pO2 Levels Research Articles

Aluminum droplets on Ni substrates: Evaluating high-temperature oxidation at the liquid/gas interface

In reactive wetting aluminum (Al)/nickel (Ni) systems, oxides at liquid/gas (L/G) interfaces received less attention compared to intermetallic compounds forming at liquid Al/solid Ni interfaces yet potentially significantly influencing wetting properties. Between 900 and 1250 °C, we observed that the shape of sessile Al droplets with dense oxides at the L/G interface and intense interactions at liquid Al/solid Ni interfaces deviates from a spherical cap and can be used as a way to characterize the oxide evolution. This approach reveals a critical temperature of 1100 °C under a PO2 level of 3.9 × 10−9 atm and a vacuum level of ∼2 × 10−2 mbar. Above it, Al2O3 oxides at the L/G interface are eliminated as Al2O gas, while at lower temperatures, they develop as a mixture of Al2O3 oxides and Al-Ni intermetallic compounds with Ni being dissolved from the substrate. At high temperatures (above 1200 °C), despite oxide-free L/G interfaces, non-spherical cap shapes were also obtained due to the formation of sharp edges at the contact line triggered by the growth of intermetallic compounds. The coupling between the droplet shapes and the interfacial interactions is further confirmed by in-situ observation of oxides, analysis of quenched samples and thermodynamic calculations. The proposed method can be potentially applied to multiple reactive wetting systems (e.g. Sn/Cu, Al/Fe, Mg/Ni systems), which are crucial for high-temperature processes such as soldering, coating, and processing of metal matrix composites.

Study of indications, associated comorbid condi-tions and outcome of patients requiring Bilevel type of Non Inva-sive Positive Pressure Ventilation in a tertiary care hospital

BiLevel non-invasive positive pressure ventilation (BiPAP) is the most utilised supportive treatment in the world of medicine for respiratory failure. COPD is the most common indication for its use. We in-vestigated the indications and effects of comorbidities on BiPAP outcomes because there have been few studies on it. It is a descriptive, observational, cross-sectional study conducted over period of 12 months, wherein 60 patients fulfilling the inclusion criteria for the requirement of BiPAP were includ-ed in the study and evaluated. The indications, associated comorbid conditions and the outcomes of NIV therapy were studied. COPD exacerbation with Type II Respiratory failure was the most common indication (71.4%), followed by asthma [near fatal/severe] (21.4%). Success with BiPAP in COPD was 67.6% . In COPD patients with co-morbidities, success came down to 47.4%. Pneumonia, ILD & Cardiogenic Pulmonary Edema (CPE) had success rates of 0%, 16.7% and 66.7% respectively with BiPAP therapy,with higher mortality rates for pneumonia and ILD. Comorbidities were present in 51.7% of patients and Hypertension (35%) and Diabetes Mellitus (21.7%) were the most common. In patients who had co-morbidities, the mean hospital stay was 12 days, which was higher than the mean hospital stay of 9.3 days in patient with no co-morbidities. The presence of co-morbidities was associated with higher failures with BiPAP (51.6%) comapred to ones with no co-morbidities (13.8%) (p value <0.05). Higher respiratory rate (>28/min), lower ABG pO2, pCO2 and bicarbonate levels and higher blood glucose and total leucocyte counts were associated with higher BiPAP failures and mortality. The conclusion was that the most common indication of BiPAP was a COPD exacerbation with type II respiratory failure and presence of comorbidities led to a poorer outcome with prolonged hospital stay. ABG parameters, blood glucose levels and total leucocyte counts has an effect on NIV outcome and mortality.

A-349 Evaluation of i-STAT® Point of Care Blood Gas Cartridges and Competitor Blood Gas Devices Against Reference Standard for PCO2 and PO2

