Chemistry Commons^™

Establishment Of Protocols To Measure Near-Ir(Nir) Surface-Enhanced Raman Scattering (Sers) Signals Of Nir Dye, Justin B. Ramsey

Forensic Science Master's Projects

Biomedical imaging techniques are crucial for early disease diagnostics, particularly for life-threatening conditions. However, traditional methods have inherent limitations, such as restricted spatial resolution and potential risks associated with repeated exposure to ionizing radiation. Near-infrared (NIR) surface-enhanced Raman spectroscopy (SERS) presents a promising alternative due to its minimal risks and potential for high-resolution biomedical imaging. A key challenge in NIR-SERS biomedical imaging is the development of biocompatible, nontoxic SERS substrates that can be safely introduced into the human body, targeting specific cells and tissues effectively.

NIR-SERS substrates typically consist of gold nanoparticles (AuNPs) modified with biorecognition elements and reporter molecules, …

The Analysis Of Artificially Flavored Coffees, Hannah Knights

Longwood Senior Thesis Proposal

This project aims to determine the molecular components that give artificially flavored coffees their advertised flavor. Much work has been conducted to determine various characteristics such as antioxidant properties, phenolic compounds, flavors, and aromas found in natural coffees. In addition, there is ample literature on the results of sensory tests for a variety of commercial coffees. However, not much work has been conducted to determine the compounds found in artificially flavored coffees that give rise to their distinctive aroma and flavor. This is, perhaps, due to the proprietary nature of the flavoring process employed by commercial producers. The goal of …

Pressure Dependence Of The Rate Coefficient Of Ozone Using Master Equation Simulations Of Recombination Kinetics, Adil Yermek

Master's Theses (2009 -)

The ozone layer in Earth’s atmosphere is distinctive and crucial for the evolution of life. Investigating the process of ozone formation aids in comprehending the evolution of our planet’s atmosphere. The reaction that forms ozone is O + O2 → O3. One can describe ozone forming reaction approximately using Lindeman mechanism, which is very handy. However, its limitation arises from assuming a steady-state approximation, which neglects transient dynamics and complexities that could impact reaction kinetics under non-equilibrium conditions. For this reason, Master Equation simulations can be seen as an enhancement or extension of the Lindemann mechanism, providing a thorough understanding …

Visible-Light-Driven Reactions From A Six-Coordinate Nickel(Ii) Complex, Lakmini Lochana Edirisinghe Arachchilage

Master's Theses (2009 -)

Transition metal complexes capable of absorbing visible light can be excited upon light irradiation and facilitate chemical bond formation and cleavage. In this approach, a transition metal-substrate complex is formed in the ground state, followed by photoinduced substrate activation via an inner-sphere mechanism. Unlike well-established photoredox catalysis that does not involve substrate binding, the ground-state interaction here is important for substrate activation. Among the 3d transition metals, nickel is considered a cost-effective alternative to Ru- and Ir-based photocatalysts due to its ability to accommodate different oxidation states. However, the application of Ni photocatalysis in synthesis had remained largely underexplored. In …

Theoretical And Experimental Evaluation Of The Electronic Relaxation Mechanisms Of 2-Pyrimidinone: The Primary Uva Absorbing Moiety Of The Dna And Rna (6–4) Photolesion, Sean J. Hoehn, Sarah E. Krul, Carlos E. Crespo-Hernández

Faculty Scholarship

The (6–4) photolesion is a key photodamage that occurs when two adjacent pyrimidine bases in a DNA strand bond together. To better understand how the absorption of UVB and UVA radiation by the 2-pyrimidinone moiety in a (6–4) lesion can damage DNA, it is important to study the electronic deactivation mechanism of its 2-pyrimidinone chromophore. This study employs theoretical (MS-CASPT2/cc-pVDZ level) and experimental (steady state and femtosecond broadband spectroscopic) methods to elucidate the photochemical relaxation mechanisms of 2-(1H)-pyrimidinone and 1-methyl-2-(1H)-pyrimidinone in aqueous solution (pH 7.4). In short, excitation at 320 nm leads to the population of the S1¹(ππ*) …

Beta Lactams Anticancer Effect On Human Breast Cancer, Mcf-7 Cell Line, Ailis A. Abalos

