Oxygen Sensor Research Articles

How can inhibition of glucose and sodium transport in the early proximal tubule protect the cardiorenal system?

What mechanisms can link the inhibition of sodium-glucose cotransporter 2 (SGLT2) in the early proximal tubule to kidney and heart protection in patients with and without type 2 diabetes? Due to physical and functional coupling of SGLT2 to other sodium and metabolite transporters in the early proximal tubule (including NHE3, URAT1), inhibitors of SGLT2 (SGLT2i) reduce reabsorption not only of glucose, inducing osmotic diuresis, but of other metabolites plus of a larger amount of sodium than expected based on SGLT2 inhibition alone, thereby reducing volume retention, hypertension and hyperuricemia. Metabolic adaptations to SGLT2i include a fasting-like response, with enhanced lipolysis and formation of ketone bodies that serve as additional fuel for kidneys and heart. Making use of the physiology of tubulo-glomerular communication, SGLT2i functionally lower glomerular capillary pressure and filtration rate, thereby reducing physical stress on the glomerular filtration barrier, tubular exposure to albumin and nephrotoxic compounds, and the oxygen demand for reabsorbing the filtered load. Together with reduced gluco-toxicity in the early proximal tubule and better distribution of transport work along the nephron, SGLT2i can preserve tubular integrity and transport function and, thereby, glomerular filtration rate in the long-term. By shifting transport downstream, SGLT2i may simulate systemic hypoxia at the oxygen sensors in the deep cortex/outer medulla, which stimulates erythropoiesis and, together with osmotic diuresis, enhances hematocrit and thereby improves oxygen delivery to all organs. The described SGLT2-dependent effects may be complemented by off-target effects of SGLT2i on the heart itself and on the microbiome formation of cardiovascular-effective uremic toxins.

Exploring the effect of porphyrin chemical structure on the performance of polymer-based Pressure-Sensitive Paints

Pressure sensitive paints (PSPs) are a powerful optical oxygen sensor technique for measuring the surface pressure distribution upon an aircraft model in wind tunnel testing. Traditional PSPs have relied heavily on platinum(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin due to its reasonable quantum yield of emission, high pressure sensitivity, resistance to photo oxidation, and commercial availability. This work investigates the effect of luminophore chemical structure on PSP performance by altering the degree, substitution pattern, and nature of halogen atom on the phenyl groups of ten different Pt(II) tetraphenyl porphyrins. From this initial screening it was found that platinum(II)-5,10,15,20-tetrakis-(3,5-bis(trifluoromethyl)phenyl)-porphyrin polymer PSPs had a substantially lower temperature sensitivity and a slightly higher pressure sensitivity. Using this new luminophore a Fluoro/Isopropyl/Butyl (FIB) polymer based PSP formulation was optimised whereby it was found that 3.2% w/v of FIB polymer and 800 μM concentration of platinum(II)-5,10,15,20-tetrakis-(3,5-bis(trifluoromethyl)phenyl)-porphyrin gave a low temperature sensitivity at 100 kPa for a single component polymer based PSP of 0.22%/K and a relatively high pressure sensitivity at 293 K of 0.846, exceeding current commercial PSP performance.

Overview of the use of oxygen sensors in automotive applications

In the process of combustion, the air-fuel ratio is important for control strategies to reduce fuel economy and improve engine performance. Oxygen sensors are key elements in electronic fuel injection systems to indicate the oxygen content and send electrical signals to the electronic control unit. Starting with the first generation of oxygen sensors, which had limited applications, all automotive manufacturers now use wideband sensors to detect oxygen concentration with rapid reaction and linear output characteristics. Also, these new sensors provide accurate information for a wide range of air coefficients (λ = 0.65-2.4), improving combustion efficiency. In this paper, several types of narrowband and wideband sensors were analyzed, measuring the activation temperature for each sensor until a reliable signal was obtained.

Study of Low-Cost Network-Enabled dissolved oxygen sensor

Dissolved oxygen (DO) is an important index to evaluate water quality, and its concentration is of great significance in various applications. In the present work, a low-cost Network-Enabled DO sensor using a galvanic probe with a simplified design is studied compared to high-end counterparts. A Nanobubble machine was used to vary the DO, and following which the DO was measured. For comparison, certified DO sensors (YSI) are also used. There was no significant difference in the measured DO between the certified and low-cost DO sensors. The calculated average error was found to be ± 0.6 mg/L which is encouraging to use of low-cost Network-Enabled DO sensors.

