Cerebral Micro-Structural Changes in COVID-19 Patients: An MRI-Based Preliminary Study

2020 ◽  
Author(s):  
Yiping Lu ◽  
Xuanxuan Li ◽  
Daoying Geng ◽  
Pu-Yeh Wu ◽  
Chu-Chung Huang ◽  
...  
Keyword(s):  
Structural Changes ◽  
Preliminary Study

scholarly journals A PRELIMINARY STUDY OF THE MANGROVE FOREST ON PULAU RAMBUT, JAKARTA BAY

1970 ◽  
Vol 18 ◽  
pp. 119-129
Author(s):  
Kuswata Kartawinata ◽  
Eko B. Walujo
Keyword(s):  
Mangrove Forest ◽  
Structural Changes ◽  
Secondary Growth ◽  
Deep Soil ◽  
On This Island ◽  
Coral Island ◽  
Preliminary Study ◽  
Disturbed Forest ◽  
Flat Profile ◽  
Shallow Soils

Pulau Rambut (± 56ha) is one of the islands of the Pulau Seribu group. It is a coral island covered by disturbed forest and secondary growth at the center, and mangrove forest at its periphery. A study in a 290 x 10 m transect running south to north across the mangrove forest shows a distinct zonation as follows : the Scyphiphora hydrophyllacea - Lumnitzera racemosa community on coral flat with patchy shallow soils on the interior, the Rhizophora mucronata community on relatively deep soil overlaying coral formation, and the R. mucronata - R. stylosa community on periodically submerged coral flat. Profile diagrams established along the transect show structural changes also. The R. mucronata forest is the most developed community and appears to be the most prevalent. R. stylosa forms the pioneer species on this island.

A preliminary study for the assessment of hypertension using static and dynamic IR thermograms

2018 ◽  
Vol 63 (2) ◽  
pp. 197-206
Author(s):  
Jayanthi Thiruvengadam ◽  
Anburajan Mariamichael
Keyword(s):  
Feature Selection ◽  
Thermal Imaging ◽  
Structural Changes ◽  
Principal Component ◽  
Normal Subjects ◽  
Skin Surface ◽  
The Body ◽  
Preliminary Study ◽  
Average Skin ◽  
Diagnosis Of Hypertension

AbstractStructural changes in blood vessels occur due to prolonged hypertension. Early detection of blood pressure (mm Hg) is essential for disease prevention. The aim of this work is to propose a computer-aided diagnostic (CADx) model for the diagnosis of hypertension using variables derived from non-contact static and dynamic thermal imaging in comparison with the pulse wave velocity (PWV)-derived parameters. Static and dynamic infrared (IR) thermograms of selected skin areas of the body from known hypertensive (n=14) and age- and sex-matched normal subjects were captured. The average skin surface temperature [SST (°C)] of selected skin areas of the body was calculated from a static IR thermogram. After denoising the dynamic IR thermogram using wavelets, the statistical variables power, mean, standard deviation (SD), variance, skewness and kurtosis were calculated. The variables derived from both static and dynamic thermograms were used to develop the CADx model. The performance of the CAD model was also tested by feature selection using principal component analysis (PCA). An accuracy of 75% (sensitivity=78.6%, specificity=71.4%) could be achieved with the average SST (°C) of the static IR thermogram alone. The statistical variables derived from the dynamic IR thermogram alone gave an accuracy of 82% (and 85% after feature selection by PCA), whereas the accuracy using standard methods like variables derived from PWV was only 71.4% (with and without feature selection). The highest accuracy of 89% could be achieved by combining variables like average SST (°C) measured from static and dynamic IR thermograms and PWV-derived variables.

