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Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado Jul 2024

Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado

Chemistry Faculty Research & Creative Works

CreE is a flavin-dependent monooxygenase (FMO) that catalyzes three sequential nitrogen oxidation reactions of L-aspartate to produce nitrosuccinate, contributing to the biosynthesis of the antimicrobial and antiproliferative natural product, cremeomycin. This compound contains a highly reactive diazo functional group for which the reaction of CreE is essential to its formation. Nitro and diazo functional groups can serve as potent electrophiles, important in some challenging nucleophilic addition reactions. Formation of these reactive groups positions CreE as a promising candidate for biomedical and synthetic applications. Here, we present the catalytic mechanism of CreE and the identification of active site residues critical to …


Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado Jul 2024

Kinetic Characterization And Identification Of Key Active Site Residues Of The L-Aspartate N-Hydroxylase, Cree, Sydney B. Johnson, Hannah Valentino, Pablo Sobrado

Chemistry Faculty Research & Creative Works

CreE is a flavin-dependent monooxygenase (FMO) that catalyzes three sequential nitrogen oxidation reactions of L-aspartate to produce nitrosuccinate, contributing to the biosynthesis of the antimicrobial and antiproliferative nautral product, cremeomycin. This compound contains a highly reactive diazo functional group for which the reaction of CreE is essential to its formation. Nitro and diazo functional groups can serve as potent electrophiles, important in some challenging nucleophilic addition reactions. Formation of these reactive groups positions CreE as a promising candidate for biomedical and synthetic applications. Here, we present the catalytic mechanism of CreE and the identification of active site residues critical to …


Iron Oxide Nanozymes Enhanced By Ascorbic Acid For Macrophage-Based Cancer Therapy, Zhongchao Yi, Xiaoyue Yang, Ying Liang, Sheng Tong Jul 2024

Iron Oxide Nanozymes Enhanced By Ascorbic Acid For Macrophage-Based Cancer Therapy, Zhongchao Yi, Xiaoyue Yang, Ying Liang, Sheng Tong

Markey Cancer Center Faculty Publications

In recent years, using pharmacological ascorbic acid has emerged as a promising therapeutic approach in cancer treatment, owing to its capacity to induce extracellular hydrogen peroxide (H2O 2) production in solid tumors. The H2 O 2 is then converted into cytotoxic hydroxyl free radicals (HO•) by redox-active Fe2+ inside cells. However, the high dosage of ascorbic acid required for efficacy is hampered by adverse effects such as kidney stone formation. In a recent study, we demonstrated the efficient catalytic conver- sion of H2 O2 to HO• by wüstite (Fe 1−xO) nanoparticles (WNPs) through a heterogenous Fenton reaction. Here, we explore …


Revealing Structural Evolution Of Nickel Phosphide-Iron Oxide Core–Shell Nanocatalysts In Alkaline Medium For The Oxygen Evolution Reaction, Ryan H. Manso, Jiyun Hong, Wei Wang, Prashant Acharya, Adam S. Hoffman, Xiao Tong, Feng Wang, Lauren F. Greenlee, Yimei Zhu, Simon R. Bare, Jingyi Chen Jul 2024

Revealing Structural Evolution Of Nickel Phosphide-Iron Oxide Core–Shell Nanocatalysts In Alkaline Medium For The Oxygen Evolution Reaction, Ryan H. Manso, Jiyun Hong, Wei Wang, Prashant Acharya, Adam S. Hoffman, Xiao Tong, Feng Wang, Lauren F. Greenlee, Yimei Zhu, Simon R. Bare, Jingyi Chen

Chemistry & Biochemistry Faculty Publications and Presentations

Metal phosphide-containing materials have emerged as a potential candidate of nonprecious metal-based catalysts for alkaline oxygen evolution reaction (OER). While it is known that metal phosphide undergoes structural evolution, considerable debate persists regarding the effects of dynamics on the surface activation and morphological stability of the catalysts. In this study, we synthesize NiPx-FeOx core–shell nanocatalysts with an amorphous NiPx core designed for enhanced OER activity. Using ex situ X-ray absorption spectroscopy, we elucidate the local structural changes as a function of the cyclic voltammetry cycles. Our studies suggest that the presence of corner-sharing octahedra in the …


