Plasma Oxidation Research Articles

Transport of microplastics treated with dielectric barrier discharge (DBD) plasma in saturated porous media

The performance of discharge plasma in treating organic pollutants and micro-organisms in water is impressive. When discharge plasma is used to treat polluted water containing organic pollutants and microorganisms, the presence of a certain amount of microplastics (MPs) in the water is unavoidable due to the complexity of the components contained in the water and the prevalence of MPs. MPs, as one of the pollutants that are difficult to be degraded by discharge plasma, undergo physical and chemical changes that increase their risk in the environment after treatment. Therefore, it is necessary to understand the fate of MPs after being treated with discharge plasma. In this study, the surface morphology of plastics before and after discharge plasma treatment was observed by scanning electron microscopy (SEM). The plastics after discharge plasma treatment were characterized by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) to determine the changes in oxygen-containing functional groups on the surface. The recovery of microplastics (MPs) in saturated porous media under different physicochemical and plasma oxidation conditions was investigated by column experiments. It has been shown that MPs exhibit increased recovery under conditions of increased flow rate and pH. A decrease in recovery was observed at elevated ionic strength and co-existing cation valence. High voltages and low air flow rates increase the oxidation of MPs by increasing the thermal effects of the dielectric barrier discharge (DBD) plasma system, the amount of reactive oxygen species (ROS) and the intensity of ultraviolet ray (UV) irradiation. The mobility of MPs is enhanced by a combination of these factors. The advection–dispersion equation (ADE) fits the transport data of MPs well. The interaction energy between quartz sand and MPs was calculated using the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. This study provides a new perspective on the potential risks of discharge plasma in water treatment.

Altered oxidant and antioxidant levels are associated with vascular stiffness and diabetic kidney disease in type 1 diabetes after exposure to acute and chronic hyperglycemia

BackgroundHyperglycemia-induced oxidative stress is a well-established pathological mediator of vascular complications in diabetes. We assessed plasma oxidant and antioxidant levels in response to acute and chronic hyperglycemia in relation to vascular stiffness and varying degrees of kidney disease in type 1 diabetes individuals.MethodsThe acute hyperglycemia study included 22 type 1 diabetic individuals with normal albumin excretion rate (AER) and 13 non-diabetic controls. These individuals received an acute glucose challenge during a 120-minute hyperglycemic clamp. The chronic hyperglycemia study included 118 type 1 diabetic individuals with chronically low (n = 60) or high (n = 58) HbA1c concentrations and varying degrees of diabetic kidney disease (DKD) classified as normal, moderate, or severe albuminuria (AER). Levels of malondialdehyde (MDA), reactive oxygen metabolites (ROMs), total antioxidant capacity (TAC), biological antioxidant potential (BAP) and superoxide dismutase (SOD) were measured from plasma or serum samples in the FinnDiane study.ResultsLevels of MDA (p < 0.01) and ROMs (p < 0.01) were elevated in type 1 diabetes individuals compared to non-diabetic controls at baseline. Acute hyperglycemia further increased MDA levels (p < 0.05) and sustained the elevation of ROMs in type 1 diabetes individuals. Acute hyperglycemic challenge impaired TAC in both non-diabetic (p < 0.05) and type 1 diabetes (p < 0.01) individuals compared to baseline whereas BAP was increased (p < 0.05) with no difference observed in non-diabetic controls. There was a positive association between high circulating MDA and AIx (r2 = 0.611, p = 0.05), and between delta ROMs and delta AIx (r2 = 0.955, p = 0.014) in combined analysis of individuals with type 1 diabetes and non-diabetic controls. Type 1 diabetes individuals with varying status of DKD, showed elevated levels of ROMs in those with high HbA1c compared to their counterpart with low HbA1c (p < 0.05). Individuals with severe albuminuria showed elevated ROM levels (p < 0.01) and depressed antioxidant capacity (p < 0.01) compared to those with normal AER of comparable HbA1c concentrations.ConclusionsBiomarkers of oxidative stress are associated with vascular stiffness and DKD following acute and chronic hyperglycemic exposure and may provide added value to HbA1c in understanding disease pathology, predicting risk and assessing the status of secondary complications of type 1 diabetes.