Abstract Background The i-STAT System provides laboratory quality results in minutes at the patient’s bedside. Accurate and rapid test results are critical for clinical decision making in the presence of blood gas disorders, including oxygenation and acid-base status, where the partial pressure oxygen (PO2) and partial pressure carbon dioxide (PCO2) are needed. The purpose of this study was to compare the analytical performance of the PO2 and PCO2 tests in the i-STAT G3+ and i-STAT CG8+ cartridges to the theoretical PO2 and PCO2 in prepared reference standards. Two other blood gas instruments, a benchtop device and a laboratory device were also compared to the reference PO2 and PCO2. Methods Venous whole blood samples were contrived using saturation tonometry with U.S. NIST (National Institute of Science and Technology) traceable gas tanks to prepare the reference standards, which were value assigned to theoretical PO2 or PCO2 levels based on the molar composition of the gas mixture used. Eleven levels spanning the reportable range of each PO2 (5 mmHg - 800 mmHg) and PCO2 (5 mmHg - 130 mmHg) were prepared and tested in duplicate on the i-STAT G3+ and i-STAT CG8+ cartridges, benchtop device, and the laboratory device. Passing-Bablok linear regression analysis was performed to evaluate the slope and correlation coefficient, comparing each blood gas device against the reference PO2 and PCO2 values. Study designs followed CLSI (Clinical and Laboratory Standards Institute) EP09C-ED3:2018, Measurement Procedure Comparison and Bias Estimation using Patient Samples, 3rd Edition. Passing-Bablok regression analysis was also performed for the i-STAT cartridges and benchtop device against the laboratory device. Results The regression analysis was performed against the reference standards. For PO2, slopes for the i-STAT cartridges ranged from 0.93 - 0.97, the slope for the benchtop device was 0.99, and the slope for the laboratory device was 0.97. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.98 - 1.02, the slope for the benchtop device was 0.85, and the slope for the laboratory device was 1.01. Correlation coefficients were 1.00 for the i-STAT cartridges and laboratory device, and 0.99 for the benchtop device. The regression analysis was also performed against the laboratory device. For PO2, slopes for the i-STAT cartridges ranged from 0.96 - 1.00, and the slope for the benchtop device was 1.02. Correlation coefficients for all devices were 1.00. For PCO2, slopes for the i-STAT cartridges ranged from 0.97 - 1.01, and the slope for the benchtop device was 0.85. Correlation coefficients were 1.00 for the i-STAT cartridges and 0.99 for the benchtop device. Conclusions The study demonstrated that the i-STAT G3+ and i-STAT CG8+ cartridges used with the i-STAT System were shown to provide laboratory quality results within 2 minutes, showing good agreement to both reference standards and laboratory quality devices. For PCO2, the i-STAT System was shown to have better agreement to both theoretical reference standards and the laboratory device than the benchtop device. These studies were funded by Abbott Laboratories.

Antioxidant and Immunological Properties of Dracocephalum moldavica Extract in Penaeus vannamei

Objectives: The effects of different concentrations of Dracocephalum moldavica extract (DME) supplement on growth, survival, antioxidants, some biochemical parameters and innate immunity of White leg shrimp (Penaeus vannamei) juveniles investigated. Methods: For 56 days, shrimp (4.5-5 g) received diets that were enhanced with 0 (control), 50, 100, 200 mg DME/kg feed to attain apparent satiety. Results: The results revealed that feeding shrimp with DME significantly improved Feed efficiency and Feed conversion ratio with an optimum level of 200 mg/kg diet. Dietary DME supplementation had no significant effects on their carcass composition. Total albumin and protein higher (P > 0.05) in DME-fed particularly at 200 mg/kg treatment On the other hand, shrimp fed 200 mg DME/kg feed experienced significant decreases in aspartate and alanine aminotransferase levels. As dietary extract levels increased, there was a significant (P < 0.05) increase in SOD and CAT activities, as well as LYZ and PO levels, so that treatments with 100 and 200 mg DME/kg feed had the highest values, and Significant (P < 0.05) reductions in MDA and NO levels were observed at high dietary extract levels of 100 and 200 mg DME/kg. Conclusion: P. vannamei's growth, antioxidant capacity and innate immunity were boosted by diets that contained 200 mg DME/kg feed.

Combined Effects of Mechanical Ventilation and Postural Drainage in Acute Respiratory Distress Syndrome

Background: Acute Respiratory Distress Syndrome (ARDS) is a severe condition impacting lung function, often requiring mechanical ventilation. Postural drainage may improve oxygenation and airway clearance in ARDS patients, particularly in those with burn injuries and inhalation trauma.Objective: This study aimed to evaluate the combined effects of mechanical ventilation and postural drainage on oxygen saturation and airway clearance in burn patients with ARDS.Methods: A randomized controlled trial was conducted with 50 burn patients, aged 20-50, admitted to the ICU. Patients were divided into two groups: Group A received postural drainage with mechanical ventilation, and Group B received only mechanical ventilation. Data were collected daily using the APACHE II scale. FiO2, PO2, pH, and HCO3 levels were measured pre- and post-treatment. Data were analyzed using SPSS version 25.Results: The post-treatment FiO2 in Group A increased from 48.80 ± 18.92% to 85.40 ± 13.69%, while PO2 increased from 66.40 ± 17.22 mmHg to 77.40 ± 15.08 mmHg. Statistically significant improvements were observed in oxygenation (p < 0.05), with no significant changes in pH and PCO2.Conclusion: Postural drainage combined with mechanical ventilation significantly improves oxygenation in burn patients with ARDS.

