Persistence of norfluoxetine in marine mussels.

The concentration of pharmaceuticals in coastal waters is tending towards increasing due to a shift of the human population into coastal zones. In parallel, the number of prescriptions of antidepressants, mainly selective serotonin reuptake inhibitors (SSRI), is constantly growing. Most of the SSRI is metabolised into active compounds; for instance, norfluoxetine (NFLU) is the main active metabolite of fluoxetine. In this study, we tested the bioaccumulation and depuration of NFLU in Mytilus trossulus at two environmentally relevant concentrations (100 and 500 ng/L, after six days of exposure and five days of depuration at 10 °C). The concentration of NFLU in the mussels' tissue seems not to be directly proportional to the exposure concentration. The levels of NFLU in the mussels' tissues after the depuration period were comparable to the levels detected at the end of exposure. This indicates that NFLU is not efficiently removed by the mussels and points to a potential risk for consumers of such marine organisms.

Perceived multiple stressor effects depend on sample size and stressor gradient length.

Multiple stressors are continuously deteriorating surface waters worldwide, posing many challenges for their conservation and restoration. Combined effect types of multiple stressors range from single-stressor dominance to complex interactions. Identifying prevalent combined effect types is critical for environmental management, as it helps to prioritise key stressors for mitigation. However, it remains unclear whether observed single and combined stressor effects reflect true ecological processes unbiased by sample size and length of stressor gradients. Therefore, we examined the role of sample size and stressor gradient lengths in 158 paired-stressor response cases with over 120,000 samples from rivers, lakes, transitional and marine ecosystems around the world. For each case, we split the overall stressor gradient into two partial gradients (lower and upper) and investigated associated changes in single and combined stressor effects. Sample size influenced the identified combined effect types, and stressor interactions were less likely for cases with fewer samples. After splitting gradients, 40 % of cases showed a change in combined effect type, 30 % no change, and 31 % showed a loss in stressor effects. These findings suggest that identified combined effect types may often be statistical artefacts rather than representing ecological processes. In 58 % of cases, we observed changes in stressor effect directions after the gradient split, suggesting unimodal stressor effects. In general, such non-linear responses were more pronounced for organisms at higher trophic levels. We conclude that observed multiple stressor effects are not solely determined by ecological processes, but also strongly depend on sampling design. Observed effects are likely to change when sample size and/or gradient length are modified. Our study highlights the need for improved monitoring programmes with sufficient sample size and stressor gradient coverage. Our findings emphasize the importance of adaptive management, as stress reduction measures or further ecosystem degradation may change multiple stressor-effect relationships, which will then require associated changes in management strategies.

Cellular level response of the bivalve Limecola balthica to seawater acidification due to potential CO2 leakage from a sub-seabed storage site in the southern Baltic Sea: TiTank experiment at representative hydrostatic pressure.

Understanding of biological responses of marine fauna to seawater acidification due to potential CO2 leakage from sub-seabed storage sites has improved recently, providing support to CCS environmental risk assessment. Physiological responses of benthic organisms to ambient hypercapnia have been previously investigated but rarely at the cellular level, particularly in areas of less common geochemical and ecological conditions such as brackish water and/or reduced oxygen levels. In this study, CO2-related responses of oxygen-dependent, antioxidant and detoxification systems as well as markers of neurotoxicity and acid-base balance in the Baltic clam Limecola balthica from the Baltic Sea were quantified in 50-day experiments. Experimental conditions included CO2 addition producing pH levels of 7.7, 7.0 and 6.3, respectively and hydrostatic pressure 900 kPa, simulating realistic seawater acidities following a CO2 seepage accident at the potential CO2-storage site in the Baltic. Reduced pH interfered with most biomarkers studied, and modifications to lactate dehydrogenase and malate dehydrogenase indicate that aerobiosis was a dominant energy production pathway. Hypercapnic stress was most evident in bivalves exposed to moderately acidic seawater environment (pH 7.0), showing a decrease of glutathione peroxidase activity, activation of catalase and suppression of glutathione S-transferase activity likely in response to enhanced free radical production. The clams subjected to pH 7.0 also demonstrated acetylcholinesterase activation that might be linked to prolonged impact of contaminants released from sediment. The most acidified conditions (pH 6.3) stimulated glutathione and malondialdehyde concentration in the bivalve tissue suggesting potential cell damage. Temporal variations of most biomarkers imply that after a 10-to-15-day initial phase of an acute disturbance, the metabolic and antioxidant defence systems recovered their capacities.

