Search

Purpose: This study aims to describe the experiences of critically ill elderly patients (CIEPs) who were treated using the high-flow nasal cannula (HFNC) after extubation. Design/methodology/approach: A descriptive phenomenological approach was conducted to interview eleven CIEPs using face-to-face semi-unstructured interviews. Participants were selected through purposive sampling. Data were analyzed using Giorgi's method. Findings: Experiences of CIEPs included their fears of failure, getting comfortable and uncomfortable, as well as asking for assistance. Fears of failure were described as involving worsening symptoms related to their diseases and failure of HFNC leading to the need for reintubation. While receiving HFNC, their breathing was comfortable, and they were free from intubation. However, they were uncomfortable because of the sensation of burning in the nasal passages. Additionally, they asked for assistance from nurses in managing their symptoms, and the alarms of HFNC oxygen therapy devices resulted in fears of HFNC failure. Originality/value: The paper indicates that CIEPs experienced physical and psychological impacts from HFNC oxygen therapy (e.g. burning sensation in the nose and fear of failure). Although they had comfortable breathing, being uncomfortable also occurred. Therefore, health-care professionals should support what CIEPs need and develop a program or guidelines for managing the complications of HFNC – neither burning noses nor psychological issues enhance the comfort of CIEPs – by considering age-related changes. [ABSTRACT FROM AUTHOR]

Clean and O-(2 2 × 2 ) R45° Cu(100) surfaces were prepared to study the impact of surface oxygen on the activation of methane dissociation. Auger electron spectroscopy, low energy electron diffraction, infrared reflection absorption spectroscopy, scanning tunneling microscope, and a quadrupole mass-spectrometer for temperature programmed desorption were used to explore the behavior of CH4 on the two surfaces. The dissociative adsorption of CH4 was observed on oxygen-pre-covered Cu(100) but not on the clean surface indicating surface oxygen promotes the dissociation of the C–H bond. This study can be a reference for the conversion of methane into other high-value-added products with high efficiency and low energy consumption. [ABSTRACT FROM AUTHOR]

The activity and adsorption behavior of oxygen on rutile TiO2(110) (RTiO2(110)) were investigated using the temperature programmed desorption (TPD) method with methanol (CH3OH) as the probe molecule. By controlling the coverage of molecular O2 on the surface via increasing or decreasing O2 exposure, two chemisorbed O2 species on the surface are confirmed, one at the bridging oxygen vacancy (OV) site (O22-/Ov) and the other at the five-fold coordinated titanium (Ti5c) site (O22--/Ti5c). At low O2 exposure, O22--/OV is the main species on the surface, which only leads to the O–H bond cleavage of CH3OH, producing methoxy groups (CH3O). However, after the OV sites are nearly filled by O2 at about 0.1 L O2 exposure, O2/Ti5c species begins to appear on R-TiO2(110) surface, resulting in the formation of formaldehyde (CH2O) via the reaction of O2/Ti5c species with CH3OH or CH3O to break the C-H bond at low surface temperature. Moreover, the yield of CH2O increases linearly with that of H2O. In addition, when the 1 L O2 covered surface is irradiated with 355 nm UV irradiation to desorb and dissociate O2/Ti5c species, the yield of CH2O decreases linearly with that of H2O. Further analysis suggests that the charge state of O2/Ti5c may not change as the exposure of O2 changes on the R-TiO2(110) surface, and O2 is most likely to adsorb on the Ti5c sites in the form of O22-, not O2−. The result not only advances our understanding on the adsorption state of O2 on TiO2, but also provides clues for low temperature C–H bond activation with O2 on TiO2. [ABSTRACT FROM AUTHOR]

This study utilizes classical molecular dynamics (MD) simulations to examine the structure and the impact of cerium (Ce4+) incorporation, serving as a surrogate for plutonium (Pu), at the zirconium (Zr4+) site on the threshold displacement energy (Ed) for each atom within the δ-phase Y4Zr3O12 material along 100 different directions. The minimum Ed values obtained for Y, Zr, and O in Y4Zr3O12 are 50 eV, 60 eV, and 25 eV, respectively. Notably, the Y cation is more prone to displacement than the Zr cations, while oxygen anions are even more easily displaced than cations, requiring less energy for displacement. Furthermore, the incorporation of Ce4+ at the Zr4+ site in the Y4Zr3-3xCe3xO12 (0 ≤ x ≤ 0.5) system reduces both the minimum and average Ed values for Zr atoms. The presence of Ce also decreases the minimum Ed for Y at x = 0.5 and for OI at x = 0.125, while increasing the minimum Ed for OII at x = 0.25. These findings suggest that the incorporation of Ce can influence the radiation resistance of the Y4Zr3O12 material, thereby offering insights into potential strategies for enhancing its performance under radiation conditions. [ABSTRACT FROM AUTHOR]

As space missions proliferate and the payload requirements increase, the environmental impact of thrusters can no longer be considered negligible. Therefore, less impactful fuels such as methane are starting to be considered for launchers. In this paper we present a design case study for such a turbopump. Using both analytical models and Computational Fluid Dynamics techniques, we were able to reduce the size and weight of the turbopump assembly. Also, due to the elimination of some auxiliary systems, the overall efficiency was enhanced. This paper's findings and methods can be transferred not only to launchers in its own class, but also to larger scale engines with a similar construction. [ABSTRACT FROM AUTHOR]

Metabolic rewiring is a defining characteristic of cancer cells, driving their ability to proliferate. Leveraging these metabolic vulnerabilities for therapeutic purposes has a long and impactful history, with the advent of antimetabolites marking a significant breakthrough in cancer treatment. Despite this, only a few in vitro metabolic discoveries have been successfully translated into effective clinical therapies. This limited translatability is partially due to the use of simplistic in vitro models that do not accurately reflect the tumor microenvironment. This Review examines the effects of current cell culture practices on cancer cell metabolism and highlights recent advancements in establishing more physiologically relevant in vitro culture conditions and technologies, such as organoids. Applying these improvements may bridge the gap between in vitro and in vivo findings, facilitating the development of innovative metabolic therapies for cancer. [ABSTRACT FROM AUTHOR]

Dissolved oxygen (DO) is a crucial water quality characteristic in the cultivation of vannamei shrimp. Increasing the DO concentration in shrimp ponds can be carried out using the aeration method with a tool called an aerator. In this study, types of fine-pore aeration tubes are chosen. This aerator offers multiple benefits, such as superior aeration efficiency, effortless installation, and minimal clogging. In practice, fine-pore aeration tubes can be arranged according to needs, so the layout used can influence the resulting aeration performance. This research uses the computational fluid dynamics (CFD) method to analyze DO distribution, water circulation, and aeration performance ( K L a 20 , SOTR, and SOTE) produced in various aerator layouts, namely straight-type, ring-type, and square-type, in a vannamei shrimp pond. The results show that the straight-type layout has the best DO distribution because it is spread throughout the pond area. The square-type layout has the best water circulation because it has the largest area with water velocities of less than 5 cm/s. The optimal aeration performance was achieved with the straight-type layout, which demonstrated a K L a 20 value of 3.16 h−1, SOTR value of 19.20 kg/h, and SOTE of 29.30%. [ABSTRACT FROM AUTHOR]