Regulatory effects of vitamin E nano-emulsion on blood metabolites, immunological variables, testicular architecture, and sperm ultrastructure of heat-stressed V-line rabbit bucks

The study investigated the beneficial effects of vitamin E-loaded nano-emulsion (NEVE) on hemato-biochemical changes, oxidative stress, inflammatory responses, immunological variables, and semen quality in heat-stressed rabbit bucks. Forty adult V-line rabbit bucks were randomly assigned to four groups and fed diets containing NEVE at 0 (NEVE0), 50 (NEVE50), 100 (NEVE100), and 200 (NEVE200) mg/kg for 12 weeks. The NEVE had a mean particle diameter of 32.6 nm, a polydispersity index of 0.6, and a zeta potential of −31.1 mV. The dietary NEVE significantly improved the hematological, blood protein, lipid profile, and liver functions of rabbit bucks (p < 0.05). The NEVE200 treated group showed higher levels of nitric oxide, TAC, and SOD in blood serum and seminal plasma compared to the control group (p < 0.05). Meanwhile, levels of MDA, IL-4, and TNF-α were significantly shrunken in response to the dietary treatment (p < 0.0001), while the IgA and IgG were improved in the NEVE100 and NEVE200 groups. The NEVE200 exhibited higher progressive motility, ejaculate volume, viability, and better libido (lower reaction time) than the untreated group (p < 0.05). TEM images illustrated that NEVE200 exhibited higher sperm cells with a normal structure, intact plasma membranes, and acrosomes than the other groups. Moreover, testicular architecture was improved with NEVE supplementation. Overall, the dietary addition of NEVE at 100 or 200 mg/kg could be an effective strategy to improve the health and semen quality of rabbit bucks during hot climates.

Tandem Oxidation Activation of Carbon for Enhanced Electrochemical Synthesis of H2O2: Unveiling the Role of Quinone Groups and Their Operando Derivatives

AbstractOxygen‐doped carbon materials show great promise to catalyze two‐electron oxygen reduction reaction (2e‐ORR) for electrochemical synthesis of hydrogen peroxide (H2O2), but the identification of the active sites is the subject of ongoing debate. In this study, a tandem oxidation strategy is developed to activate carbon black for achieving highly efficient electrochemical synthesis of H2O2. Acetylene black (AB) is processed with O2 plasma and subsequent electrochemical oxidation, resulting in a remarkable selectivity of &gt;96% over a wide potential range, and a record‐setting high yield of &gt;10 mol gcat−1 h−1 with good durability in gas diffusion electrode. Comprehensive characterizations and calculations revealed that the presence of abundant C═O groups at the edge sites positively correlated to and accounted for the excellent 2e‐ORR performance. Notably, the edge hydroquinone group formed from quinone under operando conditions, which is overlooked in previous research, is identified as the most active catalytic site.

Rapid Single Step Atmospheric Pressure Plasma Jet Deposition of a SERS Active Surface

