Exhaled volatolomics profiling facilitates personalized screening for gastric cancer.

Gastric cancer (GC) is one of the most fatal cancers, characterized by non-specific early symptoms and difficulty in detection. However, there are no valid non-invasive screening tools available for GC. Here we establish a non-invasive method that employs exhaled volatolomics and ensemble learning to detect GC. We developed a comprehensive mass spectrometry-based procedure and determined of a wide range of volatolomics from 314 breath samples. The discovery, identification and verification research screened a biomarker panel to distinguish GC from controls. This panel has achieved 0.90 (0.87-0.94, 95%CI) accuracy, with an area under curve (AUC) of 0.92 (0.89-0.94, 95%CI) in discovery cohort and 0.88 (0.83-0.91, 95%CI) accuracy with an AUC of 0.91 (0.87-0.93, 95%CI) in replication cohort, which outperformed traditional serum markers. Single-cell sequencing and gene set enrichment analysis revealed that these exhaled markers originated from aldehyde oxidation and pyruvate metabolism. Our approach advances the design of exhaled analysis for GC detection and holds promise as a non-invasive method to the clinic.

Virus-induced breath biomarkers: A new perspective to study the metabolic responses of COVID-19 vaccinees.

Coronavirus disease 2019 (COVID-19) vaccines can protect people from the infection; however, the action mechanism of vaccine-mediated metabolism remains unclear. Herein, we performed breath tests in COVID-19 vaccinees that revealed metabolic reprogramming induced by protective immune responses. In total, 204 breath samples were obtained from COVID-19 vaccinees and non-vaccinated controls, wherein numerous volatile organic compounds (VOCs) were detected by comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry system. Subsequently, 12 VOCs were selected as biomarkers to construct a signature panel using alveolar gradients and machine learning-based procedure. The signature panel could distinguish vaccinees from control group with a high prediction performance (AUC, 0.9953; accuracy, 94.42%). The metabolic pathways of these biomarkers indicated that the host-pathogen interactions enhanced enzymatic activity and microbial metabolism in the liver, lung, and gut, potentially constituting the dominant action mechanism of vaccine-driven metabolic regulation. Thus, our findings of this study highlight the potential of measuring exhaled VOCs as rapid, non-invasive biomarkers of viral infections. Furthermore, breathomics appears as an alternative for safety evaluation of biological agents and disease diagnosis.

Occurrence and sources of microplastics and polycyclic aromatic hydrocarbons in surface sediments of Svalbard, Arctic.

Due to the distinct environment condition and geographic location, Svalbard has been recognized as a potential pollution reservoir in the Arctic. In this study, 8 surface sediment samples were collected from two fjords in Svalbard (Kongsfjorden and Rijpfjorden) in 2017, and they were searched for microplastics and polycyclic aromatic hydrocarbons (PAHs). PAHs were also investigated in 10 soil samples of Ny-Ålesund for local anthropogenic source analysis. The level of microplastics and other anthropogenic particles ranged from not detected (ND) to 4.936 particles/kg dry weight (DW). Fiber was the only shape of the microplastics found and three polymers (polyester, rayon and cellulose) were detected, which suggested that fisheries-related debris and textile materials were possible sources of microplastics and anthropogenic particles. For PAHs, the level of ∑26PAH was 9.2 ng/g to 67.1 ng/g (DW), and were dominated by lnP and BghiP, indicating petroleum combustion source. Further analysis revealed that traffic emissions from cars and diesel combustion from a local power plant were major sources of PAHs in soils of Ny-Alesund, while traffic emissions from ships were the dominate source of PAHs in sediments of Kongsfjorden and Rijpfjorden. A higher level of PAHs was observed in Ny-Alesund, confirming an anthropogenic input, while transport via ocean currents might contribute to the higher abundance of microplastics in Rijpfjorden. Further research and even long-term observation of pollutants are needed to fully understand the pollution status in polar regions.

Lost but can't be neglected: Huge quantities of small microplastics hide in the South China Sea.

Large quantities of microplastics with small particle sizes were found in the South China Sea (SCS). The abundances of microplastics in seawater were 0.045±0.093and 2569±1770particles/m3 according to the bongo net and pumping sampling methods, respectively. Smaller-size fractions (size<0.3mm) contributed 92% of the number of microplastics to the total load. Continental slope is the largest reservoir of microplastics with an inventory of 295tons. 21 polymer types were found in the samples using the micro Fourier Transform Infrared Spectroscopy (FTIR), among which alkyds (22.5%) and polycaprolactone (PCL) (20.9%) accounted for almost half of the total polymer content. Lighter plastics would not only concentrate upon the coastal area, being more likely to drift further into open seas with ocean currents. The distribution characteristics showed that it was mainly controlled by terrestrial input of the Pearl River. This study, as the first report from SCS on microplastics in water for its distribution and influence factors, provided impetus for further research on the transportation fate and the behavior of this emerging pollutant from coastal zone to the open oceans.