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Articles 1 - 27 of 27

Full-Text Articles in Chemistry

The Fierce Urgency Of Now: Integrating The Youth Voice At Cop, Gillian Bowser, Pamela H. Templer, Susie S. Ho, Sarah A. Green, Sarah Hautzinger, Isabelle Zhu-Maguire, Alyssa Connaughton, Leah Dundon, Diane Husic, Mark Urban May 2023

The Fierce Urgency Of Now: Integrating The Youth Voice At Cop, Gillian Bowser, Pamela H. Templer, Susie S. Ho, Sarah A. Green, Sarah Hautzinger, Isabelle Zhu-Maguire, Alyssa Connaughton, Leah Dundon, Diane Husic, Mark Urban

Michigan Tech Publications

No abstract provided.


Synthesis And Characterization Of Humic/Melanin-Like Compounds By Oxidative Polymerization Of Simple Aromatic Precursors, Nastaran Khademimoshgenani, Sarah A. Green Apr 2023

Synthesis And Characterization Of Humic/Melanin-Like Compounds By Oxidative Polymerization Of Simple Aromatic Precursors, Nastaran Khademimoshgenani, Sarah A. Green

Michigan Tech Publications

Dissolved organic matter (DOM) is a complex mixture of naturally occurring organic molecules originating from multiple marine and terrestrial sources. DOM plays a significant role in water quality by affecting the photochemistry, trace metal transport, and acidity in aquatic systems. Understanding the chemical composition of DOM helps interpret the links between its optical properties and molecular structures. Currently, the molecular origins of the optical properties of DOM are not well-defined. In this study, we oxidize and initiate the polymerization of melanin precursors 1,8-dihydroxy naphthalene and 5,6-dihydroxy indole by the addition of hydrogen peroxide and/or with ultraviolet irradiation. Our goal is …


Selectively Modified Lactose And N-Acetyllactosamine Analogs At Three Key Positions To Afford Effective Galectin-3 Ligands †, Shuay Abdullayev, Priyanka Dipak Kadav, Purnima Bandyopadhyay, Francisco Javier Medrano, Gabriel A. Rabinovich, Tarun K. Dam, Antonio Romero, René Roy Feb 2023

Selectively Modified Lactose And N-Acetyllactosamine Analogs At Three Key Positions To Afford Effective Galectin-3 Ligands †, Shuay Abdullayev, Priyanka Dipak Kadav, Purnima Bandyopadhyay, Francisco Javier Medrano, Gabriel A. Rabinovich, Tarun K. Dam, Antonio Romero, René Roy

Michigan Tech Publications

Galectins constitute a family of galactose-binding lectins overly expressed in the tumor microenvironment as well as in innate and adaptive immune cells, in inflammatory diseases. Lactose ((β-D-galactopyranosyl)-(1→4)-β-D-glucopyranose, Lac) and N-Acetyllactosamine (2-acetamido-2-deoxy-4-O-β-D-galactopyranosyl-D-glucopyranose, LacNAc) have been widely exploited as ligands for a wide range of galectins, sometimes with modest selectivity. Even though several chemical modifications at single positions of the sugar rings have been applied to these ligands, very few examples combined the simultaneous modifications at key positions known to increase both affinity and selectivity. We report herein combined modifications at the anomeric position, C-2, and O-3′ of each of the two …


Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova Dec 2022

Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova

Michigan Tech Publications

The targeting of facilitative sugar transporters (GLUTs) has been utilized in the development of tools for diagnostics and therapy. The interest in this area is promoted by the phenomenon of alterations in cellular metabolic processes that are linked to multitudes of metabolic disorders and diseases. However, nonspecific targeting (e.g., glucose-transporting GLUTs) leads to a lack of disease detection efficiency. Among GLUTs, GLUT5 stands out as a prominent target for developing specific molecular tools due to its association with metabolic diseases, including cancer. This work reports a non-radiolabeled fluoride (19F) coumarin-based glycoconjugate of 2,5-anhydro-D-mannitol as a potential PET imaging probe that …


