Search

Climate changes significantly impact greenhouse gas emissions from wetland soil. Specifically, wetland soil may be exposed to oxygen (O2) during droughts, or to sulfate (SO42-) as a result of sea level rise. How these stressors - separately and together - impact microbial food webs driving carbon cycling in the wetlands is still not understood. To investigate this, we integrated geochemical analysis, proteogenomics, and stoichiometric modeling to characterize the impact of elevated SO42- and O2 levels on microbial methane (CH4) and carbon dioxide (CO2) emissions. The results uncovered the adaptive responses of this community to changes in SO42- and O2 availability and identified altered microbial guilds and metabolic processes driving CH4 and CO2 emissions. Elevated SO42- reduced CH4 emissions, with hydrogenotrophic methanogenesis more suppressed than acetoclastic. Elevated O2 shifted the greenhouse gas emissions from CH4 to CO2. The metabolic effects of combined SO42- and O2 exposures on CH4 and CO2 emissions were similar to those of O2 exposure alone. The reduction in CH4 emission by increased SO42- and O2 was much greater than the concomitant increase in CO2 emission. Thus, greater SO42- and O2 exposure in wetlands is expected to reduce the aggregate warming effect of CH4 and CO2. Metaproteomics and stoichiometric modeling revealed a unique subnetwork involving carbon metabolism that converts lactate and SO42- to produce acetate, H2S, and CO2 when SO42- is elevated under oxic conditions. This study provides greater quantitative resolution of key metabolic processes necessary for the prediction of CH4 and CO2 emissions from wetlands under future climate scenarios.

Cities represent a significant and growing portion of global carbon dioxide (CO2) emissions. Quantifying urban emissions and trends over time is needed to evaluate the efficacy of policy targeting emission reductions as well as to understand more fundamental questions about the urban biosphere. A number of approaches have been proposed to measure, report, and verify (MRV) changes in urban CO2 emissions. Here we show that a modest capital cost, spatially dense network of sensors, the Berkeley Environmental Air Quality and CO2 Network (BEACO2N), in combination with Bayesian inversions, result in a synthesis of measured CO2 concentrations and meteorology to yield an improved estimate of CO2 emissions and provide a cost-effective and accurate assessment of CO2 emissions trends over time. We describe nearly 5 years of continuous CO2 observations (2018-2022) in a midsized urban region (the San Francisco Bay Area). These observed concentrations constrain a Bayesian inversion that indicates the interannual trend in urban CO2 emissions in the region has been a modest decrease at a rate of 1.8 ± 0.3%/year. We interpret this decrease as primarily due to passenger vehicle electrification, reducing on-road emissions at a rate of 2.6 ± 0.7%/year.

BackgroundInfants with hypoxic-ischemic encephalopathy are often treated with therapeutic hypothermia and high-frequency ventilation. Fluctuations in PaCO2 during therapeutic hypothermia are associated with poor neurodevelopmental outcomes. Transcutaneous CO2 monitors offer a noninvasive estimate of PaCO2 represented by transcutaneously measured partial pressure of carbon dioxide (PtcCO2 ). We aimed to assess the precision between PtcCO2 and PaCO2 values in neonates undergoing therapeutic hypothermia.MethodsThis was a retrospective chart review of 10 neonates who underwent therapeutic hypothermia requiring respiratory support over 2 y. A range of 2-27 simultaneous PtcCO2 and PaCO2 pairs of measurements per neonate were analyzed via linear mixed models and a Bland-Altman plot for multiple observations per neonate.ResultsA linear mixed-effect model demonstrated that PtcCO2 and PaCO2 (controlling for sex) were similar. The 95% CI of the mean difference ranged from -2.3 to 5.7 mm Hg (P = .41). However, precision was poor as the PtcCO2 ranged from > 18 mm Hg to < 13 mm Hg than PaCO2 values for 95% of observations.ConclusionsThe neonates' PtcCO2 was as much as 18 mm Hg higher to 13 mm Hg lower than the PaCO2 95% of the time. Transcutaneous CO2 monitoring may not be a good trending tool, nor is it appropriate for estimating PaCO2 in patients undergoing therapeutic hypothermia.

Heat stress results in significant economic losses to the poultry industry. Genetics plays an important role in chickens adapting to the warm environment. Physiological parameters such as hematochemical parameters change in response to heat stress in chickens. To explore the genetics of heat stress resilience in chickens, a genome-wide association study (GWAS) was conducted using Hy-Line Brown layer chicks subjected to either high ambient temperature or combined high temperature and Newcastle disease virus infection. Hematochemical parameters were measured during three treatment phases: acute heat stress, chronic heat stress, and chronic heat stress combined with NDV infection. Significant changes in blood parameters were recorded for 11 parameters (sodium (Na+, potassium (K+), ionized calcium (iCa2+), glucose (Glu), pH, carbon dioxide partial pressure (PCO2), oxygen partial pressure (PO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), and oxygen saturation (sO2)) across the three treatments. The GWAS revealed 39 significant SNPs (p < 0.05) for seven parameters, located on Gallus gallus chromosomes (GGA) 1, 3, 4, 6, 11, and 12. The significant genomic regions were further investigated to examine if the genes within the regions were associated with the corresponding traits under heat stress. A candidate gene list including genes in the identified genomic regions that were also differentially expressed in chicken tissues under heat stress was generated. Understanding the correlation between genetic variants and resilience to heat stress is an important step towards improving heat tolerance in poultry.

An animals preference for many chemosensory cues remains constant despite dramatic changes in the animals internal state. The mechanisms that maintain chemosensory preference across different physiological contexts remain poorly understood. We previously showed that distinct patterns of neural activity and motor output are evoked by carbon dioxide (CO2) in starved adults vs dauers of Caenorhabditis elegans, despite the two life stages displaying the same preference (attraction) for CO2. However, how the distinct CO2-evoked neural dynamics and motor patterns contribute to CO2 attraction at the two life stages remained unclear. Here, using a CO2 chemotaxis assay, we show that different interneurons are employed to drive CO2 attraction at the two life stages. We also investigate the molecular mechanisms that mediate CO2 attraction in dauers vs adults. We show that insulin signaling promotes CO2 attraction in dauers but not starved adults and that different combinations of neurotransmitters and neuropeptides are used for CO2 attraction at the two life stages. Our findings provide new insight into the distinct molecular and cellular mechanisms used by C. elegans at two different life stages to generate attractive behavioral responses to CO2.

Plants with the C4 photosynthesis pathway typically respond to climate change differently from more common C3-type plants, due to their distinct anatomical and biochemical characteristics. These different responses are expected to drive changes in global C4 and C3 vegetation distributions. However, current C4 vegetation distribution models may not predict this response as they do not capture multiple interacting factors and often lack observational constraints. Here, we used global observations of plant photosynthetic pathways, satellite remote sensing, and photosynthetic optimality theory to produce an observation-constrained global map of C4 vegetation. We find that global C4 vegetation coverage decreased from 17.7% to 17.1% of the land surface during 2001 to 2019. This was the net result of a reduction in C4 natural grass cover due to elevated CO2 favoring C3-type photosynthesis, and an increase in C4 crop cover, mainly from corn (maize) expansion. Using an emergent constraint approach, we estimated that C4 vegetation contributed 19.5% of global photosynthetic carbon assimilation, a value within the range of previous estimates (18-23%) but higher than the ensemble mean of dynamic global vegetation models (14 ± 13%; mean ± one standard deviation). Our study sheds insight on the critical and underappreciated role of C4 plants in the contemporary global carbon cycle.

