Search results for "Organic Compounds"
showing 10 items of 271 documents
Control of N-Heterocyclic Carbene Catalyzed Reactions of Enals: Asymmetric Synthesis of Oxindole-γ-Amino Acid Derivatives.
2017
A strategy to control the switch between a non‐cycloaddition reaction and a cycloaddition reaction of enals, using N‐heterocyclic carbene (NHC) catalyisis, has been developed. The new scalable protocol leads to γ‐amino‐acid esters bearing a tetrasubstituted stereocenter in good yields and high stereoselectivities by homo‐Mannich reactions of enals and isatin‐derived ketimines. By simply changing the N‐ketimine substituent to an ortho‐hydroxy phenyl group, the corresponding spirocyclic oxindolo‐γ‐lactams are obtained. peerReviewed
Transformation of raw ewes' milk applying “Grana” type pressed cheese technology: development of extra-hard “Gran Ovino” cheese
2019
Abstract This work was carried out to pursue a double objective: to improve the hygienic safety of cheeses produced from raw ewes' milk; and to produce a new typology of raw ewes' milk through the application of “Grana” technology for which the name “Gran Ovino” was chosen. With this in mind, raw milk from an individual farm was transformed under controlled conditions at a dairy pilot plant. The production technology included the partial skimming of the evening and morning milk mixture by cream surfacing and the addition of a natural whey starter cultures (NWSC) prepared with four selected Streptococcus thermophilus strains (PON6, PON244, PON261 e PON413). Ten microbial groups were investig…
In vivo application and dynamics of lactic acid bacteria for the four-season production of Vastedda-like cheese.
2014
article Twelve lactic acid bacteria (LAB), previously selected in vitro (Gaglio et al., 2014), were evaluated in situ for their potential to act as starter cultures for the continuous four-season production of Vastedda-like cheese, made with raw ewes' milk. The strains belonged to Lactobacillus delbrueckii, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides and Streptococcus thermophilus .L AB werefirst inoculated in multiple-strain combinations on the basis of their optimal growth temperatures in three process conditions which differed for milk treatment and medium for strain development: process 1, growth of strains in the optimal synthetic media and pasteu…
Recovery of bioactive compounds from walnut (Juglans regiaL.) green husk by supercritical carbon dioxide extraction
2021
In this work, the use of supercritical carbon dioxide, a nontoxic solvent, was proposed to extract bioactive compounds from Juglans regia L. green husk and was compared to other traditional techniques based on solvents such as ethanol, methanol and water. Supercritical CO2 was combined with ethanol as an organic modifier at a rate of 20% of the total flow to achieve greater extraction of polar compounds. The extracts were characterised in terms of extraction yields, antioxidant activity, total polyphenol content, phenolic acids, juglone, volatile organic compounds and antifungal activity. The results showed that the extracts obtained with supercritical CO2 were rich in polyphenols (10750 mg…
Green determination of the presence of volatile organic compounds in vehicle repair shops through passive sampling.
2012
A simple, fast and green direct analytical methodology has been developed to evaluate the concentration level of volatile organic compounds (VOCs) in indoor areas of vehicle repair shops using membrane devices as passive samplers. VOCs retained in the samplers were directly determined without any sample pre-treatment and avoiding the use of solvents by head space (HS) coupled to gas chromatography-mass spectrometry (GC-MS) in only 20 min. Benzene, toluene, tetrachloroethene, m,p-xylene and o-xylene were found at concentration levels from 0.1 to 11.2 mg m(-3).
Structure and performance properties of environmentally-friendly biocomposites based on poly(ɛ-caprolactone) modified with copper slag and shale dril…
2018
The potential application of two types of industrial wastes, drill cuttings (DC) and copper slag (CS), as silica-rich modifiers of poly(ɛ-caprolactone) (PCL) was investigated. Chemical structure and physical properties of DC and CS fillers were characterized using X-ray diffractometer, X-ray fluorescence spectroscopy, particle size and density measurements. PCL/DC and PCL/CS composites with a variable content of filler (5 to 50 parts by weight) were prepared by melt compounding in an internal mixer. It was observed that lower particle size of DC filler enhanced processing of biocomposites comparing to CS filler. Smaller particles of DC filler and thus the higher specific surface area, enabl…
Interactions of silica nanoparticles with lung epithelial cells and the association to flotillins
2012
Amorphous silica nanoparticles (aSNPs) gain increasing popularity for industrial and therapeutic claims. The lung with its surface area of 100-140 m(2) displays an ideal target for therapeutic approaches, but it represents also a serious area of attack for harmful nanomaterials. The exact nature of the cytotoxic effects of NPs is still unknown. Furthermore, cellular pathways and the destiny of internalized NPs are still poorly understood. Therefore, we examined the cytotoxicity (MTS, LDH) and inflammatory responses (IL-8) for different-sized aSNPs (30, 70, 300 nm) on our lung epithelial cells line NCI H441 and endothelial cell line ISO-HAS-1. Additionally, colocalization studies have been c…
Do fluorescence and transient absorption probe the same intramolecular charge transfer state of 4-(dimethylamino)benzonitrile?
2009
International audience; We present here the results of time-resolved absorption and emission experiments for 4-(dimethylamino)benzonitrile in solution, which suggest that the fluorescent intramolecular charge transfer (ICT) state may differ from the twisted ICT (TICT) state observed in transient absorption.
Ilgstošas fosforescences dizains karbazola atvasinājumos
2020
Ilgstošas fosforescences dizains karbazola atvasinājumos. Mazarevičs A., zinātniskie vadītāji Mg. chem. Leduskrasts K., Prof., Dr. chem. Sūna E. Bakalaura darbs, 62 lapaspuse, 55 attēli, 10 tabula, 42 literatūrās avoti, 4 pielikumi. Latviešu valodā. Literatūras apskatā analizēta luminiscence un fosforescence. Iekļauti organiskās fosforescences iegūšanas piemēri izmantojot kristalizāciju, smagā atoma efektu, starpmolekulāru un iekšmolekulāru mijiedarbību veidošanu kā arī nedalīta elektronu pāra vai karbonilgrupas ievadīšanu molekulā. Rezultātu izvērtējumā aprakstīta sintezēto savienojumu iegūšana, analizētas to luminiscentās īpašības, kā arī apskatīti rentgenstruktūras attēli no sintezētajie…
Occurrence of priority pollutants in WWTP effluents and Mediterranean coastal waters of Spain
2011
A comprehensive study aimed at evaluating the occurrence, significance of concentrations and spatial distribution of priority pollutants (PPs) along the Comunidad Valenciana coastal waters (Spain) was carried out in order to fulfil the European Water Framework Directive (WFD). Additionally, PP concentrations were also analysed in the effluent of 28 WWTPs distributed along the studied area. In coastal waters 36 organic pollutants of the 71 analysed, including 26 PPs were detected although many of them with low frequency of occurrence. Only 13 compounds, which belong to four different classes (VOCs, organochlorinated pesticides, phthalates and tributyltin compounds (TBT)) showed a frequency o…