Corrosive wear at metal interfaces under aggressive environments poses a major challenge to the durability of engineering components. In internal combustion engines, exhaust gas recirculation promotes the formation of nitric acid (HNO3), accelerating the surface degradation of steel. In this study, reactive molecular dynamics simulations were employed to elucidate atomic-scale wear mechanisms at the diamond-like carbon (DLC)/iron (Fe) friction interface under H2O and HNO3 aqueous environments. In the presence of H2O, adhesive wear predominates because the Fe substrate fails to develop a protective oxide layer within the simulation time scale. Consequently, Fe atoms form Fe-C bonds with the DLC surface and are removed during sliding. In contrast, when both H2O and HNO3 are present, corrosive wear dominates while adhesive wear is suppressed. HNO3 reacts with the Fe surface to produce a layered Fe oxide and Fe nitride, which limit direct Fe-C bonding. During sliding, H2O reacts with Fe-N bonds within the nitride layer, forming Fe-NH2 structures. These reactions result in the detachment of the nitride layer as tribochemical debris whereas the oxide layer remains stable. Overall, the dominant wear mechanism at the DLC/Fe interface is environment-dependent: adhesive wear prevails in H2O, while corrosive wear becomes significant in the HNO3-H2O environment.
Sodium dithionite is a widely used reductant in biochemical and industrial applications, yet its intrinsic instability and complex redox chemistry continue to pose challenges for mechanistic interpretation. One relatively underexplored aspect is its reactivity with nitric oxide (NO˙), a small redox-active signalling molecule. While dithionite is commonly employed to reduce metal centres in enzymes, its potential interaction with NO˙ may influence experimental outcomes in aqueous redox systems. Here, we show that under anaerobic, near-neutral aqueous conditions, dithionite reacts with NO˙ leading to the formation of azanone (HNO, nitroxyl), the one-electron-reduced and protonated congener of nitric oxide. Formation of HNO is supported by direct trapping experiments using Mn(III) porphyrins and by indirect detection of N2O, a characteristic product of HNO dimerization. These findings reveal a previously overlooked route for HNO generation in dithionite-containing systems and highlight potential artefacts in biochemical experiments involving NO˙ and strong reductants, particularly in studies probing thiol reactivity or metalloprotein function.
Low-temperature plasma offers a promising pathway for sustainable production of HNO3 directly from air and H2O under ambient conditions. However, most plasma electrodes suffer from a low yield rate and selectivity of NO2, which limits the efficiency of HNO3 production. In this study, we propose a strategy to improve the NO2 yield by regulating the electron temperature (Te) in spark discharge. An array electrode with multiple vertically oriented hollow Cu rods is designed to reduce localized energy deposition and optimize Te. At an airflow rate of 300 SCCM, the array electrode achieves a yield rate for NO2 of 17.85 mmol h-1, which is 10.8 times higher than that (1.65 mmol h-1) of the conventional single electrode. Notably, after absorption in 300 mL of H2O, the array electrode produces a pure HNO3 solution with a concentration as high as 680.5 mM within a 12 h discharge time.
Three WC-10Co-4Cr coatings with different WC grain sizes were prepared by high-velocity air-fuel (HVAF) spraying. The corrosion behaviors were systematically evaluated in 0.2 mol/L H2SO4 and 0.4 mol/L HNO3 solutions through immersion tests and electrochemical measurements. The results reveal that WC grain size governs coating microstructural integrity, mechanical properties, and corrosion resistance. Among the three coatings, the medium-grained (MG) coating exhibits an optimized balance between compact microstructure, high microhardness, superior fracture toughness, and the best corrosion resistance in both acidic environments. The coarse-grained (CG) coating exhibits the worst corrosion resistance owing to its wide grain boundaries and high porosity, while the fine-grained (FG) coating is similarly compromised by slightly higher porosity and residual stress-induced microcrack networks that facilitate electrolyte penetration. The corrosion proceeds via preferential dissolution of Co in the CoCr binder phase driven by micro-galvanic coupling with WC, followed by WC particle detachment and pit formation. In a 0.4 mol/L HNO3 solution, the strong oxidizing nature accelerates both binder dissolution and direct WC oxidation.
