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In patients with out-of-hospital cardiac arrest (OHCA) who attain return of spontaneous circulation (ROSC), rearrest while in the prehospital setting represents a significant barrier to survival. To date, there are limited data to guide prehospital emergency medical services (EMS) management immediately following successful resuscitation resulting in ROSC and prior to handoff in the emergency department. Post-ROSC care encompasses a multifaceted approach including hemodynamic optimization, airway management, oxygenation, and ventilation. We sought to develop an evidenced-based, goal-directed bundle of care targeting specified vital parameters in the immediate post-ROSC period, with the goal of decreasing the incidence of rearrest and improving survival outcomes. Here, we describe the rationale and development of this goal-directed bundle of care, which will be adopted by several EMS agencies within California. We convened a group of EMS experts, including EMS Medical Directors, quality improvement officers, data managers, educators, EMS clinicians, emergency medicine clinicians, and resuscitation researchers to develop a goal-directed bundle of care to be applied in the field during the period immediately following ROSC. This care bundle includes guidance for prehospital personnel on recognition of impending rearrest, hemodynamic optimization, ventilatory strategies, airway management, and diagnosis of underlying causes prior to the initiation of transport.

Bifunctional catalase‐peroxidase (KatG) features a posttranslational methionine‐tyrosine‐tryptophan (MYW) crosslinked cofactor crucial for its catalase function, enabling pathogens to neutralize hydrogen peroxide during infection. We discovered the presence of indole nitrogen‐linked hydroperoxyl adduct (MYW‐OOH) in Mycobacterium tuberculosis KatG in the solution state under ambient conditions, suggesting its natural occurrence. By isolating predominantly MYW‐OOH‐containing KatG protein, we investigated the chemical stability and functional impact of MYW‐OOH. We discovered that MYW‐OOH inhibits catalase activity, presenting a unique temporary lock. Exposure to peroxide or increased temperature removes the hydroperoxyl adduct from the protein cofactor, converting MYW‐OOH to MYW and restoring the detoxifying ability of the enzyme against hydrogen peroxide. Thus, the N‐linked hydroperoxyl group is releasable. KatG with MYW‐OOH represents a catalase dormant, but primed, state of the enzyme. These findings provide insight into chemical strategies targeting the bifunctional enzyme KatG in pathogens, highlighting the role of N‐linked hydroperoxyl modifications in enzymatic function. [ABSTRACT FROM AUTHOR]

Purpose: Apnea duration is dependent on three factors: oxygen storage, oxygen consumption, hypoxia and hypercapnia tolerance. While current literature focuses on maximal apneas to improve apnea duration, apnea trained individuals use timed-repeated submaximal apneas, called "O2 and CO2 tables". These tables claim to accommodate the body to cope with hypoxia and hypercapnia, respectively. The aim of this study was twofold. First, to investigate the determinants of maximal apnea duration in apnea novices. Second, to compare physiologic responses to maximal apneas, O2 and CO2 tables. Methods: After medical screening, lung function test and hemoglobin mass measurement, twenty-eight apnea novices performed three apnea protocols in random order: maximal apneas, O2 table and CO2 table. During apnea, peripheral oxygen saturation (SpO2), heart rate (HR), muscle (mTOI) and cerebral (cTOI) tissue oxygenation index were measured continuously. End-tidal carbon dioxide (EtCO2) was measured before and after apneas. Results: Larger lung volumes, higher resting cTOI and lower resting EtCO2 levels correlated with longer apnea durations. Maximal apneas induced greater decreases in SpO2 (− 16%) and cTOI (− 13%) than O2 (− 8%; − 8%) and CO2 tables (− 6%; − 6%), whereas changes in EtCO2, HR and mTOI did not differ between protocols. Conclusion: These results suggest that, in apnea novices, O2 and CO2 tables did not induce a more profound hypoxia and hypercapnia, but a similar reduction in oxygen consumption than maximal apneas. Therefore, apnea novices should mainly focus on maximal apneas to improve hypoxia and hypercapnia tolerance. The use of specific lung training protocols can help to increase oxygen storage capacity. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recent advances in transition metal‐catalyzed o‐carborane B—H activation have led to the rapid development of various methodologies for cage boron functionalization. For catalytic cage B—H acyloxylation, intermolecular oxygenation gave products with different regioselectivities (B(3)‐, B(4)‐, and B(8,9)‐selectivities). Herein, an efficient palladium‐catalyzed direct cage B(4)–H oxygenation of o‐carboranylacetic acids has been achieved, where the carboxylic group serves as not only a directing group, but also a coupling partner. A wide range of substituted o‐carboranylacetic acids have been cyclized via the formation of B(4)−O bond to give the corresponding γ‐lactones in modest to excellent yields. A Pd(IV) intermediate is proposed to be involved in the catalytic cycle. This work offers valuable references for the BH/OH dehydrocoupling reactions under mild conditions to produce carborane‐featuring functional molecules. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A visible‐light‐induced and efficient one‐pot synthesis of β‐hydroxysulfides from olefins, thiosulfonates and HCOOCs using an EDA complex strategy under air atmosphere at room temperature has been disclosed. A plausible radical involved mechanism is proposed. During the reaction process, formates play a crucial role: first, as donors in the EDA complex; second, as providers of the hydrogen source; and third, by generating CO2•– to reduce peroxide intermediates, leading to the formation of β‐hydroxysulfides. In contrast to the previously reported thiol‐oxygen co‐oxidation reactions, this simple and sustainable approach features mild reaction conditions, operational simplicity, odorless and excellent functional group tolerance. [ABSTRACT FROM AUTHOR]

Cardiac arrest (CA) remains a major cause of death despite advancements in cardiopulmonary resuscitation (CPR), post-resuscitation care, and international efforts to develop evidence-based guidelines. Effectively managing ventilation and oxygenation during and after CPR is vital for patient survival and neurological outcomes, yet it remains a challenging task. This review examines current strategies for ventilation and oxygenation during and after CPR, focusing on evidence-based guidelines, the balance between ventilation effectiveness and risks, and proposed methods for monitoring ventilation quality. It emphasizes the need to provide adequate ventilation and oxygenation during and after CPR while avoiding hyperventilation and hypoventilation, which can negatively impact resuscitation and post-CA outcomes. The review also explores mechanical ventilation as an alternative to manual methods and the use of feedback devices. The impact of post-CA ventilation and oxygenation on patient outcomes and recommended management strategies are discussed. Finally, the review highlights current gaps in the literature and the need for more well-designed large clinical studies, such as the impact of different ventilation variables (tidal volume and breathing frequency) on the return of spontaneous circulation and long-term outcomes. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recent advances in transition metal‐catalyzed o‐carborane B—H activation have led to the rapid development of various methodologies for cage boron functionalization. For catalytic cage B—H acyloxylation, intermolecular oxygenation gave products with different regioselectivities (B(3)‐, B(4)‐, and B(8,9)‐selectivities). Herein, an efficient palladium‐catalyzed direct cage B(4)–H oxygenation of o‐carboranylacetic acids has been achieved, where the carboxylic group serves as not only a directing group, but also a coupling partner. A wide range of substituted o‐carboranylacetic acids have been cyclized via the formation of B(4)−O bond to give the corresponding γ‐lactones in modest to excellent yields. A Pd(IV) intermediate is proposed to be involved in the catalytic cycle. This work offers valuable references for the BH/OH dehydrocoupling reactions under mild conditions to produce carborane‐featuring functional molecules. [ABSTRACT FROM AUTHOR]

