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Power Doppler ultrasonography is used to measure blood flow within a given muscle, otherwise known as intramuscular blood flow. However, it is not fully understood how intramuscular blood flow and muscle oxygenation change with repetitive muscle contraction. The present study was conducted to assess changes in intramuscular blood flow and muscle oxygenation of the vastus lateralis (VL) during intermittent and incremental contractions. Fifteen healthy male subjects (21.7 ± 2.6 years) performed intermittent (5 s contraction, 5 s relaxation) and incremental isometric knee extensions at 30%, 40%, 50%, 60% and 70% of maximal voluntary contraction (MVC) until task failure. Intramuscular blood flow and muscle oxygen saturation (StO2${{S}_{{\mathrm{t}}{{{\mathrm{O}}}_2}}}$) were simultaneously measured using power Doppler ultrasonography and near‐infrared spectroscopy, respectively, from the right VL of the mid‐thigh. Intramuscular blood flow was increased from 0.5 ± 0.5% at rest to 13.9 ± 9.5% at task failure. Intramuscular blood flow significantly increased from rest to 30% and 40% MVC (P = 0.001), and StO2${{S}_{{\mathrm{t}}{{{\mathrm{O}}}_2}}}$ significantly decreased from 30% to 70% MVC (P = 0.004). These results indicate that intramuscular blood flow and StO2${{S}_{{\mathrm{t}}{{{\mathrm{O}}}_2}}}$ show different patterns of change, suggesting that the contribution of intramuscular blood flow to oxygen supply decreases within the VL at moderate and higher exercise intensities. What is the central question of this study?How do intramuscular blood flow and muscle oxygenation change with intermittent and incremental muscle contractions?What is the main finding and its importance?Intramuscular blood flow reached a plateau above moderate exercise intensities, but muscle oxygen saturation continued to decrease. These results indicate that the contribution of intramuscular blood flow to oxygen supply varies with exercise intensity. [ABSTRACT FROM AUTHOR]

Cerebral glucose and oxygen metabolism and blood perfusion play key roles in neuroenergetics and oxidative phosphorylation to produce adenosine triphosphate (ATP) energy molecules in supporting cellular activity and brain function. Their impairments have been linked to numerous brain disorders. This study aimed to develop an in vivo magnetic resonance spectroscopy (MRS) method capable of simultaneously assessing and quantifying the major cerebral metabolic rates of glucose (CMRGlc) and oxygen (CMRO2) consumption, lactate formation (CMRLac), and tricarboxylic acid (TCA) cycle (VTCA); cerebral blood flow (CBF); and oxygen extraction fraction (OEF) via a single dynamic MRS measurement using an interleaved deuterium (2H) and oxygen‐17 (17O) MRS approach. We introduced a single‐loop multifrequency radio‐frequency (RF) surface coil that can be used to acquire proton (1H) magnetic resonance imaging (MRI) or interleaved low‐γ X‐nuclei 2H and 17O MRS. By combining this RF coil with a modified MRS pulse sequence, 17O‐isotope‐labeled oxygen gas inhalation, and intravenous 2H‐isotope‐labeled glucose administration, we demonstrate for the first time the feasibility of simultaneously and quantitatively measuring six important physiological parameters, CMRGlc, CMRO2, CMRLac, VTCA, CBF, and OEF, in rat brains at 16.4 T. The interleaved 2H–17O MRS technique should be readily adapted to image and study cerebral energy metabolism and perfusion in healthy and diseased brains. [ABSTRACT FROM AUTHOR]

Spin‐lock (SL) pulses have been proposed to directly detect neuronal activity otherwise inaccessible through standard functional magnetic resonance imaging. However, the practical limits of this technique remain unexplored. Key challenges in SL‐based detection include ultra‐weak signal variations, sensitivity to magnetic field inhomogeneities, and potential contamination from blood oxygen level‐dependent effects, all of which hinder the reliable isolation of neuronal signals. This pilot study evaluates the performance of the stimulus‐induced rotary saturation (SIRS) technique to map visual stimulation response in the human cortex. A rotary echo spin‐lock (RESL) preparation followed by a 2D echo planar imaging readout was used to investigate 12 healthy subjects at rest and during continuous exposure to 8 Hz flickering light. The SL amplitude was fixed to the target neuroelectric oscillations at that frequency. The signal variance was used as contrast metric, and two alternative post‐processing pipelines (regression‐filtering‐rectification and normalized subtraction) were statistically evaluated. Higher variance in the SL signal was detected in four of the 12 subjects. Although group‐level analysis indicated activation in the occipital pole, analysis of variance revealed that this difference was not statistically significant, highlighting the need for comparable control measures and more robust preparations. Further optimization in sensitivity and robustness is required to noninvasively detect physiological neuroelectric activity in the human brain. [ABSTRACT FROM AUTHOR]

The recent advances in flexible and wearable electronics, along with ubiquitous biosensing technologies have enabled the continuous monitoring of health conditions outside of medical facilities. Health‐monitoring tools based on wearable sensors must be more user‐friendly, informative, and cost‐effective for daily applications owing to the increased prevalence of chronic diseases and mental illnesses. In this study, a flexible and multifunctional skin patch and a custom‐designed application for wirelessly monitoring the wearer's physical and mental health conditions are proposed. The optimized design and soft‐covering materials of the skin patch enable long‐term attachment to the body without causing discomfort or irritation to the wearer. Onboard processing of the signals enables real‐time monitoring and signal acquisition of multiple biomarkers, including the blood oxygen saturation level (SpO2), pulse rate (PR), pulse rate variability (PRV), perfusion index (PI), body movement, and temperature during daily activities. The photoplethysmography (PPG)‐based biomarkers acquired from various body sites are compared and calibrated to verify its performance. Demonstrated pilot trial shows the potential application of the skin patch for clinical decision support in psychiatric assessments that can be implemented as an assistive mental illness monitoring system for psychiatrists and researchers. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Preclinical and clinical studies have demonstrated the advantages of oxygenated hypothermic machine perfusion (HMPO2) during kidney preservation. However, the optimal oxygenation levels during HMPO2 remain undetermined. The aim of this study was to compare different levels of oxygenation (0%, 21%, 50%, and 100%) during 22 h of active oxygenated HMP (HMPO2) using oxygen preloading by bubbling oxygenation in the preservation solution and continuous surface oxygenation during MP in a porcine DCD model.After 60 min of warm ischemia time, both kidneys of an 80 kg pig were procured and randomized to one of the following groups: (1) 22‐h static cold storage (n = 6), (2) 22‐h HMP without active oxygenation (n = 6), (3) 22‐h HMPO2 21% O2 (n = 6), (4) 22‐h HMPO2 50% O2 (n = 6), and (5) 22‐h HMPO2 100% O2 (n = 6). The primary outcome measure was to compare the different oxygen levels among the different groups assessed by cortex kidney tissue oxygen partial pressures (tpO2).Continuous HMPO2 resulted in a significant modification of cortex kidney tpO2. In addition, tpO2 was dependent on the percentage of oxygenation. One hundred percent oxygen resulted in a significantly higher tpO2 compared to all other study groups. In line with that, ATP resynthesis was significantly higher in the HMPO2 100% group.This study demonstrates that continuous HMPO2 results in a significant modification of tpO2 compared with SCS, and the degree of tpO2 is positively correlated with the percentage of active oxygenation during HMP. Metabolic profile analyses (ATP resynthesis) suggest that the aerobic mechanism is better supported with higher oxygen levels (50% and 100% oxygenation). [ABSTRACT FROM AUTHOR]

