Identification,Synthesis, and Behavioral Activity of 5,11-Dimethylpentacosane,A Novel Sex Pheromone Component of the Greater Wax Moth,Galleria Mellonella (L.)

The greater wax moth, Galleria mellonella (L.), is a serious and widespread pest of the honeybee, Apis mellifera L. In contrast to most moths, for which long-range mate finding is mediated by female-produced sex pheromones, G. mellonella males attract conspecific females over long distances by emitting large amounts of a characteristic scent in combination with bursts of ultrasonic calls. The male scent for this species was previously identified as a blend of nonanal and undecanal. When these compounds were bioassayed, characteristic short-range sexual behavior, including wing fanning, was triggered in conspecific females, but the aldehyde blend failed to elicit attraction over longer distances. We identified, via analysis and synthesis, a third male-specific compound, 5,11-dimethylpentacosane. We show that it acts as a behavioral synergist to the aldehydes. In wind tunnel experiments, very few female moths responded to the aldehyde blend or to 5,11-dimethylpentacosane tested separately, but consistently showed orientation and source contact when a combination of all three compounds was applied. The level of attraction to the three-component mixture was still lower than that to male extract, indicating that the composition of compounds in the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. The identification of 5,11-dimethylpentacosane is an important step for the development of an efficient long-range attractant that will be integrated with other environmentally safe strategies to reduce damage to beehives caused by wax moths.     

Myoglobin adsorption onto poly(glycidyl methacrylate) microbeads with surface functionalized iminodiacetic acid

In this study, poly(glycidyl methacrylate) [PGMA] microbeads with surface modified iminodiacetic acid (IDA) were used for myoglobin (Mb) adsorption from buffer solutions at different pHs and ionic strengths in a packed-bed column. Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) measurements before and after the adsorption process confirmed the structural stability of adsorbed Mb. The effects of initial concentration, flow-rate, pH and ionic strength on the adsorption were investigated. The results showed that the maximum amount of protein was adsorbed at a pH 7.0, which is the protein isoelectric point. The adsorption is rationalized in terms of local electrostatic forces acting between the protein and the IDA modified PGMA surface as well as hydrophobic interactions close to the protein isoelectric point, whereas at low pH the global changes give rise to protein–protein repulsion and at high pH protein-support material repulsion.     

Effects of nitrite levels,endpoint temperature and storage on pink color development in turkey rolls

The objective of this research was to determine the relationship between minimum nitrite level, endpoint temperature and storage period on pink discoloration of turkey rolls. Rolls were prepared with 0, 3 or 5 parts per million (ppm) NO₂^–, cooked to an endpoint temperature of 75 °C or 85 °C and stored at 4 °C. During the 13-day storage period, on the 0th, 4th, 8th and 13th days cured pigment, total pigment, residual nitrite and color parameters were measured and sensory color was evaluated. At each endpoint temperature, addition of 3 ppm or 5 ppm NO₂^– significantly increased cured pigment and total pigment levels. Cured pigment levels of turkey rolls cooked to 75 °C were higher than rolls cooked to 85 °C, regardless of the NO₂^– level. There was a significant decrease in cured pigment levels at the end of the storage period (13th day). Analysis of residual NO₂^– in all treatment groups showed no detectable amounts. Endpoint temperature and addition of NO₂^– affected L* values: rolls cooked to the 75 °C endpoint had higher L* values. The additon of nitrite with the 75 °C endpoint temperature resulted in higher a* values. a* values also increased during the storage. The higher endpoint temperature (85 °C) resulted in lower a* values. Yellowness was not affected by final cooking temperature. Both the addition of NO₂^– and storage decreased b* values. The panel found no differences in pinkness intensity between the two levels of added nitrite (3 and 5 ppm). Sensory pinkness intensity in nitrite-added samples increased with increasing storage.     

