Oxygen Tension Research Articles

High-flow nasal cannula oxygen therapy for mild-moderate acute respiratory failure in patients with blunt chest trauma: An exploratory descriptive study

ObjectiveThe use of high-flow nasal cannula (HFNC) oxygen therapy is gaining popularity for the treatment of acute respiratory failure (ARF). However, limited evidence exists regarding the effectiveness of HFNC for hypoxemic ARF in patients with blunt chest trauma (BCT). MethodsThis retrospective analysis focused on BCT patients with mild-moderate hypoxemic ARF who were treated with either HFNC or non-invasive ventilation (NIV) in the emergency medicine department from January 2021 to December 2022. The primary endpoint was treatment failure, defined as either invasive ventilation, or a switch to the other study treatment (NIV for patients in the NFNC group, and vice-versa). ResultsA total of 157 patients with BCT (72 in the HFNC group and 85 in the NIV group) were included in this study. The treatment failure rate in the HFNC group was 11.1% and 16.5% in the NIV group - risk difference of 5.36% (95% CI, −5.94–16.10%; P = 0.366). The most common cause of failure in the HFNC group was aggravation of respiratory distress. While in the NIV group, the most common reason for failure was treatment intolerance. Treatment intolerance in the HFNC group was significantly lower than that in the NIV group (1.4% vs 9.4%, 95% CI 0.40–16.18; P = 0.039). Univariate logistic regression analysis showed that chronic respiratory disease, abbreviated injury scale score (chest) (≥3), Acute Physiology and Chronic Health Evaluation II score (≥15), partial arterial oxygen tension /fraction of inspired oxygen (≤200) at 1 h of treatment and respiratory rate (≥32 /min) at 1 h of treatment were risk factors associated with HFNC failure. ConclusionIn BCT patients with mild-moderate hypoxemic ARF, the usage of HFNC did not lead to higher rate of treatment failure when compared to NIV. HFNC was found to offer better comfort and tolerance than NIV, suggesting it may be a promising new respiratory support therapy for BCT patients with mild-moderate ARF.

P-609 Impact of low versus air oxygen tension on the oocyte maturation in PCOS women undergoing capacitation IVM: a sibling oocyte pilot study

Abstract Study question Does low or air oxygen tension improve the oocyte maturation rate in biphasic capacitation IVM (CAPA-IVM)? Summary answer Low oxygen tension resulted in a lower maturation rate and two-pronuclei fertilization rate compared with air oxygen tension in the CAPA-IVM culture. What is known already CAPA-IVM, with a pre-maturation step, improves the competence of oocytes matured in-vitro. The current CAPA-IVM culture condition is under air oxygen concentration. However, the impact of oxygen tension on in-vitro oocyte maturation needs to be better understood, and it remains uncertain whether the maturation process aligns with in-vivo conditions. Study design, size, duration A sibling oocyte pilot study of 416 cumulus-oocyte complexes (COCs) recruited from fifteen polycystic ovary syndrome (PCOS) women was performed at IVFMD, My Duc Phu Nhuan Hospital, Ho Chi Minh City, Vietnam from November 2023 to January 2024. The study was approved by the Institutional Ethics Committee (22/23/DD-BVMD, dated October 12th, 2023) and conducted according to Good Clinical Practice and Declaration of Helsinki 2002 principles. All participants provided written informed consent. Participants/materials, setting, methods Women (18–37 years) diagnosed with PCOS undergoing CAPA-IVM were recruited. At collection, COCs from each woman were divided into two groups based on the oxygen tension used in the two steps of CAPA-IVM culture, low oxygen tension (5% O2, 6% CO2 at 37 °C) and air oxygen tension (20% O2, 6% CO2 at 37 °C). Embryos were cultured to blastocyst stage. Primary outcome was the oocyte maturation rate. Secondary outcomes were embryology outcomes. Main results and the role of chance A total of 416 COCs from fifteen eligible women were assigned to the low oxygen (207 COCs) and air oxygen tension (209 COCs) groups. Mean age and body max index were 29.0±2.5 years and 22.6±2.6, respectively. The maturation rate was significantly lower in the low oxygen group compared to the air oxygen group (54.1% vs. 66.5%, p = 0.01, respectively). The two-pronuclei fertilization rate per COC was significantly decreased in the low oxygen group compared to the air oxygen group (35.7% vs. 49.3%, p = 0.005, respectively). Rates of day-3 embryos, blastocyst formation rate, and good quality blastocyst rate were also lower but not significant in the low oxygen tension group as compared to the air oxygen tension group. Limitations, reasons for caution The study’s limitations include a relatively small sample size and a single ethnicity group. There was a lack of data on clinical outcomes after transferring embryos from the study. Wider implications of the findings Oocyte maturation rate and two-pronuclei fertilization rate were significantly lower when oxygen tension was reduced in the process of CAPA-IVM culture. Therefore, air oxygen tension should be considered as a standard for oocyte culture in the pre-maturation step of CAPA-IVM. Trial registration number NCT06087354

