Physical Sciences and Mathematics | Open Access Articles

Acid-Triggered Self-Assembled Egg White Protein-Coated Gold Nanoclusters For Selective Fluorescent Detection Of Fe3+, No2-, And Cysteine, Wenyan Li, Xiangping Wen, Hemiao Zhao, Wenjun Yan, John F. Trant, Yingqi Li

Chemistry and Biochemistry Publications

Herein, we present a simple and economical synthesis for the first multianalyte probe able to selectively quantify the concentrations of Fe3+, NO2-, and cysteine. It comprises H+-triggered self-assembled gold nanoclusters (AuNCs@EW/H+, AuEHs), showing enhanced red fluorescence at 640 nm. The AuEH is a good fluorescent nanosensor for Fe3+ and NO2- with detection limits of 1.40 and 2.82 nM, respectively. Iron detection, through fluorescence quenching, occurs because of nanocluster aggregation elicited by the complexation of Fe3+ with amino acids on the surface of AuEH; nitrite detection likely proceeds through fluorescence quenching via the disassembly of the nanoclusters following irreversible oxidation by …

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An In Silico Approach To Enzymatic Synthesis Of Fucooligosaccharides Using Α-L-Fucosidase From Thermotoga Maritima, Emmanuel Pérez-Escalante, Luis Guillermo González-Olivares, Araceli Castañeda-Ovando, Alma Elizabeth Cruz-Guerrero, John F. Trant, Wendolyne López-Orozco, Luis Humberto Mendoza-Huizar, Sergio Alatorre-Santamaría

Chemistry and Biochemistry Publications

Abstract: Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzy- matic methods show great promise, and α-L-fucosidase from Thermotoga maritima has emerged as a powerful catalyst for their production. Nonetheless, the enzyme’s limited substrate scope has de- layed its wider application. The present work aims to compare the relative reactivity of fucose, pNP-fucose, and ethyl-fucose, while also exploring the molecular interactions of these fucosyl-donors with the enzyme through a combination DFT and docking analysis. The HOMO-LUMO band gaps range from −7.14571 to −4.24429 …

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A Mechanical Mechanism For Vitamin E Acetate In E-Cigarette/Vaping-Associated Lung Injury, Mitchell Dipasquale, Omotayo Gbadamosi, Michael H.L. Nguyen, Stuart R. Castillo, Brett W. Rickeard, Elizabeth G. Kelley, Michihiro Nagao, Drew Marquardt

Chemistry and Biochemistry Publications

Copyright © 2020 American Chemical Society. The outbreak of electronic-cigarette/vaping-Associated lung injury (EVALI) has made thousands ill. This lung injury has been attributed to a physical interaction between toxicants from the vaping solution and the pulmonary surfactant. In particular, studies have implicated vitamin E acetate as a potential instigator of EVALI. Pulmonary surfactant is vital to proper respiration through the mechanical processes of adsorption and interface stability to achieve and maintain low surface tension at the air-liquid interface. Using neutron spin echo spectroscopy, we investigate the impact of vitamin E acetate on the mechanical properties of two lipid-only pulmonary surfactant …

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Detecting Mercury (Ii) And Thiocyanate Using “Turn-On” Fluorescence Of Graphene Quantum Dots, Faezeh Askari, Abbas Rahdar, Mohadeseh Dashti, John F. Trant

Chemistry and Biochemistry Publications

In this work, 1.8 nm graphene quantum dots (GQDs), exhibiting bright blue fluorescence, were prepared using a bottom-up synthesis from citric acid. The fluorescence of the GQDs could be almost completely quenched (about 96%) by adding Hg2+. Quenching was far less efficient with other similar heavy metals, Tl+, Pb2+ and Bi3+. Fluorescence could be near quantitatively restored through the introduction of thiocyanate. This “turn-on” fluorescence can thus be used to detect both or either environmental and physiological contaminants mercury and thiocyanate and could prove useful for the development of simple point-of-care diagnostics in the future. [Figure not available: see fulltext.].

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The Synthesis Of Methotrexate-Loaded F127 Microemulsions And Their In Vivo Toxicity In A Rat Model, Abbas Rahdar, Mohammad Reza Hajinezhad, Sarah Nasri, Hamid Beyzaei, Mahmood Barani, John F. Trant

Chemistry and Biochemistry Publications

Methotrexate (MTX) has been often formulated as nano and micro-emulsions, nominally to address its poor solubility and off-target effects. Nanoformulated MTX is universally reported to be a more efficacious anti-cancer agent than direct-dissolved drug; however, these investigations generally fail to screen for in vivo toxicity. This study aims to remedy this oversight. MTX was formulated as a standard Pluronic oil-in-water microemulsion with good drug encapsulation efficiency (73.0% ± 8.4). Preliminary in vitro free radical scavenging studies found that formulation reduces drug oxidation four-fold. The toxic effects of formulated and unformulated MTX were investigated in a Wistar rat model. Rats received …

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Cannabinoids And Cannabinoid Receptors: The Story So Far, Fred Shahbazi, Victoria Grandi, Abhinandan Banerjee, John F. Trant

