Assessing marine litter in a highly polluted area in the Mediterranean: A multi-perspective approach in the Saronikos Gulf, Greece.

Marine litter poses a significant environmental challenge in the Saronikos Gulf, Greece. Employing an integrated approach, data from both beach and underwater sites were analyzed. The average litter density on beaches was 2.61 items m-2, with plastic being the most common material, notably small polystyrene fragments and cigarette butts. The western part of the Gulf exhibited higher litter density, mainly due to surface circulation patterns. Most beaches fell short of meeting Good Environmental Status criteria for marine litter. Higher litter densities were observed in autumn. Benthic litter density decreased with depth, being 23 times higher in shallower waters, with plastic being the predominant type. This extensive study offers crucial insights into the pollution status and litter distribution in the Saronikos Gulf, contributing significantly to the global understanding of marine litter distribution on coastal ecosystems. Such information is crucial for raising awareness, informing policy decisions, and driving environmental actions.

Microplastics formation based on degradation characteristics of beached plastic bags.

Environmental pollution from plastic bags is a significant issue in the global environment. Plastic bags can be transferred by the wind and ocean currents everywhere in the three dimensions and be fragmented into small particles, termed film-shaped microplastics. The purpose of this study is to provide insights on the degradation of beached plastic bags. Monitoring and sampling were performed to determine plastic bag fragmentation and the possible mechanisms. On selected samples, various spectroscopic techniques and microscopy were used. Before the imposition of the "green" plastic bag fee in Greece, field monitoring suggested that the majority of the coastal plastic bags were fragmented whereas after the "green" fee, less fragmented bags were observed. Evidence of three degradation mechanisms were observed in this study. For oxodegradable plastic bags, degradation takes place for the starch additives and the polymer part stays in the environment as microplastic particles. For thin light density polyethylene plastic bags, mechanical fragmentation takes place in the environment creating microplastics before significant chemical alterations in functional groups were observed and once chemical alteration (oxidation) is observed, fragmentation (of HC or CC bonds) is also taking place. Thus, regulating thin plastic bags usage removes problems related to plastic bags but also to film-shaped microplastics.

Modeling of floating marine litter originated from the Eastern Ionian Sea: Transport, residence time and connectivity.

A Lagrangian particle tracking model coupled to a circulation was used to explore the transport, residence time and connectivity of floating litter that originated from the Εastern Ionian Sea during 2011-2014. At the end of simulations, on average 26% of litter was retained within the coastal waters of the Eastern Ionian Sea, whereas 58% was washed into offshore waters without formulating permanent accumulation areas, as the basin-wide surface circulation was characterized by considerable interannual variability. The inflow of litter into the Adriatic and Eastern Mediterranean Seas was moderate, ranging between 9% and 20%, and the beached litter was on average 9.2%, mostly located in the northern subregions. The average residence time of litter particles ranged between 20 and 80 days, implying their temporary retention before drifting offshore. Connectivity patterns depicted an exchange of litter mainly between adjacent subareas and with a northward direction.

Clinical, functional and inflammatory characteristics in patients with paucigranulocytic stable asthma: Comparison with different sputum phenotypes.

BACKGROUND: According to induced sputum cell count, four different asthma phenotypes have been recognized (eosinophilic, neutrophilic, mixed and paucigranulocytic). The aim of this study was to detect functional and inflammatory characteristics of patients with paucigranulocytic asthma. METHODS: A total of 240 asthmatic patients were categorized into the four phenotypes according to cell counts in induced sputum. All patients underwent pulmonary function tests, and measurement of fraction of exhaled nitric oxide (FeNO). The levels of IL-8, IL-13 and eosinophilic cationic protein (ECP) were also measured in sputum supernatant. Treatment, asthma control and the presence of severe refractory asthma (SRA) were also recorded. RESULTS: Patients were categorized into the four phenotypes as follows: eosinophilic (40%), mixed (6.7%), neutrophilic (5.4%) and paucigranulocytic (47.9%). Although asthma control test did not differ between groups (P=.288), patients with paucigranulocytic asthma had better lung function (FEV1 % pred) [median (IQR): 71.5 (59.0-88.75) vs 69.0 (59.0-77.6) vs 68.0 (60.0-85.5) vs 80.5 (69.7-95.0), P=.009] for eosinophilic, mixed, neutrophilic and paucigranulocytic asthma, respectively, P=.009). SRA occurred more frequently in the eosinophilic and mixed phenotype (41.6% and 43.7%, respectively) and less frequently in the neutrophilic and paucigranulocytic phenotype (25% and 21.7%, respectively, P=.01). FeNO, ECP and IL-8 were all low in the paucigranulocytic, whereas as expected FeNO and ECP were higher in eosinophilic and mixed asthma, while IL-8 was higher in patients with neutrophilic and mixed asthma (P<.001 for all comparisons). Interestingly, 14.8% of patients with paucigranulocytic asthma had poor asthma control. CONCLUSION: Paucigranulocytic asthma most likely represents a "benign" asthma phenotype, related to a good response to treatment, rather than a "true" phenotype of asthma. However, paucigranulocytic patients that remain not well controlled despite optimal treatment represent an asthmatic population that requires further study for potential novel targeted interventions.

The degradation potential of PET bottles in the marine environment: An ATR-FTIR based approach.

The dominance and persistence of plastic debris in the marine environment are well documented. No information exists in respect to their lifespan in the marine environment. Nevertheless, the degradation potential of plastic litter items remains a critical issue for marine litter research. In the present study, polyethylene terephthalate bottles (PETs) collected from the submarine environment were characterized using ATR-FTIR in respect to their degradation potential attributed to environmental conditions. A temporal indication was used as indicative to the years of presence of the PETs in the environment as debris. PETs seem to remain robust for approximately fifteen years. Afterwards, a significant decrease of the native functional groups was recorded; some even disappear; or new-not typical for PETs-are created. At a later stage, using the PET time series collected from the Saronikos Gulf (Aegean Sea-E. Mediterranean), it was possible to date bottles that were collected from the bottom of the Ionian Sea (W. Greece). It is the first time that such a study has been conducted with samples that were actually degraded in the marine environment.

Use of ROV for assessing marine litter on the seafloor of Saronikos Gulf (Greece): a way to fill data gaps and deliver environmental education.

A visual census of marine litter on the seafloor of the Saronikos Gulf (Greece) is presented in the current work. The abundance and qualitative composition of benthic marine litter were investigated in two selected locations of the Saronikos Gulf with a Remote Operated Vehicle, where other sampling strategies couldn't be implemented. The assessment of marine litter was combined with environmental education within the PERSEUS (FP7) