5味中药醇提物对尼罗罗非鱼白细胞免疫活性的作用

将超微五倍子、白头翁、地榆、柯子、虎杖粉碎后过160目筛,按照料液比1∶10将药粉与60%的乙醇水溶液混合,再用超声波粉碎机超声1 h,用滤纸过滤收集滤液,置于多样品平行蒸发仪中浓缩后制得中药提取物。用吸取0.2 mL抗凝剂的无菌注射器自尼罗罗非鱼尾静脉采血0.5 mL,与L-15细胞培养基按体积比1∶9的比例混合成血浆,与中草药提取液单用、联用共孵育,利用氮蓝四唑还原法和流式细胞仪技术分别测定中草药提取液对尼罗罗非鱼外周血白细胞呼吸爆发活性和白细胞吞噬活性的影响。试验结果显示,五倍子、白头翁、地榆、柯子、虎杖单用均能显著提高白细胞氧呼吸爆发活性,呼吸爆发增加率分别为128.68%、123.96%、28.37%、44.44%和78.93%;试验组白细胞吞噬率分别较对照组增加44.04%、44.66%、95.00%、10.35%和64.93%。在两味中药双联用试验中,对白细胞氧呼吸爆发活性呈协同作用的组合为白头翁+地榆,呼吸爆发联用指数为1.28;对白细胞吞噬活性呈协同作用的组合为白头翁+虎杖、柯子+虎杖、五倍子+虎杖和白头翁+柯子,吞噬联用指数分别为11.45、6.20、3.03和1....     

Comparative population structure and trichothecene mycotoxin profiling of Fusarium graminearum from corn and wheat in Ontario,central Canada

Fusarium graminearum causes fusarium head blight (FHB) of wheat and gibberella ear rot (GER) of corn in Canada and also contaminates grains with trichothecene mycotoxins. Very little is known about trichothecene diversity and population structure of the fungus from corn in Ontario, central Canada. Trichothecene genotypes of F. graminearum isolated from corn (n = 452) and wheat (n = 110) from 2010 to 2012 were identified. All the isolates were deoxynivalenol (DON) type. About 96% of corn isolates and 98% of wheat isolates were 15‐acetyl deoxynivalenol (15ADON) type. The fungal population structures from corn (n = 313) and wheat (n = 73) were compared using 10 variable number tandem repeat (VNTR) markers. The fungal populations and subpopulations categorized based on host, cultivar groups, years and geography showed high gene (H = 0.818–0.928) and genotypic (GD = 0.999–1.00) diversity. Gene flow was also high between corn and wheat population pairs (Nm = 8.212), and subpopulation pairs within corn (Nm = 7.13–23.614) or wheat (Nm = 19.483) populations. Phylogenetic analysis revealed that isolates from both hosts were F. graminearum clade 7. These findings provide baseline data on 3‐acetyl deoxynivalenol (3ADON) and 15ADON profiles of F. graminearum isolates from corn in Canada and are useful in evaluating mycotoxin contamination risks in corn and wheat grains. Understanding the fungal genetic structure will assist evaluation and development of resistant cultivars/germplasm for FHB on wheat and GER on corn.     

求解野战输油管道输送能力的数学模型

野战输油管道的长度因战场的变化而不同，运用流体力学、概率论和组合数学建立了管道平均可达流量在管子可靠性、连接的可靠性、阀门可靠性、泵站可靠性、稳定时间和调节频率等因素影响下随管道长度变化的数学模型。该数学模型计算的结果表明，管道的输送能力随泵机组可靠度的降低和管道长度的增加而减小。该数学模型有助于决策者根据战场情况预知将要敷设的管道可能达到的输送量。     

Exclusion of cytoplasmic fragments in flow cytometric analysis of lymph node samples from dogs with lymphoma using membrane-permeable violet laser-excitable DNA-binding fluorescent dye (DyeCycle Violet)

