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1912 full-text articles. Page 1 of 48.

Analyzing The Kinetics Of A Bromophenol Blue Fading Reaction In Basic Conditions For An Undergraduate Lab, Zeljka Popovic 2017 Georgia College and State University

Analyzing The Kinetics Of A Bromophenol Blue Fading Reaction In Basic Conditions For An Undergraduate Lab, Zeljka Popovic

Georgia College Student Research Events

Bromophenol blue is a common pH indicator and dye used in many different industries. Once a solution of bromophenol blue is placed in a concentrated basic solution, the color fades from a blue/violet color to clear solution with a pH of 4.6 or greater. The rate law of the reaction is analyzed through the use of a small footprint visible-near-infrared spectrometer (Vis-NIR) with a diode array detector. An absorbance wavelength of 590 nm as a function of time was collected using Ocean Optics OceanView software. The results contained in the data collection file are exported to a spreadsheet ...


Kinetics Of Crystal Violet Color Fading Via A Small Footprint Diode Array Spectrometer, Paige Lott 2017 Georgia College & State University

Kinetics Of Crystal Violet Color Fading Via A Small Footprint Diode Array Spectrometer, Paige Lott

Georgia College Student Research Events

Crystal violet is a pH indicator and is commonly used to classify bacteria. In acidic solutions, crystal violet is yellow in color and at approximately the pH of 1.6, it transitions to a violet color. Over time, this violet color fades as it reacts with the CO 2 in the air until it is clear. A small footprint visible-near- infrared spectrometer (Vis-NIR) with diode array detector was employed in this investigation. Using the software that operates the spectrometer, the absorbance of crystal violet solutions can be measured at 585 nm at high concentrations of base as a function of ...


Synthesis Of 1-Phenyl-3,5-Diaryl-4-Bromopyrazoles, 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromopyrazoles, And 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromoisoxazoles., Keren Antoine, Anne K. Jean, Roseleen Almenord, Sierra A. Fleming, Titilope Akinwe, Paula Garzon, Julio C. Falcon 2017 Georgia State University

Synthesis Of 1-Phenyl-3,5-Diaryl-4-Bromopyrazoles, 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromopyrazoles, And 1-Phenyl-3-T-Butyl-5-Aryl-4-Bromoisoxazoles., Keren Antoine, Anne K. Jean, Roseleen Almenord, Sierra A. Fleming, Titilope Akinwe, Paula Garzon, Julio C. Falcon

Georgia State Undergraduate Research Conference

No abstract provided.


Characterization Of Α-Anomeric Damaged Dna In Complex With Endonuclease Iv Using Fluorescence Resonance Energy Transfer (Fret), Beatrice Edjah 2017 Georgia State University

Characterization Of Α-Anomeric Damaged Dna In Complex With Endonuclease Iv Using Fluorescence Resonance Energy Transfer (Fret), Beatrice Edjah

Georgia State Undergraduate Research Conference

No abstract provided.


Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, Jeff Brochetti 2017 Lynchburg College

Spectrofluorometric Analysis Of Bisphenol-A In Drinking Water Bottles, Jeff Brochetti

Student Scholar Showcase

Spectrofluorometric Analysis of Bisphenol-A in Drinking Water Bottles

Bisphenol-A (BPA) is of environmental concern due to its ability to act as an endocrine disruptor in humans and many other animals. In the food industry, BPA is widely used in the production of plastic bottles and plastic liners in aluminum cans. Over time, trace amounts of BPA can leach from the container and into the contents inside. A new method of testing for trace amount of BPA involved the formation of an inclusion complex with ß-Cyclodextrin. With the formation of the inclusion complex, it becomes much easier to analyze low concentrations ...


Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson 2017 University of Windsor

Determination Of The Zinc Concentration In Human Fingernails By Laser-Induced Breakdown Spectroscopy, Steven J. Rehse, Vlora A. Riberdy, Christopher J. Frederickson

Physics Publications

The absolute concentration of zinc in human fingernail clippings tested ex vivo was determined by 1064 nm laser-induced breakdown spectroscopy and confirmed by speciated isotope dilution mass spectrometry. A nail testing protocol that sampled across the nail (perpendicular to the direction of growth) was developed and validated by scanning electron microscopy energy dispersive x-ray spectroscopy. Using this protocol, a partial least squares regression model predicted the zinc concentration in five subjects’ fingernails to within 7 ppm on average. The variation of the zinc concentration with depth into the nail as determined by laser-induced breakdown spectroscopy was studied and found to ...