Orthostatic hypotension (OH) is prevalent in older adults and can cause falls and hospitalization. Diagnostic intermittent blood pressure (BP) measurements are only a proxy for cerebral perfusion and do not reflect daily-life BP fluctuations. Near-infrared spectroscopy (NIRS)-measured cerebral oxygenation potentially overcomes these drawbacks. This study aimed to determine feasibility, face validity, and reliability of NIRS in the home environment. Ten participants with OH (2 female, mean age 77, SD 3.7) and 11 without OH (5 female, mean age 78, SD 6.7) wore a NIRS sensor at home on two different days for 10–11 h per day. Preceded by a laboratory-situated test, cerebral oxygenation was measured during three standardized supine-stand tests per day and during unsupervised daily life activities. Data availability, quality, and user experience were assessed (feasibility), as well as differences in posture-related oxygenation responses between participants with and without OH and between symptomatic (dizziness, light-headedness, blurred vision) and asymptomatic postural changes (face validity). Reliability was assessed through repetitive supine-stand tests. Up to 80% of the standardized home-based supine-stand tests could be analyzed. Oxygenation recovery values were lower for participants with OH (p = 0.03–0.15); in those with OH, oxygenation showed a deeper maximum drop for symptomatic than asymptomatic postural changes (p = 0.04). Intra-class correlation coefficients varied from 0.07 to 0.40, with no consistent differences over measurements. This proof-of-concept study shows feasibility and face validity of at-home oxygenation monitoring using NIRS, confirming its potential value for diagnosis and monitoring in OH and OH-related symptoms. Further data are needed for conclusions about reliability. [ABSTRACT FROM AUTHOR]

Background: In patients with severe acute respiratory distress syndrome (ARDS), prolonged and inappropriate use of prone position ventilation (PPV) is a known risk factor for mortality. Hence, it is critical to monitor patients' response to PPV and accurately differentiate responders from non-responders at an early stage. The study aimed to investigate the relationship between oxygenation improvement after three rounds of PPV and survival rate in patients with pulmonary ARDS. Additionally, we sought to identify the earliest turning point for escalation from PPV to extracorporeal membrane oxygenation. Methods: We performed a retrospective observational study from 2015 to 2023. We included adult patients who received invasive mechanical ventilation, underwent at least three periods of at least 6 h of PPV after admission to the Intensive Care Unit, and meet the ARDS criteria. The study collected data on each PPV session, including changes in PaCO2, PaO2, pH, FiO2, PaO2:FiO2 ratio, and clinical outcomes. Results: A total of 104 patients were enrolled in the study. The change in PaCO2 from baseline to the third PPV session (P3) had the highest area under the receiver operating characteristic curve (AUC) of 0.70 (95% CI 0.60–0.80; p < 0.001) for predicting hospital mortality, with an optimal cut-off point of 3.15 (sensitivity 75.9%, specificity 56.0%). The percentage change in PaO2:FiO2 ratio from baseline to P3 also had significant AUC of 0.71 (95% CI 0.61–0.81; p < 0.001) for predicting hospital mortality, with an optimal cut-off value of 99.465 (sensitivity 79.6%, specificity 62.0%). PaCO2 responders were defined as those with an increase in PaCO2 of ≤ 3.15% from baseline to P3, while PaO2:FiO2 responders were defined as those with an increase in PaO2:FiO2 ratio of ≥ 99.465% from baseline to P3. In the multivariable Cox analysis, PaO2:FiO2 responders had a significantly lower 60-day mortality risk (hazard ratio 0.369; 95% CI 0.171–0.798; p = 0.011). Conclusions: The percentage change in PaO2:FiO2 ratio from baseline to P3 was a significant predictor of outcomes. The model fit and prediction accuracy were improved by including the variable of PaCO2 responders. [ABSTRACT FROM AUTHOR]

Background: For patients receiving one lung ventilation in thoracic surgery, numerous studies have proved the superiority of lung protective ventilation of low tidal volume combined with recruitment maneuvers (RM) and individualized PEEP. However, RM may lead to overinflation which aggravates lung injury and intrapulmonary shunt. According to CT results, atelectasis usually forms in gravity dependent lung regions, regardless of body position. So, during anesthesia induction in supine position, atelectasis usually forms in the dorsal parts of lungs, however, when patients are turned into lateral decubitus position, collapsed lung tissue in the dorsal parts would reexpand, while atelectasis would slowly reappear in the lower flank of the lung. We hypothesize that applying sufficient PEEP without RM before the formation of atelectasis in the lower flank of the lung may beas effective to prevent atelectasis and thus improve oxygenation as applying PEEP with RM. Methods: A total of 84 patients scheduled for elective pulmonary lobe resection necessitating one lung ventilation will be recruited and randomized totwo parallel groups. For all patients, one lung ventilation is initiated the right after patients are turned into lateral decubitus position. For patients in the study group, individualized PEEP titration is started the moment one lung ventilation is started, while patients in the control group will receive a recruitment maneuver followed by individualized PEEP titration after initiation of one lung ventilation. The primary endpoint will be oxygenation index measured at T4. Secondary endpoints will include intrapulmonary shunt, respiratory mechanics, PPCs, and hemodynamic indicators. Discussion: Numerous previous studies compared the effects of individualized PEEP applied alone with that applied in combination with RM on oxygenation index, PPCs, intrapulmonary shunt and respiratory mechanics after atelectasis was formed in patients receiving one lung ventilation during thoracoscopic surgery. In this study, we will apply individualized PEEP before the formation of atelectasis while not performing RM in patients allocated to the study group, and then we're going to observe its effects on the aspects mentioned above. The results of this trial will provide a ventilation strategy that may be conductive to improving intraoperative oxygenation and avoiding the detrimental effects of RM for patients receiving one lung ventilation. Trial registration: www.Chictr.org.cn ChiCTR2400080682. Registered on February 5, 2024. [ABSTRACT FROM AUTHOR]

The necessity of oxygen for metabolic processes means that hypoxia can lead to serious cell and tissue damage. On the other hand, in some situations, hypoxia occurs under physiological conditions and serves as an important regulation factor. The airway epithelium is specific in that it gains oxygen not only from the blood supply but also directly from the luminal air. Many respiratory diseases are associated with airway obstruction or excessive mucus production thus leading to luminal hypoxia. The main goal of this review is to point out how the airway epithelium reacts to hypoxic conditions. Cells detect low oxygen levels using molecular mechanisms involving hypoxia-inducible factors (HIFs). In addition, the cells of the airway epithelium appear to overexpress HIFs in hypoxic conditions. HIFs then regulate many aspects of epithelial cell functions. The effects of hypoxia include secretory cell stimulation and hyperplasia, epithelial barrier changes, and ciliogenesis impairment. All the changes can impair mucociliary clearance, exacerbate infection, and promote inflammation leading to damage of airway epithelium and subsequent airway wall remodeling. The modulation of hypoxia regulatory mechanisms may be one of the strategies for the treatment of obstructive respiratory diseases or diseases with mucus hyperproduction. [ABSTRACT FROM AUTHOR]

Purpose: There are many approaches to the quantitative BOLD (qBOLD) technique described in the literature, differing in pulse sequences, MRI parameters and data processing. Thus, in this review, we summarized the acquisition methods, approaches used for oxygenation quantification and clinical populations investigated. Methods: Three databases were systematically searched (Medline, Embase, and Web of Science) for published research that used qBOLD methods for quantification of oxygen metabolism. Data extraction and synthesis were performed by one author and reviewed by a second author. Results: A total of 93 relevant papers were identified. Acquisition strategies were summarized, and oxygenation parameters were found to have been investigated in many pathologies such as steno‐occlusive diseases, stroke, glioma, and multiple sclerosis disease. Conclusion: A summary of qBOLD approaches for oxygenation measurements and applications could help researchers to identify good practice and provide objective information to inform the development of future consensus recommendations. [ABSTRACT FROM AUTHOR]

