Physical Sciences and Mathematics Commons^™

Stacked Antiaromatic Porphyrins, Ryo Nozawa, Hiroko Tanaka, Won-Young Cha, Yongseok Hong, Ichiro Hisaki, Soji Shimizu, Ji-Young Shin, Tim Kowalczyk, Stephan Irle, Dongho Kim, Hiroshi Shinokubo

Chemistry Faculty and Staff Publications

Aromaticity is a key concept in organic chemistry. Even though this concept has already been theoretically extrapolated to three dimensions, it usually still remains restricted to planar molecules in organic chemistry textbooks. Stacking of antiaromatic π-systems has been proposed to induce three-dimensional aromaticity as a result of strong frontier orbital interactions. However, experimental evidence to support this prediction still remains elusive so far. Here we report that close stacking of antiaromatic porphyrins diminishes their inherent antiaromaticity in the solid state as well as in solution. The antiaromatic stacking furthermore allows a delocalization of the π-electrons, which enhances the two-photon absorption …

Ijns Masthead

International Journal of Nuclear Security

No abstract provided.

Letter From The Editor - Choe, Kwan Kyoo Choe

International Journal of Nuclear Security

No abstract provided.

Letter From The Editor - Frahi-Amroun, Akila Frahi-Amroun

International Journal of Nuclear Security

No abstract provided.

Letter From The Editor - Hirst, Russel K. Hirst

International Journal of Nuclear Security

No abstract provided.

Call For The Student Writing Competition

International Journal of Nuclear Security

No abstract provided.

Security Culture And Its Self-Assessment As Supplementary Tools For Nuclear Security Training, Igor Khripunov, Sara Z. Kutchesfahani, Khairul -. Khairul -

International Journal of Nuclear Security

Security Culture and its Self-Assessment as Supplementary Tools for Nuclear Security Training

Igor Khripunov, PhD

Center for International Trade and Security, University of Georgia (USA)

Sara Z. Kutchesfahani, PhD

Center for International Trade and Security, University of Georgia (USA)

Khairul Khairul

National Nuclear Energy Agency of Indonesia (BATAN)

Abstract

Nuclear security culture – an emerging and widely recognized practice – serves as a means to support and enhance nuclear security. In fact, many International Atomic Energy Agency (IAEA) publications and the Nuclear Security Summits have highlighted the vital role of nuclear security culture and raised its status to the same …

Call For Submission

International Journal of Nuclear Security

No abstract provided.

Table Of Contents

International Journal of Nuclear Security

No abstract provided.

Conformationally Superarmed S-Ethyl Glycosyl Donors As Effective Building Blocks For Chemoselective Oligosaccharide Synthesis In One Pot, Mithila Bandara, Jagodige Yasomanee, Nigam Rath, Christian Pedersen, Mikael Bols, Alexei Demchenko

Chemistry & Biochemistry Faculty Works

A new series of superarmed glycosyl donors has been investigated. It was demonstrated that the S-ethyl leaving group allows for high reactivity, which is much higher than that of equally equipped S-phenyl glycosyl donors that were previously investigated by our groups. The superarmed S-ethyl glycosyl donors equipped with a 2-O-benzoyl group gave complete β-stereoselectivity. Utility of the new glycosyl donors has been demonstrated in a one-pot one-addition oligosaccharide synthesis with all of the reaction components present from the beginning.

Dihedral-Angle-Controlled Crossover From Static Hole Delocalization To Dynamic Hopping In Biaryl Cation Radicals, Marat R. Talipov, Tushar S. Navale, Mohammad M. Hossain, Ruchi Shukla, Maxim V. Ivanov, Rajendra Rathore

Chemistry Faculty Research and Publications

In cases of coherent charge-transfer mechanism in biaryl compounds the rates follow a squared cosine trend with varying dihedral angle. Herein we demonstrate using a series of biaryl cation radicals with varying dihedral angles that the hole stabilization shows two different regimes where the mechanism of the hole stabilization switches over from (static) delocalization over both aryl rings to (dynamic) hopping. The experimental data and DFT calculations of biaryls with different dihedral angles unequivocally support that a crossover from delocalization to hopping occurs at a unique dihedral angle where the electronic coupling (H_ab) is one half of …

