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1.
采用环磷酰胺诱导免疫低下小鼠模型,通过测定模型小鼠的炭粒廓清指数、吞噬指数、胸腺指数和脾指数考察白蜡虫多糖的免疫调节能力;对接种S180瘤细胞的小鼠采用口服和注射方式提供白蜡虫多糖,以抑瘤率考察白蜡虫多糖体内抑瘤活性;以生长率为指标考察白蜡虫多糖对人白血病细胞株、人肺癌细胞株、人胃癌细胞株及人肝癌细胞株等4种肿瘤细胞的抑制作用。结果显示:白蜡虫粗多糖(Cwps)和纯化多糖(Pwps)均能明显增加免疫低下小鼠碳粒廓清指数及吞噬指数,但对胸腺指数和脾指数无改善作用;体内抑瘤试验发现,白蜡虫多糖对小鼠体内S180有明显的抑瘤效果,但对离体肿瘤细胞生长却无明显抑制作用。研究结果表明:白蜡虫多糖能增加免疫低下小鼠的非特性免疫能力,具有体内抑制肿瘤作用,但对肿瘤细胞无细胞毒作用,揭示白蜡虫多糖通过提高小鼠免疫能力达到体内抑制肿瘤的功效。  相似文献   

2.
罗昕 《沙棘》2009,22(3):6-7
探讨中药沙棘提取液对人慢性髓样性白血病细胞(K562)、人急性粒细胞白血病细胞(HL-60)、小鼠T淋巴瘤细胞(YAC-1)肿瘤细胞的杀伤作用及其作用机理。方法利用不同浓度沙棘提取液与K562、HL-60、YAC-1肿瘤细胞体外培养24h,测定肿瘤细胞DNA合成能力及脱氧尿嘧啶核酸(UdR)释放率。结果受视药对HL-60、YAC-1细胞DNA合成有抑制作用,对K562细胞DNA中UdR有释放作用。结论沙棘提取液对血液肿瘤细胞生长有明显抑制作用,其药物机理可能与沙棘对其DNA合成的解聚作用和抑制合成作用有关。  相似文献   

3.
研究马尾松树皮提取物(MPBE)体外和体内的抗肿瘤作用。采用四甲基偶氮唑蓝比色(MTT)法观察MPBE对人结肠腺癌细胞株LoVo的体外抑制作用,采用小鼠移植性肿瘤模型考察MPBE对S180荷瘤小鼠的抑瘤作用和艾氏腹水癌(EAC)小鼠的生命延长作用。结果表明:MPBE对Lo-Vo细胞的生长有较强的抑制作用,在质量浓度为500 mg/L时,MPBE对LoVo细胞作用24、48和72 h时的抑制率分别为19.83%、33.06%和58.15%;MPBE对小鼠S180肉瘤生长表现出明显的抑制作用,MPBE 50、100和200 mg/kg 3个剂量的抑瘤率分别为30.3%、37.8%和42.3%,MPBE达到200 mg/kg剂量时,反映免疫功能的胸腺指数和脾指数也明显增加;但MPBE对EAC腹水癌小鼠的生存时间没有明显的延长作用。  相似文献   

4.
试验比较了3种大孔树脂对滑菇多糖的纯化效果,并研究了纯化效果最好的大孔树脂的纯化工艺。试验结果表明,AB-8大孔树脂对滑菇子实体多糖分离纯化的效果最好,而且AB-8型树脂对滑菇多糖纯化工艺为,吸附时间3h,pH值5.0,样品浓度1.5mg/mL,洗脱剂为70%乙醇溶液,解吸时间4h,洗脱速率2mL/min,在此工艺条件下纯化效果最好,即:吸附率为86.67%,解吸率为71.38%,纯化的滑菇多糖产品中多糖含量为78.64%,是滑菇多糖粗品的1.3倍。  相似文献   

5.
桂花叶挥发油化学成分分析及其生物活性   总被引:2,自引:0,他引:2  
采用水蒸气蒸馏法(SD)提取挥发油,用气相色谱-质谱(GC-MS)联用技术分析桂花叶的精油成分,检测出 13 种成分,共确认其中 10 个化合物,占挥发油色谱总馏出峰面积的 95.13%.其中含量较高的物质为苯乙醇(60%)、苯甲醇(15%).体外抑菌实验表明,该挥发油对大肠杆菌无抑制作用,对金黄色葡萄球菌和红酵母有一定的抑制能力.Alamar Blue法测定桂花叶的挥发性物质对人非小细胞肺癌(NCI-H460)的抑制作用不大,质量浓度为 100 μg/mL时抑制率为(10.18±1.29 )%.  相似文献   

