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Articles 841 - 870 of 2574

Full-Text Articles in Analytical Chemistry

Data On Gc/Ms Elution Profile, 1h And 13c Nmr Spectra Of 1-, 3-, And 6-Nitrobenzo[A]Pyrenes, Kefa Karimu Onchoke Jan 2020

Data On Gc/Ms Elution Profile, 1h And 13c Nmr Spectra Of 1-, 3-, And 6-Nitrobenzo[A]Pyrenes, Kefa Karimu Onchoke

Faculty Publications

The data presented in this article is related to the research article entitled, “13C NMR Chemical Shift Assignments of Nitrated Benzo[a]pyrenes based on Two-dimensional Techniques and DFT/GIAO Calculations”, Kefa K. Onchoke, PeerJ., . The NMR spectral profiles of nitrated benzo[a]pyrenes is presented. Further, the article describes elution profiles of 1-, 3- and 6-NBaP, the acquisition of 1H and 13C NMR data and the J-Coupling constants (which are useful for the assignment of peaks via 2D HMQC and HMBC techniques). The data presented is useful for developing structure-activity relationships for other nitrated polycyclic aromatic hydrocarbons (NPAHs)

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Nanotoxicity Of Zrs3 Probed In A Bioluminescence Test On E. Coli Bacteria: The Effect Of Evolving H2s, Olga Zakharova, Alexander Gusev, Jehad Abourahma, Nataliia S. Vorobeva, Dmitry V. Sokolov, Dmitry S. Muratov, Denis V. Kuznetsov, Alexander Sinitskii Jan 2020

Nanotoxicity Of Zrs3 Probed In A Bioluminescence Test On E. Coli Bacteria: The Effect Of Evolving H2s, Olga Zakharova, Alexander Gusev, Jehad Abourahma, Nataliia S. Vorobeva, Dmitry V. Sokolov, Dmitry S. Muratov, Denis V. Kuznetsov, Alexander Sinitskii

Department of Chemistry: Faculty Publications

Materials from a large family of transition metal trichalcogenides (TMTCs) attract considerable attention because of their potential applications in electronics, optoelectronics and energy storage, but information on their toxicity is lacking. In this study, we investigated the toxicity of ZrS3, a prominent TMTC material, toward photoluminescent E. coli bacteria in a bioluminescence test. We found that freshly prepared ZrS3 suspensions in physiological saline solution with concentrations as high as 1 g/L did not exhibit any toxic effects on the bacteria. However, ZrS3 suspensions that were stored for 24 h prior to the bioluminescence tests were very toxic to the bacteria …

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Determination Of Lithium Ions In E-Cigarettes Using Inductively Coupled Plasma Optical Emission Spectroscopy (Icp-Oes) Technique, Kevin Folk, Rebecca Leibold, Ola Abuhamdeh, Mallorie Boron Jan 2020

Determination Of Lithium Ions In E-Cigarettes Using Inductively Coupled Plasma Optical Emission Spectroscopy (Icp-Oes) Technique, Kevin Folk, Rebecca Leibold, Ola Abuhamdeh, Mallorie Boron

Undergraduate Research Posters 2020

Electronic cigarettes (e-cigarettes) are nicotine devices that is made up of a power source (battery) and a heating element that both work to stimulate the vaporization of a flavored solution. This is then inhaled by the user. While e-cigarettes lack many of the toxic chemicals in tobacco cigarettes, their effects to human health remain unknown. This study aims to determine whether harmful oxidants are produced in electronic cigarettes using lithium batteries. For this purpose, reactive oxygen species (ROS) reactivity in the disposable components of Electronic Nicotine Delivery Systems (ENDS) associated with e-cigarette aerosols was analyzed by comparing new lithium ion …

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Quantitative Nmr-Based Biomedical Metabolomics: Current Status And Applications, Alexandra A. Crook, Robert Powers Jan 2020

Quantitative Nmr-Based Biomedical Metabolomics: Current Status And Applications, Alexandra A. Crook, Robert Powers

