Search Results (127)

The nicotine metabolite ratio (NMR) has been informative in selecting treatment choices for nicotine dependence and increasing treatment efficacy in Western settings; however, the clinical utility of the NMR among smokers in low-resource settings remains unclear. Prospective analysis was conducted using data from a randomized controlled trial of smoking cessation among adults living with HIV, to examine the association between the NMR and response to smoking cessation treatment. NMR was assessed using bio-banked urine samples collected at baseline. Self-reported smoking at 6 months was verified using a urine cotinine test and exhaled breath carbon monoxide (CO). We found no associations between the NMR and smoking abstinence (adjusted risk ratio (aRR) = 0.82; 95% CI: 0.45, 1.49; p = 0.53). No evidence of effect modification by treatment conditions was observed on the multiplicative scale (aRR = 1.17; 95% CI: 0.32, 4.30; p = 0.81) or additive scale (adjusted relative excess risk due to interaction (aRERI) = 0.10; 95% CI: −1.16, 1.36; p = 0.44). Our results suggest that the NMR may not be a viable approach for selecting smoking cessation treatment in this setting, given the minimal variability in our sample and racial/ethnic makeup of this population. Full article

Background/Objectives: Vitamin D is known to decrease the risk of contracting respiratory infections and developing exacerbations for children with asthma. This research evaluates the alterations in serum vitamin D concentrations and examines lung function in children with asthma, as indicated by clinical symptoms and paraclinical results, after experiencing SARS-CoV-2 infection or other acute respiratory infections. Material and Method: This retrospective study included 145 children with asthma. For each patient, the following variables were acquired: demographic data, serum vitamin D levels, GINA asthma control levels, the fraction of exhaled nitric oxide (FeNO), pulmonary function tests parameters, data related to allergies, and the presence of exacerbations. Children were divided into two groups, according to the presence or absence of SARS-CoV-2 infection or other acute respiratory infections. Variables were statistically processed in SPSS. Results: In total, 93 children with asthma with SARS-CoV-2 infection or other acute respiratory infections and 52 children with asthma without SARS-CoV-2 infection or other acute respiratory infections were included in the study. Median serum vitamin D values were statistically significantly lower in children with a variable airflow limitation, compared to children with normal values (p = 0.004), as well as for children with partially controlled asthma, relative to children with well controlled asthma (p < 0.0005). Similarly, children with acute respiratory infections/COVID-19 disease had lower median values of serum vitamin D, compared to children without acute respiratory infections/COVID-19 disease (p < 0.0005). A decrease in serum vitamin D value was statistically significantly associated with an increase in FeNO value for children with asthma with COVID-19 disease (p = 0.027), as well as for the entire study group (p < 0.0005). Conclusions: Children with asthma who had acute respiratory infections, including COVID-19 disease, showed considerably reduced serum vitamin D levels and were linked to more significant airflow limitation, reduced asthma control and elevated airway inflammation, suggesting its potential role in influencing asthma severity and infection response. Full article

During the early stages of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, concerns arose regarding the susceptibility of asthmatic children, one of the most common chronic conditions in childhood and a major cause of hospitalization in pediatric settings. Unexpectedly, evidences showed milder clinical courses and fewer asthma exacerbations in these patients, even if cases of critical and fatal infection, often related to specific clinical features of the patient, are not negligible. In this regard, obesity is considered not only an important comorbidity in patients with difficult-to-treat asthma but also a risk factor for more severe forms of COVID-19. These observations are of even greater concern in the context of an increase in childhood obesity that began even before the SARS-CoV-2 pandemic and has continued also as a consequence of it. Given asthma’s heterogeneity, especially in children, an endotype-based approach is crucial. This is possible through a detailed analysis of the complex metabolic pathways that correlate asthma, COVID-19 infection and obesity thanks to new high-through-put technologies, especially metabolomics, which with minimally invasive sampling, including on exhaled breath condensate (EBC), can provide precise and unbiased evidence in support of existing endotypes, making it possible to identify not only the most vulnerable individuals and thus risk stratification through specific biomarkers, but also new molecular and therapeutic targets. This review explores asthma endotypes by highlighting their shared immunometabolic pathways with COVID-19. Findings suggest that metabolomics could enable more accurate risk stratification and guide personalized interventions during viral pandemics, especially in the presence of relevant comorbidities such as obesity. Full article

