Fluoride deposition through precipitation and leaf litter in a boreal forest in the vicinity of a phosphorus plant

Results of short term monitoring of fluoride (F) deposition in soil humus through precipitation and leaf litter in a boreal forest in the vicinity of a phosphorus plant, are described in this paper. Regressional relationships of F-deposition by the two pathways to the distance from the emission source are also presented.The concentrations of fluoride in leaf litter of several species and precipitation and P, Ca, Mg, K and Na in precipitation only, are summarized. The average F-concentrations ranged from 930 to 17 ppm in severely and lightly damaged areas respectively. Corresponding F-concentrations in precipitation were 0.36 to < 0.01 ppm. Fluoride deposition in soil humus via precipitation was at least 5 times greater than through leaf litter. F-input through precipitation ranged from 3.43 to 0.15 kg/ha/year in areas of severe to light F-damage respectively. Corresponding values from leaf litter were 0.72 to 0.010 KgF/ha/year.Estimates of total and available amounts of fluoride in the upper 4 cm of soil humus were 57.0 to 1.20 kg/ha and 1.20 to 0.24 kg/ha in areas of severe and light damage respectively. The excessive concentrations of fluoride in soil humus did not appear to contribute towards the F-accumulation in foliage.     

Measurement of Starch Properties During Staling of Arabic Bread

The DSC and X-ray diffraction data showed that the starch crystallinity increased in Arabic bread (khaboos) samples during the storage period. The appearance of crystalline regions during ageing as shown by X-ray diffraction data could serve as an indication of the extent of staling that was observed in these khaboos samples. The information obtained from scanning electron microscopy could not be used for assessing the extent of staling of Arabic bread, but showed interesting differences in the gelatinization behaviour of starch granules in the crumb and crust areas. The crust areas, when viewed under the scanning electron microscope, show intact small as well as large starch granules. The limited amount of water available in the crust area of khaboos may be responsible for the incomplete gelatinization of starch granules.     

Highly potent and specific GSK-3beta inhibitors that block tau phosphorylation and decrease alpha-synuclein protein expression in a cellular model of Parkinson's disease

Research by Klein and co-workers suggests that the inhibition of GSK-3beta by small molecules may offer an important strategy in the treatment of a number of central nervous system (CNS) disorders including Alzheimer's disease, Parkinson's disease, and bipolar disorders. Based on results from kinase-screening assays that identified a staurosporine analogue as a modest inhibitor of GSK-3beta, a series of 3-indolyl-4-indazolylmaleimides was prepared for study in both enzymatic and cell-based assays. Most strikingly, whereas we identified ligands having poor to high potency for GSK-3beta inhibition, only ligands with a Ki value of less than 8 nM, namely maleimides 18 and 22, were found to inhibit Tau phosphorylation at a GSK-3beta-specific site (Ser 396/404). Accordingly, maleimides 18 and 22 may protect neuronal cells against cell death by decreasing the level of alpha-Syn protein expression. We conclude that the GSK-3beta inhibitors described herein offer promise in defending cells against MPP+-induced neurotoxicity and that such compounds will be valuable to explore in animal models of Parkinson's disease as well as in other Tau-related neurodegenerative disease states.     

Verification of some building materials as gamma-ray shields

The shielding properties for gamma rays of a few low Z materials were investigated. The values of the mass attenuation coefficient, equivalent atomic number, effective atomic number, exposure buildup factor and energy absorption buildup factor were calculated and used to estimate the shielding effectiveness of the samples under investigation. It has been observed that the shielding effectiveness of a sample is directly related to its effective atomic number. The shielding character of any sample is a function of the incident photon energy. Good shielding behaviour has been verified in soil samples in the photon energy region of 0.015-0.30 MeV and of dolomite in 3-15 MeV. The results have been shown graphically with more useful conclusions.     