Post-Polymerization Functionalization Of Poly (Ethylene Oxide)–Poly (Β-6-Heptenolactone) Diblock Copolymers To Tune Properties And Self-Assembly, Elizabeth Gillies, Brooke M. Raycraft, Jarret Macdonald

Chemistry Publications

Polyester-based amphiphilic block copolymers and their nanoassemblies are of significant interest for a wide range of applications due to the degradability of the polyester block. However, the commonly used polyesters lack functional groups on their backbones, limiting the possibilities to chemically modify these polymers. Described here are new poly(ethylene oxide) (PEO)–poly(β-6-heptenolactone) (PHEL) block copolymers having pendant alkenes at each repeat unit on the PHEL block. First, the self-assembly of these block copolymers in aqueous solution was studied and it was found that they formed solid nanoparticles and vesicles depending on the relative block lengths. Next the alkene moieties of the …

Spray Printing Of Organic Semiconducting Single Crystals, Grigorios-Panagiotis Rigas, Marcia M. Payne, John E. Anthony, Peter N. Horton, Fernando A. Castro, Maxim Shkunov

Chemistry Faculty Publications

Single-crystal semiconductors have been at the forefront of scientific interest for more than 70 years, serving as the backbone of electronic devices. Inorganic single crystals are typically grown from a melt using time-consuming and energy-intensive processes. Organic semiconductor single crystals, however, can be grown using solution-based methods at room temperature in air, opening up the possibility of large-scale production of inexpensive electronics targeting applications ranging from field-effect transistors and light-emitting diodes to medical X-ray detectors. Here we demonstrate a low-cost, scalable spray-printing process to fabricate high-quality organic single crystals, based on various semiconducting small molecules on virtually any substrate by …

Design, Synthesis, And Evaluation Of Dasatinib-Amino Acid And Dasatinib-Fatty Acid Conjugates As Protein Tyrosine Kinase Inhibitors, Rakesh Tiwari, Alex Brown, Neda Sadeghiani, Amir Nasrolahi Shirazi, Jared Bolton, Amanda Tse, Gennady M. Verkhivker, Keykavous Parang, Gongqin Sun

Pharmacy Faculty Articles and Research

Derivatives of dasatinib were synthesized via esterification with 25 carboxylic acids including amino acids and fatty acids by extending the inhibitor to interact with more diverse sites and to improve specificity. Dasatinib-L-arginine derivative (Das-R, 7) was the most potent of the inhibitors tested with IC50 values of 4.4 nM, <0.25 nM, and <0.45 nM against Csk, Src, and Abl kinases, respectively. The highest selectivity ratio obtained in our study, 91.4 Csk/Src belonged to compound 18 (Das-C10) with an IC50 of 3.2 μM for Csk compared to 35 nM for Src. Furthermore, many compounds displayed increased selectivity toward Src, as compared with Abl. Compounds 15 (Das-E) and 13 (Das-C) demonstrated the largest gains (10.2 and 10.3 Abl/Src IC50 ratios). Das-R (IC50 = 2.06 μM) was significantly more potent than Das (IC50 = 26.3 μM) against Panc-1 cells while they both showed an IC50 < 51.2 pM against BV-173 and K562 cells. Molecular modeling and binding free energy simulations revealed a good agreement with the experimental results and rationalized differences in selectivity of the studied compounds. Integration of experimental and computational approaches in the design and biochemical screening of dasatinib derivatives facilitated rational engineering and diversification of dasatinib scaffold, providing useful insights into mechanisms of kinase selectivity.

