Air Breathing Research Articles

KI-gestützte Atemgasanalyse (E-Nose) zur Früherkennung von Lungenkarzinomen

Volatile organic compounds (VOCs) are an increasingly meaningful method for the early detection of various types of cancers, including lung cancer, through non-invasive methods. Traditional cancer detection techniques such as biopsies, imaging, and blood tests, though effective, often involve invasive procedures or are costly, time consuming, and painful. Recent advancements in technology have led to the exploration of VOC detection as a promising non-invasive and comfortable alternative. VOCs are organic chemicals that have a high vapor pressure at room temperature, making them readily detectable in breath, urine, and skin. The present study leverages artificial intelligence (AI) and machine learning algorithms to enhance classification accuracy and efficiency in detecting lung cancer through VOC analysis collected from exhaled breath air. Unlike other studies that primarily focus on identifying specific compounds, this study takes an agnostic approach, maximizing detection efficiency over the identification of specific compounds focusing on the overall compositional profiles and their differences across groups of patients. The results reported hereby uphold the potential of AI-driven techniques in revolutionizing early cancer detection methodologies towards their implementation in a clinical setting.

A Breath of Fresh Air: The Role of Airway Anomalies on Outcomes in Congenital Heart Disease.

A Breath of Fresh Air: The Role of Airway Anomalies on Outcomes in Congenital Heart Disease.

Human exposure to respiratory aerosols: Impact of ventilation rates, mixing ventilation configuration, and breathing patterns

This study investigates airborne transmission dynamics between occupants in office rooms equipped with mixing ventilation (MV). The primary aim was to assess how different ventilation configurations, air change rates (ACH), breathing patterns, and supply air temperatures influence cross-exposure and infection risks. The experimental setup involved two thermal manikins simulating an infected and an exposed occupant within a climate chamber. The investigated parameters included four ACH levels (1.2, 2, 4 and 6.6 h⁻1, representing four EN 16798-1 ventilation categories), two MV configurations (near-ceiling and near-floor inlets), two breathing patterns (nose and mouth breathing), and two supply air temperatures (19°C and 21°C). Carbon dioxide (CO₂) was used as a tracer gas to simulate exhaled aerosols, enabling precise measurements of effectiveness (), intake fraction (IF), and infection probability (P). The findings indicate that higher ACH do not uniformly improve but are linked to reduced cross-exposure risk. The near-floor inlet MV configuration significantly outperformed the near-ceiling configuration in reducing IF and P by 15-41% under most investigated scenarios. Additionally, mouth breathing increased IF and P compared to nose breathing, especially at higher ACH (2, 4, and 6.6 h⁻1). The results also showed that lower supply temperatures do not always correlate with higher IF and P, as MV configuration and breathing patterns significantly influence outcomes. This research provides insights into optimizing ventilation strategies for safer indoor environments, emphasizing the importance of airflow dynamics, breathing patterns, and supply temperature in ventilation design.

Identifying viral infections through analysis of head space volatile organic compounds

Volatile organic compounds (VOCs) produced by human respiratory cells reflect metabolic and pathophysiological processes which can be detected with the use of modern technology. Analysis of exhaled breath or indoor air may potentially play an important role in screening of upper respiratory tract infections such as COVID-19 or influenza in the future. In this experimental study, air samples were collected and analyzed from the headspace of anin vitrocell culture infected by selected pathogens (influenza A H1N1 and seasonal coronaviruses OC43 and NL63). VOCs were measured with a real-time proton-transfer-reaction time-of-flight mass spectrometer and a differential mobility spectrometer. Measurements were performed every 12 h for 7 d. Non-infected cells and cell culture media served as references. In H1N1 and OC43 we observed four different VOCs which peaked during the infection. Different, individual VOCs were also observed in both infections. Activity began to clearly increase after 2 d in all analyses. We did not see increased VOC production in cells infected with NL63. VOC analysis seems to be suitable to differentiate the infected cells from those which are not infected as well as different viruses, from another. In the future, this could have practical value in both individual diagnostics and indoor environment screening.