Bioaccumulation of phenolic endocrine disruptors in the clam Rangia cuneata: Storage in shells and influence of size and sex.

This study aimed to investigate the sequestration of phenolic endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 4-nonylphenol (4-NP) in the shells of the mature clam Rangia cuneata from the Vistula Lagoon (southern Baltic Sea) and to determine the influence of sex and shell length on bioaccumulation of these contaminants. Even though there is broad interest in EDCs influences on aquatic organisms, these basic parameters are poorly understood, yet necessary for assessing environmental risks for clams. Average proportions of the total body burden (ng/individual) deposited in shells of R. cuneata were more than 70% for BPA and 4-NP and up to 32% for 4-t-OP. These results indicate that shell storage can be an important route for elimination of specific EDCs. Relationships between EDCs concentrations and the size and sex of R. cuneata indicate that females and large individuals experience greater exposures to the adverse effects of these pollutants than males and smaller clams. This effect could have significant impacts on population ecology and ultimately affect the entire ecosystem, in which bivalves play an important role. In the context of using clams to assess water pollution, the co-variation of EDCs concentrations with the size and sex of bivalves could influence the quality of monitoring data, unless accounted for in sampling design and data analysis.

Impact of environmental hypercapnia on fertilization success rate and the early embryonic development of the clam Limecola balthica (Bivalvia, Tellinidae) from the southern Baltic Sea - A potential CO2 leakage case study.

Carbon capture and storage technology was developed as a tool to mitigate the increased emissions of carbon dioxide by capture, transportation, injection and storage of CO2 into subterranean reservoirs. There is, however, a risk of future CO2 leakage from sub-seabed storage sites to the sea-floor sediments and overlying water, causing a pH decrease. The aim of this study was to assess effects of CO2-induced seawater acidification on fertilization success and early embryonic development of the sediment-burrowing bivalve Limecola balthica L. from the Baltic Sea. Laboratory experiments using a CO2 enrichment system involved three different pH variants (pH 7.7 as control, pH 7.0 and pH 6.3, both representing environmental hypercapnia). The results showed significant fertilization success reduction under pH 7.0 and 6.3 and development delays at 4 and 9 h post gamete encounter. Several morphological aberrations (cell breakage, cytoplasm leakages, blastomere deformations) in the early embryos at different cleavage stages were observed.

The effects of low seawater pH on energy storage and heat shock protein 70 expression in a bivalve Limecola balthica.

Though biological consequences of CCS (Carbon Capture and Storage) implementation into the marine environment have received substantial research attention, the impact of potential CO2 leakage on benthic infauna in the Baltic Sea remained poorly recognized. This study quantified medium-term (56-day laboratory exposure) effects of CO2-induced seawater acidification (pH 7.7, 7.0 and 6.3) on energetic reserves and heat-shock protein HSP70 expression of adult bivalve Limecola balthica from the southern Baltic. While no clear impact was evident in the most acidic treatment (pH 6.3), moderate seawater hypercapnia (pH 7.0) induced elevated catabolism of high caloric reserves (carbohydrates including glycogen and lipids) in order to provide energy to cover enhanced metabolic requirements for acid-base regulation. Biochemical response did not involve, however, breakdown of proteins, suggesting that they were not utilized as metabolic substrates. As indicated also by subtle variations in the chaperone protein HSP70, the clams demonstrated high CO2 tolerance, presumably through development of efficient defensive/compensatory mechanisms during their larval and/or ontogenic life stages.

Differing responses of the estuarine bivalve Limecola balthica to lowered water pH caused by potential CO2 leaks from a sub-seabed storage site in the Baltic Sea: An experimental study.

