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Optical Characterization Of Salt-Induced Swelling Behavior Of Poly($N$-Isopropylacrylamide) Terpolymer Hydrogel Layers, İlke Anaç, Anil Bozdoğan Jan 2019

Optical Characterization Of Salt-Induced Swelling Behavior Of Poly($N$-Isopropylacrylamide) Terpolymer Hydrogel Layers, İlke Anaç, Anil Bozdoğan

Turkish Journal of Chemistry

This study reports for the first time the effect of different sodium halide salts (NaClO$_{4}$, NaI, and Na$_{2}$CO$_{3})$ in the low concentration range (in the range of 10$^{-7}$-1 M) on the swelling behavior of photo-crosslinked, surface-immobilized poly($N$-isopropyl acrylamide) (PNIPAAm) terpolymer layers. PNIPAAm terpolymer (consisting of $N$-isopropylacrylamide, methacrylic acid, and 4-methacryloxybenzophenone) was synthesized via free radical polymerization. The PNIPAAm terpolymer layers were prepared on gold substrates via spin coating and crosslinked and surface attached via UV radiation. The swelling behavior of the layers in monovalent (NaClO$_{4}$ and NaI) and divalent (Na$_{2}$CO$_{3})$ solutions was monitored by surface plasmon/optical waveguide spectroscopy. The terpolymer …


Molecular Dynamics Simulations Of Adsorption Of Long Pyrene-Peg Chains On A Thin Carbon Nanotube, Peli̇n Deni̇z Akkuş, Ayşe Özge Kürkçüoğlu Levi̇tas Jan 2019

Molecular Dynamics Simulations Of Adsorption Of Long Pyrene-Peg Chains On A Thin Carbon Nanotube, Peli̇n Deni̇z Akkuş, Ayşe Özge Kürkçüoğlu Levi̇tas

Turkish Journal of Chemistry

Carbon nanotubes have emerged as highly promising theranostic agents due to their unique structural/physical features, high surface area, and high drug-loading capacity. The high cytotoxicity of carbon nanotubes can be eliminated by noncovalent coating using hydrophilic polymers. We investigated the adsorption of long pyrene functionalized polyethylene glycol (PEG) chains, PEG$_{2000}$ and PEG$_{5000}$, on a single-walled carbon nanotube (SWNT) from a crowded solution. Full-atom molecular dynamics simulations in explicit water were used to mimic the experimental conditions of noncovalent PEGylation with a stoichiometry of one SWNT to ten pyrene-PEG. Although the diffusional behavior of the pyrene molecules still attached to the …


Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul Jan 2019

Acetyl- And Butyrylcholinesterase Inhibitory Activity Of Selected Photochemically Synthesized Polycycles, Ivana Sagud, Irena Skoric, Dragana Vuk, Ana Ratkovic, Franko Burcul

Turkish Journal of Chemistry

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the main cause of dementia in the elderly population. Since the treatment of AD has been associated with the activity of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), their inhibitors remain the main focus of AD investigations. In this study we evaluated cholinesterase inhibitory activity of 14 bicyclo[3.2.1]octene/octadiene derivatives and naturally occurring sesquiterpene alcohol cedrol. These 14 compounds have been efficiently and ecologically prepared by a photochemical approach in batch photochemical reactors. Various compounds with the bicyclo[3.2.1]octene skeleton have already been successfully evaluated for treatment of central nervous system disorders and AD. Among …


Anticancer And Antiangiogenesis Activities Of Novel Synthesized 2-Substituted Benzimidazoles Molecules, Adem Güner, Eli̇fsu Polatli, Tamer Akkan, Hakan Bektaş, Canan Albay Jan 2019

Anticancer And Antiangiogenesis Activities Of Novel Synthesized 2-Substituted Benzimidazoles Molecules, Adem Güner, Eli̇fsu Polatli, Tamer Akkan, Hakan Bektaş, Canan Albay

