Multiplex PCR for the simultaneous detection of Salmonella spp. and Salmonella Enteritidis in food

Multiplex PCR assay (mPCR) for the detection of Salmonella spp. and S. Enteritidis was developed in this study using artificially contaminated chicken carcasses. The assay showed 100% specificity to detect approximately 1 CFU of Salmonella in 10 g of chicken skin after non‐selective enrichment. The mPCR was evaluated in Minas cheese, fresh pork sausage and chicken carcasses commercially available. Salmonella spp. was detected in nine of sixty‐six chicken carcasses, five of fifty‐two cheese samples, and five of fifty‐two sausage samples. The serovar Enteritidis was detected in two samples of contaminated sausage. The mPCR results were confirmed by conventional culture and biochemical identification of the isolates. Serotyping confirmed the presence of S. Enteritidis in sausage samples and showed contamination by serovars Schwarzengrund and Montevideo in chicken carcasses.     

Apoferritin/Vandetanib Association Is Long-Term Stable But Does Not Improve Pharmacological Properties of Vandetanib

A tyrosine kinase inhibitor, vandetanib (Van), is an anticancer drug affecting the signaling of VEGFR, EGFR and RET protooncogenes. Van is primarily used for the treatment of advanced or metastatic medullary thyroid cancer; however, its usage is significantly limited by side effects, particularly cardiotoxicity. One approach to minimize them is the encapsulation or binding of Van in- or onto a suitable carrier, allowing targeted delivery to tumor tissue. Herein, we constructed a nanocarrier based on apoferritin associated with Van (ApoVan). Based on the characteristics obtained by analyzing the average size, the surface ζ-potential and the polydispersive index, ApoVan nanoparticles exhibit long-term stability and maintain their morphology. Experiments have shown that ApoVan complex is relatively stable during storage. It was found that Van is gradually released from its ApoVan form into the neutral environment (pH 7.4) as well as into the acidic environment (pH 6.5). The effect of free Van and ApoVan on neuroblastoma and medullary thyroid carcinoma cell lines revealed that both forms were toxic in both used cell lines, and minimal differences between ApoVan and Van were observed. Thus, we assume that Van might not be encapsulated into the cavity of apoferritin, but instead only binds to its surface.     

Carnauba straw: Characterization and chemical treatments

The influence of chemical modifications, such as dewaxing with hexane and carbon tetrachloride, and alkaline treatment, on the mechanical, thermal, and sorption properties of carnauba straw was investigated for the first time. Scanning electron microscopy showed that the solvent treatments removed the wax layer, exposing the straw fibrils. The straw water sorption capacity was very high, and the treatments turned it from Fickian to non‐Fickian. The results show that the solvents used were very effective in removing the surface wax layer, whereas alkali, on the other hand, promoted a more marked change in the chemical structure of the straw. The chemical treatments demonstrated that the wax surface layer was very important in determining the final properties of this material and that its removal reduced the thermal stability and Young's modulus from 143 to 48 MPa and increased its hydrophilicity, changing the contact angle from 90 to 60°. As a result, carnauba straw is a potentially promising material to be used, for example, as a natural fiber with polymer matrices for the manufacture of low‐cost, ecofriendly composite materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

United Front: Blame Management and Scandal Response Tactics of the United Nations

In this paper we conduct a systematic study of the United Nations (UN) responses to allegations of transgression. We examine the patterns in the UN reaction to scandals, the types of accounts, the institutional providers of the responses, and the implications of scandals for the UN and its' official(s). We conduct a content analysis of the UN scandal and account coverage in international (print) media in the last 25 years, and find a scandal‐responsive UN, particularly in the case of institutional scandals. Concessions issued by the office of the Secretary General is dominant UN account to allegations of misconduct. Individual staff members implicated in the scandals offer a greater variety of accounts and often suffer resignations and severe punishments.     

Chemical and Textural Characterization of Iron Oxide Nanoparticles and Their Effect on the Thermal Decomposition of Ammonium Perchlorate

Metal oxide nanoparticles have been used as burning rate catalysts for ammonium perchlorate (AP) decomposition in composite solid propellants. Though most papers point to the efficiency of different sizes, shapes and compositions, the texture of the agglomerated particles plays an important role in the catalytic efficiency, but this aspect is not always discussed. In this paper, iron oxide and composite iron oxide/silica powders were synthesized in microemulsion systems and their effect on the decomposition of AP was investigated. X‐ray diffraction (XRD) analysis and Fourier transformed infrared spectroscopy (FT‐IR) showed that the synthesized powders have an amorphous to nanocrystalline pattern, with Fe₂O₃ composition. The use of different FT‐IR spectroscopic techniques – transmission, diffuse reflectance (DRIFT) and universal attenuated total reflectance (UATR) – allied to electron microscopy analysis allowed the characterization of the samples’ surface, indicating that silicon oxide forms a thick matrix that covers the iron oxide nanoparticles. Adsorption of N₂, light scattering and electron microscopy pointed that all samples are formed by mesoporous agglomerated nanoparticles containing micropores indicating that silicon oxide forms a thick matrix that covers the iron oxide nanoparticles. Adsorption of N₂, pointed that all samples show different microstructures and light scattering indicated results refer to agglomerated particles. Finally, the catalytic effect of the samples on the decomposition of AP was evaluated by thermogravimetric analysis coupled to differential thermal analysis (TG/DTA), showing that only the high temperature decomposition step of AP was affected by the catalyst, shifting to lower temperatures the higher the surface area of the synthesized iron oxide sample, regardless of the presence of the silica matrix.     