Facile One Pot Synthesis of Hybrid Core-Shell Silica-Based Sensors for Live Imaging of Dissolved Oxygen and Hypoxia Mapping in 3D Cell Models.

Fluorescence imaging allows for noninvasively visualizing and measuring key physiological parameters like pH and dissolved oxygen. In our work, we created two ratiometric fluorescent microsensors designed for accurately tracking dissolved oxygen levels in 3D cell cultures. We developed a simple and cost-effective method to produce hybrid core-shell silica microparticles that are biocompatible and versatile. These sensors incorporate oxygen-sensitive probes (Ru(dpp) or PtOEP) and reference dyes (RBITC or A647 NHS-Ester). SEM analysis confirmed the efficient loading and distribution of the sensing dye on the outer shell. Fluorimetric and CLSM tests demonstrated the sensors' reversibility and high sensitivity to oxygen, even when integrated into 3D scaffolds. Aging and bleaching experiments validated the stability of our hybrid core-shell silica microsensors for 3D monitoring. The Ru(dpp)-RBITC microparticles showed the most promising performance, especially in a pancreatic cancer model using alginate microgels. By employing computational segmentation, we generated 3D oxygen maps during live cell imaging, revealing oxygen gradients in the extracellular matrix and indicating a significant decrease in oxygen level characteristics of solid tumors. Notably, after 12 h, the oxygen concentration dropped to a hypoxic level of PO2 2.7 ± 0.1%.

Dynamic oxygen assessment techniques enable determination of anesthesia's impact on tissue.

Tissue oxygenation is well understood to impact radiosensitivity, with reports demonstrating a significant effect of breathing condition and anesthesia type on tissue oxygenation levels and radiobiological response. However, the temporal kinetics of intracellular and extracellular oxygenation have never been quantified, on the timescale that may affect radiotherapy studies. C57BL/6 mice were anesthetized using isoflurane at various percentages or ketamine/xylazine (ket/xyl: 100/10 mg/kg) (N = 48). Skin pO2 was measured using Oxyphor PdG4 and tracked after anesthetization began. Oxyphor data was validated with relative measurements of intracellular oxygen via protoporphyrin IX (PpIX) delayed fluorescence (DF) imaging. Ex vivo localization of both PdG4 Oxyphor and PpIX were quantified. Under all isoflurane anesthesia conditions, leg skin pO2 levels significantly increased from 12-15 mmHg at the start of anesthesia induction (4-6 minutes) to 24-27 mmHg after 10 minutes (p < 0.05). Ketamine/xylazine anesthesia led to skin pO2 maintained at 15-16 mmHg throughout the 10-minute study period (p < 0.01). An increase of pO2 in mice breathing isoflurane was demonstrated with Oxyphor and PpIX DF, indicating similar intracellular and extracellular oxygenation. These findings demonstrate the importance of routine anesthesia administration, where consistency in the timing between induction and irradiation may be crucial to minimizing variability in radiation response.

Dialoxygenation: A Preclinical Trial for Transforming the Artificial Kidney Into an Oxygenator.

Critically ill patients sometimes require tandem application of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) which is easier and cheaper. We aimed to transform the kidney membrane into a lung membrane by adding hydrogen peroxide (H 2 O 2 ) to the dialysate as the oxygen source. A solution containing H 2 O 2 and a dialysate fluid mixture was used as the final dialysate. Starting with 100% H 2 O 2 solution and gradually reducing the volume of H 2 O 2 , respectively: 50%, 10%, 5%, 4%, 3%, 2%, and 1%. PRISMAFLEX system, Prismaflex M60 set and a bag of packed red blood cells (pRBCs) were the prototype. blood flow rate was about 40 ml/minute and the dialysis rate was about 200 ml/m 2 /minute/1.73 m 2 . blood sampling times were; at the beginning ( T0 ), at 15th ( T1 ), 30th ( T2 ), 60th ( T3 ) minutes. Amongst eight attempts H 2 O 2 concentration that increased the partial oxygen pressure (pO 2 ) level significantly in a reasonable period, without any bubbles, was 3%. Methemoglobinemia was not observed in any trial. After the test with 3%, H 2 O 2 in the dialysate fluid decreased progressively without any H 2 O 2 detection at post-membrane blood. Three percent H 2 O 2 solution is sufficient and safe for oxygenation in CRRT systems. With this new oxy-dialysate solution, both pulmonary and renal replacement can be possible viaa single membrane in a simpler manner.

