Introduction to Electron Microscopy and Spectroscopy
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Sculpturing the Electron Wave Function
Sculpturing the Electron Wave Function Roy Shiloh, Yossi Lereah, Yigal Lilach and Ady Arie Department of Physical Electronics, Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv 6997801, Israel Coherent electrons such as those in electron microscopes, exhibit wave phenomena and may be described by the paraxial wave equation1. In analogy to light-waves2,3, governed by the same equation, these electrons share many of the fundamental traits and dynamics of photons. Today, spatial manipulation of electron beams is achieved mainly using electrostatic and magnetic fields. Other demonstrations include simple phase-plates4 and holographic masks based on binary diffraction gratings5–8. Altering the spatial profile of the beam may be proven useful in many fields incorporating phase microscopy9,10, electron holography11–14, and electron-matter interactions15. These methods, however, are fundamentally limited due to energy distribution to undesired diffraction orders as well as by their binary construction. Here we present a new method in electron-optics for arbitrarily shaping of electron beams, by precisely controlling an engineered pattern of thicknesses on a thin-membrane, thereby molding the spatial phase of the electron wavefront. Aided by the past decade’s monumental leap in nano-fabrication technology and armed with light- optic’s vast experience and knowledge, one may now spatially manipulate an electron beam’s phase in much the same way light waves are shaped simply by passing them through glass elements such as refractive and diffractive lenses. We show examples of binary and continuous phase-plates and demonstrate the ability to generate arbitrary shapes of the electron wave function using a holographic phase-mask. -
Electron Microscopy and the Investigation of New Infectious Diseases
Review Electron microscopy and the investigation of new infectious diseases Alan Curry@) Objectives: To review and assess the role of electron microscopy in the investigation of new infectious diseases. Design: To design a screening strategy to maximize the likelihood of detecting new or emerging pathogens in clinical samples. Results: Electron microscopy remains a useful method of investigating some viral infections (infantile gastroenteritis, virus-induced outbreaks of gastroenteritis and skin lesions) using the negative staining technique. In addition, it remains an essential technique for the investigation of new and emerging parasitic protozoan infections in the immunocompromised patients from resin-embedded tissue biopsies. Electron microscopy can also have a useful role in the investigation of certain bacterial infections. Conclusions: Electron microscopy still has much to contribute to the investigation of new and emerging pathogens, and should be perceived as capable of producing different, but equally relevant, information compared to other investigative techniques. It is the application of a combined investigative approach using several different techniques that will further our understanding of new infectious diseases. Int J Infect Dis 2003; 7: 251-258 INTRODUCTION at individually by a skilled microscopist have con- The electron microscope was developed just before tributed to the decline of electron microscopy. Against World War II in several countries, but particularly in this background, the inevitable question must be Germany.l The dramatic increase in resolution available asked-does electron microscopy still have a useful in comparison with light microscopy promised to role to play in the investigation of emerging or new revolutionize many aspects of cell biology, virology, infectious diseases? bacteriology, mycology and protozoan parasitology. -
Electron Microscopy
