Wyniki wyszukiwania - Biblioteka Nauki

1

Woltamperometria cykliczna jako metoda oznaczania aktywności antyoksydacyjnej wybranych związków niskocząsteczkowych

100%

Laskowska B. , Kurleto K. K.

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tom Vol. 65, nr 10

1059-1066

PL

W pracy przedstawiono wyniki badań dotyczące właściwości przeciwutleniających kwasu askorbinowego, kwasu kofeinowego, resveratrolu, zielonej herbaty, witaminy C (tabletka powlekana) oraz czerwonego wina - z wykorzystaniem metody woltamperometrii cyklicznej. Badania przeprowadzono w środowisku buforu fosforanowego o stałym pH. Analiza uzyskanych woltamogramów pozwoliła na porównanie właściwości antyoksydacyjnych wymienionych związków.

EN

The work presents results of cyclic voltammetric studies of antioxidant features of ascorbic acid, caffeic acid, resveratrol, green tea, vitamin C (a coated tablet) and red wine. The studies were preformed in a medium of constant pH phosphate buffer system. The close examination of results allowed to compare antioxidant features of the above compounds.

2

Korelacje pomiędzy promieniami atomowymi metali, energią wiązania elektronów a ich właściwościami

100%

Stokłosa A. , Laskowska B.

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2005

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tom R. 10, NR 1-2

7--16

PL

Przedstawiono korelacje pomiędzy odwrotnością promieni atomowych metali a energią wiązania oraz wielkościami z nią związanymi (temperatura topnienia, entalpią sublimacji, energia wiązania elektronów na ostatniej zapełnionej powłoce). Uzyskane liniowe zależności pomiędzy powyższymi wielkościami w pełni korelują z położeniem metali w układzie okresowym oraz ich struktura pasmową i wskazują, że promienie metaliczne oraz energia elektronów rdzenie jonowych może posłużyć do charakterystyki i różnicowania atomów metali pod względem ich właściwości.

EN

Correlation tween the reciprocal atomic radii of metals, bonding energy and related values (melting points, bonding energy of electrons in the outermost shell) are presented in the work. The obtained linear relationships between the above values fully correlate with the position of the metals in the Periodic Table and their band structure. The correlations demonstrated that the metallic radii and electron energy of ionic cores can be employed to characterize and differentiate the metal atoms with respect to their properties.

3

BADANIA DOŚWIADCZALNE NAD SUBSTANCJAMI PRZECIWWIRUSOWYMI - CIĄGLE AKTUALNY PROBLEM WIRUSOLOGII

100%

Luczak M. , Laskowska B.

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nr 1

4

Zastosowanie roznych zrodel wapnia dla kur niosek

80%

Jamroz D. , Skorupinska J. , Laskowska B.

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2000

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tom 46

69-86

PL

Najkorzystniejsze, chociaż nie potwierdzone statystycznie, wyniki produkcyjne, analizowane za okres 90 dni uzyskały kury z grupy III (nieśność 82,6%; łączna masa jaj 4,45 kg). Najniższe zużycie paszy odnotowano u niosek otrzymujących preparat B, jednak w tej grupie oraz w grupie II zarejestrowano najwyższy udział stłuczek. W technologicznych parametrach jakości jaj występowały istotne, lecz nieukierunkowane różnice międzygrupowe. Wytrzymałość skorupy jaja, jej masa i grubość były ogółem najkorzystniejsze przy podawaniu kurom preparatu B. Udział skorupy w masie jaj był ogółem bardzo wysoki i wynosił powyżej 13%, lecz wytrzymałość skorupy na zgniatanie była w sumie niska. Znajduje to wyjaśnienie w znacznym wydalaniu wapnia i fosforu u kur, wskazującym na zbyt niskie pobieranie wapnia przez ptaki i zaburzenia w gospodarce wapniowofosforowej. Najwyższe odkładanie wapnia w skorupie jaj wystąpiło jednak u kur z II grupy doświadczalnej.

