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  • 1
    ISSN: 1432-1866
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract In the western part of the Rheinisches Schiefergebirge three different types of epigenetic lead-zinc vein mineralization in Paleozoic rocks can be distinguished: 1. Syntectonic Variscan veins, 2. post-Variscan (Saxonian) veins mainly in Paleozoic siliceous clastic rocks, 3. post-Variscan carbonate-hosted mineralization in the Aachen-Stolberg area. Ore impregnations occur in the Triassic Buntsandstein (Bunter sandstone) and Muschelkalk of the Maubach-Mechernich triangular depression covering the Paleozoic rocks. Data points define two distinct populations in both lead isotope diagrams and thus indicate two major Variscan and post-Variscan mineralization events. The lead isotope pattern of the Paleozoic sedimentary rocks bears good evidence that this thick rock sequence may be the main source of metals for the mineralization. The metals were mobilized at deeper levels by saline fluids at different times. There are no direct indications for remobilization of the older Variscan vein ore deposits. The sandstone- and carbonate-hosted ore impregnations of Maubach-Mechernich have a similar lead isotope pattern to the post-Variscan mineralization in the Paleozoic sedimentary basement.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1866
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract In the western part of the Rheinisches Schiefergebirge three different types of epigenetic lead-zinc vein mineralization in Paleozoic rocks can be distinguished: 1. Syntectonic Variscan veins, 2. post-Variscan (Saxonian) veins mainly in Paleozoic siliceous clastic rocks, 3. post-Variscan carbonate-hosted mineralization in the Aachen-Stolberg area. Ore impregnations occur in the Triassic Buntsandstein (Bunter sandstone) and Muschelkalk of the Maubach-Mechernich triangular depression covering the Paleozoic rocks. Data points define two distinct populations in both lead isotope diagrams and thus indicate two major Variscan and post-Variscan mineralization events. The lead isotope pattern of the Paleozoic sedimentary rocks bears good evidence that this thick rock sequence may be the main source of metals for the mineralization. The metals were mobilized at deeper levels by saline fluids at different times. There are no direct indications for remobilization of the older Variscan vein ore deposits. The sandstone- and carbonate-hosted ore impregnations of Maubach-Mechernich have a similar lead isotope pattern to the post-Variscan mineralization in the Paleozoic sedimentary basement.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Mineralium deposita 32 (1997), S. 292-295 
    ISSN: 1432-1866
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract The lead isotope composition of 32 lead glasses excavated from strata of the twelfth to early fifteenth century in six countries of NW Europe made the predominance of the Harz Mountains in this period of the Medieval European lead and silver production highly probable. Post-Variscan vein type galena, Devonian syngenetic hydrothermal ore (Rammelsberg) and blended ore from both deposits in the Harz were used. Our evaluation of 200 mining sites in Germany, Britain and Ireland also demonstrated that minor lead sources for lead glass were located in Bavaria/Bohemia and England. Lead ores from the Rhenohercynian orogenic belt in Germany are derived from rock sources close to the upper continental crust composition in 238U/204Pb of about 10 and Th/U of about 4. The ores in Central England originated from rocks with 238U/204Pb of about 11.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Nicotinic acetylcholine (ACh) receptors (nAChRs) are important excitatory neurotransmitter receptors in the insect CNS. We have isolated and characterized the gene and the cDNA of a new nAChR subunit from Drosophila. The predicted mature nAChR protein consists of 773 amino acid residues and has the structural features of an ACh-binding α subunit. It was therefore named Dα3, for Drosophilaα-subunit 3. The dα3 gene maps to the X chromosome at position 7E. The properties of the Dα3 protein were assessed by expression in Xenopus oocytes. Dα3 did not form functional receptors on its own or in combination with any Drosophilaβ-type nAChR subunit. Nondesensitizing ACh-evoked inward currents were observed when Dα3 was coexpressed with the chick β2 subunit. Half-maximal responses were at ∼0.15 µM ACh with a Hill coefficient of ∼1.5. The snake venom component α-bungarotoxin (100 nM) efficiently but reversibly blocked Dα3/β2 receptors, suggesting that Dα3 may be a component of one of the previously described two classes of toxin binding sites in the Drosophila CNS.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0044-281X
