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Articles 3991 - 4020 of 33132

Full-Text Articles in Chemistry

Traffic Lights For Catalysis: Stimuli-Responsive Molecular And Extended Catalytic Systems, Grace C. Thaggard, Johanna Haimeri, Roland A. Fischer Prof. Dr., Kyoung Chul Park, Natalia B. Shustova Prof. Dr. Mar 2023

Traffic Lights For Catalysis: Stimuli-Responsive Molecular And Extended Catalytic Systems, Grace C. Thaggard, Johanna Haimeri, Roland A. Fischer Prof. Dr., Kyoung Chul Park, Natalia B. Shustova Prof. Dr.

Faculty Publications

The advances made in the field of stimuli-responsive catalysis during the last five years with a focus on the novel recently-emerged directions and applications have been surveyed. Metal-free catalysts and organometallic complexes, as well as biomimetic systems and extended structures, which display switchable catalytic activity for a variety of organic transformations, are discussed. Light-activated systems comprised of photochromic molecules capable of modulating reaction rate, yield, or enantioselectivity based on geometric and electronic changes associated with photoisomerization are the focus of the detailed discussion. Alternative stimuli, including pH and temperature, which could be applied either alone or in combination with light, …

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Increased Efficiency Of A Functional Sod Mimic Achieved With Pyridine Modification On A Pyclen-Based Copper(Ii) Complex, Magy A. Mekhail, Katherine J. Smith, David M. Freire, Kristof Pota, Nam Nguyen, Marianne E. Burnett, Kayla N. Green Mar 2023

Increased Efficiency Of A Functional Sod Mimic Achieved With Pyridine Modification On A Pyclen-Based Copper(Ii) Complex, Magy A. Mekhail, Katherine J. Smith, David M. Freire, Kristof Pota, Nam Nguyen, Marianne E. Burnett, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A series of Cu(II) complexes with the formula [CuRPyN3]2+ varying in substitution on the pyridine ring were investigated as superoxide dismutase (SOD) mimics to identify the most efficient reaction rates produced by a synthetic, water-soluble copper-based SOD mimic reported to date. The resulting Cu(II) complexes were characterized by X-ray diffraction analysis, UV–visible spectroscopy, cyclic voltammetry, and metal-binding (log β) affinities. Unique to this approach, the modifications to the pyridine ring of the PyN3 parent system tune the redox potential while exhibiting high binding stabilities without changing the coordination environment of the metal complex within …

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Application Of The Recitation Method To Improve The Competence Of Medical Laboratory Technology Students In The Immunology Field, Patricia Gita Naully, Perdina Nursidika Mar 2023

Application Of The Recitation Method To Improve The Competence Of Medical Laboratory Technology Students In The Immunology Field, Patricia Gita Naully, Perdina Nursidika

Jurnal Pendidikan Sains

An accredited mid-level MLT (Medical Laboratory Technology) must have the competence to perform medical laboratory examinations from pre-analytic, analytic, and post-analytic stages in several fields, one of which is immunology. Many D3 MLT students are facing obstacles to passed the immunology course. This obstacle is not only experienced by students of D3 MLT but also by medical students, pharmacy students, and similar majors. The purpose of this research is to determine the effect of recitation method in the form of animation video making and immunology based device on the competence of Diploma 3 (D3) MLT students. This research is a …

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Using Augmented Reality For Geometry Learning: Indonesian Elementary School Teachers' Experiences, Asep Nuryadin, Karlimah Karlimah, Dindin Abdul Muiz Lidinillah, Ika Fitri Apriani, Ikairn Rachmawati Putri, Lilis Susilawati, Ginna Islamiati, Dede Nurhidayah Mar 2023

Using Augmented Reality For Geometry Learning: Indonesian Elementary School Teachers' Experiences, Asep Nuryadin, Karlimah Karlimah, Dindin Abdul Muiz Lidinillah, Ika Fitri Apriani, Ikairn Rachmawati Putri, Lilis Susilawati, Ginna Islamiati, Dede Nurhidayah

Jurnal Pendidikan Sains

This study aims to discover Indonesian elementary school teachers' experiences (n = 257) of using Augmented Reality (AR) for learning, especially related to one of the topics in mathematics learning, namely, geometry. AR is considered to be an alternative instructional media that can be utilized for teaching geometry, including the topic of three-dimensional shapes. A questionnaire consisting of both close-ended and open-ended questions was used to collect data in this study. This study has successfully revealed teachers' use of digital instructional media during the COVID-19 pandemic, their familiarity with AR, frequency of AR use for geometry learning, and challenges in …

