Efficacy of various plant hydrosols as natural food sanitizers in reducing Escherichia coli O157:H7 and Salmonella Typhimurium on fresh cut carrots and apples

In the present study, inhibitory effects of the hydrosols of thyme, black cumin, sage, rosemary and bay leaf were investigated against Salmonella Typhimurium and Escherichia coli O157:H7 inoculated to apple and carrots (at the ratio of 5.81 and 5.81 log cfu/g for S. Typhimurium, and 5.90 and 5.70 log cfu/g for E. coli O157:H7 on to apple and carrot, respectively). After the inoculation of S. Typhimurium or E. coli O157:H7, shredded apple and carrot samples were washed with the hydrosols and sterile tap water (as control) for 0, 20, 40 and 60 min. While the sterile tap water was ineffective in reducing (P > 0.05) S. Typhimurium and E. coli O157:H7, 20 min hydrosol treatment caused a significant (P < 0.05) reduction compared to the control group. On the other hand, thyme and rosemary hydrosol treatments for 20 min produced a reduction of 1.42 and 1.33 log cfu/g respectively in the E. coli O157:H7 population on apples. Additional reductions were not always observed with increasing treatment time. Moreover, thyme hydrosol showed the highest antibacterial effect on both S. Typhimurium and E. coli O157:H7 counts. Inhibitory effect of thyme hydrosol on S. Typhimurium was higher than that for E. coli O157:H7. Bay leaf hydrosol treatments for 60 min reduced significantly (P < 0.05) E. coli O157:H7 population on apple and carrot samples. In conclusion, it was shown that plant hydrosols, especially thyme hydrosol, could be used as a convenient sanitizing agent during the washing of fresh-cut fruits and vegetables.     

Twin reversed arterial perfusion sequence in conjoined, acardiac, acephalic twins associated with a normal triplet. A case report

BACKGROUND: Twin reversed arterial perfusion (TRAP) sequence and development of an acardiac monster is a rare event. Even more rare are conjoined acardiac, acephalic twins complicating a triplet pregnancy with TRAP sequence. The mortality for the acardius is 100%, and morbidity for the normal, pump fetus is 50%. The morbidity of the pump twin or triplet is attributed mostly to in utero congestive heart failure. CASE: A 24-year-old woman, gravida 1, para 0, at 35 weeks' intrauterine pregnancy, gave birth via low transverse cesarean section to a normal female and a pair of conjoined, acardiac, acephalic, pelvipagus twins. CONCLUSION: The diagnosis of acardius in multiple gestation pregnancy, with no fetal heart tone on ultrasound, must be ruled out in every case so that proper counseling, management and avoidance of complications in these patients can be achieved.     

Effects of polyamide 6 incorporation to the short glass fiber reinforced ABS composites: an interfacial approach

The properties of 30 wt% short glass fiber (SGF) reinforced acrylonitrile-butadiene-styrene (ABS) terpolymer and polyamide 6 (PA6) blends prepared with extrusion were studied using the interfacial adhesion approach. Work of adhesion and interlaminar shear strength values were calculated respectively from experimentally determined interfacial tensions and short beam flexural tests. The adhesion capacities of glass fibers with different surface treatments of organosilanes were evaluated. Among the different silanes tested, γ-aminopropyltrimethoxysilane (APS) was found to be the best coupling agent for the glass fibers, possibly, because of its chemical compatibility with PA6. Tensile test results indicated that increasing amount of PA6 in the polymer matrix improved the strength and stiffness of the composites due to a strong acid–base interaction at the interface. Incorporation of PA6 to the SGF reinforced ABS reduced the melt viscosity, broadened the fiber length distributions and increased the toughness of the composites. Fractographic analysis showed that the incorporation of PA6 enhanced the interactions between glass fibers and the polymeric matrix.     

Wavelet based Neuro-Detector for low frequencies of vibration signals in electric motors

This study presents a Wavelet based Neuro-Detector approach employed to detect the aging indications of an electric motor. Analysis of the aging indications, which can be seen in the low frequency region, is performed using vibration signals. More specifically, two vibration signals are observed for healthy and faulty (aged) cases which are measured from the same electric motor. Multi Resolution Wavelet Analysis (MRWA) is applied in order to obtain low and high frequency bands of the vibration signals. Thus for detecting the aging properties in the spectra, the Power Spectral Density (PSD) of the subband for the healthy case is used to train an Auto Associative Neural Network (AANN). The PSD amplitudes, which are computed for the faulty case, are applied to input nodes of the trained network for the re-calling process of AANN. Consequently, the simulation results show that some spectral properties defined in low frequency region are determined through the error response of AANN. Hence, some specific frequencies of the bearing damage related to the aging process are detected and identified.     

Impact modified epoxy/montmorillonite nanocomposites: synthesis and characterization

Diglycidyl ether of bisphenol A type epoxy resin-polyether polyol-organically treated montmorillonite ternary nanocomposites were synthesized in this study. The effects of addition of polyether polyol as an impact modifier on morphological, thermal and mechanical properties of nanocomposites were investigated by X-ray diffraction, scanning electron microscopy (SEM), differential scanning calorimetry, impact and tensile testing. The results showed that organically treated montmorillonite is intercalated by epoxy, since the interlayer spacing expanded from 1.83 to 3.82 nm upon nanocomposite synthesis. The addition of polyether polyol impact modifier had no effect on the interlayer spacing. SEM examination showed that polyol forms an immiscible phase in the epoxy matrix. Thermal characterization of nanocomposites indicated an increase in T_g with respect to both polyether polyol and montmorillonite contents. The impact strength of the samples with no clay was improved approximately 160% upon adding 7 wt% polyether polyol. In polyether polyol modified nanocomposites, the impact and tensile strengths decreased with respect to increasing amount of montmorillonite and showed a maximum with respect to the polyether polyol content at constant clay loading. The Young's modulus of the nanocomposites exhibited an increase with respect to the montmorillonite loading and showed a maximum with respect to the polyol content at each clay loading.     

