- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
The assessment of autofluorescence of the crystalline lens in diabetic patients and healthy controls: can it be used as a screening test?
摘要： Background: Our purpose was to demonstrate if measuring lens autofluorescence (AF) with a scanning confocal biomicroscope may be used to identify subjects with undiagnosed type II diabetes mellitus (DM), and hence, for it to be used as a marker for the severity of diabetic retinopathy in diabetic patients. Patients and methods: In this cross-sectional, comparative study, lens AF was measured with scanning confocal lens fluorescence biomicroscope in diabetic and healthy groups. Full ophthalmological examination was performed. Blood tests of fasting plasma glucose, and glycosylated hemoglobin were also analyzed. The correlation between lens AF results and blood tests was evaluated in both groups. The cutoff value for the diagnosis of DM using lens AF was investigated. Results: The study included 191 subjects with a mean age of 52.09±6.75 years. One hundred and seven (56.0%) subjects were female, and 84 (44.0%) were male. Eighty-two (42.9%) patients had type II DM, and 109 (57.1%) subjects self-reported as normal. The fluorescence ratio (FR) values ranged from 0.09 to 0.46 (0.23±0.06) in the total group. Mean FR measurements of diabetic subjects were significantly higher (0.27±0.06) than those without DM (0.20±0.05), ( p=0.001). A statistically significant correlation was found between glycosylated hemoglobin, fasting plasma glucose, and FR. The cutoff point for the FR according to the presence of DM was found to be 0.24 and above ( p=0.001), with a sensitivity of 71.95% and a specificity of 80.73%. Conclusion: Measuring AF of human lens as an indirect evidence of increased advanced glycation end products may helpful in detecting impaired glucose metabolism. Our results show highly significant correlation between possibility of DM and FR.
关键词： fasting plasma glucose,diabetic retinopathy,screening,HgA1c,lens autofluorescence,diabetes
更新于2025-09-23 15:22:29
-
Formation of Stainless Steel Nanoballs via Submerged Glow-discharge Plasma and their Microstructural Analysis with Evaluation of Photocatalytic Activity
摘要： Stainless steel has shown potential as a catalytic material in bulk form. However, it only becomes active in an aqueous acidic environment and elevated temperatures. This study aims to produce stainless steel nanoparticles that have high photocatalytic activity in a neutral medium and at room temperature and to elucidate the photocatalytic activity mechanism of the nanoparticles. Spherical, photocatalytic nanoparticles called 'nanoballs' were synthesized by the submerged glow-discharge method. Stainless steel SUS316L grade wire was used as the cathode, platinum mesh was used as the anode while the electrolyte was potassium carbonate. The nanoballs were obtained after centrifuging and washing with water. The physical characteristics of the photocatalytic nanoballs were analysed by scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction. The nanoballs were mixed with methylene blue and irradiated with ultraviolet light for the evaluation of photocatalytic reaction. The photodecomposition samples were determined using UV-vis spectrometry. The by-products of the photodecomposition were evaluated using mass spectrometry. The results show that stainless steel nanoballs have photocatalytic activity when irradiated with ultraviolet light at room temperature. Submerged glow-discharge plasma method can synthesize nanoparticles rapidly using only metal wires as the electrode.
关键词： photocatalysis,nanoballs,stainless steel,plasma discharge,nanoparticles
更新于2025-09-23 15:22:29
-
Light-Field Imaging for Plasma Wind-Tunnel Application
摘要： Limited optical access and high apparatus complexity are the main challenges for true three-dimensional (3-D) measurements in high-enthalpy plasma flows. However, with the advent of plenoptic cameras, the one-shot and single-camera acquisition of light-field data has become possible, enabling the 3-D analysis of complex scenes with one single optical access and one single exposure. So far, this technique has mostly been applied to problems containing opaque objects or particle-loaded flows. In this paper, approaches to explore the potential of light-field analysis for the 3-D investigation of brightly luminous, high-velocity plasma flows are presented. Using gas flames from a solder torch, the feasibility of plenoptic imaging of optically thin scenes is shown. The complete structure of the flame is derived from a single exposure. The transition of this approach to plasma-flow visualization is shown with very first acquisitions of a plasma freejet, including spectral filters for the measurement of the atomic oxygen distribution.