Correlation of arterial and venous blood gas analysis in respiratory failure in children

IntroductionArterial and venous blood gases provide similar and very close measurements in terms of PH, pCO2, HCO3, pO2 levels. The study aims to investigate correlation of arterial and venous blood gas analysis in respiratory failure caused by pneumonia in children.MethodsThis cross-sectional study employed a consecutive sampling method from pediatric patients experiencing respiratory failure. Point of Care (POCT) was used to examine blood gas analysis.ResultThere was no significant difference between pH artery and venous with p = 0,232 (95% confidence interval [CI]: -14.628-59,488). The Mean difference between arterial and venous pH was 0,22 with a strong Spearman correlation of 0,643 (p < 0,001). There was a significant difference between arterial and venous pCO2 with p = 0,022 (95% confidence interval [CI]: -8,7- (− 0,69)). The mean difference between arterial and venous pCO2 was 4,69 with a moderate Spearman correlation of 0,485 (p < 0,001). There was no significant difference between arterial and venous HCO3 with p = 0,38. The Mean difference between arterial and venous HCO3 was 3,1 with a very strong Spearman correlation of 0,848 (p < 0,001). There was a very significant difference between arterial and venous pO2 with p < 0,001. The Mean difference between arterial and venous pO2 was 27,4 with a weak Spearman correlation of 0,17 (p = 0,117).ConclusionThere was strong correlation between arterial and venous pH, a moderate correlation between arterial and venous pCO2, a very strong correlation between arterial and venous HCO3 and a very weak correlation between arterial and venous pO2 using POCT.

Consistent differences in tissue oxygen levels across 15 insect species reflect a balance between oxygen supply and demand and highlight a hitherto unknown adaptation for extracting sufficient oxygen from water

Animals, including insects, need oxygen for aerobic respiration and eventually asphyxiate without it. Aerobic respiration, however, produces reactive oxygen species (ROS), which contribute to dysfunction and aging. Animals appear to balance risks of asphyxiation and ROS by regulating internal oxygen relatively low and stable, but sufficient levels. How much do levels vary among species, and how does variation depend on environment and life history? We predicted that lower internal oxygen levels occur in insects with either limited access to environmental oxygen (i.e., insects dependent on aquatic respiration, where low internal levels facilitate diffusive oxygen uptake, and reduce asphyxiation risks) or consistently low metabolic rates (i.e., inactive insects, requiring limited internal oxygen stores). Alternatively, we predicted insects with long life-stage durations would have internal oxygen levels > 1 kPa (preventing high ROS levels that are believed to occur under tissue hypoxia). We tested these predictions by measuring partial pressures of oxygen (PO2) in tissues from juvenile and adult stages across 15 species comprising nine insect orders. Tissue PO2 varied greatly (from 0 to 18.8 kPa) and variation across species and life stages was significantly related to differences in habitat, activity level, and life stage duration. Individuals with aquatic respiration sustained remarkably low PO2 (mean = 0.88 kPa) across all species from Ephemeroptera (mayflies), Plecoptera (stoneflies), Trichoptera (caddisflies), and Diptera (true flies), possibly reflecting a widespread, but hitherto unknown, adaptation for extracting sufficient oxygen from water. For Odonata (dragonflies), aquatic juveniles had higher PO2 levels (mean = 6.12 kPa), but these were still lower compared to terrestrial adults (mean = 13.3 kPa). Follow-up tests in juvenile stoneflies showed that tissue PO2 remained low even when exposed to hyperoxia, suggesting that levels were down-regulated. This was further corroborated since levels could be modulated by ambient oxygen levels in dead individuals. In addition, tissue PO2 was positively related to activity levels of insect life stages across all species and was highest in stages with short durations. Combined, our results support the idea that internal PO2 is an evolutionarily labile trait that reflects the balance between oxygen supply and demand within the context of the environment and life-history of an insect.

