PO2 Values Research Articles

Improved Oxygenation of Human Skin, Subcutis and Superficial Cancers Upon Mild Hyperthermia Delivered by WIRA-Irradiation.

Clinical trials have shown that mild hyperthermia (HT) serves as an adjunct to cancer treatments such as chemo- and radiotherapy. Recently, a high efficacy of mild HT immediately followed by hypofractionated radiotherapy (RT) in treatment of recurrent breast cancer has been documented if temperatures of 39-43°C are achieved for 40-60 min. In the present study, temperature and oxygenation profiles were measured in superficial tissues of healthy volunteers exposed to water-filtered infrared-A- (wIRA)- irradiation, to verify that adequate thermal doses together with the improved tumor oxygenation necessary for radiosensitisation are obtained. Experiments were performed using a wIRA-system equipped with two wIRA-radiators, each with a thermography camera for real-time monitoring of the skin surface temperature. Temperatures within the abdominal wall were measured with fibre optic sensors at defined tissue depths (subepidermal, and 1-20 mm inside the tissue). The corresponding tissue pO2 values were assessed with fluorometric microsensors. In selected situations, hyperspectral tissue imaging was used to visualise the oxygenation status of normal skin and superficial tumours in patients. Pre-treatment skin surface temperature was 34.6°C. Upon wIRA exposure, average skin surface temperatures reached 41.6°C within 5-12 min. Maximum tissue temperatures of 41.8°C were found at a tissue depth of 1mm, with a steady decline in deeper tissue layers (41.6°C @ 5mm, 40.8°C @ 10mm, 40.6°C @ 15mm, and 40.1°C @ 20mm). Effective HT levels ≥39°C were established in tissue depths up to 25 mm. Tissue heating was accompanied by a significant increase in tissue pO2 values [e.g., at a tissue depth of 13 mm mean pO2 rose from 46mmHg to 81mmHg (@ T=40.5°C). In the post-heating phase (+ 5min), pO2 was 79mmHg (@ T=38°C) and 15 min post-heat pO2 was 72mmHg (@ T=36.8°C)]. pO2 values remained elevated for 30-60 min post-heat. Non-invasive monitoring of normal skin and of recurrent breast cancers confirmed the improved O2 status by wIRA-HT. In conclusion, wIRA-irradiation enables effective tissue heating (T=39-43°C) associated with distinct increases in blood flow and pO2. These adjustments unequivocally meet the requirement for effective radiosensitisation.

Birthing ball on promoting cervical ripening and its influence on the labor process and the neonatal blood gas index.

BACKGROUNDTerm pregnancy-induced labor refers to the use of artificial methods to induce uterine contractions and terminate pregnancy after 37 wk. It is a common method to prevent overdue pregnancy and to deal with high-risk pregnancies. In addition, it can alleviate maternal complications and cause the fetus to leave the adverse intrauterine environment early, which is beneficial to the outcome of pregnancy.AIMTo explore the effect of a birthing ball on labor by inducing cervical ripening and its influence on labor and the neonatal blood gas index.METHODSTwenty-two women who were scheduled to undergo labor induction and delivery in the obstetrics department of our hospital were randomly divided into two groups: the delivery ball group (childbirth ball combined with COOK balloon induction) and the conventional group (COOK balloon induction alone). The cervical Bishop score before and after intervention, duration of labor at each stage, mode of delivery, neonatal umbilical venous blood pH, oxygen partial pressure (PO2), carbon dioxide partial pressure (PCO2), and the 1-min Apgar score were recorded.RESULTSAfter the intervention, the cervical Bishop score of the delivery ball group (7.84 ± 1.52) was significantly higher than that of the conventional group (7.32 ± 1.29) (P < 0.05), and the cervical Bishop scores of the two groups after intervention were significantly higher than those before intervention (P < 0.05). After the intervention, the first stage of labor (510.9 ± 98.7 min), the second stage of labor (43.0 ± 8.5 min), and the total duration of labor (560.0 ± 120.9 min) in the delivery ball group were lower than those in the routine group, with a first stage of labor of 602.1 ± 133.2 min, a second stage of labor of 48.4 ± 9.1 min, and a total duration of labor of 656.8 ± 148.5 min (P < 0.05). There was no significant difference in the time of the third stage of labor between the two groups (P > 0.05). There was no significant difference in the pH, PO2, and PCO2 values of newborns between the delivery ball group and the conventional group (P > 0.05). The 1-min Apgar score of the delivery ball group was higher than that of the conventional group (9.10 ± 0.38 points vs 8.94 ± 0.31 points, P < 0.05). The natural delivery rate of the delivery ball group was higher than that of the conventional group (91.00% vs 78.00%, P < 0.05).CONCLUSIONThe use of a birthing ball combined with a COOK balloon for inducing labor has a better effect on promoting cervical ripening, shortening the time of labor, and improving the Apgar score of newborns.

