Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 97.856
1.
Glob Chang Biol ; 30(5): e17336, 2024 May.
Article En | MEDLINE | ID: mdl-38775780

Climate change and land-use change are widely altering freshwater ecosystem functioning and there is an urgent need to understand how these broad stressor categories may interact in future. While much research has focused on mean temperature increases, climate change also involves increasing variability of both water temperature and flow regimes and increasing concentrations of atmospheric CO2, all with potential to alter stream invertebrate communities. Deposited fine sediment is a pervasive land-use stressor with widespread impacts on stream invertebrates. Sedimentation may be managed at the catchment scale; thus, uncovering interactions with these three key climate stressors may assist mitigation of future threats. This is the first experiment to investigate the individual and combined effects of enriched CO2, heatwaves, flow velocity variability, and fine sediment on realistic stream invertebrate communities. Using 128 mesocosms simulating small stony-bottomed streams in a 7-week experiment, we manipulated dissolved CO2 (ambient; enriched), fine sediment (no sediment; 300 g dry sediment), temperature (ambient; two 7-day heatwaves), and flow velocity (constant; variable). All treatments changed community composition. CO2 enrichment reduced abundances of Orthocladiinae and Chironominae and increased Copepoda abundance. Variable flow velocity had only positive effects on invertebrate abundances (7 of 13 common taxa and total abundance), in contrast to previous experiments showing negative impacts of reduced velocity. CO2 was implicated in most stressor interactions found, with CO2 × sediment interactions being most common. Communities forming under enriched CO2 conditions in sediment-impacted mesocosms had ~20% fewer total invertebrates than those with either treatment alone. Copepoda abundances doubled in CO2-enriched mesocosms without sediment, whereas no CO2 effect occurred in mesocosms with sediment. Our findings provide new insights into potential future impacts of climate change and land use in running freshwaters, in particular highlighting the potential for elevated CO2 to interact with fine sediment deposition in unpredictable ways.


Carbon Dioxide , Climate Change , Geologic Sediments , Invertebrates , Rivers , Animals , Carbon Dioxide/analysis , Geologic Sediments/analysis , Invertebrates/physiology , Hot Temperature , Water Movements , Ecosystem
2.
PLoS One ; 19(5): e0302139, 2024.
Article En | MEDLINE | ID: mdl-38717995

Cover crops have the potential to mitigate climate change by reducing negative impacts of agriculture on ecosystems. This study is first to quantify the net climate change mitigation impact of cover crops including land-use effects. A systematic literature and data review was conducted to identify major drivers for climate benefits and costs of cover crops in maize (Zea maize L.) production systems. The results indicate that cover crops lead to a net climate change mitigation impact (NCCMI) of 3.30 Mg CO2e ha-1 a-1. We created four scenarios with different impact weights of the drivers and all of them showing a positive NCCMI. Carbon land benefit, the carbon opportunity costs based on maize yield gains following cover crops, is the major contributor to the NCCMI (34.5% of all benefits). Carbon sequestration is the second largest contributor (33.8%). The climate costs of cover crops are mainly dominated by emissions from their seed production and foregone benefits due to land use for cover crops seeds. However, these two costs account for only 15.8% of the benefits. Extrapolating these results, planting cover crops before all maize acreage in the EU results in a climate change mitigation of 49.80 million Mg CO2e a-1, which is equivalent to 13.0% of the EU's agricultural emissions. This study highlights the importance of incorporating cover crops into sustainable cropping systems to minimize the agricultural impact to climate change.


Agriculture , Carbon Sequestration , Climate Change , Crops, Agricultural , Ecosystem , Zea mays , Crops, Agricultural/growth & development , Zea mays/growth & development , Agriculture/methods , Agriculture/economics , Carbon Dioxide/analysis , Carbon Dioxide/metabolism
4.
Curr Opin Crit Care ; 30(3): 251-259, 2024 Jun 01.
Article En | MEDLINE | ID: mdl-38690954

