Trace Elements in Tephra Soils of Mounts Kupe and Manengouba (Cameroon)

Eurasian Soil Science - Increasing demographic pressure in the area around the Mounts Kupe and Manengouba (Cameroon) is leading to increased agricultural activities with potential heavy metal...     

Fresh cucumber flavor in refrigerated pickles: comparison of sensory and instrumental analysis

The ability of nonacidified, refrigerated pickled cucumbers to produce the fresh cucumber flavor impact compounds (E,Z)-2,6-nonadienal and (E)-2-nonenal declined during storage. Production of these compounds decreased as the pH of refrigerated cucumbers was reduced. Despite the fact that the concentrations of (E,Z)-2,6-nonadienal and (E)-2-nonenal generated were over 10(5)-fold greater than the threshold levels, it was possible for a sensory panel to consistently detect differences in the intensity of fresh cucumber flavor, provided the pH difference between samples was 1 unit or greater. The presence of spices did not interfere with the ability of panelists to detect differences in fresh flavor intensity. There was a linear correlation between sensory scores and the amount of (E,Z)-2,6-nonadienal produced by cucumbers equilibrated at different pH levels.     

生物质微波裂解技术的研究进展

能源是人类生存与发展的物质基础,但是矿物能源资源的有限性、不可再生性及其利用所造成的环境污染,使人们越来越重视清洁可再生的生物质能源开发利用。生物质热化学裂解已引起了越来越广泛的兴趣,但微波裂解更具优势而备受关注。为梳理生物质微波裂解技术的现状和预测未来发展方向,综述了其研究进展。同时,着重介绍了微波加热的特点、机理、优势及应用,考察了微波裂解对不同原料的加工效果及其主要研究成果,综述了微波裂解气态产物和液态产物的特点、优势与应用前景。最后预测了生物质微波裂解未来的发展方向,主要包括寻求如海藻等高效低耗的生物质原料,开发更经济高效的转化技术和设备,探索有效的生物质催化裂解技术,开发高价值的生物油及其副产品等。     

NMR转折点温度对食品储存过程中Maillard反应速率影响

采用核磁共振(NMR)技术对以葡萄糖、海藻糖、蔗糖、赖氨酸构成的模型食品进行磁共振实验,绘制体系NMR状态图并计算转折点温度,同时在不同温度下进行储藏实验,考察体系中葡萄糖的变化,评估不同储藏温度下的Maillard反应速率.结果表明:模型食品体系含水量不同、非反应组分含量不同,其NMR转折点温度有所不同.低水分含量的体系具有相对高的NMR转折点温度.即使在相同的储藏温度下,含水量相同而非反应组分含量不同的情况下,体系的Maillard反应速率也有所不同.储藏温度处于体系的NMR转折点之下时,体系的Maillard反应速率明显要比在NMR转折点温度之上要慢.由此,可以通过改变食品的配方、含水量等改变体系的NMR转折点温度,可以有效地延长食品的货架期.因此,核磁共振状态图对于评估最佳的储藏温度,以及通过配方设计来延长食品的货价期具有指导意义.     

Urinary catheterisation of female dogs: a comparison between three techniques for catheter placement

The objective of this study was to describe a new technique for urinary catheterisation of female dogs using a novel catheterisation device (NCD) and to compare the time taken to place a catheter using this technique with traditional techniques. A secondary objective was to survey participants on which of the techniques they preferred. Female canine cadavers of varying sizes were utilised and veterinary students who had not previously placed a urinary catheter were enrolled. Each participant performed three catheterisation techniques, Visual with speculum (SPEC), Blind Palpation (BP) and catheterisation with NCD on three sizes of dog. Time required using each technique was compared using Kaplan–Meier plots and mixed models Cox Proportional Hazards regression. Median times to catheterisation were 300 s (IQR 261–417 s) with the SPEC method, 420 s (IQR 253–545 s) with the NCD method and 725 s (574–1032s) with the BP method. Both SPEC and NCD methods were significantly faster compared to the BP method, with Hazard Ratios of 3.66 (95% CI 1.94–6.91, P < 0.001) and 3.57 (95% CI 1.87–6.81, P < 0.001), respectively. Six of nine participants found the NCD the easiest technique, 5/9 of the participants found the palpation technique most difficult and 4/9 found the speculum technique most difficult. BP appears to be the technique of least preference and increased time requirement. The novel urinary catheterisation device may provide a simpler method of visualisation of the urethral papilla and may provide a more sterile way of placing the catheter, although further investigation is needed to confirm this.