Department of Chemistry: Faculty Publications

Nuclear Magnetic Resonance (NMR) spectroscopy is a quantitative analytical tool commonly utilized for metabolomics analysis. Quantitative NMR (qNMR) is a field of NMR spectroscopy dedicated to the measurement of analytes through signal intensity and its linear relationship with analyte concentration. Metabolomics-based NMR exploits this quantitative relationship to identify and measure biomarkers within complex biological samples such as serum, plasma, and urine. In this review of quantitative NMR-based metabolomics, the advancements and limitations of current techniques for metabolite quantification will be evaluated as well as the applications of qNMR in biomedical metabolomics. While qNMR is limited by sensitivity and dynamic range, …

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Methods Ofmaking And Using Lignin Derivatives, Mark Alan Helle, Chin Li Cheung Jan 2020

Methods Ofmaking And Using Lignin Derivatives, Mark Alan Helle, Chin Li Cheung

Department of Chemistry: Faculty Publications

Materials and methods for preparing reactive lignin and for preparing a bio-based adhesive are described herein.

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Polarization-Independent Metasurface Lens Based On Binary Phase Fresnel Zone Plate, Jonathan Baine, Jing Tang, Xing Li Jan 2020

Polarization-Independent Metasurface Lens Based On Binary Phase Fresnel Zone Plate, Jonathan Baine, Jing Tang, Xing Li

Department of Chemistry: Faculty Publications

Based on the binary phase Fresnel zone plate (FZP), a polarization-independent metasurface lens that is able to focus incident light with any polarization state, including circular, linear, and elliptical polarizations, has been proposed and investigated. We demonstrate that the metasurface lens consisting of metal subwavelength slits can operate in a wide bandwidth in the visible range, and has a higher focusing efficiency than that of an amplitude FZP lens without phase modulation. A multi-focus FZP metasurface lens has also been designed and investigated. The proposed lens can provide potential applications in integrated nanophotonic devices without polarization limitations.

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Environmental Forensics Of Complexly Contaminated Sites: A Complimentary Fingerprinting Approach, Michael A. Kruge, Azucena Lara-Gonzalo, José Luis Gallego Jan 2020

Environmental Forensics Of Complexly Contaminated Sites: A Complimentary Fingerprinting Approach, Michael A. Kruge, Azucena Lara-Gonzalo, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The environmental forensics approach is most often applied in petroleum and fuel spill incidents, for which sophisticated chemical fingerprinting procedures have evolved. In cases in which pollutant discharges occur in settings with prior contamination, more care must be taken in source discrimination, requiring further advances in methodology. Additional obstacles can arise if the spill is an atypical industrial discharge. This would necessitate painstaking characterization of unfamiliar substances lying outside of existing regulatory regimes and thus overlooked by mandated analytical protocols (i.e., contaminants of emerging concern). Towards these ends, this paper presents a systematic, multi-faceted GC-MS approach using the saturated, aromatic, …

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Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins Jan 2020

Characterization Of Coal Particles In The Soil Of A Former Rail Yard And Urban Brownfield: Liberty State Park, Jersey City (Nj), Usa, Diane F. Hagmann, Michael A. Kruge, Nina M. Goodey, Jennifer Adams Krumins

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

From the 1850's until the 1960's, the Central Railroad of New Jersey was among several major railways shipping anthracite and bituminous coal to the New York City area, transferring coal from railcar to barge at its extensive rail yard and port facility in Jersey City. The 490 ha Liberty State Park was developed on the site after the rail yard closed, but a ca. 100 ha brownfield zone within the park remains off limits to visitors pending future remediation. As part of an environmental forensic and industrial archeological investigation of this zone, the present study characterizes anthracite and bituminous coal …

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Development Of Novel Analytical Methods For Detection And Determination Of Tamoxifen In Oral Fluid And Discrimination Between Regioisomeric Aromatase Inhibitors For Doping Control Purposes, Brooke A. Sutton Jan 2020

Development Of Novel Analytical Methods For Detection And Determination Of Tamoxifen In Oral Fluid And Discrimination Between Regioisomeric Aromatase Inhibitors For Doping Control Purposes, Brooke A. Sutton

