NEAR- AND REMOTE-TERM STRUCTURAL CHANGES OF VEINS AFTER ENDOVASAL LASER COAGULATION BY RADIATION WITH A WAVE LENGTH OF 1910 nm

The purpose. to assess the potential of OCT-angiography in studying pathogenesis, diagnosing and monitoring macular telangiectasias of various genesis in children and adolescents. Material and methods. We examined and treated 4 children (5 eyes) aged from 12 to 17 years with idiopathic macular telangiectasias (2), developed against the background of Coat’s disease (1) and diabetic retinopathy (1). The examination included standard ophthalmologic inspection, as well as optical coherence tomography and OCT-angiography (RS-3000 Advance AngioSca, Nidek, Japan). Two children underwent transpupillary laser coagulation of telangiectasias (2 and 3 sessions), two received an intravitreal injection of an inhibitor of angiogenesis. Results. Ophthalmoscopically in all children microaneurysms were localized in the macular and paramacular zones and were accompanied by the development of retinal edema. According to OCT-angiography, all children had pathological structural changes (microaneurysms, vascular artery abnormalities, changes in the density of the vascular pattern) of superficial and to a greater extent deep retinal capillary plexuses. As a result of the treatment, 3 children (4 eyes) had clinically noted decrease in the number of microaneurysms. According to the data of optical coherence tomography, there was positive dynamics in decrease of the height of the retinal edema from 49 to 320 μm, аccording to OCT angiography, showed a decrease in the number of microaneurysms in the superficial and especially in the deep plexus, and in a child with diabetic retinopathy there was also a slight increase in the vascular density of the deep capillary plexus. Сonclusion. According to OCT-angiography, development of macular telangiectasias in children is accompanied by preferential changes in the deep capillary plexus, which indicates the pathogenetic significance of microcirculatory disturbances at this level. The method also reveals its value in monitoring the disease.

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Fluorescence Quantum Yield and Free Rotor Effect

Laser Chemistry ◽

10.1155/lc.4.305 ◽

1984 ◽

Vol 4 (1-6) ◽

pp. 305-310 ◽

Cited By ~ 16

Author(s):

M. S. A. Abdel-Mottaleb

Keyword(s):

Quantum Yield ◽

Fluorescence Quantum Yield ◽

Internal Conversion ◽

Structural Changes ◽

Wave Length ◽

Solvent Viscosity ◽

Dependent Rate ◽

Picosecond Time Scale ◽

Viscous Media ◽

Different Parts

It was found that the weakly fluorescent trans-2(4′-N,N-dimethylaminostyryl)- pyridinium betaine dyestuff (1) becomes efficiently fluorescent in very viscous media. The fluorescence quantum yield (φF) for dyestuff (1) approaches unity in ethanol–ether (1 : 1) glass at 98 K. Moreover, the fluorescence wave-length is blue shifted (1874 cm−1) when the temperature is lowered to 98 K. The results are rationalized as being due to solvent viscosity dependent rate constant for a radiationless internal conversion process, involving rotation of the different parts of the molecule, a free rotor effect. The rate of internal rotation was estimated to be 3.4 × 1011 s−1. The results suggest that this molecule can be used as a fluorescent probe to study microscopic structural changes in surrounding media occurring on the picosecond time scale.

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The inactivation of plant viruses by radiations

Parasitology ◽

10.1017/s0031182000016188 ◽

1942 ◽

Vol 34 (2) ◽

pp. 227-237 ◽

Cited By ~ 22

Author(s):

D. E. Lea ◽

Kenneth M. Smith

Keyword(s):

Virus Particle ◽

Gamma Rays ◽

Potato Virus ◽

Structural Changes ◽

Wave Length ◽

Plant Viruses ◽

X Rays ◽

Virus Size ◽

Size Estimates

Experiments are described on the inactivation by gamma-rays, X-rays, and alpha-rays of the viruses of tomato bushy stunt, tobacco necrosis, tobacco ringspot, tobacco mosaic and potato virus X. Within the errors of the experiment the inactivation curves appear to be exponential, and the inactivation doses increase in the order gamma-rays, X-rays, of wave-length 1·5 A., X-rays of wave-length 8·3 A., and alpha-rays.A theory is given explaining these results and correlating the inactivation dose with the virus size. Estimates of the sizes of the viruses obtained from the radiation experiments he within the range of the sizes given by other methods, but are somewhat lower than the most probable sizes. Possible explanations of the discrepancy which are discussed are (a) the virus particle is not the molecule, in the sense of the smallest infective unit, or (b) certain structural changes in the virus molecule produced by the radiation may still leave it infective. Some of these may perhaps show themselves as mutations.

