Digital Commons Network^™

Reducing Disposable Plastic Waste From Protein Quantitative Assays, Justin Buiter

All Capstone Projects

Protein concentration quantification is important for many areas of biology and biochemistry. This quantification happens in large quantities in laboratories and needs to be done accurately and quickly. The Bradford assay is one of the most common ways of accomplishing this task (1). This assay relies on the binding of the protein and the Coomassie Blue G250 dye. The anionic blue form binds to the protein and has a maximum at 595 nm. This allows for accurate quantification by reading how much of the sample absorbs at 595 nm (2).

In 2014, it was estimated that 5.5 million tons of …

Synthesis And Characterization Of Pani And Pani/Nanometal Oxides, Photocatalytic And Adsorbent Applications, Bi̇lge Budak, Si̇bel Demi̇rel

Turkish Journal of Chemistry

In this study, polymeric nanocomposites of PANI and PANI/nanometal oxides (Fe2O3, NiO, SnO2, WO3, ZrO2) as photocatalysts were synthesized with a chemical polymerization method. Structural characterizations of synthesized polymeric nanocomposites were performed as follows: FT-IR, SEM, TEM and XRD, and TGA. The effect of pure nanometal oxides (Fe2O3, NiO, SnO2, WO3, ZrO2) and polymeric nanocomposites on the degradation of naproxen, the drug active ingredient, was studied under visible light (UV-A at 365 nm) and in the absence of light. In this study, photocatalytic and adsorbent efficiency of polymeric nanometal oxides were investigated. In order to determine the effect of pure …

Dual-Reactive Hydrogels Functionalizable Using ?Huisgen Click? And ?Schiff Base? Reactions, Nergi̇z Cengi̇z

Turkish Journal of Chemistry

Hydrogels incorporating different reactive groups are important platforms for the fabrication of functional materials through the conjugation of diverse molecules. In this study, a dual-reactive hydrogel system was designed utilizing aldehyde and azide groups containing methacrylate monomers. Hydrogels were obtained in the presence of a dimethacrylate crosslinker with a combination of hydrophilic PEG-based monomers via free-radical polymerization. The azide and aldehyde sites of the hydrogel network are reactive towards alkyne and amine functional groups, respectively. The advantage of the different reactivities of these functional groups was demonstrated through the attachment of two different dye molecules onto the hydrogel platform via …

Testing Different Approaches For The Stabilization Of Mdi: Design Of Low-Valent Molybdenum Complexes In Redox-Active Environments And Capture-Release Reactions Using N-Heterocyclic Carbenes, Asanka Indrajith Dissanayake

Wayne State University Dissertations

Methylene diphenyl diisocyanate (4,4’-MDI) is an aromatic diisocyanate, which is widely used as a monomer in the polyurethane industry. One of the main challenges with using 4,4’-MDI is its dimerization into uretdione. The polyurethane industry seeks solutions that could suppress dimerization of 4,4’-MDI and extend its shelf-life. The focus of this dissertation is on the design of chemical solutions to this problem including: (1) reversible coordination of MDI (heteroallene) to low-valent mono- or dimolybdenum complexes in redox-active ligand environment, and (2) reversible coordination of MDI with two equivalents of an appropriate N-heterocyclic carbene.

MDI (isocyanate) is a heteroallene, and heteroallenes …

Tie Dye Activity Plans, Admin Stem For Success

STEM for Success Showcase

OVERVIEW:

The STEM for success ambassador program will provide high school students the opportunity to participate in STEM activities that challenge them to learn topics covered in most high school chemistry and physics courses in an environment that cultivates leadership, STEM advocacy, and the 21st century skills of creativity and collaboration. High school students will learn tie-dye science and the chemistry and physics of slime and use their learning experiences to create hands-on activities for Pre-K through 8th grade students. High school students will form teams and venture out into their communities to explore the activities they have created in …

Arginine-178 Is An Essential Residue For Itpa Function, Nicholas E. Burgis, Caitlin April, Kandise Vanwormer