Background/Objectives: The increasing prevalence of diabetes underscores the urgent need for non-invasive, rapid, and cost-effective diagnostic alternatives. This study presents a breath-based multiclass diabetes classification system leveraging only three gas sensors (CO, alcohol, and acetone) to analyze exhaled breath composition. Methods: Breath samples were collected from 58 participants (22 healthy, 7 prediabetic, and 29 diabetic), with blood glucose levels serving as the reference metric. To enhance classification performance, we introduced a novel biomarker, the alcohol-to-acetone ratio, through a feature engineering approach. Class imbalance was addressed using the Synthetic Minority Over-Sampling Technique (SMOTE), ensuring a balanced dataset for model training. A nested cross-validation framework with 3 outer and 3 inner folds was implemented. Multiple machine learning classifiers were evaluated, with Random Forest and Gradient Boosting emerging as the top-performing models. Results: An ensemble combining both yielded the highest overall performance, achieving an average accuracy of 98.86%, precision of 99.07%, recall of 98.81% and F1 score of 98.87%. These findings highlight the potential of gas sensor-based breath analysis as a highly accurate, scalable, and non-invasive method for diabetes screening. Conclusions: The proposed system offers a promising alternative to blood-based diagnostic approaches, paving the way for real-world applications in point-of-care diagnostics and continuous health monitoring. Full article

The detection of hydrogen gas is crucial for both industrial fields, as a green energy carrier, and biomedical applications, where it is a biomarker for diagnosis. TiO₂ nanomaterials are stable and sensitive to hydrogen gas, but their gas response can be negatively affected by external factors such as humidity. Therefore, a strategy is required to mitigate these influences. The utilization of organic–inorganic hybrid gas sensors, specifically metal oxide gas sensors coated with ultra-thin copolymer films, is a relatively novel approach in this field. In this study, we examined the performance and long-term stability of novel TiO₂-based sensors that were coated with poly(trivinyltrimethylcyclotrisiloxane-co-tetrafluoroethylene) (P(V3D3-co-TFE)) co-polymers. The P(V3D3-co-TFE)/TiO₂ hybrid sensors exhibit high reliability even for more than 427 days. They exhibit excellent hydrogen selectivity, particularly in environments with high humidity. An optimum operating temperature of 300 °C to 350 °C was determined. The highest recorded response to H₂ was approximately 153% during the initial set of measurements at a relative humidity of 10%. The developed organic–inorganic hybrid structures open wide opportunities for gas sensor tuning and customization, paving the way for innovative applications in industry and biomedical fields, such as exhaled breath analysis, etc. Full article

Siderite and baryte are common non-sulphide phases in sedimentary exhalative (SEDEX) deposits, but their formation remains poorly understood. Siderite is important as an exploration vector in some deposits, whereas baryte is important as a S source in some deposits. The past-producing Walton deposit (Nova Scotia, Canada) consists of two ore types: (1) a sulphide body primarily hosted by sideritised Viséan Macumber Formation limestone (0.41 Mt; head grade of 350 g/t Ag, 4.28% Pb, 1.29% Zn, and 0.52% Cu), and (2) an overlying massive baryte body of predominantly microcrystalline baryte (4.5 Mt of >90% baryte). This study used optical microscopy, SEM-EDS, cathodoluminescence (CL), LA-ICP-MS, and SIMS sulphur isotope analysis of siderite and baryte to elucidate their origin and role in deposit formation. Siderite replaces limestone and contains ≤9 wt. % Mn, is LREE-depleted (PAAS-normalised REEY diagrams), and has low (<20) Y/Ho ratios. Sideritisation occurred due to dissimilatory iron reduction (DIR) that led to the breakdown of Fe-Mn-oxyhydroxides and organic matter, as indicated by light δ¹³C_VPBD values and negative Y anomalies. The baryte body is dominated by a microcrystalline variety that locally develops a radial texture and coarsens to a tabular variety; it also occurs intergrown with, and as veins in, massive sulphides. Based on fluid inclusion data from previous studies, the coarser baryte types grew from a hot (>200 °C) saline (25 wt. % NaCl) fluid containing CO₂-CH₄ and liquid petroleum. Marine sulphate δ³⁴S_VCDT values typical of the Viséan (~15‰) characterise the baryte body and some tabular baryte types, whereas heavier (~20‰) and lighter (~10‰) values typify the remaining tabular types. The variations in tabular baryte relate to distinct zones identified by CL imaging and are attributed to the sulphate-driven anaerobic oxidation of methane (SDAOM) and oxidation of excess H₂S after sulphide precipitation. These results highlight the importance of hydrocarbons (methane and organic matter) in the formation of both the siderite and the baryte at Walton and that DIR and the SDAOM can be important contributing processes in the formation of SEDEX deposits. Full article

