ monitoring was implemented using accelerometers to capture vibrational signatures during cycling loading, enabling real-time assessment of material response and damage evolution. The WC-containing composite (S2 AZW) exhibited the lowest surface fatigue wear loss (700 × 10³ µm³), whereas the ZrC-based composite (AZZ1) showed the highest (1535 × 10³ µm³). A distinct inverse correlation was observed between the average peak acceleration and fatigue wear loss. Frequency-domain analysis of accelerometric signals revealed progressive degradation patterns consistent with post-test surface damage, indicating that such signal features may serve as effective in situ indicators for tracking material fatigue in future applications. Full article

This study deals with diamond films grown via the microwave plasma-enhanced chemical vapor deposition technique (MWPECVD) on molybdenum (Mo) substrates of different roughness. This work is motivated by the necessity of overcoming the poor adhesion of diamond films on smooth Mo substrates, to ensure their effective application as cathodes for aerospace propulsion. The deposition process was monitored in situ using pyrometric interferometry (PI), thus enabling the real-time monitoring of both the rate and the temperature of deposition. The characterization of the obtained diamond films was performed using different techniques, such as Raman spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The poor adhesion of diamond films on Mo substrates was solved by roughening their surface, which promotes residual stress reduction in the diamond films. In this work, the PI technique was also exploited to support the prediction of the adhesion and stability of diamond films before their exposure in air through the monitoring of the deposition temperature. This represents a novel point of our work that has never been discussed in other research papers, as pyrometric interferometry is generally mainly used to assess the rate and the temperature of deposition. Full article

Although cold atmospheric plasma (CAP) has shown promise in facilitating wound repair due to its non-thermal and non-invasive properties, its dynamic effects on cellular response and metabolic regulation remain poorly characterized, and the mechanism is still unclear. In this study, we developed a microfluidic experimental system that integrates a CAP treatment module with multiparametric in situ sensing capabilities, along with precise environmental control of temperature, humidity, and CO₂ concentration. A stratified microfluidic chip was engineered to co-culture HaCaT keratinocytes and HSF fibroblasts. CAP treatment was applied within this platform, and the dynamic processes of cell migration, proliferation, and multiple metabolic markers were simultaneously monitored. The experimental results show that the system can not only achieve real-time observation in the healing process under plasma intervention, but also find that the healing process is closely related to the concentration of NO₂⁻. In addition, the study also found that keratin KRT14, which is thought to be closely related to wound healing, decreased significantly in the process of plasma-induced healing. The platform provides high-resolution experimental tools to elucidate the biological effects of CAP and has the potential for parameter optimization, material evaluation, and personalized therapeutic development to advance plasma research and clinical translational applications. Full article

To enhance sensitivity in detecting phosphorus in water via laser-induced breakdown spectroscopy (LIBS), this study integrates liquid–solid conversion on graphite substrates with a PLS-SVR fusion algorithm. Optimized laser parameters (500 mJ, 13 pulses) improved plasma excitation and signal-to-noise ratios. The graphite substrate adsorbed phosphorus, converting liquid samples into a solid matrix to suppress matrix interference and intensify spectral lines (P I 213.6 nm and 214.9 nm), achieving detection limits of 0.09 mg/L and 0.23 mg/L, respectively. Calibration curves showed high accuracy (R² = 0.9936). In real-world testing, absolute errors were below 0.017 mg/L, with relative errors <12%, aligning closely with traditional ammonium molybdate spectrophotometry. The PLS-SVR algorithm boosted prediction accuracy through data enhancement and spectral feature extraction, reducing errors to 2.1% (0.625 mg/L) and 5.6% (2.5 mg/L). With rapid sample preparation (<10 min), this method offers an efficient, low-cost solution for in situ phosphorus monitoring, advancing LIBS from lab to field use and supporting precise eutrophication management. Full article

Vitamins are crucial micro-nutrients for overall well-being, making continuous monitoring essential. There are demands to provide an alternative detection, especially using a portable detection or a point-of-care-testing (POCT) device. One promising approach is employing an in situ electro-polymerised MIP (eMIP), which offers a straightforward polymerisation technique on screen-printed electrodes (SPEs). Here, we report a review based on three databases (PubMed, Scopus, and Web of Science) from 2014 to 2024 using medical subject heading (MeSH) terms “electrochemical polymerisation” OR “electropolymerisation” crossed with the terms “molecularly imprinted polymer” AND “vitamin A” OR “vitamin D” OR “vitamin E” OR “vitamin K” OR “fat soluble vitamin” OR “vitamin B” OR “vitamin C” OR “water soluble vitamin”. The resulting 12 articles covered the detection of vitamins in ascorbic acid, riboflavin, cholecalciferol, calcifediol, and menadione using monomers of catechol (CAT), 3,4-ethylenedioxythiophene (EDOT), o-aminophenol (oAP), o-phenylenediamine (oPD), pyrrole, p-aminophenol (pAP), p-phenylenediamine (pPD), or resorcinol (RES), using common bare electrodes including graphite rod electrode (GRE), glassy carbon electrode (GCE), gold electrode (GE), and screen-printed carbon electrode (SPCE). The most common electrochemical detections were differential pulse voltammetry (DPV) and linear sweep voltammetry (LSV). The imprinting factor (IF) of the eMIP-modified electrodes were from 1.6 to 21.0, whereas the cross-reactivity was from 0.0% to 29.9%. Several types of food and biological samples were tested, such as supplement tablets, poultry and pharmaceutical drugs, soft drinks, beverages, milk, infant formula, human and calf serum, and human plasma. However, more discoveries and development of detection methods needs to be performed, especially for the vitamins that have not been studied yet. This will allow the improvement in the application of eMIPs on portable-based detection and POCT devices. Full article