Online Theses and Dissertations

The use of SERMs (Selective Estrogen Receptor Modulators) – most notably the drug Tamoxifen – has significantly increased among athletes over the past decade to enhance athletic performance and/or negate certain side effects of using anabolic steroids. This “doping” is always banned by WADA (World Anti-Doping Agency) for all athletes, but SERMs can naturally increase testosterone production so they are a tempting alternative to using steroids or androgenic supplements that can cause significant health problems (e.g. acne, breast development, frequent urge to urinate, low libido, etc.). Similarly, the use of AIs (Aromatase Inhibitors) has also increased among athletes for identical …

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Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton Jan 2020

Effects Of Nutrient Overload And Environmental Conditions On Algal Bloom Formation: A Case Study Of Water Sources In Eastern Kentucky, Lauren Sutton

Online Theses and Dissertations

Eastern Kentucky is home to many private ponds used for agricultural and recreational purposes. Each year, the owners of these ponds observe harmful algal blooms (HABs) that release toxins into the water, potentially limiting the use of these ponds. A pilot study in summer 2018 observed a harmful algal bloom (HAB) occurring in one pond in Madison Country that roughly correlated with a rise in water sulfate levels with no detectable levels of nitrate or phosphate present. A follow-up study of this pond and others in the area was conducted during Summer 2019. The purpose of this project was three-fold: …

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Detection Of Biomolecules Via Ocp Measurements Using Npg Electrodes, Borkat Ullah Jan 2020

Detection Of Biomolecules Via Ocp Measurements Using Npg Electrodes, Borkat Ullah

Theses and Dissertations

In sensing application nanoporous gold (NPG) has attracted much attention. NPG is prepared by dealloying Au:Ag alloys. Characterization was done using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). In this work, the open circuit potential (OCP) of ferricyanide, cysteine, uric acid, and ascorbic acid was measured in phosphate buffer solution (PBS) and biofouling solution containing bovine serum albumin (BSA) at pH 7.4. OCP measurement has been hindered due to biofouling and surface passivation on the metal electrodes. By the use of the NPG electrodes, electrochemical activity can be maintained. From the OCP measurement of cysteine, …

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Solid Phase Extraction And High-Precision Mass Spectrometry Analysis Methods For Crassostrea Virginica Metabolome, Alyssa Darling Jan 2020

Solid Phase Extraction And High-Precision Mass Spectrometry Analysis Methods For Crassostrea Virginica Metabolome, Alyssa Darling

Theses and Dissertations

Metabolomics is the rapidly-growing field which focuses on the endpoints of biological processes, and has the capability to provide a snapshot of an organisms’ interaction with their environment on a molecular scale. The objective of the experiment herein was to develop a standard metabolic extraction technique coupled with ultrahigh-precision analytical tools to build a global metabolic pathway of the keystone species Crassostrea virginica. To achieve this, C. virginica whole-body samples were extracted using acetonitrile and methanol, then split into a dehydrated group and a diluted group. Following reversed-phase solid phase extraction (RP-SPE) of both groups, metabolites were identified using …

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Understanding The Rage Signaling Pathway And Its Contribution To Diabetic Complications, Leon Vegas Ho Jan 2020

Understanding The Rage Signaling Pathway And Its Contribution To Diabetic Complications, Leon Vegas Ho

Legacy Theses & Dissertations (2009 - 2024)

The binding of advanced glycation end products (AGEs) to the receptor for advanced glycation end products (RAGE) is an important feature of the RAGE signaling pathway that plays a role in the pathogenesis of diabetes. Under high glucose concentration, RAGE expression increases immensely from the formation of a Schiff base by glucose bounded to lysine. This triggers an inflammatory and immune response and upregulates the expression of RAGE and causes an accumulation of AGEs in the body. As a result, this leads to the development of diabetes and other complications such as, atherosclerosis, nephrothapy, and retinopathy. To remedy AGE accumulation, …

