Electrocatalytic Oxidation and Determination of Insulin at Rhodamine B –Multi-walled Carbon Nanotubes Modified Glassy Carbon Electrode

AbstractThe modified electrode surface was provided with the electropolymerization of the rhodamine B in the presence of carbon nanotube (CNT). The modified electrode offers dramatic improvements in the stability and sensitivity of voltammetric measurements of insulin compared to the bare and rhodamine B modified glassy carbon electrodes. The enhanced electrocatalytic activity towards insulin is indicated from lowering the potential of the oxidation process (starting around 0.75 vs. Ag/AgCl) and the substantially higher sensitivity over the entire potential range. A linear dynamic range (100–600nM) was achieved with a detection limit of 5nM. The accuracy of the modified electrode was indicated by insulin recovery test in the real samples as human plasma and pharmaceutical samples

Association of Serum Uric Acid Level with the Severity of Brain Injury and Patient's Outcome in Severe Traumatic Brain Injury

Introduction: The prognostic value of serum Uric Acid (UA) levels in Traumatic Brain Injury (TBI) is unclear. Aim: To investigate the relationship between serum UA levels and prognosis of patients with TBI when in hospital and at six months after discharge. Materials and Methods: All patients attended our emergency department during July 2014 and December 2015 and were consecutively entered into the study and among 890 evaluated candidates based on inclusion criteria we finally investigated the serum UA levels of 725 TBI patients. Computed Tomography (CT) images of the brain were obtained within the first 24 hours of hospitalization. Outcome was assessed using the Glasgow Outcome Scale (GOS) score at discharge and at six months after discharge. Results: Data of 725 patients (42.89 men; mean age: 54.69+/-12.37 years) were analyzed. Mean+/-Standard Deviation (SD) of Glasgow Coma Scale (GCS) scores was 4.65+/-1.76. Serum levels of UA, when in hospital and at six months after discharge, among those who died were lower than those who survived (in hospital: 0.126+/-0.026 vs. 0.243+/-0.942 mmol/l, p = 0.000; 6 months post-discharge: 0.130+/-0.044 vs. 0.286+/-0.069 mmol/l, p<0.001). The mean UA plasma was significantly different between deceased and alive patients according to GOS scores (p<0.001 and p=0.030, respectively). The UA levels showed a significant relationship with GCS scores and severity of brain injury assessed using the Marshall Classification Score (p=0.005). Conclusion: Our results showed a strong relationship between UA levels and patients' outcomes either in hospital or at six months after discharge. Serum UA level could be considered as a valuable marker for evaluating the severity of brain injury and outcomes of TBI

New Examples of Flux Vacua

Type IIB toroidal orientifolds are among the earliest examples of flux vacua. By applying T-duality, we construct the first examples of massive IIA flux vacua with Minkowski space-times, along with new examples of type IIA flux vacua. The backgrounds are surprisingly simple with no four-form flux at all. They serve as illustrations of the ingredients needed to build type IIA and massive IIA solutions with scale separation. To check that these backgrounds are actually solutions, we formulate the complete set of type II supergravity equations of motion in a very useful form that treats the R-R fields democratically.Comment: 38 pages, LaTeX; references updated; additional minor comments added; published versio

Revisiting the S-matrix approach to the open superstring low energy effective lagrangian

The conventional S-matrix approach to the (tree level) open string low energy effective lagrangian assumes that, in order to obtain all its bosonic ${\alpha'}^N$ order terms, it is necessary to know the open string (tree level) $(N+2)$-point amplitude of massless bosons, at least expanded at that order in $\alpha'$. In this work we clarify that the previous claim is indeed valid for the bosonic open string, but for the supersymmetric one the situation is much more better than that: there are constraints in the kinematical bosonic terms of the amplitude (probably due to Spacetime Supersymmetry) such that a much lower open superstring $n$-point amplitude is needed to find all the ${\alpha'}^N$ order terms. In this `revisited' S-matrix approach we have checked that, at least up to ${\alpha'}^4$ order, using these kinematical constraints and only the known open superstring 4-point amplitude, it is possible to determine all the bosonic terms of the low energy effective lagrangian. The sort of results that we obtain seem to agree completely with the ones achieved by the method of BPS configurations, proposed about ten years ago. By means of the KLT relations, our results can be mapped to the NS-NS sector of the low energy effective lagrangian of the type II string theories implying that there one can also find kinematical constraints in the $N$-point amplitudes and that important informations can be inferred, at least up to ${\alpha'}^4$ order, by only using the (tree level) 4-point amplitude.Comment: 34 pages, 3 figure, Submitted on Aug 4, 2012, Published on Oct 15, 201

