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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 6539-6541 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have investigated feasibility of GaAs interlayers for the metal/GaN interface with synchrotron-radiation photoelectron spectroscopy. We have found that the use of piranha/HCl solutions is effective as a surface cleaning technique for GaN. We have confirmed that (111) GaAs grows epitaxially on a (0001) GaN substrate. Pd/GaAs/GaN sandwich structures have been successfully fabricated with molecular beam epitaxy. We have confirmed the GaAs interlayer modifies the band diagram at the metal/GaN interface. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 2011-2013 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report a technique to characterize carrier-trapping phenomena in SiO2 by measuring the Si 2p core-level energy of Si substrates covered with thin SiO2 layers as a function of x-ray irradiation time. It is found that the Si 2p peak energy, which corresponds to the band bending at the SiO2/Si interface, changes as the x-ray irradiation time increases. We attribute this to carrier-trapping phenomena in SiO2. By using this technique, it is found that the carrier-trapping phenomena differ remarkably among several chemical oxides. We also discuss the atomic structure of the traps that cause the trapping phenomena. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Polyoxyethylene alkyl esters, which are surface-active agents, were chemically synthesized from fatty acids (C12-C18) on reaction with different moles of polyethylene oxides, and were tested for effectiveness against the toxic raphidophytes Chattonella marina (Subrahmanyan) Hara & Chihara and C. antiqua (Hada) Ono. The synthetic surfactants destroyed cultured cells from these two species. Although the synthetic surfactants also exhibited ichthyotoxicity, this was lowered by increasing the molarity of ethylene oxide (EO) in alkyl ester molecules. Young yellowtail, Seriola quinqueradiata Temminck & Schlegel, survived exposure to C. marina (5000-5500 cells mLT−1) or C. antiqua (3000-3500 cells mL−1) cultures with the addition of 4-5 p.p.m. oleyl ester EO 14, but died within an hour without the addition of this surfactant.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 27 (1997), S. 0 
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background T-cell epitopes on Der 1 and Der 2 groups, the major mite allergens, have been intensively analysed, while those on the other important allergens remain to be elucidated. We have cloned four cDNAs coding for important mite allergens on the basis of frequency and capacity of IgE binding. Stimulatory action of glutathione S-transferase-fused Mag1 on lymphocytes from mite-allergic patients was relatively high among them.Objective To identify T-cell epitopes on Mag1, we studied the stimulating activity of truncated Mag1 proteins and synthetic peptides on proliferative response of lymphocytes from mite antigen-immunized mice and mite-sensitive patients.Methods Truncated Mag1 proteins were expressed as a fusion protein with β-galactosidase in Escherichia coli pop2136 carrying a variety of deleted Mag1 inserts. Murine T-cell epitope regions were estimated by the truncated antigen-induced lymphocyte proliferation assay. Overlapping peptides covering the whole sequence of the presumed T-cell epitope regions were synthesized to identify the epitope core. sequences using murine and human Mag1-specific T-cell lines.Results Amino acid range 56–70 on Mag1 molecule showed remarkable stimulatory action on murine T cells, while amino acid ranges 51–65 and 86–100 had potent stimulatory activity on human T cells.Conclusion These results suggest that Mag1 is a valuable antigen suitable for studies on T-cell responses and T-cell epitopes in mice and humans.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of periodontal research 30 (1995), S. 0 
    ISSN: 1600-0765
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The effects of various prostaglandins (PGs) on the functions of human gingival fibroblasts (Gin-1 cells; ATCC CRL 1292) were examined by phase-contrast microscopy, cell-counting and radioautographic experiments. Tested PGs were PGA1, PGA2, PGB1, PGB2, PGD2, PGE1, PGE2, PGF1α, PGF2α, PGI2, 6-keto-PGF1α, 9α-11α-methanoepoxy-PGF2α, and thromboxane (TX) B2. PGA1, and PGD2 at 30 μM caused morphological deformation of Gin-1 cells. All the PGs tested at 30 μM suppressed the proliferation of Gin-1 cells in the logarithmic growth phase. Furthermore, all the PGs tested at 10 μM suppressed DNA synthesis, collagen synthesis, and noncollagenous protein synthesis in confluent Gin-1 cells, while exerting no effect on GAG synthesis. The concentrations of PGs used are beyond those found in healthy gingiva. However, in periodontitis the local concentrations of some PGs within the gingiva are expected to be extremely elevated beyond the physiological level. These results suggest that PGs may play an important role as a negative regulator in metabolism and some pathologic gingival conditions by suppressing the functions of gingival fibroblasts.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2307
