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Question 1 Microscopy Is the Technical Field of Using Microscopes to View Objects and Areas of Objects That Cannot Be Seen with Seen with the Naked Eye
Question 1 Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with seen with the naked eye. Microscopy dates back to the 17th- century. In the first century A.D Seneca described actual magnification by a globe of water. The first modern application of optics occurred in Florence around 1280 A.D with the use of glasses as an aid to vision. The early history of the microscope and its inventors is shrouded in much confusion. Credit for the first compound microscope is given to Hans Jansen or his son Zacharias around 1595. The description of Jansen’s microscope was preserved until the early 1600’s. The instrument consisted of three sliding tubes measuring 18 inches in length when fully extended and two inches in diameter. The microscope was said to have a magnification of 3 x when closed and 9 x when fully extended. In the 18th century many mechanical improvements were made in the microscope but images had colourful haloes and were blurry. As the lenses multiplied, so did the distortions. The best simple microscopes attain about two micron resolutions but the best compound resolutions only had five micron resolution. The colour haloes are due to chromatic aberration. This is when light is transmitted through a substance and it will be bent different amounts depending upon its wavelength. This means that a lens will have a different focus for different colours of light. The solution to this problem came not from microscopes but telescopes in the 1730’s. -
Medical News
1378 Hospital; Adolf Lucas Jacob Vischer, M.D. Bâle, Bàle University and St. Bartholomew’s Hospital; Lawrence Cecil Walker, B.A. Cantab., Cambridge University and St. Mary’s Hospital; Ronald News. Ogier Ward, B.A. Uxon., Oxford University and St. Bartholomew’s Medical Hospital; John Glegg Watson, London Hospital; Percy Whitehead, St. George’s Hospital; Frederic St. Barbe Wickham, St. Mary’s Hospital; and Harold Addison Woodruff, M.R.C.V.S., University EXAMINING BOARD IN ENGLAND BY THE ROYAL College Hospital. * COLLEGES OF PHYSICIANS OF LONDON AND SURGEONS OF M.R.C.S. Diploma granted on April llth. ENGLAND.—At the quarterly meetings of the above ROYAL COLLEGE OF SURGEONS OF ENGLAND.- Colleges held on April 25th and May 9th respectively, the At the First Professional Examination in Anatomy and Licence of the Royal College of Physicians and the Diploma Physiology for the Diploma of Fellow of the above College, of Member of the of were conferred Royal College Surgeons held on May 2nd, 3rd, 7th, 8th, 9th, and 10th, 118 on 96 gentlemen who have completed their examinations and candidates presented themselves for examination, of whom have with the The are the complied by-laws. following 31 passed and 87 were rejected. The following are the names of the successful candidates :- names of the successful candidates :- Edward Smith Abraham, Bristol University and University College Harold George Alexander, M.R.C.S., L.R.C.P., Middlesex Hospital; Hospital; Rupert Blake Adams. St. Mary’s and Middlesex Hospitals ; Lancelot Bromley, M.B., B.C., B.A. -
Subwavelength Resolution Fourier Ptychography with Hemispherical Digital Condensers
Subwavelength resolution Fourier ptychography with hemispherical digital condensers AN PAN,1,2 YAN ZHANG,1,2 KAI WEN,1,3 MAOSEN LI,4 MEILING ZHOU,1,2 JUNWEI MIN,1 MING LEI,1 AND BAOLI YAO1,* 1State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China 2University of Chinese Academy of Sciences, Beijing 100049, China 3College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710071, China 4Xidian University, Xi’an 710071, China *[email protected] Abstract: Fourier ptychography (FP) is a promising computational imaging technique that overcomes the physical space-bandwidth product (SBP) limit of a conventional microscope by applying angular diversity illuminations. However, to date, the effective imaging numerical aperture (NA) achievable with a commercial LED board is still limited to the range of 0.3−0.7 with a 4×/0.1NA objective due to the constraint of planar geometry with weak illumination brightness and attenuated signal-to-noise ratio (SNR). Thus the highest achievable half-pitch resolution is usually constrained between 500−1000 nm, which cannot fulfill some needs of high-resolution biomedical imaging applications. Although it is possible to improve the resolution by using a higher magnification objective with larger NA instead of enlarging the illumination NA, the SBP is suppressed to some extent, making the FP technique less appealing, since the reduction of field-of-view (FOV) is much larger than the improvement of resolution in this FP platform. Herein, in this paper, we initially present a subwavelength resolution Fourier ptychography (SRFP) platform with a hemispherical digital condenser to provide high-angle programmable plane-wave illuminations of 0.95NA, attaining a 4×/0.1NA objective with the final effective imaging performance of 1.05NA at a half-pitch resolution of 244 nm with a wavelength of 465 nm across a wide FOV of 14.60 mm2, corresponding to an SBP of 245 megapixels. -