Electric arc furnace (EAF) dust is an important secondary resource containing metals, such as zinc (Zn) and iron (Fe). Recovering Zn from EAF dust can contribute to resource recycling and reduce environmental impacts. However, the high chemical stability of ZnFe2O4 in EAF dust poses challenges to Zn recovery. To address this issue, a facile approach that involves oxygen-assisted chlorination using molten MgCl2 is proposed. This work focused on elucidating the role of O2 in the reaction between ZnFe2O4 and molten MgCl2. The results demonstrate that MgCl2 effectively broke down the ZnFe2O4 structure, and the high O2 atmosphere considerably promoted the separation of Zn from other components in the form of ZnCl2. The presence of O2 facilitated the formation of MgFe2O4, which stabilized Fe and prevented its chlorination. Furthermore, the excessive use of MgCl2 resulted in increased evaporation loss, and high temperatures promoted the rapid separation of Zn. Building on these findings, we successfully extracted ZnCl2-enriched volatiles from practical EAF dust through oxygen-assisted chlorination. Under optimized conditions, this method achieved exceptional Zn chlorination percentage of over 97% within a short period, while Fe chlorination remained below 1%. The resulting volatiles contained 85wt% of ZnCl2, which can be further processed to produce metallic Zn. The findings offer guidance for the selective recovery of valuable metals, particularly from solid wastes such as EAF dust. [ABSTRACT FROM AUTHOR]

Hydrographic observations and two-year current measurements revealed the flow around the Erimo Seamount between the Japan and Kuril trenches. Northward currents were observed to flow both around the seamount and on the eastern flank of the trench. Since the dissolved oxygen concentration of the former is higher than that of the latter, these currents correspond to the western and eastern branch currents of the deep western boundary current in the North Pacific, respectively. The western branch current forms a Taylor cap over the seamount, although during certain periods, it joins the eastern branch current. During such periods, a strong jet forms around the seamount and the Taylor cap is washed away. Such alternately intensified currents are consistent with previous observations of the Japan Trench. On the western flank of the trench, a southward current flows near the seafloor, while an eastward current is formed at a depth of 3360 m due to the confluence of the currents from north and south. [ABSTRACT FROM AUTHOR]

Oxygen, nitrogen and hydrogen elements in inorganic materials have attracted considerable attention. Based on more than 70 current Chinese standards and more than 40 journal papers in the past decade, the current status and development of inert gas fusion infrared absorption or thermal conductivity methods and standards for the determination of oxygen, nitrogen and hydrogen in inorganic material were reviewed, including steel and alloys, rare refractory metal alloys, light or heavy and precious non-ferrous metals, rare earth alloys, ferroalloys, non-ferrous intermediate alloys and inorganic non-metallic functional materials. The parameters in current standards were listed, including applicable objects, quantitative scope, sample mass, reference material and fluxes, as well as the main working conditions m methods from journals, such as analyte, element, instrument, crude, sample mass, fluxes, analytics power and reference material. Finally, the application prospects and development directions of gas analytics in inorganic materials were prospected. [ABSTRACT FROM AUTHOR]

Metallic titanium ingots can be manufactured via thermal decomposition of titanium sulfides. In our previous study, we thermodynamically and experimentally investigated the phase relationship of titanium oxides and sulfides under carbothermic and hydrogen gas flow atmospheres, that is, non-carbothermic atmospheres. Recently, carbon neutral processes for metallurgical processes that use plant-based biomass, which plays essential roles in environmental protection, have been focused. In this study, the gasification behavior of biomass was investigated by thermal gravimetry-differential thermal analysis, and the deoxidization and sulfurization behaviors that generate titanium sulfides were also experimentally investigated. The gasification behavior differs according to the type of biomass, including the amounts of H2O in the biomass. The reaction temperature for CO2 generation decreased with increasing biomass H2O content. However, the total amounts of generated gas ratios of H2O/CO2 were hardly different, and the partial pressures of oxygen during gasification were also fixed as a function of temperature. The products were analyzed using X-ray diffractometry and identified as titanium disulfide (TiS2), similar to a carbothermic process. [ABSTRACT FROM AUTHOR]

The development of passive NOx adsorbers with cost-benefit and high NOx storage capacity remains an on-going challenge to after-treatment technologies at lower temperatures associated with cold-start NOx emissions. Herein, Cs1Mg3Al catalyst prepared by sol--gel method was cyclic tested in NOx storage under 5 vol% water. At 100 °C, the NOx storage capacity (1219 mmol g-1) was much higher than that of Pt/BaO/Al2O3 (610 mmol g-1). This provided new insights for non-noble metal catalysts in low-temperature passive NOx adsorption. The addition of Cs improved the mobility of oxygen species and thus improved the NOx storage capacity. The XRD, XPS, IR spectra and in situ DRIFTs with NH3 probe showed an interaction between CsOx and AlOx sites via oxygen species formed on Cs1Mg3Al catalyst. The improved mobility of oxygen species inferred from O2-TPD was consistent with high NOx storage capacity related to enhanced formation of nitrate and additional nitrite species by NOx oxidation. Moreover, the addition of Mg might improve the stability of Cs1Mg3Al by stabilizing surface active oxygen species in cyclic experiments. [ABSTRACT FROM AUTHOR]

Real-time monitoring of changes in packaged food is crucial to ensure safety and alleviate environmental issues. Accordingly, the development of indicators and sensors for smart packaging has long been anticipated, especially for gases related to food deterioration and microbial growth. However, the characteristics of indicators and sensors used in food packaging cannot be adjusted according to the specific food type, making it essential to select and apply suitable indicators and sensors for each type of food. In this review, the principles and characteristics of gas indicators and sensors for oxygen, carbon dioxide, and ammonia that are commercialized or in the development phase were summarized, and their application status and prospects were assessed. Indicators and sensors for smart packaging are applied in forms such as films, labels, sachets, and devices. Their detection methods include redox reactions, analyte binding, enzyme reactions, pH changes, electron transfer, conformational changes, and electrode reactions. In this work, 9 types of indicators and sensors for oxygen, carbon dioxide, and ammonia were evaluated based on their detection and indication methods, materials, sensitivity, detection range, limit of detection, and advantages and disadvantages in food applications. We anticipate our review will propose criteria for selecting the optimal indicators and sensors for specific foods. Furthermore, this review examines the current application status and future prospects of these indicators and sensors. [ABSTRACT FROM AUTHOR]

Interplanetary (IP) shock is one of the most common phenomena that controls the shape and size of the magnetosphere. It affects the whole magnetosphere‐ionosphere‐thermosphere (MIT) system. We utilized the NO 5.3 μ ${\upmu }$m radiative emission, as observed by SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) onboard NASA's TIMED (Thermosphere Ionosphere Mesosphere Energetics Dynamics) satellite, to investigate its response to fast forward shock during 26 January 2017. The high latitude NO emission exhibits a strong enhancement (∼ ${\sim} $three times with respect to pre‐event value) during IP shock within 5 hr of onset. We analyzed both the energy dissipation sources and subsequent chemical mechanisms. The Field‐Aligned‐Current observations from Active Magnetosphere and Planetary Response Experiment (AMPERE), EISCAT measurements of Pederson conductivity and the defense Meteorological Satellite Program (DMSP F18) calculated hemispheric power demonstrate a strong intensification. The low energy particle precipitation from DMSP F18 spacecraft shows an early enhancement for energy less than 1 keV. The particle flux of higher energy responds later which remained elevated for longer duration. The thermospheric density and temperature also experience significant variation during IP shock. The NO molecule and temperature displayed an early enhancement. NO density increased by an order of magnitude with respect to the pre‐event value. About 20% $\%$ increase is noticed in the temperature variation. The atomic oxygen and atomic nitrogen illustrate an early depletion during IP event. The enhanced response of NO cooling to IP shock can be attributed to the combined effects of energy input and subsequent chemical mechanisms. Key Points: Response of thermospheric NO cooling emission to IP shock is studied during 26 January 2017The NO cooling emission shows a strong enhancement due to IP shockIt can be attributed to the increase in low energy particle precipitation, NO density and thermospheric temperature [ABSTRACT FROM AUTHOR]

