Carbon Dioxide Levels Research Articles

Impact of ocean acidification on microzooplankton grazing dynamics

This study examines the potential impacts of projected atmospheric carbon dioxide (pCO2) levels reaching 800 ppm by the end of the century, focusing on ocean acidification effects on marine ecosystems in the coastal areas of Bohai. We investigated how acidification affects the grazing patterns of microzooplankton using dilution techniques and ecophysiological methods. Our findings indicate that acidic conditions shift the phytoplankton community structure, changing dominant species. Elevated CO2 concentrations reduced grazing pressure on phytoplankton, with less steep declines in growth rates at 800 ppm CO2 (spring: 2.43 d−1 vs. 2.16 d−1, summer: −0.46 d−1 vs. −0.73 d−1, autumn: −0.45 d−1 vs. −0.90 d−1) and significant decreases in grazing pressure percentages (%Pp from 0.84 to 0.58 and %Pi from 0.64 to 0.46). Short-term acid exposure significantly increased superoxide dismutase activity in both microplankton (from 0.03 to 0.08 U mg−1, p<0.01) and nanoplankton (from 0.05 to 0.09 U mg−1, p<0.001), indicating an adaptive response to oxidative stress. These results highlight that elevated CO2 levels primarily boost phytoplankton growth by reducing microzooplankton grazing pressure, resulting in higher growth rates and a shift towards smaller-sized phytoplankton, reflecting complex short-term ecological responses to acidification. Further research is needed to understand the long-term effects of ocean acidification on microzooplankton and their role in marine secondary productivity.

Non-invasive high-frequency oscillatory ventilation (NHFOV) versus nasal continuous positive airway pressure (NCPAP) for preterm infants: a systematic review and meta-analysis

ObjectiveTo compare the efficacy and safety of non-invasive high-frequency oscillatory ventilation (NHFOV) and nasal continuous positive airway pressure (NCPAP) in preterm infants.DesignThe study conducted a comprehensive analysis across three databases,...

Investigating Methane, Carbon Dioxide, Ammonia, and Hydrogen Sulphide Content in Agricultural Waste during Biogas Production

The agricultural industry produces a substantial quantity of organic waste, and finding a suitable method for disposing of this highly biodegradable solid waste is a difficult task. The utilisation of anaerobic digestion for agricultural waste is a viable technological solution for both renewable energy production (biogas) and waste treatment. The primary objective of the study was to assess the composition of biogas, namely the percentages of methane, carbon dioxide, ammonia, and hydrogen sulphide. Additionally, the study aimed to quantify the amount of biogas produced and determine the methane yield (measured in NmL/g VS) from different agricultural substrates. The biochemical methane potential (BMP) measurements were conducted in triplicate using the BPC Instruments AMPTS II instrument. The substrates utilised in the investigation were chosen based on their accessibility. The substrates used in this study comprise cattle manure, chicken manure, pig manure, tomato plants, tomatoes, cabbage, mixed fruits, mixed vegetables, dog food, and a co-digestion of mixed vegetables, fruits, and dog food (MVMFDF). Prior to the cleaning process, the makeup of the biogas was assessed using the BIOGAS 5000, a Geotech Analyser. The AMPTS II flow cell automatically monitored and recorded the volume of bio-methane produced after the cleaning stage. The data were examined using the Minitab-17 software. The co-digestion of mixed vegetables, mixed fruits, and dog food (MVMFDF) resulted in the highest methane level of 77.4%, followed by mixed fruits at 76.6%, pig manure at 72.57%, and mixed vegetables at 70.1%. The chicken manure exhibited the greatest levels of ammonia (98.0 ppm) and hydrogen sulphide (589 ppm). Chicken manure had the highest hydrogen sulphide level, followed by pig manure (540 ppm), tomato plants (485 ppm), mixed fruits (250 ppm), and MVMFDF (208 ppm). Ultimately, the makeup of biogas is greatly affected by the unique qualities of each substrate. Substrates containing elevated quantities of hydrogen sulphide, such as chicken manure, require the process of biogas scrubbing. This is because they contain substantial amounts of ammonia and hydrogen sulphide, which can cause corrosion to the equipment in biogas plants. This emphasises the crucial need to meticulously choose substrates, with a specific focus on their organic composition and their capacity to generate elevated methane levels while minimising contaminants. Substrates with a high organic content, such as agricultural waste, are optimal for maximising the production of methane. Furthermore, the implementation of biogas scrubbing procedures is essential for efficiently decreasing carbon dioxide and hydrogen sulphide levels in biogas. By considering and tackling these problems, the effectiveness of biogas generation can be enhanced and its ecological consequences alleviated. This strategy facilitates the advancement of biogas as a sustainable energy source, hence contributing to the attainment of sustainable development goals (SDGs).

