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191.
Dicotyledons cope with ion (Fe) shortage by releasing low-molecular-weight organic compounds into the rhizosphere to mobilize Fe through reduction and complexation mechanisms. The effects induced by these root exudates on soil mineralogy and the connections between Fe mobilization and mineral weathering processes have not been completely clarified. In a batch experiment, we tested two different kinds of organic compounds commonly exuded by Fe-deficient plants, i.e., three organic acids (citrate, malate, and oxalate) and three flavonoids (rutin, quercetin, and genistein), alone or in combination, for their ability to mobilize Fe from a calcareous soil and modify its mineralogy. The effect of root exudates on soil mineralogy was assessed in vivo by cultivating Fe-deficient and Fe-sufficient cucumber plants (Cucumis sativus L.) in a RHIZOtest device. Mineralogical analyses were performed by X-ray powder diffraction. The batch experiment showed that citrate and, particularly, rutin (alone or combined with organic acids or genistein) promoted Fe mobilization from the soil. The combinations of rutin and organic acids modified the soil mineralogy by dissolving the amorphous fractions and promoting the formation of illite. These mineralogical alterations were significantly correlated with the amount of Fe mobilized from the soil. The RHIZOtest experiment revealed a drastic dissolution of amorphous components in the rhizosphere soil of Fe-deficient plants, possibly caused by the intense release of phenolics, amino acids, and organic acids, but without any formation of illite. Both batch and RHIZOtest experiments proved that exudates released by cucumber under Fe deficiency concurred to the rapid modification (on a day-scale) of the mineralogy of a calcareous soil.  相似文献   
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The dynamics of red deer Cervus elaphus populations has been investigated across different environmental conditions, with the notable exception of the European Alps. Although the population dynamics of mountain‐dwelling ungulates is typically influenced by the interaction between winter severity and density, the increase of temperatures and the reduction of snowpack occurring on the Alps since the 1980s may be expected to alter this pattern, especially in populations dwelling at medium ‐ low elevations. Taking advantage of a 29‐year time series of spring count data, we explored the role of weather stochasticity and density dependence on growth rate and vital rates (mortality and weaning success), and the density‐dependent variation in body mass in a red deer population of the Italian Alps. The interaction between increasing values of density and snow depth exerted negative and positive effects on growth and mortality rates, respectively, while weaning success was negatively affected by increasing values of density, female‐biased sex ratio and snow depth. Body mass of males and females of different age classes declined as population size increased. Our data support the role of winter severity and density dependence as key components of red deer population dynamics, and provide insight into the species' ecology on the European Alps. Despite the recent decline of snowpack on the Alpine Region, the negative impacts of winter severity and population abundance on growth rrate (possibly mediated by the density‐dependent decline in body mass) confirms the importance of overwinter mortality in affecting the population dynamics of Alpine‐dwelling red deer.  相似文献   
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Thyroid nodules are common in dogs and are increasingly likely to be detected with the increased use of advanced imaging modalities. An unsuspected, nonpalpable, asymptomatic lesion, defined as a thyroid incidentaloma, may be discovered on an imaging study unrelated to the thyroid gland. The objective of this single‐center cross‐sectional study was to assess the prevalence and computed tomography (CT) characteristics of incidental and nonincidental thyroid tumors in a large population of dogs, using prospective recruitment of patients undergoing CT examination for various reasons during the period of 2005–2015. Unilateral or bilateral thyroid masses were detected in 96/4520 dogs (prevalence, 2.12%; 95% confidence interval [CI], 1.70–2.54%). Seventy‐nine (82.3%) lesions were malignant and 17 (17.7%) were benign. Masses were discovered incidentally in 34/96 dogs (overall prevalence of incidentaloma, 0.76%; 95% CI, 0.51–1.02), and 24 (70.6%) of these 34 masses were thyroid carcinomas. Among the CT variables assessed, mineralization, vascular invasion, and tissue invasion were detected only in malignant tumors. Intratumoral vascularization was significantly associated with the presence of thyroid malignancy (P < 0.001). Although incidental thyroid nodules in dogs are relatively rare, they are often malignant. Findings indicated that the neck should be thoroughly assessed in middle‐aged and old patients undergoing body CT for various reasons. Thyroid nodules detected incidentally on CT should be sampled to avoid missing thyroid cancer.  相似文献   
