DOCSLIB.ORG

Radiotracer Methodology in Biological Science

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

AN ABSTRACT OF THE THESIS OF David Lee Willis for the Doctor of Philosophy in General Science (Name) (Degree) (Major) Date thesis is presented May 10, 1963 Title RADIOTRACER METHODOLOGY IN BIOLOGICAL SCIENCE Abstract approved (Major professor) The use of radioactive isotopes as tracers in biological sys- tems has become widespread since the close of World War II. Proper use of radiotracers requires a fundamental understanding of the physi- cal nature of radioactivity, the characteristics of ionizing radiation, and the various methods available for measuring radioactivity. More importantly, the investigator employing radioisotopic tracers must be familiar with the methodology involved in design of radio - tracer experiments, the preparation of radioactive samples for assay, and the problems inherent in analyzing data from radiotracer experi- ments. The purpose in the preparation of this thesis was to present a summary of the essential concepts and information needed by the biologist who desires to make use of radiotracer methods in his in- vestigations. The thesis is set forth in the form of an introductory text, suitable either for class or individual use. The presentation is divided into three major sections: (I) the text proper, covering the principles of radiotracer rnethodology, (?) a set of basic labora- tory exercises, intended to farniliarize the user with procedures in detecting and characterizing radioactivity, and (3) a selection of typical radiotracer experiments illustrating applications in varior.zs fields of biological science. This latter secti.on is thought to be parti- cularly valuable in that it furnishes step-by-step examples of design and execu.tion of typical radiotracer experirnents " In view of the fact that liquid sci.ntillation counting has recently come into widespread favor arnong biologists using tritium and carbon-14 labeled tracer compounds and yet no comprehensive moilo- graph is available on the subject, particular attention has been de- voted to this assay rnethod. A rnost extensive bibliography covering both the preparation of sarnples for liquid scintillation counting and the operating characteristics of the counter assembly is included" In addition, one of the laboratory exercises deals with the practical operation of a liquid scintillation counter" Other aspects of radiotracer methodology that are treated are the safe handling of radioisotopes, the proper design of radiotracer laboratory facilities, and the statistical analysis of counting data. since the biologist commonly secures his radiotracer compounds from commercial radiochemical suppliers, a chapter on the methods of primary radioisotope production and the preparation of labeled compounds has been included as background information. The re- cently popular technique of tritium labeling by gas- exposure (the Wilzbach method) has also been discussed in this connection. Although the emphasis in this presentation has been restricted primarily to the application of radiotracers to research in the biologi- cal sciences, the coverage is broad enough to be of value to investiga- tors in other fields. Copyright by DAVID LEE WILLIS 1963 RADIOTRACER METHODOLOGY IN BIOLOGICAL SCIENCE by DAVID LEE WILLIS A THESIS submitted to OREGON STATE UNIVERSITY in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY June 1963 APPROVED: Professor of Chemistry In Charge of Major rman of Departmerìt of Gene Scien Dean of G aduate School Date thesis is presented MAY \O, 19C.3 Typed by Jolene Wuest ACKNOWLEDGMENTS I would like to express my sincerest appreciation to my major professor, Dr. Chih H. Wang, without whose encouragement and ad- vice this work would never have been attempted, nor completed. Other members of the Radiotracer Laboratory in the Science Research Institute at Oregon State University, both graduate students and staff, deserve my thanks for willingly sharing their time and ex- perience. Finally I want to express my gratitude to my wife, Earline, for untold hours spent in typing, proofreading and generally assisting in the completion of this volume. TABLE OF CONTENTS Page INTRODUCTION 1 PART ONE -- PRINCIPLES OF RADIOTRACER METHODOLOGY CHAPTER 1 ATOMS AND NUCLIDES 10 A. General Structure of the Atom 10 B. The Nucleus 13 C. Nuclides and Isotopes 15 D. Stable Nuclides 17 E. Unstable Nuclides (Radioisotopes) 20 1. Naturally occuring radioisotopes 21 2. Artificially produced radioisotopes 24 a. By particle accelerators 24 b. By nuclear reactors 26 BIBLIOGRAPHY 30 2 THE NATURE OF RADIOACTIVE DECAY 32 A. Radionuclides and Nuclear Stability 32 B. Types of Radioactive Decay 34 1. Decay by negatron emission 36 2. Decay by positron emission 37 3. Decay by electron capture 39 4. Internal conversion 41 5. Isomeric transition 