Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Electronic Resource  (3,798)
  • AV-Medium
  • 2020-2022
  • 1990-1994  (3,798)
  • 1870-1879
  • Engineering General  (3,144)
  • Immunohistochemistry  (654)
Material
  • Electronic Resource  (3,798)
  • AV-Medium
Years
Year
  • 101
    ISSN: 1432-0878
    Keywords: Eye ; Lens ; Development, ontogenetic ; αA-crystallin ; αB-crystallin ; Immunohistochemistry ; Human ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of αA- and αB-crystallin in the developing lens of human (Carnegie stages 13 to 23) and rat embryos (embryonic days E11 to 18) was examined immunohistochemically. In a human embryo at stage 13, the lens placode was already immunoreactive to αB-crystallin, but not to αA-crystallin. At stage 15, the lens vesicle was intensely immunoreactive both to αA- and αB-crystallin. From stages 16 to 23, the lens epithelial cells and fiber cells were immunoreactive to αA- and αB-crystallin. In rat embryos, αA-crystallin appeared in the lens pit at E12, and αB-crystallin appeared in the elongating lens fiber cells at E14. From E15 to E18, the lens epithelial cells and fiber cells were immunoreactive to αA-crystallin. The lens fiber cells were also immunoreactive to αB-crystallin, but the epithelial cells were not. These findings suggest that αB-crystallin appears earlier than αA-crystallin in the human lens, but at a later period than αA-crystallin in the rat lens. αB-Crystallin was not detected in the epithelial cells of the rat lens, but was perisistently present in the epithelial cells of the human lens.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 102
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 276 (1994), S. 381-386 
    ISSN: 1432-0878
    Keywords: Gizzard ; Development, ontogenetic ; Muscle smooth ; Capillaries ; Immunohistochemistry ; Myosin ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Antibodies to smooth muscle and non-muscle myosin allow the development of smooth muscle and its capillary system in the embryonic chicken gizzard to be followed by immunofluorescent techniques. Although smooth muscle development proceeds in a serosal to luminal direction, angiogenetic cell clusters develop independently at the luminal side close to the epithelial layer, and the presumptive capillaries invade the developing muscle in a luminal to serosal direction. The smooth muscle and non-muscle myosin heavy chains in this avian system cannot be separated by SDS polyacrylamide gel electrophoresis and do not show isoform specificity in immunoblotting, unlike the system found in mammals. Only two myosin heavy chains with Mr of 200 and 196 kDa were separable and considerable immunological cross-reactivity was found between the denatured myosin isoform heavy chains.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 103
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 276 (1994), S. 403-410 
    ISSN: 1432-0878
    Keywords: Sympathetic nervous system ; Enteric nervous system ; Noradrenaline ; Catecholamine histofluorescence ; Immunohistochemistry ; Pteropus poliocephalus, P. scapulatus (Chiroptera)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of catecholamines in the small and large intestine of flying foxes (Pteropus spp.) was investigated using glyoxylic-acid-induced fluorescence and immunohistochemical staining of tyrosine hydroxylase and dopamine-β-hydroxylase. Dense networks of varicose axons stained by each of these methods supplied blood vessels, the mucosa and both submucous and myenteric ganglia, but were scarce in the circular and longitudinal muscle. The majority (〉90%) of submucous neuronal perikarya contained both enzymes and most of these also exhibited catecholamine fluorescence. Somata of similar staining characteristics were less common in the myenteric plexus, where single cells were found in only the minority of ganglia. All of the stained submucosal somata and mucosal axons contained vasoactive intestinal peptide, whereas catecholamine-containing axons that supplied the ganglia, external muscle and blood vessels did not. It is concluded that (1) there is dense catecholamine innervation of most tissues in the flyingfox intestine, similar to many other mammals, (2) mucosal axons originate from enteric catecholamine neurons, not found in other mammals, and (3) axons supplying the blood vessels and enteric ganglia are probably of sympathetic origin and can be distinguished from the intrinsic catecholamine-containing axons by their lack of vasoactive intestinal peptide. The roles and interactions of these two types of catecholamine innervation in the control of secretion and motility remain to be identified.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 104
    ISSN: 1432-0878
    Keywords: Glucagon-like peptide 1 ; Endocrine tumors ; Immunohistochemistry ; Ultrastructure ; Multiple endocrine neoplasia type 1 ; Co-localization ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The preproglucagon gene encodes, in addition to glucagon, two smaller peptides with structural similarity: glucagon-like peptides 1 and 2. Glucagon-like peptide 1 (GLP-1) 7–36 amide is the most powerful incretin candidate. In the present study, GLP-1 immunoreactivity was investigated in tissue specimens of various types of gastroenteropancreatic tumors, and the serum-levels of GLP-1 were assayed. Immunohistochemical staining of 88 tumors revealed GLP-1 immunoreactivity in 17 neoplasias (19.3 %), viz., in 7 out of 33 non-functioning tumors, 4 out of 20 gastrinomas, 4 out of 13 insulinomas, 1 out of 3 vasoactive-intestinal-polypeptide (VIP)omas and 1 adrenocorticotropic-hormone (ACTH)-producing tumor. In these tumors, GLP-1-immunoreactive cells were distributed either diffusely, arranged in clusters, or as single cells. All GLP-1-positive tumors were immunoreactive for glucagon or glicentin, 10 tumors were immunoreactive for pancreatic polypeptide, and 8 tumors for insulin. Ultrastructural analysis of 8 GLP-1-positive tumors, with the immunogold technique, demonstrated GLP-1 immunoreactivity mainly in cells resembling the A-cells of the pancreas or the L-cells of the gut. Of the 17 GLP-1-immunoreactive tumors, 15 were primarily located in the pancreas. Additionally, 2 non-functioning tumors of the rectum were GLP-1 immunoreactive. Five tumors were GLP-1 immunoreactive from 9 patients with multiple endocrine neoplasia I syndrome. Patients with GLP-1-immunoreactive tumors were characterized by a significantly lower rate of distant metastases (P〈0.01) and a higher rate of curative resections (P〈0.05). In 2 out of 22 patients, elevated serum-levels of GLP-1 were found: one patient with a vasoactive-intestinal-polypeptide (VIP)oma and 1 patient with a non-functioning tumor. This indicates that GLP-1 might be secreted at least by a few gastroenteropancreatic endocrine tumors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 105
    ISSN: 1432-0878
    Keywords: Suprachiasmatic nucleus ; Retinohypothalamic tract ; Immunohistochemistry ; Neuropeptides ; Cytochrome oxidase ; Acetylcholinesterase ; Circadian system ; Domestic sheep
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The retinal innervation, cytoarchitectural, and immunohistochemical organization of the suprachiasmatic nucleus (SCN) was studied in the domestic sheep. The SCN is a large elongated nucleus extending rostrocaudally for roughly 3 mm in the hypothalamus. The morphology is unusual in that the rostral part of the nucleus extends out of the main mass of the hypothalamus onto the dorsal aspect of the optic chiasm. Following intraocular injection of wheat-germ agglutininhorseradish peroxidase or tritiated amino acids, anterograde label is distributed throughout the SCN. Retinal innervation of the SCN is bilaterally symmetric or predominantly ipsilateral. Quantitative image analysis demonstrates that, although the amount of autoradiographic label is greatest in the ventral and central parts of the nucleus, density varies progressively between different regions. In addition to the SCN, retinal fibers are also seen in the medial preoptic area, the anterior and lateral hypothalamic areas, the dorsomedial hypothalamus, the retrochiasmatic area, and the basal telencephalon. Whereas the SCN can be identified using several techniques, complete delineation of the nucleus requires combined tract tracing, cytoarchitectural, and histochemical criteria. Compared with the surrounding hypothalamic regions, the SCN contains smaller, more densely packed neurons, and is largely devoid of myelinated fibers. Cell soma sizes are smaller in the ventral SCN than in the dorsal or lateral parts, but an obvious regional transition is lacking. Using Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining, the SCN can be clearly distinguished in the rostral and medial regions, but is less differentiated toward the caudal pole. Immunohistochemical demonstration of several neuropeptides shows that the neurochemical organization of the sheep SCN is heterogeneous, but that it lacks a distinct compartmental organization. Populations of different neuropeptide-containing cells are found throughout the nucleus, although perikarya positive for vasoactive intestinal polypeptide and fibers labeled for methionine-enkephalin are predominant ventrally; neurophysine-immunoreactive cells are more prominent in the dorsal region and toward the caudal pole. The results suggest that the intrinsic organization of the sheep SCN is characterized by gradual regional transitions between different zones.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 106
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 171-175 
    ISSN: 1432-0878
    Keywords: Key words: Tachykinin ; Substance P ; Sinus venosus ; Heart ; Immunohistochemistry ; Dogfish ; Scyliorhinus canicula (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The sinus venosus of the elasmobranch heart is characterized by the presence of large bundles of unmyelinated nerve fibres that bulge into the cardiac lumen, below the endocardium. In the dogfish (Scyliorhinus canicula), these fibres contain numerous dense-core membrane-bounded granules of about 200 nm in diameter. Most intramural ganglion cells of the sinus venosus also show densely packed granules similar to those found in the subendocardial fibres. We have observed strong substance-P-like immunoreactivity in the large fibre bundles and in the perikarya of the ganglion cells. Preabsorption of the antisera with fragment 7–11 of substance P has shown that the antisera recognize the tachykinin canonic sequence. Our findings suggest that an undetermined tachykinin is secreted in the elasmobranch heart, and that it is probably released into the blood stream in the context of a little-known neuroendocrine system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 107