PURPOSE OF REVIEW: To describe current and near future developments and applications of CO2 kinetics in clinical respiratory and cardiovascular monitoring. RECENT FINDINGS: In the last years, we have witnessed a renewed interest in CO2 kinetics in relation with a better understanding of volumetric capnography and its derived parameters. This together with technological advances and improved measurement systems have expanded the monitoring potential of CO2 kinetics including breath by breath continuous end-expiratory lung volume and continuous noninvasive cardiac output. Dead space has slowly been gaining relevance in clinical monitoring and prognostic evaluation. Easy to measure dead space surrogates such as the ventilatory ratio have demonstrated a strong prognostic value in patients with acute respiratory failure. SUMMARY: The kinetics of carbon dioxide describe many relevant physiological processes. The clinical introduction of new ways of assessing respiratory and circulatory efficiency based on advanced analysis of CO2 kinetics are paving the road to a long-desired goal in clinical monitoring of critically ill patients: the integration of respiratory and circulatory monitoring during mechanical ventilation.


Capnography , Carbon Dioxide , Humans , Carbon Dioxide/analysis , Capnography/methods , Monitoring, Physiologic/methods , Respiration, Artificial/methods , Kinetics , Cardiac Output/physiology , Biomarkers , Respiratory Dead Space/physiology
5.
PLoS Biol ; 22(5): e3002592, 2024 May.
Article En | MEDLINE | ID: mdl-38691548

Stomata are pores on plant aerial surfaces, each bordered by a pair of guard cells. They control gas exchange vital for plant survival. Understanding how guard cells respond to environmental signals such as atmospheric carbon dioxide (CO2) levels is not only insightful to fundamental biology but also relevant to real-world issues of crop productivity under global climate change. In the past decade, multiple important signaling elements for stomatal closure induced by elevated CO2 have been identified. Yet, there is no comprehensive understanding of high CO2-induced stomatal closure. In this work, we assemble a cellular signaling network underlying high CO2-induced stomatal closure by integrating evidence from a comprehensive literature analysis. We further construct a Boolean dynamic model of the network, which allows in silico simulation of the stomatal closure response to high CO2 in wild-type Arabidopsis thaliana plants and in cases of pharmacological or genetic manipulation of network nodes. Our model has a 91% accuracy in capturing known experimental observations. We perform network-based logical analysis and reveal a feedback core of the network, which dictates cellular decisions in closure response to high CO2. Based on these analyses, we predict and experimentally confirm that applying nitric oxide (NO) induces stomatal closure in ambient CO2 and causes hypersensitivity to elevated CO2. Moreover, we predict a negative regulatory relationship between NO and the protein phosphatase ABI2 and find experimentally that NO inhibits ABI2 phosphatase activity. The experimental validation of these model predictions demonstrates the effectiveness of network-based modeling and highlights the decision-making role of the feedback core of the network in signal transduction. We further explore the model's potential in predicting targets of signaling elements not yet connected to the CO2 network. Our combination of network science, in silico model simulation, and experimental assays demonstrates an effective interdisciplinary approach to understanding system-level biology.


Arabidopsis , Carbon Dioxide , Models, Biological , Plant Stomata , Signal Transduction , Plant Stomata/drug effects , Plant Stomata/metabolism , Plant Stomata/physiology , Carbon Dioxide/metabolism , Carbon Dioxide/pharmacology , Arabidopsis/metabolism , Arabidopsis/genetics , Arabidopsis/physiology , Computer Simulation , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics
6.
Pak J Pharm Sci ; 37(1(Special)): 235-243, 2024 Jan.
Article En | MEDLINE | ID: mdl-38747275

Stimulus-responsive mesoporous silica nanoparticles (MSNs) have displayed great potentiality for controlled-release and targeted drug delivery. In the current work, a supercritical fluid method was utilized to successfully prepare cinnamon oil loaded into chitosan grafted MSNs (CO@CS-MSNs). The influencing factors of drug loads, such as pressure, temperature, impregnation time and depressure time, were investigated. The structure of CO@CS-MSNs was demonstrated with Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry (TG) as well as X-ray diffraction (XRD). The drug release assays in vitro at various pH conditions displayed that CO@CS-MSNs had an excellent pH-responsive release behavior, which confirmed that CO was loaded successfully into the CO@CS-MSNs. The findings indicated that the supercritical fluid approach is a non-destructive and efficient approach for stimulus-responsive MSNs, which is expected to further expand its application range.


