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BACKGROUND AND OBJECTIVES: Oxygen (O2) use during neonatal cardiopulmonary resuscitation (CPR) remains a subject of controversy. The inspired O2 concentration during neonatal CPR, that hastens return of spontaneous circulation (ROSC), allows adequate cerebral and myocardial O2 delivery, and enhances survival to discharge, is not known. The optimal FiO2 during CPR should decrease incidence of hypoxia but also avoid hyperoxia, and ultimately lead to improved neurodevelopmental outcomes. Due to infrequent need for extensive resuscitation, and emergent circumstances surrounding neonatal CPR, conducting randomized clinical trials continues to be a challenge. The goal of this study was to review the evolution of oxygen use during neonatal CPR, the evidence from animal and clinical studies on oxygen use during neonatal CPR and after ROSC, the pertinent physiology including myocardial oxygen consumption and cerebral oxygen delivery during CPR, and outcomes following CPR in the DR and in the neonatal intensive care unit. METHODS: This narrative review is based on recent and historic English literature in PubMed and Google scholar over the past 35 years (January 1, 1985 - May 1, 2021). KEY CONTENT AND FINDINGS: Several studies in animal models have compared ventilation with different inspired O2 concentrations (mostly 21% and 100%) during chest compressions and after ROSC. These studies reported no difference in short-term outcomes, even with as low as 18% O2. However, in lamb models of cardiac arrest and CPR, 100% O2 during chest compressions is associated with better oxygen delivery to the brain compared to 21% O2. Abrupt weaning to 21% O2 following ROSC followed by titration to achieve preductal SpO2 of 85-95% minimizes systemic hyperoxia and oxidative stress compared to slow weaning from 100% O2 following ROSC. CONCLUSIONS: Clinical research is needed to arrive at the best strategy for assessment of oxygenation and choice of FiO2 during neonatal CPR that lead to improved survival and outcomes. In this article, we have reviewed the literature on evidence behind O2 use during neonatal advanced CPR and after ROSC.

Non-cyanobacterial diazotrophs (NCDs) are widespread and active in marine waters. The carbon and low-oxygen (O2) conditions required for their N2 fixation may be encountered on marine particles, while a putative role of light remains uninvestigated. This study explored factors that regulate N2 fixation in Rhodopseudomonas sp. BAL398--a anoxygenic phototrophic bacterium isolated from low-salinity surface waters. Light (250 µmol photons m-2 s-1) and anoxia (0 µM O2) stimulated growth and N2 fixation; however, diazotrophy in light was dependent on high organic carbon levels (35 mM, glucose:succinate). Immunolabeling revealed that cellular nitrogenase levels increased with light, decreasing inorganic nitrogen (N) and ambient O2 (250 µM). Light and O2 stimulated motility and biofilm formation on surfaces, and N2 fixation rates increased compared to the control treatment. N2 fixation rates were positively correlated with the formation of rosette-like cellular structures, and an increased concentration of nitrogenase was observed toward the center of these structures, which increased their occurrence 600 times when cultures reached maximum N2 fixation rates vs when they had low rates. Interestingly, N2 fixation was not completely inhibited under oxic conditions and was accompanied by increased formation of capsules and cysts. Rosettes, as well as capsules and cysts, may thus serve as protection against O2. Our study reveals the physiological adaptations that underlie N2 fixation in an anoxygenic phototroph, emphasizing the significance of biofilm formation for utilizing light and fixing N2 under oxic conditions, and underscores the need for deciphering the importance of light for marine NCDs. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hydrogen sulfide (H2S) is a primary cause of odor and corrosion in sewer systems. In drop structures, falling wastewater impinges the surface of bottom water pool as a jet or numerous drops, triggering a high level of turbulence and thus enhancing the emission of H2S and the absorption of oxygen (O2) at the pool surface. In this study, laboratory experiments were conducted to study the mass transfer at the pool surface with falling water drops or a single jet of water. In the test range of falling flow rate of 49–223 mm/h and falling velocity of 3.1–5.2 m/s [kinetic energy flux (KEF)=0.11–0.80 J/(m2·s)] , the mass transfer coefficient KL for the pool surface was found to be 2.6–14.8×10−5 m/s for H2S. In addition, KL was found to be 76% larger when the pool surface was impinged by water drops than by a single jet. KL was 27%−47% larger in the half of the water surface directly receiving the drops or jet than the other half. The increase of water depth in the pool promoted the mass transfer, especially for the scenario of falling jet. Equations were proposed to predict KL under drops or jet. Moreover, KL for H2S and for O2 was found almost the same, indicating O2 can be a safe surrogate gas for H2S. Finally, the research results were applied to estimate H2S emissions at the pool surface of a prototype drop structure with a falling height of up to 10 m, which showed that turbulent wastewater surface can enhance mass transfer over 100 times compared with a quiescent surface. [ABSTRACT FROM AUTHOR]