The Use Of Ammonia As A Qualitative Test For Determining When Solid Copper Has Completely Precipitated From Aqueous Solutions Containing Copper(Ii) Ions, M. Olivia Byrd, Carl J. Ohrenberg 2017 University of North Georgia

The Use Of Ammonia As A Qualitative Test For Determining When Solid Copper Has Completely Precipitated From Aqueous Solutions Containing Copper(Ii) Ions, M. Olivia Byrd, Carl J. Ohrenberg

Georgia Journal of Science

In this study, two methods were compared to efficiently determine the absence of copper ions from a copper(II) chloride dihydrate (37.274% copper by mass) solution after precipitation using solid magnesium. In one method, a solution color change from pale blue to colorless was used as indication of a completed precipitation of copper. In the alternative method, ammonia was added to aliquots of solution which indicated remaining copper ions with a royal blue complex. For both methods, magnesium turnings were added to a blue copper(II) chloride solution until it was determined, as indicated above, that all copper had ...


Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti 2017 University of South Florida

Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti

Graduate Theses and Dissertations

Differential Mobility Spectrometry (DMS) using a non-radioactive ion source (NRIS) is investigated as a possible medical diagnostic instrument for near real-time detection of breast cancer biomarkers. In previous clinical studies, concentrations of Linoleic, Palmitic and Stearic fatty acids have been observed at different levels in women with carcinoma breast cancer versus women with benign tumors or healthy women showing no signs of breast cancer. Present diagnostic methods require a biopsy of the suspect tissue and a microscopic lab analysis performed to determine its disease state. This process can take hours or days before the patient and doctor are informed of ...


Triple Pulse Amperometry: A Method Of Detection Of Carbohydrates And Alcohols For Liquid Chromatography , Scott Hughes 2017 Iowa State University

Triple Pulse Amperometry: A Method Of Detection Of Carbohydrates And Alcohols For Liquid Chromatography , Scott Hughes

Scott Hughes

Application of a triple pulse waveform is described for the anodic detection of simple alcohols and carbohydrates at a platinum electrode. The execution of the waveform incorporates the cleaning and reactivation of the platinum electrode, by alternate anodic and cathodic polarization, with measurement of the faradaic signal for the analyte at the reduced electrode surface. The waveform is completed within 0.5-1.5 s and the sampled faradaic signal exhibits no decay with time as would be the case for amperometric detection at a constant applied potential. Calibration curves made by plotting -1/I vs. 1/C are linear. This ...


Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows 2017 Oregon State University

Engineering Fret Biosensors For Microrna Presence/Absence Analysis, Nicholas E. Larkey, Sean M. Burrows

Biomedical Engineering Western Regional Conference

No abstract provided.


Energetic Effects Of Hole Transporting Materials On The Performance Of Organometal Halide Perovskite Photovoltaic Cells, So Min Park 2017 University of Kentucky

Energetic Effects Of Hole Transporting Materials On The Performance Of Organometal Halide Perovskite Photovoltaic Cells, So Min Park

Theses and Dissertations--Chemistry

Efficient, inexpensive, lightweight and flexible solar cells are desired to help meet the world’s growing energy needs. Organometal halide perovskite (OMHP) photovoltaic (PV) cells have shown dramatic increases in solar cell efficiencies increase over the last 5 years. OMHP PV cells have attracted significant attention due to their broad absorption spectra, high electron and hole mobility, and low production cost. The interface between hole transporting layer (HTL) and perovskite thin films have a significant influence on charge transfer and overall solar cell performance. 2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)9,9’-spirobifluorene (Spiro-OMeTAD) is a small molecule largely ...