Surface-enhanced Raman Spectroscopy (SERS) is a highly sensitive detection technique capable of nanomolar or lower detection limits for some analytes.1-3 The key parameter is control of the surface nanostructure to optimise this remarkable enhancement, providing non-destructive detection without the need for chemical labelling. The bottleneck for the wide applicability of SERS as a valuable analytical tool is twofold: (1) rapid fabrication with the required nanostructure and (2) the difficulty in recovering a baseline before exposure or re-exposure to the target matrix. Here we describe an atmospheric plasma jet method for rapid single-step synthesis of SERS active silver on glass and demonstrate the potential of plasma to remove the adsorbed analyte to recover a baseline.The method described in this study employs an atmospheric pressure plasma jet (APPJ) for rapid single-step deposition of nanostructured silver materials with SERS.4,5 Non-thermal plasmas under reduced pressure offer a unique redox chemistry, partly due to the highly energised electrons and are essential for processing many materials and chemical transformations. Electrochemically, a helium-conducting gas allows various redox reactions to occur, without the need of restricting solvent mediums. An APPJ presents a medium which can be considered an electrode due to the presence of electrons and electrolytes, with the ability to drive reduction processes.6 APPJs allow fascinating chemistry to occur, balancing the thermal kinetic energy distribution between electrons and other neutral and ionised species. Consequently, plasma jets are used for etching, cleaning, and medical treatments, as well as driving highly energised electrons in redox reactions.7-9 The plasma was ignited at a stainless-steel needle electrode tip positioned in a 440 mM I.D. ceramic nozzle, with a plume extending 2 mm from the nozzle tip. Silver deposits were ‘written’ precisely in a 2D regular pattern of plasma deposited silver on borosilicate glass for Raman interrogation without any post-treatment by feeding a silver salt into the APPJ. The APPJ ceramic nozzle prints 125 ± 25 m diameter silver islands with a height of approx. 370 nm, separated by 500 mm, these islands formed the rudimentary SERS substrates.The surface morphology and microstructure through SEM and AFM will be described– assessing how microstructure will correlate to SERS enhancement. The concentration dependence will be quantitatively evaluated using various analytes over a wide range of 1 x 10-7 M to 1 x 10-2 M. The detection limit was calculated using three times the lowest concentration detectable standard deviation, equating to 154 ppb. The particle morphology and SERS enhancement are compared to various commercial substrates. Using the same APPJ system for the deposition of silver metal, a helium plasma doped with 4 % oxygen, followed by a separate treatment of helium doped with 4 % hydrogen, was found effective in restoring the zero baseline Raman response. After the cleaning steps, all analytes could show zero baseline recovery with Raman response regeneration. After successive cycles of application of analyte and then oxygen and hydrogen treatment, there is a slight drop in the SERS signal.4,10 Silver readily oxidises to form silver oxide after exposure to helium plasma doped with oxygen, as confirmed using XRD and XPS. This plasma oxidation causes a change in the microstructure of the particles, ultimately sintering together with successive oxidation cycles.Plasma-prepared substrates show significant gains with respect to the economical use of materials and the rapidity of the synthesis of the substrates. We showcase using the atmospheric pressure plasma jet method for synthesis and baseline recovery as an integral part of an analytical device. This approach presents the prospect of reusing the same SERS device for analysis, which may be a key advantage for academic and industrial applications. 11-13 Figure caption:(a) Raman spectra of R6G with most prominent peak measured at 1651cm-1 after oxygen and hydrogen treatment with the black lines showing the Raman spectra of the surface before application of analyte. (b) The peak intensity at 1586cm-1 peak for 4MBA for each measurement cycle with the analyte and before analyte application (after oxygen and hydrogen treatment) (c) Depicting the cleaning and regeneration of SERS signal on a borosilicate substrate. Both 4MBA and R6G were dissolved in methanol at 1 x 10-4M and drop cast onto the substrate. (d) normal X-ray diffraction spectra of PDS between 5 – 80 o 2θ for the original plasma deposit (i), oxidised plasma clean (ii) and hydrogen plasma clean (iii). All assignment was carried out using the Bruker XRD database, using JCPDS 04-0783 and 43-0997 for Ag and Ag2O, respectively. Figure 1

High Resolution Surface Modification of WS2 via Plasma Oxidation and Electron Beam Reduction

High Resolution Surface Modification of WS2 via Plasma Oxidation and Electron Beam Reduction

Structure and Properties of Bioactive Titanium Dioxide Surface Layers Produced on NiTi Shape Memory Alloy in Low-Temperature Plasma.

The NiTi alloy, known for its shape memory and superelasticity, is increasingly used in medicine. However, its high nickel content requires enhanced biocompatibility for long-term implants. Low-temperature plasma treatments under glow-discharge conditions can improve surface properties without compromising mechanical integrity. This study explores the surface modification of a NiTi alloy by oxidizing it in low-temperature plasma. We examine the impact of process temperatures and sample preparation (mechanical grinding and polishing) on the structure of the produced titanium oxide layers. Surface properties, including topography, morphology, chemical composition, and bioactivity, were analyzed using TEM, SEM, EDS, and an optical profilometer. Bioactivity was assessed through the deposition of calcium phosphate in simulated body fluid (SBF). The low-temperature plasma oxidization produced titanium dioxide layers (29-55 nm thick) with a predominantly nanocrystalline rutile structure. Layer thickness increased with extended processing time and higher temperatures (up to 390 °C), though the relationship was not linear. Higher temperatures led to thicker layers with more precipitates and inhomogeneities. The oxidized layers showed increased bioactivity after 14 and 30 days in SBF. Low-temperature plasma oxidation produces bioactive titanium oxide layers on NiTi alloys, with a structure and properties that can be tuned through process parameters. This method could enhance the biocompatibility of NiTi alloys for medical implants.