Carbon storage in rare ecosystems relative to their encroaching forests in western Lower Michigan.

Rising atmospheric carbon dioxide levels are impacting global temperatures, ecological systems, and human societies. Natural carbon sequestration through the conservation of soil and native ecosystems may slow or reduce the amount of CO2 in the atmosphere, and thus slow or mitigate the rate of global warming. Most of the research investigating carbon sequestration in natural systems occurs in forested ecosystems, however rare ecosystems such as coastal plain marshes and wet-mesic sand prairie collectively may serve as significant carbon sinks. Our objectives were to measure and assess the importance of carbon sequestration in three rare ecosystems (oak-pine barrens, coastal plain marsh, and wet-mesic sand prairie) in western Lower Michigan. We measured carbon in standing vegetation, dead organic matter, and soils within each ecosystem and adjacent encroaching forested areas. Driven by tree carbon, total carbon stocks in encroaching areas were greater than in intact rare ecosystems. Soil organic carbon was greater in all intact ecosystems, though only significantly so in coastal plain marsh. Principal components analysis explained 72% of the variation and revealed differences between intact ecosystems and their encroaching areas. Linear models using the ratio of red to green light reflectance successfully predicted SOC in intact coastal plain marsh and wet-mesic sand prairie. Our results infer the importance of these rare ecosystems in sequestering carbon in soils and support the need to establish federal or state management practices for the conservation of these systems.

Clinical study of prone positioning in invasive respiratory support for neonatal respiratory distress syndrome

To assess the effectiveness and safety of prone positioning in the treatment of neonatal respiratory distress syndrome (NRDS) using invasive respiratory support. A prospective study was conducted from June 2020 to September 2023 at Suining County People's Hospital, involving 77 preterm infants with gestational ages less than 35 weeks requiring invasive respiratory support for NRDS. The infants were randomly divided into a supine group (37 infants) and a prone group (40 infants). Infants in the prone group were ventilated in the prone position for 6 hours followed by 2 hours in the supine position, continuing in this cycle until weaning from the ventilator. The effectiveness and safety of the two approaches were compared. At 6 hours after enrollment, the prone group showed lower arterial blood carbon dioxide levels, inspired oxygen concentration, oxygenation index, rates of tracheal intubation bacterial colonization, and Neonatal Pain, Agitation and Sedation Scale scores compared to the supine group (P<0.05). There were no significant differences between the groups in terms of pH, arterial oxygen pressure, positive end-expiratory pressure, duration of mechanical ventilation, accidental extubation, ventilator-associated pneumonia, air leak syndrome, skin pressure sores, feeding intolerance, and grades II-IV intraventricular hemorrhage (P>0.05). Compared to supine positioning, prone ventilation effectively improves oxygenation, increases comfort, and reduces tracheal intubation bacterial colonization in neonates requiring mechanical ventilation for NRDS, without significantly increasing adverse reactions.

Examining the Impact of Natural Ventilation versus Heat Recovery Ventilation Systems on Indoor Air Quality: A Tiny House Case Study

Adverse health effects can arise from indoor air pollutants, resulting in allergies, asthma, and other respiratory problems among occupants. Concurrently, the energy consumption of residential buildings, particularly concerning heating, ventilation, and air conditioning (HVAC) systems, significantly contributes to global energy usage. To address these intertwined challenges, heat recovery ventilation (HRV) has emerged as a viable solution to reduce heating and cooling demands while providing fresh ventilation rates. This study aims to investigate the indoor air quality (IAQ) of an experimental tiny house building equipped with an HRV unit by simulating real-life scenarios contributing to IAQ. The research evaluates the effectiveness of HRV compared to natural ventilation in managing particle matter (PM), total volatile organic compounds (TVOC), formaldehyde (CH2O), carbon monoxide (CO), and carbon dioxide (CO2) levels. This research significantly contributes to the understanding of the different ventilation strategies’ impact on IAQ in tiny houses and offers valuable insights for improving living conditions in a unique building typology that is underrepresented in the research literature.

