Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 14 of 14

Full-Text Articles in Entire DC Network

Regioselective Hydroamination Of Unactivated Olefins With Diazirine And Total Synthesis Of Nostodione A And Scytonemin, Qingyu Xing Jul 2024

Regioselective Hydroamination Of Unactivated Olefins With Diazirine And Total Synthesis Of Nostodione A And Scytonemin, Qingyu Xing

USF Tampa Graduate Theses and Dissertations

As an atom-economic way of carbon-nitrogen bond formation, hydroaminations are great tool for make amines, hydrazines, and other nitrogen-containing heterocycles. Specifically, radical hydroamination is a useful approach for functionalization of unactivated olefins, especially in sterically hindered environments. Diversification remains a challenge for radical hydroaminated products, since the nitrogen sources are carefully designed. In the first chapter of this dissertation, we report a highly diversifiable radical hydroamination reaction with diazirine as a nitrogen source and its potential applications in synthesis of several pharmaceutical interested compounds. Cobalt catalyzed regioselective hydroamination with diazirine shows wide function group tolerance, like phenyl thioether, ketones, esters, …


Discovery Of Small-Molecule Inhibitors For The Β-Catenin/B-Cell Lymphoma 9 Protein-Protein Interaction., Zilu Li Oct 2023

Discovery Of Small-Molecule Inhibitors For The Β-Catenin/B-Cell Lymphoma 9 Protein-Protein Interaction., Zilu Li

USF Tampa Graduate Theses and Dissertations

The Wnt/β-catenin signaling pathway is associated with activating genes that support cell proliferation, differentiation, and survival. Excessive activation of Wnt/β‐catenin signaling has been associated with development of several types of cancer and activation of stem-like cancer cells. Direct targeting of β‐catenin, the central hub in this signaling pathway, is a promising strategy to suppress the hyperactive β‐catenin signaling but has proven to be highlychallenging. Substantial efforts have been made to discover compounds that bind with β‐catenin, block β‐catenin mediated protein–protein interactions (PPIs) and suppress β‐catenin signaling. β‐catenin/BCL9 PPI has a smaller contacting area (1450 Å2) and a moderate binding affinity …


Design, Synthesis, And Self-Assembly Of Supramolecular Fractals Based On Terpyridine With Different Transition Metal Ions, Lei Wang Nov 2019

Design, Synthesis, And Self-Assembly Of Supramolecular Fractals Based On Terpyridine With Different Transition Metal Ions, Lei Wang

USF Tampa Graduate Theses and Dissertations

Fractals have existed in a variety of natural forms, and the concept of "fractal geometry" has been developed in many areas by humankind, including art, economics, mathematics, physics, chemistry, material science, and etc. In the field of chemistry, researchers have endeavored great efforts to express the concept using molecules either by theoretical prediction or using synthetic methods in the past few decades, and one successful example is the “Sierpiński triangle”. Challenge still remains to achieve other fractal geometries as well as high generation of fractals with precisely controlled shape and size. Coordination-driven self-assembly has witnessed a wide array of well-defined …


Evaluating The Evidence Base For Evidence-Based Instructional Practices In Chemistry Through Meta-Analysis, Md Tawabur Rahman Oct 2019

Evaluating The Evidence Base For Evidence-Based Instructional Practices In Chemistry Through Meta-Analysis, Md Tawabur Rahman

USF Tampa Graduate Theses and Dissertations

Investigating the effectiveness of instructional practices provides an evidence base to inform instructional decisions. Synthesizing research studies on instructional effectiveness provides an estimate of the generalizability of effectiveness across settings, along with an exploration of factors that may moderate the impact, which cannot be achieved within individual studies. This study sought to provide a synthesis of evidence- based instructional practices (EBIPs) particular to chemistry through meta-analysis. 99 studies were analyzed comprising a broader view of chemistry specific studies than past meta-analyses. The results showed that EBIPs feature a demonstrably positive impact on students’ academic performance in chemistry, although assessment topic …


Evaluation Of Trace-Metal And Isotopic Records As Techniques For Tracking Lifetime Movement Patterns In Fishes, Jennifer E. Granneman Jul 2018

Evaluation Of Trace-Metal And Isotopic Records As Techniques For Tracking Lifetime Movement Patterns In Fishes, Jennifer E. Granneman