Validation of a new combined transcutaneous tcPCO2 and tcPO2 sensor in children in the operating theater.

BackgroundArterial blood gas analysis is the gold standard for monitoring of PaCO2 and PaO2 during mechanical ventilation. However, continuous measurements would be preferred. Transcutaneous sensors continuously measure blood gases diffusing from the locally heated skin. These sensors have been validated in children mostly in intensive care settings. Accuracy in children during general anesthesia is largely unknown.AimsWe conducted a study in children undergoing general anesthesia to validate the use and to determine the accuracy of continuous transcutaneous measurements of the partial pressures of PCO2 (tcPCO2) and PO2 (tcPO2).MethodsA prospective observational study in a tertiary care pediatric hospital in The Netherlands, from April to October 2018, in children aged 0–18 years undergoing general anesthesia. Patients were included when endotracheally intubated and provided with an arterial catheter for regular blood sampling. Patients with a gestational age <31 weeks, burn victims, and patients with skin disease were excluded. TcPCO2 and tcPO2 measurements were performed with a SenTec OxiVenT™ sensor (SenTec AG). Accuracy was determined with an agreement analysis between arterial and transcutaneous PCO2 and PO2 values, and between arterial and endtidal PCO2 (etCO2) values, according to Bland and Altman, accounting for multiple measurements per subject.ResultsWe included 53 patients (median age 4.1 years, IQR 0.7–14.4 years) and retrieved 175 samples. TcPCO2‐PaCO2 agreement analysis provided a bias of 0.06 kPa (limits of agreement (LOA) −1.18 to 1.31), the etCO2‐PaCO2 agreement showed a bias of −0.31 kPa (LOA −1.38 to 0.76). Results of the tcPO2‐PaO2 agreement showed a bias of 3.40 to 0.86* (mean tension) kPa.ConclusionsThis study showed good agreement between PaCO2 and tcPCO2 in children of all ages during general anesthesia. Both transcutaneous and endtidal CO2 measurements showed good accuracy. TcPO2 is only accurate under 6 months of age.

Gestational age impacts birth to placental weight ratio and umbilical cord oxygen values with implications for the fetal oxygen margin of safety

BackgroundWe determined the impact of gestational age (GA) from near term to term to post-term on birth/placental weight ratio and cord oxygen values with implications for placental transport efficiency for oxygen, fetal O2 consumption relative to delivery or fractional O2 extraction, and oxygen margin of safety. Materials and methodsA hospital database was used to obtain birth/placental weight ratios, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA > 34 completed weeks (N = 69,852). Oxygen saturation was calculated from the cord PO2 and pH data, while fractional O2 extraction was calculated from the oxygen saturation data. The effect of GA grouping on birth/placental weight ratio, cord PO2, O2 saturation, and fractional O2 extraction values, was examined in all patients adjusting for pregnancy and labor/delivery covariates, and in a subset of low-risk patients. ResultsBirth/placental weight ratio and umbilical venous O2 values increased with advancing GA, supporting the conjecture of increasing placental transport efficiency for oxygen. However, umbilical arterial O2 values decreased while fractional O2 extraction increased with successive GA groupings, indicating that fetal O2 consumption must be increasing relative to delivery. ConclusionsFetal O2 consumption can be seen as ever ‘outgrowing’ O2 delivery over the last weeks of pregnancy and leading to a continued lowering in systemic oxygen levels. While this lowering in oxygen may trigger feedback mechanisms with survival benefit, the ‘oxygen margin of safety’ will also be lowered increasing perinatal morbidity and mortality which appear to be hypoxia related.

