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31.
ABSTRACT: To determine whether honey and sucrose would have differential effects on weight gain during long-term feeding, 45 2-mo-old Sprague Dawley rats were fed a powdered diet that was either sugar-free or contained 7.9% sucrose or 10% honey ad libitum for 52 wk (honey is 21% water). Weight gain was assessed every 1 to 2 wk and food intake was measured every 2 mo. At the completion of the study blood samples were removed for measurement of blood sugar (HbA1c) and a fasting lipid profile. DEXA analyses were then performed to determine body composition and bone mineral densities. Overall weight gain and body fat levels were significantly higher in sucrose-fed rats and similar for those fed honey or a sugar-free diet. HbA1c levels were significantly reduced, and HDL-cholesterol significantly increased, in honey-fed compared with rats fed sucrose or a sugar free diet, but no other differences in lipid profiles were found. No differences in bone mineral density were observed between honey- and sucrose-fed rats, although it was significantly increased in honey-fed rats compared with those fed the sugar-free diet. 相似文献
32.
Energy efficiency and greenhouse gas emissions are closely linked. This paper reviews agricultural options to reduce energy
intensities and their impacts, discusses important accounting issues related to system boundaries, land scarcity, and measurement
units and compares agricultural energy intensities and improvement potentials on an international level. Agricultural development
in recent decades, while increasing yields, has led to lower average energy efficiencies when comparing the 1960s and the
mid 1980s. In the two decades thereafter, energy intensities in developed countries increased, but with little impact on greenhouse
gas emissions. Efficiency differences across countries in the year 2000 suggest a maximum improvement potential of 500 million
tons of CO2 annually. If only below average countries would increase their energy efficiency to average levels of the year 2000, the
resulting emission reductions would be below 200 million tons of CO2 annually.
相似文献
Pete SmithEmail: URL: http://www.abdn.ac.uk/biologicalsci/staff/details/pete.smith |
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A supersensitivity of the formation and stabilization of transition-metal nanoclusters to the initial nanocluster concentration and temperature synthesis conditions is reported, then probed, herein for the specific case of prototype Ir(O)n nanoclusters prepared from the organometallic precursor [Bu4N]5Na3[(1,5-COD)Ir x P2W15Nb3O62] by reduction with H2 in propylene carbonate solvent. Fully isolable, redissolvable, near-monodisperse (i.e., < or = +/- 15% size distribution) and thus excellent Ir(O)n nanoclusters are formed using low temperature (22 degrees C) and moderate precursor concentration (1.2 mM) in propylene carbonate solvent. However, inferior, polydisperse (+/- 40% size distribution), non-redispersable nanoclusters are formed at the seemingly only moderately different conditions of 38 degrees C higher temperature (i.e., 60 degrees C) and 5-fold lower precursor concentration (0.24 mM). Investigation of this supersensitivity to the nanocluster synthesis conditions reveals that it derives from the dissociation of (1,5-COD)Ir(solvent)2+ from the P2W15Nb3O62(9-) polyanionic ligand/ stabilizer, subsequently resulting in a too fast, kinetically uncontrolled reduction of the quickly reduced (1,5-COD)Ir(solvent)2+ as the cause of the inferior synthesis of polydisperse, non-isolable, non-redissolvable nanoclusters. The results are significant in that they illustrate that understanding the mechanism of nanocluster formation, and then performing the nanocluster synthesis under kinetically carefully controlled, understood conditions, is necessary for the formation of superior nanoclusters in this, and by implication probably many other, cases. 相似文献
35.
Ochratoxin A in dried vine fruit: method development and survey 总被引:7,自引:0,他引:7
Susan MacDonald Pete Wilson Karen Barnes Andrew Damant Rob Massey Eileen Mortby Martin J. Shepherd 《Food Additives & Contaminants》1999,16(6):253-260
A method is described for the determination of concentrations of the mycotoxin ochratoxin A in dried vine fruits (currants, raisins and sultanas) using acidic methanolic extraction,immunoaffinity chromatography clean-up and HPLC determination. The limit of detection was estimated as 0.2mug/kg, and recoveries of 63-77% were achieved at 5mug/kg. HPLC-mass spectrometric confirmation of the identity of ochratoxin was obtained. Ochratoxin A and aflatoxins were determined in 60 samples of retail dried vine fruits purchased in the United Kingdom. Ochratoxin A was found in excess of 0.2mug/kg in 19 of 20 currant, 17 of 20 sultana and 17 of 20 raisin samples examined, an overall incidence of 88% . The maximum level found was 53.6mug/kg. No aflatoxin was found in any sample analysed, using a method with a detection limit of 0.2mug/kg for each of aflatoxin B1, B2, G1 and G2. 相似文献
36.
David Petti John Maki John Hunn Pete Pappano Charles Barnes John Saurwein Scott Nagley Jim Kendall Richard Hobbins 《JOM Journal of the Minerals, Metals and Materials Society》2010,62(9):62-66
The high outlet temperatures and high thermal-energy conversion efficiency of modular high-temperature gas-cooled reactors (HTGRs) enable an efficient and cost-effective integration of the reactor system with non-electricity-generation applications, such as process heat and/or hydrogen production, for the many petrochemical and other industrial processes that require temperatures between 300°C and 900°C. The U.S. Department of Energy (DOE) has selected the HTGR concept for the Next Generation Nuclear Plant (NGNP) Project as a transformative application of nuclear energy that will demonstrate emissions-free nuclear-assisted electricity, process heat, and hydrogen production, thereby reducing greenhouse-gas emissions and enhancing energy security. The objective of the DOE Advanced Gas Reactor (AGR) Fuel Development and Qualification program is to qualify tristructural isotropic (TRISO)-coated particle fuel for use in HTGRs. An overview of the program and recent progress is presented. 相似文献
37.