Machinability improvement of titanium alloy in face grinding by ultrasonic assisted jet plasma oxidation

A novel machining technology, namely ultrasonic assisted jet plasma oxidation modification face grinding (UAJPMG), was proposed to improve the machinability of the titanium alloy, in which the titanium alloy materials are modified by plasma oxidation followed by face grinding. This paper introduced the processing principle of UAJPMG and the design of an ultrasonic jet nozzle to promote plasma oxidation. Using the ultrasonic jet nozzle produced in-house, the effect of the ultrasonic vibration on the plasma intensity was experimentally investigated. The results revealed that the application of ultrasonic vibration can diminish the thickness of the gas film by elevating the jet flow rate, thereby reducing the generation delay time and enhancing the plasma intensity. Subsequently, a scratch test was performed to assess the difference in the mechanical strength between the plasma oxide layer and the titanium alloy substrate. It was found that the plasma oxide layer with a reduced mechanical strength exhibited a deeper scratch depth under the same normal load. Based on these, the machining performance under different conditions was examined considering the removed material of the abrasive grains. Compared with the removed material was Ti-6Al-4V substrate in conventional face grinding, the ultrasonic assisted plasma oxidized material can inhibit the chip adhesion on the wheel working surface, resulting in a reduction of the grinding force and the surface roughness and an improvement of the groove shape accuracy. The novel machining technology, i.e., UAJPMG, proposed in this paper might provide a new approach for the precision machining of critical components made from titanium alloy.

Investigating the effect of O2 plasma treatment on the operational characteristics of Schottky-gate AlGaN/GaN HEMT

This study investigates the effect of O2 plasma treatment on the physical and electrical properties of the surface region in Schottky-gate AlGaN/GaN high electron mobility transistor (HEMT). We demonstrate that O2 plasma treatment significantly reduces the gate leakage current and enhances the on/off ratio by three orders of magnitude compared to devices without treatment. The O2 plasma treatment removes organic chemical residue and forms Ga–O bonds on the AlGaN surface beneath the gate metal. X-ray photoelectron spectroscopy results indicate that the treatment effectively forms a Ga–O compound oxide layer, which provides surface passivation. Furthermore, atomic force microscope analysis reveals a 50% reduction in surface roughness after the O2 plasma treatment. Using O2 plasma oxidation treatment caused a shift in the threshold voltage (VTH ) of Schottky-gate AlGaN/GaN HEMT. Initially measured at −5.26 V, the VTH value shifted to +0.5 V. Furthermore, we also employ TCAD simulation to assist in the process developed during the manufacturing process. It is worth noting that the drain current decreases as the Ga–O compound oxide layer increases. This is due to effectively depleted the polarization charges at the AlGaN/GaN interfaces during E-mode operation when reducing the thickness of the AlGaN layer beneath the gate metal. Our results demonstrate the importance of O2 plasma surface treatment in achieving optimal device performance. This study systematically discusses the effect of O2 plasma on AlGaN/GaN surface properties and the formation of Ga–O bonding. It offers insights into developing high-performance Schottky-gate AlGaN/GaN HEMT.

Mechanistic Insights into Plasma Oxidation of Ag Nanofilms: Experimental and Theoretical Studies.

