Constant Magnetic Field as a Tool for Modification of the Properties of Polymer Composites with Silicone Rubber Matrix.

The aim of this research was to obtain new polymer composites with a silicone rubber matrix, having favorable mechanical and functional properties. They contained admixtures in the amount of 10% by weight of expanded graphite (EG) or birch bark (BB). Additionally, some composites contained magnetic particles in the form of carbonyl iron in the amount of 20% by weight. The tensile strength, water absorption, frost resistance, surface contact angle, and free surface energy were examined. Microscopic images were taken using the SEM method and the content of some elements in selected microareas was determined using the EDXS method. In the study, a constant magnetic field with magnetic induction B was used, by means of which the properties and structure of polymer composites were modified. Scientific research in the field of polymers is the driving force behind the progress of civilization. Smart materials are able to respond to external stimuli, such as magnetic fields, with significant changes in their properties. The magnetic field affects not only chemical reactions, but also the crystallographic structure and physicochemical properties of the final products. Owing to their unique properties, such materials can be used in the space industry, automotive industry, or electrical engineering.

How Does Aphasia Affect Quality of Life? Preliminary Reports.

Aphasia leads to disability, which, in turn, limits and can result in a complete breakdown of roles and social bonds. Thus, the aim of this study was to assess the impact of aphasia disorders on the quality of life of patients after an ischemic stroke. A prospective study among 116 patients with an ischemic stroke (the study group: 68 participants, 38.25% female, included patients with aphasia after a stroke; the control group: 48 patients, 37.5% female, without aphasia) was conducted at the Neurological Department of the Provincial Specialist Hospital in Wloclawek. The patients were assessed twice: the first assessment was conducted during hospitalization using the Aphasia Dynamics Assessment Scale and the Aphasia Test Method of Jadwiga Szumska, and the second assessment of the quality of life after six months was conducted using the WHOQOL-BREF questionnaire. The patients from the control group rated their overall quality of life more highly than the patients from the study group. Statistically significant differences were observed in the physical domain, the psychological domain, and the environmental domain. The analysis of sociodemographic factors indicated a negative impact on the quality of life of the following variables: female gender, 55-64 years of age, vocational education, and place of residence-rural area. The degree and type of aphasia influenced the overall quality of life. Studies with larger samples are necessary.

Investigation the Effect of MR Fluid Composition on Properties at Low Strain Ranges.

The paper presents the results of eight magnetorheological (MR) fluids of different compositions. Magnetite and carbonyl iron were used as magnetic particles. MR fluids based on glycerin and OKS 352 oil were produced using stabilizers in the form of oleic acid and Aerosil 200 (Evonik Resource Efficiency GmbH, Hanau, Germany) silica; additives such as graphite and yellow dextrin were also used. The aim of the study was to determine the properties of various combinations of components on the dynamic properties of MR fluids, i.e., properties characterizing the fluid within the range of low deformations, as well as to investigate the effect of different compositions on structural yield stress and flow stress prepared MR fluids at different magnetic field induction values.

Tests of Physicochemical and Mechanical Strength Properties of Polymer Composites on an Epoxy Resin Matrix, Modified by a Constant Magnetic Field.

The aim of the research presented in the paper was to obtain new polymer composites with strong functional properties on the Epidian 5 epoxy resin matrix. The polymer composites contained admixtures of expanded graphite, powder graphite, birch bark containing botulin, and yellow dextrin in set amounts of 20% by weight. Their various mechanical parameters and physicochemical properties were investigated. The research involved determining the effect of a constant magnetic field with magnetic induction B, under the influence of which the parameters and properties of polymer composites have been changed. For example, in a constant magnetic field with an induction of B = 0.5 T there was an increase in the hardness of the composite with an admixture of birch bark from 24.01 to 26.96 N/mm2 (12.3%), or in the composite with the addition of yellow dextrin from 26.12 to 29.93 N/mm2 (14.6%). It was also found, for example, that the water absorption of the resin itself decreased from 0.18% to 0.13%, and the composite with graphite powder from 0.48% to 0.46%. Changes in these parameters, often beneficial, may be important in terms of potential application of those new materials in industry as alternatives.