Electrochemical reduction of U(VI) to U(IV) in nitric acid-hydrazine medium is the key process step to successfully achieve the partitioning of Pu from U in the Plutonium Uranium Reduction Extraction (PUREX) process, adopted worldwide in the spent nuclear fuel reprocessing plants. The present method for the electrochemical reduction of U(VI) to U(IV) is not viable for the large-scale production of U(VI) to U(IV) due to its several drawbacks, including very high overpotential and associated hydrogen evolution reaction. In this report, we have shown that the RGO and RGO-Pt could be an attractive electrocatalyst material for the efficient production of U(IV) from U(VI) in HNO3-N2H4 medium with a significantly lower overpotential and greater selectivity. The linear sweep voltammetry (LSV) plots and corresponding Tafel slope analysis have shown that the U reduction over RGO and RGO-Pt takes a completely different pathway as compared to the reduction over Pt and Ti, which is used in commercial plants. Moreover, the cyclic voltametric and electrochemical impedance spectroscopy studies have shown that the hydrogen evolution reaction has also been greatly suppressed over the RGO as compared to the RGO-Pt and Pt rod, thus would improve the faradic efficiency for the U(VI) to U(IV) conversion reaction at higher overpotential.
Cuproptosis, a copper-dependent form of programmed cell death, has been implicated in the pathogenesis of acute kidney injury (AKI). Nitroxyl (HNO), the one-electron reduced and protonated form of nitric oxide (NO), is an emerging regulator of cellular function. However, the role of HNO in modulating cuproptosis during AKI remains largely unexplored. This study aims to investigate the effect of HNO on cuproptosis in a murine model of renal ischemia-reperfusion (IR) injury. An in vitro hypoxia/reoxygenation (HR) model using human kidney-2 (HK-2) cells and an in vivo renal IR injury mouse model were employed to determine the role of HNO in renal function. Here, we showed that baseline HNO fluorescence in HK-2 cells was enhanced by the HNO donor Angeli's salt (AS) and by the combined treatment with the hydrogen sulfide (H2S) donor NaHS and the nitric oxide (NO) donor SNP. In contrast, HR exposure significantly reduced HNO fluorescence. AS administration mitigated oxidative stress, decreased cell apoptosis, and reduced inflammation, along with an overall improvement in renal function in mice with renal IR injury. Pretreatment with AS significantly reduced HR-induced cell vitality injury, apoptosis, reactive oxygen species (ROS) formation, and mitochondrial dysfunction in HK-2 cells. HNO reduced cuproptosis by downregulating the protein expression of ferredoxin 1 (FDX1) and lipoyl synthase (LIAS), and suppressing copper accumulation. The copper ion carrier Elesclomol abolished the renal benefits of HNO. Mechanistic studies showed that HNO promoted the lysosomal localization and degradation of the copper transporter solute carrier family 31 member 1 (SLC31A1), thereby alleviating cuproptosis in renal tubular epithelial cells. Importantly, overexpression of SLC31A1 prevented the effects of HNO on cellular injury and cuproptosis. In summary, the present study demonstrated that HNO promotes the autophagy-lysosomal degradation of SLC31A1, which in turn inhibits cuproptosis and effectively alleviates AKI. These results provide experimental support for the potential of HNO as a promising agent for AKI.
This article presents a systematic study of Pu(IV) absorbance spectral features as a function of temperature to develop an understanding of this parameter's effect on chemometric models that can be used as online monitoring tools to support nuclear processing. The descriptive and predictive models that provide real-time feedback of these processes are usually constructed with data collected in conditions typical of a laboratory environment, which can differ drastically from a processing environment. To assess the impact of temperature on Pu(IV) absorbance spectra, 11 samples of Pu(IV) were synthesized with varying HNO3 concentrations ranging from 0.6 to 9.5 M and heated between 15 and 45 °C. Ultraviolet (UV)-visible (vis)-near-infrared (NIR) absorption spectra collected at different HNO3 concentrations and temperatures revealed that features associated with Pu(IV) are sensitive to temperature at all HNO3 concentrations and that changes in features depend on HNO3 concentration. The contributions of temperature and HNO3 concentration to variation in Pu(IV) spectral features were evaluated using the principal component analysis of spectra that were baseline-corrected with an asymmetric least-squares method. Furthermore, predictive modeling for HNO3 concentration with partial least-squares regression of UV-vis-NIR spectra highlighted the importance of accounting for temperature in the calibration set to optimize model performance. This methodology constitutes a new, systematic approach to account for the effect of temperature on the absorption spectra of metal ions and is useful for process monitoring applications in many industries.