Methodology to break test for surfactant-based fracturing gel

Surfactant-based fracturing gels are considered as clean gels due to the absence of insoluble residues in their composition. This kind of fluid has been developed to minimize or eliminate damages to fractures. In view of this, new studies about properties of this kind of gel have become more and more important. Gel break is an important parameter for hydraulic fracturing gels. This research was carried out with the purpose of developing a laboratory break methodology for surfactant-based fracturing gel. It was observed that the studied gel presented optimum break results, due to a viscosity decrease to 10 mPa s in the first 6 h of the test.     

Linear covariant gauges on the lattice

Linear covariant gauges, such as Feynman gauge, are very useful in perturbative calculations. Their non-perturbative formulation is, however, highly non-trivial. In particular, it is a challenge to define linear covariant gauges on a lattice. We consider a class of gauges in lattice gauge theory that coincides with the perturbative definition of linear covariant gauges in the formal continuum limit. The corresponding gauge-fixing procedure is described and analyzed in detail, with an application to the pure SU(2) case. In addition, results for the gluon propagator in the two-dimensional case are given.     

Requirements specification of real-time systems: temporal parameters and timing-constraints

The development of high-quality real-time systems depends on their correct requirements specification, which includes the analysis and specification of timing issues. This paper focuses on requirements specification of real-time systems, presenting a set of temporal parameters and timing-constraints related to the execution of systems processes. Timing-constraints are expressed by formulas, being useful for defining, representing, and validating the system temporal behavior, particularly in hard real-time systems specifications. The primary contribution over previous studies is the proposal of a more generic and complete set of timing-constraints, applied to the area of requirements engineering for real-time systems, which has not been sufficiently explored.     

Improvement of the Detection Sensitivity for <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> in Spices and Herbs

Various variants of ISO 6888-1:1999 and ISO 6888-3:2003 methods for the detection of Staphylococcus aureus were evaluated and improved for their application to conduct analysis in spices and herbs. Improvement substantiated in washing of the sample to remove compounds interfering with the analysis and in the use of PCR for final detection, instead of plating on Baird-Parker agar, to improve sensitivity at high backgrounds and to save time. The evaluation of the method variants was based on determination of the detection limit (LOD) using series of artificially contaminated spices (allspice, black pepper, cinnamon, nutmeg, paprika, vanilla) and herbs (basil, oregano, parsley, thyme). The method without enrichment, ISO 6888-1:1999, produced LODs of 10³–10⁵ CFU/g with no positive effect of washing the sample or use of PCR for final detection. The method with enrichment, ISO 6888-3:2003, had LOD of 10⁰ CFU/g for basil, black pepper, paprika and parsley. If the washing step was added and PCR was used for final detection, LOD of 10⁰ CFU/g was determined also for cinnamon, nutmeg and vanilla, and LOD of 10¹ CFU/g was determined for allspice. For oregano and thyme, which strongly inhibit the growth of S. aureus, an alternative enrichment-independent method based on direct DNA extraction coupled to real-time PCR may be advantageous.     

Young’s modulus and thermal conductivity of closed-cell,open-cell and inverse ceramic foams – model-based predictions,cross-property predictions and numerical calculations

Numerical calculations of relative Young’s modulus and thermal conductivity have been performed on computer-generated microstructures of wall-based (closed-cell) and strut-based (open-cell) cellular materials (foams) and inverse foams. The results are compared to rigorous upper bounds (Wiener-Paul, Hashin-Shtrikman), model-based predictions (power-law, exponential) and cross-property predictions (CPRs). It is shown that closed-cell foams exhibit higher property values than open-cell and inverse foams, Kelvin foams higher than random foams, and the difference between closed-cell and open-cell foams is larger than that between Kelvin and random foams. While the properties of closed-cell foams are higher than the power-law prediction, those of inverse and open-cell random foams are between the exponential and power-law predictions, and open-cell Kelvin foams follow the Gibson-Ashby power-law prediction for open-cell foams. The Pabst-Gregorová CPR is shown to predict Young’s modulus with accuracy better than ±0.02 relative property units (better than any model-based relation and any other CPR).