The relationship between Nuclear Factor-Kappa B and Inhibitor-Kappa B parameters with clinical course in COVID-19 patients.

BACKGROUND: We aimed to investigate the serum Nuclear Factor Kappa B (NF-κB) p105, NF-κB p65 and Inhibitor Kappa B Alpha (IκBα) levels in patients with mild/moderate Coronavirus Disease 2019 (COVID-19) and their association with the course of the disease. MATERIALS AND METHODS: Blood was drawn from 35 COVID-19 patients who applied to the Department of Emergency Medicine of Istanbul University-Cerrahpasa at the time of diagnosis and from 35 healthy individuals. The patients were evaluated to have mild/moderate degree of disease according to National Early Warning Score 2 (NEWS2) scoring and computed tomography (CT) findings. The markers were studied in the obtained serum samples, using enzyme-linked immunoassay (ELISA). Receiver Operating Characteristic (ROC) analysis was performed. Statistical significance was evaluated to be p < 0.05. RESULTS: NF-κB p105 levels were significantly higher in the COVID-19 group compared to the control group. C-reactive protein (CRP), D-dimer, ferritin levels of the patients were significantly higher (p < 0.001) compared to the control group, while the lymphocyte count was found lower (p = 0.001). IκBα and NF-κB p65 levels are similar in both groups. Threshold value for NF-κB p105 was above 0.78 ng/mL, sensitivity was 71.4% and specificity was 97.1% (p < 0.05). NF-κB p105 levels at the time of diagnosis of the patients who required supplemental oxygen (O2), were significantly higher (p < 0.01). CONCLUSIONS: The rise in serum NF-κB p105 levels during the early stages of infection holds diagnostic value. Besides its relation with severity might have a prognostic feature to foresee the requirement for supplemental O2 that occurs during hospitalization.

Biofilm formation and cell plasticity drive diazotrophy in an anoxygenic phototrophic bacterium.

IMPORTANCE: The contribution of non-cyanobacterial diazotrophs (NCDs) to total N2 fixation in the marine water column is unknown, but their importance is likely constrained by the limited availability of dissolved organic matter and low O2 conditions. Light could support N2 fixation and growth by NCDs, yet no examples from bacterioplankton exist. In this study, we show that the phototrophic NCD, Rhodopseudomonas sp. BAL398, which is a member of the diazotrophic community in the surface waters of the Baltic Sea, can utilize light. Our study highlights the significance of biofilm formation for utilizing light and fixing N2 under oxic conditions and the role of cell plasticity in regulating these processes. Our findings have implications for the general understanding of the ecology and importance of NCDs in marine waters.

Highly Sensitive Measurement of Oxygen Concentration Based on Reflector-Enhanced Photoacoustic Spectroscopy.

Oxygen (O2) is a colorless and odorless substance, and is the most important gas in human life and industrial production. In this invited paper, a highly sensitive O2 sensor based on reflector-enhanced photoacoustic spectroscopy (PAS) is reported for the first time. A diode laser emitting at 760 nm was used as the excitation source. The diode laser beam was reflected by the adopted reflector to pass thorough the photoacoustic cell twice and further increase the optical absorption. With such enhanced absorption strategy, compared with the PAS system without the reflector, the reflector-enhanced O2-PAS sensor system had 1.85 times the signal improvement. The minimum detection limit (MDL) of such a reflector-enhanced O2-PAS sensor was experimentally determined to be 0.54%. The concentration response of this sensor was investigated when O2 with a different concentration was used. The obtained results showed it has an excellent linear concentration response. The system stability was analyzed by using Allan variance, which indicated that the MDL for such a reflector-enhanced O2-PAS sensor could be improved to 318 ppm when the integration time of this sensor system is 1560 s. Finally, the O2 concentration on the outside was continuously monitored for 24 h, indicated that this reflector-enhanced O2-PAS sensor system has an excellent measurement ability for actual applications in environmental monitoring, medical diagnostics, and other fields.

Probing S-state advancements and recombination pathways in photosystem II with a global fit program for flash-induced oxygen evolution pattern.