Carbon Dioxide , Chitosan , Cinnamomum zeylanicum , Drug Liberation , Nanoparticles , Silicon Dioxide , Chitosan/chemistry , Silicon Dioxide/chemistry , Nanoparticles/chemistry , Hydrogen-Ion Concentration , Carbon Dioxide/chemistry , Porosity , Cinnamomum zeylanicum/chemistry , Drug Carriers/chemistry , Oils, Volatile/chemistry , Oils, Volatile/administration & dosage , X-Ray Diffraction , Spectroscopy, Fourier Transform Infrared , Microscopy, Electron, Scanning , Delayed-Action Preparations
7.
Crit Care ; 28(1): 146, 2024 04 30.
Article En | MEDLINE | ID: mdl-38693569

PURPOSE: A systematic review and meta-analysis to evaluate the impact of extracorporeal carbon dioxide removal (ECCO2R) on gas exchange and respiratory settings in critically ill adults with respiratory failure. METHODS: We conducted a comprehensive database search, including observational studies and randomized controlled trials (RCTs) from January 2000 to March 2022, targeting adult ICU patients undergoing ECCO2R. Primary outcomes were changes in gas exchange and ventilator settings 24 h after ECCO2R initiation, estimated as mean of differences, or proportions for adverse events (AEs); with subgroup analyses for disease indication and technology. Across RCTs, we assessed mortality, length of stay, ventilation days, and AEs as mean differences or odds ratios. RESULTS: A total of 49 studies encompassing 1672 patients were included. ECCO2R was associated with a significant decrease in PaCO2, plateau pressure, and tidal volume and an increase in pH across all patient groups, at an overall 19% adverse event rate. In ARDS and lung transplant patients, the PaO2/FiO2 ratio increased significantly while ventilator settings were variable. "Higher extraction" systems reduced PaCO2 and respiratory rate more efficiently. The three available RCTs did not demonstrate an effect on mortality, but a significantly longer ICU and hospital stay associated with ECCO2R. CONCLUSIONS: ECCO2R effectively reduces PaCO2 and acidosis allowing for less invasive ventilation. "Higher extraction" systems may be more efficient to achieve this goal. However, as RCTs have not shown a mortality benefit but increase AEs, ECCO2R's effects on clinical outcome remain unclear. Future studies should target patient groups that may benefit from ECCO2R. PROSPERO Registration No: CRD 42020154110 (on January 24, 2021).


Carbon Dioxide , Humans , Carbon Dioxide/analysis , Carbon Dioxide/blood , Pulmonary Gas Exchange/physiology , Respiration, Artificial/methods , Respiratory Insufficiency/therapy
8.
Sci Rep ; 14(1): 10938, 2024 05 13.
Article En | MEDLINE | ID: mdl-38740878

Plant disease often increases with N, decreases with CO2, and increases as biodiversity is lost (i.e., the dilution effect). Additionally, all these factors can indirectly alter disease by changing host biomass and hence density-dependent disease transmission. Yet over long periods of time as communities undergo compositional changes, these biomass-mediated pathways might fade, intensify, or even reverse in direction. Using a field experiment that has manipulated N, CO2, and species richness for over 20 years, we compared severity of a specialist rust fungus (Puccinia andropogonis) on its grass host (Andropogon gerardii) shortly after the experiment began (1999) and twenty years later (2019). Between these two sampling periods, two decades apart, we found that disease severity consistently increased with N and decreased with CO2. However, the relationship between diversity and disease reversed from a dilution effect in 1999 (more severe disease in monocultures) to an amplification effect in 2019 (more severe disease in mixtures). The best explanation for this reversal centered on host density (i.e., aboveground biomass), which was initially highest in monoculture, but became highest in mixtures two decades later. Thus, the diversity-disease pattern reversed, but disease consistently increased with host biomass. These results highlight the consistency of N and CO2 as drivers of plant disease in the Anthropocene and emphasize the critical role of host biomass-despite potentially variable effects of diversity-for relationships between biodiversity and disease.