Herein is studied the soot oxidation over platinum group metal oxide/CeO2–ZrO2 (PGM/CZ) catalysts. The ability to capture gas-phase oxygen was in sequence of Ru/CZ > Rh/CZ > Ir/CZ > Pt/CZ > Pd/CZ. A soot oxidation test by TG-DTA showed that Ru/CZ, Rh/CZ, and Ir/CZ are highly active catalysts. It was found that there is a good correlation between the ability to capture gas-phase oxygen and soot oxidation activity. TEM observation revealed that soot oxidation mainly occurs at the interface between soot and CZ surfaces. The Ea values and soot oxidation test using labelled oxygen suggest that highly active catalysts oxidize soot by CZ lattice oxygen. For Ir/CZ, soot oxidation at 270 °C occurred due to the reduction by soot. Ru/CZ and Rh/CZ captured gas-phase oxygen spontaneously below 250 °C, resulting in soot oxidation at 270 °C. H2-TPR results suggest that the reactivity of lattice oxygen in the CZ surface, improved by PGM, is also related to soot oxidation activity. This suggests that the ability to capture gas-phase oxygen and the reactivity of lattice oxygen in the CZ surface determine the soot oxidation activity, and that Ru, Rh, and Ir have the effect of enhancing these properties. [ABSTRACT FROM AUTHOR]

Quantifying extracellular and intracellular contributions to Cr(VI) reduction is crucial for understanding bacterial Cr(VI)-reduction mechanisms. However, this contribution under different oxygen conditions remains largely unexplored. This study quantified the extracellular/intracellular contribution to aerobic and anaerobic Cr(VI) reduction using Pseudomonas sp. HGB10, an isolated Cr(VI)-reducing bacterium, as the experimental model. Interestingly, it was found that the lower anaerobic minimum inhibitory concentration (MIC) does not necessarily imply a lower anaerobic Cr(VI)-reduction rate for HGB10. For the initial Cr(VI) concentration of 20 mg L−1, the maximum anaerobic Cr(VI)-reducing rate reached 100%, while the aerobic counterpart was only 75%, even though the value of the aerobic MIC (400 mg L−1) is twice that of the anaerobic (200 mg L−1). Additionally, the calculated extracellular contributions to aerobic and anaerobic Cr(VI) reduction were 10.76% and 55.71%, respectively, while the intracellular contributions were 68.29% and 40.38%. The sum of extracellular and intracellular contributions to Cr(VI) reduction (79.05% and 96.09%) under aerobic and anaerobic conditions was nearly balanced with the corresponding maximum values despite minor relative errors. These results indicated that anaerobic Cr(VI) reduction mainly occurred extracellularly rather than intracellularly, which differs from the existing result. Overall, our findings provide new insights into bacterial Cr(VI) reduction. [ABSTRACT FROM AUTHOR]

Context. Recent studies of the optical depth comparing [12C II] and [13C II] line profiles in Galactic star-forming regions have revealed strong self-absorption in [12C II] by low excitation foreground material. This implies a high column density for C+, corresponding to equivalent AV values of a few (up to about 10) mag. Aims. As the nature and origin of such a great column of cold C+ foreground gas are difficult to determine, it is essential to constrain the physical conditions of this material. Methods. We conducted high-resolution observations of [O I] 63 μm and [O I] 145 μm lines in M17 SW and Mon R2. The [O I] 145 μm transition traces warm PDR-material, while the [O I] 63 μm line traces the foreground material, as manifested by the absorption dips. Results. A comparison of both [O I] line profiles with [C II] isotopic lines confirm warm PDR-origin background emission and a significant column of cold foreground material, causing the self-absorption to be visible in the [12C II] and [O I] 63 μm profiles. In M17 SW, the C+ and O0 column densities are comparable for both layers. Mon R2 exhibits larger O0 columns compared to C+, indicating additional material where the carbon is neutral or in molecular form. Small-scale spatial variations in the foreground absorption profiles and the large column density (~1018 cm−2) of the foreground material suggest the emission is coming from high-density regions associated with the cloud complex – and not a uniform diffuse foreground cloud. Conclusions. The analysis confirms that the previously detected intense [C II] foreground absorption is attributable to a large column of low-excitation dense atomic material, where carbon is ionized and oxygen is in a neutral atomic form. [ABSTRACT FROM AUTHOR]

This paper addresses a general nonhomogeneous incompressible cell-fluid Navier-Stokes model incorporating chemotaxis in a two or three-dimensional bounded domain. This model comprises two mass balance equations and two general momentum balance equations, specifically for the cell and fluid phases, combined with a convection-diffusion-reaction equation for oxygen. We establish the existence and uniqueness of a local strong solution under initial data that satisfy natural compatibility conditions. Additionally, we present a blow-up criterion for the strong solution. [ABSTRACT FROM AUTHOR]

Current guidelines recommend oxygen (O2) supplementation in patients with pulmonary hypertension (PH), despite scarce data on long-term O2 therapy (LTOT). The aim of this prospective, randomized, controlled trial was to investigate the effect of LTOT in patients with precapillary PH on exercise capacity, clinical parameters and hemodynamics. Patients with precapillary PH under stable therapy and O2 desaturations at rest and/or during exercise were randomized to receive LTOT (≥ 16 h/day) or no O2 (control group) for 12 weeks. The control group was offered LTOT after 12 weeks. The primary endpoint changes of 6-minute walking distance (6MWD) from baseline to 12 weeks was hierarchically tested: (1) pre-post primary and secondary intervention (2) intervention vs. control group. Secondary endpoints included changes in clinical parameters. Twenty patients were randomized (women n = 14, age 67 ± 11.4 years, mean pulmonary arterial pressure 39.7 ± 12.5 mmHg, 70% functional class III). 6MWD significantly improved by 42.2 ± 34.20 m (p = 0.003) within 12 weeks LTOT. The intervention group significantly improved in 6MWD (38.9 ± 33.87 m) compared to the control group (− 12.3 ± 21.83 m, p = 0.015). No consistent between-group differences in other parameters were found. LTOT was well tolerated and led to significant improvement of 6MWD. The effect of LTOT should be investigated in larger controlled-trials. [ABSTRACT FROM AUTHOR]

Background and Aims Methods Results Interpretation Cell culture is a fundamental experimental tool for understanding cell physiology. However, translating these findings to in vivo settings has proven challenging. Replicating donor tissue conditions, including oxygen levels, is crucial for achieving meaningful results. Nevertheless, oxygen culture conditions are often overlooked, particularly in the context of chemotherapy‐induced neurotoxicity.In this study, we investigated the role of oxygen levels in primary neuronal cultures by comparing neuronal performance under cisplatin exposure (1 μg/mL) in supraphysiological normoxia (representing atmospheric conditions in a standard incubator; 18.5% O2) and physioxia (representing physiologic oxygen conditions in nervous tissue; 5% O2). Experiments were also conducted to assess survival, neurite development, senescence marker expression, and proinflammatory cytokine secretion.Under control conditions, both oxygen concentration conditions exhibited similar behaviors. However, after cisplatin administration, sensory neurons cultured under supraphysiological normoxic conditions show higher mortality, exhibit an evolutionarily proinflammatory cytokine profile over time, and activate apoptotic‐regulated neuron death markers. In contrast, under physiological conditions, neurons treated with cisplatin exhibited senescence marker expression and an attenuated inflammatory secretome.These results underscore the critical role of oxygen in neuronal culture, particularly in studying compounds where neuronal damage is mechanistically linked to oxidative stress. Even at identical doses of evaluated neurotoxic drugs, distinct cellular phenotypic fates can emerge, impacting translatability to the in vivo setting. [ABSTRACT FROM AUTHOR]

