Repository logo

Faculty Publications

Permanent URI for this collection

https://hdl.handle.net/10217/179925

Browse

Browsing Faculty Publications by Issue Date

Filter results by year or month
Now showing 1 - 7 of 7
  • Thumbnail Image
    ItemOpen Access
    The isolation of synaptosomes and synaptic plasma membranes from bovine cerebral cortex
    (Colorado State University. Libraries, 1977) DiVerdi, Joseph Anthony, author
    A method is described for the preparation of synaptosomes and synaptic plasma membranes from Bovine cerebral cortex. After homogenization of the tissue in isotonic sucrose, differential centrifugation yielded a crude mitochondrial fraction (P2) which was purified by centrifugation on a Ficoll-sucrose gradient. Assay of occluded Lactate Dehydrogenase and electron microscopy confirmed that synaptosomes survived the fractionation procedure and appeared in the P2B and P2C fractions, sedimenting to a density of approximately 1.117. The final membrane preparation had a specific 5' -nucleotidase activity (units/mg protein) over 10 times higher than the brain homogenate. Membrane fragments derived from outer mitochondrial membranes and microsomes appear to be the major contaminants. Gel electrophoresis revealed proteins migrating at approximately the same rate as contractile proteins.
  • Thumbnail Image
    ItemOpen Access
    Nuclear magnetic resonance of nucleic acids in the solid state
    (Colorado State University. Libraries, 1981) DiVerdi, Joseph Anthony, author
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    Modification of orthogonal tRNAs: unexpected consequences for sense codon reassignment
    (Colorado State University. Libraries, 2016-10-23) Biddle, Wil, author; Schmitt, Margaret A., author; Fisk, John D., author; Oxford University Press, publisher
    Breaking the degeneracy of the genetic code via sense codon reassignment has emerged as a way to incorporate multiple copies of multiple non-canonical amino acids into a protein of interest. Here, we report the modification of a normally orthogonal tRNA by a host enzyme and show that this adventitious modification has a direct impact on the activity of the orthogonal tRNA in translation. We observed nearly equal decoding of both histidine codons, CAU and CAC, by an engineered orthogonal M. jannaschii tRNA with an AUG anticodon: tRNAOpt. We suspected a modification of the tRNAOptAUG anticodon was responsible for the anomalous lack of codon discrimination and demonstrate that adenosine 34 of tRNAOptAUG is converted to inosine. We identified tRNAOptAUG anticodon loop variants that increase reassignment of the histidine CAU codon, decrease incorporation in response to the histidine CAC codon, and improve cell health and growth profiles. Recognizing tRNA modification as both a potential pitfall and avenue of directed alteration will be important as the field of genetic code engineering continues to infiltrate the genetic codes of diverse organisms.
  • Thumbnail Image
    ItemOpen Access
    Quantifying proximity, confinement, and interventions in disease outbreaks: a decision support framework for air-transported pathogens
    (Colorado State University. Libraries, 2021-02-19) Bond, Tami C, author; Bosco-Lauth, Angela, author; Farmer, Delphine K., author; Francisco, Paul W., author; Pierce, Jeffrey R., author; Fedak, Kristen M., author; Ham, Jay M., author; Jathar, Shantanu H., author; VandeWoude, Sue, author; Environmental Science & Technology, publisher
    The inability to communicate how infectious diseases are transmitted in human environments has triggered avoidance of interactions during the COVID-19 pandemic. We define a metric, Effective ReBreathed Volume (ERBV), that encapsulates how infectious pathogens, including SARS-CoV-2, transport in air. ERBV separates environmental transport from other factors in the chain of infection, allowing quantitative comparisons among situations. Particle size affects transport, removal onto surfaces, and elimination by mitigation measures, so ERBV is presented for a range of exhaled particle diameters: 1, 10, and 100 μm. Pathogen transport depends on both proximity and confinement. If interpersonal distancing of 2 m is maintained, then confinement, not proximity, dominates rebreathing after 10–15 min in enclosed spaces for all but 100 μm particles. We analyze strategies to reduce this confinement effect. Ventilation and filtration reduce person-to-person transport of 1 μm particles (ERBV1) by 13–85% in residential and office situations. Deposition to surfaces competes with intentional removal for 10 and 100 μm particles, so the same interventions reduce ERBV10 by only 3–50%, and ERBV100 is unaffected. Prior knowledge of size-dependent ERBV would help identify transmission modes and effective interventions. This framework supports mitigation decisions in emerging situations, even before other infectious parameters are known.
  • Thumbnail Image
    ItemOpen Access
    Electrothermal performance of heaters based on laser-induced graphene on aramid fabric
    (Colorado State University. Libraries, 2022) Naseri, Iman, author; Ziaee, Morteza, author; Nilsson, Zach N., author; Lustig, Danielle R., author; Yourdkhani, Mostafa, author; American Chemical Society, publisher
    Nanostructured heaters based on laser-induced graphene (LIG) are promising for heat generation and temperature control in a variety of applications due to their high efficiency as well as a fast, facile, and highly scalable fabrication process. While recent studies have shown that LIG can be written on a wide range of precursors, the reports on LIG-based heaters are mainly limited to polyimide film substrates. Here, we develop and characterize nanostructured heaters by direct writing of laser-induced graphene on nonuniform and structurally porous aramid woven fabric. The synthesis and writing of graphene on aramid fabric is conducted using a 10.6 μm CO2 laser. The quality of laser-induced graphene and electrical properties of the heater fabric is tuned by controlling the lasing process parameters. Produced heaters exhibit good electrothermal efficiency with steady-state temperatures up to 170 °C when subjected to an input power density of 1.5 W cm–2. In addition, the permeable texture of LIG–aramid fabric heaters allows for easy impregnation with thermosetting resins. We demonstrate the encapsulation of fabric heaters with two different types of thermosetting resins to develop both flexible and stiff composites. A flexible heater is produced by the impregnation of LIG–aramid fabric by silicone rubber. While the flexible composite heater exhibits inferior electrothermal performance compared to neat LIG–aramid fabric, it shows consistent electrothermal performance under various electrical and mechanical loading conditions. A multifunctional fiber-reinforced composite panel with integrated de-icing functionality is also manufactured using one ply of LIG–aramid fabric heater as part of the composite layup. The results of de-icing experiments show excellent de-icing capability, where a 5 mm thick piece of ice is completely melted away within 2 min using an input power of 12.8 W.
  • Thumbnail Image
    ItemOpen Access
    Contemporary topics in undergraduate experimental organic chemistry - OER project materials
    (Colorado State University. Libraries, 2023-05) Piyaratne, Panduka, author
    A supplementary OER booklet for Undergraduate Organic Chemistry Laboratory Courses offered by the Department of Chemistry, Colorado State University.