Biological and Chemical Physics Commons^™

Quantitative Reagent-Free Detection Of Fibrinogen Levels In Human Blood Plasma Using Raman Spectroscopy, Kelvin Poon, Fiona Lyng, Peter Knief, Orla L. Howe, Aidan Meade, James Curtin, Hugh Byrne, Joseph Vaughan

Articles

Fibrinogen assays are commonly used as part of clinical screening tests to investigate haemorrhagic states, for detection of disseminated intravascular coagulation and as a predictor of a variety of cardiovascular events. The Clauss assay, which measures thrombin clotting time, is the most commonly used method for measuring fibrinogen levels. Nevertheless, inconsistencies are present in inter-manufacturer reagent sources, calibration standards and methodologies. Automated coagulation analysers, which measure changes in optical density during the prothrombin time (PT-Fg), have found use in many hospitals. However, the PT-Fg method is found to give falsely elevated values due to varying choices of calibrants, reagents and …

Ogólnotechniczne Podstawy Biotechnologii Z Elementami Grafiki Inżynierskiej Ćw., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Materiały Odstresowujące, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Modeling Of Growth Kinetics And Characterization Of Membrane Mechanics, Antonio Nava

Electronic Theses and Dissertations

One growing field in alternative energy is biofuel production through microorganisms. These fields of research include hydrogen and biofuel production through the cultivation of algae. We've selected 2 different algae, Anabaena sp. cpcc 387 and Tetraselmis to study. Through mathematical modeling of Anabaena we investigate the complex multicellular relationships and colony stability when noise is introduced. In conjunction with researchers at NREL, we've set out to characterize Tetraselmis cells' membrane elasticity.

Simulated Associating Polymer Networks, Joris Billen

CGU Theses & Dissertations

Telechelic associating polymer networks consist of polymer chains terminated by endgroups that have a different chemical composition than the polymer backbone. When dissolved in a solution, the endgroups cluster together to form aggregates. At low temperature, a strongly connected reversible network is formed and the system behaves like a gel. Telechelic networks are of interest since they are representative for biopolymer networks (e.g. F-actin) and are widely used in medical applications (e.g. hydrogels for tissue engineering, wound dressings) and consumer products (e.g. contact lenses, paint thickeners).

In this thesis such systems are studied by means of a molecular dynamics/Monte Carlo …

Resonant Inelastic X-Ray Scattering Of Methyl Chloride At The Chlorine K Edge, L. El Khoury, Loic Journel, Renaud Guillemin, Stephane Carniato, Wayne C. Stolte, T. Marin, Dennis W. Lindle, Marc Simon

Chemistry and Biochemistry Faculty Research

We present a combined experimental and theoretical study of isolated CH3Cl molecules using resonant inelastic x-ray scattering (RIXS). The high-resolution spectra allow extraction of information about nuclear dynamics in the core-excited molecule. Polarization-resolved RIXS spectra exhibit linear dichroism in the spin-orbit intensities, a result interpreted as due to chemical environment and singlet-triplet exchange in the molecular core levels. From analysis of the polarization-resolved data, Cl 2px, y and 2pz electronic populations can be determined.

A New Method To Derive Electronegativity From Resonant Inelastic X-Ray Scattering, Stephane Carniato, Loic Journel, Renaud Guillemin, Maria Novella Piancastelli, Wayne C. Stolte, Dennis W. Lindle, Marc Simon

Chemistry and Biochemistry Faculty Research

Electronegativity is a well-known property of atoms and substituent groups. Because there is no direct way to measure it, establishing a useful scale for electronegativity often entails correlating it to another chemical parameter; a wide variety of methods have been proposed over the past 80 years to do just that. This work reports a new approach that connects electronegativity to a spectroscopic parameter derived from resonant inelastic x-ray scattering. The new method is demonstrated using a series of chlorine-containing compounds, focusing on the Cl 2p−1LUMO1 electronic states reached after Cl 1s→LUMO core excitation and subsequent KL radiative decay. Based on …

Thomson-Resonant Interference Effects In Elastic X-Ray Scattering Near The Cl K Edge Of Hcl, Stephane Carniato, P. Selles, Loic Journel, Renaud Guillemin, Wayne C. Stolte, L. El Khoury, T. Marin, Faris Gel'mukhanov, Dennis W. Lindle, Marc Simon

Chemistry and Biochemistry Faculty Research

We experimentally observed interference effects in elastic x-ray scattering from gas-phase HCl in the vicinity of the Cl K edge. Comparison to theory identifies these effects as interference effects between non-resonant elastic Thomson scattering and resonant Raman scattering. The results indicate the non-resonant Thomson and resonant Raman contributions are of comparable strength. The measurements also exhibit strong polarization dependence, allowing an easy identification of the resonant and non-resonant contributions.