The resident human skin microbiome is responsible for the production of most of the human scents that are attractive to mosquitoes. Hence, engineering the human skin microbiome to synthesize less of mosquito attractants or produce repellents could potentially reduce bites and prevent the transmission of deadly mosquito-borne pathogens. In order to further characterize the human skin volatilome, we quantified the major volatiles of 39 strains of skin commensals (Staphylococci and Corynebacterium). Importantly, to validate the behavioral activity of these volatiles, we first assessed landing behavior triggered by human skin volatiles. We demonstrated that landing behavior is gated by the presence of carbon dioxide and L-(+)-lactic acid. This is similar to the combinatorial coding triggering mosquito short range attraction. Repellency behavior to selected skin volatiles and terpenes was tested in the presence of carbon dioxide and L-(+)-lactic acid. In a 2-choice landing behavior context, the skin volatiles 2- and 3-methyl butyric acids reduced mosquito landing by 62.0-81.6% and 87.1-99.6%, respectively. Similarly, the terpene geraniol was capable of reducing mosquito landing behavior by 74.9%. We also tested the potential repellency effects of terpenes in mosquitoes at short-range using a 4-port olfactometer. In these assays, geraniol reduced mosquito attraction (69-78%) to a mixture of key human kairomones carbon dioxide, L-(+)-lactic acid, and ammonia. These findings demonstrate that carbon dioxide and L-(+)-lactic acid change the valence of other skin volatiles towards mosquito landing behavior. Moreover, this study offers candidate odorants to be targeted in a novel strategy to reduce attractants or produce repellents by the human skin microbiota that may curtail mosquito bites, and subsequent mosquito-borne disease.

Microbial electrosynthesis (MES) constitutes a bioelectrochemical process where bacteria uptake electrons extracellularly from a polarized electrode to incorporate them into their anabolic metabolism. However, the efficiency of current MES reactor designs can be lower than expected due to limitations regarding electron transfer and mass transport. One of the most promising bioreactor configurations to overcome these bottlenecks is the Microbial Electrochemical Fluidized Bed Reactor (ME-FBR). In this study, microbial CO2 fixation is investigated for the first time in a ME-FBR operated as a 3-phase reactor (solid-liquid-gas). An electroconductive carbon bed, acting as a working electrode, was fluidized with gas and polarized at different potentials (-0.6, -0.8 and -1 V vs. Ag/AgCl) so it could act as an electron donor (biocathode). Under these potentials, CO2 fixation and electron transfer were evaluated. Autotrophic electroactive microorganisms from anaerobic wastewater were enriched in a ME-FBR in the presence of 2-bromoethanosulfonic acid (BES) to inhibit the growth of methanogens. Cyclic voltammetry analysis revealed interaction between the microorganisms and the cathode. Furthermore, volatile fatty acids like propionate, formate and acetate were detected in the culture supernatant. Acetate production had a maximum rate of ca. 1 g L-1  day-1 . Planktonic cell biomass was produced under continuous culture at values as high as ca. 0.7 g L-1 dry weight. Overall, this study demonstrates the feasibility of employing a fluidized electrode with gaseous substrates and electricity as the energy source for generating biomass and carboxylic acids.

This study examines the causality of Per Capita Gross Domestic Production (PGDP), Renewable Energy Consumption (REC), and Non-Renewable Energy Consumption (NREC) on Carbon dioxide (CO2) emissions at the global level utilising data gathered from 1995 to 2020 across various countries categorised based on income levels as High, Low, Upper Middle and Lower Middle and analysed through wavelet coherence. The findings reveal both bidirectional and unidirectional causality between the variables which have evolved. Globally, a bi-directional relationship is observed with a positive correlation between PGDP and NREC and in contrast, a negative correlation with REC. Furthermore, the analysis highlights varying causalities between CO2 emissions and PGDP, except for high-income and lower-middle-income country categories, all other shows one-way causality in different periods in the short term. Moreover, CO2 and REC, show unidirectional causality throughout the short-term, exceptionally medium & long term have both unidirectional and bidirectional causalities across all country categories with a positive correlation. In contrast, CO2 and NREC depict similar causalities to REC, however, with a negative correlation. A cross-country analysis was performed between CO2 and PGDP, CO2 and REC, and CO2 and NREC using Granger causality which shows mixed relationships. The findings hold significant implications for policymakers, providing valuable insights into the trade-offs between economic growth, energy consumption, and carbon emissions. [ABSTRACT FROM AUTHOR]

Defect engineering has been widely applied in the field of photocatalysis, and defects can be used to modify the surface structure and photoelectric properties of catalysts so as to achieve the purpose of regulating the activity and stability of catalysts. However, design of a highly efficient photocatalyst with abundant defects remains a challenging task in current research. Therefore, in this study, graphitic carbon nitride (g-C 3 N 4) with abundant three-coordinated nitrogen (N 3C) vacancies and pore structures was obtained using a facile hydrothermal method with the assistance of glycerol. Under visible light (λ > 420 nm) irradiation, the 50CN (volume ratio of glycerol/water is 50/10) catalyst exhibits a superior CO release rate (4.18 μmol g−1 h−1), which is 12.06 times higher than the reference GCN (0.32 μmol g−1 h−1), and the corresponding apparent quantum yields (AQY) of 50CN is 0.24 %, which is significantly higher than that of GCN (0.045 %). Successful introduction of N 3C vacancies is conducive to broaden light response range of the catalyst, enhancing the separation and migration efficiency of photogenerated charges, and providing more adsorption active sites to promote the adsorption and activation of CO 2 molecules, thus effectively boosting photocatalytic CO 2 reduction activity. In addition, the N 3C vacancies can effectively lower the CO 2 activation energy barrier and reduce the energy consumption required for the reaction. This work offers valuable new insights into defect engineering in g-C 3 N 4 for the development of high-performance photocatalysts for CO 2 reduction. [ABSTRACT FROM AUTHOR]

The purpose of the analysis was to evaluate if 10 mg naloxone, administered intramuscularly, could reverse or prevent opioid‐induced respiratory depression (OIRD), including OIRD associated with the administration of lethal doses of high‐potency opioids. A naloxone population pharmacokinetic (PK) model was generated using data from two naloxone auto‐injector (NAI) clinical PK studies. Mechanistic OIRD PK‐pharmacodynamic (PD) models were constructed using published data for buprenorphine, morphine, and fentanyl. Due to the lack of published carfentanil data in humans, interspecies allometric scaling methods were used to predict carfentanil PK parameters in humans. A PD model of a combined effect‐compartment and receptor kinetics model with a linear relationship between ventilation and carbon dioxide was used to predict the respiratory depression induced by carfentanil. Model‐based simulations were performed using the naloxone population PK model and the constructed mechanistic OIRD PK–PD models. Changes in ventilation were assessed after opioid exposure and treatment with 2 mg naloxone or one or two doses of 10 mg naloxone. A higher percentage of subjects recovered back to the rescue ventilation thresholds and/or had a faster recovery to 40% or 70% of baseline ventilation with 10 mg compared with 2 mg naloxone. A second dose of 10 mg naloxone, administered 60 min post‐opioid exposure, expedited recovery to 85% of baseline ventilation and delayed time to renarcotization compared with a single dose. In addition, when 10 mg naloxone was administered at 5, 15, 30, or 60 min before fentanyl or carfentanil exposure, rapid and profound OIRD was prevented. [ABSTRACT FROM AUTHOR]

By embedding Na ions into graphitic carbon nitride, the directional migration of photo-generated electrons towards Na sites is achieved, thereby creating additional reaction sites. Moreover, the electron-rich Na sites enhance the adsorption and activation of CO 2. Consequently, the photocatalytic performance is improved to some extent. [Display omitted] The depressed directional separation of photogenerated carriers and weak CO 2 adsorption/activation activity are the main factors hampering the development of artificial photosynthesis. Herein, Na ions are embedded in graphitic carbon nitride (g-C 3 N 4) to achieve directional migration of the photogenerated electrons to Na sites, while the electron-rich Na sites enhance CO 2 adsorption and activation. Na/g-C 3 N 4 (NaCN) shows improved photocatalytic reduction activity of CO 2 to CO and CH 4 , and under simulated sunlight irradiation, the CO yield of NaCN synthesized by embedding Na at 550°C (NaCN-550) is 371.2 μmol g−1 h−1, which is 58.9 times more than that of the monomer g-C 3 N 4. By means of theoretical calculations and experiments including in situ fourier transform infrared spectroscopy, the mechanism is investigated. This strategy which improves carrier separation and reduces the energy barrier at the same time is important to the development of artificial photosynthesis. [ABSTRACT FROM AUTHOR]

