Effect of active films incorporated with montmorillonite clay and α‐tocopherol: Potential of nanoparticle migration and reduction of lipid oxidation in salmon

Fat‐rich fish such as salmon are highly susceptible to lipid oxidation, which affects the quality of the product. The compound α‐tocopherol is widely used as an antioxidant added directly to food or through the incorporation in active packaging besides having activity of vitamin E, which is an essential nutrient to the human body absorbed from food. The objective of this paper was to evaluate the montmorillonite (MMT15A) and α‐tocopherol migration potential and antioxidant effect of chitosan/MMT15A/α‐tocopherol active films on reduction of lipid oxidation in fresh salmon. Chitosan films incorporated with MMT15A (0 and 1 g/100 g) and α‐tocopherol (0, 10, and 15 g/100 g) were applied on the fresh salmon for 8 days. Samples of salmon wrapped in films 3 and 6 (10% tocopherol and 1% MMT15A + 15%tocopherol, respectively) showed the lower values of thiobarbituric acid reactive substances (TBARS) at eighth storage day at 4°C. Film 6 (1% MMT15A and 15% tocopherol) showed better result on reduction in water vapour transmission rate (WVTR) and controlled release of tocopherol. All the films containing MMT15A presented migration of minerals (Mg and Si) for the salmon during the 8 days. Thus, the use of this film for release of active substances is a promising alternative for application as food packaging in order to obtain nutritionally fortified foods and inhibit oxidation reactions.     

Alteplase vs. urokinase for occluded hemodialysis catheter: A randomized trial

Introduction Thrombosis of tunneled central venous catheters (CVC) in hemodialysis (HD) patients is common and it can lead to the elimination of vascular sites. To compare the efficacy of alteplase vs. urokinase in reestablishing adequate blood flow through completely occluded vascular catheters. Methods In this randomized study, patients with completely occluded tunneled HD catheters received 40 minutes intracatheter dwell with alteplase (1 mg/mL) or urokinase (5000 IU/mL). Primary endpoint was the proportion of patients with occluded catheters achieving post‐thrombolytic blood flow of ≥250 mL/min. Safety endpoints included the incidence of hemorrhagic and infectious complications. Findings Eligible adult patients (n = 100) were treated with alteplase (n = 44) or urokinase (n = 56). The two groups were similar in gender (male: 51.8% vs. 56.8%, P = 0.35), age (60 ± 12 vs. 59 ± 13 years, P = 0.71), time on dialysis (678 ± 203 vs. 548 ± 189 days, P = 0.77), diabetes and cardiovascular disease (55.6% vs. 70.4%, P = 0.08 and 17.8% vs. 22.7%, P = 0.38, respectively), jugular vein as main vascular access (54.8% vs. 62.5%, P = 0.57), and time of CVC (278 ± 63 vs. 218 ± 59 days, P = 0.67). Primary success with alteplase and urokinase occurred in 42/44 (95%) vs. 46/56 (82%), P = 0.06. Success was not achieved after the second dose of alteplase and urokinase in 1 and 7 cases, respectively (2% vs. 12%, P = 0.075). Serious adverse effects were not observed in both groups. There was no difference between the two groups in infectious complications (P = 0.94). Discussion Alteplase and urokinase are effective thrombolytic agents for restoring HD catheter patency. Our study has revealed a likely slight superiority of alteplase over urokinase for unblocking central lines, but which has enrolled too few patients to be able to detect a difference of this size.     

Modulating the Mechanical Performance of Macroscale Fibers through Shear‐Induced Alignment and Assembly of Protein Nanofibrils

Protein‐based fibers are used by nature as high‐performance materials in a wide range of applications, including providing structural support, creating thermal insulation, and generating underwater adhesives. Such fibers are commonly generated through a hierarchical self‐assembly process, where the molecular building blocks are geometrically confined and aligned along the fiber axis to provide a high level of structural robustness. Here, this approach is mimicked by using a microfluidic spinning method to enable precise control over multiscale order during the assembly process of nanoscale protein nanofibrils into micro‐ and macroscale fibers. By varying the flow rates on chip, the degree of nanofibril alignment can be tuned, leading to an orientation index comparable to that of native silk. It is found that the Young's modulus of the resulting fibers increases with an increasing level of nanoscale alignment of the building blocks, suggesting that the mechanical properties of macroscopic fibers can be controlled through varying the level of ordering of the nanoscale building blocks. Capitalizing on strategies evolved by nature, the fabrication method allows for the controlled formation of macroscopic fibers and offers the potential to be applied for the generation of further novel bioinspired materials.     