Owing to the highly reactive and transient nature of nitric oxide (NO) and nitroxyl (HNO), the identification of reliable NO/HNO sources is of paramount interest for the development of therapeutic strategies and for understanding NO/HNO signaling pathways. We demonstrate here that a mononuclear manganese(II)-dinitrite complex (2-Py) reacts with p-methylbenzenethiol (MeArSH) to generate the dinitrosyl species 3-Py/3'-Py. The dinitrosyl {Mn(NO)2}8 core in 3'-Py is capable of facile transfer of both NO and NO- to suitable metal centers. Interestingly, a reaction with pentafluorophenol F5ArOH with 2-Py produces a mixture of NO and nitrate via disproportionation of in situ-generated HNO2. The oxidizing nature of HNO2 has been intercepted by triphenylphosphine (Ph3P), leading to bis(triphenylphosphoranylidene)ammonium ([(Ph3P)2N]+), thereby demonstrating the intermediacy of transient HNO2 for the reaction between 2-Py and F5ArOH. Additionally, monooxygenation of the dinitrite core in 2-Py by iodosylbenzene (PhIO) affords a manganese(II)-dinitrate complex (4-Py), and dioxygenations of the {Mn(NO)2}8 species by PhIO or O2 have also been observed to yield 4-Py. Single-crystal X-ray diffraction, FTIR analyses of 14N/15N-labeled samples, and multinuclear NMR studies provide unambiguous characterization of a complete series of manganese dinitrite, dinitrosyl, and dinitrate complexes that are chemically linked through nitrite reduction, disproportionation, and oxygenation pathways.
Volatile ruthenium tetroxide (RuO4) formed during evaporation-to-dryness accidents (EDA) of high-level liquid waste (HLLW) combines high chemical toxicity with radiotoxicity from isotopes such as 103Ru and 106Ru, making it a primary hazard in nuclear-fuel reprocessing. This study experimentally elucidates the mechanisms governing RuO4 formation while testing the validity of the pragmatic nitrosyl-ruthenium ([RuNO]) surrogate model, an experimental model that assumes Ru in HLLW exists as [RuNO], and evaluates gaseous Ru release using nitric acid solutions of [RuNO], commonly used in RuO4 release assessments by comparing it with the behavior of simulated HLLW (s-HLLW). We systematically investigated potential pathways, including oxidation by liquid-phase nitric acid (HNO3(l)), gas-phase nitric acid (HNO3(g)), and oxygen (O2); thermal decomposition of [RuNO]; and matrix effects of coexisting nitrates. The results identify oxidation by activated HNO3(l), oxidation by HNO3(g) and thermal decomposition of [RuNO] as the principal routes to RuO4, with HNO3(g) playing a far more significant role than previously recognized. Crucially, the RuO₄ release profile from s-HLLW differed markedly from that predicted by the [RuNO] surrogate model, demonstrating that this model fails to capture the complex matrix effects and time-dependent chemical changes of Ru species inherent to real HLLW. These findings have significant implications for improving the accuracy of hazard assessments related to RuO4 release during HLLW EDAs, particularly by highlighting the limitations of commonly used [RuNO] surrogate models.