41 6. Decay by alpha particle emission 41 C. Rate of Radioactive Decay 42 1. The decay constant 43 2. Half -life 48 3. Practical decay considerations 53 4. Composite decay 55 5. Average life 58 D. The Standard Unit of Radioactivity -the Curie 59 E. Specific Activity 62 BIBLIOGRAPHY 64 CHAPTER Page 3 CHARACTERISTICS OF IONIZING RADIATION 65 A. Alpha Particles 66 1. Energy 66 2. Half -life and energy 67 3. Interaction with matter 70 a. Excitation 70 b. Ionization 70 c. Specific ionization 71 4. Range 73 a. Determination 73 b. Range- energy relations 73 c. In other materials 74 5. Practical considerations 76 B. Beta Particles 77 1. General nature 77 a. Negatrons and positrons 77 b. Conversion electrons 78 2. Energy of beta decay 79 a. Spectral distribution of energy 79 b. The neutrino and beta decay 82 c. The Fermi theory of beta decay 84 3. Interaction with matter 85 a. Modes of interaction 85 b. Specific ionization 85 4. Range 87 5. Practical considerations 89 a. In detection 89 b. Biological hazards 91 G. Gamma Rays 92 1. Nature and source 92 a. Electromagnetic nature 92 b. Source of gamma emission 93 c. X -rays 95 2. Mechanisms of interaction with matter 95 a. Nuclear transformation 97 b. Mössbauer effect 97 c. Bragg scattering (diffraction) 97 d. Photoelectric effect 98 e. Compton effect 98 f. Pair production 99 3. Absorption relations 101 a. Linear absorption 101 b. Mass absorption 104 Page c. Half thickness 106 d. Dependence on gamma energy and absorber density 109 4. Practical considerations 114 D. Summary 115 BIBLIOGRAPHY 116 CHAPTER 4 MEASUREMENT OF RADIOACTIVITY: GENERAL CONSIDERATIONS AND THE METHOD BASED ON GAS IONIZATION 117 A. Absolute Counting vs. Relative Counting 117 1. Types of radioactivity measurements 117 2. Considerations in relative counting 118 B. Basic Mechanisms of Radiation Detection 120 1. Gas ionization 120 2. Scintillation 120 a. In a solid fluor 120 b. In a liquid fluor 121 3. Autoradiography 122 C. Gas Ionization 122 1. Without gas amplification 124 a. Ionization chambers in general 124 b. Lauritsen electroscopes 130 c. Vibrating -reed electrometers 132 2. With gas amplification 135 a. The nature of gas amplification 135 b. The proportional region 138 c. The limited proportional region 139 d. The Geiger -Mueller region 140 (1) Dead Time 141 (2) Quenching 142 3. Proportional detectors 144 a. Construction 144 b. Operating characteristics 147 4. Geiger -Mueller detectors 149 a. Construction 149 b. Operating characteristics 154 5. Summary of gas ionization detectors 156 BIBLIOGRAPHY 158 CHAPTER Page 5 MEASUREMENT OF RADIOACTIVITY BY THE EXTERNAL - SAMPLE (SOLID)SCINTILLATION METHOD 1 60 A. Basic Facets of the Scintillation Phenomenon 160 B. External - sample (Solid) Scintillation Detectors 162 1. Mechanism of external - sample scintillation detection 162 a. Energy conversion in the fluor crystal 164 b. Energy conversion in the Photomulti- plier 165 c. Proportionality of energy conversion 166 d. Other advantages 168 e. Photomultiplier thermal noise 168 f. Gamma ray spectrometry 169 2. Components of external sample scintillation detectors 170 a. Detector housing 170 b. Fluor crystals 172 c. Photocoupling 174 d. Photomultiplier tubes 175 3. Operating characteristics of external - sample scintillation detectors 178 a. Effect of photomultiplier potential 179 b. Effect of amplifier gain 181 c. Gamma energy dependence of detection efficiency 181 BIBLIOGRAPHY 183 6 MEASUREMENT OF RADIOACTIVITY BY THE INTERNAL - SAMPLE (LIQUID) SCINTILLATION METHOD 1 85 A. Mechanism of Internal - Sample Scintillation Detection 1 87 1. Energy conversion steps in the fluor solution 1 87 2. Comparative examples of energy transfer efficiency for C14 and H3 beta particles 1 89 B. Evaluation of the Internal - Sample Scintillation Method 1 93 1. Advantages of liquid scintillation counting 193 Page 2. Problems inherent in liquid scintillation counting 1 95 a. Photomultiplier thermal noise 195 b. Counting sample preparation 197 c. Quenching 198 C. Components of an Internal- Sample Scintilla- tion Counter 201 1. The operating mechanism 201 2. The detector assembly 202 a. Optical components 202 b. Fluor solution components 203 (1) Primary solvents 204 (2) Secondary solvents 205 (3) Primary solutes 207 (4) Secondary solutes 209 D. Special Types of Liquid Scintillation Detectors 210 1. Large volume external - sample detectors 210 2. Continuous flow scintillation detectors 211 E. Operating Characteristics of Internal - Sample Scintillation Counters 213 1. Selection of optimal counter settings 214 a. Effect of photomultiplier gain and "window" settings 214 b. Balance point operation 215 c. Flat spectrum operation 217 2. Determination of counting efficiency 220 a. Internal standardization method 221 b. Dilution method
Recommended publications
  • Atmospheric Source Terms for the Idaho Chemical Processing Plant, 1957 – 1959