Design concept of co-ionic conducting solid oxide electrolyte for stable operation in a cell-imbalanced fuel cell stack

A bilayer composite electrolyte comprising BaCe0.85Y0.15O3-d (BCY15) – Gd0.2Ce0.8O2-d (GDC20) at the anode side and BaZr0.85Y0.15O3-d (BZY15) – Nd0.1Ce0.9O2-d (NDC10) at the cathode side is designed for improving the stability of co-ionic conducting solid oxide fuel cells (SOFCs) in a cell imbalanced stack. Contrary to the single layer structured SOFCs, the bi-layer cell stably operates without electrode delamination under negative voltage conditions. We measure local internal pO2 values using embedded Pt probes. Based on these values, local electronic conduction is estimated in combination with four probe DC conductivity measurements. It is found that n-type conductivity (∼10−3 Scm−1) and p-type conductivity (10−5–10−4 Scm−1) are developed in the BCY15-GDC20 near the anode side and in the BZY15-NDC10 near the cathode side, respectively. The results indicate that local electronic conduction in electrolyte regions near both the anode and cathode interfaces is a crucial factor for the durability of co-ionic SOFCs under negative voltage operation. We therefore suggest the bi-layer configuration as a practical solution to protect co-ionic SOFCs in a cell-imbalanced stack.

The Way of Severe Nursing of Respiratory System Failure.

Respiratory failure is the most common clinical symptom, seriously endangering people's health, which is mainly caused by a series of reasons, leading to serious respiratory dysfunction and severe pulmonary respiratory disorders, damaging the pulmonary airway function, and causing disability to maintain normal human gas exchange activities. At present, the main treatment of respiratory failure is to use the ventilator to help patients exchange gas and keep their breathing unobstructed. The nursing method is also around the artificial airway mechanical ventilation. The nursing of patients with respiratory failure is mainly respiratory nursing and psychological nursing. In this paper, the main research is to explore the way of severe nursing of respiratory failure. Before the nursing of respiratory failure, we should carry out nursing detection of the ventilator and test its performance, tightness, pipeline safety, and airway patency. Then carrying on the respiratory failure mechanical ventilation nursing and clarifying its mechanical ventilation nursing process is the main work of intensive care, at the same time, giving consideration to the psychological nursing of respiratory failure and implementing comprehensive nursing. In this paper, 50 patients were selected and divided into group A and group B; group A was given comprehensive nursing, and group B was given general nursing. The experimental results show that a series of situations in group A are more optimistic than those in group B. There was no doubt that the PH value of the two groups changed significantly 6 months after discharge. The pO2 value of group A was higher than that before discharge, while the pCO2 value of group B was unstable and increased. The pO2 value of group A was 55.52 before discharge and 62.36 six months after discharge. The pCO2 value of group A was 54.31 before discharge and 50.61 six months after discharge. The pCO2 value of group B was 55.23 before discharge and 57.34 six months after discharge.

O2 permeability of lipid bilayers is low, but increases with membrane cholesterol

Oxygen on its transport route from lung to tissue mitochondria has to cross several cell membranes. The permeability value of membranes for O2 (PO2), although of fundamental importance, is controversial. Previous studies by mostly indirect methods diverge between 0.6 and 125 cm/s. Here, we use a most direct approach by observing transmembrane O2 fluxes out of 100 nm liposomes at defined transmembrane O2 gradients in a stopped-flow system. Due to the small size of the liposomes intra- as well as extraliposomal diffusion processes do not affect the overall kinetics of the O2 release process. We find, for cholesterol-free liposomes, the unexpectedly low PO2 value of 0.03 cm/s at 35 °C. This PO2 would present a serious obstacle to O2 entering or leaving the erythrocyte. Cholesterol turns out to be a novel major modifier of PO2, able to increase PO2 by an order of magnitude. With a membrane cholesterol of 45 mol% as it occurs in erythrocytes, PO2 rises to 0.2 cm/s at 35 °C. This PO2 is just sufficient to ensure complete O2 loading during passage of erythrocytes through the lung’s capillary bed under the conditions of rest as well as maximal exercise.

