Inhibitory effects of flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu) on antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells

We found that two distinct flavonoid glycosides isolated from the peel of Japanese persimmon (Diospyros kaki Fuyu), isoquercitrin (Isq) and hyperin (Hyp), are capable of inhibiting antigen-stimulated degranulation in rat basophilic leukaemia RBL-2H3 cells. In order to elucidate the underlying mechanisms, we examined effects of Isq and Hyp on cellular responses induced by antigen stimulation. Treatment with both Isq and Hyp markedly inhibited antigen-stimulated elevation of intracellular free Ca²⁺ concentration and reactive oxygen species (ROS). Isq and Hyp did not affect NADPH oxidase (NOX) activity, but they possessed DPPH radical-scavenging activity similar to that of epigallocatechin gallate, a potent anti-oxidant, Finally, Isq and Hyp showed little or no effects on Ag-stimulated Syk activation or phosphorylation of signalling molecules. These results indicate that inhibition of antigen-stimulated degranulation by Isq and Hyp is mainly due to suppression of intracellular Ca²⁺ elevation, which is caused by direct scavenging of ROS that are generated by NOX. Our findings suggest that Isq and Hyp, isolated from the peel of persimmon, would be beneficial for alleviating symptoms of type I allergy.     

Performance of geosynthetic-reinforced flexible pavements in full-scale field trials

The paper presents the results of a series of full-scale trials carried out in Thailand examining the performance of geosynthetics as reinforcement for flexible pavements. The geosynthetics were embedded at different pavement depths and the structural response was monitored across four test sections by means of strain gauges, pressure sensors, deflection points and deflection plates. The results show that all reinforcement configurations helped reduce the vertical static stresses developed at the base of the pavement by up to 66% and by up to 72% for dynamic stresses. The performance enhancement expected to prolong the lifespan of the base layers. The reinforcement layers closer to the base experienced the highest lateral strains of up to 0.13%, providing evidence that geosynthetics can also effectively reduce lateral spreading. All reinforcement configurations helped enhance rut resistance with maximum traffic benefit ratio (TBR) of 13.70, effectiveness ratio (EF) of 12.70 and minimum rutting reduction ratio (RRR) of 0.74. The best configuration included a geotextile within the asphalt concrete layer and a geogrid under the base layer. Non-linear finite element analyses of the test sections predicted very well the strains and stresses in the pavement. The study provides a benchmark for future studies in this field and concludes that geosynthetics can help increase maintenance periods and extend the lifetime of flexible pavements.     

Susceptibility of anthocyanins to ex vivo degradation in human saliva

Some fruits and their anthocyanin-rich extracts have been reported to exhibit chemopreventive activity in the oral cavity. Insights regarding oral metabolism of anthocyanins remain limited. Anthocyanin-rich extracts from blueberry, chokeberry, black raspberry, red grape, and strawberry were incubated ex vivo with human saliva from 14 healthy subjects. All anthocyanins were partially degraded in saliva. Degradation of chokeberry anthocyanins in saliva was temperature dependent and decreased by heating saliva to 80 °C and after removal of cells. Glycosides of delphinidin and petunidin were more susceptible to degradation than those of cyanidin, pelargonidin, peonidin and malvidin in both intact and artificial saliva. Stability of di- and tri-saccharide conjugates of anthocyanidins slightly, but significantly, exceeded that of monosaccharide compounds. Ex vivo degradation of anthocyanins in saliva was significantly decreased after oral rinsing with antibacterial chlorhexidine. These results suggest that anthocyanin degradation in the mouth is structure-dependent and largely mediated by oral microbiota.     

紫外诱变里氏木霉Rut C-30提高木聚糖酶活力及发酵条件的研究

通过紫外照射的方法 ,对里氏木霉RutC 30进行诱变 ,选育出高产木聚糖酶活力的菌株 ,其酶活比出发菌株提高了 4 1 9%。并对选育的菌株进行了稻草与麸皮比例 ,氮源以及干料与水分比对产酶的影响 ,并通过正交实验 ,阐明培养温度、时间、MgSO4·7H2 O和KH2 PO4对产酶的影响。     

重交通抗车辙沥青路面的研究

结合山西省重载交通的特点,针对沥青路面的车辙病害,采用六种路面结构组合铺筑加速加载（ALF）试验段,通过室内配合比设计研究及对试验段路面渗水和ALF车辙试验检测结果分析,提出重交通沥青路面采用双层改性和采用SMA、GTM配合比设计是提高沥青路面抗车辙的主要技术措施;并提出了半刚性基层沥青路面结构组合形式.     