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Towards Machine Learning In Chemical Sensing : Milk Differentiation And Quality Control Through Two-Dimensional Nano-Sensor Array, Yu Sheng Chen Jan 2020

Towards Machine Learning In Chemical Sensing : Milk Differentiation And Quality Control Through Two-Dimensional Nano-Sensor Array, Yu Sheng Chen

Legacy Theses & Dissertations (2009 - 2024)

Herein, we developed a novel artificial tongue using machine learning and 12 nanoassemblies (2D-NAs) to identify and analyzed different kinds of milk beverages for quality control. This biomimetic sensor array was trained to “taste” different milk types as an “artificial tongue” which is the first time we demonstrated that this sensor array can be implemented to complex systems. Two-dimensional nanoparticles (2D-nps) and nine fluorescently labeled single stranded oligonucleotides (ssDNA) with different length and nucleobases were assembled to create 12 2D-NAs. The artificial tongue was deployed to identify and analyze five milk types. All five milk types were discriminated with 95% …

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Elemental Composition And Arsenic Speciation Analysis Of Processed Seafood Products Using Atomic Spectrometric Techniques, Austin A. Roberts Jan 2020

Elemental Composition And Arsenic Speciation Analysis Of Processed Seafood Products Using Atomic Spectrometric Techniques, Austin A. Roberts

Legacy Theses & Dissertations (2009 - 2024)

Arsenic (As) is a widely known toxic element that is highly ubiquitous and has been detected in soil, sediment, naturals waters, the atmosphere, and in organisms of the 5 kingdoms. The toxicity of As however, is dependent on the molecular form in which it takes as well as the route of exposure. For the general population, exposure to As mainly takes place via ingestion of food and water, which have led to numerous studies investigating As and it’s various species in these matrices. Seafood is one of the major sources of dietary exposure to As and has thus led to …

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Biochemical And Chemical Methods Of Key Derivation For Cryptographic Ciphers, Leif K. Mcgoldrick Jan 2020

Biochemical And Chemical Methods Of Key Derivation For Cryptographic Ciphers, Leif K. Mcgoldrick

Legacy Theses & Dissertations (2009 - 2024)

Cryptography is a vital component of digital communication and digital data in general. The use of cryptography is necessary to support the veracity of data and to protect it from outside parties with malicious intent. Cryptography focuses on two main facets that are vital for this goal: data encryption and user authentication. Encryption protects the data by transforming it into an encrypted text that would not allow someone access without having or breaking the encryption method that was used to make it. User authentication is a multiple part process that allows for one to be able to identify oneself to …

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Utilizing Raman Spectroscopy And Chemometrics For Novel Medical Diagnostic Purposes, Nicole M. Ralbovsky Jan 2020

Utilizing Raman Spectroscopy And Chemometrics For Novel Medical Diagnostic Purposes, Nicole M. Ralbovsky

Legacy Theses & Dissertations (2009 - 2024)

Many problems exist within the myriad of currently employed diagnostic techniques. Further, an incredibly wide variety of procedures are used to identify an even greater number of diseases which exist in the world. There is a definite unmet clinical need to improve the diagnostic capabilities of these methods, including improving test sensitivity and specificity, objectivity and definitiveness, and reducing cost and how invasive a test is, with an interest in replacing multiple diagnostic methods with one powerful tool. That is, the development of a singular technique which can accurately and objectively diagnose a wide variety of diseases in a cost-effective …

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Investigation Of Underpotential Deposition Of Copper At Heated Gold Loop Screen-Printed Electrodes In A Variety Of Water Samples, Eun-Ju Lee Jan 2020

Investigation Of Underpotential Deposition Of Copper At Heated Gold Loop Screen-Printed Electrodes In A Variety Of Water Samples, Eun-Ju Lee

Legacy Theses & Dissertations (2009 - 2024)

