Chemistry Commons^™

Comparison Of Antioxidant Capacities And Antioxidant Components Of Commercial Bitter Melon (Momordica Charantia L.) Products, Esi̇n Akyüz, Sercan Türkoğlu, Kevser Sözgen Başkan, Esma Tütem, Mustafa Reşat Apak

Turkish Journal of Chemistry

In this study, the total phenolic contents and total antioxidant capacities of some commercial bitter melon products (powder, packaged powder, capsule, paste in olive oil), and of unripe and ripe fruits were determined by spectrophotometric and chromatographic methods. The total antioxidant capacities of unripe and ripe bitter melon samples, determined by using the CUPRAC (cupric reducing antioxidant capacity assay) and ABTS (2,2'-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid)/HRP (horseradish peroxidase) methods, were 42.5 and 36.3 μmol TRE (Trolox equivalent) g-1, and 8.7 and 7.0 μmol TRE g-1, respectively. The TAC (total antioxidant capacity) order of the studied samples using the same 2 methods were determined …

Synthesis, Antioxidant And Antimicrobial Properties Of Novel Pyridyl-Carbonyl Thiazoles As Dendrodoine Analogs, Zafer Şahi̇n, Sevde Nur Bi̇lteki̇n, Leyla Yurttaş, Şeref Demi̇rayak

Turkish Journal of Chemistry

Marine compound dendrodoine was first obtained from tunicate species (Dendrodo grossularia). It has a five-membered ring, namely, it is a heterocycle thiadiazole, which is found rarely in natural sources. Following its biological activities, novel analogs have been investigated recently. Synthesis of the analogs for this study is realized with uncommon thiazole closure, including methylene-carbonyl condensation. Structures are elucidated by NMR (1H, 13C) and HRMS spectrums. As an alkaloid derivative, antioxidant properties were evaluated with DPPH and FRAP assays and antimicrobial effect with microdilution method. Among the series, 3bc-3cf showed higher antioxidant activity than those having 3 or 4-pyridyl substituents. There …

Synthesis Of Chromium(Ii) Complexes With Chelating Bis(Alkoxide) Ligand And Their Reactions With Organoazides And Diazoalkanes, Sudheer S. Kurup, Richard J. Staples, Richard Lord, Stanislav Groysman

Open Access Publishing Support Funded Articles

Synthesis of new chromium(II) complexes with chelating bis(alkoxide) ligand [OO]Ph (H2[OO]Ph = [1,1′:4′,1′’-terphenyl]-2,2′’-diylbis(diphenylmethanol)) and their subsequent reactivity in the context of catalytic production of carbodiimides from azides and isocyanides are described. Two different Cr(II) complexes are obtained, as a function of the crystallization solvent: mononuclear Cr[OO]Ph(THF)2 (in toluene/THF, THF = tetrahydrofuran) and dinuclear Cr2([OO]Ph)2 (in CH2Cl2/THF). The electronic structure and bonding in Cr[OO]Ph(THF)2 were probed by density functional theory calculations. Isolated Cr2([OO]Ph)2 undergoes facile reaction with 4-MeC6H4N3, 4-MeOC6H4N3, or 3,5-Me2C6H3N3 to yield diamagnetic Cr(VI) bis(imido) complexes; a structure of Cr[OO]Ph(N(4-MeC6H4))2 was confirmed by X-ray crystallography. The reaction of Cr2([OO]Ph)2 with …

Effect Of Pyridoxal Phosphate And Tetrahydrofolate Bound On Human Serine Hydroxymethyltransferase By Molecular Dynamic Simulation, Peerapong Wongpituk

Chulalongkorn University Theses and Dissertations (Chula ETD)

Serine hydroxymethyltransferase (SHMT), a pyridoxal phosphate (PLP)-dependent enzyme, is involved in one-carbon metabolism in multiple biochemical pathways, including the biosynthesis of purine and thymidine. SHMT1 is the enzyme to be studied clinically as a target for cancer chemotherapy. Therefore, the binding mechanism of this enzyme would be investigated. In this study, molecular dynamics simulations for 500 ns was applied on SHMT1 tetramer in six systems with different ligand cofactors (PLP-Lys, L-ser, PLS, PLG, THF, and MTHF) in order to understand its structural dynamics properties. The key residues Y'73, S53, H231, K257, R263 and R402 were found in all ligand cofactor/SHMT1 …