Biodiversity , Biomass , Carbon Dioxide , Nitrogen , Plant Diseases , Carbon Dioxide/metabolism , Plant Diseases/microbiology , Plant Diseases/prevention & control , Nitrogen/metabolism , Basidiomycota/genetics , Poaceae/microbiology
9.
Anal Chim Acta ; 1307: 342620, 2024 Jun 08.
Article En | MEDLINE | ID: mdl-38719413

BACKGROUND: Pharmacokinetic studies are pivotal in drug development, focusing on absorption, distribution, and excretion of active compounds. Effective sample preparation methods play a crucial role in these studies. Traditional techniques like protein precipitation and liquid-liquid extraction often involve toxic solvents and are time-consuming. Recently, deep eutectic solvent (DES) has emerged as an eco-friendly alternative due to its high efficiency, low cost, and low toxicity. This study introduces a novel sample pretreatment method using CO2-switchable DES in liquid-liquid microextraction (LLME) to enhance speed, accuracy, and sensitivity in complex biological samples analysis. RESULTS: A liquid-liquid microextraction sample pretreatment method based on switchable DES combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the analysis of urine and tissue samples. The method was optimized through systematic investigation of key parameters, including DES type, volume, molar ratio, pH, vortex time, gas purge time, and salt addition. The resulting procedure exhibited satisfying linearity (r2 ≥ 0.9958), good precision (RSD ≤6.01 %), desirable recovery (52.44%-98.12 %) and matrix effect (86.22%-119.30 %), and the accuracy and precision of stability were within the ±15 % limit. The proven methods were further applied to urinary excretion study and tissue distribution study of Nelumbinis plumula (NP) extract. The results indicated that the total cumulative excretion of liensinine, isoliensinine and neferine in urine within 240 h was 4.96 %, 0.66 % and 0.44 %, respectively. The tissue distribution study showed that alkaloids mainly distribute in liver, kidney, and spleen. SIGNIFICANCE: This research introduces a groundbreaking technique distinguished by its simplicity, speed, cost-effectiveness, and environmental friendliness. This approach, utilizing CO2-switchable DES as an extraction solvent for LLME, integrates deproteinization and removal of interfering molecules into a single step. This integration showcases its efficiency and convenience, demonstrating significant promise for various applications in the analysis of biological samples. Additionally, this study provides the first report on urinary excretion and tissue distribution of alkaloids from NP using a DES-LLME method. These findings offer valuable insights into the in vivo behavior of herbal medicine, enhancing understanding of pharmacological actions and facilitating clinical rational administration.


Carbon Dioxide , Deep Eutectic Solvents , Liquid Phase Microextraction , Tandem Mass Spectrometry , Liquid Phase Microextraction/methods , Carbon Dioxide/chemistry , Deep Eutectic Solvents/chemistry , Animals , Tissue Distribution , Tandem Mass Spectrometry/methods , Chromatography, High Pressure Liquid , Male , Rats , Rats, Sprague-Dawley
10.
Hum Vaccin Immunother ; 20(1): 2335722, 2024 Dec 31.
Article En | MEDLINE | ID: mdl-38698759

We provide estimates for (I) annual herpes zoster (HZ) cases, (II) carbon costs related to healthcare utilization, and (III) annual carbon emissions due to HZ among ≥50 years of age (YOA) United States (US) population. We estimated the annual number of HZ cases in the US based on available incidence data and demographic data of individuals ≥50 YOA. Both the healthcare resource utilization (HCRU) associated with HZ cases and the unit carbon dioxide equivalent (i.e. CO2e) costs associated with each type of HCRU in the US were estimated based on literature and studies available online. The carbon footprint associated with HZ annually among US adults ≥50 YOA was estimated by multiplying the unit carbon estimates by the HCRU. In the US population aged ≥50 YOA in 2020 (i.e. approximately 118 million), approximately 1.1 million cases of HZ occur annually assuming no vaccination. Based on 2 sources of HCRU the average kgCO2e per HZ patient ranged from 61.0 to 97.6 kgCO2e, with values by age group ranging from 40.9 kgCO2e in patients aged 50-59 to 195.9 kgCO2e in patients ≥80 YOA. The total annual HZ associated carbon ranged between 67,000 and 107,000 tons of CO2e in the US population aged ≥50 YOA. The impact of HZ on carbon footprint in the US results in considerable greenhouse gas (GHG)emissions. Assuming no vaccination, the burden of HZ is projected to rise over the coming years with the aging populations consequently worsening its impact on GHG emissions. (Figure 1).


