DOCSLIB.ORG

Implications of Glass Transition in the Devitrification Process and Storage Management of Vitrified Oocytes and Embryos

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Implications of Glass Transition in the Devitrification Process and Storage Management of Vitrified Oocytes and Embryos Sansiñena, M. ; Santos, M. V. ; Taminelli, G. ; Zaritky, N. Implications of glass transition in the devitrification process and storage management of vitrified oocytes and embryos Postprint del artículo publicado en Theriogenology, abril 2014 Facultad de Ciencias Agrarias Este documento está disponible en la Biblioteca Digital de la Universidad Católica Argentina, repositorio institucional desarrollado por la Biblioteca Central “San Benito Abad”. Su objetivo es difundir y preservar la producción intelectual de la Institución. La Biblioteca posee la autorización del autor para su divulgación en línea. Cómo citar el documento: Sansinena, M., Santos, M. V., Taminelli, G. y N. Zaritky. 2014. Implications of glass transition in the devitrification process and storage management of vitrified oocytes and embroyos [en línea]. Postprint del artículo publicado en Theriogenology: http//dx.doi.org/10.1016/j.theriogenology.2014.04.003 Disponible en: http://bibliotecadigital.uca.edu.ar/repositorio/investigacion/implications-glass-devitrification.pdf [Fecha de consulta: ….] 1 REVISED “CLEAN” COPY 2 3 4 5 Implications of glass transition in the devitrification process 6 and storage management of vitrified oocytes and embryos 7 8 9 M. Sansinena a,c,*, M.V. Santos b,c, G. Taminelli a and N. Zaritky b,c 10 11 12 13 aFacultad de Ciencias Agrarias, Pontificia Universidad Católica Argentina, 14 Cap. Gral. Ramón Freire 183, CABA 1426, Argentina. 15 16 bDepto. de Ingeniería Química, Facultad de Ingeniería, Universidad Nacional 17 de La Plata and Centro de Investigación y Desarrollo en Criotecnología de 18 Alimentos (CONICET-UNLP) , Calle 47 y 116, La Plata 1900, Argentina. 19 20 cConsejo Nacional de Investigaciones Científicas y Técnicas, CONICET. Av. 21 Rivadavia 1917, CABA 1033, Argentina. 22 23 Corresponding autor: [email protected] 24 25 1 26 ABSTRACT 27 Devitrification, the process of crystallization of a formerly crystal-free, 28 amorphous glass state, can lead to damage during the warming of cells. The 29 objective of this study was to determine the glass transition temperature of a 30 cryopreservation solution typically used in the vitrification, storage and 31 warming of mammalian oocytes and embryos using Differential Scanning 32 Calorimetry. A numerical model of the heat transfer process to analyze 33 warming and devitrification thresholds for a vitrification carrier (open-pulled 34 straw, OPS) was conducted and the implications on specimen storage in 35 nitrogen vapor phase were determined. The time required for initiation of 36 devitrification was determined by mathematical modeling and compared with 37 temperatures in the vapor phase of liquid nitrogen cryogenic dewars. Results 38 indicated that the glass transition ranged from -126 to -121ºC and 39 devitrification was initiated at -109ºC. Interestingly, samples entered rubbery 40 state at -121ºC and therefore could potentially initiate devitrification above this 41 value, with the consequent damaging effects to cell survival. Devitrification 42 times were mathematically modeled considering an initial temperature of 43 material immersed in liquid nitrogen (-196ºC) and two arbitrarily selected 44 temperatures (-50 and -70ºC) to which a sample could be exposed at the 45 neck of dewar. The mathematical model indicated samples could reach glass 46 transition temperatures and undergo devitrification in 30 seconds. Results of 47 the present study indicate storage of vitrified oocytes and embryos in the 48 liquid nitrogen vapor phase (as opposed to completely immersed in liquid 49 nitrogen) poses the potential risk of devitrification. Due to the reduced time- 50 handling period before samples reach critical rubbery and devitrification 51 values, caution should be exercised when handling samples in vapor phase. 