Background: Silage emits climate- and environment-relevant gases during fermentation and feed-out periods. This trial aimed to determine the unknown carbon dioxide (CO2), methane, nitrous oxide, ethanol, and ethyl acetate emissions of constant maize silage material over both periods. The results will be published in two consecutive articles (Part A: anaerobic fermentation period, Part B: aerobic storage period). Methods: The untreated control (CON) was compared with the chemical additive treatment (CHE; 0.5 g sodium benzoate and 0.3 g potassium sorbate per kg fresh matter) and the biological additive treatment (BIO; 108 colony-forming units (CFU) Lentilactobacillus buchneri and 107 CFU Lactiplantibacillus plantarum per kg fresh matter). Barrel silos (n = 4) were connected to gas bags to quantify gas formation during anaerobic fermentation (30 or 135 ensiling days). Glass jar silos (n = 12) were used for laboratory silage analysis. Results: CHE produced significantly (p < 0.05) less gas (6.7 ± 0.3 L per kg dry matter ensiled material (kgDM) until ensiling day 14.0 ± 0.0) and ethanol (8.6 ± 1.5 mg kgDM–1) than CON did (8.5 ± 0.2 L kgDM–1 until ensiling day 19.5 ± 6.4; 12.2 ± 1.5 (mg ethanol) kgDM–1). BIO indicates prolonged gas formation (9.1 ± 0.9 L kgDM–1 until ensiling day 61.3 ± 51.9; 12.0 ± 2.1 mg kgDM–1). CO2 is the main component of the gas formed. All treatments formed methane and nitrous oxide in small quantities. CON emitted significantly more CO2eq emissions than BIO and less than CHE (p < 0.05). Additives had no effect on ethyl acetate gas emissions. For BIO, ethanol concentrations in the material (rS = 0.609, p < 0.05) and gas quantities (rS = 0.691, p < 0.05) correlate with ethyl acetate gas quantities. All the treatments exhibited decreasing gas and CO2 quantities, and the dry matter mass increased between ensiling days 14 and 30 (− 0.810 ≤ rS ≤ 0.442; p < 0.05 to p = 0.20). Conclusion: Silage generates climate- and environmental-relevant gases during fermentation and silage additives affect this pattern. Gas formation exceeds the fixation potential, and the carbon footprint of silage fermentation is negative. [ABSTRACT FROM AUTHOR]

Purpose: To determine the ability of CO2-enhanced angiography to detect active diverticular bleeding that is not detected by iodinated contrast medium (ICM)-enhanced angiography and its impact on clinical outcomes when used to confirm embolization, particularly the risks of rebleeding and ischemic complications. Materials and methods: We retrospectively identified a cohort of patients with colonic diverticular bleeding who underwent catheter angiography between August 2008 and May 2023 at our institution. We divided them according to whether they underwent CO2 angiography following a negative ICM angiography study or to confirm hemostasis post-embolization (the CO2 angiography group) or ICM angiography alone in the absence of active bleeding or for confirmation of hemostasis post-embolization (the ICM angiography group). The ability to detect active colonic diverticular bleeding and clinical outcomes were compared between the two groups. Results: There were 31 patients in the ICM angiography group and 29 in the CO2 angiography group. The rate of detection of active bleeding by CO2 angiography that was not identified by ICM angiography was 48%. The rebleeding rate was 23% in the ICM angiography group and 6.9% in the CO2 angiography group. Among the patients who underwent TAE, the ischemic complications rate was 7.1% in the ICM angiography group and 4.5% in the CO2 angiography group. Conclusions: CO2 angiography may detect active diverticular bleeding that is not detectable by ICM angiography and appears to be associated with a lower rebleeding rate. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Seawater carbonate chemistry observations are increasingly necessary to study a broad array of oceanographic challenges such as ocean acidification, carbon inventory tracking, and assessment of marine carbon dioxide removal strategies. The uncertainty in a seawater carbonate chemistry observation comes from unknown random variations and systematic offsets. Here, we estimate the magnitudes of these random and systematic components of uncertainty for the discrete open‐ocean carbonate chemistry measurements in the Global Ocean Data Analysis Project 2022 update (GLODAPv2.2022). We use both an uncertainty propagation approach and a carbonate chemistry measurement “inter‐consistency” approach that quantifies the disagreement between measured carbonate chemistry variables and calculations of the same variables from other carbonate chemistry measurements. Our inter‐consistency analysis reveals that the seawater carbonate chemistry measurement community has collected and released data with a random uncertainty that averages about 1.7 times the uncertainty estimated by propagating the desired “climate‐quality” random uncertainties. However, we obtain differing random uncertainty estimates for subsets of the available data, with some subsets seemingly meeting the climate‐quality criteria. We find that seawater pH measurements on the total scale do not meet the climate‐quality criteria, though the inter‐consistency of these measurements improves (by 38%) when limited to the subset of measurements made using purified indicator dyes. We show that GLODAPv2 adjustments improve inter‐consistency for some subsets of the measurements while worsening it for others. Finally, we provide general guidance for quantifying the random uncertainty that applies for common combinations of measured and calculated values. [ABSTRACT FROM AUTHOR]

Using CO2 as the primary feedstock offers the potential for high-value utilization of CO2 while forging sustainable pathways for producing valuable natural products, such as l-tyrosine. Cascade catalysis is a promising approach but limited by stringent purity demands of nexus molecules. We developed an abiotic/biotic cascade catalysis using blended nexus molecules for l-tyrosine synthesis. Specifically, we begin by constructing a solid-state reactor to reduce CO2 electrochemically, yielding a mixture of acetic acid and ethanol, which serves as the blended nexus molecules. Subsequently, we use genetic engineering to introduce an ethanol utilization pathway and a tyrosine producing pathway to Escherichia coli to facilitate l-tyrosine production. The ethanol pathway synergistically cooperated with the acetic acid pathway, boosting l-tyrosine production rate (nearly five times higher compared to the strain without ethanol utilization pathway) and enhancing carbon efficiency. Our findings demonstrate that using blended nexus molecules could potentially offer a more favorable strategy for the cascade catalysis aimed at producing valuable natural products. [ABSTRACT FROM AUTHOR]

Developing efficient photocatalysts with low cost, high performance, and high selectivity is essential and imperative for CO 2 conversion and utilization, yet it remains a big challenge. Herein, a novel Ce-doped TiO 2 aerogel with oxygen vacancy anchored on the oriented carbonaceous (Ce–TiO 2 @CS) is synthesized by the sol-gel technique, combined with the freeze casting, supercritical drying technique, and heat treatment processes. The Ce–TiO 2 @CS aerogel has a typical aerogel-like structure, with the Ce–TiO 2 aerogel anchored on the oriented porous carbon, rendering a large BET-specific surface area of 124 m2/g, which leads to enhanced photocatalytic activity. The Ce-doping into the pristine TiO 2 results in impurity levels within the band gap, which extends the light response range to the visible light region. In addition, the rapid combination of electrons and holes is prevented via the two-phase microstructures and rapid transfer rate of electrons within the oriented porous carbon. The yields of CH 4 and CO are as high as 9.45 μmol h−1 g−1 and 42.26 μmol h−1 g−1, respectively, which are 28.6 and 2.46 times higher than those of pristine TiO 2 aerogel under simulated solar spectrum conditions without any sacrificial agents or co-catalysts, The density functional theory (DFT) calculation shows that larger C–O bonds of CO 2 molecule and more negative adsorption energy have occurred on the Ce–TiO 2 @CS aerogel, indicating that the CO 2 activation has been enhanced, which greatly improves the CO 2 photoreduction activity. This work may guide the designing of aerogel-based photocatalysts for CO 2 photocatalytic reduction. [ABSTRACT FROM AUTHOR]

