Chemistry Commons^™

Reduced Mediators Released By Cyanobacteria During Exoelectrogenesis Detected Using Differential Pulse Voltammetry, Laura T. Wey, Monica Brachi, Yagut Allahverdiyeva, Shelley D. Minteer

Chemistry Faculty Research & Creative Works

Cyanobacteria generate electrical current through exoelectrogenesis (extracellular electron transfer) downstream of photosynthesis, yet the identity of the endogenous redox mediator(s) responsible remains unresolved. Here, we apply differential pulse voltammetry (DPV) to detect and characterise redox-active species released by Synechocystis sp. PCC 6803 under illumination. To enable sensitive detection, we developed an electrolyte intermediate between BG11 (Blue-Green-11) growth medium and MOPS (3-(N-morpholino)propanesulfonic acid) buffer that minimises background electrochemical interference while maintaining short-term cellular functionality. DPV revealed multiple light-enhanced oxidation peaks (0.1–0.65 V vs. saturated calomel electrode (SCE)) that were not resolvable using cyclic voltammetry, providing evidence that cyanobacteria release reduced compounds …

Computational Studies Of Triplet State Formation In Zinc Dipyrrin Complexes, Reuben Kwabla Adigbli

Electronic Theses and Dissertations

Zinc dipyrromethene complexes are promising earth-abundant photosensitizers due to their strong visible-light absorption and tunable excited states. To rationally design them for photocatalysis and photodynamic therapy, a molecular-level understanding of triplet-state formation is needed, but details of intersystem crossing remain unclear. To study the effect of π-extension, we synthesized an indole-substituted zinc dipyrrin complex: the dipyrromethane ligand was prepared from indole and mesitaldehyde, oxidized to the dipyrromethene, then coordinated with zinc. DFT and TD-DFT calculations determined ground and excited-state geometries and energies in different solvents, modeled absorption spectra, and visualized charge distributions. The results show how solvent polarity shifts energies …

Study Of Fast Switching Metastable-State Photoacids And Controlled Drug Release From Polycaprolactone (Pcl) Vascular Scaffold, Rana Salman Abbood Abbood

Theses and Dissertations

Metastable-state photoacid (mPAH) has become a common tool for controlling and driving chemical processes with light. mPAHs with fast reverse reactions are desirable for precise temporal control or generating quick pulses of proton concentration. In this work, different approaches towards fast reversing mPAHs are studied. Experimental and computational results showed that stabilizing the charge–transfer intermediate is an effective way to increase the rate. A novel mPAH with a reverse reaction ≈500 times faster than the most widely used mPAH in methanol has been developed. Another water-soluble mPAH exhibited a reverse reaction with a rate constant of 7.8 s−1, the fastest …

Stimuli-Responsive Proton Transfer: Photoacid Design, Co2 Sorbent Regeneration, And Polymer Applications, Melyse Ava Laud

Theses and Dissertations

Control over proton transfer enables the regulation of many pH-dependent chemical and material processes. Stimuli-responsive functional materials provide a means of achieving this control. Functional materials such as Metastable-state photoacids (mPAHs) reversibly release large amounts of protons when stimulated by light from a weakly acidic site within their structure. However, the dark acidities of previously reported mPAHs limit their use under basic conditions. To address this limitation, a benzimidazole-type mPAH was developed with an improved ground-state pKa of 11.9 and a metastable-state pKa of 9.8, enabling reversible proton transfer under mildly basic conditions. Additional mPAHs were examined to determine how …

Efficient Removal Of Methyl Orange Dye Via A Mnfe₂O₄/Go Nanocomposite With A Ctab Dual-Layer Surfactant Coating, Taher Karami, Soleiman Bahar, Reza Mostafazadeh

Research outputs 2022 to 2026

This study investigated the adsorption of methyl orange (MO) from aqueous solutions using a novel MnFe₂O₄/GO nanocomposite coated with cetyltrimethylammonium bromide (CTAB). The dual-layer surfactant modification facilitates both electrostatic and lipophilic interactions. This enhancement significantly improves dye removal efficiency. The adsorption process was monitored using spectrophotometry at 464 nm, with various characterization techniques confirming the structural and magnetic properties of the nanocomposite. The optimized parameters for maximum adsorption include a 2-minute ultrasonic dispersion, pH 6.8, and a surfactant-to-adsorbent ratio of 1, achieving a maximum adsorption capacity of 285.7 mg/g. The kinetic data followed a pseudo-second-order model, whereas the adsorption isotherm …

Development Of A Protein Mass Spectrometric Assay For The Characterization Of Colorectal Cancer Exosomes, Frank J. Reed Iv

Science University Research Symposium (SURS)

Exosomes (sEV) carry proteins involved in intracellular communication and colorectal cancer (CRC) biology, but their morphologic overlap with non-vesicular extracellular particles (NVEPs), and other extracellular vesicles (EVs), including exomeres and supermeres, complicates proteomic characterization. This aim of this study is to develop mass spectrometric assays that evaluate sEV enrichment, purity, and distinguish sEV CRC-associated protein cargo from EV and NVEP CRC-associated protein cargo to better classify the role of sEVs in CRC biology.