Anti-counterfeiting using multiple optical output modes has drawn considerable attention for enhancing anti-fake measures. Herein, a multimodal dynamic optical information coding from the self-activated Na2-CaGe2O6 phosphor is developed. Na2CaGe2O6 phosphor exhibits two distinct emission bands associated with the intrinsic defects of oxygen vacancies (V••o) and inverse-site defects (Ge••A). The incorporation of Bi3+ ions results in an increased concentration of defects, which in turn facilitates the modulation of the corresponding photoluminescence color from purple to red with prolonged ultraviolet (UV) irradiation. Moreover, the recovery of the corresponding emission color is observed for thermal disturbance. Besides, an improved optical storage behavior as the long persistent and photo-stimulated luminescence is achieved for the incorporation of Bi3+ ions. Consequently, a multimode dynamic color-changing code is constructed using screen-printing technology, offering an alternative approach for advanced anticounterfeiting. [ABSTRACT FROM AUTHOR]

Non‐covalent chalcogen bond (ChB) interactions have found utility in many fields, including catalysis, organic semiconductors, and crystal engineering. In this study, the transition stabilizing effects of ChB interactions of oxygen and sulfur were experimentally measured using a series of molecular rotors. The rotors were designed to form ChB interactions in their bond rotation transition states. This enabled the kinetic influences to be assessed by monitoring changes in the rotational barriers. Despite forming weaker ChB interactions, the smaller chalcogens were able to stabilize transition states and had measurable kinetic effects on the rotational barriers. Sulfur stabilized the bond rotation transition state by as much as −7.2 kcal/mol without electron‐withdrawing groups. The key was to design a system where the sulfur σ ${\sigma }$ ‐hole was aligned with the lone pairs of the chalcogen bond acceptor. Oxygen rotors also could form transition state stabilizing ChB interactions but required electron‐withdrawing groups. For both oxygen and sulfur ChB interactions, a strong correlation was observed between transition state stabilizing abilities and electrostatic potential (ESP) of the chalcogen, providing a useful predictive parameter for the rational design of future ChB systems. [ABSTRACT FROM AUTHOR]

Photomediated reversible addition fragmentation chain transfer (RAFT) step‐growth polymerization is performed using a trithiocarbonate‐based chain transfer agent (CTA) and acrylate‐based monomers both with and without a photocatalyst. The versatility of photo‐mediated RAFT step‐growth is demonstrated by one‐pot synthesis of a graft copolymer via sequential monomer addition. Furthermore, oxygen‐tolerant photo‐mediated RAFT step‐growth is demonstrated, facilitated by the appropriate selection of photocatalyst and solvent pair (zinc tetraphenyl porphyrin [ZnTPP] and dimethyl sulfoxide [DMSO]), enabling ultralow volume polymerization under open‐air conditions. [ABSTRACT FROM AUTHOR]

Oxygen reduction reaction (ORR) electrocatalysis is an area of increasing interest for the in‐situ production of H2O2 or the development of energy‐related devices such as hydrogen fuel cells. Although pyrolyzed catalysts still offer the best performances to date with reference to the organic‐based catalysts, metal‐free and non‐pyrolyzed covalent organic frameworks (COFs) stands out as promising alternatives candidates due to their favourable characteristics such as crystallinity, porosity, and organic composition, allowing the study of structural‐property relationships. Herein, we present the design principles and recent advances in COFs‐based ORR electrocatalysts, demonstrating how composition influences the activity and electronic pathway of the oxygen reduction process. [ABSTRACT FROM AUTHOR]

As great potential recycling strategy, the direct regeneration of spent LiCoO2 (LCO) is beneficial for lowering environmental pollutions and promoting global sustainability. However, owing to the using of binder and electrolyte, some fluorine impurities would be remained into spent materials. Considering the doping behaviors of F‐elements, their suitable content introducing would facilitate the energy‐storage abilities of regenerated LCO. Herein, through the tailored introduction of F‐elements, spent LCO are successfully regenerated with physical‐chemical evolutions. Benefitting from the existed oxygen vacancies, the diffusion energy‐barrier of F‐elements is reduced from 1.73 eV to 0.61 eV, facilitating the establishment of gradient F‐doped subsurface, along with the formation of rigid CoO5F. Meanwhile, excess F‐elements (1 wt %, as a threshold) lead to the formation of LiF passivation layer on the surface. Thus, the as‐optimized sample displays a considerable capacity of 154.4 mAh g−1 even at 5.0 C, with retention rate (88.3 %) in 3.0–4.5 V. Supported by detailed electrochemical and kinetic analysis, the structural advantages are confirmed to boost the improved redox activity of Co‐ions and the alleviating of irreversible oxygen‐release. Give this, the work is anticipated to reveal the evolutions of regenerated LCO with the introduced F‐elements, whilst providing the practical regeneration strategies toward excellent high‐voltage properties. [ABSTRACT FROM AUTHOR]

S‐thiobenzoylthioglycolic acid possessing two sulfur and two oxygen atoms was used to synthesize an oxoorganotin(IV) carboxylate molecule, [BuSn(O)(O2CCH2SC(S)Ph)]6. The molecule is a hexanuclear cluster that has been characterized structurally by single‐crystal X‐ray diffraction analysis. The complex was used as a single‐source precursor to prepare a thin film of SnS2 by the chemical vapor deposition technique. The distinct triangular formations of SnS2 were characterized by spectral and microscopic measurements. Well‐defined boundaries and considerable sizes of SnS2 structures have been identified. [ABSTRACT FROM AUTHOR]

The unique characteristic of 2D transition‐metal dichalcogenide (TMD) semiconductor materials such as PdSe2 is the ability of the bandgap to vary on the basis of the number of layers present. This variation results in a broad bandgap range spanning from semi‐metallic to semiconducting materials, underscoring the significance of precisely controlling the material thickness. In this study, the thicknesses of chemical vapor deposited PdSe2 films are precisely controlled layer‐by‐layer via cyclic atomic layer etching (ALE), which comprised a radical adsorption step generated by oxygen and chlorine plasmas, followed by a desorption step with an organic solvent vapor such as formic acid. Cyclic etching with one monolayer of PdSe2/cycle is achieved using both types of adsorption gases while maintaining the ratio of Se/Pd underlying PdSe2 at ≈2. This cyclic ALE method is also applicable for smoothing TMD material surfaces by isotropically removing individual rough surface layers. Because this etching method only utilizes chemical reactions with radicals generated by plasmas and organic vapors, it is not only unaffected by the physical damage caused by the irradiation of energetic particles such as ions in plasmas, but also is applicable to 3D structure processing. [ABSTRACT FROM AUTHOR]

A hot spot which is a glowing orange local area appears in RE Ba 2 Cu 3 O y (RE : rare earth) ceramic rods when a voltage higher than a certain value is applied at room temperature. After the hot spot appears, the oxygen partial pressure in the ambient atmosphere changes the current through the rod, which can be used as an oxygen sensor without the need for a heating system. In this study, the authors investigated the oxygen-sensing characteristics and the power-saving effect of the sandwich structure in which the sensor layer was stacked between insulation layers. The sample rods were prepared by the solid-state reaction at 960 °C. Materials of 5 mol% Nd 2 BaCuO 5 -added Nd 1.4 Ba 1.6 Cu 3 O y and 20 mol% Nd 1.4 Ba 1.6 Cu 3 O y -added Nd 2 BaCuO 5 were used for the sensor layer and the insulation layer, respectively. The sensitivity to the oxygen increased with increasing voltage applied to the rod. Under the condition where 17.8 V was applied to the rod with the sandwich structure and 6.6 V to the rod with the monolithic structure, the sensitivities of both rods were almost the same. The sandwich structure had a reduced current value and consumed approximately 26 % less power than the monolithic structure. The response time for the sandwich structure and the monolithic structure were comparable, meaning that the insulation layer did not impair the response time. [ABSTRACT FROM AUTHOR]