USF Tampa Graduate Theses and Dissertations

The focus of this work was on the use of otolith microchemistry and fish eye lens chemical profiles to measure fish movement and provided indirect support for the use of otolith microchemistry to examine exposure to crude oil. Chapter 1 provides an introduction to the applications of otolith microchemistry and eye lens isotopic profiles. In the second chapter, which examined associations between metal exposure and lesion formation in fishes collected after the Deepwater Horizon (DWH) oil spill, I did not observe any change in oil-associated metal concentrations in otoliths coinciding with the timing of the DWH oil spill. This suggests …


Exploring Student Learning In Post-Secondary General Chemistry: Novel Tools For Measuring Linked Concepts And Study Habits, Li Ye Apr 2017

Exploring Student Learning In Post-Secondary General Chemistry: Novel Tools For Measuring Linked Concepts And Study Habits, Li Ye

USF Tampa Graduate Theses and Dissertations

This dissertation presents novel tools to help instructors measure students linking of content knowledge and the actions students perform for studying in the context of post-secondary General Chemistry.

The first tool described in this work is Creative Exercises (CEs), an open-ended assessment that has the potential to promote students making connections across the content covered in General Chemistry. Students are given a simple prompt that describes a chemistry situation, and asked to write as many statements as they can that are correct, distinct and relevant to the prompt and the course content. The written responses to CEs from both in-class …


Continuing The Career: An Oral History Of An Emeritus Professor, Kimberly Read Nov 2016

Continuing The Career: An Oral History Of An Emeritus Professor, Kimberly Read

USF Tampa Graduate Theses and Dissertations

The purpose of this study was to describe and explain the perspectives of a professor emeritus regarding his life experiences in the discipline of chemistry and in a career dedicated to research, service and teaching. Another purpose, interwoven within the perspective of this one individual, was to explore the potential influence a professor emeritus can have on his institution, and the impact the institution, its changing culture, and its shifting priorities may have on a member of the professoriate dedicated to this chosen career path. The research guiding questions for this study were: (a) What elements of this professor emeritus’ …


Evaluation And Application Of Instruments Measuring Spatial Ability And Attitude For College Chemistry Students, Xiaoying Xu Nov 2014

Evaluation And Application Of Instruments Measuring Spatial Ability And Attitude For College Chemistry Students, Xiaoying Xu

USF Tampa Graduate Theses and Dissertations

Student performance in college chemistry courses remains a concern for educators seeking to help improve the future STEM workforce. Besides math ability and prior chemistry knowledge, spatial ability and attitude toward chemistry have been considered as important factors influencing college chemistry performance. This work includes five studies and uses data collected from instruments to examine the relationships of these two factors - spatial ability and attitude - with student chemistry performance, and provides psychometric evidence for using the Purdue Visualization of Rotations test (ROT) and Attitude toward the Subject of Chemistry Inventory (ASCIv2) to measure these two factors, respectively, in …


Design And Synthesis Of Substituted 1,4-Hydrazine-Linked Piperazine-2,5- And 2,6-Diones And 2,5-Terpyrimidinylenes As Α-Helical Mimetics, Laura Anderson Jul 2009

Design And Synthesis Of Substituted 1,4-Hydrazine-Linked Piperazine-2,5- And 2,6-Diones And 2,5-Terpyrimidinylenes As Α-Helical Mimetics, Laura Anderson

USF Tampa Graduate Theses and Dissertations

The most common secondary structure of proteins is the alpha-helix. The alpha-helix can be involved in various protein-protein interactions (PPIs) through the recognition of three or more side chains along one face of the alpha-helix (Wells and McClendon, 2007). In recent years, there has been an increasing interest in the development of peptidic and non-peptidic compounds that bind to PPI surfaces. We focused on the design and synthesis of compounds that mimic the orientation of side chain residues of an alpha-helical protein domain. Although our scaffolds could potentially inhibit various PPIs, we focused mainly on the disruption of interactions among …


Animal Husbandry At Tell El Hesi (Israel): Results From Zooarchaeological And Isotopic Analysis, Shannon Marie Peck-Janssen Apr 2006

Animal Husbandry At Tell El Hesi (Israel): Results From Zooarchaeological And Isotopic Analysis, Shannon Marie Peck-Janssen

USF Tampa Graduate Theses and Dissertations

Located in today’s southern Israel, Tell el Hesi provides archaeologists with important clues to political and social changes in the ancient Near East. Zooarchaeological and stable isotopic analyses were conducted to evaluate shifts in animal husbandry practices during changing socioeconomic and sociopolitical conditions in the southern Levant.