The efficacy and safety of combined therapy with endobronchial tamponade and bronchial artery embolization for massive hemoptysis

BackgroundMassive hemoptysis is characterized by its life-threatening nature, potentially leading to airway obstruction and asphyxia. The objective of this study was to evaluate the clinical effectiveness of combining endobronchial tamponade with bronchial artery embolization (BAE) in the treatment of massive hemoptysis.MethodsBetween March 2018 and March 2022, a total of 67 patients with massive hemoptysis who underwent BAE were divided into two groups: the combination group (n = 26) and the BAE group (n = 41). Technical and clinical success rates were assessed, and adverse events were monitored following the treatment. Blood gas analysis and coagulation function indicators were collected before and after the treatment, and recurrence and survival rates were recorded during the follow-up period.ResultsAll patients achieved technical success. There were no significant differences in the clinical success rate, recurrence rates at 3 and 6 months, and mortality rates at 3 months, 6 months, and 1 year between the combination group and the BAE group. However, the hemoptysis recurrence rate at 1 year was significantly lower in the combination group compared to the BAE group (15.4% vs. 39.0%, P = 0.039). No serious adverse events were reported in either group. After treatment, the combination group showed higher levels of arterial partial pressure of oxygen (PaO2), oxygenation index (PaO2/FiO2), fibrinogen (FIB), and D-dimer (D-D) compared to the BAE group (P < 0.05). Multivariate regression analysis demonstrated a significant correlation between combined therapy and hemoptysis-free survival.ConclusionCombination therapy, compared to embolization alone, exhibits superior efficacy in improving respiratory function, correcting hypoxia, stopping bleeding, and preventing recurrence. It is considered an effective and safe treatment for massive hemoptysis.

Current incidence, risk factor and outcome of acute respiratory distress syndrome in Nasser Institute ICU, Cairo, Egypt

Abstract Background Acute respiratory distress syndrome (ARDS) represents the severe end of a spectrum of acute lung injury due to many different insults. It manifests as acute and persistent lung inflammation with increased lung permeability. Aim of the study To assess the current incidence, risk factors and outcome of acute respiratory distress syndrome at Nasser Institute ICU during the period from January 2019 till the end of July 2019. Methodology The study enrolled 50 patients who were admitted to Nasser Institute ICU and met the Berlin criteria for ARDS during the study period. Results The incidence of ARDS was (3.12%), 54% of which were severe, 26% were moderate, and 20% were mild. Mortality rate was 52%, 88.46% of which were severe cases. Severity index was positively correlated with mortality rate (P- value &amp;lt;0.001). Pneumonia with sepsis was the most common risk factor (74%) and had statistically significant positive correlation with mortality (P = 0.017). Conclusion Incidence of ARDS was relatively small at our institute (3.12%), yet, it has a serious and a potentially fatal outcome with high mortality rate (52%). Key words: Acute Respiratory Distress Syndrome, ARDS, ICU, incidence, risk factor, outcome, mortality, Nasser Institute. Abbreviations: ARDS: Acute Respiratory Distress Syndrome. PaO2: Partial pressure of oxygen. FiO2: Fraction of inspired oxygen. PEEP : Positive end expiratory pressure.TV: Tidal volume. ABG: Arterial blood gases. PH: potential hydrogen. PaCO2: partial pressure of carbon dioxide. HCO3: Bicarbonate. SO2: blood oxygen saturation. ICU: intensive care unit.