To study the underpotential deposition (UPD) of copper, three different types of water samples (TraceSelect® Ultra-pure water, Indian pond water at University at Albany and tap water) are used at a heated gold loop screen-printed electrode (GLE), which is a new type of heated working electrode for voltammetry measurements that is able to directly detect the copper content in the water samples. The anodic stripping analysis of copper is performed with these gold loop electrodes at room temperature of 25 °C and electrode temperature of 80 °C at two different deposition potentials, -0.20 V and +0.10 V. Furthermore, the concentration …

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Bioaffinity-Based Methods For Forensic, Biometric, And Clinical Purposes, Mindy Elizabeth Hair Jan 2020

Bioaffinity-Based Methods For Forensic, Biometric, And Clinical Purposes, Mindy Elizabeth Hair

Legacy Theses & Dissertations (2009 - 2024)

Biomarker analysis is a well-established discipline that involves the evaluation of biological samples for the presence of various substances indicative of personal attributes or illnesses. Sweat is one example of a biological fluid that is often overlooked for forensic and clinical analyses, even though it can contain DNA, various amino acids, and other low molecular weight compounds.1–3 The work presented in this dissertation focuses on the use of bioaffinity-based assays to quantify biomarkers in sweat for both forensic and clinical applications. The concentration of the biochemical content within an individual’s sweat are controlled by hormone-based metabolic pathways4 that fluctuate daily …

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Metabolic Changes Associated With Adaptive Resistance To Daptomycin In Streptococcus Mitis-Oralis, Allison Parrett, Joseph M. Reed, Stewart G. Gardner, Nagendra N. Mishra, Arnold S. Bayer, Robert Powers, Greg A. Somerville Jan 2020

Metabolic Changes Associated With Adaptive Resistance To Daptomycin In Streptococcus Mitis-Oralis, Allison Parrett, Joseph M. Reed, Stewart G. Gardner, Nagendra N. Mishra, Arnold S. Bayer, Robert Powers, Greg A. Somerville

Department of Chemistry: Faculty Publications

Background: Viridans group streptococci of the Streptococcus mitis-oralis subgroup are important endovascular pathogens. They can rapidly develop high-level and durable non-susceptibility to daptomycin both in vitro and in vivo upon exposure to daptomycin. Two consistent genetic adaptations associated with this phenotype (i.e., mutations in cdsA and pgsA) lead to the depletion of the phospholipids, phosphatidylglycerol and cardiolipin, from the bacterial membrane. Such alterations in phospholipid biosynthesis will modify carbon flow and change the bacterial metabolic status. To determine the metabolic differences between daptomycin-susceptible and non- susceptible bacteria, the physiology and metabolomes of S. mitis-oralis strains 351 (daptomycin-susceptible) and 351-D10 (daptomycin …

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Development Of Analytical Methods For Toxic Inhaled Hazards (Tih) And Their Metabolites, Obed Adu Gyamfi Jan 2020

Development Of Analytical Methods For Toxic Inhaled Hazards (Tih) And Their Metabolites, Obed Adu Gyamfi

Electronic Theses and Dissertations

Toxic inhalation hazards (TIHs), such as methyl isocyanate (MIC) and hydrogen cyanide (HCN), are noxious gases and vapors that are harmful, and often deadly, to humans. However, because of their low cost and high reactivity, they are extensively used for industrial productions, creating risk of exposure for both industrial workers (e.g., occupational exposure) and civilians (e.g., accidental release during transport). The illicit use of TIHs, including as terrorist agents, is also concerning. Considering the rapid toxicity of TIHs and the danger they pose to both human and animal lives, there is a critical need to develop of analytical methods for …

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Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton Jan 2020

Design, Construction, And Characterization Of A Combined Mini-Co₂/Voc Sensor And Gas Chromatograph For Field Research, Rishi Basdeo, Michael Hampton

Digital Repository: Showcase of Undergraduate Research Excellence

No abstract provided.