Nonthermal plasma (NTP) is a promising technology for the decomposition of chlorobenzene (CB), but many conditions will affect the performance of NTP. The effects of gas temperature, relative humidity, oxygen content, sulfur dioxide (SO2), and nitric oxide (NO) on the removal of CB in dielectric barrier discharge (DBD) were studied in this study. The results showed that the gas temperature with the highest CB removal rate was 50°C at 14 kV and 200°C at 18 kV. With the addition of water vapor, the removal efficiency of CB first increased and then decreased, reaching the highest (52.94%) when the relative humidity was 20% at 14 kV. The presence of oxygen inhibited the degradation of CB. At 14 kV, when the oxygen concentration increased from 0% to 25%, the degradation efficiency of CB decreased from 71.93% to 32.54%. In the discharge process, the addition of SO2 promoted the removal of CB, while NO inhibited under the same conditions. The addition of SO2 and NO did not change the specific energy density. For ozone (O3), the addition of water molecules, SO2 , and NO inhibited the formation of O3. It is of great significance to study the influence of relevant gas conditions on the degradation of CB by NTP technology, so as to provide a reference for industrial application. [ABSTRACT FROM AUTHOR]

This study showed that the dark muscle of yellowtail stored in pure O2 had almost unchanged redness, pH, and MetMb formation during 72-hour storage, while the N2 and air groups had significantly lower redness and pH, and significantly higher MetMb formation indices. Lactic acid content showed a significant negative correlation with pH. Pearson correlation analysis demonstrated that the lower redness was correlated with the lower pH and higher MetMb formation index. Thus, pure O2 could inhibit the MetMb accumulation and decrease pH, thereby suppressing discoloration and making the dark muscle more likely to gain bright red color. [ABSTRACT FROM AUTHOR]

The majority of rail vehicles worldwide use diesel as a primary fuel source. Diesel engine carbon emissions harm the environment and human health. Although railway electrification can reduce emissions, it is not always the most economical option, especially on routes with low vehicle demand. As a result, interest in hydrogen-powered trains as a way to reduce greenhouse gas (GHG) emissions has steadily grown in recent years. In this paper, we discuss advancements made in hydrogen-powered freight and commuter trains, as well as the technology used in some aspects of hydrogen-powered vehicles. It was observed that hydrogen-powered trains are already in use in Europe and Asia, unlike most developing countries in Africa. Commuter trains have received most of the research and development (R&D) attention, but interest in hydrogen-powered freight trains has recently picked up momentum. Despite the availability and use of gray and blue hydrogen, green hydrogen is still the preferred fuel for decarbonizing the rail transport sector.

• A O 2 -LITES sensor was reported. • A diode laser with high output power was adopted as the excitation source. • A minimum detection limit of 583 ppm was realized. Oxygen (O 2) is a fundamental element in the atmosphere. It is important to detect it in various fields. In this paper, a sensitive O 2 sensor based on light-induced thermoelastic spectroscopy (LITES) with a high power diode laser is reported. A distributed feedback (DFB) diode laser emitting at 760 nm with output power of 16.8 mW was employed as the light source. The O 2 absorption line at 13144.54 cm−1 was selected for the investigation. Wavelength modulation spectroscopy (WMS) technique and second harmonic signal demodulation (2 f) were adopted to improve the sensing performance. For the concentration dynamic range from 20 % to 80 %, a linear relationship between the amplitude of 2 f signal and O 2 concentration was demonstrated. Allan deviation analysis was conducted to evaluate the long-term stability of the sensor system and the minimum detection limit (MDL) was measured to be 583 ppm at the optimum integration time of 100 s. Further improvement of this O 2 -LITES sensor system was also discussed. [ABSTRACT FROM AUTHOR]

