Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Effect of Yb3+ doping on upconversion emission intensity and mechanism in Er3+/Yb3+-codoped fluorozirconate glasses under 800 nm excitation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 6143-6149 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Er3+ singly- and Er3+/Yb3+-codoped fluorozirconate glasses were prepared. The upconversion emission intensities of the Er3+ ion around both 550 and 660 nm were measured under 800 nm excitation. The absorption band of the Yb3+ ion is located around 980 nm. Though the absorption band of Yb3+ does not interact directly with the incident light at 800 nm, both upconversion intensities around 550 and 660 nm emission increased with the increasing YbF3 concentration. We calculated the upconversion intensities around 550 and 660 nm by using rate equations and evaluated the principal upconversion mechanism in Er3+ singly- and Er3+/Yb3+-codoped samples quantitatively. We also investigated the reason for the increase of the upconversion emission intensities with the codoping of Yb3+ under 800 nm excitation. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.371666
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Breakdown and destruction of heterogeneous solid dielectrics by high voltage pulses (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 6262-6267 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A mechanism explaining the breakdown of dielectrics with high intrinsic inhomogeneity like natural rocks and concrete is proposed and proved experimentally. This work has a very promising industrial application in the drilling and demolition of natural and artificial solid materials by electric pulses. The mechanism includes the breakdown of gas cavities inside the dielectric and on its surface. At a very high applied voltage, the high electric field causes the breakdown in the cavities. The displacement and conduction currents flowing through a number of such cavities result in the heating of the plasma and high pressure pulse generation. The pulsed pressure results in crack formation and finally, in the destruction of a solid material. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.368946
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Upconversion mechanism in Er3+-doped fluorozirconate glasses under 800 nm excitation (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 29-37 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The upconversion emission intensities of Er3+ ion around 550 and 660 nm in fluorozirconate glasses were measured under 800 nm excitation. Though energy transfer processes played an important role in upconversion mechanism at high concentration of ErF3, those have not been treated quantitatively. The energy transfer rates were calculated from the optical parameters assuming some distribution of Er3+ ions. We calculated the upconversion intensities around 550 and 660 nm by using rate equations. It was found that the dependence of upconversion emission intensities on the ErF3 concentration could be reproducible and the principal upconversion mechanism could be evaluated. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.369445
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Electromyographic study of the activity of jaw depressor muscles before initiation of opening movements (1999)
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 26 (1999), S. 0 
    Details
    ISSN: 1365-2842
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The authors attempted to clarify the primary factors affecting the timing of the initial electromyographic discharges in the jaw depressor muscles (EMG onset). The changes in EMG onset in the inferior head of the lateral pterygoid (Lpt) and the anterior belly of the digastric muscles (Dig) were measured by varying duration of the open–close movement or occlusal force during the open–close–clench cycle (OCC). EMG onset tended to precede the beginning of the opening movement during OCC. The duration of opening and closing phase and the duration of occluding phase showed no significant correlation with the time-lag between EMG onset and the beginning of the opening movement (onset time).The mean EMG activity of the masseter muscle (Mm), corresponding to the occlusal force, showed a highly significant correlation with the onset time. The maximal opening velocity was highly correlated with the mean EMG activity of the jaw depressors before jaw opening. In conclusion, it was found that occlusal force is a major factor in EMG onset in the jaw depressors. It is suggested that smooth opening needs tooth contact with some degree of occlusal force.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2842.1999.00401.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Radiographic evaluation of the lumbosacral disc height (1999)
    Springer
    Skeletal radiology 28 (1999), S. 638-643 
    Details
    ISSN: 1432-2161
    Schlagwort(e): Key words Lumbar spine ; Disc space narrowing ; Radiographs ; Disc degeneration ; Instability
