Improvement of wood properties by composite of diatomite and “phenol-melamine-formaldehyde” co-condensed resin     

ZHANG Ming  XU Yang  WANG Shu-liang  SHI Jun-you  LIU Chang-yu  WANG Cheng-yu 《林业研究》2013,24(4):741-746

We improved the overall performance of fast-growing poplar by utilizing a low-cost, effective and simple method. The fast-growing poplar was modified by a vacuum-pressure impregnation method with three...  相似文献   

Quantitative dynamics on stimulating regeneration and sowing seedlings of Larix gmelinii in Daxing''''an Mountains   总被引：1，自引：0，他引：1  

徐振邦  代力民  陈高  潘禄  陈涛  初得志  杨善勋 《林业研究》2000,11(4)

Introduction4LarixgmeliniiisoneofmajortimberspeciesinthenortheastDaxing'anMountainsinChina.Itplaysanimportantroleinprovidinglumber,maintainingthenaturalenvironmentinthisregionandadjustingecologicalequilibrium.Alargenumberofburnedareasandcut-overareasneedtoregenerateeveryyear.Larixgmeliniihasgreatnaturalregenerationcapabilityandenoughseedsources,andalmostmeetsabumperharvestyeareverythreeyears(Xuetal.1992;Shan1990;Xuetal.1993).Someburnedandloggedareaswouldberapidlyrestoredthroughafewofassista…  相似文献   

Dihydroartemisinin enhances radiotherapy efficiency in H22 cell tumor-bearing mice by regulating PI3K/AKT signaling pathway     

XU Jing-da  YANG Gong-li  DU Jing-feng  XU Long  ZHOU Yan-hong 《园艺学报》2000,36(10):1782-1788

AIM To study the effect of dihydroartemisinin （DHA） on the radiotherapy efficiency in hepatocellular carcinoma H22 cell tumor-bearing mice and the role of phosphatidylinositol 3-kinase （PI3K）/protein kinase B （AKT） signaling pathway in this process. METHODS A model of H22 cell tumor-bearing mice was established. The mice was divided into model group， single radiotherapy group， 5-fluorouracil （5-FU） group， and low-， medium- and high-dose DHA groups. The body weight and tumor volume in each group were measured every other day. At the end of administration， blood was collected from the tail of the mice and the animals were killed by neck removal immediately. The synergistic effect of DHA on radiotherapy was determined， and tumor growth inhibitory rate was calculated. The degree of lymphocyte transformation and natural killer （NK） cell activity were measured by MTT， the serum levels of interleukin-2 （IL-2） and IL-4 were measured by ELISA， and the protein levels of PI3K， AKT and p-AKT were determined by Western blot. RESULTS The H22 cell tumor-bearing mouse model was successfully constructed. Compared with model group， the TGT₃ （tumor growth time to reach 3 times of volume） of single radiotherapy group was remarkably increased （P<0.05）， while tumor weight， lymphocyte transformation degree， NK cell activity， IL-2 and IL-4 levels， PI3K protein level and AKT phosphorylation level were remarkably decreased （P<0.05）. Compared with single radiotherapy group， TGT₃， EF （enhancement factor）， tumor inhibitory rate， lymphocyte transformation degree， NK cell activity， IL-2 level and IL-4 level were increased with the increase in DHA dose （P<0.05）， and the PI3K protein level and AKT phosphorylation level were decreased （P<0.05）. CONCLUSION DHA may enhance the immunity of tumor-bearing mice by inhibiting the activity of PI3K/AKT signaling pathway， thereby enhancing the efficacy of radiotherapy.  相似文献   

苹果滴灌应用研究进展与述评     

徐呈祥  马艳萍 《金陵科技学院学报》2000,(4)

滴灌在国外各主要苹果生产国相当普遍 ,在我国目前还处于事实上的尝试阶段 ,但这一灌溉技术已经展示出多方面的优势和应用前景。随着经济实力的增强、科技装备水平的提高 ,滴灌技术必将在我国的苹果产业中发挥作用。文中 ,作者以近 2 0年间国内外的科技文献为据 ,综述了滴灌技术在苹果生产中的应用及相关研究 ,并对今后在这一领域的科研方向提出了见解。  相似文献   

柑桔遭受冻害后的恢复措施     

徐之龙 《贵州农业科学》2000,28(4):59-60

1999年12月22～30日,黔西南州出现了几十年来罕见的低温霜冻天气,州内栽培的主要亚热带水果柑桔,遭受了严重的冻害.据调查1级冻害面积1 200 hm2,2、3级冻害面积600 hm2,4级冻害面积320 hm2,分别占总栽培面积的33%、16.3%和8.7%,此次冻害对黔西南州柑桔生产造成了重大的损失.为尽量减少冻害所造成的损失,提早恢复树势和正常生产,特提出以下措施.  相似文献   