    Keywords: Osteonecrosis ; Serum sickness ; Immune reaction ; Animal model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Osteonecrosis (ON) was produced experimentally in rabbits by intravenous injection of horse serum. Eighty adult rabbits were used: 16 were injected twice with isotonic saline (Group A), 24 were injected once with saline and once with horse serum (Group B), and 40 were injected twice with horse serum (Group C). Both femurs of each rabbit were obtained from 2 h to 7 weeks after the final injection an were subjected to histological examination. No pathological changes were seen in Groups A and B. In Group C, 5 of 15 rabbits (33%) showed ON (necrosis of trabecula and bone marrow) in the femoral metaphysis. In Group C, the early major pathological findings in bone marrow are extravasation of erythrocytes in sinusoidal spaces and microthrombi in small arteries and arterioles near the lesion of extravasation. Immune complexes were demonstrated in the kidney within 24 h of the final injection of horse serum. The present study suggests that immunological reaction associated with serum sickness may play an important role in inducible ON and this model will contribute toward clarifying the pathogenesis of ON.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 20 (1996), S. 142-146 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé. Nous avons utilisé cliniquement des allogreffes osseuses en les traitant par dégraissage dans du chloroforme et du méthanol, par lyophilisation et par stérilisation avec du gaz d’oxyde d’éthylène. Le but du dégraissage et de la lyophilisation est de faciliter une stérilisation ultérieure en éliminant la barrière à la diffusion du gaz d’oxyde d’éthylène dans les os, d’abaisser les niveaux résiduels de l’oxyde d’éthylène et de ses sous-produits toxiques après la stérilisation, d’éliminer les iso-antigènes et de rendre possible un stockade à la température de la pièce. Des infections postopératoires, vérifiées par une culture bactérienne positive, se sont produites chez 2 patients sur 396 (0.5%) recevant cette allogreffe préparée dans des conditions propres, mais non stériles. Des sections histologiques de la zone autour de l’interface de l’allogreffe et de l’assise de l’os du receveur ont montré: 1) des ostéoblastes bordant la surface de l’allogreffe osseuse corticale avec des appositions d’os néo-formé, 2) le développement du nouvel os dans les canaux vasculaires haversiens, et 3) une légère infiltration de petites cellules rondes inflammatoires. L’incidence négligeable d’infections postopératoires a permis de confirmer l’efficacité de la stérilisation. Les sections histologiques de spécimens biopsiques ont montré la préservation de la capacité de la greffe à supporter la formation du nouvel os et éliminer les iso-antigènes. Nous pouvons donc conclure que cette méthode est fiable pour des allogreffes osseuses cliniquement stérilisées et ne présente qu’un léger effet nuisible.
    Notes: Summary. We devised a method of sterilising bone allografts which consists of defatting in chloroform and methanol, freeze-drying and sterilisation with ethylene oxide gas. The purpose of defatting and freeze-drying was to facilitate subsequent sterilisation by eliminating the barrier to diffusion of the gas into bone, to lower residual levels of ethylene oxide and its toxic by-products, to eliminate alloantigens and to make storage possible at room temperature. The efficacy and safety of the method were evaluated by testing the sterilisation of infected bone from 6 patients with active chronic osteomyelitis, the penetration of ethylene oxide into human femoral heads treated by this or by freeze-drying or freeze-thawing, and the desorption of ethylene oxide and its toxic by-products from pieces of bone treated by these methods. All the samples of infected bone tested negative for bacteria after treatment. The gas penetrated into the central area of the femoral heads in a few hours. Residual levels of ethylene oxide and its toxic by-products were much lower in the treated bone than in freeze-dried or freeze-thawed bone, and decreased quickly in flowing air. Prior defatting and freeze-drying facilitated penetration of ethylene oxide into bone during sterilisation and the desorption of ethylene oxide and its toxic by-products after sterilisation. Preparation under clean, but not sterile, conditions and storage at room temperature make bone banking more practical and efficient.