Search results for "fiber"

Numerical simulation of low temperature thermal conductance of corrugated nanofibers

2010

Effect of Stacking Sequence and Sodium Bicarbonate Treatment on Quasi-Static and Dynamic Mechanical Properties of Flax/Jute Epoxy-Based Composites

2019

The present paper deals with the investigation of quasi-static and dynamic mechanical response of epoxy-based composites reinforced with flax and/or jute plain weave fabrics. In order to evaluate the influence of the stacking sequence, two monolithic laminates reinforced with flax or jute fibers and two hybrid flax/jute laminates were manufactured through the vacuum infusion technique. Furthermore, an eco-friendly and cost-effective surface treatment based on fiber soaking in a sodium bicarbonate solution was employed to improve the fiber-matrix adhesion. The mechanical characterization (by means of quasi-static flexural, dynamic mechanical thermal analysis and Charpy impact tests) allowed …

Functional Morphology of Human Arteries During Fetal and Postnatal Development

1980

The equilibrium between the distending force of the blood pressure and the arterial wall is determined essentially by a simple law of mechanics, the law of Laplace. According to this law, the total force or tension (T) in the vessel’s wall represents the product of the radius of the vessel (r) and the blood pressure (p), T = r.p. The law of Laplace may be used to estimate and compare the tension produced by blood pressure in vessels of different size and thereby determine the increase in functional load on arteries. Since tension increases not only with blood pressure but also with the radius of the vessel, the highest tension is presumably produced in the wall of the ascending aorta where …

Fine Mapping of Gene Ordering by Elongated Chromosome Methods

2006

Publisher Summary Fluorescence in situ hybridization (FISH) can be used to localize specific DNA sequences on metaphase chromosomes, interphase nuclei, and experimentally extended DNA or chromatin fibers. Depending on the hybridization target, FISH techniques show widely different levels of DNA resolution. Mechanically stretched or elongated chromosomes fill the resolution gap between metaphase FISH and fiber FISH, allowing the rapid and straightforward ordering and localization of clones along the length of an entire chromosome with a 100- to 200-kb resolution. Although various genome projects have provided very high-resolution physical maps of human and important animal genomes, FISH is s…

The number of contacts in random fibre networks

2012

There is a wide range of materials that can be considered as nonwoven random networks of fibres. Such materials include glass-fibre mats, filters, various paper products and structural components of cells and tissues. The mechanical properties of these kinds of networks have been studied extensively for many decades. As many of such networks form more or less two-dimensional structures, they can, to a good approximation, be considered to consist of randomly distributed fibres or filaments connected at their crossings points. Recent development of the resolution of X-ray computed tomography have enabled imaging of the three dimensional structure of such materials with a resolution sufficient…

Type IV collagen and laminin in slow and fast skeletal muscle in rats--effects of age and life-time endurance training.

1988

The changes in the biochemical composition of basement membrane (BM) in slow-twitch (m. soleus, MS) and fast-twitch (m. rectus femoris, MRF) skeletal muscles of rats were studied during aging and life-time endurance training (treadmill running). The concentrations of the 7S domain of type IV collagen and of the P2 fragment of laminin were determined with radioimmunoassays in the muscles of rats aged 1, 2, 4, 10, and 24 months. The concentration of type IV collagen was higher in MS than in MRF and increased significantly with age. At older ages, the concentration tended to be higher in the MS of trained than untrained rats. The concentration of laminin was significantly higher in MRF than in…

Tachykinin-, calcitonin gene-related peptide-, and protein gene product 9.5-immunoreactive nerve fibers in alveolar walls of mammals.

1991

The presence and distribution of the presumed pan-neural marker protein gene product 9.5 (PGP)- and peptide-immunoreactive (ir) nerve fibers in alveolar walls of various species was investigated by light microscopic single and double staining immunohistochemistry. PGP-, tachykinin (TK)-, and calcitonin gene-related peptide (CRGP)-ir fibers were sparsely distributed in a similar pattern in alveolar walls of all species investigated. No vasoactive intestinal peptide-, peptide histidine isoleucine-, galanin-, and opioid-ir nerve fibers could be detected. PGP-ir fibers outnumbered those staining for TKs and CGRP. There was partial coexistence of PGP and TK as well as of TK and CRGP. PGP-, TK-, …

Peptide neuroanatomy of adjuvant-induced arthritic inflammation in rat

1988

The influence of adjuvant-induced arthritis of the rat on central and peripheral peptide neuroanatomy was investigated by immunohistochemistry. The most striking feature of arthritic rats was the differential intensification of neuronal proenkephalin- and prodynorphin-related staining in dorsal horn. Changes were ipsilateral in monoarthritic and bilateral in polyarthritic rats as compared to controls. Opioid responsive neurons were target of substance P (SP) and calcitonin gene-related peptide (CGRP) fibers. Changes of SP and CGRP predominated in peripheral inflamed tissue and consisted of intensified immunostaining and an apparent sprouting of sensory fibers particularly around venules, in…

Diagnostic potential of the diffusion tensor tractography with fractional anisotropy in the diagnosis and treatment of cervical spondylotic and postt…

2016

Background: Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI)-based methodology widely used for the evaluation of microstructural integrity of the central nervous system (CNS), particularly of brain white matter fibers and bundles. Methods: The most common parameters evaluated in a DTI study are the fractional anisotropy (FA) and mean diffusivity (MD). Combining FA and MD analyses is commonly used in the evaluation of various types of brain pathologies, such as brain tumors, where a combined analysis allows an accurate tumor characterization. Results: Recent studies have shown that FA and MD could be of value in non-oncologic spinal pathology. In this regard, it has been …

Chelation of synaptic zinc induces overexcitation in the hilar mossy cells of the rat hippocampus.

2004

Complete removal of synaptic zinc by the chelator dietyldithiocarbamate (DEDTC; 500 mg/kg i.p.) in rat was followed by convulsive behaviour including wet dog shakes alternating immobility. Histological analysis 1 day after DEDTC administration detected expression of heat shock protein in the hippocampus restricted to hilar cells. These cells colocalize the marker for neurons and the glutamate receptor GluR2/3 showing that they are excitatory neurons. Additionally, they projected to the contralateral dentate gyrus. Therefore, they correspond to hilar mossy cells. These data show that the synaptic zinc has a role in normal hippocampus avoiding overexcitation, that would impair functionality e…