Ligand-based electronic effects on the electrocatalytic hydrogen production by thiosemicarbazone nickel complexes.

This work reports on the synthesis and characterization of a series of mononuclear thiosemicarbazone nickel complexes that display significant catalytic activity for hydrogen production in DMF using trifluoroacetic acid as the proton source. The ligand framework was chemically modified by varying the electron-donating abilities of the para substituents on the phenyl rings, which was expected to impact the capability of the resulting complexes to reduce protons into hydrogen. Over the four nickel complexes that were obtained, the one with the thiomethyl substituent, NiSCH3, was found to overtake the catalytic performances of the parent complex NiOCH3 featuring lower overpotential values and similar maximum turnover frequencies.

A review of the alleged health hazards of monosodium glutamate.

Monosodium glutamate (MSG) is an umami substance widely used as flavor enhancer. Although it is generally recognized as being safe by food safety regulatory agencies, several studies have questioned its long-term safety. The purpose of this review was to survey the available literature on preclinical studies and clinical trials regarding the alleged adverse effects of MSG.

Micro-nano-bio acoustic system for the detection of foodborne pathogens in real samples.

The fast and efficient detection of foodborne pathogens is a societal priority, given the large number of food-poisoning outbreaks, and a scientific and technological challenge, given the need to detect as little as 1 viable cell in 25 gr of food. Here, we present the first approach that achieves the above goal, thanks to the use of a micro/nano-technology and the detection capability of acoustic wave sensors. Starting from 1 Salmonella cell in 25 ml of milk, we employ immuno-magnetic beads to capture cells after only 3 h of pre-enrichment and subsequently demonstrate efficient DNA amplification using the Loop Mediated Isothermal Amplification method (LAMP) and acoustic detection in an integrated platform, within an additional ½ h.

Sample-to-answer acoustic detection of DNA in complex samples.

The present study demonstrates the sensitive and label-free acoustic detection of dsDNA amplicons produced from whole Salmonella Thyphimurium cells without employing any DNA extraction and/or purification step, in the presence of the lysed bacterial cells and in a hybridization-free assay. A sample-to-answer assay is also shown during DNA detection directly in milk.

Comparative proteomic analysis of hypertrophic chondrocytes in osteoarthritis.

Background: Osteoarthritis (OA) is a multi-factorial disease leading progressively to loss of articular cartilage and subsequently to loss of joint function. While hypertrophy of chondrocytes is a physiological process implicated in the longitudinal growth of long bones, hypertrophy-like alterations in chondrocytes play a major role in OA. We performed a quantitative proteomic analysis in osteoarthritic and normal chondrocytes followed by functional analyses to investigate proteome changes and molecular pathways involved in OA pathogenesis.

Physical and chemical processes of air masses in the Aegean Sea during Etesians: Aegean-GAME airborne campaign.

High-resolution measurements of gas and aerosols' chemical composition along with meteorological and turbulence parameters were performed over the Aegean Sea (AS) during an Etesian outbreak in the framework of the Aegean-GAME airborne campaign. This study focuses on two distinct Etesian patterns, with similarities inside the Marine Atmospheric Boundary Layer (MABL) and differences at higher levels. Under long-range transport and subsidence the pollution load is enhanced (by 17% for CO, 11% for O3, 28% for sulfate, 62% for organic mass, 47% for elemental carbon), compared to the pattern with a weaker synoptic system.

Characterization and dispersion modeling of odors from a piggery facility.

Piggeries are known for their nuisance odors, creating problems for workers and nearby residents. Chemical substances that contribute to these odors include sulfurous organic compounds, hydrogen sulfide, phenols and indoles, ammonia, volatile amines, and volatile fatty acids. In this work, daily mean concentrations of ammonia (NH3) and hydrogen sulfide (H2S) were measured by hand-held devices.

Robust neural adaptive stabilization of unknown systems with measurement noise.