    ISSN: 1432-0878
    Keywords: Key words: Carotid body ; Chief cells ; Catecholamine ; Serotonin ; γ-Aminobutyric acid ; Immunohistochemistry ; Mouse (BALB/c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The immunohistochemical study revealed tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), serotonin, glutamate decarboxylase (GAD) and γ-aminobutyric acid (GABA) immunoreactivities in the mouse carotid body. TH and DBH immunoreactivities were found in almost all chief cells and a few ganglion cells, and in relatively numerous varicose nerve fibers of the carotid body. The histofluorescence microscopy showed catecholamine fluorescence in almost all chief cells. However, no PNMT immunoreactivity was observed in the carotid body. Serotonin, GAD and GABA immunoreactivities were also seen in almost all chief cells of the carotid body. From combined immunohistochemistry and fluorescence histochemistry, catecholamine and serotonin or catecholamine and GABA were colocalized in almost all chief cells. Thus, these findings suggest that noradrenaline, serotonin and GABA may be synthesized and co-exist in almost all chief cells of the mouse carotid body and may play roles in chemoreceptive functions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 108
    ISSN: 1432-0878
    Keywords: Key words: EGF ; Cartilage ; Growth plate ; Hypophysectomy ; Growth hormone ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Epiphyseal growth plate cartilages from the proximal tibia of normal, hypophysectomized, and growth hormone (GH)-treated hypophysectomized rats were subjected to immunohistochemistry for detection of epidermal growth factor (EGF). In the normal growth plate, EGF was distributed mainly in the proliferative zone. Hypophysectomy resulted in considerable atrophy of the chondrocytes and the cartilage matrix (a decreased number of mature-type chondrocytes and a decreased ratio of proliferating to hypertrophic chondrocytes) and a significant diminution of EGF immunoreactivity. Treatment with GH reversed these effects of hypophysectomy, causing an increased thickness of the growth plate and EGF-reactive sites in all chondrocyte layers. The most intense immunostaining for EGF, however, was frequently seen in the nuclei of chondrocytes with flattened appearance. It appears that EGF could be incorporated or synthesized in chondrocytes having marked mitogenic activity. The present results, taken with previous data on EGF involvement in growth of cartilaginous tissue in vivo and in vitro, strongly suggest that EGF-immunoreactive chondrocytes are involved in cartilage proliferation and growth under the specific influence of GH.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 109
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 573-578 
    ISSN: 1432-0878
    Keywords: Placenta ; Giant cells ; Chorionic gonadotropin ; Luteotropin ; Electrophoresis ; Immunohistochemistry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Obplacental giant cells are enlarged cells, found following implantation, in the antimesometrial region of the rabbit uterus. They probably originate from trophoblastic knobs that traverse the uterine epithelium during early implantation. Little is known about their function. In this study, trophoblast, placental, paraplacental and obplacental tissues at days 7–15 post-coitum, and enzyme-isolated giant cells at day 15 were studied by two-dimensional gel electrophoresis, followed by immunoblotting and light-microscopic immunohistochemistry, for the presence of human chorionic gonadotropin-like proteins. Immunostaining was performed by using anti-human chorionic gonadotropin antibodies. In gel electrophoresis of obplacental tissue and isolated giant cells, two proteins of human chorionic gonadotropin-like antigenicity at 26 kDa with pIs equivalent to pH 6.4 and 6.6 were found; they were absent in the placenta, paraplacenta, day-7 blastocyst and day-8 trophoblast. The onset of synthesis of these proteins could be observed when day-8 trophoblastic tissue was cultured in vitro for 24 h. In immunohistochemistry, only the obplacental giant cells showed a positive reaction, indicating that the production of chorionic gonadotropin occurs in this cell type.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 110
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 279 (1994), S. 221-231 
    ISSN: 1432-0878
    Keywords: Key words: Cytokeratins ; Thymus ; Immunohistochemistry ; Hassal's corpuscles ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Cytokeratin expression in normal postnatal human thymus was studied immunohistochemically by using monoclonal antibodies against various cytokeratin polypeptides. An attempt was made to characterize cell populations giving rise to the cornified structures of Hassal's corpuscles. Monoclonal antibody KB-37, a marker of squamous epithelium basal cells, was applied to distinguish the earliest cells capable of undergoing squamous differentiation. Parts of the subcapsular epithelium were extensively stained with this reagent. This epithelium, like the basal layer of certain squamous epithelia, exibited a high incidence of cytokeratins 13 and 14, and pronounced expression of cytokeratin 19. Simple epithelium cytokeratins 8, 18, and 19 were present in the cortex. Scattered cells reacted with KB-37 antibody. All stellate epithelial cells in the medulla were positive for cytokeratin 19. Most of the medullar epithelial cells were positive for cytokeratins 13, 14 and 17 of complex epithelium, in contrast to the cortex, where only a few cells were positive for these cytokeratins. A significant proportion of the medullar cells was positive for KB-37 antigen. Cytokeratins 8 and 18 were expressed in single cells and in groups of cells surrounding Hassal's corpuscles. The outermost cells of these corpuscles were positive for cytokeratin 19 and KB-37. In the peripheral parts of Hassal's corpuscles, simple epithelium cytokeratins 7, 8, 18, and cytokeratins 4, 13, 14, and 17, characteristic of stratified nonkeratinizing epithelia, were coexpressed with keratinization-specific cytokeratins 10/11. The inner parts of the swirls were uniformly positive for cytokeratins 10/11. However, the expression of other cytokeratins was reduced.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 111
    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Submucosal plexuses ; Myenteric plexus ; Neuropeptides ; Immunohistochemistry ; Intestine, small ; Horse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The architecture and neurochemistry of the enteric nervous system was studied by use of whole-mount preparations obtained by microdissection of the horse jejunum. A myenteric plexus and two plexuses within the submucosa were identified. The external submucosal plexus lying in the outermost region of the submucosa had both neural and vascular connections with the inner submucosal plexus situated closer to the mucosa. Counts of neurones stained for NADH-diaphorase demonstrated the wide variation in size, shape and neurone content of individual ganglia in both the external and internal submucosal plexuses. The average number of cells/ganglion was similar in each plexus (about 25 cells). Immunoreactivities for galanin, vasoactive intestinal peptide and neuropeptide Y were observed in nerve cell bodies and fibres of each of the plexuses. Immunoreactivity for substance P was extensive and strong in nerve fibres of all plexuses but was weaker in cell bodies of the submucosal neurones and absent in the cell bodies of the myenteric plexus. Comparative quantitative analysis of immunoreactive cell populations with total cell numbers (enzyme staining) was indicative of neuropeptide colocalization in the external submucosal plexus.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 112
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 57-64 
    ISSN: 1432-0878
    Keywords: Calbindin ; Sensory nerve endings ; Esophagus ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunoreactivity for calbindin was found in nerve endings with irregular laminar shapes in the rat esophagus. In the myenteric ganglia, laminar endings of a range of sizes formed a complex network and appeared to lie at the surface of the ganglion. The myenteric ganglia that contained nerve endings were most abundant in the upper portion of the eosphagus, their number decreasing orally to anally. Calbindin-immunoreactive nerve cell bodies were scattered throughout the esophagus. Laminar terminals were found in the connective tissue of the lamina propria immediately beneath the epithelium and in the muscularis mucosae. Occasional nerve branches formed a network of aborizing endings that surrounded part of the submucosal arterioles. Immunoreactive nerve endings in the mucosa and submucosa were present only in the upper part of the cervical esophagus. Unilateral vagotomy caused a remarkable decrease in the number of the myenteric ganglia containing the calbindin-immunoreactive laminar endings after 15 days or survival; in some of ganglia, the laminar structures disappeared and nerve endings showing weak immunoreactivity had an indistinct appearance, so that the outline of the ganglia became obscure. In operated rats at 24 days, the number of innervated ganglia was about half that in normal rats. However, there was no change in the morphology and the occurrence of the immunoreactive laminar structures in the mucosa and submucosa after denervation. The results show that many of the laminar endings that are immunoreactive for calbindin in the myenteric ganglia are derived from the vagus nerve. Thus, the calbindin-immunoreactive nerve endings with laminar expansions that are found in the rat eosphageal wall could be sensory receptors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 113
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 171-175 
    ISSN: 1432-0878