Nasal colonization by Staphylococcus aureus is an established risk factor for invasive infection, yet bacterial determinants promoting fitness on human nasal mucosa remain incompletely defined. To identify genes required for early colonization of human nasal respiratory epithelium, we colonized human nasal epithelial organoids differentiated at air-liquid interface (HNO-ALI) with a high-density transposon (Tn) library of the methicillin-resistant USA300 strain LAC. TnSeq analysis identified 165 genes that met our threshold for candidate colonization fitness factors. Among these, genes involved in D-alanine biosynthesis and use were enriched, including two encoding the enzymes that separately synthesize D-alanine in S. aureus : alanine racemase 1 ( alr1) and D-alanine aminotransferase ( dat) . Disruption of dat reduced colonization fitness in competition with the parental strain by ≥ 1,000 fold across 4 different strains from clonal complexes 8, 5, and 30. In competition with the parental strain during HNO-ALI colonization, a dat ::Tn mutant was 34-fold less fit than an alr1 ::Tn mutant. Genetic complementation with single-copy dat expressed from its native operon promoter restored parental colonization levels. Supplementation with exogenous D-alanine or L-alanine also rescued the dat ::Tn colonization defect, whereas D-glutamate did not, consistent with Dat primarily producing D-alanine on nasal mucosa. Complementation with dat under control of a putative 5' intra-operon promoter substantially restored colonization but failed to support growth in chemically defined medium lacking L-alanine, suggesting a new layer of environment-specific regulation of dat transcription. Together, these findings demonstrate that Dat is a major source of D-alanine during colonization of human nasal mucosa and is required for S. aureus fitness in this environment. Staphylococcus aureus is the second leading cause of death due to bacterial infection globally, and nasal colonization is a major risk factor for invasive disease. Using a physiologically relevant, host-derived model of human nasal respiratory epithelium (HNO-ALI) and TnSeq, we identified 165 candidate genes contributing to S. aureus fitness during nasal mucosal colonization. We found that D-alanine aminotransferase (Dat) is the predominant source of D-alanine during nasal colonization, whereas alanine racemase (Alr1) predominates in rich medium, revealing an environment-specific hierarchy of D-alanine biosynthesis. Disruption of dat caused a > 1,000-fold defect in colonization in competition with the parental strain across multiple S. aureus clonal complexes, supporting a conserved role for dat in nasal colonization fitness. Additionally, we provide evidence that dat transcription from a previously cryptic promoter might be regulated by nasal mucosal conditions. Alr1 is proposed as an antimicrobial target in other bacterial pathogens; however, our data suggest that targeting Dat may be more effective for S. aureus nasal decolonization.
In areas influenced by industrial emissions, the total metal content in medicinal plants provides limited insight into toxicological risks, as herbal preparations mobilize different chemical forms of elements with varying bioavailability. A key scientific challenge is the lack of knowledge regarding the fractional composition and extractability of potentially toxic metals from plant tissues, particularly for Cr, Ni, Cu, and Mn, which are widely emitted by combustion-based industries. Despite their environmental relevance, information on how these metals partition across operationally defined fractions and how readily they transfer into decoctions and tinctures remains scarce. This gap hampers accurate assessment of human exposure through herbal products and limits the broader understanding of metal mobility under technogenic pressure. This study investigated the distribution and mobility of Cr, Ni, Cu, and Mn in medicinal plants collected from 28 monitoring sites located in both background and impact territories surrounding the Thermal Power Station. A sequential extraction scheme was applied to differentiate the metals into Fraction I (FI, distilled H2O), Fraction II (FII, 40% C2H5OH), Fraction III (FIII, 10% HCl), and Fraction IV (FIV, concentrated HNO3 + 30% H2O2), while the residual insoluble fraction was considered Fraction V (FV). The results demonstrated that, compared to background conditions, metal concentrations increased across all fractions in the impact zone, with the greatest enrichment observed in the most mobile and easily extractable forms. In both aboveground parts and roots, the hydrochloric-acid-soluble fraction predominated, while the proportion of water- and alcohol-extractable forms increased with intensifying anthropogenic pressure. For decoctions and tinctures derived from aboveground plant tissues, substantially higher extractability was recorded relative to roots, indicating a greater potential risk associated with herbal raw materials harvested within the impact territory. For background plants, this pattern was weaker and not consistently expressed across all species. Among the studied elements, Mn and Cu showed the highest proportions in aqueous and alcoholic extracts. These findings highlight the importance of assessing not only the total metal content but also the fractional composition of pollutants in medicinal plants collected near industrial facilities, as changes in metal mobility under technogenic influence directly affect the safety of herbal preparations.
Central nervous system oxygen toxicity (CNS-OT) is a major complication of hyperbaric oxygen (HBO) characterized by seizures and neuronal damage, yet the underlying mechanisms remain incompletely understood. Using male Sprague Dawley rats (n = 6 per group) and HT22 neurons exposed to either HBO (6 ATA, 100% O2) or hyperbaric normoxia (HNO), our results demonstrate that HBO, but not HNO, caused mitochondrial structural damage and loss of mitochondrial membrane potential (ΔΨm). Transcriptomic analysis revealed enrichment of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways. Using HeLa cells stably overexpressing Parkin and Mito-Keima, a pH-sensitive mitochondrial probe system for monitoring mitophagy, we observed that mitophagic flux was initiated but proceeded too slowly to clear damaged mitochondria in a timely manner in HBO-exposed neurons. Pharmacological preconditioning to activate mitophagy enabled the prompt elimination of dysfunctional mitochondria and rescued HBO-induced mitochondrial dysfunction and cell death. In vivo, everolimus treatment promoted timely mitophagic clearance, prolonged seizure latency, attenuated ΔΨm loss, and suppressed p-p38 activation. These findings demonstrate that HBO exposure disrupts mitochondrial homeostasis and activates pro-apoptotic MAPK signaling. Meanwhile, endogenous mitophagy is initiated but fails to clear damaged mitochondria in a timely manner. Pre-activation of mitophagy by everolimus enables the timely clearance of damaged mitochondria, protecting against CNS-OT and highlighting a promising therapeutic strategy.