In the past 20 years, unspecific peroxygenases (UPOs) have emerged as promising biocatalysts for various organic transformations. Particularly, we have witnessed great attention being paid to the screening of new enzymes and expansion of the substrates/products. However, challenges such as enzyme stability, low turnover numbers, and substrate specificity hinder their widespread utilization in practical organic synthesis. This review article provides a concrete and mini-overview of the challenges associated with using UPOs in organic synthesis and discusses strategies for enzyme engineering to overcome these limitations. The article highlights recent advancements in UPO research and presents potential solutions to enhance their catalytic efficiency, stability, substrate specificity, and regioselectivity. Additionally, the review outlines the current methodologies employed for directed evolution and protein engineering of UPOs, along with computational modeling approaches for rational enzyme design. By addressing the challenges and exploring avenues for enzyme engineering, this review aims to shed light on the prospects of UPOs in organic synthesis. [ABSTRACT FROM AUTHOR]

Background: Abdominal surgery is a common surgical procedure that is frequently associated with substantial postoperative pain. However, rescue analgesia using opioids is associated with several adverse effects. The transversus abdominis plane block (TAPB) has been demonstrated to be effective as part of multimodal analgesia. This study aims to evaluate the effects of rescue analgesia using the TAPB following abdominal surgery. Methods: Ninety patients undergoing abdominal surgery and reporting a numeric rating scale (NRS) score of cough pain ≥4 on the first postoperative day were randomized to receive either sufentanil or TAPB for rescue analgesia. Pain scores and arterial oxygen pressure (PaO2) were evaluated before and after the administration of rescue analgesia. Sleep quality and gastrointestinal function were assessed postoperatively. The primary outcome was the degree of pain relief on coughing 30 min after the administration of rescue analgesia. Results: Patients of both groups reported a significantly reduced NRS score on coughing 30 min after receiving rescue analgesia (Ppaired < 0.001 for both groups). Notably, the degree of pain relief was significantly higher in the TAPB group than in the sufentanil group [median (interquartile range), −3 (−4 to −2) vs. −2 (−2 to −1), median difference = −1; 95% confidence interval, −2 to −1; P < 0.001]. Moreover, patients in the TAPB group experienced less pain than those in the sufentanil group during the following 24 h. When evaluated, PaO2 increased significantly after rescue analgesia was administered in the TAPB group (Ppaired < 0.001); however, there were no significant intragroup differences in the sufentanil group (Ppaired = 0.129). Patients receiving the TAPB experienced better quality of sleep than those receiving sufentanil (P = 0.008), while no statistical differences in gastrointestinal function were observed between the two groups. Conclusion: Rescue analgesia with the TAPB on the first postoperative day alleviated pain, enhanced oxygenation, and improved sleep quality in patients undergoing abdominal surgery; however, its effect on gastrointestinal function requires further research. [ABSTRACT FROM AUTHOR]

Mild and inexpensive copper‐catalyzed aromatization‐driven ring‐opening amination and oxygenation of spiro dihydroquinazolinones are presented, respectively. These protocols provide facile and atom‐economical access to the aminated and the carbonyl‐containing quinazolin‐4(3H)‐ones in good yields with good functional group compatibility, which are difficult to obtain by conventional methods. Remarkably, a telescoped procedure involving the condensation and the ring‐opening/functionalization for simple cycloalkanone was found to be accessible. Mechanistic studies suggest a radical pathway for this transformation. [ABSTRACT FROM AUTHOR]

Menopause is associated with reduced endothelial‐dependent vasodilation and increased cardiovascular disease (CVD) risk. Dietary nitrate, a non‐pharmacological approach, may increase vasodilatory capacity consequentially reducing CVD risk. We investigated macro‐ and microvascular function after acute nitrate supplementation in postmenopausal females (PMF). Vascular function was studied with flow‐mediated vasodilation (FMD) and near‐infrared post occlusive reactive hyperemia (PORH). Incremental handgrip exercise was performed to investigate blood flow and tissue oxygenation. We hypothesized acute dietary nitrate would not impact resting endothelial measures but would increase post ischemic vasodilation and incremental exercise blood flow. Late‐phase PMF (n = 12) participated in a randomized crossover design with 140 mL of nitrate‐rich (NR) beetroot juice or nitrate‐poor black currant juice. Testing included a 5‐min FMD, a 3‐min ischemic exercise FMD, and incremental exercise at 10%, 15%, and 20% maximal voluntary contraction to measure blood flow and pressure responses. A p ≤ 0.05 was considered significant. One‐way ANOVA indicated lower resting pressures, but no change to FMD, or PORH in either protocol. Two‐way repeated measures ANOVA indicated NR supplementation significantly reduced mean arterial pressure at rest and during incremental exercise at all intensities without changes to blood flow. Acute nitrate is effective for resting and exercising blood pressure management in PMF. [ABSTRACT FROM AUTHOR]

The regeneration of hypoxia‐impaired chronic tissue defects has long been challenging, mainly due to the inefficiency of oxygenation and the limited biological activity of existing oxygen delivery systems in regulating dynamic tissue regeneration process. Herein, a novel polyphenol‐copper coordination strategy to fabricate bioactive superoxide dismutase‐catalase self‐cascade nanozymes (SalB‐CuNCs) is reported, which can serve as an in situ oxygenator and induce angiogenesis simultaneously. The copper‐phenolic hydroxyl coordination structure in SalB‐CuNCs plays a critical role in promoting the enzyme‐like cascade reaction via catechol‐mediated Cu valence state transition and substrate capture mechanism. Furthermore, after incorporating SalB‐CuNCs into a Schiff base hydrogel (COC@SalB‐Cu), the resulting system exhibits outstanding antioxidant and robust oxygenation effect in mitigating the hypoxic microenvironment. Benefiting from the intrinsic angiogenic activity of SalB and copper, COC@SalB‐Cu hydrogel can induce a more complete tube formation by up‐regulating the expression level of vascular endothelial growth factor (VEGF), platelet‐endothelial cell adhesion molecule‐1 (CD31), and endothelial nitric oxide synthase (eNOS). In vivo experiments further demonstrate that the COC@SalB‐Cu hydrogel can significantly restore the oxygen and blood supply, leading to fast tissue regeneration. The present strategy holds enormous promise for the treatment of hypoxia‐related chronic tissue defects and vascular injury in the field of regenerative medicine. [ABSTRACT FROM AUTHOR]

Background: Extracorporeal membrane oxygenation (ECMO) has emerged as a life-sustaining measure for individuals with end-stage cardiopulmonary derangements. An estimated one-third of patients must be transferred to a specialized center to receive this intervention. Therefore, the present study sought to characterize the impact of interhospital transfer (IHT) status on outcomes following ECMO. Methods: The 2016-2020 National Inpatient Sample was queried to identify all adult (≥18 years) hospitalizations for ECMO. Patients were stratified based on transfer status from another acute care hospital. Multivariable regression models were developed to assess the association between transfer status and outcomes of interest. Patient and operative factors associated with IHT were identified using regression. Results: Of an estimated 61,180 hospitalizations entailing ECMO, 21,410 (35.0%) were transfers. Annual transfer volume doubled over the study period, from 2915 to 5945 (nptrend < .001). The predicted morality risk of non-transfers decreased between 2016 and 2020 but remained similar in transferred patients. Following adjustment, transfer was associated with increased odds of in-hospital mortality, complications, duration of stay, and hospitalization costs. Patients experiencing transfer were less likely to be of black race and private insurance status. Conclusion: Despite increasing transfer volume and utilization of ECMO, IHT was associated with significant mortality and hospital complication risks. Further work to reduce adverse outcomes, resource burden, and socioeconomic differences within IHT may improve accessibility to this life-saving modality. [ABSTRACT FROM AUTHOR]

