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  • 1
    Electronic Resource
    Electronic Resource
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 82 (1999), S. 0 
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The compound Ba3Ca1.18Nb1.82O9-delta (BCN18) has been discussed recently as a promising high-temperature proton conductor. Oxygen loss under very reducing conditions has been determined quantitatively using thermogravimetry. The thermodynamic parameters DeltaH°O= 2.58 ± 0.06 eV and DeltaS°O= 1.06 × 10-3 eV/K provide a suitable thermodynamic description for the equation O×O right arrow ½O2+V··O+ 2e´. Enthalpy and entropy of the hydrogen absorption reaction have been determined indirectly for BCN18: DeltaH°H= -0.8 eV and DeltaS°H= -6.6 × 10-4 eV/K. Hydrogen absorption is, therefore, an exothermic process. Valence changes where Nb5++e´ right arrow Nb4+ also have been taken into account under reducing conditions.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillian Magazines Ltd.
    Nature 402 (1999), S. 548-551 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Asymmetric cell divisions can be generated by the segregation of determinants into one of the two daughter cells. In Drosophila, neuroblasts divide asymmetrically along the apical–basal axis shortly after their delamination from the neuroectodermal epithelium. Several proteins, including ...
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillan Magazines Ltd.
    Nature 397 (1999), S. 660-661 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The structural versatility of solid water has been reinforced by the identification of a metastable, crystalline phase called ice XII (ref. 1). It was obtained by cooling liquid water to 260 K at a pressure of 0.55 GPa. We have found ice XII in a completely different region of water's ...
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of the American Academy of Nurse Practitioners 11 (1999), S. 0 
    ISSN: 1745-7599
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 31 (1999), S. 237-241 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A new, simplified analytical model for the calculation of the signal-to-noise ratio (SNR) in multiwavelength erbium-doped fibre amplifier (EDFA) cascades is presented. Comparisons with numerical results give excellent agreement, confirming the validity of this model and its significance for optimising system parameters.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    World journal of urology 17 (1999), S. 249-252 
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract No published study to date has adequately addressed the quality of life (QOL) of intersexuals, although three studies reviewed some of these aspects. A tool specifically for studies in intersexuality is being developed. A pilot survey tested by this author using questions from a population-specific, standardized QOL survey tool was evaluated by use on a small sampling of an intersexual patient test population. The group comprised ten adult intersexuals with an average age of 34.2 years (range: 22–47 years). Survey results disclosed that all considered themselves healthy and physically active. Family relationships were described as generally good, though in discussion most showed some family problems that centered on gender issues. Six had many friends, three had some, and one had few. Eight of the ten had experienced orgasm. Only two felt they trusted doctors. All but one were partially or completely satisfied with their overall physical appearance. Those who had surgery were distressed by the appearance of their genitals, some expressing complete dissatisfaction. With development of sensitive survey tools reflecting the attitudes and concerns of this special population, important issues relating to intersexuality can be addressed.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Rezidivgliome ; WHO-Klassifikation ; Statische DNA-Zytometrie ; Proliferationsindex ; Rezidivfreies Intervall ; Key words Recurrent gliomas ; WHO-classification ; DNA-cytophotometry ; Proliferation index ; Recurrence-free interval
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary DNA-cytophotometry is one of the methods that may contribute to a more precise evaluation of the biological behaviour of tumours in addition to the WHO-classification. In this study 121 tumour specimens of 50 patients suffering from gliomas with one or up to three recurrencies were investigated. In all cases the histological type and WHO-grade and the Ki-67/MIB1 labeling index were determined. DNA cytophotometry was performed after single cell preparation on Feulgen-stained preparations, and the following parameters were calculated: stemline ploidy, 5c-exceeding rate, and 2c-deviation index. Statistical evaluation revealed a highly significant correlation between recurrence-free interval and WHO-grade only. The DNA parameters, however, furnished additional information about increasing genetic instability in the majority of the recurrencies independently of changes in the WHO-grade. They thus seem to be useful as additional parameters for the determination of glioma progression.