Liver ischemia‐reperfusion (I/R) injury is a common cause of organ failure, developed by a sudden block in the blood and oxygen supply and subsequent restoration. I/R damage is responsible for acute and chronic rejection after organ transplantation, accounting for 10% of early graft failure. The study investigated the therapeutic properties of fangchinoline in liver injury‐induced rats. The rats were divided into three groups: Sham, I/R without pretreatment, and I/R + 10 mg/kg fangchinoline pretreatment. Blood and liver samples were collected for assays, and an in silico docking analysis was conducted to determine fangchinoline's inhibitory effect. The pretreatment with 10 mg/kg of fangchinoline effectively reduced hepatic marker enzymes such as AST, LDH, and ALT in the serum of rats with liver I/R damage. Fangchinoline treatment significantly reduced interleukin‐8 (IL‐8), IL‐6, and tumor necrosis factor‐α (TNF‐α) in I/R‐induced rats, boosting antioxidants and decreasing MDA. Histopathological studies showed liver injury protection, and fangchinoline inhibited TNF‐α and IL‐6 with improved binding affinity. Fangchinoline has hepatoprotective properties by reducing inflammation in rats with liver I/R damage, as demonstrated in the current study. Hence, it can be an effective salutary agent in preventing liver damage caused by I/R. [ABSTRACT FROM AUTHOR]

Acute mountain sickness (AMS) causes serious illness for many individuals ascending to high altitude (HA), although preventable with appropriate acclimatisation. AMS is a clinical diagnosis, with symptom severity evaluated using the Lake Louise Score (LLS). Reliable methods of predicting which individuals will develop AMS have not been developed. This systematic review evaluates whether a predictive relationship exists between oxygen saturation and subsequent development of AMS. PubMed, PubMed Central, MEDLINE, Semantic Scholar, Cochrane Library, University of Birmingham Library and clinicaltrials.gov databases were systematically searched from inception to 15 June 2023. Human studies involving collection of peripheral blood oxygen saturation (SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$) from healthy lowlanders during ascent to HA that evaluated any relationship between SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ and AMS severity were considered for eligibility. Risk of bias was assessed using a modified Newcastle–Ottawa Tool for cohort studies (PROPSPERO CRD42023423542). Seven of 980 total identified studies were ultimately included for data extraction. These studies evaluated SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ and AMS (via LLS) in 1406 individuals during ascent to HA (3952–6300 m). Risk of bias was 'low' for six and 'moderate' for one of the included studies. Ascent profiles and SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ measurement methodology varied widely, as did the statistical methods for AMS prediction. Decreasing oxygen saturation measured with pulse oximetry during ascent shows a positive predictive relationship for individuals who develop AMS. Studies have high heterogeneity in ascent profile and oximetry measurement protocols. Further studies with homogeneous methodology are required to enable statistical analysis for more definitive evaluation of AMS predictability by pulse oximetry. What is the central question of this study?Is there a predictive relationship between oxygen saturation and subsequent development of AMS?What is the main finding and its importance?A systematic review of the literature revealed there is a positive predictive trend between pulse oximetry measurements obtained around 3500 m during ascent and the development of acute mountain sickness at higher camps; however, further research is required to develop more robust prediction models. [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: 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]

Blood oxygen level‐dependent functional magnetic resonance imaging (BOLD fMRI) arises from a physiological and physical cascade of events taking place at the level of the cortical microvasculature which constitutes a medium with complex geometry. Several analytical models of the BOLD contrast have been developed, but these have not been compared directly against detailed bottom‐up modeling methods. Using a 3D modeling method based on experimentally measured images of mice microvasculature and Monte Carlo simulations, we quantified the accuracy of two analytical models to predict the amplitude of the BOLD response from 1.5 to 7 T, for different echo time (TE) and for both gradient echo and spin echo acquisition protocols. We also showed that accounting for the tridimensional structure of the microvasculature results in more accurate prediction of the BOLD amplitude, even if the values for SO2 were averaged across individual vascular compartments. A secondary finding is that modeling the venous compartment as two individual compartments results in more accurate prediction of the BOLD amplitude compared with standard homogenous venous modeling, arising from the bimodal distribution of venous SO2 across the microvasculature in our data. [ABSTRACT FROM AUTHOR]

Enhanced continental phosphorus (P) input into the oceans has been proposed as a potential trigger for the 1.57 Ga oxygenation event; however, uncertainty remains due to the absence of direct evidence for seawater P concentrations. Here, we investigate shallow marine carbonate rocks of the Gaoyuzhuang Formation in the North China Platform, using the carbonate‐associated phosphate (CAP) proxy to directly reconstruct seawater P levels at that time. Two significant CAP/(Ca + Mg) increases correspond with rises in I/(Ca + Mg) during the oxygenation event suggesting that elevated seawater P concentrations were important in triggering the oxygenation event. Furthermore, a concurrent positive shift in εNd(t) values from −12.3 to −0.9 suggests that a transition in weathering source rocks from intermediate to mafic lithologies significantly contributed to the elevated P fluxes to the oceans during the oxygenation event. This study provides new insights into assessing seawater P levels and their role in the mid‐Proterozoic oxygenation events. Plain Language Summary: Phosphorus (P), as a bio‐limiting nutrient for marine organisms, influences primary productivity, organic carbon burial, and therefore the redox conditions of the atmosphere‐ocean system on geological timescales. Previous studies have linked the transient oxygenation event at ∼1.57 Ga to an increase in oceanic P concentrations. However, uncertainty persists due to a lack of direct evidence for seawater P concentrations. Here, we investigate shallow marine carbonate rocks of the Gaoyuzhuang Formation in the North China Platform, using the carbonate‐associated phosphate (CAP) proxy to reconstruct seawater P levels at that time. The results revealed two significant increases in seawater P concentrations contemporaneously with evidence for increasing dissolved oxygen levels during the oxygenation event, suggesting that elevated seawater P concentrations may have played a crucial role in triggering this oxygenation event. Furthermore, a transition in weathering source rocks—from intermediate with relatively low P content to mafic with relatively high P content—has been identified, which likely contributed significantly to the elevated P levels during the oxygenation event. This study provides new insights into the assessment of seawater P levels and their significance during the mid‐Proterozoic oxygenation events. Key Points: Carbonate‐associated phosphate (CAP) is used to track seawater phosphorus (P) levels during the 1.57 Ga oxygenation eventTwo significant CAP increases corresponding with rises in I/(Ca + Mg) implicating P as a driver of rising O2 levelsA positive shift in εNd(t) shows enhanced P influx into seawater from the weathering of intermediate to mafic source rocks [ABSTRACT FROM AUTHOR]

Summary Introduction Methods Results Discussion High‐flow nasal oxygenation has been shown to improve oxygenation during induction of anaesthesia in parturients who are not obese. However, data on the efficacy of high‐flow nasal oxygen in parturients living with obesity are lacking. This study investigated the effects of high‐flow nasal oxygenation on pre‐oxygenation and apnoea oxygenation during tracheal intubation in parturients living with obesity.This prospective, randomised clinical trial was conducted at two tertiary hospitals and included parturients with BMI > 30 kg.m‐2 undergoing scheduled caesarean delivery under general anaesthesia. Parturients were allocated randomly to standard facemask or high‐flow nasal oxygen groups (oxygen flow rates 10 l.min‐1 and 50 l.min‐1, respectively). The primary outcome measure was arterial partial pressure of oxygen after 3 min of pre‐oxygenation.54 patients completed the study. The arterial partial pressure of oxygen after 3 min of pre‐oxygenation was significantly lower in parturients allocated to the standard facemask group compared with those allocated to the high‐flow nasal oxygen group (mean (SD) 40.1 (8.9) kPa vs. 53.8 (9.7) kPa, p < 0.001). End‐tidal oxygen concentration on commencing ventilation was also lower in parturients allocated to the standard facemask group compared with those allocated to the high flow‐nasal oxygen group (mean (SD) 78.3 (5.38)% vs. 86.2 (5.10)%, p < 0.001). The arterial partial pressure of carbon dioxide post tracheal intubation and fetal outcomes were similar in both groups.Pre‐oxygenation using high‐flow nasal oxygenation provided a higher arterial partial pressure of oxygen and end‐tidal oxygen concentration during general anaesthesia induction than standard facemask oxygenation in parturients living with obesity; however, the differences were not clinically meaningful. High‐flow nasal oxygenation may be considered as an alternative option for pre‐oxygenation during rapid sequence induction in parturients living with obesity. [ABSTRACT FROM AUTHOR]