Turkish Journal of Chemistry

In this study, novel 2-substituted benzimidazoles molecules having triazole, thiadiazole, and oxadiazole rings were synthesized and were evaluated by anticancer, antioxidant/oxidant status, genotoxicity, and antiangiogenesis assays. Anticancer activity of the compounds was determined by MTT (0.5, 5, and 50 $\mu $g/mL) and lactate dehydrogenase (LDH) release assays against human prostate and breast cancer cells. Oxidative status of cells was elicited by total oxidative stress and total antioxidant capacity methods. Chick chorioallantoic membrane assay was used to evaluate the antiangiogenic activity. Genotoxicity was evaluated by the sister chromatid exchange (SCE) and micronucleus (MN) tests in lymphocyte cultured human blood. Our results …


Glucose Oxidase Immobilized Biofuel Cell Flow Channel Geometry Analysis By Cfd Simulations, Sali̇h Obut, Tahsi̇n Bahar Jan 2019

Glucose Oxidase Immobilized Biofuel Cell Flow Channel Geometry Analysis By Cfd Simulations, Sali̇h Obut, Tahsi̇n Bahar

Turkish Journal of Chemistry

Glucose oxidase was covalently immobilized to a porous electrode, which was developed by using ferrocene functionalized polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications in our recent studies. The kinetics parameters (i.e. k$_{M}$, V$_{max})$ and other parameters required for the modeling study were determined experimentally. Fuel cell flow channel geometry was analyzed by a computational fluid dynamics modeling approach. Substrate flow rate and mass transfer for each proposed channel type were considered in the simulations. The results showed that serpentine type flow channels are advantageous over pin type or parallel flow channels to acquire sufficient performance from …


Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar Jan 2019

Stability Improvement By Crosslinking Of Previously Immobilized Glucose Oxidase On Carbon Nanotube-Based Bioanode, Tahsi̇n Bahar

Turkish Journal of Chemistry

Bioanode stability with glucose oxidase was enhanced significantly by covalent crosslinking without substantial enzymatic activity and affinity loss. Initially, glucose oxidase was immobilized by aldehyde groups on the electrode that was developed using ferrocenecarboxaldehyde, polyethyleneimine, multiwall carbon nanotubes, and carbon cloth for biofuel cell applications. The glucose oxidase half-life was extended by more than 4 times, from 27.2 to 124.7 h, after the electrode was crosslinked. Enzymatic kinetic parameters were determined for the crosslinked enzyme and they were compared to the noncrosslinked immobilized enzyme parameters on the electrode. The apparent substrate affinity of the crosslinked enzyme electrode was decreased (i.e. …


Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors, Aikohi M. Ugboya Jan 2019

Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors, Aikohi M. Ugboya

College of Graduate Studies: Theses & Dissertations

Critical to biological and environmental processes are anions because often times their relative concentration in our body can be an indicator of one’s well-being. Therefore, highly sensitive and cost-efficient methods for ions recognition is necessary for human health. In recent times, polymeric chemosensors have become a vital tool for sensing ions because of its higher sensitivity and good mechanical properties compared to their monomeric counterparts. These sensors are designed to produce a measurable response in the presence of a targeted ion such as an electrochemical or optical signal. The unique structure and the photophysical properties of the 1,2,3-triazole core coupled …


Exploring Transition Metal Chalcogenides For Bio Sensing And Environmental Remediation, Bahareh Golrokh Amin Jan 2019

Exploring Transition Metal Chalcogenides For Bio Sensing And Environmental Remediation, Bahareh Golrokh Amin

Doctoral Dissertations

“Electrocatalysts play an inevitable role in many applications including energy storage, energy conversion, and biosensing. The state-of-the-art noble metal-based electrocatalysts have long been used in full water splitting, non-enzymatic glucose sensing, and supercapacitors. However, scarcity and high cost of noble metals restrict utilization of such electrocatalysts in large-scale implementations. Transition metal-based electrodes have been considered as a potential solution to address these drawbacks as well as to enhance the electrocatalytic performance. In this work, applicability of non-oxidic transition metal based electrocatalysts is evaluated. Transition metal chalcogenides are expected to have high catalytic performance owing to their facilitated electron cloud delocalization …


