Digital Commons Network^™

Synergistic Extraction Of Silver From Nitric Acid Medium With Dithizone In The Presence Of A Secondary Amine- Amberlite La-2 Using 110mag-Radioisotope, Madhusudan Mandal Ph.D.

Karbala International Journal of Modern Science

Synergistic extraction of silver has been investigated in the presence of two different kinds of extractants, one of which is a chelating ligand, dithizone and the other is a long-chain secondary amine amberlite LA-2 at pH 3.0 using a radiotracer technique. The apparent formation constant, overall equilibrium constant and adduct formation constants were calculated from distribution coefficients. Interestingly, it was observed that the adduct formation constant is too high when the ligand concentration is increased by keeping the amine concentration fixed at 0.044 M compared to that obtained when the ligand concentration is kept fixed at 8.74×10^-4 M.

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

A Modular Strategy For Expanding Electron-Sink Capacity In Noncanonical Cluster Assemblies, Yume Mai, Alexandria K. Balzen, Rebecca K. Torren, Michael P. Callahan, Adam C. Colson

Chemistry and Biochemistry Faculty Publications and Presentations

A modular synthetic strategy is described whereby organometallic complexes exhibiting considerable electron-sink capacity may be assembled by using only a few simple molecular components. The Fe₂(PPh₂)₂(CO)₅ fragment was selected as a common electroactive component and was assembled around aromatic cores bearing one, two, or three isocyanide functional groups, with the resultant complexes possessing electron-sink capacities of two, four, and six electrons, respectively. The latter complex is noteworthy in that its electron-sink capacity was found to rival that of large multinuclear clusters (e.g., [Ni₃₂C₆(CO)₃₆]^6– and [Ni_{38 …}

Single-Variable Porous Nanomaterial Series From Polymer Structure-Directing Agents, Morgan Stefik

Faculty Publications

Block polymer structure-directing agents (SDA) enable the production of porous nanoscale materials. Most strategies rely upon polymer equilibration where diverse morphologies are realized in porous functional materials. This review details how solvent selectivity determines the polymer SDA behaviors, spanning from bulk-type to solution-type. Equilibrating behavior of either type, however, obscures nanostructure cause-and-effect since the resulting sample series convolve multiple spatial variations. Solution-type SDA behaviors include both dynamic and persistent micelles. Persistent micelle templates (PMT) use high solvent selectivity for kinetic entrapment. PMTs enable independent wall thickness control with demonstrated 2 Å precision alterations. Unimodal PMT pore size distributions have spanned …

Synthesis Of Molecular Probes For The Detection Of Toxic Analytes, Rashid Mia

Dissertations

Two different types of molecular probes have been synthesized. The first family of probes is the coumarin class of compounds. These chemodosimters are referred to as Low Molecular Weight Fluorescent probes (LMFP). The other type of molecular probe is a macrocycle known as a pillar[5]arene receptor.

The chemodosimters (2.12a-c and 3.12a) were synthesized in four to five steps. The photophysical properties were extensively studied in various solvent systems (DMSO, CH₃CN, DMF, MeOH, EtOH, Me₂CO, MeCO₂Et, CHCl₃, C₆H₅Me, and C₆H₆). Dimethyl sulfoxide (DMSO) …

Formation Of Reactive Nitrogen Species During Dichloramine Decay And Their Impact On N Nitrosodimethylamine Formation Under Drinking Water Conditions, Huong Thu Pham

Graduate Theses and Dissertations

NDMA occurrence and formation pathways in drinking water systems are reviewed and NDMA yields are compared on the basis of disinfectant type, water chemistry, and precursor category. In chloramination, despite monochloramine being the predominant species between pH 7-9, evidence suggests that dichloramine is the primary species involved in NDMA formation. This is somewhat confounding as NDMA yields are maximal at pH 9, yet at pH 9 dichloramine decays faster than it forms and hence is present at trace levels; additionally, the proposed mechanism involves a spin-forbidden incorporation of dissolved oxygen as a triplet, which is presumably kinetically slow. This review …

Aqueous-Based Associated Solvents For Protein And Peptide Fractionation And Protein Purification, Sajad Tasharofi