Lentinan (LNT) was found to reduce the aerosol transmission rate between golden hamsters from 100% (9/9) to 44.4% (4/9). The viral loads in the respiratory system, including the nasal turbinate, trachea, and lung, were significantly reduced in the infected golden hamsters that received LNT treatment. Furthermore, the amount of exhaled virus aerosols in hamsters treated with LNT was significantly lower than that in untreated hamsters throughout the entire disease progression. In detail, the amounts of virus-laden particles with aerodynamic diameters less than 5 µm exhibited a significant decreasing trend following LNT treatment. Moreover, the detection rate of infectious SARS-CoV-2 in each stage of the Anderson-6 sampler exhibited a decreasing trend following LNT treatment post-infection. In summary, our findings indicate that LNT therapy represents a promising therapeutic candidate for the treatment of COVID-19 patients. Meanwhile, during the course of treatment, LNT has the potential to reduce viral infectivity in affected individuals. Full article

This paper proposes a novel model to determine occupancy density for outdoor events to prevent infectious disease transmission caused by the impossibility of proper dilution of human effluents in the atmosphere. It uses standardization processes to calculate natural ventilation air renewal and establishes theoretical occupancy based on activity and exhaled air percentage, aiming for indoor air quality comparable to the IDA2 standards. The study focuses on mass events in Mostoles (Spain), analyzing street activities and bullring events. It found that above a certain height in the open air, infection risk is low, eliminating capacity limitations. The resulting mathematical expressions can be adapted to different pathogens, ensuring the quality of indoor air conditions through capacity control. The process determines the ventilation required based on physical activity, considering both unrestricted and restricted situations. The relationship between required and available ventilation prevents disease transmission. The method’s effectiveness is demonstrated through comparisons between estimates and environmental measurements during Mostoles events. The maximum outdoor occupancy at ground level to achieve air quality comparable to the IDA2 standards is determined to be 2.36 persons/m², while to prevent the transmission of SARS-CoV-2 it is determined to be 1.98 persons/m². In addition, transmission will not occur during mass gatherings in locations over five meters above ground level. In conclusion, this model provides an adaptable tool to prevent the spread of infectious diseases at outdoor events by ensuring adequate air quality through occupancy control. Full article

Identifying a water–nitrogen coupling strategy to achieve high efficiency, emission reduction, and optimal yield in summer maize under multi-objective conditions is crucial for enhancing nitrogen fertilizer utilization and promoting agricultural sustainability. This study conducted a field experiment on water–fertilizer coupling in summer maize, with three irrigation levels (60%θ_f, 70%θ_f, 80%θ_f, with θ_f representing field capacity) and four nitrogen application levels (0, 180, 270, 360 kg/ha). It analyzed variations in yield, partial factor productivity of nitrogen fertilizer (PFP_N), and the soil CO₂ emission flux across different water–nitrogen combinations, establishing a multi-vector optimization model. NSGA-III (non-dominated Sorting Genetic Algorithm III) was utilized to determine the most effective combination of water and nitrogen. The results indicated that maize yield initially increases and then declines as irrigation and nitrogen levels rise. PFP_N showed a decreasing trend, and its decline gradually decreased with increasing irrigation levels, suggesting that water can alleviate nitrogen stress to some extent. Soil carbon dioxide exhalation intensity increased with both irrigation and nitrogen levels. The NSGA-III optimization revealed that the optimal water–nitrogen ratio is 1086.28 m³/ha for irrigation and 265.79 kg/ha for nitrogen. Compared with the best water–nitrogen combination (W2N3) from the experiment, this optimized scheme showed no significant difference in irrigation volume, yield, or soil CO₂ emission flux while increasing PFP_N by 13.46% and saving 1.56% of nitrogen fertilizer. In summary, the optimized water–fertilizer coupling scheme provides a scientific basis for high-efficiency, high-yield, and low-emission maize production in Henan Province, supporting sustainable agricultural development. Full article

Background and Objectives: Tobacco use and exposure to tobacco products remain a major public health challenge, even among athletes. This study aimed to evaluate tobacco use and second-hand smoke exposure in athletes through urinary cotinine levels and exhaled air carbon monoxide (CO) measurements. Materials and Methods: This cross-sectional study included licensed athletes who visited the sports medicine outpatient clinic of a tertiary hospital. Participants completed an electronic questionnaire on smoking habits and second-hand smoke exposure. Urine samples were analysed for cotinine levels, while CO levels were measured in exhaled breath. Results: A total of 421 athletes participated (57.8% male, median age: 18 years). Tobacco use was reported by 29.9% (n = 126) of participants. Median urinary cotinine levels were 22.9 ng/mL among daily tobacco users and 17.4 ng/mL among athletes exposed daily to second-hand smoke, with a statistically significant difference between exposure levels (p < 0.05). The optimal cut-off value for detecting second-hand smoke exposure was identified as 12.5 ng/mL. Median exhaled air CO levels were 5 ppm in daily tobacco users. Conclusions: This study demonstrates that tobacco use prevalence among athletes mirrors Türkiye’s national rates. Despite legal measures to curb tobacco use, direct use and second-hand smoke exposure remain pressing issues among athletes. Full article

