A Device for Magnification Measurement

1972 ◽  
Vol 30 ◽  
pp. 622-623
Author(s):  
J.A. Eades ◽  
A. van Dun
Keyword(s):  
Electron Microscope ◽  
Small Displacement ◽  
Private Communication ◽  
Piezoelectric Crystal ◽  
Double Exposure ◽  
Standard Methods ◽  
Elegant Method ◽  
The Right ◽  
Piezo Electric

The measurement of magnification in the electron microscope is always troublesome especially when a goniometer stage is in use, since there can be wide variations from calibrated values. One elegant method (L.M.Brown, private communication) of avoiding the difficulties of standard methods would be to fit a device which displaces the specimen a small but known distance and recording the displacement by a double exposure. Such a device would obviate the need for changing the specimen and guarantee that the magnification was measured under precisely the conditions used.Such a small displacement could be produced by any suitable transducer mounted in one of the specimen translation mechanisms. In the present case a piezoelectric crystal was used. Modern synthetic piezo electric ceramics readily give reproducible displacements in the right range for quite modest voltages (for example: Joyce and Wilson, 1969).

Residual Gas Reactions in the Electron Microscope: I. Qualitative Observations on the Water Gas Reaction

1968 ◽  
Vol 26 ◽  
pp. 292-293
Author(s):  
Richard E. Hartman ◽  
Roberta S. Hartman ◽  
Peter L. Ramos
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Gas Phase ◽  
Absolute Temperature ◽  
Residual Gas ◽  
Gas Reactions ◽  
Image Position ◽  
The Right ◽  
Water Gas ◽  
Thinning Rate

The action of water and the electron beam on organic specimens in the electron microscope results in the removal of oxidizable material (primarily hydrogen and carbon) by reactions similar to the water gas reaction .which has the form:The energy required to force the reaction to the right is supplied by the interaction of the electron beam with the specimen.The mass of water striking the specimen is given by:where u = gH2O/cm2 sec, PH2O = partial pressure of water in Torr, & T = absolute temperature of the gas phase. If it is assumed that mass is removed from the specimen by a reaction approximated by (1) and that the specimen is uniformly thinned by the reaction, then the thinning rate in A/ min iswhere x = thickness of the specimen in A, t = time in minutes, & E = efficiency (the fraction of the water striking the specimen which reacts with it).

scholarly journals The Effect of Vascular Graft and Human Umbilical Cord Blood-Derived CD34+ Stem Cell on Peripheral Nerve Healing

2018 ◽  
Vol 6 (11) ◽  
pp. 1946-1952
Author(s):  
Ali Yilmaz ◽  
Abdullah Topcu ◽  
Cagdas Erdogan ◽  
Barbaros Sahin ◽  
Gulcin Abban ◽  
...  
Keyword(s):  
Stem Cell ◽  
Electron Microscope ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Cord Blood ◽  
Vascular Graft ◽  
Nerve Damage ◽  
Cd34 Cells ◽  
The Right ◽  
Synthetic Vascular Graft

AIM: There are many trials concerning peripheral nerve damage causes and treatment options. Unfortunately, nerve damage is still a major problem regarding health, social and economic issues. On this study, we used vascular graft and human cord blood derived stem cells to find an alternative treatment solution to this problem. MATERIAL AND METHODS: We used 21 female Wistar rats on our study. They were anesthetized with ketamine and we studied right hind limbs. On Group 1, we did a full layer cut on the right sciatic nerve. On Group 2, we did a full layer cut on the right sciatic nerve, and we covered synthetic vascular graft on cut area. On Group 3, we did a full layer cut on right sciatic nerve, and we covered the area with stem cell applied vascular graft. RESULTS: At the end of postoperative 8. weeks, we performed EMG on the rats. When we compared healthy and degenerated areas as a result of EMG, we found significant amplitude differences between the groups on healthy areas whereas there was no significant difference on degenerated  areas between the groups. Then we re-opened the operated area again to reveal the sciatic nerve cut area, and we performed electron microscope evaluation. On the stem cell group, we observed that both the axon and the myelin sheet prevented degeneration. CONCLUSION: This study is a first on using synthetic vascular graft and cord blood derived CD34+ cells in peripheral nerve degeneration. On  the  tissues  that  were  examined  with  electron  microscope,  we  observed  that  CD34+  cells  prevented  both  axonal  and  myelin  sheath degeneration. Nerve tissue showed similar results to the control group, and the damage was minimal.

scholarly journals The right to private communication using telecommunication means: National and international legal aspects of protection

2019 ◽  
Vol 68 ◽  
pp. 01021
Author(s):  
Olexandr Panasiuk ◽  
Larysa Grynko ◽  
Anna Prokhazka
Keyword(s):  
Human Rights ◽  
Personal Data ◽  
Legal Aspects ◽  
The State ◽  
European Countries ◽  
European Convention ◽  
Private Communication ◽  
Criminal Proceedings ◽  
The Right ◽  
Case Basis

Today's challenges dictate the need to strengthen the national and international legal mechanisms for the protection of personal data and the right to private communication. However, considered rights are not absolute. Legitimate restriction of guaranteed rights is possible, since these means of communication are a powerful tool in the investigation and disclosure of hard/very hard crimes, including transnational ones, especially considering the terrorist threats to Ukraine and other European countries. The possibility of restricting human rights, arising from the guarantees enshrined in the European Convention on Human Rights and consistently enshrined in the ECHR, demands from the state the least compulsory guarantee while interfering with the rights of individuals – to act “in accordance with the law”. Law protection of personal data and right to privacy are researched in the context of peculiarities of conducting investigative (search), secret investigative (search) and other procedural actions in criminal proceedings, which concern access to some telecommunication means (e.g., smartphones). Taking into account different functional purposes of technical means of telecommunication, access and collecting of evidence contained therein, should be carried out on a case-to-case basis, in a different procedural form, considering specifics of telecommunication technologies in each particular case.

EXPERIMENTAL STUDY OF THE HISTOLOGIC FINDINGS OF THE NEOENDOTHELIALIZATION ACCORDING TO LENGTH OF POLYTETRAFLUOROETHYLENE

Hand Surgery ◽  
1998 ◽  
Vol 03 (02) ◽  
pp. 263-270
Author(s):  
Kwang Suk Lee ◽  
Ki Hoon Kang ◽  
Young Sik Kim
Keyword(s):  
Experimental Study ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Microscope ◽  
Carotid Arteries ◽  
Internal Diameter ◽  
Operating Microscope ◽  
Fibril Length ◽  
The Right ◽  
Scanning Electron

The purpose of this study was to investigate the patency rates and the histologic findings of neoendothelialization according to the length of implanted polytetrafluoroethylene (PTFE) with an internal diameter of 3 mm. Under the operating microscope, grafts of 8 and 24 mm in length were implanted in the right carotid arteries of rabbits. All implanted grafts were 25 μm in fibril length and 0.39 mm in wall thickness. All the grafts were harvested at different intervals and observed for the patency rates and histologic findings with light microscope and scanning electron microscope. There was no difference in patency rates according to the length of implanted PTFE. Histologically the formation of neointima and subintim was delayed and incomplete in longer implanted PTFE.

scholarly journals Students and the SEM: The First Encounter

2007 ◽  
Vol 15 (3) ◽  
pp. 46-49
Author(s):  
V.M. Dusevich ◽  
J.D. Eick
Keyword(s):  
Electron Microscope ◽  
Undergraduate Students ◽  
Easy Task ◽  
Amount Of Information ◽  
Naked Eye ◽  
Long Time ◽  
Sem Imaging ◽  
The Right

The first demonstration of an SEM to students is a rewarding experience. Whether it is the beginning of a course in instrumentation or just an illustration of the abilities of an SEM for “prospective users”, whether students have engineering or biological backgrounds, both graduate and undergraduate students are thrilled to see a “real electron microscope”. We thus have an easy task of only having to choose the right specimens to fulfill their anticipation and to present the right amount of information that will be easily absorbed and remembered for a long time.Insects are the prima donnas of SEM imaging. We usually start our demonstrations with insects (Fig.1). Their multifaceted eyes, terrifying (at proper magnifications) mouths, exoskeletons, jointed limbs, and segmented bodies look so astonishingly alien under the microscope, so remarkably different from their familiar (to the naked eye) appearance, that insects unfailingly get the students thrilled and prepare them to absorb information.

