Sex-specific threat responding and neuronal engagement in carbon dioxide associated fear and extinction: Noradrenergic involvement in female mice

Difficulty in appropriately responding to threats is a key feature of psychiatric disorders, especially fear-related conditions such as panic disorder (PD) and posttraumatic stress disorder (PTSD). Most prior work on threat and fear regulation involves exposure to external threatful cues. However, fear can also be triggered by aversive, within-the-body, sensations. This interoceptive signaling of fear is highly relevant to PD and PTSD but is not well understood, especially in the context of sex. Using female and male mice, the current study investigated fear-associated spontaneous and conditioned behaviors to carbon dioxide (CO2) inhalation, a potent interoceptive threat that induces fear and panic. We also investigated whether behavioral sensitivity to CO2 is associated with delayed PTSD-relevant behaviors. CO2 evoked heterogenous freezing behaviors in both male and female animals. However, active, rearing behavior was significantly reduced in CO2-exposed male but not female mice. Interestingly, behavioral sensitivity to CO2 was associated with compromised fear extinction, independent of sex. However, in comparison to CO2-exposed males, females elicited less freezing and higher rearing during extinction suggesting an engagement of active versus passive defensive coping. Persistent neuronal activation marker ΔFosB immuno-mapping revealed attenuated engagement of infralimbic-prefrontal areas in both sexes but higher activation of brain stem locus coeruleus (LC) area in females. Inter-regional co-activation mapping revealed sex-independent disruptions in the infralimbic-amygdala associations but altered LC associations only in CO2-exposed female mice. Lastly, dopamine β hydroxylase positive (DβH + ve) noradrenergic neuronal cell counts in the LC correlated with freezing and rearing behaviors during CO2 inhalation and extinction only in female but not male mice. Collectively, these data provide evidence for higher active defensive responding to interoceptive threat CO2-associated fear in females that may stem from increased recruitment of the brainstem noradrenergic system. Our findings reveal distinct contributory mechanisms that may promote sex differences in fear and panic associated pathologies.

Metabolic engineering strategies to enable microbial electrosynthesis utilization of CO2: recent progress and challenges

Microbial electrosynthesis (MES) is a promising technology that mainly utilizes microbial cells to convert CO2 into value-added chemicals using electrons provided by the cathode. However, the low electron transfer rate is a solid bottleneck hindering the further application of MES. Thus, as an effective strategy, genetic tools play a key role in MES for enhancing the electron transfer rate and diversity of production. We describe a set of genetic strategies based on fundamental characteristics and current successes and discuss their functional mechanisms in driving microbial electrocatalytic reactions to fully comprehend the roles and uses of genetic tools in MES. This paper also analyzes the process of nanomaterial application in extracellular electron transfer (EET). It provides a technique that combines nanomaterials and genetic tools to increase MES efficiency, because nanoparticles have a role in the production of functional genes in EET although genetic tools can subvert MES, it still has issues with difficult transformation and low expression levels. Genetic tools remain one of the most promising future strategies for advancing the MES process despite these challenges.

Boosted Sacrificial-Agent-Free Selective Photoreduction of CO2 to CH3OH by Rhenium Atomically Dispersed on Indium Oxide

Solar-energy-driven photoreduction of CO2 is promising in alleviating environment burden, but suffers from low efficiency and over-reliance on sacrificial agents. Herein, rhenium (Re) is atomically dispersed in In2O3 to fabricate a 2Re-In2O3 photocatalyst. In sacrificial-agent-free photoreduction of CO2 with H2O, 2Re-In2O3 shows a long-term stable efficiency which is enhanced by 3.5 times than that of pure In2O3 and is also higher than those on Au-In2O3, Ag-In2O3, Cu-In2O3, Ir-In2O3, Ru-In2O3, Rh-In2O3 and Pt-In2O3 photocatalysts. Moreover, carbon-based product of the photoreduction overturns from CO on pure In2O3 to CH3OH on 2Re-In2O3. Re promotes charge separation, H2O dissociation and CO2 activation, thus enhancing photoreduction efficiency of CO2 on 2Re-In2O3. During the photoreduction, CO is a key intermediate. CO prefers to desorption rather than hydrogenation on pure In2O3, as CO binds to pure In2O3 very weakly. Re strengthens the interaction of CO with 2Re-In2O3 by 5.0 times, thus limiting CO desorption but enhancing CO hydrogenation to CH3OH. This could be the origin for photoreduction product overturn from CO on pure In2O3 to CH3OH on 2Re-In2O3. The present work opens a new way to boost sacrificial-agent-free photoreduction of CO2.

Bedroom Concentrations and Emissions of Volatile Organic Compounds during Sleep

Because humans spend about one-third of their time asleep in their bedrooms and are themselves emission sources of volatile organic compounds (VOCs), it is important to specifically characterize the composition of the bedroom air that they experience during sleep. This work uses real-time indoor and outdoor measurements of volatile organic compounds (VOCs) to examine concentration enhancements in bedroom air during sleep and to calculate VOC emission rates associated with sleeping occupants. Gaseous VOCs were measured with proton-transfer reaction time-of-flight mass spectrometry during a multiweek residential monitoring campaign under normal occupancy conditions. Results indicate high emissions of nearly 100 VOCs and other species in the bedroom during sleeping periods as compared to the levels in other rooms of the same residence. Air change rates for the bedroom and, correspondingly, emission rates of sleeping-associated VOCs were determined for two bounding conditions: (1) air exchange between the bedroom and outdoors only and (2) air exchange between the bedroom and other indoor spaces only (as represented by measurements in the kitchen). VOCs from skin oil oxidation and personal care products were present, revealing that many emission pathways can be important occupant-associated emission factors affecting bedroom air composition in addition to direct emissions from building materials and furnishings.

Perspectives on embryo maturation and seed quality in a global climate change scenario

Global climate change has already brought noticeable alterations to multiple regions of our planet. Several important steps of plant growth and development, such as embryogenesis, can be affected by environmental changes. For instance, these changes would affect how stored nutrients are used during early stages of seed germination as it transitions from a heterotrophic to autotrophic metabolism, a critical period for the seedling's survival. In this perspective, we provide a brief description of relevant processes that occur during embryo maturation and account for nutrient accumulation, which are sensitive to environmental change. As examples of the effects associated with climate change are increased CO2 levels and changes in temperature. During seed development, most of the nutrients stored in the seed are accumulated during the seed maturation stage. These nutrients include, depending on the plant species, carbohydrates, lipids and proteins. Regarding micronutrients, it has also been established that iron, a key micronutrient for various electron transfer processes in plant cells, accumulates during embryo maturation. Several articles have been published indicating that climate change can affect the quality of the seed, in terms of total nutritional content, but also, it may affect seed production. Here we discuss the potential effects of temperature and CO2 increase from an embryo autonomous point of view, in an attempt to separate the maternal effects from embryonic effects.

The heptazine-based materials through intrinsically modification for the cycloaddition of CO2 and bisepoxides

For the efficient utilization of CO2 into valuable product, the attractive carbon nitride catalysts have been widely studied. In this work, heptazine-related materials with varying degree of polymerization were designed by an intrinsically modification strategy and employed in the cycloaddition of CO2 with the bisepoxide 1, 4-butanediol diglycidyl ether (BDODGE). We initially figured out that the sample prepared at 450°C contained more melem hydrate, exhibiting the best performance. The epoxides conversion and corresponding cyclic carbonates selectivity could achieve 93.1% and 99.3% at 140°C for 20 h without any cocatalyst and solvent, respectively. Results of the catalytic tests suggested that the high catalytic activity was dependent on big size porous structure and the synergetic effect of active amino groups and -OH groups. The role of water in maintaining the specific structure and providing active site has been proved. Moreover, the CN-450-W catalyst exhibited outstanding recycling stability. And finally, a plausible reaction mechanism was proposed.