Modification of the Properties of Polymer Composites in a Constant Magnetic Field Environment.

In this paper, polymer composites based on polylactide (PLA) and epoxy resin (Epidian 5) were studied in terms of the influence of magnetic induction on their changes in physicochemical properties. The composites contained admixtures in the form of magnetite (Fe3O4) and crystalline cellulose (Avicel PH-1010) in the amount of 10%, 20%, and 30% by weight and starch in the amount of 10%. The admixtures of cellulose and starch were intended to result in the composites becoming biodegradable biopolymers to some extent. Changes in physical and chemical properties due to the impact of a constant magnetic field with a magnetic induction value B = 0.5 T were observed. The changes were observed during tests of tensile strength, bending, impact strength, water absorbency, frost resistance, chemical resistance to acids and bases, as well as through SEM microscopy and with studies of the composition of the composites that use the EDS method and of their structure with the XRD method. Based on the obtained results, it was found that the magnetic induction value changes the properties of composites. This therefore acts as one method of receiving new alternative materials, the degradation of which in the environment would take far less time.

Environmental exposure to persistent organic pollutants measured in breast milk of lactating women from an urban area in central Poland.

Mothers' milk is considered a channel by means of which new-borns are exposed to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs), environmental pollutants entering food chain and accumulating in fat-rich tissues. In this study, the concentrations of selected PCDDs, PCDFs, and dl-PCBs (a total of 29 substances) in milk samples of 110 breast-feeding women from an urban area were analyzed using the high-resolution gas chromatography/high-resolution mass spectrometry method. Environmental exposure to these substances was expressed by means of the World Health Organization Toxicity Equivalent (WHO-TEQ2005) using the Toxicity Equivalent Factor values from van der Berg et al. (Toxicol. Sci. 93: 223-241, 2006). Concentrations and WHO-TEQ2005 values were then searched for plausible relationships with selected demographic and diet-related factors. The total WHO-TEQ2005 toxicity equivalent for all 29 substances was (mean ± SD) 10.57 ± 4.57 pg/g fat, while the WHO-TEQ2005 levels of PCDDs/PCDFs and dl-PCBs were 7.90 ± 4.17 pg/g fat and 2.67 ± 1.36 pg/g fat, respectively. The concentration and WHO-TEQ2005 toxicity equivalent of dl-PCBs correlated significantly with the mothers' age (rP = 0.3814, p < 0.00005; rP = 0.2817, p < 0.005, respectively). The total WHO-TEQ2005 toxicity equivalent for all analyzed substances was found to be positively associated with the frequency of consumption of fish and dairy products (p < 0.05 for both associations). These outcomes must, however, be interpreted cautiously due to limited size of the study. The results of this paper may provide a basis for further studies on the exposure to PCDDs, PCDFs, and dl-PCBs, and mechanisms underlying their action.

Effects of a Constant Magnetic Field on the Electrochemical Reactions of Quercetin.

The paper presents a study of the effect of a constant magnetic field (CMF) on the basic processes of quercetin electrochemical reactions. According to the observation made in previous studies, the presence of a double bond in the C-ring of quercetin enhances the antioxidant properties of that compound, whereas the presence of -OH groups also affects the antioxidant properties. Using cyclic voltammetry it was found that the constant magnetic field improves the efficiency of quercetin electrooxidation, especially of the third stage of the process, i. e. the stage in which the oxidation of the OH groups in the A-ring is the most difficult. The use of HPLC confirmed the electrochemical measurements and the results of cyclic voltammetry studies. The beneficial effect of the magnetic field on the efficiency of quercetin oxidation was confirmed by the results of impedance spectroscopy measurements.

