白蜡虫多糖免疫调节与抑制肿瘤活性

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。     

中药沙棘提取液对血液肿瘤细胞杀伤作用研究

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。     

马尾松树皮提取物抗肿瘤作用的研究

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。     

滑菇子实体多糖纯化工艺的初步研究

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。     

桂花叶挥发油化学成分分析及其生物活性

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 )%.     

银杏叶聚戊烯醇对荷瘤鼠生命延长率的研究

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）。     

新防腐剂TWP橡胶木防腐试验

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。     

沙棘提取物对癌细胞DNA、蛋白质合成及体内血浆中的cAMP含量的影响

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。     

榆黄蘑多糖的提取及其抗氧化活性研究

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.     

红栀子褐斑病的发生与防治研究

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。     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Biogeochemical impacts of clearfelling and reforestation on blanket-peatland streams: II. major ions and dissolved organic carbon

Streams and drains in blanket-peatland forest in western Ireland were sampled weekly over 5 years, 1996–2000, using continuous, depth-proportional passive sampling. Analysis was for pH, alkalinity by Gran titration, anions by IC, metals by ICP, aluminium speciation by loaded-resin exchange, and dissolved organic carbon (DOC) by absorbance at 320 nm.

Effects of felling are identified graphically from two forest drains whose catchments (both about 1 ha) were clearfelled, and partial clearfelling of one larger catchment (somewhat over 1 km²), in summer 1999. Calcium concentrations and alkalinity were increased in the drain- and streamwater from the felled areas. The pH was increased in drains, while in the larger stream, pH range decreased while the mean increased. Phosphorus increased markedly with clearfell, in the absence of recent fertilising, and also increased with fertilising; these results are reported in an accompanying paper. Ammonium-nitrogen concentrations were increased in the two drains with felling, and temporarily decreased in the larger stream. Nitrate increased in some cases. Potassium and manganese concentrations also increased. Concentrations of DOC and organic monomeric aluminium increased gradually, subject to a continuing strong annual cycle. There were no clearfelling effects on concentrations of solphate, suspended solids or inorganic monomeric aluminium. In the two drains (fully clearfelled), concentrations of sodium, chloride and magnesium, and conductivity, were all reduced after felling. Fertilising effects other than for phosphorus were indistinct.

Effects of the combined clearfell–reforestation treatment were testable statistically, using randomised intervention analysis, between two larger streams (1 km²) as a treatment–control comparison. There were statistically significant positive responses in streamwater concentrations of nitrate, potassium, calcium, DOC and aluminium fractions. The implications for management practice depend on whether the loss of nutrients is sustainable for future crop productivity, and whether critical limits and loads of receiving ecosystems are exceeded.     

Effect of Drought on Growth and Mortality of Actively Growing Norway Spruce Container Seedlings Planted in Summer

Survival, root egress and height growth of 13-month-old actively growing Norway spruce ( Picea abies (L.) Karst.) container seedlings exposed to preplanting drying treatments (0, 4, and 8 days) and postplanting drought periods (1, 2, 3, and 4 weeks) were studied in the field between 5 July and 18 August 1999. The mortality of seedlings increased and the height growth and root egress decreased throughout the postplanting drought period. Postplanting performance was also affected by preplanting drying treatments. The results indicate that no risk of excessive mortality and growth restrictions occurs when actively growing seedlings are planted in summer, provided that seedlings are well watered before planting and the drought period does not exceed 3 weeks.     

Rehabilitation of diseased cacao fields in Peru through shade regulation and timing of biocontrol measures

The objective of this case study was to test the effectiveness of biocontrol for the rehabilitation of abandoned, diseased (moniliasis, witches' broom and black pod) cocoa and to develop testable hypotheses regarding the effect of shade and biocontrol timing. Three trial fields differed in their shade regimes. Biocontrol was administered starting either at flowering or pod filling. Disease incidence and yield were compared with cultural control alone. Biocontrol reduced moniliasis from 49% to 25%, independent of the shading regime and application time. Witches' broom was most severe without shade and unaffected by biocontrol. No significant effects on black pod were observed. Although biocontrol increased percentage healthy fruit independent of shading and timing, only the shaded plot with biocontrol from flowering onwards responded with increased yield. Our hypothesis is: 'In the rehabilitation of abandoned cacao, only fields under sustainable shade management and early onset of biocontrol can realise their production potential.' This revised version was published online in June 2006 with corrections to the Cover Date.     