The Importance of Hypoxia-Related to Hemoglobin Concentration in Breast Cancer.

The importance of hemoglobin (Hgb) as a novel prognostic biomarker in predicting clinical features of cancers has been the subject of intense interest. Anemia is common in various types of cancer including breast cancer (BC) and is considered to be attributed to tumoral hypoxia. Cancer microenvironments are hypoxic compared with normal tissues, and this hypoxia is associated with Hgb concentration. Recent preclinical documents propose a direct or indirect correlation of intratumoral hypoxia, specifically along with acidity, with Hgb concentration and anemia. Analysis of the prognostic value of Hgb in BC patients has demonstrated increased hypoxia in the intratumoral environment. A great number of studies demonstrated that lower concentrations of Hgb before or during common cancer treatments, such as radiation and chemotherapy, is an essential risk factor for poor prognostic and survival, as well as low quality of life in BC patients. This data suggests a potential correlation between anemia and hypoxia in BC. While low Hgb levels are detrimental to BC invasion and survival, identification of a distinct and exact threshold for low Hgb concentration is challenging and inaccurate. The optimal thresholds for Hgb and partial pressure of oxygen (pO2) vary based on different factors including age, gender, therapeutic approaches, and tumor types. While necessitating further investigations, understanding the correlation of Hgb levels with tumoral hypoxia and oxygenation could improve exploring strategies to overcome radio-chemotherapy related anemia in BC patients. This review highlights the collective association of Hgb concentration and hypoxia condition in BC progression.

P-165 Benefits of ultra-low oxygen tension (2%) in patients with low quality embryos or previous arrest: the patient as its own control

Abstract Study question Is reduction in oxygen tension from 5% to 2% after D3 of extended culture beneficial for blastocyst development in patients with previous failed culture? Summary answer Ultra-low oxygen tension in extended culture improves blastocyst development (overall blastulation rate OBR), quality (top blastulation rate TPR) and increases the pregnancy rate (PR). What is known already The practice ESHRE guidelines recommends human embryo culture at low oxygen concentrations (2-8%). Traditionally atmospheric conditions (20% O2) were used but better outcomes were observed at low monophasic 5% O2. Human embryo leaves the oviduct (5-7% O2) to cross the uterus-tubal junction around D3-4 and reaches the uterin ultra-low O2 tension (2%). This decreasing gradient coincides with the shift from pre-compaction oxidative phosphorylation in the oviduct, to post-compaction glycolysis in the uterus. Few studies with ultra-low 2% O2 incubation suggested that the best O2 level may be stage-dependent and its reduction after D3 may be a more physiological approach. Study design, size, duration Prospective observational study in a single private hospital during 2023. 71 patients experienced a failed cycle of extended culture (n = 29 cIVF, n = 37 ICSI and n = 5 Sibling oocytes) with a poor embryo quality and low OBR, under standard monophasic 5% O2 incubation. In the subsequent cycle for these 71 patients (n = 24 cIVF and n = 46 ICSI and n = 1 Sibling oocytes) the O2 level was reduced to 2% from D3 onwards. Participants/materials, setting, methods After a failed extended culture, considered as the control cycle, the patients were enrolled for the study. Blastocysts were rated by Gardner’s classification. In the control cycle embryos were cultured under monophasic 5% O2 until D6. In the subsequent cycle embryos were cultured under 5% O2 until D3 and in ultra-low 2% O2 from D3 to D6. Sage 1-Step™ media was used for both cycles. The statistical analyses were done by chi-square and fisher test. Main results and the role of chance 71 patients were included in the study regardless of age, indication or technique. Each patient was its own control. The mean age was not different between the 2 groups (36.5±4 vs 37.2±4) but the attempt rank was logically statistically higher in the study cycle (2.1±1.4 vs 3.4±1, p&amp;lt;0.001). Oocyte maturity (75% vs 76.4%) and fertilization rate (66.8 vs 70.3%) were similar between groups. The average embryo quality at D3 was poor in both groups. OBR and TBR (40.7% vs 52.4%, p=0.004 and 15.8% vs 37.5%, p&amp;lt;0.001) were statistically higher after culture in ultra-low O2 conditions. Extended culture failure with absence of usable blastocyst (57.7% vs 19.7%, p&amp;lt;0.001) was statistically lower in ultra-low incubation group and the pregnancy rate PR per cycle (3.6% vs 25%, p=0.004) was seven fold higher after ultra-low culture. Limitations, reasons for caution The small size of the sample needs to be expanded in order to confirm the encouraging findings in a larger population. The study will continue during 2024 and will compel the live birth rate and the cumulative live birth rate. Wider implications of the findings Providing embryos with the most physiologic culture system would improve IVF cost-effectiveness and a better infertility management. Embryo energetic adaptation to suboptimal conditions results in impaired viability and lower pregnancy rates. In our study extended culture of low-quality embryos under 2% O2 after D3 yielded better culture and pregnancy outcomes. Trial registration number NA