52 53 Keywords: Vitrification, embryo, glass transition, devitrification, liquid nitrogen 54 55 56 57 58 59 60 61 62 63 64 65 2 66 1. INTRODUCTION 67 Low temperature preservation of oocytes and embryos is a fundamental 68 cornerstone of assisted reproductive technologies. Cryopreservation of 69 reproductive cells has been traditionally achieved by slow cooling the samples 70 at specific rates to allow cell dehydration [1,2]. However, the preservation 71 outcome of oocytes and embryos cells by slow freezing equilibrium protocols 72 is negatively affected by cryoinjury due to formation of intra and extracellular 73 ice crystals, concentration of solutes during the freezing process and 74 prolonged cell exposures to toxic cryoprotectant and chilling temperatures [2– 75 4]. 76 Storage of cryopreserved cells is conducted in specialized cryogenic, 77 thermally insulated vacuum flask dewars that hold cryogenic fluids below their 78 boiling point [5]. Smaller to medium-sized dewars (20 to 50 L) typically used 79 by veterinary practitioners and some laboratories are routinely filled with 80 cryogenic fluid to maintain adequate chamber temperatures [6]. Even though 81 the recommendation is to maintain the dewars full at all times [5, 7], 82 manufacturers provide guideline static evaporation rates for individual models 83 and suggest close monitoring of liquid nitrogen levels based on specific usage 84 conditions [7]. 85 Cells stored in these containers are kept either immersed in liquid 86 nitrogen or in the immediate vapor phase [7] . Because the temperature of the 87 vapor phase is not a constant (as opposed to liquid nitrogen, -196ºC) a lack 88 of temperature homogeneity within the chamber is observed [8]. Noteworthy, 89 storage recommendations for oocytes and embryos in vapor phase of liquid 90 nitrogen dewars were originally formulated for cells that had been 3 91 cryopreserved using equilibrium, slow freezing protocols [25,26]. Cells 92 cryopreserved under those conditions have been reported to undergo 93 sufficient dehydration and minimal cytoplasm supercooling and thus are less 94 likely to be damaged during warming. However, these recommendations may 95 not be applicable to vitrified material, which has a higher risk of devitrification 96 and irreversible cryoinjury. 97 Vitrification, the process of solidification of a sample into an 98 amorphous, glassy-state in absence of intracellular and extracellular ice 99 crystals, requires high concentrations of cryoprotectants, extremely rapid 100 cooling rates and reduced volume handling. In the last decade, vitrification 101 has progressively become the method of choice for the cryopreservation of 102 human oocytes and embryos [10, 11] and this trend is now being followed by 103 veterinary and animal science practitioners for domestic and exotic animal 104 species [7,8]. 105 Devitrification is defined as the process of crystallization in a formerly 106 crystal-free, amorphous glass solution [12, 14-16]. Early experiments to study 107 the warming behavior of vitrified aqueous solutions were conducted by Luyet 108 [14] and Luyet and Rasmusen using differential thermal analyses to detect 109 enthalpy changes associated with transition events [17,18]. Unlike melting 110 point, devitrification phenomenon has been described not as an individual 111 point but as a temperature range determined by the composition of solution 112 and presence of nucleating particles, among other factors [14, 15, 18-21]. 113 The devitrification of the intracellular solution and the surrounding 114 extracellular medium can lead to significant damage during the warming of 115 cells [20, 21]. Several authors have indicated that above the glass transition 4 116 temperature of the cytoplasm (approximately -120 to -130°C), the vitrified 117 cytoplasm of oocytes and embryos could enter a liquid transition, promoting 118 devitrification and subsequent ice nucleation and crystallization [22-24]. There 119 are limited reports on glass transition temperatures of cryopreservation 120 solutions and those available are mostly water-sugar solutions and not the 121 complex mixtures of balanced salt solutions, permeating and non-permeating 122 cryoprotectants used in current oocyte and embryo vitrification protocols [25– 123 27]. 124 To date, there are no reports on glass transition temperatures of 125 vitrification solutions used in the storage of oocytes and embryos. This 126 information would be of value to calculate critical devitrification thresholds and 127 update recommendations for the storage of vitrified oocytes and embryos. 