Vertical distribution patterns of chlorophyll-a during autumn in a coastal environment inside the Gulf of California

An evaluation of the vertical distribution of chlorophyll-a (Chl-a) levels, as an indicator of phytoplankton biomass, has strong repercussions in any marine ecosystem since it allows evaluating its productive potential and the amount of matter that is available for the higher trophic levels of the pelagic food web. This short communication aims to report the vertical distribution patterns of Chl-a levels and some selected hydrographic parameters during autumn in the Bay of La Paz, the biggest and deepest coastal environment inside the Gulf of California, a site also recognized for its high biodiversity. Two oceanographic research cruises were carried out during November 2014 and 2016. A CTD probe configured with dissolved oxygen and active fluorescence sensors, all pre-calibrated by the manufacturer, was used to acquire high-resolution data along the water column. The results showed two distribution patterns of Chl-a: 1) deep peaks (>60 m depth, with concentrations >6 mg m-3) associated with the bottom at nearshore stations, and 2) maximum concentration peaks associated with the thermocline/pycnocline with concentrations up to 7.40 mg m-3 observed at deep stations. A multivariate statistical analysis confirmed the role played by some physical variables in the distribution patterns described. The results shown in this study complement the previous research and fill in the existing gaps for the transition periods between the warm and the cold.

Prolyl hydroxylase domain inhibitor is an effective pre-hospital pharmaceutical intervention for trauma and hemorrhagic shock

Pre-hospital potentially preventable trauma related deaths are mainly due to hypoperfusion-induced tissue hypoxia leading to irreversible organ dysfunction at or near the point of injury or during transportation prior to receiving definitive therapy. The prolyl hydroxylase domain (PHD) is an oxygen sensor that regulates tissue adaptation to hypoxia by stabilizing hypoxia inducible factor (HIF). The benefit of PHD inhibitors (PHDi) in the treatment of anemia and lactatemia arises from HIF stabilization, which stimulates endogenous production of erythropoietin and activates lactate recycling through gluconeogenesis. The results of this study provide insight into the therapeutic roles of MK-8617, a pan-inhibitor of PHD-1, 2, and 3, in the mitigation of lactatemia in anesthetized rats with polytrauma and hemorrhagic shock. Additionally, in an anesthetized rat model of lethal decompensated hemorrhagic shock, acute administration of MK-8617 significantly improves one-hour survival and maintains survival at least until 4 h following limited resuscitation with whole blood (20% EBV) at one hour after hemorrhage. This study suggests that pharmaceutical interventions to inhibit prolyl hydroxylase activity can be used as a potential pre-hospital countermeasure for trauma and hemorrhage at or near the point of injury.

Dopants Induce Persistent Room Temperature Phosphorescence in Triarylamine Boronate Esters

AbstractPurely organic materials exhibiting room temperature phosphorescence (RTP) are promising candidates for oxygen sensors and information encryption owing to their cost‐effective and environmentally friendly nature. Herein, we report a bimolecular RTP system where DTBU acts as the guest and TBBU serves as the host. In contrast to previously reported results, we find that both pure DTBU and TBBU do not exhibit RTP in the solid state even under N2 atmosphere. A DTBU/TBBU system with a low doping ratio (0.1 mol %) exhibits persistent yellowish‐green afterglow with a lifetime of 340 ms and is highly sensitive to oxygen. A DTBU/TBBU system with a higher doping ratio (10 mol %) maintains a phosphorescence lifetime of 179 ms under air. Applications of DTBU/TBBU at varied doping ratios in both oxygen sensing and information encryption are demonstrated. We propose that the T1 state of TBBU acts as an energy transfer intermediate between Tn and T1 of DTBU, ultimately leading to the generation of persistent RTP. Overall, this work demonstrates the critical importance of material purity in the design of RTP systems, and how an understanding of host–guest doping enables their photophysical properties to be precisely tuned.

Dopants Induce Persistent Room Temperature Phosphorescence in Triarylamine Boronate Esters.

