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.     

Soil insect pests of cold temperate zones of East Asia,including DPR Korea: A review

Food crops have come under increasing threat from soil insect pests as a result of monotonous use of arable land and the unavailability or ban of soil insecticides. The development of new management strategies is hindered by the limited knowledge of the identity and biology of local soil pests. A literature survey was carried out focusing on the cold temperate zones of East Asia (north-eastern China, far south-eastern Russia, both Koreas). As for DPR Korea, field surveys were added. At least 53 soil insect species appeared to have wide-ranging importance. The highest diversity of soil pests attack maize (at least 29 species), cereals (27), soybean (19), potato (19), other beans (16), peanut (16), fruit tree nurseries (14), followed by cabbage, sorghum, cotton, grassland habitats, and sweet potato. Most belong to the Melolonthidae (21 %), Scarabeidae (15 %), Noctuidae (13 %) or Elateridae (11 %). Genera containing the most species were the melolonthid Holotrichia (at least five species), scarabeid Anomala (5), agromyzid Delia (4) and noctuid Agrotis, melolonthid Maladera, and gryllotalpid Gryllotalpa (each three). Below-ground damaging pests appeared widely problematic across the cold temperate zones, probably due to the limited variety of crops suitable for rotation or strip cropping, and efficient adaptation of pests to the soil environment as a result of long overwintering periods. This review will, as a result of making some of a vast repository of non-English language information available, help to better understand the soil pest community in these regions, and support the development of more effective control methods.     

The timing and sequence of events leading to stem canker disease in populations of Brassica napus var. oleifera in the field

Natural epidemics of Leptosphaeria maculans in cultivated populations of Brassica napus var. oleifera were predominantly monocyclic, involving a sequence of five phases; latent infection of the lamina, leaf lesion expression, symptomless systemic growth down the petiole, latent infection of the stem, and stem canker development. This sequence potentially terminated in severe stem cankers if initiated from ascospore infection of any leaf between a plastochron index of PI = n + 0.5 and n +1.0 until plant growth stage 3.1 of the Harper & Berkenkamp scale. At PI < n + 0.5, infection was rare and at PI > n + 1.0, the infection sequence was usually terminated by leaf abscission. Differential effects of ambient temperature on the rates of progress of infection and leaf development determined whether abscission occurred before infection reached the stem. Based on these interrelationships, a system for predicting the incidence of severe stem cankers is proposed.     

Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks

Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.     

Field evaluations of a deep learning-based intelligent spraying robot with flow control for pear orchards

Precision Agriculture - This study proposes a deep learning-based real-time variable flow control system using the segmentation of fruit trees in a pear orchard. The real-time flow rate control,...     

Preparation of PET using homogeneous catalysts. II. Effect of BHPP, NPG and PD in Sb2O3 glycol solution catalysts

In the polycondensation reaction of polyethyleneterephthalate(PET), Sb₂O₃ can react effectively as a catalyst, if physically transformed. Sb₂O₃ powder is transformed into liquid solution by dissolving in ethylene glycol(EG). Homogeneous catalyst is made by mixing this liquid solution with glycols having different solubility. The efficient reaction of PET polymerization is expected by using homogeneous catalyst. PET was synthesized using homogeneous catalysts of 4 wt.% Sb₂O₃ solution dissolved in glycol[EG, 2,2-bis(4-(2-hydroxyethoxy)phenol)propane(BHPP), neopentyl glycol(NPG), and 1,3-propandiol(PD)]. PET using EG-BHPP(Sb₂O₃) catalysts shows the highest I.V. within a reaction time of 120 min. In the p-d analysis, PET using EG-BHPP(Sb₂O₃) catalysts has the fastest propagation rate and slowest degradation rate. EG-BHPP(Sb₂O₃) catalysts are more efficient than EG(Sb₂O₃) catalysts and Sb₂O₃ powder catalysts.     

Effect of purification method on the electrical properties of the carbon nanotube fibers

We purified as-received CNT fibers (CNTFs) with four different methods and systematically examined effects of various purifications on the morphology, structure, and electrical conductivity of the resultant CNTFs, respectively. The purified CNTFs were characterized by an optical microscope, transmission electron microscope (TEM) coupled with an energy dispersive X-ray spectrometer (EDS), Raman spectroscopy, and multiple source meters. Optical images showed that morphology of CNTFs did not largely change after purification. TEM images and EDS results showed that the Fe impurities, 21.9 wt%, in CNTFs were decreased to 0.17-1.20 wt% and were nearly eliminated by acid and alkali purifications, respectively. Raman results identified the I_D/I_G ratio of CNTFs was 0.71, while those of HCl treatment after steam with heat (HSCNTFs-HCl), NaOCl treatment after steam with heat (HSCNTFs-NaOCl), and NaOH treatment with heat without steam (NaOH-HCNTFs) were 0.45, 0.49, and 0.57, respectively, which means that purification methods of CNTFs performed in this study are thought to be satisfactory for manufacturing high-purity CNTFs. Electrical conductivity (1.4×10⁴ S/m) of NaOH-HCNTFs (one-step procedure) was twice as high as that (7.3×10³ S/m) of CNTFs, but lower than those (2.1-2.3×10⁴ S/m) of HSCNTFs-HCl and HSCNTFs-NaOCl (two-step processes), which demonstrates that two-step processes rather than one-step procedure would have a positive effect on the electrical conductivity of the resultant CNTFs.     

Performance modification of a melt-blown filter medium via an additional nano-web layer prepared by electrospinning

A poly(acrylonitrile) (PAN) nano-web was electrospun on a commercial melt-blown poly(propylene) (PP) filter medium to generate composite filter media. The performance of these media was characterized in terms of filtration efficiency and pressure drop. Quality factors calculated from these parameters were used to evaluate the overall efficacy of the filter media. Structural characterization of the composite media showed that a thin layer of nano-web could improve the overall performance by increasing filtration efficiency without significant increase of pressure drop.     

Application of nanosilver-coated zeolite as water filter media for fungal disinfection of rainbow trout (Oncorhynchus mykiss) eggs

This study investigated the indirect use of silver nanoparticles (AgNPs) for reduction of fungal infections during incubation period of fertilized rainbow trout eggs. Different concentrations of nanosilver-coated zeolite (0.5, 1, and 1.5 % AgNPs) were compared with unmodified zeolite as water filter media in semi-recirculation systems. For testing the effect of AgNPs on reduction of fungal infection, fertilized eggs were transferred in incubators receiving water from filters coated with nanosilver. The eggs in each incubator were inoculated with Saprolegnia-infected trout eggs. Any dead or infected eggs and embryos were periodically removed, while the performance of the filters was assessed by calculating the survival rates from fertilization up to completion of the yolk–sac absorption stage. The results showed that the filters containing 0.5 % AgNPs increased the survival rate by 4.56 % from fertilization to the swim up stage compared to the control (p < 0.05). Also, the additional application of activated carbon (as absorbent media) along with AgNP-coated media in filters caused an increase of about 11.24 % in the survival rate for the larval stage (p < 0.05). In contrast to the control group with about 6 % fungal infection, no infections were observed during the incubation period in the incubators containing nanosilver-coated filters. Therefore, the final results confirmed that the indirect use of AgNPs in the aforementioned filters were significantly effective for preventing fungal infections in semi-recirculation systems for rainbow trout, making them a candidate for replacing the chemical fungicides currently used during egg incubation in hatchery systems.