MetaboLights

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ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/m_MTBLS14208_LC-MS_positive_hilic_v2_maf.tsvftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/m_MTBLS14208_LC-MS_negative_hilic_v2_maf.tsvftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/a_MTBLS14208_LC-MS_negative_hilic.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/a_MTBLS14208_LC-MS_positive_hilic.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/i_Investigation.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208/s_MTBLS14208.txtprimaryOK200ftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS14208Metabolite identification was performed based on multiple dimensions, including retention time (RT), accurate mass, MS/MS fragmentation patterns, and isotopic distribution. Identification was achieved by matching features against The Human Metabolome Database (HMDB), LipidMaps (v2.3), METLIN, and a local LuMet-Animal database.The LuMet-Animal database is an LC–MS/MS spectral library developed by OE Biotech using a hardware-standardized platform and constructed based on authentic standards. It comprehensively covers more than 10,000 commonly detected and biologically relevant metabolites. Among these, over 2,000 metabolites have been validated using reference standards, with confirmed RT, MS¹, and MS² information. The database encompasses 13 major classes of metabolites, including amino acids and their derivatives, organic acids and derivatives, carbohydrates and their derivatives, organoheterocyclic compounds, nucleosides and their derivatives, indole derivatives, steroids and their derivatives, bile acids and their derivatives, acylcarnitines, lysophospholipids, benzenoids, and exposure-related metabolites.Furthermore, the LuMet-Animal database covers a wide range of key metabolic pathways, including glycolysis/gluconeogenesis, the tricarboxylic acid (TCA) cycle, phenylalanine metabolism, tryptophan metabolism, steroid biosynthesis, steroid hormone biosynthesis, primary bile acid biosynthesis, and glycerophospholipid metabolism, among many others.MetaboLightsPublicLiquid Chromatography MS - positive - hilicLiquid Chromatography MS - negative - hilicSamples were analyzed using a liquid chromatography–mass spectrometry system (Waters ACQUITY UPLC I-Class Plus / Thermo Q Exactive HF). Chromatographic separation was performed on an ACQUITY UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm), with the column temperature maintained at 45 °C. The mobile phase consisted of solvent A (water containing 0.1% formic acid) and solvent B (acetonitrile). The flow rate was set at 0.35 mL/min, and the injection volume was 5 μL.Relationship Between Vitamin D Levels and Psychological Stress-Induced Asthma Prevalence: An Untargeted Metabolomics Study Combined with the NHANES Database.zhijie zhangBeijing University of Chinese Medicineblood plasmamass spectrometry assayAfter completion of participant enrollment, plasma samples stored at −80 °C were removed and thawed slowly on ice. An aliquot of 80 μL plasma was transferred into a 1.5 mL Eppendorf tube, followed by the addition of 320 μL methanol–acetonitrile protein precipitation solution (v/v = 2:1, containing mixed internal standards). The mixture was vortexed for 1 min, ultrasonicated in an ice-water bath for 10 min, and then incubated overnight at −40 °C. Subsequently, samples were centrifuged at 12,000 rpm for 20 min at 4 °C, and 150 μL of the supernatant was transferred into LC autosampler vials with inserts for analysis.Homo sapienshttps://www.ebi.ac.uk/metabolights/MTBLS14208zhijie zhang. 1260539727@qq.com.zhijie zhang. Beijing University of Chinese Medicine. 1260539727@qq.com.The extracted metabolomics data were processed as follows:(1) Compound identification scoring and filteringAll identified compounds were evaluated using a qualitative scoring system (Score). The maximum score was 80 points, including accurate mass matching in MS1(20 points), MS/MS fragmentation matching (20 points), isotopic pattern matching (20 points), and retention time matching (20 points). In general, higher scores indicate more reliable identification. Compounds with a Score <36 were considered inaccurately identified and were excluded from further analysis.