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An Ammonia Sensor Using An Unadorned Bromocresol Layer, John Cassidy, Caoimhe Ní Néill, Merve Akdağ, Tony Betts Jan 2020

An Ammonia Sensor Using An Unadorned Bromocresol Layer, John Cassidy, Caoimhe Ní Néill, Merve Akdağ, Tony Betts

Articles

Bromocresol Purple,(BCP) cast onto an acetate sheet, was used to sense ammonia. This simple layer responded reversibly to a low concentration ( 15 ppm) of ammonia in the presence of water vapour. The BCP solution was spincoated on an acetate sheet from a solution in dichloromethane. This layer was exposed to nitrogen and NH3/H2O vapour in quick succession. The colour change occurred from yellow to purple rapidly in the solid state. The λmax for the neutral ( acid) form of the BCP was found to be 435 nm and the λmax for the dianion ( base form) of the BCP …

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Gc-Ms Analysis Of Synthesized Biodiesel, Courtney R. Whetstine Jan 2020

Gc-Ms Analysis Of Synthesized Biodiesel, Courtney R. Whetstine

Forensic Science Master's Projects

Biodiesel is an alternative energy resource that can replenish depleting natural petroleum storage. Synthesis of biodiesel is cost-efficient as it can be chemically converted from renewable wastes, such as vegetable oil or animal fat. These fuels are also biodegradable and the exhaust emissions from biodiesel are non-toxic and environmentally-friendly. Biodiesel is a stable fuel that performs reliably in all diesel engines. Biodiesel is also easy to synthesize, safe to handle, and works with diesel fuel storage and pumping systems. The United States has an abundance of vegetable oils that have not been widely used to our advantage. Additionally, fast-food restaurants …

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A Validated Uplc-Ms/Ms Method For The Determination Of Aliphatic And Aromatic Isocyanate Exposure In Human Urine, Maggy Lépine, Lekha Sleno, Jacques Lesage, Sébastien Gagné Jan 2020

A Validated Uplc-Ms/Ms Method For The Determination Of Aliphatic And Aromatic Isocyanate Exposure In Human Urine, Maggy Lépine, Lekha Sleno, Jacques Lesage, Sébastien Gagné

Études primaires

4,4′-Methylenediphenyldiisocyanate (MDI), toluenediisocyanate (2,4-TDI and 2,6-TDI), and 1,6′-hexamethylenediisocyanate (HDI) are all commonly used in the production of polyurethane-containing materials in different application areas. Workers exposed occupationally to these compounds may develop sensitization with the potential to lead to asthma. Isocyanates are metabolized in vivo by conjugation to macromolecules and/or by acetylation prior to being eliminated in urine. The hydrolysis of urine samples releases free amine compounds from these metabolites as biomarkers of exposure, specific to each parent isocyanate: 4,4′-methylenedianiline (MDA), toluenediamine (2,4-TDA and 2,6-TDA), and hexamethylenediamine (HDA). To address the need for a validated method that could be used for …

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Method Development For The Analysis Of Fatty Acids In Adipose Tissue Using Stir Bar Sorptive Extraction Coupled With Gas Chromatography-Mass Spectrometry, Angela Marisol Encerrado Manriquez Jan 2020

Method Development For The Analysis Of Fatty Acids In Adipose Tissue Using Stir Bar Sorptive Extraction Coupled With Gas Chromatography-Mass Spectrometry, Angela Marisol Encerrado Manriquez

Open Access Theses & Dissertations

The project was aimed to develop an easy and sensitive analytical tool to study the role of fatty acids (FAs) profile in periprostatic adipose tissue (PPAT) and prostate cancer (PCa). PCa is the second leading cause of cancer-related death among American men. Although obesity has been mostly ruled out by many researchers as a risk factor for developing PCa, it has shown to be associated with PCa metastasis and progression. Periprostatic adipose tissue, which was present on 48% of prostatic surfaces, has been reported to act as energy sources for facilitating a positive microenvironment for PCa tumor progression. To understand …

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Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel Jan 2020

Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel

Williams Honors College, Honors Research Projects

This method developed in the toxicology department at the Cuyahoga County Medical Examiner’s Office (CCMEO) detects 40 benzodiazepines and metabolites along with several z-drugs in blood and urine by liquid chromatography tandem mass spectrometry. A sample amount of 0.5 mL was used to detect analytes in postmortem drug facilitated sexual assault and impaired driving cases. Twenty-nine analytes met criteria for quantification while the remaining 14 were used as qualitative indicators. Bias and precision results for quality controls met criteria, staying within ±15% except for clonazolam and etizolam which were within ±20%. Quantitative reporting criteria which included dilution integrity was met …