Can Mercury Influence Carbon Dioxide Levels? Implications for the Implementation of the Minamata Convention on Mercury

The Paris Agreement and the Minamata Convention on Mercury are two of the most important environmental conventions being implemented concurrently, with a focus on reducing carbon and mercury emissions, respectively. The relation between mercury and carbon influences the interactions and outcomes of these two conventions. This perspective investigates the link between mercury and CO2, assessing the consequences and exploring the policy implications of this link. We present scientific evidence showing that mercury and CO2 levels are negatively correlated under natural conditions. As a result of this negative correlation, the CO2 level under the current mercury reduction scenario is predicted to be 2.4-10.1 ppm higher than the no action scenario by 2050, equivalent to 1.0-4.8 years of CO2 increase due to human activity. The underlying causations of this negative correlation are complex and need further research. Economic analysis indicates that there is a trade-off between the benefits and costs of mercury reduction actions. As reducing mercury emission may inadvertently undermine efforts to achieve climate goals, we advocate for devising a coordinated implementation strategy for carbon and mercury conventions to maximize synergies and reduce trade-offs.

Electroreduction of CO2 on Cu, Fe, or Ni-doped Diamane Sheets: A DFT Study

Poor mass transfer behavior and inherent activity limit the efficiency of traditional catalysts in electrocatalyzing carbon dioxide reduction reactions. However, the development of novel nanomaterials provides new strategies to solve the above problems. Herein, we propose novel single-metal atom catalysts, namely diamane-based electrocatalysts doped with Cu, Fe, and Ni, explored through density functional theory (DFT) calculations. We thoroughly investigated the doping pattern and energetics for different dopants. Furthermore, we systematically investigated the conversion process of CO2 to C1 or C2+ products, utilizing the free energy analysis of reaction pathways. Our results reveal that dopants could only be introduced into diamane following a specific pattern. Dopants significantly enhance the CO2 adsorption ability of diamane, with Fe and Ni proving notably more effective than Cu. After CO2 adsorption, Cu- and Fe-doped diamane prefer to catalyze CO2RR, while Ni-doped diamane favors hydrogen evolution reaction (HER). The C-C coupling reaction on Cu-hollow diamane, Cu-bridge diamane, and Fe-hollow diamane tends to be from C2+ products. Among all examined catalysts, Cu-hollow diamane shows better electro-catalytic performance. Our study demonstrates the feasibility of and contributes to the development of diamane-based electro-catalysts for CO2RR.

High-Toughness CO2-Sourced Ionic Polyurea Adhesives

Polyurea (PUa) adhesives are renowned for their exceptional adhesion to diverse substrates even in harsh environments. However, the presence of quadruple bidentate intermolecular hydrogen bonds in the polymer chains creates a trade-off between cohesive energy and interfacial adhesive energy. To overcome this challenge, a series of CO2-sourced ionic PUa adhesives with ultratough adhesion to various substrates are developed. The incorporated ionic segments within the adhesive serve to partially mitigate the intermolecular hydrogen bonding interactions while conferring unique electrostatic interactions, leading to both high cohesive energy and interfacial adhesive energy. The maximum adhesive strength of 10.9 MPa can be attained by ionizing the CO2-sourced PUa using bromopropane and subsequently exchanging the anion with lithium bis(trifluoromethylsulfonyl)imide. Additionally, these ionic PUa adhesives demonstrate several desirable properties such as low-temperature stability (-80 °C), resistance to organic solvents and water, high flame retardancy, antibacterial activity, and UV-fluorescence, thereby expanding their potential applications. This study presents a general and effective approach for designing high-strength adhesives suitable for a wide array of uses.

Understanding improved neonatal ventilation trends in a regional transport service

AIM

Review changes in neonatal ventilation practice within our regional transport service, Embrace, identifying interventions with greatest impact on improved rates of normocapnia during transfer.

METHODS

Using internal transport databases and UK Neonatal Transport Group data submissions, we tracked local and national rates of ventilation and normocapnia. We correlated this with internal changes in practice, including introduction of new equipment, staffing changes, educational interventions and quality improvement projects.

RESULTS

Data demonstrated improvement in normocapnia rates benchmarked against national figures, which was not explained by changes in ventilation methods or rates, or by changes in availability of post-transfer gases. Greatest improvement was identified following introduction of transcutaneous CO2 monitoring and ventilators enabling volume-guided ventilation strategies. Additionally, although less quantifiable, educational and quality improvement interventions, and case review mechanisms were felt to be influential.

CONCLUSION

Volume guided ventilation and transcutaneous CO2 monitoring have had a positive influence on the maintenance of normocapnia during transfer at Embrace Transport Service, although introduction of new equipment still presents challenges which must be overcome. Recognising the significant impact of these technologies allows for ongoing financial, time and educational investment to emphasise their importance and ensure appropriate awareness of limitations and troubleshooting options, maximising their positive impact.

Application of transcritical CO2 heat pumps to boiler replacement in low impact refurbishment projects

80% of current UK housing stock is expected to still be in use in 2050. Difficult, intrusive and expensive, refurbishment measures are required to achieve the level of insulation required for current low temperature heat pumps. Transcritical CO2 heat pumps can achieve higher efficiencies, with higher output temperatures, than current, Carnot limited, synthetic gas heat pumps, with less environmental impact. Widely deployed in water heating and supermarket chilling systems, CO2 heat pumps need heating return temperatures of 30 °C or less to function effectively. This has impeded their adoption with hydronic heating systems which have high return temperatures. This study identified system modifications external to the refrigeration cycle that address return temperatures. It modelled a transcritical CO2 air source heat pump with a hydronic heating system in a solid wall semi-detached house. Full year system coefficients of performance over 3 were achieved in four UK locations by using space heating return fluids to defrost the air source heat exchanger and to pre-heat inlet water, recovering any remaining excess return fluid heat as a source for the heat pump. Solar panels boosted this to 5.1. The levelized cost of energy for the system was calculated (with heat pump grant) at 22p/kWh, lower than a gas boiler, with 9.45 tonnes CO2 emission savings over a fifteen-year life.

A Scalable Robust Microporous Al-MOF for Post-Combustion Carbon Capture

Herein, a robust microporous aluminum tetracarboxylate framework, MIL-120(Al)-AP, (MIL, AP: Institute Lavoisier and Ambient Pressure synthesis, respectively) is reported, which exhibits high CO2 uptake (1.9 mmol g-1 at 0.1 bar, 298 K). In situ Synchrotron X-ray diffraction measurements together with Monte Carlo simulations reveal that this structure offers a favorable CO2 capture configuration with the pores being decorated with a high density of µ2-OH groups and accessible aromatic rings. Meanwhile, based on calculations and experimental evidence, moderate host-guest interactions Qst (CO2) value of MIL-120(Al)-AP (-40 kJ mol-1) is deduced, suggesting a relatively low energy penalty for full regeneration. Moreover, an environmentally friendly ambient pressure green route, relying on inexpensive raw materials, is developed to prepare MIL-120(Al)-AP at the kilogram scale with a high yield while the Metal- Organic Framework (MOF) is further shaped with inorganic binders as millimeter-sized mechanically stable beads. First evidences of its efficient CO2/N2 separation ability are validated by breakthrough experiments while operando IR experiments indicate a kinetically favorable CO2 adsorption over water. Finally, a techno-economic analysis gives an estimated production cost of ≈ 13 $ kg-1, significantly lower than for other benchmark MOFs. These advancements make MIL-120(Al)-AP an excellent candidate as an adsorbent for industrial-scale CO2 capture processes.

A new CO2 refrigeration system with two-phase ejector and parallel compression for supermarkets

This study explores the integration of parallel compression and a two-phase ejector in transcritical CO2 refrigeration systems, aiming to improve efficiency and performance. This innovative approach bridges the gap between conventional approaches and explores new energy-saving potential. The study uses thermodynamic modeling, mathematical simulation, and in-depth analysis to look at energy and exergy performance in a new configuration for applications in the retail sector at medium evaporation temperatures. The work investigates thermodynamic phenomena in a novel cycle with steady-state conditions, low pressure differentials, and adiabatic efficiency. The model is validated against experimental and theoretical published data, revealing component-specific exergy destruction and key parameters. The novel cycle efficiently extracts heat at higher temperatures, outperforming conventional and parallel cycles. Exergetic efficiency surpasses the standard cycle, with gas cooler pressure and temperature dependence enhancing efficiency by 40%-45%. The distribution of exergy destruction percentages reveals efficiency determinants, emphasizing heat exchange optimization and ejector responsiveness in energy dissipation dynamics. The study investigates the coefficient of performance (COP) dependence on gas cooler pressure and temperature, revealing superior performance compared to conventional cycles. COP increases by 50% at 80 bars, indicating enhanced efficiency. The new cycle offers exceptional efficiency gains, with a COP enhancement of over 75% for evaporator temperature transitions. Comparative analysis shows a COP superiority of up to 53% for lower evaporator temperatures and 20% for higher evaporator temperatures, demonstrating substantial energy savings and improved performance across various operating conditions.