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 22 (1998), S. 69-76 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé. Pour arthrodèse inter-somatique lombaire par voie postérieure, des allogreffes d’os corticaux stérilisées au gaz, lyophilisées et dégraissées, de configuration rectangulaire et de dimensions diverses, furent utilisées en combinaison avec des autogreffes d’os spongieux provenant des éléments postérieurs excisés. La fusion à un seul niveau avec ou sans fixation interne a étéétudiée chez 38 patients âgés de 50 ans ou moins et souffrant d’une hernie discale ou d’une post-discectomie avec stase veineuse en amont (chez les plus jeunes) et chez 33 femmes âgées de 60 ans ou plus souffant d’un spondylolisthésis dégénératif (chez les plus âgés). Les groupes les plus jeunes et les plus âgés étaient respectivement composés de 8 et 11 patients avec vissage pédiculaire, de 14 et 8 patients avec crochet et tige et de 16 et 14 patients sans fixation interne. Parmi les divers paramètres du processus de fusion, seuls les changements dans l’interface allogreffe hôte, ont prouvéêtre utiles en pratique. L’incidence d’une non-fusion chez les patients avec vissage pédiculaire, avec crochet et tige et sans fixation interne était respectivement de 0%, 7% et 19% dans le groupe des plus jeunes et de respectivement 0%, 0% et 14% dans le groupe des plus âgés. Des 6 patients avec une nonfusion 3 avaient des douleurs lombaires persistantes et 2 seulement une mobilité du foyer d’arthrodèse en flexion-extension. Il n’y a eu aucun collapsus de greffon. La perte de hauteur de l’espace intervertébral dû principalement à l’impaction de l’allogreffe dans le corps vertébral fut en moyenne de 1,1 et de 1,6 mm respectivement dans les groupes les plus jeunes et les plus âgés et s’est poursuivie en moyenne 3,8 et 5 mois respectivement dans chaque groupe après l’opération. Nous concluons que cette méthode est mécaniquement satisfaisante avec une technique simplifiée et qu’elle est efficace dans le maintien en hauteur de l’espace intervertébral. Même si la fusion osseuse n’est pas réalisée, une union fibreuse peut être obtenue sans collapsus de la greffe.
    Notes: Summary. In posterior lumbar interbody vertebral fusion operations, variously sized, rectangular shaped, defatted, freeze-dried, gas-sterilised cortical bone allografts were used in combination with cancellous bone autografts from excised posterior elements. Single-level fusion, with or without internal fixation, was undertaken in 38 patients aged 50 years or less with disc herniation or a failed discectomy (the younger group) and in 33 women aged 60 years or more with degenerative spondylolisthesis (the older group). Of the various observable indicators of union, changes in the allograft-host interface alone proved to be of practical use. The incidence of nonunion in patients managed with pedicle screws, with a hook and rod system or without internal fixation was 0 of 8 patients; 1 of 14 patients; and 3 of 16 patients, respectively, in the younger group, and 0 of 11 patients; 0 of 8 patients; and 2 of 14 patients, respectively, in the older group. Of the six patients with nonunion, three had persistent low back pain and only two had mobility of the fused segment which was evident on lateral radiographs during flexion and extension. No patient had graft collapse. The decrease in the height of the intervertebral space, chiefly due to settlement of the allograft into the vertebral bodies, in the younger and older groups averaged 1.1 and 1.6 mm, respectively. We concluded that this simplified technique is mechanically sound and effective in maintaining the height of the intervertebral space. Even when the graft failed to unite, fibrous union could be obtained without graft collapse. Combination with a simple internal fixator, such as a compression rod, facilitates bone union.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 20 (1996), S. 147-152 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé. Nous avons établi une méthode pratique et efficace pour la stérilisation d’allogreffes osseuses. Cette méthode se compose de: 1) dégraissage dans du chloroforme et du méthanol, 2) lyophilisation et, 3) stérilisation avec gaz d’oxyde d’éthylène. Le but du dégraissage et de la lyophilisation est de faciliter une stérilisation ultérieure en éliminant la barrière à la diffusion du gaz d’oxyde d’éthylène dans les os, d’abaisser les niveaux résiduels de l’oxyde d’éthylène et de ses sous-produits toxiques après la stérilisation, d’éliminer les iso-antigènes et de rendre possible un stockage à la température de la pièce. L’efficacité et la sécurité de cette méthode ont étéévaluées par: 1) la capacité de stérilisation d’os