The rapid release of new tobacco products requires high-throughput quantitative methods to support tobacco research. Sample preparation for LC-MS and GC-MS is time consuming and limits throughput. Paper spray tandem mass spectrometry (PS-MS/MS) is proposed and validated as a simple and rapid method for quantification of nicotine and cotinine in complex matrices to support tobacco-related research. Air liquid interface (ALI) human tracheobronchial epithelial cell (HTBEC) cultures were exposed to tobacco smoke using a Vitrocell VC-10 smoking machine. Apical culture washes (phosphate buffered saline, PBS) and basolateral media were analyzed with the PS-MS/MS method. GC-MS/MS was used as a comparative quantitative technique. The PS-MS/MS approach allowed for direct spotting of samples on the paper substrate, whereas the GC-MS/MS method required additional sample preparation in the form of solvent-solvent extraction. Limits of quantitation (LOQs) were higher with the PS-MS/MS approach than GC-MS/MS, but still below the relevant concentrations found in HTBEC smoke exposure experiments as well as most clinical applications. PS-MS/MS is readily achieved on mass spectrometers that include atmospheric pressure inlets, and allows for convenient quantification from complex matrices that would otherwise require additional sample preparation and chromatographic separation.
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http://dx.doi.org/10.1039/C7AY02204B | DOI Listing |
Nanotechnology
January 2025
Centre for Analysis and Synthesis, NanoLund, Lund University, Box 124, Lund, 221 00, SWEDEN.
Developing a reliable procedure for the growth of III-V nanowires (NW) on silicon (Si) substrates remains a significant challenge, as current methods rely on trial-and-error approaches with varying interpretations of critical process steps such as sample preparation, Au-Si alloy formation in the growth reactor, and nanowire alignment. Addressing these challenges is essential for enabling high-performance electronic and optoelectronic devices that combine the superior properties of III-V NW semiconductors with the well-established Si-based technology. Combining conventional scalable growth methods, such as Metalorganic Chemical Vapor Deposition (MOCVD) with in situ characterization using Environmental Transmission Electron Microscopy (ETEM-MOCVD) enables a deeper understanding of the growth dynamics, if that knowledge is transferable to the scalable processes.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Chemical Ecology, Bielefeld University, Bielefeld, Germany.
Three endophytic strains, Phomopsis sp., Fusarium proliferatum, and Tinctoporellus epimiltinus, isolated from various plants in the rainforest of the Philippines, were investigated regarding their ability to repress growth of the pathogenic fungus Colletotrichum musae on banana fruits causing anthracnose disease. An in vitro plate-to-plate assay and an in vivo sealed box assay were conducted, using commercial versus natural potato dextrose medium (PDA).
View Article and Find Full Text PDFPLoS One
January 2025
Aesthetic and Restorative Dentistry Department, College of Dentistry, University of Baghdad, Baghdad, Iraq.
This study evaluated the extent to which obturation materials bypass fractured endodontic instruments positioned in the middle and apical thirds of severely curved simulated root canals using different obturation techniques. Sixty resin blocks with simulated root canals were used, each with a 50° curvature, a 6.5 mm radius of curvature, and a length of 16.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Applied Chemistry, National Defense Academy, Kanagawa, Japan.
Bacterial endospores are ubiquitous and are responsible for various human infections. Recently, we reported that an ionic liquid (IL)-based sample preparation method (named pTRUST) facilitated highly efficient shotgun analysis of the Bacillus subtilis spore proteome in trace samples. In this study, we evaluated the efficiency and applicability of the pTRUST technology using three different spore preparations: one purified from the closely related subspecies B.
View Article and Find Full Text PDFPLoS Negl Trop Dis
January 2025
Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
Background: Schistosoma haematobium is the causative pathogen for urogenital schistosomiasis. To achieve progress towards schistosomiasis elimination, there is a critical need for developing highly sensitive and specific tools to monitor transmission in near-elimination settings. Although antibody detection is a promising approach, it is usually unable to discriminate active infections from past ones.
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