Influence of oil type on the amounts of acrylamide generated in a model system and in French fries     

Mestdagh FJ  De Meulenaer B  Van Poucke C  Detavernier C  Cromphout C  Van Peteghem C 《Journal of agricultural and food chemistry》2005,53(15):6170-6174

Acrylamide formation was studied by use of a new heating methodology, based on a closed stainless steel tubular reactor. Different artificial potato powder mixtures were homogenized and subsequently heated in the reactor. This procedure was first tested for its repeatability. By use of this experimental setup, it was possible to study the acrylamide formation mechanism in the different mixtures, eliminating some variable physical and chemical factors during the frying process, such as heat flux and water evaporation from and oil ingress into the food. As a first application of this optimized heating concept, the influence on acrylamide formation of the type of deep-frying oil was investigated. The results obtained from the experiments with the tubular reactor were compared with standardized French fry preparation tests. In both cases, no significant difference in acrylamide formation could be found between the various heating oils applied. Consequently, the origin of the deep-frying vegetable oils did not seem to affect the acrylamide formation in potatoes during frying. Surprisingly however, when artificial mixtures did not contain vegetable oil, significantly lower concentrations of acrylamide were detected, compared to oil-containing mixtures.  相似文献   

Changes in soil chemistry associated with the establishment of forest gardens on eroded,acidified grassland soils in Sri Lanka     

Ilyas Siddique  Caroline Gutjahr  Gamini Seneviratne  Broder Breckling  Sudheera W. Ranwala  Ian J. Alexander 《Biology and Fertility of Soils》2007,44(1):163-170

Topsoil properties were determined in forest gardens established about 20 years ago on eroded grassland soils (abandoned tea lands) in the wet zone of the Sri Lankan highlands. They were compared with adjacent, eroded grasslands (abandoned tea lands) on strongly weathered soils vs soils at earlier stages of pedogenic development in a two-way analysis of variance. Soil pH in forest gardens was, on average, 6.1, nearly one unit higher than in the adjacent grasslands. In the garden soils, the cation exchange capacity (CEC measured at pH 4.8) was nearly double, exchangeable calcium concentrations five times and exchangeable magnesium three times as high as in the grasslands soils. Total soil N content was found to be nearly 40% higher in the gardens. Topsoil gravel contents in the gardens were less than half as high as in the grasslands. The increases in exchangeable bases and N in gardens, relative to grasslands, were attributed to increased nutrient retention and acquisition. Higher retention was partly due to the higher CEC_pH4.8, and probably to reduced erosion and increased, continuous fine root density in the garden topsoils. Higher field CEC in gardens was likely to result from generally higher C contents and from the reversal of acidification, presumably caused by base accumulation and decomposition processes. Our results suggest that forest garden establishment on degraded grasslands can lead to accumulation of mobile nutrients in the topsoil, probably due to increased nutrient retention, subsoil uptake and litter input exceeding nutrient uptake by the standing biomass.  相似文献   

Cellular uptake and efflux of trans-piceid and its aglycone trans-resveratrol on the apical membrane of human intestinal Caco-2 cells     

Henry C  Vitrac X  Decendit A  Ennamany R  Krisa S  Mérillon JM 《Journal of agricultural and food chemistry》2005,53(3):798-803

Two stilbenes (trans-piceid and its aglycone trans-resveratrol) were investigated in the uptake across the apical membrane of the human intestinal cell line Caco-2 in order to determine their mechanisms of transport. The uptake was quantified using a reverse phase high-performance liquid chromatography method with fluorescence detection. The rate of cellular accumulation in the cells was found to be higher for trans-resveratrol than for trans-piceid. In addition, trans-resveratrol uses passive transport to cross the apical membrane of the cells, whereas the transport of trans-piceid is likely active. With regard to the mechanisms of transport, the involvement of the active transporter SGLT1 in the absorption of trans-piceid was deduced using various inhibitors directly or indirectly exploiting the activity of this transporter (glucose, phlorizin, and ouabain). Moreover, we investigated the involvement of the multidrug-related protein 2 (MRP2), an efflux pump present on the apical membrane, in stilbene efflux by Caco-2 cells. The effect of MK-571 (an MRP inhibitor) seems to implicate MRP2 as responsible for apical efflux of trans-piceid and trans-resveratrol.  相似文献   

Folic acid supplementation and social deprivation     

Relton CL  Hammal DM  Rankin J  Parker L 《Public health nutrition》2005,8(3):338-340

OBJECTIVE: To assess the use of folic acid supplementation in relation to small-area measures of social deprivation. DESIGN: Cohort study. SETTING: Antenatal clinic, Women's Outpatients Services, Cumberland Infirmary, Carlisle, UK. SUBJECTS: Four hundred and fifty women attending their 18-week antenatal clinic appointment. No selection criteria were applied. Townsend scores were allocated using postcodes to provide a small-area measure (enumeration district) of social deprivation. RESULTS: Eighty-nine per cent of women took folic acid prior to their 18-week antenatal clinic appointment; 48% of women took folic acid before 4 weeks of gestation. Younger women and more socially deprived women were less likely to use folic acid supplements before 4 weeks of gestation. Women with a family history of neural tube defects were no more likely to take folic acid than were women with no family history of neural tube defects. CONCLUSION: A high proportion of women reported taking folic acid supplements during pregnancy but less than half took them at the most important time in early pregnancy. Younger women and women who were more socio-economically deprived were much less likely to take folic acid during the critical periconceptional period. Future strategies should promote prenatal folic acid supplementation in women under the age of 24 and in women of low socio-economic status. Further attention should also be given to the use of folic acid supplements in women with a family history of neural tube defects.  相似文献   

