High Oxygen Levels Research Articles

Inoculation with extreme endophytes improves performance and nutritional quality in crop species grown under exoplanetary conditions.

Technological advances have made possible long space travels and even exoplanetary colonies in the future. Nevertheless, the success of these activities depends on our ability to produce edible plants in stressful conditions such as high radiation, extreme temperatures and low oxygen levels. Since beneficial microorganisms, such as fungal endophytes from extreme environments, have helped agriculture cope with those difficulties, endophytic fungi may be a putative tool to ensure plant growth under exoplanetary conditions. Additionally, growing crops in polyculture has been shown to increase productivity and spatial efficiency, which is essential given the likely space restrictions in such conditions. We evaluated the effect of the inoculation with a mix of two fungal endophytes from the Atacama Desert on performance (survival and biomass) and nutritional quality of three crop species (lettuce, chard and spinach) grown under exoplanetary conditions. In addition, we measured the amount of antioxidants (flavonoids and phenolics) as possible mechanisms to cope with such abiotic conditions. The exoplanetary conditions were; high UV radiation, low temperature, low water availability, and low oxygen levels. These crops were put in growing chambers in monoculture, dual culture and polyculture (the three species in the same pot) for 30 days. Our results show that inoculation with extreme endophytes improved survival by ca. 15 - 35% and biomass by ca. 30 - 35% in all crop species. The most evident increase was when grown in polyculture, except for survival in spinach, where inoculated plants had higher survival only in dual culture. Nutritional quality and the amount of the antioxidant compounds antioxidants increased in all crop species when inoculated with the endophytes. Overall, fungal endophytes isolated from extreme environments such as the Atacama Desert, the driest desert in the world, could be a key biotechnological tool for future space agriculture, helping plants cope with environmental stress. Additionally, inoculated plants should be grown in polyculture to increase crop turnover and space-use efficiency. Lastly, these results provide useful insights to face the future challenges of space-farming.

Chromium isotopes in an acidic fluvial system: Implications for modern and ancient Cr isotope records

Chromium is an important redox-active element, with significant Cr isotope fractionations driven by redox transformations in the natural environment and quantified through laboratory experiments. Recent work has demonstrated that non-redox-driven transformations can also produce small variations in Cr isotopes, but the role of these processes in controlling environmental Cr isotope variations remains unclear. The highly acidic but biologically diverse acid rock drainage system in Río Tinto, Spain (and affiliated rivers) provides a unique opportunity to examine how non-redox-related processes can substantially affect the isotopic composition of Cr in a natural system. Our results suggest that under conditions where Cr redox transformations are obviated, Cr cycling is largely controlled by formation of Fe-oxyhydroxides and Fe-hydroxysulfates, Cr adsorption, and Cr speciation, with little apparent Cr isotope fractionation between source materials, waters, and sediments. Moderate Cr isotope shifts, however, may be the result of non-redox processes, including adsorption to organic ligands and potentially biological uptake. These results add to a growing body of evidence for the importance of non-redox transformations in contributing to environmental Cr isotope variations, with implications for the use of chromium isotopes in studies of sedimentary Cr isotope records. In particular, this study is a validation of the potential for sulfide weathering in the Proterozoic to deliver relatively unfractionated Cr isotopes to the ocean, despite rising and sustained high oxygen levels.

Collagen-Derived Dipeptide Pro-Hyp Enhanced ATDC5 Chondrocyte Differentiation under Hypoxic Conditions.

Chondrocytes are surrounded by a lower oxygen environment than other well-vascularized tissues with higher oxygenation levels. Prolyl-hydroxyproline (Pro-Hyp), one of the final collagen-derived peptides, has been previously reported to be involved in the early stages of chondrocyte differentiation. However, whether Pro-Hyp can alter chondrocyte differentiation under physiological hypoxic conditions is still unclear. This study aimed to investigate whether Pro-Hyp affects the differentiation of ATDC5 chondrogenic cells under hypoxic conditions. The addition of Pro-Hyp resulted in an approximately 18-fold increase in the glycosaminoglycan staining area compared to the control group under hypoxic conditions. Moreover, Pro-Hyp treatment significantly upregulated the expression of SOX9, Col2a1, Aggrecan, and MMP13 in chondrocytes cultured under hypoxic conditions. These results demonstrate that Pro-Hyp strongly promotes the early differentiation of chondrocytes under physiological hypoxic conditions. Therefore, Pro-Hyp, a bioactive peptide produced during collagen metabolism, may function as a remodeling factor or extracellular matrix remodeling signal that regulates chondrocyte differentiation in hypoxic cartilage.

