Autoencoder-based image processing framework for object appearance modifications

Neural Computing and Applications - The presented paper introduces a novel method for enabling appearance modifications for complex image objects. Qualitative visual object properties, quantified...     

Classification and fingerprinting of kiwi and pomelo fruits by multivariate analysis of chromatographic and spectroscopic data

The fingerprinting capacity of two analytical techniques, HPLC and UV–Vis spectroscopy in the case of fruits samples (kiwi and pomelo) has been investigated. The multivariate exploratory techniques were used for sample discrimination according to the fruit species and subspecies. The combination of principal component analysis with linear discriminant analysis is opening new directions in the fingerprinting analysis. The classifications obtained were independent by the analytical techniques, which signalise that both of them may be successfully employed in the fingerprinting methodologies if they are combined with appropriate chemometric methods. One of the biggest advantages of the proposed chemometric method is the ability to discriminate different types and species and subspecies of fruits in just one analysis, which indicates that it is one of the simplest and less time consuming methods. It is strongly sustained by the good results obtained in the case of kiwi and pomelo fruit samples that were simultaneously analysed.     

Mercury in bay bolete (Xerocomus badius): bioconcentration by fungus and assessment of element intake by humans eating fruiting bodies

Concentrations of mercury (Hg) were determined in 221 specimens of bay bolete and in 221 samples of corresponding forest topsoil layer (0-10 cm) collected from 18 sites across geographically and industrially diverse regions of Poland in 2000-2008. Mercury concentrations in caps and stipes of bay bolete were strongly correlated (p < 0.0001), whereas the relationship between the Hg concentrations in soil and mushrooms varied depending on the sampling location. The bay bolete showed a lower bioconcentration potential of Hg at sites with elevated soil Hg concentrations and a higher bioconcentration at sites with lower Hg concentrations in soil. In view of Hg content, the consumption of bay boletes (caps or whole mushrooms) at the regions surveyed at least at a rate up to 2.5 kg per capita weekly in a mushrooming season is safe and will not result in exceeding of currently allowable Hg intake doses.     

Time–frequency approach to extraction of selected second-order cyclostationary vibration components for varying operational conditions

In this paper, the authors propose a method for extracting second-order cyclostationary components from a vibration signal. For a known cyclic frequency, the proposed algorithm allows to estimate the amount of energy of each cyclic component of interest in the time–frequency domain. In this way, the resulting representation contains only the chosen second-order cyclostationary component that manifests itself as a number of carrier frequencies modulated by the harmonic signal of selected frequency.     

2,3-Dihydro-1H-cyclopenta[b]quinoline Derivatives as Acetylcholinesterase Inhibitors-Synthesis, Radiolabeling and Biodistribution

In the present study we describe the synthesis and biological assessment of new tacrine analogs in the course of inhibition of acetylcholinesterase. The obtained molecules were synthesized in a condensation reaction between activated 6-BOC-hydrazinopyridine-3-carboxylic acid and 8-aminoalkyl derivatives of 2,3-dihydro-1H-cyclopenta[b]quinoline. Activities of the newly synthesized compounds were estimated by means of Ellman's method. Compound 6h (IC(50) = 3.65 nM) was found to be most active. All obtained novel compounds present comparable activity to that of tacrine towards acetylcholinesterase (AChE) and, simultaneously, lower activity towards butyrylcholinesterase (BChE). Apart from 6a, all synthesized compounds are characterized by a higher affinity for AChE and a lower affinity for BChE in comparison with tacrine. Among all obtained molecules, compound 6h presented the highest selectivity towards inhibition of acetylcholinesterase. Molecular modeling showed that all compounds demonstrated a similar binding mode with AChE and interacted with catalytic and peripheral sites of AChE. Also, a biodistribution study of compound 6a radiolabeled with (99m)Tc was performed.     