Our lab previously analyzed conditioned media from DiFi, cystic clone (CC), and spikey clone (SC) CRC cell lines purified using dialysis, concentration, and electrophoresis enrichment (DCE) by …

The Conquest For Information V The Fermi Paradox, Matthew A. Kramer

PANDION: The Osprey Journal of Research and Ideas

The concepts of intelligent life beyond earth and extraterrestrial civilizations have intrigued scientists and scholars alike. Intellectuals have suggested that extraterrestrial intelligence should be detectable somewhere in the grand universe; however, despite continued effort, no one has reliably documented evidence supporting extraterrestrial life, culminating in the Fermi Paradox. One perspective to solve the Fermi Paradox involves using logic and analytical reasoning skills to deduce the limits of detection based on what is most probabilistically determinable via the Drake equation. However, with information comes costs and these emergent energetic complexities drive civilizations to maximize computing power, converging into a blackhole transcendent …

Gravitational Constraints And Graviphilic Systems, Bradley E. Cantrell

PANDION: The Osprey Journal of Research and Ideas

Astronomical observation is revealing thousands of new worlds while inferentially suggesting the existence of countless others, as advances in gravitational-wave astronomy and cosmology continue to expand our grasp of the observable universe. This study introduces the gravitational viability factor, 𝐺v, and the concept of graviphilic systems as a framework for organizing astrobiological inquiry. 𝐺v is proposed as a conceptual framework for connecting universal biological constraints with contingent biological outcomes. Gravity is not merely a constraint on life but a useful organizing parameter for evaluating biological plausibility across environments. An abundance of potential telescope targets is available through …

Salvia Rosmarinus L.-Mediated Synthesis Of Silver Nanoparticles: Physicochemical Characterization And In Vitro Evaluation Of Antimicrobial Activity And Cytotoxicity, Raghad Ahmed Alhawi, Hawazin Ahmed Abid

Karbala International Journal of Modern Science

This study describes the biosynthesis of silver nanoparticles (AgNPs) using an aqueous Salvia rosmarinus L. (SRL) extract (Family: Lamiaceae) as a natural source of reducing and capping agents through an easy and green method assisted by blue diode laser irradiation (450 nm, 5 W, 5 min). The formation of rosemary-mediated AgNPs was verified by observing a color change in the solution and the presence of a surface plasmon resonance (SPR) band at 454 nm in the UV–Vis spectrum. XRD and FESEM revealed crystalline silver-containing nanostructures with an average estimated crystallite size of 15.53 ± 3.54 nm and particles with an …

T-Cinnamaldehyde-Driven Fe2o3 Nps: Activity Against Resistant Salmonella, Gallbladder Cancer, And Molecular Docking Focused On Bacterial Targets, Arshad Mahdi Hamad, Sarab Dalaf Khalaf, Suha Maher Abed

Karbala International Journal of Modern Science

Iron oxide nanoparticles (t-CA-Fe₂O₃ NPs) were synthesized in this study using a green preparation method with trans-cinnamaldehyde (t-CA) as a reducing agent. After observing the first sign of successful preparation, namely the color change, the properties were studied using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared spectroscopy (FTIR) techniques. All characterization results were satisfactory, indicating the success of the preparation process and the purity of the prepared nanoparticles (NPs). The molecular docking process of several proteins important in antibiotic resistance and virulence …

Bomb Calorimetry, Brian Van Hoozen

Physical Chemistry Lab

No abstract provided.

Determination Of The Acid Dissociation Constant Of Methyl Red, Brian Van Hoozen

Physical Chemistry Lab

No abstract provided.

Kinetics Of The Bromination Of Acetone, Part 1, Brian Van Hoozen

Physical Chemistry Lab

No abstract provided.

Kinetics Of The Bromination Of Acetone, Part 2, Brian Van Hoozen

Physical Chemistry Lab

No abstract provided.