Paleoclimate and Paleoenvironment Reconstructions from Middle Eocene Successions at Beni-Suef, Egypt: Foraminiferal Assemblages and Geochemical Approaches

The Eocene deposits of Egypt provide a wide variety of shallow marine facies and fossil assemblages, allowing paleoenvironmental reconstructions in this warmhouse climate interval. Forty-three rock samples have been collected from two middle Eocene sections, exposed at southeast Beni-Suef area in northern Egypt. The studied outcrops are lithologicsally subdivided into two rock units named from base to top as follows: (1) the Qarara Formation (Lutetian) and (2) the El Fashn Formation (Bartonian). Most investigated rock samples showed richness in benthic foraminiferal assemblages and only rare occurrences of index planktonic foraminifera. They yielded 160 foraminifera species which belong to 4 suborders, 19 superfamilies, 34 families, and 59 genera. The stratigraphic distribution of the identified species allowed us to define four local benthic bio-ecozones: (1) Bolivina carinata Lowest Occurrence Zone (Lutetian), (2) Cibicides mabahethi/Cancris auriculus primitivus Concurrent-Range Zone, (3) Nonion scaphum Lowest Occurrence Zone, and (4) Brizalina cookei/Nonionella insecta Concurrent-Range Zone (Bartonian). These biozones are described and discussed in detail and correlated to stratigraphic equivalents in Egypt. The rareness of index planktonic foraminifera through the studied sections does not allow a precise biostratigraphic and chronostratigraphic correlation. The shale samples show low TOC values, which may be related to low productivity, high sediment influx, and/or prevailing oxic conditions. Bulk rock geochemistry, consistent with the benthic foraminifera ecological preferences, indicated that the studied sections were deposited in moderate to high oxygen levels and warm climatic conditions in a typical shelf marine setting. The identified species showed strong similarities with nearby southern Tethys areas, reflecting migration via the trans-Sahara seaway, and minor similarities with those identified from the northwestern Tethys and the North Atlantic province attributed to the change in the environmental and climatic conditions, such as cooler, latitudinal zoned climatic conditions along the northwestern Tethys, which was unsuitable for their biological demands. The warming trend identified from Lutetian to Bartonian intervals corresponds to the onset of the Middle Eocene Climatic Optimum (MECO).

Edge Graphitized Oxygen-Rich Carbon Based on Stainless Steel-Assisted High-energy Ball Milling for High-Capacity and Ultrafast Sodium Storage.

Oxygen doping is an effective strategy for constructing high-performance carbon anodes in Na ion batteries; however, current oxygen-doped carbons always exhibit low doping levels and high-defect surfaces, resulting in limited capacity improvement and low initial Coulombic efficiency (ICE). Herein, a stainless steel-assisted high-energy ball milling is exploited to achieve high-level oxygen doping (19.33%) in the carbon framework. The doped oxygen atoms exist dominantly in the form of carbon-oxygen double bonds, supplying sufficient Na storage sites through an addition reaction. More importantly, it is unexpected that the random carbon layers on the surface are reconstructed into a quasi-ordered arrangement by robust mechanical force, which is low-defect and favorable for suppressing the formation of thick solid electrolyte interfaces. As such, the obtained carbon presents a large reversible capacity of 363mAhg-1 with a high ICE up to 83.1%. In addition, owing to the surface-dominated capacity contribution, an ultrafast Na storage is achieved that the capacity remains 139mAhg-1 under a large current density of 100Ag-1 . Such good Na storage performance, especially outstanding rate capability, has rarely been achieved before.