Asthmatic children who tested positive for COVID-19 experienced changes in lung function and persistent symptoms following SARS-CoV-2 infection, even for several months after diagnosis, and with the same features as in an acute phase. This study aimed to analyze a pediatric age group (between 0 and 17 years old) diagnosed with asthma, and SARS-CoV-2 infection attending regular monitoring visits in a Pediatric Department of a Regional Tertiary Hospital (Filantropia Clinical Municipal Hospital Craiova, Romania) during the COVID-19 pandemic and post-pandemic time interval (i.e., March 2020–July 2024), and identify how the infection influenced their long-term symptoms and treatment. Materials and Methods. The following variables were recorded: demographic data (gender, age group, residence), data related to allergies (allergic rhinitis, atopic dermatitis, and food allergies), the presence of exacerbations, the fraction of exhaled nitric oxide, the ventilatory function, the asthma phenotype (allergic or non-allergic), as well as the GINA assessment of asthma control at clinical visits were analyzed. SARS-CoV-2 infections were evaluated in terms of year of infection, symptoms, cough presence and persistence, and modifications of the asthma treatment during and after COVID-19 disease. The data were statistically analyzed with SPSS, using the Mann–Whitney U, Kruskal–Wallis H, and Chi-Square tests. Results. A lower incidence of COVID-19 cases was recorded in the first pandemic of asthmatic patients (2020 and 2021), but an increase in the rate of cases was observed at the beginning of the second pandemic, in 2022. The nitric oxide values in asthmatic children who were infected with SARS-CoV-2 were statistically significantly increased (p < 0.0005), especially for children with persistent cough for more than 4 weeks. A significant increase in the number of exacerbations was also observed in patients who tested positive for SARS-CoV-2 infection (p < 0.0005). Ventilatory function values were statistically significantly different in asthmatic children with and without SARS-CoV-2 infection (p < 0.05). Conclusions. The persistence of cough after the acute phase of SARS-CoV-2 infection as well as the changes in ventilatory tests emphasize the need of periodic medical check-ups, as well as the implementation of a therapeutic regimen appropriate for each pediatric patient. Full article

Given the potential risks of unknown and emerging infectious respiratory diseases, prioritizing an appropriate ventilation strategy is crucial for controlling aerosol droplet dispersion and mitigating cross-infection in hospital wards during post-epidemic periods. This study optimizes the layout of supply diffusers and exhaust outlets in a typical two-bed ward, employing a downward-supply and bottom-exhaust airflow pattern. Beyond ventilation, implementing strict infection control protocols is crucial, including regular disinfection of high-touch surfaces. CO₂ serves as a surrogate for exhaled gaseous pollutants, and a species transport model is utilized to investigate the airflow field under various configurations of vents. Comparisons of CO₂ concentrations at the respiratory planes of patients, accompanying staff (AS), and healthcare workers (HCWs) across nine cases are reported. A discrete phase model (DPM) is employed to simulate the spatial-temporal dispersion characteristics of four different particle sizes (3 μm, 12 μm, 20 μm, and 45 μm) exhaled by the infected patient (Patient 1) over 300 s. Ventilation effectiveness is evaluated using indicators like contaminant removal efficiency (CRE), suspension rate (SR), deposition rate (DER), and removal rate (RR) of aerosol droplets. The results indicate that Case 9 exhibits the highest CRE across all respiratory planes, indicating the most effective removal of gaseous pollutants. Case 2 shows the highest RR at 50.3%, followed by Case 1 with 40.4%. However, in Case 2, a significant portion of aerosol droplets diffuse towards Patient 2, potentially increasing the cross-infection risk. Balancing patient safety with pollutant removal efficacy, Case 1 performs best in the removal of aerosol droplets. The findings offer novel insights for the practical implementation of ventilation strategies in hospital wards, ensuring personnel health and safety during the post-epidemic period. Full article

