Hydroxyalkylation of barbituric acid. III. Product analysis and reaction pathway

Polyetherols containing a thermally stable pyrimidine ring were obtained upon the reaction of hydroxymethyl derivatives of barbituric acid with an excess of ethylene or propylene oxide. The reaction was monitored by ¹H‐NMR and IR spectroscopy for the systems with variable starting molar ratios of reagents. We found that formaldehyde rearranged from N‐hydroxymethyl and oxymethylene bridges into the end of the polyetherol chain during the reaction. Simultaneously, the O‐hydroxymethyl groups underwent blocking by oxirane. The structures of the polyetherols was deduced on the basis of the course of the reaction and the analytical data. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The effect of solar radiation on the flavonol content in broccoli inflorescence

The effect of solar radiation on the quercetin and kaempferol contents in the inflorescence of three broccoli cultivars (‘Lord’, ‘Marathon’ and ‘Fiesta’) was investigated from 1999 to 2001. Great differences in the contents of both flavonols, dependent on growing time and cultivar, were found. Quercetin and kaempferol contents varied from 14.3 to 81.0 mg kg⁻¹ f.w. and from 35.9 to 213 mg kg⁻¹ f.w., respectively. Inflorescences of the cultivar ‘Lord’ were characterised by the highest mean content of quercetin and those of cultivar ‘Fiesta’ of kaempferol. The contents of both flavonols were highly positively correlated with total solar radiation in the period from planting to the harvest of broccoli inflorescences.     

猪的遗传缺陷与异常

研究了耐盐与不耐盐番茄自交系在盐胁迫与正常栽培条件下根中蛋白质表达上的差异。耐盐番茄根系中蛋白质含量高于不耐盐番茄，正常栽培条件下番茄根系蛋白质含量高于盐处理番茄。蛋白质提取液不但在总蛋白质数量上有所不同，而且在蛋白质种类上亦有所差异。经过不同的双向凝胶电泳分离后，经过PD Quest软件和Q—TOF质谱分析结果为，在盐胁迫条件下共有8种蛋白质在表达上差异显著。磷酸葡萄糖脱氢酶、乙醇脱氢酶催化和3-异戊基苹果酸脱氢酶在盐处理的耐盐番茄根系中显著增加，异戊烯二磷酸(IDP)异构酶显著减少。     

广州港南沙港区深水航道水沙问题研究

在多年现场实测资料的基础上,对广州港南沙港区深水航道所在海区(工程海区)的水文泥沙特征进行了分析;使用TK-2D软件建立了工程海区的基于不规则三角形网格的潮流数学模型,在根据现场实测资料对模型进行充分验证的基础上对广州港南沙港区深水航道三期工程进行了潮流数值模拟研究,分析了深水航道工程造成的潮流场变化;对深水航道三期工程实施后的泥沙淤积强度和淤积量进行了计算.研究结果表明,从潮流泥沙角度讲,广州港南沙港区深水航道三期工程是完全可行的.     

Kiyoteru Tokuyasu: a pioneer of cryo‐ultramicrotomy

In July 2015 Professor K.T. Tokuyasu passed away in San Diego giving us the opportunity to reflect on the contribution this electron microscopist made to the field of immunocytochemistry. His work provided a sensitive, minimally invasive approach to producing thin sections of biological material for labeling with antibodies. His approach has been applied to a wide range of biological applications and provided important information on cellular processes.     

Drying of Herbal Product in Closed System

A new product from a low temperature drying method that reduces the loss of highly volatile essential oils is presented. The proposed drying method consists of evaporation/sublimation of water and aromatic substances in a dryer with a closed drying agent cycle. In parallel, the evaporated compounds are continuously condensed in a heat exchanger. As a result of the drying process, high-quality dried plants and Fluidolat as liquid phase containing water and volatile organic compounds are obtained. The aim of presented investigations was to optimize the developed technology for the herb lavender.     

Radiation‐induced effects in gamma‐irradiated PLLA and PCL at ambient and dry ice temperatures

The effect of γ‐rays sterilization at ambient (23°C) and at dry ice temperatures (?78°C) on two biodegradable semicrystalline polyesters, namely poly(L ‐lactide) (PLLA) and poly(ε‐caprolactone) (PCL), was studied. The radical processes generated by irradiation were investigated by electron paramagnetic resonance (EPR) spectroscopy, whereas postradiation changes were monitored for 5 months by scanning calorimetry, thermogravimetric analysis, and apparent viscosity measurements. It was confirmed that the radiation sterilization initiates degradation in both studied polymers, however, the effect is smaller in PCL than in PLLA, and that the range of changes might be limited by lowering temperature of the exposure to γ‐rays. Newly formed oxygen containing functional groups confirmed by EPR and thermogravimetric analysis methods are produced in the irradiated polyesters. In PCL, the process might give rise to thermally induced cross‐linking via oxygen containing intermolecular bridges. During storage, in both irradiated materials, morphology determined by differential scanning calorimetry is changing ‐ PCL ability toward crystallization decreases insignificantly, whereas in PLLA the tendency is opposite ‐ on irradiation a contribution of crystalline phase is growing considerably, from 18 and 19% to 41 and 31% for PLLA irradiated at 23°C and at ?78°C, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011