Adsorption and release of gemcitabine hydrochloride and oxaliplatin by hydroxyapatite

The aim of this study was to investigate the adsorption and the release profile of two anticancer drugs, gemcitabine hydrochloride (dFdU.HCl) and oxaliplatin (DACH-Pt), from hydroxyapatite (HAP) in order to evaluate HAP as local drug delivery system (DDS). Various initial concentrations of drug aqueous solutions were used in order to determine the maximum adsorption capacity of HAP after 48 h shaking. The maximum adsorption capacity of dFdU.HCl (400 mg/g HAP) was achieved after 40 h while the maximum adsorption capacity of DACH-Pt (49.1 mg/g HAP) was accomplished after 20 h. Adsorption processes for both drugs were found to fit the Freundlich equation. The release processes were studied by soaking the samples of loaded HAP in simulation body fluids (SBF). After only 1 h 65% of dFdU.HCl was released while the release of DACH-Pt from the HAP was more gradual since 55% of DACH-Pt was released in the first 24 h. Finally, in an attempt to understand the molecular basis of the drug action, the chemical interactions involved in the complex processes of drug delivery were studied theoretically.     

Anamorphic Experiences in 3D Space: Shadows,Projections and Other Optical Illusions

The paper presents recent research on the reconstruction of Anamorphic effects and other optical illusions, shadows and projections, with the use of CAD systems. The first part of the paper is a bibliographical overview about the appearance of optical illusions in art, ranging from the work of Niceron to the extravagant sculptures of contemporary artists such as Markus Raetz. The second part of the paper reports on an educational approach that introduces anamorphic geometries into the teaching of digital methods of representation at Graz University of Technology. There is an overview of the experiments and methodology for constructing optical illusions in a CAD environment as well as examples drawn from student projects. The paper concludes with some observations and remarks relating to the aforementioned educational experience.     

Interrupted by Your Pupil: An Interruption Management System Based on Pupil Dilation

Interruptions are prevalent in everyday life and can be very disruptive. An important factor that affects the level of disruptiveness is the timing of the interruption: Interruptions at low-workload moments are known to be less disruptive than interruptions at high-workload moments. In this study, we developed a task-independent interruption management system (IMS) that interrupts users at low-workload moments in order to minimize the disruptiveness of interruptions. The IMS identifies low-workload moments in real time by measuring users’ pupil dilation, which is a well-known indicator of workload. Using an experimental setup we showed that the IMS succeeded in finding the optimal moments for interruptions and marginally improved performance. Because our IMS is task-independent—it does not require a task analysis—it can be broadly applied.     

Modeling of cable-moored floating breakwaters connected with hinges

In the present paper, the overall performance of a cable-moored array of floating breakwaters connected by hinges is investigated under the action of monochromatic linear waves in the frequency domain. The performance is defined here as: (i) demonstration of acceptable levels of both response of the array and its effectiveness and (ii) non-failure of the mooring lines. The numerical analysis of the array is based on a 3D hydrodynamic formulation of the floating body coupled with the static and dynamic analyses of the mooring lines. The motions of the array of floating breakwaters associated with the hinge vertical translations are considered in the hydrodynamic analysis with the implementation of appropriate generalized modes. The stiffness and damping coefficients caused by the mooring lines in both rigid and generalized degrees of freedom are derived here in the general form. A rigorous parametric study is carried out in order to investigate the effect of different configurations (number of hinge joints and number of mooring lines) on the performance of the cable-moored array of floating breakwaters. Moreover, the performance of the various configurations of cable-moored floating breakwaters connected by hinges examined is compared with the performance of a single cable-moored floating breakwater with no hinges. It is found that the number of hinge joints and mooring lines have a direct effect on the performance of the cable-moored array of floating breakwaters.     