Sub-Seabed CCS is regarded as a key technology for the reduction of CO2 emissions, but little is known about the mechanisms through which leakages from storage sites impact benthic species. In this study, the biological responses of the infaunal bivalve Limecola balthica to CO2-induced seawater acidification (pH7.7, 7.0, and 6.3) were quantified in 56-day mesocosm experiments. Increased water acidity caused changes in behavioral and physiological traits, but even the most acidic conditions did not prove to be fatal. In response to hypercapnia, the bivalves approached the sediment surface and increased respiration rates. Lower seawater pH reduced shell weight and growth, while it simultaneously increased soft tissue weight; this places L. balthica in a somewhat unique position among marine invertebrates.

Factors determining accumulation of bisphenol A and alkylphenols at a low trophic level as exemplified by mussels Mytilus trossulus.

The aim of the study was to investigate abiotic and biotic factors influencing the accumulation of endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in mussels Mytilus trossulus from the Gulf of Gdansk (Southern Baltic). The key abiotic factor influencing BPA, OP and NP accumulation in mussels is their hydrophilicity/lipophilicity, which affects their main assimilation routes - by digestive tract for the more lipophilic OP and NP, and additionally by the gills for the less lipophilic BPA. As a result, high condition index (i.e. higher soft tissue weight) is more often correlated with high concentrations of OP and NP in mussels than with BPA. Furthermore, alkylphenols have 6-8 times greater accumulative potential than BPA. Concentration of the studied compounds was lower in females than in males following spawning, and the effect lasted longer for BPA than for alkylphenols. The influence of season and hydrological conditions on BPA, OP, NP in the mussel was more pronounced than the proximity of external sources of these compounds. An increase in water temperature in summer probably stimulated the solubility of BPA, the least lipophilic of the studied compounds, and led to increased assimilation of this compound from water (through gills). On the other hand, high OP and NP concentrations in mussels occurred in spring, which was caused by increased surface run-off and sediments resuspension.

In Search for the Best Environment for Single Molecule Studies: Photostability of Single Terrylenediimide Molecules in Various Polymer Matrices.

Photobleaching is the main limiting factor in single molecule studies by optical techniques. We investigated the dependence of photostability of terrylene diimide (TDI) derivative on its environment using confocal fluorescence microscopy. Seven different polymers were tested. Depending on the matrix, photobleaching quantum yields vary by 2 orders of magnitude. Their values correlate with parameters characterizing oxygen mobility in polymers: diffusion coefficient and permeability. Poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) exhibit the lowest photodestruction quantum yields. Additional enhancement of photostability can be achieved by aging of PVC or by flushing the sample with nitrogen, which confirms the involvement of oxygen in photodestruction. Different character of the time traces of the intensity of emission from single TDI molecules is observed for different polymer matrices, ranging from intense blinking in the least stable polycarbonate, to practically no blinking in the most stable PVC. These results suggest a photodegradation mechanism involving self-sensitized photooxidation in oxygen complexes of TDI.

Bisphenol A, 4-tert-octylphenol, and 4-nonylphenol in the Gulf of Gdansk (Southern Baltic).

The organic derivatives of phenol are classed as dangerous compounds, and their presence has been detected in surface water, bottom water, phytoplankton, zooplankton, and mussel as well as liver and muscle of fish from the Gulf of Gdansk and in liver, muscle, and guano of gulls residing in the coastal zone of this basin. The greatest sources of bisphenol A (BPA), 4-tert-octylphenol (OP), and 4-nonylphenol (NP) were found to be the Vistula River and the water purification plant in Debogórze. In living organisms, concentrations of BPA, OP, and NP ranged between the limit of quantification and several hundred ng g(-1) dry weight (dw), and the highest concentrations were found for BPA. Prolonged alimentary exposure to BPA, OP, and NP in fish and birds was indicated by liver/muscle concentration ratios generally >1. The most influential factors on BPA and alkylphenol concentrations in the tissues of fishes and gulls were mainly diet and habitat. The study confirmed possible bioaccumulation in the food web. High BPA and NP concentrations in guano (≤2,700 and ≤300 ng g(-1) dw, respectively) indicated the ability of birds to detoxify and signalled the reintroduction of these compounds to seawater. Herring, flounder, and cod from the Southern Baltic are a safe food source for human consumption because their BPA and alkylphenol contents are low.

[Functionality determinants of the integrated systems dedicated to health care institutions]. / Determinanty funkcjonalnosci zintegrowanych systemów dedykowanych podmiotom leczniczym.