Comprehensive Structural, Thermal And Toxicological Characterization Of 1-Ethyl-3-Methylimidazolium Alkylbenzenesulfonate Ionic Liquids, Hiranmayee Kandala 2017 South Dakota State University

Comprehensive Structural, Thermal And Toxicological Characterization Of 1-Ethyl-3-Methylimidazolium Alkylbenzenesulfonate Ionic Liquids, Hiranmayee Kandala

Theses and Dissertations

Synthesis and characterization of 1-ethyl-3- methylimidazolium alkylbenzenesulfonate ionic liquids for extraction of lignin from prairie cord grass have been studied. The ionic liquids (ILs) 1-ethyl-3- methylimidazolium benzenesulfonate (EBS), 1-ethyl-3- methylimidazolium toluenesulfonate (ETS) and 1-ethyl-3- methylimidazolium xylenesulfonate (EXS) have been synthesized in this research. An extensive structural, physical, thermal and toxicological characterization has been performed to understand the behavior of these ionic liquids. The reaction yield for the synthesis of EBS, ETS, and EXS ionic liquids was determined to be 91.2 ± 1.5 %, 96.1 ± 0.7 %, 99.0 ± 0.5 % respectively. Spectral analysis using NMR and FTIR confirms the ...


Gold Nanoparticle Biodistributions And Stability In Vivo From Mass Spectrometric Imaging, SUKRU GOKHAN ELCI 2017 University of Massachusetts - Amherst

Gold Nanoparticle Biodistributions And Stability In Vivo From Mass Spectrometric Imaging, Sukru Gokhan Elci

Doctoral Dissertations May 2014 - current

Their smaller size, inherent non-toxicity and tunable properties of gold nanoparticles (AuNPs) attract researchers for their use in biological applications such as drug delivery, imaging and therapeutics. Understanding the in vivo fate of these AuNPs are essential for their potential effects in both the environment and the body. In this dissertation, mass spectrometric imaging methods using laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) and laser desorption/ionization (LDI-MS) have been investigated to monitor the in vivo fate of AuNPs. AuNP injected mouse tissue samples can be obtained and readily imaged to track the injected AuNPs using these methods. A first-ever ...


Analysis Of Gold Nanoparticles And Their Use With Laser Desorption/Ionization Mass Spectrometry, Alyssa Marsico 2017 University of Massachusetts Amherst

Analysis Of Gold Nanoparticles And Their Use With Laser Desorption/Ionization Mass Spectrometry, Alyssa Marsico

Doctoral Dissertations May 2014 - current

Gold nanoparticles (AuNPs) have many unique properties that make them attractive for use in various biological applications. Laser desorption/ionization mass spectrometry (LDI-MS) has been used to monitor AuNPs in complex biological samples but there are still many ways in which AuNPs can be used with MS. In this dissertation, the use of AuNPs to assist in analyte ionization has been investigated. Their ability to enhance signal from biomolecules based on their surface chemistry, size, aggregation and method of deposition has been studied. The first use of an inkjet printer to create surfaces from which analytes can be sampled is ...


Identification Of “Kratom” (Mitragyna Speciosa) Alkaloids In Commercially Available Products, Julia Grzymkowski, Michelle R. Peace, Justin Poklis 2017 Virginia Commonwealth University

Identification Of “Kratom” (Mitragyna Speciosa) Alkaloids In Commercially Available Products, Julia Grzymkowski, Michelle R. Peace, Justin Poklis

Undergraduate Research Posters

“Kratom” is the common name for the botanical mitragyna speciosa. It is a tree native to Southeast Asia in which leaves contain the psychoactive alkaloids mitragynine and 7-hydroxymitragynine. Kratom is often ingested as teas, chewed, or smoked. It acts as a stimulant in small doses and as an opioid in large doses. Overdoses can result in vomiting, seizures, and death. Recently the Drug Enforcement Agency (DEA) placed Kratom on Schedule 1, but, due to public outcry, it was almost immediately removed.

Eleven kratom based products were obtained from various tobacco shops, “headshops” and via the internet including: Choice brand capsule ...