128 Therefore, the objective of this study was to determine the glass transition 129 temperature of a cryopreservation solution typically used in the vitrification, 130 storage and warming of mammalian oocytes and embryos. In order to analyze 131 devitrification thresholds, a numerical modeling of heat transfer for a common 132 vitrification carrier (open-pulled straw, OPS) was conducted. Finally, the 133 implications of these results on specimen storage and handling conditions in 134 nitrogen vapor phase were discussed. 135 136 2. MATERIALS AND METHODS 137 2.1 Measurement of the glass transition temperature (Tg) of the 138 vitrification solution by differential scanning calorimetry (DSC). 139 Current vitrification protocols require that cells be successively moved 140 through increasing cryoprotectant concentrations (permeable and non- 5 141 permeable) prior to their vitrification by direct plunging into liquid nitrogen and 142 long-term storage. Therefore, the glass transition temperature (Tg) of the final 143 vitrification solution routinely used in our laboratory was determined by 144 differential scanning calorimetry (DSC). 145 The Tg
Load more

Recommended publications
  • CBS SOP: Liquid Nitrogen AODA
    Liquid Nitrogen SOP Liquid Nitrogen SOP CBS-SOP-020-19 Effective: Mar 2019 Author: A. Holliss Edited: P. Scheffer Purpose To provide procedural guidance on the dispensing, transport, handling and disposal of liquid nitrogen. This document is to be used in addition to on the job training and not as a substitution. Scope All students and staff within CBS working with liquid nitrogen should be familiar with these procedures. Outside of normal working hours (weekdays 08:30 to 16:30) liquid nitrogen must not be dispensed from the pressurized storage vessel. If there is an absolute necessity for liquid nitrogen from the pressurized storage dewar at that time, this procedure must be carried out with the supervisor’s knowledge by two trained personnel working together to allow for the alarm to be raised if there is an incident/accident. The second ‘spotter’ person is to be in visual contact with the first ‘dispensing’ person but not so close to also be in danger. Definitions/Acronyms Cryogenic storage dewar – a specialized double-walled vacuum container used for storing cryogenic liquid and provides thermal insulation as the cryogenic liquid slowly boils away. Excessive pressure is released through an open top, vented cap or through a pressure relief valve to prevent the risk of explosion. Oxygen deficient atmosphere – an atmosphere with less than 19.5% oxygen by volume. Air normally contains approximately 21% oxygen. If gases other than oxygen are added or mixed with air, the oxygen concentration is reduced (diluted) and oxygen deficiency occurs. No human sense will give an indication of an oxygen-reduced atmosphere.
    [Show full text]
  • Nuclear Waste Vitrification Efficiency: Cold Cap Reactions
    Journal of Non-Crystalline Solids 358 (2012) 3559–3562 Contents lists available at SciVerse ScienceDirect Journal of Non-Crystalline Solids journal homepage: www.elsevier.com/ locate/ jnoncrysol Nuclear waste vitrification efficiency: Cold cap reactions P. Hrma a,b,⁎, A.A. Kruger c, R. Pokorny d a Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang, Republic of Korea b Pacific Northwest National Laboratory, Richland, WA 99352, USA c U.S. Department of Energy Hanford Tank Waste Treatment and Immobilization Plant Federal Project Office, Engineering Division, Richland, WA 99352, USA d Institute of Chemical Technology, Prague, Czech Republic article info abstract Article history: Batch melting takes place within the cold cap, i.e., a batch layer floating on the surface of molten glass in a Received 26 July 2011 glass-melting furnace. The conversion of batch to glass consists of various chemical reactions, phase transi- Received in revised form 5 January 2012 tions, and diffusion-controlled processes. This study introduces a one-dimensional (1D) mathematical Available online 7 March 2012 model of the cold cap that describes the batch-to-glass conversion within the cold cap as it progresses in a vertical direction. With constitutive equations and key parameters based on measured data, and simplified Keywords: boundary conditions on the cold-cap interfaces with the glass melt and the plenum space of the melter, Glass melting; Glass foaming; the model provides sensitivity analysis of the response of the cold cap to the batch makeup and melter con- Waste vitrification; ditions. The model demonstrates that batch foaming has a decisive influence on the rate of melting.