Carbon Footprint , Herpes Zoster , Humans , Herpes Zoster/epidemiology , United States/epidemiology , Aged , Carbon Footprint/statistics & numerical data , Middle Aged , Aged, 80 and over , Male , Female , Incidence , Carbon Dioxide/analysis
11.
Elife ; 132024 May 10.
Article En | MEDLINE | ID: mdl-38727716

PHOX2B is a transcription factor essential for the development of different classes of neurons in the central and peripheral nervous system. Heterozygous mutations in the PHOX2B coding region are responsible for the occurrence of Congenital Central Hypoventilation Syndrome (CCHS), a rare neurological disorder characterised by inadequate chemosensitivity and life-threatening sleep-related hypoventilation. Animal studies suggest that chemoreflex defects are caused in part by the improper development or function of PHOX2B expressing neurons in the retrotrapezoid nucleus (RTN), a central hub for CO2 chemosensitivity. Although the function of PHOX2B in rodents during development is well established, its role in the adult respiratory network remains unknown. In this study, we investigated whether reduction in PHOX2B expression in chemosensitive neuromedin-B (NMB) expressing neurons in the RTN altered respiratory function. Four weeks following local RTN injection of a lentiviral vector expressing the short hairpin RNA (shRNA) targeting Phox2b mRNA, a reduction of PHOX2B expression was observed in Nmb neurons compared to both naive rats and rats injected with the non-target shRNA. PHOX2B knockdown did not affect breathing in room air or under hypoxia, but ventilation was significantly impaired during hypercapnia. PHOX2B knockdown did not alter Nmb expression but it was associated with reduced expression of both Task2 and Gpr4, two CO2/pH sensors in the RTN. We conclude that PHOX2B in the adult brain has an important role in CO2 chemoreception and reduced PHOX2B expression in CCHS beyond the developmental period may contribute to the impaired central chemoreflex function.


Carbon Dioxide , Homeodomain Proteins , Transcription Factors , Animals , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Carbon Dioxide/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Rats , Gene Knockdown Techniques , Male , Hypoventilation/genetics , Hypoventilation/congenital , Hypoventilation/metabolism , Chemoreceptor Cells/metabolism , Rats, Sprague-Dawley , Sleep Apnea, Central/genetics , Sleep Apnea, Central/metabolism , Neurons/metabolism , Neurons/physiology
12.
Sci Adv ; 10(19): eadk7283, 2024 May 10.
Article En | MEDLINE | ID: mdl-38728392

Cyanobacterial CO2 concentrating mechanisms (CCMs) sequester a globally consequential proportion of carbon into the biosphere. Proteinaceous microcompartments, called carboxysomes, play a critical role in CCM function, housing two enzymes to enhance CO2 fixation: carbonic anhydrase (CA) and Rubisco. Despite its importance, our current understanding of the carboxysomal CAs found in α-cyanobacteria, CsoSCA, remains limited, particularly regarding the regulation of its activity. Here, we present a structural and biochemical study of CsoSCA from the cyanobacterium Cyanobium sp. PCC7001. Our results show that the Cyanobium CsoSCA is allosterically activated by the Rubisco substrate ribulose-1,5-bisphosphate and forms a hexameric trimer of dimers. Comprehensive phylogenetic and mutational analyses are consistent with this regulation appearing exclusively in cyanobacterial α-carboxysome CAs. These findings clarify the biologically relevant oligomeric state of α-carboxysomal CAs and advance our understanding of the regulation of photosynthesis in this globally dominant lineage.