During the Early Bronze Age, Tell el Hesi thrived as an agricultural grain producing center for the southern Levant. The acropolis served as both a storage and redistribution center for the inhabitants of Tell el Hesi. Coinciding with the collapse of the southern Levant, Tell el Hesi was abandoned throughout the Middle Bronze …


Prehistoric Human Subsistence Patterns In Northern Patagonia, Argentina: Isotopic Evidence For Reconstructing Diet, Scott Grammer Jan 2005

Prehistoric Human Subsistence Patterns In Northern Patagonia, Argentina: Isotopic Evidence For Reconstructing Diet, Scott Grammer

USF Tampa Graduate Theses and Dissertations

This study investigates the isotopic signatures of human skeletal remains that were recovered from several sites along the coast and inland in the north-central Patagonian region of Argentina. Human skeletal remains, dating from 2500 BP through the early historic period, are examined to determine the relative significance of terrestrial and aquatic food resources and subsequently, the extent to which coastal food resources were exploited by indigenous Argentinians. Carbon and nitrogen isotopes contained within human bone collagen and apatite are measured quantitatively to determine the relative significance of marine and terrestrial foods. This study, one of the first isotopic studies of …


Tracing The Source Of The Elephant And Hippopotamus Ivory From The 14th Century B.C. Uluburun Shipwreck: The Archaeological, Historical, And Isotopic Evidence, Kathryn Anne Lafrenz Apr 2004

Tracing The Source Of The Elephant And Hippopotamus Ivory From The 14th Century B.C. Uluburun Shipwreck: The Archaeological, Historical, And Isotopic Evidence, Kathryn Anne Lafrenz

USF Tampa Graduate Theses and Dissertations

The aim of this study is to establish the provenance of the elephant and hippopotamus ivory recovered from the 14th century B.C. Uluburun shipwreck in order to reconstruct the trade mechanisms and associated social relationships (e.g. diplomacy) operating in the eastern Mediterranean during the Late Bronze Age (LBA). Elephant ivory came either from Northeastern Libya, Southeastern Sudan via Egypt or northwestern Syria during this period. Hippopotamus ivory likewise was obtained from Syria, Palestine, or Egypt.

The Uluburun's cargo is reconstructed by the excavator, George Bass, as "royal," and primarily originates from Cyprus and Syro-Palestine. Indeed, LBA trade is largely understood …


Efforts Toward The First Enantioselective Total Synthesis Of Praziquantel And Synthetic Model Studies On Ecteinascidin 743 By Novel Aromatic C-H Insertion Methodology, Chiliu Chen Mar 2004

Efforts Toward The First Enantioselective Total Synthesis Of Praziquantel And Synthetic Model Studies On Ecteinascidin 743 By Novel Aromatic C-H Insertion Methodology, Chiliu Chen

USF Tampa Graduate Theses and Dissertations

The thesis is composed of three chapters. The aim of this thesis is to apply the novel dirhodium perfluorobutyrate-catalyzed intramolecular aromatic C-H insertion methodology to the enantioselective total synthesis of praziquantel and synthetic model studies on ecteinascidin 743, which belongs to the important tetrahydroisoquinoline family.

The first introductory chapter deals with the biological significance and previous synthetic methodologies. Our novel methodology is based on dirhodium perfluorobutyrate-catalyzed intromolecular aromatic C-H insertion reaction, which is crucial in the pivotal carbon-carbon bond formation when constructing isoquinolone moiety, which is ubiquitous in numerous natural products of significant biological and pharmacological activities.

The second chapter …


Chemical Fate Of Bunker C Fuel Oil In A Subtropical Marine Environment Following A Spill In Tampa Bay, Florida, Dana Lynn Wetzel Jul 1995

Chemical Fate Of Bunker C Fuel Oil In A Subtropical Marine Environment Following A Spill In Tampa Bay, Florida, Dana Lynn Wetzel

USF Tampa Graduate Theses and Dissertations

A hydrocarbon chemistry study was performed on sediments, oil masses and mangrove prop roots of a mangrove island in Boca Ciega Bay, Florida following a spill of Bunker C fuel oil in Tampa Bay. Normal alkane (n-alkane) and polycylic aromatic hydrocarbon (PAH) profiles were monitored for effects of degradation and weathering in these mediums for a period of one year. Initial findings indicated a loss of lower molecular weight n-alkanes and PAH's in sediments and prop roots. There was little or no loss of these low molecular weight components in the oil mass samples. Hydrocarbon profiles at the end of …