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Epistemological Obstacles Of Students In Accomplishing Hots Tests According To Field-Dependent Cognitive Style, Widi Candika Pakaya, Fattah Hanurawan Mar 2023

Epistemological Obstacles Of Students In Accomplishing Hots Tests According To Field-Dependent Cognitive Style, Widi Candika Pakaya, Fattah Hanurawan

Jurnal Pendidikan Sains

The main goal of this study is to describe the epistemological obstacles faced by students with field-dependent cognitive styles when attempting to solve HOTS questions. This study uses a qualitative-descriptive methodology. The instruments used are cognitive style tests and HOTS questions. Data is collected through interviews and student work. The research subjects were two participants in third-semester PGSD students at Universitas Negeri Gorontalo. In this study, the data were analyzed by identifying the answers of two respondents to the indicators of epistemological barriers that had been done by the students and then interviewing the respondents. The results of this study …

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Ecoliteracy Analysis And Science Teaching Materials: A Survey In Junior High Schools, Ghina Nisrina Ramadhanti, Indarini Dwi Pursitasari, Indriyani Rachman Mar 2023

Ecoliteracy Analysis And Science Teaching Materials: A Survey In Junior High Schools, Ghina Nisrina Ramadhanti, Indarini Dwi Pursitasari, Indriyani Rachman

Jurnal Pendidikan Sains

The study aims to analyze ecoliteracy and the teaching materials required for 21st century learning these days. The study employs the survey method by involving population of 104 junior high school students in grade VIII in Bogor City. The data are collected using ecoliteracy tests and interviews and analyzed using descriptive statistics techniques. The results showed that 48 students (46.15%) fall into the category of lacking ecoliteracy cognitive competence. The results of the questionnaire on the competence of attitudes, skills, and human relations with nature fall into the medium category. Therefore, in order to support the improvement of students’ ecoliteracy, …

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The Influence Of The 5e Learning Cycle Strategy With A Link Map On Students' Mastery Of Physics Concepts And Science Process Skills, Dian Farida Rosanti, Markus Diantoro, Sentot Kusairi, Erni Yulianti Mar 2023

The Influence Of The 5e Learning Cycle Strategy With A Link Map On Students' Mastery Of Physics Concepts And Science Process Skills, Dian Farida Rosanti, Markus Diantoro, Sentot Kusairi, Erni Yulianti

Jurnal Pendidikan Sains

Link maps help students correlate interconcepts in order to facilitate students mastery of the concept learned. The researcher accompanied the link map in learning to find out its effect on concept mastery and students science process skills. This study used a quasi-experimental research design by providing a posttest only for the control group. The sample consisted of two classes, divided into an experimental class and a control class. The experimental class was taught using the 5E learning cycle strategy accompanied by a link map, and the control class was taught using the 5E learning cycle strategy only. The results of …

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Kinetic Studies On The 2-Oxoglutarate/Fe(Ii)-Dependent Nucleic Acid Modifying Enzymes From The Alkb And Tet Families, Zhiyuan Peng, Jian Ma, Christo Christov, Tatyana Karabencheva-Christova, Nicolai Lehnert, Deyu Li Mar 2023

Kinetic Studies On The 2-Oxoglutarate/Fe(Ii)-Dependent Nucleic Acid Modifying Enzymes From The Alkb And Tet Families, Zhiyuan Peng, Jian Ma, Christo Christov, Tatyana Karabencheva-Christova, Nicolai Lehnert, Deyu Li

Michigan Tech Publications

Nucleic acid methylations are important genetic and epigenetic biomarkers. The formation and removal of these markers is related to either methylation or demethylation. In this review, we focus on the demethylation or oxidative modification that is mediated by the 2-oxoglutarate (2-OG)/Fe(II)-dependent AlkB/TET family enzymes. In the catalytic process, most enzymes oxidize 2-OG to succinate, in the meantime oxidizing methyl to hydroxymethyl, leaving formaldehyde and generating demethylated base. The AlkB enzyme from Escherichia coli has nine human homologs (ALKBH1-8 and FTO) and the TET family includes three members, TET1 to 3. Among them, some enzymes have been carefully studied, but for …

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Advancing Nanofiber Research: Assessing Non Solvent Contributions To Structure Using Coaxial Electrospinning, Ping Lu Mar 2023