infectés prélevés à partir du foyer d’une ostétomyélite chronique active chez six patients, 2) la pénétration du gaz d’oxyde d’éthylène dans des têtes fémorales humaines traitées par cette méthode ou par d’autres, telle que la lyophilisation ou la congélation-décongélation, et 3) l’élimination de l’oxyde d’éthylène et de ses sous-produits toxiques, chlorhydrine d’éthylène et éthylène glycol, provenant de l’os traité par cette méthode ou d’autres, telle que la lyophilisation ou la congélation-décongélation. Tous les échantillons d’os provenant d’une ostéomyélite chronique sont restés bactériologiquement stériles après traitement par cette méthode. Lorsque des têtes fémorales traitées avec cette méthode ont été exposées à l’oxyde d’éthylène, le gaz a suffisamment pénétré dans la zone centrale en quelques heures seulement. Les niveaux résiduels de l’oxyde d’éthylène et de ses sous-produits toxiques dans les os traités par cette méthode ont été bien plus faibles que ceux se trouvant dans les os lyophilisés ou congelés-décongelés, et ont rapidement diminués dans l’air ambiant. Ces résultats indiquent qu’un dégraissage antérieur et une lyophilisation ont permis de faciliter la pénétration du gaz d’oxyde d’éthylène dans l’os durant la stérilisation et l’élimination de l’oxyde d’éthylène et de ses sous-produits toxiques après stérilisation. La préparation dans des conditions propres, mais non stériles, et un stockage à la température de la pièce permettent de rendre le système de banque des os plus pratique et efficace.
    Notes: Summary. We used bone allograft treated by defatting in chloroform and methanol, freeze-drying and sterilisation with ethylene oxide gas in operations on 396 patients. The purpose of defatting and freeze-drying is to facilitate subsequent sterilisation by eliminating a barrier to the diffusion of ethylene oxide gas into bone, to lower the residual levels of the ethylene oxide and its toxic by-products after sterilisation, to eliminate alloantigens and to make storage at room temperature possible. Postoperative infections confirmed by a positive bacterial culture occurred in 2 of the 396 patients receiving the allograft, which was prepared under clean, but not sterile, conditions, one of which was thought to be due to dehiscence of the wound, rather than to the allograft. There were also 3 probable infections. Histological sections of the area around the interface of the allograft and its bony bed showed: (1) osteoblasts lining the surface of the dead cortical bone of the graft with appositional new bone; (2) ingrowth of new bone into the Haversian canals, and (3) little infiltration of inflammatory small round cells. These findings indicated the ability of the bone to support new bone formation and to eliminate antigens. The low incidence of infection confirmed the efficacy of this method of sterilisation.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 192 (1995), S. 319-328 
    ISSN: 1432-0568
    Keywords: Harderian gland ; Rat ; G-protein ; Carbachol ; Extracellular calcium ion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the secretory mechanism of the Harderian gland of rats. After perfusion with HEPES-buffered Ringer's solution containing NaF (10 mM) with AlCl3 (10 μM), a G-protein activator, the glandular cells of the Harderian gland showed massive exocytosis and apocrine-like protrusions on the luminal surface. Some of the secretory vacuoles aggregated within the cytoplasm, and large vacuoles were formed. Contraction of the myoepithelial cells covering the glandular endpieces caused a narrowing of the glandular lumina, which contained cytoplasmic fragments, and deformation of the basal contour of the glandular end-pieces. The basal regions of the glandular cells also bulged between the myoepithelial cells. Secretory vacuoles were also discharged to the lateral cell surface, and the intercellular spaces were dilated. The enhanced secretory activities of the glandular cells and the contraction of the myoepithelial cells were similar to those in rats stimulated with 10 μM carbachol (CCh). However, dilatation of the endoplasmic reticulum in glandular cells (type A cells), which leads to the formation of small vesicles, was observed in those glands stimulated by NaF+AlCl3, but not in those stimulated by CCh. Removal of Ca+2 from the perfusing HR or addition of EDTA (0.5 mM) diminished and inhibited NaF+AlCl3- or CCh-enhanced secretory activity of the glandular cells and also allayed the deformation of glandular cells caused by myoepithelial cell contraction. The present results demonstrate the involvement of G-proteins and Ca2+-influx in the lipid secretion of glandular cells and in the contraction of myoepithelial cells of the Harderian gland in rats.
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