Tobolocella levinae n. gen., n. sp., a cheilostome bryozoan from the late Maastrichtian of northern Kazakhstan: scanning electron microscope and micro-CT study

2019 ◽  
Vol 294 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Anna V. Koromyslova ◽  
Alexey V. Pakhnevich ◽  
Petr V. Fedorov
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
New Genus ◽  
Micro Ct ◽  
X Ray ◽  
Northern Kazakhstan ◽  
Ct Data ◽  
The Right ◽  
Scanning Electron

A cheilostome bryozoan Tobolocella levinae gen. et sp. nov. is described from a late Maastrichtian outcrop located on the right bank of the Tobol River in northern Kazakhstan. Its morphology is investigated in detail using combined scanning electron microscopy and X-ray micro-CT data. These studies reveal that colonies of this new genus generally consist of regularly arranged but morphologically different zooids: autozooids, T-zooids, and vicarious avicularia. The T-zooids first established in T. levinae gen. et sp. nov. are zooids with a modified cystid and can be interpreted as autozooidal polymorphs, if its polypide was identical to that of regular autozooids, or heterozooids, if its polypide was modified. The T-zooids probably can increase the distance between autozooidal polypides to improve their feeding efficiency.

scholarly journals Quality in Electron Microscopy

2003 ◽  
Vol 11 (3) ◽  
pp. 28-35
Author(s):  
Tony Bruton ◽  
Steve Chapman ◽  
Paul Harding
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Service Quality ◽  
High Standard ◽  
Competitive Environment ◽  
Total Quality ◽  
Simple Product ◽  
The Right ◽  
Quality Approach

Does quality exist in the electron microscope laboratory? What is quality? Quality is when a product or service meets all of the customers' requirements, is delivered in the correct quantity at the required time, to the right place and at a price the customer is prepared to pay.In an open competitive environment all of the above would apply. In an electron microscope laboratory are we totally satisfied that we have given consideration to our product? We also provide a service, are we happy that the service we provide is of a sufficiently high standard, a standard that we would expect if we were the customers in a hotel or a garage? If we follow the example of world trends in industry, then simple product and service quality, in isolation, fs no longer sufficient, and focus must be given to a total quality approach.

scholarly journals AN ELECTRON MICROSCOPE ANALYSIS OF NERVES INFECTED WITH THE B VIRUS

1949 ◽  
Vol 90 (4) ◽  
pp. 291-296 ◽  
Author(s):  
E. De Robertis
Keyword(s):  
Electron Microscope ◽  
Gastrocnemius Muscle ◽  
Phosphotungstic Acid ◽  
Proximal Part ◽  
Spherical Particles ◽  
B Virus ◽  
Large Particles ◽  
Electron Microscope Analysis ◽  
Sciatic Nerves ◽  
The Right

Rabbits were infected with B virus in the right gastrocnemius muscle and both sciatic nerves were fixed and analyzed under the electron microscope, after periods varying between 26 and 144 hours. Starting at 72 hours, a few neurotubules of the right sciatic show the presence of spherical particles, ranging between 300 and 600 Å. The number and size of the particles increase with time and appear to reach a maximum at 144 hours when the paralysis starts. At this moment also the proximal part of the left sciatic nerve shows the presence of dense particles. The relation of the particles with the periodic structure of the neurotubules was studied both in preparations stained in phosphotungstic acid and those shadowed with chromium. The small and medium sized particles are located within the edges of the neurotubules, and the large particles appear to be attached to the neurotubules. The possible significance of the dense particles is discussed.

Cercaria vaullegeardi Pelseneer, 1906 (Digenea: Hemiuridae); the daughter sporocyst and emergence of the cercaria

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 61-69 ◽  
Author(s):  
B. F. Matthews
Keyword(s):  
Electron Microscope ◽  
Digestive Gland ◽  
Renal Vein ◽  
Gill Filament ◽  
Mantle Cavity ◽  
Daughter Sporocyst ◽  
The Right

SUMMARYThe daughter sporocyst of Cercaria vaullegeardi has hitherto been regarded as occurring within the haemocoel of the digestive gland of Gibbula umbilicalis. A re-examination has shown that an important part of the sporocyst, previously overlooked, extends from the digestive gland, through the afferent renal vein, the right kidney haemocoel and the transverse pallial vessel into the blood channel within a gill filament, thus providing a means of exit from the host directly into the mantle cavity. The sporocyst is described at light and electron microscope levels, and the emergence of the cystophorous cercariae is discussed.

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