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Climate change and global warming are facts, and actually they are a hot topic for politics, economics, and societies. Global healthcare contributes approximately 5% of worldwide anthropogenic emissions, and this fact might produce an ethical dilemma between the Hippocratic principles of 'beneficence' (promotion of health) and of 'non-maleficence' (avoiding reinforcement of the climate crisis). Intensive care medicine has continuous high staff activity, resource use, and energy demands, and it is clear that intensive care medicine must become green to commence with practical measures to reduce their intensive care unit (ICU) carbon footprint. In this article several strategies are introduced, beginning with the creation of green teams on the ICUs from the bottom. Furthermore, systematic recycle programs, and the assessment and control of energy use are required to make ICUs more sustainable. Strategies for avoiding futile treatment combined with a choose wisely philosophy might contribute to such projects. Immediate engagement of all healthcare staff, particularly those who work in the ICU, is necessary to join the 'race to zero carbon emissions'., (© 2023. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Abstract Maintaining patients’ temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th–75th percentile: 0.2–0.8] °C at the beginning to 2.3 [2.1–2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P

Abstract Although mangrove forests are great carbon sinks, they also release carbon dioxide (CO2) from soil, plants, and water through respiration. Many studies have focused on CO2 effluxes only from soils, but the role of biogenic structures such as pneumatophore roots has been poorly studied. Hence, CO2 effluxes from pneumatophores were quantified at sediment-air (non-flooded sediment) and water–air (flooded sediment) interfaces along a salinity gradient in three mangrove types (fringe, scrub, and basin) dominated by Avicennia germinans during the dry and rainy seasons in Yucatan, Mexico. Pneumatophore abundance explained up to 91% of CO2 effluxes for scrub, 87% for fringe, and 83% for basin mangrove forests at the water–air interface. Overall, CO2 effluxes were inversely correlated with temperature and salinity. The highest CO2 effluxes were in the fringe and the lowest were in the scrub mangrove forests. Flooding decreased CO2 effluxes from the dry to the rainy season in all mangrove forests. These results highlight the contribution of pneumatophores to mangrove respiration, and the need to include them in our current carbon budgets and models, but considering different exchange interfaces, seasons, and mangrove ecotypes.

Abstract Urea used in fertilization and feed supplement, as well as a starting material for the manufacture of plastics and drugs. Urea is most commonly produced by reacting carbon dioxide with ammonia at high temperature. Photocatalysis has gained attention as a sustainable pathway for performing urea. This work focus on designing very active photocatalysts based on cerium organic framework (Ce-BTC) doped with metal oxide nanoparticles (molybdenum permanganate, Mo(MnO4)5) for production of urea from coupling of ammonia with carbon dioxide. The prepared materials were characterized using different spectral analysis and the morphology was analysed using microscopic data. The effect of catalyst loading on the production rate of urea was investigated and the obtained results showed speed rate of urea production with high production yield at low temperature. The recyclability tests confirmed the sustainability of the prepared photocatlysts (Mo(MnO4)5@Ce-BTC) which supported the beneficial of the photocatalysis process in urea production.

Abstract A novel hyper cross-linked polymer of 2-Aminobenzoic acid (HCP-AA) is synthesized for the adsorption of Cr3+ and CO2. The Brunauer–Emmett–Teller surface area of HCP-AA is 615 m2 g−1. HCP-AA of particle size 0.5 nm showed maximum adsorption of Cr3+ for lab prepared wastewater (93%) while it was 88% for real industrial wastewater. It is might be due to electrostatic interactions, cation-π interactions, lone pair interactions and cation exchange at pH 7; contact time of 8 min; adsorbent dose 0.8 g. The adsorption capacity was calculated 52.63 mg g−1 for chromium metal ions at optimum conditions. Freundlich isotherm studies R2 = 0.9273 value is the best fit and follows pseudo second order kinetic model (R2 = 0.979). The adsorption is found non-spontaneous and exothermic through thermodynamic calculations like Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were 6.58 kJ mol−1, − 60.91 kJ mol−1 and − 45.79 kJ mol−1 K−1, respectively. The CO2 adsorption capacity of HCP-AA is 1.39 mmol/g with quantity of 31.1 cm3/g (6.1 wt%) at 273Kwhile at 298 K adsorption capacity is 1.12 mmol/g with quantity 25.2 cm3/g (5 wt%). Overall, study suggests that carboxyl (–COOH) and amino (–NH2) groups may be actively enhancing the adsorption capacity of HCP-AA for Cr3+ and CO2.

Abstract The interaction of rarefied gases with functionalized surfaces is of great importance in technical applications such as gas separation membranes and catalysis. To investigate the influence of functionalization and rarefaction on gas flow rate in a defined geometry, pressure-driven gas flow experiments with helium and carbon dioxide through plain and alkyl-functionalized microchannels are performed. The experiments cover Knudsen numbers from 0.01 to 200 and therefore the slip flow regime up to free molecular flow. To minimize the experimental uncertainty which is prevalent in micro flow experiments, a methodology is developed to make optimal use of the measurement data. The results are compared to an analysis-based hydraulic closure model (ACM) predicting rarefied gas flow in straight channels and to numerical solutions of the linearized S-model and BGK kinetic equations. The experimental data shows that if there is a difference between plain and functionalized channels, it is likely obscured by experimental uncertainty. This stands in contrast to previous measurements in smaller geometries and demonstrates that the surface-to-volume ratio of 0.4 $$\upmu$$ μ m $$^{-1}$$ - 1 seems to be too small for the functionalization to have a strong influence and highlights the importance of geometric scale for surface effects. These results also shed light on the molecular reflection characteristics described by the TMAC.