Microglia Cell Line SIM-A9 Features – New Data

SIM-A9 is a line of spontaneously immortalized mouse microglia cells obtained from newborn C57BL/6 mice’s cerebrum. The aim of this work is to characterize SIM-A9 line by the ratio of cells with the resting and activated microglia phenotype, to analyze the expression of stem/progenitor cell markers CD133 and nestin, growth factors receptors CSF-1R and EGFR, and the karyotype of this line. The light microscopy, immunocytochemistry, flow cytometry and RT/PCR were used to analyze the morphology, phenotype, and gene expression levels of pro-inflammatory cytokines, and the mFISH method was used to analyze the karyotype. It was shown for the first time that SIM-A9 cells express a high level of TSPO protein, CD68, CD11b and CD45 markers on the surface membrane of cells, which corresponds to the phenotype of activated microglia. Despite this, the cells of this line respond with additional activation to LPS stimulation, which leads to an increase in the pro-inflammatory cytokine genes IL-1β, TNFα, IL-6 expression and a high level of active oxygen and nitrogen metabolites formation. It was shown that SIM-A9 cells express stem and progenitor cells markers, CD133+ and nestin, which allows us to consider the cells of this line as early poorly differentiated progenitor cells, despite their phenotype corresponding to activated microglia. It was also found that SIM-A9 cells express receptors of two growth factors CSF-1 and EGF, CSF-1R and EGFR, which indicates the possibility of SIM-A9 cells proliferation stimulation by two alternative mechanisms under the action of the corresponding factors. SIM-A9 cells have a hypotetraploid karyotype with a large number of structural and quantitative chromosome anomalies.

Murray cod waterhole woes

During bouts of prolonged drought and little to no river flow, waterholes are a haven for freshwater fishes. However, as humans divert more water for their own use and as global temperatures rise, these small bodies of water are increasingly vulnerable to climbing temperatures and low oxygen levels. Fortunately, some fishes are able to change quickly to cope with high temperatures, and occasionally these changes also help them do better with low oxygen levels. But size matters when it comes to dealing with these stressors. Big fish are thought to deal with low oxygen better than small fish, and small fish are thought to deal better with high temperatures, but all are likely to be vulnerable when both stressful circumstances occur simultaneously. To investigate how body size influences a fish's ability to tolerate both high heat and low oxygen, Darren McPhee, with researchers from the University of Queensland and the Queensland Department of Regional Development, Australia, turned to massive Murray cod – which can grow to the size of a giant panda (over 100 kg) – to find out how they deal with the combined threat.Working with fish ranging from 0.2 g to 3 kg, the team transferred the animals to water at temperatures mimicking a hot summer (28°C). After 4 weeks, all of the cod, regardless of size, increased the temperature at which they lose their balance (known as the upper thermal limit), indicating that the cod are able to deal with persistent high temperatures. But when the team tested the fish's abilities to remain upright at high temperatures as the water oxygen levels decreased, their ability to tolerate heat declined. Surprisingly, the fish's body sizes had an unusual impact on their ability to withstand high temperatures when their oxygen supply was restricted. As expected, when the fish had access to well-oxygenated water (100% and 50% oxygen saturation), the smaller animals coped better with high temperatures than the big fish. But this pattern flipped when the oxygen levels in the water were low (30% and 16% oxygen saturation), where the largest fish tolerated the high temperatures better than the smaller fish. Intriguingly, this didn't mean that the big fish were thermal tolerance champions. At the lowest oxygen level (16% oxygen saturation), the mid-sized fish coped best with the high temperatures.The scientists also tested how short-term and persistent exposure to different temperatures affected the cod's ability to survive low oxygen in several different ways. In the short term (less than 24 h), fish exposed to high temperatures breathed faster and lost their balance at an oxygen level twice as high as what they would normally handle. But when exposed to a high heat for 4 weeks, the responses to low oxygen weren't quite as drastic. Again, the largest cod were the least bothered by decreasing oxygen – not changing their breathing frequency and taking longer to lose their balance (unlike the little fish).Although Murray cod of all sizes demonstrated an amazing ability to cope with high temperatures in the lab, McPhee and colleagues also went into the wild to check the water quality of three Queensland waterholes that are much loved by the cod. The researchers found that the fish are living dangerously close to the edge – at the limit of the high temperatures and low oxygen levels that they can endure – especially during the summer. And, as the smallest cod are most vulnerable to the combined stress of high temperature and low oxygen, this slow-growing species is at genuine risk from catastrophic loss if their littlest ones succumb in the face of the deadly duo.