Determination Of Herbicides In Water Samples By Spectroscopic Techniques, Anna Prukjareonchook

Chulalongkorn University Theses and Dissertations (Chula ETD)

Atrazine and paraquat are widely used to control weeds in the agricultural areas. The residue of herbicides can harm the environment and living things. In this research, nanoporous carbon derived from melamine based polybenzoxazine or NPC-PBZ-m was used as an adsorbent for atrazine and paraquat analysis. NPC-PBZ-m was synthesized by sol-gel and pyrolysis processes. The characteristics of sorbent were investigated by FTIR, BET, XPS, and FE-SEM. For atrazine determination, NPC-PBZ-m pre-concentration column combined with a colorimetric detection based on a Konig’s reaction and HPLC-UV at 222 nm were developed. The parameters affecting the adsorption performance were optimized. The reusability of …

พลศาสตร์ของไหลเชิงคำนวณของรีฟอร์มมิงด้วยคาร์บอนไดออกไซด์ของมีเทนในเครื่องปฏิกรณ์ ฟลูอิไดซ์เบดแบบหมุนเวียนภายใน, ดุลยพัฒน์ เทียมสกุล

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในปัจจุบัน แก๊สเรือนกระจกหลักที่ปลดปล่อยออกสู่ชั้นบรรยากาศ คือ แก๊สคาร์บอนไดออกไซด์ และมีเทน เพื่อจัดการกับแก๊สเรือนกระจก เทคโนโลยีการดักจับแก๊สคาร์บอนไดออกไซด์จึงได้ถูกคิดค้นขึ้น อย่างไรก็ตาม การดักจับแก๊สคาร์บอนไดออกไซด์นั้น แก๊สคาร์บอนไดออกไซด์ยังคงอยู่ในรูป CO2 จึงนำไปสู่เทคโนโลยีการนำแก๊สคาร์บอนไดออกไซด์มาใช้ประโยชน์ ที่เป็นการเปลี่ยนแก๊สคาร์บอนไดออกไซด์ที่ดักจับได้เป็นสารอื่นที่มีมูลค่า ปฏิกิริยารีฟอร์มมิงด้วยคาร์บอนไดออกไซด์ของมีเทน เป็นการทำปฏิกิริยาระหว่าง แก๊สคาร์บอนไดออกไซด์ และมีเทน จะเห็นได้ว่าปฏิกิริยานี้เป็นการใช้แก๊สคาร์บอนไดออกไซด์ และมีเทนซึ่งเป็นสาเหตุหลักของแก๊สเรือนกระจก เครื่องปฏิกรณ์ฟลูอิไดซ์เบดแบบหมุนเวียนภายในเป็นเครื่องปฏิกรณ์ที่ได้รวมทั้งหอไรเซอร์ ไซโคลน หอดาวเนอร์ และท่อป้อนกลับ ไว้ในเครื่องปฏิกรณ์เครื่องเดียว ทำให้เครื่องปฏิกรณ์นี้สามารถดำเนินการได้ง่ายกว่าเครื่องปฏิกรณ์ฟลูอิไดซ์เบดแบบหมุนเวียนทั่วไป โดยเครื่องปฏิกรณ์ชนิดนี้ถูกแบ่ง ด้วยแผ่นกั้นเป็น 2 ฝั่ง ซึ่งทำหน้าที่เป็นไรเซอร์และดาวเนอร์ของระบบที่เชื่อมกันด้วยช่องบริเวณด้านล่างของ เครื่องปฏิกรณ์ ในงานวิจัยนี้ได้ทำการศึกษาอุทกพลศาสตร์และปฏิกิริยารีฟอร์มมิงด้วยคาร์บอนไดออกไซด์ของมีเทนที่เกิดขึ้นในเครื่องปฏิกรณ์ฟลูอิไดซ์เบดแบบหมุนเวียนภายในที่มีการออกแบบ ลักษณะตัวกระจายแก๊ส ความสูงของแผ่นกั้นระหว่างด้านไรเซอร์กับดาวเนอร์ ความกว้างของ loop seal และความกว้างของ ทางออกแก๊ส แตกต่างกัน ซึ่งได้ทำการศึกษาโดยใช้อนุภาคขนาด 200 ไมโครเมตร ความหนาแน่น 3000 กิโลกรัมต่อลูกบาศก์เมตร และมีอัตราการป้อนแก๊สด้านดาวเนอร์และด้านไรเซอร์เท่ากับ 0.3 เมตรต่อวินาที และ 1.37 เมตรต่อวินาที ตามลำดับ โดยใช้พลศาสตร์ของไหลเชิงคำนวณในการศึกษา พบว่า การออกแบบเครื่องปฏิกรณ์ฟลูอิไดซ์เบดแบบหมุนเวียนภายในที่เหมาะสม คือ ตัวกระจายแก๊สแบบยกระดับ สัดส่วนความสูงของเครื่องเป็น 2 เท่าของความสูงแผ่นกั้น สัดส่วนความกว้างของเบดเป็น 10 เท่าของ loop seal และสัดส่วนความกว้างของ freeboard zone เป็น 37.5 เท่าของช่องทางออกแก๊ส