Smith S Collaku A Heaslip L Yue Y Starkey YY Clarke G Kronfeld N 《Drug development and industrial pharmacy》2012,38(3):372-379
The objective of this study was to compare the rate and extent of paracetamol absorption from the new Paracetamol pediatric suspension (PPS) with two marketed paracetamol suspensions: Children's panadol (CP) and Panodil baby & infant (PBI). The study also assessed the effect on paracetamol absorption of light-calorie, low-fat food consumed 2?h before dosing. Twenty eight male adult volunteers received a single oral dose of 1000?mg of paracetamol from each of three treatments, in both fasted and fed states according to a randomized, single-center, open-label, six-way crossover study design. PPS was bioequivalent to both CP and PBI for AUC(0-10 h), AUC(0-inf) and C(max) in both fasted and fed state. However, PPS had greater rate of paracetamol absorption and a faster speed of onset. T(max) for PPS was significantly shorter than for PBI in both fasted (p?=?0.0005) and fed state (p?=?0.0001). Median T(max) for PPS was also 10?min shorter than CP in fasted state. Time to reach minimum effective concentration (MEC) for PPS was significantly shorter than CP and PBI. Early paracetamol exposure of PPS was significantly higher than that of the two existing paracetamol products. Food had a significant effect in the early exposure and onset of therapeutic level of paracetamol from PPS. AUC(0-30 min) was significantly higher and time to reach plasma paracetamol at MEC level was significantly shorter than in the fasted state. 相似文献
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We have recently introduced several important improvements in the measurement of distillation curves for complex fluids. The modifications include a composition-explicit data channel for each distillate fraction (for both qualitative and quantitative analysis) and corrosivity assessment of each distillate fraction. The composition-explicit information is achieved with a new sampling approach that allows precise qualitative as well as quantitative analyses of each fraction, on the fly. We have applied the new method to a variety of fluids, including simple n-alkanes, rocket propellant, gasoline, jet fuels, and a hydrocarbon fluid made corrosive with dissolved hydrogen sulfide. In the current contribution, we present the application of the advanced distillation curve method to two samples of crude oil. A primary motivation behind the work is to precisely measure the distillation curves of these oils using our advanced distillation apparatus; these low uncertainty measurements of true thermodynamic state points can be used for equation of state development and differentiation of crude oil samples. Then, the information content of each distillation was extended much further by use of the composition-explicit data channel: gas chromatography–mass spectrometry (GC–MS), infrared spectrophotometry (IR), gas chromatography with sulfur chemiluminescence detection (GC–SCD), and the copper strip corrosion test (CSCT) were used for each distillate volume fraction sampled. Consequently, for each volume fraction of crude oil distillate sampled, we can address the composition, quantitate the total sulfur content, and measure the corrosivity. 相似文献
40.
Setia R Smith P Marschner P Gottschalk P Baldock J Verma V Setia D Smith J 《Environmental science & technology》2012,46(3):1624-1631
Soil organic carbon (SOC) models are used to predict changes in SOC stocks and carbon dioxide (CO(2)) emissions from soils, and have been successfully validated for non-saline soils. However, SOC models have not been developed to simulate SOC turnover in saline soils. Due to the large extent of salt-affected areas in the world, it is important to correctly predict SOC dynamics in salt-affected soils. To close this knowledge gap, we modified the Rothamsted Carbon Model (RothC) to simulate SOC turnover in salt-affected soils, using data from non-salt-affected and salt-affected soils in two agricultural regions in India (120 soils) and in Australia (160 soils). Recently we developed a decomposition rate modifier based on an incubation study of a subset of these soils. In the present study, we introduce a new method to estimate the past losses of SOC due to salinity and show how salinity affects future SOC stocks on a regional scale. Because salinity decreases decomposition rates, simulations using the decomposition rate modifier for salinity suggest an accumulation of SOC. However, if the plant inputs are also adjusted to reflect reduced plant growth under saline conditions, the simulations show a significant loss of soil carbon in the past due to salinization, with a higher average loss of SOC in Australian soils (55 t C ha(-1)) than in Indian soils (31 t C ha(-1)). There was a significant negative correlation (p < 0.05) between SOC loss and osmotic potential. Simulations of future SOC stocks with the decomposition rate modifier and the plant input modifier indicate a greater decrease in SOC in saline than in non-saline soils under future climate. The simulations of past losses of SOC due to salinity were repeated using either measured charcoal-C or the inert organic matter predicted by the Falloon et al. equation to determine how much deviation from the Falloon et al. equation affects the amount of plant inputs generated by the model for the soils used in this study. Both sets of results suggest that saline soils have lost carbon and will continue to lose carbon under future climate. This demonstrates the importance of both reduced decomposition and reduced plant input in simulations of future changes in SOC stocks in saline soils. 相似文献