Temperature sensitivity of detrital photosynthesis

BACKGROUND AND AIMS

Kelp forests are increasingly considered blue carbon habitats for ocean-based biological carbon dioxide removal, but knowledge gaps remain in our understanding of their carbon cycle. Of particular interest is the remineralization of detritus, which can remain photosynthetically active. Here, we study a widespread, thermotolerant kelp (Ecklonia radiata) to explore detrital photosynthesis as a mechanism underlying temperature and light as two key drivers of remineralization.

METHODS

We used meta-analysis to constrain the thermal optimum (Topt) of E. radiata. Temperature and light were subsequently controlled over a 119-day ex situ decomposition experiment. Flow-through experimental tanks were kept in darkness at 15 °C or under a subcompensating maximal irradiance of 8 µmol photons m-2 s-1 at 15, 20 or 25 °C. Photosynthesis of laterals (analogues to leaves) was estimated using closed-chamber oxygen evolution in darkness and under a saturating irradiance of 420 µmol photons m-2 s-1.

KEY RESULTS

T opt of E. radiata is 18 °C across performance variables (photosynthesis, growth, abundance, size, mass and fertility), life stages (gametophyte and sporophyte) and populations. Our models predict that a temperature of >15 °C reduces the potential for E. radiata detritus to be photosynthetically viable, hence detrital Topt ≤ 15 °C. Detritus is viable under subcompensating irradiance, where it performs better than in darkness. Comparison of net and gross photosynthesis indicates that elevated temperature primarily decreases detrital photosynthesis, whereas darkness primarily increases detrital respiration compared with optimal experimental conditions, in which detrital photosynthesis can persist for ≥119 days.

CONCLUSIONS

T opt of kelp detritus is ≥3 °C colder than that of the intact plant. Given that E. radiata is one of the most temperature-tolerant kelps, this suggests that photosynthesis is generally more thermosensitive in the detrital phase, which partly explains the enhancing effect of temperature on remineralization. In contrast to darkness, even subcompensating irradiance maintains detrital viability, elucidating the accelerating effect of depth and its concomitant light reduction on remineralization to some extent. Detrital photosynthesis is a meaningful mechanism underlying at least two drivers of remineralization, even below the photoenvironment inhabited by the attached alga.

Intensified Continuous Flow Process for the Scalable Production of Bio-Based Glycerol Carbonate

A subtle combination of fundamental and applied organic chemistry toward process intensification is demonstrated for the large-scale production of bio-based glycerol carbonate under flow conditions. The direct carbonation of bio-based glycidol with CO2 is successfully carried out under intensified flow conditions, with Barton's base as a potent homogeneous organocatalyst. Process metrics for the CO2 coupling step (for the upstream production, output: 3.6 kg day-1 , Space Time Yield (STY): 2.7 kg h-1  L-1 , Environmental factor (E-factor): 4.7) outclass previous reports. High conversion and selectivity are achieved in less than 30 s of residence time at pilot scale with a stoichiometric amount of CO2 . Supporting DFT computations reveal the unique features of the mechanism in presence of Brønsted bases.

Surrounded by luxury: The necessities of subsidiary cells

The evolution of stomata marks one of the key advances that enabled plants to colonise dry land while allowing gas exchange for photosynthesis. In large measure, stomata retain a common design across species that incorporates paired guard cells with little variation in structure. By contrast, the cells of the stomatal complex immediately surrounding the guard cells vary widely in shape, size and count. Their origins in development are similarly diverse. Thus, the surrounding cells are likely a luxury that the necessity of stomatal control cannot do without (with apologies to Oscar Wilde). Surrounding cells are thought to support stomatal movements as solute reservoirs and to shape stomatal kinetics through backpressure on the guard cells. Their variety may also reflect a substantial diversity in function. Certainly modelling, kinetic analysis and the few electrophysiological studies to date give hints of much more complex contributions in stomatal physiology. Even so, our knowledge of the cells surrounding the guard cells in the stomatal complex is far from complete.

A positive feedback to climate change: The effect of temperature on the respiration of key wood-decomposing fungi does not decline with time

Heterotrophic soil microorganisms are responsible for ~50% of the carbon dioxide released by respiration from the terrestrial biosphere each year. The respiratory response of soil microbial communities to warming, and the control mechanisms, remains uncertain, yet is critical to understanding the future land carbon (C)-climate feedback. Individuals of nine species of fungi decomposing wood were exposed to 90 days of cooling to evaluate the medium-term effect of temperature on respiration. Overall, the effect of temperature on respiration increased in the medium term, with no evidence of compensation. However, the increasing effect of temperature on respiration was lost after correcting for changes in biomass. These results indicate that C loss through respiration of wood-decomposing fungi will increase beyond the direct effects of temperature on respiration, potentially promoting greater C losses from terrestrial ecosystems and a positive feedback to climate change.

Land surface conductance linked to precipitation: Co-evolution of vegetation and climate in Earth system models

Vegetation and precipitation are known to fundamentally influence each other. However, this interdependence is not fully represented in climate models because the characteristics of land surface (canopy) conductance to water vapor and CO2 are determined independently of precipitation. Working within a coupled atmosphere and land modelling framework (CAM6/CLM5; coupled Community Atmosphere Model v6/Community Land Model v5), we have developed a new theoretical approach to characterizing land surface conductance by explicitly linking its dynamic properties to local precipitation, a robust proxy for moisture available to vegetation. This will enable regional surface conductance characteristics to shift fluidly with climate change in simulations, consistent with general principles of co-evolution of vegetation and climate. Testing within the CAM6/CLM5 framework shows that climate simulations incorporating the new theory outperform current default configurations across several error metrics for core output variables when measured against observational data. In climate simulations for the end of this century the new, adaptive stomatal conductance scheme provides a revised prognosis for average and extreme temperatures over several large regions, with increased primary productivity through central and east Asia, and higher rainfall through North Africa and the Middle East. The new projections also reveal more frequent heatwaves than originally estimated for the south-eastern US and sub-Saharan Africa but less frequent heatwaves across east Europe and northeast Asia. These developments have implications for evaluating food security and risks from extreme temperatures in areas that are vulnerable to climate change.

Orphan Nuclear Receptor Family 4A (NR4A) Members NR4A2 and NR4A3 Selectively Modulate Elements of the Monocyte Response to Buffered Hypercapnia

Hypercapnia occurs when the partial pressure of carbon dioxide (CO2) in the blood exceeds 45 mmHg. Hypercapnia is associated with several lung pathologies and is transcriptionally linked to suppression of immune and inflammatory signalling through poorly understood mechanisms. Here we propose Orphan Nuclear Receptor Family 4A (NR4A) family members NR4A2 and NR4A3 as potential transcriptional regulators of the cellular response to hypercapnia in monocytes. Using a THP-1 monocyte model, we investigated the sensitivity of NR4A family members to CO2 and the impact of depleting NR4A2 and NR4A3 on the monocyte response to buffered hypercapnia (10% CO2) using RNA-sequencing. We observed that NR4A2 and NR4A3 are CO2-sensitive transcription factors and that depletion of NR4A2 and NR4A3 led to reduced CO2-sensitivity of mitochondrial and heat shock protein (Hsp)-related genes, respectively. Several CO2-sensitive genes were, however, refractory to depletion of NR4A2 and NR4A3, indicating that NR4As regulate certain elements of the cellular response to buffered hypercapnia but that other transcription factors also contribute. Bioinformatic analysis of conserved CO2-sensitive genes implicated several novel putative CO2-sensitive transcription factors, of which the ETS Proto-Oncogene 1 Transcription Factor (ETS-1) was validated to show increased nuclear expression in buffered hypercapnia. These data give significant insights into the understanding of immune responses in patients experiencing hypercapnia.

