Superior neuroprotective effects of cerebrolysin in heat stroke following chronic intoxication of Cu or Ag engineered nanoparticles. A comparative study with other neuroprotective agents using biochemical and morphological approaches in the rat

The possibility that cerebrolysin, a mixture of several active fragments of neurotrophic factors and peptides induces neuroprotection following nanoparticles induced exacerbation of brain damage in heat stroke was examined in a rat model. For this purpose, the therapeutic efficacy of Cerebrolysin (2.5 or 5 ml/kg) recommended for stroke treatment was used in comparison with other drugs in standard doses recommended for such therapy in clinical situations e.g., levetiracetam (44 mg/kg), pregabalin (200 mg/kg), topiramate (40 mg/kg,i.p.) and valproate (400 mg/kg). Rats subjected to 4 h heat stress in a biological oxygen demand (BOD) incubator at 38 degrees C (Rel Humid 45-47%; Wind vel 22.4 to 25.6 cm/sec) developed profound behavioral symptoms of heat stroke e.g., hyperthermia, profuse salivation, prostration and gastric ulcerations in the stomach. These rats also exhibited marked brain pathology at this time. Thus, breakdown of the blood-brain barrier (BBB) to proteins associated with brain edema formation could be seen in these heat stressed rats as compared to control groups. The edematous brain areas showed profound neuronal damage and/or distortion in large areas of the neuropil. These pathological symptoms were further exacerbated in Cu or Ag nanoparticles treated group (50-60 nm particle size, 50 mg/kg, i.p./day for 7 days) after identical heat stress on the 8th day. Pretreatment with cerebrolysin (2.5 ml/kg, i.v.) daily for 3 days in normal rats before heat stress significantly reduced the behavioral stress symptoms and the breakdown of the BBB function, edema formation and neuronal injuries. However, the magnitude and intensity of these neuroprotective effects were much less intense in all other drug treated rats after similar heat stress. On the other hand, almost double dose of cerebrolysin (5 ml/kg) was needed to achieve comparable neuroprotection in nanoparticles treated animals after heat stress. Whereas, double dose of all other compounds was much less effective in inducing neuroprotection in nanoparticles treated heat-exposed animals. These observations are the first to show that cerebrolysin exerts the most superior neuroprotective effects in heat stress as compared to other neuroprotective agents on brain pathology in normal and in nanoparticles treated group. Furthermore, cerebrolysin in double dose was the most effective in inducing neuroprotection in nanoparticles treated heat exposed rats on brain pathology as compared to double doses of other drugs. Taken together, our results show that cerebrolysin has the most superior neuroprotective effects on brain pathology in heat stroke in both normal and nanoparticles treated rats as compared to other contemporary neuroprotective agents, not reported earlier.     

Manipulation of protein charge states through continuous flow-extractive desorption electrospray ionization: a new ambient ionization technique

Manipulation of protein charge states in electrospray ionization-mass spectrometry (ESI-MS) has implications for the study of intact proteins, protein-protein interactions, post-translational modifications, and protein sequencing. Control of these protein charge states is often difficult to achieve with conventional methods of analysis. A novel ambient ionization configuration, continuous flow-extractive desorption electrospray ionization (CF-EDESI), is presented as a means to control the charge state distribution of proteins. A key feature of the CF-EDESI technique is the continuous flow needle, which is a hypodermic needle presented orthogonal to the electrospray source and delivers a solvent flow containing analytes for extractive desorption ionization. With this source design, the successful manipulation of cytochrome c and lysozyme charge states with the use of different additives, such as acetic acid and sulfolane, was demonstrated. Results were compared to data obtained with conventional electrospray ionization. Good agreement with previously reported studies of cytochrome c unfolding/folding studies, performed by conventional ESI-MS, is evident. In addition to the protein analysis presented, the CF-EDESI-MS technique should be applicable for analyzing atypical analyte and solvent systems by mass spectrometry while maintaining optimal electrospray source conditions.     

A fundamental study on electrowetting by traditional and multifunctional ionic liquids: possible use in electrowetting on dielectric-based microfluidic applications

Water or aqueous electrolytes are the dominant components in electrowetting on dielectric (EWOD)-based microfluidic devices. Low thermal stability, evaporation, and a propensity to facilitate corrosion of the metal parts of integrated circuits or electronics are drawbacks of aqueous solutions. The alternative use of ionic liquids (ILs) as electrowetting agents in EWOD-based applications or devices could overcome these limitations. Efficient EWOD devices could be developed using task-specific ILs. In this regard, a fundamental study on the electrowetting properties of ILs is essential. Therefore electrowetting properties of 19 different ionic liquids, including mono-, di-, and tricationic, plus mono- and dianionic ILs were examined. All tested ILs showed electrowetting of various magnitudes on an amorphous flouropolymer layer. The effects of IL structure, functionality, and charge density on the electrowetting properties were studied. The enhanced stability of ILs in electrowetting on dielectric at higher voltages was studied in comparison with water. Deviations from classical electrowetting theory were confirmed. The physical properties of ILs and their electrowetting properties were tabulated. These data can be used as references to engineer task-specific electrowetting agents (ILs) for future electrowetting-based applications.     

