Acaricidal activity of clove bud oil compounds against Dermatophagoides farinae and Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The acaricidal activity of clove (Eugenia caryophyllata) bud oil-derived eugenol and its congeners (acetyleugenol, isoeugenol, and methyleugenol) against adults of Dermatophagoides farinae and Dermatophagoides pteronyssinus was examined using direct contact application and fumigation methods and compared with those of benzyl benzoate and N,N-diethyl-m-toluamide (DEET). Responses varied according to compound, dose, and mite species. On the basis of LD(50) values, the compound most toxic to D. farinae adults was methyleugenol (0.94 microg/cm(2)) followed by isoeugenol (5.17 microg/cm(2)), eugenol (5.47 microg/cm(2)), benzyl benzoate (9.22 microg/cm(2)), and acetyleugenol (14.16 microg/cm(2)). Very low activity was observed with DEET (37.59 microg/cm(2)). Against D. pteronyssinus adults, methyleugenol (0.67 microg/cm(2)) was much more effective than isoeugenol (1.55 microg/cm(2)), eugenol (3.71 microg/cm(2)), acetyleugenol (5.41 microg/cm(2)), and benzyl benzoate (6.59 microg/cm(2)). DEET (17.85 microg/cm(2)) was least toxic. These results indicate that the lipophilicity of the four phenylpropenes plays a crucial role in dust mite toxicity. The typical poisoning symptom of eugenol and its congeners was a similar death symptom of the forelegs extended forward together, leading to death without knockdown, whereas benzyl benzoate and DEET caused death following uncoordinated behavior. In a fumigation test with both mite species, all four phenylpropenes were much more effective in closed containers than in open ones, indicating that the mode of delivery of these compounds was largely due to action in the vapor phase. Eugenol and its congeners merit further study as potential house dust mite control agents or as lead compounds.     

Acaricidal activity of butylidenephthalide identified in Cnidium officinale rhizome against dermatophagoides farinae and dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The acaricidal activity of materials derived from the rhizome of Cnidium officinale against adults of Dermatophagoides farinae and Dermatophagoides pteronyssinus was examined using direct contact application and fumigation methods and compared with that of benzyl benzoate and N,N-diethyl-m-toluamide (DEET). The active constituent of the Cnidium rhizome was identified as butylidenephthalide by spectroscopic analyses. Responses varied with dose. On the basis of 24-h LD(50) values, the acaricidal activity of butylidenephthalide (6.77 microg/cm(2)) against D. farinae adults was comparable to that of benzyl benzoate (8.54 microg/cm(2)). Very low activity was observed with DEET (37.59 microg/cm(2)). Against D. pteronyssinus adults, butylidenephthalide (6.46 microg/cm(2)) and benzyl benzoate (6.68 microg/cm(2)) were equitoxic. DEET (17.98 microg/cm(2)) was relatively inactive. The typical poisoning symptom of butylidenephthalide was lethargy of treated mites, leading to death without knockdown, whereas benzyl benzoate and DEET caused death following uncoordinated behavior. In a fumigation test with both mite species, butylidenephthalide was much more effective in closed containers than open ones. Naturally occurring C. officinale rhizome-derived materials merit further study as potential house dust mite control agents or lead compounds.     

Effects of phosphorus fertilizer supplementation on antioxidant enzyme activities in tomato fruits

The effects of soil and foliar phosphorus supplementation on the activities and levels of superoxide dismutase (SOD), guaiacol peroxidase (POX), and ascorbate peroxidase (APX) in tomato fruits were evaluated by determining enzyme activities and isoenzyme analysis. Both protein levels and enzyme activities varied depending on the variety and season. In general, phosphorus supplementation did not alter SOD, POX, and APX activities significantly;however, some treatments showed season- and stage-specific enhancement in activities as noticed with hydrophos and seniphos supplementation. Three different SOD isozymes were observed, and these isozymes showed very similar staining intensities in response to P application and during the three developmental stages studied. Two major isozymes of POX and two different APX isozymes were observed at all the developmental stages. The results suggest that antioxidant enzyme activities may be influenced by the availability of phosphorus, but are subject to considerable variation depending on the developmental stage and the season.     

Effect of maillard reaction on allergenicity of scallop tropomyosin

Scallop tropomyosin (TM), the major allergen of shellfish, was prepared from adductor muscles and reacted with four reducing sugars to investigate the effect of the Maillard reaction on the allergenicity of TM. The IgE-binding ability of TM increased significantly with the progress of the reaction with glucose, ribose, and maltose, but not with maltotriose. The allergenicity was enhanced at the early stage of the Maillard reaction, and the trend of the effect depended on the type of reducing sugar used. 2,4,6-Trinitrobenzenesulfonic acid treatment of the lysine residues in TM showed that the protein surface charge resulting from the Maillard reaction had no effect on the enhancement of the allergenicity. Thus, the change in the allergenicity would be closely related to the structural change caused by the Maillard reaction.     

