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Bdpa-Nitroxide Biradicals Tailored For Efficient Dynamic Nuclear Polarization Enhanced Solid-State Nmr At Magnetic Fields Up To 21.1 T, Dorothea Wisser, Ganesan Karthikeyan, Alicia Lund, Gilles Casano, Hakim Karoui, Maxim Yulikov, Georges Menzildjian, Arthur C. Pinon, Armin Purea, Frank Engelke, Sachin R. Chaudhari, Dominik Kubicki, Aaron Rossini, Ilia B. Moroz, David Gajan, Christophe Copéret, Gunnar Jeschke, Moreno Lelli, Lyndon Emsley, Anne Lesage, Olivier Ouari 2018 Université de Lyon

Bdpa-Nitroxide Biradicals Tailored For Efficient Dynamic Nuclear Polarization Enhanced Solid-State Nmr At Magnetic Fields Up To 21.1 T, Dorothea Wisser, Ganesan Karthikeyan, Alicia Lund, Gilles Casano, Hakim Karoui, Maxim Yulikov, Georges Menzildjian, Arthur C. Pinon, Armin Purea, Frank Engelke, Sachin R. Chaudhari, Dominik Kubicki, Aaron Rossini, Ilia B. Moroz, David Gajan, Christophe Copéret, Gunnar Jeschke, Moreno Lelli, Lyndon Emsley, Anne Lesage, Olivier Ouari

Chemistry Publications

Dynamic Nuclear Polarization (DNP) solid-state NMR has developed into an invaluable tool for the investigation of a wide range of materials. However, the sensitivity gain achieved with many polarizing agents suffers from an unfavorable field and Magic Angle Spinning (MAS) frequency dependence. We present a series of new hybrid biradicals, soluble in organic solvents, that consist of an isotropic narrow EPR line radical, BDPA, tethered to a broad line nitroxide. By tuning the distance between the two electrons and the substituents at the nitroxide moiety, correlations between the electron-electron interactions and the electronic spin relaxation times on one hand, and ...


Efforts Towards The Discovery Of Novel Methods For The Synthesis Of Pharmacologically Relevant Molecular Scaffolds, Graham Joseph Haun 2018 Rowan University

Efforts Towards The Discovery Of Novel Methods For The Synthesis Of Pharmacologically Relevant Molecular Scaffolds, Graham Joseph Haun

Theses and Dissertations

With the introductions of pharmaceuticals into modern day society many people have been using them to improve their lives. Due to this high increase in demand along with the ever-growing concern of environmental impact pharmaceutical companies have been pressed to synthesis new and existing drugs at a higher rate. This increased rate can cause low yield drugs or have a heavy environmental impact. As the use of pharmaceuticals becomes more widespread the need for greener and simpler organic synthesis methods to make these pharmaceuticals becomes more needed.

Herein is reported the methodological development of different pharmacologically relevant scaffolds. This work ...


Optical Temperature Sensing With Infrared Excited Upconversion Nanoparticles, Kory Green, Kai Huang, Hai Pan, Gang Han, Shuang Fang Lim 2018 North Carolina State University

Optical Temperature Sensing With Infrared Excited Upconversion Nanoparticles, Kory Green, Kai Huang, Hai Pan, Gang Han, Shuang Fang Lim

Open Access Articles

Upconversion Nanoparticles (UCNPs) enable direct measurement of the local temperature with high temporal and thermal resolution and sensitivity. Current studies focusing on small animals and cellular systems, based on continuous wave (CW) infrared excitation sources, typically lead to localized thermal heating. However, the effects of upconversion bioimaging at the molecular scale, where higher infrared intensities under a tightly focused excitation beam, coupled with pulsed excitation to provide higher peak powers, is not well understood. We report on the feasibility of 800 and 980 nm excited UCNPs in thermal sensing under pulsed excitation. The UCNPs report temperature ratiometrically with sensitivities in ...


Hydrogen-Deuterium Exchange Mass Spectrometry And Molecular Dynamics Simulations For Studying Protein Structure And Dynamics, Yiming Xiao 2018 The University of Western Ontario

Hydrogen-Deuterium Exchange Mass Spectrometry And Molecular Dynamics Simulations For Studying Protein Structure And Dynamics, Yiming Xiao

Electronic Thesis and Dissertation Repository

Deciphering properties of proteins are essential for human health and aiding in the development of new pharmaceuticals. This dissertation uses hydrogen-deuterium exchange (HDX) mass spectrometry (MS) and molecular dynamics (MD) simulations to study protein dynamics, for improving the understanding of protein folding/unfolding mechanisms, and ligand binding and allosteric regulation.

