Chemistry Commons^™

Baboosic Lake 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Baboosic Lake (Amherst and Merrimack, NH) for 2021.

Province Lake 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Province Lake (Wakefield, NH and Parsonsfield, ME) for 2021.

Belleau Lake 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Belleau Lake in Wakefield, NH for 2021.

Balch Pond 2021 Water Quality Highlight Report, Amanda Mcquaid, Robert Craycraft

UNH Cooperative Extension

A Water Quality Highlight Report by UNH CE Lakes Lay Monitoring Program for Balch Pond (Wakefield, NH; Acton and Newfield, ME) for sampling efforts up to 2021.

Automated Cervical Digitized Histology Whole-Slide Image Analysis Toolbox, Sudhir Sornapudi, Ravitej Addanki, R. Joe Stanley, William V. Stoecker, Rodney Long, Rosemary Zuna, Shellaine R. Frazier, Sameer Antani

Electrical and Computer Engineering Faculty Research & Creative Works

Background: Cervical intraepithelial neoplasia (CIN) is regarded as a potential precancerous state of the uterine cervix. Timely and appropriate early treatment of CIN can help reduce cervical cancer mortality. Accurate estimation of CIN grade correlated with human papillomavirus type, which is the primary cause of the disease, helps determine the patient's risk for developing the disease. Colposcopy is used to select women for biopsy. Expert pathologists examine the biopsied cervical epithelial tissue under a microscope. The examination can take a long time and is prone to error and often results in high inter-and intra-observer variability in outcomes. Methodology: We propose …

Electrocatalytic Redox Neutral [3+2] Annulation Of N-Cyclopropylanilines And Alkenes, Qi Wang, Qile Wang, Yuexiang Zhang, Yasmine M. Mohamed, Carlos Pacheco, Nan Zheng, Richard N. Zare, Hao Chen

Chemistry & Biochemistry Faculty Publications and Presentations

Although synthetic organic electrochemistry (EC) has advanced significantly, net redox neutral electrosynthesis is quite rare. Two approaches have been employed to achieve this type of electrosynthesis. One relies on turnover of the product by the reactant in a chain mechanism. The other involves both oxidation on the anode and reduction on the cathode in which the radical cation or the radical anion of the product has to migrate between two electrodes. Herein, a home-built electrochemistry/mass spectrometry (EC/MS) platform was used to generate an N-cyclopropylaniline radical cation electrochemically and to monitor its reactivity toward alkenes by mass spectrometry (MS), which …

Synthesis Of Novel Porphyrin Derived Molecules For The Study Of Self Assembly And Photophysical Properties, Alex Nguyen

Williams Honors College, Honors Research Projects

The photochemical capabilities of self-assembling porphyrins holds the potential to eliminate the use of fossil fuels. Porphyrins have the ability to absorb solar energy to excite its electrons within the highly conjugated π system of the porphyrin ring. The excited electron can then be donated thus creating a charge separated state between the porphyrin donor and the electron acceptor. With self-assembly of porphyrin monomers into a supramolecular structure, this charge separated state can be emphasized and prolonged so the energy potential generated can be harvested. Here, the synthesis of porphyrin derivatives substituted with biologically found molecules is described. The lysine …

Polyester-Pamam “Janus-Type” Linear-Dendritic Blockopolymers (Ldbcs) As Next Generation Biomaterials, Indika Chandrasiri

Electronic Theses and Dissertations

Nanomedicine is defined as the application of knowledge and tools of nanotechnology for disease treatment, diagnosis, monitoring, delivery, and sensing. Rapid advances in polymer chemistry and nanotechnology have led to an extensive development of polymeric-based therapeutic systems for nanomedical applications. Compared to traditional molecular-based therapies, polymers facilitate a higher level of versatility and functionality, such as simultaneous imaging and delivery. In particular, amphiphilic diblock copolymers and their self-assemblies have shown apparent success in nanomedicine owing to their ability to provide narrow molar mass distributions and highly ordered nanoscale multimolecular aggregates, including micelles and vesicles. However, engineering these polymeric materials to …

Advancements Toward Sustainable Solar Fuel Production Utilizing Reductive Homogeneous Electro- And Photocatalysis, Hunter Pratt Shirley