Introduction: Laparoscopic cholecystectomy is now preferred over the open procedure due to advantages such as reduced blood loss and shorter hospital stays. However, concerns have been raised regarding the potential for increased Intra-abdominal Pressure (IAP) during laparoscopic procedures, which may impact haemodynamic stability and respiratory parameters. However, there is a lack of comprehensive analysis directly comparing both surgical approaches from both haemodynamic and capnographic perspectives. Aim: To compare the haemodynamic and capnographic changes between laparoscopic and open cholecystectomy. Materials and Methods: This randomised clinical study was conducted at Department of Anaesthesiology, Assam Medical College and Hospital, Dibrugarh, Assam, India from May 2021 to June 2022. The study included 300 patients scheduled for cholecystectomy, divided into two groups: Laparoscopic Cholecystectomy (LC) Group I (n=150) and Open Cholecystectomy (OC) Group II (n=150). Haemodynamic parameters, including Pulse Rate (PR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), and Oxygen Saturation (SpO2 ), were recorded. Capnographic parameters, such as End-Tidal Carbon Dioxide (EtCO2 ) levels, were also measured at regular intervals. Data analysis was performed using the student’s t-test and Chi-square test with Statistical Package for Social Sciences (SPSS) version 21.0 software and Microsoft excel. Results: There were no significant differences in age, body weight, and sex distribution between Group I and Group II. However, significant differences were observed in PR and SBP at 15 minutes (PR: 101.46 and 95.86; SBP: 148.57 and 140.97), 30 minutes (PR: 104.52 and 99.82; SBP: 141.28 and 136.07), and 45 minutes (PR: 102.52 and 97.70; SBP: 140.59 and 133.95) (p-value

Inland waters are crucial in the carbon cycle, contributing significantly to the global CO2 fluxes. Carbonate lakes may act as both sources and sinks of CO2 depending on the interactions between the amount of dissolved inorganic carbon (DIC) inputs, lake metabolisms, and geochemical processes. It is often difficult to distinguish the dominant mechanisms driving CO2 dynamics and their effects on CO2 emissions. This study was undertaken in three groundwater-fed carbonate-rich lakes in central Spain (Ruidera Lakes), severely polluted with nitrates from agricultural overfertilization. Diel and seasonal (summer and winter) changes in CO2 concentration (CCO2) DIC, and CO2 emissions-(FCO2)-, as well as physical and chemical variables, including primary production and phytoplanktonic chlorophyll-a were measured. In addition, δ13C-DIC, δ13C-CO2 in lake waters, and δ13C of the sedimentary organic matter were measured seasonally to identify the primary CO2 sources and processes. While the lakes were consistently CCO2 supersaturated and FCO2 was released to the atmosphere during both seasons, the highest CCO2 and DIC were in summer (0.36–2.26 µmol L–1). Our results support a strong phosphorus limitation for primary production in these lakes, which impinges on CO2 dynamics. External DIC inputs to the lake waters primarily drive the CCO2 and, therefore, the FCO2. The δ13C-DIC signatures below –12‰ confirmed the primary geogenic influence on DIC. As also suggested by the high values on the calcite saturation index, the Miller-Tans plot revealed that the CO2 source in the lakes was close to the signature provided by the fractionation of δ13C-CO2 from calcite precipitation. Therefore, the main contribution behind the CCO2 values found in these karst lakes should be attributed to the calcite precipitation process, which is temperature-dependent according to the seasonal change observed in δ13C-DIC values. Finally, co-precipitation of phosphate with calcite could partly explain the observed low phytoplankton production in these lakes and the impact on the contribution to increasing greenhouse gas emissions. However, as eutrophication increases and the soluble reactive phosphorus (SRP) content increases, the co-precipitation of phosphate is expected to be progressively inhibited. These thresholds must be assessed to understand how the CO32− ions drive lake co-precipitation dynamics. Carbonate regions extend over 15% of the Earth’s surface but seem essential in the CO2 dynamics at a global scale.

Background. Given the evidence establishing airborne transmission of SARS-CoV-2, it is essential to seek new ways to reduce transmission. Monitoring through carbon dioxide (CO2) meters allows determining indoor air quality. Objective:Assess CO2 levels and use of safety measures to reduce COVID-19 transmission in university classrooms, Tegucigalpa, Honduras, April-May 2022. Methods: Cross-sectional descriptive observational study on classrooms and university students. Data were obtained by observation, measurement and documentation. The sample was by convenience. CO2 concentrations were measured in 5 classrooms using an ARANET4 infrared meter. The biosafety measures used were recorded. Univariate analysis was performed by means of frequency and measures of central tendency; Pearson correlation coefficients and p-values were calculated. Results: Of the 86 participants, 91.9% (79) applied biosafety measures. The maximum CO2 levels found in 5 classrooms were at the recommended level for classrooms (Indoor Air Quality IDA classification, Subdirección de Salud Pública, Madrid, Spain). Discussion: CO2 levels in the classrooms rose with the presence of students. However, the levels achieved do not suggest a risk. Honduras does not have air quality standards for the protection of health from the impacts of atmospheric pollutants. It is necessary to conduct studies with larger sample sizes in terms of sites and participants.

Objective: To investigate the effect of lengthy mask use on blood gas values and cognitive functions. Method: The cross-sectional study was conducted in February and March 2022 at Mersin Sehir Training and Research Hospital, Mersin, Turkey, and comprised healthcare professionals of either gender aged 20-60 years working in the 3rd level intensive care unit. Each volunteer was subjected to venous blood gas analysis at the beginning and end of the 8-hour morning shift. Coronavirus disease-2019 status was noted, and further data related to cognitive functions was collected using a 7-item questionnaire. Data was analysed using SPSS 20. Results: Of the 63 subjects, 43(68.3percent) were women and 20(31.7percent) were men. The overall mean age was 33.53±6.76 years. There were 42(66.7percent) subjects using N95 mask; 27(64.3percent) women and 15(35.7percent) men with mean age 32.38 6.54 years. There were 21(33.3percent) subjects wearing surgical masks; 16(76.2percent) women and 5(23.8percent) men with mean age 35.95 0.76 years. Intergroup comparisons were non-significant for all the markers (p 0.05). Within the N95 mask group, potential of hydrogen and lactate values were significantly different (p 0.05), while in the surgical mask group, potential of hydrogen and partial pressure of oxygen were significantly different (p 0.05). There were 28(66.7percent) subjects in the N95 group who had been affected by coronavirus disease-2019 compared to 16(76.2percent) in the surgical mask group (p 0.05). Subjects in the N95 mask group had significant impaired cognitive functions compared to the surgical mask group (p 0.05). Conclusion: Impairment in cognitive functions in intensive care unit workers using masks could be explained by the development of intermittent long-term moderate hypoxia. Key Words: Masks, Coronavirus, Carbon dioxide, Hypoxia.