Carbonic Anhydrases , Cyanobacteria , Ribulose-Bisphosphate Carboxylase , Ribulose-Bisphosphate Carboxylase/metabolism , Ribulose-Bisphosphate Carboxylase/chemistry , Ribulose-Bisphosphate Carboxylase/genetics , Carbonic Anhydrases/metabolism , Carbonic Anhydrases/genetics , Carbonic Anhydrases/chemistry , Cyanobacteria/metabolism , Cyanobacteria/genetics , Cyanobacteria/enzymology , Allosteric Regulation , Phylogeny , Ribulosephosphates/metabolism , Models, Molecular , Protein Multimerization , Carbon Dioxide/metabolism , Substrate Specificity , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/chemistry
13.
Codas ; 36(3): e20220330, 2024.
Article En | MEDLINE | ID: mdl-38695436

PURPOSE: The Awake Breathing Pattern Assessment (ABPA) is a prototypical clinical grid recently designed through an international consensus of Speech and Language Pathologists (SLPs) to categorize the awake and habitual breathing pattern during the orofacial myofunctional assessment. This cross-sectional study aims to explore the psychometric properties of the ABPA in a preschool population. METHODS: 133 children from 2;11 to 6 years old were assessed with the ABPA. The percentage of time spent breathing through the mouth was objectively measured by a CO2 sensor and used as a baseline measurement. We first performed a multivariate Latent Profile Analysis based on the CO2 measurement and a parental questionnaire to define the number of categories that best characterize the breathing pattern. Subsequently, we assessed the intra- and inter-rater reliability, internal consistency criterion validity, construct validity and sensitivity and specificity. RESULTS: The awake breathing pattern can best be described by two groups: nasal and mouth breathing. The ABPA, initially designed in three groups, was adjusted accordingly. This final version showed excellent intra-rater and inter-rater reliability. There was a significant correlation between the ABPA and the CO2 measurement. The ABPA showed a fair sensitivity and a good specificity. CONCLUSION: The reference tool based on CO2 data was used in children for the first time and was found to be reliable. The ABPA is a suitable tool for SLPs to confirm the diagnosis of mouth breathing in preschool children if more sensitive screening tools, like parental questionnaires, are used beforehand.


Mouth Breathing , Humans , Mouth Breathing/diagnosis , Mouth Breathing/physiopathology , Child, Preschool , Cross-Sectional Studies , Reproducibility of Results , Female , Male , Child , Psychometrics , Sensitivity and Specificity , Surveys and Questionnaires , Wakefulness/physiology , Respiration , Carbon Dioxide/analysis
14.
Nature ; 629(8011): 295-306, 2024 May.
Article En | MEDLINE | ID: mdl-38720037

Fossil fuels-coal, oil and gas-supply most of the world's energy and also form the basis of many products essential for everyday life. Their use is the largest contributor to the carbon dioxide emissions that drive global climate change, prompting joint efforts to find renewable alternatives that might enable a carbon-neutral society by as early as 2050. There are clear paths for renewable electricity to replace fossil-fuel-based energy, but the transport fuels and chemicals produced in oil refineries will still be needed. We can attempt to close the carbon cycle associated with their use by electrifying refinery processes and by changing the raw materials that go into a refinery from fossils fuels to carbon dioxide for making hydrocarbon fuels and to agricultural and municipal waste for making chemicals and polymers. We argue that, with sufficient long-term commitment and support, the science and technology for such a completely fossil-free refinery, delivering the products required after 2050 (less fuels, more chemicals), could be developed. This future refinery will require substantially larger areas and greater mineral resources than is the case at present and critically depends on the capacity to generate large amounts of renewable energy for hydrogen production and carbon dioxide capture.


Carbon Dioxide , Fossil Fuels , Oil and Gas Industry , Renewable Energy , Carbon Cycle , Carbon Dioxide/adverse effects , Carbon Dioxide/isolation & purification , Coal/adverse effects , Coal/supply & distribution , Fossil Fuels/adverse effects , Fossil Fuels/supply & distribution , Hydrogen/chemistry , Natural Gas/adverse effects , Natural Gas/supply & distribution , Petroleum/adverse effects , Petroleum/supply & distribution , Renewable Energy/statistics & numerical data , Oil and Gas Industry/methods , Oil and Gas Industry/trends
15.
Elife ; 122024 May 23.
Article En | MEDLINE | ID: mdl-38780431