    Atmospheric Source Terms for the Idaho Chemical Processing Plant, 1957 – 1959

    FINAL ATMOSPHERIC SOURCE TERMS FOR THE IDAHO CHEMICAL PROCESSING PLANT, 1957–1959 Contract No. 200-2002-00367 Task Order No. 1, Subtask 1 A final report to the Centers for Disease Control and Prevention Atlanta, Georgia 30335 SC&A, Inc. 6858 Old Dominion Drive, Suite 301 McLean, Virginia 22101 SENES Oak Ridge, Inc. 102 Donner Drive Oak Ridge, Tennessee 37830 Authors: Robert P. Wichner, SENES Oak Ridge, Inc. John-Paul Renier, SENES Oak Ridge, Inc. A. Iulian Apostoaei, SENES Oak Ridge, Inc. July 2005 ICPP Source Terms July 2005 TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................ES-1 1.0 SCOPE AND APPROACH ............................................................................................. 1-1 1.1 Scope .................................................................................................................. 1-1 1.2 Approach.............................................................................................................. 1-1 1.2.1 Operational RaLa Releases ...................................................................... 1-1 1.2.2 Idaho Chemical Processing Plant Criticality Approach........................... 1-2 2.0 THE RADIOACTIVE LANTHANUM (RaLa) PROCESS ............................................ 2-1 2.1 Background .......................................................................................................... 2-1 2.1.1 Requirement ............................................................................................
  • Experiments on the Application of Autoradiographic Techniques to the Study of Problems in Plant Physiology

    Experiments on the Application of Autoradiographic Techniques to the Study of Problems in Plant Physiology

    EXPERIMENTS ON THE APPLICATION OF AUTORADIOGRAPHIC TECHNIQUES TO THE STUDY OF PROBLEMS IN PLANT PHYSIOLOGY By R. THAINE4 and MADELINE C. W ALTERst [Manuscript received March 28, 1955] Summary A method of autoradiography has been developed which allows the record of single ,a-particles emitted from sections of plant tissue 5-7 ~L thick. The method allows resolution of the order of 1 ~ and magnification up to x 1500. Dissolution of the water and alcohol soluble contents of the tissue has been overcome, and it is therefore possible to determine the distribution of com­ pounds concerned in the metabolism and biosynthesis of a cell. Cellular dis­ tortion and loss of contents during fixation and photographic processing is illus­ trated, and it is hoped that an improved method of freeze-drying· will reduce this limitation. In macroscopic autoradiography the soya bean has proved to be most valuable plant material, because the thin stems and leaves allow auto­ graphs which give a detailed record of the transported compounds containing 14C. The isotope is introduced to the plant in the photosynthesis of 14C02, and after a suitable period, the plant is dissected, dried, and placed against X-ray film. After 14 days exposure the film is developed, and the photographic image records positions and relative concentration of the isotope in the plant tissue. I. INTRODUCTION The earliest experiments with radioactive tracers in plants were confined to a study of the macroscopic distribution of certain substances, such as phos­ phorus, which could be readily labelled, and successful autoradiographs of leaves and fruits were obtained (Arnon, Stout, and Sipos 1940; Colwell 1942; Harrison, Thomas, and Hill 1944; Grosse and Snyder 1947).
  • Cross Section Data for the Production of the Positron Emitting Niobium Isotope 90Nb Via the 90Zr(P, N)-Reaction