    Keywords: Schlüsselwörter Kohortenstudie – Mortalität – Soziale Integration – MONICA-Projekt Augsburg ‐ Epidemiologie ; Key words Cohort study – mortality – social ties – MONICA Survey Augsburg n‐ epidemiology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The relation between marital status, social integration and the mortality from all causes was examined in a population based cohort study. The 5-year-cohort consisted of 1,030 men and 957 women, aged 55–74 years who participated in the second MONICA Survey Augsburg, F.R.G., 1989/90 (MONICA =Monitoring of trends and determinants of cardiovascular disease). They were followed for mortality until 1995. Altogether 120 men and 45 women had died. Social integration was measured by an index of social ties. The index of social ties examined in these analyses includes (a) presence of a spouse, (b) number of close friends and relatives, (c) reported contact with close friends and relatives. Age standardized mortality rates (per 10,000 person years) were computed for men and women. Sex-specific Cox-proportional hazard models were used and hazard rate ratios (HRR) were calculated adjusting for age, hypertension, cigarette smoking, cholesterol, drinking alcohol, number of chronic diseases and self-reported health. Mortality rates were higher for men who were living alone (437.3) than for married men (235.3). Respectively in women the rates were 121.6 compared to 80.7. After controlling for age and self-reported health a HRR of 1.5 (95% CI: 1.0–2.4) was observed for single, divorced or widowed men and a HRR of 1.6 (95%) CI: 0.8–3.0) for women living alone. Low mortality rates were observed in people with many social ties (men: 180.1, women: 29.9). Mortality rates of people who gave no informations about social ties (men: 349.5, women: 124.9) were similar to those who had only few social ties (men: 321.1, women: 132.5). The findings showed that people with few social ties were more likely to die in the follow-up period than those with more extensive contacts. After adjusting for age and self-reported health the HRR for those with few ties compared to those with many social ties were 1.6 (95% CI: 1.1–2.5) for men and 2.7 (95% CI: 1.1–6.6) for women. Similar results were found for people who gave no informations about their social ties (men: HRR = 1.4, 95% CI: 0.9–2.3: women: HRR = 2.6, 95% CI: 1.0–6.9). Social relationships were shown to be important predictors of mortality in elderly women and men. These findings confirm the need for further research, which enables to take steps against high mortality of the social isolated elderly.
    Notes: Zusammenfassung In einer 5-Jahres-Follow-up-Studie im Rahmen des MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease)-Projekts 1989/90 in Augsburg wurde das Mortalitätsgeschehen in einer Kohorte von 1030 Männern und 957 Frauen im Alter von 55 bis 74 Jahren erfaßt. Bis März 1995 waren 120 Männer und 45 Frauen verstorben. Die aus der Basiserhebung verfügbaren Informationen zum Familienstand und zur sozialen Integration (Index enger Beziehungen, Netzwerkindex) wurden als Prädiktoren der Mortalität untersucht. Für Männer und Frauen wurden altersstandardisierte Mortalitätsraten (pro 10 000 Personenjahre) und mit Hilfe von Co-Proportional-Hazards-Modellen adjustierte relative Risiken berechnet. Für alleinstehende Männer war die altersstandardisierte Mortalitätsrate mit 437,3 beinahe doppelt so hoch wie für Mäner mit (Ehe-)Partnerin (235,3). Alleinstehende Frauen unterscheiden sich in der Mortalitätsrate hingegen nur geringfügig von Frauen mit Partner (121,6 vs. 80,7). Ledige, geschiedene oder verwitwete Männer haben ein relatives Sterberisiko (HRR) von 1,5 (95%-KI: 1,0; 2,4) im Vergleich zu Männern mit einer Partnerin (adjustiert nach Alter und gesundheitlicher Selbsteinschätzung). Für alleinstehende Frauen beträgt dieses Risiko 1,6 (95%-KI: 0,8; 3,0). Beim Index enger Beziehungen zeigen Männer, die keine Angaben zu den sozialen Fragen gemacht haben, eine ähnlich hohe Rate (349,5) wie Männer mit einer nur geringen sozialen Integration (321,1). Insgesamt sind die Raten dieser beiden Gruppen wesentlich ausgeprägter als bei den Männern mit (sehr) vielen engen Beziehungen (180,1). Ein ähnliches Bild zeigt sich bei den Frauen: die Raten bei Frauen, die nicht geantwortet haben, und bei schwach integrierten Frauen sind ungefähr gleich hoch (124,9 vs. 132,5) und sind deutlich höher als bei den (sehr) gut integrierten Frauen (29,9). Männer mit geringer sozialer Integration haben ein um den Faktor 1,6 (95%-KI: 1,1; 2,5) höheres Sterberisiko (adjustiert nach Alter und gesundheitlicher Selbsteinschätzung) als Männer mit (sehr) vielen engen Beziehungen. Bei Männern, die keine Angaben gemacht haben, ist das Risiko ebenfalls erhöht (HRR = 1,4; 95%-KI: 0,9; 2,3). Sozial schlecht integrierte Frauen haben ein höheres Sterberisiko (HRR = 2,7; 95%-KI: 1,1; 6,6) als Frauen mit (sehr) vielen engen Beziehungen . Ebenso zeigt sich für Frauen, die keine Angaben zum Index gemacht haben, eine Erhöhung des Risikos (HRR = 2,6; 95%-KI: 1,0; 6,9). Die hohe Relevanz schlechter sozialer Einbindungen für das Mortalitätsrisiko macht weiterführende Studien zu dieser Thematik unter Einschluß weiterer und insbesondere psychologischer Dimensionen erforderlich, aus denen sich praktikable mortalitätssenkende Konsequenzen für die älteren Bürger ermitteln lassen sollten.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1437-3262
