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  • 1
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 3215-3217 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The depth distribution of Ge implanted into thermally grown SiO2 films has been studied after annealing using transmission electron microscopy, Rutherford backscattering spectrometry, and x-ray diffraction. At annealing temperatures above 900 °C a significant redistribution of the as-implanted Ge profile was found. Crystalline Ge nanoclusters embedded in the SiO2 matrix are formed within a cluster band with well defined boundaries. The evolution of nanoclusters can be explained qualitatively by a model based on nucleation, growth and Ostwald ripening of Ge precipitates. Besides, chemical and interface reactions lead to the formation of additional Ge peaks near the surface and at the Si/SiO2 interface. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 1862-1879 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Ultrafast state-selective dynamics of diatomic molecules in the electronic ground state under the control of infrared picosecond and femtosecond shaped laser pulses is investigated for the discrete vibrational bound states and for the dissociative continuum states. Quantum dynamics in a classical laser field is simulated for a one-dimensional nonrotating dissociative Morse oscillator, representing the local OH bond in the H2O and HOD molecules. Computer simulations are based on two approaches — exact treatment by the time-dependent Schrödinger equation and approximate treatment by integro-differential equations for the probability amplitudes of the bound states only. Combination of these two approaches is useful to reveal mechanisms underlying selective excitation of the continuum states and above-threshold dissociation in a single electronic state and for designing optimal laser fields to control selective preparation of the high-lying bound states and the continuum states. Optimal laser fields can be designed to yield almost 100% selective preparation of any prescribed bound state, including those close to the dissociation threshold. State-selective preparation of the highest bound state may be accompanied by the appearance of a quasi-bound molecular state in the continuum with the kinetic energy of the fragments being close to zero. The respective above-threshold dissociation spectrum contains an additional, zero-order peak. The laser-induced dissociation from selectively prepared high-lying bound states is shown to be very efficient, with the dissociation probability approaching the maximal value. Flexible tools of state-selective laser control are developed which enable one to achieve selective control of the dissociation spectra resulting in time-selective and space-selective control of the dissociation fragments. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Cord blood (CB) as a new source for bone marrow transplantation represents advantageous features concerning stem cell and leucocyte compartments and function. We attempted to get more information about the phenotypes and function of CB cells by investigating their cell surface markers and also the production of IL-2, IFN-γ and IL-6 by mitogen and alloantigen stimulation. The CB cells were characterized by a low proportion of CD3+ T cells, CD4+ T subpopulation, activated T cells and CD3+ CD16/CD56+ cytotoxic cells, suggesting reduced graft versus host potential. The significant increase of CD19/CD3 double positive cells and decrease of CD19/HLA-DR double positive mature B cells reflect that immature B cells exist in CB. In the functional studies, a 27- and 5-fold reduction was observed in the production of IFN-γ by CB cells stimulated with PHA and allogeneic cells, respectively. The production of IL-2 in PHA-stimulated CB cells also showed a 50% determination. Decrease in the production of these cytokines by CB cells is supported by the decline of the proportion of CD3+ T cells. However, an increase was observed in the production of IL-6 by CB cells stimulated with allogeneic cells as compared with the controls. These results suggest a difference in the functional activity of the T helper cell subsets between the CB and peripheral blood and/or differences in the functional maturity of T helper cell subsets and B cells in these compartments.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1365-3180
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: The biconversion of [14C]atrazine to deaikyt-ated and hydroxylated products was studied in heteroirophic cell-suspension cultures of carrot (Daucus caroia L.), Agrostemma githago L. (corn cockle). Digitalis purpurea L. (purple foxglove), soyabean (Giycine max L. Merr; four different cultivars). Datura stramonium L. (thorn-apple) and wheat (Tritician aestivum L.). During 48 h of incubation, the herbicide was biotransformed by all species; turnovers yields differed considerably and were between 10.1% and 88.0% of applied 14C. Differences were also observed among the soyabean cultivars (10.1-73.5%). Hydroxy-atrazine, de-ethyl-, deisopropyl- and de-ethyt-deisopropylatrazine formed in the cultures were identified by thin-layer chromatography (tlc) (co-chromatography with reference compounds); deaikyiated metabolites were also proved by gas chromatography–mass spectrometry (gc–ms). In addition, highly polar transformation products emerged that were not identified. Portions of non-extractable residues were below 5% (one soyabean cultivar: 8.9%). Atrazine was metabolized by the cells, mainly to its dealkylated derivatives and hydroxyatrazine (totals of 9.4-54, 5%), whereas portions of highly polar products were lower (0.1-26.1%). Exceptions were A. githago (26.0 and 33.6%, respectively) and D, purpurea (4.5 and 25.2% respectively). Thus, plants generally contribute to the environmental degradation of atrazine.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1398-9995
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: We have previously reported a correlation between the extent of ragweed allergen (RWA)-induced in vitro serum complement activation and the symptom scores registered daily during the ragweed (RW)-blooming season in RW-allergic patients. The present study was performed in 22 15–17-year-old RW-allergic adolescents. Serum samples were incubated with 100μ/ml RWA, and the generation of different complement activation products was measured by ELISA or RIA. Symptom scores were registered for 4 weeks during the RW-blooming season. The patients were divided according to the extent (low or high) of the generation of complement activation products, and symptom scores registered in the two groups were compared by two-way ANOVA. Significantly higher symptom scores were obtained in the high than in the low complement activation group (P values: 0.049 for C1rC1sC1inh, 0.022 for CSbBbP, 0.015 for C5b-9, 0.0001 for C3a, and 0.0008 for C5a). Similar results were obtained at the measurement performed in the sera obtained from the same patients half a year before the season (P values: 0.022 for C3bBbP, and 0.005 for C5b-9). These findings indicate that complement activation induced by the allergen may enhance the clinical symptoms of RW allergy.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 12 (1998), S. 0 
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Springer
    European journal of nutrition 10 (1970), S. 111-114 
    ISSN: 1436-6215
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Medizin
    Beschreibung / Inhaltsverzeichnis: Summary 1. In aqueous phosphate buffer diacetyl tartaric acid monoglyceride is hydrolyzed to glyceride and tartaric acid. 2. Orally administered14C-labeled emulsifier to rats is absorbed to 26–31% of the activity given. 3. 21–20% are oxidized to14CO2, 8–13% are excreted in the urine, 2% are retained in the carcass.