    Cross Section Data for the Production of the Positron Emitting Niobium Isotope 90Nb Via the 90Zr(P, N)-Reaction

    Radiochim. Acta 90, 1–5 (2002) by Oldenbourg Wissenschaftsverlag, München Cross section data for the production of the positron emitting niobium isotope 90Nb via the 90Zr(p, n)-reaction By S. Busse1,2,F.Rösch1,∗ andS.M.Qaim2 1 Institut für Kernchemie, Johannes Gutenberg-Universität, D-55128 Mainz, Germany 2 Institut für Nuklearchemie, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany (Received April 19, 2001; accepted in revised form July 16, 2001) Positron emitter 90Nb / Nuclear reaction / (α, 3n)-reactions on natural yttrium. A medium-sized cy- Excitation function / Calculated integral yield / clotron would allow the production of 90Nb via the (p, n)-, Experimental thick target yield / Radionuclidic impurities (d, 2n)- or the (3He, 2n)-process. In fact even a small-sized cyclotron (Ep ≤ 16 MeV) should lead to sufficient quanti- ties of the radioisotope via the (p, n)-reaction. A few stud- Summary. The radioisotope 90Nb decays with a positron ies have shown that the (d, 2n)-reaction requires a deuteron + branching of 53% and a relatively low β -energy of energy of about 16 MeV [5–7], the (3He, 2n)-process a 3He- = . = . Emean 0 66 MeV and Emax 1 5 MeV. Its half-life of 14 6h energy of ≥ 30 MeV and the (α, 3n)-reaction an α-particle makes it especially promising for quantitative investigation energy of ≥ 45 MeV [8]. Furthermore, the systematics of of biological processes with slow distribution kinetics using (3He, 2n)- and (p, n)-reactions suggest that the production positron emission tomography. To optimise its production, 90 the excitation functions of 90Zr(p, xn)-processes were studied yield of Nb should be higher in the latter process.
  • Determining Atomic Mass Practice with Answers

    Determining Atomic Mass Practice with Answers

    Determining Atomic Mass Practice with Answers Atomic Mass • Refers to the mass of an atom. • Number of protons and neutrons • Atoms are too small to mass so mass is determined by the relative mass of a standard atom. By international agreement (IUPAC), Carbon­12 is the chosen standard atom because of its abundance here on Earth. Atomic Mass Unit ­ defined is a mass exactly equal to 1/12th of one carbon­12 atom. 1 carbon­12 atom = 12 amu Determining Atomic Mass Practice with Answers Determine Atomic Mass Unit for Hydrogen Hydrogen ­ 1 as 1 proton and 0 neutrons 1/12 = .0833 x 100 = 8.33% So hydrogen is 8.33% of one atom of Carbon­12 Atomic Mass of Hydrogen = mass of 1 atom of Carbon ­12 x 8.33% = 12 x .0833 =.9996 = 1.0 amu Through different methods of experimental testing, chemists have more accurately determined the mass of hydrogen to be 1.008, which is more like 8.40%. Determining Atomic Mass Practice with Answers Determining Average Atomic Mass: Because element's usually have more than one isotope, which means their masses are different an average must be determine to reflect the mass of all an atom's isotopes. Example: A sample of cesium is 75% Cs-133, 20% Cs-132, and 5% Cs-134. What is the average atomic mass? ANSWER: .75 x 133 = 99.75 .20 x 132 = 26.4 .05 x 134 = 6.7 Total = 132.85 amu average atomic mass unit Determining Atomic Mass Practice with Answers Isotopes and Average Atomic Mass Iodine: 80% 127 I 17% 126 I 3% 128 I ANSWER: .80 x 127 = 101.6 .17 x 126 = 21.42 .03 x 128 = 3.84 Total = 126.86 amu Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Determining Atomic Mass Practice with Answers Bromine which exists as a dark, red gas is Br2.
  • The New Nuclear Forensics: Analysis of Nuclear Material for Security