A breath of fresh air: a pilot flipped classroom approach to airway management skills training

ObjectivesWhile flipped classroom instruction has repeatedly shown efficacy in undergraduate medical education, evidence for its utility in procedural domains remains sparse. This holds particular significance for surgical subspecialties such as otolaryngology, which have limited time in undergraduate medical curricula. We designed a novel airway management skills simulation course with a flipped classroom approach and evaluated its efficacy in a pilot study.MethodsA simulation course was designed to provide instruction in seven airway management skills: bag valve mask ventilation, laryngoscopy, intubation, cricothyroidotomy, tracheotomy, and tracheostomy care. Publicly available YouTube videos were selected as pre-learning materials. Participating students completed surveys before the pre-learning assignment and after completion of the simulation center workshop.ResultsSixteen students participated in the workshop, and data was collected from 14 participants. Learners reported significant improvements in knowledge regarding all covered skills except tracheotomy; mean self-rated knowledge improved from 2.9 to 5.8 (p < 0.001) on a scale from 0 to 10. Significant increases in self-reported confidence in performing all seven skills were also observed, with an overall increase from 1.1 to 5.7 (p < 0.001). Students also rated all elements of the workshop highly, including a prevailing belief that the pre-learning materials markedly enhanced their learning.ConclusionOur novel framework for skills-based education using a flipped classroom approach demonstrated remarkable efficacy in improving learner knowledge and self-reported confidence regarding airway management skills. This educational design, including the use of high-quality, publicly available pre-learning videos, has significant implications for undergraduate medical education in surgical subspecialties.

Heterogeneity of Inflammatory Processes and Pathways Driving Chronic Obstructive Pulmonary Disease Pathology

Two symposia occurred during the European Respiratory Society (ERS) Congress 2024, highlighting the heterogeneity in chronic inflammatory pathways that underlie chronic obstructive pulmonary disease (COPD) pathophysiology. In 'A Breath of Fresh Air: A Greater Understanding of COPD With Type 2 Inflammation', Henrik Watz (Chair), German Center for Lung Research, Grosshansdorf, Germany, provided an overview of both the pathophysiology and the burden of disease of COPD. He discussed how exacerbations, which may be increased in those with evidence of Type 2 inflammation, contribute to the cycle of worsening COPD. Mona Bafadhel, King’s College London, UK, provided an examination of the mechanisms and biomarkers of Type 2 inflammation in COPD. Finally, Alberto Papi, University of Ferrara, Italy, summarised the latest research on biological treatments targeting Type 2 inflammation in COPD. The second symposium, 'Targeting interleukin-33 (IL-33) in COPD: Exploring New Frontiers for COPD Management', discussed inflammation in COPD, focusing on the central role of IL-33 as a mediator for both Type 2 and Type 1/Type 3 inflammation. Klaus Rabe (Chair), LungenClinic, Grosshansdorf, Germany, reviewed the structure and function of IL-33 and its initial processes that lead to downstream immune responses. Stephanie Christenson, University of California, San Francisco, USA, explored how genetic and environmental factors contribute to IL-33 activity in COPD pathology. Next, Paola Rogliani, University of Rome ‘Tor Vergata’, Italy, presented an examination of IL-33 inflammatory processes and evidence from COPD animal models illustrating the role of IL-33 in airway inflammation and lung function decline. Klaus Rabe concluded with an examination of IL-33 as a target for new COPD treatment approaches.

Philanthropy of Pesantren Towards Socio-Economic Welfare (Study At Markaz Bayt Al-Musaadah Social Institution, Mambaus Sholihin Gresik Islamic Boarding School)

Cases of misuse of social funds have slowed down welfare programs for the poor and dhuafa'. The establishment of Markaz Bayt Al-Musa'adah under Pesantren Mambaus Sholihin provides a breath of fresh air, with pesantren now required not only to produce a generation that understands religion, but also as a pillar of Islamic sharia economics. This research uses a qualitative method with a case study approach to explore the economic empowerment and management of philanthropic funds by Markaz Bayt Al-Musa'adah of Pesantren Mambaus Sholihin Gresik. This method involves in-depth data collection and various sources of information as well as participation in the field. The results show that Markaz Bayt Al-Musa'adah has implemented community economic empowerment through skills training programs and assistance to underprivileged students. The management of social funds is carried out transparently and accountably based on the principles of Islamic philanthropy, with managers working without taking profits, solely for the sake of Allah and the intention of khidmah to the caregiver.