Influence of preparation regimes and composition on structure, phase state and electric properties of nanogranular (FeCoZr)x(PZT)100-x (30 ≤ x ≤ 85 at.%) films

Granular films containing Fe50Co50Zr10 alloy nanoparticles inside the ferroelectric matrix Pb0.81Sr0.04(Na0.5Bi0.5)0.15(Zr0.575Ti0.425)O3 (PZT) are characterized by a complex of functional magnetic and electrical characteristics that can be effectively controlled by an external electric or magnetic field. The formation of the necessary granular structure in the case of a PZT matrix is possible only during synthesis in an oxygen-containing atmosphere, leading to significant oxidation of metal nanoparticles. In this regard, an urgent task is to study the degree of oxidation of metal nanoparticles depending on the synthesis conditions, as well as the influence of the forming phases on the electrical properties of films.The relationship of the phase composition and electrical characteristics of granular films (FeCoZr)x(PZT)100-x (30 ≤ x ≤ 85, at.%) obtained in an oxygen-containing atmosphere at a pressure of PO in the range (2.4—5.0) ⋅ 10-3 Pa was studied by X-ray diffraction analysis, EXAFS spectroscopy (Extended X-ray Absorption Fine Structure) and four-probe electrical resistivity measurements.A comparative complex analysis of the structural-phase composition and local atomic order in films (FeCoZr)x(PZT)100-x for the first time showed the fundamental influence of oxygen pressure during synthesis on the oxidation of nanoparticles and their phase composition. It is shown that in the case of oxygen pressure up to the values of PO = 3.2 ⋅ 10-3 Pa, a transition from nanoparticles of complex Fe(Co,Zr) oxides occurs with increasing x to the superposition of complex oxides and ferromagnetic nanoparticles α-FeCo(Zr,O) (or their agglomerations). At a higher oxygen pressure PO = 5.0 ⋅ 10-3 Pa, complete oxidation of nanoparticles is observed with the formation of a complex oxide (FexCo1-x)1-δO with a wustite structure.The observed structural-phase composition allows us to explain the measured temperature dependences of the electrical resistance of granular films, characterized by a negative temperature coefficient of electrical resistance (TKR) in the entire range of film compositions at high oxygen pressure (PO = 5.0 ⋅ 10-3 Pa), and the transition to positive TKR at lower oxygen pressure (PO = 3.2 ⋅ 10-3 Pa) in the synthesis atmosphere and the value x ≤ 69 at.% in films. The transition from negative to positive TKR, indicating the presence of a metallic contribution to conductivity, is fully correlated with the detection by XRD and EXAFS methods of non-oxidized ferromagnetic nanoparticles α-FeCo(Zr,O) or their agglomerations.

First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip.

ObjectiveThe overall objective of this clinical study was to validate an implantable oxygen sensor, called the ‘OxyChip’, as a clinically feasible technology that would allow individualized tumor-oxygen assessments in cancer patients prior to and during hypoxia-modification interventions such as hyperoxygen breathing.MethodsPatients with any solid tumor at ≤3-cm depth from the skin-surface scheduled to undergo surgical resection (with or without neoadjuvant therapy) were considered eligible for the study. The OxyChip was implanted in the tumor and subsequently removed during standard-of-care surgery. Partial pressure of oxygen (pO2) at the implant location was assessed using electron paramagnetic resonance (EPR) oximetry.ResultsTwenty-three cancer patients underwent OxyChip implantation in their tumors. Six patients received neoadjuvant therapy while the OxyChip was implanted. Median implant duration was 30 days (range 4–128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6–73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5–144.6 mmHg). In 83% of the measurements, there was a statistically significant (p ≤ 0.05) response to hyperoxygenation.ConclusionsMeasurement of baseline pO2 and response to hyperoxygenation using EPR oximetry with the OxyChip is clinically feasible in a variety of tumor types. Tumor oxygen at baseline differed significantly among patients. Although most tumors responded to a hyperoxygenation intervention, some were non-responders. These data demonstrated the need for individualized assessment of tumor oxygenation in the context of planned hyperoxygenation interventions to optimize clinical outcomes.

Effects of Elemental Mercury Vapor Inhalation on Arterial Blood Gases, Lung Histology, and Interleukin-1 Expression in Pulmonary Tissues of Rats.

