Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles: DFG German National Licenses  (13)
  • 2000-2004  (13)
  • 1970-1974
  • 2000  (13)
  • 1
    Electronic Resource
    Electronic Resource
    Photoacoustic and photoluminescence studies of porous silicon etched by low-concentration hydrofluoric acid (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 6444-6450 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We applied photoacoustic (PA), photoluminescence (PL), photoluminescence excitation (PLE), and atomic force microscopy (AFM) techniques on porous silicon (PS) layers to study the influence of chemical etching by low-concentration hydrofluoric acid. The chemical etching reveals the formation of PS layers of small dimensions by AFM observations, indicating the possibility of a strong quantum confinement effect. PA spectroscopy is useful to obtain the optical absorption characteristic for strongly scattering media such as PS and it helps to confirm the above speculation by indicating the blueshift of the fundamental absorption edge for the PS layer with chemical etching. PL spectroscopy also confirms the possibility of a quantum confinement effect by revealing the strong intensity and blueshift for the PS layer with chemical etching. PLE measurements suggest that the site for the radiative processes is different from that for the recombination of carriers and the PL of PS layers were dominated only by small crystallites in various size distributions. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1289220
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Local capacitance measurements on InAs dot-covered GaAs surfaces by scanning capacitance microscopy (2000)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 1994-1996 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Capacitance images responsible for surface depletion were observed on an InAs dot-covered GaAs surface by scanning capacitance microscopy. We performed local capacitance versus bias voltage measurements on quantum dots (QDs) and a wetting layer (WL) as well as conductance versus bias voltage (G–V) measurements. Both results indicate that the surface depletion is more suppressed beneath the QDs than under the WL. In addition, the conventional thermionic equation theory fitted to the measured G–V curves shows that the interface barrier height between the GaAs and the InAs QD increases as the QD size is reduced. We ascribe this result to the influence of the surrounding WL, whose surface Fermi level is strongly pinned at the midgap of the n-GaAs. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1312257
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Dental rehabilitation using endosseous implants and orthognathic surgery in patients with cleft lip and palate: report of two cases (2000)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 27 (2000), S. 0 
    Details
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We describe the use of endosseous implants in the autogenous particulate cancellous bone and marrow grafted alveoli after orthognathic surgery for dental rehabilitation of patients with cleft lip and palate. This procedure has been applied to two patients and produced good results functionally and aesthetically. The results are encouraging and indicate that implant placement after orthognathic surgery is useful for patients both with congenital missing teeth and retrognathic maxillae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2842.2000.00539.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    X-ray diffraction from an atomic plane (2000)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 56 (2000), S. 163-167 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Reflection and transmission coefficients of X-rays by a single atomic plane are obtained in the general case where the plane consists of any two-dimensional Bravais lattice and the incident and exit X-ray beams take any direction with respect to the plane. A formula obtained for the coefficients is written in a simple form, different from that obtained by Durbin [Acta Cryst. (1995), A51, 258–268]. This makes it possible to extend Darwin's dynamical theory of X-ray diffraction to general geometries which include the cases of asymmetric skew reflection and noncoplanar multibeam diffraction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108767399015068
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Dual-beam ablation of fused silica by multiwavelength excitation process using KrF excimer and F2 lasers (2000)
    Springer
    Applied physics 71 (2000), S. 23-26 
    Details
    ISSN: 1432-0630
    Keywords: PACS: 42.60; 81.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract. A new technique of dual-beam laser ablation of fused silica by multiwavelength excitation process using a 248-nm KrF excimer laser (ablation beam) coupled with a 157-nm F2 laser (excitation beam) in dry nitrogen atmosphere is reported. The dual-beam laser ablation greatly reduced debris deposition and, thus, significantly improved the ablation quality compared with single-beam ablation of the KrF laser. High-quality ablation can be achieved at the delay times of KrF excimer laser irradiation shorter than 10 ns due to a large excited-state absorption. The ablation rate can reach up to 80 nm/pulse at the fluence of 4.0 J/cm2 for the 248-nm laser and 60 mJ/cm2 for the F2 laser. The ablation threshold and effective absorption coefficient of KrF excimer laser are estimated to be 1.4 J/cm2 and 1.2×105 cm-1, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003390050020
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Pupillary dilation response as an indicator of auditory discrimination in the barn owl (2000)
    Springer
    Journal of comparative physiology 186 (2000), S. 425-434 
    Details
    ISSN: 1432-1351
    Keywords: Key words Habituation ; Frequency discrimination ; Minimum audible angle ; Sound localization ; Psychoacoustics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The pupil of an awake, untrained, head-restrained barn owl was found to dilate in response to sounds with a latency of about 25 ms. The magnitude of the dilation scaled with signal-to-noise ratio. The dilation response habituated when a sound was repeated, but recovered when stimulus frequency or location was changed. The magnitude of the recovered response was related to the degree to which habituating and novel stimuli differed and was therefore exploited to measure frequency and spatial discrimination. Frequency discrimination was examined by habituating the response to a reference tone at 3 kHz or 6 kHz and determining the minimum change in frequency required to induce recovery. We observed frequency discrimination of 125 Hz at 3 kHz and 250 Hz at 6 kHz – values comparable to those reported by others using an operant task. Spatial discrimination was assessed by habituating the response to a stimulus from one location and determining the minimum horizontal speaker separation required for recovery. This yielded the first measure of the minimum audible angle in the barn owl: 3° for broadband noise and 4.5° for narrowband noise. The acoustically evoked pupillary dilation is thus a promising indicator of auditory discrimination requiring neither training nor aversive stimuli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003590050442
