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1.
Adv Radiat Oncol ; 6(2): 100636, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33283072

RESUMO

PURPOSE: The supply of N95 masks and filtering facepiece respirators (FFRs) has been limited nationally owing to the coronavirus disease 2019 pandemic. Ultraviolet C (UVC) light has been suggested as a potential option for decontamination of FFRs by the Centers for Disease Control. There has been a lack of publications characterizing UVC dose distribution across FFRs. METHODS AND MATERIALS: A UVC light box and FFR rack system was assembled using low-pressure mercury lamps peaked at 254 nm and aluminum flashing to reduce shadowing effect. Dose was characterized with the use of ultraviolet (UV) intensity labels and an ultraviolet germicidal irradiation (UVGI) National Institute of Standards and Technology traceable meter. Ozone production was evaluated after extended bulb run time. RESULTS: Calibration of UV intensity labels was noted to have color-change saturation at 100 mJ/cm2. Dose measurements with the UV intensity labels on the FFR demonstrated symmetrical dose to all surfaces, but symmetry was not supported by measurements with the UVGI meter. There was substantial dose fall off on the lateral aspects of the FFR. No ozone production was noted in the UVC system. CONCLUSIONS: UV intensity labels for characterization of dose provided a false suggestion of symmetry compared with the UVGI meter. Estimates of appropriate exposure times to reach 1000 mJ/cm2 should be significantly increased to account for geometry of FFR and lateral dose fall off.

3.
Data Brief ; 10: 151-181, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27981206

RESUMO

The data presented in this article are related to the research article, "HPLC-based enzyme kinetics assay for glucosinolate hydrolysis facilitate analysis of systems with both multiple reaction products and thermal enzyme denaturation" (C.K. Klingaman, M.J. Wagner, J.R. Brown, J.B. Klecker, E.H. Pauley, C.J. Noldner, J.R. Mays,) [1]. This data article describes (1) the synthesis and spectral characterization data of a non-natural glucosinolate analogue, 2,2-diphenylethyl glucosinolate, (2) HPLC standardization data for glucosinolate, isothiocyanate, nitrile, and amine analytes, (3) reaction progress curve data for enzymatic hydrolysis reactions with variable substrate concentration, enzyme concentration, buffer pH, and temperature, and (4) normalized initial velocities of hydrolysis/formation for analytes. These data provide a comprehensive description of the enzyme-catalyzed hydrolysis of 2,2-diphenylethyl glucosinolate (5) and glucotropaeolin (6) under widely varied conditions.

4.
Anal Biochem ; 516: 37-47, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27742213

RESUMO

Glucosinolates are plant secondary metabolites abundant in Brassica vegetables that are substrates for the enzyme myrosinase, a thioglucoside hydrolase. Enzyme-mediated hydrolysis of glucosinolates forms several organic products, including isothiocyanates (ITCs) that have been explored for their beneficial effects in humans. Myrosinase has been shown to be tolerant of non-natural glucosinolates, such as 2,2-diphenylethyl glucosinolate, and can facilitate their conversion to non-natural ITCs, some of which are leads for drug development. An HPLC-based method capable of analyzing this transformation for non-natural systems has been described. This current study describes (1) the Michaelis-Menten characterization of 2,2-diphenyethyl glucosinolate and (2) a parallel evaluation of this analogue and the natural analogue glucotropaeolin to evaluate effects of pH and temperature on rates of hydrolysis and product(s) formed. Methods described in this study provide the ability to simultaneously and independently analyze the kinetics of multiple reaction components. An unintended outcome of this work was the development of a modified Lambert W(x) which includes a parameter to account for the thermal denaturation of enzyme. The results of this study demonstrate that the action of Sinapis alba myrosinase on natural and non-natural glucosinolates is consistent under the explored range of experimental conditions and in relation to previous accounts.


Assuntos
Glucosinolatos/química , Glicosídeo Hidrolases/química , Temperatura Alta , Proteínas de Plantas/química , Desnaturação Proteica , Sinapis/química , Cromatografia Líquida de Alta Pressão/métodos , Concentração de Íons de Hidrogênio , Cinética
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