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract  Objective. To establish criteria for the radiographic evaluation of narrowing of the L5–S1 disc height, which varies widely with transition of the L5 vertebra. Design and patients. Nondegenerated disc heights of L3–4 to L5–S1 and the thickness and length of the L5 transverse process were measured on plain radiographs of the lumbar spine in 166 outpatients, aged 18–35 years (mean 26.3 years), in whom at least the L3–4 and L5–S1 discs both showed normal signal intensity on magnetic resonance imaging. The level of the iliac crest was recorded semiquantitatively. The disc height was expressed as a percentage of the L3–4 disc height, namely ”relative disc height”. The ratio of disc height to the sagittal diameter of the overlying vertebral body was termed the ”disc height index”. Results and conclusion. The relative disc height and disc height index of L5–S1 showed strong negative correlations with two anatomic variables, which were the relative thickness of the transverse process and the level of the iliac crest (P〈0.0001). The results of linear regression analysis suggest that narrowing of the L5–S1 disc height can be evaluated on plain radiographs alone in relation to these anatomic variables.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002560050566
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Expression of CD44 variants in osteosarcoma (1999)
    Springer
    Journal of cancer research and clinical oncology 125 (1999), S. 646-652 
    Details
    ISSN: 1432-1335
    Schlagwort(e): Key words Osteosarcoma ; CD44 ; Immunohisto-chemistry ; Prognosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract The standard form of CD44 (CD44H) is a transmembranous glycoprotein, widely distributed on a variety of human lymphoid cells, epithelial cells and tumours. CD44 has many variant forms, which are generated by alternative splicing. In recent years, CD44 has been reported to be related to the degree of tumour differentiation, tumour cell invasion, and metastasis. We investigated 44 tumour specimens in 39 patients with osteosarcoma immunochemically to analyse the expression of CD44 standard (CD44H) and variant exon-encoded gene products (CD44v3, v4, v5, v6, v7, v9, and v10). Furthermore, the relationship between CD44 expression and the clinical outcome of patients with osteosarcoma was analysed. Membrane accentuation and exclusive cytoplasmic reactivity were analysed as separate staining patterns. Tumour cells and some multinucleated giant cells were markedly stained. CD44H, v3, v4, v5, v6, v7, v9, and v10 were expressed in 85%, 49%, 54%, 59%, 46%, 5%, 28%, and 10% of the specimens respectively. The cumulative 5-year metastasis-free survival was 58% in CD44v6-negative cases and 24% in CD44v6-positive cases (P=0.046). However, the cumulative 5-year metastasis-free survival was not significantly different between cases positive and negative for other variants of CD44. Multivariate analysis (Cox proportional-hazard model) with CD44v6 expression (positive or negative), chemotherapy (intensive or non-intensive), tumour site (proximal or distal), and age (at least 30 years or less than 30 years) showed that expression of CD44v6 and chemotherapy were important prognostic factors in patients with osteosarcoma. Overexpression of CD44 isoforms containing variant v6 is correlated with poor prognosis in patients with osteosarcoma.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s004320050329
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Polyostotic fibrous dysplasia (1996)
    Springer
    International orthopaedics 20 (1996), S. 227-232 
    Details
    ISSN: 1432-5195
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé. L’évolution de la maladie chez 8 patients présentant une dysplasie fibreuse diffuse suivie plus de 10 ans (moyenne 19,5 ans) a été annalysée rétrospectivement. Un patient avait un syndrome d’Albright. Deux des trois lésions du fémur proximal chez les patients qui eurent soit un curetage et une greffe osseuse, soit une ostéotomie avant la puberté ont été le siège d’une aggravation de la déformation pendant la croissance. Une des deux lésions du fémur proximal chez des patients qui eurent un curetage et une greffe osseuse après l’âge de 18 ans, furent le siège d’une déformation. Deux lésions du tibia qui ont été opérées à l’âge de 1 et de 30 ans sont ensuite restées stables. L’aspect histologique était plus actif dans les lésions des patients jeunes que chez ceux ayant terminé leur croissance.
    Notizen: Summary. Eight patients who had polyostotic fibrous dysplasia were followed up for more than 10 years. One had the Albright syndrome. Two of 3 proximal femoral lesions which were treated before puberty by either curettage and bone grafting or by osteotomy, developed progressive deformity during the growth period. One of 2 proximal femoral lesions treated by curettage and bone grafting after the age of 18 also developed a deformity. Two tibial lesions operated on at the age of one and 30 years remained stable. The histological findings showed more active lesions in young patients compared with adults.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002640050069
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Reconstruction of the hip abductors after resection of the proximal femur (1999)
    Springer
    International orthopaedics 23 (1999), S. 182-183 
    Details
    ISSN: 1432-5195
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé  3 patients opérés pour tumeur maligne de l’extrêmité proximale du fémur ont eu l’implantation d’une endo-prothèse avec reconstruction de la capsule articulaire et des abducteurs par un filet synthétique.
