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Microscope Examination (microscope + examination)

Distribution by Scientific Domains
Polymers and Materials Science33%
Medical Sciences33%
Life Sciences33%

Kinds of Microscope Examination

  • electron microscope examination
    		•

    Selected Abstracts

    Detection of Phytoplasma Infection in Rose, with Degeneration Symptoms

    JOURNAL OF PHYTOPATHOLOGY, Issue 1 2001
    M. Kami
    In 1998 a severe disease was observed on rose cvs. ,Patina', ,Papillon' and ,Mercedes' cultivated in a commercial greenhouse in Poland. The symptoms included stunted growth, bud proliferation, leaf malformation and deficiency of flower buds. Sporadically some plants yielded flower buds transformed into big-bud structures and degenerated flowers. The presence of phytoplasma in roses with severe symptoms as well as in recovered plants and Catharanthus roseus experimentally infected by grafting and via dodder was demonstrated by nested polymerase chain reaction assay with primers pair R16F2/R2 or R16F1/R0 and R16(I)F1/R1 amplifying phytoplasma 16S rDNA fragment. The polymerase chain reaction products (1.1 kb) used for restriction fragment length polymorphism analysis after digestion with endonuclease enzymes AluI and MseI produced the same restriction profiles for all samples. The restriction profiles of phytoplasma DNA from these plants corresponded to those of an aster yellows phytoplasma reference strain. Electron microscope examination of the ultra-thin sections of the stem showed wall thickenings of many sieve tubes of the diseased roses and single phytoplasma cells within a sieve element of the phloem of experimentally infected periwinkles. This paper is the first report on aster yellows phytoplasma in rose identified at a molecular level. Detektion einer Phytoplasma-Infektion bei Rosen mit Degenerationserscheinungen Im Jahr 1998 wurde eine schwere Krankheit bei Rosen der Sorten ,Patina', ,Papillon' und ,Mercedes' festgestellt, die in einem polnischen Gewächshaus für kommerzielle Zwecke kultiviert wurden. Zu den Symptomen gehörten Kümmerwuchs, durchwachsene Knospen, Blattmißbildungen und ein Mangel an Blütenknospen. Einige wenige Pflanzen trugen übergroße Blütenknospen, die degenerierte Blüten hervorbrachten. Die Anwesenheit von Phytoplasmen in Rosen mit starken Symptomen, in erholten Pflanzen und in Catharanthus roseus, der durch Pfropfen und durch Teufelszwirn (Cuscuta) experimentell infiziert worden war, wurde mittels einer genesteten Polymerase-Kettenreaktion mit den Primerpaaren R16F2/R2 oder R16F1/R0 und R16(1)F1/R1 zur Amplifikation des Phytoplasma-16S rDNA-Fragments demonstriert. Die für die Analyse der Restriktionsfragmentlängenpolymorphismen nach Verdau mit den Endonucleasen AluI und MseI verwendeten PCR-Produkte (1,1 kb) produzierten bei allen Proben die gleichen Restriktionsprofile. Die Restriktionsprofile der Phytoplasma-DNA aus diesen Pflanzen entsprachen denjenigen eines Typenstamms eines Asternvergilbung auslösenden Phytoplasmas. Elektronenmikroskopische Untersuchungen ultradünner Schnitte des Stamms zeigten Wandverdickungen bei zahlreichen Siebröhren der erkrankten Rosen und einzelne Phytoplasmazellen innerhalb eines Siebelements des Phloems experimentell infizierter Immergrün-Pflanzen. Dies ist der erste Bericht über ein auf molekularer Ebene identifiziertes Asternvergilbungs-Phytoplasma bei Rosen. [source]

    Ultrastructural features of bone marrow cells from patients with acquired sideroblastic anemia

    MICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2004
    Meir Djaldetti
    Abstract The ultrastructural findings of the bone marrow cells from 15 patients with acquired sideroblastic anemia are presented. The red cell precursors from all patients showed the presence of electron-dense material in the mitochondria, representing most probably iron deposits. A great number of these mitochondria were completely destroyed. The erythropoietic precursors from one of the patients showed markedly elongated mitochondria that measured up to 3 ,m. In addition numerous cytoplasmic vacuoles were observed. The red cell precursors from 60% of the patients showed signs of dyserythropoiesis, such as incomplete nuclear division and nuclear distortion. The polymorphonuclears from 47% of the patients presented nuclear abnormalities expressed as nuclear bridges, appendices, and blebs. In addition, phagocytosis of red blood cells was observed. The results of the study underline the advantages of the transmission electron microscope examination in visualization of intricate alterations in hematopoietic cells that cannot be detected with a light microscope. Microsc. Res. Tech. 63:155,158, 2004. © 2004 Wiley-Liss, Inc. [source]