    [Show full text]
  • User's Manual
    User’s Manual Model 331 Temperature Controller Includes Coverage For: Model 331S and Model 331E Lake Shore Cryotronics, Inc. 575 McCorkle Blvd. Westerville, Ohio 43082-8888 USA E-mail addresses: [email protected] [email protected] Visit our website at: www.lakeshore.com Fax: (614) 891-1392 Telephone: (614) 891-2243 Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake Shore Cryotronics, Inc. No government or other contractual support or relationship whatsoever has existed which in any way affects or mitigates proprietary rights of Lake Shore Cryotronics, Inc. in these developments. Methods and apparatus disclosed herein may be subject to U.S. Patents existing or applied for. Lake Shore Cryotronics, Inc. reserves the right to add, improve, modify, or withdraw functions, design modifications, or products at any time without notice. Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages in connection with furnishing, performance, or use of this material. Revision: 1.9 P/N 119-031 14 May 2009 Lake Shore Model 331 Temperature Controller User’s Manual LIMITED WARRANTY STATEMENT LIMITED WARRANTY STATEMENT (Continued) WARRANTY PERIOD: ONE (1) YEAR 9. EXCEPT TO THE EXTENT ALLOWED BY APPLICABLE LAW, 1. Lake Shore warrants that this Lake Shore product (the THE TERMS OF THIS LIMITED WARRANTY STATEMENT DO “Product”) will be free from defects in materials and NOT EXCLUDE, RESTRICT OR MODIFY, AND ARE IN workmanship for the Warranty Period specified above (the ADDITION TO, THE MANDATORY STATUTORY RIGHTS “Warranty Period”). If Lake Shore receives notice of any such APPLICABLE TO THE SALE OF THE PRODUCT TO YOU.
    [Show full text]
  • Final Vitrification Melter Evaluation
    Waste-Incidental-to-Reprocessing Evaluation for the West Valley Demonstration Project Vitrification Melter February 2012 Prepared by the U.S. Department of Energy West Valley, New York This page is intentionally blank. WASTE-INCIDENTAL-TO-REPROCESSING EVALUATION FOR THE WVDP VITRIFICATION MELTER CONTENTS NOTATION (Acronyms, Abbreviations, and Units).................................................. v 1.0 INTRODUCTION ...................................................................................................... 1 1.1 Purpose. ................................................................................................................. 2 1.2 Scope and Technical Basis ....................................................................................... 2 1.3 Consultation and Opportunity for Public Review ........................................................ 3 1.4 Background ............................................................................................................ 4 1.4.1 The Western New York Nuclear Service Center .............................................. 4 1.4.2 Spent Nuclear Fuel Processing ...................................................................... 6 1.4.3 The West Valley Demonstration Project ......................................................... 7 1.4.4 Characterization of the Vitrification Melter ..................................................... 7 1.4.5 Incorporation into a Solid Physical Form ........................................................ 8 1.4.6 Potential Waste Disposal
    [Show full text]
  • Safe Storage, Handling, Use and Disposal Procedures of Compressed Gas Cylinders
    Title: Safe Storage, Handling, Use and Disposal Procedures of Compressed Gas Cylinders Effective Date: November 2005 Revision Date: March 1, 2017 Issuing Authority: VP, Capital Projects & Facilities Responsible Officer: Director Environmental Health and Safety PURPOSE OF THE POLICY The purpose of this policy on the safe storage, handling and use of compressed gas cylinders is to provide best practice guidance for the use and storage of compressed gas cylinders. These procedures are to assist employees on information to minimize the hazards associated with this type of equipment. SCOPE OF THIS POLICY Serious fire, explosion or rupture accidents may result from the misuse or mishandling of compressed gas cylinders. Observance of the following rules will help control hazards in the storage, handling and use of compressed gas cylinders. WHO NEEDS TO KNOW THIS POLICY This policy applies to all New York University academic, commercial and residential facilities utilizing compressed gas cylinders. Responsibilities: Department of Environmental Health and Safety • Responsible for developing and updating the policy • Work with Facilities, Department Heads, and Lab Managers to ensure proper use and storage • Enforce compliance with all safety regulations and FDNY regulations Directors, Department Chairs, and Principal Investigators • Directors, Chairs, and PIs are responsible for enforcing this policy. • Periodically review and monitor the effectiveness of safe CGC use and storage. • Allocate the resources necessary for safe handling, use, and to monitor the program. Department Managers and Supervisors • Department Managers and Supervisors ensure staff working with compressed gas cylinders have the appropriate training and understand all aspects of safety associated with this equipment. • Assure the equipment associated with the movement, storage, and use of compressed gas cylinders is available and properly inspected before being used.