We investigated the effects of elemental mercury vapor inhalation on arterial blood gases (ABGs), lung histology, and interleukin-1 (IL-1) expression in pulmonary tissues in rats. A total of 42 Sprague Dawley rats were divided randomly into three groups. Rats in the first group were used as the control (CG). A short-term group (STG) and a long-term group (LTG) were exposed to 500 μg/m3 of mercury vapor 2 hrs/day for 21 days and 65 days, respectively. After exposure periods were completed, arterial blood samples were obtained, and ABGs were measured. Lung tissue sections were prepared for histology evaluation and immune-stained to detect IL-1 expression. There was a significant decrease in body weight in both STG (15%) and LTG (22%) compared with the CG. In the LTG, six out of 14 (43%) rats died, including two males and four females, while none of the rats in the STG died during the experiment. In both STG and LTG, a significant acid-base imbalance was characterized by a significant decrease in blood pH values and a significant increase in PCO2 values. Both PO2 and SpO2 blood values were significantly decreased in the STG and LTG, while no changes were observed in HCO3 values in all groups. Histological evaluation of lung tissues revealed severe lesions characterized by pulmonary emphysema and inflammatory cellular infiltrate. IL-1 expression in lung tissues was not significantly different between exposed rats and control subjects. These results indicate significant alterations in blood acid-base status characterized by severe respiratory acidosis with hypoxemia and no evidence of compensatory alkalosis in rats after exposure to short- and long-term elementary mercury vapor.

СОСТОЯНИЕ ГОМЕОСТАЗА У КРЫС С ТЕРМИЧЕСКИМ ОЖОГОМ КОЖИ, ПОЛУЧЕННЫМ В СРЕДНЕМ ПЕРИОДЕ БЕРЕМЕННОСТИ

Background. In modern medicine, the problem of treating thermal skin burns in pregnant women remains relevant due to insufficient research of pathological processes occurring in the body of a future mother suffering from thermal injury. The aim of the research. To assess the state of homeostasis in rats with thermal skin burns in the middle period of pregnancy. Material and methods. An experimental study was carried out on 36 female outbred white rats weighing 250-350 g, which underwent thermal skin burns in the middle period of pregnancy. The processes of lipid peroxidation and the total content of nitrate / nitrites were studied, the oxygen transport function of the blood and the main biochemical parameters of the blood were assessed. Results. Thermal skin burn in rats in the middle period of pregnancy leads to the development of hypoxia, as judged by the decrease in pO2 and SO2 values, as well as a decrease in the affinity of hemoglobin for oxygen. At the same time, oxidative stress develops, and an increase in the content of nitrate / nitrites is also observed, which reflects the dysfunction of the L-arginine-NO system, causing changes in the oxygen-binding properties of the blood and forming a prooxidant-antioxidant imbalance. Changes in the main biochemical parameters of blood confirm the presence of endogenous intoxication. Conclusions. The revealed violations of homeostasis in pregnant rats with thermal skin burns indicate the important role of oxygen-dependent processes in the pathogenesis of thermal injury, which must be taken into account when developing appropriate measures aimed at eliminating violations in this pathology.

Task Difficulty Moderates the Impact of Pain on Cognitive Effort

The handheld point of care analyzer is a quick and feasible option to obtain hematology data from individuals. The iSTAT-1® was used to evaluate select venous blood analytes obtained via jugular venipuncture from 238 passerine birds from South Texas. These data were used to assess the health of birds in the area while taking into consideration life history (migratory or sedentary), locale, seasonality, sex, and age. We attributed increased values of pO2 and hematocrit, in addition to hemoglobin and glucose concentrations of migratory birds compared to sedentary birds as the increased need of oxygen carrying capacity and energy for long duration flights. Increased glucose and lower ionized calcium concentrations were observed in migratory birds likely based on breakdown of fat deposits in the body to fuel the muscular endurance of migration. During the hotter months of the year, birds' responses to handling were exhibited by relative respiratory acidosis. When sedentary birds sampled from South Texas were compared to a previous study from Central Texas, venous blood analytes differed by locale but were within the ranges of healthy populations. These findings lead us to conclude that sedentary avian communities can be used as ecosystem bioindicators.

Macromolecular Design for Oxygen/Nitrogen Permselective Membranes-Top-Performing Polymers in 2020.

