Prediction of Partition Coeffecients  and Permeability of Drug Molecules in Biological Systems with Abraham Model Solute Descriptors Derived from Measured Solubilities and Water-to-Organic Solvent Partition Coefficients

Prediction of Partition Coeffecients and Permeability of Drug Molecules in Biological Systems with Abraham Model Solute Descriptors Derived from Measured Solubilities and Water-to-Organic Solvent Partition Coefficients

Date: February 10, 2012
Creator: Acree, William E. (William Eugene); Grubbs, Laura M. & Abraham, M. H. (Michael H.)
Description: Book chapter on the prediction of partition coefficients and permeability of drug molecules in biological systems with Abraham model solute descriptors derived from measured solubilities and water-to-organic solvent partition coefficients.
Contributing Partner: UNT College of Arts and Sciences
Mobile Order Theory as Applied to Polycyclic Aromatic Heterocycles

Mobile Order Theory as Applied to Polycyclic Aromatic Heterocycles

Date: August 1997
Creator: Fletcher, Kristin A.
Description: Experimental mole fraction solubilities of benzil, thianthrene, trans-stilbene, thioxanthen-9-one, diphenyl sulfone and dibenzothiophene sulfone are determined in pure noncomplexing and complexing solvents. Predicted solubility values are calculated for benzil, thianthrene, trans-stilbene and thioxanthen-9-one using expressions derived from Mobile Order theory. Large deviations between experimental and predicted solubilities in alcohol solvents exist, therefore optimized solute - solvent association constants are determined. Previously measured thianthrene solubilities in five binary alkane + cyclohexane solvent mixtures are compared with values predicted from Mobile Order theory using the measured solubility in each of the pure solvents as input parameters. The experimental mole fraction solubility of benzil in eight binary alcohol + 1-octanol solvent mixtures are also measured and compared with predicted values.
Contributing Partner: UNT Libraries
Applications of nanomanipulation coupled to nanospray mass spectrometry in trace fiber analysis and cellular lipid analysis.

Applications of nanomanipulation coupled to nanospray mass spectrometry in trace fiber analysis and cellular lipid analysis.

Date: December 2008
Creator: Ledbetter, Nicole
Description: The novel instrumentation of nanomanipulation coupled to nanospray mass spectrometry and its applications are presented. The nanomanipulator has the resolution of 10nm step sizes allowing for specific fine movement used to probe and characterize objects of interest. Nanospray mass spectrometry only needs a minimum sample volume of 300nl and a minimum sample size of 300attograms to analyze an analyte making it the ideal instrument to couple to nanomanipulation. The nanomanipulator is mounted to an inverted microscope and consists of 4 nano-positioners; these nano-positioners hold end-effectors and other tools used for manipulation. This original coupling has been used to enhance the current abilities of cellular probing and trace fiber analysis. Experiments have been performed to demonstrate the functionality of this instrument and its capabilities. Histidine and caffeine have been sampled directly from single fibers and analyzed. Lipid bodies from cotton seeds have been sampled indirectly and analyzed. The few applications demonstrated are only the beginning of nanomanipulation coupled to nanospray mass spectrometry and the possible applications are numerous especially with the ability to design and fabricate new end-effectors with unique abilities. Future study will be done to further the applications in direct cellular probing including toxicology studies and organelle analysis of ...
Contributing Partner: UNT Libraries
Investigation of Ultratrace Metallic and Organic Contaminants in Semiconductor Processing Environments

Investigation of Ultratrace Metallic and Organic Contaminants in Semiconductor Processing Environments

Date: May 1997
Creator: Xu, Fei, 1971-
Description: Detection of ultratrace levels of metallic ion impurities in hydrofluoric acid solutions and alkaline hydrogen peroxide solution was demonstrated using a silicon-based sensing electrode. The sensor's operation principle is based on direct measurements of the silicon open-circuit potential shift generated by the interaction between metallic ions and the silicon-based sensing surface. The new sensor can have practical applications in the on-line monitoring of microelectronic chemical processing. The detection of Ag+ content in KODAK waste water was carried out successfully by this novel sensor. Trace levels of organic impurities in the hydrofluoric acid solutions and in the cleanroom air were characterized by multiple internal reflection infrared spectroscopy (MIRIS) using an organics probe prepared directly from a regular silicon wafer.
Contributing Partner: UNT Libraries
Investigation of Copper Out-Plating Mechanism on Silicon Wafer Surface

Investigation of Copper Out-Plating Mechanism on Silicon Wafer Surface

Date: August 1995
Creator: Chien, Hsu-Yueh
Description: As the miniaturization keeps decreasing in semiconductor device fabrication, metal contamination on silicon surfaces becomes critical. An investigation of the fundamental mechanism of metal contamination process on silicon surface is therefore important. Kinetics and thermodynamics of the copper out-plating process on silicon surfaces in diluted HF solutions are both evaluated by several analytical methods.
Contributing Partner: UNT Libraries
Thermodynamics of Mobile Order Theory: Solubility and Partition Aspects

