Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the co-localization of organic and inorganic species in specific layers (e.g. egg yolk paint atop a glue ground). Because of this ability to localize the analytical signal to approximately 6?µm or less, the mass spectral information can be used to produce mass-resolved and spatially-resolve images which can be correlated to previous studies of the same samples. In this study, ToF-SIMS was used to analyze a paint cross section obtained from a painting attributed to Raphael, and another from a painting by the Sienese artist Matteo di Giovanni.     

接骨木果实营养成分的分析

本文利用氨基酸自动分析仪、等离子发射光谱仪和高效液相色谱仪等仪器，对接骨木果实氨基酸含量，微量元素含量营养成分进行了测定，从而为接骨木的进一步开发利用提供了营养学方面的依据。     

Profile of Plasma Amino Acid Levels in Rats Exposed to Acute Hypoxic Hypoxia

The effect of acute hypoxic hypoxia on the profile of plasma amino acids in rats was studied and compared to that resulting from acute liver injury induced by giving carbon tetrachloride. In hypoxic rats exposed to 45% air in N₂ for 5 h, the concentrations of branched chain amino acids, including valine, leucine and isoleucine, and aromatic amino acids such as phenylalanine and tyrosine were significantly increased as compared to those in normoxic rats. The ratio of branched-chain to aromatic amino acids (Fischer’s ratio) was significantly decreased. The levels of arginine and citrulline, which are related to the urea cycle, were also depressed. Furthermore, plasma proline level was reduced in hypoxic rats. The activities of plasma marker enzymes for tissue damage remained unchanged during hypoxia, indicating that tissue injury was not induced by exposure to hypoxic conditions. We suggest that the characteristic profile of plasma amino acids and the Fischer ratio are valuable tools for understanding the pathology of acute hypoxia in the absence of systemic tissue damage.     

浙江省优秀男子摔跤运动员控体前后脂肪酸的组成变化研究

以浙江省优秀男子摔跤运动员为研究对象,通过研究控体前后不同运动员血清脂肪酸的代谢情况,尤其是n-3多不饱和脂肪酸的变化情况,为运动员减控体重方案的制定与具体实施提供依据。结果显示,控体前后,运动员血清脂肪酸的组成和含量均发生了显著性变化,不饱和脂肪酸量总量都在升高,总的n-3多不饱和脂肪酸含量也都有所升高,而且不同运动员由于自身体质状况的不同,对控体前后产生的反应也存在一定的差异。     

Diagnosis of Major Organic Acidurias in Children: Two Years Experience at a Tertiary Care Centre

Organic acid disorders are inherited metabolic disorders in which organic acids accumulate in tissues and biological fluids of affected individuals. Classical organic acidurias include methylmalonic aciduria, propionic aciduria, isovaleric aciduria and maple syrup urine disease (MSUD). They are considered the most frequent metabolic disorders among severely ill children. Patients frequently present with acute symptoms early in life. 420 cases clinically suspected to have organic aciduria, with upper age limit of 12 years for a 2-year period (January 2007–December 2008) were enrolled into this study. Metabolic acidosis and neurological symptoms were the most common signs. Screening tests and thin layer chromatography were done for detection of organic acidurias. Identification and quantitation of organic acids in urine and quantification of amino acids in blood were done by high performance liquid chromatography. Out of 420 patients, 45 patients (10.7%) were found to have organic acidurias. 15 cases of methylmalonic aciduria, 16 cases of propionic aciduria, 13 cases of MSUD, and one case of isovaleric aciduria were diagnosed. Results demonstrate the importance of testing for organic acidurias. Since organic aciduria may cause irreversible brain damage if not treated, we recommend selective screening amongst severely ill children despite implied extra costs.     