Synthesis of thermoresponsive poly(N-isopropylacrylamide) brush on silicon wafer surface via atom transfer radical polymerization

Thermoresponsive poly(N-isopropylacrylamide) [poly(NIPAM)] brush on silicon wafer surface was prepared by combining the self-assembled monolayer of initiator and atom transfer radical polymerization (ATRP). The resulting polymer brush was characterized by in situ reflectance Fourier transform infrared spectroscopy, atomic force microscopy and ellipsometry techniques. Gel permeation chromatography determination of the number-average molecular weight and polydispersity index of the brush detached from the silicon wafer surface suggested that the surface-initiated ATRP method can provide relatively homogeneous polymer brush. Contact angle measurements exhibited a two-stage increase upon heating over the board temperature range 25-45 °C, which is in contrast to the fact that free poly(NIPAM) homopolymer in aqueous solution exhibits a phase transition at ca. 34 °C within a narrow temperature range. The first de-wetting transition takes place at 27 °C, which can be tentatively attributed to the n-cluster induced collapse of the inner region of poly(NIPAM) brush close to the silicon surface; the second de-wetting transition occurs at 38 °C, which can be attributed to the outer region of poly(NIPAM) brush, possessing much lower chain density compared to that of the inner part.     

Recent advances in the preparation of functionalized polysulfones

This review summarizes the studies related to chemical functionalization of polysulfones used in many different applications such as membranes with special functions, nanocomposites, biofilm formation, fuel cells etc. reported in recent years from the literature since 2000. Various strategies have been applied for the functionalization of polysulfones. One strategy is to add desired functionality into starting monomers in the solution containing the main components of commercial polysulfones, the aromatic dihalide sulfone and bisphenol monomers, or to functionalize the related monomers before the condensation. Another approach is to form difunctional polysulfone oligomers. Then, functional groups can be utilized to react with monomers or other polymers to obtain functional polymers or block copolymers. The most applied method is post‐modification of commercially available polysulfones by incorporation of functional groups to their aromatic groups and their use in the formation of graft polymers or polysulfone‐based networks. © 2013 Society of Chemical Industry     

Synthesis, characterization, and cyclopolymerization of a functional non-symmetric divinyl monomer

A non-symmetric divinyl monomer with terminal carboxylic acid functionality was readily synthesized from the reaction of ethyl α-hydroxymethylacrylate (EHMA) with maleic anhydride. The new monomer (EHMA-MA) was homopolymerized in both bulk and ethyl acetate using AIBN as an initiator to give cyclopolymers. The synthesis of the monomer and cyclopolymers were followed by ¹³C NMR, ¹H NMR, and FTIR. ¹H NMR was also utilized to obtain the degree of cyclization of the polymers, which were found to be 95% or higher in all cases. The molecular weights of the cyclopolymers were around 40-60,000 g/mol as estimated by SEC. The cyclopolymers were thermally stable up to 150 °C. Although the cyclopolymers obtained were not water-soluble; they were soluble in aqueous 1 M NaOH solution. In addition to the carboxylic acid functionality present, the cyclopolymers also had an ethyl ester and a lactone moiety. These functional groups were reacted with hexylamine to obtain a polymer with imide and amide moieties.     

The combined effects of boron and oil heat treatment on beech and Scots pine wood properties. Part 1: Boron leaching,thermogravimetric analysis,and chemical composition

The aim of the study was to screen any possible synergistic effect available with combination of plant oils and boron compounds to decrease boron leaching and improve thermal degradation of wood by means of dual treatment. In order to reduce the leachability of boron compounds, sapwood of beech and Scots pine samples were treated with oils to create a hydrophobic layer on the wood cells that may prevent water uptake. Increase (%) of boron retained in double-treated samples after leaching was approximately 20% compared to boron-treated samples without oil. The most promising results on boron leaching obtained in the case of using waste and sunflower oil. Thermogravimetric residues were increased by the higher loading of boron compounds in double-treated samples. Spectra of FTIR-Photoacoustic spectrometer showed some deformation of lignin and cellulose followed by degradation of hemicelluloses of treated wood samples due to heat effect at 160 °C.