Background and purpose: Human health is negatively affected by increase in concentration of carbon dioxide in indoor air due to the lack of proper ventilation. The aim of this study was to remove carbon dioxide from a closed space using sodium hydroxide nanofluid and determining the effect of absorbent concentration, carbon dioxide concentration, and titanium dioxide nanoparticles. Materials and methods: The experiments were conducted in a closed chamber on a laboratory scale. An air suction pump was connected to the absorption reactor and the carbon dioxide measuring device was installed inside the chamber. By injecting carbon dioxide gas inside the chamber, different concentrations in the range of 500, 2000 and 5000 ppm were created. Sodium hydroxide absorbent solution at 0.1, 0.2, and 0.4% were examined. Titanium dioxide nanoparticles (0.008%) and surfactant (0.003%) were used to prepare nanofluids. The absorption fluids’ pH, electrical conductivity, and total inorganic carbon (TIC) were measured before and after carbon dioxide absorption. Results: By using 0.4% sodium hydroxide solution containing 0.008% titanium dioxide nanoparticles, the carbon dioxide removal efficiency at 500 and 5000 ppm were 72% and 44%, respectively, that were higher than the solution without nanoparticles (20% and 10%, respectively). At 5000 ppm carbon dioxide, increasing the concentration of absorption solution from 0.1 to 0.4% doubled the removal efficiency. The average amount of total inorganic carbon (TIC) in nanofluids increased by about 20% compared to the base fluids. The average reduction of EC in nanofluid was about 25% higher than the base fluid. The average reduction in pH value was less than one unit. Conclusion: Sodium hydroxide nanofluid containing 0.008% of titanium dioxide nanoparticles is effective in removing carbon dioxide from the air.

Background Aim of this study is to investigate whether end-tidal carbon dioxide (ETCO2) values can be used instead of partial pressure of carbon dioxide (PaCO2) values in guiding treatment, and determining treatment benefits in patients that received a pre-diagnosis of chronic obstructive pulmonary disease (COPD) exacerbation at the emergency department.

The pathophysiology of sleep apnea goes beyond anatomic predisposition to airway collapse and includes additional factors such as arousal threshold and loop gain. High loop gain is a prominent feature in central and complex sleep apnea (with a mixture of obstructive and central features) where relative hypocapnia can lead to respiratory instability and periodic breathing. Existing therapies, including continuous positive airway pressure (CPAP) and adaptive servo-ventilators, often inadequately treat sleep apnea with high loop gain features. Enhanced expiratory rebreathing space (EERS) targets prevention of the hypocapnia that triggers central events in sleep by increasing dead space in amounts less than typical tidal volumes. This is accomplished by covering traditional exhalation ports on positive airway pressure masks and adding small additional tubing with distal exhalation and safety valves. This technique reduces carbon dioxide (CO2) blow-off during arousals and the associated large recovery breaths, typically producing a maximal increase in resting CO2 by 1–2 mmHg, thus increasing the CO2 reserve and making it less likely to encounter the hypocapnic apneic threshold. Typically, the amount of EERS is titrated in response to central events and periodic breathing rather than aiming for a goal CO2 level. Ideally CO2 monitoring is used during titration of EERS and the technique is avoided in the setting of baseline hypercapnia. This method has been used in clinical practice at our sleep center for over 15 years, and retrospective data suggests an excellent safety profile and high rates of successful therapy including in patients who have previously failed CPAP therapy. Limitations include decreased effectiveness in the setting of leak and decreased tolerance of the bulkier circuit. EERS represents a simple, affordable modification of existing positive airway pressure modalities for treatment of central and complex sleep apnea. Areas of future study include randomized controlled trials of the technique and study of use of EERS in combination with adaptive ventilation, and pharmacologic adjuncts targeting high loop gain physiology.

Introduction: Low back pain syndromes (LBPS) are common. One of the methods of treating LBPS is local cryotherapy, which can be based on various cooling substances. In the available literature, it is suggested that effective cold treatment may depend on the type and temperature of the cooling substance used.Research objective: The aim of the study was to evaluate the effectiveness of 2 local cryotherapy (Carbon Dioxide and Liquid Nitrogen) types among patients with low back pain syndrome (LBPS).Materials and methods: The study included 60 patients diagnosed with chronic LBPS of discopathic origin. Patients were randomised into 2 study groups. Local cryotherapy treatment with Carbon Dioxide was used in the 1st group (G1), while in the 2nd (G2), cryotherapy treatment with applied Liquid Nitrogen. Two measurements were taken, before and after 2 weeks treatment. The following were used for assessment: centralisation of symptoms (Pain Drawings), pain intensity (Numeral Rating Scale), duration of the current pain episode (Quebec Task Force Classification), level of disability (Roland-Morris Disability Questionnaire), quality and intensity of subjective pain (McGill Pain Questionnaire), patients emotional state (Adjectival Scale for Testing Emotions) and self-efficacy related to pain (Pain Self-Efficacy Questionnaire). Statistical analysis was performed via the Students t-test for dependent and independent samples.Results: In both study groups, the perceived pain was either completely eliminated or centralised to the spine, hip joint and buttock. The level of pain, disability and pain-related self-efficacy decreased significantly, regardless of the therapy used. In terms of these variables, no greater therapeutic efficacy was demonstrated with either cryostimulation treatment. Qualitative assessment of pain and emotions (especially anxiety and anger) decreased significantly in G1 and G2. However, in the nitrogen-treated group, a significantly greater improvement was noted for WOB:OC, anger and anxiety scores (for these variables, the G2 group started from a higher level prior to therapy).Conclusions: Both analysed treatments are equally effective in terms of variables such as: centralisation of symptoms, level of pain intensity, disability, joy, self-efficacy related to pain, as well as the majority of the analysed MPQ indicators. Cryostimulation with liquid nitrogen may be more effective, but only in improving the WOB: OC index of the MPQ questionnaire and the level of anger and anxiety. Nonetheless, the obtained results do not allow for definitive confirmation of these results. The use of both cryostimulation treatment methods may assist in the treatment process of LBPS.