关键词： high-enthalpy flows,light-field imaging,plasma wind tunnel,plenoptic camera,3-D reconstruction
更新于2025-09-23 15:22:29
-
[IEEE 2018 International Symposium on Electronics and Telecommunications (ISETC) - Timisoara, Romania (2018.11.8-2018.11.9)] 2018 International Symposium on Electronics and Telecommunications (ISETC) - Investigation of Wave Propagation in a Plasma Antenna using 3D FDTD
摘要： The advancement of computer technology has led numerical methods to obtain a widespread usage. One of the most frequently used numerical methods in recent years is finite difference time domain method (FDTD). The behaviour of electromagnetic waves at the boundaries of the problem space has been studied by using perfectly matched layer (PML) type boundary conditions in FDTD.On the other hand, the majority of the substances in the universe are plasma. Plasma is a well known reconfigurable medium with different dielectric and conductive properties. Operating frequency of a plasma antenna is investigated in this paper. The field distributions around the plasma antenna have been evaluated using three dimensional FDTD. It has been shown that the plasma antenna can operate with characteristics similar to a wire antenna. C/C++ and MATLAB programming environments are used for simulations.
关键词： Finite Difference Time Domain,perfectly matched layer,plasma antenna
更新于2025-09-23 15:22:29
-
Controlling Silver Ion Release from Ag-Based Nanocoatings by Plasma Surface Engineering
摘要： Environmental surfaces have been widely recognized as an important source of hospital-associated transmissions. A number of silver-based antibacterial coatings have been reported in the literature. However, the success of any antibacterial strategy depends on the ability to control the kinetics of the silver ions released from the coating. The novel strategy proposed in this work is based on plasma surface engineering for a controlled-release of silver ions. Plasma-based nanocoatings, plasma oxidation processes and surface patterning of silver coatings were designed and optimized. Surface analyses such as XPS and AFM, as well as silver ion release over 168 h, was evaluated by MIP-AES. Results showed that surface plasma engineering successfully allow tuning the silver release and bioactivity in Ag-containing antibacterial coatings.
关键词： diamond-like carbon,plasma oxidation,silver release,antibacterial activity
更新于2025-09-23 15:22:29
-
Analysis and correction of probe location errors in spherical near-field antenna measurement
摘要： Cellulose is the most abundant natural polymer on earth. With the increasing shortage of oil resources, people have been focusing more on producing natural cellulose. In this study, guaiacol was used as the model compound to investigate the degradation of lignin in luffa. A new cellulose material was extracted from natural luffa by a pretreatment based on the oxidation and acidity of glow discharge plasma in water. The produced luffa cellulose was dissolved in anhydrous phosphoric/polyphosphoric acid (aPPAC) solvent to prepare cellulose film. Results showed that the reactive species of OH·, HO2· and H3O+ were produced during the plasma discharge of water. The free radicals ·OH were useful in eliminating lignin by the destruction of aromatic structure, whereas H3O+ in eliminating hemicellulose in the luffa raw material. At the conditions of luffa powder concentration of 9.26 g/L, discharge time of 20 min, and plasma power of 100W, the cellulose component was increased to 81.2%. After 25 min, the luffa cellulose was completely dissolved in the aPPAC solvent at 0–5 ?C. Thus, a regenerated cellulose film of cellulose II was prepared. The aPPAC solvent was a good non-derivatizing solvent for the luffa cellulose. The regenerated film exhibited good mechanical properties, wettability and a compact structure. Therefore, plasma pretreatment was an environmentally friendly and high-efficiency method for luffa degumming. The luffa cellulose can be well used in dissolution and regeneration in films.
关键词： plasma treatment,film,dissolution,luffa cellulose
更新于2025-09-23 15:22:29
-
Optical analysis during reduction of nitric oxide in microwave-induced plasma promoted by activated cokes at atmospheric pressure
摘要： Emission from microwave (MW)-induced argon plasma promoted by a bed of activated coke granules was analyzed spectroscopically during non-catalytic reduction of nitric oxide (NO) at atmospheric pressure. The spectral analysis with a high resolution revealed that strong 5 peaks were recognized in a similar wavelength region to N2+ first negative band when NO molecules were included in argon plasma. The strongest peak is caused by the Ar(II) ions excited with energy corresponding to 388.033 nm in the progress of atomic transition 3s23p4(3P)4d 4D1/2 → 3s23p4(3P)4p 4D°1/2. This transition must be enhanced by an interaction with any intermediates or radical species yielded during NO reduction reactions. The plasma temperatures were determined by Boltzmann plots from intensities of any two peaks in the spectral band. The temperature was significantly different dependently on choice of two peaks, whose fact is implying non-equilibrium plasma. The maximum temperature was recognized at a high level of 40,000 K due to the activation during the reactions. The images of the plasma observed by high-speed camera showed dynamic features so that MW discharge like streamer was generated frequently in the reactor. The reaction rate could be correlated with the ratio of the area dominated by dynamic plasma to the cross section in the reactor.