Antioxidant Properties Of Water-Soluble Phthalocyanines Containing Quinoline 5-Sulfonic Acid Groups, Armağan Günsel, Esma Hande Alici, Ahmet Turgut Bi̇lgi̇çli̇, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir Jan 2019

Antioxidant Properties Of Water-Soluble Phthalocyanines Containing Quinoline 5-Sulfonic Acid Groups, Armağan Günsel, Esma Hande Alici, Ahmet Turgut Bi̇lgi̇çli̇, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir

Turkish Journal of Chemistry

In the present study, the antioxidant properties of peripherally and nonperipherally water-soluble tetra (quinoline 5-sulfonic acid) substituted metal-free (1,2), Zn(II) (3, 4), Co(II) (5, 6), and Mn(III)Cl (7, 8) phthalocyanine (Pc) derivatives were reported. In order to determine the antioxidant properties of the Pc compounds, three different commonly known antioxidant methods were used: DPPH ($\alpha $,$\alpha $-diphenyl-$\beta $-picrylhydrazyl) radical scavenging, ferrous ion chelating, and reducing power assays. Compound \textbf{6} showed the best DPPH activity among the other tested compounds except for the standards. The ferrous ion chelating IC$_{50\, }$value of compound 7 was nearly as good as that of the …


Detection Of Lard Contamination In Five Different Edible Oils By Ft-Ir Spectroscopy Using A Partial Least Squares Calibration Model, Fazeelah Munir, Syed Ghulam Musharraf, Syed Tufail Hussain Sherazi, Muhammad Imran Malik, Muhmmad Iqbal Bhanger Jan 2019

Detection Of Lard Contamination In Five Different Edible Oils By Ft-Ir Spectroscopy Using A Partial Least Squares Calibration Model, Fazeelah Munir, Syed Ghulam Musharraf, Syed Tufail Hussain Sherazi, Muhammad Imran Malik, Muhmmad Iqbal Bhanger

Turkish Journal of Chemistry

Lard is defined as animal fat acquired from the adipose tissue of pigs and is not permitted for human consumption or external use by certain religions such as Islam and Judaism. Due to its low-cost availability for commercial use, it is often mixed with other vegetable oils mistakenly or deliberately and causes loss of consumer trust; hence, its detection in food products is essential. Consumers tend to know the authenticity of commercially available edible oils. However, edible oils are subjected to adulteration risks with lard, which breaches consumer rights. In the present study, we designed a transmission Fourier transform infrared …


Synthesis Of Smz Derivatives And Investigation Of Effects On Germination, Root, And Plant Growth Of \Textit{Arabidopsis Thaliana} L., Tuğba Güngör, Ferah Cömert Önder, Fati̇h Sezer, Aslihan Özbi̇len, Kemal Meli̇h Taşkin, Mehmet Ay Jan 2019

Synthesis Of Smz Derivatives And Investigation Of Effects On Germination, Root, And Plant Growth Of \Textit{Arabidopsis Thaliana} L., Tuğba Güngör, Ferah Cömert Önder, Fati̇h Sezer, Aslihan Özbi̇len, Kemal Meli̇h Taşkin, Mehmet Ay

Turkish Journal of Chemistry

A series of sulfonamide derivatives were synthesized by reactions with various functional groups containing benzenesulfonyl chlorides and aniline derivatives under different substitution reaction conditions. The structures of SMZ derivatives were confirmed with melting point, FT-IR, $^{1}$H NMR, $^{13}$C NMR, and LC-MS/MS techniques. In order to investigate the cytotoxic effects of these derivatives, we used a model plant species. The synthesized compounds (S1-S5) and sulfamethazine (SMZ) as a positive control were applied to Arabidopsis thaliana seeds. Our results indicated that S3 and S4 induced shorter roots and lower wet weight in plants. Plants treated with S2 and S5 showed no growth …


Novel Voltammetric Investigation Of Dipyridamole At A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Lorelei Iordache, Dana Elena Popa, Mihaela Buleandra, Victor David, Emilia-Elena Iorgulescu Jan 2019

Novel Voltammetric Investigation Of Dipyridamole At A Disposable Pencil Graphite Electrode, Iulia Gabriela David, Lorelei Iordache, Dana Elena Popa, Mihaela Buleandra, Victor David, Emilia-Elena Iorgulescu