Introduction to Light Microscopy
Introduction to light microscopy A CAMDU training course Claire Mitchell, Imaging specialist, L1.01, 08-10-2018 Contents 1.Introduction to light microscopy 2.Different types of microscope 3.Fluorescence techniques 4.Acquiring quantitative microscopy data 1. Introduction to light microscopy 1.1 Light and its properties 1.2 A simple microscope 1.3 The resolution limit 1.1 Light and its properties 1.1.1 What is light? An electromagnetic wave A massless particle AND γ commons.wikimedia.org/wiki/File:EM-Wave.gif www.particlezoo.net 1.1.2 Properties of waves Light waves are transverse waves – they oscillate orthogonally to the direction of propagation Important properties of light: wavelength, frequency, speed, amplitude, phase, polarisation upload.wikimedia.org 1.1.3 The electromagnetic spectrum 퐸푝ℎ표푡표푛 = ℎν 푐 = λν 퐸푝ℎ표푡표푛 = photon energy ℎ = Planck’s constant ν = frequency 푐 = speed of light λ = wavelength pion.cz/en/article/electromagnetic-spectrum 1.1.4 Refraction Light bends when it encounters a change in refractive index e.g. air to glass www.thetastesf.com files.askiitians.com hyperphysics.phy-astr.gsu.edu/hbase/Sound/imgsou/refr.gif 1.1.5 Diffraction Light waves spread out when they encounter an aperture. electron6.phys.utk.edu/light/1/Diffraction.htm The smaller the aperture, the larger the spread of light. 1.1.6 Interference When waves overlap, they add together in a process called interference. peak + peak = 2 x peak constructive trough + trough = 2 x trough peak + trough = 0 destructive www.acs.psu.edu/drussell/demos/superposition/superposition.html 1.2 A simple microscope 1.2.1 Using lenses for refraction 1 1 1 푣 = + 푚 = physicsclassroom.com 푓 푢 푣 푢 cdn.education.com/files/ Light bends as it encounters each air/glass interface of a lens. -
The-Pathologists-Microscope.Pdf
The Pathologist’s Microscope The Pathologist’s Microscope Rudolf Virchow, the father of Pathology, had available to him wonderful microscopes during the 1850’s to 1880’s, but the one you have now is far better. Your microscope is the most highly perfected of all scientific instruments. These brief notes on alignment, the objective lens, the condenser, and the eyepieces are what you need to know to get the most out of your microscope and to feel comfortable using it. Figure 1 illustrates the important parts of a generic modern light microscope. Figure 1 - Parts of the Microscope UNC Pathology & Lab Med, MSL, July 2013 1 The Pathologist’s Microscope Alignment August Köhler, in 1870, invented the method for aligning the microscope’s optical system that is still used in all modern microscopes. To get the most from your microscope it should be Köhler aligned. Here is how: 1. Focus a specimen slide at 10X. 2. Open the field iris and the condenser iris. 3. Observe the specimen and close the field iris until its shadow appears on the specimen. 4. Use the condenser focus knob to bring the field iris into focus on the specimen. Try for as sharp an image of the iris as you can get. If you can’t focus the field iris, check the condenser for a flip-in lens and find the configuration that lets you see the field iris. You may also have to move the field iris into the field of view (step 5) if it is grossly misaligned. 5.Center the field iris with the condenser centering screws. -
The Scientific Legacy of Antoni Van Leeuwenhoek
196 Chapter 12 Chapter 12 The Scientific Legacy of Antoni Van Leeuwenhoek This final chapter discusses some of the developments in science on which Antoni van Leeuwenhoek left his mark from his death to the beginning of the 21st century. It will review the influence of his work and listen for the echoes of his name almost three hundred years after his death. Figure 12.1 Nineteenth-century microscope by George Adams with eyepiece, objective, various attachments and a mirror to illuminate the specimen © Koninklijke Brill NV, Leiden, 2016 | doi 10.1163/9789004304307_013 The Scientific Legacy of Antoni Van Leeuwenhoek 197 Microscopy Microscopes have become increasingly complex and more versatile, but much easier to use, since the time of Van Leeuwenhoek. Single-lens microscopes went out of use in the 18th century, when compound microscopes with at least two lenses ‒ an eyepiece and an objective ‒ became the norm. Many innovations came from England. Firstly, the illumination of speci- mens was improved. During Van Leeuwenhoek’s lifetime, John Marshall (1663–1725) had developed a simple illumination system using a mirror attached to the foot of the microscope. John Cuff (1708–1772) used an extra lens, a condenser, in 1744 to concentrate light on the specimen. In 1755, George Adams (1720–1773) developed a microscope with a rotating wheel holding objectives with different powers of magnification. Sliding holders in which a variety of specimens could be mounted at one time can be traced back to the rotating holders on the single-lensed microscopes used by Christiaan Huygens and J. De Pouilly (or Depovilly) in the 1670s, and were developed for use with compound microscopes. -