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Technological Solution for Preserving Nutritional Value and Increasing the Digestibility of Meat Dishes

Food Processing Techniques and Technology ◽

10.21603/2074-9414-2019-2-177-184 ◽

2019 ◽

Vol 49 (2) ◽

pp. 177-184

Author(s):

Эльшан Абдурахманов ◽

Elshan Abdurakhmanov

Keyword(s):

Heat Treatment ◽

Structural Changes ◽

Wave Length ◽

Electricity Consumption ◽

Free Water ◽

Food Product ◽

Radiation Energy ◽

Insulation Material ◽

Ir Radiation ◽

Cooking Process

Cooking perishable foods is an important and complicated process. Technological equipment plays a huge role in the cooking process, as well as the professional skills of the cook. To exclude the influence of the cook from this process, it is necessary to develop new heating equipment that would provide automatic culinary (heat) food processing without the participation of personnel, as well as intensify the process and reduce heat and energy consumption. This task is especially relevant when cooking in closed (restricted) spaces is concerned. The present research featured perspective directions of heat treatment. The authors compared the effect of microwave, ultrasonic, and infrared fields on the product and the technological process. The analysis proved that the grill mode provided the best option for heat treatment of portioned and small-sized semi-finished products from non-graded meat. Heat treatment of semi-finished products occurs without their contact with any heat transfer surface or coolant. The processing principle is based on the fact that free water contained in semi-finished products intensively absorbs IR radiation with a wave length of λ=1.0–1.2 μm, thus heating the inner layers of the food product. The radiation energy converted into heat energy is transferred to the inner layers of the product and reaches its core. Forced convection during the heat treatment in the ‘grill’ mode intensifies the speed of heating and cooking. Unlike conductive heating, the surface of the product remains open, which lets the layers cool down. This makes it possible to deliver an intense heat flux to the product. The author developed a KG-1 galley grill that can process portionedmeat (80–120 g) and small-sized semi-finished products (30–40 g) in the grill mode. The internal walls are coated with a special stuff that reflects IR-radiation, while the external walls are covered with a heat-resistant andhighly efficient quartz aerogel, which is a flexible thermal insulation material. A set of prefabricated quartz heaters are located at a distance of 4.5–5 cm from the food product, which intensifies the cooking process. The proposed structural changes decreased the temperature of the outer walls from 220°C to 60°C; lowered electricity consumption by 24–26%; shortened the cooking time by 20–25%; reduced the discharge of smoke and steam into the sewage system; improved filtering and ventilation; reduced heat losses by 1.3–1.5; increased efficiency by 16–20%; expanded the functionality and assortment of high quality meat dishes.

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Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050287 ◽

1974 ◽

Vol 32 ◽

pp. 54-55

Author(s):

S. Phyllis Steamer ◽

Rosemarie L. Devine

Keyword(s):

Structural Changes ◽

Radiation Treatment ◽

Arterial Stenosis ◽

Ultrastructural Changes ◽

Vascular Effects ◽

Microvascular Changes ◽

Surrounding Connective Tissue ◽

Fission Neutrons ◽

Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

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Evaluation of single-electron movies of glutamine synthetase molecules

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075191 ◽

1983 ◽

Vol 41 ◽

pp. 280-281

Author(s):

W. Kunath ◽

E. Zeitler ◽

M. Kessel

Keyword(s):

Electron Microscope ◽

Glutamine Synthetase ◽

Electron Irradiation ◽

Structural Damage ◽

Structural Changes ◽

Single Electron ◽

Continuous Series ◽

Digital Recording ◽

Recording Device ◽

Low Exposure

The features of digital recording of a continuous series (movie) of singleelectron TV frames are reported. The technique is used to investigate structural changes in negatively stained glutamine synthetase molecules (GS) during electron irradiation and, as an ultimate goal, to look for the molecules' “undamaged” structure, say, after a 1 e/Å2 dose.The TV frame of fig. la shows an image of 5 glutamine synthetase molecules exposed to 1/150 e/Å2. Every single electron is recorded as a unit signal in a 256 ×256 field. The extremely low exposure of a single TV frame as dictated by the single-electron recording device including the electron microscope requires accumulation of 150 TV frames into one frame (fig. lb) thus achieving a reasonable compromise between the conflicting aspects of exposure time per frame of 3 sec. vs. object drift of less than 1 Å, and exposure per frame of 1 e/Å2 vs. rate of structural damage.