Electron microscopy 1 Plan 1. De Broglie electron wavelength. 2. Davisson – Germer experiment. 3. Wave-particle dualism. Tonomura experiment. 4. Wave: period, wavelength, mathematical description. 5. Plane, cylindrical, spherical waves. 6. Huygens-Fresnel principle. 7. Scattering: light, X-rays, electrons. 8. Electron scattering. Born approximation. 9. Electron-matter interaction, transmission function. 10. Weak phase object (WPO) approximation. 11. Electron scattering. Elastic and inelastic scattering 12. Electron scattering. Kinematic and dynamic diffraction. 13. Imaging phase objects, under focus, over focus. Transport of intensity equation. 2 Electrons are particles and waves 3 De Broglie wavelength PhD Thesis, 1924: “With every particle of matter with mass m and velocity v a real wave must be associated” h p 2 h mv p mv Ekin eU 2 2meU Louis de Broglie (1892 - 1987) – wavelength h – Planck constant hc eU – electron energy in eV eU eU2 m c2 eU m0 – electron rest mass 0 c – speed of light The Nobel Prize in Physics 1929 was awarded to Prince Louis-Victor Pierre Raymond de Broglie "for his discovery of the wave nature of electrons." 4 De Broigle “Recherches sur la Théorie des Quanta (Researches on the quantum theory)” (1924) Electron wavelength 142 pm 80 keV – 300 keV 5 Davisson – Germer experiment (1923 – 1929) The first direct evidence confirming de Broglie's hypothesis that particles can have wave properties as well 6 C. Davisson, L. H. Germer, "The Scattering of Electrons by a Single Crystal of Nickel" Nature 119(2998), 558 (1927) Davisson – Germer experiment (1923 – 1929) The first direct evidence confirming de Broglie's hypothesis that particles can have wave properties as well Clinton Joseph Davisson (left) and Lester Germer (right) George Paget Thomson Nobel Prize in Physics 1937: Davisson and Thomson 7 C. -
Second Harmonic Imaging Microscopy
170 Microsc Microanal 9(Suppl 2), 2003 DOI: 10.1017/S143192760344066X Copyright 2003 Microscopy Society of America Second Harmonic Imaging Microscopy Leslie M. Loew,* Andrew C. Millard,* Paul J. Campagnola,* William A. Mohler,* and Aaron Lewis‡ * Center for Biomedical Imaging Technology, University of Connecticut Health Center, Farmington, CT 06030-1507 USA ‡ Division of Applied Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel Second Harmonic Generation (SHG) has been developed in our laboratories as a high- resolution non-linear optical imaging microscopy (“SHIM”) for cellular membranes and intact tissues. SHG is a non-linear process that produces a frequency doubling of the intense laser field impinging on a material with a high second order susceptibility. It shares many of the advantageous features for microscopy of another more established non-linear optical technique: two-photon excited fluorescence (TPEF). Both are capable of optical sectioning to produce 3D images of thick specimens and both result in less photodamage to living tissue than confocal microscopy. SHG is complementary to TPEF in that it uses a different contrast mechanism and is most easily detected in the transmitted light optical path. It also does not arise via photon emission from molecular excited states, as do both 1- and 2-photon excited fluorescence. SHG of intrinsic highly ordered biological structures such as collagen has been known for some time but only recently has the full potential of high resolution 3D SHIM been demonstrated on live cells and tissues. For example, Figure 1 shows SHIM from microtubules in a living organism, C. elegans. The images were obtained from a transgenic nematode that expresses a ß-tubulin-green fluorescent protein fusion and Figure 1 also shows the TPEF image from this molecule for comparison. -
Applications of Microscopy in Bacteriology
Microscopy Research, 2016, 4, 1-9 Published Online January 2016 in SciRes. http://www.scirp.org/journal/mr http://dx.doi.org/10.4236/mr.2016.41001 Applications of Microscopy in Bacteriology Mini Mishra1, Pratima Chauhan2* 1Centre of Environmental Studies, Department of Botany, University of Allahabad, Allahabad, India 2Department of Physics, University of Allahabad, Allahabad, India Received 28 September 2015; accepted 2 January 2016; published 5 January 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Bacteria are smallest primitive, simple, unicellular, prokaryotic and microscopic organisms. But these organisms cannot be studied with naked eyes because of their minute structure. Therefore in search for the information about the structure and composition of bacterial cells, cell biologist used light microscopes with a numerical aperture of 1.4 and using wavelength of 0.4 µm separa- tion. But there are still certain cellular structures that cannot be seen through naked eyes, and for them electron microscope is used. There are certain improved types of light microscope which can be incorporated to improve their resolving power. Hence microscopy is playing a crucial role in the field of bacteriology. Keywords AFM, SEM, TEM, Microscopy, Bacteriology 1. Introduction To get acquainted with the world of bacteria like small organisms, very effective and advanced technique is re- quired. The size of bacteria ranges between 0.5 - 5.0 micrometer in length; the smallest of them are members of mycoplasma which measures 0.3 micrometers [1]. -