P-217 Keep calm and carry on: assessing the effect of below-benchmark vitrified/warmed donor oocyte survival rates in subsequent laboratory and clinical key performance indicators

Abstract Study question When we experience below benchmark donor oocyte survival rates, are the laboratory and clinical outcomes of the recipient cycle affected? Summary answer Donor-oocyte cryo-survival rates below the benchmark (95-100%) result in slightly lower laboratory KPIs, equivalent live birth rates (LBR) and lower cumulative LBR (CLBR) per cycle. What is known already The use of vitrified/warmed donor oocytes allows overcoming many logistic challenges, but it is hindered by the loss of oocytes due to degeneration after warming. The 2012 Vienna Consensus established the benchmark rate of oocyte survival at 95-100%, competency level at &amp;gt; 85%. Results of &amp;lt; 85% cryo-survival are considered below competency, &amp;lt;70% can be considered poor, and &amp;lt;50% very poor. Below-benchmark rates of survival may not only limit the number of donor oocytes for the cycle, but they can also translate into lower per-oocyte cycle KPIs if the lower survival correlates with lower performance of the surviving oocytes. Study design, size, duration We analyzed 12690 vitrified-warmed donor oocyte recipient cycles, encompassing a total 144793 vitrified/warmed donor oocytes, carried out in a network of European private IVF units from 2018-2022. Cycles with PGT-A and spermatozoa from testicular biopsy were excluded. The primary endpoint of the study was the blastocyst utilization rate per 2PN zygote. Secondary endpoints were fertilization rate, live birth rate after the first single blastocyst transfer (SET-LBR) of each cycle, and cumulative LBR (CLBR). Participants/materials, setting, methods In all cases, fertilization was carried out by ICSI, and embryos were cultured to the blastocyst stage at low oxygen tension. Blastocysts with good or fair quality (A, B &amp; C by ASEBIR Criteria) were considered usable (transferred + cryopreserved blastocyts / zygotes). Differences in proportions were analyzed using chi-square and the adjusted odds ratio (OR) was calculated using multivariable logistic regression. Main results and the role of chance Baseline donor and patient characteristics such as age, stimulation duration and dose, total donor oocytes per cycle, male factor, and fresh/frozen/donor spem were compared between groups and adjusted for when necessary. The mean number of warmed oocytes per cycle was 11.4±3.22 with a mean survival rate of 89.2%. More oocytes per cycle were consumed in the lower survival groups, yet the total oocytes available for ICSI was smaller in the below competency, poor and very poor survival groups. There were differences in the proportion of usable blastocysts per zygote amongst the survival rate groups (benchmark: 48.9%; competence: 47.0%, below-competence: 46.0%; poor: 43.6%; very-poor:43.6%, p &amp;lt; 0.001). Fertilization rates also differed between survival groups (benchmark: 76.9%; competence: 76.5%, below-competence: 75.6%; poor: 74.7%; very-poor:75.4%, p &amp;lt; 0.001) The adjusted odds ratio of live birth on the first SET of the cycle was not lower to the benchmark survival group in all the lower survival groups (Benchmark: 40.9%; Competence: OR:0.995; 95%CI:0.971-1.018; below-competence: OR:0.996; 95%CI:0.970-1.023; poor: OR:1.044; 95%CI:1.003-1.086, and very-poor: OR:1.069; 95%CI:0.976-1.170). The CLBR decreased in lower survival groups, with 80.8% for the benchmark survival group, 80.3% (p = 0.539) for competence, 76.2% (p &amp;lt; 0.001) for below-competence, 72.5% (p &amp;lt; 0.001) for poor, and 74.8% (p = 0.056) for very-poor. Limitations, reasons for caution These results are limited to a donor-oocyte population. Wider implications of the findings Lower oocyte-cryo-survival rates resulted in a lower total number of usable blastocysts obtained for the recipient, and consequently, lower CLBR. However, the competence of surviving oocytes is encouraging, with laboratory KPIs in very close range irrespectively of the cohort survival rates, and similar implantation potential of the obtained blastocysts. Trial registration number not applicable

