Neurodevelopmental outcomes of preterm infants after randomisation to initial resuscitation with lower (FiO2 0.6) initial oxygen levels. An individual patient meta-analysis

ObjectiveTo determine the effects of lower (≤0.3) versus higher (≥0.6) initial fractional inspired oxygen (FiO2) for resuscitation on death and/or neurodevelopmental impairment (NDI) in infants <32 weeks’ gestation.DesignMeta-analysis of individual patient data from three randomised controlled trials.SettingNeonatal intensive care units.Patients543 children <32 weeks’ gestation.InterventionRandomisation at birth to resuscitation with lower (≤0.3) or higher (≥0.6) initial FiO2.Outcome measuresPrimary: death and/or NDI at 2 years of age.Secondary: post-hoc non-randomised observational analysis of death/NDI according to 5-minute oxygen saturation (SpO2) below or at/above 80%.ResultsBy 2 years of age, 46 of 543 (10%) children had died. Of the 497 survivors, 84 (17%) were lost to follow-up. Bayley Scale of Infant Development (third edition) assessments were conducted on 377 children. Initial FiO2 was not associated with difference in death and/or disability (difference (95% CI) −0.2%, −7% to 7%, p=0.96) or with cognitive scores <85 (2%, −5% to 9%, p=0.5). Five-minute SpO2 >80% was associated with decreased disability/death (14%, 7% to 21%) and cognitive scores >85 (10%, 3% to 18%, p=0.01). Multinomial regression analysis noted decreased death with 5-minute SpO2 ≥80% (odds (95% CI) 09.62, 0.98 to 0.96) and gestation (0.52, 0.41 to 0.65), relative to children without death or NDI.ConclusionInitial FiO2 was not associated with difference in risk of disability/death at 2 years in infants <32 weeks’ gestation but CIs were wide. Substantial benefit or harm cannot be excluded. Larger randomised studies accounting for patient differences, for example, gestation and gender are urgently needed.

Theoretical inversion of the fossil hydrothermal systems with oxygen isotopes of constituent minerals partially re-equilibrated with externally infiltrated fluids

ABSTRACT While the external infiltration of water has been identified from modern geothermal and/or fossil hydrothermal systems through stable isotopes, the physicochemical boundary conditions like the initial oxygen isotopes of water $( {{\rm \delta }^{ 18}{\rm O}_{\rm W}^{\rm i} } ) $ and rock as well as alteration temperature were implicitly presumed or empirically estimated by the conventional forward modelling. In terms of a novel procedure proposed to deal with partial re-equilibration of oxygen isotopes between constituent minerals and water, the externally infiltrated meteoric and magmatic water are theoretically inverted from the early Cretaceous post-collisional granitoid and intruded Triassic gneissic country rock across the Dabie orogen in central-eastern China. The meteoric water with a $ {{\rm \delta }^{ 18}{\rm O}_{\rm W}^{\rm i} } $ value of −11.01 ‰ was externally infiltrated with a granitoid and thermodynamically re-equilibrated with rock-forming minerals at 140°C with a minimum water/rock (W/R)o ratio around 1.10 for an open system. The lifetime of this meteoric hydrothermal system is kinetically constrained less than 0.7 million years (Myr) via modelling of surface reaction oxygen exchange. A gneissic country rock, however, was externally infiltrated by a magmatic water with $ {{\rm \delta }^{ 18}{\rm O}_{\rm W}^{\rm i} } $ value of 4.21 ‰ at 340°C with a (W/R)o ratio of 1.23, and this magmatic hydrothermal system could last no more than 12 thousand years (Kyr) to rapidly re-equilibrate with rock-forming minerals. Nevertheless, the external infiltration of water can be theoretically inverted with oxygen isotopes of re-equilibrated rock-forming minerals, and the ancient hydrothermal systems driven by magmatism or metamorphism within continental orogens worldwide can be reliably quantified.