The Development of High Performance Liquid
Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 3-23-2010 The evelopmeD nt of High Performance Liquid Chromatography Systems for the Analysis of Improvised Explosives Megan N. Bottegal Florida International University, [email protected] DOI: 10.25148/etd.FI10041603 Follow this and additional works at: https://digitalcommons.fiu.edu/etd Recommended Citation Bottegal, Megan N., "The eD velopment of High Performance Liquid Chromatography Systems for the Analysis of Improvised Explosives" (2010). FIU Electronic Theses and Dissertations. 154. https://digitalcommons.fiu.edu/etd/154 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida THE DEVELOPMENT OF OPTIMIZED HIGH PERFORMANCE LIQUID CHROMATOGRAPHY SYSTEMS FOR THE ANALYSIS OF IMPROVISED EXPLOSIVES A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY in CHEMISTRY by Megan Nicole Bottegal 2010 To: Dean Kenneth Furton College of Arts and Sciences This dissertation, written by Megan Nicole Bottegal, and entitled The Development of Optimized High Performance Liquid Chromatography Systems for the Anlysis of Improvised Explosives, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. ____________________________________ Jose Almirall ____________________________________ John Berry ____________________________________ William Hearn ____________________________________ Fenfei Leng ____________________________________ DeEtta Mills ____________________________________ Bruce McCord, Major Professor Date of Defense: March 23, 2010 The dissertation of Megan Nicole Bottegal is approved. -
Examples of High Performance Liquid Chromatography (HPLC) Application in Marine Ecology Studies in the Northern Adriatic
Prejeto / Received: 19.6.2009 Sprejeto / Accepted: 17.12.2009 Examples of high performance liquid chromatography (HPLC) application in marine ecology studies in the northern Adriatic Vesna FLANDER-PUTRLE Marine Biology Station, National Institute of Biology, Fornače 41, SI-6330 Piran; e-mail: [email protected] Abstract. Photosynthetic pigments have proved to be useful biomarkers of the abundance, composition and physiological status of the phytoplankton biomass in the marine environment. Using HPLC pigment analysis, we determined phytoplankton community structure in three different marine environments: in the area of a fish farm, in the area of sewage outlets, and in the mucilaginous aggregates. At the reference site we observed seasonal changes with prevalence of fucoxanthin-containing phytoplankton (i.e. diatoms) during winter/spring and autumn. In the fish farm area the concentration of chlorophyll a degradation products was higher, whereas in the locally enriched environment of sewage outlets we observed only small changes in taxonomic composition and phytoplankton biomass. The impact of season is more expressed than the impact of sewage discharge. With the use of HPLC pigment analysis we determined the development of phytoplankton community in different stages of mucilage aggregates. Phytoplankton biomass was composed primarily of diatoms, and as the aggregates aged, diatoms increased in the relative biomass. Our examples have proven the usefulness and suitability of HPLC pigment analysis in marine ecology studies. Key words: pigments, HPLC, phytoplankton, Adriatic Sea, mucilage, fish farm, sewage outlets Izvleček: PRIMERI UPORABE TEKOČINSKE KROMATOGRAFIJE VISOKE LOČLJIVOSTI (HPLC) PRI ŠTUDIJAH MORSKE EKOLOGIJE SEVERNEGA JADRANA – Fotosintezna barvila so se izkazala kot dobri kazalci abundance, sestave in fiziološkega stanja fitoplanktonske biomase v morskem okolju. -
Studying Charged Particle Optics: an Undergraduate Course