Chemistry & Biochemistry Dissertations - Archive

The focus of this dissertation is studying capabilities of a novel two-phase system in enhancing protein identification in the whole-cell proteomics studies. In this document, two types of biphasic systems have been used for two different purposes. The first type of biphasic system is formed by the addition of 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) to the aqueous solutions of water-miscible organic solvents. A combination of HFIP, organic solvent, and water forms a two-phase system in spite of the fact that every solvent pair in the three-component system is miscible and forms homogeneous solutions in water. This biphasic system is called Fluoroalcohol-Organic Associated Solvent …

Total Synthesis Of Imidazole-Containing Β-Carboline Alkaloids And Pyrrole-Imidazole Alkaloids, Moumita Singha Roy

Chemistry & Biochemistry Dissertations - Archive

The first part in this dissertation focuses on the development of an enantioselective total synthesis of villagorgin A, from another natural product haploscleridamine. Haploscleridamine was targeted first as it was thought that a successful approach to this family member would permit access to the other congeners through minor modifications, including conversion to villagorgin A. Moreover, villagorgin A has just one additional carbon atom compared to haploscleridamine, the introduction of which can be envisioned through a Pictet-Spengler reaction with formaldehyde. On completion of the haploscleridamine synthesis, attention was turned to the brominated congener, lissoclin C. Lissoclin C can be accessed from …

Mif But Not Mif-2 Recruits Inflammatory Macrophages In An Experimental Polymicrobial Sepsis Model, Pathricia Veronica Tilstam, Wibke Schulte, Thomas Holowka, Bong-Sung Kim, Jessica Nouws, Maor Sauler, Marta Piecychna, Georgios Pantouris, Elias Lolis, Lin Leng, Jürgen Bernhagen, Günter Fingerle-Rowson, Richard Bucala

Pacific Faculty Work

Excessive inflammation drives the progression from sepsis to septic shock. Macrophage migration inhibitory factor (MIF) is of interest because MIF promoter polymorphisms predict mortality in different infections, and anti-MIF antibody improves survival in experimental models when administered 8 hours after infectious insult. The recent description of a second MIF superfamily member, D-dopachrome tautomerase (D-DT/MIF-2), prompted closer investigation of MIF-dependent responses. We subjected Mif^-/- and Mif-2^-/- mice to polymicrobial sepsis and observed a survival benefit with Mif but not Mif-2 deficiency. Survival was associated with reduced numbers of small peritoneal macrophages (SPMs) that, in contrast to large peritoneal macrophages …

Identification Of Disease-Linked Hyperactivating Mutations In Ube3a Through Large-Scale Functional Variant Analysis, Kellan P. Weston, Xiaoyi Gao, Jinghan Zhao, Kwang Soo Kim, Susan E. Maloney, Jill Gotoff, Sumit Parikh, Yen Chen Leu, Kuen Phon Wu, Marwan Shinawi, Joshua P. Steimel, Joseph S. Harrison, Jason J. Yi

College of the Pacific Faculty Articles

The mechanisms that underlie the extensive phenotypic diversity in genetic disorders are poorly understood. Here, we develop a large-scale assay to characterize the functional valence (gain or loss-of-function) of missense variants identified in UBE3A, the gene whose loss-of-function causes the neurodevelopmental disorder Angelman syndrome. We identify numerous gain-of-function variants including a hyperactivating Q588E mutation that strikingly increases UBE3A activity above wild-type UBE3A levels. Mice carrying the Q588E mutation exhibit aberrant early-life motor and communication deficits, and individuals possessing hyperactivating UBE3A variants exhibit affected phenotypes that are distinguishable from Angelman syndrome. Additional structure-function analysis reveals that Q588 forms a regulatory site …

Theoretical Investigation Of The Co-C Bond Activation In Methylcobalamin And Adenosylcobalamin-Dependent Systems: Mechanistic Insights., Arghya Pratim Ghosh

Electronic Theses and Dissertations

The vitamin B₁₂ derivates, otherwise known as cobalamin (Cbl), are ubiquitous organometallic cofactors. The biologically active forms of Cbl, such as methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl), act as cofactors in different physiological reactions for both prokaryotes and eukaryotes. A crucial aspect of the Cbl-mediated systems is the activation of the organometallic Co-C bond that plays a critical role in its catalytic activity. One of the most remarkable features of this Co-C bond is its unusual activation in AdoCbl-dependent enzymatic reactions, where a trillion-fold rate acceleration of the Co-C bond cleavage is observed inside the enzyme compared to the isolated …

College Of Natural Sciences Newsletter, December 2021, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Volume 2, Issue 12