运动员补糖、支链氨基酸和乳清蛋白的临床应用观察

目的：观察补充糖饮料、支链氨基酸和乳清蛋白等能量物质对阶段性大运动量训练维持或提高运动员身体机能和疲劳恢复的影响。方法：根据冬训阶段性训练计划安排,对10名散打运动员在30d的体能训练阶段,按营养补充方案进行能量补充,观察能量补充对机体无氧能力的输出总功、最大功率、疲劳指数,有氧能力的拉桨时间、功率、桨频,生化指标血乳酸（LA）尿素氮（BUN）、血糖（GL）、肌酸激酶（CK）的影响,另选10名队友作空白组,进行自身前后对照和空白对照。结果：观察组经过阶段性能量补充前后运动员的输出总功、最大功率、疲劳指数和桨频均显著提高（P〈0．01）,与空白组相比也有明显提高（P〈0．05）,训练课后血糖水平也明显提高（P〈0．05）,补充支链氨基酸和乳清蛋白后血BUN的恢复与空白组比有极显著好转（P〈0．001）。结论：训练期间补充糖、支链氨基酸和乳清蛋白等能量物质,能明显改善运动员的有氧运动能力和无氧运动能力,明显延缓运动性疲劳的发生,加速运动性疲劳恢复的作用。     

梗阻性黄疸肝肾细胞内胆汁酸活度的变化

本实验运用离子选择性微电极技术直接测定了鼠胆道梗阻前后肝、肾细胞内的胆汁酸活度。结果表明，胆道梗阻２周，肝、肾细胞内胆汁酸活度明显升高，其中肝细胞内达５．４６ｍｍｏｌ／Ｌ，肾细胞内达０．３７ｍｍｏｌ／Ｌ，已达到或接近体外膜损害浓度，提示胆汁酸可能是梗阻性黄疸引起肝、肾细胞超微结构损害的因素之一。     

应用生物技术选育黑优粘系列新品种的研究

本文报道了糯稻黑糯14号(♀)和粘稻特优粘9号(♂)的杂交,并应用生物技术和通过多种现代测试仪器对后代植株的检测,已成功地选育出“黑优粘”系列新品种。这些新品种具有营养价值高和产量也较高的优点。     

生物芯片的应用

生物芯片的应用是将探针固定于芯片上 ,利用核酸链间的分子杂交 ,鉴定DNA和蛋白质的一种新技术。尽管生物芯片仅仅出现几年 ,但它带来的信息却蕴藏着生物学中结构与功能的内在联系 ,其应用具有十分巨大的潜力 ,它已在功能基因组研究、新药研究、物种改良和医学诊断、军事科学等方面提供或正在提供极有价值的信息 ,已成为科学家们手中的有力武器     

Post-exercise ingestion of different amounts of protein affects plasma insulin concentration in humans

Abstract

The synergistic stimulating effect of combined intake of carbohydrate and protein on plasma insulin concentration has been reported previously. However, it remains unclear whether the amount of protein ingested after exercise affects the concentrations of plasma insulin and amino acids. This study of trained men compared the effects of post-exercise co-ingestion of carbohydrate plus different amounts of whey protein hydrolysates (WPHs) with carbohydrate alone on (1) blood biochemical parameters of carbohydrate metabolism during the post-exercise phase, and (2) endurance performance. Eight trained men exercised continuously for 70 min. Immediately after exercise and 30, 60, 90, and 120 min later, the participants received supplements containing: (1) 17.5 g carbohydrate, (2) 3.0 g WPHs and 17.5 g carbohydrate (L-WPH), or (3) 8.0 g WPHs and 17.5 g carbohydrate (H-WPH). After a 2-h recovery period, the participants performed an endurance performance test. The concentrations of blood glucose were lower and plasma insulin significantly higher in the H-WPH trial compared with the carbohydrate trial. The concentrations of plasma amino acids were increased in a dose-dependent manner following ingestion of different amounts of WPHs with carbohydrate. Endurance performance was not significantly different between the three trials. Co-ingestion of carbohydrate and H-WPH was more effective than ingestion of carbohydrate alone for stimulating insulin secretion and increasing the availability of plasma amino acids. These results suggest that plasma concentrations of amino acids during the recovery period are determined by the amount of dietary protein ingested, and that it is necessary to increase the concentration of plasma amino acids above a certain level to stimulate insulin secretion.