Building The Education And Training Pillar Of The University Of Tennessee’S Institute For Nuclear Security, Howard Lewis Hall

International Journal of Nuclear Security

The University of Tennessee (UT) developed its first formal and coordinated efforts in nuclear security education in 2008-2009 with its graduate certificate program in nuclear security in the Department of Nuclear Engineering. Building on this work, in 2011 UT established the UT Institute for Nuclear Security (INS) as a collaborative center at the university to expand its curricular impact as well as foster research and partnerships with nearby major governmental facilities engaged in nuclear security work. Oak Ridge National Laboratory (ORNL), the Y-12 National Security Complex (Y-12), and Oak Ridge Associated Universities (ORAU) have joined with UT as charter members …

Promoting Excellence And Demonstrated Competence For Nuclear Security Training, Daniel Johnson, Brunelle Battistella, Roger Howsley

International Journal of Nuclear Security

The international community has spent considerable time, money, and effort attempting to establish a series of national and regional Centres of Excellence (COEs), also known as Nuclear Security Training and Support Centres (NSSCs). These Centres tend to have a wide variety of objectives, structures, and methods of delivery. Unsurprisingly, no internationally accepted standard exists on how they should operate. The IAEA has produced some excellent guidance (TECDOC 1734), but by virtue of its role cannot provide standards for benchmarking success. Against this backdrop, the World Institute for Nuclear Security (WINS) launched the WINS Academy, an initiative to provide practitioners with …

Nuclear Security Education At Pakistan Institute Of Engineering And Applied Sciences (Pieas): Current Status, Future Prospects And The Lessons Learnt, Tariq Majeed Dr.

International Journal of Nuclear Security

In this paper, the details of nuclear security education at Pakistan Institute of Engineering and Applied Sciences (PIEAS) have been discussed. Nuclear Security education was initiated at PIEAS as a sub-specialty of its MS Nuclear Engineering Program in October 2009. Two courses, Nuclear Security (NE-581) and Physical Protection Systems (NE-582) have been offered on regular basis in the 3^rd and 4^th semesters. To date, 72 students have been graduated with this sub-specialty. The most important lesson learnt is that introduction of nuclear security related courses in nuclear engineering program has opened up new venues of applications of nuclear …

Challenges And Responses For Ensuring Sustainability Of Insa Training Programs, Jongsook Kim, Hyung-Kyung Lee, Jin-Young Lee

International Journal of Nuclear Security

Providing a systematic training is critical for a state or international perspective to reinforce nuclear security regime nationally or internationally. Korea government recognizes the importance of such challenge, and established the INSA under the KINAC as a Center of Excellence for fostering national nuclear security capacity and contributing international nuclear security governance. INSA started with the government policy that the establishment of sustainable education and training infrastructure and processes is fundamental to the capacity building strategy. After established, INSA has been designing and delivering the domestic and international/regional training programs for the purpose of fostering human resources development in nuclear …

Nuclear Security And Hrd - Viet Nam’S Effort, Nu-Hoai-Vi Nguyen, Tan Huu Vuong

International Journal of Nuclear Security

Viet Nam is expanding its nuclear energy program for the application in various areas including industries, agriculture, healthcare, education and research. Recognizing the importance of the nineteen issues laid out in the IAEA document “Milestones in Development of a National Infrastructure for Nuclear Power” [1], Vietnam is considering how to address these issues. This paper describes the establishment of nuclear security infrastructure in Viet Nam and how Viet Nam has addressed one of the nineteen issues, that is human resource development in nuclear energy in general and in nuclear security in particular.

Synthesis, X-Ray Structures, Electronic Properties, And O2/No Reactivities Of Thiol Dioxygenase Active-Site Models, Anne A. Fischer, Nuru Stracey, Sergey V. Lindeman, Thomas C. Brunold, Adam T. Fiedler

Chemistry Faculty Research and Publications

Mononuclear non-heme iron complexes that serve as structural and functional mimics of the thiol dioxygenases (TDOs), cysteine dioxygenase (CDO) and cysteamine dioxygenase (ADO), have been prepared and characterized with crystallographic, spectroscopic, kinetic, and computational methods. The high-spin Fe(II) complexes feature the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (^Ph2TIP) ligand that replicates the three histidine (3His) triad of the TDO active sites. Further coordination with bidentate l-cysteine ethyl ester (CysOEt) or cysteamine (CysAm) anions yielded five-coordinate (5C) complexes that resemble the substrate-bound forms of CDO and ADO, respectively. Detailed electronic-structure descriptions of the [Fe(^Ph2TIP)(L_S,N)]BPh₄ complexes, where L …

‘A Novel Kaposi’S Sarcoma Therapy:’ Plasmonic Nanoparticles For Light-Mediated Drug Delivery, Blake Peter Kruger

Honors Theses

No abstract provided.