Semiconductor-based sensors continue to face challenges related to poor response and stability in humid conditions. Herein, Au nanoparticles (NPs) are successfully deposited on sulfur-vacancies-enriched MoS2 (SV-MoS2/Au) to develop an enhanced humidity-resistant trace NO2 sensor. The SV-MoS2/Au sensor exhibits a high response (115%) and rapid response/recovery rate (10 s/7 s) toward 50 ppb of NO2 under visible light illumination. Additionally, it exhibits satisfactory reversibility, long-term stability, low detection limit (0.1 ppb), and good selectivity in a humid environment (relative humidity ≈60%) at room temperature. The sulfur-vacancies-enriched structure facilitates firm anchoring of abundant Au NPs on the surface of SV-MoS2, leading to an effective utilization of water molecules to generate increasing free radicals (·O2- and ·OH) in the humid air. The in situ FTIR results and theoretical calculations demonstrate that the increasing formation of free radicals could effectively inhibit the formation of HNO3 and HNO2 during the reaction between NO2 and H2O. Consequently, the sensors exhibit remarkable responsiveness to NO2, providing important new perspectives for the future design of room-temperature semiconductor-based humidity-resistant gas sensors.
The objective of this work is to create a hollow cylindrical Aluminium (Al) 6061 alloy reinforced with 10 wt% Alumina (Al2O3) Functionally Graded Composite (Al 6061-10 wt% Al2O3 FGC) using horizontal centrifugal casting. Vickers microhardness testing revealed a maximum hardness of 108 HV at the Al2O3-rich exterior periphery, which is 76% higher than the Al2O3-depleted interior region. Optical microstructural and XRD (X-ray Diffraction) analysis confirmed the gradient distribution of Al2O3 particles. Acidic immersion corrosion studies on the Al2O3-rich region were performed using Sulphuric acid (H2SO4), Hydrochloric acid (HCl), and Nitric acid (HNO3) solutions for immersion durations up to 216 h. The highest Corrosion Rate (CR) (27.31 mm/yr) was observed in HCl at 72 h due to Chloride (Cl) ion attack and pitting, while the lowest CR (6.83 mm/yr) occurred in HNO3 at 216 h owing to stable oxide film formation. Taguchi's Signal-to-Noise Ratio (SNR) analysis indicated immersion duration as the most significant factor, with Analysis of Variance (ANOVA) confirming its 56.25% contribution to CR variation. High Resolution Scanning Electron Microscopy (HRSEM) analysis of corroded surfaces showed microcracks, interfacial regions, and surface damage. The findings highlight that controlling immersion duration and selecting appropriate acidic media can significantly enhance the corrosion resistance of Al2O3-reinforced Al 6061 FGCs, making them suitable for chemical industry applications.
Electrochemical detection is an applicable rapid detection technology, but it is always limited by sample treatment and matrix interference. In this study, two gel/graphite paper electrodes were obtained by drop coating of sodium alginate gel and chitosan gel onto 0.1 mm graphite paper. Comparations of anti-interference performance and stability indicated that sodium alginate gel/graphite paper electrode (GGPBE) was the preferred term for establishing a rapid determination method for Pb in fruits. Based on the contents of organic acids and main metal ions in fruits, analysis and control of matrix interference were conducted. Organic acids, such as ascorbic acid, citric acid and quinic acid, caused greater interferences than metal ions. Mg(II) and Fe(III) were the notable factors of co-interference with organic acids. Matrix interference could be controlled in 3.92% by chemical oxidation using H2O2 combined with HNO3 ultrasonic extraction. The established linear range of Pb(II) was 0.1 ∽ 21.0 µg/L and LOD was 0.0274 µg/L under square wave anodic stripping voltammetry method. In the detection of 9 fruits, the contents of Pb were below 0.1 mg/kg. This work developed an easily prepared gel/graphite paper electrode and provided a rapid sample treating-detection method of lead in fruits. The online version contains supplementary material available at 10.1007/s13197-025-06288-x.