Recent discoveries have identified intrapulmonary bronchopulmonary anastomoses (IBAs) as a relatively common phenomenon forming intrapulmonary right‐to‐left shunts. This study hypothesizes that IBAs play a significant role in the pathophysiology of heart failure. We aim to investigate the impact of these intrapulmonary right‐to‐left shunts on pulmonary arterial and venous pressures in heart failure patients, utilizing mixed venous oxygen saturation (SvO₂) as a key measurement. This study included 237 patients with heart failure who underwent cardiac catheterization. The relationships between SvO₂ and pulmonary artery systolic pressure (sPAP), pulmonary artery wedge pressure (PAWP), and left ventricular end‐diastolic pressure (LVEDP) were examined using various statistical methods (single regression analysis, partial correlation analysis, structural equation modeling, and Bayesian estimation). All statistical methods that we performed showed that SvO₂ was significantly and negatively correlated with both sPAP and PAWP (p < 0.01, respectively). However, SvO₂ did not significantly correlate with LVEDP. These results suggest that a decrease in SvO₂ leads to an increase in PAWP and sPAP, while LVEDP is only passively influenced by PAWP. This phenomenon likely reflects the impact of an intrapulmonary right‐to‐left shunt caused by IBAs. The decrease in SvO₂ causes an increase in sPAP and may also cause an increase in PAWP via IBAs. [ABSTRACT FROM AUTHOR]

ABSTRACT Health data generated by apps and devices are increasingly popular and expected to affect various aspects of doctor‐patient relationships. No longer confined to medically authorised and certified health technologies, a range of biomedical data—from heart rate to blood pressure or oxygen saturation—are captured and processed by consumer health devices. This article outlines different responses of physicians to patients collecting data with popular consumer devices and considers how the data may challenge or reify medical authority. Based on semi‐structured interviews with doctors and chronically ill patients in Germany from 2021 to 2023, we compare cases from diabetes, sleep disorders, cardiovascular conditions, obesity and ME/CFS and explore when, how and for what reasons different medical specialists consider patient‐generated data (PGD) from consumer devices in outpatient settings. Their response registers vary: whereas some physicians reject PGD that seem to compete with their diagnostic activities, others tolerate the data (collection), whereas still others more readily include them into their diagnostic practices. This suggests nuanced strategies for navigating the demarcation between accepting or rejecting ‘uninvited’ participation through PGD from consumer apps and devices. [ABSTRACT FROM AUTHOR]

Objectives Methods Results Conclusion Propofol is commonly used for endoscopic sedation. However, it can induce adverse hemodynamic effects. Remimazolam is known to have a fast onset and short duration comparable to that of propofol, but with fewer effects on hemodynamics. We assessed the Oxygen Reserve Index to verify whether a sedative dose of remimazolam would better preserve oxygenation in the mild hyperoxic range than propofol in sedated patients undergoing diagnostic upper gastrointestinal endoscopy.Patients scheduled for diagnostic upper gastrointestinal endoscopy were enrolled. Patients were randomly assigned to either the remimazolam or propofol groups and received 0.1 mg/kg remimazolam or 0.5 mg/kg propofol, respectively. Bolus injections of either 0.05 mg/kg remimazolam or 0.25 mg/kg propofol were added if required. The primary outcome was the prevalence of oxygen reserve depletion, defined as the Oxygen Reserve Index decreasing to 0.00, and hypoxia defined as peripheral oxygen saturation falling to <94%.Among 69 patients, the incidence of oxygen reserve depletion was significantly higher in the propofol group (65.7% vs. 38.2%, P = 0.022). Hypoxia was frequently observed in the propofol group, whereas none was observed in the remimazolam group (11.4% vs. 0%, P = 0.042). Additional sedative injections were frequently required to complete endoscopy in the propofol group. None of the patients in the remimazolam group required airway interventions. Nausea was frequent in the propofol group in the recovery room.Our results indicate that remimazolam is a safe and useful sedative for upper gastrointestinal endoscopy. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of mini‐pulse methylprednisolone in the treatment of patients with COVID‐19 hospitalized in the intensive care units (ICU). Methods: This is a single‐blind parallel non‐randomized clinical trial that will be carried out on 60 hospitalized COVID‐19 patients and conducted between February 2020 and December 2020 in Ardabil City Hospital, Ardabil, Iran. The t‐test and chi‐square test were used to compare the results of the two groups. A p‐value of less than 0.05 was considered statistically significant. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 26 software. Results: The mean (±SD) age of patients was 57.53 ± 13.71 years. Thirty‐five patients (58.3%) were male and 25 (14.7%) were female. Twenty‐eight patients had fever. During admission, the mean (±SD) of the oxygen saturation was 80.73 ± 8.31. No significant relationship was observed between the study variables in the two groups at baseline. Conclusion: The results of the present study showed that in patients treated with methylprednisolone, blood oxygen saturation increased and heart rate and breathing rate decreased significantly. Also, mini‐pulse treatment with methylprednisolone significantly reduced the number of days of hospitalization and the incidence of mortality. [ABSTRACT FROM AUTHOR]

Background: Serum creatinine (Scr) may be not suited to timely and accurately reflect kidney injury related to chronic liver disease. Currently, the ability of arterial spin labeling (ASL) and blood oxygen level‐dependent (BOLD) sequences to evaluate renal blood flow (RBF) and blood oxygen in chronic liver disease remains to be verified. Purpose: To investigate the value of ASL and BOLD imaging in evaluating hemodynamics and oxygenation changes during kidney injury in an animal model of chronic liver disease. Study Type: Prospective. Animal Model: Chronic liver disease model was established by subcutaneous injection of carbon tetrachloride. Forty‐three male Sprague–Dawley rats (8 weeks) were divided into a pathological group (0, 2, 4, 6, 8, 12 weeks, each group: N = 6) and a continuous‐scanning group (N = 7). Field Strength/Sequence: 3‐T, ASL, BOLD, and T2W. Assessment: Regions of interest in the cortex (CO), outer stripe of the outer medulla (OSOM), and inner stripe of the outer medulla (ISOM) are manually delineated. The RBF and T2* values at each time point (0, 2, 4, 6, 8, 12 weeks) are measured and compared. Hematoxylin–eosin score (HE Score, damage area scoring method), alpha‐smooth muscle actin (α‐SMA), hypoxia‐inducible factor‐1alpha (HIF‐1α), peritubular capillar (PTC) density, Scr, and neutrophil gelatinase‐associated lipocalin were harvested. Statistical Tests: Analysis of variance, Spearman correlation analysis, Kruskal–Wallis tests, and receiver operating characteristic analysis with the area under the curve (AUC). A P‐value <0.05 was considered statistically significant. Results: Renal RBF and T2* values of CO, OSOM, and ISOM were significantly different from baseline. Both RBF and T2* were significantly correlated with HE Score, α‐SMA, HIF‐1α, and PTC density (|r| = 0.406–0.853). RBF demonstrated superior diagnostic capability in identifying severe kidney injury in this model of chronic liver disease (AUC = 0.964). Data Conclusion: Imaging by ASL and BOLD may detect renal hemodynamics and oxygenation changes related to chronic liver disease early. Evidence Level: 5 Technical Efficacy: Stage 2 [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]