Inhibition Of The Flavin-Dependent Monooxygenase Siderophore A (Sida) Blocks Siderophore Biosynthesis And Aspergillus Fumigatus Growth, Julia S. Martín Del Campo, Nancy Vogelaar, Karishma Tolani, Karina Kizjakina, Kim Harich, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Aspergillus fumigatus is an opportunistic fungal pathogen and the most common causative agent of fatal invasive mycoses. The flavin-dependent monooxygenase siderophore A (SidA) catalyzes the oxygen and NADPH dependent hydroxylation of l-ornithine (l-Orn) to N5-l-hydroxyornithine in the biosynthetic pathway of hydroxamate-containing siderophores in A. fumigatus. Deletion of the gene that codes for SidA has shown that it is essential in establishing infection in mice models. Here, a fluorescence polarization high-throughput assay was used to screen a 2320 compound library for inhibitors of SidA. Celastrol, a natural quinone methide, was identified as a noncompetitive inhibitor of SidA with a MIC value …

Photocatalytic Reduction Of Co2 With Tunable Bandgap And Bandedge Materials, Thuhuong T. Ngo

USF Tampa Graduate Theses and Dissertations

Solar energy is a sustainable resource which has substantial potential to meet the increasing demand for renewable energy. Though there has been some success in harvesting solar energy for electricity production, converting solar energy to chemical energy as fuels is still a challenge due to low efficiency.

Since the discovery of TiO₂ photocatalysts for splitting water (4) and reducing CO₂ (5) to form useful chemical feedstock such as H₂, CO and CH₄, much research has been done to increase the efficiency of photocatalysts. However, the current conversion efficiency of photocatalysts remains low (~5%) (6, …

Graphene Quantum Dots Electrochemistry And Development Of Sensitive Electrochemical Biosensor [Hybrid Poster 1-B], Tyler Smith, Alexander Banaszak

Posters-at-the-Capitol

Graphene quantum dots (GQDs) are zero-dimensional material derived from graphene derivatives with characteristics from the structure of graphene with quantum confinement and edge effects possessing unique properties. Intense research activity in GQDs is attributed to their novel physical-chemical phenomena arising from the sp²-bonded carbon core surrounded with edge functional moieties. In this work, GQDs of optimal 5-7 nm size are investigated for their fundamental electrochemical properties and use in electrochemical sensing including enzyme-based glucose biosensor. Glucose oxidase (GO_x) was immobilized on GQDs modified glassy carbon (GC) and the UV-Vis absorption and fluorescence spectroscopy, electron microscopy, cyclic …

Molecular Sensitivity And Selectivity Of Metal Nanoparticles Decorated Graphene As ‘Smart’ Surface-Enhanced Raman Scattering (Sers) Platforms [Hybrid Poster 1-A], Alexander Banaszak, Tyler Smith

Posters-at-the-Capitol

Raman scattering signal enhancement that uses graphene as support, graphene-enhanced Raman scattering (GERS), is a recent phenomenon. It can produce clean and reproducible Raman signals of chemical molecules with significantly enhanced signal intensity in contrast to traditional surface- (SERS) and tip- enhanced Raman scattering (TERS) techniques. While enhancement in SERS and TERS arise due to the electromagnetic mechanism, GERS also relies on a chemical mechanism and therefore shows unique molecular sensitivity and selectivity. In this work, we developed graphene materials decorated with noble metal (silver and gold) nanoparticles for detection of different chemical molecules e.g. methylene blue (MB) and rhodamine …