    Notizen: Zusammenfassung 1. Die vorliegende Substanz wird in geringem Umfang, maximal zu 10–20%, im wäßrigen Medium gespalten. 2. Im Organismus der Ratte wird rd. 1/3 der14C-Aktivität der Substanz resorbiert. 3. Die Ausscheidung der14C-Aktivität erfolgt zu 12–20% via Lunge, zu 8–13 % via Niere, während der im Körper verbleibende Anteil nur 2% ausmacht.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Springer
    Monatshefte für Chemie 102 (1971), S. 180-186 
    ISSN: 1434-4475
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Abstract 5-Carboxyl-substituted 3.3-diphenyl-2-amino-1-pyrrolines are conveniently prepared by cycloaddition of α-acetaminoacrylic ester to diphenylacetonitrile. An alternative route, starting with the 4.4-diphenyl-4-cyano-2-bromobutyric acid derivatives1 b or1 d, results in poor yields owing to elimination of HBr during amination. Several amides of 3.3-diphenyl-2-aminopyrroline-5-carboxylic acid were prepared, including the β-carbamidinoethylamide (rac. diphenylnoformicin). Reduction of the ethyl ester2 f yields 3.3-diphenyl-2-amino-5-hydroxymethyl-1-pyrroline (3).
    Notizen: Zusammenfassung 5-Carboxylsubstituierte 3,3-Diphenyl-2-amino-1-pyrroline werden vorteilhaft durch Cycloaddition von α-Acetaminoacrylester an Diphenylacetonitril hergestellt. Ein zweiter Syntheseweg, ausgehend von den 4,4-Diphenyl-4-cyan-2-brombuttersäurederivaten1 b oder1 d, verläuft wegen der HBr-Eliminierung während der Aminierung mit schlechten Ausbeuten. Es werden einige Amide der 3,3-Diphenyl-2-aminopyrrolin-5-carbonsäure (2 c), darunter das β-Carbamidinoäthylamid (rac. Diphenylnoformicin) (2 h) hergestellt. Die Reduktion des Äthylesters2 f führt zum 3,3-Diphenyl-2-amino-5-hydroxymethyl-1-pyrrolin (3).
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Springer
    Monatshefte für Chemie 102 (1971), S. 627-634 
    ISSN: 1434-4475
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die Acylierung von 2-Amino-3.3-diphenyl-5-methyl-1-pyrrolin (1) und 2-Amino-3.3-diphenyl-1-pyrrolin (2) erfolgt in den hier untersuchten Fällen am N-2-(exo)-Stickstoff. Die Umsetzung der cyclischen Amidine1 und2 mit BrCN gibt jedoch neben den N-2-(exo)-auch die N-1-(endo)-Cyanamidine. Diese werden in die entsprechenden Carbamoyl- und Thiocarbamoylamidine umgewandelt.
    Notizen: Abstract Acylations of 2-amino-3.3-diphenyl-5-methyl-1-pyrroline (1) and 2-amino-3.3-diphenyl-1-pyrroline (2) occur at the N-2-(exo)-nitrogen. However, reaction of1 and2 with BrCN yields not only the N-2-(exo)-cyanoamidines but also the N-1-(endo)-isomers. Either is converted into the corresponding carbamoyl and thiocarbamoyl amidines.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Monatshefte für Chemie 102 (1971), S. 635-642 
    ISSN: 1434-4475
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Aus 2-Amino-1-pyrrolinen können durch bekannte Reaktionen stabile Carbamidinoderivate dargestellt werden. Die Addition von Bisbenzhydrylcarbodiimid an 2-Amino-1-pyrroline, gefolgt von saurer Abspaltung der Benzhydrylreste, stellt eine neue vorteilhafte Methode zur Herstellung der nor-Derivate dieser Verbindungsklasse (Tab. 2) vor. Einheitliche N2-Alkyl-und Arylsulfonylderivate dieser Reihe erhält man mit den 1-(N2-Sulfonylcarbamidino)-3.5-dimethylpyrazolen.
    Notizen: Abstract Stable carbamidine derivatives of 2-amino-1-pyrrolines have been prepared using known reactions. The addition of bis-benzhydrylcarbodiimide to 2-amino-1-pyrrolines followed by acid cleavage of the benzhydryl moieties provides an improved method for the preparation of nor-derivatives of this class of compounds (Table 2). N2-Alkyl-and arylsulfonyl derivatives of this series have been selectively obtained from 1_(N2-sulfonylcarbamidino)-3.5-dimethylpyrazoles.
    Materialart: Digitale Medien
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