Fabrication And Characterization Of Aluminum-Doped Zno/Pani Hybrid Solar Cells, S. Abdulalmohsin, S. M. Al-Mutoki, Z. Li

Journal of the Arkansas Academy of Science

We report a facile method to fabricate an AZO/PANI heterostructure by a sandwiching technique. Aluminum-doped ZnO (AZO) films were deposited onto indium tin oxide (ITO) glass using the sputtering technique while PANI films were deposited onto ITO glass using electropolymerization. The optoelectric properties of the inorganic/organic device were characterized

Current Range In Lightning Return Strokes, M. Hemmati, W. P. Childs, D. C. Waters, J. R. Christensen, B. C. Richard

Journal of the Arkansas Academy of Science

In our investigation of breakdown waves, we use a one-dimensional, steady-state, constant velocity fluid model. This investigation involves breakdown waves for which the electric field force on electrons is in the opposite direction of wave propagation. The waves are considered to be shock fronted and the electron gas partial pressure is large enough to sustain the wave propagation. Our basic set of electron fluid-dynamical equations is composed of the equations for conservation of mass, momentum and energy, coupled with Poisson’s equation. This investigation involves breakdown waves for which a large current exists behind the shock front. The current behind the …

Electrochemical Polymerization Of Ppy-Mwcnt Composite As A Counter Electrode For Dye-Sensitized Solar Cells, S. Abdulalmohsin, S. M. Al-Mutoki, Z. Li

Journal of the Arkansas Academy of Science

Polypyrrole (PPy) - multi wall carbon nanotube (MWCNT) nanocomposites were synthesized by using in situ electrochemical polymerization with different COOH-functionalized MWCNTs. The PPY-MWCNT composites were used as counter electrode in the fabrication of dye sensitized solar cells (DSCs). Compared to the DSC device with PPy counter electrode, the devices with PPY/MWCNT composite electrode offer much higher total photovoltaic conversion efficiency due to the reduced series resistance. These PPY/MWCNT nanocomposite materials proved to be a good alternate to the expensive Pt as counter electrode in DSC.

Al/Pani-Mwnt/Au-Plastic Schottky Diode Solar Cells, S. Abdulalmohsin, S. M. Al-Mutoki, Z. Li

Journal of the Arkansas Academy of Science

Al/PANI-MWNT/Au-Plastic Schottky diode solar cells were fabricated by the electrochemical polymerization technique to make polyaniline films on the top of gold nanoparticles film. The aluminum contact was deposited by thermal evaporation. The electro-optical characteristics of these devices produced at the different polymerization time were compared. Here, we achieved the highest ever reported open-circuit voltage of 0.8 V with the electrochemical polymerization technique. The polymerization of polyaniline films was thought to be a major factor in the enhanced performance. The effects of varying the polyaniline thickness on the device performance were investigated

Shaping The Future Past: Finding History, Creating Identity In The Kwan Hsu Papers, Lisa Chere' Donnelly

Dissertations and Theses

Dr. Kwan Hsu was neither a superstar nor a celebrity. Her name does not come up in conversations about important contributors to her field of biophysics nor is she instantly recognizable for her contributions to Portland State University's international program or the state of Oregon's business ties with China. Yet she was a contributor, a cog-in-the-wheel, at the very least, in all of these areas and more. She was a peripheral member of a well-known Chinese family, but few in the United States know of or perhaps have interest in, but otherwise, she had no great connections or family ties …

Hydrogen Production From Biogas By Oxy-Reforming: Reaction System Analysis, Aleksandra Terlecka, Wojciech M. Budzianowski

Wojciech Budzianowski

Oxy-reforming is emerging as an interesting alternative to conventional methods of hydrogen generation. The current article characterises this process through analysis of individual reactions: SMR (steam methane reforming), WGS (water gas shift) and CPO (catalytic partial oxidation). Analyses relate to optimisation of thermal conditions thus enabling cost-effectivenes of the process.