Chapter 2 uses HDX-MS for probing the conformational dynamics of myoglobin in the presence of N2 bubbles. We propose a dynamic model that reproduces the observed data: “semi-unfolded” “native” “globally unfolded” -> “aggregated”. Chapter 3 focuses on osteoprotegerin (OPG), which hinders bone resorption by inhibiting RANK/RANKL interactions. The dimerization ...


Mechanism Of Protein Charging And Supercharging In Electrospray Ionization: Molecular Dynamics Simulations And Experimental Investigations, Haidy S. Metwally 2018 The University of Western Ontario

Mechanism Of Protein Charging And Supercharging In Electrospray Ionization: Molecular Dynamics Simulations And Experimental Investigations, Haidy S. Metwally

Electronic Thesis and Dissertation Repository

Electrospray ionization mass spectrometry (ESI-MS) is a powerful technique for investigating protein structures, conformations, and interactions. Despite its widespread use, many fundamental aspects of ESI remain poorly understood. In this thesis, we use a combination of molecular dynamics (MD) simulations and experiments to gain insights into the hidden complexities of ESI-MS.

Chapter 2 discusses the topic of salt-induced protein signal degradation. Salts such as NaCl, CsCl, and tetrabutyl ammonium chloride (NBu4Cl) interfere with MS data acquisition, leading to adduct formation and signal suppression. MD simulations provide an explanation for these salt interferences. Signal suppression can be broken down ...


Sensitivity-Enhanced 207pb Solid-State Nmr Spectroscopy For The Rapid, Non-Destructive Characterization Of Organolead Halide Perovskites, Michael P. Hanrahan, Long Men, Bryan A. Rosales, Javier Vela, Aaron J. Rossini 2018 Iowa State University and Ames Laboratory

Sensitivity-Enhanced 207pb Solid-State Nmr Spectroscopy For The Rapid, Non-Destructive Characterization Of Organolead Halide Perovskites, Michael P. Hanrahan, Long Men, Bryan A. Rosales, Javier Vela, Aaron J. Rossini

Chemistry Publications

Organolead halide and mixed halide perovskites (CH3NH3PbX3, CH3NH3PbX3–nYn, X and Y = Cl–, Br– or I–), are promising materials for photovoltaics and optoelectronic devices. 207Pb solid-state NMR spectroscopy has previously been applied to characterize phase segregation and halide ion speciation in mixed halide perovskites. However, NMR spectroscopy is an insensitive technique that often requires large sample volumes and long signal averaging periods. This is especially true for mixed halide perovskites, which give rise to extremely broad 207Pb solid-state NMR spectra. Here, we quantitatively compare the sensitivity of the various solid-state NMR techniques on pure and mixed halide organolead perovskites and ...


Molecular Insights On Aging And Aqueous-Phase Processing From Ambient Biomass Burning Emissions-Influenced Po Valley Fog And Aerosol, Matthew Brege, Marco Paglione, Stefania Gilardoni, Maria Cristina Facchini, Lynn Mazzoleni 2018 Michigan Technological University

Molecular Insights On Aging And Aqueous-Phase Processing From Ambient Biomass Burning Emissions-Influenced Po Valley Fog And Aerosol, Matthew Brege, Marco Paglione, Stefania Gilardoni, Maria Cristina Facchini, Lynn Mazzoleni

Department of Chemistry Publications

To study the influence of regional biomass burning emissions and secondary processes, ambient samples of fog and aerosol were collected in the Po Valley (Italy) during the 2013 Supersito field campaign. After the extent of fresh vs. aged biomass burning influence was estimated from proton nuclear magnetic resonance (1H NMR) and high-resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS), two samples of fog water and two samples of PM1 aerosol were selected for ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis. Molecular compositions indicated that the water-soluble organic matter was largely non-polymeric without clearly repeating units. The selected ...


