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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 1311-1314 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The effect of thermal annealing on the InAlAs/InGaAs modulation-doped structure, passivated with a SiN film, was investigated. In contrast to the capless sample, the passivated modulation-doped sample exhibited negligible degradation in the two-dimensional electron gas concentration (NS) after annealing at 280 °C, indicating that SiN is an efficient passivation material to ensure good thermal stability for the InAlAs/InGaAs modulation-doped structure. In addition, partial recovery in NS was found by annealing the SiN-passivated sample that had experienced serious NS degradation. A series of secondary ion mass spectroscopy (SIMS) measurements and Hall effect measurements revealed that the recovery of NS is associated with the discharge of fluorine atoms from the Si-doped n-type InAlAs layer. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    BJOG 84 (1977), S. 0 
    ISSN: 1471-0528
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The levels of human placental lactogen (HPL) in the serum of expectant mothers both subjected to and not subjected to aircraft noise were measured. The HPL levels in the quiet reference area and in the noise area were similar before the 29th week of pregnancy. However, the HPL levels of subjects in the noise area tended to be lower than those in the reference area after the 30th week of pregnancy and the difference became significant after the 36th week of pregnancy. The lower HPL levels were associated with lower birth weight for infants of mothers who lived in the noise area.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 3743-3745 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Considerable relaxation of the high internal stresses which arise in HfN thin films during their deposition by a sputtering method has been accomplished through bombarding the films with energetic silicon ions. The internal stresses have been estimated from the measurements of the surface curvature. Our results indicate a relaxation of the internal compressive stresses in the films, which occurs via a transport of the interstitial defects within the thermal spikes created by a post-deposition energetic ion bombardment. The mechanical properties of HfN films before and after the treatment have been studied by depth-sensing indentation technique while the structural analysis has been made using x-ray diffraction, Rutherford backscattering, and Auger electron spectroscopy. Ion bombardment did not affect resistivity of the thin films while improving their plastic properties. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1440-1797
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    British journal of dermatology 141 (1999), S. 0 
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: In order to determine whether adrenal and gonadal weak androgens are utilized to form active androgens in human hair, we studied the expression of mRNA for androgen receptor (AR), 5α-reductase and 17β-hydroxysteroid dehydrogenase (17β-HSD) in cultured dermal papilla cells (DPCs) from various body sites. AR mRNA was expressed in beard (Be) and axillary hair (Ax) DPCs from both sexes, but only at a low level in DPCs from occipital scalp hair (OS). Type I 5α-reductase mRNA was expressed by all DPCs. Type II 5α-reductase mRNA was identified in beard DPCs, but was absent from OS and Ax DPCs. Type II 17β-HSD mRNA was strongly expressed in outer root sheath cells (ORSCs), while DPCs except for male Ax expressed no type II 17β-HSD mRNA. In contrast, type III 17β-HSD mRNA was strongly expressed in Be DPCs and Ax DPCs from both sexes; ORSCs showed a low level of expression. Expression of type III 17β-HSD mRNA was not regulated by androgen in DPCs. These results suggest that the sensitivity of hairs to androgen is partially controlled by the site-specific expression of AR, 5α-reductase and 17β-HSD in DPCs.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-8798
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary. Although human cytomegalovirus (HCMV) predominantly infects epithelial cells in vivo, the majority of studies of HCMV gene expression and replication have been conducted using non-epithelial cell lines in part because of the absence of a good experimental system using epithelial cells. To address the nature of epithelial cell infection, we investigated the susceptibility of an epithelial cell line (K-1034) established from the retinal pigment epithelium to HCMV infection. This cell line exhibited high susceptibility to HCMV, as evidenced by detection of one of the immediate early antigens, IE2, in the nuclei of more than 80% of K-1034 cells at 24 h following inoculation at a multiplicity of infection of 3 plaque forming units per cell. However, the yield after one-step growth of HCMV in K-1034 cells was about twenty-fold less than that in human embryonic lung fibroblast cells. Cytopathic effect (CPE) on K-1034 cells was not prominent in medium supplemented with 10% fetal bovine serum and viral late antigens were detected in less than 5% of K-1034 cells. Interestingly, infected cells expressing late antigens and exhibiting CPE were markedly increased in serum-free medium, even though the yield of infectious HCMV and viral genome copy numbers were almost the same in the different serum concentrations, due to viral instability in the absence of serum. Thus, the progression of late antigens expression and the induction of CPE in infected epithelial cells is influenced by physiological conditions, and are negatively regulated by some serum factor.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-1041
