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Full-Text Articles in Physics

Design, Monitoring And Management Approaches For The Root-Zone In Microgravity, Scott B. Jones Jul 2020

Design, Monitoring And Management Approaches For The Root-Zone In Microgravity, Scott B. Jones

Funded Research Records

No abstract provided.


Covid-19: In The Absence Of Vaccination – ‘Mask-The-Nation’, Roy D. Sleator, Steven Darby, Alan Giltinan, Niall Smith Jul 2020

Covid-19: In The Absence Of Vaccination – ‘Mask-The-Nation’, Roy D. Sleator, Steven Darby, Alan Giltinan, Niall Smith

Department of Biological Sciences Publications

“In the absence of a vaccine, or effective antiviral, one of our only remaining strategies for controlling COVID-19 is to physically block the spread of SARS-CoV-2 in the community”


Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue, Ermek Belekov Jul 2020

Improved Antimicrobial Properties Of Silver Nanoparticles With Methylene Blue, Ermek Belekov

Masters Theses & Specialist Projects

Photosensitizing agents are the cornerstone of photodynamic therapy (PDT) that play essential role in deactivation process of multidrug resistant pathogens and tumor treatments. In this work we studied a photosensitizing agent made from mixture of silver nanoparticles (Ag NPs) and methylene blue (MB) which possess improved important characteristics like high photostability and high singlet oxygen yield. Ag NPs were synthesized by pulsed laser ablation technique in different aqueous solutions like Polyvinylpyrrolidone (PVP), citrate and Deionized (DI) water. The synthesized Ag NPs were characterized in depth using with transmission electron microscopy (TEM), UVVisible (UV-Vis), and photoluminescence (PL) spectra. Ag NPs were ...


Testing A Thermodynamic Approach To Collective Animal Behavior In Laboratory Fish Schools, Julia A. Giannini, James G. Puckett Jun 2020

Testing A Thermodynamic Approach To Collective Animal Behavior In Laboratory Fish Schools, Julia A. Giannini, James G. Puckett

Physics and Astronomy Faculty Publications

Collective behaviors displayed by groups of social animals are observed frequently in nature. Understanding and predicting the behavior of complex biological systems is dependent on developing effective descriptions and models. While collective animal systems are characteristically nonequilibrium, we can employ concepts from equilibrium statistical mechanics to motivate the measurement of material-like properties in laboratory animal aggregates. Here, we present results from a new set of experiments that utilize high speed footage of two-dimensional schooling events, particle tracking, and projected static and dynamic light fields to observe and control the behavior of negatively phototaxic fish schools (Hemigrammus bleheri). First, we use ...


Kinetic Exclusion Assay Of Biomolecules By Aptamer Capture, Mark H. Smith, Daniel Fologea Jun 2020

Kinetic Exclusion Assay Of Biomolecules By Aptamer Capture, Mark H. Smith, Daniel Fologea

Physics Faculty Publications and Presentations

DNA aptamers are short nucleotide oligomers selected to bind a target ligand with affinity and specificity rivaling that of antibodies. These remarkable features recommend aptamers as candidates for analytical and therapeutic applications that traditionally use antibodies as biorecognition elements. Numerous traditional and emerging analytical techniques have been proposed and successfully implemented to utilize aptamers for sensing purposes. In this work, we exploited the analytical capabilities offered by the kinetic exclusion assay technology to measure the affinity of fluorescent aptamers for their thrombin target and quantify the concentration of analyte in solution. Standard binding curves constructed by using equilibrated mixtures of ...


Biological Physics Student Edition 2020: Chapter 1, Philip C. Nelson May 2020

Biological Physics Student Edition 2020: Chapter 1, Philip C. Nelson

Department of Physics Papers

Chapter 1: What the Ancients Knew


Biological Physics Student Edition 2020: Contents And Prefaces, Philip C. Nelson May 2020

Biological Physics Student Edition 2020: Contents And Prefaces, Philip C. Nelson

Department of Physics Papers

Brief Contents; Detailed Contents; To the Student; To the Instructor


Temporary Membrane Permeabilization Via The Pore-Forming Toxin Lysenin, Nisha Shrestha, Christopher A. Thomas, Devon Richtsmeier, Andrew Bogard, Rebecca Hermann, Malyk Walker, Gamid Abatchev, Raquel J. Brown, Daniel Fologea May 2020