Chemistry and Biochemistry Faculty Publications

The inosine triphosphate pyrophosphatase (ITPA) enzyme plays a critical cellular role by removing noncanonical nucleoside triphosphates from nucleotide pools. One of the first pathological ITPA mutants identified is R178C (rs746930990), which causes a fatal infantile encephalopathy, termed developmental and epileptic encephalopathy 35 (DEE 35). The accumulation of noncanonical nucleotides such as inosine triphosphate (ITP), is suspected to affect RNA and/or interfere with normal nucleotide function, leading to development of DEE 35. Molecular dynamics simulations have shown that the very rare R178C mutation does not significantly perturb the overall structure of the protein, but results in a high level of structural …

การขจัดสีย้อมอินทรีย์ด้วยการดูดซับบนเมโซพอรัสซิลิกาโหลดด้วยโลหะ, อภิญญา ศิริพร

Chulalongkorn University Theses and Dissertations (Chula ETD)

ความนิยมที่มากขึ้นในการใช้งานสีย้อมอินทรีย์ในอุตสาหกรรมสิ่งทอ จึงทำให้เกิดความกังวลเป็นอย่างมากเนื่องจากสีย้อมอินทรีย์เป็นอันตรายและก่อให้เกิดมลพิษทางน้ำ ความเป็นพิษของสีย้อมเหล่านี้ส่งผลเสียต่อระบบนิเวศ สีย้อมเหล่านี้มีความเสถียรมากเนื่องจากสีย้อมเหล่านี้ได้จากการสังเคราะห์และมีโครงสร้างโมเลกุลที่ซับซ้อน ดังนั้นงานวิจัยนี้จึงศึกษาการกำจัดสีย้อมที่ปนเปื้อนในน้ำโดยการดูดซับด้วยตัวดูดซับเมโซพอรัสซิลิกาและตัวดูดซับเมโซพอรัสซิลิกาที่โหลดด้วยโลหะ ตัวดูดซับเมโซพอรัสซิลิกาจะเตรียมโดยใช้วิธีแม่แบบชนิดอ่อน สีย้อมอินทรีย์ที่เลือกใช้ ได้แก่ สีย้อมเอซิดบลูซึ่งเป็นสีย้อมที่มีประจุลบ และสีย้อมเมทิลีนบลูซึ่งเป็นสีย้อมที่มีประจุบวก โดยมีการศึกษาผลของปัจจัยต่าง ๆ ที่มีต่อการดูดซับซึ่งจะรายงานผลในเทอมของร้อยละการกำจัดสีย้อม ลักษณะเฉพาะของตัวดูดซับสังเคราะห์จะวิเคราะห์ด้วยด้วยเทคนิคการเลี้ยวเบนของรังสีเอกซ์ การดูดซับการคายซับด้วยก๊าซไนโตรเจน เทคนิคฟูเรียร์ทรานส์ฟอร์มอินฟราเรดสเปกโตรสโคปี และ ผลรวมของประจุบนพื้นผิวตัวดูดซับเท่ากับศูนย์ จากผลการทดลองพบว่า ตัวดูดซับ 15Zn/MS600nc สามารถกำจัดสีย้อมเอซิดบลูได้ร้อยละ 100 เมื่อใช้ความเข้มข้นเริ่มต้นของสีย้อมเอซิดบลู 300 มิลลิกรัมต่อลิตร ความเป็นกรดด่างเท่ากับ 7 และปริมาณตัวดูดซับ 0.1 กรัม ภายในเวลา 15 นาที ตัวดูดซับ 15Zn/MS600c แสดงร้อยละการกำจัดสีย้อมสีเมทิลีนบลูที่ร้อยละ 94 เมื่อใช้ความเข้มข้นเริ่มต้นของสีย้อมเมทิลีนบลู 100 มิลลิกรัมต่อลิตร ความเป็นกรดด่างเท่ากับ 11 และปริมาณตัวดูดซับ 0.1 กรัม ภายในเวลา 15 นาที จากการศึกษาแบบจำลองจลนพลศาสตร์การดูดซับ พบว่า การดูดซับบนตัวดูดซับ 15Zn/MS600nc มีความสอดคล้องกับแบบจำลองของอาฟ์รามี โดยมีค่าสัมประสิทธิ์สหสัมพัทธ์เท่ากับ 0.9995 ในขณะที่ตัวดูดซับ 15Zn/MS600c เมื่อพิจารณาจากค่าสัมประสิทธิ์สหสัมพัทธ์ซึ่งมีค่าเท่ากับ 0.9695 จะมีความสอดคล้องกับแบบจำลองปฏิกิริยาอันดับสองเทียม