Importance Of Glut Transporters In Disease Diagnosis And Treatment, Abdelrahman Ismail, Marina Tanasova Aug 2022

Importance Of Glut Transporters In Disease Diagnosis And Treatment, Abdelrahman Ismail, Marina Tanasova

Michigan Tech Publications

Facilitative sugar transporters (GLUTs) are the primary method of sugar uptake in all mammalian cells. There are 14 different types of those transmembrane proteins, but they transport only a handful of substrates, mainly glucose and fructose. This overlap and redundancy contradict the natural tendency of cells to conserve energy and resources, and has led researchers to hypothesize that different GLUTs partake in more metabolic roles than just sugar transport into cells. Understanding those roles will lead to better therapeutics for a wide variety of diseases and disorders. In this review we highlight recent discoveries of the role GLUTs play in …


Synthesis And Characterization Of Alkyne-Functionalized Photo-Cross-Linkable Polyesters, Warrick Ma, Xiaochu Ding, Ying Chen, Yadong Wang Apr 2022

Synthesis And Characterization Of Alkyne-Functionalized Photo-Cross-Linkable Polyesters, Warrick Ma, Xiaochu Ding, Ying Chen, Yadong Wang

Michigan Tech Publications

An alkyne-functionalized elastomer derived from sebacic acid, 1,3-propanediol, and alkyne-functionalized serinol is synthesized via melt condensation. A low-power UV lamp triggers the cross-linking rapidly via thiol-yne click chemistry. The cross-linking behavior is studied by photorheology and NMR spectroscopy. The resultant elastomer possesses mechanical properties similar to those of human soft tissues and exhibits in vitro degradability and good cytocompatibility.


Determination Of Optical Density (Od) Of Oligodeoxynucleotide From Hplc Peak Area, Komal Chillar, Yipeng Yin, Dhananjani Eriyagama, Shiyue Fang Mar 2022

Determination Of Optical Density (Od) Of Oligodeoxynucleotide From Hplc Peak Area, Komal Chillar, Yipeng Yin, Dhananjani Eriyagama, Shiyue Fang

Michigan Tech Publications

Oligodeoxynucleotides (ODNs) are typically purified and analysed with HPLC equipped with a UV-Vis detector. Quantities of ODNs are usually determined using a UV-Vis spectrometer separately after HPLC, and are reported as optical density at 260 nm (OD260). Here, we describe a method for direct determination of OD260 of ODNs using the area of the peaks in HPLC profiles.


Emissions, Shawn Urbanski, Susan O'Neill, Amara L. Holder, Sarah Green, Rick L. Graw Jan 2022

Emissions, Shawn Urbanski, Susan O'Neill, Amara L. Holder, Sarah Green, Rick L. Graw

Michigan Tech Publications

This chapter assesses the current state of the science regarding the composition, intensity, and drivers of wildland fire emissions in the USA and Canada. Globally and in the USA wildland fires are a major source of gases and aerosols which have significant air quality impacts and climate interactions. Wildland fire smoke can trigger severe pollution episodes with substantial effects on public health. Fire emissions can degrade air quality at considerable distances downwind, hampering efforts by air regulators to meet air standards. Fires are a major global source of aerosols which affect the climate system by absorbing and scattering radiation and …


The Ion Pair Thermal Model Of Maldi Ms, Shiyue Fang Oct 2021

The Ion Pair Thermal Model Of Maldi Ms, Shiyue Fang

Michigan Tech Publications

The ion pair thermal model for MALDI MS is described. Key elements of the model include thermal desorption and ionization, strong tendency to neutralization via ion pair formation and proton transfer in the gas phase, thermal equilibrium, overall charge neutral plume, and thermal energy assisted free ion generation via ion pair separation by ion extraction potential. The quantities of ions in the solid sample and in the gaseous plume are estimated. Ion yields of different classes of molecules including peptides, nucleic acids, permanent salts and neutral molecules are estimated at the macroscale and single ion pair levels. The estimated ion …


Hydrochloric Acid Modification And Lead Removal Studies On Naturally Occurring Zeolites From Nevada, New Mexico, And Arizona, Garven M. Huntley, Rudy Luck, Michael Mullins, Nick Newberry Jul 2021