Since the milestone contribution by Chen and White in 2007, bioinspired non‐heme bis‐amino‐bis‐pyridylmethyl Fe complexes have been at the forefront of studies related to designing catalytic approaches for direct oxidative functionalization of aliphatic C−H bonds. This, however, has not developed into large‐scale synthetic applications to date. The present concept is aimed at briefly discussing the state‐of‐the‐art of non‐heme Fe catalyzed oxidations of organic molecules with H2O2, the current oxidant of choice of bioinspired oxidation catalysis, mostly focusing on C−H oxidations, and analyzing the peculiarities of their reactivity through the prism of potential applications in fine organic synthesis. [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]

Reported herein is the first total synthesis of the poly‐pseudoindoxyl natural product baphicacanthcusine A. The synthesis leverages the oxidative rearrangement of indoles to pseudoindoxyls to install vicinal pseudoindoxyl heterocycles in a diastereoselective manner. Key steps include an acid‐mediated cyclization/indole transposition, two diastereoselective oxidative ring contractions, and a site‐selective C−H oxygenation. The synthesis of the oxidation precursors was guided by recognition of an element of hidden symmetry. This work provides a foundation for the chemical synthesis of other poly‐pseudoindoxyl alkaloids. [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]

Key Clinical Message: Early and timely closure of secondary tracheoesophageal fistula (TEF) is crucial for critically ill patients. For those requiring invasive mechanical ventilation, the Amplatzer Duct Occluder II (ADO II) can be used as an emergency therapeutic option to rapidly close secondary TEF, providing opportunities for subsequent treatments. Secondary tracheoesophageal fistula (TEF) is a life‐threatening condition characterized by high mortality, high recurrence rates, and multiple complications. Reports on the management of secondary TEF in critically ill patients are limited due to the challenges in treatment and the lack of suitable therapeutic options. We report a case of secondary TEF in a 69‐year‐old male diagnosed with severe pneumonia, whose condition deteriorated rapidly following the onset of TEF. Despite invasive mechanical ventilation, maintaining blood oxygen saturation above 80% was unachievable due to the TEF. Bedside bronchoscopy revealed expansion TEF expansion caused by gastrointestinal fluid reflux and respiratory machine pressure. The TEF was urgently closed using an ADO II device during invasive mechanical ventilation to prevent further deterioration. After the patient's condition stabilized, the ADO II was replaced with a Y‐shaped tracheal membrane‐covered stent for further TEF management. The patient's condition improved, meeting the criteria for liberation from invasive mechanical ventilation, and bedside chest X‐rays revealed a gradual resolution of pulmonary inflammation. Selecting appropriate treatment modalities for early and timely closure of secondary TEF is crucial for critically ill patients. ADO II can serve as a rescue therapy to achieve rapid closure of secondary TEF in critically ill patients requiring invasive mechanical ventilation support, providing opportunities and time for subsequent treatment. [ABSTRACT FROM AUTHOR]

Functional magnetic resonance imaging (fMRI) is currently one of the most popular technologies for measuring brain activity in both research and clinical contexts. However, clinical constraints often result in short fMRI scan durations, limiting the diagnostic performance for brain disorders. To address this limitation, we developed an end‐to‐end frequency‐specific dual‐attention‐based adversarial network (FDAA‐Net) to extend the time series of existing blood oxygen level‐dependent (BOLD) data, enhancing their diagnostic utility. Our approach leverages the frequency‐dependent nature of fMRI signals using variational mode decomposition (VMD), which adaptively tracks brain activity across different frequency bands. We integrated the generative adversarial network (GAN) with a spatial–temporal attention mechanism to fully capture relationships among spatially distributed brain regions and temporally continuous time windows. We also introduced a novel loss function to estimate the upward and downward trends of each frequency component. We validated FDAA‐Net on the Human Connectome Project (HCP) database by comparing the original and predicted time series of brain regions in the default mode network (DMN), a key network activated during rest. FDAA‐Net effectively overcame linear frequency‐specific challenges and outperformed other popular prediction models. Test–retest reliability experiments demonstrated high consistency between the functional connectivity of predicted outcomes and targets. Furthermore, we examined the clinical applicability of FDAA‐Net using short‐term fMRI data from individuals with autism spectrum disorder (ASD) and major depressive disorder (MDD). The model achieved a maximum predicted sequence length of 40% of the original scan durations. The prolonged time series improved diagnostic performance by 8.0% for ASD and 11.3% for MDD compared with the original sequences. These findings highlight the potential of fMRI time series prediction to enhance diagnostic power of brain disorders in short fMRI scans. [ABSTRACT FROM AUTHOR]

Exogenous ketone supplements are a potential augmentation strategy for cognitive resilience during acute hypoxic exposure due to their capacity to attenuate the decline in oxygen (O2) availability, and by providing an alternative substrate for cerebral metabolism. Utilizing a single‐blind randomized crossover design, 16 male military personnel (age, 25.3 ± 2.4 year, body mass, 86.2 ± 9.3 kg) performed tests of cognitive performance at rest in three environments: room air (baseline), normoxia (20 min; 0 m; 20.9% O2) and hypoxia (20 min; 6096 m, 9.7% O2) using a reduced O2 breathing device (ROBD). (R)‐3‐Hydroxybutyl (R)‐3‐hydroxybutyrate (R‐BD R‐βHB) ketone monoester (KME; 650 mg/kg, split dose given at 30 min prior to each exposure) or taste‐matched placebo (PLA) was ingested prior to normoxia and hypoxic exposure. Blood R‐βHB and glucose concentrations, cognitive performance and O2 saturation (SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$) were collected throughout. KME ingestion increased blood R‐βHB concentration, which was rapid and sustained (>4 mM 30 min post; P < 0.001) and accompanied by lower blood glucose concentration (∼20 mg/dL; P < 0.01) compared to PLA. Declines in cognitive performance during hypoxic exposure, assessed as cognitive efficiency during a Defense Automated Neurobehavioral Assessment (DANA) code substitution task, were attenuated with KME leading to 6.8 (95% CL: 1.0, 12.6) more correct responses per minute compared to PLA (P = 0.018). The decline in SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$ during hypoxic exposure was attenuated (6.40% SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$; 95% CL: 0.04, 12.75; P = 0.049) in KME compared to PLA (KME, 76.8 ± 6.4% SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$; PLA, 70.4 ± 7.4% SpO2${{S}_{{\mathrm{p}}{{{\mathrm{O}}}_{\mathrm{2}}}}}$). Acute ingestion of KME attenuated the decline in cognitive performance during acute severe hypoxic exposure, which coincided with attenuation of declines in O2 saturation. What is the central question of this study?Can exogenous ketosis act as a countermeasure to declines in blood oxygen saturation and cognitive performance during acute severe hypoxic exposure at rest?What is the main finding and its importance?Acute exogenous ketosis via ingestion of a drink containing the (R)‐3‐hydroxybutyl (R)‐3‐hydroxybutyrate ketone monoester prior to acute severe hypoxic exposure attenuated hypoxia‐induced declines in blood oxygen saturation and cognitive performance at rest. [ABSTRACT FROM AUTHOR]