Design And Synthesis Of Quaternized Hyaluronic Acid-Quercetin-Carrageenan Nanocomplexes For Anticancer Drug Delivery, Ifra Aslam

Chulalongkorn University Theses and Dissertations (Chula ETD)

The objective of this research is to synthesize a polyelectrolyte nano-complex for anticancer drug delivery, utilizing natural biopolymers with enhanced therapeutic capabilities, biodegradability, and low toxicity. Traditional anticancer drugs are often hydrophobic and pose significant challenges in delivery, as well as causing toxicity to normal cells. In this study, Plai extract, known for its anticancer properties, was employed into a novel polyelectrolyte complex carrier composed of quaternized hyaluronic acid-quercetin (Quat-HA-QT) with carrageenan. The design involved: (i) utilizing hyaluronic acid (HA) for its CD-44 receptor affinity on tumor cells, (ii) modifying HA with Quat-188 to impart a positive charge and incorporating …

Scaffolds From Natural Polymers And Soy Protein For Cultured Meat Production, Utumporn Butkatanyoo

Chulalongkorn University Theses and Dissertations (Chula ETD)

To overcome the problems of livestock farming, cultured meat technologies have been developed. Cultured meat is an alternative way to produce meat by culturing cells in vitro using tissue engineering technology. The construction of cultured meat requires a scaffold to support cell proliferation and differentiation. Herein this research, polysaccharides namely high acyl gellan gum (HG) and konjac (KJ) together with a plant-based protein, soy protein isolate (SP) were used to develop scaffolds for cultured meat production. The composite scaffolds were prepared by freeze-drying and followed by ionic crosslinking. The composition of HG, KJ, and SP had a strong influence on …

การกำจัดคาร์บอนไดออกไซด์จากสารละลายไตรเอทาโนลามีนโดยใช้คอมพอสิตชีวภาพที่มีชีวิตจุลสาหร่าย-ใยบวบ, ธนกฤต คมขำ

Chulalongkorn University Theses and Dissertations (Chula ETD)

ปัจจุบัน การบรรเทาวิกฤติการเปลี่ยนแปลงสภาพภูมิอากาศเป็นปัญหาเร่งด่วนสำหรับโลกของเรา คาร์บอนไดออกไซด์ (Carbon dioxide: CO2) เป็นหนึ่งในแก๊สเรือนกระจก ซึ่งเป็นสาเหตุหลักของการเกิดภาวะโลกร้อน ความเข้มข้นเฉลี่ย CO2 ทั่วโลกมากกว่า 410 ppm หนึ่งในวิธีการทั่วไปสำหรับดักจับการปลดปล่อย CO2 ใช้ตัวทำละลายเอมีนในหน่วยดูดซึม กระบวนการนี้เป็นที่รู้กันว่ามีประสิทธิภาพและอัตราการดูดซึมสูง อย่างไรก็ตาม ข้อเสียของกระบวนการนี้ส่วนใหญ่เกี่ยวข้องกับการใช้พลังงานสำหรับการคืนสภาพตัวทำละลายจากการให้ความร้อนสูงในหน่วยไล่แก๊ส ดังนั้น จึงจำเป็นต้องหาทางเลือกอื่น เช่น การคืนสภาพเอมีนผ่านกระบวนการเชิงชีวภาพโดยใช้จุลสาหร่าย ซึ่งไม่ต้องใช้ความร้อนและสามารถสร้างผลิตภัณฑ์มูลค่าเพิ่มจากชีวมวลอย่างเชื้อเพลิงชีวภาพได้ อย่างไรก็ตาม จุลสาหร่ายมีข้อเสียในแง่ของอัตราการดูดซึม CO2 ต่ำ ดังนั้น การบูรณาการกระบวนการทั้งสองอาจเป็นกุญแจสำคัญเพื่อยกระดับความสามารถการดักจับ CO2 เมื่อไม่นานมานี้ คอมพอสิตชีวภาพที่มีชีวิต (Living biocomposites) ที่ยกระดับการเพาะเลี้ยงแขวนลอยแบบดั้งเดิมได้ถูกพัฒนาขึ้น ด้วยเทคโนโลยีนี้ การตรึงจุลสาหร่ายบนวัสดุรองรับที่เข้ากันได้ทางชีวภาพโดยใช้สารยึดเกาะเหนือกว่าระบบแขวนลอยในแง่ของอัตราการดักจับ CO2 ในงานวิจัยนี้ คอมพอสิตชีวภาพที่มีชีวิตจุลสาหร่าย-ใยบวบด้วยการตรึง Scenedesmus acuminatus TISTR 8457 โดยใช้สารยึดเกาะอะคริลิกถูกสร้างขึ้นเพื่อกำจัด CO2 จากสารละลายไตรเอทาโนลามีน (Triethanolamine: TEA) ที่เต็มไปด้วย CO2 การทดสอบการกำจัด CO2 โดยใช้ TEA 1 M ที่อัตราส่วนการโหลด CO2 แตกต่างกัน (0.2 0.4 0.6 และ 0.8 โมล CO2 ต่อโมล TEA) แสดงให้เห็นว่าคอมพอสิตชีวภาพมีอัตราการกำจัด CO2 มากกว่าระบบแขวนลอย 3 ถึง 4 เท่าในช่วงระยะเวลา 28 วันทุกอัตราส่วนการโหลด CO2 ที่ทดสอบ

