Search results for "VESSEL"
showing 10 items of 751 documents
Evaluation of Vertical Fatigue Cracks by Means of Flying Laser Thermography
2019
The present paper proposes a new procedure to analyze the temperature field distribution during Flying Laser Spot and Laser Line Thermographic scanning (FLST, FLLT) of metallic components, in order to detect vertical surface cracks. The methodology exploits the changes in the temperature field produced by a vertical crack, acting as a barrier towards heat diffusion, when the laser approaches the defect. A number of small regions of interests (ROIs) is placed nearby and around the laser source. The average temperature from each ROI is then monitored during the laser scanning. Vertical cracks can be detected by analyzing and comparing the temperature fluctuations from each ROI when the laser …
Vessel noise pollution as a human threat to fish: assessment of the stress response in gilthead sea bream (Sparus aurata, Linnaeus 1758)
2016
This study examined the effects of boat noise pollution on the stress indices of gilthead sea bream (Sparus aurata, Linnaeus 1758). To assess the stress response in these fish, biometric values and plasma parameters such as ACTH, cortisol, glucose, lactate, haematocrit, Hsp70, total protein, cholesterol, triglycerides and osmolarity were analysed. After acclimatization of the animals, the experiment was carried out in a tank fitted with underwater speakers where the fish were exposed to sound treatments (in duplicate) consisting of: 10 days of no sound (control treatment; the animals were only exposed to the experimental tank’s background noise) and 10 days of noise derived from original re…
Rays hamper intrusive growth of vessel elements
2021
Key message In some circumstances vessel elements, both broad and narrow, enlarge only symplastically in tangential direction. Rays play a special role in regulating intrusive enlargement of vessel elements. Abstract The aim of this study was to analyse relations occurring between vessel elements and surrounding cells, i.e. susceptibility to separation of walls of cells occurring in the vicinity of vessel elements, with regard to their type—cells of the axial/radial system. On the basis of separation/lack of separation of cell walls, and thus change in cell contacts/lack of change in cell contacts, we have estimated the contribution of particular types of growth—intrusive and symplastic—in …
The effectiveness of fish feeding behaviour in mirroring trawling-induced patterns
2017
The ability to observe and predict trawling-induced patterns at spatial and temporal scales that are relevant to inform realistic management strategies is a challenge which scientists have consistently faced in recent decades. Here, we use fish feeding behaviour, a biological trait easily impaired by trawling disturbance, to depict alterations in fish condition (i.e. individual fitness) and feeding opportunities. The benthivorous fish Mullus barbatus barbatus was selected as a model species. The observed trends of responses to trawling in prey species confirmed the effectiveness of a non-trawled zone in sustaining higher levels of diet diversity (e.g. quantity and quality of ingested prey) …
Online dimensional control of rolled steel profiles using projected fringes
2020
AbstractFringe projection is a versatile method for mapping the topography of surfaces. In this paper, it is used to measure the defects on the head of railroad rails while the rails are moving. Railroad rails are made by hot rolling. The quality of the finished product is generally good, but surface texture will deteriorate with increasing temperature. A method for online inspection therefore is very desirable. In the present experiment, dimensional inspection of the railroad rails was made online while moving at a speed of 1–2 m/s. Therefore, it is important to minimize the registration time. To achieve this, we apply a method of fringe location with sub-pixel accuracy that requires only …
A Fast Multiresolution Approach Useful for Retinal Image Segmentation
2018
Retinal diseases such as retinopathy of prematurity (ROP), diabetic and hypertensive retinopathy present several deformities of fundus oculi which can be analyzed both during screening and monitoring such as the increase of tortuosity, lesions of tissues, exudates and hemorrhages. In particular, one of the first morphological changes of vessel structures is the increase of tortuosity. The aim of this work is the enhancement and the detection of the principal characteristics in retinal image by exploiting a non-supervised and automated methodology. With respect to the well-known image analysis through Gabor or Gaussian filters, our approach uses a filter bank that resembles the “à trous” wav…
Endothelial cell damage is the central part of COVID-19 and a mouse model induced by injection of the S1 subunit of the spike protein☆
2021
Neurologic complications of symptomatic COVID-19 are common. Brain tissues from 13 autopsies of people who died of COVID-19 were examined. Cultured endothelial and neuronal cells were incubated with and wild type mice were injected IV with different spike subunits. In situ analyses were used to detect SARS-CoV-2 proteins and the host response. In 13/13 brains from fatal COVID-19, pseudovirions (spike, envelope, and membrane proteins without viral RNA) were present in the endothelia of microvessels ranging from 0 to 14 positive cells/200× field (mean 4.3). The pseudovirions strongly co-localized with caspase-3, ACE2, IL6, TNFα, and C5b-9. The surrounding neurons demonstrated increased NMDAR2…
In Vivo Functional Evaluation of Tissue-Engineered Vascular Grafts Fabricated Using Human Adipose-Derived Stem Cells from High Cardiovascular Risk Po…
2016
Many preclinical evaluations of autologous small-diameter tissue-engineered vascular grafts (TEVGs) utilize cells from healthy humans or animals. However, these models hold minimal relevance for clinical translation, as the main targeted demographic is patients at high cardiovascular risk such as individuals with diabetes mellitus or the elderly. Stem cells such as adipose-derived mesenchymal stem cells (AD-MSCs) represent a clinically ideal cell type for TEVGs, as these can be easily and plentifully harvested and offer regenerative potential. To understand whether AD-MSCs sourced from diabetic and elderly donors are as effective as those from young nondiabetics (i.e., healthy) in the conte…
Activation of PPARβ/δ prevents hyperglycaemia-induced impairment of Kv7 channels and cAMP-mediated relaxation in rat coronary arteries.
2016
PPARβ/δ activation protects against endothelial dysfunction in diabetic models. Elevated glucose is known to impair cAMP-induced relaxation and Kv channel function in coronary arteries (CA). Herein, we aimed to analyse the possible protective effects of the PPARβ/δ agonist GW0742 on the hyperglycaemic-induced impairment of cAMP-induced relaxation and Kv channel function in rat CA. As compared with low glucose (LG), incubation under high glucose (HG) conditions attenuated the relaxation induced by the adenylate cyclase activator forskolin in CA and this was prevented by GW0742. The protective effect of GW0742 was supressed by a PPARβ/δ antagonist. In myocytes isolated from CA under LG, forsk…
Cellular and Molecular Heterogeneity Associated with Vessel Formation Processes
2018
The microvasculature heterogeneity is a complex subject in vascular biology. The difficulty of building a dynamic and interactive view among the microenvironments, the cellular and molecular heterogeneities, and the basic aspects of the vessel formation processes make the available knowledge largely fragmented. The neovascularisation processes, termed vasculogenesis, angiogenesis, arteriogenesis, and lymphangiogenesis, are important to the formation and proper functioning of organs and tissues both in the embryo and the postnatal period. These processes are intrinsically related to microvascular cells, such as endothelial and mural cells. These cells are able to adjust their activities in r…