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Fine Structural Changes in the Adenohypophyses of Rats Following Destruction of the Pituitary Stalk

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079917 ◽

1977 ◽

Vol 35 ◽

pp. 496-497

Author(s):

K. Kovacs ◽

E. Horvath ◽

J. M. Bilbao ◽

F. A. Laszlo ◽

I. Domokos

Keyword(s):

Structural Changes ◽

Tissue Injury ◽

Anterior Lobe ◽

Uranyl Acetate ◽

Male Rats ◽

Pituitary Stalk ◽

Sequence Of Events ◽

Pituitary Glands ◽

Electrolytic Lesions ◽

Ultrathin Sections

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.

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Membrane Changes in Polymorphonuclear Leukocytes During Ionophore (A23187) - Induced Lysosomal Release

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007984x ◽

1977 ◽

Vol 35 ◽

pp. 482-483

Author(s):

P.L. Moore ◽

P.L. Sannes ◽

H.L. Bank ◽

S.S. Spicer

Keyword(s):

Structural Changes ◽

Calcium Release ◽

Clear Understanding ◽

Ionophore A23187 ◽

Enzyme Release ◽

Extracellular Medium ◽

Pmn Leukocytes ◽

Intracellular Ion Concentrations ◽

Membrane Changes ◽

Pmn Leukocyte

It is thought that calcium and/or magnesium may play important roles in polymorphonuclear (PMN) leukocyte functions such as chemotaxis, adhesion and phagocytosis. Yet, a clear understanding of the biological roles of these ions has awaited the development of techniques which permit a selective alteration of intracellular ion concentrations. Recently, treatment of cells with the ionophore A23187 has been used to alter intracellular divalent cation concentrations. This ionophore is a lipid soluble antibiotic produced by Streptomyces chartreusensis that complexes with both calcium and magnesium (3) and is believed to carry these ions across biological membranes (4). Biochemical investigations of human PMN leukocytes demonstrate that cells treated with A23187 and extracellular calcium release their lysosomal enzymes into the extracellular medium without rupturing and releasing their soluble cytoplasmic enzymes (5,6). The aim of the present study and and a companion report (7) was to investigate the structural changes that occur in leukocytes during ionophore-induced lysosomal enzyme release.

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The Reaction of Brain Structures with OsO4-Zinc-Iodide Stain

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065419 ◽

1971 ◽

Vol 29 ◽

pp. 272-273

Author(s):

Werner J. Niklowitz

Keyword(s):

Electron Microscope ◽

Structural Changes ◽

Mossy Fiber ◽

Toxic Metal ◽

Staining Technique ◽

Brain Structures ◽

Oxidase Inhibitor ◽

Fiber Layer ◽

Hippocampal Tissue ◽

Zinc Iodide

After intoxication of rabbits with certain substances such as convulsant agents (3-acetylpyridine), centrally acting drugs (reserpine), or toxic metal compounds (tetraethyl lead) a significant observation by phase microscope is the loss of contrast of the hippocampal mossy fiber layer. It has been suggested that this alteration, as well as changes seen with the electron microscope in the hippocampal mossy fiber boutons, may be related to a loss of neurotransmitters. The purpose of these experiments was to apply the OsO4-zinc-iodide staining technique to the study of these structural changes since it has been suggested that OsO4-zinc-iodide stain reacts with neurotransmitters (acetylcholine, catecholamines).Domestic New Zealand rabbits (2.5 to 3 kg) were used. Hippocampal tissue was removed from normal and experimental animals treated with 3-acetylpyridine (antimetabolite of nicotinamide), reserpine (anti- hypertensive/tranquilizer), or iproniazid (antidepressant/monamine oxidase inhibitor). After fixation in glutaraldehyde hippocampal tissue was treated with OsO4-zinc-iodide stain and further processed for phase and electron microscope studies.

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