Characterization Of Volatile Organic Compounds In Black Goji Berry Lycium Ruthenicum Juice Fermented With Lactobacillus Spp. Using Gas Chromatography-Mass Spectrometry, Sehrish Javed

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this work, volatile organic compounds (VOCs) in fermented black goji berry juice with Lactobacillus spp. (L.rhamnosus and L.paracasei) were characterized by gas chromatography-mass spectrometry combined with headspace-solid phase microextraction (HS-SPME-GC-MS). The fermented black goji berry juice samples were found to contain at least 60 VOCs, including alcohols, aldehydes, esters, ketones, phenols and organic acids, with five major VOCs such as 3,7-dimethylocta-1,6-dien-3-ol, 2-ethylidene-6-methylhepta-3,5-dienal, (E)-1-(2,6,6-trimethyl-1,3-cyclohexadien-1-yl)-2-buten-1-one, 2,5-ditert-butylcyclohexa-2,5-diene-1,4-dione, 2-ethyl-3-hydroxyhexyl-2-methylpropanoate. In overall comparison, fermented black goji berry (GB) samples promoted VOCs in order (i) 24HF > 0HF, and (ii) 10% GB slightly > 5% GB > 2.5% GB. In addition, L. rhamnosus predominantly promoted particular VOCs in …

Carbon-Based Polymer Composite For Electrochemical Sensing Of Creatinine Sodium Potassium And Calcium Ions, Kanyapat Teekayupak

Chulalongkorn University Theses and Dissertations (Chula ETD)

Electrochemical sensors have emerged as indispensable tools for various applications including environmental monitoring, food safety, and biomedical diagnostics owing to their simplicity, sensitivity, and fast response. However, traditional methods for electrode fabrication are often associated with drawbacks such as cleanroom requirements, multi-step processes involving toxic materials, high waste consumption, and high costs. To address the limitations, this dissertation evaluates the utilization of 3D printing, laser engraving, and inkjet printing technologies for the fabrication of electrochemical sensors based on carbon-based polymer composites. In the first part, a 3D-printed electrochemical sensor based on a copper oxide nanoparticle-ionic liquid/reduced graphene oxide (CuO-IL/rGO) modified …

Cascade Synthesis Of 4h-Chromenes By Dialkyldithiocarbamate Organocatalyst, Ayodele Joshua Atibioke

Chulalongkorn University Theses and Dissertations (Chula ETD)

Environmentally benign N,N-didodecylammonium N,N-didodecyldithiocarbamate (AmDTC-C12C12) is used as an organocatalyst in water. AmDTC-C12C12 self-assembles into a CatAnionic vesicular nanoreactor in water and is synthesized with a high yield (98%) from N,N-didodecylamine and carbon disulfide. The catalytic activity of AmDTC-C12C12 (10 mol%) was investigated in the cascade synthesis of 4H-chromene via double cascade Michael addition/hemiketalization between 2-hydroxy-trans-β-nitrostyrene and acetylacetone in water at room temperature, yielding 2-chromanols. Dehydration of 2-chromanols with catalytic p-toluene sulfonic acid produced 4H-chromenes in moderate yields (34–60%) and -nitro ketones as co-products (13–27%). Using Michael donors with aromatic moieties led to a spontaneous triple cascade (Michael addition/hemiketalization/retro-Claisen fragmentation) …