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Resolving The Puzzle Of Single-Atom Silver Dispersion On Nanosized Γ-Al2O3 Surface For High Catalytic Performance, Fei Wang, Jinzhu Ma, Shaohui Xin, Qiang Wang, Jun Xu, Changbin Zhang, Hong He, Xiao Cheng Zeng Jan 2020

Resolving The Puzzle Of Single-Atom Silver Dispersion On Nanosized Γ-Al2O3 Surface For High Catalytic Performance, Fei Wang, Jinzhu Ma, Shaohui Xin, Qiang Wang, Jun Xu, Changbin Zhang, Hong He, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Ag/γ-Al2O3 is widely used for catalyzing various reactions, and its performance depends on the valence state, morphology and dispersion of Ag species. However, detailed anchoring mechanism of Ag species on γ-Al2O3 remains largely unknown. Herein, we reveal that the terminal hydroxyls on γ-Al2O3 are responsible for anchoring Ag species. The abundant terminal hydroxyls existed on nanosized γ-Al2O3 can lead to single-atom silver dispersion, thereby resulting in markedly enhanced performance than the Ag cluster on microsized γ-Al2O3. Density-functional-theory calculations confirm that Ag atom is mainly …

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Carbon Oxidation State In Microbial Polar Lipids Suggests Adaptation To Hot Spring Temperature And Redox Gradients, Grayson M. Boyer, Florence Schubotz, Roger E. Summons, Jade Woods, Everett L. Shock Jan 2020

Carbon Oxidation State In Microbial Polar Lipids Suggests Adaptation To Hot Spring Temperature And Redox Gradients, Grayson M. Boyer, Florence Schubotz, Roger E. Summons, Jade Woods, Everett L. Shock

Department of Chemistry: Faculty Publications

The influence of oxidation-reduction (redox) potential on the expression of biomolecules is a topic of ongoing exploration in geobiology. In this study, we investigate the novel possibility that structures and compositions of lipids produced by microbial communities are sensitive to environmental redox conditions. We extracted lipids from microbial biomass collected along the thermal and redox gradients of four alkaline hot springs in Yellowstone National Park (YNP) and investigated patterns in the average oxidation state of carbon (ZC), a metric calculated from the chemical formulae of lipid structures. Carbon in intact polar lipids (IPLs) and their alkyl chains becomes …

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Surface Modification Of Silicon Nanowire Based Field Effect Transistors With Stimuli Responsive Polymer Brushes For Biosensing Applications, Stephanie Klinghammer, Sebastian Rauch, Sebastian Pregl, Petra Uhlmann, Larysa Baraban, Gianaurelio Cuniberti Jan 2020

Surface Modification Of Silicon Nanowire Based Field Effect Transistors With Stimuli Responsive Polymer Brushes For Biosensing Applications, Stephanie Klinghammer, Sebastian Rauch, Sebastian Pregl, Petra Uhlmann, Larysa Baraban, Gianaurelio Cuniberti

Department of Chemistry: Faculty Publications

We demonstrate the functionalization of silicon nanowire based field effect transistors (SiNW FETs) FETs with stimuli-responsive polymer brushes of poly(N-isopropylacrylamide) (PNIPAAM) and poly(acrylic acid) (PAA). Surface functionalization was confirmed by atomic force microscopy, contact angle measurements, and verified electrically using a silicon nanowire based field effect transistor sensor device. For thermo-responsive PNIPAAM, the physicochemical properties (i.e., a reversible phase transition, wettability) were induced by crossing the lower critical solution temperature (LCST) of about 32 ◦C. Taking advantage of this property, osteosarcomic SaoS-2 cells were cultured on PNIPAAM-modified sensors at temperatures above the LCST, and completely detached by simply cooling. Next, …

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