异质生境不同叶色羊草有性生殖特征的研究

采用无样方采样法,对长岭、图牧吉和沽源自然草原不同土壤类型5种叶色羊草(Leymus chinensis)的数量特征和生殖分配进行研究,以期揭示羊草叶色渐变群有性生殖的内在规律。结果表明:异质生境不同叶色羊草有性生殖特性和生物量分配具有可塑性变化。不同土壤类型5种叶色羊草的穗长、穗重、小穗数、单穗籽粒数、结实率、单穗籽粒重及生殖分配Ⅰ, Ⅱ和Ⅲ最大值多数出现在沽源地区;羊草籽粒千粒重的变化幅度较小;相同土壤类型不同叶色羊草、相同叶色不同土壤类型羊草其茎重、鞘重、叶总重、植株总重等指标的最大值与最小值差异显著或极显著,但与中间过渡叶色之间差异多数不显著;异质生境不同叶色羊草的茎重最大,其次为鞘重和叶重。因此异质生境不同叶色羊草采取有性生殖调节策略和资源分配策略,具有较强的可塑性。     

RESEARCH PAPER: Incidence of elevation of cardiac troponin I prior to and following routine general anaesthesia in dogs

ObjectiveTo estimate the incidence of raised cTnI after general anaesthesia in dogs and to explore major risk factors influencing this.Study designProspective clinical study.AnimalsA total of 107 (ASA physical status 1?2) dogs, 63% male and 37% female, median age 5 years (range 0.3–13.4), median weight 24.4 kg (range 4.2–66.5 kg) undergoing anaesthesia for clinical purposes.MethodsVenous blood samples were taken within 24 hours prior to induction and 24 hours after the termination of anaesthesia. Serum concentrations of cardiac troponin I were measured using a chemiluminescent enzyme immunometric assay with a lower level of detection of 0.20 ng mL^?1 (below this level <0.20 ng mL^?1). Continuous data were assessed graphically for normality and paired and unpaired data compared with the Wilcoxon signed ranks and Mann–Whitney U‐tests respectively. Categorical data were compared with the Chi squared or Fisher’s exact test as appropriate (p < 0.05).ResultsOf the 107 dogs recruited, 100 had pre‐ and post‐anaesthetic cTnI measured. The median pre‐anaesthesia cTnI was ‘<0.20’ ng mL^?1 (range ‘<0.20’–0.43 ng mL^?1) and the median increase from pre‐anaesthesia level was 0.00 ng mL^?1 (range ?0.12 to 0.61 ng mL^?1). Fourteen dogs had increased cTnI after anaesthesia relative to pre‐anaesthesia (14%, 95% CI 7.2–20.8%, range of increase 0.03–0.61 ng mL^?1). Six animals had cTnI levels that decreased (range 0.02–0.12 ng mL^?1). Older dogs were more likely to have increased cTnI prior to anaesthesia (OR = 5.32, 95% CI 1.35–21.0, p = 0.007) and dogs 8 years and over were 3.6 times as likely to have an increased cTnI after anaesthesia (95% CI 1.1–12.4, p = 0.028).Conclusion and clinical relevanceIncreased cTnI after anaesthesia relative to pre‐anaesthesia levels was observed in a number of apparently healthy dogs undergoing routine anaesthesia.     

四个山西地方山羊品种Pit-1基因多态性的研究

垂体释放因子1基因(Pit-1)是动物经济性状的重要候选基因之一。采用PCR-RFLP和PCR-SSCP技术对4个山西地方山羊品种的Pit-1基因进行多态性检测和分析,以了解该基因在这些品种中的遗传变异。结果表明:该基因座存在HinfⅠ限制性酶切多态性,表现AA和BB两种基因型,频率分别为0.01和0.99。洪洞奶山羊和吕梁黑山羊因突变而显著偏离Hardy-Weinberg平衡(P0.05)。利用PCR-SSCP检测出5种基因型。优势等位基因均为B,基因型频率的品种间差异明显。吕梁黑山羊和黎城大青羊显著偏离平衡状态(P0.05)。中性检验表明,4个品种处于中性突变或遗传漂变过程中。各群体的期望杂合度和观察杂合度较为接近。基于两种技术的Fst值分别为0.0102和0.0197,说明总群体中大约只有1%～2%的变异来自群体间,群体间的遗传分化较弱。     

基于均匀设计的铜绿微囊藻最适增殖条件研究

铜绿微囊藻(Microcystis aeruginosa)是中国乃至世界最易爆发水华的蓝藻之一,对水产养殖生物和人类生活产生了极坏的影响.探索其发生条件,预测和治理水华成为人们研究的重点内容.由于水华发生的原因复杂,要更好地了解铜绿微囊藻的增殖情况,预测和防治其水华暴发,必须考虑到多方面因素的综合影响.单凭一个因子就预报、评论水华是片面的.目前关于多因素的实验报道极少,本研究利用均匀设计的优势,开展5 因素多水平的研究.     

A new cytotoxic guaianolide from Chrysanthemum boreale

A new cytotoxic guaianolide was isolated from Chrysanthemum boreale Makino. The structure of guaianolide was elucidated as 8-acetoxy-4,10-dihydroxy-2,11(13)-guaiadiene-12,6-olide (1). Compound 1 exhibited cytotoxic activity (IC(50)< or =4 microg/ml) against all five human cancer cell lines tested.     

微耕机作业事故与机具设计缺陷的关联性分析

针对我国微耕机作业事故频繁发生、造成人员伤亡和经济损失的严峻形势,基于设计心理学、人因工程学、交互设计理论,分析了与微耕机作业事故相关的人、机具和环境因素,指出机具设计缺陷是微耕机作业事故的最重要因素。操作者的群体特征不易改变,作业环境无从选择,只能通过机具的安全设计来适应人的特点,弥补环境的不足,即机具的安全设计是减少事故、提高质量的根本手段。同时,进一步讨论了微耕机防护装置、操作装置、形态、色彩和标识安全设计以及材料选用。应用工业设计学科理论研究微耕机作业事故,分析事故与机具设计缺陷的关联性,是从根本上消除事故隐患及解决农机安全问题的新思路。     

YQS-120型烟草起垄施肥机的设计

ＹＱＳ－１２０型烟草起垄施肥机由机架、起垄装置、施肥装置、传动装置４部分组成。在采用圆筒排肥器深施底肥的同时,利用圆盘覆土器的正反双向两铧梨使２次起垄１次完成,解决了施肥机单一施肥,起垄机专门起垄的重复作业问题,使机械化程度大大提高。该机结构和制造工艺简单,生产成本低,具有广泛的推广价值．     

Rare Carbon-Bridged Citrinin Dimers from the Starfish-Derived Symbiotic Fungus Penicillium sp. GGF16-1-2

Four novel, rare carbon-bridged citrinin dimers, namely dicitrinones G–J (1–4), and five known analogs (5–9) were isolated from the starfish-derived fungus Penicillium sp. GGF 16-1-2. Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1–9 exhibited strong antifungal activities against Colletotrichum gloeosporioides with LD₅₀ values from 0.61 μg/mL to 16.14 μg/mL. Meanwhile, all compounds were evaluated for their cytotoxic activities against human pancreatic cancer BXPC-3 and PANC-1 cell lines; as a result, compound 1 showed more significant cytotoxicities than the positive control against both cell lines. In addition, based on the analyses of the protein-protein interaction (PPI) network and Western blot, 1 could induce apoptosis by activating caspase 3 proteins (CASP3).