A drained nutrient-poor peatland forest in boreal Sweden constitutes a net carbon sink after integrating terrestrial and aquatic fluxes

Northern peatlands provide a globally important carbon (C) store. Since the beginning of the 20th century, however, large areas of natural peatlands have been drained for biomass production across Fennoscandia. Today, drained peatland forests constitute a common feature of the managed boreal landscape, yet their ecosystem C balance and associated climate impact are not well understood, particularly within the nutrient-poor boreal region. In this study, we estimated the net ecosystem carbon balance (NECB) from a nutrient-poor drained peatland forest and an adjacent natural mire in northern Sweden by integrating terrestrial carbon dioxide (CO2 ) and methane (CH4 ) fluxes with aquatic losses of dissolved organic C (DOC) and inorganic C based on eddy covariance and stream discharge measurements, respectively, over two hydrological years. Since the forest included a dense spruce-birch area and a sparse pine area, we were able to further evaluate the effect of contrasting forest structure on the NECB and component fluxes. We found that the drained peatland forest was a net C sink with a 2-year mean NECB of -115 ± 5 g C m-2  year-1 while the adjacent mire was close to C neutral with 14.6 ± 1.7 g C m-2  year-1 . The NECB of the drained peatland forest was dominated by the net CO2 exchange (net ecosystem exchange [NEE]), whereas NEE and DOC export fluxes contributed equally to the mire NECB. We further found that the C sink strength in the sparse pine forest area (-153 ± 8 g C m-2  year-1 ) was about 1.5 times as high as in the dense spruce-birch forest area (-95 ± 8 g C m-2  year-1 ) due to enhanced C uptake by ground vegetation and lower DOC export. Our study suggests that historically drained peatland forests in nutrient-poor boreal regions may provide a significant net ecosystem C sink and associated climate benefits.

Tandem Synergistic Effect of Cu-In Dual Sites Confined on the Edge of Monolayer CuInP2 S6 toward Selective Photoreduction of CO2 into Multi-Carbon Solar Fuels

One-unit-cell, single-crystal, hexagonal CuInP2 S6 atomically thin sheets of≈0.81 nm in thickness was successfully synthesized for photocatalytic reduction of CO2 . Exciting ethene (C2 H4 ) as the main product was dominantly generated with the yield-based selectivity reaching ≈56.4 %, and the electron-based selectivity as high as ≈74.6 %. The tandem synergistic effect of charge-enriched Cu-In dual sites confined on the lateral edge of the CuInP2 S6 monolayer (ML) is mainly responsible for efficient conversion and high selectivity of the C2 H4 product as the basal surface site of the ML, exposing S atoms, can not derive the CO2 photoreduction due to the high energy barrier for the proton-coupled electron transfer of CO2 into *COOH. The marginal In site of the ML preeminently targets CO2 conversion to *CO under light illumination, and the *CO then migrates to the neighbor Cu sites for the subsequent C-C coupling reaction into C2 H4 with thermodynamic and kinetic feasibility. Moreover, ultrathin structure of the ML also allows to shorten the transfer distance of charge carriers from the interior onto the surface, thus inhibiting electron-hole recombination and enabling more electrons to survive and accumulate on the exposed active sites for CO2 reduction.

Acetamide Electrosynthesis from CO2 and Nitrite in Water

Renewable electricity driven electrocatalytic CO2 reduction reaction (CO2 RR) is a promising solution to carbon neutralization, which mainly generate simple carbon products. It is of great importance to produce more valuable C-N chemicals from CO2 and nitrogen species. However, it is challenging to co-reduce CO2 and NO3 - /NO2 - to generate aldoxime an important intermediate in the electrocatalytic C-N coupling process. Herein, we report the successful electrochemical conversion of CO2 and NO2 - to acetamide for the first time over copper catalysts under alkaline condition through a gas diffusion electrode. Operando spectroelectrochemical characterizations and DFT calculations, suggest acetaldehyde and hydroxylamine identified as key intermediates undergo a nucleophilic addition reaction to produce acetaldoxime, which is then dehydrated to acetonitrile and followed by hydrolysis to give acetamide under highly local alkaline environment and electric field. Moreover, the above mechanism was successfully extended to the formation of phenylacetamide. This study provides a new strategy to synthesize highly valued amides from CO2 and wastewater.

Enhanced CO2 Sensing by Oxygen Plasma-Treated Perovskite-Graphene Nanocomposites

Carbon dioxide (CO2) is a major greenhouse gas responsible for global warming and climate change. The development of sensitive CO2 sensors is crucial for environmental and industrial applications. This paper presents a novel CO2 sensor based on perovskite nanocrystals immobilized on graphene and functionalized with oxygen plasma treatment. The impact of this post-treatment method was thoroughly investigated using various characterization techniques, including Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The detection of CO2 at parts per million (ppm) levels demonstrated that the hybrids subjected to 5 min of oxygen plasma treatment exhibited a 3-fold improvement in sensing performance compared to untreated layers. Consequently, the CO2 sensing capability of the oxygen-treated samples showed a limit of detection and limit of quantification of 6.9 and 22.9 ppm, respectively. Furthermore, the influence of ambient moisture on the CO2 sensing performance was also evaluated, revealing a significant effect of oxygen plasma treatment.

Study of the Chemical Activities of Carbon Monoxide, Carbon Dioxide, and Oxygen Traces as Critical Inhibitors of Polypropylene Synthesis

This study outlines the investigation into how the compounds CO2, CO, and O2 interact with the active center of titanium (Ti) on the surface of MgCl2 and how these interactions impact the productivity of the Ziegler-Natta catalyst, ultimately influencing the thermal stability of the produced polypropylene. The calculations revealed that the adsorption energies of Ti-CO2-CO and O2 were -9.6, -12.5, and -2.32 Kcal/mol, respectively. Using the density functional theory in quantum calculations, the impacts of electronic properties and molecular structure on the adsorption of CO, O2, and CO2 on the Ziegler-Natta catalyst were thoroughly explored. Additionally, the Gibbs free energy and enthalpy of adsorption were examined. It was discovered that strong adsorption and a significant energy release (-16.2 kcal/mol) during CO adsorption could explain why this gas caused the most substantial reductions in the ZN catalyst productivity. These findings are supported by experimental tests showing that carbon monoxide has the most significant impact on the ZN catalyst productivity, followed by carbon dioxide, while oxygen exerts a less pronounced inhibitory effect.

The efficacy, satisfaction, and safety of carbon dioxide (CO2) fractional laser in combination with pulsed dye laser (PDL) versus each one alone in the treatment of hypertrophic burn scars: a single-blinded randomized controlled trial

The tendency to use less-invasive laser-based methods with far more obvious effectiveness has been taken into consideration today for improvement of burning scars. The present study thus aimed to assess the efficacy of two laser-based techniques including pulsed dye laser (PDL) and ablative fractional CO2 laser (AFCL) and its combination on improving different aspects of burning scars regardless of the types of scar as hypertrophic or keloid scars. This randomized single-blinded clinical trial was performed on patients suffering hypertrophic or keloid burning scars. The patients were randomly assigned into three groups scheduling for treatment with PDL alone, AFCL alone, or its combination. All patients were visited before and 40 days after the last treatment session, and their scars were assessed. In all groups, significant improvement was revealed in the Vancouver scar scale (VSS) score, the color of scar, vascular bed in the scar, the and height of scar and its pliability; however, the improvement in each item was more highlighted in the group receiving a combination therapy with PDL and AFCL techniques. In this regard, the highest improvement was found in vascular bed and pliability in the combination therapy group as compared to other groups. Although the superiority of the combined group was not statistically significant, due to the high percentage of improvement in total VSS and most of its indicators, it can be clinically significant. The efficacy of the treatment protocols was different considering subgroups of mature and immature scars (less than 1 year), so that more improvement in pliability of scar, vascularity, and color of scar was found in the group scheduling for PDL + AFCL as compared to those who were treated with PDL alone in immature scar group but not in mature scar group. Combined treatment can be much more effective in improving the appearance and pathological characteristics of scars than each individual treatment. This effectiveness can be seen mainly in immature scars.

