Low Oxygen Research Articles

Low oxygen but dynamic marine redox conditions permitted the Cambrian Radiation.

Whether metazoan diversification during the Cambrian Radiation was driven by increased marine oxygenation remains highly debated. Repeated global oceanic oxygenation events have been inferred during this interval, but the degree of shallow marine oxygenation and its relationship to biodiversification and clade appearance remain uncertain. To resolve this, we interrogate an interval from ~527 to 519 Ma, encompassing multiple proposed global oceanic oxygenation events. We integrate the spatial and temporal distribution of shallow water, in situ reef metazoans, and trilobites, with high-resolution multi-proxy redox data through the highly biodiverse Siberian Platform. We document primarily dysoxic water column conditions, suggesting that early Cambrian metazoans, including motile skeletal benthos, had low oxygen demands. We further document oxygenation events coincident with positive carbon isotope excursions that led to modestly elevated oxygen levels. These events correspond to regional increases in species richness and habitat expansion of mainly endemic species, offering a potentially globally applicable model for biodiversification during the Cambrian Radiation.

Ultrahigh Specific Strength by Bayesian Optimization of Carbon Nanolattices.

Nanoarchitected materials are at the frontier of metamaterial design and have set the benchmark for mechanical performance in several contemporary applications. However, traditional nanoarchitected designs with conventional topologies exhibit poor stress distributions and induce premature nodal failure. Here, using multi-objective Bayesian optimization and two-photon polymerization, optimized carbon nanolattices with an exceptional specific strength of 2.03MPam3kg-1 at low densities <215kg m-3 are created. Generative design optimization provides experimental improvements in strength and Young's modulus by as much as 118% and 68%, respectively, at equivalent densities with entirely different lattice failure responses. Additionally, the reduction of nanolattice strut diameters to 300nm produces a unique high-strength carbon with a pyrolysis-induced atomic gradient of 94% sp2 aromatic carbon and low oxygen impurities. Using multi-focus multi-photon polymerization, a millimeter-scalable metamaterial consisting of 18.75 million lattice cells with nanometer dimensions is demonstrated. Combining Bayesian optimized designs and nanoarchitected pyrolyzed carbon, the optimal nanostructures exhibit the strength of carbon steel at the density of Styrofoam offering unparalleled capabilities in light-weighting, fuel reduction, and contemporary design applications.

Hypoxia-activated dissociation of heteroleptic cobalt(III) complexes with functionalized 2,2'-bipyridines and a model anticancer drug esculetin.

A low oxygen level in solid tumors is behind the modern concept of selective chemotherapy by hypoxia-activated prodrugs, such as heteroleptic complexes of transition metals (cobalt(III), iron(III) or platinum(IV)) with bi- or tetradentate ligands and an anticancer drug molecule as a co-ligand. A series of new cobalt(III) complexes [Co(LR)2(esc)]ClO4 with esculetin (6,7-dihydroxycoumarin) and 2,2'-bipyridines (2,2'-bipy) functionalized by different substituents R were probed in the hypoxia-activated delivery of this model anticancer drug. Their combined study by cyclic voltammetry and in situ NMR spectroscopy allowed identifying linear correlations of the electrochemical reduction potentials and the rate of the hypoxia-activated dissociation of [Co(LR)2(esc)]ClO4 with the Hammett constants of the substituents in 2,2'-bipy ligands. The latter, therefore, should be decorated with the most electron-withdrawing groups (unless they preclude the formation of a heteroleptic complex) to promote the drug release and increase the anticancer activity towards, e.g., human epidermoid carcinoma A431.These correlations can be transferred to other types of bi- or tetradentate ligands, thereby paving the way towards the molecular design of cobalt complexes as prodrugs for hypoxia-activated anticancer drug delivery with high therapeutic efficiency.

The role of alternative oxidase in the maintenance of cellular redox balance under hypoxia via participation in nitric oxide turnover.