    Schlagwort(e): Key words Carboplatin ; Irinotecan ; Limited sampling model ; Pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract Objectives: The aim of this study was to develop limited sampling models for estimating the area under the concentration-versus-time curve (AUC) of carboplatin. Methods: Based on pharmacokinetic analyses of 14 patients who received 300 mg · m2 of carboplatin over a 90-min infusion following irinotecan, we developed limited sampling models with stepwise multiple linear regression analysis. We validated these models to be unbiased and precise using pharmacokinetic data of a second group of 14 patients. We also compared the observed and the predicted AUC in the patients using Calvert's formula with the patients' renal function. Results: We developed the following models: AUC (mg · ml−1 · min) = 0.784 × C4 + 1.30 (r 2 = 0.930) and AUC = 0.100 × C0.25 + 0.597 × C4 + 0.140 (r 2 = 0.992), where C0.25 and C4 denote unbound plasma concentrations (μg · ml−1) of carboplatin at 0.25 h and 4 h after the end of infusion, respectively. These models were validated to be unbiased and precise: a mean prediction error (MPE) with standard deviation (SD) = 2.41 (9.45)% and a root mean squared error (RMSE) = 9.42% for the one-sample model, and MPE with (SD) = 1.22 (5.56)% and RMSE = 5.49% for the two-sample model. We also calculated predicted AUC in the patients using Calvert's formula: MPE with (SD) =−5.87 (21.5)% and RMSE = 21.5%. Conclusions: These estimations were, as expected, more accurate than the prediction using Calvert's formula based on patients' renal function. The result of this study confirmed the idea that the pharmacokinetic parameters derived from limited sampling models would be more suitable for pharmacokinetic analysis of carboplatin than those obtained using Calvert's formula.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    European radiology 9 (1999), S. 1197-1202 
    ISSN: 1432-1084
    Schlagwort(e): Key words: Sleep apnea syndrome ; MR fluoroscopy ; Low-field MR imaging ; Upper airway obstruction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract. The aim of this study was to assess the upper airway status of sleep apnea syndrome (SAS) patients with low-field MR fluoroscopy. Twenty patients with clinically diagnosed SAS underwent upper airway monitoring using MR fluoroscopy for 5 min while awake and for 30 min while asleep. A 0.064-T permanent-magnet MR imaging system was used for the study. No patients required any sedative drugs because of the very small gradient noise, except in one case. No occlusion was observed while patients were awake. Nine patients showed repeated occlusion at retropalatal (Rp) pharynx, whereas 11 demonstrated both simple Rp occlusion and combined retropalato–retroglossal (Rp + Rg) occlusions (complex occlusion). The mean frequency of occlusion in complex cases was significantly higher than that in simple Rp cases (p 〈 0.05). Low-field MR fluoroscopy was useful in determining the occlusion level while asleep in patients with SAS because of its quiet gantry and long-term monitoring capability. The MR fluoroscopy technique should prove to be a valuable clinical tool for the diagnosis and for determining the appropriate therapy in patients with SAS.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-1084
    Schlagwort(e): Fallopian tubes ; Fallopian tube recanalisation ; Radiation ; Salpingography ; Sterility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Clinical results of fluoroscopic fallopian tube catheterisation and absorbed radiation doses during the procedure were evaluated in 30 infertility patients with unilateral or bilateral tubal obstruction documented on hysterosalpingography. The staged technique consisted of contrast injection through an intraurine catheter with a vacuum cup device, ostial salpingography with the wedged catheter, and selective salpingography with a coaxial microcatheter. Of 45 fallopian tubes examined, 35 (78%) were demonstrated by the procedure, and at least one tube was newly demonstrated in 26 patients (87%). Six of these patients conceived spontaneously in the follow-up perod of 1–11 months. Four pregnancies were intraurine and 2 were ectopic. This technique provided accurate and detailed information in the diagnosis and treatment of tubal obstruction in infertility patients. The absorbed radiation dose to the ovary in the average standardised procedure was estimated to be 0.9 cGy. Further improvement in the X-ray equipment and technique is required to reduce the radiation dose.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Applied physics 67 (1998), S. 23-27 
    ISSN: 1432-0630
    Schlagwort(e): PACS: 81.40.-z; 81.40.Rs; 76.30.-v
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Maschinenbau , Physik
    Materialart: Digitale Medien
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