CO2-Driven N-Formylation/N-Methylation of Amines Using C-Scorpionate Metal Complexes

C-scorpionate metal complexes, specifically, [NiCl2(tpm)]·3H2O, [CoCl2(tpm)]·3H2O and [PdCl2(tpm)] [tpm = hydrotris(1H-pyrazol-1-yl)methane], were effective in the N-formylation and N-methylation of amines using carbon dioxide, as carbon source, in the presence of sodium borohydride. Various parameters were studied, including reaction time, temperature, solvent volume, presence of additives, and catalyst amount. These parameters were found to have a significant impact on the selectivity of the product. [NiCl2(tpm)]·3H2O exhibited good conversion at 80 °C, but its selectivity towards formamide decreased with prolonged reaction time. Increasing the amount of [NiCl2(tpm)]·3H2O, the selectivity changed. [PdCl2(tpm)] showed different selectivity compared to [NiCl2(tpm)]·3H2O, while [CoCl2(tpm)]·3H2O presented poor results. Monitoring the reaction course by 1H NMR revealed the presence of an intermediate species that influenced product formation. These results highlight the versatility and catalytic potential of C-scorpionate metal complexes in the N-formylation/N-methylation of amines in the catalytic system (NaBH4/MeCN/CO2).

Modulation of active center distance of hybrid perovskite for boosting photocatalytic reduction of carbon dioxide to ethylene

Solar-driven photocatalytic CO2 reduction is an energy-efficient and sustainable strategy to mitigate CO2 levels in the atmosphere. However, efficient and selective conversion of CO2 into multi-carbon products, like C2H4, remains a great challenge due to slow multi-electron-proton transfer and sluggish C-C coupling. Herein, a two-dimensional thin-layered hybrid perovskite is fabricated through filling of oxygen into iodine vacancy in pristine DMASnI3 (DMA = dimethylammonium). The rational-designed DMASnI3(O) induces shrinkage of active sites distance and facilitates dimerization of C-C coupling of intermediates. Upon simulated solar irradiation, the DMASnI3(O) photocatalyst achieves a high selectivity of 74.5%, corresponding to an impressive electron selectivity of 94.6%, for CO2 to C2H4 conversion and an effective C2H4 yield of 11.2 μmol g-1 h-1. In addition, the DMASnI3(O) inherits excellent water stability and implements long-term photocatalytic CO2 reduction to C2H4 in a water medium. This work establishes a unique paradigm to convert CO2 to C2+ hydrocarbons in a perovskite-based photocatalytic system.

Effective Reduction of CO2 with Aromatic Amines into N-Formamides Triggered by Noble-Free Metal-Organic Framework Catalysts Under Mild Conditions

The reductive transformation of carbon dioxide (CO2 ) into high-valued N-formamides matches well with the atom economy and the sustainable development intention. Nevertheless, developing a noble-free metal catalyst under mild reaction conditions is desirable and challenging. Herein, a caged metal-organic framework (MOFs) [H2 N(CH3 )2 ]2 {[Ni3 (µ3 -O)(XN)(BDC)3 ]·6DMF}n (1) (XN = 6″-(pyridin-4-yl)-4,2″:4″,4″'-terpyridine), H2 BDC = terephthalic acid) is harvested, presenting high thermal and chemical stabilities. Catalytic investigation reveals that 1 as a renewable noble-free MOFs catalyst can catalyze the CO2 reduction conversion with aromatic amines tolerated by broad functional groups at least ten times, resulting in various formamides in excellent yields and selectivity under the mildest reaction system (room temperature and 1 bar CO2 ). Density functional theory (DFT) theoretical studies disclose the applicable reaction path, in which the CO2 hydrosilylation process is initiated by the [Ni3 ] cluster interaction with CO2 via η2 -C, O coordination mode. This work may open up an avenue to seek high-efficiency noble-free catalysts in CO2 chemical reduction into high value-added chemicals.

Atmospheric CO2 Sequestration in Seawater Enhanced by Molluscan Shell Powders

Carbon capture, utilization, and storage (CCUS) are widely recognized as a promising technology for mitigating climate change. CO2 mineralization using Ca-rich fluids and high-concentration CO2 gas has been studied extensively. However, few studies have reported CO2 mineralization with atmospheric CO2, owing to the difficulty associated with its low concentration. In seawater, the biomineralization process promotes Ca accumulation and CaCO3 precipitation, assisted by specific organic matter. In this study, we examined the conversion of atmospheric CO2 into CaCO3 in seawater using shell powders (Pinctada fucata, Haliotis discus, Crassostrea gigas, Mizuhopecten yessoensis, Turbo sazae, and Saxidomus purpurata). Among the six species, the shell powder of S. purpurata showed the highest rate of CaCO3 formation and recovery of CaCO3. NaClO treatment test revealed that the organic matter in the shells enhanced the CO2 mineralization. All materials used in this study, including atmospheric CO2, seawater, and shells, are economically feasible for large-scale applications. Using shell powder for CO2 mineralization in seawater embodies an innovative technological advancement to address climate change.

Multifunctional Biomass-Based Ionic Liquids/CuCl-Catalyzed CO2-Promoted Hydration of Propargylic Alcohols: A Green Synthesis of α-Hydroxy Ketones

α-Hydroxy ketones are a class of vital organic skeletons that generally exist in a variety of natural products and high-value chemicals. However, the traditional synthetic route for their production involves toxic Hg salts and corrosive H2SO4 as catalysts, resulting in harsh conditions and the undesired side reaction of Meyer-Schuster rearrangement. In this study, CO2-promoted hydration of propargylic alcohols was achieved for the synthesis of various α-hydroxy ketones. Notably, this process was catalyzed using an environmentally friendly and cost-effective biomass-based ionic liquids/CuCl system, which effectively eliminated the side reaction. The ionic liquids utilized in this system are derived from natural biomass materials, which exhibited recyclability and catalytic activity under 1 bar of CO2 pressure without volatile organic solvents or additives. Evaluation of the green metrics revealed the superiority of this CuCl/ionic liquid system in terms of environmental sustainability. Further mechanistic investigation attributed the excellent performance to the ionic liquid component, which exhibited multifunctionality in activating substrates, CO2 and the Cu component.

Transcanal endoscopic carbon dioxide laser resection of early-stage (A1-B1) glomus tympanicum tumours: single-centre case series

OBJECTIVE

To report a single-centre experience in the endoscopic carbon dioxide laser-assisted approach to glomus tympanicum tumours.

METHODS

A retrospective case review was conducted of patients diagnosed with class A1 to B1 glomus tympanicum tumours who underwent exclusive transcanal endoscopic carbon dioxide laser surgery.

RESULTS

Seven patients fulfilled the inclusion criteria. All patients (100 per cent) were women, with a mean age of 65.4 years (standard deviation, 13.6). There were five A2 tumours, one A1 tumour and one B1 tumour. One patient presented with a delayed tympanic membrane perforation needing myringoplasty on follow up. There were no substantial post-operative complications. The mean hospitalisation time was 9.5 hours (standard deviation, 9.8). The mean follow-up period was 32.7 months (standard deviation, 13.1), with all cases having resolution of pulsatile tinnitus and no tumour recurrence.

CONCLUSION

The study provides further evidence on the safety and efficacy of endoscopic carbon dioxide laser surgery as a minimally invasive technique for treating early-stage glomus tympanicum tumours.