The development of multi-functional and highly mixed ionic-electronic conductive perovskite oxide-based electrodes is becoming an established trend for designing and developing SOFC/SOEC reversible cells. Ideally, the same material can be employed at both electrodes provided that structural stability, high conductivity and catalytic activity are preserved in different operational atmospheres. Here, controlled Fe substitution with a small extent (0.5 mol%) of platinum at the B-site of a lanthanum strontium ferrite is proposed as an effective method to enhance the original oxide properties as both air and fuel electrode for solid oxide cells. The effects of low Pt-doping on La 0.6 Sr 0.4 FeO 3-δ structure, morphology and electrocatalytic activity are investigated and discussed. La 0.6 Sr 0.4 Fe 0.995 Pt 0.005 O 3-δ (05P-LSF) is first tested as air electrode, displaying lower area specific resistance as compared to the Pt-free perovskite. 05P-LSF structural stability and conductivity are assessed in 100 % CO 2 and 50 % CO 2 –50 % CO environments. Symmetric devices are then tested as SOECs in 100 % CO 2 , obtaining a current density output of 1.08 A/cm2 at 1.5 V. Electrochemical impedance spectroscopy (EIS) with distribution of relaxation times analysis (DRT) are used to provide insights on the electrode operation. Pt nanoparticle exsolution at the fuel electrode is induced by voltage application. The device stability under applied voltage is assessed for over 120 h. SOFC/SOEC characterization in a 50 % CO 2 /50 % CO mixture at 850 °C is also provided, obtaining a maximum power density of 270 mW/cm2 in SOFC mode, and a current density of 0.91 A/cm2 at 1.5 V in SOEC mode. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of carbon dioxide to produce high-value ethylene is often limited by poor selectivity and yield of multi-carbon products. To address this, we propose a cyanamide-coordinated isolated copper framework with both metallic copper (Cu0) and charged copper (Cu1+) sites as an efficient electrocatalyst for the reduction of carbon dioxide to ethylene. Our operando electrochemical characterizations and theoretical calculations reveal that copper atoms in the Cuδ+NCN complex enhance carbon dioxide activation by improving surface carbon monoxide adsorption, while delocalized electrons around copper sites facilitate carbon-carbon coupling by reducing the Gibbs free energy for *CHC formation. This leads to high selectivity for ethylene production. The Cuδ+NCN catalyst achieves 77.7% selectivity for carbon dioxide to ethylene conversion at a partial current density of 400 milliamperes per square centimeter and demonstrates long-term stability over 80 hours in membrane electrode assembly-based electrolysers. This study provides a strategic approach for designing catalysts for the electrosynthesis of value-added chemicals from carbon dioxide. This study reports a cyanamide-framework stabilized multivalent copper catalyst for efficient electrochemical reduction of carbon dioxide to ethylene with 77.7% selectivity at 400 mA cm−2, offering a rational strategy for CO2 conversion. [ABSTRACT FROM AUTHOR]

Metal hydrides are crucial intermediates in numerous catalytic reactions. Intensive efforts have been dedicated to constructing molecular metal hydrides, where toxic precursors and delicate mediators are usually involved. Herein, we demonstrate a facile pressure-induced methodology to generate a cost-effective heterogeneous electrocatalytic metal hydride surface for sustainable hydrogen transfer. Taking carbon dioxide (CO2) electroreduction as a model system and zinc (Zn), a well-known carbon monoxide (CO)-selective catalyst, as a model catalyst, we showcase a homogeneous-type hydrogen atom transfer process induced by heterogeneous hydride surfaces, enabling direct hydrogenation pathways traditionally considered "prohibited". Specifically, the maximal Faradaic efficiency for formate is enhanced by ~fivefold to 83% under ambient conditions. Experimental and theoretical analyses reveal that unlike the distal hydrogenation route for CO2 to CO over pristine Zn, the Zn hydride surface enables direct hydrogenation at the carbon site of CO2 to form formate. This work provides a promising material platform for sustainable synthesis. The authors demonstrate a facile pressure-induced methodology to generate a cost-effective heterogeneous electrocatalytic metal hydride surface for sustainable hydrogen transfer. [ABSTRACT FROM AUTHOR]

Maintaining patients' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th–75th percentile: 0.2–0.8] °C at the beginning to 2.3 [2.1–2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects. Trial registration: Clinicaltrials.gov: NCT04294758. [ABSTRACT FROM AUTHOR]

Bio-based carbon dioxide removal encompasses a range of (1) natural sink enhancement concepts in agriculture and on organic soils including peatlands, and in forestry, (2) bio-based building materials, and (3) bioenergy production with CO2 capture and storage (BECCS). A common database on these concepts is crucial for their consideration in strategies and implementation. In this study, we analyse standardised factsheets on these concepts. We find different dynamics of deployment until 2045: for CO2 removal rates from the atmosphere, natural sink enhancement concepts are characterised by gradually increasing rates, followed by a saturation and potentially a decrease after few decades; forest-related measures ramp up slowly and for construction projects and bioenergy plants, annually constant removal rates are assumed during operation which drop to zero afterwards. The expenses for removing 1 t CO2 from the atmosphere were found to be between 8 and 520 € t CO2−1, which arises from high divergence both in capital and operational expenditures among the concepts. This high variability of expenses seems to suggest the more cost-effective concepts should be implemented first. However, aspects from economics, resource base and environmental impacts to social and political implications for Germany need to be considered for developing implementation strategies. All concepts investigated could be deployed on scales to significantly contribute to the German climate neutrality target. [ABSTRACT FROM AUTHOR]

Neurovascular coupling (NVC), which mediates rapid increases in cerebral blood flow in response to neuronal activation, is commonly used to map brain activation or dysfunction. Here we tested the reemerging hypothesis that CO2 generated by neuronal metabolism contributes to NVC. We combined functional ultrasound and two-photon imaging in the mouse barrel cortex to specifically examine the onsets of local changes in vessel diameter, blood flow dynamics, vascular/perivascular/intracellular pH, and intracellular calcium signals along the vascular arbor in response to a short and strong CO2 challenge (10 s, 20%) and whisker stimulation. We report that the brief hypercapnia reversibly acidifies all cells of the arteriole wall and the periarteriolar space 3–4 s prior to the arteriole dilation. During this prolonged lag period, NVC triggered by whisker stimulation is not affected by the acidification of the entire neurovascular unit. As it also persists under condition of continuous inflow of CO2, we conclude that CO2 is not involved in NVC. A remerging hypothesis suggests that CO2 generated by neuronal metabolism contributes to neurovascular coupling (NVC). Here, the authors show that NVC is unaffected by the acidification of the entire arteriolar column during cerebrovascular reactivity to CO2, demonstrating that CO2 is not a mediator of NVC. [ABSTRACT FROM AUTHOR]

Wastewater treatment plants (WWTPs) contribute to the release of microplastics into the environment. While the removal efficiency of MPs in WWTPs can reach up to 99.9 %, the highest amount of microplastics is retained in the sludge. Anaerobic digestion, one of the most promising and common processes, can help reduce sludge volume and odour, and due to the formation of biogas, mainly consisting of methane (CH4) and carbon dioxide (CO2), can help decrease the operating costs of WWTPs. A test measuring the inhibition of biogas production using the OxiTop® measuring system was employed to determine the effect of added microfibres (MFs) on biogas production. Particles less than 1 mm in size of polyester, polyamide, and polyacrylic, were added to anaerobic sludge at concentrations ranging from 0.05 to 0.10 g l–1 to simulate their effect on biogas production. The yields of CH4 and CO2 produced during anaerobic digestion of the MFs-contaminated sludge were determined. The addition of MFs to sewage sludge affects methane production. The results indicated that the lowest added concentrations of 0.05 g l–1 of MFs promoted methane production, while the presence of 0.1 g l–1 decreased methane production for all types of MFs used. Polyacrylic at 0.1 g l–1 had the most negative effect on methane production (up to 27 %), while polyamide at 0.05 g l–1 reached the highest methane production (up to 25 %). [ABSTRACT FROM AUTHOR]