Alternative oxidase (AOX) regulates the level of reactive oxygen species and nitric oxide (NO) in plants. While under normoxic conditions it alleviates NO formation, there are several indications that in the conditions of low oxygen such as during seed germination before radicle protrusion, in meristematic stem cells, and in flooded roots AOX can be involved in the production of NO from nitrite. Whereas the first reports considered this role as indirect, more evidence is accumulated that AOX can act as a nitrite: NO reductase. Such activity of the structurally similar di-iron proteins in bacteria has been demonstrated. We review the literature on this topic and show that AOX can be induced under hypoxic conditions and participate in NO turnover via the phytoglobin-NO cycle. This results in the facilitation of glycolytic reactions by reoxidation of the glycolytically formed NADH and diverting the glycolytic carbon toward the formation of alanine and other amino acids. Pyruvate formed in glycolysis can activate AOX and facilitate its operation under these conditions. It is concluded that AOX is an important player in the hypoxic response in plants that regulates the redox level by participating in NO turnover as a nitrite: NO reductase in cooperation with nitrate reductase and phytoglobin.

Multifunctional Near Infrared Polymer Dots for Enhanced Synergistic Photodynamic/Photothermal Effect In Vitro.

Synergistic photodynamic/photothermal therapy (PDT/PTT) can be used to target cancer cells by locally generating singlet oxygen species or increasing temperature under laser irradiation. This approach offers higher tumor ablation efficiency, lower therapeutic dose requirements, and reduced side effects compared to single treatment approaches. However, the therapeutic efficiency of PDT/PTT is still limited by the low oxygen levels within the solid tumors caused by abnormal vasculature and altered cancer cell metabolism. To address these challenges, we developed multifunctional nanoparticles with high catalytic activity for converting tumor hydrogen peroxide (H2O2) into oxygen (O2). Using poly(styrene-co-maleic anhydride) (PSMA) as a cross-linker, we generated compact, highly fluorescent Pdots, used poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) as a near-infrared photosensitizer for both photodynamic and photothermal applications, and incorporated manganese (Mn) ions to catalyze the H2O2-to-O2 conversion. These Mn-doped Pdots significantly enhance O2 production, achieving an enhanced 1O2 quantum yield from 0.46 to 0.64 with the addition of H2O2, achieving the goal of improving PDT efficiency. With this rational design, we produced Pdots with enhanced H2O2-to-1O2 converting ability for potential use in PDT. For photothermal applications, our Pdots generate a photothermal conversion efficiency of 53%. In vitro studies using human MCF7 adenocarcinoma cells confirmed the biocompatibility of these Pdots in the absence of laser exposure with a pronounced cell killing effect under laser irradiation for synergistic PDT/PTT. These results highlight the promise of Pdots in overcoming oxygen limitations, balancing the performance of PDT/PTT, and enhancing the therapeutic efficacy of PDT/PTT in cancer cells in vitro.

A sexual dimorphism in zebrafish aggression and metabolism under acute ammonia stress.

Animals must adapt their behaviors in response to environmental stressors to enhance survival prospects. Aquatic organisms, particularly teleost fish, face unique environmental challenges, making them ideal models for studying environmental stress adaptation. While previous research on acute environmental stress acclimation provided valuable insights, it often overlooked potential sex-specific responses. Growing evidence suggests significant sexual dimorphism in physiological and behavioral responses to various environmental stressors. This emerging paradigm reveals a critical knowledge gap in our understanding of sex-specific stress acclimation strategies and their underlying mechanisms in teleost fish. To address this gap, we investigated the effects of acute ammonia exposure, a common aquatic stressor, on male and female zebrafish. We examined differential behaviors and metabolic rates between the sexes under ammonia stress and found sex-specific responses: males tended to recover aggression and reduce fighting latency without affecting outcomes, whereas females exhibited lowered oxygen consumption and reduced aggression. These findings highlight differences in acute stress adaptation strategies between males and females, contributing to a more-comprehensive understanding of sex-specific stress adaptation in aquatic environments and underscoring the importance of considering sexual dimorphism in environmental stress studies.

Characteristics of transcriptome and chromatin accessibility in the peripheral blood after acute hypoxia exposure