    The New Nuclear Forensics: Analysis of Nuclear Material for Security

    THE NEW NUCLEAR FORENSICS Analysis of Nuclear Materials for Security Purposes edited by vitaly fedchenko The New Nuclear Forensics Analysis of Nuclear Materials for Security Purposes STOCKHOLM INTERNATIONAL PEACE RESEARCH INSTITUTE SIPRI is an independent international institute dedicated to research into conflict, armaments, arms control and disarmament. Established in 1966, SIPRI provides data, analysis and recommendations, based on open sources, to policymakers, researchers, media and the interested public. The Governing Board is not responsible for the views expressed in the publications of the Institute. GOVERNING BOARD Sven-Olof Petersson, Chairman (Sweden) Dr Dewi Fortuna Anwar (Indonesia) Dr Vladimir Baranovsky (Russia) Ambassador Lakhdar Brahimi (Algeria) Jayantha Dhanapala (Sri Lanka) Ambassador Wolfgang Ischinger (Germany) Professor Mary Kaldor (United Kingdom) The Director DIRECTOR Dr Ian Anthony (United Kingdom) Signalistgatan 9 SE-169 70 Solna, Sweden Telephone: +46 8 655 97 00 Fax: +46 8 655 97 33 Email: [email protected] Internet: www.sipri.org The New Nuclear Forensics Analysis of Nuclear Materials for Security Purposes EDITED BY VITALY FEDCHENKO OXFORD UNIVERSITY PRESS 2015 1 Great Clarendon Street, Oxford OX2 6DP, United Kingdom Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide. Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries © SIPRI 2015 The moral rights of the authors have been asserted All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of SIPRI, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organizations.
  • Isotopes of M&M-Ium

    Isotopes of M&M-Ium

    Name _________________________________________________________________ Hour __________________ Isotopes of m&m-ium Elements commonly exist with differing numbers of neutrons. We call these elements isotopes and an example is Bromine-79 and Bromine-81. These isotopes are naturally occurring…but do not exist equally in nature. Br-79 is more common and occurs 55% of the time while Br-81 occurs 45% of the time. To calculate the average atomic mass (the weighted average of the masses of its isotopes) of bromine you need to take into account the relative abundance of each element. The average atomic mass = (% abundance of isotope 1)x(mass of isotope 1) + (% abundance of isotope 2)x(mass of isotope 2) (% should be expressed in decimals) Pre-Lab Questions: 1. Calculate the average atomic mass of Bromine using the % abundances above: 2. Carbon has 2 stable isotopes: C-12 with a natural abundance of 98.89% and C-14 at 1.11%. Calculate the average atomic mass of Carbon. m&mium, a recently discovered element from the chocolate mountains of Wonkaland, exits as two isotopes. m&mium has many different colors and your job is to find the average atomic mass of one color of m&mium. Safety Precautions: Never eat anything that has touched lab equipment! Use a baking cup so your group can eat the m&ms when you are done! Procedure: Show all work for all calculations. 1. Record the number of small m&m’s and large m&m’s you have (your color only) in the table. 2. Record the total number of m&m’s you have.
  • Discovery of the Bromium Isotopes

    Discovery of the Bromium Isotopes

    Discovery of the Bromium Isotopes J. Kathawa, J. Claes, M. Thoennessen∗ National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA Abstract Twenty-eight bromium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented. ∗Corresponding author. Email address: [email protected] (M. Thoennessen) Preprint submitted to Atomic Data and Nuclear Data Tables April 28, 2010 Contents 1. Introduction . 2 2. Discovery of 70−97Br ................................................................................... 3 2.1. 70Br............................................................................................. 3 2.2. 71Br............................................................................................. 3 2.3. 72Br............................................................................................. 5 2.4. 73Br............................................................................................. 5 2.5. 74Br............................................................................................. 5 2.6. 75Br............................................................................................. 5 2.7. 76Br............................................................................................. 6 2.8. 77Br............................................................................................
  • Discovery of the Selenium Isotopes

    Discovery of the Selenium Isotopes

    Discovery of the Selenium Isotopes J. Claes, J. Kathawa, M. Thoennessen∗ National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA Abstract Thirty-one selenium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented. ∗Corresponding author. Email address: [email protected] (M. Thoennessen) Preprint submitted to Atomic Data and Nuclear Data Tables April 28, 2010 Contents 1. Introduction . 3 2. Discovery of 64−94Se.................................................................................... 3 2.1. 64Se............................................................................................. 3 2.2. 65Se............................................................................................. 3 2.3. 66Se............................................................................................. 5 2.4. 67Se............................................................................................. 5 2.5. 68Se............................................................................................. 5 2.6. 69Se............................................................................................. 5 2.7. 70Se............................................................................................. 5 2.8. 71Se............................................................................................
  • Diplomarbeit

