Ammonium (NH), hydroxylamine (NHOH), nitrite (NO), and nitrate (NO) account for the most important reactive nitrogen (N) species in the N cycle, playing a key role in N elimination and N retention, as well as the production of nitrogenous trace gases. However, it is still challenging to fulfill simultaneous real-time determination of all four N compounds enriched in N. This study successfully established a novel system by coupling an utomatic imultaneous ample reparation unit to a embrane nlet ass pectrometer (4n-ASSP-MIMS) for rapid online N fraction analysis of all four key compounds in the N cycle. The limit of detection (LOD) was 20.22, 0.38, 0.17, and 0.25 μM for NH, NHOH, NO, and NO, respectively, and relative error for N fraction determination was within 5% when N enrichment was higher than 5 atom %. This 4n-ASSP-MIMS system provides a first online analytical tool to capture the real-time isotopic signals during biogeochemical transformations of NH, NHOH, NO, and NO, using the N tracing technique. Application of this system will dramatically advance our understanding of mechanisms involved in the N cycle.
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http://dx.doi.org/10.1021/acs.analchem.4c05467 | DOI Listing |
ACS Chem Neurosci
January 2025
Departments of Psychiatry and Neurology, Division of Molecular Therapeutics, New York State Psychiatric Institute, Columbia University Medical Center, New York, New York 10032, United States.
Voluntary movement, motivation, and reinforcement learning depend on the activity of ventral midbrain neurons, which extend axons to release dopamine (DA) in the striatum. These neurons exhibit two patterns of action potential activity: low-frequency tonic activity that is intrinsically generated and superimposed high-frequency phasic bursts that are driven by synaptic inputs. acute striatal brain preparations are widely employed to study the regulation of evoked DA release but exhibit very different DA release kinetics than recordings.
View Article and Find Full Text PDFFunct Integr Genomics
January 2025
Institute of Infectious Diseases, Guangdong Province, Guangzhou Eighth People's Hospital, Guangzhou Medical University, 8 Huaying Road, Baiyun District, Guangzhou, 510440, China.
Hepatocellular carcinoma (HCC) remains a malignant and life-threatening tumor with an extremely poor prognosis, posing a significant global health challenge. Despite the continuous emergence of novel therapeutic agents, patients exhibit substantial heterogeneity in their responses to anti-tumor drugs and overall prognosis. The pentose phosphate pathway (PPP) is highly activated in various tumor cells and plays a pivotal role in tumor metabolic reprogramming.
View Article and Find Full Text PDFJACC Cardiovasc Interv
December 2024
Department for Angiology, Brandenburg Medical School Theodor Fontane, Campus Clinic Brandenburg, Center for Internal Medicine I, Berlin, Germany; Department of Angiology, Sankt-Gertrauden-Krankenhaus, Berlin, Germany.
Background: Several randomized clinical trials have shown that the composite endpoint of death, stroke, and myocardial infarction (MI) is equivalent between carotid artery stenting and carotid endarterectomy. However, the risk of minor stroke has been consistently higher with carotid artery stenting.
Objectives: The authors sought to evaluate the safety and effectiveness of a novel carotid stent system comprised of a stent, an adjustable integrated embolic filter and a postdilation balloon, in patients at elevated risk for adverse events from carotid endarterectomy.
J Am Chem Soc
January 2025
Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China.
Understanding and effectively controlling molecular conformational changes are essential for developing responsive and dynamic molecular systems. Here, we report that an oriented external electric field (OEEF) is an effective catalyst for the cis-trans isomerization of stiff-stilbene, a key component of overcrowded alkene-based rotary motors. This reversible isomerization occurs under ambient conditions, is free from side reactions, and has been verified using ultraperformance liquid chromatography and UV-vis absorption spectroscopy.
View Article and Find Full Text PDFAnal Chem
January 2025
Center of Advanced Analysis and Gene Sequencing, Key Laboratory of Molecular Sensing and Harmful Substances Detection Technology, Zhengzhou University, Kexue Avenue 100, Zhengzhou, Henan 450001, P. R. China.
A novel sensing platform was constructed for the recognition and identification of dihydroxybenzene isomers based on the MOF-0.02TEA fluorescence sensor with the morphology of nanosheet microspheres through coordination modulation. Based on the sensing principle that the amino group on the MOF-0.
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