DC potential shifts are the shifts observed in the EEG baseline which can last from seconds to minutes. The significance of these low-frequency components in healthy as well as pathological states of human physiology is getting more and more attention not only in scientific research but also in clinical applications. In this paper, we present our novel multimodal measurement setup for simultaneously investigating DC potential shifts in EEG (DC-EEG) and the changes in noninvasive transcutaneous pCO2 measurements. We present preliminary results of our measurements during hyperventilation and apnea, which are two commonly used activation methods for changes in pCO2.

ABSTRACT We report the long-term outcomes of a case of prenatal gastroschisis repair using a fully percutaneous fetoscopic approach with partial carbon dioxide insufflation. Surgery was performed as an experimental procedure before the scheduled elective birth. The fetal intestines were successfully returned to the abdominal cavity without any fetal or maternal complications. Ultrasonography performed 24 hours later revealed bowel peristalsis and no signs of fetal distress. After 48 hours, partial extrusion of the small bowel was observed, and the fetus was delivered. Gastroschisis repair was immediately performed upon delivery using the EXIT-like procedure as per our institutional protocol. The newborn did not require assisted mechanical ventilation, was discharged at 14 days of age and was then exclusively breastfed. At 3-year follow-up, the patient had no associated gastroschisis-related complications. This is the first case of prenatal repair of gastroschisis, which provides baseline knowledge for future researchers on the potential hurdles and management of prenatal repair.

Cancer is still one of the major factors threatening public health, with morbidity and mortality rates at the forefront of the world. Clinical drawbacks, such as high toxicity and side effects of drug therapy, and easy recurrence after surgery affect its therapeutic effect. Gas signaling molecules are essential in maintaining biological homeostasis and physiological functions as specific chemical substances for biological information transfer. In recent years, the physiological regulatory functions of gas molecules in the cancer process have been gradually revealed and have shown broad application prospects in tumor therapy. In this paper, standard gas therapies are classified and introduced. Taking H2, CO2, NO, CO, H2S, and SO2 gases as examples, the research progress and application of gas therapies in malignant tumors are mainly introduced in terms of biological characteristics, anticancer mechanisms, and treatment strategies. Finally, the problems and prospects for developing gases as anticancer drugs are outlined.

Background. It is still a matter of debate whether the evaluation of end-tidal carbon dioxide (ETCO2) using a capnography device allows the evaluation of non-invasive monitoring of arterial carbon dioxide pressure (PaCO2). The aim of this study was to compare the value of ETCO2 by direct mainstream and PaCO2 based on arterial gas analysis (ABG) before and after cardiopulmonary bypass pump in children with congenital heart defects. Methods. Twenty nine children who were candidates for elective cardiac surgery and were admitted to the Children's Medical Center were enrolled. Before and after cardiopulmonary bypass pump, ETCO2 was evaluated based on mainstream technique and PaCO2 based on arterial gas analysis. Results. The mean difference between ETCO2 and PaCO2 values before cardiopulmonary bypass pump was 3.68±5.32 mm Hg, which considering that the difference of less than 5 mm Hg is clinically negligible, indicates an acceptable agreement between them. However, the mean difference between the two indices after cardiopulmonary bypass pump was 6.85 ±7.0 mm Hg that accordingly, the difference between the two measured values after cardiopulmonary bypass will be clinically significant. Conclusion. Preoperative ETCO2 evaluation can provide a close prediction of PaCO2 levels, but after pumping, direct arterial sampling should be taken to accurately measure PaCO2 levels in non-cyanotic patients undergoing heart surgery. Practical Implications. When confronting with a child with non-cyanotic heart defect undergoing surgery, we suggest relying on capnography as a mirror of arterial blood pressure of carbon dioxide. However, capnography may not be as reliable during early post-bypass period in this group of patients and repeated arterial blood samples may be necessary.

Objective: To compare the effectiveness of carbon dioxide fractional laser with micro needling in acne scarring. Study Design: Quasi experimental study. Place and Duration of Study: Department of Dermatology, Pak Emirates Military Hospital Rawalpindi, from Jun 2019 to Mar 2020. Methodology: Overall 40 patients with acne scars assessed by consultant dermatologist were made part of study. The patients were divided into two treatment groups through lottery method. Group A, was managed by micro needling technique, while Group B was managed by carbon dioxide fractional laser, each to be done monthly for a total of three sessions. The response was measured by the dermatologist and patients in both the groups. The side effects were also compared in both the groups. Results: Out of 40 patients with acne scars included in study, 17 (42.5%) underwent micro-needling while 23 (57.5%) underwent carbon dioxide fractional laser treatment after randomization. Thirty (75%) patients were female while 10 (25%) were male. The patients with acne scars responded better in carbon dioxide fractional laser group as compared to micro needling in opinion of dermatologists (p-value=0.01) and also patients themselves (p-value=0.03). Side effects were significantly higher in carbon dioxide fractional laser group as compared to micro needling (p-value=0.02). Conclusion: Significant number of patients respond well to carbon dioxide fractional laser treatment and the response included both expert opinion and patients own opinion, but adverse effects were seen more in same group. Therefore, better response but at the cost of more adverse effects was noted.

