葵花秆胶合人造木材研究

通过对葵花秆木质部分的分析，确定了以葵花秆木质部分改合制造人造木材的可能性。研究了用葵花秆制造人造木材的实验室工艺，研究结果表明。利用葵花秆生产人造木材是完全可行的。当产品密度为０．５８ｇ／ｃｍ３时，顺纹抗压强度为５２．５Ｎ／ｍｍ２，静曲强度为６０Ｎ／ｍｍ２，相当于中等强嵍饶静模梢月憬ㄖ媚静牡男枰     

截干封蜡技术在造林中的应用

通过对比试验表明，截干封蜡技术可以使造林成活率提高14个百分点。截干封蜡技术是提高造林成活率的有效措施之一。     

Stem quality assessment using terrestrial laser scanning technology: a case study of ash trees with a range of defects in two stands in Ireland

Information on stem quality of standing (broadleaf) timber is of great importance to the forestry sector to help optimise harvesting and marketing strategies. Manual assessment of such quality parameters in standing trees is extremely difficult, time consuming and costly. The objectives of this study were therefore to assess stem quality parameters such as taper, lean and sweep in ash (Fraxinus excelsior L.) stands, during leaves-on and leaves-off conditions, using terrestrial laser scanning technology, and to compare the estimated parameters with manually measured values in a mature and young stand. Diameter estimation was more accurate during the leaves-off condition in both stands, resulting in taper estimates that were closer to the manually obtained values as well. However, in general, the taper values did not match those obtained manually very closely. Given that the sample trees were chosen deliberately to include noticeable defects such as non-circularity, bending, swellings, knots resulting from the removal of branches and multiple leaders, this is not surprising. It probably is the case that the scanned data capture these defects more accurately than the manually collected data, especially when multi-scan data are used.     

云南红河、文山橡胶树寒害后蛀干害虫种类调查

2011年在云南红河、文山植胶区的受寒害橡胶树上采集蛀干类昆虫220头,经形态鉴定查明其隶属3科3属4种,其中暗翅材小蠹(Xyleborus semiopacus)和对粒材小蠹(Xyleborus perforans)为优势类群,锥长小蠹(Platypus solidus Walker)、双齿谷盗(Silvanus bidentatus)为常见种。     

Within‐ and Between‐population Variation of Growth and Stem Quality in a 30‐year‐old Pinus sylvestris Trial

In a combined population‐progeny experimental plantation of Pinus sylvestris at Nordanås, lat. 64°19’ long. 18°12’ alt. 400 m, a few growth characters and around 25 quality characters were meaured or assessed at age 34 from seed. The populations under study originated from latitudes 63–67. The experimental design is a split‐plot with three replications. Each population is represented by 10–20 open pollinated progenies planted in 15‐tree row plots at a spacing of 2.5x2.5 m. All growth and most quality characters showed significant population differences. Family differences were noted for approximately half of the quality characters. The family repeatability for growth and quality characters varied much between the populations in a non‐consistent way. Thanks to the strong genetic correlations between breast height diameter and stem volume, as well as between tree height and stem volume those two characters could be used to estimate stem volume.     

Preparation,cryopreservation and in vitro culture of spermatogonial stem cells of new born calves

The experiment was designed to study the preparation, cryopreservation and culture of calf spermatogonial stem cells in order to provide some data for theoretical research and practical use of calf spermatogonial stem cells. As for enzymolysis of testis tissue, two digestive method A and B. The cryopreservation cooling procedure was that spermatogonial stem cells was equilibrated at 4℃ for lh, at -20℃ for lh, at -40℃ for 2h, at -80℃ overnight and then stored in liquid nitrogen. The different concentration of three eryoprotectants were compared. The results indicated that both method A and method B achieved the same high motility rates of cells with method B needing time longer, calf spermatogonial stem cells could be well cryopreserved by the stage cooling procedure. Satisfactory cryopreservative results were gotten by adding 10% DMSO or 10% EG to cryopreservative medium, the former was better and adding sucrose could improved cryopreservative effect. The culture behaviors of spermatogonial stem cells kept the same before and after cryopreservation. It was concluded that an effective method was verified for preparation, cryopreservation and culture of new calf spermatogonial stem cells.     

Synergistic induction of wheat stem rust appressoria by chemical and topographical signals

The leaf alcohols cis -3-hexen-1-ol and trans -2-hexen-1-ol have been previously shown to induce the wheat stem rust (Puccinia graminis f. sp. tritici) to differentiate appressoria in a complex axenic culture medium. In this paper, the possible role of these chemicals in appressorium induction during infection has been analysed further. The inductive potential of ethylene and three cutin monomers were also tested because they have been found to induce appressoria in other fungi. Both hexenols were found to be inductive in aqueous solution in the absence of media constituents. 0.5–1 m trans -2-hexen-1-ol was the most inductive resulting in a maximum of 51% appressorium differentiation. trans -2-hexen-1-ol was also shown to be inductive in vapour form. In aqueous solution, trans -2-hexen-1-ol acted synergistically with topographical signals by increasing the rate of appressorium induction. Combining the two signals also increased the total number of appressoria differentiated (88%). The other chemicals tested were non-inductive although a biochemical domain rich in exposed cutin was localized around stomatal apertures of wheat leaves. The characteristic bipolar morphology of appressoria formed over stomata was found to be determined by topographical signals. Overall, our data support a role for both chemical signals (hexenols or their analogues) and topographical signals being involved in appressorium induction by wheat stem rust.     

Stem cells: classifications, controversies, and clinical applications

The application of stem cells in regenerative and reparative therapies is emerging in surgery. Published information can lead to an over simplified view of stem cells with respect to their definitions, tissues of origin, abilities to differentiate into tissue lineages, and their capacity for functional tissue regeneration. The goals of this review article are to define embryonic and adult stem cells, compare differences between them, and summarize their potential clinical applications.     

骨髓间充质干细胞的研究进展

骨髓间充质干细胞是存在于骨髓中的除造血干细胞以外的另一类具有多向分化潜能的干细胞。在一定的诱导条件下 ,这类细胞可定向分化为多种造血以外组织 ,特别是中胚层和神经外胚层来源的组织细胞。例如成骨细胞、成软骨细胞、脂肪细胞、腱细胞、肌肉细胞、神经细胞等。骨髓间充质干细胞具有贴壁生长的特性 ,在体外易分离和扩增 ,还易于外源基因的转入和表达 ,在人类医学上被认为是一种理想的治疗性细胞和基因治疗中的靶细胞。本文针对骨髓间充质干细胞的研究进展和在临床医学上的应用进行综述     

地黄脱毒技术及增产效果

对地黄脱毒技术进行了研究.从6种不同浓度激素组合的培养基中,筛选出地黄茎尖培养较适宜的培养基为MS 6-BA 1mg/L NAA 0.1mg/L,不同地黄品种在该培养基上的茎尖培养成苗率为76.6%～90.5%;适宜的快繁培养基为MS 6-BA 0.3mg/L NAA 0.02mg/L GA 0.1mg/L.建立了地黄茎尖苗的病毒检测技术,培育出4个地黄品种的脱毒苗,茎尖苗的平均脱毒率为52.3%.对地黄脱毒苗与非脱毒苗的生育性状、田间发病率及产量进行了比较,脱毒地黄种苗的株高、叶面积和叶片数明显高于非脱毒苗;脱毒地黄地上部病毒病的显症率明显下降,新生叶片数增加;脱毒地黄的增产幅度为16.5%～45.5%,平均31.0%.