The Authors of the hereby dissertation aimed at presenting the functionality concept of the integrated e-service platform dedicated to health care institutions. In the form of a problem repository the research results allowing the identification of the functionality determinants were presented. Finally, the study presents the system's structure as well as analyzing the needs for e-services in terms of society and their usefulness evaluated by branch experts.

Impact of the spinal cord position uncertainty on the dose received during head and neck helical tomotherapy.

INTRODUCTION: The study aims to establish the optimal planning risk volume (PRV) to the spinal cord (SC) for oropharyngeal cancer patients during adaptive radiation therapy with concurrent chemotherapy. METHODS: Geometrical uncertainties of the SC were evaluated. Differences between planned and delivered maximum doses to each part of the SC were established for every fraction dose and for cumulative dose. Maximum doses were evaluated as a dose received in 0.5 and 1 cm(3) of the analysed part of the SC defined as C1-C2, C3-C4, C5-C6 and C7-Th1 where Cn was a n-th cervical vertebra (n = 1, … , 7) and Th1 was the first thoracic vertebra. Finally, relations between dose differences and geometrical uncertainties were analysed using a relative risk (RR) and the importance of the PRV dose gradient to establish an optimal PRV for the SC. RESULTS: Prospective study based on the 875 observations from 25 oropharyngeal cancer patients was performed. The C1-C2 part of the SC is most exposed to risk of overdosage during chemoradiation for patients with oropharyngeal cancer due to its proximity to the clinical target volume (CTV). Doses received by other parts of the SC are smaller, with the lowest dose delivered to C7-Th1. For the C1-C2, delivered dose was higher than planned dose by 11%, while for the C7-Th1, this difference was smaller than 7%. The lowest movement of individual parts of the SC were detected for the C1-C2 and the highest for the C7-Th1. The standard deviations of the mean shift ranged respectively from 0.9 to 1.4 mm and from 1.3 to 2.9 mm. For each part of the SC delivered dose was smaller than planned dose to the PRV (RR < 1). CONCLUSION: Our study showed that for chemoradiation of oropharyngeal cancer, using daily image guidance and proper plan adaptation scheme, the current PRV margin for the SC could be reduced to 4 mm.

Use of fly ash agglomerates for removal of arsenic.

The aim of this work is to investigate the application of fly ash adsorbent for removal of arsenite ions from dilute solution (100-1,000 ppm). Experiments were carried out using material from the "Turów" (Poland) brown-coal-burning power plant, which was wetted, then mixed and tumbled in a granulator to form spherical agglomerates. Measurements of arsenic adsorption from aqueous solution were carried out at room temperature and natural pH of fly ash agglomerates, in either a shaken flask or circulating column, to compare two different methods of contacting solution with adsorbent. Adsorption isotherms of arsenic were determined for agglomerated material using the Freundlich equation. Kinetic studies indicated that sorption follows a pseudo-second-order model. Preferable method to carry out the process is continuous circulation of arsenite solution through a column.

Comparison of trace metal bioavailabilities in European coastal waters using mussels from Mytilus edulis complex as biomonitors.

Mussels from Mytilus edulis complex were used as biomonitors of the trace metals Fe, Mn, Pb, Zn, and Cu at 17 sampling sites to assess the relative bioavailability of metals in coastal waters around the European continent. Because accumulated metal concentrations in a given area can differ temporally, data were corrected for the effect of season before large-scale spatial comparisons were made. The highest concentration of Fe was noted in the North Sea and of Mn in the Baltic. Increased tissue concentrations of Pb were recorded in the mussels from the Bay of Biscay and the Baltic Sea. Low concentrations of metals were determined in the mussels from the Mediterranean Sea and the Northern Baltic. Relatively low geographic variations of Cu and Zn indicate that mussels are able to partially regulate accumulated body concentrations, which means Cu and Zn are, to some extent, independent of environmental concentrations.

Embedded silver ions-containing liposomes in polyelectrolyte multilayers: cargos films for antibacterial agents.

