The thermopower of Si nanowires was investigated on the basis of electronic transport theory, taking into account ionized impurity scattering as well as electron-phonon scattering. It was found that the enhancement of the Seebeck coefficient in nanowires arising from quantum confinement is unimportant due to the ionized impurity scattering associated with donor deactivation. Furthermore, because the electrical conductivity is degraded significantly as the nanowire size becomes smaller, despite the accompanying slightly enhanced Seebeck coefficient, the reduction of the nanowire size is not beneficial, at least for the thermopower of devices.
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http://dx.doi.org/10.1088/0953-8984/25/50/505301 | DOI Listing |
J Pharm Biomed Anal
January 2025
Key Laboratory of Forensic Medicine, Ministry of Justice, Shanghai Forensic Service Platform, Shanghai Key Laboratory of Forensic Science, Academy of Forensic Science, Guangfu West Road 1347, Shanghai 200063, China. Electronic address:
Etomidate and its structural analogues, which have anesthetic effects, are classified as controlled psychotropic drugs. Electronic cigarettes (e-cigarettes) have become more and more popular. With the increase of adding etomidate and its analogues to electronic liquids (e-liquids), there is a trend of abuse, which is a tough problem urgently need to be solved.
View Article and Find Full Text PDFJ Chromatogr Sci
January 2025
Analytical Research Laboratory, Cadila Pharmaceuticals Ltd., Dholka, Ahmedabad 382225, India.
N-nitrosamine impurities have been detected in a vast variety of drug substances and drug products, showing concern for regulatory aspects. To meet the regulatory requirement for the concerned impurity, a sensitive analytical method capable of quantifying these impurities at a lower level with accuracy and precision is required. This article focuses on the development and validation of an analytical method for the simultaneous detection of nine nitrosamine impurities in a single method for nebivolol drug product using liquid chromatography-mass spectrometry/mass spectrometry-atmospheric pressure chemical ionization (LC-MS/MS-APCI).
View Article and Find Full Text PDFJ Am Soc Mass Spectrom
January 2025
Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, 60438 Frankfurt am Main, Germany.
Electrospray mass spectrometry has become indispensable in many disciplines including the classic "omics" techniques such as proteomics or lipidomics, as well as other life science applications in molecular, cellular, and structural biology. However, a limiting factor that often arises for the detection of biomolecular analytes is their poor ionization efficiency in the ion source. Here, we present an add-on device for the electrospray source, termed MS (MS Spectral Impurity Eliminator & Value Enhancer), which is placed between the electrospray needle and the cone of the mass spectrometer.
View Article and Find Full Text PDFAppl Radiat Isot
December 2024
Radiation Physics Division, National Institute of Standards and Technology, 100 Bureau Dr., Gaithersburg, MD, 20899-8462, USA.
The massic activity of Ac in 0.1 mol/L HCl was measured by multiple primary methods over four consistent measurement campaigns. Results from the triple-to-double coincidence ratio (TDCR) method of liquid scintillation (LS) counting were in accord with other LS-based primary methods.
View Article and Find Full Text PDFRapid Commun Mass Spectrom
March 2025
Department of Pharmaceutical Analysis, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, India.
Rationale: The present study aims to establish structures of the degradation products of an anti-diabetic drug, Imeglimin (IMG) approved for the treatment of type 2 diabetes mellitus in the year 2021. Degradation pathways are proposed along with in silico toxicity assessments of the observed degradation products (DPs) of the drug.
Methods: A reversed-phase high-performance liquid chromatography (RP-HPLC), equipped with a photodiode array detector, was used to separate the observed DPs with a Phenomenex Luna PFP (250 × 4.
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