Page 1 Dean's Message
Page 2 Awards & Recognition
Page 2 Media Coverage of CNS
Page 3 Media Coverage Cont.
Page 4 Science as Art Competition
Page 5 Open PRAIRIE Data
Page 5 Grants Awarded in CNS

Super-Adsorbent Hydrogels For Removal Of Methylene Blue From Aqueous Solution: Dye Adsorption Isotherms, Kinetics, And Thermodynamic Properties, Buddhabhushan Salunkhe, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

Removal of dyes through adsorption from wastewater has gained substantial interest in recent years, especially in development of hydrogel-based adsorbents, owing to their easy use and economical nature. The aim of the present study was to design a super-adsorbent hydrogel based on sodium styrene sulfonate (NaSS) monomer for removal of dyes like methylene blue (MB). NaSS displays both an aromatic ring and strongly ionic group in its monomer structure that can enhance adsorption capacity. Poly (sodium styrene sulfonate-co-dimethylacrylamide) hydrogels were prepared by solution free radical polymerization using gelatin meth acryloyl (GelMA) as crosslinker, creating a highly porous, three-dimensionally crosslinked polymer …

Spectroscopic Studies Of The Interaction Between Phosphorus Heterocycles And Cytochrome P450, Dumei Ma, Libo Zhang, Yingwu Yin, Yuxing Gao, Qian Wang

Faculty Publications

P450 fatty acid decarboxylase OleT from Staphylococcus aureus (OleT_SA) is a novel cytochrome P450 enzyme that catalyzes the oxidative decarboxylation of fatty acids to yield primarily terminal alkenes and CO₂ or minor α- and β-hydroxylated fatty acids as side-products. In this work, the interactions between a series of cycloalkyl phosphorus heterocycles (CPHs) and OleT_SA were investigated in detail by fluorescence titration experiment, ultraviolet–visible (UV–vis) and ³¹P NMR spectroscopies. Fluorescence titration experiment results clearly showed that a dynamic quenching occurred when CPH-6, a representative CPHs, interacted with OleT_SA with a binding constant value of 15.2 …

Development Of Bioaffinity Based Assays For Forensic Applications, Juliana Maria Agudelo Cano

Legacy Theses & Dissertations (2009 - 2024)

In the field of forensic science, body fluids are a major contributor of evidence in investigations. However, body fluids are usually used only for their genetic content, overlooking its unique composition of proteins and low-molecular-weight compounds that often serve as biomarkers in clinical diagnostics. This investigation aimed to develop simple, effective, and economical models that can be used to identify different attributes of the originator. The focus of this research was to develop biocatalytic cascades that could analyze body fluids by using UV-Vis spectroscopy. These models could be implemented in forensic settings, as well as in biometric authentications. The central …

Development Of Visible-Light-Mediated Photoredox Catalysis, Sarbjeet Kaur

Legacy Theses & Dissertations (2009 - 2024)

ABSTRACT

Fluoroalcohol Induced Supramolecular Biphasic Systems Of Zwitterionic Surfactants, Mixed Amphiphiles, And Polar Organic Solvents In Proteomics And Environmental Analysis, Durga Khanal

Chemistry & Biochemistry Dissertations - Archive

In this research, we have investigated several HFIP-induced biphasic systems of zwitterionic surfactants like CHAPS and DMMAPS and their mixed amphiphilic systems for the extraction, enrichment, and fractionation of mixture of standard proteins and complex sample mixture of yeast proteins. The biphasic systems of zwitterionic surfactants (CHAPS and DMMAPS) and their mixed amphiphiles with quaternary ammonium salts (QUATS= TBAB, TEAB) provide concomitant extraction of hydrophobic membrane proteins, enrichment of lower abundance proteins to one phase, and fractionation of complex sample mixture into two phases. The results obtained from these biphasic systems were compared with control systems of aqueous solutions of …

Study Of The Cell Membrane And The Synthesis Of Chimeric Human Bacterial Phospholipids, Opeyemi O. Tade

Electronic Theses and Dissertations

Phospholipid bilayers are the principal component of the cell membrane. Membranes ensure the maintenance of processes required for cells’ survival by regulating the inflow and outflow of nutrients and other molecules using membrane proteins. However, studying the cell membrane is challenging because of its complexity and small size. In-vitro membrane models made of phospholipids are important tools for studying membranes. In this work, we aim to study the fluidity of phospholipid bilayers of different lipids using general polarization (GP) of the fluorescent probe Laurdan as a measure. We will focus on the relative importance of head groups and fatty acids …