Electronic Theses and Dissertations

Molecular CO2 and H+ reductive catalysts, whether they be electro- or photocatalytic, have been shown to be possible routes of harnessing solar energy in a clean, renewable manner. There are few electrocatalysts operating at reasonable overpotentials to prove useful in artificial photosynthetic systems, and there are a number of environmental factors within these systems that have yet to be evaluated. Photo-driven catalysis is rare, difficult to control, and rarely provides high-value CO2 reduction products. I report herein an exceptionally low overpotential H+ reduction catalyst, a method of modulating electrocatalysts in-situ to improve performance, a first-of-its-kind mononuclear proton reduction photocatalyst, a …

Application Of Passive Air Samplers For Atmospheric Research, And Determination Of Metals In Tree Rings And Marine Sapropel By Icp-Ms, Byunggwon Jeon

Electronic Theses and Dissertations

This research focuses on studies of atmospheric mercury (Hg) using passive air samplers (PAS) and studies of trace elements in tree cores and sediment using inductively coupled plasma mass spectrometry (ICP-MS). Mercury is a toxic element that is dispersed globally through the atmosphere. Accurately measuring airborne Hg concentrations aids understanding of the pollutant’s sources, distribution, cycling, and trends. Mercury PAS are designed to capture gaseous elemental mercury (GEM) at a known rate. Compared to active air sampling the low-cost of PAS allows for greater spatial coverage. We used a commercially available Hg PAS (MerPAS®) and observed differences in GEM between …

Solubility Critical Effects In Binary Liquid Mixture, Rosa Mauro

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

The Chemistry Of Superelectrophilic Phosphonium Ions, Nathan David Scanlon

Graduate Research Theses & Dissertations

A series of aryl-substituted phosphines have been prepared using superelectrophilic aromatic substitution chemistry. This chemistry involves reactive phosphonium-carbenium dications and related species. In addition to low molecular weight aryl-substituted phosphines, we also are able to prepare functionalized polystyrene products.

Nonhuman Iapp Variants Inhibit Human Iapp Aggregation, Alissa Oakes, Kate Menefee, Arleen Lamba, Larry M. Palato, Dillon J. Rinauro, Angela Tun, Betssy Jauregui, Kevin Chang, Luiza A. Nogaj, David A. Moffet

Chemistry and Biochemistry Faculty Works

The aggregation of the 37-amino acid polypeptide human islet amyloid polypeptide (hIAPP), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of human pancreatic β-islet cells in type 2 diabetes. hIAPP is considered to be one of the most amyloidogenic proteins known. The quick aggregation of hIAPP leads to the formation of toxic species, such as oligomers and fibers, that damage mammalian cells (both human and rat pancreatic cells). Whether this toxicity is necessary for the progression of type 2 diabetes or merely a side effect of the disease remains unclear. If …

Molecular Recognition Of Pet Depolymerization Products And Beta-Cyclodextrin, Thomas Palisin

Williams Honors College, Honors Research Projects

Using molecular recognition techniques to determine the binding constant of the host-guest relationships of the depolymerization products of polyethylene terephthalate (PET) and cyclodextrin species. The main method of data collection used was florescence spectroscopy. Using a titration method and measuring the florescence intensity, a nonlinear regression was used to determine the binding constant.

Stratospheric Fluorine As A Tracer Of Circulation Changes: Comparison Between Infrared Remote-Sensing Observations And Simulations With Five Modern Reanalyses, M. Prignon, S. Chabrillat, M. Friedrich, D. Smale, S. E. Strahan, Peter F. Bernath, M. P. Chipperfield, S. S. Dhomse, W. Feng, D. Minganti, C. Servais, E. Mahieu

Chemistry & Biochemistry Faculty Publications

Using multidecadal time series of ground-based and satellite Fourier transform infrared measurements of inorganic fluorine (i.e., total fluorine resident in stratospheric fluorine reservoirs), we investigate stratospheric circulation changes over the past 20 years. The representation of these changes in five modern reanalyses is further analyzed through chemical-transport model (CTM) simulations. From the observations but also from all reanalyses, we show that the inorganic fluorine is accumulating less rapidly in the Southern Hemisphere than in the Northern Hemisphere during the 21st century. Comparisons with a study evaluating the age-of-air of these reanalyses using the same CTM allow us to link this …

Bisphosohoglycertae Mutase: A Potential Target For Sickle Cell Disease, Anfal S. Aljahdali