Previous studies report contradicting age‐related neurovascular coupling (NVC). Few studies assess postural effects, but less investigate relationships between age and NVC within different postures. Therefore, this study investigated the effect of age on NVC in different postures with varying cognitive stimuli. Beat‐to‐beat blood pressure, heart rate and end‐tidal carbon dioxide were assessed alongside middle and posterior cerebral artery velocities (MCAv and PCAv, respectively) using transcranial Doppler ultrasonography in 78 participants (31 young‐, 23 middle‐ and 24 older‐aged) with visuospatial (VST) and attention tasks (AT) in various postures at two timepoints (T2 and T3). Between‐group significance testing utilized one‐way analysis‐of‐variance (ANOVA) (Tukey post‐hoc). Mixed three‐way/one‐way ANOVAs explored task, posture, and age interactions. Significant effects of posture on NVC were driven by a 3.8% increase from seated to supine. For AT, mean supine %MCAv increase was greatest in younger (5.44%) versus middle (0.12%) and older‐age (0.09%) at T3 (p = 0.005). For VST, mean supine %PCAv increase was greatest at T2 and T3 in middle (10.99%/10.12%) and older‐age (17.36%/17.26%) versus younger (9.44%/8.89%) (p = 0.004/p = 0.002). We identified significant age‐related NVC effects with VST‐induced hyperactivation. This may reflect age‐related compensatory processes in supine. Further work is required, using complex stimuli while standing/walking, examining NVC, aging and falls. [ABSTRACT FROM AUTHOR]

Satellites have been providing spaceborne observations of the total column of CO2 (denoted XCO2) for over two decades now, and, with the need for independent verification of Paris Agreement objectives, many new satellite concepts are currently planned or being studied to complement or extend the instruments that already exist. Depending on whether they are targeting natural and/or anthropogenic fluxes of CO2 , the designs of these future concepts vary greatly. The characteristics of their shortwave infrared (SWIR) observations notably explore several orders of magnitude in spectral resolution (from λ/Δλ ∼ 400 for Carbon Mapper to λ/Δλ ∼ 25 000 for MicroCarb) and include different selections of spectral bands (from one to four bands, among which there are the CO2 -sensitive 1.6 µm and/or 2.05 µm bands). The very nature of the spaceborne measurements is also explored: for instance, the NanoCarb imaging concept proposes to measure CO2 -sensitive truncated interferograms, instead of infrared spectra like other concepts, in order to significantly reduce the instrument size. This study synthetically explores the impact of three different design parameters on the XCO2 retrieval performance obtained through optimal estimation: (1) the spectral resolution, (2) the signal-to-noise ratio (SNR) and (3) the spectral band selection. Similar performance assessments are completed for the exactly defined OCO-2, MicroCarb, Copernicus CO2 Monitoring (CO2M) and NanoCarb concepts. We show that improving the SNR is more efficient than improving the spectral resolution to increase XCO2 precision when perturbing these parameters across 2 orders of magnitude, and we find that a low SNR and/or a low spectral resolution yield XCO2 with vertical sensitivities that give more weight to atmospheric layers close to the surface. The exploration of various spectral band combinations illustrates, especially for lower spectral resolutions, how including an O2 -sensitive band helps to increase the optical path length information and how the 2.05 µm CO2 -sensitive band contains more geophysical information than the 1.6 µm band. With very different characteristics, MicroCarb shows a CO2 information content that is only slightly higher than that of CO2M , which translates into XCO2 random errors that are lower by a factor ranging from 1.1 to 1.9, depending on the observational situation. The performance of NanoCarb for a single pixel of its imager is comparable to those of concepts that measure spectra at low SNR and low spectral resolution, but, as this novel concept would observe a given target several times during a single overpass, its performance improves when combining all the observations. Overall, the broad range of results obtained through this synthetic XCO2 performance mapping hint at the future intercomparison challenges that the wide variety of upcoming CO2 -observing concepts will pose. [ABSTRACT FROM AUTHOR]

This work focused on the solubility of ethane in three promising ionic liquids {1-Hexyl-3-methylimidazolium bis(trifluormethylsulfonyl) imide [HMIM][Tf2N], 1-Butyl-3-methyl-imidazolium dimethyl-phosphate [BMIM][DMP], and 1-Propyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)-imide [PMIM][Tf2N]}. The solubilities were measured at 303.15 K to 343.15 K and pressures up to 1.4 MPa using a gravimetric microbalance. The overall ranking of ethane solubility in the ionic liquids from highest to lowest is the following: [HMIM][Tf2N] > [PMIM][Tf2N] > [BMIM][DMP]. The Peng–Robinson equation of state was used to model the experimental data using three different mixing rules: van der Waals one, van der Waals two, and Wong–Sandler mixing rules combined with the Non-Random Two-Liquid model. The average absolute deviations for the three mixing rules for the ionic liquids at the three temperatures were 4.39, 2.45, and 2.45%, respectively. Henry's Law constants for ethane in [BMIM] [DMP] were the highest (lowest solubility) amongst other ionic liquids studied in this work. The solubility ranking for the 3 ILs was confirmed by calculating their overall polarity parameter (N) using COSMO-RS. The selectivity of CO2 over C2H6 was estimated at three temperatures, and the overall ranking of the selectivity was in the following order: [PMIM][Tf2N] > [BMIM][DMP] > [HMIM][Tf2N] > Selexol. Selexol is an efficient and widely used physical solvent in gas sweetening. It has lower selectivity than the three ionic liquids studied. [PMIM][Tf2N], a promising solvent, has the highest selectivity among the three ILs studied and would, therefore, be the best choice if, in addition to carbon dioxide capture, ethane co-absorption was to be avoided. The enthalpy and entropy of solvation at infinite dilution were also estimated. [ABSTRACT FROM AUTHOR]

Understanding intermolecular interactions is important for the design of deep eutectic solvents. Herein, potassium carbonate (K2CO3) and ethylene glycol (EG) are used to form deep eutectic solvents. The interactions between K2CO3 and EG are studied using nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectra. Interestingly, the interaction results indicate that the carbonate anion CO 3 2 − can react with EG to form EG-based organic carbonate, which can occur even at room temperature. The possible reaction steps between K2CO3 and EG are presented. As K2CO3 can be prepared from CO2 and KOH, the findings of this work may provide a promising strategy for CO2 capture and conversion. [ABSTRACT FROM AUTHOR]

Objective: We postulated that adding tube resistance compensation (TRC) to pressure support ventilation (PSV) would have beneficial effects on metabolic parameters in patients scheduled for weaning. Here, the PSV and PSV+TRC were compared by measuring oxygen consumption (VO2), energy expenditure (EE), and carbon dioxide production (VCO2). Materials and Methods: This was a prospective, randomised, crossover study. Seventy-eight adult patients were randomised to receive either PSV or PSV+TRC. Group 1 consisted of patients that started with PSV initially and then switched to PSV+TRC, whereas Group 2 first received PSV+TRC and then switched to PSV. After 30 minutes of monitoring and stabilization, an indirect calorimeter was connected and metabolic parameters measurement was taken every 5 minutes for 30 minutes, and the last measurement values were recorded at the 30th minute. The patient was then switched to the second treatment mode, and the procedure was repeated. Results: TRC+PSV ventilation had no clinical effects on metabolic parameters compared with PSV (EE, 1746 vs. 1763, respectively; VO2, 255 vs. 260, respectively; VCO2, 206 vs. 208, respectively; all p > 0.05). Conclusion: Adding TRC to PSV did not cause any changes in gas exchange, haemodynamic variables, or metabolic parameters in patients for weaning. [ABSTRACT FROM AUTHOR]

Background: The possibility of keeping liver grafts viable and functioning until transplantation has been explored since the 1950s. However, the current modalities of Normothermic Machine Perfusion (NMP) have shown several limitations, such as the inability to correct electrolytes and pH derangements efficiently. Combining NMP with continuous kidney replacement therapy (CKRT) might provide a promising new model to overcome these issues. Methods: An NMP that covers the organ perfusion, oxygenation, carbon dioxide removal, and thermal balance was connected to a CKRT circuit to ensure physiological hydro-electrolytes, acid–base balance, and catabolite removal from the perfusate. Results: The integration of NMP and CKRT maintains a neoplastic liver in a perfusion system with physiological perfusate for 100 h. CKRT re-established and maintained the hydro-electrolyte and acid–base status throughout the 100 h of perfusion. Significant limitations were the need for frequent monitoring of electrolytes and acid–base disorders and the loss of low molecular weight nutrients, which have to be replenished by manual infusion into the system. Conclusions: This novel CKRT-NMP integrated system may represent a practical and versatile model to support organs' perfusion and extend preservation times. Further experiments are needed to fix monitoring and adjusting processes. [ABSTRACT FROM AUTHOR]