Abstract Background In patients with severe acute respiratory distress syndrome (ARDS), prolonged and inappropriate use of prone position ventilation (PPV) is a known risk factor for mortality. Hence, it is critical to monitor patients' response to PPV and accurately differentiate responders from non-responders at an early stage. The study aimed to investigate the relationship between oxygenation improvement after three rounds of PPV and survival rate in patients with pulmonary ARDS. Additionally, we sought to identify the earliest turning point for escalation from PPV to extracorporeal membrane oxygenation. Methods We performed a retrospective observational study from 2015 to 2023. We included adult patients who received invasive mechanical ventilation, underwent at least three periods of at least 6 h of PPV after admission to the Intensive Care Unit, and meet the ARDS criteria. The study collected data on each PPV session, including changes in PaCO2, PaO2, pH, FiO2, PaO2:FiO2 ratio, and clinical outcomes. Results A total of 104 patients were enrolled in the study. The change in PaCO2 from baseline to the third PPV session (P3) had the highest area under the receiver operating characteristic curve (AUC) of 0.70 (95% CI 0.60–0.80; p

Abstract Background Pneumothorax is a little known and reported complication of COVID-19. These patients have poorer general outcomes and greater respiratory support requirements, longer hospitalization times, and higher mortality rates. The purpose of this study was to determine which factors predict mortality in patients with tube thoracostomy diagnosed with COVID-19, admitted to the COVID-19 intensive care unit (ICU), and developing pneumothorax. Methods This respective, observational study was conducted in all COVID-19 ICUs at the Marmara University Pendik Training and Research Hospital, Türkiye. Patients admitted to the ICU with diagnoses of COVID-19 pneumonia and with chest tubes inserted due to pneumothorax were investigated retrospectively. Results One hundred patients with tube thoracostomy were included in the study. Their median age was 68 (57–78), and 63% were men. The median follow-up time was 20 [10–29] days, and the median time from initial reverse transcriptase polymerase chain reaction (RT-PCR) results to tube thoracostomy was 17 [9–23] days. Initial RT-PCR results were positive in 90% of the patients, while 8% were negative, and 2% were unknown. Half the patients exhibited pulmonary involvement at thoracic computed tomography (CT) (n = 50), while 22 patients had COVID-19 reporting and data system (CO-RADS) scores of 5 (22%). Sixty-two patients underwent right tube thoracostomy, 24 left side placement, and 14 bilateral placement. The patients’ mean positive end expiratory pressure (PEEP) level was 10.31 (4.48) cm H2O, with a mean peak inspiratory pressure (PIP) level of 26.69 (5.95) cm H2O, a mean fraction of inspired oxygen (FiO2) level of 80.06 (21.11) %, a mean respiratory rate of 23.71 (5.62) breaths/min, and a mean high flow nasal cannula (HFNC) flow rate of 70 (8.17) L/min. Eighty-seven patients were intubated (87%), six used non-rebreathable reservoir masks, four HFNC, two non-invasive mechanical ventilation (NIV), and one a simple face mask. Comorbidity was present in 70 patients, 25 had no comorbidity, and the comorbidity status of five was unknown. Comorbidities included hypertension (38%), diabetes mellitus (23%), cardiovascular disease (12%), chronic obstructive pulmonary disease (5%), malignancy (3%), rheumatological diseases (3%), dementia (2%) and other diseases (9%). Twelve of the 100 patients survived. The median survival time was 20 (17.82–22.18) days, and the median 28-day overall survival rate was 29% (20-38%). The multivariate Cox proportional hazards model indicated that age over 68 (HR = 2.23 [95% CI: 1.39–3.56]; p = 0.001), oxygenation status other than by intubation (HR = 2.24 [95% CI: 1.11–4.52]; p = 0.024), and HCO3- below 22 compared with a normal range of 22 to 26 (HR = 1.95 [95% CI: 1.08–3.50]; p = 0.026) were risk factors associated with mortality in patients in the ICU. Conclusions Age over 68, receipt of oxygenation other than by intubation, and HCO3- values lower than 22 in patients with COVID-19 pneumonia emerged as prognostic factors associated with mortality in terms of pneumothorax.

Abstract Acute respiratory distress syndrome (ARDS) is a heterogeneous disease with extremely high mortality. We hypothesized that the serum β2-microglobulin (β2MG) level would be elevated and be an independent risk factor for 28-day mortality in patients with ARDS caused by bacterial infection. We retrospectively enrolled 257 patients with ARDS caused by bacterial infection from January 1, 2015 to February 28, 2021. Patients were followed for up to 28 days and were divided into a survival group and non-survival group according to their clinical outcomes. The serum β2MG levels and other clinical data were collected. The relationship between β2MG levels and 28-day mortality was explored by performing a Cox regression analysis adjusted for age, updated Charlson comorbidity index, disorders of consciousness, septic shock, albumin level, cardiac troponin I level, procalcitonin level, lactic acid level, prothrombin time, partial pressure of arterial oxygen/fraction of inspired oxygen ratio, estimated glomerular filtration rate and Sequential Organ Failure Assessment. In this cohort, 96 patients died in 28 days, yielding a 28-day mortality of 37.4%. The median level of serum β2MG for all enrolled patients was 4.7 (interquartile range [IQR]: 2.9–8.5) mg/L. Higher β2MG levels were significantly associated with 28-day mortality when the β2MG level was analysed as a continuous variable (hazard ratio [HR]: 1.053; 95% confidence interval [CI] 1.004–1.104; P = 0.032) and when it was categorized into tertiles (HR: 3.241; 95% CI 1.180–8.905; P = 0.023). The β2MG level exhibited a high diagnostic accuracy for predicting 28-day mortality (area under the curve [AUC] = 0.732; 95% CI 0.673–0.785; sensitivity: 74.0%; specificity: 64.0%; P

Recently, there has been growing interest in knowing the best hygrometry level during high-flow nasal oxygen and non-invasive ventilation (NIV) and its potential influence on the outcome. Various studies have shown that breathing cold and dry air results in excessive water loss by nasal mucosa, reduced mucociliary clearance, increased airway resistance, reduced epithelial cell function, increased inflammation, sloughing of tracheal epithelium, and submucosal inflammation. With the Coronavirus Disease 2019 pandemic, using high-flow nasal oxygen with a heated humidifier has become an emerging form of non-invasive support among clinicians. However, we cannot always assume stable humidification. Similarly, there are no clear guidelines for using humidification during NIV, although humidification of inspired gas during invasive ventilation is an accepted standard of care. NIV disturbs the normal physiological system that warms and humidifies inspired gases. If NIV is supplied through an intensive care unit ventilator that utilizes anhydrous gases from compressed wall air and oxygen, the risk of dryness increases. In addition, patients with acute respiratory failure tend to breathe through the mouth during NIV, which is a less efficient route than nasal breathing for adding heat and moisture to the inspired gas. Obstructive sleep apnea syndrome is one of the most important indications for chronic use of NIV at home. Available data suggest that up to 60% of patients with obstructive sleep apnea syndrome who use continuous positive airway pressure therapy experience nasal congestion and dryness of the mouth and nose. Therefore, humidifying the inspired gas in NIV may be essential for patient comfort and compliance with treatment. We aimed to review the available bench and clinical studies that addressed the utility of hygrometry in NIV and nasal high-flow oxygen and discuss the technical limitations of different humidification systems for both systems.