Temporary Membrane Permeabilization Via The Pore-Forming Toxin Lysenin, Nisha Shrestha, Christopher A. Thomas, Devon Richtsmeier, Andrew Bogard, Rebecca Hermann, Malyk Walker, Gamid Abatchev, Raquel J. Brown, Daniel Fologea

Physics Faculty Publications and Presentations

Pore-forming toxins are alluring tools for delivering biologically-active, impermeable cargoes to intracellular environments by introducing large conductance pathways into cell membranes. However, the lack of regulation often leads to the dissipation of electrical and chemical gradients, which might significantly affect the viability of cells under scrutiny. To mitigate these problems, we explored the use of lysenin channels to reversibly control the barrier function of natural and artificial lipid membrane systems by controlling the lysenin’s transport properties. We employed artificial membranes and electrophysiology measurements in order to identify the influence of labels and media on the lysenin channel’s conductance ...


Volume 12, Haleigh James, Hannah Meyls, Hope Irvin, Megan E. Hlavaty, Samara L. Gall, Austin J. Funk, Karyn Keane, Sarah Ghali, Antonio Harvey, Andrew Jones, Rachel Hazelwood, Madison Schmitz, Marija Venta, Haley Tebo, Jeremiah Gilmer, Bridget Dunn, Benjamin Sullivan, Mckenzie Johnson Apr 2020

Volume 12, Haleigh James, Hannah Meyls, Hope Irvin, Megan E. Hlavaty, Samara L. Gall, Austin J. Funk, Karyn Keane, Sarah Ghali, Antonio Harvey, Andrew Jones, Rachel Hazelwood, Madison Schmitz, Marija Venta, Haley Tebo, Jeremiah Gilmer, Bridget Dunn, Benjamin Sullivan, Mckenzie Johnson

Incite: The Journal of Undergraduate Scholarship

Introduction, Dr. Roger A. Byrne, Dean

From the Editor, Dr. Larissa "Kat" Tracy

From the Designers, Rachel English, Rachel Hanson

Immortality in the Mortal World: Otherworldly Intervention in "Lanval" and "The Wife of Bath's Tale" by Haleigh James

Analysis of Phenolic Compounds in Moroccan Olive Oils by HPLC by Hannah Meyls

Art by Hope Irvin

The Effects of Cell Phone Use on Gameplay Enjoyment and Frustration by Megan E. Hlavaty, Samara L. Gall, and Austin J. Funk

Care, No Matter What: Planned Parenthood's Use of Organizational Rhetoric to Expand its Reputation by Karyn Keane

Analysis of Petroleum Products ...


Got Science? Club, Nora Husein, Randa Ismail Apr 2020

Got Science? Club, Nora Husein, Randa Ismail

Honors Expanded Learning Clubs

Got Science? Club allows students to learn about the science that can be found in our daily lives using everyday items such as food and school supplies. Students will learn about these sciences through hands-on experiments, allowing them to truly experience the science around them.


Development Of A Novel Highly-Sensitive Brucellosis Sensor Based On Surface Plasmon Resonance Spectroscopy, Amal Kasry, Ihab Adly, Asharf Sayour, Hossam Sayour Jan 2020

Development Of A Novel Highly-Sensitive Brucellosis Sensor Based On Surface Plasmon Resonance Spectroscopy, Amal Kasry, Ihab Adly, Asharf Sayour, Hossam Sayour

Nanotechnology Research Centre

Brucellosis is considered a significant health threat, it is an infectious disease caused by the bacteria Brucella, which can spread from animals to humans causing severe diseases. Through this project, we aim to develop a very highly sensitive biosensor to detect Brucella early before spreading. This sensor is based on surface plasmon resonance (SPR) technique, which is used to analyze kinetics of interaction between biomolecules. It can detect down to picomolar concentrations of some proteins.


Physical Models Of Living Systems Chapter 12: Single Particle Reconstruction In Cryo-Electron Microscopy, Philip C. Nelson Nov 2019

Physical Models Of Living Systems Chapter 12: Single Particle Reconstruction In Cryo-Electron Microscopy, Philip C. Nelson

Department of Physics Papers

This chapter extends Part III of the book Physical Models of Living Systems (WH Freeman 2015). This preliminary version is made freely available as-is in the hope that it will be useful.


