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Detecting intracellular thiol redox state in leukaemia and heterogeneous immune cell populations: An optimised protocol for digital flow cytometers
摘要： Flow cytometric methods for detecting and quantifying reduced intracellular thiol content using fluorescein-5-maleimide (F5M) in viable eukaryotic cells date back to 1983 (Durand and Olive [1]). There has been little development in these methodologies since that time, a period that has witnessed huge technological advances, particularly with the emergence of digital multi-parameter flow cytometric systems. Concurrent advancement in our understanding of redox regulation within eukaryotic cellular systems has also followed, whereby it is now accepted that cysteine thiols partake in redox reactions, which regulate protein activity and function (Groitl and Jakob (2014), Won et al. (2012)). Moreover, we are at the dawn of a new era in redox biology whereby the importance of 'reductive stress' in eukaryotic cellular systems is gathering momentum (Wadley et al. (2018) [4]). It is therefore critical that methods be continually advanced to better understand these concepts in more detail at the cellular level. Flow cytometry is a powerful technique that may be used for this purpose. Henceforth we have rejuvenated these methods to address modern scientific questions. In this paper, essential detail is provided on: The adaption of a protocol initially described by Durand and Olive [1] for use with modern digital flow cytometer configurations. Here we provide optimal conditions for labelling intracellular thiols with F5M for detection using digital flow cytometers. Our modifications avoid the use of methanol fixation thus preserving cell viability in single cell suspension cultures. Demonstration that flow cytometry can detect the gain and loss of reduced intracellular thiols in cells exposed to physiological doses of hydrogen peroxide mediated by glucose oxidase (Hole et al. (2013) [5]). Validation of F5M protein labelling by coupling method to confocal microscopy and downstream proteomics, thus permitting a powerful experimental platform for potential use with next generation flow cytometry e.g. CyTOF (Lin and Maecker (2018) [6]).
关键词： Fluorescein-5 maleimide,Reactive oxygen species,Oxidative stress,Reductive stress,Flow cytometry
更新于2025-09-09 09:28:46
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(3R, 3’R)-Zeaxanthin protects the retina from photo-oxidative damage via modulating the inflammation and visual health molecular markers
摘要： Purpose: Zeaxanthin protects the macula from ocular damage due to light or radiation by scavenging harmful reactive oxygen species. In the present study, zeaxanthin product (OmniXan?; OMX), derived from paprika pods (Capsicum annum; Family-Solanaceae), was tested for its efficacy in the rat retina against photooxidation. Methods: Forty-two male 8-week-old Wistar rats exposed to 12L/12D, 16L/8D and 24L/0D hours of intense light conditions were orally administrated either 0 or 100 mg/kg BW of zeaxanthin concentration. Retinal morphology was analyzed by histopathology, and target gene expressions were detected with real-time polymerase chain reaction methods. Results: OMX treatment significantly increased the serum zeaxanthin concentration (P < 0.001) and ameliorated oxidative damage by increasing the antioxidant enzyme activities in the retina induced by light (P < 0.001). OMX administration significantly upregulated the expression of genes, including Rhodopsin (Rho), Rod arrestin (SAG), Gα Transducin 1 (GNAT-1), neural cell adhesion molecule (NCAM), growth-associated protein 43 (GAP43), nuclear factor-(erythroid- derived 2)-like 2 (Nrf2) and heme oxygenase (HO-1) and decreased the expression of nuclear factor-κB (NF- κB) and GFAP by OMX treatment rats. The histologic findings confirmed the photoreceptor cell degeneration in the retina exposed to intense light. Conclusions: This study suggests that OMX is a potent substance that can be used to protect antioxidant and gene expression data.