Chemistry and Biochemistry Publications

Like most modern molecular biology and natural product chemistry, understanding cannabinoid pharmacology centers around molecular interactions, in this case, between the cannabinoids and their putative targets, the G-protein coupled receptors (GPCRs) cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2). Understanding the complex structure and interplay between the partners in this molecular dance is required to understand the mechanism of action of synthetic, endogenous, and phytochemical cannabinoids. This review, with 91 references, surveys our understanding of the structural biology of the cannabinoids and their target receptors including both a critical comparison of the extant crystal structures and the computationally derived …

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The Structures Of Polyunsaturated Lipid Bilayers By Joint Refinement Of Neutron And X-Ray Scattering Data, Drew Marquardt, Frederick A. Heberle, Jianjun Pan, Xiaolin Cheng, Georg Pabst, Thad A. Harroun, Norbert Kučerka, John Katsaras

Chemistry and Biochemistry Publications

© 2020 Elsevier B.V. We present the detailed structural analysis of polyunsaturated fatty acid-containing phospholipids namely, 1-palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (PDPC) and 1-stearoyl-2-docosahexaenoyl-sn-glycero-3-phosphocholine (SDPC). A newly developed molecular dynamics (MD) simulation parsing scheme for lipids containing fatty acids with multiple double bonds was implemented into the scattering density profile (SDP) model to simultaneously refine differently contrasted neutron and X-ray scattering data. SDP analyses of scattering data at 30 °C yielded lipid areas of 71.1 Å2 and 70.4 Å2 for PDPC and SDPC bilayers, respectively, and a model free analysis of PDPC at 30 °C resulted in a lipid area of 72 Å2. In …

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Differential Expression Of Glucose Transporters And Hexokinases In Prostate Cancer With A Neuroendocrine Gene Signature: A Mechanistic Perspective For 18 F-Fdg Imaging Of Psma-Suppressed Tumors, Martin K. Bakht, Jessica M. Lovnicki, Janice Tubman, Keith F. Stringer, Jonathan Chiaramonte, Michael R. Reynolds, Iulian Derecichei, Rosa Maria Ferraiuolo, Bre Anne Fifield, Dorota Lubanska, So Won Oh, Gi Jeong Cheon, Cheol Kwak, Chang Wook Jeong, Keon Wook Kang, John F. Trant, Colm Morrissey, Ilsa M. Coleman, Yuzhuo Wang, Hojjat Ahmadzadehfar

Chemistry and Biochemistry Publications

Although the incidence of de novo neuroendocrine prostate cancer (PC) is rare, recent data suggest that low expression of prostatespecific membrane antigen (PSMA) is associated with a spectrum of neuroendocrine hallmarks and androgen receptor (AR) suppression in PC. Previous clinical reports indicate that PCs with a phenotype similar to neuroendocrine tumors can be more amenable to imaging by 18F-FDG than by PSMA-targeting radioligands. In this study, we evaluated the association between neuroendocrine gene signature and 18F-FDG uptake-associated genes including glucose transporters (GLUTs) and hexokinases, with the goal of providing a genomic signature to explain the reported 18F-FDG avidity of PSMA …

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Stretchable Ultrasheer Fabrics As Semitransparent Electrodes For Wearable Light-Emitting E-Textiles With Changeable Display Patterns, Yunyun Wu, Sara S. Mechael, Cecilia Lerma, R. Stephen Carmichael, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

Despite the development throughout human history of a wealth of textile materials and structures, the porous structures and non-planar surfaces of textiles are often viewed as problematic for the fabrication of wearable e-textiles and smart clothing. Here, we demonstrate a new textile-centric design paradigm in which we use the textile structure as an integral part of wearable device design. We coat the open framework structure of an ultrasheer knitted textile with a conformal gold film using solution-based metallization to form gold-coated ultrasheer electrodes that are highly conductive (3.6 ± 0.9 Ω/sq) and retain conductivity to 200% strain with R/R0 < 2. The ultrasheer electrodes produce wearable, highly stretchable light-emitting e-textiles that function to 200% strain. Stencil printing a wax resist provides patterned electrodes for patterned light emission; furthermore, incorporating soft-contact lamination produces light-emitting textiles that exhibit, for the first time, readily changeable patterns of illumination.

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Transverse Lipid Organization Dictates Bending Fluctuations In Model Plasma Membranes, Brett W. Rickeard, Michael H.L. Nguyen, Mitchell Dipasquale, Caesar G. Yip, Hamilton Baker, Frederick A. Heberle, Xiaobing Zuo, Elizabeth G. Kelley, Michihiro Nagao, Drew Marquardt

Chemistry and Biochemistry Publications

© 2020 The Royal Society of Chemistry. Membrane undulations play a vital role in many biological processes, including the regulation of membrane protein activity. The asymmetric lipid composition of most biological membranes complicates theoretical description of these bending fluctuations, yet experimental data that would inform any such a theory is scarce. Here, we used neutron spin-echo (NSE) spectroscopy to measure the bending fluctuations of large unilamellar vesicles (LUV) having an asymmetric transbilayer distribution of high- and low-melting lipids. The asymmetric vesicles were prepared using cyclodextrin-mediated lipid exchange, and were composed of an outer leaflet enriched in egg sphingomyelin (ESM) and …