A new antibacterial coating made of poly(L-lysine)/hyaluronic acid (PLL/HA) multilayer films and liposome aggregates loaded with silver ions was designed. Liposomes filled with an AgNO 3 solution were first aggregated by the addition of PLL in solution. The obtained micrometer-sized aggregates were then deposited on a PLL/HA multilayer film, playing the role of a spacer with the support. Finally, HA/PLL/HA capping layers were deposited on top of the architecture to form a composite AgNO 3 coating. Release of encapsulated AgNO 3 from this composite coating was followed and triggered upon temperature increase over the transition temperature of vesicles, found to be equal to 34 degrees C. After determination of the minimal inhibitory concentration (MIC) of AgNO 3 in solution, the antibacterial activity of the AgNO 3 coating was investigated against Escherichia coli. A 4-log reduction in the number of viable E. coli cells was observed after contact for 120 min with a 120 ng/cm (2) AgNO 3 coating. In comparison, no bactericidal activity was found for PLL/HA films previously dipped in an AgNO 3 solution and for PLL/HA films with liposome aggregates containing no AgNO 3 solution. The strong bactericidal effect could be linked to the diffusion of silver ions out of the AgNO 3 coating, leading to an important bactericidal concentration close to the membrane of the bacteria. A simple method to prepare antibacterial coatings loaded with a high and controlled amount of AgNO 3 is therefore proposed. This procedure is far superior to that soaking AgNO 3 or Ag nanoparticles into a coating. In principle, other small bactericidal chemicals like antibiotics could be encapsulated by this method. This study opens a new route to modify surfaces with small solutes that are not permeating phospholipid membranes below the phase transition temperature.

Nanocarriers as pulmonary drug delivery systems to treat and to diagnose respiratory and non respiratory diseases.

The purpose of this review is to discuss the impact of nanocarriers administered by pulmonary route to treat and to diagnose respiratory and non respiratory diseases. Indeed, during the past 10 years, the removal of chlorofluorocarbon propellants from industrial and household products intended for the pulmonary route has lead to the developments of new alternative products. Amongst these ones, on one hand, a lot of attention has been focused to improve the bioavailability of marketed drugs intended for respiratory diseases and to develop new concepts for pulmonary administration of drugs and, on the other hand, to use the pulmonary route to administer drugs for systemic diseases. This has led to some marketed products through the last decade. Although the introduction of nanotechnology permitted to step over numerous problems and to improve the bioavailability of drugs, there are, however, unresolved delivery problems to be still addressed. These scientific and industrial innovations and challenges are discussed along this review together with an analysis of the current situation concerning the industrial developments.

Shell deformations in the Baltic clam Macoma balthica from southern Baltic Sea (the Gulf of Gdansk): hypotheses on environmental effects.

High-resolution digital photography and graphical image analyses systems have been used to define external morphometric characters of shell deformations in four populations of the Baltic clam Macoma balthica from the Gulf of Gdansk (southern Baltic Sea). The proposed shell deformation indices (SDI), which were based on the relationship of selected dimensions in the posterior and the anterior part of the shell, showed at least three morphological features that provide a distinctive diagnosis of "regular" and "deformed" clams: the presence of flexure on the posterior side (SDI1), elongated posterior region (SDI2), and shell growth (SDI3). The degree and prevalence of deformed clams varied locally over space. Increase in percentage contribution of aberrated shells with depth, corresponding to oxygen depletion profile in the Gulf, suggests low oxygen concentrations as the main agent exerting a deforming influence. The observed morphological aberrations developed with age (size) of a bivalve, suggesting a long-term effect of causal factors, and were accompanied by lightening shell weight, possibly due to decalcification of previously deposited calcareous material during anaerobic metabolism. It is hypothesized that hypoxic/anoxic conditions and a subsequent presence of hydrogen sulfide on a deep organic-rich sea bottom induce shell form alterations that enable the pumping of oxygenated water from above the anoxic layer. Such a morphological modification highlights the functional significance of shell deformations in protective response to the ambient low-oxygen concentrations. Sediment organotin concentrations fall within moderate to high contamination range and, therefore, may also have an adverse impact on the shell form. DNA analyses of the fragment of mitochondrial gene cytochrome oxidase I (COI, 393 base pairs) showed homogenous genetic structure of regular and deformed clams, indicating that shell deformations in M. balthica are primarily driven by acclimatization to the ambient environmental conditions.