    Keywords: Tachykinin ; Substance P ; Sinus venosus ; Heart ; Immunohistochemistry ; Dogfish, Scyliorhinus canicula (Elasmobranchii)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The sinus venosus of the elasmobranch heart is characterized by the presence of large bundles of unmyelinated nerve fibres that bulge into the cardiac lumen, below the endocardium. In the dogfish (Scyliorhinus canicula), these fibres contain numerous dense-core membrane-bounded granules of about 200 nm in diameter. Most intramural ganglion cells of the sinus venosus also show densely packed granules similar to those found in the subendocardial fibres. We have observed strong substance-P-like immunoreactivity in the large fibre bundles and in the perikarya of the ganglion cells. Preabsorption of the antisera with fragment 7–11 of substance P has shown that the antisera recognize the tachykinin canonic sequence. Our findings suggest that an undetermined tachykinin is secreted in the elasmobranch heart, and that it is probably released into the blood stream in the context of a little-known neuroendocrine system.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 114
    ISSN: 1432-0878
    Keywords: Carotid body ; Chief cells ; Catecholamine ; Serotonin ; γ-Aminobutyric acid ; Immunohistochemistry ; Mouse (BALB/c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The immunohistochemical study revealed tyrosine hydroxylase (TH), dopamine β-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), serotonin, glutamate decarboxylase (GAD) and γ-aminobutyric acid (GABA) immunoreactivities in the mouse carotid body. TH and DBH immunoreactivities were found in almost all chief cells and a few ganglion cells, and in relatively numerous varicose nerve fibers of the carotid body. The histofluorescence microscopy showed catecholamine fluorescence in almost all chief cells. However, no PNMT immunoreactivity was observed in the carotid body. Serotonin, GAD and GABA immunoreactivities were also seen in almost all chief cells of the carotid body. From combined immunohistochemistry and fluorescence histochemistry, catecholamine and serotonin or catecholamine and GABA were colocalized in almost all chief cells. Thus, these findings suggest that noradrenaline, serotonin and GABA may be synthesized and co-exist in almost all chief cells of the mouse carotid body and may play roles in chemoreceptive functions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 115
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 379-387 
    ISSN: 1432-0878
    Keywords: Key words: Enteric nervous system ; Immunohistochemistry ; 5-Hydroxytryptamine ; Colon ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The presence of 5-hydroxytryptamine in enteric neurons of the guinea-pig distal colon was demonstrated by immunohistochemistry and the projections of the neurons were determined. 5-Hydroxytryptamine-containing nerve cells were observed in the myenteric plexus but no reactive nerve cells were found in submucous ganglia. Varicose reactive nerve fibres were numerous in the ganglia of both the myenteric and submucous plexuses, but were infrequent in the longitudinal muscle, circular muscle, muscularis mucosae and mucosa. Reactivity also occurred in enterochromaffin cells. Lesion studies showed that the axons of myenteric neurons projected anally to provide innervation to the circular muscle and submucosa and to other more anally located myenteric ganglia. The results suggest that a major population of 5- hydroxytryptamine neurons in the colon is descending interneurons, most of which extend for 10 to 15 mm in the myenteric plexus and innervate both 5-hydroxytryptamine and non-5-hydroxytryptamine neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 116
    ISSN: 1432-0878
    Keywords: Catecholamine synthesizing enzymes ; Neuropeptide Y ; Vasoactive intestinal polypeptide ; Ganglion cells ; Adrenal gland ; Immunohistochemistry ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunohistochemistry has been used to demonstrate tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH), phenylethanolamine N-methyltransferase (PNMT), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) immunoreactivities, and acetylcholinesterase (AChE) activity was demonstrated in rat adrenal glands. The TH, DBH, NPY and VIP immunoreactivities and AChE activity were observed in both the large ganglion cells and the small chromaffin cells whereas PNMT immunoreactivity was found only in chromaffin cells, and not in ganglion cells. Most intraadrenal ganglion cells showed NPY immunoreactivity and a few were VIP immunoreactive. Numerous NPY-immunoreactive ganglion cells were also immunoreactive for TH and DBH; these cells were localized as single cells or groups of several cells in the adrenal cortex and medulla. Use of serial sections, or double and triple staining techniques, showed that all TH- and DBH-immunoreactive ganglion cells also showed NPY immunoreactivity, whereas some NPY-immunoreactive ganglion cells were TH and DBH immunonegative. NPY-immunoreactive ganglion cells showed no VIP immunoreactivity. AChE activity was seen in VIP-immunopositive and VIP-immunonegative ganglion cells. These results suggest that ganglion cells containing noradrenaline and NPY, or NPY only, or VIP and acetylcholine occur in the rat adrenal gland; they may project within the adrenal gland or to other target organs. TH, DBH, NPY, and VIP were colocalized in numerous immunoreactive nerve fibres, which were distributed in the superficial adrenal cortex, while TH-, DBH- and NPY-immunoreactive ganglion cells and nerve fibres were different from VIP-immunoreactive ganglion cells and nerve fibres in the medulla. This suggests that the immunoreactive nerve fibres in the superficial cortex may be mainly extrinsic in origin and may be different from those in the medulla.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 117
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 275 (1994), S. 143-156 
    ISSN: 1432-0878
    Keywords: Larynx ; Trachea ; Endocrine cells ; Neuroepithelial bodies ; Immunohistochemistry ; Regulatory peptides ; Serotonin (5-HT) ; Golden hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The ontogeny of protein gene product 9.5 (PGP 9.5), serotonin (5-HT), calcitonin gene-related peptide (CGRP), and calcitonin (CT) immunoreactivity was evaluated in small-granule endocrine cells of hamster laryngotracheal epithelium from fetal day 11 to adulthood. Two centrifugal (proximal-to-distal) patterns of differentiation occur. The first pattern begins during fetal life. Endocrine cells, single and clustered in groups (presumptive-or protoneuroepithelial bodies, pNEBs), initially colocalize immunostaining for PGP 9.5, 5-HT, and CGRP in the larynx and proximal 2/3 of the trachea on day 12 and spread to the caudal trachea on day 13.5-HT disappears fleetingly during the 24 h preceding birth; other-wise immunoreactivity for all three substances persists into adulthood. The clusters of endocrine cells survive beyond birth but are so diluted by expansion of the nonendocrine epithelium as to become inconspicuous. Since innervation was not actually observed, these clusters may persist as pNEBs, without developing connections to afferent or efferent nerve fibers. The second pattern concerns single small-granule cells stainable for CGRP but not for 5-HT. These cells first appear in the larynx and cartilaginous part of the cranial trachea on postnatal day 3, and in the middle and caudal trachea, on day 5. The cells increase in number on day 7. In adults, they predominate among endocrine cells of the cartilaginous region. A subset of these cells begins to co-express CT proximally on postnatal day 10, reaching the caudal end of the trachea by 3 weeks. A few elements of the older 5-HT-positive population may also become immunoreactive for CT in juvenile hamsters.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 118
    ISSN: 1432-0878
    Keywords: FSH ; Immunohistochemistry ; Receptor mRNA ; In situ hybridization ; Sertoli cell ; Testis ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Testicular biopsies from 82 oligo-or azoospermic male patients were subjected to immunostaining using anti-human FSH antibodies. Histological evaluation showed normal spermatogenesis (nspg) in 7 (FSH: 2.7±0.7), mixed atrophy (ma) in 63 (FSH:5.3±0.5), and bilateral or unilateral Sertoli Cell Only syndrome (SCO) in 12 (FSH:21.7±3.5) patients. For the relationship between FSH values and testicular histology, see Bergmann et al. (1994). FSH immunoreactivity was found exclusively in Sertoli cells and in some interstitial cells. Seminiferous epithelium showing normal or impaired spermatogenesis displayed only weak immunoreactivity compared to intense immunoreaction, i.e. large and numerous vesicles in Sertoli cells of SCO tubules in biopsies showing mixed atrophy or SCO. In addition, h-FSH receptor mRNA was demonstrated by in situ hydridization using biotinylated cDNA antisense oligonucleotides. Hybridization signals were found within the seminiferous epithelium exclusively in Sertoli cell cytoplasm associated with normal spermatogenesis and in epithelia showing different signs of impairment, including SCO. It is concluded that: (1) Sertoli cells are the only cells within the seminiferous epithelium expressing FSH receptors; (2) the accumulation of FSH immunoreactivity in Sertoli cells of SCO tubules appears to be a sign of impaired Sertoli cell function.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 119
    ISSN: 1432-0878
    Keywords: Adrenal ; Autonomic nervous system ; Schwann cells ; Tyrosine hydroxylase ; GAP-43 ; Electron microscopy ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have localized at light and electron-microscopic level the growth-associated protein GAP-43 in adrenal gland using single and double labelling immunocytochemistry. Clusters of GAP-43-immunofluorescent chromaffin cells and many immunofluorescent fibres were observed in the medulla. GAP-43-immunoreactive fibres also formed a plexus under the capsule, crossed the cortex and ramified in the zona reticulata. Double labelled sections showed the coexpression of GAP-43 with a subpopulation of tyrosine hydroxylase-and of dopamine-β-hydroxylase-immunoreactive chromaffin cells. Dual colour immunofluorescence for GAP-43 and calcitonin gene-related peptide (CGRP) revealed that some of the GAP-43-immunoreactive fibres also express CGRP. Pre-embedding electron microscopy showed GAP-43 immunoreactivity associated with the plasma membranes and cytoplasm of noradrenaline-producing chromaffin cells, and with processes of nonmyelin-forming Schwann cells. Immunoreactive unmyelinated axons and terminals were also observed. The immunostained terminals made symmetrical synaptic contacts with chromaffin cells. Immunoreactive unmyelinated fibres and small terminals were present in the cortex. Our results show that GAP-43 is expressed in noradrenergic chromaffin cells and in various types of nerve fibres that innervate the adrenal. Likely origins for these fibres include preganglionic sympathetic fibres which innervate chromaffin cells, postganglionic sympathetic fibres in the cortex, and CGRP containing sensory fibres.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 120