Simple and Open 4F Koehler Transmitted Illumination System for Low- Cost Microscopic Imaging and Teaching
Simple and open 4f Koehler transmitted illumination system for low- cost microscopic imaging and teaching Jorge Madrid-Wolff1, Manu Forero-Shelton2 1- Department of Biomedical Engineering, Universidad de los Andes, Bogota, Colombia 2- Department of Physics, Universidad de los Andes, Bogota, Colombia [email protected] ORCID: JMW: https://orcid.org/0000-0003-3945-538X MFS: https://orcid.org/0000-0002-7989-0311 Any potential competing interests: NO Funding information: 1) Department of Physics, Universidad de los Andes, Colombia, 2) Colciencias grant 712 “Convocatoria Para Proyectos De Investigación En Ciencias Básicas“ 3) Project termination grant from the Faculty of Sciences, Universidad de los Andes, Colombia. Author contributions: JMW Investigation, Visualization, Writing (Original Draft Preparation) MFS Conceptualization, Funding Acquisition, Methodology, Supervision, Writing(Original Draft Preparation) 1 Title Simple and open 4f Koehler transmitted illumination system for low-cost microscopic imaging and teaching Abstract Koehler transillumination is a powerful imaging method, yet commercial Koehler condensers are difficult to integrate into tabletop systems and make learning the concepts of Koehler illumination difficult. We propose a simple 4f Koehler illumination system that offers advantages with respect to building simplicity, cost and compatibility with tabletop systems, which can be integrated with open source Light Sheet Fluorescence Microscopes (LSFMs). With those applications in mind as well as teaching, we provide -
Lord Lister Ranks with That of Pasteur by Val- Coagulation
Book Revi ews Lord Lis te r . By Sir Rickman John Godlee, Bt., his graduation Lister went to Edinburgh for k .c .v .o ., m.s ., f .r .c .s . Ed. 3, revised and reset what was intended to be a short visit to the throughout. Oxford, at the Clarendon Press, clinics of that medical center. There he met Oxford University Press, Humphrey Milford, James Syme, then at the height of his brilliant 1924. career. The acquaintance ripened quickly into The biography of the founder of antiseptic the closest friendship. Lister stayed on to work surgery, by his nephew, Sir Rickman Godlee, with Syme, and in 1855 settled down to prac- has won the great success which was predicted tice in Edinburgh, and began his lectures on for it on its first publication in 1917. The present surgery there. In 1856 he married Syme’s is the third edition and presents but few addi- daughter and was elected assistant surgeon to tions or changes from those which have pre- the Edinburgh Infirmary. While actively engaged ceded it, a statement which should be regarded in clinical surgical work he still found time to as a tribute to the skill, fullness and accuracy work with his microscope and published some with which the work was originally written. papers showing the results of his investigations In English medical literature this biography of into the phenomena of inflammation and blood Lord Lister ranks with that of Pasteur by Val- coagulation. In i860 Lister received the appoint- lery Radot in French, and it is interesting that ment of regius professor of surgery in the two great men whose labors were so closely University of Glasgow, a great honor for so associated in their ultimate results should have young a man. -
160-Series-Manual.Pdf
National Optical & Scientific Instruments Inc. 6508 Tri-County Parkway Schertz, Texas 78154 Phone (210) 590-9010 Fax (210) 590-1104 INSTRUCTIONS FOR 160 SERIES COMPOUND BIOLOGICAL MICROSCOPES Copyright © 1/2/01 National Optical & Scientific Instrument Inc. Models 160 (monocular head), 161 (dual head), 162 (binocular head), 163 (trinocular head), all have the same stand and stand features…only the head portion differs…illustrated is Model 162. Knurled diopter ring Sliding interpupillary adjustment, grips located on both left and right Widefield 10x/18 side of diopter scale eyepiece Mark on side of eyepiece tube for indexing diopter reading Interpupillary scale Knurled head locking screw Viewing head of microscope Revolving nosepiece Arm of microscope stand Objective lenses Two knurled locking screws for Specimen holder securing specimen holder to stage (mechanical stage) Stage Abbe condenser locking screw Abbe condenser 1.25 N.A. Iris diaphragm lever Coarse focus knob Filter holder for 32mm filter Control knob for Fine focus knob Abbe condenser Recess for 45mm filter Illuminator condenser Knobs controlling X and Y movement of mechanical stage Light intensity Base control knob Detachable power supply cord Tension adjustment 100v-240v, 50H/60H input 12 volt DC knob Output ON/OFF switch DC Plug Socket 12 Volt DC Switching Power Supply 3 INTRODUCTION Thank you for your purchase of a National microscope. It is a well built, precision instrument carefully checked to assure that it reaches you in good condition. It is designed for ease of operation and years of carefree use. The information in this manual probably far exceeds what you will need to know in order to operate and maintain your microscope. -
Creation and the Germ Theory.Indd