Direct determination of metformin in urine by adsorptive catalytic square-wave voltammetry.

A new adsorptive catalytic voltammetric method for voltammetric determination of metformin based on the catalytic hydrogen evolution reaction at a hanging mercury drop electrode was developed. The electrode reaction was analyzed under conditions of linear sweep voltammetry (LSV), differential pulse voltammetry (DPV) and Osteryoung-type square-wave voltammetry (SWV). The peak current depends on pH of the medium, concentration and chemical composition of the buffer solution, and instrumental parameters. The optimal conditions for quantitative determination were obtained in an acetate buffer at pH 4.7. The voltammetric procedure was characterized with respect to the repeatability, precision and the recovery. The detection and quantification limits were found to be 1.8 x 10(-8) and 5.9 x 10(-8) mol l(-1) for SWV, 3.2 x 10(-8) and 1.0 x 10(-7) mol l(-1) for DPV, and 7.7 x 10(-8) and 2.5 x 10(-7) mol l(-1) for LSV, respectively. The SW voltammetric method, as the most sensitive one, was applied for determination of metformin in human urine. The voltammetric method has been validated by using HPLC with UV detection.

Geographic and seasonal patterns and limits on the adaptive response to temperature of European Mytilus spp. and Macoma balthica populations.

Seasonal variations in seawater temperature require extensive metabolic acclimatization in cold-blooded organisms inhabiting the coastal waters of Europe. Given the energetic costs of acclimatization, differences in adaptive capacity to climatic conditions are to be expected among distinct populations of species that are distributed over a wide geographic range. We studied seasonal variations in the metabolic adjustments of two very common bivalve taxa at European scale. To this end we sampled 16 populations of Mytilus spp. and 10 Macoma balthica populations distributed from 39 degrees to 69 degrees N. The results from this large-scale comprehensive comparison demonstrated seasonal cycles in metabolic rates which were maximized during winter and springtime, and often reduced in the summer and autumn. Studying the sensitivity of metabolic rates to thermal variations, we found that a broad range of Q (10) values occurred under relatively cold conditions. As habitat temperatures increased the range of Q (10) narrowed, reaching a bottleneck in southern marginal populations during summer. For Mytilus spp., genetic-group-specific clines and limits on Q (10) values were observed at temperatures corresponding to the maximum climatic conditions these geographic populations presently experience. Such specific limitations indicate differential thermal adaptation among these divergent groups. They may explain currently observed migrations in mussel distributions and invasions. Our results provide a practical framework for the thermal ecophysiology of bivalves, the assessment of environmental changes due to climate change and its impact on (and consequences for) aquaculture.

Metal sources to the Baltic clam Macoma balthica (Mollusca: Bivalvia) in the southern Baltic Sea (the Gulf of Gdansk).

Metal concentrations of Cu, Fe, Mn, Ni, Pb and Zn in an infaunal facultative deposit-feeding bivalve, the Baltic clam Macoma balthica, in the Gulf of Gdansk (southern Baltic Sea) were assessed and compared to selected concentrations of metals in the environment. Between October 1996 and September 1997, dissolved and easy extractable (by 1M HCl) metal fractions of total suspended particulate matter (TPM) in the overlying water and of surficial sediments (<63 microm) were measured monthly at five sublittoral sites in the Gulf of Gdansk, and accumulated tissue metal concentrations in M. balthica were determined simultaneously. The study highlights the importance of sediment geochemistry as a factor modifying ambient trace metal bioavailabilities. Surficial sediments appeared to contribute most to the accumulation of Cu and Pb in M. balthica, reflecting the high metal availability in the Gulf. Assimilation of Cu from sediments is controlled by Mn components possibly through an inhibitory effect of Mn oxyhydroxides, while Pb accumulation from sediments depends on the organic content of the sediment. A dual metal uptake pathway, with a suspended particulate-bound fraction and surficial sediments, was apparent for Mn and Zn. Partitioning of Mn in sediments was related to the concentration of labile Fe, with increased levels of Fe tending to inhibit the accumulation of Mn by the clam. Tissue accumulated Zn might have been altered by the clam's internal regulation, making Zn tissue concentrations, to some degree, independent of its environmental level. The principal source of Ni accumulated by the clams exists in the soluble phase.