The elevation of atmospheric CO2 leads to a decline in plant mineral content, which might pose a significant threat to food security in coming decades. Although few genes have been identified for the negative effect of elevated CO2 on plant mineral composition, several studies suggest the existence of genetic factors. Here, we performed a large-scale study to explore genetic diversity of plant ionome responses to elevated CO2, using six hundred Arabidopsis thaliana accessions, representing geographical distributions ranging from worldwide to regional and local environments. We show that growth under elevated CO2 leads to a global decrease of ionome content, whatever the geographic distribution of the population. We observed a high range of genetic diversity, ranging from the most negative effect to resilience or even to a benefit in response to elevated CO2. Using genome-wide association mapping, we identified a large set of genes associated with this response, and we demonstrated that the function of one of these genes is involved in the negative effect of elevated CO2 on plant mineral composition. This resource will contribute to understand the mechanisms underlying the effect of elevated CO2 on plant mineral nutrition, and could help towards the development of crops adapted to a high-CO2 world.


Arabidopsis , Carbon Dioxide , Genetic Variation , Arabidopsis/genetics , Arabidopsis/metabolism , Arabidopsis/drug effects , Carbon Dioxide/metabolism , Genome-Wide Association Study
16.
PLoS One ; 19(5): e0303790, 2024.
Article En | MEDLINE | ID: mdl-38781170

We employed carbon dioxide (CO2) concentration monitoring using mobile devices to identify location-specific risks for airborne infection transmission. We lent a newly developed, portable Pocket CO2 Logger to 10 participants, to be carried at all times, for an average of 8 days. The participants recorded their location at any given time as cinema, gym, hall, home, hospital, other indoors, other outgoings, pub, restaurant, university, store, transportation, or workplace. Generalized linear mixed model was used for statistical analysis, with the objective variable set to the logarithm of CO2 concentration. Analysis was performed by assigning participant identification as the random effect and location as the fixed effect. The data were collected per participant (seven males, four females), resulting in a total of 12,253 records. Statistical analysis identified three relatively poorly ventilated locations (median values > 1,000 ppm) that contributed significantly (p < 0.0001) to CO2 concentrations: homes (1,316 ppm), halls (1,173 ppm), and gyms (1005ppm). In contrast, two locations were identified to contribute significantly (p < 0.0001) to CO2 concentrations but had relatively low average values (<1,000 ppm): workplaces (705 ppm) and stores (620 ppm). The Pocket CO2 Logger can be used to visualize airborne infectious transmission risk by location to help guide recommendation regarding infectious disease policies, such as restrictions on human flow and ventilation measures and guidelines. In the future, large-scale surveys are expected to utilize the global positioning system, Wi-Fi, or Bluetooth of an individual's smartphone to improve ease and accuracy.


Carbon Dioxide , Ventilation , Humans , Carbon Dioxide/analysis , Male , Female , Tokyo/epidemiology , Adult , Air Pollution, Indoor/analysis , Environmental Monitoring/methods , COVID-19/transmission , COVID-19/epidemiology , Middle Aged
17.
Photosynth Res ; 160(2-3): 111-124, 2024 Jun.
Article En | MEDLINE | ID: mdl-38700726

Accurate estimation of photosynthetic parameters is essential for understanding plant physiological limitations and responses to environmental factors from the leaf to the global scale. Gas exchange is a useful tool to measure responses of net CO2 assimilation (A) to internal CO2 concentration (Ci), a necessary step in estimating photosynthetic parameters including the maximum rate of carboxylation (Vcmax) and the electron transport rate (Jmax). However, species and environmental conditions of low stomatal conductance (gsw) reduce the signal-to-noise ratio of gas exchange, challenging estimations of Ci. Previous works showed that not considering cuticular conductance to water (gcw) can lead to significant errors in estimating Ci, because it has a different effect on total conductance to CO2 (gtc) than does gsw. Here we present a systematic assessment of the need for incorporating gcw into Ci estimates. In this study we modeled the effect of gcw and of instrumental noise and quantified these effects on photosynthetic parameters in the cases of four species with varying gsw and gcw, measured using steady-state and constant ramping techniques, like the rapid A/Ci response method. We show that not accounting for gcw quantitatively influences Ci and the resulting Vcmax and Jmax, particularly when gcw exceeds 7% of the total conductance to water. The influence of gcw was not limited to low gsw species, highlighting the importance of species-specific knowledge before assessing A/Ci curves. Furthermore, at low gsw instrumental noise can affect Ci estimation, but the effect of instrumental noise can be minimized using constant-ramping rather than steady-state techniques. By incorporating these considerations, more precise measurements and interpretations of photosynthetic parameters can be obtained in a broader range of species and environmental conditions.


