Investigations on Mixed Gas Chromatographic Stationary Phases. Part 3: A Generalized Approximation of Retention Indices for Polar-Nonpolar Stationary Phase Mixtures

1981 ◽  
Vol 19 (1) ◽  
pp. 46-51 ◽  
Author(s):  
A. Grobler ◽  
G. Balizs
Keyword(s):  
Stationary Phase ◽  
Stationary Phases ◽  
Retention Indices ◽  
Mixed Gas

A CONTRIBUTION TO THE QUALITATIVE GC ANALYSIS OF SOME NON-CHLORINATED XENOBIOTIC CHEMICALS IN WASTE WATERS

1994 ◽  
Vol 30 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Biljana D. Škrbic ◽  
Mirjana B. Vojinovic-Miloradov
Keyword(s):  
Experimental Data ◽  
Stationary Phases ◽  
Retention Indices ◽  
Waste Waters ◽  
Gc Analysis ◽  
Experimental Values ◽  
Xenobiotic Chemicals

Gas chromatographic unified retention indices of some chlorinated xenobiotic chemicals, as pollutants in waste waters, on OV-101 and SE-30 stationary phases are presented. These values agree well with the corresponding experimental values used in the statistical treaunent of the experimental data.

Carboxylated cyclofructan 6 as a hydrolytically stable high efficiency stationary phase for hydrophilic interaction liquid chromatography and mixed mode separations

2016 ◽  
Vol 8 (31) ◽  
pp. 6038-6045 ◽  
Author(s):  
Yadi Wang ◽  
M. Farooq Wahab ◽  
Zachary S. Breitbach ◽  
Daniel W. Armstrong
Keyword(s):  
Liquid Chromatography ◽  
Benzoic Acid ◽  
Stationary Phase ◽  
Mixed Mode ◽  
High Efficiency ◽  
Stationary Phases ◽  
Hydrophilic Interaction Liquid Chromatography ◽  
Hydrophilic Interaction

Stationary phases composed of native cyclofructan 6 (CF6) and benzoic acid modified CF6 were synthesized and evaluated for hydrophilic interaction liquid chromatography (HILIC).

scholarly journals Kovats retention index-boiling point relationship of 2-phenyl-2-alkyl-acetonitriles on stationary phases of different polarity

2005 ◽  
Vol 11 (2) ◽  
pp. 55-58 ◽  
Author(s):  
Dusan Mijin ◽  
Dusan Antonovic
Keyword(s):  
Stationary Phase ◽  
Retention Index ◽  
Boiling Point ◽  
Chemical Potential ◽  
Stationary Phases ◽  
Kovats Retention Index ◽  
Standard Chemical Potential ◽  
Relationship Of ◽  
Kováts Retention Index ◽  
Methylene Group

Linear and reciprocial Kovats retention index-boiling point relationships known from the literature were used to study the Kovats retention index-boiling point dependence of 2-phenyl-2-alkylacetonitriles on stationary phases of different polarity (OV-17, OV-210 and OV-225). The standard chemical potential of the partitioning of one methylene group of an n-alkane for the stationary phase was calculated and compared with available literature data.

scholarly journals Studies on deoxyribonucleic acid-dependent ribonucleic acid polymerase from Escherichia coli. Variations of the enzyme activity during growth

1972 ◽  
Vol 129 (2) ◽  
pp. 291-299 ◽  
Author(s):  
K. A. Abraham ◽  
K. J. Andersen ◽  
A. Rognes
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Stationary Phases ◽  
Bacteriophage T4 ◽  
Polymerase Activity ◽  
Exponential Phase ◽  
Enzyme Preparations ◽  
Rna Polymerase Activity ◽  
Enzyme Molecules ◽  
Cellular Dna

1. RNA polymerase activity of Escherichia coli extracts prepared from cells in exponential and stationary phases of growth, when measured in the presence and absence of external template, showed significant qualitative differences. 2. In both extracts, polymerase activity was higher when assayed with external template, suggesting the presence of a pool of enzyme not bound to cellular DNA. 3. In the crude extract, the fraction of enzyme bound to cellular DNA is higher during the exponential phase of growth. 4. A method is described for the purification of enzyme molecules not tightly bound to cellular DNA from exponential- and stationary-phase cultures. 5. Purified enzyme preparations showed differences in template requirement and subunit composition. 6. On phosphocellulose chromatography of stationary-phase enzyme, a major portion of polymerase activity eluted from the column with 0.25m-KCl. In the case of exponential-phase enzyme, polymerase activity eluted from a phosphocellulose column mainly with 0.35m-KCl. 7. Enzyme assays done with excess of bacteriophage T4 DNA showed a strong inhibition of stationary-phase enzyme by this template. The exponential-phase enzyme was only slightly inhibited by excess of bacteriophage T4 DNA.

scholarly journals T7 phage factor required for managing RpoS inEscherichia coli

2018 ◽  
Vol 115 (23) ◽  
pp. E5353-E5362 ◽  
Author(s):  
Aline Tabib-Salazar ◽  
Bing Liu ◽  
Declan Barker ◽  
Lynn Burchell ◽  
Udi Qimron ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Stationary Phases ◽  
Inescherichia Coli ◽  
E Coli ◽  
Bacterial Transcription ◽  
Bacterial Rna ◽  
Predominant Form ◽  
Phage Development ◽  
T7 Phage

T7 development inEscherichia colirequires the inhibition of the housekeeping form of the bacterial RNA polymerase (RNAP), Eσ70, by two T7 proteins: Gp2 and Gp5.7. Although the biological role of Gp2 is well understood, that of Gp5.7 remains to be fully deciphered. Here, we present results from functional and structural analyses to reveal that Gp5.7 primarily serves to inhibit EσS, the predominant form of the RNAP in the stationary phase of growth, which accumulates in exponentially growingE. colias a consequence of the buildup of guanosine pentaphosphate [(p)ppGpp] during T7 development. We further demonstrate a requirement of Gp5.7 for T7 development inE. colicells in the stationary phase of growth. Our finding represents a paradigm for how some lytic phages have evolved distinct mechanisms to inhibit the bacterial transcription machinery to facilitate phage development in bacteria in the exponential and stationary phases of growth.

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