Correlation between local instantaneous dose rate and oxygen pressure reduction during proton pencil beam scanning irradiation

Background and purposeOxygen dynamics may be important for the tissue-sparing effect observed at ultra-high dose rates (FLASH sparing effect). This study investigated the correlation between local instantaneous dose rate and radiation-induced oxygen pressure reduction during proton pencil beam scanning (PBS) irradiations of a sample and quantified the oxygen consumption g-value. Materials and methodsA 0.2 ml phosphorescent sample (1 μM PtG4 Oxyphor probe in saline) was irradiated with a 244 MeV proton PBS beam. Four irradiations were performed with variations of a PBS spot pattern with 5 × 7 spots. During irradiation, the partial oxygen pressure (pO2) was measured with 4.5 Hz temporal resolution with a phosphorometer (Oxyled) that optically excited the probe and recorded the subsequently emitted light. A calibration was performed to calculate the pO2 level from the measured phosphorescence lifetime. A fiber-coupled scintillator simultaneously measured the instantaneous dose rate in the sample with 50 kHz sampling rate. The oxygen consumption g-value was determined on a spot-by-spot level and using the total pO2 change for full spot pattern irradiation. ResultsA high correlation was found between the local instantaneous dose rate and pO2 reduction rate, with a correlation coefficient of 0.96–0.99. The g-vales were 0.18 ± 0.01 mmHg/Gy on a spot-by-spot level and 0.17 ± 0.01 mmHg/Gy for full spot pattern irradiation. ConclusionsThe pO2 reduction rate was directly related to the local instantaneous dose rate per delivered spot in PBS deliveries. The methodology presented here can be applied to irradiation at ultra-high dose rates with modifications in the experimental setup.

Transient Changes in Cerebral Tissue Oxygen, Glucose, and Temperature by Microstrokes: A Computational Study.

This study focuses on evaluating the disruptions in key physiological parameters during microstroke events to assess their severity. A mathematical model was developed to simulate the changes in cerebral tissue pO2, glucose concentration, and temperature due to blood flow interruptions. The model considers variations in baseline cerebral blood flow (CBF), capillary density, and blood oxygen/glucose levels, as well as ambient temperature changes. Simulations indicate that complete blood flow obstruction still allows for limited glucose availability, supporting nonoxidative metabolism and potentially exacerbating lactate buildup and acidosis. Partial obstructions decrease tissue pO2, with minimal impact on glucose level, which can remain almost unchanged or even slightly increase. Reduced CBF, capillary density, or blood oxygen due to aging or disease enhances hypoxia risk at lower obstruction levels, with capillary density having a significant effect on stroke severity by influencing both pO2 and glucose levels. Conditions could lead to co-occurrence of hypoxia/hypoglycemia or hypoxia/hyperglycemia, each worsening outcomes. Temperature effects were minimal in deep brain regions but varied near the skull by 0.2-0.8°C depending on ambient temperature. The model provides insights into the conditions driving severe stroke outcomes based on estimated levels of hypoxia, hypoglycemia, hyperglycemia, and temperature changes.

Preliminary research on tailored fluid therapy in pigs: comparing customized ionic solutions with Hartmann’s solution

BackgroundFluid therapy in veterinary medicine is pivotal for treating various conditions in pigs; however, standard solutions, such as Hartmann’s solution, may not optimally align with pig physiology. This study explored the development and efficacy of a customized fluid therapy tailored to the ionic concentrations of pig blood, aiming to enhance treatment outcomes and safety in both healthy and diseased pigs.ResultsThe study involved two experiments: the first to assess the safety and stability of customized fluids in healthy pigs, and the second to evaluate the efficacy in pigs with clinical symptoms of dehydration. In healthy pigs, the administration of customized fluids showed no adverse effects, with slight alterations observed in pO2, hematocrit, and glucose levels in some groups. In symptomatic pigs, the customized fluid group did not show any improvement in clinical symptoms, with no significant changes in blood chemistry or metabolite levels compared to controls. The customized fluid group showed a mild increase in some values after administration, yet within normal physiological ranges. The study reported no significant improvements in clinical or dehydration status, attributing the observed variations in blood test results to the limited sample size and anaesthesia effects rather than fluid characteristics.ConclusionsCustomized fluid therapy, tailored to mimic the ionic concentrations of pig blood, appears to be a safe and potentially more effective alternative to conventional solutions such as Hartmann’s solution for treating pigs under various health conditions. Further research with larger sample sizes and controlled conditions is recommended to validate these findings and to explore the full potential of customized fluid therapy in veterinary practice.

