天维菌素酰化衍生物的合成及杀虫杀螨活性

以天维菌素B、天维菌素B单糖苷和天维菌素B苷元为原料,经选择性C-5羟基保护,在C-13、C-4′和C-4″位引入不同酰基基团,合成了3个系列共23个天维菌素B酰化衍生物,并通过1H NMR、13C NMR和高分辨质谱对所有目标化合物的结构进行了表征。生物活性测定结果表明,所有衍生物对小菜蛾Plutella xylostella、朱砂叶螨Tetranychus cinnabarinus以及松材线虫Bursaphelenchus xylophilus均表现出不同程度的毒杀活性,其中天维菌素B C-4″位衍生物的活性优于C-4′位衍生物及13位衍生物。化合物8e对小菜蛾和松材线虫的毒杀活性最优,LC50值分别为9.2 mg/L和0.42 mg/L,化合物8b对朱砂叶螨的毒性最高,LC50值为0.0019 mg/L,均优于对照药天维菌素B。     

12-(取代苯氧异丁酰氧亚氨基)-1,15-十五内酯的合成及除草活性

通过取代苯氧异丁酸与12-(羟基亚氨基)十五内酯的反应,合成了取代苯氧异丁酰氧亚氨基十五内酯,并测定了其对苋菜的除草活性。所有化合物均经过1H NMR、13C NMR和元素分析确证。初步的生物活性测定结果表明,目标化合物 Ⅲa~Ⅲd 的EC50值分别为34.570、46.492、55.385、50.114 mg/L,其活性比对照药剂2,4-D(117.325 mg/L)高,而比苯磺隆(22.381 mg/L)低。     

Effect of oak (Quercus persica) acorn level on apparent digestibility,ruminal fermentation,nitrogen balance and urinary purine derivatives in pregnant goats

The aim of this experiment was to investigate the effect of dietary oak (Quercus persica) acorn (OA) level on dry matter intake (DMI), apparent nutrient digestibility, nitrogen (N) utilization, ruminal fermentation, protozoa population and urinary purine derivatives (PD) during the last 60 days of goat pregnancy. Twenty‐four multiparous pregnant goats (41.7 ± 2.3 kg BW) were assigned to one of three experimental diets consisted of control diet (C, without OA) and diets containing 20 (OA₂₀) or 40 g/100 g of OA (OA₄₀) on a DM basis in a completely randomized block design. Goats fed OA₄₀ had lower DMI (p < .01), DM (p < .01), OM (p < .01) and NDF (p < .05) digestibility, ruminal NH₃‐N concentration (p < .01), N intake (p < .01) and N retention (p < .01). Crude protein digestibility and ruminal acetate and total volatile fatty acid (VFA) concentration were lower in animals fed OA‐contained diets (p < .01), whereas ruminal propionate concentration was higher in goats fed the C diet (p < .01). Animals fed OA₄₀ had higher faecal N excretion and lower urinary N excretion (p < .01). Urinary PD was lower in goats fed diets containing OA in relation to those fed the C diet (p < .01). Total protozoa population decreased linearly with increasing OA level in the diet (p < .05). These results suggest that feeding OA, especially high level, has negative impacts on DMI, nutrient digestibility, VFA concentration, N retention and urinary PD excretion that may have adverse effects on metabolism and performance of pregnant goats.     

天气衍生品的运作机制与精算定价

天气衍生品是为了规避天气风险给天气敏感行业带来收入的不稳定性而兴起的创新型风险管理工具，其实质是通过衍生合约对天气风险进行分割、重组和交易的证券化产品。不同于传统金融衍生品，天气衍生品的价值取决于温度、湿度或降雨量等天气指数。本文在分析天气衍生品市场发展的基础上，重点探讨了最常见的天气期货和天气期权的运作机制及其精算定价。     

Hemodynamic effects of incremental doses of acepromazine in isoflurane-anesthetized dogs