The study comprehensively evaluates low-cost CO2 sensors from different price tiers, assessing their performance against a reference-grade instrument and exploring the possibility of calibration using different machine learning techniques. Three sensors (Sunrise AB by Senseair, K30 CO2 by Senseair, and GMP 343 by Vaisala) were tested alongside a reference instrument (Los Gatos precision greenhouse gas analyzer). The results revealed differences in sensor performance, with the higher cost Vaisala sensors exhibiting superior accuracy. Despite its lower price, the Sunrise sensors still demonstrated reasonable accuracy. Meanwhile, the K30 sensor measurements displayed higher variability and noise. Machine learning models, including linear regression, gradient boosting regression, and random forest regression, were employed for sensor calibration. In general, linear regression models performed best for extrapolating data, whereas decision tree-based models were generally more useful in handling non-linear datasets. Notably, a stack ensemble model combining these techniques outperformed the individual models and significantly improved sensor accuracy by approximately 65%. Overall, this study contributes to filling the gap in intercomparing CO2 sensors across different price categories and underscores the potential of machine learning for enhancing sensor accuracy, particularly in low-cost sensor applications. [ABSTRACT FROM AUTHOR]

Buildings worldwide are becoming more thermally insulated, and air circulation is being reduced to a minimum. As a result, measuring indoor air quality is important to prevent harmful concentrations of various gases that can lead to safety risks and health problems. To measure such gases, it is necessary to produce low-cost and low-power-consuming sensors. Researchers have been focusing on semiconducting metal oxide (SMOx) gas sensors that can be combined with intelligent technologies such as smart homes, smart phones or smart watches to enable gas sensing anywhere and at any time. As a type of SMOx, p-type gas sensors are promising candidates and have attracted more interest in recent years due to their excellent electrical properties and stability. This review paper gives a short overview of the main development of sensors based on copper oxides and their composites, highlighting their potential for detecting CO2 and the factors influencing their performance. [ABSTRACT FROM AUTHOR]

The R744/R404A cascade refrigeration system (CRS) has been widely used in supermarkets and hypermarkets, but due to the refrigerant regulation of R404A, research on alternative refrigerants is necessary. In addition, although there have been quite a few studies on R448A and R449A, which are well-known alternatives to R404A, few studies have analyzed the performance coefficients of the three refrigerants, and the studies that have analyzed them are not based on enough variables. Therefore, we aimed to understand the performance characteristics of CRS combined with an internal heat exchanger (IHX) by applying R744 for the low-temperature cycle (LTC) and R404A, R448A, and R449A for the high-temperature cycle (HTC). The analysis method was to analyze the coefficient of performance (COP) and mass flow rate (MFR) of the three refrigerants according to the degree of subcooling (DSC) and degree of superheating (DSH), IHX efficiency, temperature difference in the cascade heat exchanger (CHX), condensation temperature (CT), evaporation temperature (ET), and cascade evaporation temperature (CET). The purpose of this study is to compare R448A and R449A, alternative refrigerants to R404A, in an R744/R404A CRS, with R404A to provide sufficient data for optimal CRS design. The comparison results are as follows: (1) Compared with R404A, the MFR of R448A and R449A are 67.27–77.6% and 70.05–80.80%, respectively, under the same conditions. Therefore, R448A and R449A are economically favorable because they have less refrigerant charge than R404A, and R448A is more favorable than R449A. (2) The R744/R448A CRS is stable and performs better than the R744/R449A CRS in places with large changes in the surrounding environment. [ABSTRACT FROM AUTHOR]

Recognized as the third-generation biomass of the future, microalgae are increasingly viewed as a promising solution for the sustainable production of biofuels, often referred to as "green gold." Extensive research is being conducted across the upstream, midstream, and downstream sectors to develop fundamental technologies that enable efficient and economical large-scale microalgae cultivation. Recent studies suggest that microalgae-based biofuels have the potential to meet global energy demands. However, challenges such as spatial constraints in site selection and the high cost of transporting CO2—an essential component for pH regulation and photosynthesis—pose obstacles. Here, this study demonstrates that by supplementing air-only medium with CaCO3, Chlorella sorokiniana can effectively utilize airborne CO2 to produce biomass. In laboratory-scale culture conditions supplied only with air, adding 5 mM CaCO3 (pH 7.8) could maintain the pH stably compared to the untreated conditions (pH 9.5) and improved the biomass concentration and lipid content by 17.68-fold and 9.58-fold, respectively. In bench-scale conditions, cultures supplemented with 5 mM CaCO3 exhibited a 9-fold increase in the biomass and a 7.15-fold increase in the lipid concentrations compared to those cultivated with air alone. With microalgae emerging as an essential resource for future generations, cultivation technology utilizing CaCO3 will be a critical technology that enables commercial-scale microalgae cultivation using only air, without artificial CO2 supply facilities. [ABSTRACT FROM AUTHOR]

Addressing the issue of poor water injection development effectiveness caused by strong water sensitivity damage in the conglomerate reservoirs of the Xinjiang Oilfield, this paper carries out experimental research on CO2 displacement and CO2 huff-n-puff to improve oil recovery in reservoirs under the conditions of reservoirs (86 °C, 44 MPa) by using a high-temperature and high-pressure large physical modeling repulsion device based on the artificial large-scale physical modeling of conglomerate oil reservoirs in the Xinjiang oilfield. The results showed that at any displacement rate, CO2 displacement exhibits the trend where oil production initially increases and then decreases. The higher the gas injection rate, the higher the initial oil well production, and the shorter the time it takes for CO2 to break through to the bottom of the well. After a breakthrough, production declines more rapidly. The oil recovery rate varies with different gas injection rates, initially increasing and then decreasing as the injection rate changes. The highest oil recovery rate was observed at an injection rate of 1.5 mL/min (equivalent to 38 t/d in the field). The efficiency of CO2 displacement with multiple injection-production cycles is low; on the same scale of gas injection, single-cycle injection and production were more effective than multiple-cycle injection and production. CO2 huff-n-puff can improve oil recovery, with a higher CO2 injection pressure and a longer shut-in time leading to greater oil recovery. As the shut-in time increases, the efficiency of CO2 oil exchange also improves. The strong supply capacity of the large physical model results in a tendency for the oil production curves of multiple huff-n-puff cycles to converge. [ABSTRACT FROM AUTHOR]

To increase the carbon conversion of char in gasification, this paper aimed to reveal the gasification behaviours of char residues. Char residues with different ash contents in this work were prepared from Shenmu char and Tejing char. Those char residues were gasified by different CO2 gas mixtures at different temperatures. The gasification process of char residue was different from the end stage of the gasification process of the corresponding raw char: the gasification rate of the char residue increased at first and then decreased, whereas the gasification rate of the corresponding raw char kept decreasing during the end stage of gasification. The highest gasification rate was achieved at a lower conversion in the gasification of char residue than in the gasification of the corresponding raw char. Catalytic minerals, high temperature, and high CO2 partial pressure benefited the gasification of gasified char residues. The char residues that contained more catalytic minerals were more reactive in gasification and were less sensitive to changes in temperature and CO2 partial pressure. The Modified Random Pore Model (MRPM) and Random Pore Model (RPM) were used to predict the gasification kinetics of the chars, and the MRPM describes the gasification processes of gasified char residues well. [ABSTRACT FROM AUTHOR]

The thermal regeneration of CO2 sorbent is the most energy-consuming step in the CO2-capturing process. Although the addition of an acid can induce CO2 release, it does not regenerate the sorbent because the acid forms a salt with the basic sorbent and diminishes its capability for capturing CO2. In this work, a novel approach based on thermally enhanced acidity was studied. This approach utilizes an additive that does not affect the sorbent at room temperature, but its acidity significantly increases at elevated temperatures, which assists the thermal release of CO2. M-cresol was added to an aqueous solution of morpholine. The CO2 capture and release of the mixture were compared to those of a control solution without m-cresol. The amounts of carbamate, bicarbonate, and unreacted morpholine were quantitatively determined using 1H NMR and weight analysis. The results showed that m-cresol did not affect the reactivity of morpholine in the formation of carbamate with CO2 at room temperature. At elevated temperatures, the acidity of m-cresol increased according to Van't Hoff's equation, which resulted in a significantly higher rate of CO2 release than that of the control. Given the low cost of m-cresol and its derivatives, this approach could lead to practical technology in the near future. [ABSTRACT FROM AUTHOR]