Turkish Journal of Chemistry

The present paper describes the voltammetric analysis of dipyridamole (DIP) at a cheap, disposable pencil graphite electrode (PGE). The working conditions were optimized with regard to the electrode material and the supporting electrolyte. Cyclic voltammetric investigations emphasized that DIP is irreversibly oxidized at the PGE. The electrode process is pH-dependent and controlled by both diffusion and adsorption. For DIP quantitative determination a differential pulse voltammetric (DPV) method in phosphate buffer solution pH 7.00 was developed. DIP's oxidation peak current varied linearly with the analyte concentration, presenting two linear ranges, namely 5.00 $\times $ 10$^{-7}$-2.50 $\times $ 10$^{-5}$ M and 2.50 …


$N$-Acylazole Mediated Stereoselective And Regioselective Synthesis Of $N$-Substituted Azole Acrylonitriles, Osman Aydin, Şule Kökten, Hakan Ünver, İlhami̇ Çeli̇k Jan 2019

$N$-Acylazole Mediated Stereoselective And Regioselective Synthesis Of $N$-Substituted Azole Acrylonitriles, Osman Aydin, Şule Kökten, Hakan Ünver, İlhami̇ Çeli̇k

Turkish Journal of Chemistry

Regio- and stereoselective synthesis of $N$-substituted azole acrylonitriles has been achieved smoothly in $N,N$-dimethylformamide (DMF) in the presence of potassium carbonate (K$_{2}$CO$_{3})$ as a base catalyst. $N$-Substituted azole acrylonitriles were obtained in moderate to good yields (39%-87%) with a one-pot reaction between readily available $N$-acetylazoles and Baylis-Hillman nitriles. The structural determinations were accomplished by NOESY $^{1}$H NMR and X-ray crystallography.


On The Azo Dyes Derived From Benzoic And Cinnamic Acids Used As Photosensitizers In Dye-Sensitized Solar Cells, Luka Matovic, Nikola Tasic, Nemanja Trisovic, Jelena Ladarevic, Vesna Vitnik, Zeljko Vitnik, Branimir Grgur, Dusan Mijin Jan 2019

On The Azo Dyes Derived From Benzoic And Cinnamic Acids Used As Photosensitizers In Dye-Sensitized Solar Cells, Luka Matovic, Nikola Tasic, Nemanja Trisovic, Jelena Ladarevic, Vesna Vitnik, Zeljko Vitnik, Branimir Grgur, Dusan Mijin

Turkish Journal of Chemistry

In order to get a better insight into the relationship between molecular structure and photovoltaic performance, six monoazo dye molecules containing benzoic and cinnamic acid moieties were synthesized and their photovoltaic properties were studied. Three of them have not been previously used in solar cells. Spectroscopic measurements of the investigated compounds coupled with theoretical calculations were performed. Short-circuit current density, open-circuit voltage, and fill-factor were determined. It was found that a larger amount of short-circuit current density will be generated if the HOMO--LUMO energy gap is lower, determined by the stability of the molecule and the electronic effect of the …


Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner Jan 2019

Determination Of N-Acetylcysteine In The Presence Of Ciprofloxacin Or Levofloxacin In Microparticulate Dry Powder Inhalers, Yağmur Akdağ Çayli, Selma Şahi̇n, Emi̇rhan Nemutlu, Levent Öner

Turkish Journal of Chemistry

A fast and easy method was validated for simultaneous determination of ciprofloxacin hydrochloride monohydrate (CP), levofloxacin hemihydrate (LV), and N-acetylcysteine (NAC) in samples. The analysis was performed on a C$_{18}$ column (250 x 4.6 mm, 5 μm) (Inertsil ODS-3V) using an isocratic elution method with a mobile phase composed of 25 mM KH$_{2}$PO$_{4}$ (pH 3.0) and methanol (72:28, v/v) at a flow rate of 1 mL/min. UV detection was performed at 214 nm for NAC and 293 nm for CP and LV. The method was validated for linearity, accuracy, precision (repeatability and reproducibility), specificity, sensitivity, and stability. The calibration study …