9th Annual Postdoctoral Science Symposium, University Of Texas Md Anderson Cancer Center Postdoctoral Association Sep 2019

9th Annual Postdoctoral Science Symposium, University Of Texas Md Anderson Cancer Center Postdoctoral Association

MD Anderson Cancer Center Postdoctoral Association Annual Postdoctoral Science Symposium Abstracts

The mission of the Annual Postdoctoral Science Symposium (APSS) is to provide a platform for talented postdoctoral fellows throughout the Texas Medical Center to present their work to a wider audience. The MD Anderson Postdoctoral Association convened its inaugural Annual Postdoctoral Science Symposium (APSS) on August 4, 2011.

The APSS provides a professional venue for postdoctoral scientists to develop, clarify, and refine their research as a result of formal reviews and critiques of faculty and other postdoctoral scientists. Additionally, attendees discuss current research on a broad range of subjects while promoting academic interactions and enrichment and developing new collaborations.


A Harmless Wireless Quantum Alternative To Cell Phones Based On Quantum Noise, Florentin Smarandache, Robert Neil Boyd, Victor Christianto Sep 2019

A Harmless Wireless Quantum Alternative To Cell Phones Based On Quantum Noise, Florentin Smarandache, Robert Neil Boyd, Victor Christianto

Mathematics and Statistics Faculty and Staff Publications

In the meantime we know that 4G and 5G technologies cause many harms to human health. Therefore, here we submit a harmless wireless quantum alternative to cell phones. It is our hope that this alternative


Experimental Evidence Supportive Of The Quantum Dna Model, F. Matthew Mihelic May 2019

Experimental Evidence Supportive Of The Quantum Dna Model, F. Matthew Mihelic

Faculty Publications

The DNA molecule can be modeled as a quantum logic processor in which electron spin qubits are held coherently in each nucleotide in a logically and thermodynamically reversible enantiomeric symmetry, and can be coherently conducted along the pi-stacking interactions of aromatic nucleotide bases, while simultaneously being spin-filtered via the helicity of the DNA molecule. Entangled electron pairs can be separated by that spin-filtering, held coherently at biological temperatures in the topologically insulated nucleotide quantum gates, and incorporated into separate DNA strands during DNA replication. Two separate DNA strands that share quantum entangled electrons can be mitotically divided into individual cells ...


The Effects Of Organic And Inorganic Nanoparticles On Bacterial Deactivation, Lauren Cooper Apr 2019

The Effects Of Organic And Inorganic Nanoparticles On Bacterial Deactivation, Lauren Cooper

Mahurin Honors College Capstone Experience/Thesis Projects

Antibacterial resistance is one of the greatest problems in modern medicine, as healthcare professionals are experiencing more and more difficulty in providing effective care. As such, alternative methods of treatment are needed in order to overcome this issue. One recently proposed method of alternative treatment is photodynamic therapy. Photodynamic therapy is a light-based method of treatment that utilizes (1) a photosensitizing agent, (2) light, (3) produced oxygen species. When the photosensitizing agent is injected into an infected region of interest and then irradiated with a certain wavelength of light, the agent is photoactivated and begins to produce harmful forms of ...


A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak Feb 2019

A Theoretical Model Of Underground Dipole Antennas For Communications In Internet Of Underground Things, Abdul Salam, Mehmet C. Vuran, Xin Dong, Christos Argyropoulos, Suat Irmak

Faculty Publications

The realization of Internet of Underground Things (IOUT) relies on the establishment of reliable communication links, where the antenna becomes a major design component due to the significant impacts of soil. In this paper, a theoretical model is developed to capture the impacts of change of soil moisture on the return loss, resonant frequency, and bandwidth of a buried dipole antenna. Experiments are conducted in silty clay loam, sandy, and silt loam soil, to characterize the effects of soil, in an indoor testbed and field testbeds. It is shown that at subsurface burial depths (0.1-0.4m), change in soil ...