Acute ingestion of exogenous ketone supplements in the form of a (R)‐3‐hydroxybutyl (R)‐3‐hydroxybutyrate (R‐BD R‐βHB) ketone monoester (KME) can attenuate declines in oxygen availability during hypoxic exposure and might impact cognitive performance at rest and in response to moderate‐intensity exercise. In a single‐blind randomized crossover design, 16 males performed assessments of cognitive performance before and during hypoxic exposure with moderate exercise [2 × 20 min weighted ruck (∼22 kg) at 3.2 km/h at 10% incline] in a normobaric altitude chamber (4572 m, 11.8% O2). The R‐BD R‐βHB KME (573 mg/kg) or a calorie‐ and taste‐matched placebo (∼50 g maltodextrin) were co‐ingested with 40 g of dextrose before exposure to hypoxia. The R‐βHB concentrations were rapidly elevated and sustained (>3 mM; P < 0.001) by KME. The decline in oxygen saturation during hypoxic exposure was attenuated in KME conditions by 2.4%–4.2% (P < 0.05) compared with placebo. Outcomes of cognitive performance tasks, in the form of the Defense Automated Neurobehavioral Assessment (DANA) code substitution task, the Stroop color and word task, and a shooting simulation, did not differ between trials before and during hypoxic exposure. These data suggest that the acute exogenous ketosis induced by KME ingestion can attenuate declining blood oxygen saturation during acute hypoxic exposure both at rest and during moderate‐intensity exercise, but this did not translate into differences in cognitive performance before or after exercise in the conditions investigated. What is the central question of this study?Can exogenous ketosis act as a countermeasure to declines in blood oxygen saturation and cognitive performance during acute hypoxic exposure while performing a weighted ruck exercise?What is the main finding and its importance?Acute exogenous ketosis via ingestion of a drink containing the (R)‐3‐hydroxybutyl (R)‐3‐hydroxybutyrate ketone monoester prior to acute hypoxic exposure attenuated hypoxia‐induced declines in blood oxygen saturation but had no effect on cognitive performance during exercise. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this work is to apply multi‐echo spin‐ and gradient‐echo (SAGE) echo‐planar imaging (EPI) combined with a navigator‐based (NAV) prospective motion compensation method for a quantitative liver blood oxygen level dependent (BOLD) measurement with a breath‐hold (BH) task. Methods: A five‐echo SAGE sequence was developed to quantitatively measure T2 and T2* to depict function with sufficient signal‐to‐noise ratio, spatial resolution and sensitivity to BOLD changes induced by the BH task. To account for respiratory motion, a navigator was employed in the form of a single gradient‐echo projection readout, located at the diaphragm along the inferior–superior direction. Prior to each transverse imaging slice of the spin‐echo EPI‐based readouts, navigator acquisition and fat suppression were incorporated. Motion data was obtained from the navigator and transmitted back to the sequence, allowing real‐time adjustments to slice positioning. Six healthy volunteers and three patients with liver carcinoma were included in this study. Quantitative T2 and T2* were calculated at each time point of the BH task. Parameters of t value from first‐level analysis using a general linear model and hepatovascular reactivity (HVR) of Echo1, T2 and T2* were calculated. Results: The motion caused by respiratory activity was successfully compensated using the navigator signal. The average changes of T2 and T2* during breath‐hold were about 1% and 0.7%, respectively. With the help of NAV prospective motion compensation whole liver t values could be obtained without motion artifacts. The quantified liver T2 (34.7 ± 0.7 ms) and T2* (29 ± 1.2 ms) values agreed with values from literature. In healthy volunteers, the distribution of statistical t value and HVR was homogeneous throughout the whole liver. In patients with liver carcinoma, the distribution of t value and HVR was inhomogeneous due to metastases or therapy. Conclusions: This study demonstrates the feasibility of using a NAV prospective motion compensation technique in conjunction with five‐echo SAGE EPI for the quantitative measurement of liver BOLD with a BH task. [ABSTRACT FROM AUTHOR]

Arterial spin labelling (ASL) is the only non‐invasive technique that allows absolute quantification of perfusion and is increasingly used in brain activation studies. Contrary to the blood oxygen level‐dependent (BOLD) effect ASL measures the cerebral blood flow (CBF) directly. However, the ASL signal has a lower signal‐to‐noise ratio (SNR), than the BOLD signal, which constrains its utilization in neurofeedback studies. If successful, ASL neurofeedback can be used to aid in the rehabilitation of health conditions with impaired blood flow, for example, stroke. We provide the first ASL‐based neurofeedback study incorporating a double‐blind, sham‐controlled design. A pseudo‐continuous ASL (pCASL) approach with background suppression and 3D GRASE readout was combined with a real‐time post‐processing pipeline. The real‐time pipeline allows to monitor the ASL signal and provides real‐time feedback on the neural activity to the subject. In total 41 healthy adults (19–56 years) divided into three groups underwent a neurofeedback‐based emotion imagery training of the left anterior insula. Two groups differing only in the explicitness level of instruction received real training and a third group received sham feedback. Only those participants receiving real feedback with explicit instruction showed significantly higher absolute CBF values in the trained region during neurofeedback than participants receiving sham feedback. However, responder analyses of percent signal change values show no differences in activation between the three groups. Persisting limitations, such as the lower SNR, confounding effects of arterial transit time and partial volume effects still impact negatively the implementation of ASL neurofeedback. [ABSTRACT FROM AUTHOR]

Sulfur‐doped Eosin‐B (SDE‐B) photocatalysts were synthesized for the first time utilizing sublimed sulfur (S8) as a dopant in an in situ thermal copolymerization technique. Sulfur doping not only increased Eosin‐B (E‐B) absorption range for solar radiation but also improved fixation and oxygenation capabilities. The doped sulfur bridges the S‐S bond by substituting for the edge bromine of the E‐B bond. The improved photocatalytic activity of SDE‐B in the fixation and oxygenation of NAD+/NADP+ and sulfides using solar light is attributed to the photo‐induced hole of SDE‐B's high fixation and oxygenation capacity, as well as an efficient suppression of electron and hole recombination. The powerful light‐harvesting bridge system created using SDE‐B as a photocatalyst works extremely well, resulting in high NADH/NADPH regeneration (79.58/76.36%) and good sulfoxide yields (98.9%) under solar light. This study focuses on the creation and implementation of a sulfur‐doped photocatalyst for direct fine chemical regeneration and organic transformation. [ABSTRACT FROM AUTHOR]

Objectives: Hypoperfusion and tissue hypoxia have been implicated as contributory mechanisms in the neuropathology of multiple sclerosis (MS). Our objective has been to study cortical oxygenation in vivo in patients with MS and age‐matched controls. Methods: A custom, multiwavelength time‐domain near‐infrared spectroscopy system was developed for assessing tissue hypoxia from the prefrontal cortex. A cross‐sectional case–control study was undertaken assessing patients with secondary progressive MS (SPMS) and age‐matched controls. Co‐registered magnetic resonance imaging was used to verify the location from which near‐infrared spectroscopy data were obtained through Monte Carlo simulations of photon propagation. Additional clinical assessments of MS disease severity were carried out by trained neurologists. Linear mixed effect models were used to compare cortical oxygenation between cases and controls, and against measures of MS severity. Results: Thirty‐three patients with secondary progressive MS (median expanded disability status scale 6 [IQR: 5–6.5]; median age 53.0 [IQR: 49–58]) and 20 age‐matched controls were recruited. Modeling of photon propagation confirmed spectroscopy data were obtained from the prefrontal cortex. Patients with SPMS had significantly lower cortical hemoglobin oxygenation compared with controls (−6.0% [95% CI: −10.0 to −1.9], P = 0.004). There were no significant associations between cortical oxygenation and MS severity. Interpretation: Using an advanced, multiwavelength time‐domain near‐infrared spectroscopy system, we demonstrate that patients with SPMS have lower cortical oxygenation compared with controls. [ABSTRACT FROM AUTHOR]