Toxic effects of single animal hormones and their mixtures on the growth of Chlorella vulgaris and Scenedesmus armatus.

In their environments, aquatic organisms are simultaneously exposed to mixtures of several endocrine disrupting compounds, including hormones. However, most of the toxicity studies so far focused on effects of single contaminants. The available information on the potential toxicity of combined hormones on microalgae is extremely limited. For these reasons the aim of this study was to evaluate the individual and mixture effect of estrone (E1), ß-estradiol (E2), estriol (E3), 17-α-ethinylestradiol (EE2), progesterone (PRO), 5-pregnen-3ß-ol-20-one (PRE), levonorgestrel (LG) and testosterone (TST) on Chlorella vulgaris and Scenedesmus armatus. Green algae cells were exposed to different concentrations (0.1-100 mg L-1) of hormones for 14 days. Biomass in the form of dry weight and chlorophyll a was examined. The decreasing order of toxicity (based on EC50, 14d) to Chlorella vulgaris and Scenedesmus armatus was: EE2>PRO > E2>PRE > TST > E3>LG > E1 and EE2>PRO > TST > E2>PRE > LG > E1>E3, respectively. Chlorella vulgaris was more sensitive to the effects of hormones than Scenedesmus armatus. Although mixed hormones were more toxic to green algae than single hormones, in the ecosystem mixtures can pose higher ecological risk than single pollutants. Therefore, data on the toxicology of both single and mixed hormones is very valuable for assessment of the possibility of adverse ecological effects caused by these pollutants. Furthermore, these results suggest that environmental exposure to hormone mixtures may cause toxicity levels different to the sum of those of the single hormones and provides a basic understanding of their toxic effect on algae.

Cardiac resynchronization in Poland - comparable procedural routines? Insights from CRT Survey II.

INTRODUCTION: CRT Survey II was initiated by the European Heart Rhythm Association and the Heart Failure Association, to explore everyday implantation practice of cardiac resynchronization therapy (CRT) devices in a broad spectrum of hospitals in European Society of Cardiology (ESC) member countries. AIM: To compare Polish and European procedural practice. MATERIAL AND METHODS: Procedural details of Polish patients collected in 37 Polish centres (n = 1241 - Poland group) were compared to the patients enrolled throughout Europe (n = 9847 - CRT II Survey group). RESULTS: There were significant differences in: successful implantation (96.1% vs. 97.4%), type of device implanted (for CRT-D: 87% vs. 67.6%), implanting physician subspecialty (for electrophysiologist: 69.2% vs. 79.8%), type of location of procedure (for operating room: 19.4% vs. 8.9%), duration of procedure (117.8 ±44 vs. 97.5 ±46.1 min), left ventricle lead type (for multipolar lead: 50% vs. 57.9%), coronary sinus venogram with occlusion rate (41.4% vs. 47.9%) and peri-procedural complication rate (7.5% vs. 5.3%) between Poland and CRT II Survey groups, respectively. CONCLUSIONS: This study provides important information describing current differences in Polish procedural routines in relation to ESC member countries. Heterogeneous CRT implantation practices across European countries still exist. However, it may be related to different clinical profile of patients qualified for CRT implantation in Poland as well as organization of care.

Graphene oxide activation with a constant magnetic field.

The effect of constant magnetic field strength on activation of sensors modified with graphene oxide monolayers was investigated. The use of constant magnetic field resulted in improved electroanalytical properties of the sensors. It was proven that level of GO activation is clearly related to constant magnetic field strength. Moreover, it was demonstrated that observed phenomenon is stable in time.

The effect of sewage sludge application on soil properties and willow (Salix sp.) cultivation.

