Differentiating methamphetamine samples produced from ephedrine and pseudoephedrine from phenyl-2-propanone precursors is critical for assigning synthetic route information for methamphetamine profiling. The use of isotope ratio mass spectrometry data is now a key component for tracking precursor information. Recent carbon (δ(13)C) isotope results from the analysis of numerous methamphetamine samples show clear differentiation for ephedrine and pseudoephedrine-produced samples compared to P2P-produced samples. The carbon isotope differences were confirmed from synthetic route precursor studies.
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http://dx.doi.org/10.1016/j.forsciint.2013.10.022 | DOI Listing |
Sci Rep
January 2025
Faculty of Industrial and Systems Engineering, Tarbiat Modares University, Tehran, 4117-13114, Iran.
Humans encounter both natural and artificial radiation sources, including cosmic rays, primordial radionuclides, and radiation generated by human activities. These radionuclides can infiltrate the human body through various pathways, potentially leading to cancer and genetic mutations. A study was conducted using random sampling to assess the concentrations of radioactive isotopes and heavy metals in mineral water from Iran, consumable at Arak City.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
Heterotrophic denitrifiers play crucial roles in global carbon and nitrogen cycling. However, their inability to oxidize sulfide renders them vulnerable to this toxic molecule, which inhibits the key enzymatic reaction responsible for reducing nitrous oxide (NO), thereby raising greenhouse gas emissions. Here, we applied microcosm incubations, community-isotope-corrected DNA stable-isotope probing, and metagenomics to characterize a cohort of heterotrophic denitrifiers in estuarine sediments that thrive by coupling sulfur oxidation with denitrification through chemolithoheterotrophic metabolism.
View Article and Find Full Text PDFOecologia
January 2025
Department of Environmental Science, Policy, and Management, University of California -Berkeley, Berkeley, CA, 94720, USA.
Trophic niche has fundamental ecological importance, but many studies consider few niche metrics and most neglect critical structuring processes. Multiple processes shape trophic niches, including inter and intra-specific competition, predation and resource diversity. These processes interact and effects vary with time and taxa.
View Article and Find Full Text PDFDrug Metab Dispos
January 2025
Global Clinical Development, Chiesi Farmaceutici SpA, Parma, Italy.
Tanimilast is an inhaled phosphodiesterase-4 inhibitor currently in phase III clinical development for treating chronic obstructive pulmonary disease and asthma. This trial aimed to characterize the pharmacokinetics, mass balance, and metabolite profiling of tanimilast. Eight healthy male volunteers received a single dose of nonradiolabeled tanimilast via powder inhaler (Chiesi NEXThaler [3200 μg]), followed by a concomitant intravenous infusion of a microtracer ([C]-tanimilast: 18.
View Article and Find Full Text PDFEnviron Res
January 2025
State Key Laboratory of Lithospheric and Environmental Coevolution, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui, 230026, China; CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Understanding the sources and deposition processes of cadmium (Cd) in freshwater lakes is essential for effective pollution management. This study investigated the Cd concentrations and isotopes in a sediment core from Chaohu Lake, spanning the past 200 years. The results revealed that the Cd concentrations in the sediments decreased with depth, ranging from 1.
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