The success of CO2 storage projects largely depends on addressing formation damage, such as salt precipitation, hydrate formation, and fines migration. While analytical models for reservoir behaviour during CO2 storage in aquifers and depleted gas fields are widely available, models addressing formation damage and injectivity decline are scarce. This work aims to develop an analytical model for CO2 injection in a layer-cake reservoir, considering permeability damage. We extend Dietz's model for gravity-dominant flows by incorporating an abrupt permeability decrease upon the gas-water interface arrival in each layer. The exact Buckley-Leverett solution of the averaged quasi-2D (x, z) problem provides explicit formulae for sweep efficiency, well impedance, and skin factor of the injection well. Our findings reveal that despite the induced permeability decline and subsequent well impedance increase, reservoir sweep efficiency improves, enhancing storage capacity by involving a larger rock volume in CO2 sequestration. The formation damage factor d, representing the ratio between damaged and initial permeabilities, varies from 0.016 in highly damaged rock to 1 in undamaged rock, resulting in a sweep efficiency enhancement from 1–3% to 50–53%. The developed analytical model was applied to predict CO2 injection into a depleted gas field. [ABSTRACT FROM AUTHOR]

The C4F7N/CO2 mixture is considered one of the most promising alternatives to sulfur SF6. Recent studies have shown that the addition of O2 to the C4F7N/CO2 mixture can suppress carbon precipitation following electric arc discharges. This paper conducts arc-burning experimental research on SF6, 10%C4F7N/90%CO2, and 10%C4F7N/85%CO2/5%O2 mixtures. Measurements were taken of the arc voltage and arc current under a 10 kA breaking current for these three gases. Additionally, the pressure at the nozzle throat during arc and cold flow conditions, as well as the pressure in the storage chamber, were measured. The post-arc current and Rate of Rise of Recovery Voltage (RRRV) for the three gases were calculated. The study also compared the solid precipitates in the gas medium after multiple arc-burning experiments. The results indicate that adding O2 to the C4F7N/CO2 mixture can increase the pressure at the nozzle throat during the arc phase, and the inclusion of O2 has minimal impact on the peak arc-extinguishing voltage and critical RRRV. It is hypothesized that a small amount of oxygen has a negligible effect on the thermal recovery properties of the C4F7N/CO2 mixture, while also inhibiting the precipitation of carbon following electric arc discharges. This research could provide a reference for developing and optimizing eco-friendly high-voltage circuit breakers. [ABSTRACT FROM AUTHOR]

Groundwater is crucial in mediating the interactions between the carbon and water cycles. Recently, groundwater storage depletion has been identified as a significant source of carbon dioxide (CO2) emissions. Here, we developed two data-driven models—XGBoost and convolutional neural network–long short-term memory (CNN-LSTM)—based on multi-satellite and reanalysis data to monitor CO2 emissions resulting from groundwater storage depletion in South Korea. The data-driven models developed in this study provided reasonably accurate predictions compared with in situ groundwater storage anomaly (GWSA) observations, identifying relatively high groundwater storage depletion levels in several regions over the past decade. For each administrative region exhibiting a decreasing groundwater storage trend, the corresponding CO2 emissions were quantified based on the predicted GWSA and respective bicarbonate concentrations. For 2008–2019, XGBoost and CNN-LSTM estimated CO2 emissions to be 0.216 and 0.202 MMTCO2/year, respectively. Furthermore, groundwater storage depletion vulnerability was assessed using the entropy weight method and technique for order of preference by similarity to ideal solution (TOPSIS) to identify hotspots with a heightened potential risk of CO2 emissions. Western South Korean regions were particularly classified as high or very high regions and susceptible to groundwater storage depletion-associated CO2 emissions. This study provides a foundation for developing countermeasures to mitigate accelerating groundwater storage depletion and the consequent rise in CO2 emissions. [ABSTRACT FROM AUTHOR]

A viable tactic to effectively address the climate crisis is the production of renewable fuels via photocatalytic reactions using solar energy and available resources like carbon dioxide (CO2) and water. Organic polymer material-based photocatalytic materials are thought to be one way to convert solar energy into valuable chemicals and other solar fuels. The use of porous organic polymers (POPs) for CO2 fixation and capture and sequestration to produce beneficial compounds to reduce global warming is still receiving a lot of interest. Visible light-responsive organic photopolymers that are functionally designed and include a large number of heteroatoms and an extended π-conjugation allow for the generation of photogenerated charge carriers, improved absorption of visible light, increased charge separation, and decreased charge recombination during photocatalysis. Due to their rigid structure, high surface area, flexible pore size, permanent porosity, and adaptability of the backbone for the intended purpose, POPs have drawn more and more attention. These qualities have been shown to be highly advantageous for numerous sustainable applications. POPs may be broadly categorized as crystalline or amorphous according to how much long-range order they possess. In terms of performance, conducting POPs outperform inorganic semiconductors and typical organic dyes. They are light-harvesting materials with remarkable optical characteristics, photostability, cheap cost, and low cytotoxicity. Through cocatalyst loading and morphological tweaking, this review presents optimization options for POPs preparation techniques. We provide an analysis of the ways in which the preparative techniques will affect the materials' physicochemical characteristics and, consequently, their catalytic activity. An inventory of experimental methods is provided for characterizing POPs' optical, morphological, electrochemical, and catalytic characteristics. The focus of this review is to thoroughly investigate the photochemistry of these polymeric organic photocatalysts with an emphasis on understanding the processes of internal charge generation and transport within POPs. The review covers several types of amorphous POP materials, including those based on conjugated microporous polymers (CMPs), inherent microporosity polymers, hyper-crosslinked polymers, and porous aromatic frameworks. Additionally, common synthetic approaches for these materials are briefly discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Plant-based ingredients are the major constituents of poultry diets and supply a significant portion of dietary phosphorus (P). However, approximately two-thirds of the P of plant origin is bound to phytic acid, which is poorly available to monogastric animals. Broiler diets have been formulated based on non-phytate P (NPP), which might lead to the excessive use of inorganic P sources and reduced P availability for birds. Recent research has suggested using digestible P to assess availability, and due to nutritional interactions, there is also increasing interest in determining calcium (Ca) digestibility. The objectives of this study were to determine the standardized ileal digestibility (SID) of Ca and P in the feed ingredients for broilers. On day 18 post-hatch, 512 male and female broilers were individually weighed and randomly allocated to eight treatments with four replicates for each sex (eight birds/cage) in a randomized complete block design based on body weight and sex. No significant interaction between experimental diets and sex regarding the SID of Ca or P was found, and no effect of sex on the SID was observed. There were significant differences in the SID of the feed ingredients. This study aimed to determine the standardized ileal digestibility (SID) of calcium (Ca) and phosphorus (P) in various feed ingredients using the direct method. This study comprised eight experimental diets: a Ca–P-free diet and seven experimental diets, each containing monocalcium phosphate (MCP), dicalcium phosphate (DCP), monosodium phosphate (MSP) + limestone, corn, and soybean meal (SBM) as the sole sources of Ca and/or P. These diets provided 4.21 g/kg of non-phytate P from MCP, DCP, or MSP, and the MSP + limestone diet included 7.50 g/kg of Ca. The corn and SBM diets formulated to determine P digestibility maintained a dietary Ca/total P ratio of 1.4 through the addition of limestone. Chromic oxide was added to the diets as an indigestible index. On day 18, 256 male and 256 female broilers were individually weighed and randomly assigned to eight treatments, each with four replicates for each sex (eight birds per cage). This allocation followed a randomized complete block design based on body weight. On day 21, the birds were euthanized using carbon dioxide, and ileal digesta samples were collected from the distal two-thirds section of the ileum. No significant interactions between the experimental diets and sex regarding the SID of Ca or P were detected, and no effect of sex on the SID was observed. The standardized ileal Ca digestibility of MCP, DCP, limestone, corn, and SBM was found to be 84.7%, 70.1%, 52.6%, 88.6%, and 81.6%, respectively. The standardized ileal P digestibility of MCP, DCP, MSP, corn, and SBM was determined to be 91.8%, 76.8%, 94.4%, 73.1, and 88.4%, respectively. Given the variable digestibility of Ca and P across different feed ingredients, the consideration of the specific type of ingredients used in diet formulation is crucial. [ABSTRACT FROM AUTHOR]