Preparation Of Corn Starch-Alginate Beads Encapsulated Anthocyanins And Cinnamon Oil, Duangkamon Sriwichai

Chulalongkorn University Theses and Dissertations (Chula ETD)

Corn starch-alginate beads loaded with anthocyanins or cinnamon oil were prepared using different components by the ionotropic gelation method. The matrix of anthocyanin-loaded corn starch-alginate beads (or anthocyanin beads) was alginate, native corn starch and soy protein isolated (SPI). The anthocyanins were extracted from butterfly pea flowers. SPI was used due to the good anthocyanin adsorption without leaking of anthocyanin during freeze-dried process. In addition, cinnamon oil-loaded corn starch-alginate beads (or oil beads) composed of alginate, porous corn starch and cinnamon oil. Porous corn starch was obtained from enzyme hydrolysis. Both types of beads were characterized their chemical and physical …

Detection Of Hydrogen Peroxide And Persulfate Ion By Gold Nanorod Sensor, Petrada Chunnuan

Chulalongkorn University Theses and Dissertations (Chula ETD)

Gold nanorods (GNRs) multicolor sensor were developed to determine hydrogen peroxide (H2O2) and persulfate (S2O82-) based on the etching of GNRs which was detected from either naked-eye or UV-visible spectroscopic method. The changed size of GNRs was directly related to the concentration of H2O2 and S2O82-. To obtain the optimum conditions for H2O2 and S2O82- determination, CTAB concentration, FeSO4 concentration and detection time were investigated. For H2O2, the working range was 0.20 to 3.0 mM where the good linear working range was in the range of 0.20 to 0.80 mM. LOD was 0.08 mM. Moreover, the GNRs conjugated hydrogel was …

Antibiotic Drug Nanocarriers For Probing Of Multidrug Abc Membrane Transporter Of Bacillus Subtilis, Pavan Kumar Cherukuri, Preeyaporn Songkiatisak, Feng Ding, Jeam-Michel Jault, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Multidrug membrane transporters can extrude a wide range of substrates, which cause multidrug resistance and ineffective treatment of diseases. In this study, we used three different sized antibiotic drug nanocarriers to study their size-dependent inhibitory effects against Bacillus subtilis. We functionalized 2.4 ± 0.7, 13.0 ± 3.1, and 92.6 ± 4.4 nm silver nanoparticles (Ag NPs) with a monolayer of 11-amino-1-undecanethiol and covalently linked them with antibiotics (ofloxacin, Oflx). The labeling ratios of antibiotics with NPs are 8.6 × 10², 9.4 × 10³, and 6.5 × 10⁵ Oflx molecules per NP, respectively. We designed …