The aim of the study was to determine the impact of sewage sludge from three wastewater treatment plants of different sizes (small, medium and large) applied in two doses (3 and 9 tons per hectare) on soil properties, determined as the content of organic carbon and humus fractions, bacterial abundance, phytotoxicity and PCDD/PCDF TEQ concentrations. The study also evaluated the impact of this sewage sludge on the biometric and physiological parameters and detoxification reaction of willow (Salix sp.) as a typical crop used for the remediation of soil following sludge application. The cultivation of willow on soil treated with sludge was found to result in a gradual increase of humus fractions, total organic carbon content and bacterial abundance as well as soil properties measured using Lepidium sativum. However, it also produced an initial increase of soil phytotoxicity, indicated by Sinapis alba and Sorghum sacharatum, and PCDD/PCDF Toxic Equivalent (TEQ) concentrations, which then fell during the course of the experiment, particularly in areas planted by willow. Although the soil phytotoxicity and PCDD/PCDF TEQ content of the sewage sludge-amended soil initially increased, sludge application was found to have a positive influence on willow, probably due to its high nutrient and carbon content. The obtained results reveal increases in willow biomass, average leaf surface area and leaf length as well as chlorophyll a+b content. Moreover, a strong decline was found in the activity of the detoxifying enzyme glutathione S-transferase (GSTs), a multifunctional enzyme involved in the metabolism of xenobiotics in plants, again demonstrating the used sludge had a positive influence on willow performance.

The influence of the Cucurbitaceae on mitigating the phytotoxicity and PCDD/PCDF content of soil amended with sewage sludge.

The study evaluates the impact of sewage sludge on OECD - Organization for Economic Cooperation and Development and vegetable soil phytotoxicity, measured using three test species: Lepidium sativum, Sinapis alba and Sorghum saccharatum, and total and TEQ PCDD/PCDF (toxic equivalency polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans) soil concentration, measured using HRGC/HRMS - High Resolution Gas Chromatography/High Resolution Mass Spectrometry. It also evaluates the effect of zucchini and cucumber cultivation during 5-weeks period on mitigating these parameters. The application of 3, 9 and 18 t/ha of sewage sludge gradually increases the phytotoxicity of both OECD and vegetable soil. In the case of OECD soil, the highest roots growth inhibitions were observed for S. alba (73%, 86% and 87%, respectively) and the lowest for S. saccharatum (7%, 59% and 70%), while in vegetable soil inhibitions were averagely 25% lower. Sludge application also led to a 38% (3 t/ha), 169% (9 t/ha) and 506% (18 t/ha) increase in PCDD/PCDF concentration, and the TEQs were augmented by 15%, 159% and 251%. Both soil phytotoxicity and total and TEQ PCDD/PCDF concentrations were diminished as a result of zucchini and cucumber cultivation. The maximum reduction of soil phytotoxicity (83%) was observed as an effect of cucumber cultivation, while zucchini was 11% less effective. Zucchini, in turn, was more efficient in PCDD/PCDF removal (37% reduction), followed by cucumber (24%). Such differences were not observed in the case of TEQ reductions (68% and 66% for zucchini and cucumber cultivation, respectively).

Potential for Phytoremediation of PCDD/PCDF-Contaminated Sludge and Sediments Using Cucurbitaceae Plants: A Pilot Study.

The current study evaluates the impact of sewage sludge and urban reservoir sediment on changes in total and Toxic Equivalency (TEQ) PCDD/PCDF concentration in soil and phytotoxicity measured using three test species: Lepidium sativum, Sinapis alba, and Sorghum saccharatum, during 5 weeks of Cucurbita pepo L. cv 'Atena Polka' (zucchini) cultivation. 'Atena Polka' was found to reduce total PCDD/PCDF concentration by 37 % in soil amended with sludge and 32 % in soil treated with sediment from an urban reservoir. The TEQ reduction was almost twofold greater: 68 % in soil amended with sludge and 52 % with urban sediment. Addition of sludge increased root growth inhibition of L. sativum, S. alba and S. saccharatum, from 44 % to 90 %. Observed inhibitions were, however, reduced by 'Atena Polka' cultivation, and as high as 32 % promotion in root length was noted. Amendment with urban sediment, in turn, resulted in an initial 1 %-36 % promotion of root growth, while 'Atena Polka' cultivation reduced this positive effect by inhibition as high as 26 %. Results demonstrated positive influence of 'Atena Polka' on the phytotoxicity alleviation and mitigation of total and TEQ PCDD/PCDF concentrations in soil treated with bio-solids from sewage sludge and an urban reservoir.