    Diplomarbeit

    DIPLOMARBEIT Titel der Diplomarbeit „Radiosynthese, Formulierung und Qualitätskontrolle 18 von [ F]Altanserin für die Bildgebung des 5-HT2A- Rezeptors“ Verfasserin Sandra Richter angestrebter akademischer Grad Magistra der Pharmazie (Mag. pharm.) Wien, März 2012 Studienkennzahl lt. Studienblatt: A 449 Studienrichtung lt. Studienblatt: Pharmazie Betreuerin / Betreuer: O. Univ. Prof. Mag. Dr. Helmut Viernstein Danksagung Mein Dank gilt all jenen, die an der Durchführung dieser Diplomarbeit beteiligt waren. An dieser Stelle möchte ich mich recht herzlich bei O. Univ. Prof. Mag. Dr. Helmut Viernstein bedanken, der mir die Möglichkeit gegeben hat, meine Diplomarbeit am Institut für pharmazeutische Technologie und Biopharmazie durchführen zu können. Mein Dank geht an O. Univ. Prof. Dr. Robert Dudczak und Univ. Prof. DDr. Kurt Kletter für die Möglichkeit, die notwendigen praktischen Arbeiten in den Labors der Universitätsklinik für Nuklearmedizin am AKH Wien verrichten zu können. Des Weiteren möchte ich mich bei Doz. Wolfgang Wadsak und Doz. Markus Mitter- hauser für die fachliche Beratung und Unterstützung während der gesamten Arbeitszeit bedanken. Ein besonderer Dank gilt meiner Betreuerin Mag.a Johanna Ungersböck für ihre kompetente Unterstützung, ihre Hilfsbereitschaft und ihre Geduld, meine vielen Fragen zu beantworten. Bei der Arbeitsgruppe der Nuklearmedizin (Dr.in Daniela Häusler, Mag. Lukas Nics, Mag.a Cécile Philippe, und B.Sc. Markus Zeilinger) möchte ich mich herzlich für das angenehme Arbeitsumfeld und die Möglichkeit, neben meiner Diplomarbeit auch Ein- blicke in andere Forschungsbereiche erlangen zu können, bedanken. Ein besonderer Dank gilt auch meinen Eltern, die mir dieses Studium durch ihre finan- zielle und persönliche Unterstützung all die Jahre hinweg ermöglicht haben. Zusammenfassung Serotonin ist ein Neurotransmitter, der im Zentralnervensystem (ZNS), im Darm- nervensystem, im Blut und im Herz-Kreislauf-System vorkommt und dort sowohl physiologische als auch pathophysiologische Wirkungen ausübt.
  • Fields Upon Beta and Gamma Radiation,(15) Comparison of G-M, Gas Flow Peoportional, Andscintillationcounters

    Fields Upon Beta and Gamma Radiation,(15) Comparison of G-M, Gas Flow Peoportional, Andscintillationcounters

    DOCUMENT RESUME ED 029 080 VT 002 913 By-Wiens, Jacob H. Basic Course in Nucleonics. Technical Education Curriculum Development Series No. 10. California State Dept. of Education, Sacramento. Instructional Materials Lab. Pub Date 63 Note-158p. Available from-Bureau of Industrial Education, California State Department of Education, 721 Capitol MalL Sacramento, California 95814 (without charge). EDRS Price MF-S0.75 HC-$8.00 Descriptors-Atomic Theory, Community Colleges, Laboratory ExPeriments, *Nuclear Physics, Radiation, *Study Guides, *Teaching Guides, Technical Education, *Trade 'and Industrial Education Identifiers-*Nucleonics, Nucleonics Technicians This combined teaching and study guide is for use by students and teachers in post seconoary programs for nucleonics technicians: It was developed by the author under the National Defense Education Act, Title VIII. The unit headings are: (1) Physics of the Atom, (2) Natural Radioactivity and Atomic Energy, (3) induced Radioactivity and Atomic Energy, (4) Radiation Safety and Radiation Doses, (5) Geiger-Mueller Counters, (6) Determination of Half;-Life, (7) Absorption and Self-Absorption for Beta Rays, (8) Backscattering and Other Effects for Beta Rays, (9) Absorption and Inverse Square Law for Gamma Rays, (10) Resolving. Time of a g-rn Counter, (11) Calibration of g-in Counter End Window, (12) Statistical Variation in Radioactive Measurements, (13) Determination of Range and Energy of Alpha Particles, (14) Effect of Magnetic Fields upon Beta and Gamma Radiation,(15) Comparison of g-m, Gas Flow Peoportional, andScintillationCounters. (16) RadioactiveFallout,(17)Tracer Techniques, and (18) Cloud Chamber. Each unit gives objectives, introduction, teaching plan, apparatus required, textual material, _study questions, and a bibliography. Five hours of instruction should, be allotted to each of the units.
  • Tail As the .:J:J Ref~ Ax; ¥10 'T:"-T Dfgtj..Tl ~ ,..U~ [.!Lt·V

