UHPLC-PDA-ESI-TOF/MS metabolic profiling and antioxidant capacity of arabica and robusta coffee silverskin: antioxidants vs phytotoxins

A deeper knowledge of the chemical composition of coffee silverskin (CS) is needed due to the growing interest in its use as a food additive or an ingredient of dietary supplements. Accordingly, the aim of this paper was to investigate the metabolic profile of aqueous extracts of two varieties of CS, Coffee arabica (CS-A), Coffee canephora var. robusta (CS-R) and of a blend of the two (CS-b) and to compare it to the profile of Coffee arabica green coffee (GC). Chlorogenic acids, caffeine, furokauranes, and atractyligenins, phytotoxins not previously detected in CS, were either identified or tentatively assigned. An unknown compound, presumably a carboxyatractyligenin glycoside was detected only in GC. Caffeine and chlorogenic acids were quantified while the content of furokauranes and atractyligens was estimated. GC and CS were also characterized in terms of total polyphenols and antioxidant capacity. Differences in the metabolites distribution, polyphenols and antioxidant capacity in CG and CS were detailed

Mild Enzymatic Method for the Extraction of Lycopene from Tomato Paste

ABSTRACTFour commercial enzyme preparations containing cell-wall degrading enzyme activities were tested for their ability to facilitate lycopene extraction from tomato paste. At 25°C, up to 75.6% of the lycopene present in the tomato product was extracted by a two-stage procedure that consisted of a preliminary 5 hour enzyme incubation followed by a 3 hour solvent (hexane or ethyl acetate) extraction. Increasing the duration of the enzymatic treatment to 12–18 h allowed the recovery of 85–90% of total lycopene. The highest extraction yields were achieved by using enzyme preparations with polygalacturonase and pectin methylesterase in addition to pectin lyase or cellulase activities

Green synthesis of gold nanoparticles using Kiwifruit juice

The use of kiwifruit juice as a source of metal-reducing and stabilizing agents for the production of gold nanoparticles (AuNPs) was investigated. The reaction was carried out in batch by mixing appropriate amounts of kiwifruit juice and gold(III) chloride solution. The formation of AuNPs was monitored by measuring the intensity of the surface plasmon resonance (SPR) band of gold. The effects of temperature (20-60 °C), pH (8-12) and gold-to-polyphenol ratio (GPR) were investigated. Characterisation of AuNPs by XRD, DLS and zeta-potential measurements showed that they were highly crystalline, with an average hydrodynamic diameter of about 50 nm and a zeta-potential ranging between -29.2 and -21.7 mV. Under the best reaction conditions (60 °C, pH 9, GPR = 5 mol Au3+/mol GAE), AuNPs with an average size of about 30 nm were produced. The results obtained suggest that kiwifruit juice is a suitable medium for the production of small-sized and stable AuNPs

Machine-learning approaches in drug discovery: methods and applications

During the past decade, virtual screening (VS) has evolved from traditional similarity searching, which utilizes single reference compounds, into an advanced application domain for data mining and machine-learning approaches, which require large and representative training-set compounds to learn robust decision rules. The explosive growth in the amount of public domain-available chemical and biological data has generated huge effort to design, analyze, and apply novel learning methodologies. Here, I focus on machine-learning techniques within the context of ligand-based VS (LBVS). In addition, I analyze several relevant VS studies from recent publications, providing a detailed view of the current state-of-the-art in this field and highlighting not only the problematic issues, but also the successes and opportunities for further advances

Територія і кордон як фактори формування етнічної ідентичності (за матеріалами досліджень прикордонних територій Брянської області)

В статье на основе современного исследования, проведённого среди населения Брянской области России, которое проживает на пограничье с Беларусью и Украиной, отражён процесс формирования этнической идентичности у местных подростков (16–18 лет). Также проанализирован ряд идентичных критериев, факторов исторического взаимодействия трёх восточнославянских народов в сфере образования, культуры, языка, конфессиональной принадлежности и т. п.Based on the modern investigation amongst the Russian Briansk Oblast people living on the frontier with Byelorussia and Ukraine there is an elucidation of the ethnical identity formative process amidst the local teenagers (16–18-year-old). Moreover analysed is a number of the identical criteria and factors of the historical interrelations of the three Eastern Slavonic nations in the fields of education, culture, language, confession, etc