Pyrocumulonimbus Stratospheric Plume Injections Measured By The Ace‐Fts, C.D. Boone, Peter F. Bernath, M. D. Fromm

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment (ACE) is a satellite‐based mission that probes Earth's atmosphere via solar occultation. The primary instrument on board is a high‐resolution infrared Fourier transform spectrometer (Atmospheric Chemistry Experiment Fourier Transform Spectrometer, ACE‐FTS), providing altitude‐resolved volume mixing ratio measurements for numerous atmospheric constituents, including many biomass burning products. The ACE mission has observed the aftermath of three major pyrocumulonimbus events, in which extreme heat from intense fires created a pathway for directly injecting into the stratosphere plumes of gaseous and aerosol pollutants. These three events were associated with severe Australian bushfires from 2009 and 2019/2020, along with intense …

Interactive Effects Of The Co2 Enrichment And Nitrogen Supply On The Biomass Accumulation, Gas Exchange Properties, And Mineral Elements Concentrations In Cucumber Plants At Different Growth Stages, Xun Li, Jinlong Dong, Nazim S. Gruda, Wenying Chu, Zengqiang Duan

Chemistry & Biochemistry Faculty Publications

The concentration changes of mineral elements in plants at different CO₂ concentrations ([CO₂]) and nitrogen (N) supplies and the mechanisms which control such changes are not clear. Hydroponic trials on cucumber plants with three [CO₂] (400, 625, and 1200 µmol mol⁻¹) and five N supply levels (2, 4, 7, 14, and 21 mmol L⁻¹) were conducted. When plants were in high N supply, the increase in total biomass by elevated [CO₂] was 51.7% and 70.1% at the seedling and initial fruiting stages, respectively. An increase in net photosynthetic rate …

Molecular Nature Of Marine Particulate Organic Iron-Carrying Moieties Revealed By Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (Esi-Fticrms), Chen Xu, Peng Lin, Luni Sun, Hongmei Chen, Wei Xing, Manoj Kamalanathan, Patrick G. Hatcher, Maureen H. Conte, Antonietta Quigg, Peter H. Santschi

Chemistry & Biochemistry Faculty Publications

Marine sinking particulate organic matter (POM), acting as a link between surface primary production and burial of organic matter in marine sediments, undergoes a variety of physical and biochemical alterations on its way to the deep ocean, resulting in an increase in its un-characterizable proportion with diagenesis. Further, the binding ligands in POM for iron, an essential nutrient to marine life and tightly coupled with organic matter, has rarely been studied. In the current study, we employed an approach combining sequential extraction with ultrahigh resolution mass spectrometry (ESI-FTICRMS), in order to explore and unravel the chemical characteristics of organic matter …

Influences Of Hillslope Biogeochemistry On Anaerobic Soil Organic Matter Decomposition In A Tundra Watershed, Michael Philben, Neslihan Taş, Hongmei Chen, Stan D. Wullschleger, Alexander Kholodov, David E. Graham, Baohua Gu

Chemistry & Biochemistry Faculty Publications

We investigated rates and controls on greenhouse gas (CO₂ and CH₄) production in two contrasting water‐saturated tundra soils within a permafrost‐affected watershed near Nome, Alaska, United States. Three years of field sample analysis have shown that soil from a fen‐like area in the toeslope of the watershed had higher pH and higher porewater ion concentrations than soil collected from a bog‐like peat plateau at the top of the hillslope. The influence of these contrasting geochemical and topographic environments on CO₂ and CH₄ production was tested in soil microcosms by incubating both the organic‐ and mineral‐layer …

Tetrathiafulvalene: A Gate To The Mechanochemical Mechanisms Of Electron Transfer Reactions, Richard Chen, Mehmet Kerem Gokus, Silvina Pagola