Abstract Background Hypoxic pulmonary vasoconstriction is the most important regulatory mechanism by which right-to-left shunts decrease during one-lung ventilation (OLV), but the effects of pulmonary microarterial thrombosis and impaired HPV after SARS-CoV-2 infection on intrapulmonary shunt during OLV remain unknown. The aim of this study was to observe the changes of intrapulmonary shunt in patients undergoing thoracoscopic partial pneumonectomy at different periods after SARS-CoV-2 infection compared with patients without SARS-CoV-2 infection history. Methods A total of 80 patients who underwent elective thoracoscopic partial lung resection and were classified as American Society of Anaesthesiologists (ASA) grades I-II were selected and divided into 4 groups (n = 20 in each group): patients not infected with SARS-CoV-2 (Group A), patients infected with SARS-CoV-2 for 5–8 weeks (Group B), patients infected with SARS-CoV-2 for 9–12 weeks (Group C), and patients infected with SARS-CoV-2 for 13–16 weeks (Group D). For all patients, the same anaesthesia method was adopted, and anaesthesia was maintained with propofol, remifentanil, and cisatracurium. Radial artery and mixed venous blood gases were measured at 10 min of two-lung ventilation (TLV), 15 min of one-lung ventilation (OLV15), and 30 min of OLV (OLV30) in the lateral recumbent position to calculate the intrapulmonary shunt. Multiple linear regression analysis was employed to investigate the association between intrapulmonary shunt and SARS-CoV-2 infection. Results Qs/Qt at TLV was significantly higher in Groups B and C than in Group A (P

The article is devoted to the actual problem of non-invasive self-monitoring of oxygenation and blood pressure indicators by patients. The article provides an overview of the available promising approaches for monitoring the biomarkers under consideration. Also, it demonstrates the main problems associated with applying the approaches under consideration and those caused by the test sample itself.

Abstract Background For patients receiving one lung ventilation in thoracic surgery, numerous studies have proved the superiority of lung protective ventilation of low tidal volume combined with recruitment maneuvers (RM) and individualized PEEP. However, RM may lead to overinflation which aggravates lung injury and intrapulmonary shunt. According to CT results, atelectasis usually forms in gravity dependent lung regions, regardless of body position. So, during anesthesia induction in supine position, atelectasis usually forms in the dorsal parts of lungs, however, when patients are turned into lateral decubitus position, collapsed lung tissue in the dorsal parts would reexpand, while atelectasis would slowly reappear in the lower flank of the lung. We hypothesize that applying sufficient PEEP without RM before the formation of atelectasis in the lower flank of the lung may beas effective to prevent atelectasis and thus improve oxygenation as applying PEEP with RM. Methods A total of 84 patients scheduled for elective pulmonary lobe resection necessitating one lung ventilation will be recruited and randomized totwo parallel groups. For all patients, one lung ventilation is initiated the right after patients are turned into lateral decubitus position. For patients in the study group, individualized PEEP titration is started the moment one lung ventilation is started, while patients in the control group will receive a recruitment maneuver followed by individualized PEEP titration after initiation of one lung ventilation. The primary endpoint will be oxygenation index measured at T4. Secondary endpoints will include intrapulmonary shunt, respiratory mechanics, PPCs, and hemodynamic indicators. Discussion Numerous previous studies compared the effects of individualized PEEP applied alone with that applied in combination with RM on oxygenation index, PPCs, intrapulmonary shunt and respiratory mechanics after atelectasis was formed in patients receiving one lung ventilation during thoracoscopic surgery. In this study, we will apply individualized PEEP before the formation of atelectasis while not performing RM in patients allocated to the study group, and then we’re going to observe its effects on the aspects mentioned above. The results of this trial will provide a ventilation strategy that may be conductive to improving intraoperative oxygenation and avoiding the detrimental effects of RM for patients receiving one lung ventilation. Trial registration www.Chictr.org.cn ChiCTR2400080682. Registered on February 5, 2024.

Abstract Serine proteases are important regulators of airway epithelial homeostasis. Altered serum or cellular levels of two serpins, Scca1 and Spink5, have been described for airway diseases but their function beyond antiproteolytic activity is insufficiently understood. To close this gap, we generated fly lines with overexpression or knockdown for each gene in the airways. Overexpression of both fly homologues of Scca1 and Spink5 induced the growth of additional airway branches, with more variable results for the respective knockdowns. Dysregulation of Scca1 resulted in a general delay in fruit fly development, with increases in larval and pupal mortality following overexpression of this gene. In addition, the morphological changes in the airways were concomitant with lower tolerance to hypoxia. In conclusion, the observed structural changes of the airways evidently had a strong impact on the airway function in our model as they manifested in a lower physical fitness of the animals. We assume that this is due to insufficient tissue oxygenation. Future work will be directed at the identification of key molecular regulators following the airway-specific dysregulation of Scca1 and Spink5 expression.

After systematic realization of decarboxylative functionalization of carboxylic acids under heating conditions in our group, we herein reported an electrochemical method for Ni‐catalyzed decarboxylative oxygenation of arylacetic acids under open air conditions. The protocol provided corresponding carbonyls including aldehydes and ketones in moderate to satisfactory yields with good functional group tolerance, furthermore, the practicability and advantage of the method was highlighted through Ni‐catalyzed oxidative decarboxylation of carboxylic acid‐containing drugs and preformation of scalable transformation. Mechanistic studies demonstrated that the possible involvement of free radical intermediate in the conversion. [ABSTRACT FROM AUTHOR]

Background: Hypoxic pulmonary vasoconstriction is the most important regulatory mechanism by which right-to-left shunts decrease during one-lung ventilation (OLV), but the effects of pulmonary microarterial thrombosis and impaired HPV after SARS-CoV-2 infection on intrapulmonary shunt during OLV remain unknown. The aim of this study was to observe the changes of intrapulmonary shunt in patients undergoing thoracoscopic partial pneumonectomy at different periods after SARS-CoV-2 infection compared with patients without SARS-CoV-2 infection history. Methods: A total of 80 patients who underwent elective thoracoscopic partial lung resection and were classified as American Society of Anaesthesiologists (ASA) grades I-II were selected and divided into 4 groups (n = 20 in each group): patients not infected with SARS-CoV-2 (Group A), patients infected with SARS-CoV-2 for 5–8 weeks (Group B), patients infected with SARS-CoV-2 for 9–12 weeks (Group C), and patients infected with SARS-CoV-2 for 13–16 weeks (Group D). For all patients, the same anaesthesia method was adopted, and anaesthesia was maintained with propofol, remifentanil, and cisatracurium. Radial artery and mixed venous blood gases were measured at 10 min of two-lung ventilation (TLV), 15 min of one-lung ventilation (OLV15), and 30 min of OLV (OLV30) in the lateral recumbent position to calculate the intrapulmonary shunt. Multiple linear regression analysis was employed to investigate the association between intrapulmonary shunt and SARS-CoV-2 infection. Results: Qs/Qt at TLV was significantly higher in Groups B and C than in Group A (P < 0.05), and PaO2 at TLV was significantly lower in Groups B and C than in Group A (P < 0.05). Qs/Qt values at OLV15 and OLV30 were significantly higher in Group B, C or D than in Group A (P < 0.05), and PaO2 values at OLV15 and OLV30 were significantly lower in Groups B, C or D than in Group A (P < 0.05). Multiple linear regression analysis revealed that SARS-CoV-2 infection (95%CI -4.245 to -0.679, P = 0.007) was an independent risk factor for increased intrapulmonary shunt during TLV, while SARS-CoV-2 infection (95%CI 0.124 to 3.661, P = 0.036), exacerbation of COVID-19 clinical classification (95%CI -5.203 to -1.139, P = 0.003), and persistent symptoms (95%CI -12.122 to -5.522, P < 0.001) were independent risk factors for increased intrapulmonary shunt during OLV after SARS-CoV-2 infection. Conclusion: SARS-CoV-2 infection increased intrapulmonary shunt and reduced oxygenation. Although oxygenation improved at TLV after 13–16 weeks of infection, intrapulmonary shunt and oxygenation under OLV took longer to recover. Trial registration: Chinese Clinical Trial Registry, Retrospectively registered, Full date of first registration: 17/05/2023, Registration number: ChiCTR2300071539. [ABSTRACT FROM AUTHOR]