Volume 11, Jacob Carney, Ryan White, Joseph Hyman, Jenny Raven, Megan Garrett, Ibrahim Kante, Summer Meinhard, Lauren Johnson, William "Editha" Dean Howells, Laura Gottschalk, Christopher Siefke, Pink Powell, Natasha Woodmancy, Katharine Colley, Abbey Mays, Charlotte Potts Jan 2019

Volume 11, Jacob Carney, Ryan White, Joseph Hyman, Jenny Raven, Megan Garrett, Ibrahim Kante, Summer Meinhard, Lauren Johnson, William "Editha" Dean Howells, Laura Gottschalk, Christopher Siefke, Pink Powell, Natasha Woodmancy, Katharine Colley, Abbey Mays, Charlotte Potts

Incite: The Journal of Undergraduate Scholarship

Table of Contents:

Introduction, Dr. Roger A. Byrne, Dean

From the Editor, Dr. Larissa "Kat" Tracy

From the Designers, Rachel English, Rachel Hanson

Synthesis of 3,5-substituted Parabens and their Antimicrobial Properties, Jacob Coarney, Ryan White

Chernobyl: Putting "Perestroika" and "Glasnot" to the Test, Joseph Hyman

Art by Jenny Raven

Watering Down Accessibility: The Issue with Public Access to Alaska's Federal Waterways, Meagan Garrett

Why Has the Democratic Republic of the Congo outsourced its Responsibility to Educate its Citizens? Ibrahim Kante

Art by Summer Meinhard

A Computational Study of Single Molecule Diodes, Lauren Johnson

Satire of the State through ...


Memory Formation In Matter, Joseph Paulsen, Nathan C. Keim, Zorana Zeravcic, Srikanth Sastry, Sidney R. Nagel Jan 2019

Memory Formation In Matter, Joseph Paulsen, Nathan C. Keim, Zorana Zeravcic, Srikanth Sastry, Sidney R. Nagel

Physics

Memory formation in matter is a theme of broad intellectual relevance; it sits at the interdisciplinary crossroads of physics, biology, chemistry, and computer science. Memory connotes the ability to encode, access, and erase signatures of past history in the state of a system. Once the system has completely relaxed to thermal equilibrium, it is no longer able to recall aspects of its evolution. The memory of initial conditions or previous training protocols will be lost. Thus many forms of memory are intrinsically tied to far-from-equilibrium behavior and to transient response to a perturbation. This general behavior arises in diverse contexts ...


Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George Dec 2018

Generating High-Order Optical And Spin Harmonics From Ferromagnetic Monolayers, G.P. Zhang, M.S. Si, M. Murakami, Y.H. Bai, Thomas George

Chemistry & Biochemistry Faculty Works

High-order harmonic generation (HHG) in solids has entered a new phase of intensive research, with envisioned band-structure mapping on an ultrashort time scale. This partly benefits from a flurry of new HHG materials discovered, but so far has missed an important group. HHG in magnetic materials should have profound impact on future magnetic storage technology advances. Here we introduce and demonstrate HHG in ferromagnetic monolayers. We find that HHG carries spin information and sensitively depends on the relativistic spin–orbit coupling; and if they are dispersed into the crystal momentum k space, harmonics originating from real transitions can be k-resolved ...


Optimization Of Detergent-Mediated Reconstitution Of Influenza A M2 Protein Into Proteoliposomes, Catherine Hirshfeld Crouch, Margaret H. Bost , '17, Tae H. Kim , '14, Bryan M. Green , '16, Douglas Stuart Arbuckle , '17, Carl H. Grossman, Kathleen P. Howard Dec 2018

Optimization Of Detergent-Mediated Reconstitution Of Influenza A M2 Protein Into Proteoliposomes, Catherine Hirshfeld Crouch, Margaret H. Bost , '17, Tae H. Kim , '14, Bryan M. Green , '16, Douglas Stuart Arbuckle , '17, Carl H. Grossman, Kathleen P. Howard

Physics & Astronomy Faculty Works

We report the optimization of detergent-mediated reconstitution of an integral membrane-bound protein, full-length influenza M2 protein, by direct insertion into detergent-saturated liposomes. Detergent-mediated reconstitution is an important method for preparing proteoliposomes for studying membrane proteins, and must be optimized for each combination of protein and membrane constituents used. The purpose of the reconstitution was to prepare samples for site-directed spin-labeling electron paramagnetic resonance (SDSL-EPR) studies. Our goals in optimizing the protocol were to minimize the amount of detergent used, reduce overall proteoliposome preparation time, and confirm the removal of all detergent. The liposomes were comprised of (1-palmitoyl-2-oleyl-sn-glycero-phosphocholine (POPC) and 1-palmitoyl-2-oleyl-sn-glycero-3- ...


