A new kind of sorbent with high adsorption capacity and stability was prepared using chitosan and epichlorohydrin through a cross-linking reaction and assessed by using methyl orange. The sorption capability was evaluated by means of kinetics and equilibrium studies. Relevant factors for such sorption process were also assessed. After optimization of the relevant sorption factors, the percentages for methyl orange removal by chitosan and by modified chitosan were 82%, and 67%, respectively. Although the cross-linked chitosan offered the lowest removal percentage, this sorbent presented other relevant advantages when compared to non-modified chitosan, such as higher chemical and thermal stabilities.

The Directive 2013/39/EU has reviewed the list of priority substances under the European Water Framework Directive (WFD; Directive 2000/60/EC) and has strengthened the principle of flexibility for Member States in applying the Environmental Quality Standard (EQS) for alternative matrices. Coherently, it has established new EQS for biota and it has invited Member States to set EQS for more opportune matrices, able to advantage the monitoring strategy and offer the same level of protection, such as sediment. The present work developed a (HS)SPME-GC-MS/MS method for the analysis of Tributyltin (TBT) in sediment samples and, through an in depth validation process, it assessed the compliance with the technical specification required by the EU Directive 2009/90/EC for chemical status analysis under the scope of the WFD. The EQS established for TBT in sediment by the Italian Environmental Ministry was used as reference. The method fulfils the minimum performance criteria required by the EU Directive 2009/90/EC (Method Detection Limit (MDL) and Minimum Level Of Quantitation (ML), expressed as ng Sn g-1 d.w., were 0.2 and 0.5, respectively). More generally, the analytical figures of merit achieved, were satisfying for the target TBT concentration range (recovery: 90-111%, intermediate precision range: 6-12%).

A simple, rapid, sensitive and selective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for the quantification of pravastatin in human plasma. Pravastatin-D3 was used as an internal standard. The analyte was extracted from human plasma samples by liquid-liquid extraction technique. Due to the presence of isobaric metabolites, 3α-iso-pravastatin and 6-epi-pravastatin, chromatographic conditions were optimized, with a C18 column by using a mixture of 0.1% acetic acid in water and acetonitrile/ methanol (43:57,v/v) as the mobile phase at a flow rate of 0.6 mL/min. The calibration curve obtained was linear (r2 ≥ 0.9900) over the concentration range of 0.500-500 ng/mL. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. The method was suitable for supporting clinical studies.

In this paper we investigate the problem of tracking a moving but non-vibrating cylindrical object and estimating its size and shape using an artificial lateral line system, an d determine the lower bound that the estimator can be reached. Based on a nonlinear analytical model for the moving object-induced flow field, a two-stage extended Kalman filter is proposed to estimate the location, velocity, size, and shapes of the object. Simulation results on tracking an ellipsoidal cross-section are presented to illustrate the approach.

The most efficient method of controlling diseases of economic importance in agricultural crops is breeding of resistant varieties. The objective of the study was to determine the extent of the attack of smut of maize /Ustilago maydis/ on 22 hybrids and 4 maize standards under conditions, conducive to the spread of the pathogen.

The study was conducted in the experimental fields of the Institute of Agriculture and Seed Science “Obraztsov Chiflik”, Ruse during the period 2012 - 2014. 26 germplasms of Preliminary Variety Trial N 2 (PVT) were included.

Ustilago maydis is a common disease in most parts of the world, where maize is grown. In all above-ground organs of the plant, tumors of smutty mass are formed. The pathogen attack leads to stunted growth of the host plant, reducing yield, and economic losses.

The analysis of data about the new hybrids of IASS “Obraztsov Chiflik” - Ruse showed that fifteen of them were resistant.

The resistance was the highest in the hybrids: St.20, Eks.12, Eks.10, Eks.23, Eks.16, Eks.2, Eks.3, Eks.4, Eks.6, Eks.9, Eks.13, Eks.17, Eks.19, Eks.20, 2 Eks.6. They may be used as sources of resistance. Susceptible were: Eks.15, Eks.11, Eks.8, Eks.24, Eks.1, Eks.5, St.7, Eks.14, Eks.18, Eks.22, Eks.25.

Medicinal plants contain a wide variety of chemicals which have very important roles in numerous applications including medicinal and those related with industry. Essential oils represent valuable sources for natural antioxidants. The aim of our study was to evaluate the chemical composition and antioxidant activity of the essential oils extracted from leaves of Syrian Vitex agnus-castus L. and Rosmarinus officinalis L., where is both essential oils were extracted and analyzed by gas chromatography-mass spectrometry. The antioxidant activities of these essential oils were determined by three different test systems, scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radical, total phenolic and flavonoids contents. The main constituents found in Vitex agnus-castus L. essential oil were 1,8-Cineole (19.34%) and Sabinene (12.50%), while the major constituents in Rosmarinus officinalis L. essential oil were 1,8-Cineole (28.03%) and α-Pinene (14.70%). The results showed that 2,2-diphenyl-1-picrylhydrazyl radical scavenging and total phenolic contents of Vitex agnus-castus L. essential oil were higher than Rosmarinus officinalis L. essential oil. Total flavonoids contents were not detected in both essential oils. The Vitex agnus-castus L. and Rosmarinus officinalis L. essential oils are sources of natural antioxidants. Therefore, further work is needed to identify the compound(s) responsible for the antioxidant activity of Vitex agnus-castus L. and Rosmarinus officinalis L. essential oils.