Synthesis, Characterization, And Nonlinear Optical Properties Of Some New Series Of S-(5-Aryl-1,3,4-Oxadiazol-2-Yl) 2-Chloroethanethioate Derivatives, Zahra Dono Ghezelbash, Hamideh Motiei, Miri Mahmoody, Karim Akbari Delmaghani Jan 2019

Synthesis, Characterization, And Nonlinear Optical Properties Of Some New Series Of S-(5-Aryl-1,3,4-Oxadiazol-2-Yl) 2-Chloroethanethioate Derivatives, Zahra Dono Ghezelbash, Hamideh Motiei, Miri Mahmoody, Karim Akbari Delmaghani

Turkish Journal of Chemistry

In the present investigation, some novel S-(5-aryl-1,3,4-oxadiazol-2-yl)2-chloroethanethioate (3a-3e) derivatives were synthesized and their impact on optical properties was studied. They have also been characterized by elemental analysis and various spectroscopic methods including FTIR, $^{1}$H NMR, $^{13}$C NMR, and UV-Vis techniques. The nonlinear refractive indexes of 3a-3e were also measured in dichloromethane via Z-scan method using a continuous wave diode-pumped laser at 532 nm wavelength. The nonlinear refractive coefficient of compounds was obtained from ${10}^{11}\, \, {m}^{{2}}{/W}$ order. Regarding the appropriate nonlinearity of these compounds, they could be considered good candidates for biooptical and photonic applications. All the synthesized compounds (3a-3e) …


Bisbenzoxazole Derivatives Had An Antiinflammatory Effect On In Vitro Stimulated Macrophages, Furkan Ayaz, Rusmeenee Kheeree, Qadar Ahmed Isse, Ronak Haj Ersan, Özteki̇n Algül Jan 2019

Bisbenzoxazole Derivatives Had An Antiinflammatory Effect On In Vitro Stimulated Macrophages, Furkan Ayaz, Rusmeenee Kheeree, Qadar Ahmed Isse, Ronak Haj Ersan, Özteki̇n Algül

Turkish Journal of Chemistry

Benzoxazoles are DNA base bioisosteres and studies suggest that their derivatives have antiproliferative activities. Based on their antiproliferative activities they have been mostly studied as new generation anticancer drugs. In our study we exploited their antiproliferative effect, aiming to delineate bisbenzoxazole derivatives' (RHE 231 and RHE 238) potential antiinflammatory effect on mouse macrophages that are activated in vitro through danger signal LPS stimulation. RAW 267.4 mammalian macrophages were activated in the presence of our derivatives with or without danger mimic E. coli derived LPS. We present data that support the strong antiinflammatory activity of the bisbenzoxazole derivatives RHE 231 and …


Synthesis, Characterization And Antibacterial Properties Of Silver(I) N-(4-Pyridyl) Benzamide Complexes With Varying Conterions, Mauro J. Ruiz Jan 2019

Synthesis, Characterization And Antibacterial Properties Of Silver(I) N-(4-Pyridyl) Benzamide Complexes With Varying Conterions, Mauro J. Ruiz

Open Access Theses & Dissertations

Organic semiconductor materials composed of - stacking aromatic compounds have been under intense investigation for their potential uses in flexible electronics and other advanced technologies. Herein we report a new family of seven - stacking compounds of Silver(I) N-(4-pyridyl) Benzamide with varying counterions, namely [Ag(NPBA)2]X, where NPBA is N-(4-pyridyl) Benzamine, X = NO3- (1), ClO4- (2), CF3SO3- (3), PF6- (4), BF4- (5), CH3PhSO3- (6), and PhSO3- (7), which form extended - stacking networks in one-dimensional (1D), 2D and 3D directions in the crystalline solid-state via the phenyl moiety, with average inter-ring distances of 3.823 Å. Interestingly, the counterions that contain …