The oxygen-evolving complex (OEC) in photosystem II catalyzes the oxidation of water to molecular oxygen. Four decades ago, measurements of flash-induced oxygen evolution have shown that the OEC steps through oxidation states S(0), S(1), S(2), S(3) and S(4) before O(2) is released and the S(0) state is reformed. The light-induced transitions between these states involve misses and double hits. While it is widely accepted that the miss parameter is S state dependent and may be further modulated by the oxidation state of the acceptor side, the traditional way of analyzing each flash-induced oxygen evolution pattern (FIOP) individually did not allow using enough free parameters to thoroughly test this proposal. Furthermore, this approach does not allow assessing whether the presently known recombination processes in photosystem II fully explain all measured oxygen yields during Si state lifetime measurements. Here we present a global fit program that simultaneously fits all flash-induced oxygen yields of a standard FIOP (2 Hz flash frequency) and of 11-18 FIOPs each obtained while probing the S(0), S(2) and S(3) state lifetimes in spinach thylakoids at neutral pH. This comprehensive data treatment demonstrates the presence of a very slow phase of S(2) decay, in addition to the commonly discussed fast and slow reduction of S(2) by YD and QB(-), respectively. Our data support previous suggestions that the S(0)→S(1) and S(1)→S(2) transitions involve low or no misses, while high misses occur in the S(2)→S(3) or S(3)→S(0) transitions.

An Assessment of Three Different In Situ Oxygen Sensors for Monitoring Silage Production and Storage.

Oxygen (O2) concentration inside the substrate is an important measurement for silage-research and-practical management. In the laboratory gas chromatography is commonly employed for O2 measurement. Among sensor-based techniques, accurate and reliable in situ measurement is rare because of high levels of carbon dioxide (CO2) generated by the introduction of O2 in the silage. The presented study focused on assessing three types of commercial O2 sensors, including Clark oxygen electrodes (COE), galvanic oxygen cell (GOC) sensors and the Dräger chip measurement system (DCMS). Laboratory cross calibration of O2 versus CO2 (each 0-15 vol.%) was made for the COE and the GOC sensors. All calibration results verified that O2 measurements for both sensors were insensitive to CO2. For the O2 in situ measurement in silage, all O2 sensors were first tested in two sealed barrels (diameter 35.7 cm; height: 60 cm) to monitor the O2 depletion with respect to the ensiling process (Test-A). The second test (Test-B) simulated the silage unloading process by recording the O2 penetration dynamics in three additional barrels, two covered by dry ice (0.6 kg or 1.2 kg of each) on the top surface and one without. Based on a general comparison of the experimental data, we conclude that each of these in situ sensor monitoring techniques for O2 concentration in silage exhibit individual advantages and limitations.

Effect of temperature acclimation on red blood cell oxygen affinity in Pacific bluefin tuna (Thunnus orientalis) and yellowfin tuna (Thunnus albacares).

Hemoglobin-oxygen (Hb-O2) binding properties are central to aerobic physiology, and must be optimized for an animal's aerobic requirements and environmental conditions, both of which can vary widely with seasonal changes or acutely with diving. In the case of tunas, the matter is further complicated by large regional temperature differences between tissues within the same animal. This study investigates the effects of thermal acclimation on red blood cell Hb-O2 binding in Pacific bluefin tuna (T. orientalis) and yellowfin tuna (T. albacares) maintained in captive tanks at acclimation temperatures of 17°, 20° and 24 °C. Oxygen binding properties of acclimated tuna isolated red blood cells were examined under varying experimental temperatures (15°-35 °C) and CO2 levels (0%, 0.5% and 1.5%). Results for Pacific bluefin tuna produced temperature-independence at 17 °C- and 20 °C-acclimation temperatures and significant reverse temperature-dependence at 24 °C-acclimation in the absence of CO2, with instances of reverse temperature-dependence in 17 °C- and 24 °C-acclimations at 0.5% and 1.5% CO2. In contrast, yellowfin tuna produced normal temperature-dependence at each acclimation temperature at 0% CO2, temperature-independence at 0.5% and 1.5% CO2, and significant reverse temperature-dependence at 17 °C-acclimation and 0.5% CO2. Thermal acclimation of Pacific bluefin tuna increased O2 binding affinity of the 17 °C-acclimation group, and produced a significantly steeper oxygen equilibrium curve slope (nH) at 24 °C-acclimation compared to the other acclimation temperatures. We discuss the potential implications of these findings below.