Purely organic materials exhibiting room temperature phosphorescence (RTP) are promising candidates for oxygen sensors and information encryption owing to their cost-effective and environmentally friendly nature. Herein, we report a bimolecular RTP system where DTBU acts as the guest and TBBU serves as the host. In contrast to previously reported results, we find that both pure DTBU and TBBU do not exhibit RTP in the solid state even under N2 atmosphere. A DTBU/TBBU system with a low doping ratio (0.1 mol %) exhibits persistent yellowish-green afterglow with a lifetime of 340 ms and is highly sensitive to oxygen. A DTBU/TBBU system with a higher doping ratio (10 mol %) maintains a phosphorescence lifetime of 179 ms under air. Applications of DTBU/TBBU at varied doping ratios in both oxygen sensing and information encryption are demonstrated. We propose that the T1 state of TBBU acts as an energy transfer intermediate between Tn and T1 of DTBU, ultimately leading to the generation of persistent RTP. Overall, this work demonstrates the critical importance of material purity in the design of RTP systems, and how an understanding of host-guest doping enables their photophysical properties to be precisely tuned.

Ti-Doped AgNbO3 as Novel Dense Diffusion Barriers of Limiting Current Oxygen Sensors

Ti-Doped AgNbO₃ as Novel Dense Diffusion Barriers of Limiting Current Oxygen Sensors

(136) Development and Evaluation of a Novel Penile Blood Oxygen Sensor for Assessing Tissue Oxygenation

Abstract Introduction Penile blood oxygen concentration is a relatively unexplored clinical parameter that can provide valuable insights into various disease processes. Despite the significant role of oxygenation in maintaining penile tissue health and function, there is a paucity of research focusing specifically on monitoring penile blood oxygen levels. This knowledge gap hinders our understanding of the physiological and pathophysiological mechanisms underlying penile disorders and limits the development of targeted therapeutic interventions. Objective The aim of this project was to develop and test a novel noninvasive penile blood oxygen sensor that can accurately assess the oxygen concentration in the penis, enabling a deeper exploration of its clinical significance and potential implications in disease management. Methods We developed a novel prototype of an oxygen sensor designed specifically for penile blood-oxygen assessment. Ethical approval from the Institutional Review Board (IRB) was obtained prior to conducting the study. The trial participants consisted exclusively of patients scheduled to undergo penile duplex ultrasonography at our center. The study population was categorized into three distinct groups: the first group comprised patients diagnosed with Peyronie's Disease (PD) but without clinical erectile dysfunction (ED), serving as our control group; the second group consisted of patients clinically diagnosed with ED, who utilized the sensor with a band and an adhesive film; and the third group included patients who used the sensor without the adhesive film. Results At the time of submission, preliminary data analysis was performed for multiple patients with ED. The analysis of sensor data revealed a distinctive pattern during the initial calibration period, wherein the penile partial pressure of oxygen (pO2) exhibited a gradual decline, likely due to equilibration of the sensor with the penile oxygen concentration. Following the injection, a sharp increase in penile oxygen concentration was observed. Approximately 3-5 minutes following erection, the data from multiple patients showed a discernible downward trend towards the baseline level in penile pO2 levels, and changes in penile oxygenation could be detected as a result of penile manipulation both prior to and after injection. An examination of a patient’s penile changes in pO2 is summarized in Figure 1. Conclusions The observed temporal sequence of changes in penile oxygenation offers valuable insights into the dynamic physiological responses that occur during distinct stages of the erectile process. These findings contribute to our understanding of the intricate mechanisms underlying penile vascular physiology and their roles in erectile function. An analysis of the full patient cohort is currently ongoing. Disclosure Yes, this is sponsored by industry/sponsor: PETROS. Clarification: Industry funding only - investigator initiated and executed study. Any of the authors act as a consultant, employee or shareholder of an industry for: Disclosures: Consultant for AbbVie, Marius, Tolmar, Endo, Petros, Boston Scientific, Coloplast Investor: Sprout.