Bioactivity Assessment Of Veratrum Californicum Alkaloids, Madison Dirks

Boise State University Theses and Dissertations

The native Idaho plant Veratrum californicum is known to contain steroidal alkaloids that function as inhibitors of hedgehog signaling, a pathway utilized for the growth and differentiation of cells as well as proper tissue development. Veratrum californicum was originally noticed when pregnant ewes consumed the plant and later gave birth to lambs with craniofacial mutations such as a cyclopean eyes. These malformations were caused by the plant’s steroidal alkaloid cyclopamine blocking the hedgehog signaling pathway. This same pathway is used by more than 20 types of cancer for multiplication of cells. Additional alkaloids have been found in Veratrum californicum, …

Fast & Efficient Simulation For Long Polymeric Chains, Naeyma N. Islam

LSU New Orleans Theses and Dissertations

No abstract provided.

Determining The Presence Of Biological Fluids In Peruvian Mummy Cloths Using The Liquid Chromatography Quadruple Time Of Flight Instrument, Tim Perksen, Joshua Sebree Ph.D.

Fall 2021 - Chemical Analysis Class Projects

A poster presenting the processes used and the results of analyzing the cloth from Peruvian mummies for the presence of biological fluids.

Techniques For The Enantioselective Asymmetric Synthesis Of Benzyl Substituted Malonic Acid Esters, Madison Hansen

Honors Theses

A popular method for the enantioselective synthesis of substituted malonic half esters is hydrolysis via Pig Liver Esterase (PLE), however some substrates produce low enantiomeric excess, namely benzyl-substituted malonic esters. Presented here are alternative methods explored for this synthesis, the first being phase-transfer catalyzed hydrolysis via N-benzyl quaternary ammonium salts derived from cinchona alkaloids. The second method utilized chiral auxiliary directed benzylation with auxiliaries including menthol and oxazolidinones. Though unsuccessful, this research provided valuable groundwork in the investigation for the enantioselective asymmetric synthesis of benzyl-substituted malonic acid esters.

Keywords: Pig Liver Esterase, Enantioselectivity, Phase-Transfer Catalysis, Cinchona Alkaloids, Quaternary Ammonium …

Investigation Of N-Sulfonyliminium Ion Triggered Cyclizations For The Synthesis Of Piperidine Scaffolds, Kaitlyn Birkhoff

Honors Theses

In consideration of the on-going global pandemic, immediate access to Food and Drug Administration approved pharmaceutical medications and vaccines is a matter of utmost priority to our national healthcare system. One significant modality in managed care is the dispensation of prescription drugs for the prevention or treatment of illnesses and diseases. According to the Centers for Disease Control and Prevention, physicians order and provide over 2.9 billion prescriptions each year with analgesics, antihyperlipidemics, and dermatological agents being the most prescribed therapeutic classes. Within those classes exists a disparate variety of chemical structures that must be prepared on a metric ton …

Triple Oxygen Isotope Constraints On Atmospheric O2 And Biological Productivity During The Mid-Proterozoic, Peng Liu, Jingjin Liu, Aoshaung Ji, Christopher T. Reinhard, Noah J. Planavsky, Dmitri Babikov, Raymond G. Najjar, James F. Kasting

Chemistry Faculty Research and Publications

Reconstructing the history of biological productivity and atmospheric oxygen partial pressure (pO₂) is a fundamental goal of geobiology. Recently, the mass-independent fractionation of oxygen isotopes (O-MIF) has been used as a tool for estimating pO₂ and productivity during the Proterozoic. O-MIF, reported as Δ′¹⁷O, is produced during the formation of ozone and destroyed by isotopic exchange with water by biological and chemical processes. Atmospheric O-MIF can be preserved in the geologic record when pyrite (FeS₂) is oxidized during weathering, and the sulfur is redeposited as sulfate. Here, sedimentary sulfates from …

Computational Investigations Of The Photochemical Properties Of B12-Dependent Systems: From Solution To Enzymes., Megan Toda Mackintosh

