Search results for "vine"

Synthesis of alkaloids by Stevens rearrangement of nitrile-stabilized ammonium ylides: (±)-laudanosine, (±)-laudanidine, (±)-armepavine, (±)-7-methox…

2013

The Stevens rearrangement of nitrile-stabilized ammonium ylides in conjunction with the reductive removal of the nitrile function permits the facile construction of α-branched amines from α-aminonitriles. We employed this reaction sequence for the preparation of (±)-laudanosine, (±)-laudanidine and (±)-armepavine, (±)-7-methoxycryptopleurine, and (±)-xylopinine from two closely related and readily accessible bicyclic α-aminonitriles. The final products were obtained in high to almost quantitative yields (71–98%) from the quaternary ammonium salts obtained by N-alkylation of these starting materials.

Nitrogen and sulfur co-doped carbon nanodots toward bovine hemoglobin: A fluorescence quenching mechanism investigation

2018

A deep understanding of the molecular interactions of carbon nanodots with biomacromolecules is essential for wider applications of carbon nanodots both in vitro and in vivo. Herein, nitrogen and sulfur co-doped carbon dots (N,S-CDs) with a quantum yield of 16% were synthesized by a 1-step hydrothermal method. The N,S-CDs exhibited a good dispersion, with a graphite-like structure, along with the fluorescence lifetime of approximately 7.50 ns. Findings showed that the fluorescence of the N,S-CDs was effectively quenched by bovine hemoglobin as a result of the static fluorescence quenching. The mentioned quenching mechanism was investigated by the Stern-Volmer equation, temperature-dependent…

Noble gases investigation in fluid inclusions of olivines and pyroxenes from Etnean products erupted in the 2001-2004 period.

2008

Alternative nursery propagation for vineyards establishment

2016

Dead vines are often a problem present in many vineyards and are due to physiological or pathological causes whereby the vines need to be replaced. The aim of the trial was to create in the nursery plant material of four cultivars in order to easily replace the dead vines in the vineyards but also to anticipate the first harvest and to improve the vineyard uniformity and synchronize the vineyard management practices during the first two years of plantation. During the first year in the nursery, the effect of plant density on the percentage of success and vegetative growth was evaluated. During the second year, in the open field and only for one cultivar, the vegetative and reproductive para…

Computational study of the interaction of proflavine with d(ATATATATAT)2 and d(GCGCGCGCGC)2

2009

Abstract The interaction of proflavine (PR) with two B-DNA decamers of alternating AT and GC sequence, called [deca(dG-dC)]2 and [deca(dA-dT)]2, respectively, was computationally investigated by the ONIOM method, exploiting a three-layer QM/QM/MM hybrid approach. The highest level QM method was applied to the model system, which comprises the intercalation site (5th and 6th base pairs) and the inserted PR molecule. The connecting sugar phosphate backbone was added in the medium layer region. Both higher and medium level layers, differing in the size of the basis set used, were treated by the DFT MPWB1K functional. The full system in the lower layer was described by the empirical AMBER force…

A polyphasic approach to the identification of ochratoxin A-producing black Aspergillus isolates from vineyards in Sicily.

2008

Aspergillus strains belonging to section Nigri isolated during a two year survey in eight Sicilian vineyards located on the slopes of Mount Etna (Sicily, Italy) were analysed analyzed in order to characterize species responsible for ochratoxin A (OTA) contamination of grapes. The polyphasic approach permitted analysis of biodiversity of Aspergillus isolates in relation to their morphology, ochratoxigenicity and genetic variability. We assessed OTA production by A. carbonarius, A. niger, A. tubingensis and A. japonicus using an enzyme-linked immunosorbent assay. A. carbonarius isolates were the strongest OTA producers. A subset of 66 representative strains was selected for further DNA-based …

Simple liquid chromatography assay for analyzing ochratoxin a in bovine milk

2006

Kognitiivinen kuorma ohjelmoinnin oppimisessa

2016

Ohjelmoinnin oppiminen on kognitiivisesti kuormittavaa. Kuorman hallintaan on löydetty mahdollisia hallintakeinoja, kuten tehtävätyyppien sovittaminen oppilaan taitotasolle, opetusmateriaalin esittäminen kuormaa vähentävästi ja tyypillisten vaikeuksien huomioiminen. Tässä kirjallisuuskatsauksessa eritellään näitä keinoja ja sovelletaan tietoa käytännön ohjelmointikursseihin. Learning programming happens to have high cognitive load on the learner. Studies have found multiple ways to manage this cognitive load. These ways are: providing right kind of task based on learners level, presenting study material in a load-reducing way and taking into consideration typical difficulties that students …

Dehydration of melt inclusions in olivine and implications for the origin of silica-undersaturated island-arc melts

2019

Highlights • New experiments with melt inclusions in olivine at 1200 °C and 300 MPa. • Coupled behavior H2O and SiO2 in inclusions during re-hydration and dehydration. • SiO2 mobility results from formation/destruction of metal vacant olivine. • SiO2-undersaturated arc melt inclusions may originate by dehydration. • New method to assess initial H2O in dehydrated inclusions. Abstract Primary subduction-related magmas build up modern continental crust and counterbalance massive recycling of crustal material into the deep mantle occurring at this tectonic setting. Melt inclusions in Mg-rich olivine are believed to be the best probes of primary subduction-related melts. However, unexpectedly, m…

Crystallization of late-stage MORB under varying water activities and redox conditions: Implications for the formation of highly evolved lavas and ox…

2018

Abstract In order to understand late magmatic processes that occur in the deep oceanic crust, we performed a phase-equilibria study in a representative late-stage system at a pressure of 200 MPa with a special focus on the role of water and oxygen fugacity. The starting composition for the experiments was evaluated based on a statistical approach using evolved fresh MORB glasses from the database PETDB highest in FeO and TiO2 (in average 17.92 wt% and 3.73 wt%, respectively), assumed to represent frozen liquids erupted at the seafloor generated by extensive differentiation of MORB. We conducted crystallization experiments in a range of temperatures from 850 to 1050 °C with water activities …