The effect of poly(ethylene glycol) mixed with poly(l‐lactic acid) on the crystallization characteristics and properties of their blends

The non‐isothermal and isothermal crystallizations of extruded poly(l ‐lactic acid) (PLLA) blends with 10, 20 and 30 wt% poly(ethylene glycol) (PEG) were investigated with differential scanning calorimetry. The formation of α‐form crystals in the blend films was verified using X‐ray diffraction and an increase in crystallinity indexes using Fourier transformation infrared spectroscopy. Crystallization and melting temperatures and crystallinity of PLLA increased with decreasing cooling rate (CR) and showed higher values for the blends. Although PLLA crystallized during both cooling and heating, after incorporation of PEG and with CR = 2 °C min^?1 its crystallization was completed during cooling. Increasingly distinct with CR, a small peak appeared on the lower temperature flank of the PLLA melting curve in the blends. A three‐dimensional nucleation process with increasing contribution from nuclei growth at higher CR was verified from Avrami analysis, whereas Kissinger's method showed that the diluent effect of 10 and 20 wt% PEG in PLLA decreased the effective energy barrier. During isothermal crystallization, crystallization half‐time increased with temperature (T_ic) for the blends, decreased with PEG content and was lower than that of pure PLLA. In addition, the Avrami rate constants were significantly higher than those of pure PLLA, at the lower T_ic. Different crystal morphologies in the PLLA phase were formed, melting in a broader and slightly higher T_m range than pure PLLA. The crystallization activation energy of PLLA decreased by 56% after the addition of 10 wt% PEG, increasing though with PEG content. Finally, PEG/PLLA blends presented improved flexibility and hydrophilicity. © 2019 Society of Chemical Industry     

Electrochemical modeling and study of copper deposition from concentrated ammoniacal sulfate solutions

A fundamental investigation of the electrolytic deposition of copper from concentrated aqueous ammoniacal solutions has been carried out based on the thermodynamic analysis of the system Cu–NH₃–H₂O. The speciation of copper vs. pH and redox potential was modeled in high ionic strength solutions, in which the activity coefficients of the system species were estimated according to the Modified Bromley's Methodology. The electrochemical behavior of the redox system Cu(0)/Cu(I)/Cu(II) in concentrated aqueous ammoniacal solutions was studied at pH = 9.5 and the cathodic reactions in these solutions were determined. It was found that metallic copper was formed under strongly reductive redox conditions, while under mildly reductive to mildly oxidative conditions the cuprous di-ammine complex species dominate. Under highly oxidative conditions the cupric tetra-ammine complex species predominated. According to the theory and results, the cathodic deposition of copper from concentrated aqueous ammoniacal solutions proceeds in a two-step reduction mechanism. The cupric ammine species are first reduced to cuprous di-ammine, which in turn is reduced to metallic copper. The electrochemical experiments revealed that copper deposition over time follows a sigmoid-type curve, verifying the two-step mechanism. The main feature of these sigmoid curves was the presence of an induction period with negligible copper deposition, followed by an acceleration period where the copper deposition rate gradually increased. By increasing the applied cell voltage, the induction period was significantly reduced or disappeared.     

Hardware Architectures for the Efficient Implementation of Multi-Service Broadband Access and Multimedia Home Networks

In multimedia applications, the stringent requirements for balancing transmission capacity, flexible service provisioning and cost reduction lead the manufactures to provide highly integrated System-on Chip (SoC) solutions. This paper analyzes the application of high-bandwidth-networking SoCs to improve on the cost efficiency of multimedia service distribution in home networks. We present a case study, where we utilize the inherent protocol processing capabilities and high bandwidth interfaces of a modern network processor, scaled down to match the performance targets and low cost requirements of the home networking environment. An efficient, low cost Residential Gateway architecture results by mapping the home services onto the processing and memory blocks of this SoC. This revised version was published online in September 2006 with corrections to the Cover Date.     

Inhalation of 30% nitrous oxide impairs people's learning without impairing people's judgments of what will be remembered.

Many hypotheses have been proposed to account for the effects of nitrous oxide on memory, with one emerging possibility being that it has a global effect on memory-related functioning. This possibility was explored by examining the effects of nitrous oxide on memory performance and on the accuracy of people's judgments about their memory performance. Participants inhaled 30% nitrous oxide or a placebo gas while items were studied and while judgments were made about the likelihood of recall for each item. Next, all participants inhaled the placebo during paired-associate recall. Although administration of nitrous oxide during study impaired recall, it did not affect the predictive accuracy of the metacognitive judgments. These results provide pharmacological evidence for a distinction between memory and metamemory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)