Highlights • The accuracy and dynamic range of a dual-wavelength laser-based DIAL measurement extend with simultaneously transmission and detection the spectrally closed "on" and "off" wavelengths; in addition to size, weight, and cost reduction. • Differential absorption lidar (DIAL) equipped with the dual-wavelength laser at 762 nm (on-wavelength) and 773 nm (off-wavelength) on 3D remote measurement of oxygen molecules, O 2. • A concentration of less than 1 ppm by volume is detectable by the system if a path length of 1 km is used. • The system can be used from a satellite to quickly characterize O 2 in H 2 O matrices on outer solar system bodies. • The wavelengths 762 nm and 773 nm lay in the water-window region (650–1350 nm) enabling system for laser remote sensing dissolved oxygen in water. Abstract Recently, we have demonstrated a longitudinally pumped tunable dual-wavelength Ti:sapphire laser that can operate at simultaneous dual-wavelength (765.0, 771.3 nm), (763.9, 772.2 nm), (763.5, 772.2 nm) and (762.4, 773.7 nm) with a pulse width of ∼20 ns and a maximum average power of ∼2.98 W at 1-kHz pulse repetition rate, corresponding to a slope efficiency of ∼34.7% [1]. In this paper, the feasibility of the contactless differential absorption lidar (DIAL) equipped with the dual-wavelength laser emitting at 762 nm (on-wavelength) and 773 nm (off-wavelength) on remote 3D-measurement of molecular oxygen, O 2 , has been investigated. Absorption by atmospheric oxygen A-band at 761.9 nm corresponds to the magnetic dipole transition b 1 Σ b + (v ′ = 0) ← X 3 Σ g − (v ″ = 0) with absorption cross section of 5.749 × 10−3 cm−2 atm−1 at STP. The accuracy and dynamic range of the DIAL measurement can be extended by simultaneous transmission and detection the spectrally close "on" and "off" wavelengths generated in a compact single laser, in addition to reduce the cost, volume, and weight of the system. The results demonstrate that a concentration of less than 1 ppm by volume is detectable by the system if a path length of 1 km is used. It is noticeable that the wavelengths 762 nm and 773 nm in the near-infrared window spectral range (650–950 nm) allow lidar system to monitor dissolved oxygen in ambient water. This system can also be used from a satellite to quickly characterize O 2 in H 2 O matrices in the outer solar system bodies. [ABSTRACT FROM AUTHOR]

Background and Objectives: Oxygen (O 2 ) use during neonatal cardiopulmonary resuscitation (CPR) remains a subject of controversy. The inspired O 2 concentration during neonatal CPR, that hastens return of spontaneous circulation (ROSC), allows adequate cerebral and myocardial O 2 delivery, and enhances survival to discharge, is not known. The optimal FiO 2 during CPR should decrease incidence of hypoxia but also avoid hyperoxia, and ultimately lead to improved neurodevelopmental outcomes. Due to infrequent need for extensive resuscitation, and emergent circumstances surrounding neonatal CPR, conducting randomized clinical trials continues to be a challenge. The goal of this study was to review the evolution of oxygen use during neonatal CPR, the evidence from animal and clinical studies on oxygen use during neonatal CPR and after ROSC, the pertinent physiology including myocardial oxygen consumption and cerebral oxygen delivery during CPR, and outcomes following CPR in the DR and in the neonatal intensive care unit., Methods: This narrative review is based on recent and historic English literature in PubMed and Google scholar over the past 35 years (January 1, 1985 - May 1, 2021)., Key Content and Findings: Several studies in animal models have compared ventilation with different inspired O 2 concentrations (mostly 21% and 100%) during chest compressions and after ROSC. These studies reported no difference in short-term outcomes, even with as low as 18% O 2 . However, in lamb models of cardiac arrest and CPR, 100% O 2 during chest compressions is associated with better oxygen delivery to the brain compared to 21% O 2 . Abrupt weaning to 21% O 2 following ROSC followed by titration to achieve preductal SpO 2 of 85-95% minimizes systemic hyperoxia and oxidative stress compared to slow weaning from 100% O 2 following ROSC., Conclusions: Clinical research is needed to arrive at the best strategy for assessment of oxygenation and choice of FiO 2 during neonatal CPR that lead to improved survival and outcomes. In this article, we have reviewed the literature on evidence behind O 2 use during neonatal advanced CPR and after ROSC.