BackgroundHuman responses and acclimation to the environmental stresses of high altitude and low oxygen are multifaceted and regulated by multiple genes. However, the mechanism of how the body adjusts in a low-oxygen environment is not yet clear.ResultsHence, we performed RNA sequencing (RNA-seq) and ATAC sequencing (ATAC-seq) to observe the changes of transcriptome and chromatin accessibility in the peripheral blood of eight individuals at 1 h post adaptation in a simulated plateau environment with 3500 m and 4500 m altitude, respectively. Differential expression analysis and the Boruta algorithm identified differentially expressed genes (DEGs) and differentially accessible regions (DARs) associated with hypoxia adaptation. Specifically, RNA-seq identified 93 and 7 DEGs after 1 h post adaptation with 3500 m altitude and 45 and 8 DEGs after 1 h adaptation with 4500 m. Additionally, ATAC-seq screened 12 and 4 DARs in 3500 m altitude adaption and 15 and 5 DARs in 4500 m altitude adaption. Moreover, the combined analysis of RNA-seq and ATAC-seq revealed that 10 hub genes were independently identified from the protein–protein interaction (PPI) network for each altitude. Gene enrichment analysis displayed that most hub genes were related with hypoxia pathways.ConclusionsOur results can provide the reference for the early response of the organism to hypoxic adaptation.

How to combine SBR and A/O process for pollutant removal in treating digested effluent of swine wastewater.

To solve the problem of low chemical oxygen demand (COD)/N and poor efficiency of single-stage sequencing batch reactor (SBR) or anoxic/oxic process (A/O) in treatment of digested effluent of swine wastewater, combined SBR-A/O and A/O-SBR processes were employed in the addition ratios of 0, 10%, 30%, and 40% (V/V)) of raw swine wastewater (RS). Analysis of pollutants removal performance of SBR-A/O and A/O-SBR systems showed no significant difference between the two systems without RS addition. However, after adding RS, the pollutants removal efficiency of the two systems increased with the increase in the ratio of RS, with SBR-A/O system presenting better pollutants removal performance than A/O-SBR system. The SBR-A/O system exhibited the best pollutant removal performance in the 40% RS addition, with the effluent concentrations of COD, ammonium nitrogen (NH4+-N), and total inorganic nitrogen (TIN) reaching 428, 8.82, and 134mg/L, respectively. The first-stage reactor (SBR) of SBR-A/O system ensured high NH4+-N and TIN removal owing to its high COD/NOx-N and dissolved oxygen levels, while the second-stage reactor (A/O) of the SBR-A/O system ensured low effluent COD. The COD, NH4+-N, and TIN removal efficiencies of the SBR-A/O system were 3.3, 0.2, and 0.6 percentage points higher than those of the A/O-SBR system in the 40% RS addition, respectively. The better pollutants removal efficiency of SBR-A/O system could be attributed to the higher sludge concentration, sludge specific activity, and functional bacterial abundance, when compared with those in the A/O-SBR system.

Role of Exercise Stress Echocardiography in Systemic Sclerosis: Pathophysiological and Prognostic Significance of the Systemic Sclerosis with a Heart Failure and Preserved Ejection Fraction Phenotype.

Left ventricular (LV) diastolic dysfunction and heart failure with preserved ejection fraction (HFpEF) are common cardiac complications of patients with systemic sclerosis (SSc). Exercise stress echocardiography is often used in symptomatic patients with SSc to detect abnormal increases in pulmonary pressures during exercise, but the pathophysiologic and prognostic significance of exercise stress echocardiography to assess the presence of HFpEF in these patients is unclear. Patients with SSc (n=140) underwent ergometry exercise stress echocardiography with simultaneous expired gas analysis. The HFA-PEFF score ≥ 5 points was used to diagnose HFpEF. Thirty-five patients met the HFpEF criteria (prevalence 25%). Compared to patients with SSc-non-HFpEF, those with SSc-HFpEF were older and had a higher prevalence of coronary artery disease, more severe LV diastolic dysfunction (by definition), depressed right ventricular systolic function, reduced exercise capacity (lower peak oxygen consumption), and poorer ventilatory efficiency. Exercise right heart catheterization (RHC) was performed in 25 patients and it confirmed elevated pulmonary capillary wedge pressure during peak exercise in patients with SSc-HFpEF. Participants were followed up to assess the primary composite endpoint: all-cause mortality, HF hospitalization, unplanned hospital visits requiring intravenous diuretics, or oral diuretic intensification. Compared to SSc-non-HFpEF, SSc-HFpEF had a 5.3-fold increased risk of the composite outcomes (hazard ratio 5.29, confidence intervals 2.06-13.5, p=0.0005). In addition to pulmonary hemodynamics, exercise stress echocardiography may be useful to identify the HFpEF phenotype that has different pathophysiology and clinical outcomes in patients with SSc.

