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991.
Park EK Watanabe T Gee SJ Schenker MB Hammock BD 《Journal of agricultural and food chemistry》2008,56(2):333-336
A simple, sensitive, and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for determining urinary creatinine was developed and used to evaluate 24 h urine samples collected during an exposure study. Urine (1 microL) was diluted with methanol and then directly applied to LC-MS/MS. Under electrospray ionization (ESI) conditions, the transition molecules of creatinine and creatinine- d3 were observed at m/ z 114 > 44 and m/ z 117 > 47, respectively. The retention time of creatinine was 0.59 min. The linear range was 1-2000 ng/mL, with a detection limit in urine of 1 ng/mL. LC-MS/MS and colorimetric end-point methods were significantly associated ( R2 = 0.8785, p < 0.0001). The LC-MS/MS method to determine creatinine in 24 h urine samples had shorter retention times, was more sensitive, reliable, reproducible, simple, selective, and used a smaller sample size than other LC-MS/MS or commercial methods. 相似文献
992.
993.
Pablo Modernel Valentin Picasso Martin Do Carmo Walter A. H. Rossing Marc Corbeels Pablo Soca Santiago Dogliotti Pablo Tittonell 《Grass and Forage Science》2019,74(4):636-649
Droughts in southern South America affect grazing systems in many ways. They reduce biomass productivity; decrease livestock feed intake, weight and reproductive performance; increase farmers’ costs; and reduce farm income. It was hypothesized that simple grazing management variables affect the resilience of grazing systems to droughts at the paddock and farm scales. The effects of grazing management on herbage and animal production were assessed at paddock level, and how technological and structural variables relate to the production and economic performances at farm level. Results of a grazing experiment controlling herbage allowance at paddock level showed that resistance of herbage accumulation and animal live weight to drought was significantly higher for paddocks with higher pre‐drought herbage allowance than for those managed to low herbage allowance treatments. A strong positive linear relationship was found between pre‐drought herbage height and resistance of herbage accumulation rate (p < .01). In a longitudinal study of nine farms in Uruguay, resistance of cow pregnancy rate to drought was positively correlated with cow pregnancy rate (r = .72, p = .02) and farm net income (r = .78, p = .02), and negatively correlated with sheep‐to‐cattle ratio (r = ?.80, p = .01). These correlations suggest that farms with higher incomes and low proportions of sheep in the herd withstand drought better (in terms of pregnancy rate). Four common regional production strategies were identified that react differently when farmers face drought, and these results can aid farmers in those regions to design more resilient mixed livestock farming systems and can inform policymakers about effective strategies for mitigating drought impacts in the region. 相似文献
994.
Causes of color changes in wood during drying 总被引:3,自引:0,他引:3
The forest industry operates in a dynamic and global market where change and competition are the rule rather than the 相似文献
995.
与肠道有关的健康问题,如慢性肠炎,正不断成为世界各地广为认可的疾病.荷兰研究人员发现一种天然的饲料原料与额外添加的维生素和矿物质联合使用是对抗母鸡慢性肠炎的一种有前途的方法. 相似文献
996.
997.
Bartholomay LC Waterhouse RM Mayhew GF Campbell CL Michel K Zou Z Ramirez JL Das S Alvarez K Arensburger P Bryant B Chapman SB Dong Y Erickson SM Karunaratne SH Kokoza V Kodira CD Pignatelli P Shin SW Vanlandingham DL Atkinson PW Birren B Christophides GK Clem RJ Hemingway J Higgs S Megy K Ranson H Zdobnov EM Raikhel AS Christensen BM Dimopoulos G Muskavitch MA 《Science (New York, N.Y.)》2010,330(6000):88-90
998.
999.
Anne-Marie Gagné Konstantin V Danilenko Serge G Rosolen Marc Hébert 《Journal of circadian rhythms》2009,7(1):14-7
Background
In the eye, melatonin plays a role in promoting light sensitivity at night and modulating many aspects of circadian retinal physiology. It is also an inhibitor of retinal dopamine, which is a promoter of day vision through the cone system. Consequently, it is possible that oral melatonin (an inhibitor of retinal dopamine) taken to alleviate circadian disorders may affect cone functioning. Our aim was to assess the impact of melatonin on the cone response of the human retina using electroretinography (ERG). 相似文献1000.
Sanden M Stubhaug I Berntssen MH Lie Ø Torstensen BE 《Journal of agricultural and food chemistry》2011,59(23):12697-12706
The objective of the present study was to investigate the effects of replacing high levels of marine ingredients with vegetable raw materials and with emphasis on lipid metabolism and net production of long-chain polyunsaturated ω-3 fatty acids (EPA + DHA). Atlantic salmon were fed three different replacement vegetable diets and one control marine diet before sensory attributes, β-oxidation capacity, and fatty acid productive value (FAPV) of ingested fatty acids (FAs) were evaluated. Fish fed the high replacement diet had a net production of 0.8 g of DHA and a FAPV of 142%. Fish fed the marine diet had a net loss of DHA. The present work shows that Atlantic salmon can be a net producer of marine DHA when dietary fish oil is replaced by vegetable oil with minor effects on sensory attributes and lipid metabolism. 相似文献