Exploring The Neural Mechanisms Of Physics Learning, Jessica E. Bartley Nov 2018

Exploring The Neural Mechanisms Of Physics Learning, Jessica E. Bartley

FIU Electronic Theses and Dissertations

This dissertation presents a series of neuroimaging investigations and achievements that strive to deepen and broaden our understanding of human problem solving and physics learning. Neuroscience conceives of dynamic relationships between behavior, experience, and brain structure and function, but how neural changes enable human learning across classroom instruction remains an open question. At the same time, physics is a challenging area of study in which introductory students regularly struggle to achieve success across university instruction. Research and initiatives in neuroeducation promise a new understanding into the interactions between biology and education, including the neural mechanisms of learning and development. These ...


Structural And Wetting Properties Of Nature's Finest Silks (Order Embioptera), Grace Y. Stokes, Evangelea N. Dicicco, Trevor J. Moore, Vivian C. Cheng, Kira Y. Wheeler, John Soghigian, Richard P. Barber Jr., Janice Edgerly-Rooks Sep 2018

Structural And Wetting Properties Of Nature's Finest Silks (Order Embioptera), Grace Y. Stokes, Evangelea N. Dicicco, Trevor J. Moore, Vivian C. Cheng, Kira Y. Wheeler, John Soghigian, Richard P. Barber Jr., Janice Edgerly-Rooks

Physics

Insects from the order Embioptera (webspinners) spin silk fibres which are less than 200 nm in diameter. In this work, we characterized and compared the diameters of single silk fibres from nine species—Antipaluria urichi, Pararhagadochir trinitatis, Saussurembia calypso, Diradius vandykei, Aposthonia ceylonica, Haploembia solieri, H. tarsalis, Oligotoma nigra and O. saundersii. Silk from seven of these species have not been previously quantified. Our studies cover five of the 10 named taxonomic families and represent about one third of the known taxonomic family-level diversity in the order Embioptera. Naturally spun silk varied in diameter from 43.6 ± 1.7 nm ...


Activities And Classroom Demonstrations In Biological Physics: A Resource Document, Philip C. Nelson, William Berner Jul 2018

Activities And Classroom Demonstrations In Biological Physics: A Resource Document, Philip C. Nelson, William Berner

Department of Physics Papers

We give detailed recipes for a number of classroom demonstrations relevant to biological physics instruction. We developed them mainly for use in 2nd-3rd year undergraduate Physics courses. But you can (and we do) use them for primary school, through high school, up to PhD candidates. You adapt the words for each audience, but a phenomenon is a phenomenon.

We also outline a 1-hour introduction to Python for undergraduate scientific computing.

Finally we document some outcomes from courses taught at U Pennsylvania using these resources and others cited here. This material was presented at a workshop at the AAPT meeting in ...


Computer Design Of Microfluidic Mixers For Protein/Rna Folding Studies, Venkatesh Inguva, Sagar V. Kathuria, Osman Bilsel, Blair James Perot Jun 2018

Computer Design Of Microfluidic Mixers For Protein/Rna Folding Studies, Venkatesh Inguva, Sagar V. Kathuria, Osman Bilsel, Blair James Perot

Open Access Articles

Kinetic studies of biological macromolecules increasingly use microfluidic mixers to initiate and monitor reaction progress. A motivation for using microfluidic mixers is to reduce sample consumption and decrease mixing time to microseconds. Some applications, such as small-angle x-ray scattering, also require large ( > 10 micron) sampling areas to ensure high signal-to-noise ratios and to minimize parasitic scattering. Chaotic to marginally turbulent mixers are well suited for these applications because this class of mixers provides a good middle ground between existing laminar and turbulent mixers. In this study, we model various chaotic to marginally turbulent mixing concepts such as flow turning, flow ...


