Amount Of Available Oxygen Research Articles

Study of the Structure of Zn and Na Borophosphate Glasses Using X-ray and Neutron Scattering Techniques

The atomic structures of Zn and Na borophosphate glasses were studied using X-ray and neutron scattering techniques. Peaks assigned to the B−O, P−O, and O−O distances confirm that only BO4 units co-exist with the PO4 tetrahedra. The Zn−O and Na−O coordination numbers are found to be a little larger than four. The narrowest peaks of the Zn−O first-neighbor distances exist for the glasses along a line connecting the Zn(PO3)2 and BPO4 compositions (50 mol% P2O5), which is explained by networks of ZnO4, BO4, and PO4 tetrahedra with twofold coordinated oxygens. The calculated amounts of available oxygen support this interpretation. Broadened peaks occur for glasses with lower P2O5 contents, which is consistent with the presence of threefold coordinated oxygens. The two distinct P−O peak components of the Zn and Na borophosphate glasses differ in their relative abundances. This is interpreted as follows: Na+ cations coordinate oxygens in some P−O−B bridges, which is something not seen for the Zn2+ ions.

Use of Meltblown Nonwoven Fabric Filter for Stormwater Runoff Treatment

Anthropogenic activities (e.g., rural urbanization) play major roles in preventing the achievement of sustainable water quality, where eutrophication—the exacerbation of increase in nutrient concentrations combined with warmer temperatures and lower light availability, leading to the dense growth of plant life depleting the amount of available oxygen and killing aquatic life—remains a major challenge for surface water bodies. Filtration mechanisms, with a wide range of applicability, capture common waterborne pathogens as small as 0.1–20.0 μm (bacteria, cysts, spores) and 0.001–0.100 μm (protein, viruses, endotoxins) through the process of microfiltration and ultrafiltration. This study follows the premise of using a designed water flow-through system, with meltblown nonwoven fabrics to measure its performance to capture water contaminant constituents of surface water contamination and eutrophication: total coliforms, nitrate, and orthophosphate. The achieved fabric filtration mechanism showed capture of total coliforms (59%), nitrate (51%), and orthophosphate (46%). The current study provides an alternative solution to more common and traditional water treatment technologies, such as chlorine and ozone disinfection, which (1) introduces disinfection or treatment byproducts and (2) cannot adapt to the permanent changing conditions and newer environmental challenges.

Edge effects on decomposition in Sphagnum bogs: Implications for carbon storage

AbstractPeatlands provide multiple ecosystem services, including extensive carbon sequestration and storage, yet many peatlands have been degraded or destroyed. Peatlands' carbon storage capacity is connected to inherently low decomposition rates, causing the buildup of organic matter. This pattern could be explained by waterlogged conditions that reduce the amount of available oxygen for the decomposer community, a low pH that inhibits bacterial decomposition, or colder temperatures lowering metabolic rates. This study focused on edge effects on decomposition in the transition zone (lagg) between Sphagnum bogs and the surrounding forest, with the expectation that decomposition is lowest in the bog and highest in the forest but with a mix of factors causing intermediate decomposition rates near the bog edge. Transitional decomposition rates were measured across six bogs in central Sweden during the summer of 2021, following the Tea Bag Index. Three 20‐m transects, each containing seven pairs of tea bags, were buried across the margins of each bog, centered at the edge of the Sphagnum moss. Soil moisture content, pH, and plant composition were also recorded at each burial site, and temperature loggers placed evenly among four of the bogs. Our results confirmed our hypothesis regarding edge effects, with soil moisture levels showing a strong negative interaction with decomposition rate. The interaction between pH and decomposition rate was significant, but with an unexpected negative relation, most likely due to low pH in the surrounding forest. Temperature displayed no significance, and plants indicative of low decomposition rates included Vaccinium oxycoccos, Drosera rotundifolia, and Sphagnum species. In contrast to other studies, we did not find an increase in decomposition with increased species richness among the studied bog ecosystems. In conclusion, there is an edge effect on decomposition, and maintaining, or restoring, the hydrology of a peatland is the most important factor for continued carbon storage, with a rough estimation of an area decomposition rate possible to be estimated based on its vegetation.

