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  • 1
    Electronic Resource
    Electronic Resource
    Observation of linear isomers of the ionized rare gas tetramers Ar4+ and Xe4+ (1999)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 111 (1999), S. 2513-2518 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ionized rare gas clusters Ar4+ and Xe4+ have been studied by photofragmentation. Center-of-mass velocities of the neutral and ionized photofragments have been measured for photon energies between 1.6 and 4.4 eV. In almost all of the examined photon energy region, both clusters exhibit fragment velocity distributions which show that they consist of a linear ionized trimer with an additional atom loosely attached to its side. For the lowest photon energies, however, fragmentation patterns are observed which can only be explained by a linear tetramer structure. This demonstrates that stable linear isomers of the ionized rare gas tetramers exist. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.479529
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  • 2
    Electronic Resource
    Electronic Resource
    Spin–orbit effects in the photodissociation of ionized rare gas trimers: Comparison of He+3, Ar+3, and Xe+3 (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 3450-3462 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The velocities of neutral and charged photofragments of the rare gas trimers He+3, Ar+3, and Xe+3 have been examined in a comprehensive study for photon energies ranging from 1.5 to 6 eV. For this purpose, a novel time-of-flight technique has been applied which allows the simultaneous examination of both neutral and charged fragments. The general fragmentation pattern of all three species was that of a linear trimer with a parallel transition moment and a totally repulsive excited state: In the course of the dissociation, two of the particles gain high velocities in opposite directions, while the third particle (the middle particle of the linear trimer) only obtains a small velocity. The positive charge generally localizes on one of the fast outer particles, as can be expected from the symmetry properties of the excited state. For Ar+3 and Xe+3, however, also localization of the charge on the slow particle can be observed. This effect strongly depends on the energy of the absorbed photon, and can be quenched by decreasing the vibrational excitation of the trimer. Comparison of the results with new potential energy surface calculations indicate that mainly spin–orbit coupling induced conical intersections are responsible for this charge redistribution phenomenon. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.470229
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  • 3
    Electronic Resource
    Electronic Resource
    Beam formation at the Munich atomic beam source : Proceedings of the 7th international conference on ion sources (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 750-752 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A Stern–Gerlach atomic-beam ion source (ABS) with an electron cyclotron resonance (ECR) ionizer and a Cs gas target as charge exchange units will replace the Munich Lamb–Shift polarized hydrogen source. The goal is to achieve intense negative beams of polarized H− and D− of high brightness for injection into the 14 MV MP tandem accelerator and beam intensity of about 2 μA on the target. At the entrance of the ECR ionizer the observed intensity of the neutral beam of polarized atoms is 6.4±0.4×1016 H/s, equivalent to 10 particle/mA before ionization. Comparing beam transport calculations with beam intensity measurements under various conditions allows a consistent description of the beam formation in the ABS with respect to the degree of dissociation ((similar, equals)80%), peaking ((similar, equals)1.6), beam absorption ((similar, equals)40%), and pumping speeds to be made. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148565
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  • 4
    Electronic Resource
    Electronic Resource