    ISSN: 1432-0878
    Keywords: Nervous system, insect ; Octopamine ; DUM neurons ; Immunohistochemistry ; Accessory glands ; Periplaneta americana (Insecta)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The musculature of the mushroom-shaped accessory gland receives innervation from trunks 5C1 of the phallic nerves, which arise from the posterior part of the terminal abdominal ganglion of the male cockroach Periplaneta americana. Anterograde cobalt filling through trunks 5C1 with the subsequent precipitating procedure has shown the fine innervation of the accessory gland. By retrograde cobalt filling through the same trunks, different types of cells have been mapped in the terminal abdominal ganglion. About 25 dorsal unpaired median (DUM) neurons have been identified among them. About 36 octopamine-like immunoreactive DUM neurons with large somata have been characterized in whole-mount preparations of the terminal abdominal ganglion. The combination of the cobalt-filling technique with immunohistochemical mapping of cells suggests an octopaminergic innervation of the musculature of the accessory gland by DUM neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 121
    ISSN: 1432-0878
    Keywords: Key words: β-Galactoside-binding lectin ; Dermis ; Skin ; Chick embryo ; Immunohistochemistry ; Keratinization ; Mucous metaplasia ; Domestic fowl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In order to elucidate the roles of metal-independent animal lectins, we systematically investigated changes in expression of 2 kinds of β-galactoside-binding isolectins (MW 14 and 16 kDa) in the dermis of chick embryonic tarsometatarsal skin during the course of development. These lectins were immunohistochemically located at different stages of development both in ovo and in vitro by light and electron microscopy. Light- microscopic observation showed that while positive staining for the 14-kDa lectin was weak at days 8 and 10 it became intense after day 13. In contrast, staining for the 16-kDa lectin was intense at days 8, 10, and 13, but it became weak after day 17 when keratinization of the epidermis was completed. Immuno-electron-microscopic observation revealed that both the 14 and 16-kDa lectins were located on the basement membrane, in the extracellular matrix, and in both the cytoplasm and the nucleus of dermal fibroblasts. Distribution of the 2 isolectins was also examined in cultured skin explants in vitro. The results were almost the same as those obtained in ovo when the skin explant was keratinized in the presence of hydrocortisone. However, in the skin explant where keratinization was prevented and mucous metaplasia was induced by the addition of vitamin A, the distribution of the 14-kDa lectin in the epidermis was significantly affected. These results indicate that (1) the expression of the 2 isolectins is differently regulated in both the dermis and epidermis, (2) the 16-kDa lectin is involved in the early stage of the formation of the dermis and the basement membrane and is replaced by the 14-kDa lectin as keratinization of the epidermis occurs, and (3) the expression of the 2 isolectins in the dermis is not significantly affected by the induction of mucous metaplasia, in contrast to their drastic changes in the epidermis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 122
    ISSN: 1432-0878
    Keywords: Brain mapping ; GABA ; Immunohistochemistry ; Visual reflexes ; Salamanders, Pleurodeles waltli, Triturus alpestris (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of GABAergic neurons in brains of the family Salamandridae (Pleurodeles waltli, Triturus alpestris) has been investigated immunohistochemically with an antibody against gamma-aminobutyric acid (GABA). In adult animals, immunoreactive neurons, fibers, and terminals are abundantly labeled. In the telencephalon, pallial areas contain fewer GABAergic neurons and fibers than basal forebrain areas. The amygdalar complex and the habenulae have a complex pattern of GABA-immunoreactivity that is especially pronounced within the neuropil. The pretectal and basal optic systems are provided with GABAergic neurons, corroborating electrophysiological results. The dorsal thalamus and parts of the torus semicircularis are almost completely devoid of GABA-immunoreactive neurons. In the torus, magnocellular neurons known to project to the contralateral counterpart are distinctly GABA-immunoreactive. During ontogeny, GABAergic neurons arise early when the first reflexive movements occur after mechanical stimulation. At stage 28, cells are labeled initially near the nucleus of the medial longitudinal fasciculus, which is the first supraspinal tract to appear in ontogeny. At stage 30 (still before hatching), GABAergic neurons are found in the pretectum, immunoreactive neurons arising in the dorsal tegmentum slightly later. Both systems are known to mediate basic reflexes in gaze stabilization. The commissura posterior is GABAergic at early stages suggesting an important functional role in homonymous inhibition between both sides. Thus in salamanders, the neurotransmitter GABA displays a complex distribution, similar to that in other vertrebrates. This pattern emerges early in ontogeny.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 123
    ISSN: 1432-0878
    Keywords: EGF ; Cartilage ; Growth plate ; Hypophysectomy ; Growth hormone ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Epiphyseal growth plate cartilages from the proximal tibia of normal, hypophysectomized, and growth hormone (GH)-treated hypophysectomized rats were subjected to immunohistochemistry for detection of epidermal growth factor (EGF). In the normal growth plate, EGF was distributed mainly in the proliferative zone. Hypophysectomy resulted in considerable atrophy of the chondrocytes and the cartilage matrix (a decreased number of mature-type chondrocytes and a decreased ratio of proliferating to hypertrophic chondrocytes) and a significant diminution of EGF immunoreactivity. Treatment with GH reversed these effects of hypophysectomy, causing an increased thickness of the growth plate and EGF-reactive sites in all chondrocyte layers. The most intense immunostaining for EGF, however, was frequently seen in the nuclei of chondrocytes with flattened appearance. It appears that EGF could be incorporated or synthesized in chondrocytes having marked mitogenic activity. The present results, taken with previous data on EGF involvement in growth of cartilaginous tissue in vivo and in vitro, strongly suggest that EGF-immunoreactive chondrocytes are involved in cartilage proliferation and growth under the specific influence of GH.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 124
    ISSN: 1432-0878
    Keywords: Placenta ; Protease inhibitors ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Proteases and their inhibitors play a pivotal role in developmental and differentiative processes. In the present report we investigated the immunohistochemical localization of α1-antitrypsin, α1-antichymotrypsin and inter-α-trypsin inhibitor in first trimester as well as in term human placentas. For this purpose polyclonal antibodies against these serine-protease inhibitors were used. All inhibitors were expressed in the villous syncytiotrophoblast of first and last trimester placentas. Placental fibrinoid was positively stained for α1-antitrypsin and inter-α-trypsin inhibitor throughout gestation. α1-Antitrypsin and α1-antichymotrypsin showed a strong immunostaining in the Hofbauer cells (first trimester and full term placentas). Extravillous cytotrophoblast was negative for the three protease inhibitors throughout gestation. The presence of the three inhibitors in the syncytiotrophoblast suggests a role in coagulative, invasive and immunomodulatory processes. Fibrinoid, staining for α1-antitrypsin and inter-α-trypsin inhibitor, could also have an important immunoprotective function. The presence of protease inhibitors in the Hofbauer cells suggests an involvement of these cells in villous remodelling and differentiative processes.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 125
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 278 (1994), S. 379-387 
    ISSN: 1432-0878
    Keywords: Enteric nervous system ; Immunohistochemistry ; 5-Hydroxytryptamine ; Colon ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The presence of 5-hydroxytryptamine in enteric neurons of the guinea-pig distal colon was demonstrated by immunohistochemistry and the projections of the neurons were determined. 5-Hydroxytryptamine-containing nerve cells were observed in the myenteric plexus but no reactive nerve cells were found in submucous ganglia. Varicose reactive nerve fibres were numerous in the ganglia of both the myenteric and submucous plexuses, but were infrequent in the longitudinal muscle, circular muscle, muscularis mucosae and mucosa. Reactivity also occurred in enterochromaffin cells. Lesion studies showed that the axons of myenteric neurons projected anally to provide innervation to the circular muscle and submucosa and to other more anally located myenteric ganglia. The results suggest that a major population of 5-hydroxytryptamine neurons in the colon is descending interneurons, most of which extend for 10 to 15 mm in the myenteric plexus and innervate both 5-hydroxytryptamine and non-5-hydroxytryptamine neurons.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 126
    ISSN: 1432-0878
    Keywords: Key words: Macrophages ; Adrenal cortex ; Chromaffin cells ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. There is increasing evidence for an immune-adrenal interaction in which macrophages may play an important role. However, few data are available with respect to a human intra-adrenal macrophage system. In this study, we have investigated the density, distribution and phenotype of human adrenal macrophages using monoclonal antibodies. Macrophages are localized in all zones of the adrenal gland. These cells exhibit the phenotype of the phagocytotic macrophage compartment (CD11c+, KiM8+). At the ultrastructural level, macrophages are frequently attached to the endothelial wall, but also lie in direct contact with cortical and chromaffin cells. This investigation reveals the cellular basis for the possible role of macrophages in the local immune-neuroendocrine axis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 127
    ISSN: 1432-0878