Plasma oxidation of metals has been studied extensively to fabricate nanoporous oxides with the merits of room temperature treatment and facile control of the oxidation rate. Plasma oxidation of Ag, motivated by studies on atomic oxygen corrosion of Ag, is one of the most studied systems. However, several important questions remain unaddressed and even overlooked traditionally: the critical role played by atomic O in promoting oxidation, evolution of microstructures during plasma exposure, and a sound framework for quantitative oxidation kinetic analyses. In this paper, the O2 plasma oxidation behavior of Ag films deposited on Si substrates was systematically studied both experimentally and theoretically. The effects of plasma pressure and power on the microstructural evolution and oxidation kinetics of Ag films of various thicknesses were investigated using comprehensive characterization, as well as numerical analysis of plasma chemistry for deriving atomic O concentration. The findings here provide a full picture and deep mechanistic insights into the morphology and microstructure evolution of Ag films and the growth of dense or porous Ag2O and AgO oxide layers by plasma oxidation, revealing the intricate interplay between atomic O, vacancy creation, Ag ion diffusion, Kirkendall effect, formation of pores, and interfacial void coalescence. The methodology developed here can be easily transferred to help understand the plasma oxidation behavior of other metals.

Digital etching of AlGaN/GaN heterostructures with GaN cap using inductively coupled oxygen plasma process combined with wet chemical treatment

In this work, AlGaN with a GaN cap has been etched in a cyclical process with ICP-RIE O2 plasma oxidation and wet etching in dilute HCl. The oxygen plasma ICP-RIE etching of the AlGaN at an ICP plasma power of 200 W and radio frequency bias power of 100 W led to an etch depth of ∼1.5 nm per digital cycle with increased surface roughness. The AlGaN remained unaffected by the wet etching process alone without any ICP-RIE O2 plasma oxidation, maintaining a surface roughness similar to that of the substrate. AlGaN was etched to a depth of ∼12 nm after six cycles of digital etching with an etch rate of 1.9–2.1 nm/cycle showing an improved surface roughness. The XPS analysis at each stage of the etching process reveals that the O2 plasma oxidation initially oxidizes the GaN cap and the AlGaN layer and is later effectively removed by the HCl solution. The digital etching method has proven effective in controlling etch depth and surface roughness, which are needed to fabricate AlGaN high electron mobility transistors.

Degradation of methyl orange using hydrodynamic cavitation coupled with plasma oxidation and ultraviolet C

Combining multiple advanced oxidation processes (AOPs) is essential for the efficient treatment of dye wastewater. In this study, the degradation efficiencies of various oxidation methods, including hydrodynamic cavitation (HC), dielectric barrier discharge (DBD) plasma oxidation, ultraviolet C (UVC), and their combination HC + DBD + UVC, were investigated for Methyl Orange (MO). The photolysis of ozone (O3) and the degradation mechanism associated with HC + DBD + UVC were analyzed to elucidate the pathway of MO degradation. The results demonstrated that the combination of HC + DBD + UVC exhibited a significantly enhanced degradation efficiency compared to other process combinations, achieving a removal efficiency exceeding 91% within a 5-min timeframe. Optimal parameters for achieving a 99.5% degradation rate of 10 mg/L MO were determined as follows: pH 4, inlet pressure of 1.5 MPa, utilization of eight UV lamps with a power input of 46.11 W. During the degradation process, hydroxyl radicals (·OH) and ozone (O3) played crucial roles, while the incorporation of UV lamps effectively mitigated ozone (O3) emissions and enhanced the oxidation of ozone (O3). In conjunction with the analysis of degradation products using liquid chromatography-mass spectrometry, it is highly probable that the MO degradation pathway involves reductive cleavage of the azo bond through ·OH attack. Compared to other experimental methods in literature, HC + DBD + UVC exhibits significant advantages such as enhanced efficiency and absence of additives. This innovative approach offers a rapid and practical on-site solution for efficient MO dye wastewater treatment.

Oxidised Albumin Levels in Plasma and Skeletal Muscle as Biomarkers of Disease Progression and Treatment Efficacy in Dystrophic mdx Mice.

Redox modifications to the plasma protein albumin have the potential to be used as biomarkers of disease progression and treatment efficacy in pathologies associated with inflammation and oxidative stress. One such pathology is Duchenne muscular dystrophy (DMD), a fatal childhood disease characterised by severe muscle wasting. We have previously shown in the mdx mouse model of DMD that plasma albumin thiol oxidation is increased; therefore, the first aim of this paper was to establish that albumin thiol oxidation in plasma reflects levels within mdx muscle tissue. We therefore developed a method to measure tissue albumin thiol oxidation. We show that albumin thiol oxidation was increased in both mdx muscle and plasma, with levels correlated with measures of dystropathology. In dystrophic muscle, albumin content was associated with areas of myonecrosis. The second aim was to test the ability of plasma thiol oxidation to track acute changes in dystropathology: we therefore subjected mdx mice to a single treadmill exercise session (known to increase myonecrosis) and took serial blood samples. This acute exercise caused a transient increase in total plasma albumin oxidation and measures of dystropathology. Together, these data support the use of plasma albumin thiol oxidation as a biomarker to track active myonecrosis in DMD.