Molecules, Surfaces, Crystals: A Quantum Chemical Quest From Fundamentals To Applications, Loredana Valenzano

TechTalks

My research focuses on applying fundamental laws governing the behavior of molecules and materials to predict their real-world performance. Using state-of-the-art quantum chemical approaches as my tool set, I computationally model a wide range of molecular and condensed-matter systems: explosives, pharmaceuticals, porous materials, catalysts, nanomaterials, polymers, soft-matter, films, membranes, surfaces, interfaces, layered materials; hybrid systems: molecules interacting with substrates; and, their properties: structural, energetic, vibrational, electronic, mechanical, adsorption, diffusion. Chemical processes such as reactivity and the change of properties after exposure to external agents (e.g. durability) can also be explored. The results of my investigations can contribute to speeding up, …

Introducing The New 2d-Liquid Chromatograph And High-Resolution Mass Spectrometer In The Chemical Advanced Resolution Methods (Charm) Core Facility At Michigan Tech, Lynn Mazzoleni

TechTalks

A Thermo Scientific Orbitrap Elite Mass Spectrometer (high-resolution Orbitrap Elite MS) and a Dionex UltiMate 3000 two-dimensional liquid chromatographic (2d LC) system were recently acquired. The Orbitrap Elite MS is a hybrid instrument, which includes a dual pressure linear ion trap MS and a compact high-field Orbitrap MS. The instrument design enables high-quality, fast MSn characterization with ultrahigh resolution measurements (R = 240,000 at m/z 400) for mass measurements with less than 1 ppm mass error. Therefore, the instrument has the qualitative capability to identify molecular formulas and structure and, when paired with modern chromatography, provides quantitative assessment of analytes. …

Enriching Health-Related Research Through Glycobiological Approaches, Tarun K. Dam

TechTalks

In the Laboratory of Mechanistic Glycobiology at Michigan Technological University, we have been working in four distinct but related areas. Our findings can significantly influence human health-related research. (1) We have documented a molecular strategy that can improve drug designing. (2) We have shown that the tumor-associated protein galectin-3 can create problems in cancer biomarker assays by hiding the biomarkers. (3) In another project, we reported that the role of galectin-3 in cancer could be more complicated than what is reported in the literature. (4) Our team also detected a novel natural product with anti-fungal and anti-cancer activities.

Hydrolytic And Nonhydrolytic Sol-Gel Zirconia-, Titania-, And Niobia-Based Capillary Microextraction Coatings For The Preconcentration And Hplc Analysis Of Catecholamine Neurotransmitters And Phosphorylated Peptides, Abdullah Awadh Alhendal

USF Tampa Graduate Theses and Dissertations

Sample preparation is the most error-prone step in chemical analysis. A great deal of efforts has been made to develop efficient techniques and protocols for sample preparation to accomplish important goals such as miniaturization and implementation of green analytical methodologies. Solid-phase microextraction (SPME) has successfully eliminated the use of hazardous organic solvents in extraction sampling, sample preparation, preconcentration and sample introduction to the analytical instrument in an effective manner. Ensuring thermal- and solvent-instability of traditional SPME extraction phases represented one of their main drawbacks. This was solved by the introduction of sol-gel SPME phases characterized by enhanced thermal-, solvent-, and …

Development Of In Vivo Systems For Detecting And Studying Ribosome Inhibition By Small Molecules, Shijie Huang

Chemistry and Chemical Biology ETDs

The ribosome is the quintessential antibacterial drug target, with many structurally and mechanistically distinct classes of antibacterial agents acting by inhibiting ribosome function. Detecting and quantifying ribosome inhibition by small molecules and investigating their binding modes and mechanisms of action are critical to antibacterial drug discovery and development efforts. To develop a ribosome inhibition assay that is operationally simple, yet provides direct information on the drug target and the mechanism of action, we have developed engineered E. coli strains harboring an orthogonal ribosome controlled green fluorescent protein reporter that produce fluorescent signal when the O-ribosome is inhibited. As a proof …