Fate & transport of vinyl chloride in soil vapor

AbstractVinyl chloride (VC) is a common risk driver in vapor intrusion (VI) studies. At many sites, initial screening shows potential indoor air impacts for VC at unacceptable levels. During follow‐up site characterization, however, the VI pathway for VC is rarely if ever found to be complete. This paper sets forth a conceptual model for understanding these results and summarizes data from several field sites to illustrate the concepts. VC can be formed under anaerobic conditions via reductive dechlorination of tetrachloroethylene or trichloroethylene. The ultimate fate of any VC that is produced depends on the amount of available oxygen. If sufficient oxygen is available, VC will readily undergo aerobic biodegradation. Data are presented for multiple field sites to illustrate the fate and transport of VC. The sites are drawn from various regions of the United States and cover a range of conditions. At these sites, VC was detected at relatively high concentrations in groundwater. It may also have been detected in deeper soil gas, but generally was fully attenuated before reaching shallow soil depths. Indoor air results were consistently non‐detect. The behavior is also discussed for sites with very shallow groundwater, where VC was found in some subslab soil gas samples but not in the overlying indoor air.

Pressure-assisted direct joining of Ti3AlC2 ceramics in air

We introduced a novel strategy for direct joining Ti3AlC2 ceramics in air without the need for any interlayer and vacuum/ inert gas protection. This was achieved by applying constant external pressure to manipulate the amount of available oxygen for oxidation at the Ti3AlC2―Ti3AlC2 interface. The shear strength of the joints bonded under a pressure of 10 MPa was approximately 3 times higher than that without pressure. The joining mechanisms were addressed based on the atomic interdiffusion and preferential oxidation of Al in lamellar Ti3AlC2 grains.

Porous Venturi-Orifice Microbubble Generator for Oxygen Dissolution in Water

Microbubbles with slow rising speed, higher specific area and greater oxygen dissolution are desired to enhance gas/liquid mass transfer rate. Such attributes are very important to tackle challenges on the low efficiency of gas/liquid mass transfer that occurs in aerobic wastewater treatment systems or in the aquaculture industries. Many reports focus on the formation mechanisms of the microbubbles, but with less emphasis on the system optimization and assessment of the aeration efficiency. This work assesses the performance and evaluates the aeration efficiency of a porous venturi-orifice microbubble generator (MBG). The increment of stream velocity along the venturi pathway and orifice ring leads to a pressure drop (Patm > Pabs) and subsequently to increased cavitation. The experiments were run under three conditions: various liquid velocity (QL) of 2.35–2.60 m/s at fixed gas velocity (Qg) of 3 L/min; various Qg of 1–5 L/min at fixed QL of 2.46 m/s; and free flowing air at variable QLs. Results show that increasing liquid velocities from 2.35 to 2.60 m/s imposes higher vacuum pressure of 0.84 to 2.27 kPa. They correspond to free-flowing air at rates of 3.2–5.6 L/min. When the system was tested at constant air velocity of 3 L/min and under variable liquid velocities, the oxygen dissolution rate peaks at liquid velocity of 2.46 m/s, which also provides the highest volumetric mass transfer coefficient (KLa) of 0.041 min−1 and the highest aeration efficiency of 0.287 kgO2/kWh. Under free-flowing air, the impact of QL is significant at a range of 2.35 to 2.46 m/s until reaching a plateau KLa value of 0.0416 min−1. The pattern of the KLa trend is mirrored by the aeration efficiency that reached the maximum value of 0.424 kgO2/kWh. The findings on the aeration efficiency reveals that the venturi-orifice MBG can be further optimized by focusing on the trade-off between air bubble size and the air volumetric velocity to balance between the amount of available oxygen to be transferred and the rate of the oxygen transfer.

Removal of Coomassie Brilliant Blue R-250 Using Iron Oxide-Graphene Oxide Composite via Fenton-like Reaction