Currently, the lattice oxygen is the key factor affecting the thermal conductivity of AlN ceramics. In this paper, three methods are proposed to limit lattice oxygen, namely reducing the original powder oxygen content, changing the debinding atmosphere, and extending the sintering time. The results show that the low powder oxygen content and protective debinding atmosphere alter the carbon and oxygen content, and further promote the formation of the Y 4 Al 2 O 9 (YAM) phase. The generated YAM phase can effectively reduce the lattice oxygen in terms of thermodynamics. Prolonged high temperatures can provide kinetic conditions to reduce the lattice oxygen to 0.0343 wt%. In addition, morphological changes of the phase at the grain edges and their influence on the mechanical properties were noted. Finally, AlN ceramics with a thermal conductivity of 220 W m−1 K−1 and a flexural strength of 340 MPa were obtained. This study can provide a valuable reference for the industrial production of AlN ceramics. [ABSTRACT FROM AUTHOR]

A novel methodology for the synthesis of 2-pyridones bearing a 2-pyridyl group on nitrogen and carbon atoms, starting from 2-bromopyridines, was developed employing a simple Ru(II)–KOPiv–Na2CO3 catalytic system. Unsubstituted 2-bromopyridine was successfully converted to the penta-heteroarylated 2-pyridone product using this method. Preliminary mechanistic studies revealed a possible synthetic pathway leading to the multi-heteroarylated 2-pyridone products, involving consecutive oxygen incorporation, a Buchwald–Hartwig-type reaction, and C–H bond activation. [ABSTRACT FROM AUTHOR]

Objective This study aimed to describe target oxygen saturation (SpO 2) ranges used for premature infants in United States' neonatal intensive care units (NICUs) and to describe if these target SpO 2 ranges have changed in recent years. Study Design A 29-question survey focused on target SpO 2 practices and policies was distributed via the NICU medical directors listservs for the American Academy of Pediatrics Section of Neonatal-Perinatal Medicine and Pediatrix Medical Group between August and October of 2021. Results were collected via Research Electronic Data Capture (REDCap). Results We received responses representing 170 unique, levels 2, 3, and 4 NICUs from 36 states. Most NICUs (130, 78%) have recently changed their SpO 2 targets in response to target SpO 2 clinical trials. Over time, the most commonly reported target SpO 2 range has shifted from 88–92% to 90–95. Of NICUs that changed limits, the most common lower SpO 2 limits increased from 88 to 90% and the upper SpO 2 limits changed from 92 to 95%. The interquartile range for lower SpO 2 limit shifted from 85–88% to 88–90% and the IQR for upper SpO 2 limit decreased from 92–95 to 94–95%. Most NICUs had designated conditions that would allow for deviations from standard target SpO 2 ranges. These most commonly include pulmonary hypertension (152, 95%), severe bronchopulmonary dysplasia (81, 51%), and retinopathy of prematurity (51, 32%). Conclusion Oxygen saturation limits have changed over time with an overall increase in targeted SpO 2. However, there remains considerable interunit variation in SpO 2 policies. There is a need to achieve consensus to optimize clinical outcomes. Key Points What are the SpO 2 ranges in United States' NICUs? There is a shift in SpO 2 ranges for preterm infants in NICUs across United States. Variability still persists in SpO 2 ranges for preterm infants in United States' NICUs. [ABSTRACT FROM AUTHOR]

Objective Administering surfactant timely and appropriately is important to minimize lung injury but remains challenging in preterm neonates with respiratory distress syndrome. The published literature supports that lung ultrasound (LUS) score can predict surfactant need. Neonatal LUS scanning specification and parameter setting guidelines have been recently published for standardization. However, variations in scanning protocols and machine settings hinder its clinical implementation widely. This observational study aims to internally validate the suggested LUS protocol in a neonatal intensive care unit to establish a correlation between LUS scores and surfactant need as the first step of integrating LUS in the clinical practice. Study Design LUS was performed on 40 eligible preterm neonates within 3 hours after birth or before surfactant administration between May 2020 and March 2021. The neonates were between 27 and 32 weeks' gestational age, and all had respiratory distress. Neonates with known congenital anomalies were excluded. A high-frequency linear probe was used to obtain LUS images from six lung zones which were scored using a 0 to 3 system, yielding a maximum of 18 points. Treating physicians were blinded to the LUS score. Receiver operating characteristic analysis determined the optimal LUS score cut-off for predicting surfactant need. Results Fifteen of the 40 neonates (38%) required higher oxygen fraction and received surfactant. In our cohort, an LUS score ≥10 was identified as the optimal cut-off for predicting surfactant need, with a sensitivity of 80% and specificity of 84%. The area under the curve was 0.8 (p = 0.0003). LUS predicted surfactant need at a median of 3.5 hours earlier than traditional clinical decision (p < 0.0037). Conclusion LUS is a helpful adjunct for predicting surfactant need in preterm neonates. This study describes an approach to implement the LUS protocol and score for clinical decision-making in the clinical practice. Key Points LUS is a helpful adjunct for predicting surfactant need in preterm neonates. Machine setting variation and probe selection may affect LUS image and score. LUS score should be validated at the local unit before clinical implementation. [ABSTRACT FROM AUTHOR]

Objective Cerebral oximetry using near-infrared spectroscopy (NIRS) is a noninvasive optical technology widely used in neonatology. The present study aimed to define reference ranges for cerebral tissue oxygen saturation (crSO 2) with a new four-wavelength NIRS device, Masimo O3 oximeter, during immediate transition after birth and compare values with those obtained previously with NIRO 200NX ®. Study Design This was a prospective observational study using Masimo O3 device to measure crSO 2 and regional cerebral fractional tissue oxygen extraction (cFTOE) in healthy term newborns delivered by primary cesarean section, during the 15 minutes after cord clamping. The neonates who required any medical support were excluded. The NIRS sensor was placed on the right forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry. Previous studies which established centiles for crSO 2 with NIRO 200NX were used for comparison. Results A total of 44 newborns were included. The median crSO 2 and cFTOE (interquartile range) at 2, 5, and 7 minutes was 54% (49–54), 71% (64–86), and 79% (73–84) and 0,25 (0,18–0,33), 0,19 (0,15–0,23), and 0,16 (0,12–0,21), respectively, with no further changes afterwards. The crSO 2 measurements were significantly higher with Masimo O3 compared with NIRO-200NX. Conclusion The present observational study presented reference ranges for crSO 2 and cFTOE measured with Masimo O3 oximeter during the immediate neonatal transition. Values obtained with O3 were higher than those obtained with other oximeters. For this reason, crSO 2 is device-specific so there must be known reference values for each oximeter to define therapeutic interventions based on crSO 2 and assess cerebral oxygenation in clinical studies. Key Points Masimo O3 uses four wavelengths to measure regional oxygen saturation value. O3 values of crSO 2 and cFTOE differ with other neonatal oximeters at birth. Knowledge of reference range of O3 at birth is essential to guide resuscitation. [ABSTRACT FROM AUTHOR]