    Keywords: Macrophages ; Adrenal cortex ; Chromaffin cells ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract There is increasing evidence for an immune-adrenal interaction in which macrophages may play an important role. However, few data are available with respect to a human intra-adrenal macrophage system. In this study, we have investigated the density, distribution and phenotype of human adrenal macrophages using monoclonal antibodies. Macrophages are localized in all zones of the adrenal gland. These cells exhibit the phenotype of the phagocytotic macrophage compartment (CD11c+, KiM8+). At the ultrastructural level, macrophages are frequently attached to the endothelial wall, but also lie in direct contact with cortical and chromaffin cells. This investigation reveals the cellular basis for the possible role of macrophages in the local immune-neuroendocrine axis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 128
    ISSN: 1615-2573
    Keywords: Cardiac annexin V ; Ischemic myocardium ; Immunohistochemistry ; Rat Langendorff method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We isolated and purified 35kDa protein from the myocardium of the beagle dog and identified it to be annexin V from partial amino acid sequence determination. It was confirmed that anticanine cardiac annexin V rabbit polyclonal antibody, which was produced using the 35 kDa protein, cross-reacts with annexin V of the myocardium, lung, liver, kidney, and brain of the rat. The localization of cardiac annexin V and the effect of ischemia for 30–180 min in the rat were immunohistochemically studied with the use of the Langendorff perfusion heart. In the normal myocardium, annexin V, accompanied by cross-striation, was observed throughout the cell. In ischemia of 30 min, extracellular leakage of annexin V was observed with uneven staining in the cytoplasm. When the ischemic time exceeded 60 min, annexin V was observed in the cell membrane with a decrease of annexin V in the cytoplasm. Also, extracellular leakage of annexin V was observed prominently. In ischemia for 180 min, almost all the annexin V in the cytoplasm disappeared. These results suggest that the level of ischemia can be estimated from the changes in localization of annexin V.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 129
    ISSN: 1573-7365
    Keywords: Cerebral ischemia ; Hippocampus ; Heat shock protein 70 ; Astrocyte ; Immunohistochemistry ; Gerbil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Immunohistochemical changes of heat shock protein 70 (HSP 70) and glial fibrillary acidic protein (GFAP) were investigated in the gerbil hippocampus 1 h-7 days after 10 min of cerebral ischemia. Transient cerebral ischemia caused HSP 70 expression in GFAP-positive astrocytes in a delayed fashion, as compared with a rapid induction in vulnerable neurons such as hilar neurons. The present results may offer clues to elucidate the mechanisms of ischemic neuronal damage.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 130
    ISSN: 1434-9949
    Keywords: Rheumatoid Arthritis ; Synovium ; Extracellular Matrix ; Basement Membrane Proteins ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rheumatoid arthritis is a complex disease of unknown origin. In consequence of some immunological reactions, proliferative invading synovial tissue leads to destruction of normal joint architecture. The aim of this study was to investigate qualitative changes in extracellular matrix distribution of proliferating rheumatoid synovium and their cellular origin. Synovial tissues from 57 clinically indicated arthrotomies were investigated with immunofluorescence, using specific antibodies against extracellular matrix proteins in tissue slides and cultured cells, which were also studied for collagen biosynthesis. Results indicated that synovial fibroblast-like cells synthesize and secrete basement membrane proteins laminin and collagen type IV as e.g. endothelial cells or organogenic fibroblasts. Laminin and collagen type IV were specifically demonstrated pericellularly in the hyperplastic lining layer of active rheumatoid synovitis. These findings are discussed with respect to the possible implication of altered cell-matrix interactions in rheumatoid synovial proliferation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 131
    Electronic Resource
    Electronic Resource
    Springer
    Clinical rheumatology 13 (1994), S. 641-644 
    ISSN: 1434-9949
    Keywords: Lupus Erythematosus Panniculitis ; Monoclonal Antibodies ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An immunohistochemical study on a case of lupus erythematosus panniculitis (LEP), without discoid lupus erythematosus (DLE) or systemic lupus erythematosus (SLE) signs, showed that the cells in skin infiltrates were immunologically committed lymphocytes (OKT4, OKT8, OKT11 and HLA-DR positive cells) and elements of the monocyte-macrophage lineage (Leu M3 and Leu M5 positive). No immunophenotypically identifiable B-lymphocytes were seen. Immunofluorescent IgG, IgM, C3 and C4 deposits were found in blood vessel walls of the deep dermis. These findings, similar to that described in the skin changes of SLE and DLE, suggest that immunological mechanisms are operative in localized LEP, where the dermal lesions are the only expression of the disease.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 132
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 107 (1994), S. 132-140 
    ISSN: 1437-1596
    Keywords: Time of death ; Sweat glands ; Immunohistochemistry ; Electron microscopy ; Todeszeit ; Schweißdrüsen Immunhistochemie ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Diese Untersuchung zeigt postmortale autolytische Veränderungen in der Haut auf zellulärer und subzellulärer Ebene und identifiziert Parameter, welche helfen können, die Zeit des Todes in den ersten Stunden postmortem zu bestimmen. Hautproben von der Beugeseite des Arms wurden, 3, 6, 9 und 12. Stunden nach dem Tode von insgesamt 29 Leichen entnommen (verschiedene Altersklassen, keine Zeichen für Hauterkrankungen, verschiedene Todesursachen). Drei Arten der Untersuchungen wurden durchgeführt: zytochemisch (Hematoxylin-Eosin and Alcian-PAS), immunhistochemisch (S-100, CEA, Cytokeratin, ASM) und ultrastrukturell (Elektronenmikroskopie). Die Elektronenmikroskopie erwies sich als nützlich für die Identifizierung von Transformationen die für jeden chronologischen Schritt spezifisch waren: Reduktion des intrazellulären Glykogens in hellen Zellen und Reduktion der sekretorischen Granula in dunklen Zellen sind typische Zeichen für die erste Phase (3 Stunden) nach dem Tode; mitochondriale Dilatation und Rarifizierung der Cristae in hellen und dunklen Zellen sind typisch für die 2. Phase (6 Stunden); Rarifizierung der Microvilli in dunklen und hellen Zellen sind typisch für die 3. Phase (9 Stunden) und Kernpyknose von dunklen und hellen Zellen ist ein Zeichen der letzten Phase (12 Stunden). Zytochemie und Immunhistochemie sorgen für eine nützliche Information — dies gilt nicht für alle chronologischen Stadien, welche hier einbezogen wurden, aber für individuelle Phasen (3 Stunden für Hematoxylin-Eosin und 6 Stunden für Alcian-PAS). Es ist jedoch besonders wichtig, die Resultate von allen solchen Techniken simultan einzubeziehen, so daß die Frage der exakten Todeszeit innerhalb der ersten 12 Stunden postmortem genauer beantwortet werden kann.
    Notes: Abstract This study demonstrates post-mortem autolytic alterations in the skin at cellular and subcellular levels and identifies parameters which may assist in determining the time of death in the first few hours post-mortem. Serial skin samples from the ventral surface of the arm were taken at intervals of 3, 6, 9 and 12 h after death in 29 subjects of various ages, with no signs of skin disease; causes of death were various. Three types of tests were performed: cytochemical (hematoxylin-eosin and alcian-PAS), immunohistochemical (S-100, CEA, Cytokeratin, ASM) and ultrastructural (electron microscopy). Electron microscopy proved useful for identifying transformations which were found to be specific for each chronological step considered: reduction of intracellular glycogen in clear cells and reduction of secretory granules in dark cells are typcial signs of the first stage (3 h) after death; mitochondrial dilatation and rarefaction of cristae in clear and dark cells are typical of the second stage (6 h); rarefaction of microvilli in dark and clear cells is a sign of the last stage (12 h). Cytochemistry and immunohistochemistry supply useful information — not for all the chronological stage considered here, but for individual phases (3 h for hematoxylin-eosin and 6 h for alcian-PAS). However, it is particularly important to use the results from all such techniques simultaneously, so that the question of the exact time of death within the first 12 h post-mortem may be more accurately answered.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 133
    Electronic Resource
    Electronic Resource
    Springer
    International journal of legal medicine 106 (1994), S. 249-253 
    ISSN: 1437-1596
    Keywords: SIDS ; Pituitary morphology ; Newborn ; Immunohistochemistry ; SIDS ; Hypophysen ; Morphologie ; Sdugling ; Immunhistochemie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung 100 Hypophysen von SIDS-Fällen (58 männlichen und 42 weiblichen Geschlechtes mit einem Durchschnittsalter von 5,34 ± 3,12 Monaten) wurden untersucht. Die Kontrollgruppe bestand aus 19 Hypophysen (14 männlichen und 5 weiblichen Geschlechtes mit einem Durchschnittsalter von 5,63 ± 2,52 Monaten) mit jeweils eindeutig geklärter (z. T. nicht-natürlicher) Todesursache. Die lichtmikroskopischen und immunhistologischen Untersuchungen zur Typisierung der einzelnen Zellgruppen zeigten regelrecht entwickelte Hypophysen. Unspezifische Nekrosen und Blutungen fanden wir in zwei SIDS Fällen und keinem Fall der Kontrollgruppe. Hyperämien bestanden in 51 (30 M/21 W) SIDS-Fällen. Mikrofollikel (54%), Zysten der Intermediärzone (14%), Reste der Rathke'schen Tasche (44%), Erdheim'sches Plattenepithel (8%) oder Speicheldrüsenheterotopien (3%) bildeten keine als signifikant zu wertenden Befunde. Bezüglich der immunhistologischen Verteilungsmuster der dargestellten Zellen fanden sich für die Quantitäten keine Auffälligkeiten. Die intrazellulären Vacuolen bei ACTH- und gonadotropen Zellen zeigten keine signifikanten Unterschiede. Die S-100 Protein-positiven Zellen ließen sich altersentsprechend stellenweise gar nicht und sonst nur regelhaft darstellen. Die Ergebnisse können als Folgen der terminalen Agonie, nicht aber als Ursache des plötzlichen Kindstodes interpretiert werden.