Theses and Dissertations

Cancer is a disease where abnormal cells replicate uncontrollably in that same region and/or other parts of the body. One in eight women are diagnosed with breast cancer, thus making it the second leading cause of cancer-related deaths in the U.S. Chemotherapy, is the utilization of medicinal compounds (drugs) to treat cancer. While most are nonspecific and target both cancer and healthy cells, more emphasis is on developing drugs with specificity (only target tumor cells) and low toxicity. Interestingly, Beta Lactams (β-lactams) have emerged as a class of compounds that are effective in the treatment of various cancers. The benefits …

Modulating Covalency In A Ni-H-Al Subunit: Synthesis And Characterization Of A Series Of Electronically Differentiating Ni-Al Heterometallics, Aleida Guadalupe Gonzalez

Theses and Dissertations

Metal hydrides are moieties that are present in a variety of applications as intermediates in catalysis. Despite the vast utilization of metal hydrides, monometallic metal hydride complexes bear limitations in inert-bond activation and functionalization. A strategy to overcome these limitations and access more challenging reactivity is utilizing metal-metal cooperativity on a single platform to further activate hydride moieties. Although incorporating multiple metal centers on a single ligand scaffold has been realized, access to heterometallic hydride-bearing complexes is a greater synthetic challenge. Given the limitations in accessing such systems, the reactivity and electronic structure of heterometallic hydrides are seldom studied. Recently, …

A Deep Dive Into The Conformations Of Fluorine-Substituted Benzoic Acids And Ethanesulfonic Acid And Spectroscopic Characterizations Of Their Hydrogen-Bonded Complexes, Alitza Gianina Gracia

Theses and Dissertations

Microwave spectroscopy is a technique used to study the molecular structures of a wide range of systems. The first part of the thesis focuses on fluorinated benzoic acids and complexes they form through hydrogen bonding to explore the fluorination effect, while the last part shifts to ethanesulfonic acid and its interaction with water. The study of 3,4,5-triflurorbenzoic acid with formic acid offers insight on the proton tunneling process, which is a process that occurs in many chemical and biological processes. Microwave spectroscopy can help provide dynamic information for the better understanding of this fundamental process. Solvation is another topic that …

Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe

Markey Cancer Center Faculty Publications

Werner syndrome (WS) is an autosomal recessive disease caused by loss of function of WRN. WS is a segmental progeroid disease and shows early onset or increased frequency of many characteristics of normal aging. WRN possesses helicase, annealing, strand exchange, and exonuclease activities and acts on a variety of DNA substrates, even complex replication and re- combination intermediates. Here, we review the genetics, biochemistry, and probably physiological functions of the WRN protein. Although its precise role is unclear, evidence suggests WRN plays a role in pathways that respond to replication stress and maintain genome stability particularly in telomeric regions.

A Comparison Of Structure, Bonding And Non-Covalent Interactions Of Aryl Halide And Diarylhalonium Halogen-Bond Donors, Nicole Javaly, Theresa M. Mccormick, David R. Stuart

Chemistry Faculty Publications and Presentations

Halogen bonding permeates many areas of chemistry. A wide range of halogen-bond donors including neutral, cationic, monovalent, and hypervalent have been developed and studied. In this work we used density functional theory (DFT), natural bond orbital (NBO) theory, and quantum theory of atoms in molecules (QTAIM) to analyze aryl halogen-bond donors that are neutral, cationic, monovalent and hypervalent and in each series we include the halogens Cl, Br, I, and At. Within this diverse set of halogen-bond donors, we have found trends that relate halogen bond length with the van der Waals radii of the halogen and the non-covalent or …

Carbon-Based Nanocomposite Membranes For Membrane Distillation: Progress, Problems And Future Prospects, Chhabilal Regmi, Yuwaraj K. Kshetri, S. Ranil Wickramasinghe