Minimalistic Supramolecular Proteoglycan Mimics By Co-Assembly Of Aromatic Peptide And Carbohydrate Amphiphiles, Alexandra Brito, Yousef M. Abul-Haija, Diana Soares De Costa, Ramon Novoa-Carballal, Rui L. Reis, Rein V. Ulijn, Ricardo A. Pires, Iva Pashkuleva Jan 2019

Minimalistic Supramolecular Proteoglycan Mimics By Co-Assembly Of Aromatic Peptide And Carbohydrate Amphiphiles, Alexandra Brito, Yousef M. Abul-Haija, Diana Soares De Costa, Ramon Novoa-Carballal, Rui L. Reis, Rein V. Ulijn, Ricardo A. Pires, Iva Pashkuleva

Advanced Science Research Center

We report the co-assembly of aromatic carbohydrate and dipeptide amphiphiles under physiological conditions as a strategy to generate minimalistic proteoglycan mimics. The resulting nanofibers present a structural, fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) core and a functional carbohydrate (Fmoc-glucosamine-6-sulfate or -phosphate) shell. The size, degree of bundling and mechanical properties of the assembled structures depend on the chemical nature of the carbohydrate amphiphile used. In cell culture medium, these nanofibers can further organize into supramolecular hydrogels. We demonstrate that, similar to proteoglycans, the assembled gels prolong the stability of growth factors and preserve the viability of cultured cells. Our results demonstrate that this approach …


Ibuprofen As A Probe Of Lipid Metabolism, Jose Antonio Rosales Jan 2019

Ibuprofen As A Probe Of Lipid Metabolism, Jose Antonio Rosales

Open Access Theses & Dissertations

The hypothesis that deracemization of racemic ibuprofen (IBU) occurs via the enolization of a Candida rugosa lipase (CRL)-ibuprofen ester (Scheme 1.6.2) was disproven by reacting racemic IBU under the conditions that were used to deracemize ibuprofen methyl ester (IME), namely pH 7.6. At pH 7.6, IME through IBU butyl esters were not formed in-situ and racemic IBU was not deracemized by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL.

At pH 7.6, hexyl through dodecyl IBU esters were formed in-situ by reacting the corresponding primary alcohol with racemic IBU in the presence of CRL. The …


Application Of Urinary Metabolites For Cancer Detection, Qin Gao Jan 2019

Application Of Urinary Metabolites For Cancer Detection, Qin Gao

Open Access Theses & Dissertations

Prostate cancer (PCa) is the 3rd most common cause of male cancer mortality in the US. Early diagnosis and treatment of PCa will improve the quality of care and reduce mortality. The prostate specific antigen (PSA) is commonly used in the current PCa screening, but its limitation has resulted in an intense search for more reliable biomarkers. Studies showed that dogs could differentiate PCa patients from negative control by sniffing their urine. As the odor profiles are generated by volatile organic compounds (VOCs), the finding suggests that particular VOCs could be linked to PCa, PCa risk levels and other cancers. …


Synthesis Of Advanced Functional Nanomaterials For Sustainable Water Treatment Technologies, Md Tariqul Islam Jan 2019

Synthesis Of Advanced Functional Nanomaterials For Sustainable Water Treatment Technologies, Md Tariqul Islam

Open Access Theses & Dissertations

Water is the most essential resource for the sustenance of life. Water is also necessary for agriculture, industry, household, and environmental conservation. However, due to large population growth and industrial expansion, access to clean water is becoming increasingly difficult around the world. Current water treatment technologies have not changed in over one hundred years and require a large infrastructure due to their low efficiencies and large-scale needs. In this context, the utilization of advanced functional nanomaterials and the adaptation of nanotechnology could potentially allow for miniaturizing water treatment and develop de-centralized solutions for rural areas. This Dissertation presents the design, …


The Export Flux Of Particulate Organic Carbon Derived From 210po/210pb Disequilibria Along The North Atlantic Geotraces Ga01 Transect: Geovide Cruise, Yi Tang, Nolwenn Lemaitre, Maxi Castrillejo, Montserrat Roca-Martí, Pere Masqué, Gillian Stewart Jan 2019