    Tail As the .:J:J Ref~ Ax; ¥10 'T:"-T Dfgtj..Tl ~ ,..U~ [.!Lt·V

    Anomalies in the Fermi Effect • ... be conbi~e~,.CL bjvsome as equally probable, or even more ~:Sa"b ~ s tfi:aR the fixst=aite"!'f'l'autive •. While we "ffhal.l ~ 4 ~ a.~.a,.fyf---c __.,. emphasize the pas si bili ty o 4his eeeond vie'fvj~we will · t.A----~ . (J ¢::6 d.t"ia: -; ~~.... ~. ,,-..A( ~ not discuss £? in ~ etail as the .:j:j rEf~ ax; ¥10 't:"-t dfGtJ..tL ~ ,..u~ [.!lt·v ...... ~YJ ~- ~. r/ ~ This unequal treatment is not due to a biased opinion in . ~,.,,,~ . ~ !-'. ' 'M·•/. favour of one of e ·· ' views, and seems -t;o-..b€ just'fied (/~A rt• f.-# £r.~- .-/ ~ e.e i.o I~,_,_ "-!- H . .t:/ ,d"~ t~t .vrlk t.~ 1 ~-.. a : . , . - · by t h e fact that the f1Fst VJ:ew- leads \ to a number of p otentially pas si ble ~l r ( • (-(;;-- -~~ "1:1 /experiments wnich may decide / 3:-rr~~~ , ·o-: a ~ n. ~ , I~ - "/Z,_ - /t , .y /I(, " ,. /.. ' . .... I /7<Vt.. (,_.1' ~~ whereas it se5!ms to be diffipul t to think of cn ~. t'- ,.. (, ...... 1 #t.r t~- ....-.~..., "'<../ t<t.,.-< ""'"' t t( /'l'n J ( "t·C experiments,. ~t'O a:mc t · decision o·n-~ a - - - "' ANOMALIB.S IN TilE FERMI EFFECT 1) Amaldi, D'Agostino and Segre have found that neutrons Which have been slowed down by paraffin wax induce in indium two radio­ active half-life periods (16 eea. and 54 min.). T.A. Cha~ers and 2) I have subsequently reported that indium can also be comparatively strongly activated with a third period of several hours if irradiated by neutrons from a radon alpha-particle beryllium source in the ab- sence of hydrogen-containing substances, and we raised the question whether its existence can be satisfactorily explained without a new assumption.
  • Crmsto)Jwrflnce ~

    Crmsto)Jwrflnce ~

    UCRL 8730 ' ... UNIVERSITY OF CALIFORNIA CrmstO)jwrflnCe ~..... Ctdiation ... SPINS, MOMENTS, AND HYPERFINE STRUCTURES OF SOME BROMINE ISOTOPES 9 • 0 BERKELEY, CALIFORNIA r . ',,,, DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal 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 its 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, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California. UCRL-8730 Physics and Mathematics UNIVERSITY OF CALIFORNIA Lawrence Radiation Laboratory Berkeley. California Contract Noo W -7405-eng·-48 SPINS, MOMENTS, AND HYPERFINE STRUCTURES OF SOME BROMINE ISOTOPES Thomas Myer Green9 Ill (Thesis) June 1959 Printed for the U.S. Atomic Energy Commission • i.'"' • ., ' ·•·;- ... /~~ - .... ·-· Printed 1n USA. Price $2.50. Available from the Office of Techaical Services U. S. Department of Commerce Washington 25, D. C. -2- SPINS, MOMENTS, AND HYPERFINE STRUCTURES OF SOME BROMINE ISOTOPES Contents Abstract 3 I.