Chemical Engineering Faculty Publications and Presentations

The development of an ideal membrane for membrane distillation (MD) is of the utmost importance. Enhancing the efficiency of MD by adding nanoparticles to or onto a membrane’s surface has drawn considerable attention from the scientific community. It is crucial to thoroughly examine state-of-the-art nanomaterials-enabled MD membranes with desirable properties, as they greatly enhance the efficiency and reliability of the MD process. This, in turn, opens up opportunities for achieving a sustainable water–energy–environment nexus. By introducing carbon-based nanomaterials into the membrane’s structure, the membrane gains excellent separation abilities, resistance to various feed waters, and a longer lifespan. Additionally, the use …

Improvement Of Triboelectric Nanogenerator By As-Prepared Lithium Niobate For Energy Harvesting And Sensing Applications, Jahid Inam Chowdhury

Theses and Dissertations

One readily available green energy source that is used to address the small-scale energy requirement is mechanical energy. To harvest mechanical energy, supply energy for upcoming electronic devices, and enable flexible health monitoring, triboelectric nanogenerators composed of perovskite and lightweight polymers have garnered significant interest. A material named lithium niobate (LiNbO3) was produced in two different phases and used to make a flexible triboelectric nanogenerator (TENG). Furthermore, lightweight polydimethylsiloxane (PDMS), Polyvinyl Alcohol (PVA), and LiNbO3 nanoparticles were used to produce a small triboelectric nanogenerator that successfully converts mechanical energy into electricity. LiNbO3 nanoparticles were first created and loaded into polydimethylsiloxane …

Synthetic And Mechanistic Studies Of Ruthenium Catalyzed C–N And C–H Bond Activation Reactions, Krishna Prasad Gnyawali

Dissertations (1934 -)

Transition metal catalyzed C–H and C–N functionalization methods have emerged as an innovative tool for designing efficient synthesis of fine chemicals by using readily available starting materials without the formation of wasteful byproducts. One of the paramount challenges in C–H functionalization research field has been to promote regio- and stereoselective C–H bond activation on saturated hydrocarbon substrates. While much progress has been achieved on promoting selective sp2 C–H activation reactions on unsaturated hydrocarbon substrates in the past decades, catalytic sp3 C–H bond and functionalization methods on saturates hydrocarbon substrates remain as the frontier topic of C–H functionalization research. The well-defined …

Precision Deuteration And Hydrofunctionalization Of Aryl Alkynes And Alkenes, Samantha E. Sloane

Dissertations (1934 -)

The similar nature of the hydrogen atom to its isotope, deuterium, allows for the simple exchange of hydrogen atoms for deuterium atoms in drug molecules to alter the absorption, distribution, metabolism, and excretion properties. Installing the deuterium functionality into a specific site in the molecule is essential. Selective hydrofunctionalization reactions of alkynes and alkenes using the highly reactive catalytic Cu–H species have been well developed, and synthetic organic chemistry methods to selectively incorporate one or two deuterium atoms into the benzylic site of organic compounds, a key metabolic position, are elusive. A Cu–H catalytic approach offers selectivity and reactivity to …

Preferential Crystallization Of (±)-Pinenyllithium·Tmeda, Alexander N. Erickson, Curtis Haltiwanger, Masoumeh Rahim, Charles M. Garner

Chemistry Faculty Research and Publications

(±)-Pinenyllithium·TMEDA or (tetra­methyl­ethylenedi­amine-κ²N,N′)(η³-6,6-di­methyl-2-methylenebi­cyclo­[3.1.1]hept­yl)lithium, [Li(C₁₀H₁₅)(C₆H₁₆N₂)], is readily pre­pared from β-pinene, butyl­lithium and TMEDA, and the racemic material pre­fer­entially crystallizes even from 96:4 (92% ee) mixtures of (−)- and (+)-β-pinene, respectively. The structure is monomeric, with the geminal-dimethyl bridge of the bicyclic structure shielding one face of the allyl system, restricting the lithium to the opposite face and preventing the Li–all­yl–Li aggregation observed with some other allyl­lithium systems. The symmetry of the allyl system, bond lengths, bond angles and out-of-plane deviations …

Study Of Atypical Alarmone Synthesis In Clostridioides Difficile, Declan Nathaniel Butler