Multicomponent Analysis Using A Confocal Raman Microscope, Zhengyuan Tang, Sinead J. Barton, Thomas E. Ward, John P. Lowry, Michelle M. Doran, Hugh Byrne, Bryan M. Hennelly Jun 2018

Multicomponent Analysis Using A Confocal Raman Microscope, Zhengyuan Tang, Sinead J. Barton, Thomas E. Ward, John P. Lowry, Michelle M. Doran, Hugh Byrne, Bryan M. Hennelly

Articles

Measuring the concentration of multiple chemical components in a low volume aqueous mixture by Raman spectroscopy has received significant interest in the literature. All of the contributions to date focus on the design of optical systems that facilitate the recording of spectra with high signal-to-noise ratio, by collecting as many Raman scattered photons as possible. In this study, the confocal Raman microscope set-up is investigated for multicomponent analysis. Partial Least Squares Regression is used to quantify physiologically relevant aqueous mixtures of glucose, lactic acid, and urea. The predicted error is 17.81 mg/dL for glucose, 10.6 mg/dL ...


Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne May 2018

Raman Spectral Analysis For Rapid Screening Of Dengue Infection, Tahir Mahmood, Haq Nawaz, A. Ditta, M.I. Majeed, M.A. Hanif, N. Rashid, H.N. Bhatti, H.F. Nargis, M. Saleem, Franck Bonnier, Hugh Byrne

Articles

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated ...


Characterization And Analysis Of Ultrathin Cigs Films And Solar Cells Deposited By 3-Stage Process, Grace Rajan, Krishna Aryal, Shankar Karki, Puruswottam Aryal, Robert W. Collins, Sylvain Marsillac May 2018

Characterization And Analysis Of Ultrathin Cigs Films And Solar Cells Deposited By 3-Stage Process, Grace Rajan, Krishna Aryal, Shankar Karki, Puruswottam Aryal, Robert W. Collins, Sylvain Marsillac

Electrical & Computer Engineering Faculty Publications

In view of the large-scale utilization of Cu(In,Ga)Se2 (CIGS) solar cells for photovoltaic application, it is of interest not only to enhance the conversion efficiency but also to reduce the thickness of the CIGS absorber layer in order to reduce the cost and improve the solar cell manufacturing throughput. In situ and real-time spectroscopic ellipsometry (RTSE) has been used conjointly with ex situ characterizations to understand the properties of ultrathin CIGS films. This enables monitoring the growth process, analyzing the optical properties of the CIGS films during deposition, and extracting composition, film thickness, grain size, and ...


Alluvial Substrate Mapping By Automated Texture Segmentation Of Recreational-Grade Side Scan Sonar Imagery, Daniel Hamill, Daniel Buscombe, Joseph M. Wheaton Mar 2018

Alluvial Substrate Mapping By Automated Texture Segmentation Of Recreational-Grade Side Scan Sonar Imagery, Daniel Hamill, Daniel Buscombe, Joseph M. Wheaton

Watershed Sciences Faculty Publications

Side scan sonar in low-cost ‘fishfinder’ systems has become popular in aquatic ecology and sedimentology for imaging submerged riverbed sediment at coverages and resolutions sufficient to relate bed texture to grain-size. Traditional methods to map bed texture (i.e. physical samples) are relatively high-cost and low spatial coverage compared to sonar, which can continuously image several kilometers of channel in a few hours. Towards a goal of automating the classification of bed habitat features, we investigate relationships between substrates and statistical descriptors of bed textures in side scan sonar echograms of alluvial deposits. We develop a method for automated segmentation ...


Characterization Of Pharmaceutical Cocrystals And Salts By Dynamic Nuclear Polarization-Enhanced Solid-State Nmr Spectroscopy, Li Zhao, Michael P. Hanrahan, Genetech, Inc., Aaron J. Rossini Feb 2018

Characterization Of Pharmaceutical Cocrystals And Salts By Dynamic Nuclear Polarization-Enhanced Solid-State Nmr Spectroscopy, Li Zhao, Michael P. Hanrahan, Genetech, Inc., Aaron J. Rossini

Ames Laboratory Accepted Manuscripts

Multicomponent solids such as cocrystals have emerged as a way to control and engineer the stability, solubility, and manufacturability of solid active pharmaceutical ingredients (APIs). Cocrystals are typically formed by solution- or solid-phase reactions of APIs with suitable cocrystal coformers, which are often weak acids. One key structural question about a given multicomponent solid is whether it should be classified as a salt, where the basic API is protonated by the acid, or as a cocrystal, where the API and coformer remain neutral and engage in hydrogen bonding interactions. It has previously been demonstrated that solid-state NMR spectroscopy is a ...