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. [ABSTRACT FROM AUTHOR]

Three-dimensional periodic molecular models of amorphous cis-1,4-polybutadiene ( cis-PBD) were constructed using the Materials Studio (MS)® software to study the effects of temperature on the diffusion of oxygen (O2). The radial distribution function, solubility parameter and others clearly proved the three-dimensional periodic molecular model was able to reproduce bulk experimental data of the authentic materials. The volume fraction of accessible oxygen was reckoned by fractional free volume with a probe radius of 1.8 Å. The diffusion coefficients (D) of O2 were calculated, and researches on the diffusion mechanism were made. Data obtained corresponded with the trend from available experiments and previously published simulation work. The results confirmed the accelerating effect of high temperatures on the diffusion of O2 and meanwhile suggested the favourable binding sites of thermo-oxidative aging reactions. Our findings have an important significance for promoting the development of membrane separation technology and provide valuable guidance for further research on thermo-oxidative aging of cis-PBD. [ABSTRACT FROM AUTHOR]

Abstract: Life Support Systems (LSS) are essential for human spaceflight. They are the key element for humans to survive, to live and to work in space. Ambitious goals of human space exploration in the next 40 years like a permanently crewed surface habitat on Moon or a manned mission to Mars require technologies which allow for a reduction of system and resupply mass. Enhancements of existing technologies, new technological developments and synergetic components integration help to close the oxygen, water and carbon loops. In order to design the most efficient LSS architecture for a given mission scenario, it is important to follow a dedicated design process: definition of requirements, selection of candidate technologies, development of possible LSS architectures and characterisation of LSS architectures by system drivers and evaluation of the LSS architectures. This paper focuses on the approach of a synergetic integration of Polymer Electrolyte Membrane Fuel Cells (PEFC) and microalgae cultivated in photobioreactors (PBR). LSS architectures and their benefits for selected mission scenarios are demonstrated. Experiments on critical processes and interfaces were conducted and result in engineering models for a PEFC and PBR system which fulfil the requirements of a synergetic integrative environment. The PEFC system (about 1kW) can be operated with cabin air enriched by stored or biologically generated oxygen instead of pure oxygen. This offers further advantages with regard to thermal control as high oxygen concentrations effect a dense heat production. The PBR system consists of an illuminated cultivation chamber (about 5 l), a nutrients supply and harvesting and analytics units. Especially the chamber enables a microgravity adapted cultivation of microalgae. However, the peripheral units still have to be adapted in order to allow for a continuous and automated cultivation and harvesting. These automation processes will be tested and evaluated by means of a parabolic flight experiment. Both engineering models are being specified in dimensions, components, mass and energy flows. They will serve as a platform for getting operational experience, reliability data and identifying technical problems before the next step is to be realized: in-orbit verification in a spaceflight experiment. [Copyright &y& Elsevier]

Highlights: [•] Cadmium sulfide nanoparticles were synthesized by chemical co-precipitation method. [•] Nanoparticles were spherical in shape and the size of NPs is 5–65nm in diameter. [•] The particles were highly stable. [•] Cadmium sulfide nanoparticles possessed efficient photocatalytic property. [•] The particles exhibited excellent antimicrobial activity. [Copyright &y& Elsevier]

Abstract: The aim of this study was to understand the enhancement mechanism of H2 photoproduction in Chlorella protothecoides under simultaneous nitrogen limitation and sulfur deprivation (LNS). Nitrogen limitation (LN) rather than sulfur deprivation significantly inhibited relative variable fluorescence at K-step (W K) and J-step (V J), photochemical efficiency of PSII (photosystem II), F v/F m, during the process of incubation in the light. Under such conditions, photosynthetic O2 evolution decreased and the anaerobiosis was established after 12 h of incubation. The algae generated large amounts of H2 under nitrogen limitation but generated only trace amounts under sulfur deprivation. Obviously, nitrogen limitation rather than sulfur deprivation was the decisive factor that induced H2 photoproduction in C. protothecoides under LNS. The LNS culture generated much more H2 than the LN culture in the presence of DCMU during incubation, suggesting that a PSII-independent electron source contributed many more electrons for transfer to hydrogenase in the LNS culture. PSII electron transport includes linear electron flow (LEF) and cyclic electron flow (CEF) of PSII in C. protothecoides. In the PSII-dependent electron source for H2 photoproduction, PSII supplies electrons to hydrogenase through the LEF. The LNS culture showed much higher LEF and lower CEF than the LN culture during the H2 photoproduction phase, as indicated by the large lower quantum yield of PSII electron transport (Φ PSII) in the LNS culture in the presence of DCMU. Therefore, compared with nitrogen limitation, simultaneous nitrogen limitation and sulfur deprivation enhanced H2 photoproduction in C. protothecoides mainly due to enhanced PSII-dependent and -independent electron sources. [Copyright &y& Elsevier]