A flow cytometric assay for global estimation of tyrosine phosphorylation associated with capacitation of spermatozoa from two marsupial species, the tammar wallaby (Macropus eugenii) and the brushtail possum (Trichosurus vulpecula)

The phosphorylation of tyrosine residues in cellular proteins is a major signal transduction event during sperm capacitation. In this study protein phosphorylation was monitored using a fluorescein isothiocyanate (FITC)-labeled antiphosphotyrosine monoclonal antibody and a flow cytometric procedure optimized for sperm. Using this technique, the correlation between tyrosine phosphorylation and sperm capacitation was examined in two marsupial species, the brushtail possum and the tammar wallaby and compared with that of ram spermatozoa. The levels of tyrosine phosphorylation in sperm from all three species were increased by the addition of cyclic AMP (cAMP) and vandate, a phosphotyrosine phosphatase inhibitor and were decreased by the addition of the phosphotyrosine kinase inhibitor, staurosporine. Oviductal conditioned media (CM) induced a progressive increase in tyrosine phosphorylation in both marsupial species and also induced morphological transition from a streamlined to a 'T'-shape configuration in brushtail possum spermatozoa but not in tammar wallaby spermatozoa. Transition to the 'T'-shape orientation associated with capacitation in marsupial spermatozoa was observed by 2 h of incubation in both species when tyrosine phosphorylation was increased by higher levels of cAMP i.e. 5 mM dibutyryl cAMP plus 3 mM pentoxyphylline. Thus the tyrosine phosphorylation trigger with CM may differ in these two marsupial species. Ram sperm tyrosine phosphorylation could be increased by addition of lower levels of cAMP (1 mM). These results support the finding that tyrosine phosphorylation is associated with sperm capacitation in marsupials. Similar results were obtained by using SDS PAGE/Western blot analysis of tyrosine phosphorylation in the brushtail possum spermatozoa. The specificity, efficiency and sensitivity of the procedure described here make it applicable for routine assessment of capacitation in large numbers of samples and in other species.     

Fate of phytic acid during bread making

The effect of malt addition and yeast concentration on the hydrolysis of phytic acid during different stages of bread making has been reported. There was a considerable hydrolysis of phytic acid with the addition of yeast and malt. In the breads of S-308 and WL-711 wheat varieties, the loss of phytic phosphorus was 6.6. 8,1; 24.6, 23.0 and 26.6, 27.7% in case of nonyeasted, 1.5% and 3% yeasted dough of whole wheat flour (Atta) respectively. However in white bread, the loss of phytic phosphorus was 14.0 and 18.4; 46.2 and 41.5; 51.7 and 49.4%, in non-yeasted, 1.5% and 3% yeasted doughs of S-308 and WL-711 wheat varieties respectively. A significant loss of phytic acid was observed at a yeast level of 1.5 and 3% and with 0.4% malt addition as compared with the control. Most of the phytic acid was hydrolysed during the fermentation and proofing stages in both types of bread samples.     

基于统计聚类分析的短期风电功率预测

考虑到短期风电功率预测模型建立时,样本的选取对预测模型的精度有较大影响,提出了运用聚类方法对历史风速数据进行处理,实现了历史数据的自动分类.根据预测日的平均风速和最大风速等特征参数,按照相似度最大的原则,选择合适的类别作为预测建模用的训练样本.运用时间序列方法,建立风速预测模型,与不经过预处理的相比,所建立预测精度得到了提高,验证了运用聚类进行数据预处理的正确性.运用风力发电机的出力曲线,得到了未来日的风电功率的预测值,为含风电系统的电力系统运行计划的制定,提供了基础数据支持.     

Erosion-corrosion behaviour of Ni-based superalloy Superni-75 in the real service environment of the boiler

The super-heater and re-heater tubes of the boilers used in thermal power plants are subjected to unacceptable levels of surface degradation by the combined effect of erosion-corrosion mechanism, resulting in the tube wall thinning and premature failure. The nickel-based superalloys can be used as boiler tube materials to increase the service life of the boilers, especially for the new generation ultra-supercritical boilers. The aim of the present investigation is to evaluate the erosion-corrosion behaviour of Ni-based superalloy Superni-75 in the real service environment of the coal-fired boiler of a thermal power plant. The cyclic experimental study was performed for 1000 h in the platen superheater zone of the coal-fired boiler where the temperature was around 900°C. The corrosion products have been characterized with respect to surface morphology, phase composition and element concentration using the combined techniques of X-ray diffractometry (XRD), scanning electron microscopy/energy-dispersive analysis (SEM/EDAX) and electron probe micro analyser (EPMA). The Superni-75 performed well in the coal-fired boiler environment, which has been attributed mainly to the formation of a thick band of chromium in scale due to selective oxidation of the chromium.