Biological Microelectromechanical Systems (Biomems) Devices
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Agarose Gel Electrophoresis
Laboratory for Environmental Pathogen Research Department of Environmental Sciences University of Toledo Agarose gel electrophoresis Background information Agarose gel electrophoresis of DNA is used to determine the presence and distinguish the type of nucleic acids obtained after extraction and to analyze restriction digestion products. Desired DNA fragments can be physically isolated for various purposes such as sequencing, probe preparation, or for cloning fragments into other vectors. Both agarose and polyacrylamide gels are used for DNA analysis. Agarose gels are usually run to size larger fragments (greater than 200 bp) and polyacrylamide gels are run to size fragments less than 200 bp. Typically agarose gels are used for most purposes and polyacrylamide gels are used when small fragments, such as digests of 16S rRNA genes, are being distinguished. There are also specialty agaroses made by FMC (e.g., Metaphor) for separating small fragments. Regular agarose gels may range in concentration from 0.6 to 3.0%. Pouring gels at less or greater than these percentages presents handling problems (e.g., 0.4% agarose for genomic DNA partial digests requires a layer of supporting 0.8% gel). For normal samples make agarose gels at 0.7%. The chart below illustrates the optimal concentrations for fragment size separation. The values listed are approximate and can vary depending on the reference that is used. If you do not know your fragment sizes then the best approach is to start with a 0.7% gel and change subsequently if the desired separation is not achieved. Nucleic acids must be stained prior to visualization. Most laboratories use ethidium bromide but other stains (e.g., SYBR green, GelStar) are available. -
An Introduction to Inhomogeneous Liquids, Density Functional Theory, and the Wetting Transition Adam P
An introduction to inhomogeneous liquids, density functional theory, and the wetting transition Adam P. Hughes, Uwe Thiele, and Andrew J. Archer Citation: American Journal of Physics 82, 1119 (2014); doi: 10.1119/1.4890823 View online: http://dx.doi.org/10.1119/1.4890823 View Table of Contents: http://scitation.aip.org/content/aapt/journal/ajp/82/12?ver=pdfcov Published by the American Association of Physics Teachers Articles you may be interested in Density functional theory of inhomogeneous liquids. II. A fundamental measure approach J. Chem. Phys. 128, 184711 (2008); 10.1063/1.2916694 Mean-field density-functional model of a second-order wetting transition J. Chem. Phys. 128, 114716 (2008); 10.1063/1.2895748 Surface phase transitions in athermal mixtures of hard rods and excluded volume polymers investigated using a density functional approach J. Chem. Phys. 125, 204709 (2006); 10.1063/1.2400033 Homogeneous nucleation at high supersaturation and heterogeneous nucleation on microscopic wettable particles: A hybrid thermodynamic∕density-functional theory J. Chem. Phys. 125, 144515 (2006); 10.1063/1.2357937 Perfect wetting along a three-phase line: Theory and molecular dynamics simulations J. Chem. Phys. 124, 244505 (2006); 10.1063/1.2206772 This article is copyrighted as indicated in the article. Reuse of AAPT content is subject to the terms at: http://scitation.aip.org/termsconditions. Downloaded to IP: 128.176.202.20 On: Wed, 03 Dec 2014 08:24:19 An introduction to inhomogeneous liquids, density functional theory, and the wetting transition Adam P. Hughes Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom Uwe Thiele Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom and Institut fur€ Theoretische Physik, Westfalische€ Wilhelms-Universitat€ Munster,€ Wilhelm Klemm Str. -
Effect of Temperature on Wetting Angle