    [Show full text]
  • Progress in Nuclear Waste Vitrification by Ceramic Melter Technique
    JP9950237 PROGRESS IN NUCLEAR WASTE VITRIFICATION BY CERAMIC MELTER TECHNIQUE S. WEISENBURGER Forschungszentrum Karlsruhe Institut fur Nukleare Entsorgungstechnik P.O.BOX 3640, 76021 Karlsruhe, Germany ABSTRACT Nuclear waste vitrification by using the liquid-fed ceramic-lined waste glass melter process started in 1973 with the pioneering development at Batelle Pacific Northwest Laboratory. The first radioactive plant applying this technique was the PAMELA plant in Mol/ Belgium which was put into hot operation in 1985. A main part of the technology for this plant including the melter was developed by the Institut fur Nukleare Entsorgungstechnik (INE) of Forschungszentrum Karlsruhe (FZK)! For the time being there is an increasing demand for the availability of small-scale vitrification units for processing of small stocks of high level liquid wastes (HLLW). Limited quantities of HLLW solutions were obtained during the period of development of reprocessing techniques at various international sites. One example is the former WAK (Wiederaufarbeitungs-anlage Karlsruhe) reprocessing plant. It is located at the site of Forschungszentrum Karlsruhe and is now under decommissioning. The overall decommissioning program includes vitrification of 70 m3 of stored HLLW with a total p7y radioactivity of 8.9 x E17 Bq. This paper focuses on progress achieved in the design of small-scale liquid-fed ceramic glass melters for these purposes. Improvements are described regarding extension of power electrode life time by optimized air cooling, glass pouring operation, off-gas pipe cleaning, glass level detection system in the melt tank, and arrangement of a small-scale melter in a hot a cell. Some test results achieved with the new melter are also outlined.
    [Show full text]
  • Commodity Master List
    Commodity Master List 005 ABRASIVES 010 ACOUSTICAL TILE, INSULATING MATERIALS, AND SUPPLIES 015 ADDRESSING, COPYING, MIMEOGRAPH, AND SPIRIT DUPLICATING MACHINE SUPPLIES: CHEMICALS, INKS, PAPER, ETC. 019 AGRICULTURAL CROPS AND GRAINS INCLUDING FRUITS, MELONS, NUTS, AND VEGETABLES 020 AGRICULTURAL EQUIPMENT, IMPLEMENTS, AND ACCESSORIES (SEE CLASS 022 FOR PARTS) 022 AGRICULTURAL IMPLEMENT AND ACCESSORY PARTS 025 AIR COMPRESSORS AND ACCESSORIES 031 AIR CONDITIONING, HEATING, AND VENTILATING: EQUIPMENT, PARTS AND ACCESSORIES (SEE RELATED ITEMS IN CLASS 740) 035 AIRCRAFT AND AIRPORT, EQUIPMENT, PARTS, AND SUPPLIES 037 AMUSEMENT, DECORATIONS, ENTERTAINMENT, TOYS, ETC. 040 ANIMALS, BIRDS, MARINE LIFE, AND POULTRY, INCLUDING ACCESSORY ITEMS (LIVE) 045 APPLIANCES AND EQUIPMENT, HOUSEHOLD TYPE 050 ART EQUIPMENT AND SUPPLIES 052 ART OBJECTS 055 AUTOMOTIVE ACCESSORIES FOR AUTOMOBILES, BUSES, TRUCKS, ETC. 060 AUTOMOTIVE MAINTENANCE ITEMS AND REPAIR/REPLACEMENT PARTS 065 AUTOMOTIVE BODIES, ACCESSORIES, AND PARTS 070 AUTOMOTIVE VEHICLES AND RELATED TRANSPORTATION EQUIPMENT 075 AUTOMOTIVE SHOP EQUIPMENT AND SUPPLIES 080 BADGES, EMBLEMS, NAME TAGS AND PLATES, JEWELRY, ETC. 085 BAGS, BAGGING, TIES, AND EROSION CONTROL EQUIPMENT 090 BAKERY EQUIPMENT, COMMERCIAL 095 BARBER AND BEAUTY SHOP EQUIPMENT AND SUPPLIES 100 BARRELS, DRUMS, KEGS, AND CONTAINERS 105 BEARINGS (EXCEPT WHEEL BEARINGS AND SEALS -SEE CLASS 060) 110 BELTS AND BELTING: AUTOMOTIVE AND INDUSTRIAL 115 BIOCHEMICALS, RESEARCH 120 BOATS, MOTORS, AND MARINE AND WILDLIFE SUPPLIES 125 BOOKBINDING SUPPLIES
    [Show full text]
  • Vitrification of Ion-Exchange (IEX) Resins: Advantages and Technical Challenges
    WSRC-MS-95-0518 Vitrification of Ion-Exchange (IEX) Resins: Advantages and Technical Challenges bv C. M. Jantzen Westinghouse Savannah River Company Savannah River, Site Aiken, South Carolina 29808 D. K. Paster G. A. Cicero A document prepared for AMERICAN CERAMIC SOCIETY ANNUAL MEETING, NUCLEAR DIVISION at Indianapolis frorrt 04/14/95 - 04/17/95. DOE Contract No. DE-AC09-89SR18035 This paper was prepared in connection with work done under the above contract number with the U. S. Department of Energy. By acceptance of this paper, the publisher and/or recipient acknowledges the U. S. Government's right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper, along with the right to reproduce and to authorize others to reproduce all or part of the copyrighted paper. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed,.or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