The challenges of identifying pulmonary embolism in patients hospitalized for exacerbations of COPD

BackgroundChronic obstructive pulmonary disease (COPD) is associated with airflow obstruction that threatens global health. During the hospitalization of patients with acute exacerbations of COPD (AECOPD), the high prevalence of pulmonary embolism (PE) seriously affects the prognosis of disease. This study aims to assess the differences in clinical data between patients with AECOPD and patients with AECOPD-PE, and to identify the relevant factors of PE. MethodsWe performed a retrospective case-control study in AECOPD patients between January 2018 and December 2021. Due to suspected PE, all patients underwent radiological examination. Patients without PE were included as controls. Clinical data and laboratory tests were recorded. Univariate analysis and multivariate logistic regression analysis were used to investigate the independent predictors of PE. Receiver operating characteristics (ROC) curves was performed to evaluate the effect of risk factors on PE prediction. ResultsA total of 191 patients were included for analysis, divided into the AECOPD group (96 cases) and AECOPD-PE group (95 cases). No statistic differences were detected in demographic characteristics between patients with AECOPD and patients with AECOPD and PE. Average PO2 and PCO2 levels, lung function, and Echocardiographic indicator were not associated with PE. The concentration of D-dimer, the proportion of simplified wells score ≥ 2, and the incidence rate of lower extremity deep vein thrombosis (DVT) remarkably increased in AECOPD-PE group than AECOPD individuals. At multivariate analysis, the above three indicators were closely relevant to the occurrence of PE. The AUC value for D-dimer combined with lower extremity DVT and Simplified Wells Score was 0.729. ConclusionsD-dimer, lower extremity DVT, and simplified wells score ≥ 2 were relevant to higher risks of PE, which will help to improve clinicians’ understanding of PE secondary to AECOPD.

Hypoxia-mediated programmed cell death is involved in the formation of wooden breast in broilers

BackgroundWooden breast (WB) myopathy is a common myopathy found in commercial broiler chickens worldwide. Histological examination has revealed that WB myopathy is accompanied by damage to the pectoralis major (PM) muscle. However, the underlying mechanisms responsible for the formation of WB in broilers have not been fully elucidated. This study aimed to investigate the potential role of hypoxia-mediated programmed cell death (PCD) in the formation of WB myopathy.ResultsHistological examination and biochemical analysis were performed on the PM muscle of the control (CON) and WB groups. A significantly increased thickness of the breast muscle in the top, middle, and bottom portions (P<0.01) was found along with pathological structure damage of myofibers in the WB group. The number of capillaries per fiber in PM muscle, and the levels of pO2 and sO2 in the blood, were significantly decreased (P < 0.01), while the levels of pCO2 and TCO2 in the blood were significantly increased (P < 0.05), suggesting hypoxic conditions in the PM muscle of the WB group. We further evaluated the PCD-related pathways including autophagy, apoptosis, and necroptosis to understand the consequence response to enhanced hypoxic conditions in the PM muscle of birds with WB. The ratio of LC3 II to LC3 I, and the autophagy-related factors HIF-1α, BNIP3, Beclin1, AMPKα, and ULK1 at the mRNA and protein levels, were all significantly upregulated (P < 0.05), showing that autophagy occurred in the PM muscle of the WB group. The apoptotic index, as well as the expressions of Bax, Cytc, caspase 9, and caspase 3, were significantly increased (P < 0.05), whereas Bcl-2 was significantly decreased (P < 0.05) in the WB-affected PM muscle, indicating the occurrence of apoptosis mediated by the mitochondrial pathway. Additionally, the expressions of necroptosis-related factors RIP1, RIP3, and MLKL, as well as NF-κB and the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6, were all significantly enhanced (P < 0.05) in the WB-affected PM muscle.ConclusionsThe WB myopathy reduces blood supply and induces hypoxia in the PM muscle, which is closely related to the occurrence of PCD including apoptosis, autophagy, and necroptosis within myofibers, and finally leads to abnormal muscle damage and the development of WB in broilers.

Non-Targeted Metabolomics Analysis of Mother and Infant in Gestational Diabetes Mellitus and Neonatal Clinical Characterization.