    Review of accelerator based sources (invited) (abstract) : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 1999-1999 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The development of storage rings for synchrotron radiation have now arrived at so-called third-generation and have straight sections with optical functions optimized for undulators and electron beams of very small emittances. The beam optics of the ring is chosen so as to minimize the quantum excitation of betatron oscillations which determine the emittance. This can be achieved with a ring containing many cells with a small bending angle and with strong focusing in each cell. The first point results in large and expensive rings and both points require strong sextupole magnets for the chromaticity correction which can limit the dynamic acceptance. The optimization of storage rings with these points in mind lead to lattices which have achromatic cells with two, three, or more bending magnets. Studies for future rings consider further methods like the use of wigglers, combined function magnets, increased transverse damping partitions, etc. in order to obtain even smaller emittances which approach the diffraction limit. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145781
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  • 5
    Electronic Resource
    Electronic Resource
    The Kostomuksha greenstone belt, NW Baltic Shield: remnant of a late Archaean oceanic plateau? (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Terra nova 9 (1997), S. 0 
    Details
    ISSN: 1365-3121
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences
    Notes: The Kostomuksha greenstone belt consists of two lithotectonic terranes, one mafic igneous and the other sedimentary, separated by a major shear zone. The former contains submarine 2.8 Gyr old komatiite-basalt lavas and volcaniclastic lithologies with trace element and isotopic compositions resembling those of recent oceanic flood basalts [ɛNd(T) =+ 2,8, μ.1= 8.73 (Nb/Th)N= 1.5–2.1 (Nb/La)N= 1.0–1.5]. We suggest that the mafic terrane is a remnant of the upper crustal part of an Archaean oceanic plateau derived from partial melting of a mantle plume head. When the plateau reached the continental margin, it collided with the sedimentary terrane but was too buoyant to subduct. As a result, the volcanic section of the plateau was imbricated and obducted thus becoming a new piece of continental crust. The deeper zones were subducted and disappeared from the geological record.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3121.1997.tb00009.x
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  • 6
    Electronic Resource
    Electronic Resource
    Risk of invasive carcinoma in colorectal adenomas assessed by size and site (1997)
    Springer
    International journal of colorectal disease 12 (1997), S. 267-271 
    Details
    ISSN: 1432-1262
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé. Problématique: Le risque de développer un carcinoma invasif en cas d'adénome colorectal est influencé par nombre de caractéristiques à la fois des patients et des adénomes dans le collectif d'échantillons analysés. Patients et méthodes: Entre 1978 et 1993, plus de 20,000 polypes ont été documentés prospectivement dans le registre des polypes colorectaux de Erlangen et analysés au moyen d'une analyse statistique de régression logique. Résultats: La taille des adénomes s'est révélée être le facteur le plus important en cas d'adénome de plus de 15 mm en comparaison avec des lésions plus petites. Cinq mille cent trente sept adénomes de moins de 5 mm sont porteurs d'un carcinome invasif. Les adénomes du côlon droit présentent un risque inférieur de malignité que ceux du côlon gauche ou du rectum mais le risque de dégénérescence augmente avec la taille de l'adénome. Dans le cas d'adénomes de moins de 36 mm de diamètre, le risque de carcinomes invasifs est observé plus fréquemment s'ils siègent au niveau du rectum ou du côlon gauche alors que des adénomes de plus de 36 mm sont plus fréquemment porteurs de carcinomes s'ils sont localisés dans le côlon droit ou le côlon gauche plutôt que le rectum. En conclusion: Une analyse multi-variée de 11,380 adénomes détectés à une première pancolonoscopie montre que les facteurs de siège et de taille qui peuvent tous deux être déterminés par la seule colonoscopie sont à même de prédire le risque de malignité de manière adéquate, tant sur le plan statistique que sur le plan clinique.