IOP PUBLISHING EUROPEAN JOURNAL OF PHYSICS Eur. J. Phys. 29 (2008) 251–256 doi:10.1088/0143-0807/29/2/007 Studying charged particle optics: an undergraduate course V Ovalle1,DROtomar1,JMPereira2,NFerreira1, RRPinho3 and A C F Santos2,4 1 Instituto de Fisica, Universidade Federal Fluminense, Av. Gal. Milton Tavares de Souza s/n◦. Gragoata,´ Niteroi,´ 24210-346 Rio de Janeiro, Brazil 2 Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, Rio de Janeiro, Brazil 3 Departamento de F´ısica–ICE, Universidade Federal de Juiz de Fora, Campus Universitario,´ 36036-900, Juiz de Fora, MG, Brazil E-mail: [email protected] (A C F Santos) Received 23 August 2007, in final form 12 December 2007 Published 17 January 2008 Online at stacks.iop.org/EJP/29/251 Abstract This paper describes some computer-based activities to bring the study of charged particle optics to undergraduate students, to be performed as a part of a one-semester accelerator-based experimental course. The computational simulations were carried out using the commercially available SIMION program. The performance parameters, such as the focal length and P–Q curves are obtained. The three-electrode einzel lens is exemplified here as a study case. Introduction For many decades, physicists have been employing charged particle beams in order to investigate elementary processes in nuclear, atomic and particle physics using accelerators. In addition, many areas such as biology, chemistry, engineering, medicine, etc, have benefited from using beams of ions or electrons so that their phenomenological aspects can be understood. Among all its applications, electron microscopy may be one of the most important practical applications of lenses for charged particles. -
1 Transport of Charged Particle Beams
COURSE OUTLINE Final September 30, 2013 CPOTS 2013 CHARGED PARTICLE OPTICS – THEORY AND SIMULATION (CPOTS) Erasmus Intensive Programme Physics Department University of Crete August 15 – 31, 2013 Heraklion, Crete, Greece Participating Institutions and Instructors 1. University of Crete (UoC) Prof. Theo Zouros* (Project coordinator) 2. Afyon Kocatepe University (AKU) Prof. Mevlut Dogan (contact) Dr. Zehra Nur Ӧzer* 3. Selçuk University (SU) Prof. Hamdi Sukur Kilic (contact) 4. Universidad Computense Madrid (UCM) Prof. Genoveva Martinez - Lopez (contact) Pilar Garcés* 5. University of Ioannina (UoI) Prof. Manolis Benis* (contact) 6. Technische Universität Wien (TUW) Prof. Christoph Lemell* 7. Queen’s University Belfast (QUB) Prof. Jason Greenwood* (contact) Louise Belshaw* 8. University of Debrecen (UoD) Prof. Béla Sulik (contact) 9. University of Athens (UoA) Prof. Theo Mertzimekis (contact – was not able to be present) *SIMION user CPOTS 2013 – Erasmus IP August 15 –31, Heraklion, Crete Page 1 COURSE OUTLINE Final September 30, 2013 CPOTS 2013 Medical University of South Carolina Prof. Dan Knapp (guest) General IP rules and participant information Attendance sheet An attendance sheet will be maintained for all lectures and labs for all participants (teachers and students). Teachers 1. Minimum suggested stay at an Erasmus IP including travel both ways: 5 days (as certified by the attendance sheet). 2. Minimum number of suggested lecturing + lab hours at an Erasmus IP: 5 hours(as certified by the attendance sheet). 3. A minimum of two laboratory instructors will be available at every afternoon laboratory session. 4. The instructor in charge of each unit will be responsible for: i) The proper execution of the lectures as described in the work program. -
Microscopy, Optical Spectroscopy, and Macroscopic Techniques Series: Methods in Molecular Biology, Vol
C. Jones, B. Mulloy, A.H. Thomas Microscopy, Optical Spectroscopy, and Macroscopic Techniques Series: Methods in Molecular Biology, Vol. 22 This is the second of three volumes of Methods in Molecular Biology that deal with Physical Methods of Analysis. The first of these, Spectroscopic Methods and Analyses dealt with NMR spec troscopy, mass spectrometry, and metalloprotein techniques, and the third will cover X-ray crystallographic methods. As with the first volume. Microscopy, Optical Spectroscopy, and Macroscopic Techniques is intended to provide a basic understand ing for the biochemist or biologist who needs to collaborate with spe cialists in applying the techniques of modern physical chemistry to biological macromolecules. The methods treated in this book fall into four groups. Part One covers microscopy, which aims to visualize individual molecules or complexes of several molecules. Electron microscopy is the more familiar of these, while scanning tunneling microscopy