Theses and Dissertations

Bisphosphoglycerate mutase (BPGM) is a part of the erythrocyte glycolysis system. Specifically, it is a central enzyme in the Rapoport-Leubering pathway, a side glycolytic pathway involved in the regulation of the concentration of the natural allosteric effector of hemoglobin (Hb), 2,3-bisphosphoglycerate (2,3-BPG). BPGM catalyses the synthesis and hydrolysis of 2,3-BPG through its synthase and phosphatase activities. The synthase activity is the main role of BPGM, while the phosphatase activity is low and is activated by the physiological effector, 2-phosphoglycolate (2-PG) with the latter mechanism poorly understood.

BPGM activity and 2,3-BPG levels in red blood cells (RBCs) have a significant role …

Benzotriazole And Tolytriazole Analysis In Select Surface Waters Near Wilmington Air Park, Lee A. Raska

Browse all Theses and Dissertations

Previous investigations into the presence of benzotriazole (BTZ) and corresponding analogs done in early 2019 found elevated levels near the Wilmington Air Park in Wilmington, Ohio. The analogs detected were 4-methyl-1H-benzotriazole and 5-methyl-1H-benzotriazole: known together as tolytriazole (TTZ). BTZ and TTZ are emerging environmental contaminants of concern that are often found in aircraft de-icing solutions, anti-icing solutions and detergents. The Wilmington Air Park has two facilities used to pre-treat runoff water before its subsequent release into surrounding streams. Three sites were chosen: Lytle Creek, Indian Run, and Cowan Creek. For the 2019 and 2019/2020 investigative projects, Cowan Creek was designated …

Multiple Wetting−Dewetting States Of A Water Droplet On Dual-Scale Hierarchical Structured Surfaces, Yurui Gao, Yuan Liu, Jian Jiang, Chongqin Zhu, Craig Zuhlke, Dennis Alexander, Joseph S. Francisco, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Surfaces with microscale roughness can entail dualscale hierarchical structures such as the recently reported nano/ microstructured surfaces produced in the laboratory (Wang et al. Nature 2020, 582, 55−57). However, how the dual-scale hierarchical structured surface affects the apparent wetting/ dewetting states of a water droplet, and the transitions between the states are still largely unexplored. Here, we report a systematic large-scale molecular dynamics (MD) simulation study on the wetting/dewetting states of water droplets on various dual-scale nano/near-submicrometer structured surfaces. To this end, we devise slab-water/slab-substrate model systems with a variety of dual-scale surface structures and with different degrees of intrinsic …

Peroxo Species Formed In The Bulk Of Silicate Cathodes, Zhenlian Chen, Bjoern Schwartz, Xianhui Zhang, Wenqiang Du, Lirong Zheng, Ailing Tian, Ying Zhang, Zhiyong Zhang, Xiao Cheng Zeng, Zhifeng Zhang, Liyuan Huai, Jinlei Wu, Helmut Ehrenberg, Deyu Wang, Jun Li

Department of Chemistry: Faculty Publications

Oxygen redox in Li-rich oxides may boost the energy density of lithium-ion batteries by incorporating oxygen chemistry in solid cathodes. However, oxygen redox in the bulk usually entangles with voltage hysteresis and oxygen release, resulting in a prolonged controversy in literature on oxygen transformation. Here, we report spectroscopic evidence of peroxo species formed and confined in silicate cathodes amid oxygen redox at high voltage, accompanied by Co2+/Co3+ redox dominant at low voltage. First-principles calculations reveal that localized electrons on dangling oxygen drive the OO dimerization. The covalence between the binding cation and the O-O dimer determines the degree of electron …

Dynamic Manipulation Of Droplets Using Mechanically Tunable Microtextured Chemical Gradients, Ali J. Mazaltarim, John J. Bowen, Jay M. Taylor, Stephen Morin

Department of Chemistry: Faculty Publications

Materials and strategies applicable to the dynamic transport of microdroplets are relevant to surface fluidics, self-cleaning materials, thermal management systems, and analytical devices. Techniques based on electrowetting, topographic micropatterns, and thermal/chemical gradients have advanced considerably, but dynamic microdroplet transport remains a challenge. This manuscript reports the fabrication of mechano-tunable, microtextured chemical gradients on elastomer films and their use in controlled microdroplet transport. Specifically, discreet mechanical deformations of these films enabled dynamic tuning of the microtextures and thus transport along surface-chemical gradients. The interplay between the driving force of the chemical gradient and the microtopography was characterized, facilitating accurate prediction of …

