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Articles 4531 - 4560 of 33135

Full-Text Articles in Chemistry

Cup Is Essential For Oskar Mrna Translational Repression During Early Drosophila Oogenesis, Livia V. Bayer, Samantha Milano, Stephen K. Formel, Harpreet Kaur, Rishi Ravichandran, Juan A. Cambeiro, Lizaveta Slinko, Irina E. Catrina, Diana P. Bratu Jan 2023

Cup Is Essential For Oskar Mrna Translational Repression During Early Drosophila Oogenesis, Livia V. Bayer, Samantha Milano, Stephen K. Formel, Harpreet Kaur, Rishi Ravichandran, Juan A. Cambeiro, Lizaveta Slinko, Irina E. Catrina, Diana P. Bratu

Publications and Research

Study of the timing and location for mRNA translation across model systems has begun to shed light on molecular events fundamental to such processes as intercellular communication, morphogenesis, and body pattern formation. In D. melanogaster, the posterior mRNA determinant, oskar, is transcribed maternally but translated only when properly localized at the oocyte’s posterior cortex. Two effector proteins, Bruno1 and Cup, mediate steps of oskar mRNA regulation. The current model in the field identifies Bruno1 as necessary for Cup’s recruitment to oskar mRNA and indispensable for oskar’s translational repression. We now report that this Bruno1-Cup interaction leads …


C-Glycopyranosyl Aldehydes: Emerging Chiral Synthons In Organic Synthesis, Sandeep Kumar, Vinod Khatri, Priyanka Mangla, Rajni Johar Chhatwal, Virinder S. Parmar, Ashok K. Prasad Jan 2023

C-Glycopyranosyl Aldehydes: Emerging Chiral Synthons In Organic Synthesis, Sandeep Kumar, Vinod Khatri, Priyanka Mangla, Rajni Johar Chhatwal, Virinder S. Parmar, Ashok K. Prasad

Publications and Research

Herein, we have summarized the vast array of synthetic processes that have been developed for the synthesis of C-glycopyranosyl aldehydes and diverse C-glycoconjugates derived from them by covering the literature reported from 1979 to 2023. Notwithstanding its challenging chemistry, C-glycosides are considered stable pharmacophores and are used as important bioactive molecules. The discussed synthetic methodologies to access C-glycopyranosyl aldehydes take advantage of seven key intermediates, viz. allene, thiazole, dithiane, cyanide, alkene, and nitromethane. Furthermore, the integration of complex C-glycoconjugates derived from varied C-glycopyranosyl aldehydes involves nucleophilic addition/substitution, reduction, condensation, oxidation, cyclo condensation, coupling, and …


Molecular Mechanism Behind The Safe Immunostimulatory Effect Of Withania Somnifera, Kriti Kalpana, Shen Yap, Moriya Tsuji, Akira Kawamura Jan 2023

Molecular Mechanism Behind The Safe Immunostimulatory Effect Of Withania Somnifera, Kriti Kalpana, Shen Yap, Moriya Tsuji, Akira Kawamura

Publications and Research

Withania somnifera (L.) Dunal (family Solanaceae) is a medicinal plant known for, among many pharmacological properties, an immune boosting effect. Our recent study revealed that its key immunostimulatory factor is lipopolysaccharide of plant-associated bacteria. This is peculiar, because, although LPS can elicit protective immunity, it is an extremely potent pro-inflammatory toxin (endotoxin). However, W. somnifera is not associated with such toxicity. In fact, despite the presence of LPS, it does not trigger massive inflammatory responses in macrophages. To gain insights into the safe immunostimulatory effect of W. somnifera, we conducted a mechanistic study on its major phytochemical constituent, …


I. Preparation Of Strategic Synthetic Building Blocks For World Health Organization Essential Medicines. Ii. Applying The Principles Of Process Intensification To The Synthesis Of Fluoroquinolone Antibiotics., Jeffrey M. Noble Jan 2023

I. Preparation Of Strategic Synthetic Building Blocks For World Health Organization Essential Medicines. Ii. Applying The Principles Of Process Intensification To The Synthesis Of Fluoroquinolone Antibiotics., Jeffrey M. Noble

Theses and Dissertations

The synthesis of active pharmaceutical ingredients is often a time-consuming and expensive process. Due to the nature of pharmaceutical manufacturing, these costs are carried forward to the final purchase price by the consumer. Although there are many factors which are involved in the final costing of a pharmaceutical, the cost associated with the synthesis is the primary one which can be managed by chemists and engineers.