The Vibronic Absorption Spectrum Of Iodine, Brian Van Hoozen

Physical Chemistry Lab

No abstract provided.

Physicochemical Characterization Of Surfactant-Stabilized Nanobubbles And Their Effect On Crystallization From Metastable Supersaturated Solutions, Vuk Uskoković

Administration and Staff Articles and Research

Present to a finite degree in atmospheric liquids, nanoscale air bubbles are fundamentally different in structure from their microscopic counterparts and their effects on chemical reactions have been relatively understudied. The objective of this study was to assess how nanobubbles stabilized by amphiphilic molecules of different ionic nature—including cationic cetyltrimethylammonium bromide (CTAB), anionic sodium dodecyl sulfate (SDS) and nonionic polyoxyethylene sorbitan monolaurate (Tween 20)—affect crystallization from metastable supersaturated solutions. These experiments were preceded by thorough spectroscopic, refractometric and light scattering characterization of ultrapure water containing surfactant-stabilized nanobubbles. ¹H and ¹³C NMR analyses suggested that the ionic surfactant molecules …

Optimizing Multi-Layer/Multi-Physics Passive Adaptive Thermal Enclosures For Climate-Responsive Energy Regulation: A Numerical Study, Rajae Bousselham, Mingjiang Tao, Sergio Granados-Focil, Adriana Hera, Steven Van Dessel

Chemistry

Adaptive facades regulate heat transfer by adjusting their thermal behavior in response to environmental conditions. Passive adaptive systems, including stimuli-responsive thermal storage materials, tunable radiative coatings, and variable-conductivity layers, offer significant potential for material-based thermal regulation. However, their combined potential remains unexplored, as most studies examine individual mechanisms in isolation. As a result, trade-offs among energy savings, material usage, design complexity, and climate responsiveness are often underrepresented, overlooking coupled interactions in multilayer assemblies limiting their effectiveness. This study develops a transient three-dimensional numerical framework coupling heat transfer with multi-objective optimization to evaluate trade-offs between minimizing annual energy consumption and enclosure …

A Review Of Gallium And Germanium Recovery From Industrial Solid Residues, Ernest V. Oteng, Marthias Silwamba, Lana Alagha, Alex Luyima

Mining Engineering Faculty Research & Creative Works

The global demand for critical elements such as gallium (Ga) and germanium (Ge), and the shift toward circular mining has accelerated the development of new extraction and recovery processing these metals from industrial solid residues. This transition is driven by a substantial surge in demand for advanced technologies and the depletion of primary ore. Consequently, industrial solid residues, particularly zinc processing residues, smelter slags, flue dusts, and coal fly ash, are emerging as viable alternative sources. These residues incorporate Ga and Ge through isomorphic substitution in phases such as ferrites, silicates, and glassy aluminosilicates, and are enriched by industrial processes, …

Conserved Iq Motifs, Divergent Apo-Calmodulin Recognition In Ube3b And Ube3c, Emily G. Schaffter, Xiaohuan Lu, Anna E. Tinklenberg, Megan G. Hill, Rafael H. Levin, Javier F. Tabima, Shuanghong Huo, Donald E. Spratt

Chemistry

Calmodulin (CaM) regulates diverse signaling proteins through recognition of short linear motifs, including isoleucine-glutamine (IQ) motifs that commonly bind Ca2+-free CaM (apo-CaM). The homologous to E6AP carboxyl terminus (HECT) E3 ubiquitin ligases ubiquitin protein ligase E3B (UBE3B) and ubiquitin protein ligase E3C (UBE3C) are closely related enzymes that both contain N-terminal IQ motifs, yet whether these motifs encode conserved modes of apo-CaM recognition has remained unclear. Here, we combined isothermal titration calorimetry, nuclear magnetic resonance (NMR) spectroscopy, and computational modeling to compare apo-CaM binding by the UBE3B and UBE3C IQ motifs. The UBE3B IQ motif bound apo-CaM with high affinity …

The Structure And Regulatory Mechanism Of The Emrb Rna Motif In Lactobacillus Acidophilus, Isabella J. Mezzenga, Brian M. Lee

Journal of the South Carolina Academy of Science

Major facilitator superfamily (MFS) transporters aid bacteria in expelling toxic compounds such as antibiotics, bile acids, and other substances. Previous bioinformatic studies identified the emrB motif as a potential regulatory RNA element. In Lactobacillus, this RNA motif is generally found in the intergenic region upstream of an MFS transporter gene with homology to the emrB gene from Escherichia coli. Secondary structure predictions of the intergenic region were used to define the structural features of this RNA motif. The emrB motif comprises two hairpins, though inclusion of neighboring regions is predicted to stabilize alternative secondary structures. A potential rho independent terminator …