Anionomeric waterborne poly(urethane semicarbazide) dispersions and their adhesive properties

Aqueous polyurethane dispersions were prepared from isocyanate‐terminated ionic polyurethane prepolymers by chain extension with dihydrazides. These water‐borne dispersions had excellent adhesive properties and were used to bond leather and canvas. The base polymers were varied with respect to (1) the ionic content with the same chain extender and (2) the nature of the chain extender with the ionic content kept constant. Studies on the particle size and viscosity revealed that the ionic content had an influence on the aforementioned properties: the particle size decreased and the viscosity increased with increasing ionic content. The polarity of the films cast from the dispersions were determined with contact‐angle measurements: hydrophilic character was exhibited by all the compositions. X‐ray studies revealed that the increase in the ionic content led to increasing intensities of the diffraction peaks due to increased secondary forces of bonding. The tensile strength measurements showed that the films were highly elastomeric and had good mechanical strength, which varied with the composition. A shear strength and peel strength analysis of specimens obtained through the bonding of leather to leather, leather to canvas, and canvas to canvas revealed that the waterborne dispersions were excellent adhesives for bonding leather surfaces. Thus, a very efficient, ecofriendly waterborne dispersion of polyurethane that could find applications in bonding leather in the footwear industry was prepared successfully. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Wear Behavior of Disk Shape Spray Formed Al-Si-Pb Alloys

Wear behavior of spray formed Al-Si-Pb alloys was investigated using a pin on disk type wear testing machine. Wear rate behavior with applied load was observed to depict three stages, in the second stage rate of increase in wear rate was the lowest and in the third stage it was the highest. The wear rate decreased with the increase in distance from center to periphery of the spray deposit. It decreased linearly with the increase in lead content and it was lower for 12% Si as compared to that of 6% Si in Al-Si-Pb alloys. The coefficient of friction decreased rapidly up to the load of 40 N and beyond this load the friction coefficient was almost constant. The coefficient of friction was lower for higher lead content.     

EMUNE: Architecture for Mobile Data Transfer Scheduling with Network Availability Predictions

With the mobile communication market increasingly moving towards value-added services, the network cost will need to be included in the service offering itself. This will lead service providers to optimize network usage based on real cost rather than simplified network plans sold to consumers traditionally. Meanwhile, today’s mobile devices are increasingly containing multiple radios, enabling users on the move to take advantage of the heterogeneous wireless network environment. In addition, we observe that many bandwidth intensive services such as video on demand and software updates are essentially non real-time and buffers in mobile devices are effectively unlimited. We therefore propose EMUNE, a new transfer service which leverages these aspects. It supports opportunistic bulk transfers in high bandwidth networks while adapting to device power concerns, application requirements and user preferences of cost and quality. Our proposed architecture consists of an API, a transport service and two main functional units. The well defined API hides all internal complexities from a programmer and provides easy access to the functionalities. The prediction engine infers future network and bandwidth availability. The scheduling engine takes the output of the prediction engine as well as the power and monetary costs, application requirements and user preferences into account and determines which interface to use, when and for how long for all outstanding data transfer requests. The transport service accordingly executes the inferred data transfer schedule. The results from the implementation of EMUNE’s and of the prediction and scheduling engines evaluated against real user data show the effectiveness of the proposed architecture for better utilization of multiple network interfaces in mobile devices.     

Microstructure and Polarization Studies on Interlayer Free La0.65Sr0.3Co0.2Fe0.8O3–δ Cathodes Fabricated on Yttria Stabilized Zirconia by Solution Precursor Plasma Spraying

Nano‐structured cathodes of La_0.65Sr_0.3Co_0.2Fe_0.8O_3–δ (LSCF) are fabricated by solution precursor plasma spraying (SPPS) on yttria stabilized zirconia (YSZ) electrolytes (LSCF‐SPPS‐YSZ). Phase pure LSCF is obtained at all plasma power. Performances of LSCF‐SPPS‐YSZ cathodes are compared with conventionally prepared LSCF cathodes on YSZ (LSCF‐C‐YSZ) and gadolinium doped ceria (GDC) (LSCF‐C‐GDC) electrolytes. High R_p is observed in the LSCF‐C‐YSZ (∼42 Ohm cm² at 700 °C) followed by LSCF‐C‐GDC (R_p ∼ 1.5 Ohm cm² at 700 °C) cathodes. Performance of the LSCF‐SPPS‐YSZ cathodes (R_p ∼ 0.1 Ohm cm² at 700 °C) is found to be even superior to the performance of LSCF‐C‐GDC cathodes. High performance in LSCF‐SPPS‐YSZ cathodes is attributed to its nano‐structure and absence of any interfacial insulating phase which may be attributed to the low temperature at the interaction point of LSCF and YSZ and low interaction time between LSCF and YSZ during SPPS process. In the time scale of 100 h, no change in the polarization resistances is observed at 750 °C. Based on the literature and from the present studies it can be stated that SOFC with YSZ electrolyte and LSCF‐SPPS‐YSZ cathode can be operated at 750 °C for a longer duration of time and good performance can probably be achieved.