    Notizen: Abstract  Three patients with malignant bone tumors of the proximal femur underwent implantation of an endoprosthesis with reconstruction of the joint capsule and hip abductors using artificial mesh.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002640050342
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Magnetic resonance chemical shift imaging in bone and soft tissue tumours (1997)
    Springer
    International orthopaedics 21 (1997), S. 9-13 
    Details
    ISSN: 1432-5195
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé. Ce travail étudie la localisation tumorale et le diagnostic des tumeurs de l’os et des parties molles par la technique de Dixon (technique 3 PD) qui sépare, en résonance magnétique, les signaux d’origine graisseuse ou hydrique. Nous comparons les résultats obtenus par cette technique avec résonance magnétique conventionnelle et utilisation de Gadolinium qui réhausse les images pondérées en T1. Cette étude a été faite dans 14 cas de tumeur de l’os et des parties molles avec un appareil à 0.5 Tesla. La localisation des tumeurs était améliorée par la méthode de Dixon comparée à la résonance magnétique conventionnelle. La différenciation entre les composants hydriques ou graisseux fut aussi possible. Des images obtenues avec Gadolinium étaient très sensibles pour le réhaussement des tissus. La technique 3 PD est utile quand la détection de la zone tumorale est difficile et quand des informations sur les composants tumoraux sont nécessaires. De plus, ces images peuvent être obtenues avec un champ magnétique de faible intensité.
    Notizen: Summary. A study was carried out in 14 patients to assess the location and differential diagnosis of bone and soft tissue tumours with a 0.5 Tesla scanner, using water and fat images obtained by the three-point Dixon technique. We compared the magnetic resonance imaging findings obtained with this technique with conventional MRI, T1- T2-weighted images, and gadalinium-diethylenetriamine penta-acetic acid enhanced T1-weighted images. Localisation was better with the three-point Dixon technique than with conventional magnetic resonance imaging. Differentiation between the fat and water component around the tumour was possible. The gadalinium-diethylenetriamine penta-acetic acid enhanced water images were very sensitive to enhancement of the tissue. The three-point Dixon technique is useful when the tumour area is difficult to detect by conventional magnetic resonance imaging and information about its components is needed; these images can be made at the low magnet field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002640050109
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Immunohistochemically demonstrated variation in expression of cathepsin E between uracil-induced papillomatosis and N-butyl-N-(4-hydroxybutyl)nitrosamine-induced preneoplastic and neoplastic changes in rat urinary bladder (1996)
    Springer
    Virchows Archiv 427 (1996), S. 589-594 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Cathepsin E ; Uracil ; N-Butyl-N-(4-hydroxybutyl)nitrosamine ; Rat urinary bladder carcinogenesis ; Papillomatosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Expression of rat urinary bladder cathepsin E in benign papillomatosis induced by uracil and various stages of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced carcinogenesis was investigated immunohistochemically. Seven-week-old, male F344/DuCrj rats were used. In the normal urothelium of control rats, cathepsin E stained in all layers of cells, although in umbrella cells and some basal cells the reaction was relatively weak. In rats given a diet containing 3% uracil for 5 weeks immunoreactivity of cathepsin E in uracil-induced papillomatosis was consistently homogeneous in all layers, but weaker than in normal urothelium. In rats given 0.05% BBN in drinking water for 12 weeks and subsequently maintained without treatment for 48 weeks cells with little cathepsin E, never observed in normal urothelium, appeared at 5 weeks above the basement membrane in the earliest stage of BBN-induced urinary bladder cancer (simple hyperplasia). Throughout the neoplastic process, groups of cells with a little cathepsin E were randomly distributed, with expression in the urothelium being markedly unstable. Almost all areas of squamous cell proliferation in TCC were negative for cathepsin E. Instability of cathepsin E expression in rat urothelium therefore appears characteristic for carcinogenesis and offers the possibility of using this feature as an early biomarker for urinary bladder carcinogenesis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00202890
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...