First Review Of Equilibrium Landscape Of Ingress/Egress Channels And Gating Residues Of The Cytochrome P450 3a4, Edward Ackad Ph.D, Maria Kontoyianni

SIUE Faculty Research, Scholarship, and Creative Activity

The review document and changes made to "Equilibrium Landscape of Ingress/Egress Channels and Gating Residues of the Cytochrome P450 3A4".

Sound The (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide Pgpp, Areej Malik, Megan A. Hept, Erin B. Purcell

Chemistry & Biochemistry Faculty Publications

It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been …

Thermotrophy Exploratory Study, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The question of whether environmental heat energy could be utilized as a source of energy for biological metabolism is the center of this exploratory research. In 1979, this author postulated a hypothesis for the existence of thermotrophs that could isothermally utilize environmental heat energy as a source of their energy on Earth. According to this hypothesis, the thermotrophs could be the first primitive forms of life in the early Earth environment. The chemotrophs and phototrophs that we currently are all well familiar with might have been evolved somehow from the primitive thermotrophs. Furthermore, all the organisms currently regarded as the …

Telp Theory: Elucidating The Major Observations Of Rieger Et Al. 2021 In Mitochondria, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

The transmembrane-electrostatically localized protons (TELP) theory may represent a complementary development to Mitchell's chemiosmotic theory. The combination of the two together can now excellently explain the energetics in mitochondria. Our calculated transmembrane-attractive force between an excess proton and an excess hydroxide explains how TELP may stay within a 1-nm thin layer at the liquid-membrane interface. Consequently, any pH sensor (sEcGFP) located at least 2–3 nm away from the membrane surface will not be able to see TELP. This feature as predicted from the TELP model was observed exactly in the experiment of Rieger et al., 2021. In contrast to their …

Detection And Quantification Of Antiviral Drug Tenofovir Using Silver Nanoparticles And Surface Enhanced Raman Spectroscopy (Sers) With Spatially Resolved Hotspot Selection, Marguerite R. Butler, Jana Hrncirova, Terry A. Jacot, Sucharita Dutta, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper

Chemistry & Biochemistry Faculty Publications

This study introduces a convenient and ultra-sensitive method of detection and quantification of the antiviral drug, tenofovir (TFV), by surface-enhanced Raman spectroscopy (SERS). Novel spatially resolved instrumentation for spectral acquisition and subsequent statistical analysis for hot spot selection was developed for convenient quantification of TFV in an aqueous matrix. Methods of statistical analysis include the use of partial least squares (PLS) regression vector analysis and spectral ranking by quality indices computed using CHAOS theory. Hydroxylamine-reduced Ag colloidal nanoparticles evaporated to dryness on an aluminum well-plate were used as the SERS substrate. To our knowledge, quantification of TFV down to 25 …

Enhancing The Conformational Stability Of The Cl-Par-4 Tumor Suppressor Via Site-Directed Mutagenesis, Samjhana Pandey, Krishna K. Raut, Antoine Baudin, Lamya Djemri, David S. Libich, Komala Ponniah, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Intrinsically disordered proteins play important roles in cell signaling, and dysregulation of these proteins is associated with several diseases. Prostate apoptosis response-4 (Par-4), an approximately 40 kilodalton proapoptotic tumor suppressor, is a predominantly intrinsically disordered protein whose downregulation has been observed in various cancers. The caspase-cleaved fragment of Par-4 (cl-Par-4) is active and plays a role in tumor suppression by inhibiting cell survival pathways. Here, we employed site-directed mutagenesis to create a cl-Par-4 point mutant (D313K). The expressed and purified D313K protein was characterized using biophysical techniques, and the results were compared to that of the wild-type (WT). We have …

Developing Mesoporous Silica Nanoparticle-Based Stimuli-Responsive Nanocarriers For Delivery Of Small Molecule Therapeutics Against Colon Cancer Cells, Nisitha Lakmal Wellala Wijewantha