Chemistry & Biochemistry Theses & Dissertations

Clostridioides difficile is a Gram-positive anaerobic bacterium that causes infections in humans that costs healthcare systems billions per year. C. difficile infection has high rates of recurrence due to multiple antibiotic resistance. When bacteria are in stressful environments, they produce hyperphosphorylated guanosine ribonucleotide signaling molecules called alarmones. The accumulation of alarmones activates the stringent response (SR), in which bacterial cells induce transcription of stress survival genes to delay growth and replication. The C. difficile SR is regulated by enzymatic activity of a bifunctional synthetase/hydrolase, RelA/SpoT homolog (RSH), and a monofunctional small alarmone synthetase (RelQ). Additionally, the SR is potentially regulated …

Students’ Science Literacy On Discussion-Based Contextual Approaches Of Human Reproductive System Learning, Yeni Mulyaningsih, Chaerul Rochman, Adam Malik, Tri Wahyu Agustina, Yulia Sukmawardani, Nur Hamidah, Nurul Annisa

Jurnal Pendidikan Sains

The aim of this study was to enhance students’ science literacy through a discussion-based contextual approach in the learning of the human reproductive system. This quantitative research employed an experimental method with a quasi-experimental posttest-only design. The study involved 60 students, with 30 students each in class XI MIPA 4 serving as the experimental group and class XI MIPA 5 serving as the control group. The control group received instruction through a conceptual approach-based lecture method, whereas the experimental group engaged in learning through a contextual approach-based discussion method. The research instrument comprised 10 open-ended science literacy questions pertaining to …

Analysis Of Genetic Engineering Material Misconceptions In Biology Textbooks For Ninth-Grade In Yogyakarta, Silfi Pratiwi, Purwanti Pratiwi Purbosari, Oktira Roka Aji, Rinaldi Rizal Putra

Jurnal Pendidikan Sains

Textbooks play a pivotal role in the pedagogical landscape, serving as indispensable aids for learning, founts of knowledge, and platforms for practical application. This study endeavors to scrutinize the content of textbooks, specifically focusing on ninth-grade biology textbooks within the educational milieu of Yogyakarta City, and to juxtapose these contents with existing literature to discern potential misconceptions. Employing a descriptive qualitative approach, the investigation centers on printed biology textbooks utilized in ninth-grade curricula across junior high schools in Yogyakarta. The selection of textbooks for analysis was based on their prevalence as instructional materials, as determined through survey data. Genetic engineering …

Problem-Based Learning Model Assisted With A Humanistic-Merdeka Belajar Approach Improved Biology Students’ Learning Ownership, Dita Tri Mulyani, Dwi Listyorini

Jurnal Pendidikan Sains

Fostering ownership over learning constitutes a pivotal aspect for students to cultivate a comprehensive understanding, employ cognitive strategies effectively, hone essential skills, and refine learning methodologies. Preliminary studies have underscored a prevalent deficiency in the learning ownership among biology students, categorizing it as notably low. The purpose of this study is to ascertain the effect of the Project Based Learning (PBL) model assisted with a Humanistic-Merdeka Belajar (HMB) approach, in nurturing students’ ownership of their learning endeavors. Employing a quasi-experimental design, the research adopts a pre-test post-test non-equivalent control group configuration, administered both prior to and following the intervention within …

Asistensi Mengajar (Am) Program In Merdeka Belajar Kampus Merdeka (Mbkm) As A Pedagogical Mastery Accelerator For Vocational High School Teacher Candidates, Muhammad Idris Effendi, Yoto Yoto, Widiyanti Widiyanti

Jurnal Pendidikan Sains

This research delves into the issue of inadequate pedagogical proficiency among vocational high school (SMK) teacher candidates, primarily stemming from the constrained timeframe of educational internships, typically spanning a mere two months. As an option, this study suggests the implementation of an Asistensi Mengajar (AM) initiative within the framework of the Merdeka Belajar Kampus Merdeka Program (MBKM), extending over a semester’s duration. Employing a literature review methodology, the research highlights that the brevity of conventional two-month internships poses a significant impediment to the development of pedagogical acumen among SMK teacher candidates. The proposed option entails an AM program under MBKM, …

Identify Resources Activated By Students When Solving Straight Motion Kinematics Problems With Different Representation, Nur Utami Amaliah, Sutopo Sutopo, Eny Latifah, Hutkemri Zulnaidi