A nanoflower-like FeCo-hydro(oxy)oxide catalyst is successfully fabricated using a simple one-step electrodeposition technique. The optimized Fe 9 -Co 1 catalyst exhibits good performance for OER (η 50 = 222 mV) and overall water splitting (1.73 V@100 mA cm−2). The reconstructed FeOOH/CoOOH serves as the real active sites, and a small amount of Co species can optimize the activation energies between the active sites and oxygen-containing intermediates, thereby improving the performance of water splitting. [Display omitted] • A nanoflower-like FeCo hybrids is synthesized by a facile electrodeposition method. • The Fe 9 -Co 1 catalyst delivers a good OER activity (η 50 = 222 mV) and stability. • The reconstructed FeOOH/CoOOH serves as the real active sites during OER process. • The synergy between Co and Fe species reduces the activation energies with intermediates and improves OER activity. Iron hydroxide (FeOOH) is a potential active component in iron-based electrocatalysts for water electrolysis. However, its catalytic performance is constrained by its slow oxygen evolution reaction (OER) kinetics. Herein, we synthesized a nanoflower-like FeCo-hydro(oxy)oxides composite with tunable Fe/Co ratios (Fe x -Co y) on nickel foam (NF) via a one-step electrodeposition technique. This method allows for precise control over the morphology and composition of the hybrid nanoflowers. The optimized Fe 9 -Co 1 discloses favorable OER performance with a low overpotential of 222 mV at 50 mA cm−2 and demonstrates good stability exceeding 60 h at 10 mA cm−2. Further, an assembled Fe 9 -Co 1 (+)||Pt/C(−) dual-electrode configuration achieves a low cell voltage of 1.73 V at the current density of 100 mA cm−2 for water splitting, with long-term stability for 70 h and minimal degradation. Studies indicate that the distinctive nanoflower morphology of Fe 9 -Co 1 enhances active site exposure, while both FeOOH and reconstructed CoOOH serve as catalytic centers, contributing to the observed OER performance. This work introduces a facile approach for synthesizing OER electrocatalysts, underscoring the role of the high-valence state of Fe/Co as active sites in the OER process. [ABSTRACT FROM AUTHOR]

The removal of Congo red (CR) and heavy metal ion nickel (Ni(II)) from wastewater is a critical concern for safeguarding the aquatic environment and promoting sustainable development. Herein, a novel citric acid steam-assisted decomposition method is applied to form meso-macroporous magnesium oxide (MgO) with rich oxygen defects. As the gelation process of xerogel precursor could be significantly promoted by the steam-assisted process with citric acid solution as steam source, the morphology structure of MgO changes into loose aggregates with sharp edges and is covered by a layer of MgO nanoparticles. The synthesized MgO, with a high surface area (103.60 m2 g−1), meso-macroporous structure and abundant oxygen defects, exhibits super adsorption capacities for CR (7109.85 mg g−1) and Ni(II) (1405.88 mg g−1). The MgO (0.4 g L−1) could completely remove CR (200 mg L−1) in 30 min, while 10 min for Ni(II) (200 mg L−1) adsorption. The adsorption mechanism of MgO for CR and Ni(II), including electrostatic interaction, oxygen vacancy capture, hydrogen bonding and ion exchange, is effectively enhanced due to the appearance of meso-macroporous structure and oxide defects, such as 5-coordinated oxygen anion (O 5C 2−) for terrace, 4-coordinated oxygen anion (O 4C 2−) for edge and 3-coordinated oxygen anion (O 3C 2−) for corner. The easy calcination is applied to recycle MgO after CR adsorption and the CR removal efficiencies are above 98 % after five cycles. Meanwhile, a nickel chelator (Na 2 EDTA) and calcination are used to regenerate the MgO after Ni(II) adsorption and the adsorbent shows an insignificant removal efficiency loss after three cycles. The meso-macroporous MgO with rich oxygen defects has the characteristics of high adsorption speed, high adsorption capacity and convenient recovery property, and is expected to become an ideal material for the rapid treatment of high concentration wastewater. [ABSTRACT FROM AUTHOR]

The ozone layer is often noted to exhibit self-healing, whereby depletion of ozone aloft induces ozone increases below, explained as resulting from enhanced ozone production due to the associated increase in ultraviolet (UV) radiation below. Similarly, ozone enhancement aloft can reduce ozone below (reverse self-healing). This paper considers self-healing and reverse self-healing to manifest a general mechanism we call photochemical adjustment, whereby ozone perturbations lead to a downward cascade of anomalies in UV and ozone. Conventional explanations for self-healing imply that photochemical adjustment is stabilizing, damping perturbations towards the surface. However, photochemical adjustment can be destabilizing if the enhanced UV disproportionately increases the ozone sink, as can occur if the enhanced UV photolyzes ozone to produce atomic oxygen, which speeds up catalytic destruction of ozone. We analyze photochemical adjustment in two linear ozone models (Cariolle v2.9 and LINOZ), finding that (1) photochemical adjustment is destabilizing above 40 km in the tropical stratosphere and (2) self-healing often represents only a small fraction of the total photochemical stabilization. The destabilizing regime above 40 km is reproduced in a much simpler model: the Chapman cycle augmented with destruction of O and O 3 by generalized catalytic cycles and transport (the Chapman+2 model). The Chapman+2 model reveals that photochemical destabilization occurs where the ozone sink is more sensitive than the source to perturbations in overhead column ozone, which is found to occur when the window of overlapping absorption by O 2 and O 3 is optically unsaturated, i.e., when overhead slant column ozone is below approximately 10 18 molec. cm -2. [ABSTRACT FROM AUTHOR]

The concentration of hydrogen in oxygen (HTO) is a crucial factor in determining the load limit of alkaline water electrolysis (AWE) due to the risk of explosion with high HTO levels. In this study, we analysed the impact of circulating electrolytes, carrying dissolved gas, on HTO in a home-designed zero-gap alkaline water electrolysis system, operating at atmospheric pressure and constant temperature. By comparing the experimental results from mixed and separated cycles, we found that the amount of dissolved hydrogen in the electrolyte significantly contributes to HTO. We then developed a theoretical model to predict HTO values and experimentally confirmed a linear relationship between the HTO and the ratio of electrolyte circulation to gas production (Q L / Q O 2 ). Based on this evidence, we proposed a new electrolyte circulation control strategy that reduces the HTO value by as much as 63.56%. These findings could help overcome the load limit of alkaline water electrolysis systems, which is crucial for their large-scale application. [Display omitted] • Electrolyte circulation contributes significantly to HTO. • Circulating electrolytes carries dissolved hydrogen that increases HTO. • Optimization of electrolyte circulation helps to reduce HTO by up to 63.56%. [ABSTRACT FROM AUTHOR]

The rapid discharge of oxygen on the anode side of a proton exchange membrane electrolytic cell (PEMEC) plays a significant role in the production of hydrogen. This study proposes a serpentine flow field model with circular arc columns on the anode side of the proton exchange membrane electrolysis cell system. In this model, the circular arc columns are incorporated at the bends of the flow field. The Taguchi design is carried out to optimize performance parameters. The advantages of a serpentine flow field model with circular arc columns are analyzed, the results demonstrate that the new model can effectively expel oxygen, thus enhancing hydrogen production performance of the PEMEC. The performance of the improved serpentine flow field model is influenced by the shape parameters, the Taguchi design is carried out to optimize performance parameters. Among them, the upper gap parameter has the greatest impact, followed by the lower gap and angle parameters. The improved performance of the model is attributed to the narrowing of channel, which creates a pressure difference between the two sides of edges, increases fluid velocity, reduces bubble adhesion to the wall surface, and shortens the time for bubbles to pass through the bends, eventually enhances transport of oxygen bubbles. The fitting results show that the oxygen discharge of the optimized model in this study is increased by 22.4% compared to that of the initial serpentine flow field. [Display omitted] • Novel serpentine flow model with circular arc columns enhances PEMEC efficiency. • Improved design boosts oxygen expulsion, enhancing hydrogen production. • Key parameters—upper gap, lower gap, and angle—optimized for oxygen transport. • Enhances fluid velocity, reduces bubble adhesion, and shortens bend passage times. • Achieves 22.4% higher oxygen discharge compared to the initial serpentine flow. [ABSTRACT FROM AUTHOR]