In materials science, the increasing use of lightweight and multi-material structures has made improving the interfacial bonding characteristics of polymer-based adhesive systems increasingly important. Accordingly, chemical surface activation and interfacial engineering strategies have attracted considerable attention for enhancing polymer-fiber compatibility and adhesion performance. However, the combined effects of fiber content, surface treatment, and orientation on adhesion behavior remain insufficiently understood. In the present study, natural fibers obtained from the rachis part of the palm tree were chemically modified and incorporated into an epoxy adhesive matrix to investigate the effect of surface functionalization on polymer-fiber interfacial adhesion. In the first stage, the effects of fiber ratios (5-20 wt%) and chemical surface treatments (methanol cleaning and methanol +2-6% HNO3) on adhesion behavior were evaluated. Tensile tests showed that specimens treated with methanol cleaning followed by 4% HNO3 oxidation and containing 10 wt% fiber exhibited an approximately 48% increase in failure load compared to neat joints. In the second stage, the influence of fiber orientation (0-90°) was examined using the optimized parameters. The results indicate that interfacial load-transfer capability increased as the fiber orientation approached perpendicular alignment, reaching maximum performance at 90°. Based on SEM observations, nitric acid treatment was found to increase the surface roughness of the fibers and strengthen the polymer-fiber interfacial bond. FTIR, XPS and contact angle measurements suggested the development of oxygen-containing surface functionalities and improved wettability, consistent with enhanced interfacial adhesion. These findings demonstrate that appropriate chemical surface treatment, fiber content, and orientation can effectively enhance the interfacial adhesion and bonding efficiency of epoxy-based adhesive systems, providing practical guidance for the design of high-performance bonded structures.
Fever is an important symptom in pediatric ear, nose, and throat (ENT) infections. The current German S3 guideline, "Fever Management in Children and Adolescents," addresses the management of acute fever in otherwise healthy children and adolescents in an outpatient setting. The aim of this article is to summarize the key statements of the S3 guideline on fever management and to assess their practical relevance to the field. The focus is on clinical assessment, temperature measurement, symptom-oriented therapy, parental counseling, and rational antibiotic use. A narrative review was conducted based on the current "Fever management in children and adolescents" S3 guideline from the Association of the Scientific Medical Societies in Germany (AWMF), with particular consideration of ENT-relevant clinical situations and related topics such as earache, sore throat, and rhinosinusitis. The assessment of feverish children depends not only on temperature readings, but above all on their general condition, warning signs, and clinical context. In children over 1 year of age, tympanic temperature measurement is considered sufficiently accurate in most cases, while axillary measurement is not recommended for reliable temperature determination. When fever is rising, with cold hands and feet or shivers, children and youths should be cared for and covered according to their need for warmth. Antipyretics can be used to alleviate discomfort and pain-not solely to lower the temperature. They are not suitable for preventing febrile seizures. Antibiotics should be prescribed restrictively, rationally, and in accordance with guidelines, as fever itself is not an indication for antibiotics. These recommendations support a structured, cautious, and safety-oriented approach to febrile children. In addition to recognizing warning constellations, clear caregiver counselling, symptom-based treatment, and consistent antibiotic stewardship are key elements of care. HINTERGRUND: Fieber ist ein wichtiges Symptom bei kindlichen Infektionen im HNO-Bereich. Die aktuelle S3-Leitlinie „Fiebermanagement bei Kindern und Jugendlichen“ adressiert das Management akut auftretenden Fiebers bei ansonsten gesunden Kindern und Jugendlichen im ambulanten Setting. Ziel des vorliegenden Beitrags ist es, die Kernaussagen der S3-Leitlinie zum Fiebermanagement zusammenzufassen und deren praktische Bedeutung für das Fach