This work discusses the synthetic routes of four active pharmaceutical ingredients as well as the synthetic techniques and equipment used with an emphasis on how the application of specific techniques can be applied to …


Investigating The Dynamics And Fragmentation Of Nitroaromatic Radical Cations Through Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Hugo Andres Lopez Pena Jan 2023

Investigating The Dynamics And Fragmentation Of Nitroaromatic Radical Cations Through Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Hugo Andres Lopez Pena

Theses and Dissertations

Chemists have sought to control molecular dissociation with lasers for decades. Effective control of unimolecular dissociation was only achieved with the development of high-intensity ultrashort pulsed lasers and coherent control techniques that operate on timescales faster than vibrational energy redistribution. In view of this, our lab has specialized in the study of polyatomic radical cations using femtosecond time-resolved mass spectrometry (FTRMS). The interest in radical cations stems from the fact that they are highly reactive species that contribute to many physical, chemical, and biological processes. For instance, radical cations participate in shock initiation of detonated energetic materials used as explosives …


Asymmetric Cuh-Catalyzed Reductive Coupling Of Allenamides With Carbonyl Electrophiles & Development Of Nanocatalysts For Heterogeneously Catalyzed Buchwald-Hartwig Amination, Raphael K. Klake Jan 2023

Asymmetric Cuh-Catalyzed Reductive Coupling Of Allenamides With Carbonyl Electrophiles & Development Of Nanocatalysts For Heterogeneously Catalyzed Buchwald-Hartwig Amination, Raphael K. Klake

Theses and Dissertations

Many drugs and natural products contain multiple stereogenic carbons bearing heteroatoms throughout their carbon framework. Therefore, methods that can efficiently install multiple heteroatoms on a molecule are valuable. Reductive coupling reactions have been extensively studied, and the allylation of carbonyls via the reductive coupling approach has been a key method for generating chiral tertiary and secondary allylic alcohols. This work utilizes inexpensive Cu for the asymmetric reductive coupling of allenamides with carbonyls to simultaneously install two heteroatoms (oxygen and nitrogen) on the product. These molecules have a polarity profile that make them difficult to make using traditional methods. Herein, we …


Synthesis And Application Of Redox-Active Covalent Organic Frameworks In Rechargeable Batteries, Mohammad K. Shehab Jan 2023

Synthesis And Application Of Redox-Active Covalent Organic Frameworks In Rechargeable Batteries, Mohammad K. Shehab

Theses and Dissertations

Synthesis and Application of Redox-Active Covalent Organic Frameworks in Rechargeable Batteries

Mohammad K. Shehab

Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States

Abstract

In recent years, lithium-ion batteries (LIBs) have been considered the dominant energy storage devices for portable electronics and electric vehicles due to their high energy density, low self-discharge rate, and long cycle life. In LIBs, the traditional positive electrodes employed are mainly derived from metal-containing inorganic compounds composed of cobalt, iron, nickel, or manganese (LiCoO2, LiMn2O4, and LiFePO4) coupled with graphite as the negative electrode. Despite …


Adiabatic Trajectory Approximation: A New General Method In The Toolbox Of Mixed Quantum/Classical Theory For Collisional Energy Transfer, Bikramaditya Mandal, Carolin Joy, Dulat Bostan, Alexander Eng, Dmitri Babikov Jan 2023

Adiabatic Trajectory Approximation: A New General Method In The Toolbox Of Mixed Quantum/Classical Theory For Collisional Energy Transfer, Bikramaditya Mandal, Carolin Joy, Dulat Bostan, Alexander Eng, Dmitri Babikov