PurposeThe vasodilatory response to inhaled CO2 occurs in the acute stroke ischemic penumbra and may be a potential therapeutic modality.MethodsTwenty-two Sprague-Dawley rats were subjected to 90-min occlusion of the M2 segment of the middle cerebral artery (M2CAO) by endovascular technique. The animals were administered different C02 concentrations and scanned serially with 9.4 T MRI. Infarct tissue was determined by diffusion-weighted imaging (DWI) and hypoperfused tissue was determined by arterial spin labeling (PWI).Results4 animals were administered room air (RA)+ 6% CO2 (group 1), 6 animals RA+12% CO2 (Group 2) and 4 animals only RA (group 3). In the rats with CO2 administered (groups 1 and 2), the DWI lesion to cerebral hypoperfusion volume ratio (SD) at pre-CO2 administration, was 0.145(0.168), which increased to 0.708(0.731) during CO2 administration and reduced to 0.533(0.527) post-CO2 administration. In 9 of 10 rats the hypoperfused volume decreased when CO2 was administered. When CO2 was stopped the hypoperfused volume became larger again. Administration of RA+12% CO2 (Group 2) decreased the volume of CBF hypoperfusion significantly compared to the control group (95%CI: 0.084 ± 0.0213, p = 0.004).ConclusionInhaled CO2 appears to reduce the size of the hypoperfused tissue volume during acute stroke and may be a potential modality for treatment of acute ischemic stroke. These findings will nonetheless need to be validated in a larger cohort in other centers.

BACKGROUND AND OBJECTIVE: Considerable increase in carbon dioxide gas in the Earth's atmosphere has caused several problems such as increasing the temperature of the earth, droughts and sudden changes in the climate. The purpose of this study was to evaluate the capability of carbon dioxide as greenhouse gas absorption using activated nanobiocarbon from the Crataegus Sanguinea core. METHODS: In this experimental study, the carbon dioxide gas penetration time in three subgroups with pressure (5,10,15 bars), flow (5,10,15 ml/min) and temperatures (20,30,60 °C) at concentrations of 0 to 1 gr / ml through a carbon dioxide gas capsule in a fixed bed column filled with 2 g of adsorbent synthesized by a carbon dioxide gas sensor. The synthesized nano-biocarbon adsorbent from the Crataegus Sanguinea Core was pyrolysed at a temperature of 300 ° C and activated at 600 °C. The research data were examined with pseudo -first-order and pseudo-second-order models. FINDINGS: Significant increase in gas infiltration time was observed at 15 bars pressure (86.71±0.09 min, p0.98 on empirical data from absorption. CONCLUSION: The results of the study showed that increasing pressure and decreasing temperature and flow increase the time of carbon dioxide penetration onto synthesized adsorbent.

Associative learning allows animals to use past experience to predict future events. The circuits underlying memory formation support immediate and sustained changes in function, often in response to a single example. Larval Drosophila is a genetic model for memory formation that can be accessed at molecular, synaptic, cellular, and circuit levels, often simultaneously, but existing behavioral assays for larval learning and memory do not address individual animals, and it has been difficult to form long-lasting memories, especially those requiring synaptic reorganization. We demonstrate a new assay for learning and memory capable of tracking the changing preferences of individual larvae. We use this assay to explore how activation of a pair of reward neurons changes the response to the innately aversive gas carbon dioxide (CO2). We confirm that when coupled to CO2 presentation in appropriate temporal sequence, optogenetic reward reduces avoidance of CO2. We find that learning is switch-like: all-or-none and quantized in two states. Memories can be extinguished by repeated unrewarded exposure to CO2 but are stabilized against extinction by repeated training or overnight consolidation. Finally, we demonstrate long-lasting protein synthesis dependent and independent memory formation.

The aim of this systematic review was to summarise the comparative evidence on the risk of contrast-associated acute kidney injury (CA-AKI) with CO2 or iodinated contrast medium (ICM) for peripheral vascular interventions. We searched Ovid MEDLINE, Cochrane Library, Embase, Epistemonikos, PubMed-similar-articles, clinical trial registries, journal websites, and reference lists up to February 2022. We included studies comparing the risk of CA-AKI in patients who received CO2 or ICM for peripheral angiography with or without endovascular intervention. Two reviewers screened the references and assessed the risk of bias of the included studies. We extracted data on study population, interventions and outcomes. For the risk of CA-AKI as our primary outcome of interest, we calculated risk ratios (RRs) with a 95% confidence interval (CI) and performed random-effects meta-analyses. We identified three RCTs and five cohort studies that fully met our eligibility criteria. Based on a random-effects meta-analysis, the risk of CA-AKI was lower with CO2 compared to ICM (8.6% vs. 15.2%; RR, 0.59; 95% CI 0.33–1.04). Only limited results from a few studies were available on procedure and fluoroscopy time, radiation dose and CO2-related adverse events. The evidence suggests that the use of CO2 for peripheral vascular interventions reduces the risk of CA-AKI compared to ICM. However, due to the relevant residual risk of CA-AKI with the use of CO2, other AKI risk factors must be considered in patients undergoing peripheral vascular interventions.