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The compensation heat pulse (CHP) method is widely used to estimate sap flow and transpiration in conducting organs of woody plants. Previous studies have reported a natural azimuthal variability in sap flow, which could have practical implications in locating the CHP probes and integrating their output. Sap flow of several olive trees (Olea europaea L. cv. 'Arbequina') previously grown under different irrigation treatments were monitored by the CHP method, and their xylem anatomical characteristics were analyzed from wood samples taken at the same location in which the probes were installed. A significant azimuthal variability in the sap flow was found in a well-irrigated olive tree monitored by eight CHP probes. The azimuthal variability was well related to crown architecture, but poorly to azimuthal differences in the xylem anatomical characteristics. Well-irrigated and deficit-irrigated olive trees showed similar xylem anatomical characteristics, but they differed in xylem growth and in the ratio of nocturnal-to-diurnal sap flow (N/D index). The results of this work indicate that transpiration cannot be accurately estimated by the CHP method in olive trees if a small number of sensors are employed and that the N/D index could be used as a sensitive water status indicator.  相似文献   
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To evaluate the effect of genotype, year and location on 1000 kernel weight, falling number, alpha- and beta-amylase activity, pasting properties, β-glucan, fructan, total starch, amylose, resistant starch and dietary fibre contents of wholemeal flour, four einkorns and one control bread wheat were cropped in Italy for two years in four different locations.  相似文献   
200.
There is high current interest in the chemopreventive potential of Brassica vegetables (cruciferae), particularly due to their content in glucosinolates (GL), which upon myrosinase hydrolysis release the corresponding isythiocyanates (ITC). Some ITCs, such as sulforaphane (SFN) from broccoli ( Brassica oleacea italica), have been found to possess anticancer activity through induction of apoptosis in selected cell lines, as well as indirect antioxidant activity through induction of phase II detoxifying enzymes. Japanese daikon ( Raphanus sativus L.) is possibly the vegetable with the highest per capita consumption within the Brassicaceae family. Thanks to a recently improved gram scale production process, it was possible to prepare sufficient amounts of the GL glucoraphasatin (GRH) as well as the corresponding ITC 4-methylthio-3-butenyl isothiocyanate (GRH-ITC) from its sprouts. This paper reports a study on the cytotoxic and apoptotic activities of GRH-ITC compared with the oxidized counterpart 4-methylsulfinyl-3-butenyl isothiocyanate (GRE-ITC) on three human colon carcinoma cell lines (LoVo, HCT-116, and HT-29) together with a detailed kinetic investigation of the direct antioxidant/radical scavenging ability of GRH and GRH-ITC. Both GRH-ITC and GRE-ITC reduced cell proliferation in a dose-dependent manner and induced apoptosis in the three cancer cell lines. The compounds significantly ( p < 0.05) increased Bax and decreased Bcl2 protein expression, as well as producing caspase-9 and PARP-1 cleavage after 3 days of exposure in the three cancer cell lines. GRH-ITC treatment was shown to have no toxicity with regard to normal human lymphocytes (-15 +/- 5%) in comparison with SFN (complete growth inhibition). GRH and GRH-ITC were able to quench the 2,2-diphenyl-1-picrylhydrazyl radical, with second-order rate constants of 14.0 +/- 2.8 and 43.1 +/- 9.5 M(-1) s(-1), respectively (at 298 K in methanol), whereas the corresponding value measured here for the reference antioxidant alpha-tocopherol was 425 +/- 40 M (-1) s (-1). GRH reacted with H2O2 and tert-butyl hydroperoxide in water (pH 7.4) at 37 degrees C, with rate constants of 1.9 +/- 0.3 x 10(-2) and 9.5 +/- 0.3 x 10(-4) M(-1) s (-1) (paralleling recently developed synthetic antioxidants) being quantitatively (>97%) converted to GRE. It is demonstrated that GRH-ITC has interesting antioxidant/radical scavenging properties, associated with a selective cytotoxic/apoptotic activity toward three human colon carcinoma cell lines, and very limited toxicity on normal human T-lymphocytes.  相似文献   
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