qPCR quantification of Ophiognomonia clavigignenti‐juglandacearum from infected butternut trees under different release treatments

The use of a molecular assay for quantifying conidia of Ophiognomonia clavigignenti‐juglandacearum, the fungal pathogen responsible of butternut canker, was investigated. Purified DNA from conidia collected on glass fibre filters of a passive rain collectors was quantified using a TaqMan real‐time quantitative polymerase chain reaction (qPCR) assay. The qPCR assay could specifically discriminate the target species from all other North American known species of Ophiognomonia, and it was sensitive enough to repeatedly detect one conidium. A linear relationship between numbers of conidia and qPCR C_t values was determined, and used to assess the sporulation of the pathogen under trees that were released to promote their vigour. In total, 977 samples of field‐captured conidia from 49 trees, at two locations, and from two successive growing seasons were analysed. No significant difference of sporulation was observed under control and release treatments. However, our results demonstrated that qPCR assay was reliable for detecting and quantifying O. clavigignenti‐juglandacearum from environmental samples, which will be useful to assess further control methods for this disease.     

The potential of alley cropping in improvement of cultivation systems in the high rainfall areas of Zambia I. Chitemene and Fundikila

Three trials investigating the potential of alley cropping to improve the traditional systems of cultivation, chitemene and fundikila, in the Northern Province of Zambia are described. Flemingia congesta, Tephrosia vogelii, and Sesbania sesban, were grown in association with finger millet, groundnut, cowpea, and maize in various traditional cropping sequences. The indigenous species Tephrosia vogelii and Sesbania sesban were not able to withstand repeated pruning and the long following dry season, and were replaced with Calliandra calothyrsus, and Cassia spectabilis.Over a four year period, there was no benefit by alley cropping with any of the tree species on crop yields, and yields in alley crop treatments even dropped significantly below the control treatments in the fourth year, casting doubt on the potential of alley cropping for sustainable production. There was also no consistent effect on soil chemical characteristics in any of the trials. It was suggested that this lack of beneficial response to alley cropping was due to low tree biomass production low quality of prunings, and an inappropriate cropping sequence. There was no evidence that alley cropping contributed to enhanced nutrient recycling, despite substantial localised pools of soil nutrients, particularly in the chitemene, with which recycling could potentially occur.     

Toxicity of biocide GCSC-BtA on arthropod pests under different temperature conditions

The present research dealt with the toxicity of GCSC-BtA (Germany–China Scientific Cooperation-Bacillus thuringiensis-Abamectin), a new type biocide developed by conjugating a toxin from Bacillus thuringiensis (B.t.) with Abamectin from Streptomyces avermitilis, on arthropod pests under different temperature conditions. The results showed that GCSC-BtA possessed higher toxicity than B.t. crystal, Abamectin or Cypermethrin, with pest mortalities of 97.9, 93.7, 96.4, 82.3 and 96.7% for Tetranychus cinnabarinus (Boisd.) (Acari, Tetranychidae), Frankliniella occidentalis Pergande (Thys., Thripidae), Aphis fabae Scopoli (Hom., Aphididae), Plutella xylostella (L.) (Lep., Plutellidae) and Cameraria ohridella Deschka et Dimić (Lep., Gracillariidae), respectively. Toxicities of GCSC-BtA to T. cinnabarinus and P. xylostella decreased significantly at the older developmental stage with an exception that egg stage had the highest tolerance, in which LC₅₀s of GCSC-BtA were 0.0001, 0.0019 and 0.0708 mg/ml for nymph, adult and egg of T. cinnabarinus, and that 0.0399, 0.2035 and 0.9033 mg/ml for the 2nd instar larvae, 4th instar larvae and egg of P. xylostella, respectively. Also, the biocide was more effective to the lower stage of A. fabae than the higher one with LC₅₀s of 0.0023, 0.0086 and 0.0171 mg/ml against 1st instar nymph, 3rd instar nymph and adult, respectively. In general, toxicity of the new type of biocide was positively related to temperature against all the tested pests, except against T. cinnabarinus, where it was almost similar at the three temperature conditions. GCSC-BtA displayed significantly lower toxicities at 15/20°C than 20/25°C or 25/30°C against F. occidentalis, A. fabae, P. xylostella and C. ohridella. However, no significant difference was found in the toxicities against F. occidentalis, A. fabae and C. ohridella above 20°C, whereas toxicity against P. xylostella increased as temperature raised. Therefore, to achieve higher efficacy in the field, application rate and time should be devised according to these factors.