Recent Advances In Supramolecular Affinity Separations: Affinity Chromatography And Related Methods, Ashley G. Woolfork, Sazia Iftekhar, Susan Ovbude, Kyungah Suh, Sadia Sharmeen, Isaac Kyei, Jacob Jones, David S. Hage

David Hage Publications

Contents

1 Introduction

2 Supports for Affinity Chromatography

 2.1 Natural Supports and Related Materials

 2.2 Inorganic Supports

 2.3 Synthetic Supports

 2.4 Magnetic Beads and Particles

 2.5 Smart Materials

 2.6 Nanomaterials

 2.7 Support Formats

3 Immobilization Methods

 3.1 Non-Covalent Immobilization

 3.2 Covalent Immobilization

4 Binding Agents Used in Affinity Chromatography

 4.1 Biological Agents as Affinity Ligands

4.1.1 Immunoaffinity Chromatography

4.1.2 Immunoglobulin-Binding Proteins

4.1.3 Lectins

4.1.4 Enzymes

4.1.5 Serum Proteins

4.1.6 Biotin, Avidin, and Streptavidin

4.1.7 Carbohydrates

4.1.8 Lipids

4.1.9 Nucleic Acids

 4.2 Non-Biological Agents as Affinity Ligands

4.2.1 Boronates and Related Mixed Ligands

4.2.2 Dye-Ligands

4.2.3 Immobilized Metal-Ion Chelates

4.2.4 Molecularly …

Polymer-Based And Functionalized 3d Microelectrode Array (Mea) Biosensors, Nilab Azim

Electronic Theses and Dissertations, 2020-2023

Microphysiological systems are three-dimensional (3D) in vitro systems that recapitulate crucial biological aspects of cell heterogeneity and native tissue architecture by mimicking complex structures that are impossible in two-dimensional (2D) cell cultures. Microelectrode arrays (MEAs) are biosensors used to spatially and temporally monitor the activity of microphysiological systems by transducing cellular signals into electronic signals to provide quantitative data on the in vitro system. Conventional MEAs are typically planar in nature, however, 3D MEAs offer several advantages such as better simulation of an in vivo cellular environment and improved signal-to-noise ratio and cell-electrode coupling. MEA fabrication utilizing traditional cleanroom methods …

Highly Reproducible Electrochemical Sensors Towards Wearable Applications And Pharmaceutical Analysis, Mohammad Rostampour Kakroudi

Electronic Theses and Dissertations, 2020-2023

Ion-selective electrodes (ISEs) are widely used to monitor ions in various applications from environmental to clinical settings and pharmaceutical analysis. ISEs are a type of potentiometric sensor that provides a versatile, cost-effective, and efficient platform towards wearable sensing applications. Among the two different platforms of ISEs (solid-contact and liquid-contact), solid-contact ISEs are superior to ISEs with internal electrolytes (liquid-contact) since they are easy to be miniaturized, can be used in any environment and their portability is facilitated. Unfortunately, mass production and commercialization of such devices is often constrained by the requirement of sensor calibration. Thus, approaches for sensor manufacturing towards …

Activity Of Saccharomyces Cerevisiae By Single Entity Electrochemistry, John Lutkenhaus

Graduate Research Posters

According to the Centers of Disease Control and Prevention, antibiotics decrease in effectiveness as bacteria gain resistance for previously treatable illnesses. Currently, antibiotic susceptibility is typically carried out via the Kirby-Bauer method. Even with automation, this process requires two incubation periods so a less time-consuming technique is desirable. Single entity electrochemistry (SEE) detects changes in current when collisions of individual particles at an ultramicroelectrode (UME) are linked with an electrochemical event. Our group has obtained step-like and spike-like responses of Saccharomyces cerevisiae at the UME surface as a result of adsorption and desorption, respectively. This response is due to the …

Collisions Or Adsorption: An Electrochemical Random Walk Decides, Junaid U. Ahmed, Julio C. Alvarez