    Notes: Abstract . Background: The risk of invasive carcinoma developing in colorectal adenomas is influenced by a number of characteristics of both patients and adenomas, and the composition of the sample analysed. Patients and methods: Between 1978 and 1993 more than 20 000 polyps were prospectively documented at the Erlangen Registry of Colorectal Polyps, and analysed statistically by logistic regression. Results: The size of the adenomas proved to be the most important factor for adenomas equal to or larger than 15 mm as compared with smaller lesions. In 5137 diminutive adenomas (≤5 mm) invasive carcinoma was never found. Adenomas in the right-sided colon had a lower risk than those in the left colon or rectum, but with increasing adenoma size, the malignancy rate showed a right-sided shift. In adenomas of up to 36 mm in diameter, invasive carcinoma was found more often when they were located in the rectum or left colon while adenomas larger than 36 mm were more likely to harbour invasive carcinoma when located in the right or left colon rather than in the rectum. Conclusions: A multivariate analysis of 11380 adenomas detected at the first total colonoscopy showed that the factors size and site, both of which can be assessed by endoscopic inspection alone, were found to enable a statistically and clinically adequate assessment of the malignancy risk.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003840050103
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  • 7
    Electronic Resource
    Electronic Resource
    Tierexperimentelle Untersuchungen zur gewerbetoxikologischen Beurteilung von 2-Chloräthylisocyanat (1972)
    Springer
    Archives of toxicology 29 (1972), S. 73-84 
    Details
    ISSN: 1432-0738
    Keywords: 2-Chloroethyl Isocyanate ; Generation of Vapour Atmospheres ; Inhalation Toxicity ; Threshold Limit Values ; orter: 2-Chloräthylisocyanat ; Erzeugung von Dampf-Luft-Gemischen ; Inhalationstoxicität ; Maximale Arbeitsplatzkonzentration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die akute orale Toxicität von 2-Chloräthylisocyanat (CAIC) beträgt 396 mg/kg für männliche Ratten und 630 mg/kg für weibliche Mäuse. Am Kaninchenauge löste die außerordentlich geringe Menge von 5μl CAIC schwere Reizerscheinungen vor allem an der Conjunctiva aus. Auch die irritative Wirkung an der Kaninchenhaut war beträchtlich. In inhalationstoxikologischen Versuchen, deren Methodik durch Beschreibung eines einfachen Verfahrens zur Beladung von Luft ergänzt wurde, erwies sich CAIC als Reizgas ohne erkennbare systemischtoxische Wirkung. Die LC50 für Ratten beträgt bei sechsstündiger Exposition 6,3 ppm. In zwei subakuten Versuchen über 10 Tage mit Konzentrationen von 3,1 und 3,8 ppm überlebten alle Ratten. Zehn Tage nach Versuchsende wurden außer im Respirationstrakt (Tracheobronchitis. Bronchopneumonie) histologisch keine pathologischen Veränderungen gefunden. Es wird eine maximale Arbeitsplatzkonzentration (MAK) von 0,02 ppm vorgeschlagen.
    Notes: Abstract The acute oral toxioity of 2-chloroethyl isocyanate (CAIC) is 396 mg/kg for male rats and 630 mg/kg for female mice. The extremely small quantity of 5 μl CAIC caused severe irritation in the eyes of rabbits, particularly of the conjunctiva. The skin was also affected considerably. Inhalation experiments, involving a new version of a proven method for generating air-vapour mixtures, produced no evidence of systemic toxicity, but let CAIC be classified as an irritant vapour to the respiratory tract. The LC50 for rats is 6.3 ppm after exposure for 6 h, while rats in two experiments involving ten-day exposures to vapour concentrations of 3.1 and 3.8 ppm, respectively, survived. After a fortnight's withdrawal following each experiment, histological examinations showed tracheobronchitis and bronchopneumonia but no pathological change in any other organ examined. A threshold limit value (TLV) of 0.02 ppm is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00316517
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  • 8
    Electronic Resource
    Electronic Resource
    Notes and documents concerning the discovery of LSD (1970)
    Springer
    Inflammation research 1 (1970), S. 148-150 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01982402
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  • 9
    Electronic Resource
    Electronic Resource
    Hydrous, silica-rich melts in the sub-arc mantle and their relationship with erupted arc lavas (1995)
    [s.l.] : Nature Publishing Group
    Nature 377 (1995), S. 595-600 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Hydrous, silica-rich melts migrating through the mantle are preserved as glass inclusions in mantle minerals in xenoliths from Philippine arc lavas. These melts, with chemistries that indicate an origin by very low degrees of melting of the subducted ocean crust, have altered their host ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/377595a0
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  • 10
    Electronic Resource
    Electronic Resource
    Mantle geochemistry: the message from oceanic volcanism (1997)
    [s.l.] : Nature Publishing Group
    Nature 385 (1997), S. 219-229 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Basaltic volcanism 'samples' the Earth's mantle to great depths, because solid-state convection transports deep material into the (shallow) melting region. The isotopic and trace-element chemistry of these basalts shows that the mantle contains several isotopically and chemically distinct ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/385219a0
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