San Jose State University SJSU ScholarWorks Faculty Publications, Biomedical, Chemical, and Biomedical, Chemical and Materials Materials Engineering Engineering 7-1-1997 Effect of Temperature on Wetting Angle Guna S. Selvaduray San Jose State University, [email protected] R. Brindos San Jose State University Follow this and additional works at: https://scholarworks.sjsu.edu/chem_mat_eng_pub Part of the Chemical Engineering Commons Recommended Citation Guna S. Selvaduray and R. Brindos. "Effect of Temperature on Wetting Angle" National Educators' Workshop: Update 96 - Standard Experiments in Engineering Materials Science and Technology, NASA Publication 3354 (1997): 137-151. This Article is brought to you for free and open access by the Biomedical, Chemical and Materials Engineering at SJSU ScholarWorks. It has been accepted for inclusion in Faculty Publications, Biomedical, Chemical, and Materials Engineering by an authorized administrator of SJSU ScholarWorks. For more information, please contact [email protected]. NASA Conference Publication 3354 National Educators' Workshop: Update 96 Standard Experiments.in Engineering Materials Science and Technology Compiled by James E. Gardner and Ginger L. Freeman Langle~; Research Center • Hampton, Virginia James A. Jacobs Norfolk State University • Norfolk, Virginia Don M. Parkin Los Alamos National Laboratory • Los Alamos, New Mexico Proceedings of a workshop sponsored jointly by the United States Department of Energy, Los Alamos, New Mexico, the National Aeronautics and Space Administration, -
Wetting−Dewetting Transition Line in Thin Polymer Films K
Subscriber access provided by NATL INST STANDARDS & TECH Research Article Wetting−Dewetting Transition Line in Thin Polymer Films K. M. Ashley, D. Raghavan, J. F. Douglas, and A. Karim Langmuir, 2005, 21 (21), 9518-9523• DOI: 10.1021/la050482y • Publication Date (Web): 09 September 2005 Downloaded from http://pubs.acs.org on February 10, 2009 More About This Article Additional resources and features associated with this article are available within the HTML version: • Supporting Information • Links to the 9 articles that cite this article, as of the time of this article download • Access to high resolution figures • Links to articles and content related to this article • Copyright permission to reproduce figures and/or text from this article Langmuir is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 9518 Langmuir 2005, 21, 9518-9523 Wetting-Dewetting Transition Line in Thin Polymer Films K. M. Ashley,† D. Raghavan,*,† J. F. Douglas,*,‡ and A. Karim*,‡ Polymer Program, Department of Chemistry, Howard University, Washington, DC 20059, and Polymers Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 Received February 23, 2005. In Final Form: June 14, 2005 Thin polymeric films are increasingly being utilized in diverse technological applications, and it is crucial to have a reliable method to characterize the stability of these films against dewetting. The parameter space that influences the dewetting of thin polymer films is wide (molecular mass, temperature, film thickness, substrate interaction) and a combinatorial method of investigation is suitable. We thus construct a combinatorial library of observations for polystyrene (PS) films cast on substrates having orthogonal temperature and surface energy gradients and perform a series of measurements for a range of molecular masses (1800 g/mol < M < 35 000 g/mol) and film thicknesses h (30 nm < h < 40 nm) to explore these primary parameter axes. -
MEMS Technology for Physiologically Integrated Devices
A BioMEMS Review: MEMS Technology for Physiologically Integrated Devices AMY C. RICHARDS GRAYSON, REBECCA S. SHAWGO, AUDREY M. JOHNSON, NOLAN T. FLYNN, YAWEN LI, MICHAEL J. CIMA, AND ROBERT LANGER Invited Paper MEMS devices are manufactured using similar microfabrica- I. INTRODUCTION tion techniques as those used to create integrated circuits. They often, however, have moving components that allow physical Microelectromechanical systems (MEMS) devices are or analytical functions to be performed by the device. Although manufactured using similar microfabrication techniques as MEMS can be aseptically fabricated and hermetically sealed, those used to create integrated circuits. They often have biocompatibility of the component materials is a key issue for moving components that allow a physical or analytical MEMS used in vivo. Interest in MEMS for biological applications function to be performed by the device in addition to (BioMEMS) is growing rapidly, with opportunities in areas such as biosensors, pacemakers, immunoisolation capsules, and drug their electrical functions. Microfabrication of silicon-based delivery. The key to many of these applications lies in the lever- structures is usually achieved by repeating sequences of aging of features unique to MEMS (for example, analyte sensitivity, photolithography, etching, and deposition steps in order to electrical responsiveness, temporal control, and feature sizes produce the desired configuration of features, such as traces similar to cells and organelles) for maximum impact. In this paper, (thin metal wires), vias (interlayer connections), reservoirs, we focus on how the biological integration of MEMS and other valves, or membranes, in a layer-by-layer fashion. The implantable devices can be improved through the application of microfabrication technology and concepts. -