Fundamental Limits In Measuring The Anisotropic Rotational Diffusion Of Single Molecules, Weiyan Zhou, Tingting Wu, Matthew D. Lew Jul 2024

Fundamental Limits In Measuring The Anisotropic Rotational Diffusion Of Single Molecules, Weiyan Zhou, Tingting Wu, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

Many biophysical techniques, such as single-molecule fluorescence correlation spectroscopy, Förster resonance energy transfer, and fluorescence anisotropy, measure the translation and rotation of biomolecules to quantify molecular processes at the nanoscale. These methods often simplify data analysis by assuming isotropic rotational diffusion, e.g., that molecules wobble within a circular cone. This simplification ignores the anisotropy present in many biological contexts that may cause molecules to exhibit different degrees of diffusion in different directions. Here, we loosen this assumption and establish a theoretical framework for describing and measuring anisotropic rotational diffusion using fluorescence imaging. We show that anisotropic wobble is directly quantified …


Cutting-Edge Developments In Zinc Oxide Nanoparticles: Synthesis And Applications For Enhanced Antimicrobial And Uv Protection In Healthcare Solutions, Egwonor Loveth Irede, Raymond Femi Awoyemi, Babatunde Owolabi, Omowunmi Rebecca Aworinde, Rofiat Odunayo Kajola, Ajibola Hazeez, Ayuba Adawale Raji, Latifat Oluwatobi Ganiyu, Chimezie O. Onukwuli, Asishana Paul Onivefu, Ikhazuagbe Hilary Ifijen Jul 2024

Cutting-Edge Developments In Zinc Oxide Nanoparticles: Synthesis And Applications For Enhanced Antimicrobial And Uv Protection In Healthcare Solutions, Egwonor Loveth Irede, Raymond Femi Awoyemi, Babatunde Owolabi, Omowunmi Rebecca Aworinde, Rofiat Odunayo Kajola, Ajibola Hazeez, Ayuba Adawale Raji, Latifat Oluwatobi Ganiyu, Chimezie O. Onukwuli, Asishana Paul Onivefu, Ikhazuagbe Hilary Ifijen

Michigan Tech Publications

This paper presents a comprehensive review of recent advancements in utilizing zinc oxide nanoparticles (ZnO NPs) to enhance antimicrobial and UV protective properties in healthcare solutions. It delves into the synthesis techniques of ZnO NPs and elucidates their antimicrobial efficacy, exploring the underlying mechanisms governing their action against a spectrum of pathogens. Factors impacting the antimicrobial performance of ZnO NPs, including size, surface characteristics, and environmental variables, are extensively analyzed. Moreover, recent studies showcasing the effectiveness of ZnO NPs against diverse pathogens are critically examined, underscoring their potential utility in combatting microbial infections. The study further investigates the UV protective …


Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg Jul 2024

Tribocorrosion And Metal Release From Austenitic Stainless Steels 304 And 201 In Simulated Cassava Food Contact, Robert Addai, Temitope E. Olowoyo, Thalia E. Standish, Jeffrey Daniel Henderson, Ubong Eduok, Yolanda Hedberg

Chemistry Publications

Cassava is the third most significant calorie source in the tropics. Its processing has changed from traditional methods to stainless steel processing machines. This study investigated the influence of cassava on metal release from two common stainless steels, ASTM 304 and 201, with and without friction, and on tribocorrosion (multianalytically) of 304. Cassava was relatively corrosive and hindered repassivation of the surface oxide of stainless steel, but it also acted as a lubricant against mechanical friction. The combined action of friction and cassava caused a significant increase in iron, chromium, nickel, and manganese release from the stainless steels (30–35- fold …


Removing Methane Via Atmospheric Oxidation Enhancement: The Legal Framework, Romany M. Webb, Martin Lockman, Korey Silverman-Roati Jul 2024

Removing Methane Via Atmospheric Oxidation Enhancement: The Legal Framework, Romany M. Webb, Martin Lockman, Korey Silverman-Roati