Cost-Effective Fabrication of Polydimethylsiloxane (PDMS) Microfluidics for Point-of-Care Application

Microfluidics fabrication pertains to the construction of small-scale devices and systems that manipulate and control small volumes of fluids. This process involves precise engineering and manufacturing procedures aimed at designing and producing these devices, which find applications in healthcare, environmental monitoring, and chemical analysis. The present study showcases an inexpensive approach to fabricate microfluidics channels using PDMS biopolymer and soft lithography technique to achieve laminar fluid flow. Initially, a robust and adhesive mold was created by fabricating a master template using several layers of SU-8 5 and SU-8 2015 negative photoresists. Subsequently, PDMS microfluidics channels were replicated and sealed onto a glass substrate through plasma bonding treatment. High-power microscopy images and profilometer analyses demonstrated successful fabrication with minimal deviation from the initial designs and the fabricated devices (less than 0.07 mm, less than 0.6°). Both the SU-8 master template and PDMS replicate displayed average microchannel height values and surface roughness of 100 μm and 0.26 μm or lower, respectively. Additionally, the fluid test confirmed laminar flow without any leakage post plasma oxidation, indicating the completion of an efficient and cost-effective fabrication process.

The differences between the hydrogenation by means of photon-injection and electron-injection for N-type tunnel oxide passivated contacts solar cells

Tunnel Oxide Passivated Contact (TOPCon) solar cells have received widespread attention in recent years, especially in improving conversion efficiency. This paper investigated the impact of hydrogenation technology using photon-injection (HPI) and electron-injection (HEI) processes on TOPCon solar cells, highlighting the higher improvement effect and broader application scope of HPI compared to HEI. In TOPCon cells, several methods are available to prepare the tunneling oxide layer, such as plasma oxidation (PO) and indirect thermal oxidation (TO). The research results indicated that significant improvement differences could be observed when utilizing the HEI treatment for TOPCon solar cells prepared by PO and TO methods, with values of 0.133%abs. and −0.039%abs., respectively. Meanwhile, HPI treatment induced a more significant efficiency improvement for these two types of cells, and the increase in efficiency is 0.247%abs. and 0.244%abs., respectively. The experimental results demonstrated that the passivation effect for TOPCon solar cells prepared by PO and TO methods remained almost the same under the HPI treatment, and the improvement effect is less dependent on the tunnel oxidation technique used. Thus, the different passivation effects between HPI and HEI were further investigated, and the reason for the difference was attributed to the charge states and concentrations of hydrogen and non-equilibrium carriers during the hydrogenation. The results provided an improved scheme for enhancing the efficiency of TOPCon solar cells, shedding light on the role of HPI and HEI in the passivation process. This work brings further insights to TOPCon solar cells.

#1073 Changes in endothelial function in patients with impaired central and renal hemodynamics respiratory pathology