    Notes: Summary The morphological structure and immunohistochemical reactions of 100 pituitaries from cases of SIDS children (58 males and 42 females, average age 5.34 ±3.12 months) were studied. Controls consisted of 19 pituitaries from children (14 males and 5 females, average age 5.63 ± 2.52 months) with a clearly identifiable cause of death e.g. drowning or strangulation. The microscopical and immunohistochemical studies for identifying pituitary cell types revealed normally developed organs. Unspecific necroses and haemorrhages were observed in 2 cases of SIDS but in none of the controls. Hyperaemia was detected in 51 (30 male/21 female) cases of SIDS. No significant differences were found in the distribution of microfollicles (54%), cysts of the intermediate zone (14%), persistency of the Ratlike's pouch (44%), Erdheim's squamous epithelium (8%) or heterotopic salivary glands (3%). The semiquantitative immunohistochemical evaluations of the different cell types showed no significant variations from the control group. The pattern of distribution of the intracytoplasmic vacuolisations of the ACTH and gonadotropic cells showed no significant differences. Folliculo-stellate cells were either not demonstrable — commensurate with age — or showed a normal distribution. The results for both study groups may be defined as consequences of terminal agony, but failed to reveal the cause of the sudden infant death.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 134
    Electronic Resource
    Electronic Resource
    Springer
    Documenta ophthalmologica 88 (1994), S. 105-112 
    ISSN: 1573-2622
    Keywords: Immunohistochemistry ; Pathogenesis ; Proliferative vitreous-retinopathy ; Retinal detachment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Proliferative vitreo-retinopathy (PVR) and subretinal membrane proliferation are the most common complication and cause of failure in retinal-detachment (RD) surgery. In this study, material withdrawn from 21 patients was observed. The vitreal taps of 16 bulbs affected by PVR and which had undergone vitrectomy, along with 5 bulbs obtained by enucleation, were stained with Hematoxylin Eosin and studied immunohistochemically. The cells involved in this proliferative tissue include macrophages, cellular elements of pigmented epithelium origin, fibroblasts and myofibroblasts. From the examination of enucleated bulbs, we can easily recognize that the cellular components of the membrane are represented by fibroblasts, capillaries, and occasional macrophages; meanwhile, PE cells remain at the base of the newly formed tissue.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 135
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 251 (1994), S. 137-142 
    ISSN: 1434-4726
    Keywords: Otitis media with effusion ; Ventilation tubes Middle ear collagen ; Immunohistochemistry ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Morphometric quantitation of the area fractions of collagen types I, II, IV and V was determined in the normal rabbit middle ear mucosa and in relation to otitis media with effusion (OME) using a three-layered peroxidase-antiperoxidase technique. The effects of substituting normal low-oxygen middle ear gas (non-ventilated) with atmospheric air (ventilated) were studied in both healthy ears and ears with OME. Based upon previous histological examinations in rabbits, only ears with OME for more than 8 weeks were included to ensure the presence of chronic inflammation (COME). Atmospheric air was introduced into the middle ears by insertion of ventilation tubes or by an enlarged myringotomy. Collagen type I was predominant in all groups studied. The area fractions of collagen types I, II and IV were increased significantly in COME, with collagen type II elevated in particular. Ventilation of the normal ears resulted in a significantly increased area fraction of cells, while the area fractions and distributions of the collagen types were unaffected. None of the ventilated ears in COME improved or healed spontaneously. The total fraction of collagen in COME was not changed significantly by the introduction of atmospheric air. However, the individual distribution of the collagen types was altered, with significantly larger area fractions of types II and V found in ventilated ears with COME. Possible explanations for the differences found are discussed, including the role of oxygen-derived free radicals.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 136
    ISSN: 1860-1499
    Keywords: Vasoactive intestinal polypeptide (VIP) ; Intestinal ischemia ; Immunohistochemistry ; Ganglionic cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Alterations in the distribution of vasoactive intestinal polypeptide (VIP) in normal and ischemic small intestines of dogs were studied by using conventional transmission electron microscope, and immunohistochemistry for light and electron microscopy. At the light microscopic level, immunoreactivity was evident in the intestinal ganglionic cells of control segments. At the electron microscopic level using a pre-embedding method, the entire cytoplasm of the ganglionic cells in the control segments was filled with VIP immunoreactive products, while the post-embedding experiment showed positive reactions only within the VIP granules and Golgi vesicles. After 30 min of ischemia, immunoreactivity was greatly decreased in the ganglionic cells and a large amount of VIP immunoreactive product appeared in the striated border of epithelial cells and in nerve fibers of the subepithelial layer. These results suggest that intestinal ischemia might lead to the release of VIP, which seems to bind to the microvillus membrane of epithelial cells. The relationship between the changes in VIP distribution and its protecting mechanisms of ischemic damage is discussed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 137
    ISSN: 1860-1499
    Keywords: PCNA ; Laminin ; Tannic acid ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The distribution of proliferating cell nuclear antigen (PCNA), laminin, and basement membrane in surface epithelial-stromal ovarian tumors was studied using immunohistochemical and cytochemical techniques. PCNA is a useful means of differentiating between borderline and malignant tumors. The distribution of laminin-positive materials in malignant tumors showed that laminin synthesis in these tumors is quite different from that which occurs in benign or borderline tumors. This corresponded with electron microscopic findings by tannic acid fixation showing pleomorphism of cell organelles and discontinuity of the basement membrane in malignant tumors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 138
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994) 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 139
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 1-9 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An iterative method is introduced for computing second-order partial derivatives (sensitivities) of eigenvalues and eigenvectors of matrices which depend on a number of real design parameters. Numerical tests confirm the viability of the method and support our theoretical analysis. Alternative methods are reviewed briefly and compared with the one proposed here.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 140
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 11-19 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the formulation of the semi-Loof element the rotation of the tangent plane is derived from the interpolation of the transverse displacement, while the rotation of the normal is interpolated separately by another set of shape functions. The geometric stiffness matrix can be formulated by use of either of the two rotation representations. It is demonstrated that the use of the tangent plane representation in the geometric stiffness matrix is far superior to the common form at present.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 141
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 21-32 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An efficient solution to boundary-value problems may be based on the application of a suitably truncated T-complete set of Trefftz functions over individual subdomains and on linking the fields by a least-squares procedure. Although it yields a symmetric system of linear equations, this approach as originally presented by Zielinski and Zienkiewicz is not suited for implementation into FE codes. The present paper presents two equivalent formulations, which take respectively the form of the finite (FE) and non-conventional boundary-element (BE) approach. Both allow the resulting simultaneous equations to be assembled following the standard direct stiffness methods and can readily be implemented into existing FE codes.As in the conventional p-method, the accuracy may be controlled within large limits without increasing the number of elements. The present approach allows substantial saving in computer time in comparison with the so-called hybrid-Trefftz (HT) elements, though the assumed displacement fields are identical. The practical efficiency of the new T-element approach is assessed on the problem of stress concentration in a symmetrically compressed perforated panel.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 142
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 167-178 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A sixth-order polynomial shape function is developed for BIE analysis. The function is applied over only three-noded elements, but with the support for the function extending over adjacent elements. This avoids the oscillations near the ends of the range which otherwise are characteristic of high-order polynomial interpolation. Various test problems are explored, and it is shown that results as accurate as those from conventional quadratic elements are obtained with larger nodal spacings, and thus giving the potential for significant reductions in matrix storage requirements and solution times.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 143
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 155-166 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element formulation based on superposition is proposed for a lifting aerofoil in incompressible potential flow. An accuracy improvement technique for the singularity at the aerofoil trailing edge is discussed. It is shown that the quarter-node quadrilateral element can be readily employed to simulate this singularity. It is also demonstrated that the circulation in the flow field can be easily represented by a single constraint equation rather than introducing an artificial cut line in the mesh. The influence of finite-element mesh size on solution accuracy and the correct form of the boundary condition have been investigated as well. Numerical examples are given for both steady and quasisteady Joukowski aerofoils of various thicknesses and at a range of incidences. In all test cases, good agreement is observed between the analytical solution and the numerical result.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 144
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994) 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 145
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 183-194 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An 8-node element (HMITC) for 3D non-linear analysis of solids is presented. The new element is based on an element developed by Wilson and Ibrahimbegovic, that incorporates incompatible modes, and on the method of mixed interpolation of tonsorial components. The HMITC element does not contain spurious zero energy modes and satisfies Irons' Patch Test. The numerical experimentation indicates that the HMITC has good performance even with distorted meshes.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 146
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 203-215 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In this paper we consider an explicit finite-element method, with elements adaptively oriented in space-time, for the solution of one-dimensional conservation laws, extending previous work dealing with linear convection-diffusion and incompressible flow. In particular we consider Burgers' equation and the compressible Euler equations.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 147
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 195-201 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A numerical method, based on neural-network-based functions, for solving partial differential equations is reported in the paper. Using a ‘universal approximator’ based on a neural network and point collocation, the numerical problem of solving the partial differential equation is transformed to an unconstrained minimization problem. The method is extremely easy to implement and is suitable for obtaining an approximate solution in a short period of time. The technique is illustrated with the aid of two numerical examples.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 148
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 217-225 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An efficient algorithm for consideration of axial and cyclic symmetry in the boundary-element method is presented. The appropriate transformation relationships was derived. The algorithm is then implemented in a boundary element program for the analysis of 2D elastostatic problems. Through analysis of typical problems the validity of the algorithm and its implementation is verified. A high level of accuracy and substantial reduction in computer time and storage was achieved.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 149
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 227-235 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The diffusion of oxygen into an absorbing medium as an example of an implicit moving boundary problem has been dealt with by a number of authors using various numerical techniques, and, where appropriate, approximate analytical expressions. To evaluate the time for complete absorption, extrapolation is usually employed. An unconditionally stable explicit numerical scheme that avoids the limitations of such methods is presented and tested herein. Unlike existing schemes this method is fully numerical; it avoids the large array size, generally required for existing methods, by using a variable-length time step. The time for complete absorption emerges from the final step in the normal computing procedure with no recourse to extrapolation. Furthermore, owing to the implicit condition prevailing at the moving boundary, no iterations are needed to evaluate the time step required for the moving boundary to move a single space increment. The numerical results obtained compare very favourably with those due to earlier authors.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 150
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 237-248 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the paper we have developed a new formulation for solution of structural-acoustic coupling problems by boundary elements using the multiple reciprocity method. It is assumed that the structure is composed of plate components and is excited by the external or the internal noise source. The efficiency of the proposed formulation becomes especially remarkable if the boundary-value problem is to be solved repeatedly for different values of frequency. The accuracy of the numerical computations has been compared with the analytical solution in a test example.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 151
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 257-265 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Techniques for stress- and strain-controlled in situ homogenization of inelastic periodic composites are presented. The results of homogenization computations on a specific elastoplastic composite solid are then employed to validate the form of an orthotropic elastoplasticity model with a tensorial kinematic hardening law.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 152