Hydrochloric Acid Modification And Lead Removal Studies On Naturally Occurring Zeolites From Nevada, New Mexico, And Arizona, Garven M. Huntley, Rudy Luck, Michael Mullins, Nick Newberry

Michigan Tech Publications

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving …


Targeting Of Glut5 For Transporter-Mediated Drug-Delivery Is Contingent Upon Substrate Hydrophilicity, Nazanin Nahrjou, Avik Ghosh, Marina Tanasova May 2021

Targeting Of Glut5 For Transporter-Mediated Drug-Delivery Is Contingent Upon Substrate Hydrophilicity, Nazanin Nahrjou, Avik Ghosh, Marina Tanasova

Michigan Tech Publications

Specific link between high fructose uptake and cancer development and progression highlighted fructose transporters as potential means to achieve GLUT-mediated discrimination between normal and cancer cells. The gained expression of fructose-specific transporter GLUT5 in various cancers offers a possibility for developing cancer-specific imaging and bioactive agents. Herein, we explore the feasibility of delivering a bioactive agent through cancer-relevant fructose-specific transporter GLUT5. We employed specific targeting of GLUT5 by 2,5-anhydro-D-mannitol and investigated several drug conjugates for their ability to induce cancer-specific cytotoxicity. The proof-of-concept analysis was carried out for conjugates of chlorambucil (CLB) in GLUT5-positive breast cancer cells and normal breast …


Ratiometric Near-Infrared Fluorescent Probes Based On Hemicyanine Dyes Bearing Dithioacetal And Formal Residues For Ph Detection In Mitochondria, Yunnan Yan, Yibin Zhang, Shuai Xia, Shulin Wan, Tara Vohs, Marina Tanasova, Rudy Luck, Haiying Lui Apr 2021

Ratiometric Near-Infrared Fluorescent Probes Based On Hemicyanine Dyes Bearing Dithioacetal And Formal Residues For Ph Detection In Mitochondria, Yunnan Yan, Yibin Zhang, Shuai Xia, Shulin Wan, Tara Vohs, Marina Tanasova, Rudy Luck, Haiying Lui

Michigan Tech Publications

Ratiometric near-infrared fluorescent probes (AH+ and BH+) have been prepared for pH determination in mitochondria by attaching dithioacetal and formal residues onto a hemicyanine dye. The reactive formyl group on probe BH+ allows for retention inside mitochondria as it can react with a protein primary amine residue to form an imine under slightly basic pH 8.0. Probes AH+ and BH+ display ratiometric fluorescent responses to pH changes through the protonation and deprotonaton of a hydroxy group in hemicyanine dyes with experimentally determined pKa values of 6.85 and 6.49, respectively. Calculated pKa values from a variety of theoretical methods indicated that …


Insights On Dissolved Organic Matter Production Revealed By Removal Of Charge-Transfer Interactions In Senescent Leaf Leachates, Karl M. Meingast, Brice K. Grunert, Sarah A. Green, Evan S. Kane, Nastaran Khademimoshgenani Aug 2020

Insights On Dissolved Organic Matter Production Revealed By Removal Of Charge-Transfer Interactions In Senescent Leaf Leachates, Karl M. Meingast, Brice K. Grunert, Sarah A. Green, Evan S. Kane, Nastaran Khademimoshgenani

Michigan Tech Publications

Dissolved organic matter (DOM) is a critical part of the global carbon cycle. Currently, it is understood that at least a portion of the chromophoric DOM (CDOM) character can be described through an electronic interaction of charge transfer (CT) complexes. While much work has been done to understand the influence of CT on soil and aquatic reference standard DOM, little is known about the influence of CT in fresh terrestrially derived DOM. In this study, leaf litter leachates from three tree species were treated (reduced) with sodium borohydride to determine the contribution of CT on a source of fresh terrestrial …