In this study, we present a novel face mask engineered for the collection of exhaled breath condensate (EBC) and its application and performance in a clinical study of COVID-19 infection status assessment versus the gold standard polymerase chain reaction (PCR) nasopharyngeal swab testing. EBC was collected within a clinical trial of COVID-19-infected and non-infected patients and analyzed by reverse transcription quantitative (RT-q) PCR, with the results being compared with nasopharyngeal sampling of the same patient. The cycle threshold (Ct) values of the nasopharyngeal samples were generally lower than those of EBC, with viral loads in EBC ranging from 1.2 × 10⁴ to 5 × 10⁸ viral particles mL⁻¹ with 5 min of breathing. From the 60 clinical patients’ samples collected, 30 showed a confirmed SARS-CoV-2 infection. Of these 30 individuals, 22 (73%) had Ct values < 40 (representing the threshold for SARS-CoV-2 infectivity) using both amplification of ORF1a/b and the E-gene. The 30 EBC samples from non-infected participants were all identified as negative, indicating a 100% specificity. These first results encourage the use of the face mask as a noninvasive sampling method for patients with lung-related diseases, especially with a view to equipping the face mask with miniaturized sensing devices, representing a true point-of-care solution in the future. Full article

In recent years, the use of electronic cigarettes (e-cigs) has increased. However, their long-term effects on oral health and saliva remain poorly understood. Therefore, this study aimed to evaluate the saliva of e-cig users and investigate possible biomarkers. Participants were divided into two groups: the Electronic Cigarette Group (EG)—25 regular and exclusive e-cig users—and Control Group (CG)—25 non-smokers and non-e-cig users, matched in sex and age to the EG. The clinical analysis included the following parameters: age, sex, heart rate, oximetry, capillary blood glucose, carbon monoxide (CO) concentration in exhaled air, and alcohol use disorder identification test (AUDIT). Qualitative and quantitative analyses of saliva included sialometry, viscosity, pH, and cotinine concentrations. Furthermore, the EG and CG salivary metabolomes were compared using gas chromatography coupled with mass spectrometry (GC-MS). Data were analyzed using the Mann–Whitney test. The MetaboAnalyst 6.0 software was used for statistical analysis and biomarker evaluation. The EG showed high means for exhaled CO concentration and AUDIT but lower means for oximetry and salivary viscosity. Furthermore, 10 metabolites (isoleucine, 2-hydroxyglutaric acid, 3-phenyl-lactic acid, linoleic acid, 3-hydroxybutyric acid, 1,6-anhydroglucose, glucuronic acid, valine, stearic acid, and elaidic acid) were abundant in EG but absent in CG. It was concluded that e-cig users had high rates of alcohol consumption and experienced significant impacts on their general health, including increased cotinine and CO concentration in exhaled air, decreased oximetry, and low salivary viscosity. Furthermore, they showed a notable increase in salivary metabolites, especially those related to inflammation, xenobiotic metabolism, and biomass-burning pathways. Full article

There are many different factors affecting indoor air quality: environmental ones such as temperature, humidity, human activities within the building, smoking, cooking, and cleaning, but also external pollutants such as particulate matter, biological contaminants, and viruses or allergens. This study investigated the indoor air quality (IAQ) of a primary-school classroom in Cracow, Poland, based only on CO₂ concentration levels exhaled by occupants. In the 1960s, over a thousand schools were built in Poland using similar technology. Most of them are still in use, and in many cases, modernization works are being carried out to improve their building envelope and the comfort of their use. The analyzed school is one of several hundred similar ones in southern Poland. Therefore, analyzing the possibilities of improving IAQ is an important topic, and the results can be used in the modernization process for many other buildings. Measurements indicated that the CO₂ levels significantly exceeded acceptable standards, signaling poor air quality during usage time. This problem was connected mainly with the low efficiency of the natural ventilation system being used in the classroom. It is worth emphasizing that this type of ventilation system is the most commonly used ventilation solution in Polish schools. To address this problem, the classroom environment was simulated using CONTAM software, and the model was validated by comparing the simulated measurement data against the collected measurement data. Next, simulations for the entire heating season in Cracow were conducted, revealing that the IAQ remained consistently poor throughout this period. These findings highlight the persistent problem of inadequate ventilation in the classroom, which can have adverse effects on the health and performance of students and teachers. This article shows the usefulness of CONTAM for modeling not only gravity ventilation but also the window-opening process. The validated CONTAM model will be subsequently utilized to simulate annual IAQ conditions under various ventilation strategies in order to identify the most effective methods for maintaining acceptable IAQ while minimizing energy consumption. In our future analysis, the validated model will be used to test the following systems: demand-controlled ventilation (DCV), exhaust ventilation, and DCV/balanced ventilation with heat recovery. Full article