Adsorption of trypsin onto magnetic ion‐exchange beads of poly(glycidylmethacrylate‐co‐ethyleneglycoldimethacrylate)

Magnetic beads were prepared from glycidyl methacrylate (GMA), and ethyleneglycol dimethylmethacrylate (EGDMA) in the presence of Fe₃O₄ nano‐powder via suspension polymerization. The magnetic beads were characterized by surface area measurement, electron spin resonance (ESR), and scanning electron microscopy (SEM). ESR data revealed that the beads were highly super‐paramagnetic. The effects of contact time, pH, ionic strength, and temperature on the adsorption process have been studied. Adsorption equilibrium was established in about 120 min. The maximum adsorption of trypsin on the magnetic beads was obtained as 84.96 mg g^?1 at around pH 7.0. At increased ionic strength, the contribution of the electrostatic component to the overall binding decreased, and so the adsorption capacity. The experimental equilibrium data obtained trypsin adsorption onto magnetic beads fitted well to the Langmuir isotherm model. The result of kinetic analyzed for trypsin adsorption onto magnetic ion‐exchange beads showed that the second order rate equation was favorable. It was observed that after six adsorption–elution cycle, magnetic beads can be used without significant loss in trypsin adsorption capacity. Finally, the magnetic beads were used for separation of bovine serum albumin (BSA) and trypsin from binary solution in a batch system. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Comparison of antioxidant activities of juice, peel, and seed of pomegranate (Punica granatum L.) and inter-relationships with total phenolic, Tannin, anthocyanin, and flavonoid contents

In this study, the antioxidant activities of juice, peel, and seed parts of pomegranate were investigated by using DPPH scavenging activity, β-carotene bleaching method, reducing power, and metal chelating activity. Sample of pomegranates which are named Punica granatum L. cv. Hicaznar, genotype 19–121, genotype 17–67, and genotype 19–66 obtained from BATEM (West Mediterranean Agricultural Research Institute) in Anlalya. The EC₅₀ values of DPPH scavenging activities in peel extracts (PE) had 23.4-fold higher than the juice extracts (JE), and the seed extracts (SE) had 2.3-fold higher than JE. The reducing power in peel extracts was found to be 4.7-fold higher than SE and 10.5-fold higher than the JE. The highest metal chelating capacity (37.22%) was determined in peel, while the lowest (7.151%) in seed. Generally, in peel, the total polyphenol, flavonoid, tannin contents, and in juice, the total polyphenol, anthocyanin, tannin contents, and acidity significantly affected to antioxidant activities.     

Carotid-jugular arteriovenous fistula and cerebrovascular infarct: a case report of an iatrogenic complication following internal jugular vein catheterization

Central venous catheterization is frequently performed for perioperative management and long-term intravenous access. Although complications associated with central venous catheter insertion have been widely reported, there are few reports of carotid-jugular arteriovenous fistula formation. Endovascular procedures are associated with a risk of immediate and delayed thromboembolic and ischemic complications. We describe a case of a carotid-jugular arteriovenous fistula and a cerebrovascular infarct following the insertion of a double-lumen catheter for hemodialysis access. We provide recommendations for the prevention and the early detection of this iatrogenic complication.     

Perceptual quality‐based image communication service framework for wireless sensor networks

Wireless multimedia sensor networks (WMSNs) have an increasing variety of multimedia‐based applications including image and video transmission. In these types of applications, multimedia sensor nodes should ideally maximize perceptual quality and minimize energy expenditures in communication. For the required perceptual quality to be obtained, quality‐aware routing is a key research area in WMSNs. However, mapping the system parameters to the end user's perceptual quality‐of‐service measures is a challenging task because of incomplete identification metrics. Unfortunately, unless disputable assumptions and simplifications are made, optimal routing algorithm is not tractable. In this paper, we propose a novel image transmission framework to optimize both perceptual quality and energy expenditure in WMSNs. Our framework aims to provide acceptable perceptual quality at the end user by using an analytical distortion prediction model that is able to predict the image distortion resulting from any given error pattern. The innovation of the proposed scheme lies in the combined use of a content‐aware packet prioritization with an energy‐aware and quality‐aware routing protocol, named as image quality‐aware routing. Additionally, it does not only propose an energy‐efficient route selection policy but also manages the network load according to the energy residues of nodes, thus leading to a great energy economy. The results reveal that the framework is capable of identifying true metrics for mapping required image quality to network parameters. Copyright © 2011 John Wiley & Sons, Ltd.     