Dissertations and Theses

This dissertation delves into the innovative application of mesoporous silica nanoparticles (MSNs) for targeted drug delivery in colorectal cancer (CRC), one of the most prevalent and deadly forms of cancer worldwide. The initial focus of the research is on developing enzyme-responsive MSNs loaded with veratridine (VTD), an alkaloid derived from natural sources that demonstrates potent anticancer activity. The nanoparticles have been engineered to deliver VTD selectively to CRC cells, releasing the payload upon being exposed to specific enzymes primarily secreted by these cells. This strategy has dual advantages of amplifying the anticancer effects while minimizing potential side effects on healthy …

Designing Metal-Organic Supercontainers For Functional Applications: From Selective Anion Binding To Surface Enhanced Raman Scattering, Kriti Chitrakar

Dissertations and Theses

Synthetic container molecules that emulate biological structures and feature well-defined nanocavities have attracted tremendous interest among supramolecular chemists due to their promising potentials in ion recognition, catalysis, and chemical sensing. Our laboratory has developed a new class of container molecules, namely, metal-organic supercontainers (MOSCs), which feature both endo and exo cavities suitable for binding guest molecules. The overarching theme of this thesis was to use synthetic manipulations to modify the chemical structure and enhance the functional application of MOSCs in two specific areas, anion binding and chemical sensing. For the application of anion binding, we have designed and synthesized a …

Silica Particles Convert Thiol-Containing Molecules To Disulfides, Yangjie Li, Kurt W. Kolasinski, Richard N. Zare

Chemistry Faculty Publications

Synthetic amorphous silica is a common food additive and a popular cosmetic ingredient. Mesoporous silica particles are also widely studied for their potential use in drug delivery and imaging applications because of their unique properties, such as tunable pore sizes, large surfaces areas, and assumed biocompatibility. Such a nanomaterial, when consisting of pure silicon dioxide, is generally considered to be chemically inert, but in this study, we showed that oxidation yields for different compounds were facilitated by simply incubating aqueous solutions with pure silica particles. Three thiol-containing molecules, L-cysteine, glutathione, and D-penicillamine, were studied separately, and it was found that …

Using Wastewater-Based Epidemiology To Study Chlamydia Occurrence On A College Campus, Jessie E. Chin Quee

Honors Undergraduate Theses

Chlamydia is a sexually transmitted disease caused by Chlamydia trachomatis, commonly affecting sexually active college-aged adults. Presently, opportunistic testing, self-testing, and information campaigns are methods to screen vulnerable populations and raise awareness about chlamydia. Chlamydia remains underdiagnosed and undertested due to a lack of participation by individuals who may have been exposed to it. Wastewater-based epidemiology is a rising biomonitoring tool that detects the presence of disease- and drug-specific biomarkers in a community's wastewater. In this study, wastewater-based epidemiology was used to detect the presence of C. trachomatis on the University of Central Florida campus. Wastewater samples were collected …

Structural Engineering Of Thermostable Fluorescent Proteins Tgp-E And Ytp-E And Crystal Structure Of Tgp-E, Matthew Ryan Anderson

Graduate Theses/Dissertations

Thermostable fluorescent proteins, such as thermal green protein (TGP) and yellow thermal protein (YTP), could be used as biosensors to monitor cellular activity and as a fusion tag to monitor a protein of interest. The use of fluorescent proteins can sometimes be limited in certain organelles with low pH and in thermophilic organisms. This research aims to improve the thermal stability of TGP and YTP. TGP was created from a synthetically derived eCGP123 protein to improve solubility by substituting residues on the positively charged b- barrel surface with negatively charged glutamate (E) at Los Alamos National Lab. YTP was developed …

Impact Of Sample Conditions On Dna Phosphodiester Backbone Bi/Bii Conformational Equilibrium Dynamics, Autumn C. Pilarski

Graduate Theses/Dissertations

DNA damage, such as single base lesions and mismatches, is highly prevalent within cells. If these DNA damage events are not repaired, they could lead to mutations and thus disease and cancer. Intricate repair mechanisms are in place to fix these damage events, one such being Base Excision Repair (BER) and associated enzyme: Thymine DNA Glycosylase (TDG). The first step of this repair process, recognition of the lesion by TDG, is not well understood. The following thesis presents results to better understand the fundamental biophysical question of how a DNA lesion within a mismatch context is recognized in a million …

