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  • 1
    Electronic Resource
    Electronic Resource
    Topical application of α-tocopherol modulates the antioxidant network and diminishes ultraviolet-induced oxidative damage in murine skin (1998)
    Oxford BSL : Blackwell Science Ltd
    British journal of dermatology 138 (1998), S. 0 
    Details
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of this study was to investigate the effects of topical α-tocopherol application on epidermal and dermal antioxidants and its ability to prevent ultraviolet (UV)-induced oxidative damage. Hairless mice received topical applications of α-tocopherol 24 h before a single, acute UV irradiation (10 × minimal erythemal dose). The four major antioxidant enzymes (catalase, superoxide dismutase, glutathione reductase and glutathione peroxidase), hydrophilic and lipophilic antioxidants, and lipid hydroperoxides, markers of oxidative damage, were assayed in both epidermis and dermis of hairless mice. Topical α-tocopherol treatment increased dermal superoxide dismutase activity by 30% (P 〈 0.01) and protected epidermal glutathione peroxidase and superoxide dismutase from depletion after UV irradiation. Total and reduced glutathione levels in the epidermis increased by 50% after the topical treatment (P 〈 0.05), as did dermal ascorbate levels (by 40%; P 〈 0.01). The topical treatment increased α-tocopherol levels both in the epidermis (62-fold) and the dermis (22-fold; P 〈 0.001 in each layer). Furthermore, α-tocopherol treatment significantly reduced the formation of epidermal lipid hydroperoxides after UV irradiation (P 〈 0.05). These results demonstrate that topical administration of α-tocopherol protects cutaneous tissues against oxidative damage induced by UV irradiation in vivo, and suggest that the underlying mechanism of this effect involves the up-regulation of a network of enzymatic and non-enzymatic antioxidants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2133.1998.02062.x
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  • 2
    Electronic Resource
    Electronic Resource
    ZnSe-based birefringent waveguide as Pockels retarder in the blue-green spectral range (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 2332-2334 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electro-refractive modulation in the blue-green spectral range is demonstrated in strained, MBE-grown ZnSe waveguides with cladding layers of ZnMnSe on n-GaAs substrates. Utilizing the Pockels effect in Schottky-contacted structures with built-in birefringence, a contrast ratio better than 80:1 at 2.485 eV is achieved. The rise time of (4.7±0.5) ns is RC limited. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.115848
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  • 3
    Electronic Resource
    Electronic Resource
    Perpendicular magnetic anisotropy and magnetic domain structure in sputtered epitaxial FePt (001) L10 films (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 5686-5692 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The magnetic domain structure and magnetization curves of chemically ordered epitaxial FePt (001) films with perpendicular magnetic anisotropy are discussed. Films were dc magnetron sputtered from a Fe50Pt50 alloy target onto Pt seeded MgO (001) at substrate temperatures of 550 °C. The thickness of the FePt layers was varied between 18 and 170 nm. Specular and grazing incidence x-ray diffraction measurements confirm the presence of the anisotropic, face centered tetragonal (L10) crystal structure. Long range chemical order parameters of up to 0.95 and small mosaic spread, similar to results reported for FePt (001) films grown by molecular beam epitaxy. For film thicknesses ≥50 nm in-plane and out-of-plane hysteresis measurements indicate large perpendicular magnetic anisotropies and at the same time low (about 10%) perpendicular remanence. Magnetic force microscopy reveals highly interconnected perpendicular stripe domain patterns. From their characteristic widths, which are strongly dependent on the film thickness, a value of the dipolar length D0∼50±5 nm is derived. Assuming an exchange constant of 10−6 erg/cm, this value is consistent with an anisotropy constant K1∼1×108 erg/cc. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368831
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  • 4
    Electronic Resource
    Electronic Resource
    Structures and energetics of Ni24–Ni55 clusters (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 572-580 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We predict stable geometrical structures and interaction energies of Ni clusters using non self-consistent electron density functional based corrected effective medium (CEM) and MD/MC-CEM methods. A plot of the reaction energies for the atomic ejection process, NiN+1→NiN+Ni, for Ni24–Ni55 displays a number of informative characteristics: (a) peaks and valleys represent internal structural rearrangement in which the number of core atoms increases by at least one and; (b) a plateau at N=50–54 is associated with the closing of the second MacKay icosahedron at Ni55. The lowest energy structures of NiN clusters for N=24–55 are dissimilar generally to those of both rare gas clusters and fragments of the bulk crystal lattice except where a stable icosahedral or bulk core is present. The growth scheme for N〈50 is determined by the stability and structure of the changing number of core atoms. By contrast, the growth scheme for 51≤N≤55 is determined by the addition of surface atoms to a very stable and invariant 13-atom icosahedral core. The theoretical predictions are compared to available model growth schemes and experimental data. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.471910
