Abstract In this paper, the Gurson-Tvergraad-Needleman (GTN) model is used to study damage of stainless steel springs at high temperatures. The basic material and GTN parameters are determined from stress-strain curves tensile tests. Then evolution 300 °C 900 analyzed based on finite element simulations. results show that below 600 °C, change volume fraction holes in spring, along with increase...

BACKGROUND Anal fissure is a common painful condition affecting the anal canal. The majority of acute fissures heal spontaneously. However, some of these acute fissures do not resolve but become chronic. Chronic anal fissures were traditionally treated by anal dilation or by lateral sphincterotomy. However, both of these surgical treatments may cause a degree of incontinence in up to 30% of pat...

Problematic. A combination of experimental and computational methods for studying the processes crack initiation propagation in various specimen’s types is used to determine mechanical properties materials, as well improve accuracy assessing strength durability structural elements. Research objective. Determination parameters Gurson-Tvergaard-Needleman (GTN) material damage model based on numer...

BACKGROUND The effects of vasoactive substances on cerebral haemodynamics are not fully known. We studied the effects of norepinephrine and glyceryl trinitrate (GTN) on cerebral haemodynamics in healthy volunteers. METHODS The effects of norepinephrine (n=10) and GTN (n=10) on the middle cerebral artery flow velocity (MCAFV), cerebral autoregulation, reactivity to carbon dioxide, and estimate...

Aldehyde dehydrogenase-2 (ALDH2) catalyzes the bioactivation of nitroglycerin (glyceryl trinitrate, GTN) in blood vessels, resulting in vasodilation by nitric oxide (NO) or a related species. Because the mechanism of this reaction is still unclear we determined the three-dimensional structures of wild-type (WT) ALDH2 and of a triple mutant of the protein that exhibits low denitration activity (...

OBJECTIVES We investigated the development of nitrate tolerance after continuous exposure to nitroglycerin (GTN) as compared with pentaerythritol tetranitrate (PETN) in humans. BACKGROUND Sustained therapy with GTN causes tolerance and has been associated with increased production of free oxygen radicals by the endothelium. Pentaerythritol tetranitrate is an organic nitrate that has been used...

OBJECTIVE Continuous administration of nitroglycerin (GTN) causes tolerance and endothelial dysfunction by inducing reactive oxygen species (ROS) production from various enzymatic sources, such as mitochondria, NADPH oxidase, and an uncoupled endothelial nitric oxide synthase (eNOS). In the present study, we tested the effects of type 1 angiotensin (AT(1))-receptor blockade with telmisartan on ...

BACKGROUND/AIM Nitric oxide (NO) may be involved in non-adrenergic non-cholinergic (NANC) inhibitory innervation of the sphincter of Oddi (SO). The effects of topical application of glyceryl trinitrate (GTN), a NO donor, upon SO motility were examined. METHODS Nineteen patients undergoing routine SO manometry for investigation of abdominal pain were studied. After routine recording of SO moti...

We have carried out a prospective double-blind randomized study in 40 patients with infusion-related thrombophlebitis. Twenty-two patients were included in the glyceryltrinitrate (GTN) ointment group and 18 patients in the control heparinoid group. Pain was assessed by an analogue scale. At 48 hours the analgesic index was 84.6 +/- 18 units with GTN and 49 +/- 45 units with heparinoid ointment ...

High doses of the organic nitrate glyceryl trinitrate (GTN), a nitric oxide (NO) donor, are known to trigger apoptosis in human cancer cells. Here, we show that such a cytotoxic effect can be obtained with subtoxic concentrations of GTN when combined with H89, N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinolinesulphonamide.2HCl. This synergistic effect requires the generation of reactive oxygen sp...