Continuous Bioproduction of Alginate Bacterial under Nitrogen Fixation and Nonfixation Conditions

Alginate is a biomaterial produced by Azotobacter vinelandii, a diazotroph that, under nitrogen-fixing conditions, can fix nitrogen under high oxygen levels. In A. vinelandii, alginate is synthesized from fructose-6P via synthesis of precursor, polymerization, and modification/exportation. Due to its viscosifying, gelling, and thickening characteristics, alginate is widely used in food, pharmaceutical, and cosmetical industries. This study aimed to develop a continuous bioprocess and a comparative analysis of alginate production under diazotrophic and nondiazotrophic conditions. Continuous cultures were developed at three dilution rates (0.06, 0.08 and 0.10 h−1). In steady state, the respiratory activity, alginate production, alginate molecular weight and the genes encoding alginate polymerase were determined. Under the conditions studied, the specific oxygen uptake rate and respiratory quotient were similar. The diazotrophic conditions improved the conversion of sucrose to alginate and the specific productivity rate, which was 0.24 ± 0.03 g g−1 h−1. A higher alginate molecular weight (725 ± 20 kDa) was also achieved under diazotrophic conditions, which can be explained by an increase in the gene expression of genes alg8 and alg44 (encoding polymerase). The results of this work show the feasibility of enhancing alginate production (yields and specific productivity rates) and quality (molecular weight) under nitrogen-fixing conditions, opening the possibility of developing a continuous bioprocess to produce alginate with specific characteristics under conditions of diazotrophy.

Comparative analysis of active networks reveals the changes of key proteins and their interactions under different oxygen levels in Shewanella oneidensis MR-1

PurposeThe extracellular electron transfer (EET) capability enables electroactive microorganisms have a wide range of applications in energy production, wastewater treatment, bioremediation and chemical synthesis. Because the oxygen levels will sharply affect the EET process, we integrated transcriptome changes under different oxygen levels with protein–protein interaction (PPI) network to study the specific changes under these conditions in a typical electroactive microorganism Shewanella oneidensis MR-1 (S. oneidensis MR-1).MethodsFirst, the mRNA expression data of S. oneidensis MR-1 under different oxygen levels were integrated into its PPI network to construct the active protein networks. Then, we studied the changes of key proteins and their interactions by comparative analysis of multiple pairs of active networks.ResultsThe analysis of node centrality and its changes in the active networks under high and low oxygen levels shows that most of the key nodes in the network are ribosomes or proteins closely related to ribosomes. The results of our centrality versus centrality change analysis of nodes show that the two proteins FlgB and PetA are the largest changed proteins. Among these proteins, the FlgB protein is the structural component of flagella, while PetA protein is closely related to cytochrome c. Furthermore, we also analyzed the changes in protein–protein interactions in the active networks under different oxygen levels, identified the key interactions in each pair of active networks, and finally screened out the key interaction Tig-RplX that exists in three pairs of active networks.ConclusionOur results indicate that the translational processes of proteins and the corresponding translation efficiency may play an important role before and after the activation of the EET process of S. oneidensis MR-1. Furthermore, this study can also provide some guidance for identifying key proteins and interactions under different conditions for this species.

Enhanced photocatalytic activity of g-C[formula omitted]N[formula omitted]–n-p type flower-like ZnO/BiOBr heterojunction for hexavalent chromium and dye wastewater degradation

Construction of a composite g-C3N4, a 2D material with a layered structure, and flower-like ZnO/BiOBr heterojunction photocatalyst is an optimal strategy for the enhancement of photocatalytic performance to reduce the charge carrier recombination at the interface and increase the UV light absorption range to improve simultaneous oxidation of methyl orange (MO) and reduction of Cr(VI) using synthesized photocatalysts. Since the electron requirements for Cr(VI) reduction are theoretically higher than that of MO degradation, the amount of ZnO/BiOBr heterojunction catalyst and the different molar ratios of Bi/Zn for Cr(VI) degradation have been studied. The involved hydroxyl radicals (•OH) and superoxide anion radicals (•O2−) were also investigated. With the initial concentration of C0=20 mg/L of MO and C0=10 mg/L of Cr(VI) at pH 2, the optimized amount of 0.05 g g-C3N4-0.2 g ZnO/BiOBr-0.5 (molar ratio of Bi/Zn=0.5) and 0.05 g g-C3N4-0.4 g ZnO/BiOBr-2 (molar ratio of Bi/Zn=2) were observed to achieve 99.3 % in 130 min of dye decolorization (rate constant=0.036 min −1) and 96 % of Cr(VI) removal in 180 min (rate constant=0.0105 min −1), respectively, indicating more electron requirements observed for Cr(VI) reduction are higher than that of MO degradation theoretically and experimentally. The rate constants were 20 % higher than those of the compared experiments, demonstrating excellent photocatalytic activity that is superior to that of pristine composite either g-C3N4-ZnO-BiOBr or ZnO-BiOBr alone. After four reuse cycles, the photoactivity of the photocatalyst was not significantly reduced, demonstrating the stability of the synthesized g-C3N4-ZnO/BiOBr. Therefore, the synthesized g-C3N4-n-p type flower-like ZnO/BiOBr heterojunction catalyst has outstanding potential for the Cr(VI) removal, and MO dye decolorization. The results showed that the flower-like structure can promote the desorption of high levels of active surface oxygen and enhance reducibility.