As the demand for advanced bronchoscopic procedures increases, prolonged sedation with adequate oxygenation has become essential. Traditionally, these procedures require an anesthesiologist to provide (positive‐pressure or jet) ventilator support. However, recent innovations have enabled advanced bronchoscopy under high‐flow endotracheal oxygenation and deep sedation without these requirements. Following oropharyngeal lidocaine anaesthesia, deep sedation was induced using fentanyl and remimazolam. Thereafter lidocaine was instilled into the larynx, trachea, and main bronchi using a flexible bronchoscope with a spray catheter. Finally, either an uncuffed endotracheal tube (Case 1) or a rigid bronchoscope (Case 2) was inserted, and advanced bronchoscopic procedures, such as cryobiopsy and stent insertion, were successfully performed without a ventilator or an anesthesiologist. Our novel technique is expected to facilitate the easier and adequate performance of advanced high‐level bronchoscopic procedures by pulmonologists, even in resource‐limited settings. [ABSTRACT FROM AUTHOR]

Background: Cerebrovascular reactivity (CVR) is a measure of the change in cerebral blood flow (CBF) in response to a vasoactive challenge. It is a useful indicator of the brain's vascular health. Purpose: To evaluate the factors that influence successful and unsuccessful CVR examinations using precise arterial and end‐tidal partial pressure of CO2 control during blood oxygen level–dependent (BOLD) MRI. Study Type: Retrospective. Subjects: Patients that underwent a CVR between October 2005 and May 2021 were studied (total of 1162 CVR examinations). The mean (±SD) age was 46.1 (±18.8) years, and 352 patients (43%) were female. Field Strength/Sequence: 3 T; T1‐weighted images, T2*‐weighed two‐dimensional gradient‐echo sequence with standard echo‐planar readout. Assessment: Measurements were obtained following precise hypercapnic stimuli using BOLD MRI as a surrogate of CBF. Successful CVR examinations were defined as those where: 1) patients were able to complete CVR testing, and 2) a clinically useful CVR map was generated. Unsuccessful examinations were defined as those where patients were not able to complete the CVR examination or the CVR maps were judged to be unreliable due to, for example, excessive head motion, and poor PETCO2 targeting. Statistical Analysis: Successful and unsuccessful CVR examinations between hypercapnic stimuli, and between different patterns of stimulus were compared with Chi‐Square tests. Interobserver variability was determined by using the intraclass correlation coefficient (P < 0.05 is significant). Results: In total 1115 CVR tests in 662 patients were included in the final analysis. The success rate of generating CVR maps was 90.8% (1012 of 1115). Among the different hypercapnic stimuli, those containing a step plus a ramp protocol was the most successful (95.18%). Among the unsuccessful examinations (9.23%), most were patient related (89.3%), the most common of which was difficulty breathing. Data Conclusion: CO2‐BOLD MRI CVR studies are well tolerated with a high success rate. Evidence Level: 4 Technical Efficacy: Stage 3 [ABSTRACT FROM AUTHOR]

The study evaluated the impact of adding new clinical variables to the Sequential Organ Failure Assessment (SOFA) score to improve predictive accuracy for in-hospital mortality. The modified SOFA (mSOFA) score included additional components such as high-flow nasal oxygenation, platelet transfusion, and lactate levels. However, the study found that these additions did not significantly enhance the predictive power of the score due to the high score assignment for new items. The research suggests that adjusting clinical thresholds rather than simply adding new items may lead to more accurate predictions in critical care settings. [Extracted from the article]

Advances in neuroimaging acquisition protocols and denoising techniques, along with increasing magnetic field strengths, have dramatically improved the temporal signal‐to‐noise ratio (tSNR) in functional magnetic resonance imaging (fMRI). This permits spatial resolution with submillimeter voxel sizes and ultrahigh temporal resolution and opens a route toward performing precision fMRI in the brains of individuals. Yet ultrahigh spatial and temporal resolution comes at a cost: it reduces tSNR and, therefore, the sensitivity to the blood oxygen level‐dependent (BOLD) effect and other functional contrasts across the brain. Here we investigate the potential of various smoothing filters to improve BOLD sensitivity while preserving the spatial accuracy of activated clusters in single‐subject analysis. We introduce adaptive‐weight smoothing with optimized metrics (AWSOM), which addresses this challenge extremely well. AWSOM employs a local inference approach that is as sensitive as cluster‐corrected inference of data smoothed with large Gaussian kernels, but it preserves spatial details across multiple tSNR levels. This is essential for examining whole‐brain fMRI data because tSNR varies across the entire brain, depending on the distance of a brain region from the receiver coil, the type of setup, acquisition protocol, preprocessing, and resolution. We found that cluster correction in single subjects results in inflated family‐wise error and false positive rates. AWSOM effectively suppresses false positives while remaining sensitive even to small clusters of activated voxels. Furthermore, it preserves signal integrity, that is, the relative activation strength of significant voxels, making it a valuable asset for a wide range of fMRI applications. Here we demonstrate these features and make AWSOM freely available to the research community for download. [ABSTRACT FROM AUTHOR]

Entropy measures are increasingly being used to analyze the structure of neural activity observed by functional magnetic resonance imaging (fMRI), with resting‐state networks (RSNs) being of interest for their reproducible descriptions of the brain's functional architecture. Temporal correlations have shown a dichotomy among these networks: those that engage with the environment, known as extrinsic, which include the visual and sensorimotor networks; and those associated with executive control and self‐referencing, known as intrinsic, which include the default mode network and the frontoparietal control network. While these inter‐voxel temporal correlations enable the assessment of synchrony among the components of individual networks, entropic measures introduce an intra‐voxel assessment that quantifies signal features encoded within each blood oxygen level‐dependent (BOLD) time series. As a result, this framework offers insights into comprehending the representation and processing of information within fMRI signals. Multiscale entropy (MSE) has been proposed as a useful measure for characterizing the entropy of neural activity across different temporal scales. This measure of temporal entropy in BOLD data is dependent on the length of the time series; thus, high‐quality data with fine‐grained temporal resolution and a sufficient number of time frames is needed to improve entropy precision. We apply MSE to the Midnight Scan Club, a highly sampled and well‐characterized publicly available dataset, to analyze the entropy distribution of RSNs and evaluate its ability to distinguish between different functional networks. Entropy profiles are compared across temporal scales and RSNs. Our results have shown that the spatial distribution of entropy at infra‐slow frequencies (0.005–0.1 Hz) reproduces known parcellations of RSNs. We found a complexity hierarchy between intrinsic and extrinsic RSNs, with intrinsic networks robustly exhibiting higher entropy than extrinsic networks. Finally, we found new evidence that the topography of entropy in the posterior cerebellum exhibits high levels of entropy comparable to that of intrinsic RSNs. [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]