Ecological patterns of phytoplankton across lake cross-section: insights into co-evolution of physicochemical conditions in Chashma Lake on Indus River.

Physicochemical properties of water influence planktonic diversity and distribution, which is essential in obtaining basic knowledge of aquatic biodiversity. Thus current study aims to investigate the spatiotemporal diversity, abundance ratio, and distribution of phytoplankton species and their association with water quality parameters of Chashma Lake, Pakistan. During the study period from 2018 to 2019, we measured 13 physicochemical parameters across three selected sampling sites (S1, S2, and S3) in Chashma Lake, revealing both spatial and temporal variability. Dissolved oxygen (DO) was higher in S3, while S1 exhibited higher alkalinity levels, carbon dioxide, phosphorus, and chloride levels. The study identified 77 phytoplankton species grouped into five taxonomic categories, with Cyanobacteria dominating (39.90%), followed by Chlorophyta (33.4%) and Bacillariophyta (24.88%). Euglenozoa and Ochrophyta were less abundant (1.3% and 0.41%, respectively). Spatial variations in phytoplankton distribution were noted, with Chlorophyta being more abundant at S2, Bacillariophyta and Cyanobacteria at S1, and Euglenozoa dominating at S3. Canonical Correspondence Analysis (CCA) revealed the influence of various physicochemical parameters on phytoplankton distribution. This comprehensive study provides valuable insights for the ecological assessment and monitoring of water bodies. It is recommended that continuous monitoring is required to capture long-term trends, further explore the specific environmental drivers impacting phytoplankton dynamics, and consider management strategies for maintaining water quality and biodiversity in Chashma Lake.

Influence of relative humidity on carbon sequestration and crystal morphology of air lime: A sustainable building material

This study investigated the carbon sequestration potential of air lime by carbonation in two different relative humidity conditions. The carbonation rate and amount of carbon dioxide captured were quantified using weight gain and various analytical techniques. Samples cured in high relative humidity showed almost complete carbon capture by sequestering 94.8 % of carbon dioxide from atmospheric air within 56 days, with calcite crystal formation and a high crystallinity index. Similarly, samples cured in low relative humidity conditions showed slightly less carbonation around 83.8 % with different calcium carbonate polymorphs like aragonite and vaterite, along with amorphous calcium carbonate. Results demonstrated that carbonation of lime is a promising technology for carbon capture and utilization in buildings as non-load bearing mortars or plasters and could be used to reduce carbon dioxide levels in the atmosphere.

Real time monitoring of carbon dioxide levels in surgical helmet systems worn during hip and knee arthroplasty

BackgroundOrthopaedic surgical helmet systems (SHS) rely on an intrinsic fan to force clean external air over the wearer. Carbon dioxide (CO2) is produced through aerobic metabolism and can potentially accumulate inside the SHS. Levels above 2500 ppm have previously been shown to affect cognitive and practical function. Maximum Health and Safety Executive (HSE) 8-h exposure limit is 5000 ppm. There is a paucity of data on real-world CO2 levels experienced during arthroplasty surgery whilst wearing a SHS. ObjectivesTo determine intra-operative levels of CO2 experienced within SHS. MethodsCO2 levels were continuously recorded during 30 elective arthroplasties, both primary and revision. Data was recorded at 0.5Hz throughout the procedure utilising a Bluetooth CO2 detector, worn inside a surgical helmet worn with a toga gown. Five surgeons contributed real time data to the study. ResultsThe average CO2 level across all procedures was 3006 ppm, with 23 of the cases measured within the surgeons’ helmets having a mean above 2500 ppm, but none having a mean above 5000 ppm. For each procedure, the time spent above 2500 and 5000 ppm was calculated, with the means being 72.6 % and 5.4 % respectively. Minimum fan speed was associated with only a marginally higher mean CO2 value than maximum fan speed. DiscussionThe use of surgical helmet systems for elective orthopaedic surgery, can result in CO2 levels regularly rising to a point which may affect cognitive function. ConclusionFurther research is needed to corroborate these findings however, we recommend that future designs of SHS include active management of exhaust gases, possibly returning to Charnley's original design principles of the body exhaust system.