Transformation of CO2 to Carbon Nanotubes by Catalytic Chemical Vapor Deposition using a Metal-Supported Hierarchical Zeolite Template

The conversion of CO2 into valuable substances is a topic of great interest in current research. Carbon nanotubes (CNT) have emerged as highly promising materials for CO2 conversion. In this study, we successfully developed a catalyst by loading active transition metals (Fe or Ni) onto hierarchical zeolite for CNT synthesis. Our catalyst demonstrated excellent performance under synthetic conditions. The most favorable CNT was obtained using the 25 wt.% FeHieFAU catalyst, which exhibited a diameter size of 23.1 nm, a CNT yield of 15.4 %, and an ID /IG ratio of 0.56, indicating high quality. Additionally, we investigated the beneficial effects of the synthesized CNT by testing their current response. Notably, the current response of the synthesized CNT surpassed that of commercial CNT when using a 0.5 M H2 SO4 supporting electrolyte and cyclic voltammetry (V vs. Ag/AgCl). These findings highlight the significant contributions of the small diameter and superior quality of our synthesized pure CNT, which offer potential improvements in current response compared to commercial CNT. This research opens new avenues for utilizing CNT in CO2 conversion and electrochemical applications.

Mitocentricity

Worldwide, interest in mitochondria is constantly growing, as evidenced by scientific statistics, and studies of the functioning of these organelles are becoming more prevalent than studies of other cellular structures. In this analytical review, mitochondria are conditionally placed in a certain cellular center, which is responsible for both energy production and other non-energetic functions, without which the existence of not only the eukaryotic cell itself, but also the entire organism is impossible. Taking into account the high multifunctionality of mitochondria, such a fundamentally new scheme of cell functioning organization, including mitochondrial management of processes that determine cell survival and death, may be justified. Considering that this issue is dedicated to the memory of V. P. Skulachev, who can be called mitocentric, due to the history of his scientific activity almost entirely aimed at studying mitochondria, this work examines those aspects of mitochondrial functioning that were directly or indirectly the focus of attention of this outstanding scientist. We list all possible known mitochondrial functions, including membrane potential generation, synthesis of Fe-S clusters, steroid hormones, heme, fatty acids, and CO2. Special attention is paid to the participation of mitochondria in the formation and transport of water, as a powerful biochemical cellular and mitochondrial regulator. The history of research on reactive oxygen species that generate mitochondria is subject to significant analysis. In the section "Mitochondria in the center of death", special emphasis is placed on the analysis of what role and how mitochondria can play and determine the program of death of an organism (phenoptosis) and the contribution made to these studies by V. P. Skulachev.

The synergistic reduction effect of PM2.5 and CO2: evidence from national key ecological functional areas in China

China faces the dual pressure of haze pollution control and carbon emission reduction. The goals of national key ecological functional areas (NKEFAs) are to improve ecological quality and enhance ecological supply. In this paper, a time-varying difference-in-differences model is used to assess the impact of NKEFAs on PM2.5 and CO2 by the panel data of prefecture-level cities of China and then investigate the synergistic reduction effect. This quasi-natural experiment reveals that NKEFAs can effectively reduce both PM2.5 and CO2 and then achieve the synergistic emission reduction effect. Land use pattern optimization and productivity enhancement are identified as key drivers for promoting this synergistic effect. This effect is observed in NKEFAs of water conservation and soil conservation types, as well as in the northern region, middle and lower reaches of the Yangtze River, and southeast coastal areas of the southern region. This study provides valuable theoretical references and empirical insights for realizing a synergistic status of environmental improvement and low-carbon transformation.

A curated data resource to support safe carbon dioxide transport-route planning

Supporting the national target of net-zero greenhouse gas emissions in the United States by 2050, the Bipartisan Infrastructure Law (BIL) authorized investments into carbon capture and storage (CCS), highlighting the need for the safe and sustainable transport of carbon dioxide (CO2). Curated to support CO2 pipeline route planning optimization and assess existing energy transport corridors, the CCS Pipeline Route Planning Database is a compilation of 47 publicly available, authoritative geospatial data resources, spanning the contiguous U.S., and some including Alaska and Hawaii. Key considerations were identified following comprehensive literature review, which included state legislation, known pipeline stressors, and energy, environmental, and social justice (EJSJ) considerations. Data layers were sorted into relevant categories (i.e., natural hazards, boundaries) and assigned preliminary weights representing potential social, environmental, and economic costs associated with routing pipelines. Version one of the CCS Pipeline Route Planning Database, made available on the Energy Data eXchange® (EDX), contains categorized vector features representing protected areas, public and energy infrastructure, EJSJ factors, potential risks, federal and state regulations and legislation, and natural features, along with associated metadata. This paper provides details on individual layers, methods used to identify data needs, acquire, and process the disparate data, as well as planned enhancements to future versions of this database.

Exploring Carbon Monoxide and Carbon Dioxide Adsorption on (5,5) Aluminum Nitride Nanotubes for Enhanced Sensor Applications: A DFT Study

This study examined the sensitivity of single-walled (5,5) aluminium nitride nanotubes ((5,5) AlNNTs) to carbon monoxide (CO) and carbon dioxide (CO2) gas molecules by performing DFT calculations using a hybrid functional, specifically, B3LYP (Becke's three-parameter, Lee-Yang-Parr) exchange-correlation functional at a 6-31G* basis set. This research investigates the adsorption behavior of CO2 and CO molecules on pristine and silicon-doped aluminum nitride nanotubes (AlNNTs) and examines their implications for sensor applications. The study assesses each system's adsorption energy, sensing potential, and recovery time to gain insights into their binding strength and practical viability. For CO2 adsorption on (5,5) AlNNT, significant adsorption energy of -24.36 kcal/mol was observed, indicating a strong binding to the nanotube surface, with a sensing potential of 8.95%. However, the slow recovery time of approximately 4.964 days may limit its real-time application. Si-(5,5) AlNNT exhibited a CO2 adsorption energy of -19.69 kcal/mol, a sensing potential of 5.40%, and a relatively short recovery time of approximately 2.978 min, making it a promising candidate for CO2 sensing. CO adsorption on (5,5) AlNNT showed an adsorption energy of -25.20 kcal/mol, a sensing potential of 9.095%, but a longer recovery time of approximately 20.130 days. Si-(5,5) AlNNT displayed a high CO adsorption energy of -20.78 kcal/mol, a sensing potential of 4.29%, and a recovery time of approximately 18.320 min. These findings provide insights into the adsorption characteristics of carbon molecules on AlNNTs, highlighting their potential for CO2 and CO sensing applications.

Assembling of a Water-Soluble N^C^N-Coordinated Pt(II) Complex Aggregate Assisted by Carbon Dioxide in Basic Aqueous Solution

We report an unprecedented result of self-aggregation of [Pt(L1 )Cl] (HL1 =1,3-di(5-carboxy-2-pyridyl)benzene) triggered by CO2 in basic aqueous solution. The color of basic aqueous solution containing [Pt(L1 )Cl] changes from yellow to blue-green during the aggregation resulted from a reaction with CO2 in air. Upon CO2 gas bubbling, strong and broad absorption bands of aggregate assigned to the metal-metal-to-ligand charge-transfer transition appeared at 701 and 1152 nm. Recrystallization of [Pt(L1 )Cl] from Na2 CO3 aqueous solution afforded polymorphic crystals of red and blue-green forms. A single X-ray crystallography revealed that the red form of crystal consists of a Pt-Pt stacked dimer bridged by CO3 2- ion and one of the carboxy groups of L1 is deprotonated. An elemental analysis provided evidence that the blue-green crystal is constructed by linear array consisting of the [Pt(L2 )(CO3 )]3- (HL2 =1,3-di(5-carboxylate-2-pyridyl)benzene) units. The formation process of blue-green aggregate in aqueous solution was monitored through a transient absorption spectrum, and the absorption of aggregates involved in the spectral change were examined by a global analysis. A singular value decomposition and kinetic analysis provide that there are four species resulted from the self-assembling reaction in the solution and the maximal degree of aggregation is at least 32-mer.

Corrigendum: State-resolved studies of CO2 sticking to CO2 ice

[This corrects the article DOI: 10.3389/fchem.2023.1250711.].