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  • 5
    Electronic Resource
    Electronic Resource
    Structure Elucidation of a Glycoside of 2β,3β,23-Trihydroxy-16-oxoolean-12-en-28-oic Acid from Bellis bernardii Using Mass Spectrometry for the Sugar Sequence Determination (1995)
    s.l. : American Chemical Society
    Journal of natural products 58 (1995), S. 152-155 
    Details
    ISSN: 1520-6025
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/np50115a026
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  • 6
    Electronic Resource
    Electronic Resource
    Antisense inhibition of the sucrose transporter in potato: effects on amount and activity (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 19 (1996), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The sucrose proton-cotransporter gene from potato (StSUT1) is mainly expressed in the phloem of mature, exporting leaves. To study the in vivo role of the protein, potato plants were transformed with antisense constructs of the sucrose transporter cDNA under control of the CaMV35S and the rolC promoters, respectively. Both types of transgenic plant develop symptoms characteristic of an inhibition of phloem loading. To determine the level of inhibition, immunological and transport studies were performed. Purified antibodies directed against a peptide from the central loop of SUT1 recognized a transporter with an apparent molecular mass of 47 kDa in leaf plasma membrane vesicles. Antisense repression under control of the non-specific CaMV35S promoter led to a strong reduction in SUT1 protein, whereas no such reduction could be detected when the companion cell-specific rolC promoter was used. Similarily. sucrose uptake in plasma membrane vesicles was reduced by 50–75% in CaMV35S but not in rolC plants. These data suggest that, unlike the rolC promoter, the sucrose transporter is expressed not only in the companion cells but also in other leaf cells. However, inhibition of the transporter by rolC-controlled antisense repression is sufficient to impair phloem loading.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1996.tb00427.x
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  • 7
    Electronic Resource
    Electronic Resource
    Decision-related activity in the macaque dorsal visual pathway (1999)
    Oxford, UK : Blackwell Science Ltd
    European journal of neuroscience 11 (1999), S. 0 
    Details
    ISSN: 1460-9568
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Brain areas at higher levels of cortical organization are thought to be more involved in decision processes than are earlier, i.e. lower, sensory areas. Hence, neuronal activity correlated with decisions should vary with an area’s position in the cortical hierarchy. To test this proposal, we investigated whether a change in neuronal activity during error trials depends in a systematic way on cortical hierarchical position. While macaque monkeys discriminated the direction of moving visual stimuli, the activity of direction-selective neurons was recorded in four extrastriate visual areas: V3A, the middle temporal area, the middle superior temporal area and the posterior part of the superior temporal polysensory area. Neuronal activity was significantly reduced in all areas when the monkeys made errors in judging the direction of stimuli moving in the preferred direction with low and intermediate luminance contrast. The amount of activity reduction was ≈ 50% in all of the visual areas. Thus, the activity on error trials is reduced in early visual processing, independent of the hierarchy in the dorsal visual pathway. The activity reduction depended on stimulus contrast and the direction of the decision relative to the stimulus motion. It was profound and significant in all areas at low stimulus contrast. However, it was nonsignificant at high stimulus contrast. Our data suggest that activity reduction on error trials is due to lack of attention in association with stimulus expectation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1460-9568.1999.00630.x
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  • 8
    Electronic Resource
    Electronic Resource