Photosynthesis , Plant Stomata , Photosynthesis/physiology , Plant Stomata/physiology , Carbon Dioxide/metabolism , Water/metabolism , Plant Leaves/physiology , Plant Leaves/metabolism
18.
Rev Assoc Med Bras (1992) ; 70(5): e20231499, 2024.
Article En | MEDLINE | ID: mdl-38775509

OBJECTIVE: Heart failure is a disease with cardiac dysfunction, and its morbidity and mortality are associated with the degree of dysfunction. The New York Heart Association classifies the heart failure stages based on the severity of symptoms and physical activity. End-tidal carbon dioxide refers to the level of carbon dioxide that a person exhales with each breath. End-tidal carbon dioxide levels can be used in many clinical conditions such as heart failure, asthma, and chronic obstructive pulmonary disease. The aim of the study was to reveal the relationship between end-tidal carbon dioxide levels and the New York Heart Association classification of heart failure stages. METHODS: This study was conducted at Kahramanmaras Sütçü Imam University Faculty of Medicine Adult Emergency Department between 01/03/2019 and 01/09/2019. A total of 80 patients who presented to the emergency department with a history of heart failure or were diagnosed with heart failure during admission were grouped according to the New York Heart Association classification of heart failure stages. The laboratory parameters, ejection fraction values, and end-tidal carbon dioxide levels of the patients were measured and recorded in the study forms. RESULTS: End-tidal carbon dioxide levels and ejection fraction values were found to be significantly lower in the stage 4 group compared to the other groups. Furthermore, pro-B-type natriuretic peptide (BNP) values were found to be significantly higher in stage 4 group compared to the other groups. CONCLUSION: It was concluded that end-tidal carbon dioxide levels could be used together with pro-BNP and ejection fraction values in determining the severity of heart failure.


Carbon Dioxide , Heart Failure , Severity of Illness Index , Stroke Volume , Humans , Heart Failure/classification , Heart Failure/metabolism , Carbon Dioxide/analysis , Carbon Dioxide/metabolism , Female , Male , Middle Aged , Aged , Stroke Volume/physiology , Adult , Tidal Volume/physiology , Natriuretic Peptide, Brain/blood , Natriuretic Peptide, Brain/analysis , Breath Tests/methods , Emergency Service, Hospital
20.
Biomacromolecules ; 25(5): 2925-2933, 2024 May 13.
Article En | MEDLINE | ID: mdl-38691827

A "one-step" strategy has been demonstrated for the tunable synthesis of multifunctional aliphatic polycarbonates (APCs) with ethylene oxide (EO), ethylene carbonate (EC), and cyclohexene oxide (CHO) side groups by the copolymerization of 4-vinyl-1-cyclohexene diepoxide with carbon dioxide under an aminotriphenolate iron/PPNBz (PPN = bis(triphenylphosphine)-iminium, Bz = benzoate) binary catalyst. By adjusting the PPNBz-to-iron complex ratio and incorporating auxiliary solvents, the content of functional side groups can be tuned within the ranges of 53-75% for EO, 18-47% for EC, and <1-7% for CHO. The yield and molecular weight distribution of the resulting multifunctional APCs are affected by the viscosity of the polymerization system. The use of tetrahydrofuran as an auxiliary solvent enables the preparation of narrow-distribution polycarbonates at high conversion. This work presents a novel perspective for the preparation of tailorable multifunctional APCs.


Carbon Dioxide , Polycarboxylate Cement , Polymerization , Carbon Dioxide/chemistry , Polycarboxylate Cement/chemistry , Epoxy Compounds/chemistry , Ethylene Oxide/chemistry , Cyclohexenes/chemistry , Catalysis , Viscosity , Dioxolanes
...