Chemistry & Biochemistry Faculty Publications

This report describes aspects of our previous studies of the mechanochemical synthesis of charge transfer complexes of the electron donor tetrathiafulvalene, which are relevant to the use of laboratory X-ray powder diffraction for ex situ monitoring of mechanochemical reactions toward investigating their mechanisms. In particular, the reaction of tetrathiafulvalene and chloranil was studied under neat mechanochemical conditions and liquid-assisted grinding with diethyl ether (1 μL/mg). The product in both cases is the green tetrathiafulvalene chloranil polymorph and the mechanism of the redox reaction is presumably the same. However, while the kinetic profile of the neat mechanochemical synthesis was fitted with …

Measured Optical Absorption Cross Sections Of Tio, Peter Bernath

Chemistry & Biochemistry Faculty Publications

A laboratory emission spectrum of TiO in the visible and near-infrared regions (476–1176 nm) has been calibrated and corrected. High-resolution experimental absorption cross sections for TiO with natural isotopic abundance are provided at a temperature of about 2300 K. These cross sections have been compared with those derived from the ExoMol line list. The experimental cross sections can be used directly as a template for cross correlation TiO detection in hot Jupiter exoplanets.

Thyroxine Binding To Type Iii Iodothyronine Deiodinase, Craig A. Bayse, Eric S. Marsan, Jenna R. Garcia, Alexis T. Tran-Thompson

Chemistry & Biochemistry Faculty Publications

Iodothyronine deiodinases (Dios) are important selenoproteins that control the concentration of the active thyroid hormone (TH) triiodothyronine through regioselective deiodination. The X-ray structure of a truncated monomer of Type III Dio (Dio3), which deiodinates TH inner rings through a selenocysteine (Sec) residue, revealed a thioredoxin-fold catalytic domain supplemented with an unstructured Ω-loop. Loop dynamics are driven by interactions of the conserved Trp207 with solvent in multi-microsecond molecular dynamics simulations of the Dio3 thioredoxin(Trx)-fold domain. Hydrogen bonding interactions of Glu200 with residues conserved across the Dio family anchor the loop's N-terminus to the active site Ser-Cys-Thr-Sec sequence. A key long-lived loop …

Oxidation Of Aldehydes To Nitriles With An Oxoammonium Salt: Preparation Of Piperonylonitrile, Nathaniel D. Kaetzel, Kyle M. Lambert, Christopher B. Kelly

Chemistry & Biochemistry Faculty Publications

No abstract provided.

Nrlmsis 2.0: A Whole-Atmosphere Empirical Model Of Temperature And Neutral Species Densities, J. T. Emmert, D. P. Drob, J. M. Picone, D. E. Siskind, M. Jones Jr., M. G. Mlynczak, Peter F. Bernath, X. Chu, E. Doornbos, B. Funke, L. P. Goncharenko, M. E. Hervig, M. J. Schwartz, P. E. Sheese, F. Vargas, B. P. Williams, T. Yuan

Chemistry & Biochemistry Faculty Publications

NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to the exobase and describes the average observed behavior of temperature, eight species densities, and mass density via a parametric analytic formulation. The model inputs are location, day of year, time of day, solar activity, and geomagnetic activity. NRLMSIS 2.0 is a major, reformulated upgrade of the previous version, NRLMSISE-00. The model now couples thermospheric species densities to the entire column, via an effective mass profile that transitions each species from the fully mixed region below ~70 km altitude to the diffusively separated region above ~200 km. Other …

Recent Developments In The Pyscf Program Package, Qiming Sun, Xing Zhang, Samragni Banerjee, Peng Bao, Marc Barbry, Nick S. Blunt, Nikolay A. Bogdanov, George H. Booth, Jia Chen, Zhi-Hao Cui, Janus J. Eriksen, Yang Gao, Sheng Gun, Jan Hermann, Matthew R. Hermes, Kevin Koh, Peter Koval, Susi Lehtola, Zhendong Li, Junzi Liu, Narbe Mardirossian, James D. Mcclain, Mario Motta, Bastien Mussard, Hung Q. Pham, Artem Pulkin, Wirawan Purwanto, Paul J. Robinson, Enrico Ronca, Elvira R. Sayfutyarova, Maximillian Scheurer, Henry F. Schurkus, James E.T. Smith, Chong Sun, Shi-Ning Sun, Shiv Upadhyay, Lucas K. Wagner, Xiao Wang, Alec White, James Daniel Whitfield, Mark J. Williamson, Sebastian Wouters, Jun Yang, Jason M. Yu, Tianyu Zhu, Timothy C. Berkelbach, Sandeep Sharma, Alexander Yu Sokolov, Garnet Kin-Lic Chan