Stochastic particle packing with specified granulometry and porosity

This work presents a technique for particle size generation and placement in arbitrary closed domains. Its main application is the simulation of granular media described by disks. Particle size generation is based on the statistical analysis of granulometric curves which are used as empirical cumulative distribution functions to sample from mixtures of uniform distributions. The desired porosity is attained by selecting a certain number of particles, and their placement is performed by a stochastic point process. We present an application analyzing different types of sand and clay, where we model the grain size with the gamma, lognormal, Weibull and hyperbolic distributions. The parameters from the resulting best fit are used to generate samples from the theoretical distribution, which are used for filling a finite-size area with non-overlapping disks deployed by a Simple Sequential Inhibition stochastic point process. Such filled areas are relevant as plausible inputs for assessing Discrete Element Method and similar techniques.     

Study of Some Functional Properties of Casein: Effect of pH and Tryptic Hydrolysis

The trypsin was used to hydrolyze commercial casein at varied times and pH range. The functional properties studied were the emulsifying capacity (EC), the emulsifying activity index (EAI), and the emulsion stability (ES). The dispersed phase used was corn oil. The tryptic hydrolysis was beneficial to the solubility and EC of casein in practically all pH values and reaction times. In case of EAI, this same effect was less intense and was observed only in acid region (pH 3.0 to 5.0), while for ES the trypsin action was mainly deleterious in almost all pH range and reaction times.     

Parameter Estimation of Fouling Models in Crude Preheat Trains

Several fouling mitigation techniques depend on the capacity of predicting fouling rates. Therefore, the identification of accurate fouling rate models is an important task. Crude fouling rates are usually evaluated through empirical or semiempirical models. In both alternatives, there are parameters that must be determined through laboratory or process data. In this context, the article presents an analysis of the parameter estimation problem involving fouling rate models. A proposed procedure for addressing this problem is described through the development of a computational routine called HEATMODEL. An important aspect of this study is focused on the obstacles associated to the search for the optimal set of parameters of the Ebert and Panchal models and its variants. This optimization problem may present some particularities that complicate the utilization of traditional algorithms. In the article, the performance of a conventional optimization algorithm (Simplex) is compared with a more modern numerical technique (a hybrid genetic algorithm) using real data from a Brazilian refinery. The results indicated that, due to the complexity of the parameter estimation problem, the Simplex method may be trapped in poor local optima, thus indicating the importance of the utilization of global optimization techniques for this problem.     

Delineating the construct network of the Personnel Reaction Blank: Associations with externalizing tendencies and normal personality.

Integrity testing has long been utilized in personnel selection to screen for tendencies toward counterproductive workplace behaviors. The construct of externalizing from the psychopathology literature represents a coherent spectrum marked by disinhibitory traits and behaviors. The present study drew on a sample of male and female undergraduates to examine the construct network of the Personnel Reaction Blank (PRB; H. G. Gough, R. D. Arvey, & P. Bradley, 2004), a measure of integrity, in relation to externalizing as well as normal-range personality constructs assessed by the Multidimensional Personality Questionnaire (MPQ; A. Tellegen & N. G. Waller, 2008). Results revealed moderate to strong associations between several PRB scales and externalizing, which were largely accounted for by MPQ traits subsumed by Negative Emotionality and Constraint. After accounting for MPQ traits in the prediction of externalizing, a modest predictive increment was achieved when adding the PRB scales, particularly biographical indicators from the Prosocial Background subscale. The findings highlight externalizing as a focal criterion for scale development in the integrity testing literature and help delineate the construct network of the PRB within the domains of personality and psychopathology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aspect-oriented Programming for Dynamic Web Service Selection,Integration and Management

In service-oriented computing, applications are often created by integrating third-party Web Services. Current integration approaches, however, require client applications to hardcode references to specific Web Services, thereby affecting adaptability and robustness. Moreover, support for client-side management is rarely provided. To enable the development of more flexible and robust applications, we propose to insert a new layer between the client applications and the Web Services: the Web Services Management Layer (WSML). This layer decouples Web Services from client applications and enables hot-swapping between semantically equivalent Web Services based on availability. This mechanism allows for dynamic switching between Web Services based on selection policies that encapsulate changing business requirements. In addition, with WSML, client-side management concerns (e.g., caching, billing and logging) can be decoupled from the applications. In this paper, we identify a list of requirements for WSML to realize dynamic integration and client-side service management, and provide support for service criteria to govern the selection, integration and composition of Web Services. We also show that dynamic Aspect-Oriented Programming (AOP) is well suited to implement the core functionality of WSML.     

From the specification to the implementation of norms: an automatic approach to generate rules from norms to govern the behavior of agents

Open multi-agent systems composed of heterogeneous, autonomous and independently designed agents are usually governed by a set of norms. The established norms regulate the behavior of the agents by pointing out their permissions, prohibitions and obligations. This paper presents a normative language to specify norms and proposes the implementation of such norms by using a rule-based system. The implementation is achieved by automatically transforming the specification of each norm of the system into a set of rules used to govern the behavior of the agents according to the norm. The governance system is able to activate and deactivate norms, to point out the norms violations and fulfillments and to inform about punishments and rewards.