Procyanidin fractions from pine (Pinus pinaster) bark: radical scavenging power in solution, antioxidant activity in emulsion, and antiproliferative effect in melanoma cells

Pine (Pinus pinaster) bark is a rich source of procyanidin oligomers. From a total polyphenolic extract, we have generated fractions of different procyanidin composition. The mixtures, devoid of gallate esters, were active as free radical scavengers against ABTS(*+), DPPH, and HNTTM. Pine bark fractions were tested for antioxidant activity in solution (hydrogen donation and electron transfer) and emulsion (inhibition of lipid peroxidation) and compared with their galloylated counterparts from grape origin. While galloylation clearly influenced the free radical scavenging efficiency in solution, it did not seem to play a determinant role in protection against lipid peroxidation in emulsion. The fractions were very mild inhibitors of cell proliferation. Because gallate esters appear to interfere with crucial cell functions, gallate free pine procyanidins may be the innocuous chemopreventative agents of choice for many applications in food and skin protection.     

美国本地阔叶材获得新的市场地位

木地板行业显现的趋势之一就是其产品将从采用进口树种回归至国内树种。在过去几年中由于非法采伐造成价格下降,燃起了人们对进口树种的热情,但是行业主管人员相信今年春季逐步实施的雷斯法案正在拉平价格,国外树种价格将会上升,从而促使国外树种需求下降。     

秋季国外地板全扫描

尽管近来购买者多是看得多买得少,但是商家不乏推介新产品以引起购买者的关注。供应商力争使其产品与众不同,并且帮助商家利用新的盈利手段来推动秋季销售。其中最值得关注的是：     

Double haploids,markers and QTL analysis in vegetable brassicas

Double haploid (DH) plants of Brassica spp. can be produced via anther culture or culture of microspores. This paper reviews the uses of double haploids in crop improvement research in vegetable brassicas (B. oleracea). Applications of DH lines are described for breeding; construction of linkage maps; genetic analysis of quantitative traits and capturing genetic variation. The advantages and disadvantages of DH lines are discussed     

The fate and toxicity of the flavonoids naringenin and formononetin in soil

The flavonoid class of plant secondary metabolites play a multifunctional role in below-ground plant–microbe interactions with their best known function as signals in the nitrogen fixing legume–rhizobia symbiosis. Flavonoids enter rhizosphere soil as a result of root exudation and senescence but little is known about their subsequent fate or impacts on microbial activity. Therefore, the present study examined the sorptive behaviour, biodegradation and impact on dehydrogenase activity (as determined by iodonitrotetrazolium chloride reduction) of the flavonoids naringenin and formononetin in soil. Organic carbon normalised partition coefficients, log K_oc, of 3.12 (formononetin) and 3.19 (naringenin) were estimated from sorption isotherms and, after comparison with literature log K_oc values for compounds whose soil behaviour is better characterised, the test flavonoids were deemed to be moderately sorbed. Naringenin (spiked at 50 μg g^?1) was biodegraded without a detectable lag phase with concentrations reduced to 0.13±0.01 μg g^?1 at the end of the 96 h time course. Biodegradation of formononetin proceeded after a lag phase of ～24 h with concentrations reduced to 4.5±1% of the sterile control after 72 h. Most probable number (MPN) analysis revealed that prior to the addition of flavonoids, the soil contained 5.4×10⁶ MPN g^?1 (naringenin) and 7.9×10⁵ MPN g^?1 (formononetin) catabolic microbes. Formononetin concentration had no significant (p>0.05) effect on soil dehydrogenase activity, whereas naringenin concentration had an overall but non-systematic impact (p=0.045). These results are discussed with reference to likely total and bioavailable concentrations of flavonoids experienced by microbes in the rhizosphere.     

Response of American sycamore seedlings to maleic hydrazide and sodium chloride

American sycamore (Platanus occidentals L.) seedlings grown in a hydroponics system were treated with a growth regulator, maleic hydrazide (MH) or sodium chloride, or a combination of the two. Application of maleic hydrazide or sodium chloride retarded plant growth, but combined application did not show significant interaction effects. Treatment with both sodium chloride and MH reduced the dry weight of plant tissue to a greater extent than sodium chloride application alone. Elemental analyses of various plant parts revealed that MH was generally without effect on the level of either sodium or chloride ions. In old stem tissue, however, treatment with MH had no effect in the absence of sodium chloride but was associated with lower chloride content in its presence.     

Forest School and its impacts on young children: Case studies in Britain

As Forest School has become more widespread throughout Britain an understanding is needed of its impact. This paper outlines a two-phase evaluation project undertaken in Wales and England from 2002 to 2005. The evaluation was undertaken through a partnership between Forest Research and the New Economics Foundation. A methodology was developed to explore the impacts of Forest School on children and this was then used to track changes in 24 children at three case study areas over an 8-month period. The research highlights that children can benefit in a range of ways. Six themes emerged from the data of the positive impacts on children in terms of confidence, social skills, language and communication, motivation and concentration, physical skills and knowledge and understanding. Two further themes highlight the wider impacts of Forest School on teachers, parents, and the extended family. Contact with the natural environment can be limited for children and young people in contemporary society due to concerns about safety outdoors and issues of risk and liability. Forest School provides an important opportunity for children to gain access to and become familiar with woodlands on a regular basis, while learning academic and practical skills. The constructivist theory of learning seems to be particularly suited to the Forest School approach as children make meaning from their direct experiences. The participatory action research approach taken in this study promoted reflective practice amongst the stakeholders involved and provided them with a sense of ownership of the study, as well as an opportunity to learn from each other.