Electronic Theses and Dissertations

The photochemical properties of the B₁₂ family of molecules (cobalamins = Cbls) have been known for many years yet only until the 21^st century have applications for the light-sensitivity of Cbls come to the surface. Photolabile Cbls can be used for the delivery of therapeutics with spatial and temporal control, in the generation of hydroxyl radicals, and in nature, as demonstrated in the catalytic cycle of coenzyme B₁₂-dependent photoreceptors. This dissertation describes the use of computational methods to explore the photochemical properties of Cbl systems including antivitamins B₁₂, a thiolato-cobalamin, and the coenzyme B …

Conserved And Divergent Features Of Neuronal Camkii Holoenzyme Structure, Function, And Highorder Assembly, Olivia R. Buonarati, Adam P. Miller, Steven J. Coultrap, K. Ulrich Bayer, Steve L. Reichow

Chemistry Faculty Publications and Presentations

Neuronal CaMKII holoenzymes (^a and ^b isoforms) enable molecular signal computation underlying learning and memory but also mediate excitotoxic neuronal death. Here, we provide a comparative analysis of these signaling devices, using single-particle electron microscopy (EM) in combination with biochemical and live cell imaging studies. In the basal state, both isoforms assemble mainly as 12-mers (but also 14-mers and even 16-mers for the b isoform). CaMKIIa and ^b isoforms adopt an ensemble of extended activatable states (with average radius of 12.6 versus 16.8 nm, respectively), characterized by multiple transient intra- and interholoenzyme interactions associated with distinct functional properties. The …

Electrospun Pcl And Pcl/Gel Microfiber Scaffolds As Prototypes For Anterior Cruciate Ligament (Acl) Regeneration And Repair, Diego Rivera

Theses and Dissertations

Polycaprolactone (PCL) is a polymer that has been a focus of tissue engineering due to its range of applicability for biomedical applications. Synthesis of PCL from a microwave-assisted and stannous octoate-catalyzed ring-opening reaction with ε-caprolactone was accomplished. Aligned-fiber microfiber mats were generated via electrospinning for characterization. PCL microfiber mats were characterized via FTIR and scanning electron microscopy. These PCL microfiber mats were mechanically tested to examine their applicability as tools for knee ligament repair. During tensile testing, non-fiber aligned mats lacked the sufficient elastic modulus. Fiber-aligned PCL samples both and gelatin-coated were tested and showed enhanced elastic modulus and extension …

The Impacts And In-Depth Study Of The Environmental Contaminant, Perfluorooctane Sulfonic Acid, And Its Interactions With Water, Karla Veronica Salazar

Theses and Dissertations

Perfluorooctanesulfonic acid (PFOS), similar to perfluorooctanoic acid (PFOA), is a synthetic chemical that has been classified as a persistent organic pollutant (POP) by the Stockholm Convention since 2009. Due to the wide previous usage, high stability, high bio-accumulative, and low degradative properties is the reason that PFOS has been found in several compartments of the environment including ocean water, ground water, air, and sediments. Due to the strong interactions generated by the sulfonic acid end, this compound has a tendency to stay in the environment for long periods of time and has proved to be difficult in the removal from …

Computational Analysis Of The Spin Trapping Properties Of Lipoic Acid And Dihydrolipoic Acid, Matthew Bonfield

Electronic Theses and Dissertations

While the spin trapping properties of thiols have been investigated through EPR analysis and kinetics studies, few groups have studied these properties using strictly computational methods. In particular, α-lipoic acid (ALA) and its reduced form, dihydrolipoic acid (DHLA), one of the strongest endogenously produced antioxidants, show potential for being effective, naturally occurring spin traps for the trapping of reactive oxygen species. This research covers electronic structure calculations of ALA, DHLA, and their corresponding hydroxyl radical spin adducts, performed at the cc-pVDZ/B3LYP/DFT level of theory. The effects on DHLA introduced by other radicals such as ·OOH, ·OCH₃, …

Preparation And Study Of Bacterial Membrane Models, Enoch Asimbisa

Electronic Theses and Dissertations

Fuel molecules are organic solvents that have disruptive effects on the bacterial membrane. This is a significant barrier in biofuel production, as it limits the fuel concentration that can be achieved through fermentation. One potential way of overcoming this barrier is to identify lipid compositions that can better withstand solvent stress, for which it is important to understand how organic solvents disrupt the membrane. Use of biophysical characterization techniques to quantify physical properties like fluidity and thickness will enable us to understand the mechanism by which solvents disrupt membranes. Native membranes are very complex, and we sought to develop in-vitro …