Effectiveness of High Flow Nasal Cannula and Standard Non-Rebreathing Mask for Oxygen Therapy in Moderate Category COVID-19 Pneumonia: A Randomized Controlled Study

Background: To compare the effectiveness of High Flow Nasal Cannula (HFNC) and standard non rebreathing mask (NRBM) as oxygen delivery device, in moderate cases of COVID-19 Pneumonia.Methods: A single-centre, prospective, open label randomized controlled trial was conducted between February 2021 and April 2021. Sixty enrolled patients were randomly divided into two groups according to the oxygen delivery device used. Group 1 (n = 30) received HFNC and group 2 (n = 30) received NRBM as initial oxygen delivery device, to maintain a target saturation of ≥ 96% in both groups. The success rate of oxygen therapy, time to progression to severe disease, PaO2, PaO2/FiO2 ratio, respiratory rate, heart rate, blood pressure, number of patients requiring NIV or endotracheal intubation, time for de-escalation of oxygen therapy to lower Fio2 device and patient satisfaction level were compared among the two groups.Results: Demographic, clinical variables and treatment given were comparable in the two groups. In the HFNC group 83.3% patients had successful outcomes with the initial oxygen therapy device used as compared to 66.6% in the NRBM group. However, the use of HFNC resulted in improved oxygenation (P < 0.001), better patient satisfaction (P < 0.001) and shorter time for de-escalation of oxygen therapy to a lower FIO2 device (3.75 ± 1.032 vs. 6.83 ± 0.928).Conclusions: HFNC is a reliable oxygen therapy modality for moderate category COVID-19 pneumonia that results in better oxygenation and a greater patient satisfaction level as compared to a non-rebreathing mask.Trial Registration: ctri.nic.in; Reg No: CTRI/2021/01/030829; Date of Reg: 05/02/2021

Resuscitation with an Intact Cord Enhances Pulmonary Vasodilation and Ventilation with Reduction in Systemic Oxygen Exposure and Oxygen Load in an Asphyxiated Preterm Ovine Model

(1) Background: Optimal initial oxygen (O2) concentration in preterm neonates is controversial. Our objectives were to compare the effect of delayed cord clamping with ventilation (DCCV) to early cord clamping followed by ventilation (ECCV) on O2 exposure, gas exchange, and hemodynamics in an asphyxiated preterm ovine model. (2) Methods: Asphyxiated preterm lambs (127–128 d) with heart rate <90 bpm were randomly assigned to DCCV or ECCV. In DCCV, positive pressure ventilation (PPV) was initiated with 30–60% O2 and titrated based on preductal saturations (SpO2) with an intact cord for 5 min, followed by clamping. In ECCV, the cord was clamped, and PPV was initiated. (3) Results: Fifteen asphyxiated preterm lambs were randomized to DCCV (N = 7) or ECCV (N = 8). The inspired O2 (40 ± 20% vs. 60 ± 20%, p < 0.05) and oxygen load (520 (IQR 414–530) vs. 775 (IQR 623–868), p-0.03) in the DCCV group were significantly lower than ECCV. Arterial oxygenation and carbon dioxide (PaCO2) levels were significantly lower and peak pulmonary blood flow was higher with DCCV. (4) Conclusion: In asphyxiated preterm lambs, resuscitation with an intact cord decreased O2 exposure load improved ventilation with an increase in peak pulmonary blood flow in the first 5 min.

A New Approach to Obtaining Nano-Sized Graphene Oxide for Biomedical Applications

Graphene oxide (GO) is one of the most exciting and widely used materials. A new method of nanographene oxide (n-GO) formation is presented. The described unique sequence of ultrasonication in dimethyl sulfoxide solution allows us to obtain different sizes of n-GO sheets by controlling the timing of the cutting and re-aggregation processes. The obtained n-GO exhibits only minor spectral changes, mainly due to the formation of S-containing surface groups; thus, it can be concluded that the material is not reduced during the process. Maintaining the initial oxygen functionalities together with the required nano-size (down to 200 nm) and high homogeneity are beneficial for extensive applications of n-GO. Moreover, we prove that the obtained material is evidently biocompatible. The calculated half-maximal effective concentration (EC50) increases by 5-fold, i.e., from 50 to 250 µg/mL, when GO is converted to n-GO. As a consequence, the new n-GO neither disturbs blood flow even in the narrowest capillaries nor triggers a toxic influence in surrounding cells. Thus, it can be a serious candidate for drugs and biomolecule carriers administered systemically.