Background: Cytoplasmic fragments derived from fragile neoplastic lymphocytes are common in samples of lymph nodes collected from dogs with lymphoma. These cytoplasmic fragments interfere with accurate gating of target cells and quantification protocols used for flow cytometry because of their variable size and expression of lymphoid cell surface antigens on their membranes. Objective: The aim of this study was to develop a method to efficiently exclude cytoplasmic fragments from flow cytometric analysis of canine lymph nodes in which lymphoma was present. Methods: Single‐cell suspensions of neoplastic cells were prepared from biopsy samples and fine‐needle aspirates of lymph nodes from 23 dogs with lymphoma. Suspensions were stained using a violet laser‐excitable (405 nm) membrane‐permeable DNA‐binding fluorescent dye (DyeCycle Violet [DCV]), incubated with antibodies against CD3, CD5, CD21, CD22, and CD45, and then stained with 7‐amino‐actinomycin D (7‐AAD), an argon‐excitable (488 nm) membrane‐impermeable DNA‐binding fluorescent dye. Multiparameter flow cytometry was used for analysis based on selective uptake and laser‐activated fluorescence of these dyes. Results: Cytoplasmic fragments, which were DCV‐negative and CD45‐positive, and dead cells, which were positive for 7‐AAD, were efficiently separated from neoplastic cells. Conclusion: Staining with DCV is a useful method to improve flow cytometric gating methods and quantitative analyses of lymph node samples from dogs with lymphoma.     

Instream mesohabitat biodiversity in three groundwater streams under base‐flow conditions

1. Concerns regarding the ecological functioning and biodiversity of groundwater‐dominated rivers have been highlighted in the wake of increased water resource pressures, channel management activities and natural drought. 2. The macroinvertebrate communities within three groundwater‐dominated streams in the UK, subject to different management strategies, were examined in relation to substratum mesohabitat diversity. 3. The mesohabitat structure was similar at all three sites examined but the number of taxa present at each site varied markedly. 4. Differences found at each site are related to (i) recent hydrological conditions (drought severity) and (ii) management activities, and are discussed with reference to the conservation and restoration of riverine systems. Copyright © 1999 John Wiley & Sons, Ltd.     

Effect of acute intraocular pressure elevation on blood flow velocity and resistance in the rabbit ophthalmic artery

Objective To determine the effect of intraocular pressure (IOP) on blood flow velocity and resistance in the rabbit ophthalmic artery. Animals Ten adult New Zealand White rabbits were used. Procedures Right eyes were cannulated and the IOP was raised in a stepwise manner from 20 to 70 mmHg. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) in the ophthalmic artery were measured by color Doppler imaging. Values of PSV, EDV and RI were compared at various IOPs via the analysis of variance (anova ) of a randomized block design with post hoc Bonferroni test. Results Significant differences of PSV, EDV and RI at different IOP points (all P < 0.001) were observed. Over the entire IOP range, linear regression showed a negative correlation between IOP and both PSV and EDV (β = ?0.07434, P = 0.0020 and β = ?0.07829, P < 0.001, respectively), as well as a positive correlation between the RI and IOP (β = 0.00221, P < 0.001). Moreover, line plots identified a point with IOP = 40 mmHg, splitting the IOP range with different regression slopes. Piecewise linear regression indicated no correlation between PSV, EDV, RI and IOP when the IOP was elevated from 20 to 40 mmHg (P = 0.1832, P = 0.5932 and P = 0.5819, respectively). However, piecewise linear regression detected a stronger negative correlation between PSV, EDV and IOP (β = ?0.15760, P = 0.0011 and β = ?0.11872, P = 0.001, respectively) and a stronger positive correlation between RI and IOP (β = 0.00273, P = 0.0015) during the stage from 40 to 70 mmHg. Conclusions The ophthalmic artery in the rabbits was capable of maintaining normal blood velocity and resistance when IOP was below 40 mmHg. However, the autoregulatory capacity was greatly limited when IOP was over 40 mmHg.     

巴西橡胶树ADF6基因的克隆与表达分析

肌动蛋白解聚因子(Actin Depolymerizing Factor,ADF)是一种重要的肌动蛋白结合蛋白。ADF通过参与调控肌动蛋白的装配和解聚在多种生理过程中发挥重要作用。本研究通过RT-PCR技术从橡胶树胶乳中获得HbADF6基因的cDNA和基因组序列,序列分析显示HbADF6基因的开放阅读框为441 bp,共编码146个氨基酸,基因组序列由2个内含子和3个外显子组成。实时荧光定量PCR结果表明,HbADF6基因在所有检测组织中均表达,其中树皮中表达量最高,叶片中表达量最低。HbADF6基因的表达受乙烯利(ET)和碘化钾(KI)调控,并与排胶时间和死皮有关。此结果表明HbADF6基因可能在橡胶树乙烯响应、死皮和排胶过程中发挥重要作用。      