    Characterization of carp thrombocytes with specific monoclonal antibodies (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 49 (1996), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Monoclonal antibodies (WCL6) specific for carp Cyprinus carpio thrombocytes were produced by immunizing mice with membrane lysates of IgM-negative peripheral blood leucocytes (PBL) and selected on the negative reaction with B cells. WCL6 was reactive with a membrane molecule of approximately 90 kDa and to a lesser extent with molecules of approximately 95 and 110 kDa. In general, between 30 and 40% of PBL were WCL6+ and appeared to be round to spindle-shaped cells. Immunohistochemical analysis of cryo-sections showed much higher numbers of WCL6+ cells in the spleen than in the pronephros, intestine and thymus. Flow cytometric analysis of cell suspensions isolated from these organs only revealed WCL6+ cells (4–10%) in the spleen. Electron microscopy of immunogold-stained WCL6+ PBL showed round but also some spindle-shaped cells with canalicular and granular structures, and a more irregular and electron-dense nucleus than found in lymphocytes. WCL6+ cells with electrondense pyknotic nuclei (without a clear nuclear envelope) were found also and their frequency increased with the length of the isolation and staining procedure used. In the spleen, several differentiation steps of WCL6+ cells were found and hence the spleen seems to be the thrombopoietic organ in carp. Thrombocytes from blood could be activated with collagen; the collagen-activated cells showed a higher side (90°) scatter by flow cytometric analysis and finally considerable cell death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1996.tb00047.x
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  • 9
    Electronic Resource
    Electronic Resource
    Apoptosis and expression of bcl-2 protein are inverse factors influencing tumour cell turnover in primary carcinoid tumours of the lung (1998)
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Histopathology 33 (1998), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: This study evaluates potential regulating factors in primary pulmonary carcinoid tumours, 16 typical and four atypical samples, with special emphasis on apoptosis and the bcl-2 gene family. Furthermore, p53-related oncogenes were analysed in a search for associated biological parameters.〈section xml:id="abs1-2"〉〈title type="main"〉Methods and resultsThe in-situ end-labelling technique (ISEL) was used to determine apoptotic cells, in addition to immunohistochemical methods, which were used to investigate the expression of the Ki67 antigen (avidin–biotin complex (ABC) method) and bcl-2, bcl-x, p53, p21/waf1, p27 and mdm-2 proteins (catalysed reporter deposition (CARD) technique). The incidence of apoptotic tumour cells was significantly enhanced in typical carcinoids. The bcl-2 protein was expressed to a higher degree in atypical carcinoids, which displayed a higher proliferative capacity as well. In contrast, bcl-x was observed predominantly in so-called typical carcinoids. The tumour cell turnover index was the most distinguishing parameter between both entities. All carcinoid tumours failed to show a staining for p53, p21/waf, p27 and mdm-2 proteins.〈section xml:id="abs1-3"〉〈title type="main"〉ConclusionsThe different biological behaviour of the carcinoid tumours under study seems to be influenced by the bcl-2 gene family preventing programmed cell death. We speculate that this results in a more aggressive course in atypical carcinoid tumours.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1998.00466.x
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  • 10
    Electronic Resource
    Electronic Resource
    Fluorescence in-situ hybridization (FISH) reveals that in chronic myelogenous leukaemia (CML) following interferon-α therapy, normalization of megakaryocyte size is associated with the loss of bcr/abl translocation (1997)
    Oxford, UK : Blackwell Science Ltd
    Histopathology 31 (1997), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In addition to predominant granulocytic proliferation, bone marrow morphology in Philadelphia chromosome positive (Ph1+) CML is characterized by atypical dwarf or microforms of megakaryocytes. However, following therapy with interferon-α2b (IFN), these micromegakaryocytes occur less frequently. The purpose of this study was to elucidate whether the reappearance of normal megakaryocytes may be associated also with a reduction of the bcr/abl-positive cell clone.〈section xml:id="abs1-2"〉〈title type="main"〉Methods and results:Fluorescence in-situ hybridization (FISH) technique in combination with immunomorphometry (CD61) was performed on trephine biopsies. A total of 311 CD61-positive megakaryocytes, including precursors and atypical microforms, were evaluated in pre-treatment specimens derived from 11 patients with Ph1+ CML. A specific fusion site marking the bcr/abl translocation was found in 87% of megakaryocytes which showed a size of 169 ± 35 μm2. In untreated patients, atypical microforms (size 200 μm2) were observed in 66% of the total megakaryocytic population. Following IFN therapy 369 megakaryocytes could be analysed in sequential examinations and were found to display a significant decrease (63%) in positive fusion signals. In addition there was also a significant enhancement in average size (252 ± 66 μm2) reflecting a reduction in the number of micromegakaryocytes (43%). These findings were particularly conspicuous in three patients with a major to complete cytogenetic remission.〈section xml:id="abs1-3"〉〈title type="main"〉Conclusions:A normalization of megakaryocyte size following IFN therapy in CML is significantly associated with a loss of the bcr/abl translocation site and therefore indicates a (partial) recovery of normal haematopoiesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1997.2480853.x
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