Oxygen/nitrogen permselective membranes play particularly important roles in fundamental scientific studies and in a number of applications in industrial chemistry, but have not yet fulfilled their full potential. Organic polymers are the main materials used for such membranes because of the possibility of using sophisticated techniques of precise molecular design and their ready processability for making thin and large self-supporting membranes. However, since the difference in the properties of oxygen and nitrogen gas molecules is quite small, for example, their kinetic diameters are 3.46 Å and 3.64 Å, respectively, the architectures of the membrane macromolecules should be designed precisely. It has been reported often that oxygen permeability (PO2) and oxygen permselectivity (α = PO2/PN2) have trade-off relationships for symmetric membranes made from pure polymers. Some empirical upper bound lines have been reported in (ln α − ln PO2) plots since Robeson reported an upper bound line in 1991 for the first time. The main purpose of this review is to discuss suitable macromolecular structures that produce excellent oxygen/nitrogen permselective membranes. For this purpose, we first searched extensively and intensively for papers which had reported α and PO2 values through symmetric dense membranes from pure polymers. Then, we examined the chemical structures of the polymers showing the top performances in (ln α − ln PO2) plots, using their aged performances. Furthermore, we also explored progress in the molecular design in this field by comparing the best polymers reported by 2013 and those subsequently found up to now (2020) because of the rapid outstanding growth in this period. Finally, we discussed how to improve α and PO2 simultaneously on the basis of reported results using not only symmetric membranes of pure organic polymers but also composite asymmetric membranes containing various additives.

Micronutrients Supplementation in Pregnant Women during COVID-19 Pandemy: Pros and Cons

Coronavirus can negatively affect the immune system. This complication can be exaggerated in pregnant women with micronutrient and elemental deficiencies. Also, coronavirus itself can induce micronutrients malabsorption and result in their severe deficiencies that can lead to increased risk of infection in these groups of patients. Serum calcium, zinc, iron, and selenium values have a positive correlation with PO2 values and a negative correlation with severe COVID-19 infection, lung involvement, fever, and C-reactive protein (CRP) concentration. In this mini-review study, the safety and efficacy of different suggested micronutrients including zinc, selenium, iron, vitamin A, C, D, E, and myo-inositol in pregnant women with COVID-19 have been discussed. According to the clinical practice findings and previous reports, administration of essential micronutrients including zinc, selenium, and iron and vitamins including vitamin A, B8, C, D, and E with optimum recommended dietary allowances (RDAs) during pregnancy would be promising and suggestive to improve maternal/neonatal complications during COVID-19 infection due to the enhanced immunity system against viral infection and COVID-19 pneumonia.

Synthesis and thermochemical redox cycling of porous ceria microspheres for renewable fuels production from solar-aided water-splitting and CO2 utilization

Porous ceria-based architected materials offer high potential for solar fuels production via thermochemical H2O and CO2-splitting cycles. Novel porous morphologies and micro-scale architectures of redox materials are desired to provide suitable thermochemical activities and long-term stability. Considering particle-based solar reactors, porous ceria microspheres are promising because of their excellent flowability and large surface area. In this work, such porous microspheres with perfect spherical shape, high density, and interconnected pore network were fabricated by a chemical route involving ion-exchange resins. The method involved the cationic loading of the resin in an aqueous medium followed by thermal treatment for oxide formation and porous microstructure stabilization. The utilization of these microspheres (∼150–350 μm in size) as redox materials for solar fuel production was investigated in packed-bed solar reactors (directly and indirectly irradiated). Superior redox performance was obtained for the pure ceria microspheres in comparison with other morphologies (powders and reticulated foams). Low pO2 values thermodynamically favored the reduction extent and associated fuel yield, whereas high pCO2 kinetically promoted the oxidation rate. The highest fuel production rate reached 1.8 mL/min/g with reduction step at 1400 °C, low total pressure (∼0.1 bar), and oxidation step below 1050 °C under pure CO2. Low pressure during reduction both improved reduction extent (oxygen under-stoichiometry δ up to 0.052) and associated fuel production yield (331 μmol/g CO). After 19 redox cycles (∼32 h under high-flux solar irradiation), the porous microspheres maintained their individual integrity (no agglomeration), spherical shape, and internal porosity, with great potential for stable fuel production capacity in particle-based solar reactors.

