Influence of wood origin in the polyphenolic composition of a Spanish red wine aging in bottle, after storage in barrels of Spanish, French and American oak wood

In this paper, the changes in the composition of a red wine obtained from Tempranillo grapes (Vitis vinifera L.), stored from 12 to 24 months in bottles were studied. The wine was previously aging for 21 months in barrels made of Spanish oak wood (Quercus spp.). The changes of chromatic data, global polyphenolic families assessment (polyphenols, catechins, proanthocyanidins and anthocyanins) and individually polyphenols by HPLC during their storage time in bottles were studied and compared with these of the same wine aged in barrels made of French oak and American oak and stored in bottle for 24 months. Samples of wines obtained after 12 months in bottle were also compared with those after 24 months. The stepwise discriminant analysis with data of chromatic parameters and global polyphenolic families indicates that the wines aged in Spanish and French oak wood barrels, after 24 months stored in bottle, have similar characteristics, but they are significantly different to those of wines aged in barrels made of American oak wood. Regarding the analysis of individually non-anthocyanic polyphenols, discriminant analysis shows that wines stored for 24 months in bottle, aged in barrels made of Spanish, French and American oak woods, show overlapping results, while those from wines after 12 months in bottle are more dispersed. The discriminant analysis carried out on anthocyanidin concentrations of wines stored 24 months in bottles has shown three groups according the kind of wood used, indicating that wines aged in Spanish and French oak barrels are much more similar in anthocyanidin concentrations than those aged in the American barrels.     

老化甜菜种子微波处理与苗期发育的生化响应

以不同时间和功率的微波对老化甜菜种子进行预处理,对盆栽条件下甜菜幼苗叶片Rubisco含量、蛋白水解酶活性、内源性H2O2水平、抗氧化酶活性及相关性进行了研究。结果表明,微波能不同程度的影响老化甜菜种子萌发后幼苗体内的早期碳氮代谢及物质转化,其影响强度因微波处理时间和生化指标的敏感度不同而异。400W8-13S微波处理,显著缓解了因种子老化造成的氧化胁迫,降低了心O,水平,SOD、APX的同步高水平表达及APX的持续作用,有机调控了老化甜菜种子幼苗体内ROS的产生和清除之间的动态平衡。400W13-18S微波处理,蛋白水解酶活性最低,说明该剂量的微波辐射通过对H2O2的去毒作用,降低了蛋白水解酶的活性和对这一分子信号的敏感性。ROS水平的变化,钝化了蛋白水解酶系统,从而减缓了Rubisco的降解,并激活了Rubisco相关基因的表达,使叶片中主要执行光合作用的可溶性蛋白Rubisco合成增加。在设定处理组合中,中火400W瞬时处理13s为促进老化种子苗期发育的最佳处理。     

Aging and failure mode of electrochemical double layer capacitors during accelerated constant load tests

Electrochemical double layer capacitors of the BCAP0350 type (Maxwell Technologies) were tested under constant load conditions at different voltages and temperatures. The aging of the capacitors was monitored during the test in terms of capacitance, internal resistance and leakage current. Aging was significantly accelerated by elevated temperature or increased voltage. Only for extreme conditions at voltages of 3.5 V or temperatures above 70 °C the capacitors failed due to internal pressure build-up. No other failure events such as open circuit or short circuit were detected. Impedance measurements after the tests showed increased high frequency resistance, an increased distributed resistance and most likely an increase in contact resistance between electrode and current collector together with a loss of capacitance. Capacitors aged at elevated voltages (3.3 V) exhibited a tilting of the low frequency component, which implies an increase in the heterogeneity of the electrode surface. This feature was not observed upon aging at elevated temperatures (70 °C).     

Resveratrol: preventing properties against vascular alterations and ageing

Cardiovascular diseases are the leading cause of death in developed countries where the common pathological substrate underlying this process is atherosclerosis. Several new concepts have emerged in relation to mechanisms that contribute to the regulation of the vascular diseases and associated inflammatory effects. Recently, potential antioxidants (vitamin E, polyphenols) have received much attention as potential anti-atherosclerotic agents. Among the polyphenols with health benefic properties, resveratrol, a phytoalexin of grape, seem to be a good candidate protecting the vascular walls from oxidation, inflammation, platelet aggregation, and thrombus formation. In this review, we focus on the mechanism of resveratrol cardiovascular benefic effects. We analyze, in relation with the different steps of atherosclerotic process, the resveratrol properties at multiple levels, such as cellular signaling, enzymatic pathways, apoptosis, and gene expression. We show and discuss the relationship with reactive oxygen species, regulation of pro-inflammatory genes including cycloxygenases and cytokines in molecular inflammatory and aging processes, and how the regulation of these activites by resveratrol can lead to a prevention of vascular diseases.     