Background: Upper limb motor impairment is a common consequence of stroke, and the effectiveness and underlying mechanisms of rehabilitation therapy for improving upper limb function remain uncertain. Functional nearinfrared spectroscopy, a reliable wearable neuroimaging technique, holds promise for investigating brain activity during functional tasks. This study aims to explore the synchronous oxygenation characteristics of the central cortex and upper-limb flexors during a grasping task and investigate the rehabilitation mechanisms of upper limb motor function in individuals with stroke. Methods: Participants with stroke who demonstrate the ability to grasp and lift cubic wood blocks of different sizes (2.5cm3, 5cm3, and 10cm3) using their affected hand will be divided into three groups: A, B, and C. Each group will consist of twenty stroke patients, resulting in a total of sixty participants with stroke. Additionally, twenty matched healthy subjects will be enrolled as a control group. Comprehensive assessments will be conducted before and after the intervention, including blood oxygen parameter monitoring of the cerebral cortex and upper limb flexors using fNIRS during the grasping task. Other assessments will include MyotonPRO, the Modified Ashworth Scale, the upper extremity section of the Fugl-Meyer Assessment, the Action Research Arm Test, and the Modified Barthel Index. The study will be undertaken between January 2024 and September 2025. Conclusions: The results of this trial will provide an in-depth understanding of the Characteristics of central cortex and upper-limb flexors synchronous oxygenation during grasping task and how it may relate to the rehabilitation mechanism of upper limb motor function in people with stroke. [ABSTRACT FROM AUTHOR]

Diabetic foot ulcers (DFUs), a serious and increasingly common chronic issue among diabetics, often do not respond well to generalized treatment strategies. Hypoxia and the overexpression of reactive oxygen species (ROS), resulting in inflammatory dysregulation and subsequent imbalance in macrophage phenotypes, are critical factors contributing to the prolonged non‐healing of DFU wounds. These two issues often interact in a continuous, problematic cycle. Presently, there is a lack of comprehensive strategies aimed at addressing both of these factors simultaneously to interrupt this detrimental cycle. Herein, an immunomodulatory hydrogel (PHG2) is developed for reshaping the hostile DFU microenvironment. The engineered PHG2 not only removes excess internally‐produced ROS but also generates O2, with its efficiency further boosted by local hyperthermia (42.5 °C) activated by near‐infrared light. Through both in vitro and in vivo studies, along with transcriptomic assessment, it is confirmed that PHG2 disrupts the detrimental feedback loop between ROS and inflammation while also lowering the M1/M2 macrophage ratio. Such discoveries contribute to a significant enhancement in the healing process of injuries that undergo a gradual increase in movement, covering wounds from the back, mouth, to the foot. Ultimately, this method provides an easy, safe, and highly effective solution for treating DFUs. [ABSTRACT FROM AUTHOR]

Herein, we report a general copper‐catalyzed method for the tunable oxygenative rearrangement of tetrahydrocarbazoles to cyclopentyl‐bearing spiroindolin‐2‐ones and spiroindolin‐3‐ones. The method demonstrates excellent chemoselectivity, regioselectivity, and product control simply by using the H2O and O2 as oxygen source, respectively. This open‐flask method is safe and simple to operate, and no other chemical oxidants are required. Besides, inspired from the unique pathway of 1, 2‐migration rearrangement, a highly controllable hydroxylation of indoles for the construction of C3a‐hydroxyl iminium indolines was also developed. Mechanistic experiments suggest that a single‐electron transfer‐induced oxidation process is responsible for the tunable selectivity control. [ABSTRACT FROM AUTHOR]

Research suggested that color vision evolved for the purpose of seeing skin color modulations signaling emotion or mood. Hence people want to find the connection of the cone sensitivities with the skin spectral reflectance. In this article the W and V shapes based on skin spectral reflectance measured at different positions and from different ethnic groups (Kurdish, Caucasian, Thai, Chinese) were investigated. First, it was found that the measured skin spectral reflectance from all body positions and ethnic groups have a V shape between 400 and 450 nm and a W shape between 520 and 610 nm. The W and V shapes from the measured skin spectral reflectance are clearly different from those from the spectral reflectance generated from the physical model. The V shape and W shape do not exist with spectral reflectances measured from artificial skin color. Second, it was found that the wavelengths where the left trough assumes for the W shape are different from the wavelength where the M cone peaks, and the wavelengths where the central peak of the W shape assumes are different from the wavelength where the L cone peaks, which are different from the results from literature. Third, it was found that the skin spectral reflectance varies with body positions and ethnic groups. The W shapes turn to be a “U” shape for the spectral reflectance measured at back of the hand and inner forearm positions. The spectral reflectance measured from Kurdish starts decreasing for each body positions for wavelength greater than 700 nm, which is clearly different from the spectral reflectance measured from the Chinese and Caucasian ethnic groups. The findings of this paper are valuable for improving the physical model for generating skin spectral reflectance, reconstructing skin spectral reflectance based on image, identifying human skin color from spectral imaging and rendering of human skin color in computer graphics. [ABSTRACT FROM AUTHOR]

We report an iron‐catalyzed decarboxylative C(sp3)−O bond‐forming reaction under mild, base‐free conditions with visible light irradiation. The transformation uses readily available and structurally diverse carboxylic acids, iron photocatalyst, and 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO) derivatives as oxygenation reagents. The process exhibits a broad scope in acids possessing a wide range of stereoelectronic properties and functional groups. The developed reaction was applied to late‐stage oxygenation of a series of bio‐active molecules. The reaction leverages the ability of iron complexes to generate carbon‐centered radicals directly from carboxylic acids by photoinduced carboxylate‐to‐iron charge transfer. Kinetic, electrochemical, EPR, UV/Vis, HRMS, and DFT studies revealed that TEMPO has a triple role in the reaction: as an oxygenation reagent, an oxidant to turn over the Fe‐catalyst, and an internal base for the carboxylic acid deprotonation. The obtained TEMPO adducts represent versatile synthetic intermediates that were further engaged in C−C and C‐heteroatom bond‐forming reactions using commercial organo‐photocatalysts and nucleophilic reagents. [ABSTRACT FROM AUTHOR]

Summary: Background: Impaired oxygenation during anaesthesia can be detrimental. Bodyweight and body shape influence arterial oxygen tension (PaO2) but the effect of body condition score (BCS) has not been investigated. Objectives: To examine the effect of BCS on respiratory indices. Study design: Retrospective. Methods: In total, 524 anaesthetic records were reviewed. Records from healthy adult horses under isoflurane anaesthesia in dorsal recumbency, receiving controlled mechanical ventilation, with complete ventilation and arterial blood gas data and BCS assessment by one person (KL) were included in data analysis. Data were analysed using student's t‐test, Mann–Whitney U test, chi‐squared analysis and logistic regression. Results: In total, 135 records for 85 horses with BCS <6/9 (Group N) and 50 horses with BCS ≥6/9 (Group O) met the inclusion criteria. Overall, there was a strong negative correlation between BCS and PaO2 (Spearman's r = 0.72, p < 0.001). Group O had significantly lower PaO2 (112 [50–546 mmHg]) compared to Group N (380 [65–658 mmHg], p < 0.001) which remained when horses were further categorised by bodyweight >500 kg (118 mmHg vs. 390 mmHg, p < 0.001) and <500 kg (160 mmHg vs. 451 mmHg, p < 0.04). Group O were 34 times more likely to be hypoxaemic (PaO2 < 100 mmHg) compared to Group N (χ2 = 34.39, p = 0.03). Alveolar dead space fraction was greater in Group O (0.27 [0.10–0.41]) versus Group N (0.24 [0.12–0.35]), p < 0.001. Multivariate logistic regression analysis identified a significant association between PaO2 and bodyweight (p = 0.01), alveolar dead space fraction (p = 0.005) and BCS (p < 0.001). Main limitations: Retrospective design. Conclusions: Body condition score ≥6/9 has a detrimental effect on PaO2, alveolar dead space fraction and is a risk factor for hypoxaemia in healthy anaesthetised horses in dorsal recumbency. [ABSTRACT FROM AUTHOR]