Oxygen-dependent histone lysine demethylase 4 restricts hepatitis B virus replication

Mammalian cells have evolved strategies to regulate gene expression when oxygen is limited. Hypoxia-inducible factors (HIF) are the major transcriptional regulators of host gene expression. We previously reported that HIFs bind and activate hepatitis B virus (HBV) DNA transcription under low oxygen conditions; however, the global cellular response to low oxygen is mediated by a family of oxygenases that work in concert with HIFs. Recent studies have identified a role for chromatin modifiers in sensing cellular oxygen and orchestrating transcriptional responses, but their role in the HBV life cycle is as yet undefined. We demonstrated that histone lysine demethylase 4 (KDM4) can restrict HBV, and pharmacological or oxygen-mediated inhibition of the demethylase increases viral RNAs derived from both episomal and integrated copies of the viral genome. Sequencing studies demonstrated that KDM4 is a major regulator of the hepatic transcriptome, which defines hepatocellular permissivity to HBV infection. We propose a model where HBV exploits cellular oxygen sensors to replicate and persist in the liver. Understanding oxygen-dependent pathways that regulate HBV infection will facilitate the development of physiologically relevant cell-based models that support efficient HBV replication.

Transferability Assessment of OBD-Related Calibration and Validation Activities from the Vehicle to HiL Applications

With the Euro 7 pollutant emission legislation currently under discussion, advanced and more efficient exhaust aftertreatment systems are being developed. The technologies required for these are leading to an increase in the number of components and control systems requiring diagnoses strategies under the on-board diagnostics (OBD) legislation. With concurrent shorter development times and significant reductions in budgets allocated to conventional powertrain development, challenges in the field of OBD calibration and verification are already rising sharply. In response to these challenges, hardware-in-the-loop (HiL) approaches have been successfully introduced to support and replace conventional development methods. The use of complex simulation models significantly improves the quality of calibrations while minimizing the number of required prototype vehicles and test resources, thus reducing development costs. This paper presents a feasibility study for moving OBD-related calibration and validation tasks from the vehicle to a HiL platform. In this context, the calibration and verification process of an active diagnostic for monitoring the condition of the three-way catalyst (TWC) and the oxygen sensors in the exhaust aftertreatment system is presented. It is shown that all relevant signals are simulated with sufficient accuracy to ensure a robust transfer from the vehicle to a HiL test bench. Special attention is given to the simulation of aged components and their influence on the emission behavior of the system. Furthermore, it is discussed that transferring OBD tasks from the vehicle to the HiL test bench could result in significant savings in development time and a reduction in the number of physical prototype vehicles and test resources required.

An Indirect Method for the Estimation of Sodium Vapour Concentration Using an Online Oxygen Sensor

An online method is developed for the estimation of sodium vapour concentration in a confined volume using an oxygen sensor. First, the sodium vapour is made to react with a known amount of oxygen and the change in oxygen concentration in the presence and absence of the sodium vapour are measured using a YSZ-based potentiometric sensor. The sodium vapour concentration in the confined volume is then calculated from the consumed oxygen concentration. This methodology utilizes an indirect way for the estimation of sodium vapour concentration.

Abstract WMP1: Neuroprotection by Normobaric Oxygen (NBO): Modulating Inflammasome (NLRP3) Activation and Stress Granule Formation in Ischemic Stroke

Background: NBO has emerged as a promising neuroprotective strategy for ischemic stroke. Key to comprehending these effects is understanding its mechanisms. This study examines the pivotal roles of HIF-1α as an oxygen sensor, the protective emergence of stress granules (SGs) in response to various stimuli, and the inflammatory cell death process known as pyroptosis, triggered by inflammasomes. We elucidated the interplay between HIF-1α, SGs, inflammasomes in ischemia/reperfusion injury and in NBO-induced neuroprotection. Methods: A total of 132 adult male SD rats were subjected to 2 h middle cerebral artery occlusion (MCAO), followed by 2, 6, 24 or 48 h of reperfusion. At the onset of reperfusion, oxygen was inhaled for 2 h at concentration of 95% and flow rate of 2 L/min. YC-1 (HIF-1α inhibitor) was administered 2 h before MCAO. Brain damage was evaluated by infarct volumes (TTC), LDH and ROS levels (ELISA), apoptotic cell death (flow cytometry and TUNEL). Pyroptosis was evaluated by flow cytometry. mRNA and protein levels of HIF-1α and inflammasome related factors, including IL-18, IL-1β, ASC, NLRP3, TXNIP, N-GSDMD, cleaved-Caspase-1, as well as SGs proteins including DDX3X, G3BP1, TIA-1 were examined. Co-IP was used to detect the interaction between DDX3X and G3BP1, as well as DDX3X and NLRP3. Results: Infarct volumes, LDH and ROS levels, apoptotic and pyroptotic cell death, as well as HIF-1α expression were all increased after ischemia/reperfusion. All these increases were reversed by either NBO or YC-1. NBO or YC-1 further reversed the increase in expression of NLRP3 inflammasome related proteins and suppressed the interaction between DDX3X and NLRP3, thereby suppressing inflammasome activation. NBO or YC-1 stimulated the expressions of SGs proteins and facilitated the interaction between DDX3X and G3BP1, thereby promoting the formation of SGs, in association with cell protection. Conclusion: Our findings highlight the neuroprotective effects of NBO in ischemic stroke. This protection is attributed to its dual capacity to inhibit NLRP3 inflammasome activation while simultaneously promoting formation of SGs. Central to these processes, HIF-1α, as an instrumental modulator, sheds light on potential therapeutic targets for stroke intervention.