Oxygen modulates iron homeostasis by switching iron sensing of NCOA4

To ensure proper utilization of iron and avoid its toxicity, cells are equipped with iron-sensing proteins to maintain cellular iron homeostasis. We showed previously that nuclear receptor coactivator 4 (NCOA4), a ferritin-specific autophagy adapter, intricately regulates the fate of ferritin; upon binding to Fe3+, NCOA4 forms insoluble condensates and regulates ferritin autophagy in iron-replete conditions. Here, we demonstrate an additional iron-sensing mechanism of NCOA4. Our results indicate that the insertion of an iron-sulfur (Fe-S) cluster enables preferential recognition of NCOA4 by the HERC2 (HECT and RLD domain containing E3 ubiquitin protein ligase 2) ubiquitin ligase in iron-replete conditions, resulting in degradation by the proteasome and subsequent inhibition of ferritinophagy. We also found that both condensation and ubiquitin-mediated degradation of NCOA4 can occur in the same cell, and the cellular oxygen tension determines the selection of these pathways. Fe-S cluster-mediated degradation of NCOA4 is enhanced under hypoxia, whereas NCOA4 forms condensates and degrades ferritin at higher oxygen levels. Considering the involvement of iron in oxygen handling, our findings demonstrate that the NCOA4-ferritin axis is another layer of cellular iron regulation in response to oxygen levels.

Investigation on Properties of Raw and Alkali Treated Novel Cellulosic Root Fibres of Zea Mays for Polymeric Composites

Today, new materials based on natural fibres have been emerging day by day to completely eradicate plastics to favour our environmental nature. In this view, the present work is based on the extraction and characterisation of the novel root fibres of the Zea mays (Zm) plant, grown by the hydroponic method. Both the dried untreated and alkali treated root fibres are investigated using a variety of structural, morphological, thermal, elemental and mechanical tests by subjecting both the samples to p-XRD, FT-IR, SEM-EDAX, TGA-DTA, CHNS and tensile strength analyses. Thermal conductivity of the untreated and treated fibres is found using Lee's disc experiment. From p-XRD analysis, the Crystallinity Index, Percentage Crystallinity and Crystallite size of the samples are found. FT-IR studies clarify the different vibrational groups associated with the fibre samples. SEM images show that the surface roughness increases for the chemically treated samples, such that it may be effectively utilised as reinforcement for polymeric composites. The diameter of the fibre samples is found using SEM analysis. According to the EDAX spectrum, Zm fibres in both their raw and processed forms have high levels of Carbon (C) and Oxygen (O). The TGA-DTA tests revealed that the samples of natural fibre have good thermal characteristics. CHNS studies show that Carbon content is high for these samples, which is the characteristic of many natural fibres. Chemical analysis is used to ascertain the prepared samples' chemical makeup. It reveals that both samples have significant amounts of cellulose. The density of the fibres is found to be in the range 0.3-0.6 g/cc, which is much less than any other natural fibre. Therefore, it can be used in light weight applications. From the tensile strength analysis, physical properties such as Young's modulus and micro-fibril angle are determined. The fibres in the roots exhibit a lower tensile strength. Thus, these fibres can be used in powdered form as reinforcement for natural rubber or epoxy composites. After examining all of its properties, it could be reasonably speculated that Zea mays root fibres can be considered as an efficient reinforcement for various matrices to produce attractive bio-composites.

Ribonuclease E strongly impacts bacterial adaptation to different growth conditions

ABSTRACT Adaptation of bacteria to changes in their environment is often accomplished by changes of the transcriptome. While we learned a lot on the impact of transcriptional regulation in bacterial adaptation over the last decades, much less is known on the role of ribonucleases. This study demonstrates an important function of the endoribonuclease RNase E in the adaptation to different growth conditions. It was shown previously that RNase E activity does not influence the doubling time of the facultative phototroph Rhodobacter sphaeroides during chemotrophic growth, however, it has a strong impact on phototrophic growth. To better understand the impact of RNase E on phototrophic growth, we now quantified gene expression by RNA-seq and mapped 5’ ends during chemotrophic growth under high oxygen or low oxygen levels and during phototrophic growth in the wild type and a mutant expressing a thermosensitive RNase E. Based on the RNase E-dependent expression pattern, the RNAs could be grouped into different classes. A strong effect of RNase E on levels of RNAs for photosynthesis genes was observed, in agreement with poor growth under photosynthetic conditions. RNase E cleavage sites and 5’ ends enriched in the rne ts mutant were differently distributed among the gene classes. Furthermore, RNase E affects the level of RNAs for important transcription factors thus indirectly affecting the expression of their regulons. As a consequence, RNase E has an important role in the adaptation of R. sphaeroides to different growth conditions.