The Export Flux Of Particulate Organic Carbon Derived From 210po/210pb Disequilibria Along The North Atlantic Geotraces Ga01 Transect: Geovide Cruise, Yi Tang, Nolwenn Lemaitre, Maxi Castrillejo, Montserrat Roca-Martí, Pere Masqué, Gillian Stewart

Research outputs 2014 to 2021

The disequilibrium between 210Po activity and 210Pb activity in seawater samples was determined along the GEOTRACES GA01 transect in the North Atlantic during the GEOVIDE cruise (May-June 2014). A steady-state model was used to quantify vertical export of particulate 210Po. Vertical advection was incorporated into one version of the model using time-averaged vertical velocity, which had substantial variance. This resulted in large uncertainties for the 210Po export flux in this model, suggesting that those calculations of 210Po export fluxes should be used with great care. Despite the large uncertainties, there is no question that the deficits of 210Po in the …


Raman Spectroscopy As A Potential Tool For Label Free Therapeutic Drug Monitoring In Human Serum: The Case Of Busulfan And Methotrexate, Drishya Parachalil, Franck Bonnier, Deirdre Commerford, Igor Chourpa, Jennifer Mcintyre, Hugh Byrne Jan 2019

Raman Spectroscopy As A Potential Tool For Label Free Therapeutic Drug Monitoring In Human Serum: The Case Of Busulfan And Methotrexate, Drishya Parachalil, Franck Bonnier, Deirdre Commerford, Igor Chourpa, Jennifer Mcintyre, Hugh Byrne

Articles

A methodology is proposed, based on Raman spectroscopy coupled with multivariate analysis, to determine the Limit of Detection (LOD) and Limit of Quantification (LOQ) for therapeutic drug monitoring in human serum, using the examples of Busulfan, a cell cycle non-specific alkylating antineoplastic agent, and, Methotrexate, a chemotherapeutic agent and immune system suppressant. In this study, ultrafiltration is employed to fractionate spiked human pooled serum to efficiently recover the drug in the filtrate prior to performing Raman analysis. The drug concentration ranges were chosen to encompass the recommended therapeutic ranges and toxic levels in patients. Raman spectra were collected from the …


Spheroid-3d And Monolayer-2d Intestinal Electrochemical Biosensor For Toxicity/Viability Testing: Applications In Drug Screening, Food Safety, And Environmental Pollutant Analysis, Evangelia Flampouri, Shahzad Imar, Kieran O'Connell, Baljit Singh Jan 2019

Spheroid-3d And Monolayer-2d Intestinal Electrochemical Biosensor For Toxicity/Viability Testing: Applications In Drug Screening, Food Safety, And Environmental Pollutant Analysis, Evangelia Flampouri, Shahzad Imar, Kieran O'Connell, Baljit Singh

Articles

The rise of three-dimensional cell culture systems that provide in vivo-like environments for pharmaco-toxicological models has prompted the need for simple and robust viability assays suitable for complex cell architectural structures. This study addresses that challenge with the development of an in vitro enzyme based electrochemical sensor for viability/cytotoxicity assessment of two-dimensional (2D) monolayer and three-dimensional (3D) spheroid culture formats. The biosensor measures the cell viability/toxicity via electrochemical monitoring of the enzymatic activity of nonspecific esterases of viable cells, through the hydrolysis of 1-naphthyl acetate to 1-naphthol. The proposed sensor demonstrated strong correlation (r = 0.979) with viable …


Flavin Oxidation In Flavin-Dependent N-Monooxygenases, Reeder M. Robinson, Catherine A. Klancher, Pedro J. Rodriguez, Pablo Sobrado Jan 2019

Flavin Oxidation In Flavin-Dependent N-Monooxygenases, Reeder M. Robinson, Catherine A. Klancher, Pedro J. Rodriguez, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Siderophore A (SidA) from Aspergillus fumigatus is a flavin-containing monooxygenase that hydroxylates ornithine (Orn) at the amino group of the side chain. Lysine (Lys) also binds to the active site of SidA; however, hydroxylation is not efficient and H2O2 is the main product. The effect of pH on steady-state kinetic parameters was measured and the results were consistent with Orn binding with the side chain amino group in the neutral form. From the pH dependence on flavin oxidation in the absence of Orn, a pKa value >9 was determined and assigned to the FAD-N5 atom. In the …