Commencing with the breakdown of the diabetic osteoimmune microenvironment, multiple pathogenic factors, including hyperglycemia, inflammation, hypoxia, and deleterious cytokines, are conjointly involved in the progression of diabetic periodontal bone regeneration. Based on the challenge of periodontal bone regeneration treatment and the absence of real‐time feedback of blood oxygen fluctuation in diabetes mellitus, a novel self‐adaptive hyperthermia supramolecular cascade nano‐reactor ACFDG is constructed via one‐step supramolecular self‐assembly strategy to address multiple factors in diabetic periodontal bone regeneration. Hyperthermia supramolecular ACFDG possesses high photothermal conversion efficiency (32.1%), and it can effectively inhibit the vicious cycle of ROS‐inflammatory cascade through catalytic cascade reactions, up‐regulate the expression of heat shock proteins (HSPs) under near‐infrared (NIR) irradiation, which promotes periodontal bone regeneration. Remarkably, ACFDG can provide real‐time non‐invasive diagnosis of blood oxygen changes during periodontal bone regeneration through photoacoustic (PA) imaging, thus can timely monitor periodontal hypoxia status. In conclusion, this multifunctional supramolecular nano‐reactor combined with PA imaging for real‐time efficacy monitoring provides important insights into the biological mechanisms of diabetic periodontal bone regeneration and potential clinical theranostics. [ABSTRACT FROM AUTHOR]

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

White matter (WM) functional activity has been reliably detected through functional magnetic resonance imaging (fMRI). Previous studies have primarily examined WM bundles as unified entities, thereby obscuring the functional heterogeneity inherent within these bundles. Here, for the first time, we investigate the function of sub‐bundles of a prototypical visual WM tract—the optic radiation (OR). We use the 7T retinotopy dataset from the Human Connectome Project (HCP) to reconstruct OR and further subdivide the OR into sub‐bundles based on the fiber's termination in the primary visual cortex (V1). The population receptive field (pRF) model is then applied to evaluate the retinotopic properties of these sub‐bundles, and the consistency of the pRF properties of sub‐bundles with those of V1 subfields is evaluated. Furthermore, we utilize the HCP working memory dataset to evaluate the activations of the foveal and peripheral OR sub‐bundles, along with LGN and V1 subfields, during 0‐back and 2‐back tasks. We then evaluate differences in 2bk‐0bk contrast between foveal and peripheral sub‐bundles (or subfields), and further examine potential relationships between 2bk‐0bk contrast and 2‐back task d‐prime. The results show that the pRF properties of OR sub‐bundles exhibit standard retinotopic properties and are typically similar to the properties of V1 subfields. Notably, activations during the 2‐back task consistently surpass those under the 0‐back task across foveal and peripheral OR sub‐bundles, as well as LGN and V1 subfields. The foveal V1 displays significantly higher 2bk‐0bk contrast than peripheral V1. The 2‐back task d‐prime shows strong correlations with 2bk‐0bk contrast for foveal and peripheral OR fibers. These findings demonstrate that the blood oxygen level‐dependent (BOLD) signals of OR sub‐bundles encode high‐fidelity visual information, underscoring the feasibility of assessing WM functional activity at the sub‐bundle level. Additionally, the study highlights the role of OR in the top‐down processes of visual working memory beyond the bottom‐up processes for visual information transmission. Conclusively, this study innovatively proposes a novel paradigm for analyzing WM fiber tracts at the individual sub‐bundle level and expands understanding of OR function. [ABSTRACT FROM AUTHOR]

Aim: Surgery for congenital scoliosis correction in children is often associated with considerable blood loss. Decrease in regional oxygen saturation (rScO2) can reflect insufficient cerebral perfusion and predict neurological complications. This retrospective observational study explored the relationship between blood loss during this surgery and a decrease in rScO2 in children. Methods: The following clinical data of children aged 3–14 years who underwent elective posterior scoliosis correction between March 2019 and July 2021 were collected: age, sex, height, weight, baseline rScO2, basal mean invasive arterial pressure (MAP), preoperative Cobb angle, number of surgical segments, preoperative and postoperative haemoglobin level, percentage of lowest rScO2 below the baseline value that lasted 3 min or more during the operation (decline of rScO2 from baseline, D‐rScO2%), intraoperative average invasive MAP, end‐tidal carbon dioxide pressure, fluid infusion rate of crystalloids and colloids, operation time, and percentage of total blood loss/patient's blood volume (TBL/PBV). Results: A total of 105 children were included in the study. Massive haemorrhage (TBL/PBV ≥50%) was reported in 53.3% of patients, who had significantly higher D‐rScO2 (%) (t = −5.264, P < 0.001) than those who had non‐massive haemorrhage (TBL/PBV <50%). Multiple regression analysis revealed that TBL/PBV (β = 0.04, 95% CI: 0.018–0.062, P < 0.05) was significantly associated with D‐rScO2%. Conclusions: Intraoperative massive blood loss in children significantly increased D‐rScO2%. Monitoring should be improved, and timely blood supplementation should be performed to ensure maintenance of the blood and oxygen supply to vital organs, improve the safety of anaesthesia, and avoid neurological complications. [ABSTRACT FROM AUTHOR]

This study aims to investigate how inert gas affects the partial pressure of alveolar and venous blood using a fast and accurate operator splitting method (OSM). Unlike previous complex methods, such as the finite element method (FEM), OSM effectively separates governing equations into smaller sub‐problems, facilitating a better understanding of inert gas transport and exchange between blood capillaries and surrounding tissue. The governing equations were discretized with a fully implicit finite difference method (FDM), which enables the use of larger time steps. The model employed partial differential equations, considering convection‐diffusion in blood and only diffusion in tissue. The study explores the impact of initial arterial pressure, breathing frequency, blood flow velocity, solubility, and diffusivity on the partial pressure of inert gas in blood and tissue. Additionally, the effects of anesthetic inert gas and oxygen on venous blood partial pressure were analyzed. Simulation results demonstrate that the high solubility and diffusivity of anesthetic inert gas lead to its prolonged presence in blood and tissue, resulting in lower partial pressure in venous blood. These findings enhance our understanding of inert gas interaction with alveolar/venous blood, with potential implications for medical diagnostics and therapies. [ABSTRACT FROM AUTHOR]

A simple and efficient methodology for the selective oxygenation of benzylic C(sp3)−H bond and oxidation of primary and secondary alcohols using non‐noble photoredox copper catalyst under visible light irradiation is described. Notably, non‐noble copper photoredox catalysts were found to be good for the oxidation reactions when compared to various commercially available photoredox catalysts employed in the present methodology. In addition, oxygen as clean oxidant at room temperature and compatible for both the oxygenation and oxidation reactions. A wide range of carbonyl compounds bearing both electron rich and electron deficient substituents was synthesized in moderate to excellent yields under milder and environmentally friendly conditions. Also, a thorough investigation was carried out to understand the mechanism of both oxidation reactions. [ABSTRACT FROM AUTHOR]

Purpose: Non‐invasive measurement of cerebral venous oxygenation (Yv) is of critical importance in brain diseases. The present work proposed a fast method to quantify regional Yv map for both large and small veins. Methods: A new sequence was developed, referred to as TRU‐VERA (T2 relaxation under velocity encoding and rapid acquisition, which isolates blood spins from static tissue with velocity‐encoding preparation, modulates the T2 weighting of venous signal with T2‐preparation and utilizes a bSSFP readout to achieve fast acquisition with high resolution. The sequence was first optimized to achieve best sensitivity for both large and small veins, and then validated with TRUST (T2 relaxation under spin tagging), TRUPC (T2 relaxation under phase contrast), and accelerated TRUPC MRI. Regional difference of Yv was evaluated, and test–retest reproducibility was examined. Results: Optimal Venc was determined to be 3 cm/s, while recovery time and balanced SSFP flip angle within reasonable range had minimal effect on SNR efficiency. Venous T2 measured with TRU‐VERA was highly correlated with T2 from TRUST (R2 = 0.90), and a conversion equation was established for further calibration to Yv. TRU‐VERA sequences showed consistent Yv estimation with TRUPC (R2 = 0.64) and accelerated TRUPC (R2 = 0.79). Coefficient of variation was 0.84% for large veins and 2.49% for small veins, suggesting an excellent test–retest reproducibility. Conclusion: The proposed TRU‐VERA sequence is a promising method for vessel‐specific oxygenation assessment. [ABSTRACT FROM AUTHOR]