(2) Data preprocessing after merging positive and negative ion modesAfter filtering, data from positive and negative ion modes were merged, and the combined data matrix was processed as follows:RSD filtering: Ion features with a relative standard deviation (RSD) >30% in quality control (QC) samples were removed.Missing value processing and zero-value imputation: Ion features with >50% missing values (zero values) within each group were excluded. The remaining zero values were replaced with half of the minimum ion intensity across all samples.Log2 transformation: The processed data were log2-transformed prior to subsequent analyses.(3) Metabolite identification confidence levelsMetabolites were classified into four confidence levels based on retention time (RT) and fragmentation score:Level 1: RT tolerance ±0.3 min (18 s) and fragmentation score ≥45Level 2: RT tolerance ±0.3 min (18 s) and 0 ≤ fragmentation score <45Level 3: Fragmentation score ≥45 (without RT matching)Level 4: Fragmentation score <45 (without RT matching)(4) Data matricesMissing value matrix: The merged dataset prior to zero-value imputation and log2 transformation.Final data matrix: The processed dataset after zero-value imputation and log2 transformation, which was used for subsequent statistical analyses.PSA1260539727@qq.comAll patients were recruited from the outpatient clinic of the Department of Respiratory Medicine at the Beijing University of Chinese Medicine Third Affiliated Hospital between March and October 2025. On the morning of their appointment, fasting venous blood samples were collected using ethylenediaminetetraacetic acid (EDTA) anticoagulant tubes. The samples were centrifuged at 3,000 rpm for 10 minutes at 4°C, after which the supernatant plasma was collected and stored at −80°C pending further analysis.MetabolomicsMetabolomicsWaters ACQUITY UPLC I-Class PLUS Systemblood plasmauntargeted analysisvitamin Dliquid chromatography-tandem mass spectrometryHomo sapiensasthmaThermo Scientific Q Exactive HFMetabolomicsWaters ACQUITY UPLC I-Class PLUS Systemblood plasmauntargeted analysisvitamin Dliquid chromatography-tandem mass spectrometryHomo sapiensasthmaThermo Scientific Q Exactive HFUltrasonic cleaner (F-060SD, Shenzhen Fuyang Technology Group Co., Ltd., China) Vortex mixer (TYXH-I, Shanghai Hanno Instrument Co., Ltd., China) Benchtop high-speed refrigerated centrifuge (5430R, Eppendorf, Germany) Liquid chromatography–mass spectrometry system (ACQUITY UPLC I-Class Plus coupled with Q Exactive HF, Waters, USA / Thermo Fisher Scientific, USA) UPLC column (ACQUITY UPLC HSS T3, 100 mm × 2.1 mm, 1.8 μm, Waters, USA)Mass spectrometry was performed using a heated electrospray ionization (HESI) source operated in both positive and negative ion modes. The detailed parameters were as follows: spray voltage, 3,800 V (positive mode) and −3,200 V (negative mode); capillary temperature, 320 °C; auxiliary gas heater temperature, 350 °C; sheath gas flow rate, 35 Arb; auxiliary gas flow rate, 8 Arb; S-lens RF level, 50.The mass scan range was set to m/z 70–1050. The resolution for Full MS was 60,000, and for MS/MS was 15,000. Data were acquired using stepped normalized collision energy (NCE) at 10, 20, and 40.falseRelationship Between Vitamin D Levels and Psychological Stress-Induced Asthma Prevalence: An Untargeted Metabolomics Study Combined with the NHANES DatabaseThe incidence of psychological stress–induced asthma has been increasing annually, and numerous previous studies have shown that vitamin D is associated with the development of asthma as well as anxiety and depression. However, no studies to date have clarified the relationship between vitamin D and the onset of psychological stress-induced asthma (PSA). Therefore, this study aimed to integrate an NHANES-based analysis with untargeted metabolomics to explore the potential association between vitamin D and PSA.2026-04-162026-04-02MTBLS14208