Solvent Effects And Charge Transfer States In Organic Photovoltaics, Kangmin Liu Jan 2019

Solvent Effects And Charge Transfer States In Organic Photovoltaics, Kangmin Liu

Wayne State University Dissertations

Due to their various advantages, including lightweight, flexible, and cheap manufacturing, organic photovoltaic materials have gained enormous research interest. Over nearly two decades, the power conversion efficiency of organic solar devices has increased dramatically. However, it is still low compared to traditional inorganic semiconductors. In order to improve efficiency, a better understanding of the basic thermodynamic properties of the light-to-electricity power conversion process is needed. One nontrivial aspect of organic solar cells is the low dielectric constant, which leads to tightly-bound excitons upon vertical excitations. The separation of electron-hole pairs requires a larger driving force to overcome the Coulombic binding …


Functional Characterization Of Accessory Proteins And Novel Activities In Direct And Indirect Trna Aminoacylation, Udumbara Menike Rathnayake Jan 2019

Functional Characterization Of Accessory Proteins And Novel Activities In Direct And Indirect Trna Aminoacylation, Udumbara Menike Rathnayake

Wayne State University Dissertations

Indirect tRNA aminoacylation is essential for most bacteria and archaea, particularly when these species do not have genes encoding asparaginyl- and/or glutaminyl-tRNA synthetase (AsnRS and GlnRS). In the absence of AsnRS, the first step in Asn-tRNAAsn synthesis involves misacylation of tRNAAsn with aspartate to produce Asp-tRNAAsn; this reaction is catalyzed by a non-discriminating aspartyl-tRNA synthetase (ND-AspRS). Subsequently, in bacteria, an amidotransferase called GatCAB converts Asp-tRNAAsn to Asn-tRNAAsn. An analogous, two-step processes exist to produce Gln-tRNAGln. In this case, a non-discriminating glutamyl-tRNA synthetase (ND-GluRS) misacylates tRNAGln to produce Glu-tRNAGln, which is then converted to Gln-tRNAGln by GatCAB. The central hub of …


Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman Jan 2019

Limited Sequence Diversity Within A Population Supports Prebiotic Rna Reproduction, Ryo Mizuuchi, Niles Lehman

Chemistry Faculty Publications and Presentations

The origins of life require the emergence of informational polymers capable of reproduction. In the RNA world on the primordial Earth, reproducible RNA molecules would have arisen from a mixture of compositionally biased, poorly available, short RNA sequences in prebiotic environments. However, it remains unclear what level of sequence diversity within a small subset of population is required to initiate RNA reproduction by prebiotic mechanisms. Here, using a simulation for template-directed recombination and ligation, we explore the effect of sequence diversity in a given population for the onset of RNA reproduction. We show that RNA reproduction is improbable in low …


Targeting Mitochondria In Cancer Therapy Could Provide A Basis For The Selective Anticancer Activity, Dmitri Rozanov, Anton Cheltsov, Aaron Nilsen, Christopher Boniface, Isaac Forquer, James Korkola, Joe Gray, Multiple Additional Authors Jan 2019

Targeting Mitochondria In Cancer Therapy Could Provide A Basis For The Selective Anticancer Activity, Dmitri Rozanov, Anton Cheltsov, Aaron Nilsen, Christopher Boniface, Isaac Forquer, James Korkola, Joe Gray, Multiple Additional Authors

Chemistry Faculty Publications and Presentations

To determine the target of the recently identified lead compound NSC130362 that is responsible for its selective anti-cancer efficacy and safety in normal cells, structure-activity relationship (SAR) studies were conducted. First, NSC13062 was validated as a starting compound for the described SAR studies in a variety of cell-based viability assays. Then, a small library of 1,4-naphthoquinines (1,4-NQs) and quinoline-5,8-diones was tested in cell viability assays using pancreatic cancer MIA PaCa-2 cells and normal human hepatocytes. The obtained data allowed us to select a set of both non-toxic compounds that preferentially induced apoptosis in cancer cells and toxic compounds that induced …