Bronchopulmonary Dysplasia: Ongoing Challenges from Definitions to Clinical Care.

Bronchopulmonary dysplasia (BPD) is the most common complication of extreme prematurity. Its etiology is multifactorial and is attributed to genetic susceptibility to prenatal and postnatal factors. As advancements in neonatology have led to the increased survival of premature infants, a parallel increase in the incidence of BPD has occurred. Over time, the definition and diagnostic criteria for BPD have evolved, as have management strategies. However, challenges continue to exist in the management of these infants, which is not surprising given the complexity of the disease. We summarize the key diagnostic criteria and provide insight into the challenges related to various aspects of BPD definitions, data comparisons, and clinical care implementation.

Effects of oxygen on the adsorption/oxidation of aqueous Sb(III) by Fe-loaded biochar: An X-ray absorption spectroscopy study.

Fe-loaded biochar (FeBC) has been considered for Sb(III) adsorption, but the effects of oxygen (O2) on the adsorption need further investigation. Liquid-/solid-phase analyses were conducted to investigate the role of O2 in the Sb(III) adsorption by FeBC. The adsorption was best described by the pseudo-second-order (PSO) model for kinetic results and by the Langmuir model for thermodynamic results. More than 96.8 % of Sb(III) was adsorbed by FeBC, and available O2 increased the liquid-phase Sb(III) oxidation efficiency by 2.1-7.5 times. The peak changes at ~1640 and 3450 cm-1 in FTIR spectra indicated the occurrence of inner-sphere complexation between Sb(III)/Sb(V) and hydroxyl (-OH)/carboxyl (-COOH) groups in FeBC under aerobic and anaerobic conditions. Fe/Sb X-ray absorption spectroscopy (XAS) analysis results showed aqueous Sb(III) complexed to the edge-sharing Fe(III)-O-Fe(III) in FeBC. Regardless of whether O2 was available or not, solid-phase edge-sharing Fe(III)-O-Sb(V) complexes (~3.05 Å), which had lower toxicity and migration ability than aqueous Sb(III), formed through a ligand-to-metal charge-transfer (LMCT) process. More than 91 % of adsorbed Sb(III) was oxidized to edge-sharing Fe(III)-O-Sb(V) complexes in 3 h. Additionally, the Sb(V) from liquid-phase oxidation could also directly complex to the Fe(III)-O-Fe(III) and form edge-sharing Fe(III)-O-Sb(V) complexes. These results provide evidence to inform further FeBC application for the Sb-contaminated water treatment.

Direct Patterning of a Carbon Nanotube Thin Layer on a Stretchable Substrate.

Solution-based direct patterning on an elastomer substrate with meniscus-dragging deposition (MDD) enables fabrication of very thin carbon nanotube (CNT) layers in the nanometer scale (80-330 nm). To fabricate the CNT pattern with CNT solution, contact angle, electrical variation, mechanical stress, and surface cracks of elastomer substrate were analyzed to identify the optimal conditions of O2 treatment (treatment for 30 s with RF power of 50 W in O2 atmosphere of 50 sccm) and mixture ratio between Ecoflex and polydimethylsiloxane (PDMS) (Ecoflex:PDMS = 5:1). The type of mask for patterning of the CNT layer was determined through quantitative analysis for sharpness and uniformity of the fabricated CNT pattern. Through these optimization processes, the CNT pattern was produced on the elastomer substrate with selected mask (30 µm thick oriented polypropylene). The thickness of CNT pattern was also controlled to have hundreds nanometer and 500 µm wide rectangular and circular shapes were demonstrated. Furthermore, the change in the current and resistance of the CNT layer according to the applied strain on the elastomer substrate was analyzed. Our results demonstrated the potential of the MDD method for direct CNT patterning with high uniformity and the possibility to fabricate a stretchable sensor.