Study of the impact of reactants utilization on the performance of PEMFC commercial stacks by impedance spectroscopy

Reactants utilization is a key stake for a PEMFC system: a too low utilization leads to a waste of reactant but a too high utilization may result in a detrimental starvation. To study these impacts, two commercial stacks were characterised by impedance spectroscopy under different hydrogen and oxygen utilizations (from nominal conditions to quasi-starvation). One was fresh while the other was operated on-field during 10,000 h. This study shows that the two capacitive loops in the lowest frequency range (1 Hz and below) correspond respectively to oxygen and hydrogen mass transfer limitations: the limiting reactant can be clearly identified from the impacted frequencies. The size of these loops was increased by up to 30% when the cell operated at high reactant utilizations. These results could therefore pave the way to the development of algorithms able to estimate the degree of starvation of some cells.     

板栗制品老化检测方法的研究

本文研究了检测板栗制品老化的几种方法.结果表明:硬度法,离心水质量法,碘吸光度法和酶水解法为检测板栗制品老化的代表方法.其中,硬度法比较简单,但不适合于精确测量;离心水法适合检测与直链淀粉有关的老化;碘吸光度法可以间接地反映淀粉的老化;酶水解法可用于检测淀粉的老化,但是过程比较繁琐.     

The prevalence of olfactory deficits and their effects on eating behavior from childhood to old age: A large-scale study in the French population

Olfaction is crucial for many aspects of daily life and its alteration is quite common. Here, we set up a large-scale investigation of olfactory deficits in a sample of French individuals in order to examine the prevalence of smell dysfunction and its effects on eating behavior across lifespan, by combining self-reports and psychophysical testing. In a sample of 3685 male and female individuals aged 4 to 89 years old, we showed that the overall prevalence of olfactory dysfunction as measured by psychophysical testing was 17% and varied with age and gender: from 10% in 4–12 year-old children to >30% after 60 years of age; overall, women were less often affected than men. When olfactory abilities were self-evaluated, the prevalence was 6%, suggesting that a large majority of participants were unaware of their olfactory disorder. The prevalence of qualitative smell disorders (parosmia and phantosmia) was much lower (1%). In terms of eating behavior, the effects were present but small: olfactory deficits impact eating behavior of people in different age groups differently. Taken together, these findings highlight the high prevalence of olfactory dysfunctions in the general population, not only in the elderly. They also emphasize the potential consequences of smell dysfunctions on eating behavior. The present results should attract health services’ attention since smell dysfunctions may have consequences on nutrition and health especially in the elderly.     

丝织品人工老化水解实验研究

模拟丝织品文物出土前在水中浸泡的状况,对植物染色的桑蚕丝绸进行水解老化实验,研究潮湿环境对丝织品文物老化所产生的影响,探讨染色丝绸的色彩在去离子水长期浸泡情况下的变化规律。研究涉及了6种丝绸样品:白色丝绸、红色丝绸、黄色丝绸、茶色丝绸、蓝色丝绸和黑色丝绸。通过对实验样品的色差分析,发现了各种颜色的丝绸样品在水解老化时的色泽变化规律,可以作为确定彩色丝织品文物保存环境的参考。     

Hydrogen diffusion and the effect of hydrogen on structural transformations in binary TiNi based alloys

The paper analyzes the effect of electrolytic hydrogenation on martensite transformation temperatures in binary TiNi alloys. The analysis shows that this effect can be strong or weak depending on the phase state of TiNi. Research data are presented on the diffusivity of hydrogen in binary TiNi alloys in martensite and austenite states. The diffusion coefficient of hydrogen is estimated from its distribution measured by glow discharge spectroscopy in TiNi after hydrogenation. The experimental results about the formation of TiNiH hydride in the martensitic and austenitic state in binary TiNi based alloys are also presented.