Intelligent Tuned Harmony Search for Solving Economic Dispatch Problem with Valve-point Effects and Prohibited Operating Zones

Economic dispatch with valve point effect and Prohibited Operating Zones (POZs) is a non-convex and discontinuous optimization problem. Harmony Search (HS) is one of the recently presented meta-heuristic algorithms for solving optimization problems, which has different variants. The performances of these variants are severely affected by selection of different parameters of the algorithm. Intelligent Tuned Harmony Search (ITHS) is a recently developed variant, which mitigates the drawbacks of parameter initializing by maintaining a proper balance between diversification and intensification throughout the search process. The proposed method is applied to five different cases of power systems and the effectiveness, feasibility, and robustness of method is explored through the comparison with reported results in recent literature. First three case studies are systems with 3, 13, and 40-units, considering valve- point effect. The fourth and fifth cases are six and 15-generation unit taking into account generator constraints including POZs, ramp rate limit and transmission line losses which is a challenging Economic Dispatch (ED) problem due to restriction in search space. Computation results imply the efficiency of the proposed method toward other optimization methods reported in recent literature, judged in terms of the objective function value and solution robustness

Determination of silver(I) by flame atomic absorption spectrometry after separation/preconcentration using modified magnetite nanoparticles

AbstractA new, simple, fast and reliable method has been developed for the separation/preconcentration of trace amounts of silver ions using 2-mercaptobenzothiazole/sodium dodecyl sulfate immobilized on alumina-coated magnetite nanoparticles (MBT/SDS-ACMNPs) and their determination by flame atomic absorption spectrometry (FAAS). Optimal experimental conditions, including pH, sample volume, eluent concentration and volume, and co-existing ions, have been studied and established. Under optimal experimental conditions, the enrichment factor, detection limit, linear range and relative standard deviation (RSD) of Ag(I) ions were 250 (for 500 mL of sample solution), 0.56 ng mL−1, 2.0–100.0 ng mL−1 and 3.1% (for 5.0 μg mL−1, n=10), respectively. The presented procedure was successfully applied for determination of silver content in the different samples of water

Power Management in a Utility Connected Micro-Grid with Multiple Renewable Energy Sources

As an efficient alternative to fossil fuels, renewable energy sources have attained great attention due to their sustainable, cost-effective, and environmentally friendly characteristic. However, as a deficiency, renewable energy sources have low reliability because of their non-deterministic and stochastic generation pattern. The use of hybrid renewable generation systems along with the storage units can mitigate the reliability problem. Hence, in this paper, a grid connected hybrid micro-grid is presented, which includes wind and photovoltaic resources as the primary power sources and a hydrogen storage system (including fuel cell and electrolyzer) as a backup. A new power management strategy is proposed to perform a proper load sharing among the micro-grid units. Hybrid (distributed/central) control method is applied for the realization of the control objectives such as DC bus voltage regulation, power factor control, synchronous grid connection, and power fluctuation suppression. Distributed controllers have the task of fulfilling local control objectives such as MPPT implementation and storage unit control. On the other hand, the central control unit is mainly responsible for power management in the micro-grid. Performance and effectiveness of the proposed power management strategy for the presented micro-grid are verified using a simulation study

Compositional Verification and Optimization of Interactive Markov Chains

Interactive Markov chains (IMC) are compositional behavioural models extending labelled transition systems and continuous-time Markov chains. We provide a framework and algorithms for compositional verification and optimization of IMC with respect to time-bounded properties. Firstly, we give a specification formalism for IMC. Secondly, given a time-bounded property, an IMC component and the assumption that its unknown environment satisfies a given specification, we synthesize a scheduler for the component optimizing the probability that the property is satisfied in any such environment