Field phenotyping of ten wheat cultivars under elevated CO2 shows seasonal differences in chlorophyll fluorescence, plant height and vegetation indices

In the context of climate change and global sustainable development goals, future wheat cultivation has to master various challenges at a time, including the rising atmospheric carbon dioxide concentration ([CO2]). To investigate growth and photosynthesis dynamics under the effects of ambient (~434 ppm) and elevated [CO2] (~622 ppm), a Free-Air CO2 Enrichment (FACE) facility was combined with an automated phenotyping platform and an array of sensors. Ten modern winter wheat cultivars (Triticum aestivum L.) were monitored over a vegetation period using a Light-induced Fluorescence Transient (LIFT) sensor, ground-based RGB cameras and a UAV equipped with an RGB and multispectral camera. The LIFT sensor enabled a fast quantification of the photosynthetic performance by measuring the operating efficiency of Photosystem II (Fq'/Fm') and the kinetics of electron transport, i.e. the reoxidation rates Fr1' and Fr2'. Our results suggest that elevated [CO2] significantly increased Fq'/Fm' and plant height during the vegetative growth phase. As the plants transitioned to the senescence phase, a pronounced decline in Fq'/Fm' was observed under elevated [CO2]. This was also reflected in the reoxidation rates Fr1' and Fr2'. A large majority of the cultivars showed a decrease in the harvest index, suggesting a different resource allocation and indicating a potential plateau in yield progression under e[CO2]. Our results indicate that the rise in atmospheric [CO2] has significant effects on the cultivation of winter wheat with strong manifestation during early and late growth.

Long-term changes in the daytime growing season carbon dioxide exchange following increased temperature and snow cover in arctic tundra

Increasing temperatures and winter precipitation can influence the carbon (C) exchange rates in arctic ecosystems. Feedbacks can be both positive and negative, but the net effects are unclear and expected to vary strongly across the Arctic. There is a lack of understanding of the combined effects of increased summer warming and winter precipitation on the C balance in these ecosystems. Here we assess the short-term (1-3 years) and long-term (5-8 years) effects of increased snow depth (snow fences) (on average + 70 cm) and warming (open top chambers; 1-3°C increase) and the combination in a factorial design on all key components of the daytime carbon dioxide (CO2 ) fluxes in a wide-spread heath tundra ecosystem in West Greenland. The warming treatment increased ecosystem respiration (ER) on a short- and long-term basis, while gross ecosystem photosynthesis (GEP) was only increased in the long term. Despite the difference in the timing of responses of ER and GEP to the warming treatment, the net ecosystem exchange (NEE) of CO2 was unaffected in the short term and in the long term. Although the structural equation model (SEM) indicates a direct relationship between seasonal accumulated snow depth and ER and GEP, there were no significant effects of the snow addition treatment on ER or GEP measured over the summer period. The combination of warming and snow addition turned the plots into net daytime CO2 sources during the growing season. Interestingly, despite no significant changes in air temperature during the snow-free time during the experiment, control plots as well as warming plots revealed significantly higher ER and GEP in the long term compared to the short term. This was in line with the satellite-derived time-integrated normalized difference vegetation index of the study area, suggesting that more factors than air temperature are drivers for changes in arctic tundra ecosystems.

Hypercapnia and its relationship with respiratory infections

INTRODUCTION

Hypercapnia is developed in patients with acute and/or chronic respiratory conditions. Clinical data concerning hypercapnia and respiratory infections interaction is limited.

AREAS COVERED

Currently, the relationship between hypercapnia and respiratory infections remains unclear. In this review, we summarize studies on the effects of hypercapnia on models of pulmonary infections to clarify the role of elevated CO2 in these pulmonary pathologies. Hypercapnia affects different cell types in the alveoli, leading to changes in the immune response. In vitro studies show that hypercapnia downregulates the NF-κβ pathway, reduces inflammation and impairs epithelial wound healing. While in vivo models show a dual role between short- and long-term effects of hypercapnia on lung infection. However, it is still controversial whether the effects observed under hypercapnia are pH dependent or not.

EXPERT OPINION

The role of hypercapnia is still a controversial debate. Hypercapnia could play a beneficial role in mechanically ventilated models, by lowering the inflammation produced by the stretch condition. But it could be detrimental in infectious scenarios, causing phagocyte dysfunction and lack of infection control. Further data concerning hypercapnia on respiratory infections is needed to elucidate this interaction.

Shift in algal blooms from micro- to macroalgae around China with increasing eutrophication and climate change

Blooms of microalgal red tides and macroalgae (e.g., green and golden tides caused by Ulva and Sargassum) have caused widespread problems around China in recent years, but there is uncertainty around what triggers these blooms and how they interact. Here, we use 30 years of monitoring data to help answer these questions, focusing on the four main species of microalgae Prorocentrum donghaiense, Karenia mikimotoi, Noctiluca scintillans, and Skeletonema costatum) associated with red tides in the region. The frequency of red tides increased from 1991 to 2003 and then decreased until 2020, with S. costatum red tides exhibiting the highest rate of decrease. Green tides started to occur around China in 1999 and the frequency of green tides has since been on the increase. Golden tides were first reported to occur around China in 2012. The frequency of macroalgal blooms has a negative linear relationship with the frequency and coverage of red tides around China, and a positive correlation with total nitrogen and phosphorus loads as well as with atmospheric CO2 and sea surface temperature (SST). Increased outbreaks of macroalgal blooms are very likely due to worsening levels of eutrophication, combined with rising CO2 and SST, which contribute to the reduced frequency of red tides. The increasing grazing rate of microzooplankton also results in the decline in areas affected by red tides. This study shows a clear shift of algal blooms from microalgae to macroalgae around China over the past 30 years driven by the combination of eutrophication, climate change, and grazing stress, indicating a fundamental change in coastal systems in the region.

Instantaneous CO2 emission modelling for a Euro 6 start-stop vehicle based on portable emission measurement system data and artificial intelligence methods

One of the increasingly common methods to counteract the increased fuel consumption of vehicles is start-stop technology. This paper introduces a methodology which presents the process of measuring and creating a computational model of CO2 emissions using artificial intelligence techniques for a vehicle equipped with start-stop technology. The method requires only measurement data of velocity, acceleration of vehicle, and gradient of road to predict the emission of CO2. In this paper, three methods of machine learning techniques were analyzed, while the best prediction results are shown by the gradient boosting method. For the developed models, the results were validated using the coefficient of determination, the mean squared error, and based on visual evaluation of residual and instantaneous emission plots and CO2 emission maps. The developed models present a novel methodology and can be used for microscale environmental analysis.

Brain Stress Test for Assessing Risk for Hemodynamic Stroke

BACKGROUND

In patients with intracranial steno-occlusive disease (SOD), the risk of hemodynamic stroke depends on the poststenotic vasodilatory reserve. Cerebrovascular reactivity (CVR) is a test for vasodilatory reserve. We tested for vasodilatory reserve by using PETCO2 as the stressor, and Blood Oxygen Level Dependent (BOLD) MRI as a surrogate of blood flow. We correlate the CVR to the incidence of stroke after a 1-year follow-up in patients with symptomatic intracranial SOD.

METHODS

In this retrospective study, 100 consecutive patients with symptomatic intracranial SOD that had undergone CVR testing were identified. CVR was measured as % BOLD MR signal intensity/mmHg PETCO2. All patients with normal CVR were treated with optimal medical therapy; those with abnormal CVR were offered revascularization where feasible. We determined the incidence of stroke at 1 year.

RESULTS

83 patients were included in the study. CVR was normal in 14 patients and impaired in 69 patients ipsilateral to the lesion. Of these, 53 underwent surgical revascularization. CVR and symptoms improved in 86% of the latter. The overall incidence of stroke was 4.8 % (4/83). All strokes occurred in patients with impaired CVR (4/69; 2/53 in the surgical group, all in the nonrevascularized hemisphere), and none in patients with normal CVR (0/14).

CONCLUSION

Our study confirms that CO2-BOLD MRI CVR can be used as a brain stress test for the assessment of cerebrovascular reserve. Impaired CVR is associated with a higher incidence of stroke and normal CVR despite significant stenosis is associated with a low risk for stroke.