Sabin Center for Climate Change Law

To achieve the Paris Agreement’s goal of limiting the increase in global average temperatures to “well below 2 degrees Celsius,” and ideally 1.5 degrees Celsius, above pre-industrial levels, global greenhouse gas (“GHG”) emissions must reach net zero in the second half of the century. The global community is not currently on track to achieve net zero emissions. In fact, with the exception of a slight dip during the Covid-19 pandemic, emissions have risen steadily in recent years. This, together with the increasingly visible impacts of climate change, has prompted growing interest in the possibility of removing GHGs directly from the …


Poly(Thioether) Thermosets With Gated Photodegradation, Surabhi Jha Jul 2024

Poly(Thioether) Thermosets With Gated Photodegradation, Surabhi Jha

Dissertations

Photodegradable polymer networks are attractive due to the precise spatiotemporal control and large-area applicability of light. Chemical linkages that enable these polymer networks to be photo-responsive, also hinder their applicability in ambient light. Photostable and photodegradable networks have recently been reported to overcome this challenge by combining other stimuli with light for degradation. We report the design of a network that responds to a simultaneous, dual stimulus for photodegradation. We design poly(thioether acetal) networks with benzylidene acetal moieties that are known to undergo β-scission in the presence of free thiols. By blocking these free thiols with a thermally labile protecting …


Beta Lactams Anticancer Effect On Human Breast Cancer, Mcf-7 Cell Line, Ailis A. Abalos Jul 2024

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 …


Synthesis And Characterization Of Cobalt-Based Complexes And Metal-Organic Frameworks For Hydrogen Evolution Catalysis Under Acidic Conditions, Elizabeth A. Tonsel-White Jul 2024

Synthesis And Characterization Of Cobalt-Based Complexes And Metal-Organic Frameworks For Hydrogen Evolution Catalysis Under Acidic Conditions, Elizabeth A. Tonsel-White

Chemistry & Biochemistry Theses & Dissertations

The synthesis of two cobalt(II) complexes: the novel complex [Co(phen)₃]₂[Co(pytc)₂]•16.25H₂O 1 and the previously reported [Co(bpy)₃](OH)₂•7H₂O 2, along with a cobalt(II/III)-containing MOF, Co-PPF2, previously reported as well, was achieved. These complexes were characterized by elemental analysis, X-ray crystallography, microscopy, conductivity measurements, TGA, SEM, CV , and UV-visible , and FTIR spectroscopies. From the CV scan rates, diffusion coefficients for complexes 1 and 2 were determined to be 1.0 × 10−6 cm2 s−1 and 4.8 × 10−7 cm2 s−1. Electrocatalytic studies with complexes 1 and 2 revealed insights into the mechanistic aspects of …


Response To Replication Stress And Maintenance Of Genome Stability By Wrn, The Werner Syndrome Protein, David K. Orren, Amrita Machwe Jul 2024

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.


Improvement Of Triboelectric Nanogenerator By As-Prepared Lithium Niobate For Energy Harvesting And Sensing Applications, Jahid Inam Chowdhury Jul 2024

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 …


Carbon-Based Nanocomposite Membranes For Membrane Distillation: Progress, Problems And Future Prospects, Chhabilal Regmi, Yuwaraj K. Kshetri, S. Ranil Wickramasinghe Jul 2024

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 …


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 Jun 2024

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, …


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 Jun 2024

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 …


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 Jun 2024

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 …


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 Jun 2024

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 …


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 Jun 2024

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 …


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 Jun 2024

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 Jun 2024

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 …


Interpenetrated Lattices Of Quaternary Chalcogenides Displaying Magnetic Frustration, High Na-Ion Conductivity, And Cation Redox In Na-Ion Batteries, Santhoshkumar Sundaramoorthy, Srikanth Balijapelly, Sudip Mohapatra, Sutapa Bhattacharya, Kartik Ghosh, Amitava Choudhury Jun 2024

Interpenetrated Lattices Of Quaternary Chalcogenides Displaying Magnetic Frustration, High Na-Ion Conductivity, And Cation Redox In Na-Ion Batteries, Santhoshkumar Sundaramoorthy, Srikanth Balijapelly, Sudip Mohapatra, Sutapa Bhattacharya, Kartik Ghosh, Amitava Choudhury

