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Radiometry
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
In many applications, the detector system is designed to monitor one kind of radiation, for example, gamma-ray spectrometry. However, some applications require that more than one radiation quality can be monitored simultaneously. This can be achieved by using two or more detectors in the same instrument housing – for example, combining a GM tube for gamma-ray detection with a Ag-doped zinc sulphide, ZnS(Ag), detector for detection of alpha particles.
Drug Substance and Excipient Characterization
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Parind M. Desai, Lai Wah Chan, Paul Wan Sia Heng
IR, particularly Fourier transform IR spectrometry, can also be employed to study interaction [95]. In the same way, modifications in the spectra obtained by Raman spectroscopy indicate that chemical interactions have occurred. The Raman spectra can be processed to give unambiguous identification of both drugs and excipients, and the relative intensity of the drug and excipient bands can be used for quantitative analysis. More information about the different Raman techniques can be obtained from the literature [97].
Ultraviolet and Light Absorption Spectrometry
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Zoltan M. Dinya, Ferenc J. Sztaricskai
Therefore, the authors believe that summarization of topics in ultraviolet and visible spectral properties of the individual groups of antibiotics—with respect to their structural feature—is extremely reasonable, together with the discussion of the possible analytical applications. In addition to the term, “ultraviolet and visible spectrometry,” in the treatment of this subject the internationally accepted abbreviation UV-VIS will be also used.
Prevalence of Stimulant, Hallucinogen, and Dissociative Substances Detected in Biological Samples of NPS-Intoxicated Patients in Italy
Published in Journal of Psychoactive Drugs, 2021
Pietro Papa, Antonella Valli, Marcello Di Tuccio, Eleonora Buscaglia, Elena Brambilla, Giulia Scaravaggi, Mariapina Gallo, Carlo Alessandro Locatelli
Our data show that a broad variety of excitatory NPS (44 different substances) were involved in the investigated cases. NPS were consumed either singularly or in combination with other NPS and/or conventional drugs. The dissociative class was the most frequently detected one (47.2% of positive cases). In particular the misuse of ketamine was detected in 105 cases, thus resulting in the most frequent NPS involved in serious poisoning in Italy. Considering the high prevalence of ketamine, routine drug screening should include this substance in EDs. Hallucinogens (30.9%) was the second most frequent NPS involved. Stimulants were found in 20% of the positive cases with a considerable presence of cathinones (45 cases). NPS-intoxicated patients were prevalently male (74.8%), with a similar distribution in each class of excitatory substance of abuse: (85.4% for hallucinogens, 69.7% for dissociatives, and 73% for stimulants). The age of intoxicated patients ranged from 14 to 68 years (mean 27.3). The mean age was 34, 27.5, and 24.6 years for stimulants, hallucinogens, and dissociatives, respectively. These data confirm that the NPS market continues to be dynamic. New substances continue to emerge, with some establishing themselves on the market and others disappearing after a short time. Taking these issues into account, NPS analysis needs “open” methods that can be readily adaptable to identify with the adequate sensitivity, selectivity, and specificity for a large number of new substances in biological matrices. Basically, chromatographic techniques coupled to mass spectrometry satisfy these needs.
Metabolism of bioconjugate therapeutics: why, when, and how?
Published in Drug Metabolism Reviews, 2020
Hanlan Liu, Jayaprakasam Bolleddula, Andrew Nichols, Lei Tang, Zhiyang Zhao, Chandra Prakash
For LDC development, metabolism studies should be part of the drug in vitro activity screening at an early stage of drug discovery. Connecting functional activities in human disease-relevant target cells with the release of drug molecule from LDC and/or metabolites of the released drug molecule with respect to both the extent and the kinetics builds confidence in the mechanism of action and facilitates the transition to in vivo experiments. Questions to be addressed by these studies include: Is the LDC active in the cells? Is the drug released from LDC intracellularly? How much released drug and LDC are in the cells? Is the LDC more active than the non-conjugated drug? Are there any other intermediate metabolites beyond the released drug? Are those intermediate metabolites active? Rapid advances in fluorescence imaging and mass spectrometry imaging could be explored to address some of the aforementioned questions.
Therapeutic prospective of plant-induced silver nanoparticles: application as antimicrobial and anticancer agent
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Krushna C. Hembram, Rahul Kumar, Laxman Kandha, Pankaj K. Parhi, Chanakya N. Kundu, Birendra K. Bindhani
UV visible spectrometry analysis is commonly used as the primary quantitative analysis for confirming the nanoparticle formation and also used to monitor the stability. UV visible spectroscopy is very simple technique, sensitive and fast. Most importantly it is selective for different nanoparticles Synthesis was monitored by the colour change of AgNO3 from colourless to brownish yellow and its absorption spectra appeared at 410–430 nm. It quantifies the amount of UV or visible radiation observed by the sample in the solution. In nanoparticles, the free moving electron produces surface Plasmon resonance (SPR) spectra due to combined oscillation of electrons of AgNPs with the incident light. Nanoparticles morphology, chemical composition, size and dielectric medium are the determinant for its absorption spectra.