Absolute Quantification Of Gene Expression In Individual Bacterial Cells Using Two-Photon Fluctuation Microscopy, Matthew L. Ferguson, Dominique Le Coq, Matthieu Jules, Stéphane Aymerich, Nathalie Declerck, Catherine A. Royer

Matthew L. Ferguson

Quantification of promoter activity or protein expression in gene regulatory networks is generally achieved via measurement of fluorescent protein (FP) intensity, which is related to the true FP concentration by an unknown scaling factor, thereby limiting analysis and interpretation. Here, using approaches originally developed for eukaryotic cells, we show that two-photon (2p) fluorescence fluctuation microscopy, specifically scanning number and brightness (sN&B) analysis, can be applied to determine the absolute concentrations of diffusing FPs in live bacterial cells. First, we demonstrate the validity of the approach, despite the small size of the bacteria, using the central pixels and spatial averaging. We …

Molecular Dynamics Studies Of Interactions Of Phospholipid Membranes With Dehydroergosterol And Penetrating Peptides, Amir Mohsen Pourmousa Abkenar

Electronic Thesis and Dissertation Repository

We have performed molecular modeling of membrane and peptide systems by employing the classical molecular dynamics method and force field parameterizations. In this thesis, our main interest is the interaction of sterols as well as peptides with membranes. The thesis consists of three related projects. The first project focuses on cholesterol (CHOL) and dehydroergosterol (DHE) interacting with palmitoyl-oleoyl phosphatidylcholine (POPC) lipid bilayers. We study the effects of both sterols on the bilayer and compare them with each other. We first study the condensing and ordering effect of these sterols. Then, we study their orientations within the bilayer and relate them …

Spectroscopic Studies Of Melamine At High Pressure, Martin Donald Galley

UNLV Theses, Dissertations, Professional Papers, and Capstones

We have performed mid- and far- Infra Red (IR) absorption, Raman spectroscopy, and angular dispersive x-ray diffraction (XRD) studies on melamine under high pressure and room temperature. We have verified the presence of two prior reported phase transitions, the first between 1-2 GPa, and the second between 7-9 GPa. We have also found evidence of a third unreported phase transition between 14-16 GPa, during which, there was a sudden disappearance of all low energy peaks (^-1 ) in both the Raman and IR spectra. The far-IR peak movement experiences a discontinuity as the rate of peak movement suddenly changes. …

Progress In The Prediction Of Pka Values In Proteins, Emil Alexov, Ernest L. Mehler, Nathan Baker, Antonio Baptista, Yong Huang, Francesca Milletti, Jens Erik Nielsen, Damien Farrell, Tommy Carstensen, Mats H.M. Olsson, Jana K. Shen, Jim Warwicker, Sarah Williams, J Michael Word

Publications

The pK_a-cooperative aims to provide a forum for experimental and theoretical researchers interested in protein pK_a values and protein electrostatics in general. The first round of the pK_a-cooperative, which challenged computational labs to carry out blind predictions against pK_as experimentally determined in the laboratory of Bertrand Garcia-Moreno, was completed and results discussed at the Telluride meeting (July 6–10, 2009). This article serves as an introduction to the reports submitted by the blind prediction participants that will be published in a special issue of PROTEINS: Structure, Function and Bioinformatics. …

Developing Hybrid Approaches To Predict Pka Values Of Ionizable Groups, Shawn Witham, Kemper Talley, Lin Wang, Zhe Zhang, Daquan Gao, Wei Yang, Emil Alexov

Publications

Accurate predictions of pKa values of titratable groups require taking into account all relevant processes associated with the ionization/deionization. Frequently, however, the ionization does not involve significant structural changes and the dominating effects are purely electrostatic in origin allowing accurate predictions to be made based on the electrostatic energy difference between ionized and neutral forms alone using a static structure. On another hand, if the change of the charge state is accompanied by a structural reorganization of the target protein, then the relevant conformational changes have to be taken into account in the pKa calculations. Here we report a hybrid …

Photolithographic Surface Micromachining Of Polydimethylsiloxane (Pdms), Weiqiang Chen, Raymond H. W. Lam, Jianping Fu

Weiqiang Chen

A major technical hurdle in microfluidics is the difficulty in achieving high fidelity lithographic patterning on polydimethylsiloxane (PDMS). Here, we report a simple yet highly precise and repeatable PDMS surface micromachining method using direct photolithography followed by reactive ion etching (RIE). Our method to achieve surface patterning of PDMS applied an O2 plasma treatment to PDMS to activate its surface to overcome the challenge of poor photoresist adhesion on PDMS for photolithography. Our photolithographic PDMS surface micromachining technique is compatible with conventional soft lithography techniques and other silicon-based surface and bulk micromachining methods. To illustrate the general application of our …