    Notes: Zusammenfassung Eine genaue Bestimmung der biologischen Wertigkeit glialer Tumoren erfordert über die WHO-Klassifikation hinaus die Entwicklung und den Einsatz von Spezialmethoden, wozu auch die DNA-Zytophotometrie gehört. In der vorliegenden Studie wurden an insgesamt 121 histopathologisch klassifizierten Proben von Gliomen bei 50 Patienten mit mindestens 1 und bis zu 3 Rezidiven eine Reihe von DNA-Parametern (Stammlinienploidie, 5c-exceeding rate, 2c-deviation index) nach Zellvereinzelung und Feulgen-Reaktion mittels statischer Feulgen-DNA-Zytometrie bestimmt. Daneben wurde die Proliferationsaktivität (immunhistochemischer Ki-67/MIB-1-labeling index) morphometrisch ermittelt. Diese Parameter wurden mit den WHO-Graden und der Länge der rezidivfreien Intervalle statistisch verglichen. In den Rezidiven sowohl mit ansteigendem als auch mit gleichbleibendem WHO-Grad fand sich eine statistisch signifikante Zunahme des 2c DI, der 5c ER und des Ki-67/MIB-1 LI. Dabei ergab sich eine hochsignifikante Korrelation zwischen den WHO-Graden und der Länge der rezidivfreien Intervalle p〈0,00001). Eine statistisch signifikante Korrelation zwischen den DNA- bzw. Proliferationsparametern ließ sich zur Länge des rezidivfreien Intervalls nicht, zum WHO-Grad nur im Falle der ersten Rezidive für die DNA-Parameter herstellen. Die Ergebnisse bestätigen die hohe prognostische Relevanz des WHO-Grades. Die Bestimmung der DNA-Parameter liefert insbesondere bei gleichbleibendem WHO-Grad zusätzliche Informationen über die zunehmende genetische Instabilität des Tumors, welche wie die zunehmende Proliferationsaktivität für die weitere Tumorprogression von Bedeutung ist.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 158 (1999), S. 362-366 
    ISSN: 1432-1076
    Keywords: Key words Type 1 diabetes ; Children ; Risk factors ; Case control ; Environmental
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to investigate environmental risk factors in the development of type 1 diabetes mellitus in a population-based case-control study. Parents of all patients with manifestation of type 1 diabetes between 1989 and 1994 in Vienna were asked to complete a questionnaire (n = 114). Control children (n = 495), matched for age and sex, were randomly recruited from all schools in Vienna. Fathers of diabetic children were significantly older at the time their children were born than fathers of control children (P = 0.015). Children with diabetes were more likely to be second- or third-born children (P 〈 0.05) and fewer went to kindergarten than the control group children (P = 0.007). No significant difference in duration of gestation, percentage of delivery by caesarean section, birth weight or length was found. Neonatal jaundice was more often observed in the patient group (P = 0.038). Breast feeding was reported by 82.7% of mothers of diabetic children and by 81% of mothers of control children, and the duration of breast feeding was longer in patients than in controls (n.s.). Conclusion In our study, the development of type 1 diabetes mellitus was associated with higher paternal age and neonatal jaundice. No correlation could be found with dietary intake of cow's milk products in early infancy, vaccination and other environmental factors.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-1084
    Keywords: Key words: Interventional MRI ; Diagnostic brain biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. The purpose of our study was to evaluate the feasibility and accuracy of brain biopsies performed within a vertically opened MR system. We worked with the interventional 0.5-T MR “SIGNA SP” (General Electric Medical Systems, Milwaukee, Wis.) with an integrated tracking device “Flashpoint Position Encoder” (Image Guided Technologies, USA). As a holding device for this instrument we constructed a special frame. The whole system allows an exact adjustment of an optimum biopsy direction and guidance of the biopsy in a non-stereotactic, interactive mode in near real-time. As biopsy tools we used MR-compatible aspiration and specially made side-cut needles (Daum, Germany; E-Z-EM, USA). We performed a prospective diagnostic brain biopsy study in 18 patients. Guidance of the needle was carried out using gradient-echo single-slice technique. The sample was taken after controlling the exact position of the needle tip on spin-echo images. In 12 cases an exact neuropathological diagnosis was possible. In 6 cases of negative biopsy (4 aspiration biopsies) the samples were not representative. Our results demonstrate the feasibility of interactive MR-guided minimally invasive brain biopsies in an open MR system. The best results were achieved using cut needles for biopsies of contrast-enhancing lesions visible on T1-weighted gradient-echo guidance sequence.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-0711
    Keywords: Key words Contraceptive knowledge in adolescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  The aim of the survey was to determine the contraceptive behavior and knowledge on contraceptive methods of adolescents. We defined six clusters according to personality, leisure activities, and sociodemographic characteristics: conventionalists, careerists, idealists, bouncers, desperadoes, and outsiders. 1010 Austrian adolescents aged 14–24 years participated in the survey. 96%–100% indicated that they were familiar with the condom and the contraceptive pill. The two most popular contraceptive methods cited were the condom (39%) and OC (34%). Whereas 40% of conventionalists reported that OC were their preferred method of contraception, 53% of idealists indicated that they preferred the condom. 66% of the desperadoes indicated that they considered the pill expensive. 85% of conventionalists and careerists believe that OC offer the best protection against pregnancy. Clusters with higher self-esteem and those with a higher educational level were more likely to believe that this method is unreliable. The results obtained indicate that outsiders, desperatoes, and bouncers show deficits in sex education; only careerists and idealists appeared to be better informed. Research on adolescent contraceptive behavior should drop the traditional stratifying criteria and appreciate the diversity of adolescent populations in order to be better able to classify adolescents according to their contraceptive attitudes.
    Type of Medium: Electronic Resource
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