Oxidation of Cu-Pb-As Ternary Alloys at 960–1080°C with Various Oxygen Partial Pressures and the Distribution Behavior of Arsenic

Oxidation of Cu-Pb-As Ternary Alloys at 960–1080°C with Various Oxygen Partial Pressures and the Distribution Behavior of Arsenic

Preparation and characterization of chromium oxide thin films: The response of morphology, crystal structure, and electrical properties to oxygen pressure under magnetron sputtering

This study focuses on Cr2O3 prepared via reactive magnetron sputtering, a direct deposition technique that significantly impacts the microstructure and optoelectronic properties of the films. Reactive sputtering alters grain size, density, and surface morphology, which in turn affects the structural order and stoichiometry. By adjusting the ratio of process gases, particularly the oxygen partial pressure, the stoichiometry of the deposited films was controlled. This is crucial for managing the oxidation state of chromium and the concentration of free electrons. An optimal oxygen partial pressure of 75 % was identified, substantially reducing oxygen interstitial defects in the CrOx materials and enhancing conductivity by nearly two orders of magnitude. Additionally, increasing the oxygen partial pressure helped integrate more oxygen atoms into the lattice, transitioning the electronic structure from a metallic state in CrO2 to a semiconductive state in CrO3. This fine-tuning of oxygen doping not only adjusts carrier concentrations but also optimizes the photoelectric properties of the materials, achieving a tailored high band gap of 3.34 eV. This study highlights the potential of reactive magnetron sputtering to customize semiconductor materials through oxygen doping, offering a novel approach to enhance the versatility and application range of chromium oxide materials in advanced technological applications.

First-principles studies on the oxygen vacancy formation in α-Na2FePO4F and β-Na2FePO4F

The orthorhombic β-Na2FePO4F has been extensively studied, however, a novel monoclinic α-Na2FePO4F has not been explored sufficiently. Oxygen vacancies (VO) can affect the physical and chemical properties of materials, and oxygen vacancy formation energy reflects the difficulty of VO formation. Using first-principles methods, we have calculated the formation energies of VO and their relevant charge states in both α-Na2FePO4F and β-Na2FePO4F. Our results reveal that charged vacancies (VO+1 or VO+2) are easier to form than neutral vacancies (VO0). The reduction of the Fermi level, the decrease in the oxygen partial pressure, or the increase of the temperature are found to decrease the formation energy of VO. The formation energy of VO in α-Na2FePO4F is slightly lower than that in β-Na2FePO4F. The electronic density of states of α-Na2FePO4F and β-Na2FePO4F suggest that more defect states are introduced into the band gap as the charge states increase. These defect states are mainly the 3d orbitals of the Fe atoms. The introduction of oxygen vacancies distorts the [FeO4F2] octahedra, which affect the charge density distribution and the defect states introduced in the band gap. Significantly, oxygen vacancies have a local impact on the charge density redistribution in both α-Na2FePO4F and β-Na2FePO4F. These findings provide theoretical insights into the formation of oxygen vacancies and the control of oxygen release.

Computational thermal fluid enabled multi-physics transport processes analysis of ceramic hollow fiber membrane for oxygen separation

A comprehensive hollow fiber membrane model is developed using an experimental system as a physical base, where Multiphysics transport processes in the membrane are coupled with a large-scale thermal fluid transport processes in the test assembly and furnace. Systematic parametric studies are carried out to understand fundamental mechanisms and membrane performance. Results indicate that oxygen partial pressure at the permeate side asymptotically increases from the inlet toward the outlet of hollow fiber membrane. Longitudinal distribution of oxygen vacancy concentration follows the opposite trend to that of oxygen partial pressure at the permeate side while oxygen flux distribution follows the profile of oxygen vacancy distribution at the permeate surface. High air pressure at the feed side and low gas pressure at the permeate side facilitate to enhance oxygen permeation performance. Surface exchange resistance at the permeate side dominates the total resistance of the membrane while the bulk diffusion resistance accounts for the minimum contribution in substrate-supported thin film hollow fiber membrane. The modeling study may obtain an insightful understanding of fundamental mechanisms and can provide guidance for membrane design and operations to achieve better performance for oxygen production.