A Density Functional Theory Study of Hydrogen Adsorption in MOF-5
17974 J. Phys. Chem. B 2005, 109, 17974-17983 A Density Functional Theory Study of Hydrogen Adsorption in MOF-5 Tim Mueller and Gerbrand Ceder* Department of Materials Science and Engineering, Massachusetts Institute of Technology, Building 13-5056, 77 Massachusetts AVenue, Cambridge, Massachusetts 02139 ReceiVed: March 8, 2005; In Final Form: August 3, 2005 Ab initio molecular dynamics in the generalized gradient approximation to density functional theory and ground-state relaxations are used to study the interaction between molecular hydrogen and the metal-organic framework with formula unit Zn4O(O2C-C6H4-CO2)3. Five symmetrically unique adsorption sites are identified, and calculations indicate that the sites with the strongest interaction with hydrogen are located near the Zn4O clusters. Twenty total adsorption sites are found around each Zn4O cluster, but after 16 of these are populated, the interaction energy at the remaining four sites falls off significantly. The adsorption of hydrogen on the pore walls creates an attractive potential well for hydrogen in the center of the pore. The effect of the framework on the physical structure and electronic structure of the organic linker is calculated, suggesting ways by which the interaction between the framework and hydrogen could be modified. Introduction ogies can be synthesized using a variety of organic linkers, One of the major obstacles to the widespread adoption of providing the ability to tailor the nature and size of the pores. hydrogen as a fuel is the lack of a way to store hydrogen with Several frameworks have been experimentally investigated for sufficient gravimetric and volumetric densities to be economi- their abilities to store hydrogen, but to date none are able to do cally practical. -
Sensitivity of Wetland Methane Emissions to Model Assumptions: Application and Model Testing Against Site Observations
Biogeosciences, 9, 2793–2819, 2012 www.biogeosciences.net/9/2793/2012/ Biogeosciences doi:10.5194/bg-9-2793-2012 © Author(s) 2012. CC Attribution 3.0 License. Sensitivity of wetland methane emissions to model assumptions: application and model testing against site observations L. Meng1, P. G. M. Hess2, N. M. Mahowald3, J. B. Yavitt4, W. J. Riley5, Z. M. Subin5, D. M. Lawrence6, S. C. Swenson6, J. Jauhiainen7, and D. R. Fuka2 1Department of Geography and Environmental Studies Program, Western Michigan University, Kalamazoo, MI 49008, USA 2Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14850, USA 3Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14850, USA 4Department of Natural Resources, Cornell University, Ithaca, NY 14850, USA 5Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley CA 94720, USA 6NCAR-CGD, P.O. Box 3000, Boulder, CO 80307, USA 7Department of Forest Sciences, P.O. Box 27, University of Helsinki, Helsinki 00014, Finland Correspondence to: L. Meng ([email protected]) Received: 14 June 2011 – Published in Biogeosciences Discuss.: 30 June 2011 Revised: 13 June 2012 – Accepted: 29 June 2012 – Published: 30 July 2012 −1 Abstract. Methane emissions from natural wetlands and wetlands contributed 201 Tg CH4 yr , or 78 % of the global rice paddies constitute a large proportion of atmospheric wetland flux. Northern latitude (>50 N) systems contributed −1 methane, but the magnitude and year-to-year variation of 12 Tg CH4 yr . However, sensitivity studies show a large −1 these methane sources are still unpredictable. Here we de- range (150–346 Tg CH4 yr ) in predicted global methane scribe and evaluate the integration of a methane biogeochem- emissions (excluding emissions from rice paddies). -
Surface Science 675 (2018) 26–35