Background: Many studies have reported minor complications and disturbance of the gut microbiota after colonoscopy. Compared with air, carbon dioxide (CO2) insufflation could decrease minor complications, but its impact on gut microbiota remains unknown. Methods: Thirty-eight healthy subjects were assessed and twenty were randomized to receive either CO2 or air insufflation during colonoscopy. Neither the participants nor the staff involved in the follow-up knew which gas was used. Minor complications were assessed using symptom scores. Fecal samples were collected at eight time-points for microbiome analysis by full-length 16S rRNA gene amplicon analysis. Results: Baseline characteristics were similar in both groups. The recovery of minor complications after colonoscopy was faster in the CO2 group (the day of the colonoscopy) than in the air group (the day after the colonoscopy). There was no significant reduction in alpha diversity (species richness) of the first stool after colonoscopy in the CO2 group (115.0 ± 32.81 vs. 97.4 ± 42.31, p = 0.28) compared with the air group (123.8 ± 37.25 vs. 84.8 ± 31.67, p = 0.04). However, there were no differences in beta diversity between the groups. Linear discriminant analysis effect size (LEfSe) analysis indicated that anaerobic probiotics such as Bacteroides caccae, Bacteroides finegoldii and Bacteroides thetaiotaomicron were more abundant in the CO2 group than in the air group within 14 days after colonoscopy. On the contrary, the content of Escherichiacoli, Ruminococcus torques and Ruminococcus guavus was higher in the air group. Conclusions: CO2 is beneficial to gut microbiota homeostasis during colonoscopy in healthy subjects. The effects in patients with different diseases need to be further studied.

Nephroprotective imaging in peripheral arterial disease (PAD) is often crucial. We compared the diagnostic performance of non-contrast Quiescent-interval single-shot magnetic resonance angiography (QISS MRA) and carbon-dioxide digital subtraction angiography (CO2 DSA) in chronic lower extremity PAD patients. A 19-segment lower extremity arterial model was used to assess the degree of stenosis (none, 70%) and the image quality (5-point Likert scale: 1-non-diagnostic, 5-excellent image quality). Intra-class correlation coefficient (ICC) was calculated for inter-rater reliability. Diagnostic accuracy and interpretability were evaluated using CO2 DSA as a reference standard. 523 segments were evaluated in 28 patients (11 male, mean age: 71 ± 9 years). Median and interquartile range of subjective image quality parameters for QISS MRA were significantly better compared to CO2 DSA for all regions: (aortoiliac: 4 [4–5] vs. 3 [3–4]; femoropopliteal: 4 [4–5] vs. 4 [3–4]; tibioperoneal: 4 [3–5] vs. 3 [2–3]; all regions: 4 [4–5] vs. 3 [3–4], all p < 0.001). QISS MRA out-performed CO2 DSA regarding interpretability (98.3% vs. 86.0%, p < 0.001). Diagnostic accuracy parameters of QISS MRA for the detection of obstructive luminal stenosis (70%

Neuroendocrine systems in animals maintain organismal homeostasis and regulate stress response. Although a great deal of work has been done on the neuropeptides and hormones that are released and act on target organs in the periphery, the synaptic inputs onto these neuroendocrine outputs in the brain are less well understood. Here, we use the transmission electron microscopy reconstruction of a whole central nervous system in the Drosophila larva to elucidate the sensory pathways and the interneurons that provide synaptic input to the neurosecretory cells projecting to the endocrine organs. Predicted by network modeling, we also identify a new carbon dioxide-responsive network that acts on a specific set of neurosecretory cells and that includes those expressing corazonin (Crz) and diuretic hormone 44 (Dh44) neuropeptides. Our analysis reveals a neuronal network architecture for combinatorial action based on sensory and interneuronal pathways that converge onto distinct combinations of neuroendocrine outputs.

Background and purpose: CO2 is the main cause of greenhouse effect. Previous studies have shown that CO2 in methane and coal flue gas can lead to microalgae growth. The aim of this research was to study the CO2 biofixation by Spirulina and injecting kerosene flue gas. Materials and methods: A photo bioreactor was fabricated in which kerosene flue gas and air were separately injected. The photo bioreactor was filled by growth medium without carbon source. Light source was four fluorescent lamps (10 Klux intensity) operated in continuous and intermittent modes. The concentration of CO2 was chosen in the range of 580 to 6000 ppm that was measured by NDIR CO2 detector. The initial concentration of algae was 20 mgL-1. The algal biomass production was measured during the experiment. Results: The maximum production of algae by air and kerosene flue gas containing 5500 ppm CO2 using artificial intermittent light was 0.07 and 0.41 gL-1 d-1 and maximum concentrations of biomass were 0.25 and 1.63 gL-1, respectively. CO2 biofixation rates were between 2.27% and 4.03% at different runs. Biomass productivity with intermittent light was 15% less than continuous light and it reached 1.91 gL-1 with 5500 ppm CO2 using continuous light. Conclusion: In this study, the ability of a photo bioreactor was confirmed in the removal of CO2. Also, increase in CO2 contributes to increase in biomass production.

Background and purpose: Lack of healthy air in classrooms and homes will reduce the level of health and disrupts students’ learning. The aim of this study was to determine the relationship between CO2 concentration and other environmental parameters with sick building syndrome in schools and homes in Babol, north of Iran, 2018. Materials and methods: To measure carbon dioxide, temperature, and humidity, the TES 1370 was used. This study was conducted among 85 students in five primary, secondary, and high schools. Selection of schools, classrooms, and students was performed using a multistage random sampling. Data were collected through interviews using MM040EA questionnaire. Chi-square, ANOVA, and T-test were used to determine the relationship between sick building syndrome and environmental parameters. Results: The most common symptoms of building syndrome were fatigue (45.8%) in winter and headache (35.3%) in spring. T-test showed significant relationships between carbon dioxide and building syndrome signs in winter (P= 0.02) and spring (P= 0.01) in classrooms and homes. But there was no significant relationship between the syndrome and moisture and temperature. Among the risk factors investigated in winter and spring, noise was reported as an annoying risk factor. Conclusion: The study showed that concentration of carbon dioxide has a significant relationship with development of sick building syndrome in students. The symptoms of sick building syndrome were found to be mild in our samples, but due to poor physical conditions in some schools and even in home settings, optimization of these spaces should be done.