The presence of organic dyes in the environment greatly affects the photosynthetic capabilities of underwater organisms as these compounds block sunlight and reduce the amount of available oxygen. Moreover, the structural diversity of dyes makes them highly resistant to light, heat, and oxidizing agents; thus, new approaches for dye remediation are continuously being developed. The use of iron oxide-graphene oxide composite (IOGOC) with persulfate oxidant via a Fentonlike reaction for the removal of Coomassie Brilliant Blue (CBB) R-250 in aqueous solutions was investigated. The IOGOC adsorbent was synthesized and then characterized using FTIR (Fouriertransform infrared spectrophotometry), SEM (scanning electron microscope), and XRD (X-ray powder diffraction). Adsorption isotherm and kinetic studies revealed that the adsorption of the dye on IOGOC was best described by Langmuir isotherm with a maximum adsorption capacity of 14.31 ± 0.65 mg CBB R-250/ g IOGOC and followed the pseudo-second-order kinetic model. Batch adsorption studies were done to determine the effect of dye concentration, adsorbent loading, oxidant concentration, and pH on dye removal. Results showed that the parameters for the dye degradation that afforded a significantly higher degree of dye removal were 10 mg/L adsorbate amount at pH 3.0 with 7 mg adsorbent loading and 3 mM persulfate solution for 270 min contact time. End product analyses indicate that the treated water sample contains 1.84 ± 0.30 mg dissolved iron/ L solution, which is within the limits based on Department of Environment and Natural Resources’ (DENR) Water Quality Guidelines and General Effluent Standards of 2016 and a 73 ± 19% chemical oxygen demand (COD) removal. Recyclability studies show that the synthesized composite can be used for four times without a significant decrease in the dye removal efficiency.

Hydrodynamic effect of biofouling in fish cage aquaculture netting

This paper presents a numerical study to assess the hydrodynamic effects of different levels of biofouling in fish cage aquaculture netting. The methodology adopted includes high resolution Large Eddy Simulation (LES) coupled to a regional model implemented within the framework of the Coastal and Regional Ocean Community Model (CROCO). The physical coherence of this approach has been previously verified and published by the authors. Three levels of biofouling were considered to describe a clean fish cage netting with no biofouling, medium biofouling and high biofouling growth levels. Clean and biofouled fish cage netting were described using a porous media model and the porous media coefficients were taken from the literature. A salmon farm located in the Estero Elefantes Channel in Patagonia (45°39′16.50 S 73°35′59.40 W) was used as study case. A change in the biofouling level in aquaculture fish cages netting can lead to drastic changes in the local velocity field. The high biofouling level produces the largest change in velocity direction and magnitude not only locally in near-cage areas, but also changing features in the overall fjord circulation. Velocity reduction in the shadow zone of fish cages reached values between 30% and 10% of the incident current for null and high biofouling levels, respectively. Simulations also showed dramatic effects of biofouling on flushing time. The predicted water availability of the salmon farm shows decreases of 27% and 36% considering medium and high levels of biofouling. This decrease in the available water is also related to a reduction in the amount of available oxygen and accumulation of waste products, affecting not only the health of farmed fish but also the environment. These and other environmental and productive implications are discussed.

A phase field model for thermo‐oxidative aging in cracked polymers

AbstractWhen dealing with polymers, the behavior of aging processes is of great interest in many applications in engineering, as the usually very complex mechanisms can result in a drastic reduction of the lifetime of machine parts. In addition, those single mechanisms are coupled, which results in even more complexity. A crack creates new surfaces deeper inside the material and thus enables oxidation processes beyond the original surface. Once being oxidized, the crack resistance might be reduced, which may result in further crack propagation, which, again, enables oxidation even deeper.In the present work, a new approach for diffusion limited oxidation is introduced. The approach is based on the phase field method, which has become an important and versatile tool to model different phase evolutions in materials. An evolution equation is underlain by a gradient energy term to capture an interface energy and by a second term, which corresponds to the phase change representing the oxidation state. A diffusion equation controls the amount of available oxygen which is able to trigger the phase change. The phase change, in turn, drains a specific amount of oxygen in the coupled system of differential equations. In this work, cracks are able to expedite the oxidation process deeper into the specimen. The model has been implemented into the FE code FEAP and investigated by means of two academic examples.

Towards a low CO2 emission building material employing bacterial metabolism (1/2): The bacterial system and prototype production.

The production of concrete for construction purposes is a major source of anthropogenic CO2 emissions. One promising avenue towards a more sustainable construction industry is to make use of naturally occurring mineral-microbe interactions, such as microbial-induced carbonate precipitation (MICP), to produce solid materials. In this paper, we present a new process where calcium carbonate in the form of powdered limestone is transformed to a binder material (termed BioZEment) through microbial dissolution and recrystallization. For the dissolution step, a suitable bacterial strain, closely related to Bacillus pumilus, was isolated from soil near a limestone quarry. We show that this strain produces organic acids from glucose, inducing the dissolution of calcium carbonate in an aqueous slurry of powdered limestone. In the second step, the dissolved limestone solution is used as the calcium source for MICP in sand packed syringe moulds. The amounts of acid produced and calcium carbonate dissolved are shown to depend on the amount of available oxygen as well as the degree of mixing. Precipitation is induced through the pH increase caused by the hydrolysis of urea, mediated by the enzyme urease, which is produced in situ by the bacterium Sporosarcina pasteurii DSM33. The degree of successful consolidation of sand by BioZEment was found to depend on both the amount of urea and the amount of glucose available in the dissolution reaction.