Chemistry Faculty Research & Creative Works

A series of quaternary selenides, NaxMGaSe4 (M = Mn, Fe, and mixed Zn/Fe), have been synthesized for the first time employing a high-temperature solid-state synthesis route through stochiometric or polychalcogenide flux reactions. Along with the selenides, a previously reported sulfide analogue, NaxFeGaS4, is also revisited with new findings. These compounds form an interpenetrated structure made up of a supertetrahedral unit. The electrochemical evaluations exhibit a reversible (de)intercalation of ∼0.6 and ∼0.45 Na-ions, respectively, from Na2.87FeGaS4 (1a) and Na2.5FeGaSe4 (2) involving Fe2+/Fe3+ redox when cycled between 1.5 and 2.5 …


Designing Dual-Responsive Drug Delivery Systems: The Role Of Phase Change Materials And Metal-Organic Frameworks., Wanying Wei, Ping Lu Jun 2024

Designing Dual-Responsive Drug Delivery Systems: The Role Of Phase Change Materials And Metal-Organic Frameworks., Wanying Wei, Ping Lu

College of Science & Mathematics Departmental Research

Stimuli-responsive drug delivery systems (DDSs) offer precise control over drug release, enhancing therapeutic efficacy and minimizing side effects. This review focuses on DDSs that leverage the unique capabilities of phase change materials (PCMs) and metal-organic frameworks (MOFs) to achieve controlled drug release in response to pH and temperature changes. Specifically, this review highlights the use of a combination of lauric and stearic acids as PCMs that melt slightly above body temperature, providing a thermally responsive mechanism for drug release. Additionally, this review delves into the properties of zeolitic imidazolate framework-8 (ZIF-8), a stable MOF under physiological conditions that decomposes in …


Analysis On Development Trend Of Global Hypersonic Technology, Xiaorong Huang, Yunwei Chen, Haichen Zhou Jun 2024

Analysis On Development Trend Of Global Hypersonic Technology, Xiaorong Huang, Yunwei Chen, Haichen Zhou

Bulletin of Chinese Academy of Sciences (Chinese Version)

Hypersonic technology is a key technology in the aerospace field in the future and is of very important strategic and forward-looking significance. Using bibliometric methods, it is found that research on hypersonic technology is mainly concentrated in the military field, among which power propulsion technology, navigation guidance and control technology, thermal protection technology and new materials are important research directions in this field. After sorting out the research and development situation of various countries, it is found that the relevant core technologies related to the development of hypersonic weapons are still the focus of future research. At the same time, …


Implementing 1.5 Millimeter Internal Diameter Columns And A Portable Capillary Column Instrument Into Monoclonal Antibody Analytical Workflows, Benjamin Libert Jun 2024

Implementing 1.5 Millimeter Internal Diameter Columns And A Portable Capillary Column Instrument Into Monoclonal Antibody Analytical Workflows, Benjamin Libert

Theses and Dissertations

Using 1.5 mm inner diameter (i.d.) columns to bridge the gap between routinely used 2.1 mm i.d. columns and capillary bore columns allows for a sequential but significant increase in performance without the need for specialized equipment associated with very low dispersion liquid chromatography (LC) systems. These 1.5 mm i.d. columns balance an increase in sensitivity compared to 2.1 mm i.d. columns (theoretically doubling the time-domain peak area in mass sensitive detectors for the same mass load), while mitigating the efficiency losses due to extra-column dispersion effects that are commonly observed with 1.0 mm i.d. columns. Here, the use of …


The Glucosylamine Oxidation Pathway Of Vitamin C Recycling, James M. Hempe, Daniel S. Hsia, Arthur Hagar, Larry Byers Jun 2024

The Glucosylamine Oxidation Pathway Of Vitamin C Recycling, James M. Hempe, Daniel S. Hsia, Arthur Hagar, Larry Byers

School of Medicine Faculty Publications

The proposed glucosylamine oxidation pathway (GOP) is a two-step, intraerythrocyte, thermodynamically favorable nonenzymatic reaction that first binds glucose to the N-terminal valine of beta globin (βVal1) to form a closed-chain glucosylamine that can spontaneously reduce oxidized vitamin C to its antioxidant form. This review summarizes analytical, biochemical and clinical research supporting the existence of the GOP and the surprising hypothesis that βVal1 glucosylamine is a reducing agent that works cooperatively with reduced glutathione to dynamically regulate vitamin C recycling during naturally occurring periods of transiently or chronically elevated blood glucose and oxidant production. Rationale for the existence of the GOP …