The Disease Triangle of Chestnut: A review of host, pathogen, and environmental interactions of chestnuts cultivated in the eastern United States

Chestnuts, the edible seeds of the genus Castanea, are a perennial food crop closely tied to the global migration of humans throughout history and have recently been gaining popularity in agriculture and forest restoration in eastern North America. Cultivation of chestnuts yields nutritionally balanced food while fostering economic development, food security, and environmental health. However, diseases and insect pests threaten successful ecological restoration and food production. In this review we explore conditions affecting chestnuts in the eastern United States through the lens of the disease triangle. A “host” in the disease triangle is not merely a single tree, but a tree including its constituent population of fungal endophytes. Chestnut trees are rich with microbial life, and the sustainability of chestnuts in forest and cultivated settings may lie in understanding and manipulating microbial communities to improve plant health and control destructive diseases. To benefit from the ecological and economic potential of chestnuts on the landscape, it may be necessary to select locally adapted chestnut trees, regardless of pedigree, that are resilient against cosmopolitan pathogens. With transport of plants and pathogens throughout the globe, and with landscape level environmental changes over the last century, chestnut trees in the eastern United States (U.S.) are in a unique disease landscape compared to their ancestors. Diseases of economic concern from fungi and fungal-like organisms include chestnut blight (Cryphonectria parasitica) and ink disease (Phytophthora cinnamomi) on American and European chestnuts, oak wilt (Bretziella fagacearum) on all chestnut species, and the emerging diseases of brown rot (Gnomoniopsis smithogilvyi) and chestnut anthracnose (Colletotrichum henanense). The eastern U.S. has experienced profound environmental changes over the 20th century and into the early 21st century. These changes happen to coincide with the demise of the American chestnut in the eastern forest, efforts to re-establish chestnut as a forest species, and the rise in cultivation of multiple chestnut species and hybrids as a culinary crop. Chestnut trees growing in the early 21st century face different environmental circumstances than the American chestnuts of pre-colonial times, including changes in forest composition, rainfall changes and acidification, industrialized agriculture’s increased chemical inputs, rising global temperatures, and increased levels of carbon dioxide in the atmosphere. We conclude that chestnut tree species for both forestry and agriculture should be considered based on current fitness, adaptability, and economic and ecological value considering continued dynamics in host and pathogens distributions and anthropogenically driven climatic and edaphic conditions.

Effects of Hemp-Derived Cannabidiol Supplementation on Blood Variables, Carcass Characteristics, and Meat Quality of Goats.

Stress experienced by animals during pre-mortem management handling significantly affects both their welfare and the quality of the meat produced. Using hemp-derived CBD may offer several benefits in alleviating this issue. In this study, we investigated the effects of hemp-derived CBD supplementation on blood variables, growth performance, carcass characteristics, and meat quality in goats. Sixteen crossbred Boer goats were divided into four groups receiving a basal diet supplemented with 0 (control), 0.1, 0.2, or 0.3 mL CBD/30 kg body weight over 90 days. Although growth, carcass characteristics, and pH remained unaffected, CBD supplementation influenced several blood variables. Specifically, dietary CBD at 0.1-0.3 mL increased white blood cell (WBC) counts, while 0.3 mL CBD increased serum total protein, globulin, sodium, and carbon dioxide levels, potentially affecting protein metabolism and electrolyte balance. Over time, significant changes were noted in hematological profiles, kidney markers, protein profiles, and some electrolytes, indicating physiological adaptations. Regarding meat quality, supplementation with 0.2-0.3 mL of CBD linearly improved color redness and stability; moreover, CBD supplementation improved tenderness and textural properties, resulting in a softer meat texture. However, analysis using an E-nose indicated increased ammonia and organic solvent vapors in meat from the higher CBD groups. This study concluded that CBD supplementation up to 0.3 mL of CBD/30 kg body weight beneficially modulated blood biomarkers, meat color, and tenderness without adverse impacts on growth or carcass characteristics in goats.

A microfluidic chip for immobilization and imaging of Ciona intestinalis larvae.