Acaricidal activity of Paeonia suffruticosa root bark-derived compounds against Dermatophagoides farinae and Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)

The acaricidal activities of materials derived from the root bark of Paeonia suffruticosa against adults of Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using direct contact and fumigation bioassays and compared with those of benzyl benzoate, dibutyl phthalate, and N,N-diethyl-m-toluamide (deet), widely used acaricides. The active constituents of Paeonia root bark were identified as paeonol and benzoic acid by spectroscopic analyses. On the basis of 24-h LD50 values, the acaricidal activities of paeonol (7.82 microg/cm3) and benzoic acid (6.58 microg/cm3) against adult D. farinae were comparable to that of benzyl benzoate (7.72 microg/cm3) but higher than those of deet (36.34 microg/cm3) and dibutyl phthalate (33.92 microg/cm3). Against adult D. pteronyssinus, the acaricidal activities of paeonol (7.08 microg/cm3) and benzyl benzoate (7.22 microg/cm3) were comparable to that of benzyl benzoate (7.14 microg/cm3). Deet and dibutyl phthalate were less effective. In fumigation tests with both mite species, paeonol and benzoic acid were much more effective in closed containers than open ones, indicating that the effect of these compounds was largely a result of action in the vapor phase. Neither benzyl benzoate, deet, nor dibutyl phthalate exhibited fumigant toxicity. Paeonia root bark-derived materials, particularly paeonol and benzoic acid, merit further study as potential acaricides or lead compounds for the control of D. farinae and D. pteronyssinus.     

Feline adipose tissue-derived mesenchymal stem cells pretreated with IFN-γ enhance immunomodulatory effects through the PGE2 pathway

BackgroundPreconditioning with inflammatory stimuli is used to improve the secretion of anti-inflammatory agents in stem cells from variant species such as mouse, human, and dog. However, there are only few studies on feline stem cells.ObjectivesThis study aimed to evaluate the immune regulatory capacity of feline adipose tissue-derived (fAT) mesenchymal stem cells (MSCs) pretreated with interferon-gamma (IFN-γ).MethodsTo assess the interaction of lymphocytes and macrophages with IFN-γ-pretreated fAT-MSCs, mouse splenocytes and RAW 264.7 cells were cultured with the conditioned media from IFN-γ-pretreated MSCs.ResultsPretreatment with IFN-γ increased the gene expression levels of cyclooxygenase-2, indoleamine 2,3-dioxygenase, hepatocyte growth factor, and transforming growth factor-beta 1 in the MSCs. The conditioned media from IFN-γ-pretreated MSCs increased the expression levels of M2 macrophage markers and regulatory T-cell markers compared to those in the conditioned media from naive MSCs. Further, prostaglandin E₂ (PGE₂) inhibitor NS-398 attenuated the immunoregulatory potential of MSCs, suggesting that the increased PGE₂ levels induced by IFN-γ stimulation is a crucial factor in the immune regulatory capacity of MSCs pretreated with IFN-γ.ConclusionsIFN-γ pretreatment improves the immune regulatory profile of fAT-MSCs mainly via the secretion of PGE₂, which induces macrophage polarization and increases regulatory T-cell numbers.     

Ferroelectric Field Effect in Epitaxial Thin Film Oxide SrCuO2/Pb(Zr0.52Ti0.48)O3 Heterostructures

A ferroelectric field effect in epitaxial thin film SrCuO(2)/Pb(Zr(0.52)Ti(0.48))O(3) heterostructures was observed. A 3.5 percent change in the resistance of a 40 angstrom SrCuO(2) layer (a parent high-temperature superconducting compound) was measured when the polarization field of the Pb(Zr(0.52)Ti(0.48))O(3) layer was reversed by the application of a pulse of small voltage (<5 volts). This effect, both reversible and nonvolatile, is attributed to the electric field-induced charge at the interface of SrCuO(2) and Pb(Zr(0.52)Ti(0.48))O(3). This completely epitaxial thin film approach shows the possibility of making nonvolatile, low-voltage ferroelectric field effect devices for both applications and fundamental studies of field-induced doping in novel compounds like SrCuO(2).     

Resurrection of crushed magnetization and chaotic dynamics in solution NMR spectroscopy

We show experimentally and theoretically that two readily observed effects in solution nuclear magnetic resonance (NMR)-radiation damping and the dipolar field-combine to generate bizarre spin dynamics (including chaotic evolution) even with extraordinarily simple sequences. For example, seemingly insignificant residual magnetization after a crusher gradient triggers exponential regrowth of the magnetization, followed by aperiodic turbulent spin motion. The estimated Lyapunov exponent suggests the onset of spatial-temporal chaos and the existence of chaotic attractors. This effect leads to highly irreproducible experimental decays that amplify minor nonuniformities such as temperature gradients. Imaging applications and consequences for other NMR studies are discussed.     

Development of carbon composite bike fork using finite element analysis and a new pressure molding process

The aim of this study was to develop a new carbon composite part for a road bike. Through finite element analysis, an optimum structure of the bike fork including a lay-up sequence of each ply was obtained. The designed part was manufactured using a new press molding process called a “double blowing process”, which uses dual air bladders to remove voids inside the resin. The mechanical properties of the composite fork were characterized and compared with the analysis results, showing a reasonable agreement between them. The failure analysis was carried out using the Tsai-Wu criterion, demonstrating that the composite bike fork was well designed using the current methodology involving prototype design based on expert knowledge, refined design using finite element method, manufacture of the design part, and comparison between the experiment and simulation.