High temperature and pressure inside a dissolving oxygen nanobubble.

Numerical simulations of dissolution of an oxygen (O2) nanobubble into water without dynamic stimuli have been performed in order to study the possibility of OH radical formation from oxygen nanobubbles experimentally reported by Liu et al. (2016). The dissolution of an oxygen nanobubble is much faster than that of an air nanobubble due to higher solubility of oxygen in water. However, the temperature and pressure inside an oxygen nanobubble at the final moment of the bubble dissolution are about 2800 K and 4.5 GPa, respectively, which are slightly lower than those inside an air nanobubble due to higher thermal conductivity of oxygen. A few molecules of OH radicals may be formed per 107 bubbles according to the numerical simulation. The estimated production rate of OH radicals is 13 orders of magnitude smaller than the experimentally reported one.

Using Oxygen Plasma Pretreatment to Enhance the Properties of F-Doped ZnO Films Prepared on Polyimide Substrates.

In this study, a radio frequency magnetron sputtering process was used to deposit F-doped ZnO (FZO) films on polyimide (PI) substrates. The thermal expansion effect of PI substrates induces distortion and bending, causing FZO films to peel and their electrical properties and crystallinity to deteriorate. To address these shortcomings, oxygen (O2) plasma was used to pretreat the surface of PI substrates using a plasma-enhanced chemical vapor deposition system before the FZO films were deposited. The effects of O2 plasma pretreatment time on the surface water contact angle, surface morphologies, and optical properties of the PI substrates were investigated. As the pretreatment time increased, so did the roughness of the PI substrates. After the FZO films had been deposited on the PI substrates, variations in the surface morphologies, crystalline structure, composition, electrical properties, and optical properties were investigated as a function of the O2 plasma pretreatment time. When this was 30 s, the FZO films had optimal optical and electrical properties. The resistivity was 3.153 × 10-3 Ω-cm, and the transmittance ratios of all films were greater than 90%. The X-ray photoelectron spectroscopy spectra of the FZO films, particularly the peaks for O1s, Zn 2p1/2, and Zn 2p3/2, were determined for films with O2 plasma pretreatment times of 0 and 30 s. Finally, a HCl solution was used to etch the surfaces of the deposited FZO films, and silicon-based thin-film solar cells were fabricated on the FZO/PI substrates. The effect of O2-plasma pretreatment time on the properties of the fabricated solar cells is thoroughly discussed.

Modelling levels of nitrous oxide exposure for healthcare professionals during EMONO usage.

BACKGROUND: Computational fluid dynamics (CFD) has been used to compute nitrous oxide (N2O) levels within a room during the administration of an equimolar mix of N2O/oxygen (EMONO) in the clinical setting. This study modelled realistic scenarios of EMONO usage in hospital or primary care, in order to estimate the potential N2O exposure of healthcare professionals (HCP) with routine EMONO use and to provide guidance for EMONO users. METHODS: Sixteen scenarios were defined by carrying out a survey of practitioners. CFD simulations were performed for each scenario and N2O concentrations over time were calculated. N2O exposures (time-weighted average of concentration over 8 h [TWA-8 h]) were calculated at the HCPs' mouth to be compared with a predefined occupational exposure limit (OEL). RESULTS: Administration duration and ventilation type were the main factors influencing N2O levels; ventilation type also influenced wash-out time between EMONO administrations. N2O concentration showed a plume distribution towards the ceiling and was highly heterogeneous, highlighting the importance of measurement location. Although estimated TWA-8 h varied widely, 13 of the 16 scenarios had an N2O TWA-8 h of <100 parts per million. CONCLUSIONS: Data demonstrate that EMONO usage in well ventilated rooms - as recommended - helps to ensure that N2O exposure does not exceed the OEL and does not signal any major risks for HCPs when recommendations are followed. Although these data are numerical simulations and should be considered as such, they can provide guidance for EMONO users.