6.
以银杏叶为原料,采用皂化反应、溶剂冷冻和Ⅱ级分子蒸馏分离聚戊烯醇不皂化物,精制银杏叶聚戊烯醇(GP),纯度87.3%。通过建立人脑瘤SF763、人肺腺瘤A549和艾氏腹水瘤Ec移植小鼠模型,GP口服给药,研究GP对人脑瘤SF763裸鼠和艾氏腹水瘤Ec小鼠的生命延长率,观察GP对人肺腺瘤A549裸鼠的抑瘤率。结果表明:生药剂量320mg/kgGP联合2mg/kg阿霉素(ADM),其生命延长率为88%(P〈0.01),GP能明显延长荷人脑瘤SF763裸鼠生命;GP在大于40mg/kg时对人肺腺瘤A549裸鼠具有明显的抑制作用(P〈0.05),最佳剂量为GP80mg/kg,接种时间11d,抑瘤率为82.2%(P〈0.01);GP对艾氏腹水瘤EC小鼠的生存期呈现负量效关系,GP最佳剂量范围在5-10mg/kg,最高生命延长率为32.77%(P〈0.05)。  相似文献   

7.
新防腐剂TWP橡胶木防腐试验   总被引:3,自引:0,他引:3  
施振华  谭淑清 《林业科学》1992,28(6):524-531
TWP防腐剂对木腐菌的毒性剂量为2.2—3.2kg/m~3,毒杀双钩异翅长蠹初龄幼虫的剂量为1.0kg/m~3,抑制蓝变菌和霉菌的毒性浓度分别为1%及1.5—2.0%,对雄性小鼠口服半致死剂量(LD_(50))为1301mg/kg,使用时对人、畜和环境比较安全,并保持木材原有色泽。生产性应用试验结果表明,橡胶木生材用2.0—2.5%TWP,满细胞法或振荡加压法处理,净药保持量4±0.7kg/m~3,防腐效果相当干硼酚合剂12kg/m~3,并优于进口防腐剂。  相似文献   

8.
李忌  王肖萱  郑荣梁 《沙棘》2008,21(1):8-10
采用同位素示踪技术和蛋白质结合法研究了沙棘汁和沙棘油的抗癌机理,结果显示:沙棘汁对L7712白血病、S110肉瘤、腹水型肝癌等细胞的DNA、蛋白质合成均无抑制作用。沙棘油浓度在0.005mg/L-1.0mg/L时对L7712白血瘸细胞DNA合成有抑制作用,且此时抑制率与浓度呈负相关,沙棘汁ip注射剂量为1/5LD50时,沙棘汁对小鼠血浆cAMP含量略有提高。  相似文献   

9.
红栀子褐斑病的发生与防治研究   总被引:3,自引:1,他引:2  
红栀子褐斑病Phyllosticta spp.主要危害植株的中、下部叶片形成褐斑,严重时叶片枯萎脱落。病菌以菌丝体或分生孢子器在病落叶或病叶上越冬,每年3—11月病害都可发生。气温在25℃以上,病害发生严重。50%多菌灵WP1000倍,30%利德隆悬浮剂2500倍对红栀子褐斑病有较好的防治效果,连续施药3次后防治效果90%以上。  相似文献   

10.
以榆黄蘑多糖浸出量为指标,获得榆黄蘑多糖的最佳热提工艺参数为:料液比1∶50,温度为90℃,时间为40 min;榆黄蘑多糖含量为8.422%.以VC为对照,对榆黄蘑多糖体外抗氧化活性测定,结果表明:榆黄蘑多糖对DPPH自由基的清除效果较好,1.0 mg/mL时达到52.28%;对·OH清除率随浓度的增加而增高,1.0 mg/mL时,达到74.01%;对·O2-清除率较低,1.0 mg/mL时为28.12%.榆黄蘑多糖有一定的还原力,但远低于VC.  相似文献   

11.

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.  相似文献   

12.

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.  相似文献   

13.

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.  相似文献   

14.

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.  相似文献   

15.
本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。  相似文献   

16.

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.  相似文献   

17.
18.

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.  相似文献   

19.
In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.  相似文献   

20.
The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha−1 target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha−1. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1); (2) Lolium perenne L. var. Tove (25 kg ha−1) + Trifolium repens L. group Ladino (4 kg ha−1) + Trifolium pratense L. var. Marino (1 kg ha−1). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m2, with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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