    Keywords: Micropalaeontology Palaeo-oceanography ; Plankton ; Sediment traps Recent and Holocene sediments ; Actualistic approach ; Norwegian-Greenland Sea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract A synoptic study is carried out to reconstruct the development of the plankton community in the late Quaternary in the Norwegian-Greenland Sea. It comprises quantitative analyses of coccolithophores, dinoflagellate cysts, diatoms and radiolarians. An actualistic approach is applied to evaluate the different fossil records of these plankton groups. The preliminary results of the current investigation are reported here. The composition and distribution of living communities of coccolithophores are presented as an example. A close relationship between the distribution of regional groups and surface water masses is observed. Seasonal vertical fluxes of coccolithophores and radiolarians through the water column show similar patterns within different years. However, diatoms are highly variable, both in absolute fluxes and species composition. The differentiation of sporadic and periodic processes is evident only after several years of observation. During settling and sedimentation biotic and abiotic processes such as grazing, dissolution and lateral transport alter the assemblages. Investigation of death assemblages in surface sediments reveals that in spite of these alteration processes the abundance and species distribution are related to surface water masses. Higher abundances and diversities are usually found in sediments underlying the warm Norwegian Current. Concentrations decrease to the north-west towards the cold polar water masses. The sediment assemblages of all groups are strongly altered relicts of former living communities. They are characterized by distinct changes in species composition and absolute abundances related to palaeo-oceanographic development. Their variation through the sedimentary record is used to distinguish four ecostratigraphic units during the late Weichselian and Holocene.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Mund-, Kiefer- und Gesichtschirurgie 3 (1999), S. S70 
    ISSN: 1434-3940
    Keywords: Schlüsselwörter Atrophe Maxilla ; Knochenkondensation ; Minimal invasiver Sinuslift ; Endoskop ; Augmentation ; Key words Atrophic maxilla ; Bone condensing ; Minimal invasive sinus lift ; Endoscopic control ; Augmentation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The minimal invasive sinus lift is a procedure done by osteotome technique via a crestal approach in contrast to the sinus elevation via lateral osteotomy to achieve adequate bone-height for setting of implants. The purpose of this anatomical and clinical study was to evaluate by endoscopic control if the minimal sinus lift is practicable by a residual bone height of less than 8 mm without mucosal damage. An endoscopic controlled sinus lift was done on 10 fresh cadavers. The original bone height was 3–6 mm in the lateral maxilla. The sinus mucosa was elevated by an osteotome at least up to 10 mm. A sinus augmentation was performed with a bone substitute material (Algipore®) over the implant bed. There was no tear visible on endoscopic control. Finally, the maxilla was removed and the mucosa inspected. No laceration of the mucosa was found in any case. The clinical study included 7 patients. 5 Patients had bone condensation, augmentation of bone and implantation of 13 mm implants in a one stage procedure. The originally bone height was between 6–8 mm in all patients. One of the five patients did show a small perforation of the mucosa during mucosal elevation at one implant-bed. The implant was inserted and an endoscopic control after 6 weeks showed regular mucosa. 2 patients received augmentation only at a primary bone height of only 3–5 mm. A post-operative CT-scan showed that the bone height was augmented to a total height of 13–16 mm. As a result of our study a sufficient bone height can be achieved by the minimal invasive sinus lift procedure. The advantage of this crestal approach is the protection of the intraosseous vessels in the maxilla and less postoperative morbidity. As a disadvantage, the insertion of bone material limited only to the area surrounding the implant bed, might be discussed.