The goal was to analyze serums of GDM patients and healthy pregnant women using HPLC-MS and preliminarily screen differential metabolites by metabolomics. Sixty pregnant women who underwent elective cesarean section at term in Dongguan Dalang Hospital from January 2023 to April 2023 were selected and divided into the GDM group and healthy pregnancy group. Pre-pregnancy and pregnancy examination information, such as age, BMI, OGTT results, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and other clinical data were col-lected for statistical analysis. Non-targeted metabolomics of serum from 30 GDM patients and 30 healthy pregnant women were studied by HPLC-MS, and different ions were searched. The structures of differential metabolites were identified by HMDB database. The metabolic pathways of differential metabolites were analyzed by KEGG database. The OGTT result, pCO2, pO2, HCO3, BE, Apgar score, and bilirubin levels in the GDM group were higher than those in the healthy pregnancy group (p < 0.05). However, there were no significant differences in age, triglyceride, total cholesterol, newborn birth weight, newborn birth blood glucose, and blood gas pH between the two groups (all p > 0.05). Using p < 0.05 as the screening standard, 55 differential metabolites were identified in serum, mainly including fatty acyl, carboxylic acids and their derivatives, steroids and their derivatives, ketoacids and their derivatives, and pyrimidine nucleosides, etc., all of which were up-regulated or down-regulated to varying degrees. The 55 metabolites were mainly involved in the metabolism of pyrimidine, pyruvate, alanine, aspartic acid, glutamic acid, and arachidonic acid, glycolysis, and biosynthesis of unsaturated fatty acids. The discovery of these metabolites provides a theoretical basis for an indepth understanding of GDM pathogenesis. Non-targeted metabonomics analysis of blood metabonomics research technology has shown great potential value in the early diagnosis of obstetric diseases and the study of disease mechanisms.

Ocean deoxygenation dampens resistance of diatoms to ocean acidification in darkness

Respiratory activity in the oceans is declining due to the expansion of hypoxic zones and progressive deoxygenation, posing threats to marine organisms along with impacts of concurrent ocean acidification. Therefore, understanding the combined impacts of reduced pO2 and elevated pCO2 on marine primary producers is of considerable significance. Here, to simulate diatoms’ sinking into the aphotic zone of turbid coastal water, we exposed the diatoms Thalassiosira pseudonana and Thalassiosira weissflogii in darkness at 20°C to different levels of pO2 and pCO2 conditions for ~3 weeks, and monitored their biomass density, photosynthetic activity and dark respiration, and examined their recovery upon subsequent exposure to light at 20°C, simulating surface water conditions. Along with decreased cell abundance and size, measured photosynthetic capacity and dark respiration rates in these two diatoms both gradually decreased during the prolonged darkness. Reduced pO2 alone did not negatively affect the photosynthetic machinery in both the dark-survived diatom, and enhanced their subsequent recovery upon light exposure. Nevertheless, the combination of the elevated pCO2 and reduced pO2 (equivalent to hypoxia) led to the biomass loss by about 90% in T. pseudonana, and delayed the recovery of both species upon subsequent exposure to light, though it did not reduce the cell concentration of T. weissflogii during the elongated darkness. Our results suggest that reduced O2 availability diminishes the abilities of the diatoms to cope with the acidic stress associated with ocean acidification, and the expansion of hypoxic waters could delay the photosynthetic recovery of coastal diatoms when they are transported upwards through mixing from dark layers to sunlit waters.

Phosphate-associated sulfate in Lingula shells represents a potential archive for seawater sulfate composition