Chemistry Faculty Research and Publications

A new version of the MQCT program is presented, which includes an important addition, adiabatic trajectory approximation (AT-MQCT), in which the equations of motion for the classical and quantum parts of the system are decoupled. This method is much faster, which permits calculations for larger molecular systems and at higher collision energies than was possible before. AT-MQCT is general and can be applied to any molecule + molecule inelastic scattering problem. A benchmark study is presented for H2O + H2O rotational energy transfer, an important asymmetric-top rotor + asymmetric-top rotor collision process, a very difficult problem …


Impact Of A Low-Stakes Assessments Model With Retake In General Chemistry: Connecting To Student Attitudes And Self-Concept, Vijay Vyas, Llanie Nobile, James R. Gardinier, Scott A. Reid Jan 2023

Impact Of A Low-Stakes Assessments Model With Retake In General Chemistry: Connecting To Student Attitudes And Self-Concept, Vijay Vyas, Llanie Nobile, James R. Gardinier, Scott A. Reid

Chemistry Faculty Research and Publications

Across a variety of fields, the use of low-stakes assessments has led to reductions in achievement gaps and improved student success. Here, we probe the use of a low-stakes assessment model with a retake option for failed quizzes in a two-semester general chemistry sequence. We find that the quiz-retake rate in general chemistry II was significantly higher for students who had completed a retake in a general chemistry I section, and the percentage of students who failed at least one quiz in general chemistry I but passed all quizzes in general chemistry II was significantly higher for students who had …


Excitonic Coupling In Fluorene-Based Bichromophoric Systems: Vibrational Quenching And The Transition From Weak To Intermediate Coupling, Damian L. Kokkin, Neil Reilly, Maxim V. Ivanov, Rajendra Rathore, Scott A. Reid Jan 2023

Excitonic Coupling In Fluorene-Based Bichromophoric Systems: Vibrational Quenching And The Transition From Weak To Intermediate Coupling, Damian L. Kokkin, Neil Reilly, Maxim V. Ivanov, Rajendra Rathore, Scott A. Reid

Chemistry Faculty Research and Publications

Excimeric systems (i.e., excited dimers) have well served as model compounds for the study of the delocalization of electronic energy over weakly interacting chromophores. However, there remain relatively few isolated systems in which such interactions can be studied experimentally at a level to afford detailed comparisons with theory. In this Article, we examine a series of covalently and noncovalently linked dimers of fluorene, as a model aromatic chromophore, where the formation of excimers requires a π-stacked, cofacial orientation at van der Waals contact. Building upon a series of seminal prior studies that examined vibronic quenching of the excitation interaction in …


Contrasting Seasonal Cycling Of Arsenic In A Series Of Subarctic Shield Lakes With Different Morphometric Properties, Jeremy Harbinson Jan 2023

Contrasting Seasonal Cycling Of Arsenic In A Series Of Subarctic Shield Lakes With Different Morphometric Properties, Jeremy Harbinson

Theses and Dissertations (Comprehensive)

The subarctic shield near Yellowknife, Northwest Territories (NWT), is populated with thousands of small lakes (<1.5 km2) and several large lakes. Historic mining activities in the region have left a legacy of environmental impacts and widespread arsenic (As) contamination in both aquatic and terrestrial environments. In particular, several small subarctic lakes near Yellowknife have been previously documented to be contaminated with high levels of As. Subarctic lakes are characterized by seasonal ice-cover that can persist for more than half of the year, yet little is known about the under-ice spatial and seasonal dynamics of As cycling. The objective of …


Mechanistic Studies Of Co2 Electrochemical Reduction (Co2er) On Cu And Cuo Nanoparticles With In-Situ Atr-Ftir Spectroscopy, Jason Hsu Jan 2023

Mechanistic Studies Of Co2 Electrochemical Reduction (Co2er) On Cu And Cuo Nanoparticles With In-Situ Atr-Ftir Spectroscopy, Jason Hsu

Theses and Dissertations (Comprehensive)

Global climate change is a major challenge facing the world in the 21st century. This environmental crisis originated from excess amounts of atmospheric carbon dioxide (CO2) released from burning fossil fuels. One promising remediation method to decrease atmospheric CO2 levels is called carbon dioxide electrochemical reduction (CO2ER). In CO2ER, the CO2 gas undergoes chemical reduction to other hydrocarbon fuels. For CO2ER to take place, an energy source and a catalyst are needed. In this thesis, three aspects of CO2ER were investigated using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy coupled with other surface sensitive characterization tools. First, we studied …