Clinical characteristics of infants with respiratory syncytial virus infection under 3 months of age before, during, and after the SARS-CoV-2 pandemic

Objectives: To assess the changes in epidemiologic and clinical characteristics of respiratory syncytial virus (RSV) infection among inpatient under 3 months of age with lower respiratory tract infection (LRTI) in different stages of the SARS-CoV-2 pandemic. Methods: A retrospective cohort study was conducted. Clinical data on general condition and laboratory tests were collected from 3 144 RSV-positive LRTI infants less than 3 months of age hospitalized at Children's Hospital, Zhejiang University School of Medicine from January 2017 to January 2024. Based on the admission date, all patients were categorized into three groups: pre-SARS-CoV-2 infection, during SARS-CoV-2 infection and after SARS-CoV-2 infection. Clinical data from three groups of patients were compared using ANOVA or chi-square test or Kruskal Wallis text to assess the impact of the SARS-CoV-2 infection on the epidemiological and clinical characteristics of RSV. Results: Among the 3 144 RSV-positive children, there were 1 872 males and 1 272 females, with an age of 42 (24, 61) d. The pre-SARS-CoV-2 infection, during SARS-CoV-2 infection and after SARS-CoV-2 infection in 1 224, 1 173 and 747 cases respectively. There were statistically significant differences in RSV infection in winter, summer and autumn (all P<0.001). Compared with the pre-SARS-CoV-2 pandemic and during the SARS-CoV-2 pandemic, children with RSV infection in the post-SARS-CoV-2 pandemic had higher hospitalization costs (8 831.3 (5 925.0, 12 887.6) vs.7 153.8 (4 918.0, 9 834.2) vs. 7 842.0 (4 920.0, 11 414.2) yuan, H=57.57, P<0.001), lower admission oxygen saturation (0.95 (0.94,0.97) vs. 0.97 (0.95,0.98) vs. 0.97 (0.95,0.98), H=143.96, P<0.001), an increased rate of intravenous glucocorticosteroid application (56.8% (424/747) vs. 35.9% (439/1 224) vs. 29.9% (351/1 173), χ2=144.58, P<0.001), immunoglobulin application (27.7% (207/747) vs. 16.2% (198/1 224) vs. 14.6% (171/1 173), χ2=58.41, P<0.001), respiratory support (45.5% (340/747) vs. 38.9% (476/1 224) vs. 36.7% (431/1 173), χ2=15.03, P=0.001), and intensive care unit admission (3.9% (29/747) vs. 1.3% (16/1 224) vs. 3.0% (35/1 173), χ2=13.86, P=0.001). Conclusions: During the post-SARS-CoV-2 pandemic, there were off-season outbreaks of RSV, with peaks occurring in the summer and fall. RSV-positive infants in the post-SARS-CoV-2 infection period had lower oxygen saturation on admission and higher rates of intravenous glucocorticosteroids, immunoglobulin application, respiratory support, and admission to the intensive care unit.

Chromium-Doped NiBP Micro-Sphere Electrocatalysts for Green Hydrogen Production under Industrial Operational Conditions.

Wide spread adaptation of green hydrogen can help to mitigate the serious climate issues, increasing global energy demands and the development of advanced electrocatalysts robust under industrial conditions is one of the key technological challenges. Herein, chromium-doped nickel-boride-phosphide (Cr/NiBP) micro sphere (MS) electrocatalyst is demonstrated via a two-step hydrothermal approach along with post-annealing. The Cr/NiBP MS demonstrates low hydrogen evolution reaction and oxygen evaluation reaction over potentials of 78 and 250 mV at 100 mA cm-2 in 1 m KOH, out performing most of the reported catalysts. The Cr/NiBP ǁ Cr/NiBP exhibits only 1.54 V at 100 mA cm-2 in 1 m KOH and surpasses the benchmark of RuO2 (+) ǁ Pt/C (-) up to 2000 mA cm-2, which sets it as one of the best bifunctional electrocatalysts. Impressively, it maintains stable performance for over 240 h at 1000 mA cm-2 in 6 m KOH at 60°C, demonstrating rapid response, anti-corrosion resistance, and robust structural integrity to meet the industrial operational conditions. Further, Cr/NiBP ǁ Pt/C exhibits a super-low cell-voltage of 2.25 V at 2000 mA cm-2. The small amount of Cr atoms incorporation can significantly enhance active sites and intrinsic properties, accelerating water dissociation and rapid intermediate formation.