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Pathogenic protein aggregates, called amyloids, are etiologically relevant to various diseases, including neurodegenerative Alzheimer disease. Catalytic photooxygenation of amyloids, such as amyloid‐β (Aβ), reduces their toxicity; however, the requirement for light irradiation may limit its utility in large animals, including humans, due to the low tissue permeability of light. Here, we report that Cypridina luciferin analogs, dmCLA‐Cl and dmCLA‐Br, promoted selective oxygenation of amyloids through chemiexcitation without external light irradiation. Further structural optimization of dmCLA‐Cl led to the identification of a derivative with a polar carboxylate functional group and low cellular toxicity: dmCLA‐Cl‐acid. dmCLA‐Cl‐acid promoted oxygenation of Aβ amyloid and reduced its cellular toxicity without photoirradiation. The chemiexcited oxygenation developed in this study may be an effective approach to neutralizing the toxicity of amyloids, which can accumulate deep inside the body, and treating amyloidosis. [ABSTRACT FROM AUTHOR]

Serine proteases are important regulators of airway epithelial homeostasis. Altered serum or cellular levels of two serpins, Scca1 and Spink5, have been described for airway diseases but their function beyond antiproteolytic activity is insufficiently understood. To close this gap, we generated fly lines with overexpression or knockdown for each gene in the airways. Overexpression of both fly homologues of Scca1 and Spink5 induced the growth of additional airway branches, with more variable results for the respective knockdowns. Dysregulation of Scca1 resulted in a general delay in fruit fly development, with increases in larval and pupal mortality following overexpression of this gene. In addition, the morphological changes in the airways were concomitant with lower tolerance to hypoxia. In conclusion, the observed structural changes of the airways evidently had a strong impact on the airway function in our model as they manifested in a lower physical fitness of the animals. We assume that this is due to insufficient tissue oxygenation. Future work will be directed at the identification of key molecular regulators following the airway-specific dysregulation of Scca1 and Spink5 expression. [ABSTRACT FROM AUTHOR]

Due to oxygenation, carbon nanotubes cannot operate field emission for a long period of time. So far, the emission-induced oxygenation mechanism has not been studied in detail; particularly, the underlying mechanism that causes a drastic increase of the emitting current contiguous to the turn-on voltage remains unclear. Cold plasma is a nonthermal equilibrium process and can also oxygenate carbon materials through radiolysis. In this work, electrical measurements of single-walled carbon nanotubes are in situ carried out in O2 and N2 plasma irradiation, and the tube resistance due to irradiative damages is found to increase in three steps, defined as regions I, II, and III. In region I, the increase is rapid and involves extraction of intercalated O2 between the nanotubes. The nanotubes become severely oxygenated in region II, thus enhancing the on-tube scattering and resistance. Nanotube segmentation takes place in region III, where the opened edges are likely bonded with oxygenated and nitride groups. Experimental data successfully explain the field emission instability of carbon nanotubes, including a low life cycle, sudden increase in emitting current around the turn-on voltage, and thermal decomposition of carbon lattices. [ABSTRACT FROM AUTHOR]

Background: Pulse oximetry is widely used in the NICU and PICU to monitor oxygenation in newborns and children with respiratory distress. This study aimed to evaluate the relationship between arterial partial pressure of oxygen (PaO2) and pulse oxygen saturation (SpO2) values in this patient population. Methods: A total of 50 newborns and children with respiratory distress admitted to the NICU and PICU were included in this observational study. PaO2 and SpO2 values were obtained simultaneously, and their relationship was analyzed using correlation, linear regression, and agreement analyses. Results: A strong positive correlation was found between PaO2 and SpO2 (r = 0.78, p < 0.001). The linear regression equation was PaO2 = 21.5 + 0.46 x SpO2 (R-squared = 0.61, adjusted R-squared = 0.60, p < 0.001). The mean difference between PaO2 and SpO2 was 2.8 (SD = 8.2), with 95% limits of agreement ranging from -13.3 to 18.9. The sensitivity and specificity of SpO2 for detecting hypoxemia (PaO2 < 60 mmHg) were 85.7% and 91.2%, respectively. Conclusions: SpO2 is a reliable tool for monitoring oxygenation in newborns and children with respiratory distress, showing a strong correlation with PaO2. However, its accuracy may be influenced by factors such as the FiO2 level and the severity of hypoxemia. Clinicians should use SpO2 in conjunction with other clinical parameters and diagnostic tools when assessing and managing this patient population. [ABSTRACT FROM AUTHOR]

Until the late 20th century, the idea of identifying wildfires in deep time was not generally accepted. One of the basic problems was the fact that charcoal-like wood fragments, so often found in sedimentary rocks and in coals, were termed fusain and, in addition, many researchers could not envision wildfires in peat-forming systems. The advent of Scanning Electron Microscopy and studies on modern charcoals and fossil fusains demonstrated beyond doubt that wildfire residues may be recognized in rocks dating back to at least 350 million years. Increasing numbers of studies on modern and fossil charcoal assemblages from the 1970s through the 1990s established the potential importance of wildfires in the fossil record, using Carboniferous examples in particular. Since the 1990s, extensive progress has been made in understanding modern wildfires and their byproducts. New techniques to study ancient charcoals have allowed considerable progress to be made to integrate modern and ancient fire studies, both before and after the evolution of mankind. Four important developments have made a reassessment of Carboniferous wildfires necessary: the recognition of the role of atmospheric oxygen in controlling the occurrence of wildfire; the development of new microscopical techniques allowing more detailed anatomical data to be obtained from charcoal; the integration of molecular studies with the evolution of fire traits; and new developments in or understanding of post-fire erosion/deposition systems. [ABSTRACT FROM AUTHOR]

Brachial artery flow-mediated dilation (BAFMD) is induced by hyperemic wall shear rate (WSR) following forearm ischemia. In older adults, there appears to be a reduced brachial hyperemic WSR and altered stimulus-response relationship compared with young adults. However, it is unclear if an altered forearm microvascular response to ischemia influences brachial hyperemic WSR in older adults. We determined associations between brachial hyperemic WSR and forearm skeletal muscle oxygen saturation in young and older adults. Healthy young (n = 17, 29 ± 7 yr) and older (n = 32, 65 ± 4 yr) adults participated in the study. BAFMD by a multigate spectral Doppler system and forearm skeletal muscle oxygen saturation by near-infrared spectroscopy were concurrently measured. When compared with the young, older adults showed reduced oxygen extraction kinetics (OE, 0.15 [0.12–0.17] vs. 0.09 [0.05–0.12]%s−1) and magnitude (S o 2deficit, 3,810 ± 1,420 vs. 2,723 ± 1,240%s) during ischemia, as well as oxygen resaturation kinetics (S o 2slope, 2.5 ± 0.7 vs. 1.7 ± 0.7%s−1) upon reperfusion (all P < 0.05). When OE in the young and S o 2slope in older adults were stratified by their median values, young adults with OE above the median had greater hyperemic WSR parameters compared with those below the median (P < 0.05), but S o 2slope in older adults did not show clear differences in hyperemic WSR parameters between those above/below the median. This study demonstrates that, in addition to a reduced microvascular response to ischemia, there may be a dissociation between microvascular response to ischemia and brachial hyperemic WSR in older adults, which may result in a further impairment of BAFMD in this cohort. NEW & NOTEWORTHY: Microvascular response to ischemia and subsequent reperfusion is diminished in older adults compared with the young. Furthermore, there appears to be a dissociation between the microvascular response to ischemia and brachial hyperemic WSR in older adults, which may further disturb the BAFMD process in this cohort. A reduced BAFMD in older adults may be a result of multiple alterations occurring both at macro- and microcirculation. [ABSTRACT FROM AUTHOR]