An International Laboratory Comparison Of Dissolved Organic Matter Composition By High Resolution Mass Spectrometry: Are We Getting The Same Answer?, Jeffrey A. Hawkes, Juliana D'Andrilli, Jeffrey N. Agar, Mark P. Barrow, Stephanie M. Berg, Núria Catalán, Hongmei Chen, Rosalie K. Chu, Richard B. Cole, Thorsten Dittmar, Rémy Gavard, Gerd Gleixner, Patrick G. Hatcher, Chen He, Nancy J. Hess, Ryan H.S. Hutchins, Amna Ijaz, Hugh E. Jones, William Kew, Maryam Khaksari, Diana Catalina Palacio Lozano, Jitao Lv, Lynn Mazzoleni, Beatriz E. Noriega-Ortega, Helena Osterholz, Nikola Radoman, Shuzhen Zhang, Phoebe Zito, David C. Podgorski Jun 2020

An International Laboratory Comparison Of Dissolved Organic Matter Composition By High Resolution Mass Spectrometry: Are We Getting The Same Answer?, Jeffrey A. Hawkes, Juliana D'Andrilli, Jeffrey N. Agar, Mark P. Barrow, Stephanie M. Berg, Núria Catalán, Hongmei Chen, Rosalie K. Chu, Richard B. Cole, Thorsten Dittmar, Rémy Gavard, Gerd Gleixner, Patrick G. Hatcher, Chen He, Nancy J. Hess, Ryan H.S. Hutchins, Amna Ijaz, Hugh E. Jones, William Kew, Maryam Khaksari, Diana Catalina Palacio Lozano, Jitao Lv, Lynn Mazzoleni, Beatriz E. Noriega-Ortega, Helena Osterholz, Nikola Radoman, Shuzhen Zhang, Phoebe Zito, David C. Podgorski

Michigan Tech Publications

High-resolution mass spectrometry (HRMS) has become a vital tool for dissolved organic matter (DOM) characterization. The upward trend in HRMS analysis of DOM presents challenges in data comparison and interpretation among laboratories operating instruments with differing performance and user operating conditions. It is therefore essential that the community establishes metric ranges and compositional trends for data comparison with reference samples so that data can be robustly compared among research groups. To this end, four identically prepared DOM samples were each measured by 16 laboratories, using 17 commercially purchased instruments, using positive-ion and negative-ion mode electrospray ionization (ESI) HRMS analyses. The …


Role Of Structural Dynamics In Selectivity And Mechanism Of Non-Heme Fe(Ii) And 2-Oxoglutarate-Dependent Oxygenases Involved In Dna Repair, Sodiq Waheed, Rajeev Ramanan, Shobhit Chaturvedi, Nicolai Lehnert, Christopher J. Schofield, Christo Z. Christov, Tatyana Karabencheva-Christova May 2020

Role Of Structural Dynamics In Selectivity And Mechanism Of Non-Heme Fe(Ii) And 2-Oxoglutarate-Dependent Oxygenases Involved In Dna Repair, Sodiq Waheed, Rajeev Ramanan, Shobhit Chaturvedi, Nicolai Lehnert, Christopher J. Schofield, Christo Z. Christov, Tatyana Karabencheva-Christova

Michigan Tech Publications

AlkB and its human homologue AlkBH2 are Fe(II)- and 2-oxoglutarate (2OG)-dependent oxygenases that repair alkylated DNA bases occurring as a consequence of reactions with mutagenic agents. We used molecular dynamics (MD) and combined quantum mechanics/molecular mechanics (QM/MM) methods to investigate how structural dynamics influences the selectivity and mechanisms of the AlkB- and AlkBH2-catalyzed demethylation of 3-methylcytosine (m3C) in single (ssDNA) and double (dsDNA) stranded DNA. Dynamics studies reveal the importance of the flexibility in both the protein and DNA components in determining the preferences of AlkB for ssDNA and of AlkBH2 for dsDNA. Correlated motions, including of a …


Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak May 2020

Richardsite, Zn2cugas4, A New Gallium-Essential Member Of The Stannite Group From The Gem Mines Near Merelani, Tanzania, Luca Bindi, John A. Jaszczak