Jurnal Pendidikan Sains

This research aims to explore kinematic resources in linear kinematics by utilizing different forms of problem representation. The study was conducted by administering 15 reasoned multiple-choice questions to 146 high school students from three districts in Central Sulawesi, Indonesia. The research instrument covers topics in linear kinematics, including distance, displacement, speed, and velocity, presented through diagrammatic representations, graphs, and mathematical equations. The students’ written answers were analyzed both quantitatively and qualitatively. Quantitative analysis was conducted to determine descriptive statistics from the data, while qualitative analysis identified the resources students activated when solving these questions. The findings reveal that the various …

Pseudo-Siamese Network Combined With Label-Free Raman Spectroscopy For The Quantification Of Mixed Trace Amounts Of Antibiotics In Human Milk: A Feasibility Study, Jing Yi Mou, Muhammad Usman, Jia Wei Tang, Quan Yuan, Zhang Wen Ma, Xin Ru Wen, Zhao Liu, Liang Wang

Research outputs 2022 to 2026

The utilization of antibiotics is prevalent among lactating mothers. Hence, the rapid determination of trace amounts of antibiotics in human milk is crucial for ensuring the healthy development of infants. In this study, we constructed a human milk system containing residual doxycycline (DXC) and/or tetracycline (TC). Machine learning models and clustering algorithms were applied to classify and predict deficient concentrations of single and mixed antibiotics via label-free SERS spectra. The experimental results demonstrate that the CNN model has a recognition accuracy of 98.85% across optimal hyperparameter combinations. Furthermore, we employed Independent Component Analysis (ICA) and the pseudo-Siamese Convolutional Neural Network …

Effects Of The Biochar Of Senna Tora On The Soil Fertility Of Misau Farmlands, Bauchi State, Northern Nigeria, Ozoilo Onyeka Calistus, Umar Faruk Hassan, Auwal Adamu Mahmoud, Haruna Baba, Hamza Badamasi, Hannatu Akanang

Journal of Bioresource Management

The use of biochar as an amendment to the soil is attracting the scientific community's attention because of its cost-effectiveness, eco-friendliness, and its promising success in increasing the fertility of the soil and crop yield. In the present study, the effects of biochar from Senna tora applications on soil characteristics and the availability of micronutrients in Misau, Bauchi State, Nigeria, were explored. A completely randomized approach was adopted and duplicated three times, with reference soil (no biochar), 30-day, and 60-day biochar treatments. The biochar was removed at the end of the treatment, and soil samples from the various treatments were …

Discovering Potential In Non-Cancer Medications: A Promising Breakthrough For Multiple Myeloma Patients., Omar S Al-Odat, Emily Nelson, Tulin Budak-Alpdogan, Subash C. Jonnalagadda, Dhimant Desai, Manoj K Pandey

College of Science & Mathematics Departmental Research

Multiple myeloma (MM) is a common type of cancer that unfortunately leads to a significant number of deaths each year. The majority of the reported MM cases are detected in the advanced stages, posing significant challenges for treatment. Additionally, all MM patients eventually develop resistance or experience relapse; therefore, advances in treatment are needed. However, developing new anti-cancer drugs, especially for MM, requires significant financial investment and a lengthy development process. The study of drug repurposing involves exploring the potential of existing drugs for new therapeutic uses. This can significantly reduce both time and costs, which are typically a major …

Study Of Modified Salinomycin Analogs On Inhibition Of Triple Negative Breast Cancer Metastasis And Invasion, Farnaz Malekmarzban

Theses and Dissertations

Triple negative breast cancer (TNBC) is a more aggressive type of breast cancer which contains faster growth, higher metastasis rate and worse prognosis. The main challenge toward treatment of this type of cancer is being heterogeneous. Recently, Salinomycin (SAL) has been considered as a potential agent for triple negative breast cancer treatment. However, chemical modification of SAL is needed to improve SAL selectivity to cations and decrease its cytotoxicity. The purpose of this study was to evaluate the effect of chemically modified analogs of SAL on the viability, metastasis, Wnt pathway as well as angiogenesis of Triple negative breast cancer …