Renewable Fuels: Molecular Dynamics Investigations Into Pyrolysis Of Methyl Linoleate, Elson Osakpolor Eguaosa

Graduate Theses/Dissertations

With the rapid depletion of the world’s supply of fossil fuels, especially petroleum products, petroleum prices have risen by approximately 800% between the 1970s and now and are projected to continue rising. It is also expected that the world’s consumption of energy will increase commensurate with its growing population. Although biodiesel is a good renewable alternative, it has its limitations including high production costs and poor low-temperature performance. We seek to improve conventional biodiesel with pyrolysis to produce low molecular-weight compounds with high energy densities. Understanding the pyrolysis path on the atomic scale is key as it will allow us …

Effect Of Okra Bast Fillers On Biodegradation Properties Of Poly(Vinyl Alcohol) Composites, Gazi Md Arifuzzaman Khan, Nazi̇re Deni̇z Yilmaz

Turkish Journal of Chemistry

This paper focuses on the effect of okra bast fillers on biodegradation of poly(vinyl alcohol) composites. Fibers were obtained from okra plant stems via biological degumming and subjected to different chemical treatments such as scouring, alkalizing, maleic anhydride treatment, and vinyl acetate grafting. The fibers were ground and PVA-okra bast filler composites were produced at 20 wt% fiber load via the solution casting method. The obtained composites were tested in terms of mechanical properties and exposed to biodegradation in soil. Effects of okra bast filler addition and chemical treatments on changes in mass, breaking strength, elasticity modulus, and breaking elongation …

Evaluation Of Photochemically Cross-Linked Collagen/Gold Nanoparticle Composites As Potential Skin Tissue Scaffolds, Evri̇m Meri̇ç Yelkuvan, Özge Erdemli̇, Bengi̇ Yilmaz, Ömer Aktürk

Turkish Journal of Chemistry

Collagen type I is the main structural unit in skin tissue and is therefore used preferentially in skin tissue scaffolds. However, collagen-based 3D scaffolds have weak aqueous stability and degradation profiles in their uncross-linked states and chemical cross-linking reagents arise toxicity concerns, which generally restrict the spectrum of their biomedical applicability. Here, the research goal is to photochemically cross-link collagen type I with rose bengal (RB) when subjected to green laser light and to investigate the effect of silk sericin-capped gold nanoparticles (S-AuNP) when incorporated into scaffolds on the cross-linking process and thus on the scaffold properties. All the collagen …

Structure-Emission Relationship Of Some Coumarin Laser Dyes And Related Molecules: Prediction Of Radiative Energy Dissipation And The Intersystem Crossing Rate Constants, Msa Abdelmottaleb

Turkish Journal of Chemistry

Dye lasers are commonly used in optical investigation because their solutions in organic solvents deliver tunable, coherent emissions. They exhibit intense fluorescence owing to some specific spectroscopic characteristics. One drawback of the laser dyes is that it shows excessive triplet-state losses (TSLs.) The lack of theoretical predictions of fluorescence rates, intersystem crossing (ISC), and phosphorescence in laser dyes prompted us to report on the predicted rates of radiative and nonradiative transitions of some laser dyes. Structural engineering by some substituents influencing the simulated rates of coumarin laser dye derivatives for an efficient operation was investigated. The NH$_{2}$ functional group renders …

Enhanced Ionic Conductivity And Mechanical Strength In Nanocomposite Electrolytes With Nonlinear Polymer Architectures, Recep Bakar, Saeid Darvishi, Erkan Şenses

Turkish Journal of Chemistry

Solvent-free polymer-based electrolytes (SPEs) have gained significant attention to realize safer and flexible lithium-ion batteries. Among all polymers used for preparing SPEs electrolytes, poly(ethylene oxide), a biocompatible and biodegradable polymer, has been the most prevalent one mainly because of its high ionic conductivity in the molten state, the capability for the dissolution of a wide range of different lithium salts as well as its potential for the environmental health and safety. However, linear PEO is highly semicrystalline at room temperature and thus exhibits weak mechanical performance. Addition of nanoparticles enhances the mechanical strength and effectively decreases the crystallization of linear …