58 research outputs found
UVSat: a concept of an ultraviolet/optical photometric satellite
Time-series photometry from space in the ultraviolet can be presently done
with only a few platforms, none of which is able to provide wide-field
long-term high-cadence photometry. We present a concept of UVSat, a twin space
telescope which will be capable to perform this kind of photometry, filling an
observational niche. The satellite will host two telescopes, one for
observations in the ultraviolet, the other for observations in the optical
band. We also briefly show what science can be done with UVSat.Comment: 6 pages, 2 figures, accepted for publication in the Proceedings of
the PAS (Proc. of the 2nd BRITE Science conference, Innsbruck
Surface science of soft scorpionates
The chemisorption of the soft scorpionate Li[PhTmMe] onto silver and gold surfaces is reported. Surface enhanced Raman spectroscopy in combination with the Raman analysis of suitable structural models, namely, [Cu(κ3-S,S,S-PhTmMe)(PCy3)], [Ag(κ3-S,S,S-PhTmMe)(PCy3)], [Ag(κ2-S,S-PhTmMe)(PEt3)], and [Au(κ1-S-PhTmMe)(PCy3)], are employed to identify the manner in which this potentially tridentate ligand binds to these surfaces. On colloidal silver surface-enhanced Raman spectroscopy (SERS) spectra are consistent with PhTmMe binding in a didentate fashion to the surface, holding the aryl group in close proximity to the surface. In contrast, on gold colloid, we observe that the species prefers a monodentate coordination in which the aryl group is not in close proximity to the surface
Natural and constructed littoral zones as nutrient traps in eutrophicated shallow lakes
Nutrient Cycling and Retention Along a Littoral Gradient in a Dutch Shallow Lake in Relation to Water Level Regime
Epidemiologiczne badania nad giardioza u mieszkancow Szczecina
The aim of the studies was to establish the prevalence of Giardia intestinalis in Szczecin population. The studies were carried out in 1991-1996. In this period 46 584 persons - 22 371 adults and 24 213 children were examined. Faecal samples were examined with two methods - coprological and immunoenzymatic (ELISA) test. A total of 356 persons (0.78%) were found to be infected with G. intestinalis. No statistically significant differences between the infection rate of adults and children were observed. The adults were infected in 0.73% and the children in 0.80%. The analysis of the annual dynamics of G. intestinalis infection shows twice as large infection rate in September- October (1.18 %) as in the remaining months (0.66 %)
Aktywność antyoksydacyjna herbat dostępnych na polskim rynku, otrzymywanych z liści Camellia sinensis (L.) Kuntze podczas róznych procesów produkcyjnych
The leaves of Camellia sinensis (L.) Kuntze are used to produce many types of tea; this variety
results from the production process. The extracts, especially from teas rich in polyphenols, are also used in
the prevention and treatment of certain diseases, in addition to their application for consumption.
The aim of the study was to compare the antioxidant activity and total phenolic content in extracts
from the following types of tea: white, green, oolong, black and Pu-erh.
The aqueous and methanolic extracts from the teas were analysed by spectrophotometric
methods. The method with the Folin-Ciocalteu reagent was used to determine total phenolic content;
the antioxidant activity was investigated by means of the reaction with the DPPH radical.
Total phenolic content and the antioxidant activity of examined extracts differed significantly. The
alcoholic and aqueous extracts from white and green tea of the highest content of polyphenols (97.1–84.4
mg GAE/g) showed the greatest antioxidant activity (IC50 0.263–0.329 mg/ml), similar to that of BHA. The
methanolic extracts from black and Pu-erh tea demonstrated much weaker activity.
The antioxidant activity of extracts from investigated teas is closely correlated with content of
polyphenolic compounds, which depends on the type of tea and the solvent used for extraction.Liście Camellia sinensis (L.) Kuntze są używane do produkcji wielu rodzajów herbat, których różnorodność
wynika z procesu produkcyjnego. Wyciągi, zwłaszcza z herbat bogatych w polifenole, poza zastosowaniem
spożywczym, są wykorzystywane również w profilaktyce i wspomaganiu leczenia niektórych
chorób.
Celem pracy było porównanie aktywności antyoksydacyjnej i zawartości sumy polifenoli w wyciągach
z herbaty: białej, zielonej, oolong, czarnej i Pu-erh.
Wyciągi wodne i metanolowe z herbat analizowano metodami spektrofotometrycznymi. Do oznaczenia
sumy polifenoli użyto metody z odczynnikiem Folin-Ciocalteu, aktywność antyoksydacyjną badano
w oparciu o reakcję z rodnikiem DPPH.
Zawartość sumy polifenoli i aktywność antyoksydacyjna badanych ekstraktów znacznie się różniły.
Wyciągi alkoholowe i wodne z herbaty białej i zielonej, o najwyższej zawartości polifenoli (97,1-84,4 mg GAE/
g), wykazywały też najwyższą, zbliżoną do BHA, aktywność przeciwutleniającą (IC50 0,263-0,329 mg/ml).
Ekstrakty metanolowe z herbaty czarnej i Pu-erh posiadały wielokrotnie słabsze działanie.
Aktywność antyoksydacyjna wyciągów z badanych herbat jest ściśle skorelowana z zawartością
w nich związków polifenolowych, która zależy od rodzaju herbaty i użytego do ekstrakcji rozpuszczalnika
Comparison of aspartate proteinase activity of Candida albicans strains isolated from children with and without Helicobacter pylori
Aktywnosc lekow azolowych in vitro wobec szczepow Candida albicans o roznych kodach wyodrebnionych z przewodu pokarmowego dzieci
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