Effect of carbon nanotube purification on the electrical and mechanical properties of poly(ethylene terephthalate) composites with carbon nanotubes in low concentration

Surface properties of carbon nanotubes (CNTs) were altered by purification with nitric acid, sulfuric acid, ammonium hydroxide, and hydrogen peroxide. As‐received and purified CNT‐based conductive poly (ethylene terephthalate) composites were prepared with a twin‐screw extruder. The effects of CNT purification on the surface properties of the CNTs and on the morphology and electrical and mechanical properties of CNT‐based composites were investigated. Surface energy measurements showed that the acidic component of the surface energies of the CNTs increased after purification. According to Fourier transform infrared (FTIR) spectroscopy, the purification resulted in the formation of oxygen‐containing functional groups on the surfaces of the CNTs. Electron spectroscopy for chemical analysis results indicate the removal of the metallic catalyst residues and an increase in the oxygen content of the CNT surfaces as a result of the purification procedure. X‐ray diffraction analyses revealed a change in the crystalline structure of the CNTs after purification. All of the composites prepared with the purified CNTs had higher electrical resistivities and tensile and impact strength values than the composites based on the as‐received CNTs because of the functional groups and defect sites formed on the surfaces of the CNTs during purification. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Functional Group Effects of New Calixarene Derivatives on Catalytic and Enantioselective Behavior of Lipase

ABSTRACT

In this study, two new calixarene derivatives bearing thiourea and carbamate moieties were synthesized and characterized. Moreover, thiourea- and carbamate-bridged calixarene derivatives with Fe₃O₄ magnetic nanoparticle were employed for the first time as the convenient additives in the encapsulation process of lipase. The results of catalytic activity and enantioselectivity of the encapsulated lipases in the hydrolysis reaction of racemic flurbiprofen methyl ester indicate that both of the encapsulated lipases (Enc-TuC[4]@Fe₃O₄ and Enc-CbC[4]@Fe₃O₄) exhibit higher conversion and enantioselectivity compared to the free-encapsulated lipase (Enc-Lipase). However, the highest affinities result was obtained when the encapsulated lipase (Enc-CbC[4]@Fe₃O₄) was used in the kinetic resolution reaction of racemic flurbiprofen methyl ester.     

Synthesis,characterization and cytotoxicity of novel modified poly[(maleic anhydride)‐ co‐(vinyl acetate)]/noradrenaline conjugate

Poly[(maleic anhydride)‐co‐(vinyl acetate)] (MAVA) copolymer was synthesized by free radical polymerization reaction, in methyl ethyl ketone at 80 °C, using benzoyl peroxide as the initiator. The copolymer was then modified with a biomolecule, noradrenaline (NA). The modification reaction was performed at 70 °C in dimethylformamide containing triethylamine as the catalyst. The modified polymer was named MAVA/NA. Structural characterization of the copolymer and the modified product was carried out by Fourier transform infrared (FTIR) and ¹H NMR and ¹³C NMR spectroscopy. The FTIR, ¹H NMR and ¹³C NMR spectra confirmed that NA was successfully covalently bound to the MAVA copolymer backbone. Surface morphology was visualized by atomic force microscopy. The cumulative release of NA from MAVA/NA was determined in phosphate buffered saline solution for 7 days at 37 °C and compared with MAVA. Cytotoxicity of the MAVA/NA was evaluated by using a mouse fibroblast cell line (L929). Results obtained indicated that MAVA/NA had almost no toxicity and no negative effect on cell viability at 250 µg mL^?1 concentration. © 2012 Society of Chemical Industry     

Modification of maleic anhydride–styrene copolymer with noradrenaline by chemical and enzymatic methods

Maleic anhydride copolymer was modified with another biologically active agent, noradrenaline (NA), using both chemical and enzymatic methods. The modification and synthesized products were named as follows: chemical modification, MASTNAc; enzymatic modification, MASTNAe; enzymatically synthesized MASTNA from individual monomers, MASTNAem. Chemical and enzymatic reactions were performed at 70°C and 38°C, respectively. In the chemical reactions azobisisobutyronitrile was used as the initiator. In the enzymatic reactions, an extracellular extract, including an enzyme with peroxidase‐like activity, was used. All the reactions were performed in an organic medium, methyl ethyl ketone. Structural characterization of the copolymer and modified copolymer were carried out by Fourier transform infrared (FTIR) and nuclear magnetic resonance (¹H NMR). FTIR and ¹H NMR spectra confirmed that NA was successfully covalently bound onto the MAST copolymer backbone by both chemical and enzymatic methods. Surface morphology of the samples was studied by scanning electron microscopy. Results obtained indicated that chemical and enzymatic addition of NA to MAST backbone yielded products having quite similar physical and chemical properties. On the other hand, MASTNA‐modified copolymer synthesized by individual monomers appeared to be different in its chemical structure. Furthermore, enzymatic modification and synthesis appeared to provide a good alternative method because it required much milder conditions such as low temperature, and better product qualities: higher solubility in water, higher yield and purity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011