Microfluidic-Aerosol Hyphenated Synthesis of Metal-Organic Framework-Derived Hybrid Catalysts for CO2 Utilization

A new and efficient technique is developed by combining the hyphenated microfluidic- and aerosol-based synthesis with the coupled differential mobility analysis for the effective and continuous synthesis and simultaneous analysis of metal-organic frameworks (MOFs)-derived hybrid nanostructured products. HKUST-1, a copper-based MOF, is chosen as the representative to fabricate Cu-based hybrid catalysts for reverse water-gas shift (RWGS) reaction, an effective route for CO2 utilization. The effect of precursor concentration and carrier selection on the properties of the resulting products, including mobility size distribution, crystallization degree, surface area, and metal dispersion are investigated, as well as the correlation between the material properties of the synthesized catalysts and their catalytic performance in RWGS reaction in terms of conversion ratio/rate, selectivity, and operational stability. The results indicate that the continuous microfluidic droplet system can successfully synthesize MOF colloids, followed by the continuous production of MOF-derived hybrid materials through the tandem aerosol spray-drying-reaction system. High catalytic activity and low initiate temperature toward RWGS (turnover frequency = 0.0074 s-1 ; 450 °C) are achievable. The work facilitates the production and the designed concept of relevant MOF-derived hybrid nanostructured catalysts in the continuous synthesis system and the enhancement of applications in CO2 capture and utilization.

Assessment of Cerebrovascular Reactivity Using CO2 -BOLD MRI: A 15-Year, Single Center Experience

BACKGROUND

Cerebrovascular reactivity (CVR) is a measure of the change in cerebral blood flow (CBF) in response to a vasoactive challenge. It is a useful indicator of the brain's vascular health.

PURPOSE

To evaluate the factors that influence successful and unsuccessful CVR examinations using precise arterial and end-tidal partial pressure of CO2 control during blood oxygen level-dependent (BOLD) MRI.

STUDY TYPE

Retrospective.

SUBJECTS

Patients that underwent a CVR between October 2005 and May 2021 were studied (total of 1162 CVR examinations). The mean (±SD) age was 46.1 (±18.8) years, and 352 patients (43%) were female.

FIELD STRENGTH/SEQUENCE

3 T; T1-weighted images, T2*-weighed two-dimensional gradient-echo sequence with standard echo-planar readout.

ASSESSMENT

Measurements were obtained following precise hypercapnic stimuli using BOLD MRI as a surrogate of CBF. Successful CVR examinations were defined as those where: 1) patients were able to complete CVR testing, and 2) a clinically useful CVR map was generated. Unsuccessful examinations were defined as those where patients were not able to complete the CVR examination or the CVR maps were judged to be unreliable due to, for example, excessive head motion, and poor PET CO2 targeting.

STATISTICAL ANALYSIS

Successful and unsuccessful CVR examinations between hypercapnic stimuli, and between different patterns of stimulus were compared with Chi-Square tests. Interobserver variability was determined by using the intraclass correlation coefficient (P < 0.05 is significant).

RESULTS

In total 1115 CVR tests in 662 patients were included in the final analysis. The success rate of generating CVR maps was 90.8% (1012 of 1115). Among the different hypercapnic stimuli, those containing a step plus a ramp protocol was the most successful (95.18%). Among the unsuccessful examinations (9.23%), most were patient related (89.3%), the most common of which was difficulty breathing.

DATA CONCLUSION

CO2 -BOLD MRI CVR studies are well tolerated with a high success rate.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 3.

Prehospital blood gas analyses in acute patients treated by a ground-based physician-manned emergency unit: a cohort study

BACKGROUND

The prehospital patients treated by ambulances and mobile emergency care units (MECU) are potentially critically ill or injured. Knowing the risks of serious outcomes in these patients is important for guiding their treatment. Some settings allow for prehospital arterial blood gas analyses. This study aimed to assess the outcomes of prehospital patients in relation to their prehospitally measured lactate, pH, and CO2 levels. The primary outcome was 7-day mortality.

METHODS

This register-based cohort study included patients with one or more prehospital blood gas analyses during their prehospital treatment by a physician-manned MECU, from January 2015 to December 2018. The blood samples were analyzed on an ABL90 Flex analyzer. Absolute values with percentages and odds ratios (OR) with 95% confidence intervals (CI) were calculated for the primary and secondary outcomes within prespecified subgroups.

RESULTS

The study included 745 patients, with an overall 7-day mortality rate of 20.0%.

LACTATE LEVEL

The 7-day mortality rates were 11.5% in patients with normal lactate levels (< 2.0 mmol/L), 14.4% with intermediate lactate levels (2.0-3.9 mmol/L), and 33.0% with high lactate levels (≥ 4.0 mmol/L). This corresponded to an OR of 1.30 (95% CI: 0.75-2.24) in the intermediate lactate group (2.0-3.9 mmol/L) and an OR of 3.77 (95% CI: 2.44-5.85) in the high lactate group (≥ 4.0 mmol/L), compared to the reference group with normal lactate.

PH LEVEL

The ORs of 7-day mortality rates were 4.82 (95% CI: 3.00-7.75) in patients with blood pH of < 7.35 and 1.33 (95% CI: 0.65-2.72) in patients with blood pH > 7.45, compared to the reference group with normal pH (7.35-7.45). CO2 LEVEL : The ORs of 7-day mortality rates were 2.54 (95% CI: 1.45-4.46) in patients with blood CO2 of < 4.3 kPa and 2.62 (95% CI: 1.70-4.03) in patients with blood CO2 > 6.0 kPa, compared to the reference group with normal CO2 (4.3-6.0 kPa).

CONCLUSIONS

This study found a strong correlation between increasing 7-day mortality rates and high blood lactate levels, low levels of pH, and abnormal CO2 blood levels, in prehospital patients undergoing prehospital blood analysis.

Co-drivers of Air Pollutant and CO2 Emissions from On-Road Transportation in China 2010-2020

Co-controlling the emissions of air pollutants and CO2 from automobiles is crucial for addressing the intertwined challenges of air pollution and climate change in China. Here, we analyze the synergetic characteristics of air pollutant and CO2 emissions from China's on-road transportation and identify the co-drivers influencing these trends. Using detailed emission inventories and employing index decomposition analysis, we found that despite notable progress in pollution control, minimizing on-road CO2 emissions remains a formidable task. Over 2010-2020, the estimated sectoral emissions of VOCs, NOx, PM2.5, and CO declined by 49.9%, 25.9%, 75.2%, and 63.5%, respectively, while CO2 emissions increased by 46.1%. Light-duty passenger vehicles and heavy-duty trucks have been identified as the primary contributors to carbon-pollution co-emissions, highlighting the need for tailored policies. The driver analysis indicates that socioeconomic changes are primary drivers of emission growth, while policy controls, particularly advances in emission efficiency, can facilitate co-reductions. Regional disparities emphasize the need for policy refinement, including reducing dependency on fuel vehicles in the passenger subsector and prioritizing co-reduction strategies in high-emission provinces in the freight subsector. Overall, our study confirms the effectiveness of China's on-road control policies and provides valuable insights for future policy makers in China and other similarly positioned developing countries.

Use of fractionated laser therapy for the treatment of androgenetic alopecia: a systematic review and meta-analysis

Procedural management, including fractionated laser therapy, has been increasingly investigated for the management of androgenetic alopecia (AGA). However, no comprehensive resources exist detailing the efficacy of fractionated laser therapies used for the treatment of AGA. A systematic review investigating fractionated laser use for AGA was performed, separated into each distinct fractionated laser modality. A meta-analysis was performed to examine improvement in hair counts and hair shaft diameter. Fourteen studies were included for systematic review, which identified the use of erbium-glass, thulium, erbium-ytrrium:aluminum garnet (YAG), and carbon dioxide (CO2) fractionated laser for the treatment of AGA. In the meta-analysis, fractionated laser combination therapy showed significant improvement in hair shaft diameter (2.51, 95% CI 2.37-2.65, I2 = 90.54). Fractionated laser monotherapy alone significantly improved hair shaft diameter (2.28 95% CI 2.03-2.52, I2 = 91.20%). This effect was durable on subgroup analysis for both erbium-glass (2.36 95% CI 2.01-2.71, I2 = 92.05%) and thulium (1.61 95% CI 1.08-2.15, I2 = < 0.00%). There was no improvement in hair shaft count for any laser modality. Erbium-glass laser is an effective modality as either monotherapy or combination with topical/injectable therapies to improve hair shaft diameter in AGA.