Comparative Study of Air Pollution with Ayurveda and its Management

Background Environmental pollution is increasing day by day and imposing severe and irreversible damage to the world. Air pollution is one of the biggest threats for the environment and affecting humans, animals, crops, cities, forests, aquatic ecosystems. Environmental Toxicology is the science concerned with study of harmful effects of various chemical, biological and physical agents on living organisms. In Ayurveda Charakacharya has briefly described the environmental health in chapter named Janpadodhvansaniyavimanam. Ayurveda has a dedicated branch called Agadatantra which deals with the toxicological aspects of living entities of environment. Aims and objectives We aim to relate and validate this knowledge pertaining to the air pollution. Material and method the references available regarding the air pollution in classical texts were studied and compared with the available information in the contemporary medical literatures. Signs of air pollution given in the text compared and studied with signs of Air pollution. Discussion Ayurveda terms of Vikrut and Prakrut Vayu described in Granthas are found to be relatable with contemporary findings. Conclusion Air pollution described in Ayurveda are very precise and explanatory. Management of air pollution with this ancient science are the new open windows for healthy air breathing for every living organism.

A Breath of Fresh Air: A Comprehensive Review of a Handheld Metabolic Device

A Breath of Fresh Air: A Comprehensive Review of a Handheld Metabolic Device

Efficacy of sevoflurane flush out and activated charcoal filtration—a bench study

PurposeA bench study to assess the elimination of sevoflurane from an anesthetic workstation using three different processing methods.MethodsSevoflurane concentrations from samples of the inspiratory breathing hose and air samples from within the investigation room were assessed during predetermined flush out intervals using Gas Chromatography-Ion Mobility Spectrometry. The primary objective was to determine the time to reach concentrations below 5 ppmv.ResultsReduction of sevoflurane volume concentrations below a threshold of 5 ppmv was achieved within the first minute after removal of the vaporizer and the complete exchange of the soda and the breathing system and within the 15 min measurement interval after inclusion of two activated charcoal filters without a 90 s of flushing and without changing of the breathing hoses as required by the manufacturer.ConclusionsComplete removal of the vaporizer and an exchange of the soda and the ventilation unit most quickly reduced sevoflurane concentrations, but the total processing interval may exceed 30 min. Inserted activated charcoal filters without a previous 90 s of flushing and without changing the breathing hoses followed by flushing only with raised fresh gas flow allow ventilation below trigger threshold to be reached within due time.

Photoionization ion mobility analyzer for on-site measurement of exhaled acetone by coupling miniature thermoelectric cooling dehydration

The breath concentration of acetone holds significant clinical importance, the development of on-site and accurate analyzer for exhaled acetone is highly demanded. A photoionization ion mobility analyzer based on a low-pressure krypton discharge lamp has been developed for direct and rapid determination of the acetone concentration. The difficulty for sensitive measurement of acetone by vacuum ultraviolet photoionization was the strong absorption of water molecules in the breath air. An online dehydration device with a miniature thermoelectric cooling quartz trap has been developed, which was capable for reducing the relative humidity from over 90 % to below 1 %. The dehydration could enhance the signal intensity of acetone about 85 times. The response time of current thermoelectric cooling dehydration was only 1/20 of the Nafion tube dehydration. A limit of detection 0.02 ppmV and linear response up to 2.0 ppmV were achieved. The interferences from ammonia in exhaled breath was eliminated using a calibration method based on ion number density, achieving recoveries ranging from 90 % to 110 %. In the final, the variation trends of exhaled acetone level in healthy individuals following the ingestion of glucose under fasting conditions were carried out to demonstrate the potential application of the analyzer.

A breath of fresh air: Perspectives on inhaled nutrients and bacteria to improve human health

We propose that the human respiratory system and olfactory pathways sequester airborne nutrients (vitamins, fatty acids and trace minerals) that are beneficial for health, which we term 'aeronutrients'. In addition, airborne bacteria, termed 'aeromicrobes', have the potential for positive health effects by improving species diversity in the microbiotas of the respiratory and gastrointestinal tracts. These concepts have implications for people living in urban areas or those who have limited access to nature, such as astronauts exposed for long periods to highly filtered air which may be depleted of aeronutrients and aeromicrobes. The possibility that fresh air contributes to human nutrition and health may stimulate a re-evaluation of guidelines pertaining to nutrition and access to natural environments, and will open new avenues of scientific enquiry.