How To Fold And Protect Mitochondrial Ribosomal Rna With Fewer Guanines, Maryam Hosseini, Poorna Roy, Marie Sissler, Craig L. Zirbel, Eric Westhof, Neocles B. Leontis 2018 Bowling Green State University

How To Fold And Protect Mitochondrial Ribosomal Rna With Fewer Guanines, Maryam Hosseini, Poorna Roy, Marie Sissler, Craig L. Zirbel, Eric Westhof, Neocles B. Leontis

Chemistry Faculty Publications

Mammalian mitochondrial ribosomes evolved from bacterial ribosomes by reduction of ribosomal RNAs, increase of ribosomal protein content, and loss of guanine nucleotides. Guanine is the base most sensitive to oxidative damage. By systematically comparing high-quality, small ribosomal subunit RNA sequence alignments and solved 3D ribosome structures from mammalian mitochondria and bacteria, we deduce rules for folding a complex RNA with the remaining guanines shielded from solvent. Almost all conserved guanines in both bacterial and mammalian mitochondrial ribosomal RNA form guaninespecific, local or long-range, RNA–RNA or RNA– protein interactions. Many solvent-exposed guanines conserved in bacteria are replaced in mammalian mitochondria ...


Unraveling The Stereodynamics Of Cold Controlled Hd−H2 Collisions, James F. E. Croft, Naduvalath Balakrishnan, Meng Huang, Hua Guo 2018 University of Nevada, Las Vegas

Unraveling The Stereodynamics Of Cold Controlled Hd−H2 Collisions, James F. E. Croft, Naduvalath Balakrishnan, Meng Huang, Hua Guo

Chemistry and Biochemistry Faculty Publications

Measuring inelastic rates with partial-wave resolution requires temperatures close to a Kelvin or below, even for the lightest molecule. In a recent experiment, Perreault, Mukherjee, and Zare [Nat. Chem. 10, 561 (2018).] studied collisional relaxation of excited HD molecules in the v=1, j=2 state by para- and ortho-H2 at a temperature of about 1 K, extracting the angular distribution of scattered HD in the v=1, j=0 state. By state preparation of the HD molecules, control of the angular distribution of scattered HD was demonstrated. Here, we report a first-principles simulation of that experiment which enables us ...


An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman 2018 University of Kentucky

An Overview Of Dynamic Heterogeneous Oxidations In The Troposphere, Elizabeth A. Pillar-Little, Marcelo I. Guzman

Chemistry Faculty Publications

Due to the adverse effect of atmospheric aerosols on public health and their ability to affect climate, extensive research has been undertaken in recent decades to understand their sources and sinks, as well as to study their physical and chemical properties. Atmospheric aerosols are important players in the Earth’s radiative budget, affecting incoming and outgoing solar radiation through absorption and scattering by direct and indirect means. While the cooling properties of pure inorganic aerosols are relatively well understood, the impact of organic aerosols on the radiative budget is unclear. Additionally, organic aerosols are transformed through chemical reactions during atmospheric ...


Illuminating Biology With Membrane Penetrating Sulfonate Delivery Scaffolds And Near-Infrared Azasiline Fluorophores, Adam Choi 2018 University of Massachusetts Medical School

Illuminating Biology With Membrane Penetrating Sulfonate Delivery Scaffolds And Near-Infrared Azasiline Fluorophores, Adam Choi

GSBS Dissertations and Theses

Near-infrared (NIR) light, with wavelengths of 650 to 900 nanometers, effectively penetrates tissues. The high signal to noise ratio and low phototoxicity of NIR light makes this wavelength range ideal for deep tissue imaging. However, current NIR fluorophores are generally large hydrophobic molecules that are prone to aggregation. Sulfonation can enhance aqueous solubility, but their anionic nature prevents membrane diffusion, and thus, restricts the applications of sulfonated molecules to in vitro or fixed cells.

The repertoire of commercially available sulfonated NIR probes is mostly limited cyanines, which have low photostability. Moreover, larger cyanines require multiple sulfonates to maintain aqueous solubility ...


Enhancement Of Triplet-Sensitized Upconversion In Rigid Polymers Via Singlet Exciton Sink Approach, Steponas Raišys, Saulius Juršėnas, Yoan C. Simon, Christoph Weder, Karolis Kazlauskas 2018 Vilnius University

Enhancement Of Triplet-Sensitized Upconversion In Rigid Polymers Via Singlet Exciton Sink Approach, Steponas Raišys, Saulius Juršėnas, Yoan C. Simon, Christoph Weder, Karolis Kazlauskas

Faculty Publications

To increase the practical usefulness of solid-state sensitized upconversion (UC) materials as components of solar energy harvesting systems, it is important to identify and suppress loss mechanisms, and increase the UC quantum yield (ΦUC). Here we focus on a benchmark UC system consisting of the emitter 9,10-diphenylanthracene (DPA) and the sensitizer platinum octaethylporphyrin (PtOEP) in a rigid poly(methyl methacrylate) (PMMA) matrix, and show that one of the major losses originates from Förster resonant energy transfer (FRET) from DPA back to PtOEP. Even though DPA emission lies within the PtOEP transparency window, the quantitative assessment of singlet exciton ...


