Here we present the UCI Fluxtron, a cost-effective multi-enclosure dynamic gas exchange system that provides an adequate level of control of the experimental conditions for investigating biosphere-atmosphere exchange of trace gases. We focus on the hardware and software used to monitor, control, and record the air flows, temperatures, and valve switching, and on the software that processes the collected data to calculate the exchange flux of trace gases. We provide the detailed list of commercial materials used and also the software code developed for the Fluxtron, so that similar dynamic enclosure systems can be quickly adopted by interested researchers. Furthermore, the two software components -Fluxtron Control and Fluxtron Process- work independently of each other, thus being highly adaptable for other experimental designs. Beyond plants, the same experimental setup can be applied to the study of trace gas exchange by animals, microbes, soil, or any materials that can be enclosed in a suitable container.

Consumer spray products (CSPs) are widely used in daily life, yet it is challenging to find products that fully disclose all components posing health risks. Existing studies primarily focus on product components or VOC quantities emitted during use. Therefore, this study aimed to measure the VOC concentrations emitted by CSPs at varying distances. 47 CSPs available in the Korean market were selected, spanning three spray groups: antiseptics/insecticides (11), aromatic deodorants (16), and coating/polishing agents (20). VOC in air samples were collected using Tenax TA tube at a distance of 1 and 3 m from the sprayed CSPs and then analyzed by thermal desorption-gas chromatography-mass spectrometry system. Discrepancies were found between labeled and actual product components. Aromatic deodorants exhibited the highest total VOCs (TVOCs), while antiseptic/insecticide sprays exhibited the lowest. In the antiseptic/insecticide group and coating/polishing agent group, benzene as a propellant had a maximum concentration (30.9 ± 25.6 ppb), and as trigger, its concentration was 33.7 ± 30.7 ppb. Quantitative analysis using advanced analytical instruments only explained 26.1 ± 20.4% of toluene-equivalent TVOCs, suggesting the presence of additional substances. Concentrations varied by distance due to substance volatility and usage. Maintaining a distance of at least 1 m from CSPs is recommended.

In this study, the flavor characteristics and physicochemical properties of salted egg yolk (SEY) under different cooking methods (steaming/baking/microwaving) were investigated. The microwave-treated SEY exhibited the highest levels of salt content, cooking loss, lightness, and b* value, as well as the highest content of flavor amino acids. A total of 31, 27, and 29 volatile compounds were detected after steaming, baking, and microwave treatments, respectively, covering 10 chemical families. The partial least squares discriminant analysis confirmed that 21 compounds, including octanol, pyrazine, 2-pentyl-furan, and 1-octen-3-ol, were the key volatile compounds affecting the classification of SEY aroma. The electronic nose revealed a sharp distinction in the overall flavor profile of SEY with varying heat treatments. However, no dramatic differences were observed in terms of fatty acid composition. Microwave treatment was identified as presenting a promising approach for enhancing the aroma profile of SEY. These findings contribute novel insights into flavor evaluation and the development of egg products as ingredients for thermal processing.

Preservation of the breath sample integrity during storage and transport is one of the biggest challenges in off-line exhaled breath gas analysis. In this context, adsorbent tubes are frequently used as storage containers for use with analytical methods employing gas chromatography with mass spectrometric detection. The key objective of this short communication is to provide data on the recovery of selected breath volatiles from Tenax®TA adsorbent tubes that were stored at -80 °C for up to 90 d. For this purpose, an Owlstone Medical\'s ReCIVA®Breath Sampler was used for exhaled breath collection. The following fifteen compounds, selected to cover a range of chemical properties, were monitored for their stability: isoprene, n-heptane, n-nonane, toluene, p-cymene, allyl methyl sulfide, 1-(methylthio)-propane, 1-(methylthio)-1-propene,α-pinene, DL-limonene,β-pinene,γ-terpinene, 2-pentanone, acetoin and 2,3 butanedione. All compounds, but one (acetoin), were found to be stable during the first 4 weeks of storage (recovery within ± 2 × RSD). Furthermore, n-nonane was stable during the whole of the investigated period.

Metal-oxide-based gas sensors are extensively utilized across various domains due to their cost-effectiveness, facile fabrication, and compatibility with microelectronic technologies. The copper (Cu)-based multifunctional polymer-enhanced sensor (CuMPES) represents a notably tailored design for non-invasive environmental monitoring, particularly for detecting diverse gases with a low concentration. In this investigation, the Cu-CuO/PEDOT nanocomposite was synthesized via a straightforward chemical oxidation and vapor-phase polymerization. Comprehensive characterizations employing X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and micro Raman elucidated the composition, morphology, and crystal structure of this nanocomposite. Gas-sensing assessments of this CuMPES based on Cu-CuO/PEDOT revealed that the response current of the microneedle-type CuMPES surpassed that of the pure Cu microsensor by nearly threefold. The electrical conductivity and surface reactivity are enhanced by poly (3,4-ethylenedioxythiophene) (PEDOT) polymerized on the CuO-coated surface, resulting in an enhanced sensor performance with an ultra-fast response/recovery of 0.3/0.5 s.

