Application of screen-printed sensors for the determination of painkillers

<p>This paper addresses the problem of the intensive development of the pharmaceutical industry and its consequences for the natural environment. The characteristics of the most commonly consumed pharmaceutical preparations and the ways of these substances penetrating into water ecosystems are presented. Attention was paid to the need to monitor environmental contamination and to search for new methods that would enable routine quality control of natural water samples. The application of modern, miniature screen-printed sensors for the determination of trace concentrations of selected active substances of pharmaceutical preparations are presented.</p>

Possibilities of recovery and separation of rare earth elements

Rare earth metals are a group of elements widely used in high technology products. They are included in the group of critical mineral resources for the EU economy. Rare earth elements are found in computers and mobile phones, as well as in low-emission energy technologies. They are also applied in chemical processes as catalysts in the oil refining. Some of them occur even in considerable quantities in the earth's crust but not very often in the concentrations justifying the profitability of their extraction. Additionally, the constantly growing demand and the current market situation cause that alternative resources of rare earth elements recovery are sought after. Therefore, the recovery and separation methods as well as recovery from the secondary sources are becoming more and more important. The following paper presents the possibilities of recovery and separation of rare earth elements from primary and secondary sources.

The application of lignin as renewable raw material in chemical industry

<p>The overutilization of fossil fuels will inevitably cause the global environmental problems and dwindling of available resources. For that reason, identifying renewable sustainable alternatives has attracted an increasing attention. Lignocellulosic biomass has been considered to be one of the most logical feedstock to replace traditional fossil resources as one of the most accessible renewable forms of carbon. One of the primary components of lignocellulosic biomass, next to hemicellulose and cellulose is lignin. It is a by-product in paper and pulp industry. Lignin is mainly used as fuel directly, without further utilization which is suggested to be a waste of natural resources. With this purpose, the valorization of lignin into value-added products needs particular attention of researchers. This review article focuses on chosen possible applications of lignin in chemical industry.</p>

Synthesis and characterization of linear and crosslinked polymers with the addition of DMSPS

<p>The aim of this research was the synthesis of polymers with the addition of S,S'-thiodi-4,1-phenylene bis(thiomethacrylate) (DMSPS) by bulk polymerization. Styrene (St), divinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA) were used for the copolymerization as main monomers. The chemical structures of sulfur-containing polymers were confirmed by the spectroscopic analysis (ATR/FT-IR). In order to determine the impact of the sulfur derivative (DMSPS) addition on thermal properties of the obtained copolymers, differential scanning calorimetry (DSC) was performed. The hardness tests of the obtained copolymers were also applied using a Shore durometer.</p>

Artificial skin composites

<p>Skin injuries are a health problem and can lead to serious, significant deterioration in the quality of life and, consequently, even illness and disability. Therefore, after wounding, immediate regeneration of the tissue is necessary to avoid further complications and pathogenesis. Consequently, many wound healing strategies have been developed, leading to the progress in constructing of multifunctional tissue substitutes for the skin, biomembranes, scaffolds and intelligent dressings. The field of science focusing on the creation of the above-mentioned products is tissue engineering (TE). Its main goal is to find a system that is able to replace or be a model that perfectly mimics the form and function of the skin. Research carried out on such constructs is mainly based on the analysis of mechanical properties (porosity, elasticity), as well as the assessment of the impact of individual components on processes related to the formation of new tissue as cell proliferation and differentiation, proliferation, angiogenesis - through <em>in vivo</em> studies (using animal models: mice, New Zealand rabbits) and <em>in vitro</em> (most often using mouse fibroblasts - L929). Skin constructions may have potential applications as wound dressings or skin substitutes in cases of severe skin damage.</p>

Strategies in poorly soluble drug delivery systems

<p>The form of the active drug administered to patients is important as far as effectiveness of the disease therapy is concerned. From this point of view modifications of medicinal substances are searched for that the obtained compounds have the best physicochemical and pharmacodynamic properties. Pharmaceutical companies allocate significant funds for this type of research. The key property that needs to be improved is the solubility of biologically active substances. This is related to the fact that over 40% of drugs available on the pharmaceutical market are characterized by low solubility in water.</p><p>Thus, the paper describes the most important strategies used in the poorly soluble drug delivery systems, e.g. physical and chemical modifications, formulation based, modification of partition coefficient and lipid systems. The authors discussed various techniques used to enhance solubility of poorly water soluble drugs with their advantages and limitations.</p>

Does the storage time of food packaging material influence the migration degree of 4-phenylobenzophenone photoinitiator from packaging materials to food?

<p>Nowadays, it is not possible to produce food packaging without the use of polygraphic varnishes. Their main task is to protect packaging from the effects of external factors, as well as to give the effect of clarity with greater exposure of the colors used. However, such varnishes contain in their composition low-molecular-weight photoinitiators that can easily migrate to a protected product. The aim of this work was to determine the migration of 4-PBZ from various types of substrates used in the printing industry, i.e. paper, aluminum foil and polyethylene foil. In addition, extensive studies on the impact of the storage conditions of a fresh reprint on the change in the migration of the photoinitiator to food were carried out.</p>

Significance of the receding contact angle in the determination of surface free energy

<p>Surface free energy measurements of solids are a very important issue in various fields of science. Many functional, chemical and physical properties of a given material depend on its surface free energy. The basic method of the surface free energy determination are the contact angle measurements. There are several empirical methods useful to calculate the surface free energy of solids. They are based on the measurements of the contact angle of liquids with the defined surface tension. The aim of this paper is to examine the significance of the receding contact angle measurements in the determination of surface free energy of solids.</p>

Synthesis, properties and applications of CMK-3-type ordered mesoporous carbons

For the last two decades the CMK-3-type carbon was the subject of study by researchers from all over the world for wide range of applications: adsorptive, catalytic, magnetic and electric. Changing of modification strategies resulted in obtaining carbonaceous materials with interesting properties. In this review the synthesis, properties and applications of the CMK-3-type nanocarbon are described.

A role of free silanol groups of nanosilica surface in interaction with poly(vinyl pyrrolidone)

In this work, a role of the number of free silanol groups at a nanosilica surface (specific surface area S_BET = 250 m²/g, initial amount of silanols α_ОН = 0.60-0.62 mmol/g) was analyzed in interaction with poly(vinyl pyrrolidone) (PVP) vs. the degree (Q_TMS) of silica hydrophobization by hexamethyldisilazane at 100 ^oC. The value of Q_TMS was 0.07, 0.42, 0.67, 0.81, 0.82, and 1.0. Adsorption of PVP onto a nanosilica surface was carried out from a water and water-ethanol (1:1) solutions of the polymer. It was shown that free silanol groups play a crucial role in the adsorption of poly(vinyl pyrrolidone). The value of the maximal adsorption (monolayer capacity) on completely hydrophobic nanosilica surface is approximately by 6.5 times lower than that for unmodified nanosilica