University Administration Publications

PySCF is a Python-based general-purpose electronic structure platform that supports first-principles simulations of molecules and solids as well as accelerates the development of new methodology and complex computational workflows. This paper explains the design and philosophy behind PySCF that enables it to meet these twin objectives. With several case studies, we show how users can easily implement their own methods using PySCF as a development environment. We then summarize the capabilities of PySCF for molecular and solid-state simulations. Finally, we describe the growing ecosystem of projects that use PySCF across the domains of quantum chemistry, materials science, machine learning, and …

Synthesis And Evaluation Of Nebraska Red Derivatives For Protein Labeling Studies, Lauren Lesiak

Honors Program: Senior Projects (Public)

G protein-coupled receptors (GPCRs) play a vital role in cell signaling, and imaging the internalization of these proteins will allow for better understand of protein trafficking within the cell, as well as identification of potential drug targets. However, there is a need for further development of fluorescent protein labels that are able to effectively monitor GPCR internalization in the near-infrared (NIR) range. We recently described a series of NIR fluorophores in which a phosphinate functionality is inserted at the bridging position of the xanthene scaffold, called the Nebraska Red (NR) dye series. These dyes are attractive reagents for the imaging …

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 …

Synthesis, Characterization, And Biological Activity Of Imidazolium Salts, David Weader

Williams Honors College, Honors Research Projects

Nonmuscle invasive bladder cancer (NMIBC) inflicts thousands of Americans annually, and is typically treated with the immunotherapy BCG. However, due to a BCG shortage, there is a new need for novel treatments of NMIBC. Addressing this issue, several imidazolium salt derivatives were synthesized and characterized with the intent of treatment within the bladder. These imidazolium salts were tested against different human bladder cancer cell lines in vitro to determine their reactivity and cytotoxicity. Among these results are GI50 concentrations for each drug, which is the concentration of drug needed to see growth inhibition in 50% of treated cells. Previous published …

Spectroscopic Techniques To Characterize And Develop Sensing Methods For Titanium Dioxide Nanoparticles In Water, Reagan Scott Turley

Open Access Theses & Dissertations

Titanium dioxide nanoparticles are being used in ever increasing amounts and applications in many consumer products and industrial processes including water treatment. These nanoparticles have not been shown to be toxic to humans via ingestion, but it is worthwhile to develop a portable and rapid detection method to quantify the concentration of nanoparticles in treated drinking water. Current detection methods include single particle inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, tunneling electron microscopy and scanning electron microscopy. While extremely sensitive, these techniques are expensive and sometimes require extensive sample preparation before analysis. A preliminary study on …

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 …

Life Cycle Studies To Evaluate The Physiological And Biochemical Effects Of Copper Oxide And Surface-Coated Titanium Dioxide Nanoparticles On Green Onion (Allium Fistulosum) And Carrot (Daucus Carota L.) Plants: Insights Utilizing Two-Photon Microscopy And Spectroscopy, Yi Wang

Open Access Theses & Dissertations

With the recent increase of nanomaterial production, nano copper oxide (nCuO) and surface-modified titanium dioxide nanoparticles (nTiO2) are among the most widely applied nanoparticles in industry and daily lives. Their use has resulted in accumulation in soils as a consequence of their direct or indirect release. Hence, these NPs may raise a potential risk to crops cultivated in soils. Moreover, the physiological effects of nCuO on green onion (Allium fistulosum) and surface-coated nTiO2 on full-grown carrot (Daucus carota L.) are still unknown. Green onion is characterized by its high content of the antioxidant allicin, and carrot is a worldwide economic …

Expression, Purification, And Characterization Of Recombinant Human Npas2, Brenda Moreno