is a new and rapidly developing tool. Methods for determining the shapes and sizes of molecules in solution are described in Part Two, which includes chapters on X-ray and neutron scattering, 1994, XI, 251 p. light scattering, and ult- centrifugation. Calorimetry, described in Part Three, provides the means to monitor processes involving thermodynamic changes, whether these are A product of Humana Press intramolecular, such as conformational transition, or the interactions between solutes or between a solute and its sol vent. Part Four is concerned with optical and infrared Printed book spectroscopy and describes applications ranging from the measurement of protein concentration by UV absorbance to the analysis of secondary struc ture using circular Hardcover dichroism and Fourier-transform infrared spec troscopy. -
Proximity Scanning Transmission Electron Microscopy/Spectroscopy
Proximity Scanning Transmission Electron Microscopy/Spectroscopy Ing-Shouh Hwang . Institute of Physics, Academia Sinica, Nankang, Taipei, Taiwan Email: [email protected] Abstract Here a new microscopic method is proposed to image and characterize very thin samples like few-layer materials, organic molecules, and nanostructures with nanometer or sub-nanometer resolution using electron beams of energies lower than 20 eV. The microscopic technique achieves high resolution through the proximity (or near-field) effect, as in scanning tunneling microscopy (STM), while it also allows detection of transmitted electrons for imaging and spectroscopy, as in scanning transmission electron microscopy (STEM). This proximity transmission electron microscopy (PSTEM) does not require any lens to focus the electron beam. It also allows detailed characterization of the interaction of low-energy electron with materials. PSTEM can operate in a way very similar to scanning tunneling microscopy, which provides high-resolution imaging of geometric and electronic structures of the sample surface. In addition, it allows imaging and characterization of the interior structures of the sample based on the detected transmission electron signals. PSTEM comprises a family of spectroscopies that address the transport and scattering of low-energy electrons in materials. Thus rich information can be extracted from the measurements. PSTEM offers a fundamentally new and powerful way to investigate thin materials. New analysis methods of thin materials and new physics may be uncovered by this method. Scanning tunneling microscopy (STM) [1] has been a powerful technique to study topographic and electronic properties of sample surfaces with atomic resolution. Fig. 1a illustrates a schematic of STM. A metal tip is brought to a conductive sample surface to within ~ 1 nm. -
Introduction to Confocal Laser Scanning Microscopy (LEICA)
Introduction to Confocal Laser Scanning Microscopy (LEICA) This presentation has been put together as a common effort of Urs Ziegler, Anne Greet Bittermann, Mathias Hoechli. Many pages are copied from Internet web pages or from presentations given by Leica, Zeiss and other companies. Please browse the internet to learn interactively all about optics. For questions & registration please contact www.zmb.unizh.ch . Confocal Laser Scanning Microscopy xy yz 100 µm xz 100 µm xy yz xz thick specimens at different depth 3D reconstruction Types of confocal microscopes { { { point confocal slit confocal spinning disc confocal (Nipkov) Best resolution and out-of-focus suppression as well as highest multispectral flexibility is achieved only by the classical single point confocal system ! Fundamental Set-up of Fluorescence Microscopes: confocal vs. widefield Confocal Widefield Fluorescence Fluorescence Microscopy Microscopy Photomultiplier LASER detector Detector pinhole aperture CCD Dichroic mirror Fluorescence Light Source Light source Okular pinhole aperture Fluorescence Filter Cube Objectives Sample Plane Z Focus Confocal laser scanning microscope - set up: The system is composed of a a regular florescence microscope and the confocal part, including scan head, laser optics, computer. Comparison: Widefield - Confocal Y X Higher z-resolution and reduced out-of-focus-blur make confocal pictures crisper and clearer. Only a small volume can be visualized by confocal microscopes at once. Bigger volumes need time consuming sampling and image reassembling.