Thermodynamics of Mobile Order Theory: Solubility and Partition Aspects

Date: August 2004
Creator: De Fina, Karina M.
Description: The purpose of this thesis is to analyze the thermochemical properties of solutes in nonelectrolyte pure solvents and to develop mathematical expressions with the ability to describe and predict solution behavior using mobile order theory. Solubilities of pesticides (monuron, diuron, and hexachlorobenzene), polycyclic aromatic hydrocarbons (biphenyl, acenaphthene, and phenanthrene), and the organometallic ferrocene were studied in a wide array of solvents. Mobile order theory predictive equations were derived and percent average absolute deviations between experimental and calculated mole fraction solubilities for each solute were as follows: monuron in 21 non-alcoholic solvents (48.4%), diuron in 28 non-alcoholic solvents (60.1%), hexachlorobenzene (210%), biphenyl (13.0%), acenaphthene (37.8%), phenanthrene (41.3%), and ferrocene (107.8%). Solute descriptors using the Abraham solvation model were also calculated for monuron and diuron. Coefficients in the general solvation equation were known for all the solvents and solute descriptors calculated using multilinear regression techniques.
Contributing Partner: UNT Libraries
Synthesis and Characterization of Copper Releasing Polymer Nanoparticles

Synthesis and Characterization of Copper Releasing Polymer Nanoparticles

Date: May 2011
Creator: Harris, Alesha N.
Description: Polymeric nanoparticles were synthesized and loaded with Cu²⁺ to explore the therapeutic potential for catically active transition metal ions and complexes other than cisplatin. Two types of nanoparticles were synthesized to show the potential for polymer based vectors. Copper loading and release were characterized via inductively coupled plasma mass spectrometry (ICP MS), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and elemental analysis. Results demonstrated that Cu could be loaded to the nano-sized carriers in an aqueous environment, and that the release was pH-dependent. The toxicity of these particles was measured in HeLa cells where significant toxicity was observed in vitro via dosing of high Cu-loaded nanoparticles. No significant toxicity was observed in cells dosed with Cu-free nanoparticles.
Contributing Partner: UNT Libraries
Homework versus daily quizzes: The effects on academic performance within high school pre-AP chemistry.

Homework versus daily quizzes: The effects on academic performance within high school pre-AP chemistry.

Date: August 2010
Creator: King, Jo Laurie Marushia
Description: This research proposed to evaluate whether homework or daily quizzes were better for academic success within high-school pre-AP chemistry or if differences in the two methods were detectable. The study involved two years of data where homework was assigned and graded and one year of data where homework was suggested but daily quizzes provided the assessment. The mean of each of the unit tests were evaluated and t-tests were calculated. The results showed that over two-thirds of the units had statistically significant data when daily quizzes were utilized.
Contributing Partner: UNT Libraries
Thermodynamics of the Abraham General Solvation Model: Solubility and Partition Aspects

Thermodynamics of the Abraham General Solvation Model: Solubility and Partition Aspects

Date: August 2006
Creator: Stovall, Dawn Michele
Description: Experimental mole fraction solubilities of several carboxylic acids (2-methoxybenzoic acid, 4-methoxybenzoic acid, 4-nitrobenzoic acid, 4-chloro-3-nitrobenzoic acid, 2-chloro-5-nitrobenzoic acid,2-methylbenzoic acid and ibuprofen) and 9-fluorenone, thianthrene and xanthene were measured in a wide range of solvents of varying polarity and hydrogen-bonding characteristics. Results of these measurements were used to calculate gas-to-organic solvent and water-to-organic solvent solubility ratios, which were then substituted into known Abraham process partitioning correlations. The molecular solute descriptors that were obtained as the result of these computations described the measured solubility data to within an average absolute deviation of 0.2 log units. The calculated solute descriptors also enable one to estimate many chemically, biologically and pharmaceutically important properties for the ten solutes studied using published mathematical correlations.
Contributing Partner: UNT Libraries
Synthetic and Structural Chemistry of Ligand-substituted Triosmium Clusters and a Rhenium(i) Complex

Synthetic and Structural Chemistry of Ligand-substituted Triosmium Clusters and a Rhenium(i) Complex

Date: August 2013
Creator: Lin, Chen-Hao
Description: The reaction of 2-[(diphenylphosphino)methyl]-6-methylpyridine (PN) with Os3(CO)12-n(MeCN)n [where n = 0 (1), 1 (2), 2 (3)] has been investigated. Os3(CO)12 reacts with PN in the presence of Me3NO to afford the clusters Os3(CO)11(1-PN) (4) and 1,2-Os3(CO)10(1-PN)2 (5). X-ray diffraction analyses confirm the equatorial coordination of the phosphine(s) in 4 and 5, with the two phosphines in the latter cluster exhibiting a 1,2-trans orientation about the Os-Os vector that contains the two ligands. Treatment of the MeCN-substituted cluster Os3(CO)11(MeCN) and PN (1:1 ratio) in CH2Cl2 gives clusters 4 and 5, in addition to HOs3(η1-Cl)(CO)10(1-PN) (6) as a result of competitive activation of the reaction solvent. Cluster 6 contains 48e- and the diffraction structure reveals the presence of axial chloride and equatorial phosphine ligands which are located on adjacent osmium atoms. The bridging hydride ligand in 6 spans the Cl,P-substituted Os-Os vector. The reaction of Os3(CO)10(MeCN)2 with PN furnishes 5, 6, and 1,1-Os3(CO)10(2-PN) (7) in yields that are dependent on the reagent stoichiometry and reaction solvent. The solid-state structure of 7 confirms the chelation of the PN ligand to a single osmium atom via the pyridine and phosphine moieties at axial and equatorial sites, respectively. The bonding in 7 relative to other ...
Contributing Partner: UNT Libraries
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