关键词： zeaxanthin,Light-emitting diode (LED),photo-oxidation,oxidative stress,retina
更新于2025-09-09 09:28:46
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Evaluation of the SPARSE Dual-Source Model for Predicting Water Stress and Evapotranspiration from Thermal Infrared Data over Multiple Crops and Climates
摘要： Using surface temperature as a signature of the surface energy balance is a way to quantify the spatial distribution of evapotranspiration and water stress. In this work, we used the new dual-source model named Soil Plant Atmosphere and Remote Sensing Evapotranspiration (SPARSE) based on the Two Sources Energy Balance (TSEB) model rationale which solves the surface energy balance equations for the soil and the canopy. SPARSE can be used (i) to retrieve soil and vegetation stress levels from known surface temperature and (ii) to predict transpiration, soil evaporation, and surface temperature for given stress levels. The main innovative feature of SPARSE is that it allows to bound each retrieved individual ?ux component (evaporation and transpiration) by its corresponding potential level deduced from running the model in prescribed potential conditions, i.e., a maximum limit if the surface water availability is not limiting. The main objective of the paper is to assess the SPARSE model predictions of water stress and evapotranspiration components for its two proposed versions (the “patch” and “layer” resistances network) over 20 in situ data sets encompassing distinct vegetation and climate. Over a large range of leaf area index values and for contrasting vegetation stress levels, SPARSE showed good retrieval performances of evapotranspiration and sensible heat ?uxes. For cereals, the layer version provided better latent heat ?ux estimates than the patch version while both models showed similar performances for sparse crops and forest ecosystems. The bounded layer version of SPARSE provided the best estimates of latent heat ?ux over different sites and climates. Broad tendencies of observed and retrieved stress intensities were well reproduced with a reasonable difference obtained for most of the points located within a con?dence interval of 0.2. The synchronous dynamics of observed and retrieved estimates underlined that the SPARSE retrieved water stress estimates from Thermal Infra-Red data were relevant tools for stress detection.
关键词： remote-sensing,water stress,model,partition,evapotranspiration
更新于2025-09-09 09:28:46
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Slow crack growth in silica aerogels: A review
摘要： The sub-critical crack growth in hydrophobic (as prepared) and hydrophilic (oxidized) silica aerogel was studied using the Dynamic fatigue experiment and the Double-Cleavage-Drilled-Compression test (DCDC). The effect of oxidation treatment is clearly evidenced. The temperature and water vapor content dependence on the crack growth rate is measured between 22 °C and 110 °C with relative air moisture ranging from 5 to 80% RH. Like dense silica, crack growth velocities were found to decrease when increasing the temperature at a constant water vapor concentration. Surprisingly, the crack velocity also decreases when increasing water vapor content at constant temperature. Such a behavior is contrary to expected results usually encountered in glasses. We assume that a capillary condensation phenomenon of water vapor inside the aerogel porosity takes place, inducing internal compressive stresses.
关键词： Silica aerogels,Slow crack growth,Stress corrosion effect
更新于2025-09-09 09:28:46
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[IEEE 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Varna, Bulgaria (2018.9.20-2018.9.22)] 2018 Seventh Balkan Conference on Lighting (BalkanLight) - Automated Recognition of Affect and Stress evoked by Audio-Visual stimuli
摘要： In the present work, we consider the automated detection of negative emotions and high-arousal negative-valence (HANV) states, which are akin to acute stress occurring in specific context. We investigate the influence and intricacy which subjective perception of negative emotions and acute stress brings to the process of automated recognition of these states. For that purpose we experimentally evaluate the advantages of modelling based on the person-independent tags of the audio-video stimuli, and models built with the person-specific self-reported tags. Based on the self-reported tags, which are obtained with only tiny extra effort, we report a relative improvement of the HANV detection accuracy with up to 5%.
关键词： Stress detection,galvanic skin response (GSR),Emotion recognition,electrocardiography (ECG)
更新于2025-09-09 09:28:46
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - The Application of Pulsed Electric Fields and Other Types of Electromagnetic Radiation in Therapy of Cancer
摘要： since the beginning of 21-th century the investigations in the area of cancer therapy by electric fields become more numerous. These investigations may be divided in three groups: studies carried out on cell cultures, studies on animal models and case reports describing applications of pulsed electric fields for treatment of cancer patients. Very important is to chose adequate methods of measuring the cell damage and speaking more generally – cell response to stress. In Kharkov University various investigations in the area of cell response to electromagnetic influences were carried out and some new methods were proposed. In this paper the analysis of recent works in this area is done and perspectives of the research are discussed.
关键词： electromagnetic pulse,cell proliferation,cell membrane permeability,cell response to electromagnetic stress,apoptosis,cancer therapy,necrosis
更新于2025-09-09 09:28:46
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[IEEE 2018 34th International Conference on Lightning Protection (ICLP) - Rzeszow (2018.9.2-2018.9.7)] 2018 34th International Conference on Lightning Protection (ICLP) - Finite Element Simulation of a ZnO Varistor Stressed by a 4/10μs Current Impulse
摘要： When ZnO varistors are stressed by 4/10μs current impulses, mechanical cracking occasionally occurs. Based on finite element method, an electro-thermal-mechanical simulation of a ZnO varistor exposed to a 4/10μs current impulse is shown in the present paper focusing on temperature and thermal-induced mechanical stress distribution. The goal is to obtain a better understanding of the failure phenomenon under high current impulse with short duration. Conclusions of varistor design and manufacture are drawn after simulation analysis.
