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91.
The antiradical activity of water-soluble components contained in mushrooms (Psalliota campestris), onions (Allium cepa), white cabbage (Brassica oleracea var. alba), and yellow bell peppers (Capsicum annuum) against hydroxyl radicals was tested in a chemical and biological system. The vegetable juices were obtained by centrifugation of a vegetable homogenate processed at 2 degrees C or heated at 102 degrees C. The chemical system consisted of a buffered reaction mixture composed of Fe(III)-EDTA, 2-deoxy-D-ribose, ascorbic acid, and H(2)O(2) generating the hydroxyl radical. The antiradical activity was expressed as an inhibition of deoxyribose degradation. The biological system consisted of IMR32 neuroblastoma cells exposed to H(2)O(2) in the presence or absence of the vegetable juices. Cells were pretreated for either 24 h or 1 h with the vegetable juices, and reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used as a cell viability assay. All vegetable juices inhibited the degradation of deoxyribose and increased the viability of H(2)O(2) treated cells. Raw mushroom juice proved to be the most active in both cases. Boiling significantly affected the activity of mushroom juice, but did not change significantly the effect on onions and yellow bell peppers, and partially increased the activity of white cabbage juice. Mushroom antiradical activity was also confirmed by a cytofluorimetric analysis.  相似文献   
92.
Using a multi-dimensional ecological design, this study aimed first to analyse whether local environmental conditions can account for the spatial segregation of two Italian native decapods, the crayfish Austropotamobius italicus and the river crab Potamon fluviatile, in Central Italy freshwater ecosystems. Second, we aimed to analyse which environmental variables were more closely associated with the presence/absence of the two decapods in specific sites within their distribution area. Following a factorial design, a total of 32 sites were selected in two neighbouring geographic areas, one occupied by crayfish and one by crabs. Within each distribution area, eight streams where the decapod was present and eight where it was not present were selected. At each site, macro-invertebrate community composition and 16 abiotic variables were recorded and analysed with multi-variate methods. Variations in physical (minimum and maximum temperatures), chemical (calcium, oxygen, nitrate and nitrite) and geomorphological (substrate composition) parameters explained spatial segregation of P. fluviatile and A. italicus in the study area. The occurrence of crayfish reflected variations of chemistry (such as pH, calcium, nitrate and nitrite concentrations), temperature, water depth and substrate composition. On the contrary, the presence of the river crab, within its occurrence zone, was not associated to any biotic and abiotic parameters and was probably affected by anthropogenic pressure and uncontrolled harvesting. These findings provide fundamental ecological data for the maintenance of the two decapod natural populations as well as for the selection of areas and streams adequate for their reintroduction.  相似文献   
93.
The effect of various sourdoughs and additives on bread firmness and staling was studied. Compared to the bread produced with Saccharomyces cerevisiae 141, the chemical acidification of dough fermented by S. cerevisiae 141 or the use of sourdoughs increased the volume of the breads. Only sourdough fermentation was effective in delaying starch retrogradation. The effect depended on the level of acidification and on the lactic acid bacteria strain. The effect of sourdough made of S. cerevisiae 141-Lactobacillus sanfranciscensis 57-Lactobacillus plantarum 13 was improved when fungal alpha-amylase or amylolytic strains such as L. amylovorus CNBL1008 or engineered L. sanfranciscensis CB1 Amy were added. When pentosans or pentosans, endoxylanase enzyme, and L. hilgardii S32 were added to the same sourdough, a greater delay of the bread firmness and staling was found. When pentosans were in part hydrolyzed by the endoxylanase enzyme, the bread also had the highest titratable acidity, due to the fermentation of pentoses by L. hilgardii S32. The addition of the bacterial protease to the sourdough increased the bread firmness and staling.  相似文献   
94.
Rotenone and rotenoids (deguelin, beta-rotenolone (12a beta-hydroxyrotenone), tephrosin (12a beta-hydroxydeguelin), 12a alpha-hydroxyrotenone, and dehydrorotenone) were determined in cubè resins and formulations. Cubè resins from Lonchocarpus contain large quantities of deguelin (ca. 21.2%) and smaller quantities of tephrosin (ca. 3.5%) and beta-rotenolone (ca. 3.0%). The composition of commercial formulations may present very different rotenoid contents depending on the extracts used to prepare them. Because these rotenoids also present insecticide activity, the efficacy of these formulations may be very different. The storage stability and photodegradation of some rotenone formulations were studied. Rotenone and rotenoids are very sensitive to solar radiation, which degrades them rapidly, with half-lives in the order of a few tens of minutes. Some formulations show greater disappearance rates than that of cubè resin, indicating that not much attention has been paid to protecting the active ingredients from photodegradation in the formulation. A study on the residues on olives was also carried out to assess not only the rotenone content, but also that of the main rotenoids. At harvest, the residues of deguelin, tephrosin, and beta-rotenolone were 0.10, 0.06, and 0.10 mg/kg, respectively, very similar to rotenone (0.08 mg/kg), and though a few data indicate similar acute toxicity values for deguelin, only rotenone is taken into consideration in the legal determination of the residue.  相似文献   
95.