    Development of the blood-nerve barrier in neonatal rats

    MICROSURGERY, Issue 7 2001
    Christopher E. Smith M.D.
    The blood-nerve barrier (BNB) is constituted by the perineurium and the endothelium of endoneurial microvessels. We investigated the age at which the vascular component of BNB function is established in the rat and the ultrastructural modifications accompanying changes in permeability. BNB permeability was assessed with injections of Evans blue albumin (EBA) and horseradish peroxidase (HRP) in rats of different ages. Sciatic nerve sections were studied using fluorescence and electron microscopy. Nerves from animals injected with EBA indicated that the BNB is not functional before 13 days of life but that its function is established by 16 days. These results were confirmed by electron microscope examination of nerve sections from animals injected with HRP, which showed clefts between the endothelial cells of endoneurial vessels in young rats. In rats over 18 days, these clefts were occluded by tight junctions, which prevented HRP from leaving the vessel lumen and conferred BNB function. Systematic morphometric analysis of nerves from different age groups allowed the establishment of baseline normal histologic neural development with age. © 2001 Wiley-Liss, Inc. MICROSURGERY 21:290,297 2001 [source]

    Effect of surface treatment on the impact behaviour of fly-ash filled polymer composites

    POLYMER INTERNATIONAL, Issue 12 2002
    Kishore
    Abstract The impact behaviour of epoxy specimens containing 10% by volume of fly-ash particles with their surface treated for improving or decreasing adhesion is studied. The resulting behavioural patterns are listed and compared to those of composites containing untreated fly-ash particles and unreinforced (ie neat) epoxy. It was noticed that samples involving adhesion-increasing (ie acetone and silane) treatments show greater absorption of energy and maximum load compared to untreated samples and those subjected to adhesion-reducing treatments. Ductility index, however, showed a reversed trend with adhesion-reducing treatment yielding the highest value. In contrast, the energy absorbed was highest for neat resin and lowest for oil surface bearing ash particulate composites. Scanning electron microscope examination of the failed samples was carried out to obtain information on the fracture features with the aim of correlating microstructure to impact response. Thus, the higher ductility indices cases are shown to be distinct and different from composites containing other surface treatments for fillers. © 2002 Society of Chemical Industry [source]

    Intercellular Junctions in Rabbit Eye Ora Serrata

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2006
    L. Nobeschi
    Summary The aim of this study was to describe and localize the intercellular junctions in the ora serrata region of albino and pigmented rabbit eyes. Eyes of albino and pigmented rabbits were fixed and processed for transmission electron microscopy. Light and electron microscope examination was carried out on semithin and ultrathin sections. The ora serrata region showed adherens, gap and tight junctions in the retinal and ciliary margins of albino and pigmented rabbit eyes. In the retinal margin, zonulae adherens between Müller cells and photoreceptors are associated with tight junctions. In the ciliary margin, epithelial cells are joined by adherens, gap and tight junctions localized between apical and apicolateral cell membranes. Tight junctions appear as zonulae occludens in the non-pigmented apicolateral cell membranes and as tight focal junctions between pigmented and non-pigmented apical cell membranes. Between the ciliary and retinal margins there are adherens and tight focal junctions which attach pigmented apical cell membranes to adjacent cells. There were no differences in the distribution of intercellular junctions between albino and pigmented rabbits. [source]

    The effect of overload on the fatigue crack growth behaviour of 304 stainless steel in hydrogen

    FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 1 2001
    M. H. Kelestemur
    Fatigue crack growth (FCG) behaviour and its characteristics following tensile overloads were investigated for AISI 304 stainless steel in three different atmospheres; namely dry argon, moist air and hydrogen. The FCG tests were performed by MTS 810 servohydraulic machine. CT specimens were used for the tests and crack closure measurements were made using an extensometer. FCG rates of 304 stainless steel at both dry argon and moist air atmospheres have shown almost the same behaviour. In other words, the effect of moisture on FCG of this material is very small. However, in a hydrogen atmosphere, the material showed considerably higher crack growth rate in all regimes. In general, for all environments, the initial effect of overloads was to accelerate the FCG rate for a short distance (less than a mm) after which retardation occurred for a considerable amount of time. The main causes for retardation were found as crack blunting and a long reinitiation period for the fatigue crack. Regarding the environmental effect, the overload retardation was lowest in a hydrogen atmosphere. This low degree of retardation was explained by a hydrogen embrittlement mechanism. In a general sense, hydrogen may cause a different crack closure mechanism and hydrogen induced crack closure has come in to the picture. Scanning electron microscope and light microscope examinations agreed well with the above results. [source]