Development of an IoT-Based Automatic Remote Health Monitoring System

A well-planned health monitoring system is essential for the modern health center, and a portable remote health monitoring system with many intellectual features is becoming a great improvement in healthcare arrangements. The proposed system includes various micro-electronics medical devices and applications that come through network-connected devices and help to monitor patients' real-time medical data. In this paper, the patient's health condition has been monitored by using the four types of major health parameters temperature sensor, heart pulse rate sensor, blood pressure sensor module, and blood oxygen (SpO2) sensor. All the sensor nodes are connected to the Raspberry Pi-based embedded system. The real-time health data are recorded, stored, and transmitted to the doctor via the internet with the help of a Raspberry Pi-based embedded system and IoT server. The system will benefit the patient from remote areas with quick diagnosis, remote observation, home observation, and a medical data storage system. Journal of Engineering Science 14(2), 2023, 21-30

Oceanographic dataset collected during the 2021 scientific expedition of the Canadian Coast Guard Ship Amundsen

Abstract. Since 2003, the state-of-the-art Canadian Coast Guard Ship (CCGS) research icebreaker Amundsen has furrowed the Canadian Arctic waters to support novel research endeavors and collect oceanographic data. This paper presents the data acquisition, the processing methods and an overview of the data collected during the 2021 expedition as the ship traveled over 30 000 km during 122 d across the Canadian Arctic Ocean, collecting sea surface, atmospheric and seabed underway measurements. A total of 266 casts of a conductivity, temperature and depth profiler mounted on a Conductivity Temperature Depth rosette (CTD Rosette) were also conducted to monitor the main physical, chemical and biological parameters of the water column. More specifically, the data presented here were collected with the CTD Rosette across historical sampling transects in Davis Strait, the North Water Polynya (NOW) and Cape Bathurst. A 182 km dedicated survey using the Moving Vessel Profiler® (MVP), equipped with CTD, transmissometer, dissolved oxygen, fluorescence and sound velocity sensors, was conducted across Hudson Strait. We also present an overview of the data collected by the underway systems (seabed, thermosalinograph and atmospheric). Such data are essential in understanding the impacts of climate warming on the unique environments of the Canadian Arctic Ocean. Amundsen Science supports and promotes easy access and sharing of such valuable data to the scientific community.

Brain oxygen responses induced by opioids: focus on heroin, fentanyl, and their adulterants.

Opioids are important tools for pain management, but abuse can result in serious health complications. Of these complications, respiratory depression that leads to brain hypoxia is the most dangerous, resulting in coma and death. Although all opioids at large doses induce brain hypoxia, danger is magnified with synthetic opioids such as fentanyl and structurally similar analogs. These drugs are highly potent, act rapidly, and are often not effectively treated by naloxone, the standard of care for opioid-induced respiratory depression. The goal of this review paper is to present and discuss brain oxygen responses induced by opioids, focusing on heroin and fentanyl. In contrast to studying drug-induced changes in respiratory activity, we used chronically implanted oxygen sensors coupled with high-speed amperometry to directly evaluate physiological and drug-induced fluctuations in brain oxygen levels in awake, freely moving rats. First, we provide an overview of brain oxygen responses to physiological stimuli and discuss the mechanisms regulating oxygen entry into brain tissue. Next, we present data on brain oxygen responses induced by heroin and fentanyl and review underlying mechanisms. These data allowed us to compare the effects of these drugs on brain oxygen in terms of their potency, time-dependent response pattern, and potentially lethal effect at high doses. Then, we present the interactive effects of opioids during polysubstance use (alcohol, ketamine, xylazine) on brain oxygenation. Finally, we consider factors that affect the therapeutic potential of naloxone, focusing on dosage, timing of drug delivery, and contamination of opioids by other neuroactive drugs. The latter issue is considered chiefly with respect to xylazine, which strongly potentiates the hypoxic effects of heroin and fentanyl. Although this work was done in rats, the data are human relevant and will aid in addressing the alarming rise in lethality associated with opioid misuse.