The impact of orbitally shaking bioreactors (OSRs) on the biopharmaceutical industry is becoming increasingly important. In the preliminary exploration of the orbitally shaking bioreactor performance, the vessel wall shape has a crucial influence on the mixing and mass transfer in the bioreactor. However, the shape of OSRs still maintains a cylindrical structure, significantly limiting the advantages of the orbital shaking mixing. Therefore, in order to further improve the mixing and mass transfer performance of OSRs, a novel wall shape is proposed in this paper. This novel wall shape consists of cylindrical and square parts and looks like a square tank with a large circular chamfer (STCC), which was found could effectively enhance the efficiency of material mixing and mass transfer theoretically. Based on the same specific volumetric power consumption, a comparative analysis was conducted on the mixing time and oxygen transfer efficiency of OSRs with different shape walls using simulation and experimental methods. The results showed that the OSR with STCC was expected to perform higher mixing and oxygen transfer efficiency than the OSR with cylindrical wall. These findings suggested a promising prospect for the future application of the OSRs with STCC. • Developing a novel wall structure (STCC) improving the mixing performance of OSRs. • Both oxygen mass transfer and mixing efficiency were increased with the STCC effect. • Improving the bioreactor performance with low calculated shear stress. • Mixing speed was found significantly lower in the vortex center than other regions. • Promising prospect for the future application of the OSRs with STCC. [ABSTRACT FROM AUTHOR]

Chromene derivatives are important oxygen heterocycles, which are met in numerous natural products, pharmaceuticals, and organic functional materials. This review survey the achievements in the synthesis of chromene derivatives from α,β‐unsaturated aldehydes. Particular attention is paid to the use of catalytic systems, synthetic advantages and mechanistic aspects of the reactions. The works published over the past 15 years are covered. [ABSTRACT FROM AUTHOR]

Background: Posterior reversible encephalopathy syndrome (PRES) is an uncommon neurological disorder which is characterised by variable symptoms. The transient clinical condition may be underestimated and misdiagnosed as other conditions, especially, among pregnant women with severe preeclampsia, eclampsia, and HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome in the puerperium. We hereby contribute to the literature this rare complication and hightlight the appropriate management of PRES. Presentation case: A pregnant woman (gravida 3, parity 2) had a normal antenatal course. However, she was diagnosed with severe preeclampsia and HELLP syndrome at 29 weeks and 5 days of gestation. Therefore, she was indicated for a medical termination of pregnancy following a patient's consent at our tertiary referral hospital. Severely, the patient developed rapidly with altered mental health in early puerperium. In result, PRES was diagnosed based on a brain magnetic resonance imaging (MRI) evidence with typical findings. After a strict multidisciplinary management, the clinical condition improved after 5 days of onset and recovered completely after a 4-month follow-up without any sequelae. Conclusion: In summary, despite its rarity, clinicians ought to be knowledgeable and raise an aware of PRES during pregnancy. Importantly, a brain imaging modalities should be taken into account among pregnant women with neurological symptoms subsequent to severe preeclampsia. In addition to early diagnosis, a timely appropriate treatment with multidisciplinary team is strongly indicated. Further studies with a large case series are required for this uncommon entity. [ABSTRACT FROM AUTHOR]

Lattice‐oxygen activation has emerged as a popular strategy for optimizing the performance and selectivity of oxide‐based thermocatalysis and electrolysis. However, the significance of lattice oxygen in oxide photocatalysts has been ignored, particularly in gas–solid reactions. Here, using methane oxidation over a Ru1@ZnO single‐atom photocatalyst as the prototypical reaction and via 18O isotope labelling techniques, we found that lattice oxygen can directly participate in gas–solid reactions. Lattice oxygen played a dominant role in the photocatalytic reaction, as determined by estimating the kinetic constants in the initial stage. Furthermore, we discovered that dynamic diffusion between O2 and lattice oxygen proceeded even in the absence of targeted reactants. Finally, single‐atom Ru can facilitate the activation of adsorbed O2 and the subsequent regeneration of consumed lattice oxygen, thus ensuring high catalyst activity and stability. The results provide guidance for next‐generation oxide photocatalysts with improved activities and selectivities. [ABSTRACT FROM AUTHOR]

The commercialization of magnesia–air batteries (Mg–air) necessitates the development of highly efficient, cost-effective, and durable electrocatalysts for the oxygen reduction reaction (ORR), replacing expensive and unstable precious metal electrocatalysts. A hard template-assisted synthesis of FeCo nanoparticles immobilized on N-doped porous carbon (Fe–Co–C–N) for the ORR is reported. The half-wave potential of Fe–Co–C–N for ORR (E1/2 = 0.88 V vs. RHE) is elevated by 40 mV compared to that of 20 wt% Pt/C (E1/2 = 0.84 vs. RHE). The catalyst exhibits exceptional catalytic performance and remarkable stability. The discharge voltage of the Mg–air battery, utilizing Fe–Co–C–N as the cathode catalyst (1.29 V), surpasses that of the battery employing 20 wt% Pt/C as the cathode catalyst (1.28 V). The Mg–air battery with Fe–Co–C–N as the cathode catalyst exhibited excellent discharge stability and maintained a stable discharge for over 200 hours. The present study offers valuable insights into the structural design and regulatory mechanisms governing the performance of M–N–C catalysts in Mg–air batteries. [ABSTRACT FROM AUTHOR]

Adding dopants to the structure and coupling cocatalysts on the surface are traditional strategies to inhibit carrier recombination and high catalytic barriers for enhancing the performance of water splitting of the BiVO4 photoanode. An inexpensive post-treatment method was developed herein via modifying the BiVO4 (BVO) photoanode with KBr solution. Unlike the traditional strategies, this approach effectively overcomes carrier recombination on the BVO photoanode surface. The Br–BiVO4 (Br–BVO) photoanode was optimized and exhibited a remarkable cathodic shift (350 mV) of the onset potential, as well as an excellent photocurrent density, which was increased to 256% of the pure BVO photoanode. The Faraday efficiencies of oxygen evolution and hydrogen evolution (FEO2, FEH2) were 98.4% and 96.7%, respectively. The photoelectrochemical (PEC) characterization revealed that the adsorption of Br− on the BVO photoanode induced surface polarization and can rapidly trap holes and prolong carriers' lifetimes, facilitating the participation of most holes in the oxygen evolution reaction (OER). Adsorption of Br− also decreased the overpotential of the OER on the BVO photoanode, consequently enhancing reaction kinetics. This study presents a straightforward and feasible approach to enhance the PEC performance of the BiVO4-based photoanode. [ABSTRACT FROM AUTHOR]