Cysticercus fasciolaris: Fine surface structural changes in the tegument following in vitro low doses of the antihelminthic drug, oltipraz

1989 ◽  
Vol 47 ◽  
pp. 1104-1105
Author(s):  
Betty Ruth Jones ◽  
Randolph Taylor
Keyword(s):  
Structural Changes ◽  
Highly Active ◽  
Immunological Mechanisms ◽  
Cysticercus Fasciolaris ◽  
Distal Surface ◽  
Preliminary Study ◽  
Adult Cat ◽  
Taenia Taeniaeformis ◽  
Rats And Mice

Cysticercus fasciolaris is the larval form of the adult cat tapeworm, Hydatigera taeniaeformis (Taenia taeniaeformis). It is of increasing interest because of the considerable pathological conditions produced in a rat or mouse host in which it is normally found. The larvae encapsulate and develop on the liver of rats and mice and as a result of this infection, a serious cancer- like growth may develop (Noble and Noble, 1974). The surface tegument of cestodes 1ike that of schistosomes is a highly active layer in which many processes occur (Smyth 1969, 1966). It is a metabolically active syncytial, protoplasmic layer formed by cytoplasmic extensions from tegumental cells lying in the subtegumental zone. The tegument has two major components, namely the distal cytoplasmic zone (surface syncytium) and the perinuclear cytoplasmic zone (cytoplasm in the region of tegumental cells). Under the light microscope the surface of the distal cytoplasmic zone appears as a fringe of fine hair-like processes (Smyth, 1969; Jones et al., 1977a, 1977b Lumsden and Specian, 1980). At the electron microscope level, the distal surface is revealed as spine-like processes which morphologically resemble the brush border of many vertebrate and invertebrate cells and have been referred to as microtriches, microvilli, or tegumental projections (Smyth, 1969 Shivers et al., 1986). The tegument functions to: (1 mediate the absorption of nutrients by the worm from the host environment, (2) protect the integrity of the worm against the alien environment of its host, and (3) bear the immunologicaL mechanisms whereby the parasite is able to resist inactivation by antibodies produced against the invader by its host (Lumsden and Specian, 1980) . Though oltipraz has received less attention than the antihelminthic drug, praziquantel, recent clinical and biological tolerance studies have shown that patients administered the drug have shown a high proportion of egg reduction. The mechanism of action of oltipraz is unclear but there are indications that it might inhibit the parasite’s glutathione levels (Cerf et al. 1982; Bella et al., 1983; Lapierre et al. 1983; Rey et al., 1984; Kardaman et al.,1985; Bieder and Jumeau, 1985), The effects of radioactively labeled praziquantel has been reported in experimental cysticercosis (Anrews et al., 1980). However, the effects of oltipraz on the tegument of cestodes has received little attention. Thus, the objective of this preliminary study is to show the in vitro effects of oltipraz on the tegument of c. fasciolaris in relation to dose and time using scanning electron microscopy.

Preliminary study of structural changes in Li2MnSiO4 cathode material during electrochemical reaction

2016 ◽  
Vol 09 (04) ◽  
pp. 1641003 ◽  
Author(s):  
Michał Świętosławski ◽  
Marcin Molenda ◽  
Marta Gajewska
Keyword(s):  
Cathode Material ◽  
Structural Changes ◽  
Electrochemical Reaction ◽  
Electrochemical Reactions ◽  
Li Ion Batteries ◽  
Lithium Ions ◽  
Transmission Electron ◽  
Working Cell ◽  
Li Ion ◽  
Preliminary Study

In this paper, we present exsitu observations of a structure of particular Li2MnSiO4 grains at different states of charge (SOC). The goal of these studies is structural analysis of Li2MnSiO4 cathode material for Li-ion batteries at different stages of electrochemical reaction using transmission electron microscopy. Performed analysis suggests that amorphization process of Li2MnSiO4 is not directly connected with lithium ions deintercalation but with additional electrochemical reactions running in the working cell.

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

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.

Evaluation of single-electron movies of glutamine synthetase molecules

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.

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

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.

Sign in / Sign up

Export Citation Format

Share Document