    [Show full text]
  • Transformation (T TT) Diagram for EPY® Epoxy System
    18 2018, 63, nr 1 Glass transition temperature-cure temperature- ® -transformation (TgTT) diagram for EPY epoxy system Magdalena Urbaniak1) DOI: dx.doi.org/10.14314/polimery.2018.1.3 Abstract: The EPY® epoxy system applied for the production of machine foundation chocks was iso- thermally cured at varying cure temperatures and times. The thermal behavior during the curing of the system was monitored by means of the glass transition temperature (Tg) and conversion degree (α) measured using differential scanning calorimetry (DSC) and rotational viscometry (ARES). Also, the thermal decomposition was measured by thermogravimetry and differential thermal analysis (TG-DTA). The results were analyzed and summarized in the generalized phase diagram, as well as in the Tg-cure temperature-transformation (TgTT) cure diagram. The phase diagram has reference to the transformations (in liquid, ungelled glass, gelled glass and rubber state) encountered at time to gelation and vitrification. Whereas theT gTT diagram shows that there are three types of behavior related to the temperature of cure and makes a useful framework for understanding and analyzing the relations and interdependencies during the curing process of the epoxy system. Keywords: epoxy system, curing, gelation, vitrification, glass transition temperature, glass transition temperature-cure temperature-transformation diagram. Diagram temperatura zeszklenia-temperatura sieciowania-przemiana (TgTT) dla układu epoksydowego EPY® Streszczenie: Próbki układu epoksydowego EPY®, używanego do wytwarzania podkładek funda- mentowych maszyn, sieciowano izotermicznie stosując różne temperatury i różny czas sieciowania. Metodami różnicowej kalorymetrii skaningowej (DSC) i wiskozymetrii rotacyjnej (ARES) zbadano przemiany tak przygotowanych układów pod wpływem zmian temperatury wyznaczając temperaturę zeszklenia (Tg) i stopień konwersji (α). Badano także rozkład termiczny próbek za pomocą symulta- nicznej termograwimetrycznej i różnicowej analizy termicznej (TG-DTA).
    [Show full text]
  • Facts on File DICTIONARY of CHEMISTRY
    The Facts On File DICTIONARY of CHEMISTRY The Facts On File DICTIONARY of CHEMISTRY Fourth Edition Edited by John Daintith The Facts On File Dictionary of Chemistry Fourth Edition Copyright © 2005, 1999 by Market House Books Ltd All rights reserved. No part of this book may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval systems, without permission in writing from the publisher. For information contact: Facts On File, Inc. 132 West 31st Street New York NY 10001 For Library of Congress Cataloging-in-Publication Data, please contact Facts On File, Inc. ISBN 0-8160-5649-8 Facts On File books are available at special discounts when purchased in bulk quantities for businesses, associations, institutions, or sales promotions. Please call our Special Sales Department in New York at (212) 967-8800 or (800) 322-8755. You can find Facts On File on the World Wide Web at http://www.factsonfile.com Compiled and typeset by Market House Books Ltd, Aylesbury, UK Printed in the United States of America MP PKG 10 9 8 7 6 5 4 3 2 1 This book is printed on acid-free paper. PREFACE This dictionary is one of a series designed for use in schools. It is intended for stu- dents of chemistry, but we hope that it will also be helpful to other science students and to anyone interested in science. Facts On File also publishes dictionaries in a variety of disciplines, including biology, physics, mathematics, forensic science, weather and climate, marine science, and space and astronomy.