Active Blood Acidification Greatly Enhances Oxygen Supply to the Teleost Retina

Most ray-finned fishes possess a unique system for retinal oxygen delivery, where intracellular acidification of red blood cells (RBCs) in the retinal capillaries induces oxygen offloading from pH-sensitive hemoglobin. A countercurrent vascular network, the choroid rete mirabile, posterior to the retina augments this “oxygen-secretory” mechanism and confers retinal PO2 values that can exceed 1300 mmHg in some species. We hypothesized that the choroid rete mirabile exerts an active role in intracellular RBC acidification to facilitate retinal oxygen secretion. We show the presence and enzymatic activities of extracellular carbonic anhydrase (CA) and vacuolar-type H+-ATPase (VHA) in the lumen of the choroid rete mirabile. These data are consistent with a pathway, where VHA secretes H+ into the choroid rete mirabile lumen, which combines with HCO3– to form CO2 (catalyzed by extracellular CA) that rapidly diffuses into the RBC facilitating hemoglobin oxygen offloading. Next, we validated the model in vivo by injecting an extracellular CA inhibitor (C18) into the dorsal aorta of anesthetized rainbow trout with a PO2 electrode implanted into the retina. Here, the inhibition of extracellular CA resulted in a rapid reduction in retinal PO2 from 517 to 226 mmHg within minutes. These data strongly support the proposed model for RBC acidification in the choroid rete mirabile. Further, in vivo data show that this mechanism primarily augments oxygen diffusion to the inner retinal segments involved in signal-processing and that the evolution of this pathway was tightly associated with the morphological expansion of this part of the retina. Together, these data suggest that the evolutionary origin of retinal oxygen secretion in the early history of the ray-finned fishes was associated with a greatly enhanced capacity for visual processing, potentially permitting improved visual prey detection and the colonization of novel environments.

Estimation of pO2 distribution in EPR oximetry

Electron paramagnetic resonance (EPR) oximetry, using oxygen-sensing implant such as OxyChip, is capable of measuring oxygen concentration in vivo – a critical tissue information required for successful medical treatment such as cancer, wound healing and diabetes. Typically, EPR oximetry produces one value of the oxygen concentration, expressed as pO2 at the site of implant. However, it is well recognized that in vivo one deals with a distribution of oxygen concentration and therefore reporting just one number is not representative_a long-standing critique of EPR oximetry. Indeed, when it comes to the assessment of radiation efficacy one should be guided not by the mean or median but the proportion of oxygenated cancer cells which can be estimated only when the whole oxygen distribution in the tumor is known. Although there is a handful of papers attempting estimation of the oxygen distribution they suffer from the problem of negative frequencies and no theoretical justification and no biomedical interpretation. The goal of this work is to suggest a novel method using the empirical Bayesian approach realized via nonlinear mixed modeling with a priori distribution of oxygen following a two-parameter lognormal distribution with parameters estimated from the multi-implant single component EPR scan. Unlike previous work, the result of our estimation is the distribution with positive values for the frequency and the associated pO2 value. Our algorithm based on nonlinear regression is illustrated with EPR measurements on OxyChips equilibrated with gas mixtures containing four values of pO2 and computation of the proportion of volume with pO2 greater than any given threshold. This approach may become crucial for application of the EPR oximetry in clinical setting when the sucsess of the treatment depends of the proportion of tissue oxygenated.

Evaluation of the Role of Routine Laboratory Biomarkers in COVID-19 Patients: Perspective from a Tertiary Care Hospital in India.