Isoprostanes - A novel major group of oxidative stress markers.

Isoprostanes are a recently discovered group of prostaglandin isomers. Results of previous studies suggest that they can be used as oxidative stress markers, because in a number of cardiovascular, pulmonary and neurological diseases their levels in biological samples considerably increase. It has been found that people suffering from diabetes, obesity, homozygous familial hypercholesterolemia, moderate hypercholesterolemia, and smokers have higher levels of isoprostanes in urine. The same refers to patients with asthma, Alzheimer disease and Down syndrome. This paper reviews the results of relevant studies.

The Role of Hydrology in the Polychlorinated Dibenzo--dioxin and Dibenzofuran Distributions in a Lowland River.

Persistent organic pollutants such as polychlorinated dibenzo--dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are environmental contaminants that have widespread distribution and pose a serious threat to aquatic ecosystems. We conducted a study to quantify the distribution, patterns, and transport of PCDDs and PCDFs along the Pilica River in central Poland under different hydrological conditions to estimate the loads of these compounds and understand their fate in aquatic systems. Water samples were collected at five sampling points along the river that represent a range of hydrological conditions including flooding and stable and low water flows. Reduced river water flow was associated with lower average total and toxic equivalent (TEQ) concentrations of PCDDs plus PCDFs: 33.6 pg L and 4.21 pg TEQ L for flooding; 28.3 pg L and 3.6 pg TEQ L for stable flow; 18.4 pg L and 1.0 pg TEQ L for low-water flow. Similar results were observed for daily loadings of total and TEQ concentrations: the highest values were observed during flooding (331.1-839.4 mg d and 27.8-110.7 mg TEQ d), medium under stable hydrological conditions (55.8-121.0 mg d and 7.7-15.3 mg TEQ d), and the lowest values during low water flow (30.9 and 40.3 mg d and 1.4-2.4 mg TEQ d). The results demonstrate that diffuse sources of pollution play a key role during periods of high water flow (i.e., flooding season), whereas point sources of pollution, including municipal and industrial wastewater treatment plant discharges, mainly determine the PCDD and PCDF concentrations seen during low water periods.

Today's oxidative stress markers.

Oxidative stress represents a situation where there is an imbalance between the reactive oxygen species (ROS) and the availability and the activity of antioxidants. This balance is disturbed by increased generation of free radicals or decreased antioxidant activity. It is very important to develop methods and find appropriate biomarkers that may be used to assess oxidative stress in vivo. It is significant because appropriate measurement of such stress is necessary in identifying its role in lifestyle-related diseases. Previously used markers of oxidative stress, such as thiobarbituric acid reactive substances (TBARS) or malondialdehyde (MDA), are progressively being supplemented by new ones, such as isoprostanes (IsoPs) and their metabolites or allantoin. This paper is focusing on the presentation of new ones, promising markers of oxidative stress (IsoPs, their metabolites and allantoin), taking into account the advantage of those markers over markers used previously.

The use of PowerPrep and HRGC/HRMS for biological monitoring of exposure to PCDD, PCDF and dl-PCB in Poland.