Effects of substrate availability and mitochondrial disruption on oxidative metabolism and sperm motility in fertile dogs.

In several mammalian species, the measurement of mitochondrial oxygen consumption (MITOX) under different metabolic conditions has demonstrated a positive correlation with sperm motility and may be a sensitive indicator of mitochondrial health. In general, the maintenance of sperm motility and many key sperm functions and fertilizing events are heavily energy-dependent processes, and some species-specific substrate preferences exist. Although canine sperm have been known to undergo capacitation and maintain motility with supplementation of a wide range of energy substrates, the relationship between mitochondrial function, and the maintenance of oxidative metabolism and sperm motility remain unclear. The objective of this study was to explore the metabolic flexibility of canine sperm, and to investigate the relationship between mitochondrial function, and maintenance of motility under differing nutrient conditions. We explored substrate preferences and the bioenergetics underlying maintenance of canine sperm motility by monitoring mitochondrial oxidative function and sperm kinematics in the presence of mitochondrial effector drug treatments: FCCP, antimycin (ANTI), and oligomycin (OLIGO). We hypothesized that canine sperm possess the ability to use compensatory pathways and utilize diverse nutrient sources in the maintenance of motility. Oxygen consumption (change in pO2, oxygen partial pressure) and sperm kinematics (CASA) were measured concurrently (t0-t30) to assess the relationship between oxidative metabolism and maintenance of sperm motility in dogs. Four media were tested: containing glucose, lactate, and pyruvate (GLP), containing glucose (G), fructose (F), or lactate and pyruvate (LP). In the absence of pharmacological inhibition of the electron transport chain, energetic substrate had no effect on sperm kinematics in fertile dogs. Following mitochondrial disruption by ANTI and OLIGO, mitochondrial oxygen consumption was negatively correlated with several sperm motility parameters in GLP, G, F, and LP media. In every media, FCCP treatment quickly induced significantly higher oxygen consumption than in untreated sperm, and spare respiratory capacity, the maximal inducible oxidative metabolism, was high. With respiratory control ratios RCR >1 there was no indication of bioenergetic dysfunction in any media type, indicating that sperm mitochondria of fertile dogs have a high capacity for substrate oxidation and ATP turnover regardless of substrate. Our results suggest MITOX assessment is a valuable tool for assessing mitochondrial functionality, and that canine sperm employ flexible energy management systems which may be exploited to improve sperm handling and storage.

Clinically-relevant reductions in oxygen partial pressure as possible contributor to cardiovascular benefits of sauna practice

The practice of sauna has been found to have both acute and long-term cardiovascular benefits, which are generally postulated to be a result of thermoregulatory physiological adaptations. Another element of sauna conditions which has been overlooked is that the extremely high absolute water content of air at sauna temperature, even at low relative humidity, results in significantly decreased partial pressure of oxygen. Using the Arden-Buck equation for water-carrying capacity of air along with the barometric formula, it is shown in this hypothesis that typical sauna conditions have an oxygen partial pressure reduction that may be equivalent to significant elevations above sea level. This effect may also be enhanced by lower air density further reducing available oxygen relative to respiratory volume.This paper presents the hypothesis that altitude adaptation may be a contributing factor in the cardiovascular benefits of sauna treatments, suggesting that sauna should be considered as an alternative in instances where intermittent hypoxic training is indicated but not available, and that clinical research into sauna treatment is merited for conditions in which intermittent hypoxic training is known to have applications. The hypothesis could be investigated through pulse oximetry of subjects under sauna conditions and by tracking blood markers of altitude adaptation compared to a control group using steam rooms.