Sea squirts (Tunicata) are chordates and develop a swimming larva with a small and defined number of individually identifiable cells. This offers the prospect of connecting specific stimuli to behavioral output and characterizing the neural activity that links these together. Here, we describe the development of a microfluidic chip that allows live larvae of the sea squirt Ciona intestinalis to be immobilized and recorded. By generating transgenic larvae expressing GCaAMP6m in defined cells, we show that calcium ion levels can be recorded from immobilized larvae, while microfluidic control allows larvae to be exposed to specific waterborne stimuli. We trial this on sea water carrying increased levels of carbon dioxide, providing evidence that larvae can sense this gas.

Innovative house structures for malaria vector control in Nampula district, Mozambique: assessing mosquito entry prevention, indoor comfort, and community acceptance.

Insecticide-treated mosquito bed nets and indoor residual spraying are widely used for malaria vector control. However, their effectiveness can be affected by household members' habits, requiring alternative approaches toward malaria vector control. To assess the effectiveness of modified houses in preventing mosquito entry; to assess the impact of house modifications on indoor air conditions and evaluate the acceptability of modified houses in the community where the study was conducted. Five traditional and five modified houses were constructed in Nampula district, Mozambique and underwent a 90-day overnight indoor mosquito collection using Centers for Disease Control and nitride ultraviolet light traps during the rainy season. Mosquitoes were identified morphologically. Indoor temperature, relative humidity, carbon dioxide levels and wind speed were also collected. The Student's t-test was used to compare the means of the number of mosquitos and environmental factors between both house types. A binomial form of the Generalized Linear Model identified the factors associated with the community volunteer's preference for house type. Modified houses reduced the number of Anopheles by an average of 14.97 mosquitos (95% CI, 11.38-18.56, p < 0.000) and non-Anopheles by 16.66 mosquitoes (95% CI, 8.23-25.09, p < 0.000). Although fewer mosquitoes were trapped in modified houses compared to traditional ones, the modifications were more effective against Anopheles (94% reduction) than for non-Anopheles (71% reduction). The average temperature increased at 0.25°C in modified houses but was not statistically significant (95% CI, -0.62 to 0.12, p = 0.181). Community volunteers preferred modified houses due to reduced mosquito buzzing. The efficacy of modified houses including its acceptability by community, highlight its potential to lower malaria risk. Effective integration of modified houses into the vector control strategy will require raising awareness among communities about malaria risks associated with house structure and training them to modify their houses.

Global warming&amp;rsquo;s grip on agriculture: Strategies for sustainable production amidst climate change using regression based prediction

The intersection of climate change and food production is emerging as a critical area of research, focusing on both the potential benefits and the significant challenges posed by changing climate conditions. Elevated levels of carbon dioxide alongside rising global temperatures could theoretically boost crop yields, benefiting both human and animal consumption. This study examines the impact of various climate variables&amp;mdash;temperature, humidity, precipitation, and soil moisture&amp;mdash;on the primary production of essential foods such as rice, wheat, livestock, milk, eggs, vegetables, and fruits. Utilizing data from different countries spanning from 2000 to 2020, drawn from world development indicators, this research employs econometric analysis coupled with deep learning-based cluster analysis. Additionally, it projects future production trends up to 2100 using the moving average time series forecasting method. The findings reveal a direct correlation between climate variables and the production levels of vegetables and other food items, highlighting the immediate effects of climatic changes on agriculture. The study also points out the uneven distribution of these climate impacts, with developing countries facing more severe challenges due to their limited resources and adaptive capacities. This uneven impact contributes to increased uncertainty in food supply and affects market stability. Furthermore, concerns about food safety are intensifying under the influence of climate change, although some regions have implemented effective food conservation and control measures to mitigate these risks. This research underscores a complex landscape where the risks and benefits of climate change on food production are not uniformly distributed, but rather are influenced by a myriad of factors including geographic location, economic conditions, and the level of technological advancement in food safety practices. The nuanced understanding of these dynamics is crucial for developing targeted strategies to enhance food security in the face of a changing climate.