EN

Experiment was carried out on layers of Hisex Brown breed during the 42-54 weeks of their laying period. Hens were allocated according to analogue method into 3 groups, each consisted of 12 replications (cages), 3 animals per cage. After 8 days of introductory period, in that the experimental mixtures diversified in the kind of mineral additives, that is to say limestone (I) and calcium preparations A (II) or B (III) were given, the basal laying performance evaluation was launched. Mentioned mineral supplements were characterized by a different particle-size of calcium compounds and 4,5% of limestone of each mixture was replaced with them, respectively. The number and weight of eggs, quantity of feed intake, share of cracked-eggs in total eggs production as well as Ca level in blood serum were estimated. In two series of measurements, 60 eggs from each feeding group was evaluated according to technological standards. Nitrogen and phosphorus balances were carried out during 45-46 as well as during 51-52 weeks of laying. Also, the solubility degree ofused calcium chemicals in 0,1; 0,2; 0,3 and 3 nHCl as well as their particle-size using sieveanalysis were estimated. Calcium preparation A has contained 36 and preparation B has had 77% of particles > 2 mm. Preparation B was characterized by a worse solubility. Most profitable, however statisticaly not proved productive results, analysed for 90 days, in the hens from III group were obtained (laying rate 82,6%, total egg weight 4,45 kg). Lowest feed utilization was observed in the hens given B preparation (III) but in this and II group highest share of cracked-eggs were noted. In technological parameters of eggs quality, there were significant but without clear tendency differences between groups. The strength of egg-shell, its weight and thickness were totally most profitable when the hens were fed calcium preparation B. The share of shell in total egg mass was totally very high and amounted over 13% but the anti-crushing shell strength was in all low. It found the explanation in a great calcium and phosphorus excretion, pointed on too low calcium intake and disturbances in calcium-phosphorus status. Highest shell-Ca storage in hens from II experimental group was observed.

5

Wpływ warunków parzenia na zawartość antyoksydantow w naparach różnych rodzajów herbat

61%

Kurleto K. , Kurowski G. , Laskowska B. , Malinowska M. , Sikora E. , Vogt O.

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tom [Z] 67, 11-12

1129--1147

EN

Tea has been consumed all over the World for over two thousand years and now it is the most popular caffeine-containing beverage. Its worldwide consumption is second only to water [1–3]. The tea is not only important because of its popularity but also due to its beneficial influence on human health [4]. The biological benefits of tea are due to their flavanol content [5–13]. Tea flavanols are a group of natural polyphenols (Fig. 2). Therapeutic effects of tea have been extensively examined in many in vitro and in vivo tests. It was confirmed that tea leaves ingredients have antibacterial, antifungial, antiviral properties, they also prevent cell mutations and they inhibit progress of heart diseases. Moreover, tea can stimulate neural system and regulate its functions [14–20]. All this activities are mostly due to antioxidant ability of tea polyphenols (Fig. 4). Tea production process can be run in different ways and this affects of the tea taste, aroma, colour and antioxidants content. According to fermentation degree, different tea kinds can be obtained (Fig. 1). During the manufacturing process of black and oolong teas, tea leaves are crushed to allow polyphenol oxidase to catalyze the oxidation and polymerization of catechins to polymers called theaflavins and thearubigins (Fig. 3) [21–23]. Green or white teas are obtained through shorter fermentation, so the catechin concentration remains higher. Tea is prepared by infusing tea leaves in hot water. Brewing process conditions like temperature, brewing time, pH, besides other factors has a significant influence on polyphenols content [24-32]. Many studies have determined total flavonoids content and antioxidant activity according to different tea type and brewing conditions, tea plantation type or fermentation process. The amount of total polyphenol was determined using the F-C method, catechins, caffeine and polyphenolic acids were analysed using High Performance Liquid Chromatography with reversed phase. Obtained results let compare how different production and brewing processes affect the tea quality [33–56].