Oxygen-Carrier-Aided Combustion in a Bench-Scale Fluidized Bed

In a circulating fluidized bed (CFB) boiler, one of the basic functions of the bed materials is to transport heat between different parts of the boiler to decrease heat gradients and, thereby, smoothen the operation. A novel concept, oxygen-carrier-aided combustion (OCAC), replaces some or all of the bed materials with an oxygen carrier, which is a metal oxide that, through chemical redox reaction, not only transports heat but also transports oxygen between oxygen-lean and oxygen-rich areas of the boiler. The oxygen carrier also acts as internal oxygen storage, which increases the total amount of available oxygen in the boiler. The concept of OCAC was demonstrated by Thunman et al. at Chalmers University of Technology, where the bed material (sand) in a 12 MW boiler was replaced with iron titanium mineral (ilmenite). In this work, a small fluidized bed reactor is used to mimic the condition in OCAC with regard to fuel conversion as well as NO formation and to test other oxygen carrier materials. Four oxyg...

Timeline: Cellular Oxygen Sensing

Since the 1950s, researchers have recognized that red blood cell numbers expand or contract as needed, according to the amount of available oxygen. The later discoveries that erythropoietin and VEGF levels adapt to oxygen levels launched a new field aimed at understanding how cells sense and respond to normal- and low-oxygen environments. The 2016 Albert Lasker Basic Medical Research Award recognizes key discoveries about this global oxygen sensing pathway and its impacts on pathogenesis, including cancer and inflammation.

Thermal stability study of NiAl2O4 binders for Chemical Looping Combustion application

The influence of the preparation method of NiAl2O4 binders on their thermal stability was studied. For this purpose, the reactivity of two different NiAl2O4 binders with CO as fuel was studied in a fixed bed reactor device. Successive oxidation–reduction cycles were performed on the two binders to study their reactivity with the fuel and their structural modifications as cycles proceed. Results reveal that binders are not inert in reducing atmosphere; they both react with the fuel to produce CO2. The total reduction capacity (TRC) of the first binder (B1, synthetized by pyrolytic pulverization) increases during the first cycles and levels off after 20 cycles. However, the TRC of the second binder (B2, synthetized by calcination of a mixture of Ni(OH) and γ-Al2O3), increases progressively and reaches a maximum after 80 cycles. The growing amount of available oxygen in the binders leads both binders to structural modifications. X-ray Diffraction studies performed on fresh and aged binders presented a shift of the peaks related to NiAl2O4. Moreover, quantitative X-ray Diffraction studies and Temperature Programmed Reduction measurements were performed in order to quantify the NiO present in each binder before and after oxidation–reduction cycles. These experiments revealed the presence of NiO in fresh binders due to the preparation method, and an increase of this amount after oxidation–reduction cycles. Therefore, NiAl2O4 in the binder is progressively decomposed producing NiO and Al2O3. Finally, the decomposition of the binder NiAl2O4 as cycles proceed was also observed in studies performed on the oxygen carrier NiO/NiAl2O4. This work showed that the binder reacts with the fuel and therefore it can contribute to the modification of the oxygen carrier reactivity.

Empirical Combustion Modelling of a Qualitatively Governed Spark Ignition Engine Using Burning Velocity Correlations

Empirical combustion modelling of a qualitatively governed spark ignition (SI) engine incorporating Exhaust Gas Recirculation (EGR) was studied using AVL Boost. SI engines are quantitatively governed by controlling the quantity of charge inducted, leading to high throttling losses, and reduction in thermal efficiency. In this article, the charge purity was reduced by incorporating EGR, thereby reducing the amount of available oxygen in the charge inducted, to qualitatively govern the engine. The effect of charge dilution is also to slow down the flame development and propagation, increasing the combustion duration. A combustion model was developed, which estimates the laminar and turbulent burning velocities using the predictions of the in-cylinder traces and the turbulence intensity, using published empirical correlations. This algorithm resulted in a curve fit equation, to predict the combustion duration and the start of combustion as a function of turbulent burning velocity. Using qualitative governing, the brake mean effective pressure was reduced by 20% using a maximum of ∼20% EGR. This also led to 20% reduction in both NO x and CO at full load, with only a 2.5% increase in brake specific fuel consumption, however the unburned HC emissions have also increased by 50%.

