718 research outputs found
Chemical Composition and Antioxidant Activity of Propolis Prepared in Different Forms and in Different Solvents Useful for Finished Products
Different products from a unique propolis extract obtained by using various solvents such as hydroalcoholic, glycolic (98% propylene glycol), and glyceric solutions, and oil, as well as in powder form, named ESIT12, were prepared. The molecular composition of the different preparations was evaluated and their antioxidant activity determined. All the preparations showed a quite similar polyphenol composition and comparable percentage even if ESIT12 was found to be richer in phenolic acids (caffeic, coumaric, ferulic, and isoferulic). Overall, flavones and flavonols ranged from ~20% up to ~36% in the glyceric extract, while flavanones and diidroflavonols were between ~28% and ~41%. Besides their quite similar composition, glycolic and hydroalcoholic extracts were found to be richer in the total polyphenols content. When the antioxidant properties were determined for the four preparations, the activity was similar among them, thus revealing that it is strictly related to the polyphenols content for propolis products whose composition is quite comparable. To date, very few data are available on propolis composition in glyceric and glycolic extracts and information has never been published on propolis in oil. This study could be of interest to the food and nutraceutical industries to choose suitable solvents and conditions to produce propolis preparations useful for active finished products
Identified Hadrons and Jet Chemistry for p+p and Au+Au Collisions at RHIC
The study of hadron spectra at high in p+p collisions provides a good
test of perturbative quantum chromo-dynamic calculations (pQCD) and baseline
for measurements of nuclear modification factors in Au+Au collisions. Using
events triggered by the Barrel Electro-Magnetic Calorimeter, identified charged
hadron transverse momentum () spectra are measured up to 15 GeV/ at
mid-rapidity ( 0.5) and neutral kaon spectra up to 12
GeV/ in p + p collisions at = 200 GeV. The particle ratios
of , and / in p + p
collisions are shown and compared with next-to-leading order pQCD calculations.
In central Au+Au collisions, we report nuclear modification factors ()
for pion, kaon, proton and and discuss several model calculations:
color-charge dependence of jet quenching and jet conversion. Finally,
centrality dependence of at high ( 5.5 GeV/c) for kaon are
compared with that of pion in Au + Au collisions at 200 GeV.Comment: 6 pages, 4 figures, SQM 2009 contributio
Recent advances in analytical approaches for the standardization and quality of polyphenols of propolis
Analytical approaches utilized for the characterization of polyphenols from propolis useful for the
determination of its quality is investigated in this study. A qualitative and quantitative evaluation of
propolis bioactive molecules is of interest in medicine and nutraceuticals. Recent powerful analytical
techniques are of great utility to separate and quantify polyphenols in extracts and finished products
due to their capacity to produce typical fingerprints and a reliable identification of many components.
According to this, an HPLC-UV-MS procedure was validated and applied for the characterization and
quantification of bioactive substances in propolis and for an accurate assessment of their content in
extract samples. By using this analytical approach, we obtained specific compositions related to brown
propolis acquired from different geographic areas (and preparations and treatment). This is more
important by considering the scientific opinion of European Food Safety Authority (EFSA) which
provided a negative response related to health claims of propolis and its polyphenols. These results
prove that HPLC-MS is an attractive tool for the standardization and quality control of propolis and may
be realistically applied to screen raw material and to evaluate finished commercial preparations and
nutraceutical benefits
Nonacceptability criteria and closure properties for the class of languages accepted by binary systolic tree automata
AbstractIn this paper a contribution is given to the solution of the problem of finding an inductive characterization of the class of languages accepted by binary systolic tree automata, L(BSTA), in terms of the closure of a class of languages with respect to certain operations. It is shown that L(BSTA) is closed with respect to some new operations: selective concatenation, restricted concatenation and restricted iteration. The known nonclosure of L(BSTA) with respect to classical language operations, like concatenation and Kleene iteration is proved here by using a new nonacceptability criterion
Fauna do solo e suas relações com atributos físico-químicos.
Este trabalho objetivou avaliar a diversidade da fauna edáfica e suas relações com os atributos físico-químicos. Foram escolhidas sete áreas, representativas da região Oeste do estado de Santa Catarina (região de Chapecó, SC), abrangendo as seguintes condições de uso: 1) Plantio convencional com rotação de culturas (PCRC1); 2) Plantio direto com rotação de culturas (PDRC2); 3) Plantio convencional com sucessão de cultura (PCSC3); 4) Plantio direto com sucessão de culturas (PDSC4); 5) Cultivo mínimo com sucessão de culturas (CMSC5); 6) Plantio direto com sucessão de culturas (PDSC6) e 7) Plantio direto com sucessão de cultura (PDSC7). Foram analisados nos mesmos pontos de coleta a fauna edáfica e atributos físico-químicos e microbiológicos do solo. Alguns grupos da fauna edáfica apresentaram potencial para serem usados como indicadores da qualidade do solo, pois se mostraram sensíveis ao sistema de preparo e cultivo do solo. Ao considerarmos todos os atributos edáficos, o tratamento PDRC2 ficou mais afastado dos outros com melhores condições físico-químicas e biológicas do solo, em comparação aos demais, especialmente CMSC5 e PDSC6
PURIFICATION OF PROPOLIS FROM POLYCYCLIC AROMATIC HYDROCARBONS AND PRESERVATION OF ACTIVE POLYPHENOL COMPONENT.
Organic pollutants have become an increasing concern due to their potential of mutagenicity, carcinogenicity, teratogenicity and high bioaccumulation. The adverse effects on health and environment caused by specific organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) have been considered as critical problems. The European Food Safety Authority (EFSA) has defined 16 priority PAH that are both genotoxic and carcinogenic and identified eight (PAH8) or four (PAH4) priority PAH as good indicators of the toxicity and occurrence of PAH in food. Several available techniques (photocatalytic degradation, combined photo-fenton and ultrasound, advanced oxidation, aerobic degradation, filtration, ozonation, coagulation, flocculation, distillation, extraction, precipitation, and adsorption, etc.) have been developed for PAH removal.
Food supplements containing propolis were also found to show relatively high PAHs. As a consequence, a main goal is to adopt purification procedures to remove PAH from propolis and preserve its polyphenol components before its use in finished products. Here we report an extractive procedure (M.E.D., Multi Dynamic Extraction) able to purify propolis from a great content of PAH by using a balanced mixture of organic and water solvents. Obtained propolis extracts are still rich in polyphenols and glycosylated derivatives showing PAH8 and specific benzo[a]pyrene content below limits recommended by EFSA
Recent results on strangeness production from NA49
We present a summary of measurements of strange particles performed by the
experiment NA49 in inelastic p+p interactions, as well as semi-central C+C and
Si+Si, central Pb+Pb, and minimum bias Pb+Pb collisions in the energy range
= 6.3 - 17.3 GeV. New results on , and
production in minimum bias Pb+Pb collisions at = 8.7 and 17.3
are shown. Furthermore the strangeness enhancement factor at =
17.3 GeV is presented and compared to the results from NA57 and STAR. Energy
dependence of strange particle yields normalized to pion yields is presented.
New data on production are shown at = 17.3
GeV. Furthermore we present the energy dependence of and
fluctuations. The data are compared with model predictions.Comment: 9 pages, 7 figures, Submitted to J. Phys. G (Proceedings of the
International Conference on Strangeness in Quark Matter, Buzios, Rio de
Janeiro, Brazil, September 27 - October 2, 2009
Determinação de estoques e formas estruturais de carbono em solos sob diversas culturas agrícolas do interior de São Paulo.
Entrada padronizada: BOMFIM, P. F
- …