The positive and negative ion fast atom bombardment (FAB) mass spectra of four glycolipids obtained from microbial cultures are reported. The spectra of the glycolipids in the positive ion mode are characterized by abundant [M + Na]+, [M + Na + matrix]+ and [M + 2Na - H]+ species. In negative FAB conditions the molecules yield [M - H]-. Our understanding of the FAB behaviour of glycolipids in both positive and negative modes has been considerably aided in the structure elucidation, without any derivatization or degradation reaction of the compounds studied. The technique allows unambiguous molecular weight determination of low-microgram amounts of these glycolipids purified from biological sources and provides useful fragmentation information.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/bms.1200181203 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Fast single atom imaging for optical lattice arrays.
Nat Commun
January 2025
Department of Physics, Harvard University, Cambridge, MA, USA.
High-resolution fluorescence imaging of ultracold atoms and molecules is paramount to performing quantum simulation and computation in optical lattices and tweezers. Imaging durations in these experiments typically range from a millisecond to a second, significantly limiting the cycle time. In this work, we present fast, 2.
View Article and Find Full Text PDFFluidized Electrochemical Exfoliation of Layered Transition Metal Dichalcogenides toward Fast Production of High-Quality Nanosheets in the Aqueous Phase.
Nano Lett
January 2025
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
The transformation of bulk transition-metal dichalcogenide (TMD) particles into ultrathin nanosheets with both an acceptable yield and preserved crystalline integrity presents a substantial challenge in electrochemical exfoliation. This challenge arises from the continuous potential stress that the materials experience in traditional exfoliation setups. Herein, we propose a new fluidized electrochemical exfoliation (FEE) method to efficiently transform TMD powders into high-quality, few-layered TMD nanosheets in the aqueous phase.
View Article and Find Full Text PDFAccelerating Quantum Anharmonic Vibrational Calculations by Atom-Specific Hybrid Basis Set-Based Potential Energy Surface Approach.
J Phys Chem A
January 2025
Department of Chemistry and Chemical Sciences, Central University Jammu, Samba 181143, Jammu and Kashmir, India.
The development of accurate yet fast quantum mechanical methods to calculate the anharmonic vibrational spectra of large molecules is one of the major goals of ongoing developments in this field. This study extensively explores and validates a hybrid electronic basis set approach for anharmonic vibrational calculations, where the molecule is segregated into different computational layers, and such layers are then treated with different levels of electronic basis sets. Following the system-bath model, the atoms corresponding to the active sites are treated in more accurate but computationally slower, large basis set and the rest of the atoms in less accurate but computationally faster, small basis set to construct the anharmonic hybrid potential energy surface (PES).
View Article and Find Full Text PDFLaser Synthesis of Platinum Single-Atom Catalysts for Hydrogen Evolution Reaction.
Nanomaterials (Basel)
January 2025
Department of Materials, School of Natural Science, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
Platinum (Pt)-based heterogeneous catalysts show excellent performance for the electrocatalytic hydrogen evolution reaction (HER); however, the high cost and earth paucity of Pt means that efforts are being directed to reducing Pt usage, whilst maximizing catalytic efficiency. In this work, a two-step laser annealing process was employed to synthesize Pt single-atom catalysts (SACs) on a MOF-derived carbon substrate. The laser irradiation of a metal-organic framework (MOF) film (ZIF67@ZIF8 composite) by rapid scanning of a ns pulsed infrared (IR; 1064 nm) laser across the freeze-dried MOF resulted in a metal-loaded graphitized film.
View Article and Find Full Text PDFBone Turnover Markers Predict Changes in Bone Mineral Density in Men Treated with Abaloparatide: Results from ATOM.
J Bone Miner Res
January 2025
Radius Health Inc, Boston, MA, United States.
Early increases in bone turnover markers (BTMs) in response to anabolic therapy correlate with 18-month bone mineral density (BMD) increases in postmenopausal women with osteoporosis; however, this relationship has not been assessed in men. In this analysis, the correlation between changes from baseline in fasting intact serum procollagen type I N propeptide (PINP) and serum carboxy-terminal cross-linking telopeptide of type I collagen (CTX) at 1, 3, 6, and 12 months and percent increase from baseline in BMD at 12 months in men from the randomized phase 3 ATOM study (NCT03512262) were evaluated using Pearson's correlation coefficients. The uncoupling index (UI), a measure of the balance between markers of bone formation (PINP) and bone resorption (CTX), with positive UI favoring bone formation, was calculated.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!