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 249-255 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An algorithm for evaluation of friction in general contact-impact interfaces is described. The algorithm is based on an explicit finite-element method. Coulomb's friction law is assumed. The defence node algorithm is used such that the sticking condition can be imposed with the Lagrange multiplier method even in explicit dynamic analysis. The algorithm is supposed to be applicable in general situations, including large deformations of the contact-impact bodies and large relative sliding between the contact-impact boundaries. Numerical results are presented to demonstrate the performance of the algorithm.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 153
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 275-277 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 154
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994) 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 155
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 267-273 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A generalization of the r(1-m)/m strain singularity of higher-order isoparametric elements is presented. It is shown that, by variable placement of the side nodes between their original and singular positions, the point of singularity sensed by the element can be controlled. The transition elements have a strain singularity outside their domain. The singular and non-singular elements are elements are special cases of the general mapping. The transition elements, together with the singular isoparametric elements, can be used for solving crack problems.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 156
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 279-290 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the design of members with flaws, it is necessary to keep the stress intensity factor K of any sharp crack below the fracture toughness Kcr of the materials. Stress-intensity factor equations for the more common basic specimen geometries and various loading conditions are available in the literature. The application of these equations to complex structures involves geometric problems such as the identification of the outline of each member and the sizing of the equivalent specimen for each flaw. The paper gives a response to such difficulties.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 157
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 303-312 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A simple, yet storage-effective ‘linear’ programming code is given. The assumption of non-negative variables is bypassed without increasing the size of the problem. Furthermore, the objective is allowed to be summed over not just linear, but also concave, functions. A specific truss topology optimization example is shown.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 158
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 291-296 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: We propose in this paper a nine-point, fourth-order difference method for the numerical solution of the quasilinear Poisson equation \documentclass{article}\pagestyle{empty}\begin{document}$$ Au_{zz} + \frac{1}{r}u_r + Bu_{rr} = f\left({r,z,u,u_r,u_z} \right) $$\end{document} with appropriate boundary conditions. The method is based on five evaluations of f. The numerical results of four problems obtained using this method are listed. The results demonstrate the fourth-order accuracy of the method.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 159
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 297-302 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Singularly perturbed second-order elliptic equations with boundary layers are considered. These may be considered as model problems for the advection of some quantity such as heat or a pollutant in a flow field or as linear approximations to the Navier-Stokes equations for fluid flow. Numerical methods composed of central-difference operators on special piece-wise-uniform meshes are constructed for the above problems. Numerical results are obtained which show that these methods give approximate solutions with error estimates that are independent of the singular perturbation parameter. An open theoretical problem is posed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 160
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 313-320 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the paper we present a superconvergent patch recovery technique for obtaining higher-order-accurate finite-element solutions and thus a postprocessed type of L2 norm error estimate. Two modifications make our procedure different from the one proposed by Zienkiewicz and Zhu (1992), in which higher-order-accurate derivatives of the finite-element solution at nodes are determined. Firstly, the recovery process is made for element, not for nodes. An ‘element patch’, which represents the union of an element under consideration and the surrounding elements, is introduced. Secondly, the local error estimate is calculated directly from the improved solution for this element. Numerical tests on both 1D and 2D model problems show that this method can provide an asymptotically exact a posteriori L2 norm error estimate if the used element possesses superconvergent points for the solutions.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 161
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 321-331 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new approach to developing serendipity quadrilateral infinite elements is presented. Using these elements universal matrices for quasiharmonic equation are developed. For a particular member of the family these matrices are independent of the size and shape of the element. Using these matrices the element stiffness matrix can be generated in a simpler manner by taking into account the size and shape of the element.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 162
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 333-338 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new global secant relaxation (GSR)-method-based improvement procedure is used to improve the overall convergency performance of the modified Newton-Raphson iteration in carrying out the solution of discrete systems resulting from the finite-element discretization of a certain class of structural problems involving non-linear deformation behaviour.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 163
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 339-353 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Theoretical and experimental analysis of free-surface electrohydrodynamic flow is fragmented and incomplete. Simulation studies of this phenomenon are further limited by the inherent complexities in the modelling process. In this note a mathematical model is developed to analyse free-surface electrohydrodynamic flow in two dimensions, and preliminary results of the simulation are described. The configurations examined include electrified conducting surfaces, the dielectrophoretic forces, and a conducting jet. The simulation is compared with analytical results in the first two investigations and is shown to be quite accurate. In the last simulation it is demonstrated that in the initial formation of a conducting jet, a 10 per cent increase in applied voltage results in about a 10 per cent increase in fluid velocity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 164
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 355-357 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 165
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 359-360 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 166
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994) 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 167
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 361-371 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The dual reciprocity boundary element method, first proposed by Nardini and Brebbia (1982, 1985), is a powerful technique for solving elliptic partial differential equations. Adopting this approach, a singular volume integral, which needs to be evaluated with a traditional boundary element method, can be converted into a boundary integral. However, when the governing equation is of a certain type, this conversion fails due to the singularities being introduced inside the physical domain and on the boundary arising by differentiating distance functions. We avoid these artificially created singularities by constructing a transformation which leads to improved numerical results.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 168
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 743-749 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This is a study about one of the core questions in the GMRES(k) method regarding the obtaining of vector yk for the least-squares problem, argminy |Hky - β(n)e1|2 (see Saad and Schultz1). We propose a simple but efficient approach to the resolution of this problem and a low cost computation of the residual and the residual norm, including both in a complete and detailed FGMRES(k) algorithm. The whole algorithm of minimization only involves two backward substitutions with triangular matrices and a dot product. The residual and the residual norm are computed, making use of results in the least-squares problem.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 169
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 759-760 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 170
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994), S. 761-762 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 171
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Communications in Numerical Methods in Engineering 10 (1994) 
    ISSN: 1069-8299
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 172
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1481-1497 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A procedure for the optimization of stretched triangular grids is described. The method is based on the construction and minimization of a function that represents a generalized version for stretched grids of a non-linear spring system. The function is minimized using a gradient method based on the steepest descent. Examples are provided to show the applicability of the method to computational fluid dynamics problems.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 173
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1465-1480 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Multigrid method is used to accelerate the convergence of the numerical solution of the set of partial differential equations for generating the Body-Fitted Co-ordinate system (BFC) for both simply and doubly connected domain problems. The multigrid method is based on the full approximation scheme with bilinear interpolation as prolongation operator. The other components of the multigrid method such as the relaxation method, restriction operator, number of relaxation sweeps per cycle and direction of relaxation sweeps are varied with a view to obtaining the general principle in implementing an efficient multigrid algorithm for the generation of the BFCs.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 174
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1531-1555 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In Part I of this work, Paulino et al.1 have presented an algorithm for profile and wavefront reduction of large sparse matrices of symmetric configuration. This algorithm is based on spectral properties of a Finite Element Graph (FEG), An FEG has been defined as a nodal graph G, a dual graph G* or a communication graph G· associated with a generic finite element mesh. The novel algorithm has been called Spectral FEG Resequencing (SFR). This algorithm has specific features that distinguish it from previous algorithms. These features include (1) use of global information in the graph, (2) no need of a pseudoperipheral vertex or the endpoints of a pseudodiameter, and (3) no need of any type of level structure of the FEG. To validate this algorithm in a numerical sense, extensive computational testing on a variety of problems is presented here. This includes algorithmic performance evaluation using a library of benchmark test problems which contains both connected and non-connected graphs, study of the algebraic connectivity (λ2) of an FEG, eigensolver convergence verification, running time performance evaluation and assessment of the algorithm on a set of practical finite element examples. It is shown that the SFR algorithm is effective in reordering nodes and/or elements of generic finite element meshes. Moreover, it computes orderings which compare favourably with the ones obtained by some previous algorithms that have been published in the technical literature.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 175
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1557-1572 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: To exploit the benefits of parallel computer architectures for multibody system simulation, an interdisciplinary approach has been pursued, combining knowledge of the three disciplines of dynamics, numerical mathematics and computer science. An analysis of the options available for the formulation and numerical solution of the dynamical system equations yielded a surprising result. A method initially proposed to solve the inverse problem of dynamics is the best choice to generate the system equations required for solving the simulation problem, when relying on implicit integration routines. Such routines have the particular advantage of handling stiff systems, too. The new O(N)-residual formalism, generating the system equations in a form required for implicit numerical integration, has a high potential to benefit from parallel computer architectures. Two strategies of medium and coarse grain parallelization have been implemented on a Transputer network to obtain a package for parallel multibody simulation. An analysis of the performance of this package demonstrates for typical multibody simulation problems that the new code is five times faster than existing codes when implemented on a serial computer. An additional speed-up by the same order of magnitude is obtained when the code is implemented on a Transputer network.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 176
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 181-201 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A general Finite Volume Method (FVM) for the analysis of structural problems is presented. It is shown that the FVM can be considered to be a particular case of finite elements with a non-Galerkin weighting. For structural analysis this can readily be interpreted as equivalent to the unit displacement method which involves mainly surface integrals. Both displacement and mixed FV formulations are presented for static and dynamic problems.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 177
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 229-256 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An element-free Galerkin method which is applicable to arbitrary shapes but requires only nodal data is applied to elasticity and heat conduction problems. In this method, moving least-squares interpolants are used to construct the trial and test functions for the variational principle (weak form); the dependent variable and its gradient are continuous in the entire domain. In contrast to an earlier formulation by Nayroles and coworkers, certain key differences are introduced in the implementation to increase its accuracy. The numerical examples in this paper show that with these modifications, the method does not exhibit any volumetric locking, the rate of convergence can exceed that of finite elements significantly and a high resolution of localized steep gradients can be achieved. The moving least-squares interpolants and the choices of the weight function are also discussed in this paper.
