Oxygen transport
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Bacterial ferrous iron transport: the Feo system Open
To maintain iron homeostasis within the cell, bacteria have evolved various types of iron acquisition systems. Ferric iron (Fe(3+)) is the dominant species in an oxygenated environment, while ferrous iron (Fe(2+)) is more abundant under an…
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Molecular Mechanisms of Iron and Heme Metabolism Open
An abundant metal in the human body, iron is essential for key biological pathways including oxygen transport, DNA metabolism, and mitochondrial function. Most iron is bound to heme but it can also be incorporated into iron-sulfur clusters…
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Effects of Oxygen Mobility in La–Fe-Based Perovskites on the Catalytic Activity and Selectivity of Methane Oxidation Open
The mechanism and structure requirements of selective and total oxidation of methane in a chemical looping process are both experimentally and theoretically examined on La1–xSrxFeO3−δ (x = 0, 0.2, and 0.5) and La0.5Sr0.5Fe1–xCoxO3−δ (x = 0…
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Regulation of blood flow and volume exchange across the microcirculation Open
Oxygen delivery to cells is the basic prerequisite of life. Within the human body, an ingenious oxygen delivery system, comprising steps of convection and diffusion from the upper airways via the lungs and the cardiovascular system to the …
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Understanding Lactatemia in Human Sepsis. Potential Impact for Early Management Open
Rationale: Hyperlactatemia in sepsis may derive from a prevalent impairment of oxygen supply/demand and/or oxygen use. Discriminating between these two mechanisms may be relevant for the early fluid resuscitation strategy.Objectives: To un…
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Oxygen solubility and transport in Li–air battery electrolytes: establishing criteria and strategies for electrolyte design Open
Li–air or Li–oxygen batteries promise significantly higher energies than existing commercial battery technologies, yet their development hinges on the discovery and selection of suitable electrolytes.
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Control of oxygen tension recapitulates zone-specific functions in human liver microphysiology systems Open
This article describes our next generation human Liver Acinus MicroPhysiology System (LAMPS). The key demonstration of this study was that Zone 1 and Zone 3 microenvironments can be established by controlling the oxygen tension in individu…
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How Bar-Headed Geese Fly Over the Himalayas Open
Bar-headed geese cross the Himalayas on one of the most iconic high-altitude migrations in the world. Heart rates and metabolic costs of flight increase with elevation and can be near maximal during steep climbs. Their ability to sustain t…
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Depth-dependent flow and pressure characteristics in cortical microvascular networks Open
A better knowledge of the flow and pressure distribution in realistic microvascular networks is needed for improving our understanding of neurovascular coupling mechanisms and the related measurement techniques. Here, numerical simulations…
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Heme as a Target for Therapeutic Interventions Open
Heme is a complex of iron and the tetrapyrrole protoporphyrin IX with essential functions in aerobic organisms. Heme is the prosthetic group of hemoproteins such as hemoglobin and myoglobin, which are crucial for reversible oxygen binding …
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A Nanomotor-Based Active Delivery System for Intracellular Oxygen Transport Open
Active transport of gas molecules is critical to preserve the physiological functions of organisms. Oxygen, as the most essential gas molecule, plays significant roles in maintaining the metabolism and viability of cells. Herein, we report…
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Impact of Microporous Layer Pore Properties on Liquid Water Transport in PEM Fuel Cells: Carbon Black Type and Perforation Open
The oxygen and water transport through various microporous layers (MPLs) is investigated by fuel cell tests in a 5 cm2 active area cell under differential-flow conditions, analyzing polarization curves, the associated high-frequency resist…
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Chloroplast Iron Transport Proteins – Function and Impact on Plant Physiology Open
Chloroplasts originated about three billion years ago by endosymbiosis of an ancestor of today's cyanobacteria with a mitochondria-containing host cell. During evolution chloroplasts of higher plants established as the site for photosynthe…
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Biomimetic Rebuilding of Multifunctional Red Blood Cells: Modular Design Using Functional Components Open
The design and synthesis of artificial materials that mimic the structures, mechanical properties, and ultimately functionalities of biological cells remains a current holy grail of materials science. Here, based on a silica cell bioreplic…
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Iron Metabolism in Cardiovascular Disease: Physiology, Mechanisms, and Therapeutic Targets Open
The cardiovascular system requires iron to maintain its high energy demands and metabolic activity. Iron plays a critical role in oxygen transport and storage, mitochondrial function, and enzyme activity. However, excess iron is also cardi…