Charcoal production through selective logging leads to degradation of dry woodlands:a case study from Mutomo District,Kenya

Provision of woodfuel is an important ecosystem service of dry forests and woodlands.However,charcoal production through selective logging of preferred hardwood species has the potential to alter the physiognomic composition of the residual or re-growth woodlands and may lead to their deterioration and degradation.This study,conducted through forest inventory in Mutomo District in Kenya,assessed the impact of charcoal production on unprotected dry woodlands in terms of tree density,targeted species basal area,species richness,evenness and Shannon diversity.The parameters of the disturbed woodlands were evaluated for significant differences with those of the neighbouring protected Tsavo East National Park,which served as a reference for an ecologically undisturbed ecosystem.By evaluating a consequence of tree harvesting for charcoal production,this study confirmed the overall significant differences between the protected and unprotected woodlands in all the tested parameters.To confirm if the differences in the land-covers of the woodlands had any influence on their degradation,all mentioned parameters were compared between the four differentiated classes and their respective control plots in the protected areas.At the "land-cover level",the statistically significant difference in the basal area of tree species preferred for charcoal production between the protected and unprotected open trees confirms that the class with a high density of large mature trees is the prime target of charcoal producers.In addition,there seems to be a general trend of lower values of tree species richness,evenness and Shannon diversity for the unprotected woodlands subjected to charcoal production.On the other hand,the disturbed woodlands display the potential to recover through their comparably high saplings density.The findings make an important contribution to the discourse on the impact of charcoal production in dry woodlands,a topic that is highly controversial among researchers.     

侧流道泵研究现状及发展趋势

侧流道泵或侧通道泵(side channel pump)是一种介于容积式泵和离心泵之间的径向式叶片泵,由叶轮一侧有一个横截面为半圆形的侧流道而得名,通常具有超低比转数特性和自吸能力,其体积小,流量低,但是扬程却很高.与普通离心泵相比,侧流道泵作为一种新型泵,更适用于极端条件下气液两相流体和接近临界状态流体的输送.首先介绍了侧流道泵的组成和工作原理,简要阐述了流体在侧流道泵内的运动轨迹.同时,按照时间顺序分析了侧流道泵的研究情况,重点分析了近年来国内外关于侧流道泵的研究现状.最后根据前面所述的研究成果,展望了侧流道泵研究的发展趋势.认为优化设计可提高侧流道泵的性能,完善侧流道泵理论模型,利用先进的内部流动测试手段,例如PIV,LDA等,分析测量侧流道泵内部流动规律和旋涡演变机理,设计开发多功能侧流道泵是今后侧流道泵的研究重点.     

半滑舌鳎成鱼开放流水与循环水养殖模式下生长及肌肉营养成分差异研究

为半滑舌鳎的集约化养成提供基础数据,设定开放流水和循环水两种养殖模式,以处于快速生长期的大规格鱼种(0.640 ±0.063) kg为研究对象,检测半滑舌鳎的生长及肉质相关指标,实验共进行7个月,结果显示:①半滑舌鳎在两种养殖模式下的成活率分别为79.89％和90.38％,月增重率分别是0.154 7和0.1109 kg,肥满度分别是0.920和0.838,生长激素分泌量分别是2.812和2.706 μg/L.循环水养殖模式组在成活率、增重率、肥满度和生长激素分泌量上分别高于开放流水养殖模式组13.13％、39.5％、9.8％和3.92％.②两种养殖模式,开放流水养殖模式组在粗蛋白、氨基酸、PUFA上更占优势,但在粗脂肪、MUFA上循环水养殖模式明显占优势,分别高于开放流水养殖模式组41.732％和16.912％.实验表明,循环水养殖模式优越的水质环境更适合半滑舌鳎的育肥.本实验说明,半滑舌鳎在循环水养殖模式下具有很好的适应性,其生长处于较好的状态,营养品质上也能够得到保证.同时,也说明循环水养殖模式可以极大地发掘半滑舌鳎的养殖潜力,是一种适合半滑舌鳎集约化养殖的具有优势的养殖模式.