Advancing Nanofiber Research: Assessing Non Solvent Contributions To Structure Using Coaxial Electrospinning, Ping Lu

College of Science & Mathematics Departmental Research

Nanofibers play a vital role as precursors for fabricating a wide array of products spanning environmental and energy sustainability, biomedical, and healthcare applications The nanofiber characteristics, such as porosity, domains, and interfaces, are strongly influenced by the phase separation behavior among polymers, solvents, and nonsolvents in the liquid jet during the nanofabrication process However, the precise control and understanding of these phenomena at the level of individual nanofibers still need to be improved due to the need for more current technologies to provide sufficient spatial and temporal resolution To address this challenge, we employed coaxial electrospinning with a nonsolvent core …

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Stabilizing G-Quadruplex Dna And Rna Structures With Ionic Liquids, Timothy Vaden Mar 2023

Stabilizing G-Quadruplex Dna And Rna Structures With Ionic Liquids, Timothy Vaden

College of Science & Mathematics Departmental Research

Stabilizing DNA and RNA for long-term room-temperature storage is important for many biotechnological applications including oncology pharmaceuticals and mRNA-based vaccines (e.g. Covid vaccines). This poster shows that ionic liquids can improve the thermal stability of G-quadruplex DNA and RNA structures, and motivates further studies of ionic liquid-based materials for DNA / RNA stabilization.

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Virtual And In Vitro Screening Of Natural Products Identifies Indole And Benzene Derivatives As Inhibitors Of Sars-Cov-2 Main Protease (MPro), Dony Ang, Riley Kendall, Hagop S. Atamian Mar 2023

Virtual And In Vitro Screening Of Natural Products Identifies Indole And Benzene Derivatives As Inhibitors Of Sars-Cov-2 Main Protease (MPro), Dony Ang, Riley Kendall, Hagop S. Atamian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The rapid spread of the coronavirus disease 2019 (COVID-19) resulted in serious health, social, and economic consequences. While the development of effective vaccines substantially reduced the severity of symptoms and the associated deaths, we still urgently need effective drugs to further reduce the number of casualties associated with SARS-CoV-2 infections. Machine learning methods both improved and sped up all the different stages of the drug discovery processes by performing complex analyses with enormous datasets. Natural products (NPs) have been used for treating diseases and infections for thousands of years and represent a valuable resource for drug discovery when combined with …

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Damped Oscillating Phosphoryl Transfer Reaction In The Cyanobacterial Circadian Clock, Hye In Jang, Pyonghwa Kim, Yongick Kim Mar 2023

Damped Oscillating Phosphoryl Transfer Reaction In The Cyanobacterial Circadian Clock, Hye In Jang, Pyonghwa Kim, Yongick Kim

Chemistry Faculty Research

Most organisms have circadian clocks to ensure the metabolic cycle to resonate with the rhythmic environmental changes without “damping,” or losing robustness. Cyanobacteria is the oldest and simplest form of life that is known to harbor this biological intricacy. Its KaiABC-based central oscillator proteins can be reconstituted inside a test tube, and the post-translational modification cycle occurs with 24 h periodicity. KaiC’s two major phosphorylation sites, Ser-431 and Thr-432, become phosphorylated and dephosphorylated by interacting with KaiA and KaiB, respectively. Here, we mutate Thr-432 into Ser to find the oscillatory phosphoryl transfer reaction damps. Previously, this mutant KaiC was reported …

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Recent Research Progresses Of Solid-State Lithium-Sulfur Batteries, Yu Luo, Ru-Qin Ma, Zheng-Liang Gong, Yong Yang Mar 2023

Recent Research Progresses Of Solid-State Lithium-Sulfur Batteries, Yu Luo, Ru-Qin Ma, Zheng-Liang Gong, Yong Yang

Journal of Electrochemistry

All solid-state lithium-sulfur batteries (ASSLSBs) are considered to be one of the most promising next-generation energy storage systems, due to the promises of high energy density and safety. Although the use of solid-state electrolytes could effectively suppress the "shuttle effect" and self-discharge of the conventional liquid lithium-sulfur (Li-S) battery, the commercialization of ASSLSBs has been seriously hampered by the electrolyte degradation, electrode/electrolyte interfacial deterioration, electrochemo-mechanical failure, lithium dendrite growth and electrode pulverization, etc. This paper provides a comprehensive review of recent research progresses on the solid-state electrolytes, sulfur-containing composite cathodes, lithium metal and lithium alloy anodes, and electrode/electrolyte interfaces in …