Determination of optimum operating conditions and simulation of drying in a textile drying process

In this study, drying behavior of viscose yarn bobbins was investigated experimentally to specify the optimum drying conditions and a drying model was proposed for simulation of drying. The experiments were conducted in a pressurized hot-air bobbin dryer, which was designed and manufactured based on the dryers used in the textile industry. Drying process was performed for various drying parameters: bobbin diameter, drying temperature, drying pressure, and volumetric flow rate of drying air. The results show that total drying time is strongly dependent on drying pressure, drying temperature, and volumetric flow rate and increase at these parameters shortens the drying time considerably. The results also show that the minimum energy consumption is for lower values of drying temperature and drying pressure and modest and higher values of volumetric flow rate. Simulation results show that the most appropriate model in describing the drying curves of viscose yarn bobbins is the stretched exponential model.     

Location area planning and cell-to-switch assignment in cellular networks

Location area (LA) planning plays an important role in cellular networks because of the tradeoff caused by paging and registration signalling. The upper boundary for the size of an LA is the service area of a mobile services switching center (MSC). In that extreme case, the cost of paging is at its maximum but no registration is needed. On the other hand, if each cell is an LA, the paging cost is minimal but the cost of registration is the largest. Between these extremes lie one or more partitions of the MSC service area that minimize the total cost of paging and registration. In this paper, we seek to determine the location areas in an optimum fashion. Cell to switch assignments are also determined to achieve the minimization of the network cost. For that purpose, we use the available network information to formulate a realistic optimization problem, and propose an algorithm based on simulated annealing (SA) for its solution. Then, we investigate the quality of the SA-based technique by comparing it to greedy search, random generation methods, and a heuristic algorithm.     

A review: Recent advances in sol-gel-derived hydroxyapatite nanocoatings for clinical applications

The prospect of modifying the surface properties of the substrate (or base) material to enhance its corrosion and wear resistance as well as its reliability, performance, and more importantly its bioactivity is made possible using nanocoatings. An effective technique of synthesizing high purity nanocoatings in addition to nanopowders and fibers is to utilize the sol-gel approach. It is an attractive and versatile method that can be carried out with relative ease. Ceramic coatings, such as hydroxyapatite (HAp), can be fabricated through chemical means from solutions and consequently complex shapes can be coated economically. Given the fact that mixing takes place on the atomic scale, one of the key advantages of the sol-gel technique is its capacity to produce homogeneous materials, and it has been shown that the mechanical properties of sol-gel coatings are enhanced due to the presence of nanocrystalline grain structures. This review covers a brief insight into the recent application of HAp nanocoatings derived from sol-gel technique.     

Some Biochemical Properties of Lipase from Bay Laurel (<Emphasis Type="Italic">Laurus nobilis</Emphasis> L.) Seeds

Lipase was isolated from bay laurel (Laurus nobilis L.) seeds, some biochemical properties were determined. The bay laurel oil was used as the substrate in all experiments. The pH optimum was found to be 8.0 in the presence of this substrate. The temperature optimum was 50 °C. The specific activity of the lipase was found to be 296 U mg protein⁻¹ in optimal conditions. The enzyme activity is quite stable in the range of pH 7.0–10. The enzyme was stable for 1 h at its optimum temperature, and retained about 68% of activity at 60 °C during this time. K _m and V _max values were determined as 0.975 g and 1.298 U mg protein⁻¹, respectively. Also, storage stability and metal effect on lipolytic activity were investigated. Enzyme activity was maintained for 9, 12, and 42 days at room temperature, 4 and −20 °C, respectively. Ca²⁺, Co²⁺, Cu²⁺, Fe²⁺, and Mg²⁺ lightly enhanced bay laurel lipase activity.     

Complexity Model Based Proactive Dynamic Voltage Scaling for Video Decoding Systems

Significant power savings can be achieved on voltage/ frequency configurable platforms by dynamically adapting the frequency and voltage according to the workload (complexity). Video decoding is one of the most complex tasks performed on such systems due to its computationally demanding operations like inverse filtering, interpolation, motion compensation and entropy decoding. Dynamically adapting the frequency and voltage for video decoding is attractive due to the time-varying workload and because the utility of decoding a frame is dependent only on decoding the frame before the display deadline. Our contribution in this paper is twofold. First, we adopt a complexity model that explicitly considers the video compression and platform specifics to accurately predict execution times. Second, based on this complexity model, we propose a dynamic voltage scaling algorithm that changes effective deadlines of frame decoding jobs. We pose our problem as a buffer-constrained optimization and show that significant improvements can be achieved over the state-of-the-art dynamic voltage scaling techniques without any performance degradation. Index