Surface Science 675 (2018) 26–35 Contents lists available at ScienceDirect Surface Science journal homepage: www.elsevier.com/locate/susc Molecular and dissociative adsorption of DMMP, Sarin and Soman on dry T and wet TiO2(110) using density functional theory ⁎ Yenny Cardona Quintero, Ramanathan Nagarajan Natick Soldier Research, Development & Engineering Center, 15 General Greene Avenue, Natick, MA 01760, United States ARTICLE INFO ABSTRACT Keywords: Titania, among the metal oxides, has shown promising characteristics for the adsorption and decontamination of Adsorption of nerve agents on TiO2 chemical warfare nerve agents, due to its high stability and rapid decomposition rates. In this study, the ad- Molecular and dissociative adsorption sorption energy and geometry of the nerve agents Sarin and Soman, and their simulant dimethyl methyl Dry and hydrated TiO2 phosphonate (DMMP) on TiO2 rutile (110) surface were calculated using density functional theory. The mole- Slab model of TiO 2 cular and dissociative adsorption of the agents and simulant on dry as well as wet metal oxide surfaces were DFT calculations of adsorption energy considered. For the wet system, computations were done for the cases of both molecularly adsorbed water Nerve agent dissociation mechanisms Nerve agent and simulant comparison (hydrated conformation) and dissociatively adsorbed water (hydroxylated conformation). DFT calculations show that dissociative adsorption of the agents and simulant is preferred over molecular adsorption for both dry and wet TiO2. The dissociative adsorption on hydrated TiO2 shows higher stability among the different configura- tions considered. The dissociative structure of DMMP on hydrated TiO2 (the most stable one) was identified as the dissociation of a methyl group and its adsorption on the TiO2 surface. -
Microchip Electrophoresis
Entry Microchip Electrophoresis Sammer-ul Hassan Mechanical Engineering, University of Southampton, Southampton SO17 1BJ, UK; [email protected] Definition: Microchip electrophoresis (MCE) is a miniaturized form of capillary electrophoresis. Electrophoresis is a common technique to separate macromolecules such as nucleic acids (DNA, RNA) and proteins. This technique has become a routine method for DNA size fragmenting and separating protein mixtures in most laboratories around the world. The application of higher voltages in MCE achieves faster and efficient electrophoretic separations. Keywords: electrophoresis; microchip electrophoresis; microfluidics; microfabrications 1. Introduction Electrophoresis is an analytical technique that has been applied to resolve complex mixtures containing DNA, proteins, and other chemical or biological species. Since its discovery in the 1930s by Arne [1], traditional slab gel electrophoresis (SGE) has been widely used until today. Meanwhile, new separation techniques based on electrophoresis continue to be developed in the 21st century, especially in life sciences. Capillary electrophoresis (CE) provides a higher resolution of the separated analytes and allows the automation of the operation. Thus, it has been widely used to characterize proteins and peptides [2], biopharmaceutical drugs [3], nucleic acids [4], and the genome [5]. The development of microfabrication techniques has led to the further miniaturization of electrophoresis known Citation: Hassan, S.-u. Microchip as microchip electrophoresis (MCE). MCE offers many advantages over conventional Electrophoresis. Encyclopedia 2021, 1, capillary electrophoresis techniques such as the integration of different separation functions 30–41. https://dx.doi.org/10.3390/ onto the chip, the consumption of small amounts of sample and reagents, faster analyses encyclopedia1010006 and efficient separations [6,7]. -
QPNC-PAGE Standardized Protocol for Acidic, Basic and Neutral Metalloproteins MW 6 - > 200Kda USE ONLY FRESH GELS
QPNC-PAGE Standardized Protocol For Acidic, Basic and Neutral Metalloproteins MW 6 - > 200kDa USE ONLY FRESH GELS Correspondence: Bernd Kastenholz • Research Centre Juelich • Institute of Chemistry and Dynamics of the Geosphere – Phytosphere (ICG-3) • Juelich 52425 • Germany • E-mail: [email protected] Recommended Tools (Bio-Rad) Model 491 Prep Cell (U.S. patent no. 4,877,510) Power Pac 1000: Constant Power: 5 W; Time: 8 hr Model EP-1 Econo Pump: 1 mL/min; 5 mL/fraction; 80 mL prerun V; 480 ml total V (Eluent) Model 2110 Fraction Collector: 80 Fractions Model EM-1 Econo UV Monitor: AUFS 1.0; Detection Wavelength 254 nm Model 1327 Econo Recorder: Range: 100 