OBJECTIVE To evaluate methods for euthanizing cave cockroaches (CCs; Blaberus giganteus) and Madagascar hissing cockroaches (MHCs; Gromphadorhina portentosa). It was hypothesized that both suggested methods would be effective for humane mass euthanasia of both species. SAMPLE Approximately 800 CC. METHODS The CCs were separated into replicate groups of 25, 50, 75, 100, and 150 grams and placed into 3.8-L plastic bags. Twenty-seven MHCs were divided into groups of 2 to 3. The study took place from January to March 2023. All CC groups were exposed to 100% carbon dioxide (CO2) at a rate of 4 L/min until the bag was full. Madagascar hissing cockroaches were similarly anesthetized using either CO2 or 2 mL of isoflurane on a cotton ball in a 1-L container or a combination of CO2 and isoflurane. Once cockroaches were immobile, secondary euthanasia steps were performed. One bag of CCs per weight category was exposed to soapy water (5% Dawn dishwashing liquid), and the second was placed into a −80°C freezer. The containers of MHCs were evenly exposed to the 2 euthanasia methods. Individuals remained in their secondary euthanasia method for 30 minutes. RESULTS Regardless of the weight of the CCs within each bag, there was no impact on time (1.8 ± 0.4 minutes [mean ± SD]) to immobility. The failure rates for both species were 0.2% CI (−0.1% to 1.5% [1/413]) for soapy water and 0.5% CI (0.005% to 1.9% [2/414]) for the freezer method. These results support the use of both 2-step euthanasia methods in CCs and MHCs. CLINICAL RELEVANCE These methods will serve as an evidence-based alternative for humane mass euthanasia in cockroaches. [ABSTRACT FROM AUTHOR]

Atmospheric CO2 concentration is elevated globally, which has "CO2 fertilization effects" and potentially improves plant photosynthesis, yield, and productivity. Despite the beneficial effect of CO2 fertilization being modulated by vapor pressure deficit (VPD), the underlying mechanism is highly uncertain. In the present study, the potential roles of hormones in determining CO2 fertilization effects under contrasting high and low VPD conditions were investigated by integrated physiological and transcriptomic analyses. Beneficial CO2 fertilization effects were offset under high VPD conditions and were constrained by plant water stress and photosynthetic CO2 utilization. High VPD induced a large passive water driving force, which disrupted the water balance and consequently caused plant water deficit. Leaf water potential, turgor pressure, and hydraulic conductance declined under high VPD stress. The physiological evidence combined with transcriptomic analyses demonstrated that abscisic acid (ABA) and jasmonic acid (JA) potentially acted as drought-signaling molecules in response to high VPD stress. Increased foliar ABA and JA content triggered stomatal closure to prevent excessive water loss under high VPD stress, which simultaneously increased the diffusion resistance for CO2 uptake from atmosphere to leaf intercellular space. High VPD also significantly increased mesophyll resistance for CO2 transport from stomatal cavity to fixation site inside chloroplast. The chloroplast "sink" CO2 availability was constrained by stomatal and mesophyll resistance under high VPD stress, despite the atmospheric "source" CO2 concentration being elevated. Thus, ABA- and JA-mediated drought-resistant mechanisms potentially modified the beneficial effect of CO2 fertilization on photosynthesis, plant growth, and yield productivity. This study provides valuable information for improving the utilization efficiency of CO2 fertilization and a better understanding of the physiological processes. [ABSTRACT FROM AUTHOR]

A magnetic solid-phase extraction method with the dispersion of magnetic hypercrosslinked polystyrene (MHCPS) by carbon dioxide is proposed for the extraction and preconcentration of amphenicols (chloramphenicol, florfenicol, and thiamphenicol) from honey and milk before their determination by HPLC–MS/MS. Effervescent tablets, consisting of sodium bicarbonate, citric acid, and MHCPS in the case of honey and sodium bicarbonate and MHCPS in the case of milk, were used. The conditions for obtaining tablets were selected (the amount and ratio of the acid, base, and MHCPS in the composition of a tablet and its mass), ensuring the quantitative release of amphenicols. Procedures for the determination of amphenicols in honey and milk with the dispersion of the sorbent by carbon dioxide and the subsequent determination of the compounds by HPLC–MS/MS are developed. The limits of detection are 0.3–1 and 0.02–0.05 μg/kg for honey and milk, respectively. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Automated measurements of the ratio of concentrations of methane and carbon dioxide, [CH 4 ]:[CO 2 ], in breath from individual animals (the so-called "sniffer technique") and estimated CO 2 production can be used to estimate CH 4 production, provided that CO 2 production can be reliably calculated. This would allow CH 4 production from individual cows to be estimated in large cohorts of cows, whereby ranking of cows according to their CH 4 production might become possible and their values could be used for breeding of low CH 4 -emitting animals. Estimates of CO 2 production are typically based on predictions of heat production, which can be calculated from body weight (BW), energy-corrected milk yield, and days of pregnancy. The objectives of the present study were to develop predictions of CO 2 production directly from milk production, dietary, and animal variables, and furthermore to develop different models to be used for different scenarios, depending on available data. An international dataset with 2,244 records from individual lactating cows including CO 2 production and associated traits, as dry matter intake (DMI), diet composition, BW, milk production and composition, days in milk, and days pregnant, was compiled to constitute the training dataset. Research location and experiment nested within research location were included as random intercepts. The method of CO 2 production measurement (respiration chamber [RC] or GreenFeed [GF]) was confounded with research location, and therefore excluded from the model. In total, 3 models were developed based on the current training dataset: model 1 ("best model"), where all significant traits were included; model 2 ("on-farm model"), where DMI was excluded; and model 3 ("reduced on-farm model"), where both DMI and BW were excluded. Evaluation on test dat sets with either RC data (n = 103), GF data without additives (n = 478), or GF data only including observations where nitrate, 3-nitrooxypropanol (3-NOP), or a combination of nitrate and 3-NOP were fed to the cows (GF+: n = 295), showed good precision of the 3 models, illustrated by low slope bias both in absolute values (−0.22 to 0.097) and in percentage (0.049 to 4.89) of mean square error (MSE). However, the mean bias (MB) indicated systematic overprediction and underprediction of CO 2 production when the models were evaluated on the GF and the RC test datasets, respectively. To address this bias, the 3 models were evaluated on a modified test dataset, where the CO 2 production (g/d) was adjusted by subtracting (where measurements were obtained by RC) or adding absolute MB (where measurements were obtained by GF) from evaluation of the specific model on RC, GF, and GF+ test datasets. With this modification, the absolute values of MB and MB as percentage of MSE became negligible. In conclusion, the 3 models were precise in predicting CO 2 production from lactating dairy cows. [ABSTRACT FROM AUTHOR]

Summary: Mesophyll conductance (gm) describes the ease with which CO2 passes from the sub‐stomatal cavities of the leaf to the primary carboxylase of photosynthesis, Rubisco. Increasing gm is suggested as a means to engineer increases in photosynthesis by increasing [CO2] at Rubisco, inhibiting oxygenation and accelerating carboxylation. Here, tobacco was transgenically up‐regulated with Arabidopsis Cotton Golgi‐related 3 (CGR3), a gene controlling methylesterification of pectin, as a strategy to increase CO2 diffusion across the cell wall and thereby increase gm. Across three independent events in tobacco strongly expressing AtCGR3, mesophyll cell wall thickness was decreased by 7%–13%, wall porosity increased by 75% and gm measured by carbon isotope discrimination increased by 28%. Importantly, field‐grown plants showed an average 8% increase in leaf photosynthetic CO2 uptake. Up‐regulating CGR3 provides a new strategy for increasing gm in dicotyledonous crops, leading to higher CO2 assimilation and a potential means to sustainable crop yield improvement. [ABSTRACT FROM AUTHOR]