To evaluate the role of routine laboratory biomarkers like C Reactive Protein (CRP), Lactate Dehydrogenase (LDH), Interleukin 6 (IL6), Ferritin, Creatinine, Procalcitonin (PCT), Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Serum Albumin, Total Bilirubin (T Bil), High Sensitive Troponin I (hs troponin I), N Terminal-pro B-type Natriuretic Peptide (NT proBNP), Blood Urea Nitrogen (BUN) and Blood Gases in COVID 19 patients who are admitted with SARS CoV-2 positive test results by real-time reverse transcriptase polymerase chain reaction (rRT PCR) in Kokilaben Dhirubhai Ambani Hospital & Medical Research Institute, Mumbai, India. 100 individuals detected with COVID-19 belonging to the age group 12–83 years (median age 62 years) within the period of 1st March 2020 to 10th July 2020 were studied. The case group consisted of 72 males and 28 females. 40 healthy adults without any history or clinical evidence suggestive of COVID-19 and without any comorbidities, like diabetes, hypertension chronic lung disease, cardiac disease, cancer, and immune-compromised individuals were considered as a control group for the study. Routine laboratory findings of these 100 patients were used to evaluate the abnormalities found in COVID-19 patients. Statistical analysis was carried out on the data after determining whether the data had a normal/log-normal distribution and their significance was determined by calculating the p-value. The percentage of patients showing a decrease or increase from the normal value was calculated. Trend analysis was carried out for the 100 patients considered in the case group. Among them, 6 patients were used as representatives to show the trend in these biomarkers during the course of hospital stay. These 5 severe cases consisted of 2 adult males, 2 adult females, and 1 adolescent girl. This selection is to demonstrate the representation of COVID-19 infection in adult males and females and pediatric multisystem inflammatory syndrome associated with COVID-19 in the younger age group. One mild case (adult male) was also selected in the case study. We found a significant increase in mean values of AST, ALT, Total Billirubin, Creatinine, CRP, PCT, LDH, IL6, Ferritin, Lactate, hsTroponin I, NT Pro BNP and decrease in mean values of Albumin, SO2, and PO2 in COVID 19 cases than control. We applied Receiver Operating Curve (ROC) curve to discriminate case population more precisely than the control population. Therefore, Routine laboratory biomarkers appear to play a significant role in COVID-19 patients.

Ultrahigh oxygen permeability of the desilylated membranes of halogen-containing diphenylacetylene copolymers

Extremely high gas-permeable polymers were synthesized via the metathesis copolymerization of 1-(3,4-difluorophenyl)-2-(4-trimethylsilylphenyl)acetylene (FS) and 1-(3,4-dichlorophenyl)-2-(4-trimethylsilylphenyl)acetylene (CS). The PO2 values of the copolymers (PFCS) were determined to be 5,600–14,000 barrer. It was found that desilylation remarkably enhanced the gas permeability, with the obtained desilylated membranes (DPFC) exhibiting ultrahigh oxygen permeabilities of 8,300–25,100 barrer, which are the highest among existing polymer materials. The effects of physical aging on the PO2 values of PFCS and DPFC were fairly small, thereby indicating their good stabilities.

Investigation of the effect of anesthesia implementation with bispectral index on postoperative neurocognitive functions and delirium in open heart surgery

Background: Neurological complications of coronary artery bypass surgery are still the major causes of mortality and morbidity despite all advances in this field.&#x0D; Aims and Objectives: We investigated the effect of bispectral index (BIS) monitoring of the patient consciousness on the postoperative neurocognitive functions in our study.&#x0D; Materials and Methods: A total of 40 patients in the age range from 25 to 75 years were included in our study, who were electively operated for isolated coronary artery bypass grafting (CABG) surgery in the period from January 2014 to June 2014. The patients were assigned to two groups based on whether BIS monitoring was performed or not. The patients were consecutively allocated to either group when they were found eligible to be included based on the exclusion criteria. Administration of the anesthesia was monitored with BIS in the respective group (Group 1). All patient follow-up parameters were compared in both groups. Neurocognitive function tests (the clock drawing test and standardized mini mental test) were administered to the patients in the preoperative and postoperative period(1 st day and day before discharge). The results were compared.&#x0D; Results: There were no significant findings in the demographic features and the routine follow-up parameters between the two groups. The time of extubation, intensive care unit (ICU) follow-up parameters, and the length of stay in the ICU were not significantly different between the groups; however, the length of stay at the hospital was significantly longer in the group of patients, who were not monitored with BIS (p&lt;0.05). The mean arterial blood pressure was statistically significantly higher in group 1 (BIS monitoring) at all phases of the operation and during the postoperative follow-ups. A significant acidosis was present in the arterial blood pressure tests of the patients in group 1 during their stay at the ICU. The Po2 values following cross-clamping and extubation were significantly higher in group 1. In the group monitored with BIS, the results of the neurocognitive tests, which were the clock drawing test and the standardized mini mental test, were both clinically and statistically superior (p&lt;0.05).&#x0D; Conclusıons: BIS monitoring provides favorable contributions for the follow-up of the patients undergoing CABG surgery and it is helpful in estimating the consciousness state of the patients after the surgery.