PURPOSE: The aim of this study was to design the optimized laboratory protocol as a tool for human biomonitoring of selected Persistent Organic Pollutants (POPs) in Poland. In this study, we present the method developed for the determination of 29 congeners of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs), as well as individual results of the measurements in 40 human breast milk samples collected in central Poland in 2008-2010. METHODS: The protocol of sample preparation and quantitative analysis of PCDD/Fs and dl-PCBs was optimized for the isotopic dilution method with high resolution gas chromatography/high resolution mass spectrometry HRGC/HRMS. Fat content in the extracts was determined gravimetrically. The results were corrected by fat content in the samples. RESULTS: The average sum of PCDD/F and dl-PCBs in the human milk samples from the urban area was 7.429 WHO-TEQpg/g fat (with the range 0.431-14.27), and in the rural area it was 6.448pg WHO-TEQ/g fat (0.539-12.61). CONCLUSIONS: The results obtained in this study indicate that the mothers were exposed uniformly to PCDD/Fs and PCBs regardless of location. The significant difference of p<0.1 between the milk samples from the urban and rural mothers in 2,3,7,8-TCDD; 1,2,37,8,9-HxCDD and 2,3,4,6,7-HxCDF were observed. For the other 14 PCDD/F and 12 dl-PCB congeners, the observed differences were not significant. The total WHO-TEQ values are lower in comparison with the average results in Europe from the fourth round of a WHO-coordinated study.

Levels and sources of PCDDs, PCDFs and dl-PCBs in the water ecosystems of central Poland - a mini review.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are unwanted by-products in a variety of industrial and thermal processes. They have been present on Earth long before the human era, since they may be also formed as a result of forest fires or volcanic explosions. Polychlorinated biphenyls (PCBs) in turn, have been intentionally produced by humans. Poland was a minor producer of PCB mixtures (Chlorofen and Tarnol), which were a source of direct and indirect environmental diffusion with PCB and less with PCDDs/PCDFs. Industrial accidents with PCDDs/PCDFs were absent in Poland. Their stability and resistance to thermal breakdown made them very dangerous for environment and, in consequence, due to their environmental persistence, bioaccumulation and biomagnification in the terrestrial and aquatic food chains, to humans. Humans may become affected by PCDDs/PCDFs and PCBs through environmental (soil and water contamination, fish and food), occupational (incinerators; pulp, paper and metallurgy industry; copper production), or accidental (Seveso accident) exposure. The aim of this review was to evaluate environmental hazard caused by PCDDs, PCDFs and dioxin-like-PCBs in the central region of Poland based on the accessible data on diffusion of those compounds in sediments and riverine, reservoir and storm water from our previous studies and discussed in the context of other achievements in Poland and elsewhere.

Effects of polybrominated diphenyl ethers on thyroid hormone, neurodevelopment and fertility in rodents and humans.

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants. Due to their widespread use in many consumer products, PBDEs can be found in food as well as in the environment. Their presence has also been found in the human serum, human adipose tissue and human breast milk. Results of experimental studies suggest that the presence of PBDE in the environment is not neutral to our health. In rats and mice exposed to PBDE disturbances in thyroid hormone homeostasis and reproductive system such as changes in reproductive organs weight and disorders in sperm motility and motion were found. In rodents, pre- and postnatal exposure to PBDE can cause neurobehavioral effects. Also in humans disturbances in thyroid hormone system, weight of reproductive organs and concentrations of sex hormones associated with PBDEs serum concentrations were found. Exposure to PBDEs during pregnancy may lead to slower mental and psychomotor development in infants. In this paper the results of previous animal and human studies are reviewed.

[Polybrominated diphenyl ethers: sources of exposure and expected health effects]. / Polibromowane etery difenylowe--zródla narazenia i potencjalne skutki zdrowotne.

Polybrominated diphenyl ethers (PBDE) along with hexabromocyclododecan, tetrabromobisphenol A and polybrominated biphenyls have been widely used for several decades as flame retardants. They have been added to consumer products, such as car and furniture upholstery, TV sets and computers. PBDE are not chemically bound to the polymers therefore, they can leach into the environment. They have been found in household dust, food, human breast milk, human adipose tissue and human serum. In this paper the potential major sources of emission of PBDEs, human biomonitoring data and results of experimental studies are reviewed. The available data shows that this group of compounds requires a particular concern because of their possibly adverse effects on human health and the environment.