Abstract: Oxidative stress is a common hallmark of neuronal cell death associated with neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, as well as brain stroke/ischemia and traumatic brain injury. Increased accumulation of reactive species of both oxygen (ROS) and nitrogen (RNS) has been implicated in mitochondrial dysfunction, energy impairment, alterations in metal homeostasis and accumulation of aggregated proteins observed in neurodegenerative disorders, which lead to the activation/modulation of cell death mechanisms that include apoptotic, necrotic and autophagic pathways. Thus, the design of novel antioxidant strategies to selectively target oxidative stress and redox imbalance might represent important therapeutic approaches against neurological disorders. This work reviews the evidence demonstrating the ability of genetically encoded antioxidant systems to selectively counteract neuronal cell loss in neurodegenerative diseases and ischemic brain damage. Because gene therapy approaches to treat inherited and acquired disorders offer many unique advantages over conventional therapeutic approaches, we discussed basic research/clinical evidence and the potential of virus-mediated gene delivery techniques for antioxidant gene therapy. [Copyright &y& Elsevier]

Abstract: Asthma is a chronic inflammatory disorder that causes contraction in the smooth muscle of the airway and blocking of airflow. Reversal the contractile process is a strategy for the search of new drugs that could be used for the treatment of asthma. This work reports the semisynthesis, ex vivo relaxing evaluation and SAR studies of a series of 18 coumarins. The results pointed that the ether derivatives 1–3, 7–9 and 13–15 showed the best activity (E max = 100%), where compound 2 (42 μM) was the most potent, being 4-times more active than theophylline (positive control). The ether homologation (methyl, ethyl and propyl) in position 7 or positions 6 and 7 of coumarins lead to relaxing effect, meanwhile formation of esters generated less active compounds than ethers. The SAR analysis showed that it is necessary the presence of two small ether groups and the methyl group at position 4 (site 3) encourage biological activity through soft hydrophobic changes in the molecule, without drastically affecting the cLogP. [Copyright &y& Elsevier]

Highlights: [•] Comprehensive review of neuroprotective gases for multiple neural diseases. [•] Summary of underlying mechanisms for their neuroprotective effects. [•] Possible limitations hindering clinical translation of neuroprotective gases. [ABSTRACT FROM AUTHOR]

Abstract: The present study examines how different pCO2 acclimations affect the CO2- and light-dependence of photophysiological processes and O2 fluxes in four Southern Ocean (SO) key phytoplankton species. We grew Chaetoceros debilis (Cleve), Pseudo-nitzschia subcurvata (Hasle), Fragilariopsis kerguelensis (O'Meara) and Phaeocystis antarctica (Karsten) under low (160μatm) and high (1000μatm) pCO2. The CO2- and light-dependence of fluorescence parameters of photosystem II (PSII) were determined by means of a fluorescence induction relaxation system (FIRe). In all tested species, nonphotochemical quenching (NPQ) is the primary photoprotection strategy in response to short-term exposure to high light or low CO2 concentrations. In C. debilis and P. subcurvata, PSII connectivity (p) and functional absorption cross-sections of PSII in ambient light (σPSII′) also contributed to photoprotection while changes in re-oxidation times of Qa acceptor (τQa) were more significant in F. kerguelensis. The latter was also the only species being responsive to high acclimation pCO2, as these cells had enhanced relative electron transport rates (rETRs) and σPSII′ while τQa and p were reduced under short-term exposure to high irradiance. Low CO2-acclimated cells of F. kerguelensis and all pCO2 acclimations of C. debilis and P. subcurvata showed dynamic photoinhibition with increasing irradiance. To test for the role and presence of the Mehler reaction in C. debilis and P. subcurvata, the light-dependence of O2 fluxes was estimated using membrane inlet mass spectrometry (MIMS). Our results show that the Mehler reaction is absent in both species under the tested conditions. We also observed that dark respiration was strongly reduced under high pCO2 in C. debilis while it remained unaltered in P. subcurvata. Our study revealed species-specific differences in the photophysiological responses to pCO2, both on the acclimation as well as the short-term level. [Copyright &y& Elsevier]

