[Hepatic metabolic clearance with galactose].
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Galactose↗
Biomedical subjects
C Enache
Publications and source records attributed to C Enache.
Menu software for the processing of spectrofluorometry analysis.
Menu software is presented for the computer-assisted spectrofluorometric analysis of the 3,4-benzopyrene contents of different samples, determined by a method implying the addition of fluorescent substances in the presence of other fluorochromes. A system consisting of an SPF-500 spectrofluorometer interfaced to a Felix-M18 microcomputer was used for this purpose. The advantages of the computer-assisted processing of spectrofluorometric analyses are discussed.
Benzo(a)pyrene↗
Automation of laboratory instrumentation--recent achievements in the Stefan S. Nicolau Institute of Virology.
An automated system consisting of an SPF-500 spectrofluorometer interfaced to a Felix-M18 microcomputer was provided with a series of additional accessories benefitting from the inputs and outputs through the interface. An adequate set of programs for computer-controlled operations was developed. The system has allowed the performance of more than 15,000 absorption, emission and light scattering determinations. The role of interfacing to low cost computers in the automation of presently available laboratory instrumentation is discussed.
Academies and Institutes↗
RNA--streptomycin interaction on cellulose.
Bichromatic paper disk spectrophotometry allowed the demonstration of an analogy between the increase in the solubility of highly polymerized RNA complexed with streptomycin cations (which accounts for the preservation in vivo of the infectivity of a viral RNA--streptomycin complex) and the effect of a cellulose/solution interface on the distribution of the highly polymerized RNA.
Cellulose↗
Nucleic acid spectrophotometry on paper disks.
A bichromatic spectrophotometry study in the near UV spectral range was performed on paper disks impregnated with DNA and RNA in NaCl solutions of different concentrations. Absorbance curves plotted versus a NaCl molarity log-scale degree of polymerization and the solubility of the polynucleotide. The -a/b value, determined by a previously reported equation, appeared to be constant for a given nucleic acid, irrespective of the wavelength in the spectral range 205-280 nm. This phenomenon cannot be attributed to a heterogeneous macroscopic distribution of the nucleic acid throughout the disk.
DNA↗
2-propanol dependent RNA absorbance.
RNA absorbances Ad were determined by bichromatic spectrophotometry at 240, 260 and 280 nm, versus 350 nm values, on paper disks containing different 2-propanol concentrations and NaCl amounts. No significant differences in terms of the NaCl content could be observed at alcohol concentrations higher than 70%; the maximum Ad value was found to correspond to about 50% 2-propanol. The possible phenomena implied in the absorbance changes are discussed taking into account the peculiar action of 2-propanol on the water structure and content in the bulk phase within the paper capillaries and inside the macromolecular and aggregation structures of RNA and cellulose.
1-Propanol↗
RNA hydrolysis detection by paper disk spectrophotometry.
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Absorption↗
Felix-M18 microcomputer-controlled automation of spectrofluorometric measurements with applications in virology.
A system consisting of an Aminco SPF-500 spectrofluorometer interfaced to the Felix-M18 microcomputer was used in the automation of spectrofluorometric measurements with applications in virology. Programs, routines and subroutines in BASIC and in assembly language allow the operation of the spectrofluorometer and the processing of photometric data. The high efficiency of the system is illustrated by an application: the characterization of the fluorescence anisotropy value in polarized light of an influenza virus suspension preincubated with a fluorescent probe.
Computers↗
RNA absorbances in modified cellulose disks.
Bichromatic spectrophotometry determinations were performed on Whatman chromatographic paper disks impregnated with rRNA solutions of different concentrations, at ionic strengths ranging from nearly 0 to 1.4 M. The disks consisted of cellulose, either native or modified (by grafting of carboxymethyl, phosphate, Ecteola or DEAE groups, or by loading with silica gel). The results demonstrate that: 1) there is a positive correlation between the absorbance enhancement by multiple light scattering and the nearness of the nucleic acid molecules in relation to the surface of cellulose fibrils; b) the action on absorbance of ionic strength and of other physical factors differs in terms of the electric charges and of the exposure of other groups that may interact with nucleic acids through hydrogen bonds or Van der Waals forces.
Absorption↗
The distribution of nucleic acid chromophores at cellulose-water interfaces. 2. Thermodynamic parameters.
A Previous theoretical' model (O. L. Hörer, Adriana Grigorescu Rev. roum. Virol, 1992, 43, 33) allowed us to appraise the "absorbed" mole fraction chi of chromophores, using the Multiple Light Scattering Enhanced Absorbance (MLSEA) bichromatic photometry. In the present paper the data were used to express thermodynamic parameters, based on the Gibbs free enthalpy G. In terms of the ion exchange capacity of several chromatography papers used in the former paper, the RNA chromophore distribution at the interface was correlated with thermodynamic parameter, showing characteristic patterns. The thermally denatured DNA was studied in the same way and a new insight of the helix-coil transition in terms of ionic strength was achieved.
Adsorption↗