Expansion of cultivated lands and field management impacts greenhouse gas (GHG) emissions from agriculture soils. Soils naturally cycle GHGs and can be sources or sinks depending on physical and chemical properties affected by cultivation and management status. We looked at how cultivation history influences GHG emissions from subtropical soils. We measured CO2, N2O, and CH4 fluxes, and soil properties from newly converted and continuously cultivated lands during the summer rainy season in calcareous soils from south Florida. Newly converted soils had more soil organic matter (OM), more moisture, higher porosity, and lower bulk density, leading to more GHG emissions compared to historically cultivated soils. Although more nutrients make newly converted lands more desirable for cultivation, conversion of new areas for agriculture was shown to release more GHGs than cultivated lands. Our data suggest that GHG emissions from agricultural soils may decrease over time with continued cultivation.

We aimed to estimate the association between PaCO2 level in the patient after out-of-hospital cardiac arrest (OHCA) resuscitation with patient outcome based on a multicenter prospective cohort registry in Japan between June 2014 and December 2015. Based on the PaCO2 within 24 h after return of spontaneous circulation (ROSC), patients were divided into six groups as follows: severe hypocapnia (55 mmHg), or exposure to both hypocapnia and hypercapnia. Multivariate logistic regression analysis was conducted to calculate the adjusted odds ratios (aORs) and 95% confidence interval (CI) for the 1-month poor neurological outcome (Cerebral Performance Category ≥ 3). Among the 13,491 OHCA patients, 607 were included. Severe hypocapnia, mild hypocapnia, severe hypercapnia, and exposure to both hypocapnia and hypercapnia were associated with a higher rate of 1-month poor neurological outcome compared with mild hypercapnia (aORs 6.68 [95% CI 2.16–20.67], 2.56 [1.30–5.04], 2.62 [1.06–6.47], and 5.63 [2.21–14.34], respectively). There was no significant difference between the outcome of patients with normocapnia and mild hypercapnia. In conclusion, maintaining normocapnia and mild hypercapnia during the 24 h after ROSC was associated with better neurological outcomes than other PaCO2 abnormalities in this study.

CO2 insufflation has proven effective in reducing patients’ pain after colonoscopies but has not been examined in esophagogastroduodenoscopies. Therefore, we examined the effect of CO2 insufflation in examinees who underwent transnasal endoscopies without sedation. This study is a single-center, prospective, double-blind, case-control trial conducted between March 2017 and August 2018. Subjects were assigned weekly to receive insufflation with either CO2 or air. The primary outcome was improvement of abdominal pain and distension at 2 h and 1-day postprocedure. In total, 336 and 338 examinees were assigned to the CO2 and air groups, respectively. Visual analog scale (VAS) scores for abdominal distension (15.4 vs. 25.5; p < 0.001) and distress from flatus (16.0 vs. 28.8; p < 0.001) at 2 h postprocedure were significantly reduced in the CO2 group. VAS scores for pain during the procedure (33.5 vs. 37.1; p = 0.059) and abdominal pain after the procedure (3.9 vs. 5.7; p = 0.052) also tended to be lower at 2 h postprocedure, but all parameters showed no significant difference at 1-day postprocedure. All procedures were safely completed through the planned program, and no apparent adverse events requiring treatment or follow-up occurred. In conclusion, CO2 insufflation may reduce postprocedural abdominal discomfort from transnasal esophagogastroduodenoscopies. (UMIN000028543).

Seven patients with nine primary well-defined pigmented basal cell carcinomas (BCC), regardless of size, were successfully treated with carbon dioxide laser. There has been no evidence of recurrence in the 3 months to 2 years following surgery. This may be the result of the dermal pigment at the lesion shoulder that more clearly marks the tumor margin. However, if the tumor was located in the reticular dermis, healing occurred with an atrophic scar. Surgical excision is recommended in cases of deep BCCs located in the convex area in terms of cosmetic results. It is therefore suggested that, in addition to the BCC subtype, the depth of invasion should always be stated in the routine histopathological report in order to determine the most appropriate treatment.

Previously, we showed that the evolution of high acuity vision in fishes was directly associated with their unique pH-sensitive hemoglobins that allow O2 to be delivered to the retina at PO2s more than ten-fold that of arterial blood (Damsgaard et al., 2019). Here, we show strong evidence that vacuolar-type H+-ATPase and plasma-accessible carbonic anhydrase in the vascular structure supplying the retina act together to acidify the red blood cell leading to O2 secretion. In vivo data indicate that this pathway primarily affects the oxygenation of the inner retina involved in signal processing and transduction, and that the evolution of this pathway was tightly associated with the morphological expansion of the inner retina. We conclude that this mechanism for retinal oxygenation played a vital role in the adaptive evolution of vision in teleost fishes.

Alfalfa in China is mostly planted in the semi-arid or arid Northwest inland regions due to its ability to take up water from deep in the soil and to fix atmospheric N2 which reduces N fertilizer application. However, perennial alfalfa may deplete soil water due to uptake and thus aggravate soil desiccation. The objectives of this study were (1) to determine the alfalfa forage yield, soil property (soil temperature (ST), soil water content (SWC), soil organic carbon (SOC) and soil total nitrogen (STN)) and greenhouse gas (GHG: methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2)) emissions affected by alfalfa stand age and growing season, (2) to investigate the effects of soil property on GHG emissions, and (3) to optimize the alfalfa stand age by integrating the two standard criteria, the forage yield and water use efficiency, and the total GHG efflux (CO2-eq). This study was performed in alfalfa fields of different ages (2, 3, 5 and 7 year old) during the growing season (from April to October) in a typical salinized meadow with temperate continental arid climate in the Northwest inland regions, China. Despite its higher total GHG efflux (CO2-eq), the greater forage yield and water use efficiency with lower GEIhay and high CH4 uptake in the 5-year alfalfa stand suggested an optimal alfalfa stand age of 5 years. Results show that ST, SOC and RBM alone had positive effects (except RBM had no significant effect on CH4 effluxes), but SWC and STN alone had negative effects on GHG fluxes. Furthermore, results demonstrate that in arid regions SWC superseded ST, SOC, STN and RBM as a key factor regulating GHG fluxes, and soil water stress may have led to a net uptake of CH4 by soils and a reduction of N2O and CO2 effluxes from alfalfa fields. Our study has provided insights into the determination of alfalfa stand age and the understanding of mechanisms regulating GHG fluxes in alfalfa fields in the continental arid regions. This knowledge is essential to decide the alfalfa retention time by considering the hay yield, water use efficiency as well as GHG emission.