The Design And Characterization Of Gold Nanoclusters As Elementary Building Blocks, Heather Gaebler Jan 2023

The Design And Characterization Of Gold Nanoclusters As Elementary Building Blocks, Heather Gaebler

Theses and Dissertations (Comprehensive)

Gold nanoclusters with diameters in the quantum size regime (< ~2 nm) are promising building blocks for the design of novel nanomaterials as they exhibit unique size-dependent properties that can be altered and fine-tuned. The research outlined in this PhD thesis employs density functional theory to construct and analyze small ligand-protected cage and rod-shaped nanoclusters. Chapter 2 reports stable halide-protected gold nanocages that were engineered to have a closed-shell valence electron count of 18. This study finds that nanocages comprised of 19 and 20 gold atoms can be converted into stable magic number species containing 18 valence electrons by modifying their charged states via adsorption of halide ligands to the cage’s surface. Chapter 3 reports stable ligand-protected gold nanoclusters with a tetrahedral Au4 core that were engineered to have a closed-shell valence electron count of 2. This study investigates the structural and electronic effects of halide and alkoxy ligands on the tetrahedral nanocluster and concludes that the results support the broader conclusion that it’s possible to fine-tune the stability and electronic properties of small gold nanoclusters using appropriate ligands. Chapter 4 reports stable gold nanorods that have diameters in the quantum regime that were constructed from elementary building blocks that contain “halide-staples”. This study presents different orientations of the “halide-staple” motifs on …


Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer Jan 2023

Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer

Theses and Dissertations (Comprehensive)

Phosphorus (P) is a fundamental element necessary for all life forms and a key component in the fertilizer industry. Meanwhile, the excessive load of P to water bodies due to human activities has the potential to promote eutrophication. Wastewater treatment plants remove P either biologically or chemically and produce P rich sludge which could be a potential renewable source for P. At present, commercial technologies exist for P recovery from biological wastewater sludge. However, P recovery from chemical sludge particularly iron(III)-phosphate (Fe-P) sludge generated in chemical P removal plants that use iron(III) salts remains a challenge.

This study explored, in …


Effects Of Flexibility In Coarse-Grained Models For Bovine Serum Albumin And Immunoglobulin G, Frank Hirschmann, Hender Lopez, Felix Roosen-Runge, Tilo Seydel, Frank Schreiber, Martin Oettel Jan 2023

Effects Of Flexibility In Coarse-Grained Models For Bovine Serum Albumin And Immunoglobulin G, Frank Hirschmann, Hender Lopez, Felix Roosen-Runge, Tilo Seydel, Frank Schreiber, Martin Oettel

Articles

We construct a coarse-grained, structure-based, low-resolution, 6-bead flexible model of bovine serum albumin (BSA, PDB: 4F5S), which is a popular example of a globular protein in biophysical research. The model is obtained via direct Boltzmann inversion using all-atom simulations of a single molecule, and its particular form is selected from a large pool of 6-bead coarse-grained models using two suitable metrics that quantify the agreement in the distribution of collective coordinates between all-atom and coarse-grained Brownian dynamics simulations of solutions in the dilute limit. For immunoglobulin G (IgG), a similar structure-based 12-bead model has been introduced in the literature [Chaudhri …


Combustion Soot Nanoparticles: Mechanism Of Restructuring And Mechanical Properties, Ali Hasani Dec 2022

Combustion Soot Nanoparticles: Mechanism Of Restructuring And Mechanical Properties, Ali Hasani

Dissertations

Soot, a product of incomplete combustion of fossil fuels, is a global warming agent. The effect of soot particles on climate depends on their morphology. Freshly released soot particles are fractal lacey aggregates, but they often appear collapsed in atmospheric samples collected away from emission sources. A body of work has concluded that the collapse is caused by liquid shells when they form by vapor condensation around soot aggregates. However, some recent studies argue that soot remains fractal even when engulfed by the shells, collapsing only when the shells evaporate. To reconcile this disagreement, the effects of the condensation and …


Amphiphilic Block Copolymers And The Applications In Therapeutics Delivery, Jie Dou Dec 2022

Amphiphilic Block Copolymers And The Applications In Therapeutics Delivery, Jie Dou

Dissertations

Well-defined thermo-responsive triblock copolymers containing polyethylene oxide (PEO) and poly(N-isopropyl acrylamide) PNIPAM are synthesized by a type of living controlled polymerization, named iniferter polymerization. The polymers are amphiphilic in nature and are self-assembled into a micelle. Their properties and application are characterized and investigated in this work.