Surface Structures And Properties Of High-Voltage Licoo2: Reviews And Prospects, Jian-Jun Fang, Yu-Hao Du, Zi-Jian Li, Wen-Guang Fan, Heng-Yu Ren, Hao-Cong Yi, Qing-He Zhao, Feng Pan

Journal of Electrochemistry

Nowadays, the development of high-voltage LiCoO₂ (lithium cobalt oxide, LCO) cathodes has attracted the widespread attention from both the academic and industry fields. Among the multiple concerns, researches on the surface issues would provide the most effective performance optimization pathway for the synthesis of high-voltage LCO. In this work, the issues of high-voltage LCO, including the phase transitions and crack formation, the oxygen redox related issues and side reactions, as well as the surface structure degradation, have been systematically reviewed. Then, we further clarify the surface modulations, and the interplay between the surface modulation and electrolyte tuning. Finally, we …

In Situ Diffuse Reflectance Spectroelectrochemistry Of Cathode Materials In Lithium-Ion Batteries, Lu-Lu Chen, Hao-Ran Li, Wei-Yi Liu, Wei Wang

Journal of Electrochemistry

Developing in situ spectroelectrochemistry methods, which can provide detailed information about species transformation during electrochemical reactions, is very important for studying electrode reaction mechanisms and improving battery performance. Studying real-time changes in the surface of electrode materials during normal operation can be an effective way to assess and optimize the practical performance of electrode materials, thus, in situ and in operando characterization techniques are particularly important. However, batteries are hard to be studied by in situ characterization measurements due to their hermetically sealed shells, and there is still much room for battery characterizations. In this work, a specially designed battery …

Molybdenum Disulfide And Carbon Nanotubes Composite Electrode For Electrochemical Conversion Of Salinity Gradient Energy, Jia-Jun Li, Wei-Bin Zhang, Xin-Yu Liu, Jing-Lei Yang, Yi Yin, Ze-Qin Yang, Xue-Jing Ma

Journal of Electrochemistry

The ocean accounts for 97% of the total water resources on earth, covering over 70% of the map's surface area. With the continuous consumption of non-renewable energy sources such as fossil fuels and the rapid development of renewable energy, humans are increasingly paying attention to the utilization of ocean resources. Ocean energy includes tidal energy, wave energy, temperature difference energy, and salinity gradient energy. Salinity gradient energy is the energy generated by the interaction of seawater and fresh water, which is the ocean energy existing in the form of chemical energy. This energy is mostly generated in estuaries. The osmotic …

Harnessing Redox Polymer Dynamics For Enhanced Glucose-Oxygen Coupling In Dual Biosensing And Therapeutic Applications, Wassim El Housseini, Egor Baiarashov, Rokas Gerulskis, Adam Milam, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

The burgeoning field of continuous glucose monitoring (CGM) for diabetes management faces significant challenges, particularly in achieving precise and stable biosensor performance under changing environmental conditions such as varying glucose concentrations and O₂ levels. To address this, we present a novel biosensor based on the electroless coupling of glucose oxidation catalyzed by flavin-dependent glucose dehydrogenase (FAD-GDH) and O₂ reduction catalyzed by bilirubin oxidase (BOD) via a redox polymer, dimethylferrocene-modified linear poly(ethylenimine), FcMe₂-LPEI. Initial cyclic voltammetry tests confirm the colocalization of both enzymatic reactions within the potential range of the polymer, indicating an effective electron shuttle mechanism. …

The Discovery Of First Ret Protac With In Vivo Activity, Yafeng Wang

USF Tampa Graduate Theses and Dissertations

This report mainly discusses the development of RET Proteolysis targeting chimera PROTAC molecules based on Selpercatinib (LOXO-292) and Sulfono-γ-AApeptide PROTAC. A PROTAC molecule is a bifunctional molecule composed of two active domains and a linker. It works by inducing selective protein intracellular degradation. This technology was first discussed by Kathleen Sakamoto, Ray Deshaies and Craig Crews in 2001. Using various E3 Ligase, such as CRBN, pVHL, beta-TrCP1, Mdm2, DCAF15, DCAF16, RNF114, and c-IAP1, the PROTAC technology has been applied to several novel drug development,. Yale University licensed the PROTAC technology to Arvinas in 2013–14. For my research, Chapter one summarizes …