Machine learning models applied to predicate post activity oxygen saturation levels

Machine learning is a rapidly growing field with widespread application in various industries, including healthcare. In recent years, significant advancements in machine learning have enhanced our understanding of data analytics and prediction models in analyzing physiological data, such as blood oxygen levels, heart rate, and blood pressure. This paper focuses on physical activity in adolescence during the pandemic period. The study showed that going outside for a short walk can increase blood oxygen levels. Furthermore, the consumption of certain foods can also raise oxygen saturation levels. Maintaining a high blood oxygen level during exercise can improve athletic performance and reduce injury risk. However, during exercise, the blood oxygen level tends to decrease as the heart rate increases to supply more oxygen to the body. When the blood oxygen level drops too low during exercise, it can lead to fatigue, shortness of breath, and even fainting. By tracking heartbeats, blood oxygen levels, and other physiological parameters during exercise with the YAMAY Smart Watch wearable device, individuals can gain insights into their body's response to physical activity and adjust their exercise routine accordingly. After collecting data using wearable devices and mobile apps, machine learning algorithms can be trained to predict changes in physiological parameters of post-activity, providing valuable insights into the effectiveness of different exercises and identifying potential health risks. Our study used supervised machine learning classification algorithms to predict the expected data with the target data. We used K-fold cross-validation techniques to split the dataset into training, validation, and test sets for the supervised machine learning classification algorithms. After testing each of the machine learning models (K-Nearest Neighbor (KNN), Naïve Bayes, and Random Forest), it was found that the Random Forest had the best prediction accuracy of 98.75%. On the other hand, KNN had a poor prediction accuracy, lower than 41.1%. Therefore, the Random Forest model can accurately predict the effect of change on the oxygen saturation level during exercise.

Effect of Different Early Oxygenation Levels on Clinical Outcomes of Patients Presenting in the Emergency Department With Severe Traumatic Brain Injury.

Despite the almost universal administration of supplemental oxygen in patients presenting in the emergency department (ED) with severe traumatic brain injury, optimal early oxygenation levels are unknown. Therefore, we aimed to examine the effect of different early oxygenation levels on the clinical outcomes of patients presenting in the emergency department with severe traumatic brain injury. We performed a secondary analysis of the Resuscitation Outcomes Consortium Traumatic Brain Injury Hypertonic Saline randomized controlled trial by including patients with Glasgow Coma Scale ≤8. Early oxygenation levels were assessed by the worst value of arterial partial pressure of oxygen (PaO2) during the first 4 hours of presentation in the emergency department. The primary outcome was 6-month neurologic status, as assessed by the Extended Glasgow Outcome Scale. A binary logistic regression was utilized, and an odds ratio (OR) with 95% (95% confidence intervals) was calculated. A total of 910 patients were included. In unadjusted (crude) analysis, a PaO2 of 101 to 250 mmHg (OR, 0.59 [0.38 to 0.91]), or 251 to 400 mmHg (OR, 0.53 [0.34 to 0.83]) or ≥401 mmHg (OR, 0.31 [0.20 to 0.49]) was less likely to be associated with poor neurologic status when compared with a PaO2 of ≤100 mmHg. This was also the case for adjusted analyses (including age, pupillary reactivity, and Revised Trauma Score). High oxygenation levels as early as the first 4 hours of presentation in the emergency department may not be adversely associated with the long-term neurologic status of patients with severe traumatic brain injury. Therefore, during the early phase of trauma, clinicians may focus on stabilizing patients while giving low priority to the titration of oxygenation levels.