Changes in photosynthesis and antioxidant metabolism of cotton (Gossypium hirsutum L.) plants in response to manganese stress     

Renan Francisco Rimoldi Tavanti  Grace David Queiroz  Anne Caroline Da Rocha Silva  Walmor Moya Peres  Amanda Pereira Paixão  Fernando Shintate Galindo 《Archives of Agronomy and Soil Science》2020,66(6):743-762

ABSTRACT

This study aimed to assess the physiological and biochemical responses of cotton plants to manganese (Mn²⁺) nutrition. Four cotton genotypes (G1 – TMG 47; G2 – FM 975 WS; G3 – TMG 11 WS and G4 – IMA 8405 GLT) were grown in nutrient solution under two Mn²⁺ concentrations (2 and 200 µmol L^?1) for 10 days. No visible symptoms of Mn²⁺ toxicity were observed in the genotypes tested. All genotypes showed a marked increase in leaf chlorophylls, pheophytins, carotenoids, sucrose and total sugars concentration in response to high Mn²⁺ in a nutrient solution. However, the net photosynthetic rate, stomatal conductance, internal carbon dioxide concentration and transpiration decreased in genotypes G1 and G2 growing under 200 µmol L^?1. Antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activities increased in genotypes G1, G3 and G4. Cotton genotypes showed an increased leaf antioxidant and sugar metabolism as a possible strategy to mitigate oxidative stress. The decrease in the net photosynthetic rate and stomatal conductance; the increased antioxidant enzymes activities (SOD, APX and GR); and the increase in leaf sucrose and total sugar concentration were the main physiological and biochemical responses in cotton plants to Mn²⁺ stress.  相似文献   

Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis     

Jen JC  Chan WM  Bosley TM  Wan J  Carr JR  Rüb U  Shattuck D  Salamon G  Kudo LC  Ou J  Lin DD  Salih MA  Kansu T  Al Dhalaan H  Al Zayed Z  MacDonald DB  Stigsby B  Plaitakis A  Dretakis EK  Gottlob I  Pieh C  Traboulsi EI  Wang Q  Wang L  Andrews C  Yamada K  Demer JL  Karim S  Alger JR  Geschwind DH  Deller T  Sicotte NL  Nelson SF  Baloh RW  Engle EC 《Science (New York, N.Y.)》2004,304(5676):1509-1513

The mechanisms controlling axon guidance are of fundamental importance in understanding brain development. Growing corticospinal and somatosensory axons cross the midline in the medulla to reach their targets and thus form the basis of contralateral motor control and sensory input. The motor and sensory projections appeared uncrossed in patients with horizontal gaze palsy with progressive scoliosis (HGPPS). In patients affected with HGPPS, we identified mutations in the ROBO3 gene, which shares homology with roundabout genes important in axon guidance in developing Drosophila, zebrafish, and mouse. Like its murine homolog Rig1/Robo3, but unlike other Robo proteins, ROBO3 is required for hindbrain axon midline crossing.  相似文献   

CoRoT measures solar-like oscillations and granulation in stars hotter than the Sun     

Michel E  Baglin A  Auvergne M  Catala C  Samadi R  Baudin F  Appourchaux T  Barban C  Weiss WW  Berthomieu G  Boumier P  Dupret MA  Garcia RA  Fridlund M  Garrido R  Goupil MJ  Kjeldsen H  Lebreton Y  Mosser B  Grotsch-Noels A  Janot-Pacheco E  Provost J  Roxburgh IW  Thoul A  Toutain T  Tiphène D  Turck-Chieze S  Vauclair SD  Vauclair GP  Aerts C  Alecian G  Ballot J  Charpinet S  Hubert AM  Lignières F  Mathias P  Monteiro MJ  Neiner C  Poretti E  de Medeiros JR  Ribas I  Rieutord ML  Cortés TR  Zwintz K 《Science (New York, N.Y.)》2008,322(5901):558-560

Oscillations of the Sun have been used to understand its interior structure. The extension of similar studies to more distant stars has raised many difficulties despite the strong efforts of the international community over the past decades. The CoRoT (Convection Rotation and Planetary Transits) satellite, launched in December 2006, has now measured oscillations and the stellar granulation signature in three main sequence stars that are noticeably hotter than the sun. The oscillation amplitudes are about 1.5 times as large as those in the Sun; the stellar granulation is up to three times as high. The stellar amplitudes are about 25% below the theoretic values, providing a measurement of the nonadiabaticity of the process ruling the oscillations in the outer layers of the stars.  相似文献   

Reimagining cities. Introduction     

Ash C  Jasny BR  Roberts L  Stone R  Sugden AM 《Science (New York, N.Y.)》2008,319(5864):739

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Trypanosomatid genomes. Introduction     

Ash C  Jasny BR 《Science (New York, N.Y.)》2005,309(5733):399

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Preserved feedforward but impaired top-down processes in the vegetative state     

Boly M  Garrido MI  Gosseries O  Bruno MA  Boveroux P  Schnakers C  Massimini M  Litvak V  Laureys S  Friston K 《Science (New York, N.Y.)》2011,332(6031):858-862

Frontoparietal cortex is involved in the explicit processing (awareness) of stimuli. Frontoparietal activation has also been found in studies of subliminal stimulus processing. We hypothesized that an impairment of top-down processes, involved in recurrent neuronal message-passing and the generation of long-latency electrophysiological responses, might provide a more reliable correlate of consciousness in severely brain-damaged patients, than frontoparietal responses. We measured effective connectivity during a mismatch negativity paradigm and found that the only significant difference between patients in a vegetative state and controls was an impairment of backward connectivity from frontal to temporal cortices. This result emphasizes the importance of top-down projections in recurrent processing that involve high-order associative cortices for conscious perception.  相似文献