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Influence of the Gas Diffusion Layer Compression on the Oxygen Transport in PEM Fuel Cells at High Water Saturation Levels Open
The impact of the gas diffusion layer (GDL) compression on the oxygen transport is investigated in single cell assemblies at 50°C, RH = 77%, 200 kPaabs and under differential flow conditions. For this, the oxygen transport resistance at lo…
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Textile Inspired Lithium–Oxygen Battery Cathode with Decoupled Oxygen and Electrolyte Pathways Open
The lithium–air (Li–O 2 ) battery has been deemed one of the most promising next‐generation energy‐storage devices due to its ultrahigh energy density. However, in conventional porous carbon–air cathodes, the oxygen gas and electrolyte oft…
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More homogeneous capillary flow and oxygenation in deeper cortical layers correlate with increased oxygen extraction Open
Our understanding of how capillary blood flow and oxygen distribute across cortical layers to meet the local metabolic demand is incomplete. We addressed this question by using two-photon imaging of resting-state microvascular oxygen parti…
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Symmorphosis and skeletal muscle : <i>in vivo</i> and <i>in vitro</i> measures reveal differing constraints in the exercise‐trained and untrained human Open
Key points The concept of symmorphosis predicts that the capacity of each step of the oxygen cascade is attuned to the task demanded of it during aerobic exercise at maximal rates of oxygen consumption ( ) such that no single process is li…
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Three-dimensional lattice-Boltzmann model for liquid water transport and oxygen diffusion in cathode of polymer electrolyte membrane fuel cell with electrochemical reaction Open
Polymer electrolyte membrane (PEM) fuel cells have higher efficiency and energy density and are capable of rapidly adjusting to power demands. Effective water management is one of the key issues for increasing the efficiency of PEMFC. In t…
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Analysis of Inkjet Printed PEFC Electrodes with Varying Platinum Loading Open
PEFC electrodes manufactured using inkjet printing are investigated. Cell performance, Tafel slope, reaction order and local oxygen transport resistance of electrodes with varying Pt loadings of 0.014 to 0.113 mg/cm2 are studied in order t…
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Oxygen supply capacity in animals evolves to meet maximum demand at the current oxygen partial pressure regardless of size or temperature Open
The capacity to extract oxygen from the environment and transport it to respiring tissues in support of metabolic demand reportedly has implications for species’ thermal tolerance, body-size, diversity and biogeography. Here we derive a qu…
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Red Blood Cell Metabolism In Vivo and In Vitro Open
Red blood cells (RBC) are the most abundant cell in the human body, with a central role in oxygen transport and its delivery to tissues. However, omics technologies recently revealed the unanticipated complexity of the RBC proteome and met…
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Mechanisms of Toxicity and Modulation of Hemoglobin-based Oxygen Carriers Open
Several adverse events have been associated with the infusion of hemoglobin-based oxygen carriers (HBOCs), including transient hypertension, gastrointestinal, pancreatic/liver enzyme elevation, and cardiac/renal injury in humans. Although …
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Factors Affecting Iron Absorption and Mitigation Mechanisms: A review Open
Iron has many special functions in the body. More than 65 percent of the body’s iron is in the blood in the form of hemoglobin, which is a protein in red blood cells that transports oxygen to tissues in the body. A compound that carries ox…
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Treatment of sickle cell disease by increasing oxygen affinity of hemoglobin Open
The issue of treating sickle cell disease with drugs that increase hemoglobin oxygen affinity has come to the fore with the US Food and Drug Administration approval in 2019 of voxelotor, the only antisickling drug approved since hydroxyure…
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Blood flow, capillary transit times, and tissue oxygenation: the centennial of capillary recruitment Open
The transport of oxygen between blood and tissue is limited by blood’s capillary transit time, understood as the time available for diffusion exchange before blood returns to the heart. If all capillaries contribute equally to tissue oxyge…
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High-altitude champions: birds that live and migrate at altitude Open
High altitude is physiologically challenging for vertebrate life for many reasons, including hypoxia (low environmental oxygen); yet, many birds thrive at altitude. Compared with mammals, birds have additional enhancements to their oxygen …
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Limitations to oxygen transport and utilization during sprint exercise in humans: evidence for a functional reserve in muscle O<sub>2</sub> diffusing capacity Open
Key points Severe acute hypoxia reduces sprint performance. Muscle during sprint exercise in normoxia is not limited by O 2 delivery, O 2 offloading from haemoglobin or structure‐dependent diffusion constraints in the skeletal muscle of yo…
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Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation Open
Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-le…