关键词： High-speed camera images,Argon plasma,Microwave discharge,Spectroscopic measurement,de-NOx
更新于2025-09-23 15:22:29
-
Development and preliminary results of phase contrast imaging diagnostic on HL-2A
摘要： Phase Contrast Imaging (PCI) diagnostic has been developed on HL-2 A tokamak. The chord integral density fluctuations of plasma can be obtained by measuring the phase shift of CO2 laser which has a wavelength of 10.6 μm after passing through plasma. The 32-channel detector array enables PCI to diagnose density fluctuations with wavenumbers ranging from 2 cm?1 to 15 cm?1. The temporal resolution of PCI is better than 2 μs which makes it suitable for broadband turbulence research. Calibration by the sound source confirms that PCI is able to discriminate a wide range of wavenumbers. The plasma density fluctuations measured by PCI on HL-2 A is presented for the first time. Comparison of MHD instability investigations with magnetic probe data shows the reliability of this PCI diagnostic.
关键词： Phase shift,Plasma density fluctuations,PCI
更新于2025-09-23 15:22:29
-
Effect of tantalum content on the structural properties and sensing performance of YbTaxOy electrolyte-insulator-semiconductor pH sensors
摘要： In this work, we developed YbTaxOy sensing membranes displaying super-Nernstian pH-sensitivity for use in electrolyte-insulator-semiconductor (EIS) pH sensors. We examined the effect of tantalum content on the structural properties and sensing characteristics of the YbTaxOy sensing membranes deposited through reactive co-sputtering onto Si substrates. X-ray diffraction, atomic force microscopy, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy revealed the structural, morphological, depth, and chemical features, respectively, of these YbTaxOy films prepared under various Ta plasma power conditions (from 80 to 160 W). Among the tested systems, the YbTaxOy EIS device prepared at the 120 W condition exhibited the super-Nernstian sensitivity (70.24 mV/pH), the lowest hysteresis voltage (1.5 mV), and the lowest drift rate (0.26 mV/h). Presumably, this condition optimized the stoichiometry of YbTaO4 in the film and its surface roughness while reducing the crystal defect and suppressing silicate formation at the YbTaxOy-Si interface. The super-Nernstian pH-sensitivity may be attributed to the incorporation of Ta ions in the Yb2O3 forming a YbTaO4 stoichiometric film, enhancing a change in oxidation state of Yb from trivalent ion to bivalent ion and thus transferring one electron to two protons in the redox reaction.
关键词： Electrolyte-insulator-semiconductor (EIS),Sensing characteristics,Plasma power,pH sensitivity,YbTaxOy
更新于2025-09-23 15:22:29
-
3D core-multishell piezoelectric nanogenerators
摘要： The thin film configuration presents obvious practical advantages over the 1D implementation in energy harvesting systems such as easily manufacturing and processing, and long-lasting and stable devices. However, ZnO-based piezoelectric nanogenerators (PENGs) generally rely on the exploitation of single-crystalline nanowires because of their self-orientation in the c-axis direction and ability to accommodate long deformations resulting in high piezoelectric performance. Herein, we show an innovative approach to produce PENGs by combining polycrystalline ZnO layers fabricated at room temperature by plasma-assisted deposition with supported small-molecule organic nanowires (ONWs) acting as 1D scaffolds. Such hybrid nanostructures present convoluted core-shell morphology, formed by a single-crystalline organic nanowire conformally surrounded by a poly-crystalline ZnO shell and combine the organic core mechanical properties with the ZnO layer piezoelectric response. In a step forward towards the integration of multiple functions within a single wire, we have also developed ONW-Au-ZnO nanoarchitectures including a gold shell acting as inner electrode achieving output piezo-voltages up to 170 mV. The synergistic combination of functionalities in the ONW-Au-ZnO devices promotes an enhanced performance generating piezo-currents one order of magnitude larger than the ONW-ZnO nanowires and superior to the thin film nanogenerators for equivalent and higher thicknesses.
关键词： piezoelectric nanogenerators,organic nanowires,ZnO,small-molecules,plasma deposition,core-shell nanowires
更新于2025-09-23 15:22:29