Bulk photovoltaic effect in Cu-doped LiNbO3 single crystals with controlled oxidation state

We investigate the bulk photovoltaic (PV) effect of Cu-doped LiNbO3 single crystals with various oxidation states of Cu. The Cu-doped samples exhibit the PV response under below-bandgap excitation, and the onset of photocurrent shifts depending on partial oxygen pressures (pO2) during the annealing treatment. Open-circuit voltages (V oc) under simulated sunlight (AM 1.5 G) illumination are changed by pO2, and crystals annealed at pO2 = 1.0 × 10−10 atm exhibit the highest V oc of 1700 V. Moreover, density functional theory (DFT) calculations for Cu-doped LiNbO3 cells with Cu2+ on the Li site and the Nb site indicate that half-filled gap states derived from 3d orbitals of Cu are formed within the bandgap. Based on Glass coefficients obtained by the analyses of polarization angle-dependent photocurrent densities and the DFT calculations, we consider that Cu2+ on the Li site is the major active site for the generation and separation of electron–hole pairs under visible light at hν = 2.4 eV.

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.

Extrapolating into no man’s land enables accurate estimation of surface properties with multiparameter equations of state

Thermodynamic properties of homogeneous fluids in the metastable and unstable regions are needed to describe confined fluids, interfaces, nucleating embryos and estimate critical mass flow rates. The most accurate equations of state (EoS) called multiparameter EoS, have a second, non-physical Maxwell loop that renders predictions unreliable in these regions. We elaborate how information from the stable region can be used to reconstruct the metastable and unstable regions. For a simple interaction potential, comparison to results from molecular simulations reveals that isochoric expansion of the pressure from stable states reproduces simulation results in the metastable regions. By constructing a dome that extends above the critical point, we obtain an extrapolated pressure from multiparameter EoS that is free of second Maxwell loops. A reconstructed EoS is developed next, by integrating the extrapolated pressure from a stable state to obtain the Helmholtz energy. The consistency of the reconstructed EoS is gauged by computing phase equilibrium densities, pressures, and enthalpies of evaporation, which are in reasonable agreement with experimental values. Combined with density gradient theory, the reconstructed EoS yields surface tensions of water, carbon dioxide, ammonia, hydrogen and propane that deviate, on average, 4.4%, 1.6%, 6.0%, 0.7% and 5.4% from experimental values respectively. The results reveal a potential to develop more accurate extrapolation protocols, which can be leveraged to obtain prediction of metastable properties, surface properties or used as constraints in fitting multiparmeter EoS.

Network Meta-analysis of Chinese patent medicines in treatment of chronic pulmonary heart disease

Network Meta-analysis was performed to compare the efficacy and safety of Chinese patent medicines in treating chronic pulmonary heart disease. CNKI, VIP, Wanfang, SinoMed, PubMed, Web of Science, EMbase, and Cochrane Library were searched for randomized controlled trial(RCT) of treating chronic pulmonary heart disease with Chinese patent medicines with the time interval from inception to December 2023. The Cochrane risk-of-bias tool was used for quality assessment of the included articles. RevMan 5.4 and Stata 17.0 were employed to establish the risk of bias map and perform the network Meta-analysis, respectively. Ultimately, a total of 95 RCTs involving 8 787 cases and 11 different Chinese patent medicines were included. Network Meta-analysis yielded the following results based on the surface under the cumulative ranking curve(SUCRA).(1)In terms of cardiac function improves clinical total effective rate, SUCRA the top three were Wenxin Granules + conventional western medicine, Tongxinluo Capsules + conventional western medicine, and Qishen Yiqi Dropping Pills + conventional western medicine.(2)For improving forced expiratory volume in the first se-cond(FEV1), SUCRA the top three were Danting Feixin Granules + conventional western medicine, Tongxinluo Capsules + conventional western medicine, and Bufei Huoxue Capsules + conventional western medicine.(3)Regarding increasing the FEV1/forced vital capacity(FVC%) value, SUCRA the top three were Qili Qiangxin Capsules + conventional western medicine, Shexiang Baoxin Pills + conventional western medicine, and Qishen Yiqi Dropping Pills + conventional western medicine.(4)In terms of increasing the partial pressure of oxygen(PaO_2), SUCRA the top three were Qili Qiangxin Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(5)In terms of reducing the partial pressure of carbon dioxide(PaCO_2), SUCRA the top three were Tongxinluo Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(6)In terms of increasing left ventricular ejection fraction(LVEF), SUCRA the top three were Bufei Huoxue Capsules + conventional western medicine, Qishen Yiqi Dropping Pills + conventional western medicine, and Shexiang Baoxin Pills + conventional western medicine.(7)In terms of decreasing brain natriu-retic peptide(BNP), SUCRA the top three were Compound Danshen Dropping Pills + conventional western medicine, Qili Qiangxin Capsules + conventional western medicine, and Tongxinluo Capsules + conventional western medicine.(8)In terms of improving the hematocrit level, SUCRA the top three were Qishen Yiqi Dropping Pills + conventional western medicine, Compound Danshen Dropping Pills + conventional western medicine, and Tongxinluo Capsules + conventional western medicine. In terms of safety, 26 RCTs reported adverse reactions, which primarily involved the circulatory and digestive systems. The combination of Chinese patent medicines with conventional western medicine has demonstrated enhanced therapeutic effects on chronic pulmonary heart disease. However, due to the varying quality and sample sizes of included studies and the absence of direct comparisons between Chinese patent medicines, the conclusions should be further validated by multicenter studies with larger sample sizes and higher methodological rigor.