Multiscale study of bacterial growth: Experiments and model to understand the impact of gas exchange on global growth.

Using a millifluidics and macroscale setup, we study quantitatively the impact of gas exchange on bacterial growth. In millifluidic environments, the permeability of the incubator materials allows an unlimited oxygen supply by diffusion. Moreover, the efficiency of diffusion at small scales makes the supply instantaneous in comparison with the cell division time. In hermetic closed vials, the amount of available oxygen is low. The growth curve has the same trend but is quantitatively different from the millifluidic situation. The analysis of all the data allows us to write a quantitative modeling enabling us to capture the entire growth process.

A Review on an Opportunity to Reduce Exhaust Emission from Diesel Engine Using Exhaust Gas Recirculation

Internal combustion engines, plays an important role in the transportation sector and also in individual transport. Also it is a major source of manmade emissions. Presently there are many technologies are developed which are used to reduce the fuel consumption and exhaust emission from a diesel engine. In a CI engine fuel consumptions is reduced to a considerable amount, but the emission of NOx (Nitrogen Oxide) is a critical issue. This paper tries to present a review about the impact of EGR system on the exhaust emission of a CI engine. This is one of the methods which reduce the nitrogen oxide emissions of a diesel engine to a considerable level. In EGR – Exhaust Gas Recirculation method, a part of the exhaust gases is recirculated into the combustion chamber. Due to complete combustion of unburned fuel particles, there is a reduction in peak combustion temperature which in turn reduces the formation of NOX. By controlling the amount of available oxygen, which makes possibilities of reduction in the flame temperature in the combustion chamber, EGR system is effectively reduce the NOx emission from an engine.

Is there an association between body temperature and serum lactate levels in hip fracture patients?

Introduction Hyperlactataemia is associated with adverse outcomes in trauma cases. It is thought to be the result of anaerobic respiration during hypoperfusion. This produces much less energy than complete aerobic glycolysis. Low body temperature in the injured patient carries an equally poor prognosis. Significant amounts of energy are expended in maintaining euthermia. Consequently, there may be a link between lactate levels and dysthermia. Hyperlactataemia may be indicative of inefficient energy production and therefore insufficient energy to maintain euthermia. Alternatively, significant amounts of available oxygen may be sequestered in thermoregulation, resulting in anaerobic respiration and lactate production. Our study investigated whether there is an association between lactate levels and admission body temperature in hip fracture patients. Furthermore, it looked at whether there is a difference in the mean lactate levels between hip fracture patients with low (<36.5°C), normal (36.5-37.5°C) and high (>37.5°C) body temperature on admission, and for patients who have low body temperature, whether there is a progressive rise in serum lactate levels as body temperature falls. Methods The admission temperature and serum lactate of 1,162 patients presenting with hip fracture were recorded. Patients were divided into the euthermic (body temperature 36.5-37.5°C), the pyrexial (>37.5°C) and those with low body temperature (<36.5°C). Admission lactate and body temperature were compared. Results There was a significant difference in age between the three body temperature groups (p=0.007). The pyrexial cohort was younger than the low body temperature group (mean: 78 vs 82 years). Those with low body temperature had a higher mean lactate level than the euthermic (2.2mmol/l vs 2.0mmol/l, p=0.03). However, there was no progressive rise in serum lactate level as admission temperature fell. Conclusions The findings suggest that in hip fracture patients, the body attempts initially to maintain euthermia, incurring an oxygen debt. This would explain the difference in lactate level between the low body temperature and euthermic cohorts. The fact that there is no correlation with the degree of temperature depression and lactate levels indicates that the body does not fuel thermohomeostasis indefinitely with oxygen. Instead, in part, it abandons thermoregulatory mechanisms. Consequently, in this population, active rewarming may be indicated rather than depending on patients' own thermogenic ability.

Low-oxygen tensions found in Salmonella-infected gut tissue boost Salmonella replication in macrophages by impairing antimicrobial activity and augmenting Salmonella virulence.