The catalytic properties of Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) toward the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR) are constrained by severe Sr segregation from the BSCF lattice. Herein, we address this problem by loading CeO2 nanoparticles on the BSCF surface. Compared with pristine BSCF, the obtained hybrid catalyst (BSCF@CeO2-10) with strong compressive stress shows greatly improved catalytic activity and stability toward both the OER and MOR. Furthermore, we deduce that the OER process on the BSCF@CeO2-10 surface follows synergistic catalytic mechanism combining the adsorption evolution and lattice oxygen oxidation mechanisms. The greatly improved MOR catalytic activity of BSCF@CeO2-10 can be ascribed to the deposition of CeO2 facilitating the adsorption of methanol and reducing the overall energy barrier of the rate-determining step during *OCH2 into *OCH. This work can provide new insights for designing novel perovskite electrocatalysts for both the OER and MOR. [ABSTRACT FROM AUTHOR]

Classic period Maya populations were mobile, and both burial patterns and dietary analyses suggest that many movers were incorporated into local communities. This paper presents a multi‐isotopic (Sr, O, S, C, and N) study of the diet and mobility of 18 Late (AD 550–800) and Terminal Classic (AD 800–900) individuals from the site of Pacbitun, Belize. Three distinct isotope systems identify where people lived at different stages of life, from the childhood origins of migrant and local Pacbitun populations to their final residences. The enamel strontium isotope ratios of the Court 3 individuals were higher than local ranges established by faunal and human bone values, suggesting elite migration, or even residential mobility within the polity. Sulfur isotope values reveal information about the local population, where all but one individual in the sample lived at the site for many years before they died. The exception was an isotopically nonlocal individual in a dedicatory deposit, as reported in other studies. Diet also informs on the receiving community and how migrants assimilated, as people with local and nonlocal isotope values ate isotopically similar foods. Individuals from elite site core contexts and those in Pacbitun's peripheral settlements both consumed C4‐enriched proteins, though there were more isotopically diverse protein sources in peripheral settlements during the Terminal Classic period. Sulfur, carbon, and nitrogen isotope data also reveal some differences in where food was acquired, including use of nonlocal fauna. Combining isotope systems that sample different body tissues also may blur the line between migrants and locals, terms that may describe the same person at different stages of life and show the need for a more nuanced discussion of ancient mobility. [ABSTRACT FROM AUTHOR]

The crystal structure, oxygen content and homogeneity range of Pr 1-x Sr x CoO 3-õ solid solutions from room temperature (RT) up to 1100 °C in air were studied. It has been shown that an increase in temperature and Sr content causes an Orthorhombic → Rhombohedral → Cubic transformation of the crystal structure. The heterovalent substitution of Sr2+ for Pr3+ is compensated by an increase in the mean oxidation state of Co ions (z Co) and the formation of oxygen vacancies. The temperature dependences of thermal expansion and conductivity of Pr 1-x Sr x CoO 3-õ solid solutions are explained from the point of view of crystal and defect structure. The diagram of phase relation in the PrCoO 3 – "SrCoO z " cross section has been constructed. [ABSTRACT FROM AUTHOR]

The newly developed portable oxygen concentrator with an auto-demand oxygen delivery system (auto-DODS) automatically switches between 3 sensitivities according to the negative pressure gradient of inhalation and supplies oxygen only during inhalation. The aim of this study was to verify the effectiveness and safety of auto-demand devices compared with a continuous flow oxygen concentrator, during sleep, in a randomized crossover noninferiority trial. We alternatively used an auto-DODS or a continuous-flow oxygen concentrator, all night on separate days for HOT (Home Oxygen Therapy) patients with nocturnal hypoxemic symptoms. The primary endpoints were the mean value of oxygen saturation (SpO2) over the total sleep time. The secondary endpoints included the efficacy endpoints and the safety endpoints. Regarding the primary endpoint, the difference in SpO2 between the auto-DODS and continuous flow was 0.835%. Since the upper limit of this difference did not exceed 2.8, which was set as the noninferiority margin, it was shown that the auto-DODS did not reduce SpO2 by at least 2.8% on average compared to continuous flow. No equipment failure or exacerbation of disease was observed, confirming the safety of the auto-DODS during the night. [ABSTRACT FROM AUTHOR]

Although Ru‐based materials are among the outstanding catalysts for the oxygen evolution reaction (OER), the instability issue still haunts them and impedes the widespread application. The instability of Ru‐based OER catalysts is generally ascribed to the formation of soluble species through the over‐oxidation of Ru and structural decomposition caused by involvement of lattice oxygen. Herein, an effective strategy of selectively activating the lattice oxygen around Ru site is proposed to improve the OER activity and stability. Our synthesized spinel‐type electrocatalyst of Ru and Zn co‐doped Co3O4 showed an ultralow overpotential of 172 mV at 10 mA cm−2 and a long‐term stability reaching to 100 hours at 10 mA cm−2 for alkaline OER. The experimental results and theoretical simulations demonstrated that the lattice oxygen site jointly connected with the octahedral Ru and tetrahedral Zn atoms became more active than other oxygen sites near Ru atom, which further lowered the reaction energy barriers and avoided generating excessive oxygen vacancies to enhance the structural stability of Ru sites. The findings hope to provide a new perspective to improve the catalytic activity of Ru‐incorporated OER catalysts and the stability of lattice‐oxygen‐mediated mechanism. [ABSTRACT FROM AUTHOR]

Introduction Inhaled nitric oxide (INO) is a selective pulmonary vasodilator delivered from compressed gas cylinders filled to 2,200 psig (137.8 bar) with 800 ppm of NO in a balance of nitrogen. NO is currently FDA-approved for use in term or near-term infants with hypoxemia and signs of pulmonary hypertension in the absence of cardiac disease. INO has also been shown to improve oxygenation in adults with refractory hypoxemia. Current doctrine precludes the use of NO during military aeromedical transport owing to the requirement for large compressed gas cylinders. We performed a bench evaluation of 2 delivery systems that create NO from room air without the need for pressurized cylinders, Materials and Methods We evaluated 2 portable nitric oxide INO generation systems (LungFit PH, Beyond Air Inc, Garden City, NJ and a prototype NO generator, Odic Inc, Littleton, MA) at ground level, 8,000, and 14,000 feet (2,437 and 4,267 meter) simulated altitude in an altitude chamber. The output from each device was injected into the inspiratory limb of the ventilator circuit that was attached to a test lung. A 731 ventilator (Zoll Medical, Chelmsford, MA) and T1 (Hamilton Medical, Reno, NV) were used employing 24 combinations of ventilator settings each repeated in duplicate. An INOmax DS IR was used to measure delivered INO and NO2 via a sampling line attached in the ventilator circuit inspiratory limb. A fast response oxygen analyzer (O2CAP, Oxigraf Inc, Sunnyvale, CA) was used to measure inspired FiO2. Target INO concentration was 20 ppm. Results Across all ventilator settings, the LungFit device delivered INO was 19.8 ± 1.6 ppm, 16.1 ± 1.9 ppm, and 11.6 ± 1.7 ppm at ground level, 8,000 ft (2,437 meter), and 14,000 ft (4,267 meter), respectively. The Odic device delivered INO dose was 20.6 ± 1.4 ppm, 21.3 ± 5.5 ppm, and 20.4 ± 9.1 ppm at ground level, 8,000 ft (2,437 meter), and 14,000 ft (4,267 meter), respectively. Conclusions Both devices delivered a reliable INO dose at ground level. Altitude significantly affected INO delivery accuracy at 14,000 ft (4,267 meter) (P  < 0.01) with both devices and at 8,000 ft (2,437 meter) (P  < 0.01) with LungFit. Differences in INO dosage were not statistically significant with the Odic device at 8,000 ft (2,437 meter)(P  > 0.05) although there were large variations with selected ventilator settings. With careful monitoring, devices creating INO from room air without cylinders could be used during aeromedical transport without the need for pressurized cylinders. [ABSTRACT FROM AUTHOR]