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The Antioxidant Vitamin E As A Membrane Raft Modulator: Tocopherols Do Not Abolish Lipid Domains, Mitchell Dipasquale, Michael H.L. Nguyen, Brett W. Rickeard, Nicole Cesca, Christopher Tannous, Stuart R. Castillo, John Katsaras, Elizabeth G. Kelley, Frederick A. Heberle, Drew Marquardt

Chemistry and Biochemistry Publications

© 2020 Elsevier B.V. The antioxidant vitamin E is a commonly used vitamin supplement. Although the multi-billion dollar vitamin and nutritional supplement industry encourages the use of vitamin E, there is very little evidence supporting its actual health benefits. Moreover, vitamin E is now marketed as a lipid raft destabilizing anti-cancer agent, in addition to its antioxidant behaviour. Here, we studied the influence of vitamin E and some of its vitamers on membrane raft stability using phase separating unilamellar lipid vesicles in conjunction with small-angle scattering techniques and fluorescence microscopy. We find that lipid phase behaviour remains unperturbed well beyond …

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A Review And Critique Of Academic Lab Safety Research, A. Dana Ménard, John F. Trant

Chemistry and Biochemistry Publications

Over the past ten years, there have been several high-profile accidents in academic laboratories around the world, resulting in significant injuries and fatalities. The aftermath of these incidents is often characterized by calls for reflection and re-examination of the academic discipline’s approach to safety research and policy. However, the study of academic lab safety is still underdeveloped and necessary data about changes in safety attitudes and behaviours has not been gathered. This Review article critically examines the state of academic chemical safety research from a multifactorial stance, including research on the occurrence of lab accidents, contributors to lab accidents, the …

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Full-Text Articles in Physical Sciences and Mathematics

Acid-Triggered Self-Assembled Egg White Protein-Coated Gold Nanoclusters For Selective Fluorescent Detection Of Fe3+, No2-, And Cysteine, Wenyan Li, Xiangping Wen, Hemiao Zhao, Wenjun Yan, John F. Trant, Yingqi Li

Chemistry and Biochemistry Publications

Chemistry and Biochemistry Publications

A Mechanical Mechanism For Vitamin E Acetate In E-Cigarette/Vaping-Associated Lung Injury, Mitchell Dipasquale, Omotayo Gbadamosi, Michael H.L. Nguyen, Stuart R. Castillo, Brett W. Rickeard, Elizabeth G. Kelley, Michihiro Nagao, Drew Marquardt

Chemistry and Biochemistry Publications

Detecting Mercury (Ii) And Thiocyanate Using “Turn-On” Fluorescence Of Graphene Quantum Dots, Faezeh Askari, Abbas Rahdar, Mohadeseh Dashti, John F. Trant

Chemistry and Biochemistry Publications

The Synthesis Of Methotrexate-Loaded F127 Microemulsions And Their In Vivo Toxicity In A Rat Model, Abbas Rahdar, Mohammad Reza Hajinezhad, Sarah Nasri, Hamid Beyzaei, Mahmood Barani, John F. Trant

Chemistry and Biochemistry Publications

Cannabinoids And Cannabinoid Receptors: The Story So Far, Fred Shahbazi, Victoria Grandi, Abhinandan Banerjee, John F. Trant

Chemistry and Biochemistry Publications

The Structures Of Polyunsaturated Lipid Bilayers By Joint Refinement Of Neutron And X-Ray Scattering Data, Drew Marquardt, Frederick A. Heberle, Jianjun Pan, Xiaolin Cheng, Georg Pabst, Thad A. Harroun, Norbert Kučerka, John Katsaras

Chemistry and Biochemistry Publications

Chemistry and Biochemistry Publications

Stretchable Ultrasheer Fabrics As Semitransparent Electrodes For Wearable Light-Emitting E-Textiles With Changeable Display Patterns, Yunyun Wu, Sara S. Mechael, Cecilia Lerma, R. Stephen Carmichael, Tricia Breen Carmichael

Chemistry and Biochemistry Publications

Transverse Lipid Organization Dictates Bending Fluctuations In Model Plasma Membranes, Brett W. Rickeard, Michael H.L. Nguyen, Mitchell Dipasquale, Caesar G. Yip, Hamilton Baker, Frederick A. Heberle, Xiaobing Zuo, Elizabeth G. Kelley, Michihiro Nagao, Drew Marquardt

Chemistry and Biochemistry Publications

The Antioxidant Vitamin E As A Membrane Raft Modulator: Tocopherols Do Not Abolish Lipid Domains, Mitchell Dipasquale, Michael H.L. Nguyen, Brett W. Rickeard, Nicole Cesca, Christopher Tannous, Stuart R. Castillo, John Katsaras, Elizabeth G. Kelley, Frederick A. Heberle, Drew Marquardt

Chemistry and Biochemistry Publications

A Review And Critique Of Academic Lab Safety Research, A. Dana Ménard, John F. Trant

Chemistry and Biochemistry Publications