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A Review On Solid-State Li-S Battery: From The Conversion Mechanism Of Sulfur To Engineering Design, Huan-Huan Jia, Chen-Ji Hu, Yi-Xiao Zhang, Li-Wei Chen Mar 2023

A Review On Solid-State Li-S Battery: From The Conversion Mechanism Of Sulfur To Engineering Design, Huan-Huan Jia, Chen-Ji Hu, Yi-Xiao Zhang, Li-Wei Chen

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries attract sustained attention because of their ultrahigh theoretical energy density of 2567 Wh·kg–1 and the actual value over 600 Wh·kg–1. Solid-state Li-S batteries (SSLSBs) emerge in the recent two decades because of the enhanced safety when compared to the liquid system. As for the SSLSBs, except for the difference in the conversion mechanism induced by the cathode materials themselves, the physical-chemical property of solid electrolytes (SEs) also significantly affects their electrochemical behaviors. On account of various reported Li-S batteries, the advantages and disadvantages in performance and the failure mechanism are discussed in this review. …

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Bimetallic Compound Catalysts With Multiple Active Centers For Accelerated Polysulfide Conversion In Li-S Batteries, Wu-Xing Hua, Jing-Yi Xia, Zhong-Hao Hu, Huan Li, Wei Lv, Quan-Hong Yang Mar 2023

Bimetallic Compound Catalysts With Multiple Active Centers For Accelerated Polysulfide Conversion In Li-S Batteries, Wu-Xing Hua, Jing-Yi Xia, Zhong-Hao Hu, Huan Li, Wei Lv, Quan-Hong Yang

Journal of Electrochemistry

Practical applications of lithium-sulfur (Li-S) batteries are hindered mainly by the low sulfur utilization and severe capacity fading derived from the polysulfide shuttling. Catalysis is an effective remedy to those problems by promoting the conversion of polysulfides to reduce their accumulation in the electrolyte, which needs the catalyst to have efficient adsorption ability to soluble polysulfides and high activity for their conversion. In this work, we have proposed a bimetallic compound of NiCo2S4 anchored onto sulfur-doped graphene (NCS@SG) to fabricate a catalytic interlayer for Li-S batteries. Compared to CoS, the NiCo2S4 demonstrated much higher …

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Coni-Based Bimetal-Organic Framework Derived Carbon Composites Multifunctionally Modified Separators For Lithium-Sulfur Batteries, Yan-Jie Wang, Hong-Yu Cheng, Ji-Yue Hou, Wen-Hao Yang, Rong-Wei Huang, Zhi-Cong Ni, Zi-Yi Zhu, Ying Wang, Ke-Yi Wei, Yi-Yong Zhang, Xue Li Mar 2023

Coni-Based Bimetal-Organic Framework Derived Carbon Composites Multifunctionally Modified Separators For Lithium-Sulfur Batteries, Yan-Jie Wang, Hong-Yu Cheng, Ji-Yue Hou, Wen-Hao Yang, Rong-Wei Huang, Zhi-Cong Ni, Zi-Yi Zhu, Ying Wang, Ke-Yi Wei, Yi-Yong Zhang, Xue Li

Journal of Electrochemistry

The commercial application of lithium-sulfur batteries (LSB) is still limited by the irreversible capacity fading caused by the shuttle of lithium polysulfides (LIPS). To address this issue, a bimetal (nickel, cobalt)-organic framework (MOF) derived carbon, (Ni, Co)/C, was prepared to modify the separator. The multifunctionally modified separator effectively captures LIPS, ensuring the stability and reversibility of sulfur fixation, while providing catalytic activity and improving ionic conductivity. The cobalt metal has a larger coordination number, more pore structure distribution, larger specific surface area, more surface C=O, and smaller particle size to achieve a large and rapid chemical sulfur fixation. The high …

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Preface To The Special Issue On Lithium-Sulfur Batteries, Jia-Jia Chen, Ren-Jie Chen, Zhong Jin Mar 2023

Preface To The Special Issue On Lithium-Sulfur Batteries, Jia-Jia Chen, Ren-Jie Chen, Zhong Jin

Journal of Electrochemistry

No abstract provided.