The loach haplotype-resolved genome and the identification of Mex3a involved in fish air breathing

Fish air breathing is crucial for the transition of vertebrates from water to land. So far, the genes involved in fish air breathing have not been well identified. Here, we performed gene enrichment analysis of positively selected genes (PSGs) in loach (Misgurnus anguillicaudatus, an air-breathing fish) in comparison to Triplophysa tibetana (a non-air-breathing fish), haplotype-resolved genome assembly of the loach, and gene evolutionary analysis of air-breathing and non-air-breathing fishes and found that the PSG mex3a originated from ancient air-breathing fish species. Deletion of Mex3a impaired loach air-breathing capacity by inhibiting angiogenesis through its interaction with T-box transcription factor 20. Mex3a overexpression significantly promoted angiogenesis. Structural analysis and point mutation revealed the critical role of the 201st amino acid in loach Mex3a for angiogenesis. Our findings innovatively indicate that the ancient mex3a is a fish air-breathing gene, which holds significance for understanding fish air breathing and provides a valuable resource for cultivating hypoxia-tolerant fish varieties.

Mathematical modeling of sound propagation through the respiratory tract in a modified gas environment

The aim of the work was to develop a mathematical model of sound propagation through the human respiratory tract when breathing certain respiratory gas mixtures. We based the model on an assembler model of branching of the respiratory tract. For calculations, we presented the human tracheobronchial tree in the form of an equivalent T-shaped cut section diagram, which includes parameters of the walls of the respiratory tract. We carried the simulation out in two main stages. At the first stage, we calculated the impedance of the flow from the small airways to the larger airways. At the second stage, we calculated the sound pressure caused by breathing. As a result, we obtained the curves of the impedance dependence on the frequency spectrum, as well as the sound power from the respiratory flow. We noted that when breathing air, the impedance value remains constant with increasing frequency. Moreover, we also noted that when exposed to a heavier gas than air, the impedance value constantly increases, and when exposed to lighter gases, after reaching a maximum, the impedance value decreases. We found that the highest sound pressure is typical for the oxygen-krypton mixture, and the lowest for the oxygen–helium mixture. We also found that in the case of modeling the laminar flow regime (with a critical Reynolds number equal to 1800), sound affects how many generations of bronchi more than in the case of modeling the transient flow regime (with a critical Reynolds number equal to 2700). Thus, we drew conclusions about the influence of the physical properties of gaseous media on the amount of sound pressure and the propagation of sound through the human respiratory tract.

Numerical investigation of the distributed combustion in the thermal choked solid fuel combined cycle engine

In this study, a solid fuel combined cycle engine concept based on the distributed combustion and the self-adaptive thermal choking is proposed, which can operate effectively within a wide Mach number range. By regulating the heat release through the distributed fuel injection, the thermal choking can be formed in the fixed geometry combustor. The air intake controls the flow capture and circulation area through the movement of its head cone, ensuring stable air breathing over a wide range. Numerical simulations conducted under Ma = 3.0 and 6.0 conditions using the validated Eulerian-Lagrangian method coupled with gaseous and particle reaction models demonstrate the concept's capability to operate within the Mach number range of 3.0–6.0, delivering improved mixing, combustion, and specific impulse performance.

Influence of liquid electrolyte and liquid flowing electrolyte on the performance of an air breathing direct methanol fuel cell (ABDMFC)

Influence of liquid electrolyte and liquid flowing electrolyte on the performance of an air breathing direct methanol fuel cell (ABDMFC)

Numerical simulations of a low-pressure electrodeless ion source intended for air-breathing electric propulsion

Abstract Air breathing electric propulsion (ABEP) systems offer a promising solution to extend the lifetime of very low earth orbit (VLEO) missions by using residual atmospheric particles as propellants. Such systems would operate in very low-pressure environments where plasma ignition and confinement prove challenging. In this contribution, we present results of a global plasma model (GPM) of a plasma ignited in a very low-pressure air mixture. The results are validated against experimental measurements acquired using a laboratory electrodeless ion source utilizing a resonator for plasma ignition. The device is specifically designed to operate within low-pressure environments as it holds potential applications in ABEP systems for VLEO missions. Parametric studies are carried out via GPM to investigate the resonant behavior and its implications. The potential of the model serving as a predictive tool is assessed through experimental validation against measured data, mainly investigating the extracted ion current dependency on operational pressure and external magnetic field strength. The verified model is further utilized to extrapolate additional information about the resonant plasma such as ion composition or a degree of ionization.