Foremost, the initiator of the polymerization (iniferter) is designed and synthesized by condensation polymerization, where PEO is incorporated into the structure to improve biocompatibility, which has great potential for biological application. Moreover, this iniferter reagent could be applied to more than 70 percent of vinyl monomers.

NIPAM, a commercial vinyl monomer, is chosen …


Mineralogical And Physicomechanical Characterization Of Kaolinitic Clay From Moshi, Northern Tanzania For Potential Ceramic Utilization, Samwel Paul Mziray, Harieth Hellar-Kihampa, Esther H.J. Lugwisha, Leonard Douglas Akwilapo Dec 2022

Mineralogical And Physicomechanical Characterization Of Kaolinitic Clay From Moshi, Northern Tanzania For Potential Ceramic Utilization, Samwel Paul Mziray, Harieth Hellar-Kihampa, Esther H.J. Lugwisha, Leonard Douglas Akwilapo

Tanzania Journal of Science

Kaolin clay from Moshi, northern Tanzania has been characterized for potential ceramics productions. Clay samples taken from three different levels of the deposit were analysed by XRD and XRF. Firing experiments were carried out on experimental briquettes at a maximum temperature of 1300 °C at the rate of 100 °C/hour. The results revealed dominance of kaolinite and illite in the raw clay. The samples were composed majorly by silica (36.88–41.62%), alumina (30.83–32.40%) and hematite (9.29–12.70%). Granulometric analysis showed that the amount of clay decreased with deposit depth. The physicomechanical properties of the clay fired at the optimal temperature of 1300 …


Non-Traditional Methods For The Green Synthesis Of Fine Chemicals, Tara Renée Mooney Dec 2022

Non-Traditional Methods For The Green Synthesis Of Fine Chemicals, Tara Renée Mooney

Graduate Masters Theses

Herein, the advancement of microwave-assisted flow synthesis is reviewed and the green nitration of arenes is investigated. First, microwave-assisted flow systems are described, followed by their synthetic and environmental applications. Microwave-assisted flow synthesis has been applied successfully in organic, inorganic, material, and biochemical syntheses as well as environmental applications such as water desalination and the removal of volatile organic compounds from the atmosphere. In the second part of the Thesis, the methodological development of the first catalyst and solvent-free nitration of m-xylene using only nitric acid is detailed. This environmentally friendly reaction proceeds without the use of harsh Brønsted acids, …


Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto Dec 2022

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto

ASEAN Journal of Community Engagement

This project focused on the introduction of liquid smoke and bio briquette manufacturing technology to small and medium enterprises (SMEs) located in Bohol Village, Gunungkidul, Indonesia through technology transfer, training, and mentoring. These SMEs are engaged in the food business with the main product jenang ketan, a traditional food from Gunungkidul, especially in Rongkop District, and very popular among communities around and outside Gunungkidul. The traditional preparation of jenang ketan produces several by-products in the form of waste, which is dominated by coconut shell biomass. The project’s technology transfer was carried out through the procurement of a series of pyrolysis …


Palladium (Ii)-Catalyzed Selective Reduction Of 4’-(Phenylethynl)Acetophenone In The Presence Of A Formic Acid-Triethylamine Mixture, Suzanne Chayya, Akram Hijazi, Anis Daou, Ali Alaaeddine, Mohamad Sakr, Ghassan Younes, Mohammad El-Dakdouki Dec 2022