The Analysis Of Flavor Compounds In Green Tea Using Ice Concentration Linked With Extractive Stirrer (Icecles), Abdullah Alluhayb 2017 South Dakota State University

The Analysis Of Flavor Compounds In Green Tea Using Ice Concentration Linked With Extractive Stirrer (Icecles), Abdullah Alluhayb

Theses and Dissertations

Sample preparation of target components from food samples is one of the most difficult steps in this type of analysis. Many extraction techniques have been used for this purpose, such as liquid-liquid extraction (LLE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), solid-phase extraction (SPE), solid-phase microextraction (SPME), and stir bar sorptive extraction (SBSE). Although each of these techniques works well, they each have a number of disadvantages, including selectivity, relatively high cost, long preparation time, and matrix effects. Ice concentration linked with extractive stirrer (ICECLES) is a promising new sample preparation technique, especially for the extraction of relatively polar compounds ...


Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey 2017 University of Nebraska Medical Center

Amino Acid Catabolism In Staphylococcus Aureus And The Function Of Carbon Catabolite Repression, Cortney R. Halsey, Shulei Lei, Jacqueline K. Wax, Mckenzie K. Lehman, Austin S. Nuxoll, Laurey Steinke, Marat Sadykov, Robert Powers, Paul D. Fey

Faculty Publications -- Chemistry Department

Staphylococcus aureus must rapidly adapt to a variety of carbon and nitrogen sources during invasion of a host. Within a staphylococcal abscess, preferred carbon sources such as glucose are limiting, suggesting that S. aureus survives through the catabolism of secondary carbon sources. S. aureus encodes pathways to catabolize multiple amino acids, including those that generate pyruvate, 2-oxoglutarate, and oxaloacetate. To assess amino acid catabolism, S. aureus JE2 and mutants were grown in complete defined medium containing 18 amino acids but lacking glucose (CDM). A mutation in the gudB gene, coding for glutamate dehydrogenase, which generates 2-oxoglutarate from glutamate, significantly reduced ...


Fluorogenic Protein Labeling Using A Genetically Encoded Unstrained Alkene, Xin Shang, X. Song, C. Faller, R. Lai, H. Li, R. Cerny, Wei Niu, Jiantao Guo 2017 University of Nebraska-Lincoln

Fluorogenic Protein Labeling Using A Genetically Encoded Unstrained Alkene, Xin Shang, X. Song, C. Faller, R. Lai, H. Li, R. Cerny, Wei Niu, Jiantao Guo

Faculty Publications -- Chemistry Department

We developed a new fluorogenic bioorthogonal reaction that is based on the inverse electron-demand Diels–Alder reaction between styrene (an unstrained alkene) and a simple tetrazine. The reaction forms a new fluorophore with no literature precedent. We have identified an aminoacyl-tRNA synthetase/tRNA pair for the efficient and site-specific incorporation of a styrene-containing amino acid into proteins in response to amber nonsense codon. Fluorogenic labeling of purified proteins and intact proteins in live cells were demonstrated. The fluorogenicity of the styrene–tetrazine reaction can be potentially applied to the study of protein folding and function under physiological conditions with low ...


Fidelity Of Implementation: An Overlooked Yet Critical Construct To Establish Effectiveness Of Evidence-Based Instructional Practices, Marilyne Stains, Trisha Vickrey 2017 University of Nebraska-Lincoln

Fidelity Of Implementation: An Overlooked Yet Critical Construct To Establish Effectiveness Of Evidence-Based Instructional Practices, Marilyne Stains, Trisha Vickrey

Faculty Publications -- Chemistry Department

The discipline-based education research (DBER) community has been invested in the research and development of evidence-based instructional practices (EBIPs) for decades. Unfortunately, investigations of the impact of EBIPs on student outcomes typically do not characterize instructors’ adherence to an EBIP, often assuming that implementation was as intended by developers. The validity of such findings is compromised, since positive or negative outcomes can be incorrectly attributed to an EBIP when other factors impacting implementation are often present. This methodological flaw can be overcome by developing measures to determine the fidelity of implementation (FOI) of an intervention, a construct extensively studied in ...


Ryan Caylor, Ryan Caylor 2016 Concordia University - Portland

Ryan Caylor, Ryan Caylor

Matthew E. Wise

Determination of the optical and physical properties of secondary organic aerosol particles
Measurement of the peroxide content of secondary organic aerosol particles


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