Abstract Background and Aims To determine the degree of influence of endothelial dysfunction on the hemodynamics of renal and central vessels in respiratory pathology, as well as to determine the effectiveness of complex therapy regimens with carvedilol. Method Studies were conducted in 26 patients with chronic obstructive pulmonary disease (COPD) of II- III severity (group 1, in whom the level of glomerular filtration rate of the kidneys eGFR CKD-EPI ≥6 ml/min/1.73 m2 was determined) and 32 patients with COPD of IV severity (group 2, they were determined e GFR CKD-EPI ≥60 ml/min/1.73 m2). Patients received one course of ten-day standard therapy (GOLD, 2020) in combination with a beta–blocker drug, T. carvedilol 5 mg (Vertex). Doppler echocardiographic examination of peripheral vessels, heart and renal vessels of patients was performed. Stable metabolites of nitric oxide (Cm NO) in blood plasma, ventilation and perfusion state of the lungs were determined. Results A significant decrease in the functional state of the respiratory system was parallel with a decrease in Cm NO synthesis, which was clearly reflected in the second group (by 11%) compared with the first group (by 7%). Pronounced structural changes with remodeling of the right parts of the heart, as well as a pronounced degree of pancreatic hypertrophy in the second group were accompanied by a sharp change in renal filtration function (eGFR ≤60 ml/min/1.73 m2). When measuring the state of diastolic dysfunction of the right parts of the heart, a decrease in E/As well as an increase in the circulatory vascular resistance index and mean blood pressure were significantly higher in the first group of patients (where еGFR ≥6 ml/min/1.73 m2). After a course of treatment with t. carvedilol, based on basic treatment, normalization of endothelial function was determined, reflected in an increase in the concentration of stable metabolites of nitric oxide by 1.05 and 1.5 times (p&amp;lt;0.05) in the biological fluid, respectively, in the first and second groups. In the dynamics of the course of therapy in groups of patients with 75% and 35% decrease in lung ventilation capacity, mean pulmonary arterial pressure decreased by 18.1 and 14.3%, respectively, and the hemodynamic resistance index decreased by 7.9% and 5.7% in parallel (p&amp;lt;0.05). Conclusion When monitoring the functional state of central and renal hemodynamics and ventilation-perfusion function of the bronchopulmonary system after complex treatment with carvedilol, a long-term hypotensive effect, a decrease in endothelial dysfunction, respectively, and an improvement in central and renal hemodynamics were determined.

Antenatal creatine supplementation reduces persistent fetal lung inflammation and oxidative stress in an ovine model of chorioamnionitis.

Chorioamnionitis is a common antecedent of preterm birth and induces inflammation and oxidative stress in the fetal lungs. Reducing inflammation and oxidative stress in the fetal lungs may improve respiratory outcomes in preterm infants. Creatine is an organic acid with known anti-inflammatory and antioxidant properties. The objective of the study was to evaluate the efficacy of direct fetal creatine supplementation to reduce inflammation and oxidative stress in fetal lungs arising from an in utero proinflammatory stimulus. Fetal lambs (n = 51) were instrumented at 90 days gestation to receive a continuous infusion of creatine monohydrate (6 mg·kg-1·h-1) or saline for 17 days. Maternal chorioamnionitis was induced with intra-amniotic lipopolysaccharide (LPS; 1 mg, O55:H6) or saline 7 days before delivery at 110 days gestation. Tissue creatine content was assessed with capillary electrophoresis, and inflammatory markers were analyzed with Luminex Magpix and immunohistochemistry. Oxidative stress was measured as the level of protein thiol oxidation. The effects of LPS and creatine were analyzed using a two-way ANOVA. Fetal creatine supplementation increased lung creatine content by 149% (PCr<0.0001) and had no adverse effects on lung morphology. LPS-exposed groups showed increased levels of interleukin-8 in the bronchoalveolar lavage (PLPS<0.0001) and increased levels of CD45+ leukocytes (PLPS<0.0001) and MPO+ (PLPS<0.0001) cells in the lung parenchyma. Creatine supplementation significantly reduced the levels of CD45+ (PCr=0.045) and MPO+ cells (PCr=0.012) in the lungs and reduced thiol oxidation in plasma (PCr<0.01) and lung tissue (PCr=0.02). In conclusion, fetal creatine supplementation reduced markers of inflammation and oxidative stress in the fetal lungs arising from chorioamnionitis.NEW & NOTEWORTHY We evaluated the effect of antenatal creatine supplementation to reduce pulmonary inflammation and oxidative stress in the fetal lamb lungs arising from lipopolysaccharide (LPS)-induced chorioamnionitis. Fetal creatine supplementation increased lung creatine content and had no adverse effects on systemic fetal physiology and overall lung architecture. Importantly, fetuses that received creatine had significantly lower levels of inflammation and oxidative stress in the lungs, suggesting an anti-inflammatory and antioxidant benefit of creatine.

Influence of MXene Composition on Triboelectricity of MXene-Alginate Nanocomposites.