Abstract Number ‐ 8: HEMERA 1 CarboxyHEMoglobin OxygEn delivery for Revascularization in Acute Stroke: Phase 1 Clinical Trial

Introduction Despitehigh rates ofrecanalizationafter mechanical thrombectomy(MT),only 33–71% of patients achieve functional independence at 90 days.Experimental ischemia hashighlightedthe complexity of several pathophysiological events occurring at the level of the neurovascular unit and has revealed potential targets for neuroprotection. Apossible target is to increasebloodflow in the collateral circulationwhile delivering high levels of oxygen in the ischemic area.Hemoglobin based oxygen carriers (HBOC) as a transfusion media that can treat ischemic tissue have been investigatedfor a decade. More recently, a polyethylene glycol modifiedHBOCin the carboxy state (PP‐007)increases blood flow in the collateral circulationinrat modelsof middle cerebral artery occlusion (MCAO).PP‐007 may deliver more oxygen than Hb contained in RBCs because of increased diffusional surface area in plasma, and by facilitation of oxygen transport from RBC to endothelium.In addition,dilation ofcollateral circulationby diffusion of CO mayslow down infarct expansion andimprove the efficacy of reperfusion. Methods HEMERA 1 is a phase 1 safety clinical trialof PP‐007 in patient with acute ischemic strokewith LVO (ClinicalTrials.gov NCT04677777). Inclusion criteria are patients with Intracranial ICA and/or MCA‐M1 or M2 occlusion,baseline NIHSS ≥ 6, Baseline ASPECTS score ≥ 5 on NCCT and/or Core Volumes <70mL + Mismatch > 50mL on CT perfusion (CTP), time fromlast seen well to start ofPP‐007infusion ≤ 24 hours,pre‐MorbidmRS< 2, and ineligibility for intravenous thrombolysis. The trial plans to enroll approximately 16–20 subjectswith3:1 randomizationtoPP‐007 (320 mg/kg with 30 min bolus + 2‐hour infusion) plus MT versus MT alone. Results Tenpatients have been enrolled so far.Mean age was 76.1 (STD±11.6), ASPECT score = 7.8 (±1.8), NIHSS at baseline = 17.3 (±5.6),TICI 2b or c in 7, TICI 3 in 3. Seven patients were randomized PP‐007 and received the complete infusion. Two patients were randomized to standard of care (MT only) and1was randomized to PP‐007 but not treated.Three patients had elevation of Partial Prothrombin Time (PTT) after the PP‐007 infusion that however had no clinical consequences. Conclusions HEMERA 1 isphase 1 clinical trialcurrently enrolling patients.No safety concerns were identified so far.

Steroids use in Severe/ Life Threatening COVID-19 Pneumonia: Does the Type or Dose Matter?

Objective: To compare the effect of different doses of methylprednisolone and dexamethasone on in-hospital mortality in severe COVID-19 pneumonia Methods: This retrospective chart review was done by reviewing old medical reports of patients with severe
 disease admitted to COVID-19 Intensive Care and High Dependency Unit from October 2020 to September 2021. Those with suspected COVID-19 infection (suggestive radiological findings but negative PCR for SARSCoV- 2 on at least two occasions) were excluded. Patients requiring high flow oxygen (>6 liters per minute) or higher levels of respiratory support were classified as having severe disease. We recorded the type of steroids used and the doses. Methylprednisolone in doses up to 40mg per day, or other steroids in equivalent doses, were considered low dose. Primary outcome of interest was in- hospital mortality. Results: There were 279 patients aged 52.53± 11.31 years, including 216 (77.42%) males. Mean hospital stay was 10.18± 3.13 days. During hospital stay, 96 (34.41%) patients died. Amongst patients receiving dexamethasone, 70 (44.87%) expired, whereas 26 (21.14%) out of 123 patients who received methylprednisolone expired (p

Simulation of exchange routes on the Qinghai-Tibetan Plateau shows succession from the neolithic to the bronze age and strong control of the physical environment and production mode

