Some Studies Involving Pyridine N-oxide Reductase (open access)

Some Studies Involving Pyridine N-oxide Reductase

The study herein described involved the detection of pyridine N-oxide reductase activity in cell-free extracts of E. coli 9723, the determination of co-factors necessary for the enzymatic process, a study of the optimum conditions for enzyme catalysis, and a general characterization of the enzyme.
Date: August 1968
Creator: Waters, Samuel Wayne
System: The UNT Digital Library
Synthesis of Certain Aminooxy Compounds (open access)

Synthesis of Certain Aminooxy Compounds

The research described herein is concerned with the synthesis of certain organic compounds which have the amino-oxy grouping and are related in structure to the naturally occurring amines, putrescine, spermidine and spermine.
Date: January 1970
Creator: Lewis, Wassel Andrew
System: The UNT Digital Library
Synthesis and Study of Certain Amino Acids Containing the Pyridine Ring (open access)

Synthesis and Study of Certain Amino Acids Containing the Pyridine Ring

This study reported herein involves the synthesis and determination of certain biological activities of 4,5-dihydroxy-2-pyridinealanine and the synthesis of 3-pyridine-N-methylalanine.
Date: January 1969
Creator: Sanders, Edward Henry
System: The UNT Digital Library
The Ascorbic Acid Metabolism of Fifty College Women in the North Texas State Teachers College (open access)

The Ascorbic Acid Metabolism of Fifty College Women in the North Texas State Teachers College

A study of the ascorbic acid metabolism of a group of fifty college women in the North Texas State Teachers College between the months of April and July, 1943.
Date: 1943
Creator: Harshbarger, Marjorie
System: The UNT Digital Library
Regulation of Pyridine Nucleotide Metabolism in Saccharomyces cerevisiae (open access)

Regulation of Pyridine Nucleotide Metabolism in Saccharomyces cerevisiae

The levels of total nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), and their redox states were determined as the function of growth in S. cerevisiae. Cells growing in a medium containing 0.8% glucose exhibit two phases of exponential growth, utilizing glucose and ethanol, respectively. The NAD pool is 50% reduced during both stages of growth while the NADP pool is 67% reduced in glucose growth and 48% reduced in ethanol growth. The NAD/NADP ratio is constant during growth on glucose and a two-fold increase in the NAD/NADP ratio occurs upon exhaustion of glucose. The increased ratio is maintained during growth on ethanol. This alteration in the regulation of the relative levels of NAD and NADP may be due to a change in the regulation of NAD kinase and/or NADP phosphatase activities. These changes may be related to the redox state of the NADP pool.
Date: May 1976
Creator: Ting, Haung-yu
System: The UNT Digital Library
Selective Lipid Absorption (open access)

Selective Lipid Absorption

An experiment was designed to study in the same animal any preferential absorption of a free fatty acid in the presence of a triglyceride of the same fatty acid. Rats were administered a mixture of free fatty acid and its triglyceride labeled with carbon-13 and carbon-14 respectively. Each isotope in the fed lipid and in the lipid recovered from the gastrointestinal tract was measured. The isotope effect, if any, was studied by administering a mixture of palmitic acid-1-C13 and palmitic acid-1-C14.
Date: January 1960
Creator: Marcia, John Albion
System: The UNT Digital Library
Kinetic Investigation of Atomic Hydrogen with Sulfur-Containing Species (open access)

Kinetic Investigation of Atomic Hydrogen with Sulfur-Containing Species

The reactions of atomic hydrogen with methanethiol and that of atomic hydrogen with carbon disulfide were studied experimentally using flash-photolysis resonance-fluorescence techniques. Rate constants were determined over a range of temperatures and pressures, and through analysis and comparison to theoretical work details of the reactions were ascertained.
Date: December 2014
Creator: Kerr, Katherine Elaine
System: The UNT Digital Library
Studies on the Biological Activity of N-nitrosamines (open access)

Studies on the Biological Activity of N-nitrosamines

Two aspects of the biological activity of N-nitrosamines were studied. First, the effect of ascorbate on the mutagenicity of N-nitrosopiperidines was studied in the Ames Salmanella/ mammalian microsome mutagenicity test. The addition of ascorbate significantly enhanced the mutagenicity of these compounds. This enhancement was selective for N-nitrosamines suggesting a possible role of ascorbate in N-nitrosamine induced carcinogenicity. Second, the technique of velocity sedimentation in alkaline sucrose density gradients was applied to the detection of N-nitrosamine induced DNA damage in Balb/c 3T3 cells. This technique detected N-nitrosamine induced DNA damage when the cells were made permeable before treatment. This technique compares favorably with other test systems used to evaluate N-nitrosamines and should be useful in further studies of N-nitrosamines.
Date: August 1980
Creator: Barton, Rodney A. (Rodney Alan)
System: The UNT Digital Library
Analysis of Trace Amounts of Adulterants Found in Powders/Supplements Utilizing Direct Inject, Nanomanipulation, and Mass Spectrometry (open access)

Analysis of Trace Amounts of Adulterants Found in Powders/Supplements Utilizing Direct Inject, Nanomanipulation, and Mass Spectrometry

The regulations of many food products in the United States have been made and followed very well but unfortunately some products are not put under such rigorous standards as others. This leads to products being sold, that are thought to be healthy, but in reality contain unknown ingredients that may be hazardous to the consumers. With the use of several instrumentations and techniques the detection, characterization and identification of these unknown contaminates can be determined. Both the AZ-100 and the TE2000 inverted microscope were used for visual characterizations, image collection and to help guide the extraction. Direct analyte-probed nanoextraction (DAPNe) technique and nanospray ionization mass spectrometry (NSI-MS) was the technique used for examination and identification of all adulterants. A Raman imaging technique was than introduced and has proven to be a rapid, non-destructive and distinctive way to localize a specific adulterant. By compiling these techniques then applying them to the FDA supplied test samples three major adulterants were detected and identified.
Date: August 2016
Creator: Nnaji, Chinyere
System: The UNT Digital Library