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The assessment of pathological changes in cerebral blood flow in hypertensive rats with stress-induced intracranial hemorrhage using Doppler OCT: Particularities of arterial and venous alterations/Die Beurteilung von pathologischen Veränderungen der Hirndurchblutung bei hypertensiven Ratten mit Stress-induzierten intrakraniellen Blutungen mittels Doppler-OCT: Besonderheiten von arteriellen und venösen Veränderungen
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Abstract<p>Hemorrhagic insult is a major source of morbidity and mortality in both adults and newborn babies in the developed countries. The mechanisms underlying the non-traumatic rupture of cerebral vessels are not fully clear, but there is strong evidence that stress, which is associated with an increase in arterial blood pressure, plays a crucial role in the development of acute intracranial hemorrhage (ICH), and alterations in cerebral blood flow (CBF) may contribute to the pathogenesis of ICH. The problem is that there are no effective diagnostic methods that allow for a prognosis of risk to be made for the development of ICH. Therefore, quantitative assessment of CBF may significantly advance the understanding of the nature of ICH. The aim of this study was to determine the particularities of alterations in arterial and venous cerebral circulation in hypertensive rats at different stages of stress-related development of ICH using three-dimensional Doppler optical coherence tomography (DOCT).</p><p>Experiments were performed in mongrel adult rats. To induce ICH, hypertensive rats underwent stress (effect of severe sound, 120 dB during 2 h). To induce the renal hypertension (two kidneys, one clip) the rats were clipped at the left renal artery with a silver clip. Seven weeks after clipping, the hypertensive rats were used in the experiment. The monitoring of CBF was performed in anesthetized rats with fixed heads using a commercially available swept source OCT system (OCS1300SS; Thorlabs) in the masked period of ICH (4 h after stress) and during ICH (24 h after stress).</p><p>It could be shown that in stressed rats, compared with non-stressed animals, the latent stage of stress-induced ICH (4 h after stress-off) is characterized by an increase in diameter of the superior sagittal vein with decrease in speed of the blood flow in the venous network, whereas no changes in the CBF in the arterial tree were found in this period. These facts suggest that the masked period of ICH is accompanied by decreasing venous outflow and the development of venous insufficiency. The incidence of ICH, 24 h after stress, is associated with progression of pathological alterations in cerebral venous circulation. All hypertensive rats with ICH demonstrated a greater increase in the diameter of the superior sagittal vein than stressed rats at the latent stage of ICH (in 2.5-fold,</p><p>In summary, using DOCT we have shown that the latent stage of stress-induced ICH is characterized by a decrease in venous outflow. The incidence of ICH is associated with the progression of pathological alterations in cerebral venous circulation that is accompanied by a decrease in blood flow in the arterial tree. The evaluation of cerebral venous insufficiency is an important diagnostic approach for the prognosis of the risk of developing cerebral hypotension and ICH.</p>
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Publication Date
Wed Jul 05 2017
Journal Name
Chemical Engineering Communications
Microwave-assisted preparation of mesoporous-activated carbon from coconut (<i>Cocos nucifera</i>) leaf by H<sub>3</sub>PO<sub>4</sub>activation for methylene blue adsorption
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Publication Date
Sat Jun 03 2023
Journal Name
Iraqi Journal Of Science
Effect Effect Effect Effect Effect Effect Effect of Thickness on Some Physical PropertiesThickness on Some Physical PropertiesThickness on Some Physical PropertiesThickness on Some Physical PropertiesThickness on Some Physical Properties Thickness on Some
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The effect of thickness variation on some physical properties of hematite α-Fe2O3 thin films was investigated. An Fe2O3 bulk in the form of pellet was prepared by cold pressing of Fe2O3 powder with subsequent sintering at 800 . Thin films with various thicknesses were obtained on glass substrates by pulsed laser deposition technique. The films properties were characterized by XRD, and FT-IR. The deposited iron oxide thin films showed a single hematite phase with polycrystalline rhombohedral crystal structure .The thickness of films were estimated by using spectrometer to be (185-232) nm. Using Debye Scherrerś formula, the average grain size for the samples was found to be (18-32) nm. Atomic force microscopy indicated that the films had

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