Bioprocess exploitation of microaerobic auto-induction using the example of rhamnolipid biosynthesis in Pseudomonas putida KT2440

BackgroundIn biomanufacturing of surface-active agents, such as rhamnolipids, excessive foaming is a significant obstacle for the development of high-performing bioprocesses. The exploitation of the inherent tolerance of Pseudomonas putida KT2440, an obligate aerobic bacterium, to microaerobic conditions has received little attention so far. Here low-oxygen inducible promoters were characterized in biosensor strains and exploited for process control under reduction of foam formation by low aeration and stirring rates during biosynthesis of rhamnolipids.ResultsIn this study, homologous promoters of P. putida inducible under oxygen limitation were identified by non-targeted proteomic analyses and characterized by fluorometric methods. Proteomics indicated a remodeling of the respiratory chain and the regulation of stress-related proteins under oxygen limitation. Of the three promoters tested in fluorescent biosensor assays, the promoter of the oxygen-sensitive cbb3-type cytochrome c oxidase gene showed high oxygen-dependent controllability. It was used to control the gene expression of a heterologous di-rhamnolipid synthesis operon in an auto-inducing microaerobic two-phase bioprocess. By limiting the oxygen supply via low aeration and stirring rates, the bioprocess was clearly divided into a growth and a production phase, and sources of foam formation were reduced. Accordingly, rhamnolipid synthesis did not have to be controlled externally, as the oxygen-sensitive promoter was autonomously activated as soon as the oxygen level reached microaerobic conditions. A critical threshold of about 20% oxygen saturation was determined.ConclusionsUtilizing the inherent tolerance of P. putida to microaerobic conditions in combination with the application of homologous, low-oxygen inducible promoters is a novel and efficient strategy to control bioprocesses. Fermentation under microaerobic conditions enabled the induction of rhamnolipid production by low oxygen levels, while foam formation was limited by low aeration and stirring rates.

Study of Children Aged Under 2 Years Admitted With RSV at Four Australian Hospitals [2021-2022

Primary aim was to review severe acute respiratory infections (SARI) hospitalisations caused by respiratory syncytial virus (RSV) in children aged < 2 years in paediatric hospitals in Australia. Secondary aims included RSV subtyping, assessing RSV seasonality and contributing to the World Health Organisation's RSV surveillance programme. We prospectively reviewed the medical records of children (< 2 years of age) with a confirmed SARI who were admitted to one of four major Australian paediatric hospitals and had a respiratory sample analysed by Polymerase Chain Reaction (PCR). A detailed dataset was completed for RSV positive cases. Between 1 January 2021 and 31 December 2022, 2290 RSV (laboratory-confirmed) admissions were identified (53.4% of all SARI admissions). Approximately 50% of all RSV cases were aged 0-6 months. RSV-A predominated in 2021 with peak infections observed in summer while in 2022 RSV-B predominated with peak infections in the more traditional winter months. The median total length of stay (LOS) for RSV positive admissions was 46 h (IQR: 22-82 h). 9% of these children required an ICU admission with a prolonged median LOS 68 h (IQR: 40-112 h). Respiratory support utilisation was consistent over the 2 years. 1.8% required mechanical ventilation; 4.6% continuous positive airway pressure; 23.3% high flow oxygen; and 50.8% low flow oxygen. RSV in children continues to cause a significant disease burden at Australian tertiary paediatric centres. Ongoing hospital surveillance is required to document the impact of RSV preventative therapies that have become available in 2024.

Insights into the diverse roles of the terminal oxidases in Burkholderia cenocepacia H111

Burkholderia cenocepacia H111 is an obligate aerobic bacterium which has been isolated from a cystic fibrosis (CF) patient. In CF lungs the environment is considered micro-oxic or even oxygen-depleted due to bacterial activities and limited oxygen diffusion in the mucus layer. To adapt to low oxygen concentrations, bacteria possess multiple terminal oxidases. In this study, we identified six terminal oxidases of B. cenocepacia H111 and constructed reporter strains to monitor their expression in different environments. While the heme-copper oxidase aa3 (cta) was constitutively expressed, the bd-1 oxidase (cyd) was induced under oxygen-limited growth conditions. The cyanide-insensitive bd-type terminal oxidase (cio-1) was mainly expressed in cells grown on the surface of solid medium or in liquid cultures in presence of cyanide, which is known to be produced in the CF lung by the often co-residing CF pathogen Pseudomonas aeruginosa. Indeed, a cio-1 insertional mutant was not able to grow in the presence of cyanide confirming the important role of Cio-1 in cyanide resistance. The caa3 oxidase (caa), was only expressed under nutrient limitation when cells were grown on the surface of solid medium. We also investigated the involvement of two regulatory systems, Anr and RoxS/RoxR, in the expression of cio-1 and cyd. Our data suggest, that, given that Cio-1 is only present in prokaryotes and plays an important role in the defense against cyanide-producing P. aeruginosa, it may be a valuable drug target for treatment of polymicrobial infections in CF patients.