Background: Carbon dioxide is a normal by-product of aerobic metabolism that maintains the equilibrium of respiratory act, being eliminated from the lungs. Despite of an increasing number of researches concerning carbon dioxide metabolism and its effects on human homeostasis, there are still discussions about carbon dioxide metabolism, physiology and its implication in anaesthetic management, ICU, critically ill patient. The use of mild to moderate hypercapnia during general anaesthesia and in mechanically ventilated patients is growing, based on scientifical researches of last years. Material and methods: There has been scientifically evaluated data from PubMed, 2002-2017. Key words used in search are: “carbon dioxide”, “ventilation”, “metabolism”, “gas change”. There were selected articles, taking in consideration their title, and chosen abstracts. The article contains a qualitative analysis and synthesis of the recommendation, concerning anaesthetic management and metabolism of carbon dioxide. Conclusions: Carbon dioxide metabolism and its anaesthetic management, represents a challenge that will be actual for many years in future. The amount of controversial studies about effects of carbon dioxide on patients under general anaesthesia or mechanical ventilation, determined us to perform a review of literature, and evaluate it. There are known facts about carbon dioxide metabolism, such as normal values, how it is produced in human body, how it is evacuated, effects on cardiovascular, nervous systems, and still there are many controversial studies on that topic, that determine to study it more and find new research results.

Since the development of lasers in 1960, the use of these instruments has become more popular in medicine and dentistry. All lasers consist of a laser medium, an optical cavity, and a source of energy to pump the laser medium. The laser medium can be in the form of: a gas, eg, carbon dioxide (CO2), argon, or helium-neon (He-Ne); a liquid (eg, a dye); a solid, eg, yttrium-aluminum-garnet bar doped with neodymium (Nd:YAG), holmium (Ho:YAG) or erbium (Er:YAG); or a semiconductor, eg, gallium-aluminum arsenide (Ga-Al-As). The laser beam can be transformed to radiant energy that can be focused to a very small spot size to yield the enormous power densities which are necessary for the cutting, vaporizing and coagulating effects of lasers. This paper presents a review of the literature for potential laser applications in periodontics. [ABSTRACT FROM AUTHOR]

Introduction: the impact environment trough the anthropogenic action has been contributed to the fast production of greenhouse gases effect (GHG), a way to estimate the quantity of these substances is the carbon footprint (CF), nowadays it does not exist enough models for the calculation of food carbon footprint. Objective: the aim of this study was to design a calculation model for the measurement of the carbon footprint on the Mexican food equivalent system. Methods: it was about a retrospective study, a bibliographic review was made with original and review articles in different specialized researchers, there were included publications in English and Spanish, also published from 2000 to 2016. Results: a reference table was proposed for the food carbon footprint calculation on the Mexican food equivalent system trough the carbon intensity indicator, which is determined by the grams of emissions equivalents of carbon dioxide (CO2) in relation with the energetic contribution of each food equivalent. Conclusion: in a conclusion manner, estimating food carbon footprint is still a challenge, mean while the calculation models proposal is important to estimate the production of GHG trough a more sustainable food system.

To improve the growth of Grammatophyllum scriptum (Lindl.) Bl. in vitro plantlet, a photoautotrophic micropropagation system (PMS) was developed by growing in vitro plantlet on VW medium with varying concentration of sucrose (0, 5, 10, and 20 g/L) and additional carbon dioxide from the air (bottle covered with cap or filter). The result showed that the leaf length would increase up to 6.5 cm with PMS and it would keep growing by the adding of 5 g/L sucrose. Average number of leaves increased by 6.7 strands with PMS and the addition of sucrose increased the average quantity of leaves up to 7.7 strands. Average number and root length would increase with PMS and would even increase more with 5 g/L sucrose addition. PMS with 5 g/L sucrose can increase chlorophyll a and b concentration. The number of stomata per unit area in PMS was lower than closed culture. This shows that PMS can increase the growth of G. scriptum in vitro plantlet and the growth increase would be effective if it is combined with sucrose addition.

Postural orthostatic tachycardia syndrome (POTS) typically occurs in youths, and early accurate POTS diagnosis is challenging. A recent hypothesis suggests that upright cognitive impairment in POTS occurs because reduced cerebral blood flow velocity (CBFV) and cerebrovascular response to carbon dioxide (CO2) are nonlinear during transient changes in end-tidal CO2 (PETCO2). This novel study aimed to reveal the interaction between cerebral autoregulation and ventilatory control in POTS patients by using tilt table and hyperventilation to alter the CO2 tension between 10 and 30 mmHg. The cerebral blood flow velocity (CBFV), partial pressure of end-tidal carbon dioxide (PETCO2), and other cardiopulmonary signals were recorded for POTS patients and two healthy groups including those aged >45 years (Healthy-Elder) and aged ETCO2 relationship and cerebral vasomotor reactivity (CVMR). Among the estimated parameters, the curve-fitting Model I for CBFV and CVMR responses to CO2 for POTS patients demonstrated an observable dissimilarity in CBFVmax (p = 0.011), mid-PETCO2 (p = 0.013), and PETCO2 range (p = 0.023) compared with those of Healthy-Youth and in CBFVmax (p = 0.015) and CVMRmax compared with those of Healthy-Elder. With curve-fitting Model II for POTS patients, the fit parameters of curvilinear (p = 0.036) and PETCO2 level (p = 0.033) displayed significant difference in comparison with Healthy-Youth parameters; range of change (p = 0.042), PETCO2 level, and CBFVmax also displayed a significant difference in comparison with Healthy-Elder parameters. The results of this study contribute toward developing an early accurate diagnosis of impaired CBFV responses to CO2 for POTS patients.