Preparatory study for carbon sequestration modelling of agroforestry systems in Hungary: The assessment of the yield class distribution of windbreaks

The escalating carbon dioxide emissions leading to global climate change are acknowledged as a paramount environmental challenge in the twenty-first century. The significance of land use systems in stabilising carbon dioxide levels and enhancing carbon sink potential has gained noteworthy attention from both the scientific and political communities. The Intergovernmental Panel on Climate Change emphasises that agroforestry systems present vital prospects for synergising climate change adaptation and mitigation efforts, offering substantial technical mitigation potential. Windbreaks are well-known agroforestry systems in Hungary and form an important part of agricultural landscapes. The improved agroforestry subsidy system in our country makes it relevant to model the carbon sequestration potential of windbreaks. In the framework of the ForestLab project we plan to develop a carbon sequestration model specific for Hungarian agroforestry systems. In this study, as a preparatory step of the model development, we assessed the yield class distribution of Hungarian windbreaks by tree species group and identified variables that had significant effect on yield class based on the data of the National Forestry Database. Our results show that among the examined effects the most important predictor of the yield class of windbreaks was the tree species group, followed by the thickness of the productive soil layer and the hydrology of the site.

Polyoxometalates for carbon dioxide activation: Current progress and perspective

AbstractThe elevated level of carbon dioxide (CO2) in the troposphere is playing a crucial role in changing the earth's climatic system. Excess CO2 concentration is trapping a substantial proportion of heat imparting adverse range of environmental effects like extreme weather events, agricultural impacts and disruption of the ecosystem. Strategies such as CO2 capturing and storage are being pursued using polyoxometalates (POMs) to mitigate the elevated level of CO2 and their efficient conversion into useful chemicals. This review outlines the importance of CO2 reduction by electrocatalytic and photocatalytic reduction of CO2. POMs have several advantages for CO2 activation because of their promising catalytic activity, high selectivity and versatility for incorporating different metal ions and ligands. The efficient redox active metal center facilitates the conversion of CO2 by providing sufficient activation energy. Their robust structure also enables them resist harsh conditions, including high temperature and acidic or basic conditions. Owing to these properties, POMs can be a catalyst, co‐catalyst, photosensitizer or multielectron donor for CO2 reduction. Finally, we stated the challenges and future insight for CO2 activation using POMs.

Effectiveness of corticosteroids and epinephrine use in neonates for the first extubation attempt: A retrospective study

BackgroundThis study aimed to analyze the use of corticosteroids and epinephrine in neonates for the first extubation attempt and compared clinical characteristics of infants with successful and failed extubation events. MethodsThis was a retrospective cohort study conducted at a single level III neonatal intensive care unit in Taiwan. The study included 215 infants born between 2020 and 2021 who had been intubated for more than 48 h before their first extubation attempt. We compared perinatal and peri-extubation characteristics and outcomes between the two groups. Successful extubation was defined as freedom from invasive ventilatory support 72 h after extubation. The relationship between corticosteroids, local epinephrine, and successful extubation was determined using multivariate logistic regression analysis. ResultsIn the univariate analysis, the failed extubation group received a significantly higher proportion of intravenous dexamethasone (p = 0.006) than the successful extubation group. Furthermore, the failed extubation group had a longer duration of nebulized epinephrine (p = 0.034) and more episodes of local application of epinephrine to the superior larynx (p = 0.003) than the successful extubation group. Multivariate analysis revealed that the absence of lung atelectasis, tachycardia 72 h after extubation, and lower post-extubation PCO2 were the key factors associated with successful extubation. ConclusionsThere were trends toward systemic dexamethasone, local application of epinephrine to the superior larynx, and longer duration of nebulized epinephrine in the reintubation group. However, corticosteroid or local epinephrine use was not significantly associated with successful extubation. Lung atelectasis, elevated levels of carbon dioxide, and tachycardia were identified as risk factors for extubation failure.

Addition of Mask to High-flow Nasal Oxygen: A Strategy to Improve Oxygenation in Hypoxemic Respiratory Failure Secondary to COVID-19.