    Notes: Zusammenfassung Implantate im atrophen Oberkieferseitenzahnbereich können meist erst nach einer Knocheneinlagerung im Bereich des Kieferhöhlenbodens gesetzt werden. Der minimal invasive Sinuslift ermöglicht über einen Zugang am Alveolarkamm durch die Knochenkondensation die Implantatsetzung bei ausreichender Knochenhöhe. Im Rahmen einer anatomischen und klinischen Studie sollte unter endoskopischer Kontrolle überprüft werden, ob auch bei geringerem Knochenangebot (〈 8 mm) die Schleimhaut soweit abpräpariert werden kann, daß nach Einlagerung von Knochen Implantate gesetzt werden können. An 10 Leichen mit zahnlosem Oberkiefer wurde der minimal invasive Sinuslift vorgenommen. Die Knochenhöhe im Seitenzahnbereich betrug zwischen 3 und 6 mm. Die Schleimhaut, die bis auf 10 mm abhebbar war, war sowohl endoskopisch als auch nach der Oberkieferentnahme nicht verletzt. Die klinische Anwendung erfolgte bei 7 Patienten. Bei 5 Patienten konnte bei einer minimalen Restknochenhöhe von 6 mm durch Knochenkondensation und Einsetzen eines Knochen-Algipore ® -Gemisches ein Implantat von 13 mm Länge inseriert werden. Bei einer Implantatsetzung kam es zu einer Perforation der Schleimhaut, die bei einer endoskopischen Kontrolle 6 Wochen später reizlos erschien. Bei 2 Patienten wurde bei einer Knochenhöhe von 3–5 mm unter endoskopischer Kontrolle eine alleinige Knochenaugmentation vorgenommen. Die erzielte absolute Knochenhöhe betrug im Dental-CT zwischen 10 und 13 mm. Die Limitation des Operationsverfahrens liegt darin, daß der Knochen nur über das Implantatbett appliziert werden kann. Der minimal invasive Sinuslift ermöglicht durch die endoskopische Kontrolle einen alveolären Zugang und schont gleichzeitig die intraossären lateralen Knochengefäße. Ferner ist die Denudation des Weichgewebes vermindert.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The effect of soil sterilization by chloroform fumigation on the release of fallout radiocesium incorporated in the fungal biomass of the organic layer of two forest soils was investigated by applying a sequential extraction procedure for radiocesium. The amount of the biomass in all soil samples was estimated by determination of the dissolved organic carbon (DOC) before and after fumigation, and qualitatively also by the ergosterol test. The five fractions obtained by sequential extraction (modified Tessier procedure) were: (I) easily exchangeable, (II) bound to oxides, (III) bound to organic matter, (IV) persistently bound, (V) residual. For the samples from the soil under spruce trees, no significant effects were apparent in any of these five fractions as a result of chloroform fumigation, indicating that the amount of radiocesium in the biomass of this soil was obviously negligibly small compared with the radiocesium associated with other soil constituents. The results obtained for the soil samples from the beech stand, however, reveal that the destruction of the biomass by chloroform fumigation modified considerably the extent of the association (i.e., binding) of radiocesium with the various other soil constituents (especially the clay minerals). As a result of this rapid redistribution of radiocesium released by the fungal biomass, it is not possible, in general, to attribute the observed increase of radiocesium in fraction I (easily exchangeable) after soil sterilization quantitatively to radiocesium released by the biomass. A reliable method to determine the amount of radiocesium incorporated in the fungal biomass of the soil samples which also contain clay minerals has, therefore, still to be developed.
    Type of Medium: Electronic Resource
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