    Additional Material: 26 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 178
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 37-48 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A pseudo-transient (static) linear, geometric, material and combined geometric and material non-linear analyses of composite laminates are presented. A nine-noded isoparametric quadrilateral finite element belonging to the Lagrangiar family is used in space discretization. An explicit time marching scheme is employed for time integration of the resulting discrete ordinary differential equations with the special forms of diagonal fictitious mass and/or damping matrices. Elasto-plastic material behaviour is incorporated using the flow theory of plasticity. In particular, a modified version of Hill's initial yield criterion is used in which anisotropy parameters of plasticity are introduced. The shear deformation is accounted for by assuming a constant transverse shear strain across the thickness of the laminate and the geometric non-linearity is considered in the sense of von Karman strains. The layered element approach is adopted for the treatment of plastic behaviour through the thickness. A wide range of numerical examples is presented to demonstrate the validity and efficiency of the present approach. The results for combined non-linearity are also presented. The variety of results presented here, which are based on realistic material properties of often-used advanced laminated composite plates, and especially those for combined non-linear analysis, should serve as a reference for future investigations.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 179
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 91-105 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A variationally coupled finite element-boundary element method is developed for transient problems. A single variational statement is obtained for the entire domain and the unknown tractions, which may be discontinuous on the interface and are often a source of difficulties, are eliminated. Moreover, no interface conditions need be taken into consideration at the level of the discretized equation. The discrete equations for the coupled system can be obtained directly without any intermediate steps. The method generalizes a coupling method previously developed by the authors for statics. Numerical examples show that the solutions obtained by the present method agree very well with those obtained by analytical solutions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 180
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 431-455 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A six-node triangle plate/shell element is developed for the analysis of laminated composite structures. This model is formulated using Hamilton's principle along with a first-order (Reissner/Mindlin) shear deformation theory. The element is based upon an isoparametric representation along with an interdependent interpolation strategy; bicubic polynomials for the transverse displacement and biquadratic polynomials for the element geometry, in-plane displacements and rotations. The resulting element, which is evaluated using exact numerical integration, has correct rank and is free of shear ‘locking’. Numerical results are presented that validate the new element and prove its outstanding convergence capabilities in comparison to existing triangular elements using standardized test problems (elastic eigenvalue analysis, patch test, static simply supported square-plate solutions) and experimentally measured vibration data of cantilevered isotropic and composite plates.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 181
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 475-496 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The collapse of ordinary finite elements to generate the desired strain singularity at the crack tip for fracture mechanics applications can lead to unwanted additional singularities in that area. Although neither the quarter-point nor the half-point 8-node two-dimensional (2-D) and 20-node three-dimensional (3-D) elements exhibit this behaviour, the present article proves that arbitrarily small deviations from the quarter-point element can be constructed which do have additional singularities. Since the general behaviour of the half-point element is not affected by small modifications, this element is better suited to match complex body geometries.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 182
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 537-538 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 183
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 517-536 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The superconvergent patch derivative recovery method of Zienkiewicz and Zhu is enhanced by adding the squares of the residuals of the equilibrium equation and natural boundary conditions. In addition, a new conjoint polynomial for interpolating the local patch stresses over the element which significantly improves the local projection scheme is presented. Results show that in the 4-node quadrilateral, the equilibrium and boundary condition residuals usually improve accuracy but not the rate of convergence, whereas in the 9-node quadrilateral, results are mixed. The conjoint polynomial always improves the accuracy of the derivative field within the element as compared to the standard nodal interpolation, particularly in 4-node quadrilaterals.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 184
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 279-296 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: An hybrid stress element formulation based on internal, incompatible displacements is used to develop efficient Mindlin plate elements. The 4-node quadrilateral Mindlin plate element is derived from a modified energy functional. Both displacements and stresses are defined in the natural co-ordinate interpolation system. The assumed stress field is obtained by tensor transformation and so chosen as to ensure that the element is co-ordinate invariant and stable. Shear locking is avoided through an appropriate identification of the internal, incompatible displacement field. The role played by incompatible displacements in the formulation of hybrid stress elements for thin and moderately thick plates is discussed. Numerical applications are presented to illustrate the accuracy and reliability of the suggested Mindlin plate element.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 185
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 605-621 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: In the present paper, we analyse the computational performance of the Lanczos method and a recent optimization technique for the calculation of the p (p ≤ 40) leftmost eigenpairs of generalized symmetric eigenproblems arising from the finite element integration of elliptic PDEs. The accelerated conjugate gradient method is used to minimize successive Rayleigh quotients defined in deflated subspaces of decreasing size. The pointwise Lanczos scheme is employed in combination with both the Cholesky factorization of the stiffness matrix and the preconditioned conjugate gradient method for evaluating the recursive Lanczos vectors. The three algorithms are applied to five sample problems of varying size up to almost 5000. The numerical results show that the Lanczos approach with Cholesky triangularization is generally faster (up to a factor of 5) for small to moderately large matrices, while the optimization method is superior for large problems in terms of both storage requirement and CPU time. In the large case, the Lanczos-Cholesky scheme may be very expensive to run even on modern quite powerful computers.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 186
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 387-411 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new eight-node quadrilateral shear-bending Reissner-Mindlin plate finite element for the very thin and thick plates without locking and spurious zero-energy modes is presented. The element has very good convergence characteristics both for thin and thick plates, is hardly insensitive to mesh distortions, and passes the patch tests. The formulation of the element is derived from a displacement variational principle and some general criteria to compute inconsistent transverse shear strains. These criteria have been applied with success to four- and eight-node quadrilateral plate finite elements and could be applied to construct triangular elements. The eight-node quadrilateral shear-bending plate finite element proposed has been found to be very efficient.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 187
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 457-474 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A theory is proposed in this paper to explain, in a unified manner, the three rational approaches using the incompatible displacements uλ in the hybrid element formulation. Limited to the plane stress case, the theory suggests that the introduction of uλ is to constrain the total value of the invariant I2(= σxσy - τxy2) of the assumed stresses over the element to zero. In the plane stress case, this is the well-known condition for the stress distributions to be independent of the elastic constants of the material. The theory proposed is also used to explain the closeness of the performances of the four 4-node hybrid stress membrane elements, 5β-I, 5β-II, 5β-A and 5β-C, that have been developed previously. The differences among them are shown to be of the second degree in the distortion measures of the element shape, when they are compared on the basis of the non-vanishing total value of I2 of their respectively adopted assumed stress field. Several numerical examples are used to verify and to illustrate the proposed theory.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 188
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 189
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1825-1840 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents a boundary element formulation for the permanent Navier-Stokes equations in which the well-known closed-form fundamental solution for the steady Stokes equations is employed. In this way, from the integral representation formulae for the Stokes' equations, an integral equation is found in which the original non-linear convective terms of the Navier-Stokes equations appear as a domain integral. Additionally, the method of dual reciprocity is used to transform the domain integral to boundary integrals (this method is closely related to the method of particular integrals also used in the literature to transform domain integrals to boundary integrals). Numerical results are presented for the three-dimensional internal flow in a cylindrical container with a rotating cover, in which the accuracy of the method is shown.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 190
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 2291-2309 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: The helicoidal beam model developed in the first part of this work is applied here to the development of a mixed finite element for space-curved and twisted beams undergoing large displacements and finite rotations. Starting from the governing weak form expressed by the principle of virtual work, a consistent linearization is obtained in the following and a novel updated Lagrangian finite element implementation is thoroughly discussed.The unique features and the distinguishing properties previously claimed for the helicoidal model are shown here to imply remarkable numerical consequences. For this purpose, meaningful example problems regarding the non-linear static response of beams are addressed in the following and the results are compared with those available from the literature.Furthermore, a finite element in time for the rigid body dynamic problem is developed within the framework of the helicoidal geometry. The underlying philosophy of this novel finite element for dynamics is the realization of the helicoidal decomposition of the rigid body motion within a time step.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 191
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 192
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 2311-2335 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A finite element approach for shape optimization in two-dimensional (2-D) frictionless contact problems is presented in this work. The goal is to find the shape that gives a constant distribution of stresses along the contact boundary.The whole formulation, including mathematical model for the unilateral problem, sensitivity analysis and geometry definition is treated in a continuous form, independently of the discretization in finite elements. Shape optimization is performed by direct modification of geometry through B-spline curves and an automatic mesh generator is used at each new configuration to provide the finite element input data for numerical analysis and sensitivity computations. Using augmented-Lagrangian techniques (to solve the contact problem) and an interior-point mathematical-programming algorithm (for shape optimization), we obtain several results reported at the end of the article.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 193
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 2337-2338 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 194
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1881-1896 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: This paper presents the first endeavour to exploit a generalized differential quadrature method as an accurate, efficient and simple numerical technique for structural analysis. Firstly, drawbacks existing in the method of differential quadrature (DQ) are evaluated and discussed. Then, an improved and simpler generalized differential quadrature method (GDQ) is introduced to overcome the existing drawback and to simplify the procedure for determining the weighting coefficients. Subsequently, the generalized differential quadrature is systematically employed to solve problems in structural analysis. Numerical examples have shown the superb accuracy, efficiency, convenience and the great potential of this method.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 195
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 3015-3018 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 196
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 3019-3021 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 197
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994) 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 198
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 3005-3014 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Since Soize introduced the concept of fuzzy structures in structural acoustics there has been little activity clarifying the basic elements which underlie his theory. Soize's papers are not easy reading due to the high level of mathematical formalism. In addition Soize simultaneously bases this fuzzy structure theory on two components: (1) a model for one Degree Of Freedom (DOF) fuzzy oscillators, and (2) a medium frequency solution method developed previously. It is unclear as to the role of the two components, although others have already undertaken a study of the medium frequency method by itself.In the present paper a fundamental analysis of the first component, the one-DOF fuzzy oscillators, is undertaken. The symbolic manipulation program Mathematica is utilized to gain insight into this component of Soize's fuzzy theory. The resulting Mathematica simulations are easy to use and interpret, and they provide valuable insight into the parameters composing Soize's fuzzy oscillators. It is determined that in many cases of structural acoustics, where there is small damping and a medium to high modal density, the fuzzy mass primarily determines what effect a discrete fuzzy oscillator will have as an attachment.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 199
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 3023-3036 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A new numerical approach has been devised for performing accurate absorbing-emitting non-scattering radiation calculations for Cartesian co-ordinate based problems with one ordinate symmetry using only the solution plane formed by the other two ordinates. To accomplish this, the method makes use of ‘effective intensity rays’ which only exist and have meaning in the solution plane of the problem but which are made, through a special procedure, to contain the information of the third dimension. This novel procedure thus eliminates the problem of solid angles and greatly reduces both the complexity and computational expense involved in the solution of such problems. Yet it can do this without producing loss in accuracy. The approach is ultimately intended for use in combustion problems involving high temperatures and optically thin media. For verification purposes the method is applied to the problem of heat exchange in infinitely long rectangular enclosures and is found to give excellent results over a optical thickness range that includes the optically very thin case.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 200
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 37 (1994), S. 1978-1979 
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...