High-flow nasal cannula (HFNO) reduces the need for invasive mechanical ventilation in COVID-19 patients with hypoxemic-respiratory failure. During HFNO entrainment of room air dilutes the delivered fractional inspiratory oxygen (FiO2), thereby preventing improvement in oxygenation. The placement of a mask over HFNO to improve oxygenation has provided conflicting results. We aimed to determine and compare the effect of placing various mask types over HFNO on oxygen saturation (SPO2). In this prospective physiological study 40 patients with COVID-19-associated hypoxemic respiratory failure on HFNO with O2 concentration <92% were included. The effect of placing different masks over HFNO on oxygenation, respiratory rate, heart rate, blood pressure, patient comfort, and partial pressure of carbon dioxide level (pCO2) was recorded after a prespecified time interval. We observed a significantly higher mean SPO2 and lower mean respiratory rate on using various study masks over HFNO compared to HFNO alone. On comparing various mask types, the use of N95 masks and nonrebreather (NRB) masks with O2 showed a significant increase in O2 concentration and reduction in respiratory rate compared to surgical mask (SM) and NRB without O2. The proportion of patients who achieved SPO2 of >92% was higher with the use of N95 masks (47.5%) or NRB with O2 (45%) over HFNO compared to SM (35%) and NRB without O2 (35%). No significant change was observed in heart rate, blood pressure, and CO2 level with the use of any mask over HFNO. This study demonstrates improvement in oxygenation and reduction in respiratory rate with the use of various masks over HFNO in patients of COVID-19-related hypoxemic-respiratory-failure. Significantly greater benefit was achieved with the use of N95 or NRB with O2 compared to SM or NRB without O2.

Analysis of the Long-Term Correlates Between Obstructive Sleep Apnea and Chronic Obstructive Pulmonary Disease: A 10-Year Retrospective Study

Aim This study aims to assess the prevalence of overlap syndrome (OS) in Chronic Obstructive Pulmonary Disease (COPD) patients with Obstructive Sleep Apnea(OSA) symptoms undergoing polysomnography. We investigated the impact of hypoventilation and long-term oxygen therapy (LTOT) on the severity of OSA. Material and Methods We retrospectively reviewed COPD patients with OSA symptoms who underwent polysomnography from August 2012 to September 2022. The individuals' body mass index (BMI), apnea-hypopnea index (AHI), oxygen desaturation index (ODI), minimum and mean oxygen saturation values (minSpO2 and meanSpO2), sleep activities, REM period percentages (REM%), whether they used LTOT, and blood hematocrit levels and awake arterial carbon dioxide (PaCO2) levels were recorded. Results A total of 81 individuals with COPD were included in the study. The number of individuals with AHI&gt;5 was 76(93.9%). Participants included 9 with mild OSA, 24 with moderate OSA and 43 with severe OSA. The mean sleep efficiency was found to be %78.3. The mean value of REM% was 7.3. Sixteen of the patients (19.7%) were receiving LTOT. Sleep efficiency was statistically higher in the group using LTOT (p=0.048). AHI and ODI values were statistically higher in the group with high PaCO2 than in the group without (respectively; p=0.048, p=0.008). The mean values of min SpO2 and meanSpO2 were found to be lower in the group with high PaCO2 (p=0.013, p=0.008; respectively) Conclusion In OS participants, sleep efficiency is low, and having high PaCO2 is associated with lower minSpO2 and meanSpO2, higher ODI, and AHI. The use of LTOT increases sleep efficiency.

A Service-Learning Experience in Secondary Education to Promote STEM Learning Through Collaboration Between Research and Education Centers

The needs of the digital revolution and the knowledge-based economy impose a transformation of traditional education to improve technical and scientific knowledge and include alternative abilities. This work presents a service-learning initiative with multiple goals: to improve scientific, technical, engineering, and mathematic (STEM) knowledge at school, to enhance students’ engagement, and to make people aware of the repercussions of poor indoor air quality. The initiative involves four actors: the administration which steers the initiative, students who are the receivers of the knowledge, teachers as facilitators of the activity and research centers as expert references. Within this service-learning initiative, a real-life project has been proposed, focusing on measuring carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) levels in classrooms and correlating them with indoor airborne infection transmission. Reference experts have developed two systems provided to teachers and students for project implementation. The project involves an engineering step where students set up the systems, and a scientific step where students hypothesize, develop experiments, analyse data, and communicate results gaining experience with the scientific method. Through the combined efforts and appropriate allocation of responsibilities, this experience has yielded excellent results in STEM knowledge transmission and has proven effective in fostering student commitment to their learning process.