Development And Validation Of An Ai-Assisted Eco-Batik Gringsing Student Worksheet, Intan Kurniawati, Arif Widiyatmoko, Bambang Subali 5, Novi Ratna Dewi

Jurnal Pendidikan dan Pembelajaran

Background: Science literacy among Indonesian students remains low, indicating a need for contextual learning resources that connect scientific concepts with students’ environments. Local cultural heritage such as Batik Gringsing, combined with artificial intelligence (AI) as a supporting tool, offers a promising context, yet their integration in a single student worksheet remains underexplored.

Objectives: This study aimed to develop and validate an AI-assisted Eco-Batik Gringsing student worksheet for science learning.

Methods: The study employed a research and development (R&D) approach adapted from the 4D model, covering the Define, Design, and Develop stages. The evaluation focused on the validity and practicality of …

Analytical Judgment In Chemical Education: Connecting Evidence, Reasoning, And Decisions, Paulo R.M. Correia, MaríLia Soares, Thiago R.L.C. PaixãO, David T. Harvey, Ian M. Kinchin

Chemistry & Biochemistry Faculty Publications

Students of analytical chemistry are often able to carry out procedures, perform calculations, and use technical terminology yet still struggle to interpret results and justify analytical decisions. These situations are widely recognized in teaching, but their underlying natures are rarely made explicit. This commentary addresses this difficulty through the concept of analytical judgment, described as the disciplined interpretation of analytical evidence under conditions of uncertainty to support justified decisions. The concept brings together cognitive and epistemic practices already recognized in science education while characterizing the particular configuration that they assume in analytical chemistry, where disciplinary concepts, evidence, uncertainty, and contextual …

Metal Oxide Semiconductor Gas Sensors For Exhaled Breath Cancer Biomarker Detection, Guang-Lan Chen, Hui-Hui Luo, Wen-Wen Peng, Shi-Yu Xu, Yu-Ting Li, Hui-Jie Ke, Si-Hui Zhong, Jia-Ao Wei, Tong Chen, Xiao-Kun Li, You-Lin Zhang, Wei Chen

Journal of Electrochemistry

Early cancer screening can significantly improve therapeutic outcomes, volatile organic compounds (VOCs) and other related gases in exhaled breath, as cancer-specific biomarkers, offer a novel approach for non-invasive diagnosis. Metal oxide semiconductor (MOS)-based gas sensors are pivotal for exhaled breath VOCs detection, featuring compact size, cost-effectiveness, and rapid response. This review summarizes the most recent five-year research advances in cancer biomarker detection, and clarifies the core mechanisms of electrical property changes from sensing material-VOCs interactions and key performance metrics including sensitivity, selectivity, humidity tolerance, response/recovery time, stability, and operating temperature. This review also highlights the optimization strategies of sensing materials …

Electrocatalytic Oxidation Of Ethylene Glycol To Glycolic Acid: From Mechanism And Catalyst Design To Emerging Neutral Electrolyte Systems, Man Zhang, Xue Li, Xin-Yu Peng, Lin Wang, Wen-Wen Chen, Yao-Yue Yang

Journal of Electrochemistry

Polyethylene terephthalate (PET) waste represents both an environmental burden and a loss of carbon resources. Alkaline depolymerization of PET yields terephthalic acid and ethylene glycol (EG). Electrocatalytic oxidation of EG to glycolic acid (GA), the monomer of biodegradable polyglycolic acid (PGA), offers a sustainable route driven by renewable electricity. However, the ethylene glycol oxidation reaction (EGOR) involves competing pathways toward C2 products (GA and oxalic acid) and C1 products (formic acid and CO₂), making selective GA production a central challenge. This review provides a comprehensive overview of recent progress in selective EG-to-GA electrooxidation from catalyst design, mechanistic understanding, …

Regularization-Based Crystallite Size Distribution Analysis Of Pt/C Catalysts From X-Ray Diffraction, Cheng-Long Ma, Wei-Yu Shi, Zhong-Jun Hou