In Salmonella infection, the Salmonella pathogenicity island-2 (SPI-2)-encoded type three secretion system (T3SS2) is of key importance for systemic disease and survival in host cells. For instance, in the streptomycin-pretreated mouse model SPI-2-dependent Salmonella replication in lamina propria CD11c(-)CXCR1(-) monocytic phagocytes/macrophages (MΦ) is required for the development of colitis. In addition, containment of intracellular Salmonella in the gut critically depends on the antimicrobial effects of the phagocyte NADPH oxidase (PHOX), and possibly type 2 nitric oxide synthase (NOS2). For both antimicrobial enzyme complexes, oxygen is an essential substrate. However, the amount of available oxygen upon enteroinvasive Salmonella infection in the gut tissue and its impact on Salmonella-MΦ interactions was unknown. Therefore, we measured the gut tissue oxygen levels in a model of Salmonella enterocolitis using luminescence two-dimensional in vivo oxygen imaging. We found that gut tissue oxygen levels dropped from ∼78 Torr (∼11% O2) to values of ∼16 Torr (∼2% O2) during infection. Because in vivo virulence of Salmonella depends on the Salmonella survival in MΦ, Salmonella-MΦ interaction was analysed under such low oxygen values. These experiments revealed an increased intracellular replication and survival of wild-type and t3ss2 non-expressing Salmonella. These findings were paralleled by blunted nitric oxide and reactive oxygen species (ROS) production and reduced Salmonella ROS perception. In addition, hypoxia enhanced SPI-2 transcription and translocation of SPI-2-encoded virulence protein. Neither pharmacological blockade of PHOX and NOS2 nor impairment of T3SS2 virulence function alone mimicked the effect of hypoxia on Salmonella replication under normoxic conditions. However, if t3ss2 non-expressing Salmonella were used, hypoxia did not further enhance Salmonella recovery in a PHOX and NOS2-deficient situation. Hence, these data suggest that hypoxia-induced impairment of antimicrobial activity and Salmonella virulence cooperate to allow for enhanced Salmonella replication in MΦ.

Qualitative Governing Approach of a Spark Ignition Engine Using Exhaust Gas Recirculation

Abstract A qualitative governing approach of a Spark Ignition (SI) engine incorporating Exhaust Gas Recirculation (EGR) was studied using AVL Boost. SI engines being quantitatively governed by controlling the quantity of charge inducted, leading to high throttling losses. To qualitatively govern the engine, charge purity was reduced by incorporating EGR, thereby reducing the amount of available oxygen in the charge inducted. The effect of charge dilution is to slow down the flame development and propagation, increasing the combustion durations. A simulation model which includes a curve fit equation to predict the combustion duration and start of combustion was created. The engine could be qualitatively governed by a maximum of 19% EGR, to reduce the brake mean effective pressure (bmep) by 20%. This led to 20% reduction in NOx and CO at full load, with 2.5% increase in brake specific fuel consumption (bsfc), also an increase in HC emissions by 50%.

PCB 126 perturbs hypoxia-induced HIF-1α activity and glucose consumption in human HepG2 cells

Aerobic organisms strongly depend on the availability of oxygen for respiration and countless other metabolic processes to maintain cellular homeostasis. Under certain conditions, the amount of available oxygen can be limited. To support survival in environments with limited oxygen supply, hypoxia-inducible factors (HIFs) reprogram vital components of cellular metabolism. HIF-1α is an important mediator of acute and adaptive responses to hypoxic stress. Interestingly, the heterodimeric partner required by HIF-1α to function as transcription factor, known as ARNT, is also an essential part of the aryl hydrocarbon receptor (AhR) transcription factor complex. Thus, via ARNT a crosstalk exists between these two pathways that might affect HIF-1α-mediated processes. In this study we sought to assess the effect of the AhR agonist PCB 126 on HIF-1α activity as well as on HIF-1α-regulated targets involved in cellular metabolism in human HepG2 cells. Our results show that PCB 126 reduced HIF-1α localization to the nucleus. Furthermore, in an in vivo setting, rats exposed to parenteral PCB 126 also displayed reduced hepatocyte nuclear localization of HIF-1α. Additionally, HepG2 cells exposed to PCB 126 displayed reduced hypoxia-regulated HRE-luciferase reporter gene expression as well as a reduction in glucose consumption in conditions of hypoxia. In summary, this study reveals that HIF-1α-regulated cellular metabolic processes are negatively affected by PCB 126 which might ultimately affect adaptive responses and cell survival in hypoxic environments.