Spectral characterization of a Cryo-Cooled CO laser operating with CO2 laser gas mixture

This study explores the emission spectra and performance characteristics of a cryo-cooled CO laser system operating with CO2 laser gas mixture under various operating conditions, viz., N2 free gas mixture, different coolant temperatures and in grating tuned configuration. The narrow operational window in case of N2 free gas mixture, increased output power and richer emission spectrum obtained with the addition of N2 gas indicates enhanced discharge stability and efficient excitation in presence of Nitrogen. The emission spectrum revealed shifting of the trapping levels towards lower vibrational quantum number with reducing coolant temperature and the same was also corroborated by theoretical calculations. No lasing was observed for vibrational levels V>15 which is attributed to the higher partial pressure of oxygen inherently present in the gain medium formed due to dissociation of CO2. The system lased on more than 20 transitions in grating tuned configuration with power exceeding 100mW on several lines. The presence of higher concentration of O2 in the discharge prevents carbon deposition − a common issue in CO lasers. This study underscores the significance of this unconventional CO laser system offering reliable operation in the 5 µm wavelength region without the usage of extraneous CO gas.

A case of self-limiting respiratory distress in a postpartum mother &amp;ndash; transfusion related acute lung injury

A 37-year-old woman, treated for postpartum haemorrhage, developed sudden-onset acute respiratory distress characterised by tachypnoea, desaturation and widespread crepitations, on the first day postpartum. She had low partial pressure of oxygen to the fractional inspired oxygen concentration (PaO2/FiO2) ratio and bilateral patchy opacities in chest radiograph. Despite having a high oxygen requirement, her clinical and radiographic abnormalities spontaneously resolved in 30 hours, after a conservative treatment approach. This case report delves into the rare, yet serious entity of transfusion-related acute lung injury (TRALI) and underscores the importance of considering it among other potential causes of shortness of breath following blood transfusion in postpartum patients.

An unconventional approach for the efficient recovery of iron, cobalt, copper and silicon from copper slag

High-grade heavy metal elements in copper slag (CS) are worth recovering. Unfortunately, the high viscosity of leaching solution, low leaching efficiency, difficult filtration and low separation efficiency of valuable components exist in the traditional sulfuric acid leaching process. In this study, the above problems are solved by sulfuric acid pretreatment + curing + water leaching. Moreover, iron, cobalt and copper ions in solution are separated by stepwise precipitation. The final iron, cobalt, copper and silicon recoveries are 99.01 %, 98.45 %, 93.13 % and 99.52 %, respectively. Thermodynamic calculations show that H4SiO4 can be converted to insoluble SiO2 to improve filtration properties under curing conditions of sulfur dioxide partial pressures of 10−20∼0 atm, oxygen partial pressures of 10−20∼0 atm and 400–600k. Simulation studies of the phase equilibria of the components of the leach solution by Visual MINTEQ showed that the oxidation of Fe2+ to Fe3+ is necessary for the removal of Fe2+ from the solution by precipitation. This study provides a new idea for the efficient utilization of CS.