Journal of Electrochemistry

Accurate determination of the platinum crystallite size distribution in carbon-supported platinum (Pt/C) catalysts is critical for evaluating both the initial performance and long-term durability of proton exchange membrane fuel cells (PEMFCs). Conventional characterization approaches—including transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and the Scherrer equation—are limited by restricted statistical sampling, sensitivity to support interference, or the inability to resolve the full breadth of the size distribution. In this work, we present a regularization-based inversion framework that extracts the volume-weighted crystallite size distribution directly from X-ray diffraction (XRD) line profiles, without requiring any a priori assumption regarding the functional form …

Autofield-Poa: A Hybrid Automl–Metaheuristic Framework For Automated Feature Selection In Recommender Systems, Mohammed Dheyaaldeen Taha, Waleed Kareem Ahmed, Rana Saad Mohammed, Zied O. Ahmed

Karbala International Journal of Modern Science

The problem of automated feature selection is one of the most important aspects of modern recommender systems, as overestimating the number of feature fields used, which can increase model complexity, inference latency, and performance degradation due to redundancy and noise. Although differentiable Automated Machine Learning (AutoML) based feature selection methods, including AutoField, are effective, they remain susceptible to initialization and local optima. Conversely, population-based metaheuristic algorithms are effective at global exploration, but are often inefficient in high-dimensional discrete spaces when randomly initialized. This paper presents AutoField-POA, a hybrid AutoML-metaheuristic framework that combines a differentiable controller with the Pelican Optimization Algorithm …

A Yolov8x Framework For Breast Lesion Localization Using Real-World Mammographic Images, Hadeel Abdul Majeed Ghazi, Yarub Alazzawi, Hussein Hasan Nsaif

Karbala International Journal of Modern Science

Breast cancer is one of the leading causes of mortality among women worldwide, and early and accurate mammographic assessment is important for timely diagnosis and improved patient survival. However, accurate breast lesion detection requires overcoming the issues of low lesion contrast, dense breast tissue, image noise, and variation in mammographic acquisition. In this study, we present a YOLOv8x-based computer-aided detection framework for automated breast lesion localization in full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) images acquired under heterogeneous clinical conditions. The framework was developed and evaluated using 501 clinical mammographic images obtained from multiple mammography systems, namely GE …

An Object-Level Semantic Video Transmission Framework For Iomt Based On Lightweight Yolo And Motion Triggering, Iman Kadhum Abbood, Alaa Shawqi Jaber

Karbala International Journal of Modern Science

In Internet of Multimedia Things (IoMT) environments, video capture and frame transmission consume substantial sensor energy and impose considerable network overhead because of redundant data transmission. Traditional approaches often rely on repeated pixel-level operations and frequent execution of deep segmentation models, thereby increasing computational and transmission costs. This paper proposes an Object-Level Semantic Video Transmission Framework (OSVT) for resource-constrained IoMT environments in which high-definition visual data must be transmitted over low-bandwidth wireless multimedia sensor networks (WMSNs). The proposed OSVT incorporates a dual-stage wake-up mechanism that remains in sleep mode during static scenes, thereby reducing transmission load. The high-power YOLOv11-seg module …

Systematic Profiling Of Encoder Architectures And Multimodal Embeddings In Protein Foundation Models Reveals Data Set-Driven Separability Regimes In Prediction Of Allosteric And Orthosteric Binding Sites, Alina Bazarova, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Allosteric regulation represents a fundamental mechanism of protein function, yet distinguishing allosteric from orthosteric protein-binding sites remains a persistent computational challenge. While multimodal protein foundation models offer the potential to integrate complementary biological signals, including sequence, structure, functional annotations, and conformational dynamics, their performance determinants in allosteric binding site detection remain poorly understood. We introduce a unified computational framework for profiling multimodal protein foundation models across distinct binding site separability regimes. Rather than evaluating models solely by predictive accuracy, the framework combines systematic modality embedding ablations, encoder architecture comparisons, and variance decomposition to characterize how evolutionary, structural, functional, and dynamical …

Berlin Walls In Our Neighborhood: A Social Justice Excursion For Community College Students In Chemistry, Vuk Uskoković

Administration and Staff Articles and Research

Social inequalities, pervasive in the modern world, silently shape access to education and educational outcomes, especially in the sciences. Yet, natural science curricula rarely acknowledge these influences, often under the assumption that their commitment to objectivity must imply political and socioeconomic neutrality. This paper presents an educational initiative that addresses this disconnect by integrating elemental analytical chemistry with social justice themes. A field trip was designed for chemistry students at Fullerton College, pairing hands-on exposure to optical emission spectroscopic techniques with a socio-environmental investigation of heavy metal contamination across different neighborhoods in Orange County, California. This design deliberately tackled two …