T Cell Epitope Engineering: An Avian H7n9 Influenza Vaccine Strategy For Pandemic Preparedness And Response, Leonard Moise, Bethany M. Biron, Christine M. Boyle, Nese Kurt Yilmaz, Hyesun Jang, Celia A. Schiffer, Ted M. Ross, William D. Martin, Anne S. De Groot 2018 University of Rhode Island

T Cell Epitope Engineering: An Avian H7n9 Influenza Vaccine Strategy For Pandemic Preparedness And Response, Leonard Moise, Bethany M. Biron, Christine M. Boyle, Nese Kurt Yilmaz, Hyesun Jang, Celia A. Schiffer, Ted M. Ross, William D. Martin, Anne S. De Groot

Schiffer Lab Publications

The delayed availability of vaccine during the 2009 H1N1 influenza pandemic created a sense of urgency to better prepare for the next influenza pandemic. Advancements in manufacturing technology, speed and capacity have been achieved but vaccine effectiveness remains a significant challenge. Here, we describe a novel vaccine design strategy called immune engineering in the context of H7N9 influenza vaccine development. The approach combines immunoinformatic and structure modeling methods to promote protective antibody responses against H7N9 hemagglutinin (HA) by engineering whole antigens to carry seasonal influenza HA memory CD4(+) T cell epitopes - without perturbing native antigen structure - by galvanizing HA-specific memory ...


Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, Barry Herschy, Sae Jung Chang, Ruth Blake, Aivo Lepland, Heather Abbott-Lyon, Jacqueline Sampson, Zachary Atlas, Terence P. Kee, Matthew A. Pasek 2018 University of South Florida

Archean Phosphorus Liberation Induced By Iron Redox Geochemistry, Barry Herschy, Sae Jung Chang, Ruth Blake, Aivo Lepland, Heather Abbott-Lyon, Jacqueline Sampson, Zachary Atlas, Terence P. Kee, Matthew A. Pasek

Faculty Publications

The element phosphorus (P) is central to ecosystem growth and is proposed to be a limiting nutrient for life. The Archean ocean may have been strongly phosphorus-limited due to the selective binding of phosphate to iron oxyhydroxide. Here we report a new route to solubilizing phosphorus in the ancient oceans: reduction of phosphate to phosphite by iron(II) at low (<200 >°C) diagenetic temperatures. Reduction of phosphate to phosphite was likely widespread in the Archean, as the reaction occurs rapidly and is demonstrated from thermochemical modeling, experimental analogs, and detection of phosphite in early Archean rocks. We further demonstrate that the ...


Flexible And Versatile Soft Templates For Mesoporous Silicas And Organosilicas Based On Pluronic Block Copolymer Surfactants And Their Mixtures, George Farid 2018 The Graduate Center, City University of New York

Flexible And Versatile Soft Templates For Mesoporous Silicas And Organosilicas Based On Pluronic Block Copolymer Surfactants And Their Mixtures, George Farid

All Dissertations, Theses, and Capstone Projects

In this dissertation, the work will be discussed that was focused on the synthesis of consolidated periodic mesoporous materials such as 2-D hexgonal ordered mesoporous silicas (SBA-15) as well as single-micelle-templated silica and organosilica nanotubes and nanospheres using triblock copolymer surfactants and their mixtures in the presence of a swelling agent. The introductory section, Chapter 1, will address the current state of the tunability of single-micelle-templated silica and organosilica nanotubes and will compare it with the work presented in this dissertation on the use of a dual-surfactant templating systems. Chapter 2 of the dissertation discusses transmission electron microscopy characterization of ...