The marine sulfur cycle is highly sensitive to redox environments at the Earth's surface. Fluctuations in atmospheric pO2 level or marine redox environments are commonly associated with changes in seawater sulfate concentration, sulfate sulfur (S) and oxygen (O) isotopes. Thus, the marine S cycle through the Earth's ancient past provides a first-order constraint on the redox evolution of the Earth's surface. Reconstructions of the marine S cycle have been approached through analyses of various sulfate-bearing geological materials, such as sedimentary barite, evaporitic sulfate (e.g., gypsum), carbonate associated sulfate (CAS), and phosphate-associated sulfate (PAS) in phosphatic ores. These geological materials have their own pros and cons. In this study, we focus on PAS in Lingula brachiopods, which possess phosphatic shells and have a long evolutionary history since Cambrian times. Biogenic phosphate typically has a higher sulfate concentration than carbonate and phosphate ores, and is less vulnerable to diagenetic alteration. Here, we analyzed modern Lingula shells from the South China Sea and fossil Lingula shells collected from the Late Devonian Xiejingsi Formation of South China. Living and fossil Lingula shells have similar P/S ratios (PO43−/SO42−) of ∼76, and S and O isotopes of PAS (δ34SPAS and δ18OPAS) in each group show limited variations. For living Lingula shells, the mean values of δ34SPAS and δ18OPAS are +15.0 ± 1.5‰ and + 9.8 ± 0.4‰, respectively, which are ∼6‰ lower and comparable to those of modern seawater sulfate compositions (δ34SSW and δ18OSW-SO4), probably due to vital effects. For fossil Lingula shells, δ18OPAS (14.1 ± 0.9‰) is identical to coeval evaporite. The range of δ34SPAS is encompassed by the values of both coeval evaporite and CAS, but the mean value of δ34SPAS (29.5 ± 0.9‰) is higher. Thus, fossil Lingula shells show a good potential for reconstructing δ34SSW and δ18OSW-SO4 values.

A Correlated‐K Parameterization for O2 Photolysis in the Schumann‐Runge Bands

AbstractA recent study comparing ozone column depths and methane lifetimes at varied atmospheric O2 (pO2) levels calculated in the Kasting‐group 1‐D photochemical model and the Whole Atmosphere Community Climate Model version 6 (WACCM6) 3‐D model (Ji, Kasting, et al., 2023; https://doi.org/10.1098/rsos.230056) has exposed weaknesses in both models in parameterizing photolysis in the O2 Schumann‐Runge bands, 175–205 nm. WACCM6 does a good job for Earth's present atmosphere but neglects scattering, which becomes important at low pO2. The 1‐D model includes scattering but is based on an out‐of‐date band model, and it neglects the temperature dependence of photolysis at low pO2. We have revised and improved the 1‐D photochemical model by replacing the old O2 photolysis algorithm with a new correlated‐k parameterization, which improves accuracy for all O2 levels and all temperature profiles. The WACCM6 parameterization was also included in the 1‐D model for comparative purposes. The correlated‐k and WACCM6 photolysis algorithms agree well for both the present atmosphere and for an atmosphere containing 10−3 times the present O2 level, but only if multiple scattering is included at low pO2. The correlated‐k parameterization will be made available to photochemical modeling groups who might choose to adopt it.

Resistive spontaneous breathing exacerbated lipopolysaccharide-induced lung injury in mice

BackgroundSpontaneous respiratory mechanical force interacted with the primary lung injury and aggravated the progression of ARDS clinically. But the exact role and involved mechanism of it in the pathogenesis of ARDS animal model remained obscure. AimThis study was to investigate the effect of spontaneous respiratory mechanical force on lung injury of ARDS in mice. MethodsFemale C57BL/6 mice were subjected to resistive spontaneous breathing (RSB) by tracheal banding after 4–6 h of intranasal inhalation of LPS. Pulmonary function was examined by Buxco system, partial pressures of oxygen and carbon dioxide (PO2 and PCO2) were measured by a blood gas analyzer, and lung pathological changes were analyzed with hematoxylin and eosin staining. The levels of inflammatory markers were quantified by ELISA, total protein assay, and FACS analysis. The expression levels of mechanosensitive ion channels were detected by qRT-PCR and immunohistochemistry. ResultsThe airway resistance (Raw) was increased and the tidal volume (TV) was decreased remarkedly in RSB group. RSB treatment did not affect PO2, PCO2, pathology and inflammation levels of lung in mice. The Raw increased and ventilatory indicators decreased in RSB + ARDS compared to ARDS significantly. Besides, RSB treatment deteriorated the changes of PO2, PCO2 and level of lactic acid induced by LPS. Meanwhile, RSB significantly promoted LPS-induced pulmonary histopathological injury, and elevated the levels of IL-1β, IL-6, TNF-α and total proteins, increased neutrophils infiltration. The expression level of Piezo1 in RSB + ARDS group was remarkably reduced compared to ARDS group and consistent with the severity of pulmonary damage. ConclusionRSB exacerbated LPS-induced ARDS hypoxemia and hypercapnia, inflammation and damage. The mechanosensitive protein Piezo1 expression decreased and may play an important role in the process.