Thermal Effects On The Voc-Sensitive Polydimethylsiloxane Holographic Gratings, Aleksandra Hernik, Faolan Radford Mcgovern, Patrick Iftime, Izabela Naydenova Jun 2024

Thermal Effects On The Voc-Sensitive Polydimethylsiloxane Holographic Gratings, Aleksandra Hernik, Faolan Radford Mcgovern, Patrick Iftime, Izabela Naydenova

Conference Papers

The imperative for monitoring volatile organic compounds (VOCs) emerges from their harmful impact on human health when inhaled excessively over a long term. Polydimethylsiloxane (PDMS), valued for its transparency and excellent flexibility, has already been demonstrated as a promising biocompatible and cost-effective transducer for optical VOCs sensing. Moreover, it facilitates further functionalisation with adsorbing materials to enhance sensitivity and selectivity for specific VOCs detection. We fabricated and examined PDMS-based surface diffraction gratings after exposure to selected VOCs, demonstrating different response for polar and non-polar molecules. Investigated gratings were prepared by replicating sinusoidal surface relief structures inscribed in acrylamide photopolymer using …


Synthetic Assembly Of Antibacterial Agents And Metal Chelating Ligands, Zachary Joseph Liveris Jun 2024

Synthetic Assembly Of Antibacterial Agents And Metal Chelating Ligands, Zachary Joseph Liveris

Dissertations

The exploitation of chemical synthesis exemplifies the notion of bridging both innovation and curiosity for the strategic assembly of sophisticated molecular infrastructures. By exerting this continuously evolving and versatile tool, synthesis has been applied in the development and influence of a myriad of ligands, biological probes, and persists to direct pharmaceutical innovation and modern medicine alike. Since pathogenic multidrug-resistant (MDR) microbial strains remain to be a persistent threat to both clinical healthcare and society, the need to develop selective and efficacious antibacterial agents that can impede microbe pathogenicity and regulate cellular mortality is paramount. In contrast to pharmaceutical development, organic …


Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy Jun 2024

Investigation Of The Uv-Resistance Of Photopolymerisable Glass For Space Applications, Luca Sorridente, Tatsiana Mikulchyk, Izabela Naydenova, Kevin Murphy

Articles

The progress of space based scientific research leads to an increasing demand for more efficient and less bulky instruments. Conventional refractive elements make up a critical part of many optical instruments launched into space; however, they can be bulky and heavy. Holographic optical elements are an efficient alternative to replace the conventional optical elements as they are lightweight and can be miniaturized. Current materials typically used for volume holographic optical elements are not robust enough for use in space environment. Recently a promising photopolymerisable glass has been developed using a sol-gel technique, which can provide dry layers suitable for holographic …


Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy Jun 2024

Photopolymer Material Durability And Safety In Holographic Diffusers For Visual Applications, Matthew Hellis, Alan Casey, Edoardo Splendi, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

This study introduces novel holographic diffuser applications employing acrylamide- or diacetone acrylamide-based photopolymers, patterned within the volume on a micron scale by a single-beam holographic recording process. These diffusers have previously been presented as potential treatments for amblyopia and diplopia. This work has now been extended to spectrometric analysis to determine their properties under broadband light. Diffusive elements with higher diffusion efficiencies exhibited a marginal reduction (< 5%) in diffusion efficiency across most of the visible spectrum. Given the intended application of these holographic diffusers, cytotoxicity assessments were also performed. This is significant as there is a difference in toxicity between the crystalline acrylamide (classified as a category 3 material) and diacetone acrylamide (classified as a category 4 material). The findings indicated substantially lower toxicity in holograms produced with diacetone acrylamide-based photopolymer. The accelerated ageing of both formulations of holographic diffusers indicated that the acrylamide-based holographic diffusers did not reduce efficacy in the 292 days of ageing. The diacetone acrylamide-based holographic diffusers exhibited reduced efficacy by day 182. Despite this, both formulations have been shown to perform for prolonged periods as the treatment modality would require. These results emphasise that holographic diffusers exhibit minimal spectral impact, and longevity on the scale of treatment regimes which are crucial considerations for their prospective use case as treatments for amblyopia and diplopia.