A novel radial air-breathing proton exchange membrane fuel cell for miniaturized applications with effective stacking potentials

Increasing volumetric power density in fuel cells can be accomplished by increasing its compactness or output power. This is very crucial for miniaturized applications due to constraints in available spaces. In this study, a three-dimensional, multiphase, and non-isothermal computational fluid dynamics (CFD) tool is used to develop a novel radial air-breathing (AB) PEM fuel cell for miniaturized applications, which has unique stack-ability feature. The noted cell can accommodate multiply higher active area in cathode electrode with respect to planar and tubular AB designs. Increasing the cathode side active area, the electrode with the highest sources of losses for the kinetics of reactions in proton exchange membrane (PEM) fuel cells, has shown to play a significant role in performance enhancement of radial AB cells. For instance, at 0.4 Acm−2 the radial AB PEM fuel cell, can deliver 27.9 % and 10 % more power than the earlier planar and tubular AB ones, respectively. The stack-ability of AB fuel cells usually face severe challenges due to non-uniform air supply to the cells, resulting in imbalance of the cells output power. As opposed to tubular and planar AB cells, one unique feature for the present radial AB stack design is its attack-ability that ensures adequate and uniform supply of air/oxygen to all cells.

Insights into the fluid dynamics of bioaerosol formation in a model respiratory tract

Bioaerosols produced within the respiratory system play an important role in respiratory disease transmission. These include infectious diseases such as common cold, influenza, tuberculosis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among several others. It is, therefore, of immense interest to understand how bioaerosols are produced within the respiratory system. This has not been extensively investigated. The present study computationally investigates how bioaerosols are produced in a model respiratory tract due to hydrodynamic interactions between breathed air and a thin mucus layer, which lines the inner surface of the tract. It is observed that Kelvin–Helmholtz instability is established in the thin mucus layer due to associated fluid dynamics. This induces interfacial surface waves which fragment forming bioaerosols under certain conditions. A regime map is created—based on pertinent dimensionless parameters—to enable identification of such conditions. Analysis indicates that bioaerosols may be produced even under normal breathing conditions, contrary to expectations, depending on mucus rheology and thickness of the mucus layer. This is possible during medical conditions as well as during some treatment protocols. However, such bioaerosols are observed to be larger (∼O(100)μm) and are produced in less numbers (∼100), as compared to those produced under coughing conditions. Treatment protocols and therapeutic strategies may be suitably devised based on these findings.

CO2 Breathing Prior to Simulated Diving Increases Decompression Sickness Risk in a Mouse Model: The Microbiota Trail Is Not Forgotten.

Decompression sickness (DCS) with neurological disorders is the leading cause of major diving accidents treated in hyperbaric chambers. Exposure to high levels of CO2 during diving is a safety concern for occupational groups at risk of DCS. However, the effects of prior exposure to CO2 have never been evaluated. The purpose of this study was to evaluate the effect of CO2 breathing prior to a provocative dive on the occurrence of DCS in mice. Fifty mice were exposed to a maximum CO2 concentration of 70 hPa, i.e., 7% at atmospheric pressure, for one hour at atmospheric pressure. Another 50 mice breathing air under similar conditions served as controls. In the AIR group (control), 22 out of 50 mice showed post-dive symptoms compared to 44 out of 50 in the CO2 group (p < 0.001). We found that CO2 breathing is associated with a decrease in body temperature in mice and that CO2 exposure dramatically increases the incidence of DCS (p < 0.001). More unexpectedly, it appears that the lower temperature of the animals even before exposure to the accident-prone protocol leads to an unfavorable prognosis (p = 0.046). This study also suggests that the composition of the microbiota may influence thermogenesis and thus accidentology. Depending on prior exposure, some of the bacterial genera identified in this work could be perceived as beneficial or pathogenic.