对里氏木霉Rut C-30所产非淀粉多糖酶系的分析

通过里氏木霉RutC 3 0以稻草和麸皮为基质进行固态发酵 ,对其产生的非淀粉多糖酶(NSP酶 )进行分析 ,试验表明里氏木霉RutC 3 0产生的NSP酶系较全 ,分别有纤维素酶、木聚糖酶、β 葡聚糖酶、β 甘露聚糖酶、果胶酶等 5种不同的NSP酶。并探讨了不同碳源及添加不同底物诱导物对里氏木霉RutC 3 0产生的NSP酶系的影响     

响应面法优化里氏木霉Rut C-30产纤维素酶液体培养基

该试验在单因素对里氏木霉(Trichoderma reesei)Rut C-30产纤维素酶的液体培养基优化的基础上,以滤纸酶活为响应值,采用响应面法确定其最佳培养基。首先通过Plackett-Burman(PB)设计筛选出影响滤纸酶活的显著因素,结晶纤维素和麸皮;通过最陡爬坡试验逼近最大酶活力区域;最后通过Central Composite Design(CCD)设计及响应面分析确定产酶最佳培养基,其中影响酶活的显著性因素结晶纤维素41.8g,麸皮19.1g。经过优化,滤纸酶活力最高为8.21U/mL,比单因素优化结果7.03U/mL提高了16.78%,同时测得CMC酶活为63.64IU/mL,木聚糖酶活为27.4IU/mL,葡萄糖苷酶酶活0.96IU/mL。     

TLA改性沥青的研究和应用

特立尼达湖沥青是世界上最著名、使用最广泛、历史最悠久的天然沥青，与国产重交通石油沥青混合后使用，可以提高道路、机场、隧道、桥梁等各种重载路面的使用性能，达到舒适耐久、延长使用寿命、降低维修费用的目的。     

里氏木霉Rut C-30产非淀粉多糖酶发酵条件的研究

在接种量与培养温度分别为8%和30℃条件下,采用正交试验表L9(34)设计对培养基组成、发酵时间、培养基湿度和发酵容器4个试验因子进行产酶影响力排序和条件组合优化,同时分析各指标间相关性。结果:对纤维素酶,培养基组成>发酵时间>发酵容器>初始湿度,最优组合酶活力456.3u/g;对木聚糖酶,发酵时间>培养基组成>发酵容器>初始湿度,最优组合酶活力5529.9u/g;对β-甘露聚糖酶,发酵容器>培养基组成>初始湿度>发酵时间,优化组合酶活力367.6u/g;对果胶酶,培养基组成>发酵容器>发酵时间>初始湿度,最优组合酶活力为544.6u/g;培养基发酵失重与β-甘露聚糖酶活力极显著正相关(r=0.811,P<0.01)、纤维素酶与木聚糖酶活力显著正相关(r=0.724,P<0.05)。结论:通过改变发酵条件可调控该菌株产饲用NSP酶谱的酶活水平与比例,指标之间相关性可用于监测发酵过程中的酶活力状态。该菌株较适合作为饲用NSP复合酶制剂生产的菌株。     

抗车辙沥青混合料组成设计方法探讨

以沥青路面车辙深度值、温度开裂数量、疲劳开裂面积等定量指标作为沥青混合料组成设计的直接控制指标，目前已成为沥青路面材料设计的发展方向，本文在传统沥青混合料设计方法—马歇尔设计法的基础上，结合道路的路面结构、交通、气候条件，建立了一种能定量控制沥青路面车辙深度，同时兼顾沥青路面抗裂、抗疲劳及耐久性的沥青混合料组成设计方法。