鸭源新城疫病毒单克隆抗体的研制     

王海燕  徐向明 《中国家禽》2010,32(23)

<正>新城疫(Newcastle disease,ND)是由新城疫病毒(Newcastle disease virus,NDV)引起的禽类的一种高度接触性、烈性传染病,给世界养禽业造成严重的经济损失和危害。以往文献报道水禽为NDV的自然贮存宿主,可以感染但不发病[1]。然而,  相似文献   

不同颜色防虫网覆盖栽培对豇豆生长发育的影响   总被引：1，自引：0，他引：1  

许如意  李劲松  袁廷庆  吴乾兴  肖日升 《热带农业科学》2011,31(8):46-50

研究了不同颜色（白色、黑色、红色、蓝色、绿色、银灰色）防虫网覆盖对栽培豇豆生长发育的影响。从豇豆的生育期、株高、茎粗、叶面积及叶绿素含量指数、产量和病虫害等方面综合考虑,在三亚地区绿色防虫网是较适合豇豆栽培的覆盖材料。  相似文献   

Polymorphism of IGFBP2 Gene and Its Association with Meat Quality Traits in Pigs     

LIU Hai-xia  ZHU Ai-wen 《中国畜牧兽医》2017,44(10):3016-3022

This study was aimed to analyze the genetic variation of insulin-like growth factor binding protein 2 (IGFBP2) gene effect on meat quality traits in pigs. A pair of primer was designed,which based on DNA sequence of IGFBP2 gene (GenBank accession No.:BV727778). The genetic polymorphism of IGFBP2 gene was detected by PCR-RFLP in Sujiang pig, Jiangquhai pig and Landrace pig, and the association between IGFBP2 gene polymorphism and meat quality traits in three pig breeds was analyzed. The results showed that three genotypes (AA, AB and BB) were detected. The Chi-square test results showed that the genotype distribution of three pig breeds was in Hardy-Weinberg equilibrium (P > 0.05). The polymorphism information content (PIC) were moderately polymorphic in three pig breeds. According to the association analysis of different genotypes, significant difference was found in color value, intramuscular fat content and marbling, the color value (except for Jianquhai pig) and intramuscular fat content of AA genotype were significantly higher than AB and BB genotypes (P < 0.05), the marbling of AA and AB genotypes was significantly higher than BB genotype (P < 0.05). In conclusion,the polymorphism of IGFBP2 gene intron 3 had significant effects on meat quality traits, and was candidate gene for the potential impact on meat quality traits of pigs.  相似文献   

发酵诺尼果种子中有效成分及其抗氧化性     

徐树英  傅中乔  王天赐  张德拉  张玉苍 《热带生物学报》2017,8(1)

为了有效利用已发酵诺尼果(Noni)种子,探讨提取发酵诺尼种子中有效成分的方法,进一步研究发酵诺尼果种子有效成分的抗氧化性。笔者分别用水蒸气蒸馏和有机溶剂95%乙醇萃取,再对2种提取方法分别获得的发酵诺尼果提取物进行气相色谱质谱(GC-MS)分析;采用A320电子顺磁共振波谱仪对乙醇萃取获得的发酵诺尼果种子精油的抗氧化性进行分析。结果表明,发酵诺尼果种子提取物中的有效成分绝大多数为酯类物质,此外还含有酸类和醇类物质。95%乙醇萃取物经GC-MS分析,首次在发酵诺尼果种子提取物中发现了角鲨烯,其相对含量为12.95%。电子顺磁共振法可简便、快速检测发酵诺尼果种子精油的抗氧化性,乙醇萃取发酵诺尼果种子精油不同层DPPH清除能力表现不同,在提取物相同体积时,样品清除自由基的反应速度很快,其中乙醇萃取发酵诺尼果种子精油下层在2 min能够完全清除自由基,而精油上层在20min不能完全清除自由基。说明其精油下层的抗氧化活性高于上层。笔者认为,已发酵诺尼果种子含有开发价值的活性物质,且该活性物质具有抗氧化性。  相似文献   

“巴仙银尖”的加工工艺及品质研究报告     

梁月荣  龚淑英 《茶叶》1999,25(4):202-204

探讨了利用云南大叶种茶树鲜叶生产名优绿茶－“巴仙银尖”的加工工艺，证明通过合理嫩有，适度摊放，高温杀青，中温慢烘的技术措施，能生产出名优绿茶。文中同时介绍了“巴仙银尖”茶的品质，化学特征。  相似文献