ObjectiveTo evaluate the effects of incremental doses of acepromazine on hemodynamics in isoflurane-anesthetized dogs.Study designProspective, experimental study.AnimalsHealthy, adult, mixed-breed dogs (two male and four female) weighing 16.8 ± 5.1 kg (mean ± standard deviation).MethodsDogs were anesthetized with propofol (7 mg kg^–1) intravenously (IV) and isoflurane. Thermodilution and arterial catheters were placed for hemodynamic monitoring and arterial blood sampling for blood gas analysis. Baseline measurements were performed with stable expired concentration of isoflurane (Fe′Iso) at 1.8%. Each dog was then administered four incremental acepromazine injections (10, 15, 25 and 50 μg kg^–1) IV, and measurements were repeated 20 minutes after each acepromazine injection with Fe′Iso decreased to 1.2%. The four acepromazine injections resulted in cumulative doses of 10, 25, 50 and 100 μg kg^–1 (time points ACP₁₀, ACP₂₅, ACP₅₀ and ACP₁₀₀, respectively).ResultsCompared with baseline, cardiac index (CI) increased significantly by 34%, whereas systemic vascular resistance index (SVRI) decreased by 25% at ACP₅₀ and ACP₁₀₀. Arterial oxygen content (CaO₂) was significantly lower than baseline after all acepromazine injections (maximum decreases of 11%) and was lower at ACP₅₀ and ACP₁₀₀ than at ACP₁₀. No significant change was found in heart rate, stroke index, oxygen delivery index and systolic, mean and diastolic blood pressures. Hypotension (mean arterial pressure < 60 mmHg) was observed in one dog at baseline, ACP₁₀, ACP₂₅ and ACP₁₀₀, and in two dogs at ACP₅₀.Conclusions and clinical relevanceCompared with isoflurane alone, anesthesia with acepromazine–isoflurane resulted in increased CI and decreased SVRI and CaO₂ values. These effects were dose-related, being more pronounced at ACP₅₀ and ACP₁₀₀. Under the conditions of this study, acepromazine administration did not change blood pressure.     

几种二氮氧化喹恶啉甲醛新衍生物的合成及其抑菌活性的研究

合成了5种二氮氧化喹恶啉甲醛的新衍生物并用HNMR谱和元素分析对其结构进行了表征。用新的化合物对5种常见的植物病菌进行了抑菌活性并进行了抑菌活性和结构关系的初步探讨。     

公共项目公私合伙制中政府保证的会计问题研究

政府部门应该以国际公共部门会计准则为依据对PPP项目中的政府保证进行会计确认，反映PPP项目中政府保证的成本及其隐含的风险，增强政府部门的成本意识，避免过度提供保证。根据业绩担保类政府保证的看跌期权性质，建议应用期权定价的技术进行会计计量，将其确认为报表中的金融负债。并可通过建立政府保证基金的方式解决政府保证单独估价造成的成本高估问题。     

Phenolic compounds in plant disease resistance

We propose that an important first line in plant defense against infection is provided by the very rapid synthesis of phenolics and their polymerization in the cell wall. This rapid synthesis, which leaves no time forde novo enzyme synthesis, is regulated by the extreme pH-dependence of the hydroxylase, catalyzing the formation of caffeoyl-CoA from 4-coumaroyl-CoA. We further propose that elicitor treatment or infection causes rapid membrane changes leading to a decrease in cytoplasmic pH. This decrease would have the effect of activating the hydroxylase.     

Characterization of new photosynthesis-inhibiting imidazolidine derivatives. 1. Interpretation of post-emergence herbicidal performance from photosynthesis-inhibiting activity and systemicity

An attempt was made to account for quantitatively measured herbicidal performance of foliage-applied 5-hydroxy-3-methyl-2–oxo-imidazolidine-1-carboxamide derivatives by their photosynthesis-inhibiting activity and systemicity. Photosynthesis-inhibiting activity was estimated from the increase of chlorophyll fluorescence intensity in Chlorella vulgaris Beijer cells measured by a microplate scanner, and systemicity was also evaluated by computer-aided chlorophyll fluorescence imaging. The highest herbicidal performance was recorded for N-cyclohexyl-5-hydroxy-3-methyl-2-oxo-imidazo～idine-l-carboxamide, a compound with the second strongest photosynthesis-inhibiting activity and intermediate systemicity. Though neither photosynthesis-inhibiting activity nor systemicity showed significant correlation with the actual herbicidal performance in simple regression analyses, a high predictability was found for a multiple regression on both parameters as two independent variables, suggesting that these two factors work cooperatively in the field performance.     

分子修饰前后人参皂苷体外抗马立克氏病毒鸡胚成纤维细胞模型的建立

用雏鸡将马立克氏病毒(MDV)血毒复壮,分离发病鸡淋巴细胞并接种于鸡胚成纤维细胞,观察其病变。获得适应鸡胚成纤维细胞(CEF)的MD强毒,通过电镜观察、琼脂扩散实验进一步鉴定病毒,并建立了MDV感染CEF细胞模型,为研究人参皂苷及其衍生物的体外抗病毒作用及其机制奠定基础。