Graduate Research Posters

Current-time recordings of toluene microdroplets emulsified in water and containing 20 mM Ferrocene (Fc), show multiple electrochemical peaks from oxidation of Fc on disk microelectrodes (5μm-diameter). The average droplet diameter (~0.7 μm) determined from area integration of the peaks was close to Dynamic Light Scattering measurements (~1 μm). Random walk simulations were performed deriving equations to simulate droplet electrolysis using the diffusion and thermal velocity expressions established by Einstein. The simulations show that multiple droplet-electrode collisions, lasting ~0.11 μs each, occur before a droplet wanders away. Updating the Fc-concentration at every collision shows that a droplet only oxidizes ~0.58 % …

Transcriptional Repressor Protein Based Macrolide Biosensor Development With Improved Sensitivity, Jayani A. Christopher

Graduate Research Posters

Macrolide antibiotics are in high demand for clinical applications. Macrolides are biosynthesized via giant assembly line polyketide synthases (PKS) which are arranged in a modular fashion. Combinatorial biosynthetic methods have been used to produce diversified macrolides by reprograming these modules and modifying tailoring enzymes required for post synthetic modifications. However it is challenging due to the size and complexity of PKSs. To overcome this challenge, new enzymes for macrolide diversification could be obtained by directed evolution where a large number of enzyme variants need to be screened. Therefore it is important to develop high throughput screening methods to identify the …

Extending Single Entity Electrochemistry Towards The Detection Of Single Bacteria In Micro Volumes, Ashley Tubbs, Junaid Ahmed, Julio C. Alvarez

Graduate Research Posters

Single entity electrochemistry (SEE) is an emerging electroanalytical technique with the ability to push the limit of detection of electrochemical sensors to the single particle level. It measures the change in current over time, making SEE rapid, simple, and cost-effective. The type of current response observed in the scan can provide information about the physiochemical processes underlying the signal. While SEE was originally developed to detect single molecules and nanoparticles, it has been widely applied to micron-sized particles, including emulsion droplets, bacteria, viruses, and mammalian cells. Some recent advances in this technique have focused on the detection of microscopic quantities …

Fundamentals And Applications Of Charge Transfer Dissociation Mass Spectrometry, Zachary Joseph Sasiene

Graduate Theses, Dissertations, and Problem Reports (ETD)

The recent surge in the analysis of biomolecules has driven the need for robust, versatile, sensitive, and accurate techniques such as tandem mass spectrometry for compound structural elucidation. Many fragmentation techniques have been developed over the years, but each has their own limitations, such as the loss of post-translational modifications (PTMs), inability to fragment singly charged precursor ions or cost prohibitiveness. To help fill this gap, a novel fragmentation technique called charge transfer dissociation (CTD) has been developed to fragment stored precursor ions through radical-driven fragmentation processes using kiloelectronvolt reagent cations. CTD has shown success in the analysis of proteins, …

Artisanal Mining Impacts In Urbanized Semi-Arid Environments: Lessons From Historic Arsenic Mining Near San Diego, California, James A. Wright

Theses

Anomalously elevated arsenic concentrations occur at an abandoned artisanal mine site in an open space recreational park in urban San Diego County, California. Although mining at the site ceased 100 years ago little to no remediation efforts took place leaving shafts, adits, waste piles and derelict infrastructure accessible by inquisitive hikers and adventurers frequenting Black Mountain Open Space Park. This study evaluates the geochemical mechanisms of As transport downgradient from the mine and examines the contribution of both climate and urbanization on the restriction of As mobility. Sediment As concentrations reach 2,320 mg/kg (483 times background crustal concentrations; n=73) along …

A Determination Of The Aerosolization Efficiency Of Drugs Of Abuse In A Eutectic Mixture With Nicotine In Electronic Cigarettes, Laerissa Reveil

Master of Science in Forensic Science Directed Research Projects

Electronic cigarettes (e-cigarettes) were originally advertised as an alternative nicotine delivery system to facilitate smoking cessation. However, their popularity for recreational use has increased due to focuses on their trendiness, convenience, and discreteness along with concerns for its use to consume drugs other than nicotine (DOTN). With the adulteration of e-liquids, usually containing nicotine, with other substances, a greater understanding on how DOTN interact with the e-liquid constituents and how they are delivered to the user is necessary. E-liquids were prepared with 50:50 propylene glycol:vegetable glycerin, pure nicotine, pure methadone hydrochloride, and 1:1 methadone hydrochloride:nicotine and aerosolized via an automated …