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Paek- And Pes-Like Perarylated Phosphonium Ionenes: Synthesis, Thermal Properties, And Conductivity, Samantha M. Sims, Hannah Brown, Jalisha R. Hunter, R. Daniel Johnson, Rachel E. Whittaker, Kevin M. Miller Mar 2023

Paek- And Pes-Like Perarylated Phosphonium Ionenes: Synthesis, Thermal Properties, And Conductivity, Samantha M. Sims, Hannah Brown, Jalisha R. Hunter, R. Daniel Johnson, Rachel E. Whittaker, Kevin M. Miller

Faculty & Staff Research and Creative Activity

Perarylated phosphonium salts are known to exhibit high degrees of thermal stability, often in excess of 400 °C. Here, the thermal and conductive properties of a series of perarylated phosphonium ionenes, prepared utilizing a PAEK-/PES-like synthetic approach, is described. All of the ionenes were found to display Td5% values in excess of 365 °C. Structural changes in the polymer backbone were found to have a prominent impact on Tg, with the meta-analogs exhibiting values ∼45 °C below the para-analogs, emphasizing the significant impact that solid-state packing can have on thermal transitions. All of the phosphonium ionenes …

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Conformational Dynamics And Free Energy Studies Of Dna And Other Biomolecules, Paul B. Orndorff Mar 2023

Conformational Dynamics And Free Energy Studies Of Dna And Other Biomolecules, Paul B. Orndorff

USF Tampa Graduate Theses and Dissertations

This work uses molecular dynamics simulations and enhanced sampling methods to investigate both the qualitative and quantitative properties of biomolecular systems. Conformational dynamics are critical in the study of biomolecular systems. Application of computer simulations to study dynamics of biomolecular systems allows for motions to be readily investigated at a resolution not possible in experimental techniques. In this work, the dynamics of uracil damaged and undamaged DNA is studied via molecular dynamics simulations. Uracil results in DNA from either misincorporation in the replication process or through spontaneous deamination of cytosine, and its presence in DNA can lead to mutations in …

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Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji Mar 2023

Synthesis And Characterization Of New Azo Dyes Derived From Acyclovir And Sulfamethoxazole And Study Their Biological Activity, Abdul Rahman Y. Wahoud, Thanaa Shriteh, Ali Yousef, Mohammad Mazen Kondakji

Hadhramout University Journal of Natural & Applied Sciences

In this research, two new azo dyes, 9-(2-Hydroxy-ethoxymethyl)-2-(2-hydroxy5nitrophenylazo)-1,9-dihydro-purin-6-one and 4-(2-Hydroxy-napHthalen-1-ylazo)-N-(5-methyl-isoxazol-3-yl)-benzenesulfonamide, derived from Acyclovir and Sulfamethoxazole was synthesized. The first dye synthesis was started by diazation of acyclovir, then combined with 4-nitrophenol activated with potassium hydroxide 10%, yielding 80%, and its purity was verified by thin layer chromatography (TLC). The second dye synthesis was started by diazation of Sulfamethoxazole then combined with β-naphthol activated with potassium hydroxide 10%, yielding 87%, and its purity was verified by thin layer chromatography (TLC). The identity of the resulting pigments was determined based on spectroscopic methods such as infrared spectroscopy, proton nuclear magnetic resonance spectrum …

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Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder Mar 2023

Synthesis, Characterization, And Cytotoxicity Studies Of A Copper(Ii) Complex With Vanillin 3-Ethyl-Thiosemcarbazone A Ligand, Novia Mann, Ifeoluwa Oyeyemi, Duaa R. Alajroush, Elizabeth A. Tonsel-White, Stephen J. Beebe, Alvin Holder

Undergraduate Research Symposium

Triple-negative breast cancer (TNBC) is one of the most aggressive and challenging breast cancer subtypes to treat, as these cancer cells lack three common receptors: estrogen, progesterone, and human epidermal growth factor receptor 2. The multiple oxidation states transition metals can occupy have made this narrowly explored group popular for anti-cancer research in recent decades. Furthermore, the success of cisplatin, which has platinum as a metal center, while being a cancer-fighting agent with serious side effects, has caused other metal centers to be investigated as possible alternatives as chemotherapeutic drugs. Copper, as a biologically essential metal, makes an attractive candidate …

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Carbon Dioxide-Induced Corrosion Of Aisi 4140 Steel In Acidified Artificial Geothermal Brine, Anawati Anawati, Rayhan Izzat, Riene Kaelamanda Pragitta, Rafli Ihsan Hernandi Mar 2023

