Search results for "Rite"
showing 10 items of 2726 documents
Rapid Self-Healing and Thixotropic Organogelation of Amphiphilic Oleanolic Acid–Spermine Conjugates
2021
Natural and abundant plant triterpenoids are attractive starting materials for the synthesis of conformationally rigid and chiral building blocks for functional soft materials. Here, we report the rational design of three oleanolic acid–triazole–spermine conjugates, containing either one or two spermine units in the target molecules, using the Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction. The resulting amphiphile-like molecules 2 and 3, bearing just one spermine unit in the respective molecules, self-assemble into highly entangled fibrous networks leading to gelation at a concentration as low as 0.5% in alcoholic solvents. Using step-strain rheological measurements, we show ra…
Efficacy of different concentrations of sodium hypochlorite and chlorhexidine in disinfection of contaminated Resilon cones.
2011
Objectives: The aim of this study was to evaluate the effectiveness of different concentrations of Chlorhexidine (CHX) and sodium hypochlorite (NaOCl) in disinfecting contaminated Resilon cones within one minute. Study design: Fifty Resilon cones were divided into seven experimental groups and three control groups of 5 cones each. The cones of experimental groups were contaminated with Entrococcus faecalis and subsequently disinfected with different concentrations of NaOCl or CHX. The cones were then transferred into glass tubes containing thioglycollate media and incubated for 7 days. The tubes were examined for turbidity every 24 hours, and if bacterial growth occurred, samples were plate…
Initiation of an Aquaculture of Sponges for the Sustainable Production of Bioactive Metabolites in Open Systems: Example, Geodia cydonium.
1999
Among Metazoa, sponges (phylum Porifera) are the richest source for different bioactive compounds. The availability of the raw material is, however, restricted. To obtain enough of the bioactive compounds for application in human therapy, sponges have to be cultured in in vitro systems. One technique for the establishment of a long-term cell culture from sponges has recently been elaborated. Here, we present a procedure to cultivate tissue samples from sponges in an open system. The species Geodia cydonium, which produces bioactive compounds, has been selected. Tissue samples of approximately 10 g were attached to the bottoms of cultivation trays. After 2 to 3 days, the tissue samples forme…
Multi-Criteria Decision Making support system for pancreatic islet transplantation
2011
Pancreatic islet transplantation consists of replacing insulin-producing cells to restore normal glycemia in diabetic patients. This is a minimal invasive procedure that has been proved successful. Unfortunately unpredictability of islet transplant outcome remains a frustrating and costly issue limiting the clinical implementation of this procedure. Multiple variables are involved in the procedure and assessment is subjective to individual operators. The aim of this study was to generate a system expressing the probability of transplant success in relation to four classes of identified variables (donor, organ, isolation and recipient). We have proposed the utilization of Multi-Criteria Deci…
Correlation of welded ignimbrites on Pantelleria (Strait of Sicily) using paleomagnetism
2011
Although the oldest volcanic rocks exposed at Pantelleria (Strait of Sicily) are older than 300 ka, most of the island is covered by the 45–50 ka Green Tuff ignimbrite, thought to be related to the Cinque Denti caldera, and younger lavas and scoria cones. Pre-50 ka rocks (predominantly rheomorphic ignimbrites) are exposed at isolated sea cliffs, and their stratigraphy and chronology are not completely resolved. Based on volcanic stratigraphy and K/Ar dating, it has been proposed that the older La Vecchia caldera is related to ignimbrite Q (114 ka), and that ignimbrites F, D, and Z (106, 94, and 79 ka, respectively) were erupted after caldera formation. We report here the paleomagnetic direc…
Solution and recrystallisation processes and associated landforms in gypsum outcrops of Sicily
2003
Abstract Four small areas of Messinian (Upper Miocene) age gypsum, outcropping in western Sicily, are described. Messinian age evaporites are found in Sicily over a 1000-km 2 area. Here, gypsum outcrops extensively as a consequence of soil erosion induced by human impact. Geomorphological maps show how the rocky surfaces are characterized by a wide range of forms. There are large, medium, small, and microsized forms, which can be identified as belonging to different morphotypes. The morphotypes can be classified into two main categories: those that originated by solution and those that originated through recrystallisation. Four areas, illustrated by geomorphological maps, were specifically …
Zircon ages, geochemistry and Nd isotopic systematics for the Palaeoproterozoic 2.3–1.8 Ga Kuilyu Complex, East Kyrgyzstan – The oldest continental b…
2017
Abstract Precambrian microcontinents represent key tectonic units in the accretionary collages of the western Central Asian Orogenic Belt (CAOB), and their geological history is reasonably well established since the Mesoproterozoic but remains weakly constrained for older epochs due to a scarcity of exposed Palaeoproterozoic and Archaean rocks. Early Precambrian rocks were previously reported from several metamorphic complexes in the Kyrgyz Tianshan orogenic belt, mainly based on multigrain conventional zircon dating, but the present study only confirmed such rocks at one site, namely in the Kuilyu Complex of eastern Kyrgyzstan. New single grain SHRIMP II zircon ages, geochemical data, and …
Lightning-induced weathering of Cascadian volcanic peaks
2020
Abstract The process of meteorological lightning-induced modification of coherent volcanic rocks is examined by geochemical, textural, and experimental analysis of fulgurites from South Sister volcano, Oregon Cascades, USA. Lightning's effects on volcanic target rocks was simulated with an arc-welding device in order to reproduce the geochemical and textural features of natural fulgurites and to constrain temperatures of melting and devolatilization behavior during lightning strikes. Melting of volcanic target rocks produces melts of exceptional compositional diversity, ranging from those with pure mineral compositions (e.g., diopside and plagioclase), resulting from congruent melting react…
Porites corals from Crete (Greece) open a window into Late Miocene (10Ma) seasonal and interannual climate variability
2006
Variations in the biotic composition of marine shallow water carbonates document global climatic changes. However, a discontinuous stratigraphic record and uncertainties regarding the ages limit the significance of shallow water carbonates as palaeoclimatic archives on geological time-scales. Notwithstanding these deficits, the environmental information stored in the skeleton of reef biota is a unique source of information that resolves seasonal to interannual climate variability in geological time. Application of the method to corals from carbonate rocks is usually restricted to the past 130,000yr, because the aragonite skeleton undergoes rapid diagenetic alteration. Consequently, reconstr…
The complexities of zircon crystllazition and overprinting during metamorphism and anatexis: An example from the late Archean TTG terrane of western …
2017
Abstract There are different viewpoints on metamorphic and anatectic zircons recording ages of 2.45–2.48 Ga or even younger in some areas of the North China Craton where both late Neoarchean and late Paleoproterozoic tectono-thermal events are well developed. These are: 1) partial resetting of the U-Pb isotopic system in the late Neoarchean zircons, 2) metamorphism lasting from the late Neoarchean to the earliest Paleoproterozoic, and 3) earliest Paleoproterozoic metamorphism as separate different event. Western Shandong Province is an area where the late Neoarchean tectono-thermal event is widely developed but the late Paleoproterozoic event has not been identified. This provides an opport…