mV; Chart Speed: 6 cm/hr Model SV-3 Diverter Ventil Buffer Recirculation Pump: Flow Rate: 95 mL/min (Electrophoresis Buffer) Stock Solutions 1) 200 mM Tris-HCl 10 mM NaN3 pH 10.00 – Keep RT. 2) 200 mM Tris-HCl 10 mM NaN3 pH 8.00 – Keep RT. 3) 40 % Acrylamide/Bis 2.67 % C - Keep 4°C. 4) 10 % Ammonium Persulfate (APS) - Keep 4°C (freshly prepared). Electrophoresis Buffer 20 mM Tris-HCL 1 mM NaN3 pH 10.00 degassed – Keep 4°C Upper Electrophoresis Chamber (Prep Cell): 500 mL Electrophoresis Buffer Lower Electrophoresis Chamber (Prep Cell): 2000 mL Electrophoresis Buffer Eluent 20 mM Tris-HCL 1 mM NaN3 pH 8.00 degassed – Keep 4°C Elution Chamber (Prep Cell): 700 mL Elution Buffer Separating Gel Acrylamide 4% T Volume: 40 mL ingredients: 4 mL 40 % Acrylamide/Bis 2.67 % C 4 mL 200 mM Tris-HCl 10 mM NaN3 pH 10.00 32 mL H2O 200 µL 10% APS 20 µL TEMED Add TEMED and APS at the end. -
Control of Molecular Motor Motility in Electrical Devices
Control of Molecular Motor Motility in Electrical Devices Thesis submitted in accordance with the requirements of The University of Liverpool for the degree of Doctor in Philosophy By Laurence Charles Ramsey Department of Electrical Engineering & Electronics April 2014 i Abstract In the last decade there has been increased interest in the study of molecular motors. Motor proteins in particular have gained a large following due to their high efficiency of force generation and the ability to incorporate the motors into linear device designs. Much of the recent research centres on using these protein systems to transport cargo around the surface of a device. The studies carried out in this thesis aim to investigate the use of molecular motors in lab- on-a-chip devices. Two distinct motor protein systems are used to show the viability of utilising these nanoscale machines as a highly specific and controllable method of transporting molecules around the surface of a lab-on-a-chip device. Improved reaction kinetics and increased detection sensitivity are just two advantages that could be achieved if a motor protein system could be incorporated and appropriately controlled within a device such as an immunoassay or microarray technologies. The first study focuses on the motor protein system Kinesin. This highly processive motor is able to propel microtubules across a surface and has shown promise as an in vitro nanoscale transport system. A novel device design is presented where the motility of microtubules is controlled using the combination of a structured surface and a thermoresponsive polymer. Both topographic confinement of the motility and the creation of localised ‘gates’ are used to show a method for the control and guidance of microtubules. -
Adsorption and Desorption Performance and Mechanism Of
molecules Article Adsorption and Desorption Performance and Mechanism of Tetracycline Hydrochloride by Activated Carbon-Based Adsorbents Derived from Sugar Cane Bagasse Activated with ZnCl2 Yixin Cai 1,2, Liming Liu 1,2, Huafeng Tian 1,*, Zhennai Yang 1,* and Xiaogang Luo 1,2,3,* 1 Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology & Business University (BTBU), Beijing 100048, China; [email protected] (Y.C.); [email protected] (L.L.) 2 School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, LiuFang Campus, No.206, Guanggu 1st road, Donghu New & High Technology Development Zone, Wuhan 430205, Hubei Province, China 3 School of Materials Science and Engineering, Zhengzhou University, No.100 Science Avenue, Zhengzhou 450001, Henan Province, China * Correspondence: [email protected] (H.T.); [email protected] (Z.Y.); [email protected] or [email protected] (X.L.); Tel.: +86-139-8627-0668 (X.L.) Received: 4 November 2019; Accepted: 9 December 2019; Published: 11 December 2019 Abstract: Adsorption and desorption behaviors of tetracycline hydrochloride by activated carbon-based adsorbents derived from sugar cane bagasse modified with ZnCl2 were investigated. The activated carbon was tested by SEM, EDX, BET, XRD, FTIR, and XPS. This activated carbon 2 1 exhibited a high BET surface area of 831 m g− with the average pore diameter and pore volume 3 1 reaching 2.52 nm and 0.45 m g− , respectively. The batch experimental results can be described by Freundlich equation, pseudo-second-order kinetics, and the intraparticle diffusion model, 1 while the maximum adsorption capacity reached 239.6 mg g− under 318 K.