The Qinghai-Tibetan Plateau (QTP) is essential for converging eastern, western, and northern prehistoric cultural spheres of Asia and Europe and for human adaptation to extreme environments. Reconstruction of the location and development of prehistoric exchange routes on the Qinghai-Tibetan Plateau underpins understanding human response to harsh environments and interaction and exchange between the three cultural spheres. This study simulates exchange routes for the Neolithic and Bronze Ages, using elevation, slope, vegetation, and rivers as cost data and site points as node data. A weighted network consisting of nodes and lines is constructed within the Qinghai-Tibetan Plateau using a weighted cumulative cyclic connectivity model among nodes-the simulation abstracts exchange routes as a path search problem on this weighted network. The final simulated route is the road with the lowest incremental cost. The results give a total length of Neolithic routes of about 16,900 km, with 15 main roads, and a total length of Bronze Age routes of approximately 16,300 km, with 18 main roads. Pathway development from the Neolithic to the Bronze Age shows an apparent successional relationship, with a spatial evolution from the marginal corridor to the marginal hinterland. The simulated routes overlap highly with archaeological evidence for transmission routes of corn and millet agriculture and wheat agriculture-domesticated animals-bronze metallurgy technology, indicating the reliability of the simulation results. Further analysis showed that the unique physical geography of the QTP constrained the formation and evolution of routes. River valleys were commonly chosen as routes to acclimatize people to the high, cold, and low oxygen levels of the Qinghai-Tibetan Plateau. Scattered small agricultural bases, established in areas of the QTP suitable for agricultural planting, are the basis for intersecting exchange routes. Road formation also reflects the clear differentiation in the agro-pastoral industry between high and low altitudes related to climate, ecological environment, and elevation. Interaction between agricultural and nomadic populations is the crucial motivation for forming and developing the exchange routes.

Influences of oxygen and temperature interaction on the antibacterial activity, antioxidant activity, serum biochemical indices, blood indices and growth performance of crucian carp.

The well-being of fish used in aquaculture is of great interest. Oxygen and temperature are the main factors affecting the welfare of the crucian carp (carassius); however, there are few studies on the combined effects of these on the species. Therefore, this study investigated the impact of different temperatures (18°C, 24°C, 30°C) and oxygen concentrations (2.1 mgL-1, 5.4 mgL-1, 9.3 mgL-1) on serum antibacterial activity, antioxidant activity, hematological parameters and growth performance of the crucian carp. The results showed that there were greater antibacterial properties under conditions of hypoxia at 18°C (L18) and hyperoxia at 24°C (H24). The activities of catalase, glutathione peroxidase and total superoxide dismutase were the highest at 24°C under hypoxia and hyperoxia. In addition, the contents of glucose and total protein first increased and then decreased with the change of temperature; triglycerides were the lowest at 30°C. The blood parameters of the carp were within a normal range at 24°C; however, the growth rate was at its lowest under hypoxia treatment at 30°C (L30). This study showed that high temperature impairs the antibacterial ability, antioxidant capacity and growth performance of the crucian carp, and high oxygen levels can alleviate these adverse reactions. This research provides a theoretical basis for subsequent aquaculture studies.

Ruthenium(II) polypyridyl complexes with visible light-enhanced anticancer activity and multimodal cell imaging.

Ruthenium(II) polypyridyl complexes have drawn growing attention due to their photophysical properties and anticancer activity. Herein we report four ruthenium(II) polypyridyl complexes [(N^N)2RuII(L)]2+ (1-4, L = 4-anilinoquinazoline derivatives, N^N = bidentate ligands with bis-nitrogen donors) as multi-functional anticancer agents. The epidermal growth factor receptor (EGFR) is overexpressed in a broad range of cancer cells and related to many kinds of malignance. EGFR inhibitors, such as gefitinib and erlotinib, have been approved as clinical anticancer drugs. The EGFR-inhibiting 4-anilinoquinazoline ligands greatly enhanced the in vitro anticancer activity of these ruthenium(II) polypyridyl complexes against a series of human cancer cell lines compared to [Ru(bpy)2(phen)], but interestingly, these complexes were actually not potent EGFR inhibitors. Further mechanism studies revealed that upon irradiation with visible light, complexes 3 and 4 generated a high level of singlet oxygen (1O2), and their in vitro anticancer activities against human non-small-cell lung (A549), cervical (HeLa) and squamous (A431) cancer cells were significantly improved. Specifically, complex 3 displayed potent phototoxicity upon irradiation with blue light, of which the photo-toxicity indexes (PIs) against HeLa and A431 cells were 11 and 8.3, respectively. These complexes exhibited strong fluorescence emission at ca. 600 nm upon excitation at about 450 nm. A subcellular distribution study by fluorescence microscopy imaging and secondary ion mass spectrometry imaging (ToF-SIMS) demonstrated that complex 3 mainly localized at the cytoplasm and complex 4 mainly localized in the nuclei of cells. Competitive binding with ctDNA showed that complex 4 was more favorable to bind to the DNA minor groove than complex 3. These differences support that complex 3 possibly exerts its anticancer activities majorly by photo-induced 1O2 generation and complex 4 by binding to DNA.