Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision (13)C/(12)C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01-1 APE) of uniformly labeled [U-(13)C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of (13)C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor-product relationships.
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http://dx.doi.org/10.1021/jf500947x | DOI Listing |
Sci Rep
December 2024
Gateway Antarctica, University of Canterbury, Christchurch, New Zealand.
The Tibetan Plateau is home to numerous glaciers that are important for freshwater supply and climate regulation. These glaciers, which are highly sensitive to climatic variations, serve as vital indicators of climate change. Understanding glacier-fed hydrological systems is essential for predicting water availability and formulating climate adaptation strategies.
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December 2024
Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
E-cigarette/vaping-associated lung injury (EVALI) is strongly associated with vitamin E acetate and often occurs with concomitant tetrahydrocannabinol (THC) use. To uncover pathways associated with EVALI, we examined cytokines, transcriptomic signatures, and lipidomic profiles in bronchoalveolar lavage fluid (BALF) from THC-EVALI patients. At a single center, we prospectively enrolled mechanically ventilated patients with EVALI from THC-containing products (N = 4) and patients with non-vaping acute lung injury and airway controls (N = 5).
View Article and Find Full Text PDFNat Commun
December 2024
School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China.
Fine particulate matter has been linked with acute coronary syndrome. Nevertheless, the key constituents remain unclear. Here, we conduct a nationwide case-crossover study in China during 2015-2021 to quantify the associations between fine particulate matter constituents (organic matter, black carbon, nitrate, sulfate, and ammonium) and acute coronary syndrome, and to identify the critical contributors.
View Article and Find Full Text PDFJ Neuroimaging
December 2024
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Background And Purpose: In idiopathic normal pressure hydrocephalus (iNPH) patients, cerebrospinal fluid (CSF) flow is typically evaluated with a cardiac-gated two-dimensional (2D) phase-contrast (PC) MRI through the cerebral aqueduct. This approach is limited by the evaluation of a single location and does not account for respiration effects on flow. In this study, we quantified the cardiac and respiratory contributions to CSF movement at multiple intracranial locations using a real-time 2D PC-MRI and evaluated the diagnostic value of CSF dynamics biomarkers in classifying iNPH patients.
View Article and Find Full Text PDFGround Water
December 2024
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
Quantifying lacustrine groundwater discharge (LGD) is important for understanding the dynamics of lake ecosystems and their expansion. This study focuses on Lake Qinghai, employing radium isotope models to evaluate the contributions of both shallow and deep groundwater. The data indicate that the activity of Ra and Ra demonstrates a pronounced gradient, decreasing from the shoreline to the center of Lake Qinghai.
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