Open Access Theses & Dissertations

Many living organisms have biological clocks known as circadian rhythms that control various physiological and behavioral processes, tailored with the day and night. At the cellular level, the circadian clock drives daily rhythms with a transcriptional-translational feedback loop (TTFL) established by multiple transcription factors and genes under their regulation. Circadian Locomotor Output Cycles Kaput (CLOCK) and Brain and Muscle ARNT-like protein 1 (BMAL1) are two of those transcription factors, initiating the TTFL by forming a heterodimeric complex that bind to DNA promoters. Neuronal PAS domain protein 2 (NPAS2) is a functional analog to CLOCK. Less knowledge about NPAS2, in contrast …

Discovery Of Glycan-Based Biomarkers For Cutaneous Leishmaniasis And Chagas Disease By Reversed Immunoglycomics, Alba Lucia Montoya

Open Access Theses & Dissertations

Protozoa are the causative agents of a number of diseases that affect humans and mammalian animals. Several forms of leishmaniasis are caused by different Leishmania species (Leishmania spp.), while Chagas disease (CD) is caused by the parasite Trypanosoma cruzi (T. cruzi). These members of the Trypanosomatidae family have characteristic glycoconjugates broadly distributed on their cell surfaces, which can be useful for diagnosis and follow-up of chemotherapy for the diseases.

Leishmania spp. expresses an “exotic” surface glycocalyx mainly composed of a number of glycosyl-phosphatidylinositol (GPI)-anchored proteins, a complex lipophosphoglycan (LPG) and a family of low-molecular mass glycoinositol-phospholipids (GIPLs), some of them …

Antioxidant Intervention In Radical-Induced Protein Damage, Emmanuel Zubia

Open Access Theses & Dissertations

Many environmental toxicants are known to increase free-radical production, which can create cellular havoc and lead to a myriad of ailments. Antioxidants can be used to ameliorate the prevalence of free radicals, potentially serving as prophylactics against radical-induced disorders. Many exogenous antioxidants are phytochemicals in origin, such as ascorbic acid, gallic acid, and ellagic acid. Some of these antioxidants can be found in traditional medicine, like tanshinone and brazilin, which have been studied and are known to have low cytotoxicity. Here we test the radical rescue capacity of a selected group of phytochemical antioxidants on protein rescue models. Specifically, our …

Observation Of Reduced Thermal Conductivity In A Metal-Organic Framework Due To The Presence Of Adsorbates, Hasan Babaei, Mallory E. Decoster, Minyoung Jeong, Zeinab M. Hassan, Timur Islamoglu, Helmut Baumgart, Alan J.H. Mcgaughey, Engelbert Redel, Omar K. Farha, Patrick E. Hopkins, Jonathan A. Malen, Christopher E. Wilmer

Electrical & Computer Engineering Faculty Publications

Whether the presence of adsorbates increases or decreases thermal conductivity in metal-organic frameworks (MOFs) has been an open question. Here we report observations of thermal transport in the metal-organic framework HKUST-1 in the presence of various liquid adsorbates: water, methanol, and ethanol. Experimental thermoreflectance measurements were performed on single crystals and thin films, and theoretical predictions were made using molecular dynamics simulations. We find that the thermal conductivity of HKUST-1 decreases by 40 – 80% depending on the adsorbate, a result that cannot be explained by effective medium approximations. Our findings demonstrate that adsorbates introduce additional phonon scattering in HKUST-1, …

Polymer Chemistry Education To Increase Student Awareness Of Plastic Pervasiveness And Environmental Impact, Victoria Hill

Master's Theses and Doctoral Dissertations

A polymer-pollution-focused laboratory sequence was written to teach general chemistry concepts in a course for pre-service elementary teachers. Students experienced the difficulties related to polymer pollution clean-up and made bio-based materials to see possible alternatives. In order to determine whether this laboratory sequence changed student understanding of the importance of polymers and their environmental impact, student opinions were gathered with pre/post-course sequence surveys, observations, post-laboratory surveys, and focus group interviews. These same data collection methods were also used to determine the likelihood that the pre-service elementary teachers would teach these polymer and environmental laboratories or their concepts in the future. …