Highly deformable and strongly magnetic semi-interpenetrating hydrogels based on alginate or cellulose

The effective implementation of many of the applications of magnetic hydrogels requires the development of innovative systems capable of withstanding a substantial load of magnetic particles to ensure exceptional responsiveness, without compromising their reliability and stability. To address this challenge, double-network hydrogels have emerged as a promising foundation, thanks to their extraordinary mechanical deformability and toughness. Here, we report a semi-interpenetrating polymer networks (SIPNs) approach to create diverse magnetic SIPNs hydrogels based on alginate or cellulose, exhibiting remarkable deformability under certain stresses. Achieving strong responsiveness to magnetic fields is a key objective, and this characteristic is realized by the incorporation of highly magnetic iron microparticles at moderately large concentrations into the polymer network. Remarkably, the SIPNs hydrogels developed in this research accommodate high loadings of magnetic particles without significantly compromising their physical properties. This feature is essential for their use in applications that demand robust responsiveness to applied magnetic fields and overall stability, such as a hydrogel luminescent oxygen sensor controlled by magnetic fields that we designed and tested as proof-of-concept. These findings underscore the potential and versatility of magnetic SIPNs hydrogels based on carbohydrate biopolymers as fundamental components in driving the progress of advanced hydrogels for diverse practical implementations.

Bromine indirubin FLIM/PLIM sensors to measure oxygen in normoxic and hypoxic PDT conditions

BackgroundThe induction of phototoxicity during photodynamic therapy (PDT) is dependent on oxygen availability. For this reason, the development of sensors to measure oxygen and oxygen consumption is extremely important. ApproachIn this project we have used Fluorescence Lifetime imaging (FLIM) and Phosphorescence Lifetime Imaging/ delayed Fluorescence Lifetime Imaging (PLIM/dFLIM) to investigate the ability of bromine indirubin derivatives as oxygen sensors. ResultsThe oxygen sensitivity of bromine indirubins was detected through PLIM/dFLIM. Moreover, we have observed, by measuring nicotinamide adenine dinucleotide (NADH) FLIM, that bromine indirubin has a significant impact on cellular metabolism by shifting the SCC-4 Cells metabolism from oxidative phosphorylation (OXPHOS) to glycolysis. ConclusionsIn conclusion, this study successfully achieves its goals and provides important insights into the use of indirubin as a potential oxygen consumption sensor with the capability to identify and differentiate between normoxic and hypoxic regions within the cells.

Personal safety monitoring system of electric power construction site based on AIoT Technology

For the purpose of real-time monitoring the hazard information on the electric power construction site, a personal safety monitoring system based on Artificial intelligence internet of things (AIoT) technology is designed. After the system sensing layer collects the gas information of the construction site through the gas sensor, limit current oxygen sensor and DS1820B temperature sensor, the edge computing device of the edge layer directly stores its calculation in the database of the platform layer through the data gateway. The Artificial Intelligence (AI) analysis module of this layer invokes the monitoring data of the power construction site of the database, and uses the personal safety identification method of the power construction site based on artificial intelligence technology, to complete the abnormal identification of monitoring data and realize personal safety monitoring. In addition, the system is also equipped with a power-fail detection module, which can collect the working voltage through the voltage transformer and compare it with the mains power standard to judge whether there is a power-fail risk, so as to prevent the problem of threatening personal safety due to the power-fail of the energized equipment. After testing, the system can monitor the operation status of the construction site in real time to protect personal safety.