Drowning is the process of respiratory impairment from immersion or submersion in a liquid. Worldwide, approximately 360,000 deaths annually can be attributed to drowning. Morbidity and mortality are a result of hypoxia, so the focus during resuscitation should be on airway management and optimizing oxygenation. This article describes several drowning scenarios and discusses appropriate response and treatment algorithms. [ABSTRACT FROM AUTHOR]

Introduction: Dynamic contrast-enhanced (DCE) MRI and arterial spin labeling (ASL) MRI enable non-invasive measurement of renal blood flow (RBF), whereas blood oxygenation level-dependent (BOLD) MRI enables non-invasive measurement of the apparent relaxation rate (R2*), an indicator of oxygenation. This study was conducted to evaluate the potential role of these MRI modalities in assessing RBF and oxygenation in dogs. The correlation between contrast-enhanced ultrasound (CEUS) and the MRI modalities was examined and also the ability of the MRI modalities to detect pharmacologically induced changes. Methods: RBF, using CEUS, ASL- and DCE-MRI, as well as renal oxygenation, using BOLD-MRI of eight adult beagles were assessed at two time-points, 2-3 weeks apart. During each time point, the anesthetized dogs received either a control (0.9% sodium chloride) or a dopamine treatment. For each time point, measurements were carried out over 2 days. An MRI scan at 3 T was performed on day one, followed by CEUS on day two. Results: Using the model-free model with caudal placement of the arterial input function (AIF) region of interest (ROI) in the aorta, the DCE results showed a significant correlation with ASL measured RBF and detected significant changes in blood flow during dopamine infusion. Additionally, R2* negatively correlated with ASL measured RBF at the cortex and medulla, as well as with medullary wash-in rate (WiR) and peak intensity (PI). ASL measured RBF, in its turn, showed a positive correlation with cortical WiR, PI, area under the curve (AUC) and fall time (FT), and with medullary WiR and PI, but a negative correlation with medullary rise time (RT). During dopamine infusion, BOLD-MRI observed a significant decrease in R2* at the medulla and entire kidney, while ASL-MRI demonstrated a significant increase in RBF at the cortex, medulla and the entire kidney. Conclusion: ASL- and BOLD-MRI can measure pharmacologically induced changes in renal blood flow and renal oxygenation in dogs and might allow detection of changes that cannot be observed with CEUS. However, further research is needed to confirm the potential of ASL- and BOLD-MRI in dogs and to clarify which analysis method is most suitable for DCE-MRI in dogs. [ABSTRACT FROM AUTHOR]

Prolonged ventilation remains the most common cause of tracheal stenosis. Tracheal reconstruction is the gold standard treatment in these cases. The success of surgery is based on results of the pulmonary function test (PFT) which relies on patients' performance and their cooperation. The objective of the study was to investigate the impact of tracheal reconstruction in cases of tracheal stenosis on blood gas indices as well as airflow indices and whether arterial blood gas (ABG) can be a better surrogate of adequacy of tracheal reconstruction. This was a retrospective observational study of 61 patients with tracheal stenosis between the ages of 21 and 65 years who underwent tracheal reconstruction. The preoperative and postoperative values of various blood gas indices like partial pressure of oxygen (pO2), partial pressure of carbon dioxide (pCO2), and potential of hydrogen (pH) and airflow indices like forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) were evaluated and found that all the parameters showed significant improvement after tracheal reconstruction with P < 0.0001. Tracheal reconstruction resulted in improvement of oxygenation and airflow parameters which led to relief of symptoms. Hence, ABG can be used as a surrogate marker for denoting the success of the surgery. [ABSTRACT FROM AUTHOR]

IntroductionTo characterize early-gestation changes in placental structure, perfusion, and oxygenation in the context of ischemic placental disease (IPD) as a composite outcome and in individual sub-groups.MethodsIn a single-center prospective cohort study, 199 women were recruited from antenatal clinics between February 2017 and February 2019. Maternal magnetic resonance imaging (MRI) studies of the placenta were temporally conducted at two timepoints: 14-16 weeks gestational age (GA) and 19-24 weeks GA. The pregnancy was monitored via four additional study visits, including at delivery. Placental volume, perfusion, and oxygenation were assessed at both MRI timepoints. The primary outcome was defined as pregnancy complicated by IPD, with group assignment confirmed after delivery.ResultsIn early gestation, mothers with IPD who subsequently developed fetal growth restriction (FGR) and/or delivered small-for gestational age (SGA) infants showed significantly decreased MRI indices of placental volume, perfusion, and oxygenation compared to controls. The prediction of FGR or SGA by multiple logistic regression using placental volume, perfusion, and oxygenation revealed receiver operator characteristic curves with areas under the curve of 0.81 (Positive predictive value (PPV) = 0.84, negative predictive value (NPV) = 0.75) at 14-16 weeks GA and 0.66 (PPV = 0.78, NPV = 0.60) at 19-24 weeks GA.DiscussionMRI indices showing decreased placental volume, perfusion and oxygenation in early pregnancy were associated with subsequent onset of IPD, with the greatest deviation evident in subjects with FGR and/or SGA. These early-gestation MRI changes may be predictive of the subsequent development of FGR and/or SGA.

In the past 20 years, unspecific peroxygenases (UPOs) have emerged as promising biocatalysts for various organic transformations. Particularly, we have witnessed great attention being paid to the screening of new enzymes and expansion of the substrates/products. However, challenges such as enzyme stability, low turnover numbers, and substrate specificity hinder their widespread utilization in practical organic synthesis. This review article provides a concrete and mini-overview of the challenges associated with using UPOs in organic synthesis and discusses strategies for enzyme engineering to overcome these limitations. The article highlights recent advancements in UPO research and presents potential solutions to enhance their catalytic efficiency, stability, substrate specificity, and regioselectivity. Additionally, the review outlines the current methodologies employed for directed evolution and protein engineering of UPOs, along with computational modeling approaches for rational enzyme design. By addressing the challenges and exploring avenues for enzyme engineering, this review aims to shed light on the prospects of UPOs in organic synthesis.

Abstract Menopause is associated with reduced endothelial‐dependent vasodilation and increased cardiovascular disease (CVD) risk. Dietary nitrate, a non‐pharmacological approach, may increase vasodilatory capacity consequentially reducing CVD risk. We investigated macro‐ and microvascular function after acute nitrate supplementation in postmenopausal females (PMF). Vascular function was studied with flow‐mediated vasodilation (FMD) and near‐infrared post occlusive reactive hyperemia (PORH). Incremental handgrip exercise was performed to investigate blood flow and tissue oxygenation. We hypothesized acute dietary nitrate would not impact resting endothelial measures but would increase post ischemic vasodilation and incremental exercise blood flow. Late‐phase PMF (n = 12) participated in a randomized crossover design with 140 mL of nitrate‐rich (NR) beetroot juice or nitrate‐poor black currant juice. Testing included a 5‐min FMD, a 3‐min ischemic exercise FMD, and incremental exercise at 10%, 15%, and 20% maximal voluntary contraction to measure blood flow and pressure responses. A p ≤ 0.05 was considered significant. One‐way ANOVA indicated lower resting pressures, but no change to FMD, or PORH in either protocol. Two‐way repeated measures ANOVA indicated NR supplementation significantly reduced mean arterial pressure at rest and during incremental exercise at all intensities without changes to blood flow. Acute nitrate is effective for resting and exercising blood pressure management in PMF.