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Dome-shaped proximal tibial osteotomy using percutaneous drilling for osteoarthritis of the knee (2000)
    Springer
    Archives of orthopaedic and trauma surgery 120 (2000), S. 32-37 
    Details
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have improved a surgical technique for proximal tibial osteotomy that involves percutaneous drillings. We performed the modified dome-shaped proximal tibial osteotomy on 44 knees in 42 patients (8 men and 34 women) with an average age of 66 years (range 50–78 years) for osteoarthritis of the knee. The mean follow-up period was 39 months (range 24–63 months). The varus angle was 4°± 3.6° (mean ± SD) preoperatively, and the valgus angle was 12°± 3.3° postoperatively. Pain relief was obtained in all cases postoperatively. Transient pin tract infection occurred in one case, but it resolved completely following local irrigation. Intercondylar fracture of the upper fragment with no displacement was noted in two patients. They were treated with AO cancellous screw fixation, and improvement of pain was obtained in both cases. Osteotomy drill guide instruments are useful for accurately performing dome-shaped osteotomy. Our proximal tibial dome osteotomy with an external fixator allowed early motion and accurately maintained the angle of correction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004020050435
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Cyclosporine A-associated fatal central nervous system angiopathy in a bone marrow transplant recipient: an autopsy case (2000)
    Springer
    Acta neuropathologica 99 (2000), S. 680-684 
    Details
    ISSN: 1432-0533
    Keywords: Key words Basilar artery ; Vasoconstriction ; Cyclosporine A ; Bone marrow transplantation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report here the case of a 32-year-old woman who suffered from a unique angiopathy in the central nervous system (CNS). She died of multiple infarcts in the brain stem and cerebellum during treatment with cyclosporine A after bone marrow transplantation for refractory anemia with excess of blasts. The autopsy findings showed segmental narrowing of the basilar artery, in which circumferential dissection of the internal elastic lamina had occurred. The distal portion of the basilar artery was obstructed by upward dislocation of the dissected intima. Similar angiopathy was also observed at multiple sites along the basilar artery branches. These findings suggest endothelial damage, including vasoconstriction and dissection of the CNS arteries.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010051179
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Cloning and expression of the chicken immunoglobulin joining (J)-chain cDNA (2000)
    Springer
    Immunogenetics 51 (2000), S. 85-91 
    Details
    ISSN: 1432-1211
    Keywords: Key words J chain ; Polymeric immunoglobulin ; Ontogeny ; Evolution ; Comparative immunology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The J chain is a component of polymeric immunoglobulin (Ig) molecules and may play an important role in their polymerization and the transport of polymeric Ig across epithelial cells. In this study, the primary structure of the chicken J chain was determined by sequencing cDNA clones. The cDNA had an open reading frame of 476 nucleotides encoding a putative protein of 158 amino acid residues including the signal sequence. The 3′ untranslated region consisted of 1216 nucleotides and a poly(A) tail. The deduced amino acid sequence of the chicken J chain had a high degree of homology to that of human, cow, rabbit, mouse, frog, and earthworm, with eight conserved Cys residues identical to the mammalian J chains. Northern blot hybridization performed with total RNA from various chicken tissues revealed high levels of J-chain mRNA expression in spleen, intestine, Harderian gland, and bursa of Fabricius, and low levels in the thymus. The J chain was expressed in the bursa as early as day 15 of embryogenesis. These data indicated that the chicken J-chain gene displays a high degree of homology with that of other species, and is expressed at an early stage of development of the chicken immune system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050016
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Role of nuclear factor-κ B in the expression by tumor necrosis factor-α of the human polymeric immunoglobulin receptor (pIgR ) gene (2000)
    Springer
    Immunogenetics 51 (2000), S. 289-295 
    Details
    ISSN: 1432-1211
    Keywords: Key words Human ; Mucosa ; Gene regulation ; Cytokines ; Transcription factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  We analyzed the mechanism of human polymeric immunoglobulin receptor (pIgR) gene upregulation by tumor necrosis factor (TNF)-α. Northern blot analysis showed that the expression of pIgR mRNA was enhanced by TNF-α stimulation. This activation was completely inhibited by RNA polymerase or protein synthesis inhibitors, suggesting that the regulation of pIgR gene expression depends on de novo RNA and protein synthesis. Furthermore, the stimulation of pIgR mRNA by TNF-α was decreased by pyrrolidinedithiocarbamate and l-1-4′-tosylamino-phenylethyl-chloromethyl ketone, which are known nuclear factor (NF)-κB inhibitors. For further analysis of gene regulation, we cloned and sequenced the 1.5-kb 5′-flanking region of the pIgR gene. In the upstream region, we found two NF-κB-binding motifs (named κB1 and κB2 from the 5′ region). An electrophoretic mobility shift assay indicated that two components of the NF-κB/Rel family, p50 and p65, bound with higher affinity to the κB2 element than to the κB1 element. We also analyzed pIgR gene expression using reporter plasmids expressing the firefly luciferase gene. Stimulation by TNF-α significantly activated the pIgR gene promoter, as a 775-bp upstream region of the pIgR gene increased luciferase gene expression in cells treated with TNF-α. The activation of promoter activity by TNF-α was abolished when a mutation was inserted into κB1 or κB2. These data indicated that pIgR gene expression induced by TNF-α is transcriptionally regulated via activation of NF-κB. In addition, there is a possibility that another factor may act in concert with NF-κB.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050622
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...