Animal Production over Rice-Pasture Rotation System: Animal Performance

Fluctuations in commodity prices, determine the need to find strategies to stabilize production in farming systems. The rice - pastures rotation systems are a good example of this, where animal production takes place in the moments where rice is rotated with pastures (3 years rice and 2 years pastures). In this context, INIA has developed a technology adjusted to the east of the country, with the use of summer tillage to intensify livestock production through the incorporation of lambs fattening. These technologies, comercially validated with sheep-rice farming systems, can move the process of cattle backgrounding (males and females), but requires technological adjustments related to planting winter annuals species and the strategic use of the supplementation and subsequent evaluation of the impact of these proposed intensifications of the livestock production phase and subsequent rice production. There are now new tools to study the feasibility of these alternatives (productive and economic) through modelling, but the validity of their results will be based on the certainty of technical coefficients. These coefficients must be generated in real situations where all the factors interact (Deambrosi 2009). The objective of the present experiments, was to com-pare livewieght (LW) per hectare, daily gain (DG) and weight gain (WG) per animal on an annual ryegrass (‘LE 284’) sown over rice stubble, used for calf backgrounding, under the effect of two stocking rate, in the north of Uruguay

Reaction between quinone and thiazolidine. A study on the formation mechanism of new antiproliferative quinolindiones

Reaction between quinolinquinone and thiazolidine in basic medium was investigated. 2-Arylthiazolidine-4-carboxylic acid ethyl esters undergo two different cleavages in basic medium, yielding the 1-aryl-2-azadiene and a thiolic species. In the presence of quinolinquinone, the isomeric 1-aryl-3-ethoxycarbonyl-pyridoisoquinolin-5,10-diones and 3-amino-3-ethoxycarbonyl-dihydrothienoquinolin- 4,9-diones are formed by a hetero-Diels–Alder reaction and 1,4-Michael addition reaction, respectively. A mechanism for the formation of the reaction products is presented

'Making it count': incentives, student effort and performance

This paper examines how incentives to participate in online assessments (quizzes) affect students’ effort and performance. Our identification strategy exploits within-student weekly variation in incentives to attempt online quizzes. We find tournament incentives and participation incentives to be ineffective in increasing quiz participation. In contrast, making the quiz counts towards the final grade substantially increases participation. We find no evidence of displacement of effort between weeks. Using a natural experiment which provides variation in assessment weighting of the quizzes between two cohorts, we find that affected students obtain better exam grades. We estimate the return to 10% assessment weighting to be around 0.27 of a standard deviation in the in-term exam grade. We find no evidence that assessment weighting has unintended consequences, i.e., that increased quiz effort: displaces effort over the year; reduces other forms of effort; or reduces (effort and thus) performance in other courses. Finally, assessment weighting induced effort increases most for students at and below median ability, resulting in a reduction of the grade gap by 17%

Discovery of a Novel Small Molecule Inhibitor Targeting the Frataxin/Ubiquitin Interaction via Structure-Based Virtual Screening and Bioassays

Friedreich ataxia (FRDA) is an autosomal recessive neuro- and cardiodegenerative disorder for which there are no proven effective treatments. FRDA is caused by decreased expression and/or function of the mitochondrial protein frataxin. Here, we report findings that frataxin is degraded via the ubiquitin-proteasomal pathway and that it is ubiquitinated at residue K147 in Calu-6 cells. A theoretical model of the frataxin-K147/Ub complex, constructed by combining bioinformatics interface predictions with information-driven docking, revealed a hitherto unnoticed, potential ubiquitin-binding domain in frataxin. Through structure-based virtual screening and cell-based assays, we discovered a novel small molecule (compound (+)-11) able to prevent frataxin ubiquitination and degradation. (+)-11 was synthesized and tested for specific binding to frataxin by an UF-LC/MS based ligand-binding assay. Follow-up scaffold-based searches resulted in the identification of a lead series with micromolar activity in disrupting the frataxin/Ub interaction. This study also suggests that frataxin could be a potential target for FRDA drug development

Non-contact Reverse Engineering Modeling for Additive Manufacturing of Down Scaled Cultural Artefacts

Abstract In recent years, reverse engineering has achieved a relevant role in the cultural heritage field. The availability of 3D digital models of artefacts opens the door to a new era of cultural heritage: virtual museum creation, artefact cataloguing, conservation, planning and simulation of restoration, monitoring of artefacts subjected to environmental degradation, virtual reconstruction of damaged or missing parts, reproduction of replicas, etc. In this paper, two different non-contact reverse engineering scanning systems were utilized for 3D data acquisition of a cultural heritage artefact. The digital data acquisition and processing procedures of the scanned geometry have been illustrated and compared to evaluate the performance of both systems in terms of data acquisition time, processing time, reconstruction precision and final model quality. Finally, additive manufacturing technologies were applied to reconstruct a down scaled copy of the artefact