In this paper, we consider the problem of adaptive stabilizing unknown nonlinear systems whose state is contaminated with external disturbances that act additively. A uniform ultimate boundedness property for the actual system state is guaranteed, as well as boundedness of all other signals in the closed loop. It is worth mentioning that the above properties are satisfied without the need of knowing a bound on the "optimal" weights, providing in this way higher degrees of autonomy to the control system.

Tracking control of multi-input affine nonlinear dynamical systems with unknown nonlinearities using dynamical neural networks.

The purpose of this paper is to design and rigorously analyze a tracking controller, based on a dynamic neural network model for unknown but affine in the control, multi input nonlinear dynamical systems, Lyapunov stability theory is used to guarantee a uniform ultimate boundedness property for the tracking error, as well as of all other signals in the closed loop. The controller derived is smooth. No a priori knowledge of an upper bound on the "optimal" weights and modeling errors is required.

Evolutionary algorithm based offline/online path planner for UAV navigation.

An evolutionary algorithm based framework, a combination of modified breeder genetic algorithms incorporating characteristics of classic genetic algorithms, is utilized to design an offline/online path planner for unmanned aerial vehicles (UAVs) autonomous navigation. The path planner calculates a curved path line with desired characteristics in a three-dimensional (3-D) rough terrain environment, represented using B-spline curves, with the coordinates of its control points being the evolutionary algorithm artificial chromosome genes. Given a 3-D rough environment and assuming flight envelope restrictions, two problems are solved: i) UAV navigation using an offline planner in a known environment, and, ii) UAV navigation using an online planner in a completely unknown environment.

Attenuation of ocular wall pulsation in eyes containing a gas bubble after vitrectomy.

Purpose: To evaluate the effect of an intraocular gas bubble on ocular wall pulsation.

Methods: Eight patients that underwent vitrectomy with intraocular gas injection for various reasons were studied. Ocular pulsation was evaluated in a semi-quantitative way by means of Goldman applanation tonometry in both eyes before and after the operation.

Neural adaptive regulation of unknown nonlinear dynamical systems.

With this paper we extend our previous work on the subject, by including the case where the number of control inputs is different from the number of states which is frequently faced in control engineering problems. Uniform ultimate boundedness of the state and uniform boundedness of all other signals in the closed loop is guaranteed. Robustness of our algorithm due to the presence of a modeling error term which has linear growth with unknown growth coefficient is also established.

Convergence properties of a class of learning vector quantization algorithms.

A mathematical analysis of a class of learning vector quantization (LVQ) algorithms is presented. Using an appropriate time-coordinate transformation, we show that the LVQ algorithms under consideration can be transformed into linear time-varying stochastic difference equations. Using this fact, we apply stochastic Lyapunov stability arguments, and we prove that the LVQ algorithms under consideration do indeed converge, provided that some appropriate conditions hold.

A class of robust entropic functionals for image restoration.

This paper considers the concept of robust estimation in regularized image restoration. Robust functionals are employed for the representation of both the noise and the signal statistics. Such functionals allow the efficient suppression of a wide variety of noise processes and permit the reconstruction of sharper edges than their quadratic counterparts.

High-order neural network structures for identification of dynamical systems.

Several continuous-time and discrete-time recurrent neural network models have been developed and applied to various engineering problems. One of the difficulties encountered in the application of recurrent networks is the derivation of efficient learning algorithms that also guarantee the stability of the overall system. This paper studies the approximation and learning properties of one class of recurrent networks, known as high-order neural networks; and applies these architectures to the identification of dynamical systems.

Serum erythropoietin in regularly transfused thalassemic patients.

Serum erythropoietin levels were measured in 67 regularly transfused thalassemic patients with pre-transfusion hematocrit ranging from 25-32% and in 40 normal individuals. In patients, mean erythropoietin levels were slightly increased (mean 91.5 miu/ml) as compared to normal individuals (mean 42 miu/ml).