Michigan Tech Publications

The new mineral richardsite occurs as overgrowths of small (50–400 μm) dark gray, disphenoidal crystals with no evident twinning, but epitaxically oriented on wurtzite–sphalerite crystals from the gem mines near Merelani, Lelatema Mountains, Simanjiro District, Manyara Region, Tanzania. Associated minerals also include graphite, diopside, and Ge,Ga-rich wurtzite. It is brittle, dark gray in color, and has a metallic luster. It appears dark bluish gray in reflected plane-polarized light, and is moderately bireflectant. It is distinctly anisotropic with violet to light-blue rotation tints with crossed polarizers. Reflectance percentages for Rmin and Rmax in air at the respective wavelengths are 23.5, 25.0 …


Antibacterial Properties Of Mussel-Inspired Polydopamine Coatings Prepared By A Simple Two-Step Shaking-Assisted Method, Pegah Kord Fooroshani, Elizabeth Polega, Kevin Thomson, Mohammad Saleh Akram Bhuiyan, Rattapol Pinnaratip, Mikhail Trought, Chito E. Kendrick, Yuesheng Gao, Kahryn Perrine, Lei Pan, Bruce P. Lee Sep 2019

Antibacterial Properties Of Mussel-Inspired Polydopamine Coatings Prepared By A Simple Two-Step Shaking-Assisted Method, Pegah Kord Fooroshani, Elizabeth Polega, Kevin Thomson, Mohammad Saleh Akram Bhuiyan, Rattapol Pinnaratip, Mikhail Trought, Chito E. Kendrick, Yuesheng Gao, Kahryn Perrine, Lei Pan, Bruce P. Lee

Michigan Tech Publications

A simple two-step, shaking-assisted polydopamine (PDA) coating technique was used to impart polypropylene (PP) mesh with antimicrobial properties. In this modified method, a relatively large concentration of dopamine (20 mg ml−1) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg ml−1) to promote the formation and deposition of large aggregates of PDA nanoparticles. Gentle shaking (70 rpm) was employed to increase the deposition of PDA nanoparticle aggregates and the formation of a thicker PDA coating with nano-scaled surface roughness (RMS = 110 …


Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni Aug 2019

Extensive Soot Compaction By Cloud Processing From Laboratory And Field Observations, Janarjan Bhandari, Swarup China, Kamal Kant Chandrakar, Greg Kinney, Will Cantrell, Raymond Shaw, Lynn Mazzoleni, Giulia Girotto, Noopur Sharma, Kyle Gorkowski, Stefania Gilardoni, Stefano Decesari, Maria Cristina Facchini, Nicola Zanca, Giulia Pavese, Francesco Esposito, Manvendra K Dubey, Allison C Aiken, Rajan K Chakrabarty, Hans Moosmüller, Timothy B Onasch, Rahul A Zaveri, Barbara V Scarnato, Paulo Fialho, Claudio Mazzoleni

Michigan Tech Publications

Soot particles form during combustion of carbonaceous materials and impact climate and air quality. When freshly emitted, they are typically fractal-like aggregates. After atmospheric aging, they can act as cloud condensation nuclei, and water condensation or evaporation restructure them to more compact aggregates, affecting their optical, aerodynamic, and surface properties. Here we survey the morphology of ambient soot particles from various locations and different environmental and aging conditions. We used electron microscopy and show extensive soot compaction after cloud processing. We further performed laboratory experiments to simulate atmospheric cloud processing under controlled conditions. We find that soot particles sampled after …


Spontaneous Selective Deposition Of Iron Oxide Nanoparticles On Graphite As Model Catalysts, Chathura De Alwis, Timothy Leftwich, Pinaki Mukherjee, Alex Denofre, Kahryn Perrine Aug 2019

Spontaneous Selective Deposition Of Iron Oxide Nanoparticles On Graphite As Model Catalysts, Chathura De Alwis, Timothy Leftwich, Pinaki Mukherjee, Alex Denofre, Kahryn Perrine