Palladium (Ii)-Catalyzed Selective Reduction Of 4’-(Phenylethynl)Acetophenone In The Presence Of A Formic Acid-Triethylamine Mixture, Suzanne Chayya, Akram Hijazi, Anis Daou, Ali Alaaeddine, Mohamad Sakr, Ghassan Younes, Mohammad El-Dakdouki

BAU Journal - Science and Technology

An efficient and straightforward palladium acetylacetonate-catalyzed hydrogen transfer of 4'- (phenylethynyl)acetophenone was developed in this study. Formic Acid was found to be the best hydrogen source in this catalytic system in the presence of triethylamine. Excellent conversions and selectivity were obtained in reducing the starting internal aromatic alkyne to either (E)-1-(4- styrylphenyl)ethanone or an interesting cyclic product, 1-(phenanthrene-3-yl)ethenone, over the ketone functional group present. Over-reduction was rarely seen. The reaction conditions were optimized in terms of the choice of the palladium catalyst, temperature, solvent, and the H-donor/base combination. Using this catalytic system, a one-step synthetic pathway of the …


Feasibility Studies For Use Of Copper Slag In Clinker Manufacture, Suresh Vanguri, Suresh Palla, Gonthi Prasad, Sanjeev Kumar Chaturvedi, Bibekananda Mohapatra Dec 2022

Feasibility Studies For Use Of Copper Slag In Clinker Manufacture, Suresh Vanguri, Suresh Palla, Gonthi Prasad, Sanjeev Kumar Chaturvedi, Bibekananda Mohapatra

Makara Journal of Science

This study investigated the feasibility of using copper slag (CS-C) as a raw material in the production of Portland cement (PC). The effect of addition of 0%-3.5% CS-C on the clinkerization process, mineralogy, microstructure, and compressive strength development was studied. The Presence of CS-C in the raw mix resulted in the reduced temperature of clinkerization by about 50 °C. The quality of clinker prepared from the raw mix containing 3% CS-C and burned at 1400 °C was comparable to that of clinker prepared from the raw mix containing no CS-C and burned at 1450 °C. Gradual polymorphic modification of alite …


Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang Dec 2022

Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang

Journal of Electrochemistry

Lithium-ion batteries (LIBs) have become one of the best solutions to the energy storage issue in modern society. However, the battery materials and device development are both complex, and involve multivariable problems. Traditional trial-and-error approach, which relies on researchers to conduct experiments, has encountered bottlenecks in the improvement of the battery performance. Artificial intelligence (AI) is the most potential technology to deal with this issue due to its powerful high-speed and capabilities of processing massive data. In particular, the capability of machine learning (ML) algorithms in assessing multidimensional data variables and discovering patterns in the sets are expected to assist …


Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang Dec 2022

Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries are deemed as high-promising next-generation energy storage technique due to their ultrahigh theoretical energy density, where the sulfur cathodes with high specific capacity guarantee the energy density advantage and directly determine the battery performances. After decades of exploration, the most promising sulfur cathodes are sulfur/carbon composite (S/C) cathodes and sulfurized polyacrylonitrile (SPAN) cathodes. In this manuscript, recent advances on S/C and SPAN cathodes in Li-S batteries are comprehensively reviewed. The electrochemical reaction circumstances on S/C and SPAN cathodes are firstly introduced and compared to reveal the working mechanisms of the two types of Li-S batteries. The S/C …


Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu Dec 2022

Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu

Journal of Electrochemistry

The continuous development of the global energy structure transformation has put forward higher demands upon the development of batteries. The improvements of the energy density have become one of the important indicators and hot topic for novel secondary batteries. The energy density of existing lithium-ion battery has encountered a bottleneck due to the limitations of material and systems. Herein, this paper introduces the concept and development of multi-electron reaction materials over the past twenty years. Guided by the multi-electron reaction, light weight electrode and multi-ion effect, current development strategies and future trends of high-energy-density batteries are highlighted from the perspective …


Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian Dec 2022

Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian

Journal of Electrochemistry

Ionic liquid (IL) electrolyte-based supercapacitors (SCs) have advantages of high operating voltage window, high energy density and nonflammability, as compared to conventional acetonitrile-based organic electrolyte SCs, and are typically suitable for the large-scale energy storage in the era of carbon neutrality full of renewable, but unstable electricity. However, current efforts were concentrated on the study with coin-cell type of IL-SCs, and less has been reported on the pouch type of IL-SCs for a long cycling time yet. To fabricate a reliable SC for the life time test or for the accelerated aging test under high temperature, one should concern the …


Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang Dec 2022

Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang

Journal of Electrochemistry

Sulfurized polyacrylonitrile (SPAN) is regarded as an attractive cathode candidate of lithium-sulfur (Li-S) batteries for its non-dissolution mechanism and effective alleviation of polysulfides shuttling issue in Li-S batteries, displaying high utilization of cathode active material, outstanding cycle stability and structural stability. However, the relation between cyclization degree and cycle stability of SPAN is still unveiled. In this work, SPAN-C-V composites were synthesized by co-introduction of CuSO4 and zinc n-ethyl-n-phenyldithiocarbamate (ZDB) in the co-heating of sulfur and polyacrylonitrile. The co-introduction of CuSO4 and ZDB reduced the cyclization reaction onset temperature of PAN while increased the C—C/C=C within SPAN-C-V, thus …


Multiomics Approach Captures Hepatic Metabolic Network Altered By Chronic Ethanol Administration, Isin Tuna Sakallioglu, Bridget Tripp, Jacy Kubik, Carol A. Casey, Paul G. Thomes, Robert Powers Dec 2022

Multiomics Approach Captures Hepatic Metabolic Network Altered By Chronic Ethanol Administration, Isin Tuna Sakallioglu, Bridget Tripp, Jacy Kubik, Carol A. Casey, Paul G. Thomes, Robert Powers

Department of Chemistry: Faculty Publications

Using a multiplatform and multiomics approach, we identified metabolites, lipids, proteins, and metabolic pathways that were altered in the liver after chronic ethanol administration. A functional enrichment analysis of the multiomics dataset revealed that rats treated with ethanol experienced an increase in hepatic fatty acyl content, which is consistent with an initial development of steatosis. The nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography–mass spectrometry (LC-MS) metabolomics data revealed that the chronic ethanol exposure selectively modified toxic substances such as an increase in glucuronidation tyramine and benzoyl; and a depletion in cholesterol-conjugated glucuronides. Similarly, the lipidomics results revealed that ethanol …


Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova Dec 2022

Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova

Michigan Tech Publications, Part 1

The targeting of facilitative sugar transporters (GLUTs) has been utilized in the development of tools for diagnostics and therapy. The interest in this area is promoted by the phenomenon of alterations in cellular metabolic processes that are linked to multitudes of metabolic disorders and diseases. However, nonspecific targeting (e.g., glucose-transporting GLUTs) leads to a lack of disease detection efficiency. Among GLUTs, GLUT5 stands out as a prominent target for developing specific molecular tools due to its association with metabolic diseases, including cancer. This work reports a non-radiolabeled fluoride (19F) coumarin-based glycoconjugate of 2,5-anhydro-D-mannitol as a potential PET imaging probe that …


Preparation Of Methanediamine (Ch2(Nh2)2)—A Precursor To Nucleobases In The Interstellar Medium, Joshua H. Marks, Jia Wang, Ryan C. Fortenberry, Ralf I. Kaiser Dec 2022

Preparation Of Methanediamine (Ch2(Nh2)2)—A Precursor To Nucleobases In The Interstellar Medium, Joshua H. Marks, Jia Wang, Ryan C. Fortenberry, Ralf I. Kaiser

Faculty and Student Publications

Although methanediamine (CH2(NH2)2) has historically been the subject of theoretical scrutiny, it has never been isolated to date. Here, we report the preparation of methanediamine (CH2(NH2)2)—the simplest diamine. Low-temperature interstellar analog ices composed of ammonia and methylamine were exposed to energetic electrons which act as proxies for secondary electrons produced in the track of galactic cosmic rays. These experimental conditions, which simulate the conditions within cold molecular clouds, . result in radical formation and initiate aminomethyl (ĊH2NH2) and amino (NH2) radical chemistry. Exploiting tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReToF-MS) to make isomer-specific assignments, methanediamine was identified in the gas …