Carbon Dioxide-Induced Corrosion Of Aisi 4140 Steel In Acidified Artificial Geothermal Brine, Anawati Anawati, Rayhan Izzat, Riene Kaelamanda Pragitta, Rafli Ihsan Hernandi

Makara Journal of Science

Carbon dioxide (CO2)-induced corrosion often occurs in the structural materials of geothermal industry. The presence of CO2 influences the formation of various corrosion products. This research investigates the effect of dissolved CO2 in acidic brines on the corrosion behavior of AISI 4140 steel at atmospheric pressure. The brines were the standard brine, Ca-free brine, and high-salinity brine. The corrosion behavior was studied using electrochemical and immersion tests. A cyclic polarization test showed that the corrosion rate was higher in dissolved CO2 brine than in non-CO2 brine, and an immersion test demonstrated a similar result. …

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Quantitation Of Female Newt Tetrodotoxin Concentrations And Their Impact In The Newt-Garter Snake Evolutionary Arms Race, Anna Frey, David Green Dr., Lee Kats Dr., Gary Bucciarelli Dr. Mar 2023

Quantitation Of Female Newt Tetrodotoxin Concentrations And Their Impact In The Newt-Garter Snake Evolutionary Arms Race, Anna Frey, David Green Dr., Lee Kats Dr., Gary Bucciarelli Dr.

Seaver College Research And Scholarly Achievement Symposium

As this work is not yet published, the authors have requested the removal of the abstract.

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Studies On Bonding, Syntheses, And Applications Of Diarylhalonium Compounds, Shubhendu Karandikar Mar 2023

Studies On Bonding, Syntheses, And Applications Of Diarylhalonium Compounds, Shubhendu Karandikar

Dissertations and Theses

Organic compounds containing functionalized benzenoid rings have found tremendous applications in pharmaceuticals, agrochemicals, commodity chemicals, and beyond. As a result, development of methods for the synthesis of functionalized benzenoid rings has gained much attention from the synthetic community. Although many transition-metal mediated methods to functionalize benzenoid rings are known, there has been an upsurge of activity in developing protocols for decoration of benzenoid cores promoted by p-block elements. This excitement stems from the sustainability of earth-abundant elements and unique reactivity patterns observed within the p-block. Among these, transformations promoted by hypervalent halogen compounds, and especially, the diarylhalonium salts are very …

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Docking And Selectivity Studies Of Covalently Bound Janus Kinase 3 Inhibitors, Haizhen Zhong, Suliman Almahmoud Mar 2023

Docking And Selectivity Studies Of Covalently Bound Janus Kinase 3 Inhibitors, Haizhen Zhong, Suliman Almahmoud

Chemistry Faculty Publications

The Janus kinases (JAKs) are a family of non-receptor cytosolic protein kinases critical for immune signaling. Many covalently bound ligands of JAK3 inhibitors have been reported. To help design selective JAK inhibitors, in this paper, we used five model proteins to study the subtype selectivity of and the mutational effects on inhibitor binding. We also compared the Covalent Dock programs from the Schrodinger software suite and the MOE software suite to determine which method to use for the drug design of covalent inhibitors. Our results showed that the docking affinity from 4Z16 (JAK3 wild-type model), 4E4N (JAK1), 4D1S (JAK2), and …

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Microcystin-Lr Removal From Water Via Enzymatic Linearization And Ultrafiltration, Abelline Fionah, Cannon Hackett, Hazim Aljewari, Laura Brady, Faisal Alqhtani, Isabel C. Escobar, Audie K. Thompson Mar 2023

Microcystin-Lr Removal From Water Via Enzymatic Linearization And Ultrafiltration, Abelline Fionah, Cannon Hackett, Hazim Aljewari, Laura Brady, Faisal Alqhtani, Isabel C. Escobar, Audie K. Thompson

Chemistry Faculty Publications

Microcystin-LR (MC-LR) is a toxin produced by cyanobacteria that can bloom in freshwater supplies. This study describes a new strategy for remediation of MC-LR that combines linearization of the toxin using microcystinase A, MlrA, enzyme with rejection of linearized byproducts using membrane filtration. The MlrA enzyme was expressed in Escherichia coli (E. coli) and purified via a His-tag with 95% purity. Additionally, composite membranes made of 95% polysulfone and 5% sulfonated polyether ether ketone (SPEEK) were fabricated and used to filter a solution containing cyclic and linearized MC-LR. Tests were also performed to measure the adsorption and desorption of MC-LR …