Michigan Tech Publications

Iron oxide nanomaterials participate in redox processes that give them ideal properties for their use as earth-abundant catalysts. Fabricating nanocatalysts for such applications requires detailed knowledge of the deposition and growth. We report the spontaneous deposition of iron oxide nanoparticles on HOPG in defect areas and on step edges from a metal precursor solution. To study the nucleation and growth of iron oxide nanoparticles, tailored defects were created on the surface of HOPG using various ion sources that serve as the target sites for iron oxide nucleation. After solution deposition and annealing, the iron oxide nanoparticles were found to nucleate …


Detecting Zn(Ii) Ions In Live Cells With Near-Infrared Fluorescent Probes., Mingxi Fang, Shuai Xia, Jianheng Bi, Travis P Wigstrom, Loredana Valenzano, Jianbo Wang, Marina Tanasova, Rudy Luck, Haiying Liu Apr 2019

Detecting Zn(Ii) Ions In Live Cells With Near-Infrared Fluorescent Probes., Mingxi Fang, Shuai Xia, Jianheng Bi, Travis P Wigstrom, Loredana Valenzano, Jianbo Wang, Marina Tanasova, Rudy Luck, Haiying Liu

Michigan Tech Publications

Two near-infrared fluorescent probes (A and B) containing hemicyanine structures appended to dipicolylamine (DPA), and a dipicolylamine derivative where one pyridine was substituted with pyrazine, respectively, were synthesized and tested for the identification of Zn(II) ions in live cells. In both probes, an acetyl group is attached to the phenolic oxygen atom of the hemicyanine platform to decrease the probe fluorescence background. Probe A displays sensitive fluorescence responses and binds preferentially to Zn(II) ions over other metal ions such as Cd2+ ions with a low detection limit of 0.45 nM. In contrast, the emission spectra of probe B is …


Production Of Trimethylaluminum (Me3al) With Counterfeit Refrigerant Chloromethane (R-40), Reactivity Of Me3al With Refrigerant Oils And Methods To Deactivate Me3al, Zhichao Chen, Rudy Luck Jun 2018

Production Of Trimethylaluminum (Me3al) With Counterfeit Refrigerant Chloromethane (R-40), Reactivity Of Me3al With Refrigerant Oils And Methods To Deactivate Me3al, Zhichao Chen, Rudy Luck

Michigan Tech Publications

Reactions between Al containing materials and counterfeit refrigerant chloromethane (R-40) were investigated under various conditions. The addition of Mg effected a reaction indicating that trimethylaluminum may have been produced in the reaction. A different study involving Al-foil, AlCl3 and chloromethane resulted in cracks detected on the Al-foil which reduced in weight by 19% and methane was detected. Studies conducted either at room temperature or at 80°C with two other genuine refrigerants, R-142b (1-chloro-1,1-difluoroethane) and R-133a (2-chloro-1,1,1-trifluoroethane) did not form organoaluminum compounds. Several commercially available refrigerant oils were subjected to Me3Al. Only polyester oil resulted in a decrease …


Metabolism-Driven High-Throughput Cancer Identification With Glut5-Specific Molecular Probes, Srinivas Kannan, Vagarshak Begoyan, Joseph Fedie, Shuai Xia, Łukasz J. Weseliński, Marina Tanasova, Smitha Rao Apr 2018

Metabolism-Driven High-Throughput Cancer Identification With Glut5-Specific Molecular Probes, Srinivas Kannan, Vagarshak Begoyan, Joseph Fedie, Shuai Xia, Łukasz J. Weseliński, Marina Tanasova, Smitha Rao

Michigan Tech Publications

Point-of-care applications rely on biomedical sensors to enable rapid detection with high sensitivity and selectivity. Despite advances in sensor development, there are challenges in cancer diagnostics. Detection of biomarkers, cell receptors, circulating tumor cells, gene identification, and fluorescent tagging are time-consuming due to the sample preparation and response time involved. Here, we present a novel approach to target the enhanced metabolism in breast cancers for rapid detection using fluorescent imaging. Fluorescent analogs of fructose target the fructose-specific transporter GLUT5 in breast cancers and have limited to no response from normal cells. These analogs demonstrate a marked difference in adenocarcinoma and …


Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov Dec 2017

Mechanistic Insights Into The Reaction Of Chlorination Of Tryptophan Catalyzed By Tryptophan 7-Halogenase., Tatyana Karabencheva-Christova, Juan Torras, Adrian J Mulholland, Alessio Lodola, Christo Christov

Michigan Tech Publications

Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed …


Green Chemistry: Progress And Barriers, Sarah A. Green Oct 2016

Green Chemistry: Progress And Barriers, Sarah A. Green

Michigan Tech Publications

Green chemistry can advance both the health of the environment and the primary objectives of the chemical enterprise: to understand the behavior of chemical substances and to use that knowledge to make useful substances. We expect chemical research and manufacturing to be done in a manner that preserves the health and safety of workers; green chemistry extends that expectation to encompass the health and safety of the planet. While green chemistry may currently be treated as an independent branch of research, it should, like safety, eventually become integral to all chemistry activities. While enormous progress has been made in shifting …


Extracellular Expression Of Alkaline Phytase In Pichia Pastoris: Influence Of Signal Peptides, Promoters And Growth Medium, Mimi Yang, Sasha Teymorian, Philip Olivares, Pushpalatha P.N. Murthy Jun 2015

Extracellular Expression Of Alkaline Phytase In Pichia Pastoris: Influence Of Signal Peptides, Promoters And Growth Medium, Mimi Yang, Sasha Teymorian, Philip Olivares, Pushpalatha P.N. Murthy

Michigan Tech Publications

Alkaline phytase isolated from pollen grains of Lilium longiflorum (LlALP) possesses unique catalytic and thermal stability properties that suggest it has the potential to be used as a feed supplement. However, substantial amounts of active enzymes are needed for animal feed studies and endogenous levels of LlALP in lily pollen are too low to provide the required amounts. Active rLlALP2 (coded by LlAlp2, one of two isoforms of alkaline phytase cDNA identified in lily pollen) has been successfully expressed in intracellular compartments of Pichia pastoris, however enzyme yields have been modest (25-30 mg/L) and purification of the enzyme has been …


Atmospheric Peroxyacetyl Nitrate (Pan): A Global Budget And Source Attribution, E. V. Fischer, D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, D. B. Millet, J. Mao, F. Paulot, H. B. Singh, A. Roiger, L. Ries, R. W. Talbot, K. Dzepina, S. Pandey Deolal Mar 2014

Atmospheric Peroxyacetyl Nitrate (Pan): A Global Budget And Source Attribution, E. V. Fischer, D. J. Jacob, R. M. Yantosca, M. P. Sulprizio, D. B. Millet, J. Mao, F. Paulot, H. B. Singh, A. Roiger, L. Ries, R. W. Talbot, K. Dzepina, S. Pandey Deolal

Michigan Tech Publications

Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals (NOx =NO+NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it …


A Semi-Lagrangian View Of Ozone Production Tendency In North American Outflow In The Summers Of 2009 And 2010, B. Zhang, R. C. Owen, J A Perlinger, A. Kumar, S. Wu, M. Val Martin, L. Kramer, D. Helmig, R. E. Honrath Mar 2014

A Semi-Lagrangian View Of Ozone Production Tendency In North American Outflow In The Summers Of 2009 And 2010, B. Zhang, R. C. Owen, J A Perlinger, A. Kumar, S. Wu, M. Val Martin, L. Kramer, D. Helmig, R. E. Honrath

Michigan Tech Publications

The Pico Mountain Observatory, located at 2225 m a.s.l. in the Azores Islands, was established in 2001 to observe long-range transport from North America to the central North Atlantic. In previous research conducted at the observatory, ozone enhancement (> 55 ppbv) in North American outflows was observed, and efficient ozone production in these outflows was postulated. This study is focused on determining the causes for high d[O3] / d[CO] values (~1 ppbv ppbv−1) observed in the summers of 2009 and 2010. The folded retroplume technique, developed by Owen and Honrath (2009), was applied to combine upwind FLEXPART transport …