To reiterate from above, glycolysis occurs during sleep, while eating and procreating as well as below the first or second threshold; over 70% of the La SP - sp produced in heavy intensity exercise is removed through oxidation (Brooks I et al i . 1984), and I R i SB a sb matches I R i SB d sb . Therefore, a rise in blood La SP - sp concentration ([La SP - sp ]) during exercise indicates neither anaerobiosis (an O SB 2 sb lack) nor a threshold of O SB 2 sb lack. Critical power, gas exchange threshold, glycolysis, lactate, lactate threshold, oxygen (O2) Keywords: critical power; gas exchange threshold; glycolysis; lactate; lactate threshold; oxygen (O2) EN critical power gas exchange threshold glycolysis lactate lactate threshold oxygen (O2) 1711 1712 2 03/03/21 20210301 NES 210301 We thank Dr MacIntosh and colleagues (MacIntosh I et al i . 2021) for revisiting concerns surrounding nomenclature and the use of the term "anaerobic threshold" (AT), in response to our recent review (Poole I et al i . 2021). [Extracted from the article]

Abstract: An in vivo model in rat was developed by intraperitoneally administration of Fe-dextran to study oxidative stress triggered by Fe-overload in rat brain. Total Fe levels, as well as the labile iron pool (LIP) concentration, in brain from rats subjected to Fe-overload were markedly increased over control values, 6h after Fe administration. In this in vivo Fe overload model, the ascorbyl (A )/ascorbate (AH−) ratio, taken as oxidative stress index, was assessed. The A /AH− ratio in brain was significantly higher in Fe-dextran group, in relation to values in control rats. Brain lipid peroxidation indexes, thiobarbituric acid reactive substances (TBARS) generation rate and lipid radical (LR ) content detected by Electron Paramagnetic Resonance (EPR), in Fe-dextran supplemented rats were similar to control values. However, values of nuclear factor-kappaB deoxyribonucleic acid (NFκB DNA) binding activity were significantly increased (30%) after 8h of Fe administration, and catalase (CAT) activity was significantly enhanced (62%) 21h after Fe administration. Significant enhancements in Fe content in cortex (2.4 fold), hippocampus (1.6 fold) and striatum (2.9 fold), were found at 6h after Fe administration. CAT activity was significantly increased after 8h of Fe administration in cortex, hippocampus and striatum (1.4 fold, 86, and 47%, respectively). Fe response in the whole brain seems to lead to enhanced NF-κB DNA binding activity, which may contribute to limit oxygen reactive species-dependent damage by effects on the antioxidant enzyme CAT activity. Moreover, data shown here clearly indicate that even though Fe increased in several isolated brain areas, this parameter was more drastically enhanced in striatum than in cortex and hippocampus. However, comparison among the net increase in LR generation rate, in different brain areas, showed enhancements in cortex lipid peroxidation, without changes in striatum and hippocampus LR generation rate after 6h of Fe overload. This information has potential clinical relevance, as it could be the key to understand specific brain damage occurring in conditions of Fe overload. [Copyright &y& Elsevier]

Abstract: The objective of the study was to investigate the effects of an in ovo injection of CuNano and the timing of injection on metabolic rate (O2 consumption and heat production, HP) and development of layer hatchlings. On day 1 of incubation, 192 fertile eggs from 29-week-old Lohmann breeder strain chickens were distributed into four groups that were administered colloidal CuNano on: day 1 and/or 10. Gaseous exchange was measured in an open-air-circuit respiration unit, and HP was calculated for 16- and 19-day-old embryos. Yolk free body weight (YFBW) at 24h after hatching and the relative organ weights were used as a measure of hatchling development. In ovo injection of CuNano on different days during incubation significantly decreased O2 consumption and HP compared with the control group. The residual yolk sac weight in the treated groups was significantly higher than in the control group (P<0.0001), indicating that CuNano injection reduced lipid oxidation, which could be associated with the lower O2 consumption (P=0.001). Accordingly, the organ weights (intestine, heart, liver) relative to YFBW were also lower in embryos injected with CuNano (all; P<0.05). Interestingly, the difference in metabolic rate and organ weights between treatments was not reflected in YFBW (P>0.05). Furthermore, the plasma concentrations of IgM and IgG and the mRNA expression of NF-kB and TNF-α were not affected (both; P>0.05), indicating the absence of inflammatory modulation by CuNano. These preliminary results demonstrated that CuNano, regardless of the day of injection, altered the metabolic rate of embryos and depressed the development of organs; however, it did not affect YFBW, immunoglobulin concentrations and the expression of immuno-related genes. [Copyright &y& Elsevier]

Highlights: [•] Impact of CO2 on dissolution rate under conditions emulating wine fermentations. [•] CO2 bubbling increases the volumetric mass transfer coefficient. [•] CO2 bubbling reduces oxygen solubility. [•] Overall, CO2 bubbling reduces oxygen dissolution rate. [ABSTRACT FROM AUTHOR]