关键词： temperature,high current impulse,ZnO varistor,stress
更新于2025-09-09 09:28:46
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Trapping Effects Induced by Gate OFF-State Stress in AlGaN/GaN High-Electron-Mobility Transistors with Fe-Doped Buffer
摘要： This paper investigates the trapping characteristics in passivated Al0.23Ga0.77N/GaN High-Electron-Mobility transistors (HEMTs) with an Fe-doped buffer on Sapphire substrate. Double pulsed current–voltage (I–V ) measurements clearly exhibited the current collapse and slow detrapping transients characteristics. It is attributed to the injection of electron from gate to the traps located in the interface, the Al0.23Ga0.77N barrier and the Fe-doped buffer. By various pulse-widths of 0.5 μs, 5 μs, 10 μs, 50 μs and 0.1 ms and amplitudes of pulse-baseline (VGS-Q, VDS-Q) of ?6 V and ?8 V, we spatially analyzed the locations and corresponding detrapping time constants of the dominant traps in the device. Three different types of traps were found: a fast one with the time constant τ = 12–16 μs at the interface under gate, a middle one with τ = 0.12 ms in the AlGaN barrier layer, and a slow one in the Fe-doped GaN buffer under high reverse OFF-state stress with τ = 1.78 ms. Thus in the high voltage applications, the buffer-related deep traps are most significant.
关键词： Gate OFF-State Stress,Fe-Doped Buffer,Pulsed I–V,AlGaN/GaN HEMT,Trapping
更新于2025-09-09 09:28:46
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Photoplethysmographic Waveform Versus Heart Rate Variability to Identify Low Stress States. Attention Test
摘要： Our long-term goal is the development of an automatic identifier of attentional states. In order to accomplish it, we should firstly be able to identify different states based on physiological signals. So, the first aim of this work is to identify the most appropriate features, to detect a subject high performance state. For that, a database of electrocardiographic (ECG) and photopletysmographic (PPG) signals is recorded in two unequivocally defined states (rest and attention task) from up to 50 subjects as a sample of the population. Time and frequency parameters of heart/pulse rate variability have been computed from the ECG/PPG signals respectively. Additionally, the respiratory rate has been estimated from both signals and also six morphological parameters from PPG. In total, twenty six features are obtained for each subject. They provide information about the autonomic nervous system and the physiological response of the subject to an attention demand task. Results show an increase of sympathetic activation when the subjects perform the attention test. The amplitude and width of the PPG pulse were more sensitive that the classical sympathetic markers (PLFn and RLF/HF) for identifying this attentional state. State classification accuracy reaches a mean of 89 ± 2%, a maximum of 93% and a minimum of 85%, in the hundred classifications made by only selecting four parameters extracted from the PPG signal (pulse amplitude, pulse width, pulse downward slope and mean pulse rate). These results suggest that attentional states could be identified by PPG.
关键词： Heart Rate Variability,Low Stress,Photoplethysmographic Waveform,Bagging
更新于2025-09-09 09:28:46
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Residual Stress Image Inspections based on Bending Testing for Flexible Transparent Conducting Substrates by Single-direction Common-path Image Interferometry
摘要： This paper proposes a method for automatic inspection of residual stress images based on bending testing for flexible transparent conducting substrates. A flexible characteristics inspection system with single-direction common-path image interferometry is utilized to inspect residual stress images automatically during the bending testing operation. Accordingly, a 5×5 cm2 residual stress image of a 203-μm line pattern on a conducting indium tin oxide (ITO) film deposited on polyethylene terephthalate (PET) substrate with up to 11,000 bending cycles is inspected and analyzed. The relationship between the residual stresses and resistance characteristics of the 203-μm line pattern on the ITO-deposited-on-PET substrate based on bending testing is also analyzed. It was found that the change results of residual stress can predict the resistance characteristics of the ITO-deposited-on-PET substrate sufficiently. Therefore, the inspection results of residual stress images depicted on flexible electronics may help designers and manufacturers to develop products and ensure quality control, respectively, in a manufacturing process.
关键词： residual stress image,bending testing,image single-direction common-path interferometry,flexible characteristics inspection system,ITO-deposited-on-PET substrate
更新于2025-09-09 09:28:46