The brain relies on an effective clearance mechanism to remove metabolic waste products for the maintenance of homeostasis. Recent studies have focused on elucidating the forces that drive the motion of cerebrospinal fluid (CSF), responsible for removal of these waste products. We demonstrate that vascular responses evoked using controlled manipulations of partial pressure of carbon dioxide (PaCO2) levels, serve as an endogenous driver of CSF clearance from the brain. To demonstrate this, we retrospectively surveyed our database, which consists of brain metastases patients from whom blood oxygen level‐dependent (BOLD) images were acquired during targeted hypercapnic and hyperoxic respiratory challenges. We observed a correlation between CSF inflow signal around the fourth ventricle and CO2‐induced changes in cerebral blood volume. By contrast, no inflow signal was observed in response to the nonvasoactive hyperoxic stimulus, validating our measurements. Moreover, our results establish a link between the rate of the hemodynamic response (to elevated PaCO2) and peritumoral edema load, which we suspect may affect CSF flow, consequently having implications for brain clearance. Our expanded perspective on the factors involved in neurofluid flow underscores the importance of considering both cerebrovascular responses, as well as the brain mechanical properties, when evaluating CSF dynamics in the context of disease processes. [ABSTRACT FROM AUTHOR]

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]

Blood scarcity is one of the main causes of healthcare disruptions worldwide, with blood shortages occurring at an alarming rate. Over the last decades, blood substitutes have aimed at reinforcing the supply of blood, with several products (e.g., hemoglobin (Hb)‐based oxygen (O2) carriers, perfluorocarbons (PFC)) achieving a limited degree of success. Regardless, there is still no widespread solution to this problem due to persistent challenges in product safety and scalability. In this Review, different advances are described in the field of blood substitution, particularly in the development of artificial red blood cells, otherwise known as engineered erythrocytes (EE). The different strategies are categorized into natural, synthetic, or hybrid approaches, and discuss their potential in terms of safety and scalability. Synthetic EEs are identified as the most powerful approach, and describe erythrocytes from a materials engineering perspective. Their biological structure and function are reviewed, as well as explore different methods of assembling a material‐based cell. Specifically, it is discussed how to recreate size, shape, and deformability through particle fabrication, and how to recreate the functional machinery through synthetic biology and nanotechnology. It is concluded by describing the versatile nature of synthetic erythrocytes in medicine and pharmaceuticals and propose specific directions for the field of erythrocyte engineering. [ABSTRACT FROM AUTHOR]

Aberrant aggregates of amyloid‐β (Aβ) and tau protein (tau), called amyloid, are related to the etiology of Alzheimer disease (AD). Reducing amyloid levels in AD patients is a potentially effective approach to the treatment of AD. The selective degradation of amyloids via small molecule‐catalyzed photooxygenation in vivo is a leading approach; however, moderate catalyst activity and the side effects of scalp injury are problematic in prior studies using AD model mice. Here, leuco ethyl violet (LEV) is identified as a highly active, amyloid‐selective, and blood‐brain barrier (BBB)‐permeable photooxygenation catalyst that circumvents all of these problems. LEV is a redox‐sensitive, self‐activating prodrug catalyst; self‐oxidation of LEV through a hydrogen atom transfer process under photoirradiation produces catalytically active ethyl violet (EV) in the presence of amyloid. LEV effectively oxygenates human Aβ and tau, suggesting the feasibility for applications in humans. Furthermore, a concept of using a hydrogen atom as a caging group of a reactive catalyst functional in vivo is postulated. The minimal size of the hydrogen caging group is especially useful for catalyst delivery to the brain through BBB. [ABSTRACT FROM AUTHOR]

The selective oxidation of benzylic C−H bonds is a pivotal transformation in organic synthesis. Undoubtedly, achieving efficient and highly selective aerobic oxidation of methylarenes to benzaldehydes has been highly challenging due to the propensity of benzaldehyde to undergo overoxidation under typical aerobic conditions. Herein, we propose an innovative approach to address this issue by leveraging electrocatalytic processes, facilitated by ion‐pair mediators [Ph3C]+[B(C6F5)4]−. By harnessing the power of electrochemistry, we successfully demonstrated the effectiveness of our strategy, which enables the selective oxidation of benzylic C−H bonds in benzylic molecules and toluene derivatives. Notably, our approach exhibited high efficiency, excellent selectivity, and compatibility with various functional groups, underscoring the broad applicability of our methodology. [ABSTRACT FROM AUTHOR]

Background: A nonvolitional diagnostic method based on FES‐Cycling technology has recently been demonstrated for mechanically ventilated patients. This method presents good sensitivity and specificity for detecting muscle dysfunction and survival prognosis, even in unconscious patients. As the clinical relevance of this method has already been reported, we aimed to evaluate its safety and feasibility. Methods: An observational prospective study was carried out with 20 critically ill, mechanically ventilated patients. The FES‐cycling equipment was set in a specific diagnostic mode. For safety determination, hemodynamic parameters and peripheral oxygen saturation were measured before and immediately after the diagnostic protocol, as well as venous oxygen saturation and blood lactate. The creatine phosphokinase level (CPK) was measured before and 24, 48, and 72 h after the test. The time taken to carry out the entire diagnostic protocol and the number of patients with visible muscle contraction (capacity of perceptive muscular recruitment) were recorded to assess feasibility. Results: Heart rate [91 ± 23 vs. 94 ± 23 bpm (p = 0.0837)], systolic [122 ± 19 vs. 124 ± 19 mm Hg (p = 0.4261)] and diastolic blood pressure [68 ± 13 vs. 70 ± 15 mm Hg (p = 0.3462)], and peripheral [98 (96–99) vs. 98 (95–99) % (p = 0.6353)] and venous oxygen saturation [71 ± 14 vs. 69 ± 14% (p = 0.1317)] did not change after the diagnostic protocol. Moreover, blood lactate [1.48 ± 0.65 vs. 1.53 ± 0.71 mmol/L (p = 0.2320)] did not change. CPK did not change up to 72 h after the test [99 (59–422) vs. 125 (66–674) (p = 0.2799) vs. 161 (66–352) (p > 0.999) vs. 100 (33–409) (p = 0.5901)]. The time taken to perform the diagnostic assessment was 11.3 ± 1.1 min. In addition, 75% of the patients presented very visible muscle contractions, and 25% of them presented barely visible muscle contractions. Conclusions: The FES cycling‐based muscular dysfunction diagnostic method is safe and feasible. Hemodynamic parameters, peripheral oxygen saturation, venous oxygen saturation, and blood lactate did not change after the diagnostic protocol. The muscle damage marker (CPK) did not increase up to 72 h after the diagnostic protocol. [ABSTRACT FROM AUTHOR]

The development of a low‐cost, reusable, and sustainable approach is a difficult and emerging demand in the coming arena. Here, we demonstrate the selective oxidation of primary alcohol, styrene to aldehyde, and alkyl benzene to appropriate ketone, under Blue LED irradiation. The developed approaches employ reusable catalysts (V2O5/TIO2) and green solvents (ACN, H2O) at room temperature. The substrate scope is widely investigated for various compounds of different functionalities. Organic transformations are supported by reaction mechanistic studies. The gram scale reaction and catalytic recyclability were also carried out to maximize the protocol's synthetic utility. [ABSTRACT FROM AUTHOR]