MXenes are highly versatile and conductive 2D materials that can significantly enhance the triboelectric properties of polymer nanocomposites. Despite the growing interest in the tunable chemistry of MXenes for energy applications, the effect of their chemical composition on triboelectric power generation has yet to be thoroughly studied. Here, we investigate the impact of the chemical composition of MXenes, specifically the Ti3CNTx carbonitride vs the most studied carbide, Ti3C2Tx, on their interactions with sodium alginate biopolymer and, ultimately, the performance of a triboelectric nanogenerator (TENG) device. Our results show that adding 2 wt % of Ti3CNTx to alginate produces a synergistic effect that generates a higher triboelectric output than the Ti3C2Tx system. Spectroscopic analyses suggest that a higher oxygen and fluorine content on the surface of Ti3CNTx enhances hydrogen bonding with the alginate matrix, thereby increasing the surface charge density of the alginate oxygen atoms. This was further supported by Kelvin probe force microscopy, which revealed a more negative surface potential on Ti3CNTx-alginate, facilitating high charge transfer between the TENG electrodes. The optimized Ti3CNTx-alginate nanogenerator delivered an output of 670 V, 15 μA, and 0.28 W/m2. Additionally, we demonstrate that plasma oxidation of the MXene surface further enhances triboelectric performance. Due to the diverse surface terminations of MXene, we show that Ti3CNTx-alginate can function as either tribopositive or tribonegative material, depending on the counter-contacting material. Our findings provide a deeper understanding of how MXene composition affects their interaction with biopolymers and resulting tunable triboelectrification behavior. This opens up new avenues for developing flexible and efficient MXene-based TENG devices.

Fabrication of silicon sharp nanocones using dry etch with periodic oxygen plasma shrinking and wet etch

Silicon (Si) nanocones have a wide range of applications in microelectromechanical systems and nanoelectromechanical systems. There is an increasing demand for precise control over the size and shape of nanocones. This paper proposed a novel method combining Si dry etch with periodic oxygen plasma shrinking, wet etch, and oxidation sharpening to achieve well-defined sharp Si nanocones. First, the standard Bosch process was employed to create the base part of nanocones. Second, two alternating steps of etching with sulfur hexafluoride/octafluorocyclobutane plasma and photoresist shrinkage with oxygen plasma were used to form the cone-shaped structures on top of the cylindrical bases. Third, to obtain a sharp tip, wet etching was carried out in either potassium hydroxide or a nitric acid/hydrofluoric (HF) acid mixture. To further sharpen the Si tips, thermal oxidation and HF dipping were conducted and the apex of nanocones can be down to 20 nm. This technique provides a cost-effective way to manufacture nanocones for various applications.

High-κ Dielectric (HfO2)/2D Semiconductor (HfSe2) Gate Stack for Low-Power Steep-Switching Computing Devices.

Herein, a high-quality gate stack (native HfO2 formed on 2D HfSe2) fabricated via plasma oxidation is reported, realizing an atomically sharp interface with a suppressed interface trap density (Dit ≈ 5 × 1010 cm-2 eV-1). The chemically converted HfO2 exhibits dielectric constant, κ ≈ 23, resulting in low gate leakage current (≈10-3 A cm-2) at equivalent oxide thickness ≈0.5 nm. Density functional calculations indicate that the atomistic mechanism for achieving a high-quality interface is the possibility of O atoms replacing the Se atoms of the interfacial HfSe2 layer without a substitution energy barrier, allowing layer-by-layer oxidation to proceed. The field-effect-transistor-fabricated HfO2/HfSe2 gate stack demonstrates an almost ideal subthreshold slope (SS) of ≈61 mV dec-1 (over four orders of IDS) at room temperature (300 K), along with a high Ion/Ioff ratio of ≈108 and a small hysteresis of ≈10 mV. Furthermore, by utilizing a device architecture with separately controlled HfO2/HfSe2 gate stack and channel structures, an impact ionization field-effect transistor is fabricated that exhibits n-type steep-switching characteristics with a SS value of 3.43 mV dec-1 at room temperature, overcoming the Boltzmann limit. These results provide a significant step toward the realization of post-Si semiconducting devices for future energy-efficient data-centric computing electronics.