β-Carboline heterocyclic amines (β-CHAs), known for their synergistic neurotoxic and carcinogenic effects, are predominantly produced by humans through cigarette smoke and food and are found particularly in meats cooked at high temperatures. Few studies have explored the differences in the mechanisms of accumulation of β-CHAs in smoked meat and meat processed at high temperatures. In this research, the concentration of β-CHAs in smoked meats prepared using a variety of wood materials was measured using LCMS/MS. Additionally, key volatile organic compound markers associated with β-CHAs accumulation in smoke were identified through GCMS and multivariate statistical analysis and subsequently confirmed in a chemical simulation system. Three types of strainers, each with a distinct aperture size, were used to assess the efficacy of particle filtration in reducing β-CHAs levels in smoked meat. The findings indicated that smoke exposure indeed increases the β-CHAs content of meat. However, only the strainer capable of filtering PM2.5-sized particles reduced the amount of β-CHAs present compared to the control group. In contrast, strainers with larger pore sizes facilitated excessive accumulation of β-CHAs. The presence of aldehydes such as 1 H-pyrrole-2-carboxaldehyde, 5-methylfurfural, benzaldehyde, furfural, and nonanal exhibited a positive correlation with the accumulation of β-CHAs. Conversely, phenolic compounds, including 2-methoxy-4-vinylphenol, 2-methoxy-5-methylphenol, p-cresol, phenol, 2-methoxy-4-(1-propenyl)-, (Z)-, phenol, 3-ethyl-, and phenol, 4-ethyl-2-methoxy-, showed a negative correlation. Thus, filters made from chelated carbonyl trap materials both chemically and physically disrupt the buildup of β-CHAs in smoked meats. The use of this approach will not only improve the quality of these products but will also contribute to decreasing the amount of inhalation pollutants released into the environment.

Detection of exhaled volatile organic compounds (VOCs) is promising for noninvasive screening of esophageal cancer (EC). Cellular VOC analysis can be used to investigate potential biomarkers. Considering the crucial role of methionine (Met) during cancer development, exploring associated abnormal metabolic phenotypes becomes imperative. In this work, we employed headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) to investigate the volatile metabolic profiles of EC cells (KYSE150) and normal esophageal epithelial cells (HEECs) under a Met regulation strategy. Using untargeted approaches, we analyzed the metabolic VOCs of the two cell types and explored the differential VOCs between them. Subsequently, we utilized targeted approaches to analyze the differential VOCs in both cell types under gradient Met culture conditions. The results revealed that there were five/six differential VOCs between cells under Met-containing/Met-free culture conditions. And the difference in levels of two characteristic VOCs (1-butanol and ethyl 2-methylbutyrate) between the two cell types intensified with the increase of the Met concentration. Notably, this is the first report on VOC analysis of EC cells and the first to consider the effect of Met on volatile metabolic profiles. The present work indicates that EC cells can be distinguished through VOCs induced by Met regulation, which holds promise for providing novel insights into diagnostic strategies.

CONCLUSIONS: One of seven Solanum taxa studied displayed associations between pollen presence and floral scent composition and volume, suggesting buzz-pollinated plants rarely use scent as an honest cue for foraging pollinators. Floral scent influences the recruitment, learning, and behaviour of floral visitors. Variation in floral scent can provide information on the amount of reward available or whether a flower has been visited recently and may be particularly important in species with visually concealed rewards. In many buzz-pollinated flowers, tubular anthers opening via small apical pores (poricidal anthers) visually conceal pollen and appear similar regardless of pollen quantity within the anther. We investigated whether pollen removal changes floral scent composition and emission rate in seven taxa of buzz-pollinated Solanum (Solanaceae). We found that pollen removal reduced both the overall emission of floral scent and the emission of specific compounds (linalool and farnesol) in S. lumholtzianum. Our findings suggest that in six out of seven buzz-pollinated taxa studied here, floral scent could not be used as a signal by visitors as it does not contain information on pollen availability.

The different immune system cells communicate and coordinate a response using a complex and evolved language of cytokines and chemokines. These cellular interactions carry out multiple functions in distinct cell types with numerous developmental outcomes. Despite the plethora of different cytokines and their cognate receptors, there is a restricted number of signal transducers and activators to control immune responses. Herein, we report on a new class of immunomodulatory signaling molecules based on volatile molecules (VMs, namely, volatile organic compounds [VOCs]), by which they can affect and/or control immune cell behavior and transcriptomic profile without any physical contact with other cells. The study demonstrates the role of VMs by analyzing non-contact cell communication between normal and cancerous lung cells and U937 monocytes, which are key players in the tumor microenvironment. Integrated transcriptome and proteome analyses showed the suggested regulatory role of VMs released from normal and cancer cells on neighboring monocytes in several molecular pathways, including PI3K/AKT, PPAR, and HIF-1. Presented data provide an initial platform for a new class of immunomodulatory molecules that can potentially mirror the genomic and proteomic profile of cells, thereby paving the way toward non-invasive immunomonitoring.

Phytoremediation has become famous for removing particulate matter (PM) and volatile organic compounds (VOCs), but the ability is affected by plant health. Lately, the priming technique was a simple approach to studying improving plant tolerance against abiotic stress by specific metabolites that accumulated, known as \"memory\", but the mechanism underlying this mechanism and how long this \"memory\" was retained in the plant was a lack of study. Sansevieria trifasciata was primed for one week for PM and VOC stress to improve plant efficiency on PM and VOC. After that, the plant was recovered for two- or five-weeks, then re-exposed to the same stress with similar PM and VOC concentrations from cigarette smoke. Primed S. trifasciata showed improved removal of PMs entirely within 2 h and VOC within 24 h. The primed plant can maintain a malondialdehyde (MDA) level and retain the \"memory\" for two weeks. Metabolomics analysis showed that an ornithine-related compound was accumulated as a responsive metabolite under exposure to PM and VOC stress. Exogenous ornithine can maintain plant efficiency and prevent stress by increasing proline and antioxidant enzymes. This study is the first to demonstrate plant \"memory\" mechanisms under PM and VOC stress.