Antiviral activity and mechanism of action of novel thiourea containing chiral phosphonate on tobacco mosaic virus

Using half-leaf method O,O'-diisopropyl (3-(L-1-(benzylamino)-1-oxo-3- phenylpropan-2-yl)thioureido)(phenyl)methyl phosphonate (2009104) was studied for its activity on tobacco mosaic virus (TMV). It showed good curative activity in vivo and the curative activity at 500 μg/mL was found to be 53.3%. In vivo treatment with the control agent Ningnanmycin at 500 μg/mL resulted in 51.2% inhibition and curative inhibition rates respectively. Dot-ELISA test was employed to verify the efficacy of activity of compound 200910 for anti-TMV activity. The mechanism of action of compound 2009104 to resist TMV was also studied. The results showed that the resistance enzymes PAL, POD, SOD activity and chlorophyll content after TMV inoculation K(326) (Nicotiana tabacum K(326)) of tobacco plants followed by treatment with compound 2009104 were significantly enhanced. The study of the effect of compound 2009104 on TMV capsid protein (CP) showed that it inhibited the polymerization process of TMV-CP in vitro.     

以BINOL为骨架的手性Brφnsted酸催化剂的研究进展

简要介绍了近年BINOL母体的BrФnsted酸催化剂的研究进展,包括了催化剂结构的变化,底物结构的变化,以及影响对映体过量值的因素。     

Opportunistic maintenance of multi‐equipment system: a case study

A case study on preventive maintenance (PM) of a multi‐equipment system is presented in this paper. Each equipment of the system consists of many components/subsystems connected in series. Because of the series structure, opportunistic maintenance (OM) policies are more effective for the components of the equipment. A new OM policy based on the classification of opportunities has been proposed. Various OM policies have been evaluated using simulation modeling, and the new policy has been found to be more effective than the existing OM policies. The impact of this policy on the overall system has also been simulated. Copyright © 2000 John Wiley & Sons, Ltd.     

Biodiesel preparation,optimization, and fuel properties from non-edible feedstock,Datura stramonium L.

This is a study on the feasibility of biodiesel preparation from a new and promising non-edible feedstock, Datura stramonium L. oil (DSO). First, important physical–chemical properties, such as oil content of seed (21.4 wt%), acid value (7.93 mg KOH/g) and fatty acid composition of expressed oil, were determined. Second, under the optimal two-step catalyzed reaction conditions, the maximum fatty acid methyl ester (FAME) yield (87%) and FAME content of more than 98 wt% were obtained. Furthermore, the fuel properties of DSO biodiesel were determined and evaluated. Compared with Jatrpha curcas L. (JC) and beef tallow (BT) biodiesel, DSO biodiesel possessed the best kinematic viscosity (4.33 mm²/s) and cold filter plug point (?5 °C). Based on the results, D. stramonium L. was identified as a promising species for biodiesel feedstock.     

有机双功能团小分子催化剂的研究进展

在过去的10年时间里,有机小分子催化剂作为一门环境友好的有机合成方法学在不对称催化合成中的应用得到了重新发掘,新颖的有机小分子催化剂受到广泛的关注。其中,有机双功能团小分子催化剂的分子中存在两个活性位点同时和底物相互作用,导致了反应速率的加快和立体选择性的提高,成为国内外的研究热点。本文简要介绍了近几年来有机双功能团催化剂的研究进展,包括联二萘酚为母体的B rφnsted酸催化剂、硫脲催化剂及奎宁催化剂。     

Optimizing subsidies for the location of distribution centers

The paper introduces a three-level model of location. On the lowest level, customers purchase the good from a firm. On the next higher level, the firm will decide how many distribution centers it will establish and where these centers are to be located. In addition to its location costs, the firm’s location decision will also be guided in part by the subsidy offered by a regional planner. Finally on the highest level, the regional planner will use its own revenue that it derives from the firm’s economic activities to offer a subsidy to the firm. This subsidy is assumed to be based purely on economic, rather than political considerations. In other words, the regional planner’s objective is to maximize its revenue. The paper then formally constructs models for the firm and the regional planner and examines their relations. It turns out that the models can be combined and greatly simplified. Computational tests on a set of published data confirm the solvability of the model. They also reveal the strong decrease of the proportion of unmet demand as economic multipliers and/or prices increase. This also implies an increase in the subsidy that must be paid to the firm, as the regional planner wants to convince it to locate the number of centers it prefers at the sites it wants them to be. Additional tests investigate the effects that result from price and related demand changes in case of elastic demand.     

3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中的应用

从一系列3,3’-位杂原子取代的BINOL（1,1’-联二萘酚）类手性催化剂不对称催化反应类型的不同,探讨了3,3’-位杂原子取代的BINOL类手性催化剂在不对称合成中应用的研究进展,指出3,3’-位杂原子取代的BINOL类手性催化剂不对称催化底物高效的对映体选择性,并对该类手性催化剂的发展进行了展望。     

A facile and feasible method to evaluate and control the quality of Jatropha curcus L. seed oil for biodiesel feedstock: Gas chromatographic fingerprint

To establish a facile and feasible method to evaluate and control the quality of Jatropha curcus L. seed oil for biodiesel feedstock, Gas chromatographic (GC) fingerprint technology was introduced and employed. Initially, the chromatograms of the 13 oil samples from various plantation zones in Guizhou, China were obtained under optimized GC conditions. Ten common peaks were selected as the characteristic peaks for chemometrics, seven of which were identified and quantified by comparing with the standards. The mean chromatogram of S7 (n = 3) was selected as the reference spectrum for similarity analysis based on the influence of the fatty acid composition of the raw material on the fuel properties of resulting biodiesel. Furthermore, the result of SA was confirmed by hierarchical clustering analysis and principal component analysis. By this method, all samples can be classified into three groups. The similarity value of samples approaching 1.000 compared with sample 7 was indicative of the desired fuel properties of biodiesel, indicating the potential practical applications in the quality evaluation and control of biodiesel feedstock.     

Reachability of locational Nash equilibria

This paper examines the location of duopolists on a tree. Given parametric prices, we first delineate necessary and sufficient conditions for locational Nash equilibria on trees. Given these conditions, we then show that Nash equilibria, provided they exist, can be reached in a repeated sequential relocation process in which both facilities follow short-term profit maximization objectives.