einzuordnen. Der Schwerpunkt liegt auf klinischer Einschätzung, Temperaturmessung, symptomorientierter Therapie, Elternberatung und rationalem Antibiotikaeinsatz. Eine narrative Übersichtsarbeit wurde auf Grundlage der aktuellen S3-Leitlinie „Fiebermanagement bei Kindern und Jugendlichen“ der Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften e. V. (AWMF) unter besonderer Berücksichtigung typischer klinischer Konstellationen wie Ohrenschmerzen, Halsschmerzen und Rhinosinusitis erstellt. Entscheidend für die Beurteilung fiebernder Kinder sind nicht allein Temperaturwerte, sondern v. a. Allgemeinzustand, Warnzeichen und klinischer Kontext. Bei Kindern ab einem Jahr gilt die tympanale Messung in den meisten Fällen als ausreichend genau, während die axilläre Messung nicht zur verlässlichen Temperaturbestimmung empfohlen wird. Im Fieberanstieg mit Frösteln, kalten Händen und Füßen oder Schüttelfrost sollten Kinder und Jugendliche ihrem Wärmebedarf entsprechend versorgt und zugedeckt werden. Antipyretika können zur Linderung von Beeinträchtigung und Schmerzen eingesetzt werden – nicht allein zur Senkung der Temperatur. Zur Verhinderung von Fieberkrämpfen sind sie nicht geeignet. Antibiotika sollen restriktiv, rational und leitlinienkonform verordnet werden, da Fieber an sich keine Antibiotikaindikation darstellt. Daraus ergibt sich ein strukturierter und sicherheitsorientierter Umgang mit fiebernden Kindern. Neben der Erkennung von Warnkonstellationen sind klare Elternberatung, die symptomorientierte Behandlung und rationaler Antibiotikaeinsatz zentrale Elemente.
As a low-cost precursor for hard carbon (HC) anodes in sodium-ion batteries, oxidized asphalt (OP) suffers from excessive carbon-layer ordering and insufficient development of closed-pore structure during pyrolysis, which limits low-voltage sodium storage and initial Coulombic efficiency. Herein, a synergistic strategy combining HNO3 oxidation with ZnCl2 activation is developed to regulate the microstructure of oxidized asphalt-derived HC. The oxygen-containing functional groups introduced by oxidation promote the anchoring of Zn species and facilitate the in situ generation of ZnO intermediates during pyrolysis, thereby reconfiguring the activation process and carbonization behavior. As a result, the ordered stacking of carbon layers is effectively suppressed, leading to an enlarged interlayer spacing of 0.391 nm and a closed-pore-rich structure. The obtained N-Zn-OP exhibits a defect-rich turbostratic framework with a specific surface area of 359.67 m2 g-1. Benefiting from the cooperative optimization of carbon layers and pore structure, the N-Zn-OP anode delivers a reversible capacity of 403.52 mAh g-1 at 15 mA g-1, with 51.13% of the capacity contributed by the low-voltage plateau, and retains 90% of its capacity after 100 cycles at 0.1C.
CGRP is a potent, clinically relevant coronary vasodilator known to play a role in cardioprotection. Here, we investigated the precise intracellular signalling pathways leading to vasodilation in small coronary arteries. This study used ex vivo myography and intracellular recording techniques to investigate α-CGRP-induced vasorelaxation and vascular smooth muscle cell (VSMC) hyperpolarization in myogenically active rat isolated coronary arteries. CGRP-induced vasorelaxation was not dependent on the endothelium, but relied heavily on K+ channel activation. Immunohistochemistry indicated KV7 and BKCa channel expression in VSMC and endothelial cells. A combination of the KV7 channel inhibitor, linopirdine and the BKCa channel inhibitor, paxilline, significantly attenuated CGRP-induced vasorelaxation in endothelium-intact or denuded arteries. Electrophysiology confirmed that CGRP caused hyperpolarization and showed this was prevented by linopirdine and paxilline, also demonstrating a role for KV7 and BKCa channels in suppressing depolarizing smooth muscle spikes. These spikes were also suppressed by NO• and HNO donors, resulting in hyperpolarization. Gβγ subunit inhibition with gallein markedly right-shifted CGRP-induced vasorelaxation in both endothelium-intact and denuded coronary arteries. α-CGRP stimulates robust vasorelaxation in the coronary microvasculature that relies on Gβγ subunit-activated VSMC hyperpolarization involving KV7 and BKCa channels. These data enhance understanding of coronary microvascular physiology and inform the design of future therapeutic strategies targeting coronary vascular dysfunction.