Preferential Protection of Low Coordinated Sites in Pt Nanoparticles for Enhancing Durability of Pt/C Catalyst

Protecting low coordinated sites (LCS) of Pt nanoparticles, which are vulnerable to dissolution, may be an ideal solution for enhancing the durability of polymer electrolyte fuel cells (PEMFCs). However, the selective protection of LCSs without deactivating the other sites presents a key challenge. Herein, we report the preferential protection of LCSs with a thiol derivative having a silane functional group, (3-mercaptopropyl) triethoxysilane (MPTES). MPTES preferentially adsorbs on the LCSs and is converted to a silica framework, providing robust masking of the LCSs. With the preferential protection, the initial oxygen reduction reaction (ORR) activity is marginally reduced by 8% in spite of the initial electrochemical surface area (ECSA) loss of 30%. The protected Pt/C catalyst shows an ECSA loss of 5.6% and an ORR half-wave potential loss of 5 mV after 30,000 voltage cycles between 0.6 and 1.0 V, corresponding to a 6.7- and 2.6-fold durability improvement compared to unprotected Pt/C, respectively. The preferential protection of the vulnerable LCSs provides a practical solution for PEMFC stability due to its simplicity and high efficacy.

Highlights of Newborn Resuscitation Science, 2020

In October 2020, the neonatal resuscitation science update was published with several new treatment guidelines. The changes are based on an extensive review of literature using the GRADE process, addressing 22 topics. Topics for the review of interest include initial oxygen concentration for term and preterm infants, suctioning for clear and meconium-stained liquor, use of sustained lung inflation for ventilation, appropriate route for drug delivery, and extent of duration of resuscitation.

Impact of hypothermia on the biomechanical effect of epithelium-off corneal cross-linking

Background The corneal cross-linking (CXL) photochemical reaction is essentially dependent on oxygen and hypothermia, which usually leads to higher dissolved oxygen levels in tissues, with potentially greater oxygen availability for treatment. Here, we evaluate whether a reduction of corneal temperature during CXL may increase oxygen availability and therefore enhance the CXL biomechanical stiffening effect in ex vivo porcine corneas. Methods One hundred and twelve porcine corneas had their epithelium manually debrided before being soaked with 0.1% hypo-osmolaric riboflavin. These corneas were equally assigned to one of four groups. Groups 2 and 4 underwent accelerated epithelium-off CXL using 9 mW/cm2 irradiance for 10 min, performed either in a cold room temperature (group 2, 4 °C) or at standard room temperature (group 4, 24 °C). Groups 1 and 3 served as non-cross-linked, temperature-matched controls. Using a stress-strain extensometer, the elastic moduli of 5-mm wide corneal strips were analyzed as an indicator of corneal stiffness. Results Accelerated epithelium-off CXL led to significant increases in the elastic modulus between 1 and 5% of strain when compared to non-cross-linked controls (P < 0.05), both at 4 °C (1.40 ± 0.22 vs 1.23 ± 0.18 N/mm) and 24 °C (1.42 ± 0.15 vs 1.19 ± 0.11 N/mm). However, no significant difference was found between control groups (P = 0.846) or between groups in which CXL was performed at low or standard room temperature (P = 0.969). Conclusions Although initial oxygen availability should be increased under hypothermic conditions, it does not appear to play a significant role in the biomechanical strengthening effect of epithelium-off CXL accelerated protocols in ex vivo porcine corneas.