Abstract: Background: There is a need for reliable prognostic parameters in pulmonary arterial hypertension (PAH), especially in children. Pulsatile components of the right ventricular afterload, represented by pulmonary arterial compliance (PACi) and pulmonary stroke volume (PSVi), may provide important additional prognostic information to conventional static haemodynamic parameters. The aim of this study was to determine the prognostic value of PACi and PSVi in paediatric PAH. Methods: Right heart catheterization data of 52 consecutive paediatric idiopathic/hereditary PAH and PAH associated with congenital heart disease patients with full haemodynamic evaluation seen at the Dutch national referral centre for paediatric pulmonary hypertension between 1993 and 2010 were reviewed. A control group was composed of patients with normal pulmonary vascular resistance. PSVi and PACi were calculated and tested for predictive value for transplant-free survival. Results: PAH patients had significantly lower PSVi and PACi compared to control patients. PSVi and PACi were lower in patients with higher WHO-functional class compared to those with lower functional classes. Higher PSVi, PACi and mSAP and lower mPAP/mSAP and heart rate were associated with improved survival, independent from WHO-functional class and PAH-targeted therapy. In multivariate analyses PSVi, heart rate and mSAP emerged as the strongest haemodynamic predictors of survival. The effect of vasodilator challenge on the haemodynamic variables did not provide additional prognostic information. Conclusions: The parameters of both the pulsatile and static pulmonary circulations are strong independent predictors for transplant-free survival, and therefore can be of complementary value in assessing disease severity, predicting survival and guiding treatment in paediatric PAH. [Copyright &y& Elsevier]

Abstract: Mitochondrial DNA damage has been used as a successful and unique biomarker of tissue stress. A valuable example of this is sun damage in human skin which leads to ageing and skin cancer. The skin is constantly exposed to the harmful effects of sunlight, such as ultraviolet radiation, which causes it to age with observable characteristic features as well as clinical precancerous lesions and skin cancer. Formation of free radicals by the sun's harmful rays which contribute to oxidative stress has been linked to the induction of deletions and mutations in the mitochondrial DNA. These markers of mitochondrial DNA damage have been proposed to contribute to the mechanisms of ageing in many tissues including skin and are associated with many diseases including cancer. In this article we highlight the role of this important organelle in ageing and cancer with particular emphasis on experimental strategies in the skin. [Copyright &y& Elsevier]

Abstract: Recent years have witnessed a new round of research on one of the most studied proteins - myoglobin (Mb), the oxygen (O2) carrier of skeletal and heart muscle. Two major discoveries have stimulated research in this field: 1) that Mb has additional protecting functions, such as the regulation of in vivo levels of the signaling molecule nitric oxide (NO) by scavenging and generating NO during normoxia and hypoxia, respectively; and 2) that Mb in vertebrates (particularly fish) is expressed as tissue-specific isoforms in other tissues than heart and skeletal muscle, such as vessel endothelium, liver and brain, as found in cyprinid fish. Furthermore, Mb has also been found to protect against oxidative stress after hypoxia and reoxygenation and to undergo allosteric, O2-linked S-nitrosation, as in rainbow trout. Overall, the emerging evidence, particularly from fish species, indicates that Mb fulfills a broader array of physiological functions in a wider range of different tissues than hitherto appreciated. This new knowledge helps to better understand how variations in Mb structure and function may correlate with differences in animals' lifestyles and hypoxia-tolerance. This review integrates old and new results on Mb expression patterns and functional properties amongst vertebrates and discusses how these may relate to adaptive variations in different species. This article is part of a special issue entitled: Oxygen Binding and Sensing Proteins. [Copyright &y& Elsevier]

Abstract: We observed electric quadrupole transitions in the O2 A-band, b 1Σg +←X 3Σg −(0,0), in high solar zenith angle atmospheric spectra recorded with the high-resolution solar-viewing Fourier transform spectrometer at Park Falls, WI. We identified 12 ΔN=±3 transitions for the first time, including the first detection of N O-branch transitions and extended the T S-branch observations of Brault [J Mol Spectrosc 1980;80:384–8] up to N″=23. Additionally, we observed six electric quadrupole transitions of the ΔN=−1 P O-branch. These observations demonstrate the excellent sensitivity and long-term stability of the new generation of solar-viewing Fourier transform spectrometers. [Copyright &y& Elsevier]