Answers in Depth, Vol. 4, (2009), pp. 82–91. https://assets.answersingenesis.org/doc/articles/aid/v4/creation-germ-theory.pdf Creation and the Germ Theory Alan L. Gillen, Ph.D. J. Douglas Oliver, Ph.D. Keywords creation, germs, germ theory, Bible, worldview, disease, infection, Christians, creationists, Anton van Leeuwenhoek, Joseph Baron Lister, Louis Pasteur, fermentations, antiseptics, antiseptic surgery, Robert Koch, Koch’s postulates, tuberculosis, contagion, Lister Limb microscope, early light microscopes The news media writes frequently that germs cause disease. Infectious diseases such as swine fl u, Salmonella, Escherichia coli, MRSA, multi-drug resistant tuberculosis, and AIDS have captured the national headlines in recent months. With each passing year, these headlines reveal that some new disease outbreak or plague threatens thousands of lives. For example, in 2009 the news fl ash “Swine Flu Threatens the Globe” was broadcast across the nation, alarming many people. The emergence of a new strain of fl u (H1N1) was said to place millions at risk. Today, we take for granted that germs cause disease, and many people fear them. Yet for centuries, the concept of germs was virtually unknown. Leprosy, plagues, and pestilence were diseases of mystery through most of history. The cause of infectious (or contagious diseases) was not known. Many speculated that mysterious miasmas caused sickness or that mysterious elements were spontaneously generated. Miasma was thought to be a poisonous gas- or vapor-fi lled particle of decaying miasmata (matter) that caused various sickness and disease. Today, the term germ is well known and refers to disease-causing microbes, that is, pathogens. -
How to Perform DIC Microscopy Introduction Principle
How To Perform DIC Microscopy Technical Support Note #T-3 Date Created: 12/5/03 Category:Techniques Date Modified: 00/00/00 Keywords: DIC, Differential Interference Contrast, Axiovert 200M Introduction Many biological specimens cannot be effectively visualized using ordinary bright-field microscopy because their images produce very little contrast, rendering them essentially invisible. Differential Interference Contrast (DIC) microscopy is an excellent method for generating contrast by converting specimen optical path gradients into amplitude differences that can be visualized by the human eye. Images produced using DIC optics have a distinct relief-like, shadow-cast appearance giving an illusion of three dimensionality. This tutorial will cover the optical components used in DIC microscopy, the basic principles governing how it works, and the proper alignment of DIC optical components for the Zeiss Axiovert 200M research microscope. Principle DIC microscopy utilizes a system of dual-beam interference optics that transforms local gradients in optical path length in a specimen into regions of contrast in an image. Optical path length is a product of the refractive index and thickness between two points on an optical path and is directly related to the transit time and number of cycles of vibration exhibited by a wave of light traveling between two points. The basic principle of DIC is illustrated in figure 4. Waves of plane polarized light are split into two beams by the condenser prism. These pairs of beams emerge from the condenser lens traveling in parallel to one another and pass through the specimen. The spacing between these paired beams of light varies depending on the prism used, but generally ranges between 0.2-2µm. -
Setting up Kohler Illumination on the Nikon TE2000U Inverted Microscope
Setting up Kohler Illumination on the Nikon TE2000U Inverted Microscope Koehler illumination1 is an illumination technique that provides optimum resolution and contrast when using a bright-field light microscope. It does this by aligning and focussing the illumination light path, and critically setting the iris apertures of the microscope to best match the objective lens. This sheet is only for aligning the condenser on the Nikon inverted microscope. 1) Place a slide on the stage and bring the specimen into focus. If the microscope condenser is way out of alignment, you will have to roughly adjust the condenser height to give adequate illumination to focus on the specimen. There are two white tape indicators on the left side of the condenser that will be nearly aligned when the condenser is at the correct height. 2) Stop down the Field Diaphragm Iris so that you can see it in the field of view. This is the vertical diaphragm [black] slider at the top right hand of the condenser [at the highest point of the microscope]. You slide the lever downwards to close [stop down] the iris, and up again to re-open the iris. 3) Focus the Condenser by adjusting its height. Turn the focus knob on the left or right side of the condenser until the shadow edge of the Field Diaphragm Iris is in sharp focus when viewed down the microscope eyepieces. This iris edge may be blurred if your specimen is very thick, so get it as sharp in focus as possible. 4) Open the Field Diaphragm Iris to near the edge of the field of view and centre it to the middle, using the condenser centering controls.