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Pyrrolopyrrole-Based Materials For High-Contrast Electrochromics, Allison Marie Hawks Mar 2023

Pyrrolopyrrole-Based Materials For High-Contrast Electrochromics, Allison Marie Hawks

Master of Science in Chemical Sciences Theses

Understanding structure-property relationships of underutilized p-conjugated chromophores is an important task for the continued discovery of materials that will find utility in organic electronic applications. Dihydropyrrolo[3,2-b]pyrroles (DHPPs) are synthetically simple and highly tailorable chromophores that can be decorated with diverse functionalities that readily manipulate optoelectronic properties useful for a variety of applications. However, a thorough understanding of how these functionalities influence properties of DHPPs that will be useful in applications such as electrochromism is unknown. Motivated to exploit the synthetic simplicity and tailorability of DHPPs, a family of DHPP chromophores was synthesized to probe how functionality and connectivity …

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Storage And Algal Association Of Bacteria That Protect Microchloropsis Salina From Grazing By Brachionus Plicatilis, Carolyn L. Fisher, Michelle V. Fong, Pamela D. Lane, Skylar Carlson, Todd W. Lane Mar 2023

Storage And Algal Association Of Bacteria That Protect Microchloropsis Salina From Grazing By Brachionus Plicatilis, Carolyn L. Fisher, Michelle V. Fong, Pamela D. Lane, Skylar Carlson, Todd W. Lane

Pacific Faculty Work

Loss of algal production from the crashes of algal mass cultivation systems represents a significant barrier to the economic production of microalgal-based biofuels. Current strategies for crash prevention can be too costly to apply broadly as prophylaxis. Bacteria are ubiquitous in microalgal mass production cultures, however few studies investigate their role and possible significance in this particular environment. Previously, we demonstrated the success of selected protective bacterial communities to save Microchloropsis salina cultures from grazing by the rotifer Brachionus plicatilis. In the current study, these protective bacterial communities were further characterized by fractionation into rotifer-associated, algal-associated, and free-floating bacterial fractions. …

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Ferrocenophanium Stability And Catalysis, Sai Anvesh Bezawada, Neira Ušto, Chloe Wilke, Michael Barnes-Flaspoler, Rajamoni Jagan, Eike B. Bauer Mar 2023

Ferrocenophanium Stability And Catalysis, Sai Anvesh Bezawada, Neira Ušto, Chloe Wilke, Michael Barnes-Flaspoler, Rajamoni Jagan, Eike B. Bauer

Educator Preparation & Leadership Faculty Works

Ferrocenium catalysis is a vibrant research area, and an increasing number of ferrocenium-catalyzed processes have been reported in the recent years. However, the ferrocenium cation is not very stable in solution, which may potentially hamper catalytic applications. In an effort to stabilize ferrocenium-type architectures by inserting a bridge between the cyclopentadienyl rings, we investigated two ferrocenophanium (or ansa-ferrocenium) cations with respect to their stability and catalytic activity in propargylic substitution reactions. One of the ferrocenophanium complexes was characterized by single crystal X-ray diffraction. Cyclic voltammetry experiments of the ferrocenophane parent compounds were performed in the absence and presence of alcohol …

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7-Deazaguanines In Dna: Functional And Structural Elucidation Of A Dna Modification System, Samanthi Herath Gedara, Andrew Gustafson, Dirk Iwata-Reuyl, Multiple Additional Authors Mar 2023

7-Deazaguanines In Dna: Functional And Structural Elucidation Of A Dna Modification System, Samanthi Herath Gedara, Andrew Gustafson, Dirk Iwata-Reuyl, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

The modified nucleosides 2′-deoxy-7-cyano- and 2′-deoxy-7-amido-7-deazaguanosine (dPreQ0 and dADG, respectively) recently discovered in DNA are the products of the bacterial queuosine tRNA modification pathway and the dpd gene cluster, the latter of which encodes proteins that comprise the elaborate Dpd restriction–modification system present in diverse bacteria. Recent genetic studies implicated the dpdA, dpdB and dpdC genes as encoding proteins necessary for DNA modification, with dpdD–dpdK contributing to the restriction phenotype. Here we report the in vitro reconstitution of the Dpd modification machinery from Salmonella enterica serovar Montevideo, the elucidation of the roles of each protein and the X-ray …

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