Abstract: The reaction mechanisms of CF and CCl with O2 have been investigated theoretically on the doublet potential energy surfaces (PESs). The QCISD/6-311++G(d,p) single-point calculations are performed using the B3LYP/6-311++G(d,p) optimized geometries to accurately determine the energetics. The two product channels, F+CO2 and FCO+O, have been found in the CF+O2 reaction. The former is more competitive because the formation pathway of it undergoes fewer reaction steps and lower barriers than that of FCO+O. In the case of the CCl+O2 reaction, the two similar channels of Cl+CO2 and ClCO+O have also been identified, and the first is less preferable. The title reactions in question are of practical significance in high-temperature processes, because the initial associations are barrier-present. This paper also discusses the effects of halogenations on the reactivity, the reaction pathways, the product channels and the reaction enthalpies of the three CX+O2 reactions (X=H, F or Cl). The reactivity of CX+O2 decreases in the order of CH, CF and CCl. [Copyright &y& Elsevier]

Abstract: A metabolic model for cell growth and recombinant protein overproduction in Escherichia coli, which includes expression vector properties such as plasmid copy number and promoter strength as input parameters, was developed. Linear programming was used to obtain pathway fluxes for selected systems. The experimentally observed slow growth of recombinant E. coli XL1 in minimal medium supplemented with glucose accompanied with significant acetic acid secretion was successfully simulated by metabolic flux analysis (MFA) computations. The expression of the fusion protein GI-malE induced by IPTG caused a severe retardation in cell growth rate from μ=0.066 to 0.006h-1 and increased acetic acid secretion to the medium. The metabolic flux analysis of this transition in growth condition show that cells shift the usage of the available substrate from anabolic to catabolic pathways to increase their ability to produce energy for plasmid-encoded protein synthesis, stress protein synthesis and maintenance requirements. The increase in catabolic fluxes led to increased acetic acid secretion rate. MFA analysis of EcoRI endonuclease expression in E. coli 294 at high growth rate and accompanied by low growth rate depression showed that the flux distribution was very similar for both host and induced cells. The pathway utilization simulate exponential growth condition with preference for the PP pathway and activation of the glyoxalate shunt to meet the high demand for NADPH, NADH and biosynthetic intermediates at high growth rate. For both of the systems studied the pathway utilization and relative flux distributions obtained from MFA are in good agreement with reported E. coli gene expression profiles at different stages of growth and during recombinant protein overexpression. [Copyright &y& Elsevier]

The effects of increasing mitochondrial oxidative phosphorylation (OXPHOS), by enhancing electron transport chain components, were evaluated on 1-methyl-4-phenylpyridinium (MPP+) toxicity in brain neuroblastoma cells. Although glucose is a direct energy source, ultimately nicotinamide and flavin reducing equivalents fuel ATP produced through OXPHOS. The findings indicate that cell respiration/mitochondrial O2 consumption (MOC) (in cells not treated with MPP+) is not controlled by the supply of glucose, coenzyme Q10 (Co-Q10), NADH+, NAD or nicotinic acid. In contrast, MOC in whole cells is highly regulated by the supply of flavins: riboflavin, flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), where cell respiration reached up to 410% of controls. In isolated mitochondria, FAD and FMN drastically increased complex I rate of reaction (1300%) and (450%), respectively, having no effects on complex II or III. MPP+ reduced MOC in whole cells in a dose-dependent manner. In isolated mitochondria, MPP+ exerted mild inhibition at complex I, negligible effects on complexes II–III, and extensive inhibition of complex IV. Kinetic analysis of complex I revealed that MPP+ was competitive with NADH, and partially reversible by FAD and FMN. Co-Q10 potentiated complex II (∼200%), but not complex I or III. Despite positive influence of flavins and Co-Q10 on complexes I–II function, neither protected against MPP+ toxicity, indicating inhibition of complex IV as the predominant target. The nicotinamides and glucose prevented MPP+ toxicity by fueling anaerobic glycolysis, evident by accumulation of lactate in the absence of MOC. The data also define a clear anomaly of neuroblastoma, indicating a preference for anaerobic conditions, and an adverse response to aerobic. An increase in CO2, CO2/O2 ratio, mitochondrial inhibition or O2 deprivation was not directly toxic, but activated metabolism through glycolysis prompting depletion of glucose and starvation. In conclusion, the results of this study indicate that the mechanism of action for MPP+ involves the inhibition of complexes I and IV, leading to impaired OXPHOS and MOC. Moreover, the results also indicate that flavin derivatives control the rate of complex I and more specifically complex IV, leading to impaired OXPHOS and MOC. [Copyright &y& Elsevier]

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.