Adaptation of high-throughput screening in drug discovery-toxicological screening tests

High-throughput screening (HTS) is one of the newest techniques used in drug design and may be applied in biological and chemical sciences. This method, due to utilization of robots, detectors and software that regulate the whole process, enables a series of analyses of chemical compounds to be conducted in a short time and the affinity of biological structures which is often related to toxicity to be defined. Since 2008 we have implemented the automation of this technique and as a consequence, the possibility to examine 100,000 compounds per day. The HTS method is more frequently utilized in conjunction with analytical techniques such as NMR or coupled methods e.g., LC-MS/MS. Series of studies enable the establishment of the rate of affinity for targets or the level of toxicity. Moreover, researches are conducted concerning conjugation of nanoparticles with drugs and the determination of the toxicity of such structures. For these purposes there are frequently used cell lines. Due to the miniaturization of all systems, it is possible to examine the compound's toxicity having only 1-3 mg of this compound. Determination of cytotoxicity in this way leads to a significant decrease in the expenditure and to a reduction in the length of the study.     

Ozonation Kinetics Of o-phenylphenol in Aqueous Solutions

This study investigated the oxidation and reaction kinetics of biocide o-phenylphenol (o-PP) during ozonation. The second-order rate constants for direct reaction of molecular ozone with o-PP were determined in homogenous system using classical and competition kinetics. Obtained values of the second-order rate at pH 2 are equal to (3.79 ± 0.23)?×?10² M^?1 s^?1 and (4.42 ± 0.64)?×?10² M^?1 s^?1, for the two methods, respectively. The rate constant for the dissociated form of o-PP was also determined. It was found that the rate constants for the reaction of o-PP with ozone increase significantly with increasing pH.     

Tunability and stability of gold nanoparticles obtained from chloroauric Acid and sodium thiosulfate reaction

ABSTRACT: In the quest for producing an effective clinically relevant therapeutic agent, scalability, repeatability, and stability are paramount. In this paper, gold nanoparticles (GNPs) with precisely controlled near infrared (NIR) absorption are synthesized by a single step reaction of HAuCl4 and Na2S2O3, without assistance of additional templates, capping reagents or seeds. The anisotropy in the shape of gold nanoparticles offers high NIR absorption making it therapeutically relevant. The synthesized products consist of GNPs with different shape and size, including small spherical colloid gold particles and non-spherical gold crystals. The NIR absorption wavelengths and particle size increase with increasing molar ratio of HAuCl4/Na2S2O3. Non-spherical gold particles can be further purified and separated by centrifugation to improve the NIR absorbing fraction of particles. In-depth studies reveal that GNPs with good structural and optical stability only form in a certain range of the HAuCl4/Na2S2O3 molar ratio, whereas higher molar ratios result in unstable GNPs, which lose their NIR absorption peak due to decomposition and reassembly via Ostwald ripening. Tuning the optical absorption of the gold nanoparticles in the NIR regime via a robust and repeatable method will improve many applications requiring large quantities of desired NIR absorbing nanoparticles.     

Suppressing harmonic powerline interference using multiple-notch filtering methods with improved transient behavior

In signal processing it is often required to have multiple-notch filters which simultaneously possess a very selective magnitude response and a transient response of short duration. Multiple-notch filters are usually used to remove the powerline hum and its harmonics. It is known, that sharper notches are obtained by either using more coefficients in FIR filters, or by placing the pole closer to the unit circle in IIR filters. However, increasing the filter selectivity also increases the duration of the transient process in the filter after the action of the excitation. This paper presents and compares two methods for suppressing the transient response in multiple-notch filters. As an example, these methods have been used to eliminate the powerline noise from the ECG signal. Both filtering techniques are characterized by improved transient behavior compared to the traditional multiple-notch filters. In the first part of the paper a concept of digital IIR multiple-notch filters whose pole radius changes with time is proposed. Owing to a temporary change in the value of the pole radius, the transient can be considerably reduced. In the second part of this review the technique which uses the vector projection to find better initial values for time-invariant multiple-notch filter is presented. Simulations verifying the effectiveness of the proposed IIR multiple-notch filter with time-varying pole radius and the filter with non-zero initial conditions are presented and compared to the performance of the traditional time-invariant filter using an ECG signal with unwanted fixed-frequency harmonic interferences as a study case.