Nascent O2 (A1ΔG, V = 0, 1) Rotational Distributions From The Photodissociation Of Jet‐Cooled O3 In The Hartley Band, Michelle L. Warter, Carolyn E. Gunthardt, Wei Wei, George McBane, Simon W. North 2018 Texas A & M University - College Station

Nascent O2 (A1ΔG, V = 0, 1) Rotational Distributions From The Photodissociation Of Jet‐Cooled O3 In The Hartley Band, Michelle L. Warter, Carolyn E. Gunthardt, Wei Wei, George Mcbane, Simon W. North

Peer Reviewed Articles

We report rotational distributions for the O2 (a 1Δg) fragment from photodissociation of jet‐cooled O3 at 248, 266, and 282 nm. The rotational distributions show a population alternation that favors the even states, as previously reported for a 300 K sample by Valentini et al. (J. Chem. Phys. 86, 6745 (1987)). The alternation from the jet‐cooled precursor is much stronger than that observed by Valentini et al., and in contrast to their observations does not depend strongly on O2 (a 1Δg) vibrational state or photolysis wavelength. The odd/even alternation diminishes ...


Native V. Californicum Alkaloid Combinations Induce Differential Inhibition Of Sonic Hedgehog Signaling, Matthew W. Turner, Roberto Cruz, Jordan Elwell, John French, Jared Mattos, Owen M. McDougal 2018 Boise State University

Native V. Californicum Alkaloid Combinations Induce Differential Inhibition Of Sonic Hedgehog Signaling, Matthew W. Turner, Roberto Cruz, Jordan Elwell, John French, Jared Mattos, Owen M. Mcdougal

Chemistry Faculty Publications and Presentations

Veratrum californicum is a rich source of steroidal alkaloids such as cyclopamine, a known inhibitor of the Hedgehog (Hh) signaling pathway. Here we provide a detailed analysis of the alkaloid composition of V. californicum by plant part through quantitative analysis of cyclopamine, veratramine, muldamine and isorubijervine in the leaf, stem and root/rhizome of the plant. To determine whether additional alkaloids in the extracts contribute to Hh signaling inhibition, the concentrations of these four alkaloids present in extracts were replicated using commercially available standards, followed by comparison of extracts to alkaloid standard mixtures for inhibition of Hh signaling using Shh-Light ...


Fundamental Chemistry Related To The Separations And Coordination Of Actinium-225, Thorium-227, And Technetium-99, Jasmine L. Hatcher 2018 The Graduate Center, City University of New York

Fundamental Chemistry Related To The Separations And Coordination Of Actinium-225, Thorium-227, And Technetium-99, Jasmine L. Hatcher

All Dissertations, Theses, and Capstone Projects

This work explores the fundamental chemistry of actinium, thorium, and technetium in an effort to develop methodologies which help to address complications specific to each of these elements. Developing fundamental knowledge in inorganic chemistry has the power to meaningfully address a number of real world problems. By using simple systems and experiments like following an electron or changing the solvent system, we are able to gain invaluable information which can be used to address major issues.

Actinium-225 (t½: 9.92 d) is an alpha-emitting radionuclide with nuclear properties well suited for alpha therapy of malignant tumors. The present global ...


Characterization And Quantification Of Covalent Modification Of Proteins Using Mass Spectrometry, Pratikkumar N. Rathod 2018 The Graduate Center, City University of New York

Characterization And Quantification Of Covalent Modification Of Proteins Using Mass Spectrometry, Pratikkumar N. Rathod

All Dissertations, Theses, and Capstone Projects

Identification and characterization of various post-translational modifications of protein is a key to understanding many unknown cellular processes. In the last few decades, mass spectrometry has evolved as an essential and effective analytical tool for qualitative and quantitative analysis of proteins. In this research, we have developed a novel MALDI-MS2 based quantification method for Desmosine and Isodesmosine, which served as cross-linking amino acids of elastin, in order to measure the elastin degradation in the body. This is the first quantification method that not only illustrates the potential of MALDI-Ion Trap MS2, but also improvement over the current LC-MS ...


Nmr Characterizations Of Candidate Battery Electrolytes, Stephen A. Munoz 2018 The Graduate Center, City University of New York

Nmr Characterizations Of Candidate Battery Electrolytes, Stephen A. Munoz

All Dissertations, Theses, and Capstone Projects

Enormous strides have been made in next-generation power sources to build a more sustainable society. Energy storage has become a limiting factor in our progress, and there are huge environmental and financial incentives to find the next step forward in battery technology. This work discusses NMR methods for characterizing materials for use in battery application, with a special focus on relaxometry and diffusometry. Examples are provided of various recent investigations involving novel candidate electrolyte materials with different collaborators. Works discussed in this thesis include: the characterization of a new disruptive solid polymer electrolyte technology, investigations of the dynamics of super ...


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