    [Show full text]
  • Cryoelectron Microscopy of a Nucleating Model Bile in Vitreous Ice: Formation of Primordial Vesicles
    1436 Biophysical Journal Volume 76 March 1999 1436–1451 Cryoelectron Microscopy of a Nucleating Model Bile in Vitreous Ice: Formation of Primordial Vesicles Donald L. Gantz,* David Q.-H. Wang,# Martin C. Carey,# and Donald M. Small* *Department of Biophysics, Boston University School of Medicine, Boston, Massachusetts 02118, and #Department of Medicine, Gastroenterology Division, Brigham and Women’s Hospital, Harvard Medical School and Harvard Digestive Disease Center, Boston, Massachusetts 02115 USA ABSTRACT Because gallstones form so frequently in human bile, pathophysiologically relevant supersaturated model biles are commonly employed to study cholesterol crystal formation. We used cryo-transmission electron microscopy, comple- mented by polarizing light microscopy, to investigate early stages of cholesterol nucleation in model bile. In the system studied, the proposed microscopic sequence involves the evolution of small unilamellar to multilamellar vesicles to lamellar liquid crystals and finally to cholesterol crystals. Small aliquots of a concentrated (total lipid concentration ϭ 29.2 g/dl) model bile containing 8.5% cholesterol, 22.9% egg yolk lecithin, and 68.6% taurocholate (all mole %) were vitrified at 2 min to 20 days after fourfold dilution to induce supersaturation. Mixed micelles together with a category of vesicles denoted primordial, small unilamellar vesicles of two distinct morphologies (sphere/ellipsoid and cylinder/arachoid), large unilamellar vesicles, multilamellar vesicles, and cholesterol monohydrate crystals were imaged. No evidence of aggregation/fusion of small unilamellar vesicles to form multilamellar vesicles was detected. Low numbers of multilamellar vesicles were present, some of which were sufficiently large to be identified as liquid crystals by polarizing light microscopy. Dimensions, surface areas, and volumes of spherical/ellipsoidal and cylindrical/arachoidal vesicles were quantified.
    [Show full text]
  • To Make a Glass – Avoid the Crystal
    To make a glass – avoid the crystal Thomas Palberg1, Eckhard Bartsch2, Richard Beyer1, Maximilian Hofmann1, Nina Lorenz1,3, Janina Marquis1, Ran Niu1,4 and Tsuneo Okubo5 Abstract Colloidal model systems allow for a flexible tuning of particle sizes, particle spacings and mutual interactions at constant temperature. Colloidal suspensions typically crystallize as soon as the interactions get sufficiently strong and long-ranged. Several strategies have been successfully applied to avoid crystallization and instead produce colloidal glasses. Most of these amorphous solids are formed at high particle concentrations. This paper shortly reviews experimental attempts to produce amorphous colloidal solids using strategies based on topological, thermodynamic and kinetic considerations. We complement this overview by introducing a (transient) amorphous solid forming in a thoroughly deionized aqueous suspension of highly charged spheres at low salt concentration and very low volume fractions. Key words: colloidal model systems, colloidal glasses, structural glasses, light scattering, crystal nucleation, polydispersity, eutectic phases, frustration, dynamic arrest, Thomas Palberg [email protected] 1 Institute of Physics, Johannes Gutenberg University, D-55099 Mainz, Germany 2 Institute of Physical Chemistry, Albert-Ludwigs-University, D-79104 Freiburg, Germany 3 present address: Sentronics Metrology, Mannheim, Germany 4 on leave from: Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China 5 Institute for Colloidal Organization, Hatoyama 3-1-112 Uji, Kyoto 611-0012, Japan Introduction Colloidal suspensions are well known experimental model systems to study the structural and dynamic properties of condensed matter [1, 2, 3, 4]. Typically, spherical particles of sub- micron size suspended in a liquid carrier medium are studied as a model for simple atomic solids and liquids [5].
    [Show full text]