Two different egg based media, with and without the incorporation of sodium pyruvate, were used to isolate M. paratuberculosis from sheep, goat and cattle samples obtained at our laboratory for two years. Both media were adequate for bovine material, with a slightly improved isolation rate for Herrold's egg yolk medium incorporating sodium pyruvate; however, most of the small ruminant strains grew only on L?wenstein-Jensen medium without sodium pyruvate. Those results point out the need to use different media when working with small ruminant samples and provide further evidence for the existence of different varieties of M. paratuberculosis causing paratuberculosis in cattle and in small ruminants.  相似文献   
96.
A pulsed wave-Doppler ultrasonographic evaluation of common carotid arterial blood flow was carried out on 63 healthy Italian Saddlebred horses. Vessel diameter and tracing morphology were evaluated were evaluated and blood flow parameters (systolic, diastolic and mean velocity, acceleration and deceleration of the systolic wave, cartid pulse volume) were calculated and correlated with class variables (sex, age and body weight). On the basis of the presence of an incisure in the ascending branch of the systolic curve, subjects were divided in two groups: one with a bifid systolic curve and the other with a monophasic aspect. Correlations between: 1) diameter of the vessel and body weight and 2) carotid pulse volume and flow velocity (systolic, diastolic and mean) were found. A greater systolic pulse volume was found in male subjects, in subjects with greater body weight and in those which had a monophasic systolic wave.  相似文献   
97.
The relationship between postweaning DNA accumulation and body weight was calculated for a reference growing steer. Accumulation of DNA (hyperplasia) was calculated from patterns of protein accretion derived from literature data and protein-to-DNA ratios (Pro/DNA) measured in samples of muscles from chuck, round and plate, hides, intestines, rumens and livers of steers slaughtered at body weights ranging from 150 to 700 kg. Amounts of protein relative to DNA found in muscles from chuck, round and plate were used to estimate Pro/DNA changes in carcass. Corresponding values from intestines, rumen and liver were used to estimate Pro/DNA patterns for viscera. This ratio increased in carcass until animals reached body weights of approximately 300 kg and leveled off thereafter. No cell enlargement was evident in viscera. Thus, postweaning protein accretion in carcass results from both cell enlargement (hypertrophy) and DNA accumulation (hyperplasia) until body weights of 300 kg are attained, subsequent growth appeared to be hyperplastic in nature. In viscera, hyperplasia was the primary determinant of protein accretion.  相似文献   
98.
99.
ABSTRACT Thirty-eight bacterial strains isolated from hazelnut (Corylus avellana) cv. Tonda Gentile delle Langhe showing a twig dieback in Piedmont and Sardinia, Italy, were studied by a polyphasic approach. All strains were assessed by fatty acids analysis and repetitive sequence-based polymerase chain reaction (PCR) fingerprinting using BOX and ERIC primer sets. Representative strains also were assessed by sequencing the 16S rDNA and hrpL genes, determining the presence of the syrB gene, testing their biochemical and nutritional characteristics, and determining their pathogenicity to hazelnut and other plants species or plant organs. Moreover, they were compared with reference strains of other phytopathogenic pseudomonads. The strains from hazelnut belong to Pseudomonas syringae (sensu latu), LOPAT group Ia. Both fatty acids and repetitive-sequence-based PCR clearly discriminate such strains from other Pseudomonas spp., including P. avellanae and other P. syringae pathovars as well as P. syringae pv. syringae strains from hazelnut. Also, the sequencing of 16S rDNA and hrpL genes differentiated them from P. avellanae and from P. syringae pv. syringae. They did not possess the syrB gene. Some nutritional tests also differentiated them from related P. syringae pathovars. Upon artificial inoculation, these strains incited severe twig diebacks only on hazelnut. Our results justify the creation of a new pathovar because the strains from hazelnut constitute a homogeneous group and a discrete phenon. The name of P. syringae pv. coryli is proposed and criteria for routine identification are presented.  相似文献   
100.
The effects of age of ascospores (0–18 days after discharge), photon flux density (0–494 mol m–2 s–1 PAR), temperature (4–30 °C), frost (–15 °C for 30 min), relative humidity (RH; 0–100%), pH (2.5–6.5) and dryness (0 and 53% RH for up to 40 min) on the germination of the ascospores of the mycotoxin-producing fungus Gibberella zeae (anamorph Fusarium graminearum) were studied. Freshly discharged ascospores germinated within 4 h at 20 °C and 100% RH. The rate of germination and the percentage of viable ascospores decreased over time after the spores were discharged from perithecia. The time course of ascospore germination was not significantly affected by photon flux density. The period of time required to obtain 50% germinated ascospores at 100% RH was 26.90 h at 4 °C, 10.40 h at 14 °C, 3.44 h at 20 °C and 3.31 h at 30 °C. There was no significant effect of frost on the percentage of viable ascospores. A small percentage (6.6 ± 3.8%) of the ascospores germinated at 53% RH. At RH 84% and 20 °C almost 100% of the freshly discharged ascospores germinated. The time course of ascospore germination was affected by pH. The maximum rate of ascospore germination was estimated to be at pH 3.76. Ascospores lost their ability to germinate following exposure to 0% RH almost instantaneously. No germinating spores were detected after an incubation period of 1 min at 0% RH. Incubating the ascospores at 53% RH decreased the percentage of viable spores from 93 to 6% within 10 min. The data demonstrate that age of spores, relative humidity, temperature and pH, but not photon flux density, are key factors in germination of G. zeae ascospores.  相似文献   
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