Module-A Sensor Performance Tests Used In Laboratory-Type Silage Production, Data Acquisition and Control System

The primary objective of this study is to investigate the performance of sensors integrated into the laboratory-type silage production, data acquisition, and control system. The system is a PLC-controlled and multi-sensor based system designed to enable numerous studies aimed at improving silage quality. It consists of grinding, weighing, silo, data acquisition, and control units. It provides the capability to apply/change/simulate various parameters during the silage production process. The silo unit is composed of two modules, module-A (compression principle) and module-B (vacuum principle). This research focuses on measurements conducted with plexiglass silos (24,5 cm3) in the module-A unit. This silos were equipped with oxygen sensor (±0-100 %), carbon dioxide sensor (0-5000 ppm), temperature sensor (±0.53 °C, -10 – 80 °C), humidity sensor (0-100 %), pH sensor (2-12), and pressure sensor (± 1000 mbar). The research utilized second-crop silage corn material with a dry matter content (DM) of 32%. Four different compaction forces were applied during the experiments. Sensor measurements were recorded as one data per second by connecting them to the data recording unit using analog sensors. Due to the abundance of data, average values were taken. The data were displayed and monitored on the HMI operator panel programmed with GOP HMI editor software and stored in Excel format. The measurements were carried out during the silage (aerobic) and post-silage (anaerobic) periods. According to the research results, it was observed that the six tested sensors performed accurate readings. However, issues related to the oxygen and carbon dioxide sensors were encountered. Due to the difficulty in reading at points with very low oxygen content, it was decided to be supported by controlling with sensors of different types and specifications. During measurements conducted at the compression stage in module-A, the pressure values varied between 0,34-0,67 bar with increasing compaction force. The temperature ranged from 16-33 °C, humidity from 60-100 %, pH from 5,8-5,6 O2 level from 8,1-0 mmol L-1, and CO2 level from 0-40 mmol L-1. The measured value ranges in silage varied depending on the duration of silage, and accurate measurements were obtained in the desired direction. Sensor placements were updated considering measurement accuracy.

Effect of Al/O Ratio on Acicular Ferrite Formation in Low Oxygen Weld Metals

Effect of Al/O Ratio on Acicular Ferrite Formation in Low Oxygen Weld Metals

Polysomnographic findings and psychiatric symptoms in patients with comorbid insomnia and sleep apnea: a retrospective study focusing on sex differences.

Comorbid insomnia and obstructive sleep apnea (COMISA) present significant clinical challenges, given their overlapping symptoms and detrimental effects on health. Only a few studies have explored sex differences in patients with obstructive sleep apnea (OSA) and COMISA. This retrospective study investigated sex differences in psychiatric symptoms and polysomnographic findings between patients with COMISA and those with OSA alone. Patients who underwent polysomnography (PSG) and completed questionnaires at a single tertiary hospital sleep center were enrolled. Patients diagnosed with OSA using PSG (apnea-hypopnea index ≥ 5) were categorized based on the Insomnia Severity Index-Korean version (ISI) into OSA without insomnia (OSA-only group; ISI < 15) and OSA with insomnia (COMISA group; ISI ≥ 15). This study included 1,096 adult patients diagnosed with OSA, of whom 426 (38.9%) were in the COMISA group. COMISA was more common in women than in men (50.7% vs. 34.5%, p < 0.001). The COMISA group reported more severe subjective psychiatric symptoms, including depression, anxiety, and daytime sleepiness in both men and women. The male COMISA group had lower sleep efficiency (p = 0.02) and longer sleep latency (p = 0.002) than those had by the OSA-only group. The male COMISA group had a higher apnea-hypopnea index (p = 0.04) and a lower mean oxygen saturation (p = 0.004) than those had by the OSA-only group. These findings highlight the importance of considering sex-specific clinical and polysomnographic characteristics when managing patients with COMISA.

