نتایج جستجو برای: mass spectroscopy
تعداد نتایج: 633953 فیلتر نتایج به سال:
The reaction between trialkyl phosphites with dialkyl actylenedicarboxylates in the presence of 2-hydroxyquinoline (2-quinolinol) leads to β-aminophsphonates derivatives which they have many applications in medicinal chemistry. When the reaction was performed by triphenylphosphite, a new pyrano quinoline compounds were obtained in fairly good yields. These compounds also ...
This article examines the manner in which some new methodologies and novel concepts have contributed to our understanding of how pulmonary surfactant reduces alveolar surface tension. Investigations utilizing small angle X-ray diffraction, inverted interface fluorescence microscopy, time of flight-secondary ion mass spectroscopy, atomic force microscopy, two-photon fluorescence microscopy and e...
Zero-kinetic-energy (ZEKE) photoelectron spectra of metalcarbide anions are presented, allowing a high resolu tion spectroscopic access to intermediates in catalytic reac tions of hydrocarbons on metal surfaces. As a first compound, FeC2 (an intermediate of the iron/acetylene system) has been chosen. Important for successful ZEKE spectroscopy was a special anion source and the selection by ti...
Staphylococcus sp. strain BP/SU1, capable of degrading the biopolymer and utilize it as a source of carbon and energy, was isolated from activated sludge using METABOLIX (MBX D411G). It was found that this strain was capable of accumulating poly(3-hydroxybutyric acid) P(3-HB), as granule poly (3-hydroxybutyric acid), p(3-HB), inclusion bodies when grown under suitable nutrient conditions. These...
Bacteriochlorophyll b (bchl b) has been isolated from the halophilic photosynthetic bacterium, Ectothiorhodospira halochloris. The pigment and a series of derivatives thereof are different from Bchl b from Rhodopseudomonas viriais by HPLC analysis, but similar by uv-vis spectroscopy. The chromatographic difference originates in different esterifying alcohols in the two pigments. The one from Rp...
An important aspect of understanding enzymatic reaction mechanisms is the determination of the molecular structures of enzyme-bound substrates and products. NMR spectroscopy is in a unique position in that it is the only relatively high resolution structural technique which can focus on specific parts of the molecule, such as enzyme-bound intermediates. It has been widely applied to the study o...
The electronic spectroscopy and photodissociation dynamics of the I3 radical are investigated with two experimental methods. The ground and several low-lying excited states of the I3 radical are characterized by photoelectron spectroscopy of I3 2 at 213 nm. Assignments of these states are discussed with reference to recent calculations. In addition, photodissociation of the I3 radical was inves...
High-performance liquid chromatography was used in combination with infrared ion spectroscopy for the identification of positional isomers of hydroxy-atorvastatins, the primary metabolites of the drug atorvastatin. The results demonstrate the direct applicability of infrared ion spectroscopy in the field of drug metabolism and, more generally, its promising role in state-of-the-art analytical l...
TiO2 films prepared by template-assisted sol-gel method were characterized by X-ray diffraction spectroscopy, scanning and atomic force electron microscopy, and Fourier transform infrared (FT-IR) spectroscopy. Based on the hexane adsorption-desorption analysis, the films have a surface area of 390-540 m(2)/g with pore size distribution narrowly centered around 10 nm. Optimal component ratio and...
pycnocycla spinosa aerial parts were collected weekly during four-month growth. hydrodistillation and gas chromatography coupled with mass spectroscopy techniques were used for essential oil and sesquiterpenes investigation. thirty-four components were identified, of which the characteristic sesquiterpenes were a -copaene, caryophyllene, a -humulene, b-ionene, d-cadinene, a -calacorene, caryoph...
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