Comprehensive analysis of determining factors of the effective work function of TiAlC/TiN metal gates for advanced gate-all-around CMOS integration

Abstract We have examined the determining factor of the effective work function (EWF) for an n-channel MOSFET (n-type EWF) in TiAlC/TiN metal gates on high-k gate dielectrics (HK). From electrical and physical evaluations of the bottom TiN between HK and TiAlC (BTM-TiN), the obtained results suggest that the dominant factor for the n-type EWF of TiAlC/TiN metal gates is not the fixed charge in the gate dielectric but the vacuum work function of BTM-TiN. It was found that TiN with low oxygen content has a vacuum work function of 3.8 eV, suitable for an n-channel MOSFET although TiN has been believed to be suitable for a p-channel MOSFET. We also found that its vacuum work function increases with increasing oxygen content. Based on these results, we proposed an oxygen scavenging from BTM-TiN(O) by Al in TiAlC as a novel mechanism for the n-type EWF for TiAlC/TiN metal gates.

The systemic evolutionary theory of the origin of cancer (SETOC): an update

The Systemic Evolutionary Theory of the Origin of Cancer (SETOC) is a recently proposed theory founded on two primary principles: the cooperative and endosymbiotic process of cell evolution as described by Lynn Margulis, and the integration of complex systems operating in eukaryotic cells, which is a core concept in systems biology. The SETOC proposes that malignant transformation occurs when cells undergo a continuous adaptation process in response to long-term injuries, leading to tissue remodeling, chronic inflammation, fibrosis, and ultimately cancer. This process involves a maladaptive response, wherein the 'endosymbiotic contract’ between the nuclear-cytoplasmic system (derived from the primordial archaeal cell) and the mitochondrial system (derived from the primordial α-proteobacterium) gradually breaks down. This ultimately leads to uncoordinated behaviors and functions in transformed cells. The decoupling of the two cellular subsystems causes transformed cells to acquire phenotypic characteristics analogous to those of unicellular organisms, as well as certain biological features of embryonic development that are normally suppressed. These adaptive changes enable cancer cells to survive in the harsh tumor microenvironment characterized by low oxygen concentrations, inadequate nutrients, increased catabolic waste, and increased acidity. De-endosymbiosis reprograms the sequential metabolic functions of glycolysis, the TCA cycle, and oxidative phosphorylation (OxPhos). This leads to increased lactate fermentation (Warburg effect), respiratory chain dysfunction, and TCA cycle reversal. Here, we present an updated version of the SETOC that incorporates the fundamental principles outlined by this theory and integrates the epistemological approach used to develop it.

Stress Response of the Juvenile Tri-Spine Horseshoe Crab Tachypleus tridentatus to Hypoxia: Insights From Phenotypic, Metabolomic, and Microbial Analyses.

Over the past few decades, ocean hypoxia has been increasing due to human activities. Hypoxic stress, characterized by a reduced level of dissolved oxygen, is an escalating threat to marine ecosystems, with potentially devastating effects on the viability of endangered species such as the tri-spine horseshoe crab Tachypleus tridentatus. Even though this species is remarkably resilient to low oxygen levels, persistent hypoxia can negatively impact its population's survivability. The objective of this research was to examine the impact of short-term hypoxia on the behavior, gut microbiota, and metabolomics of juvenile T. tridentatus. First instar juvenile horseshoe crabs were subjected to hypoxic stress (2mg O2/L) for 14 days and then recovered for 7 days in an environment with normal dissolved oxygen. The findings demonstrated that short-term hypoxia reduced the rates of swimming and burrowing of horseshoe crabs, and induced the change of tissue metabolites and intestinal flora malfunction. Additionally, in the hypoxia groups on day 14, 86 distinct metabolites showed a trend of downregulation, while 29 metabolites showed an upregulation trend. Arginine biosynthesis; histidine metabolism; vitamin B6 metabolism; aminoacyl-tRNA biosynthesis; and alanine, aspartate, and glutamate metabolism were the top five metabolic KEGG pathways (p < 0.05) enriched with 8 metabolites. In conclusion, our results provided new insights related to the behaviors, microbiota, and metabolites involved in juvenile T. tridentatus exposed to short-term hypoxic conditions and confirmed that hypoxia impairs their behavioral and physiological status.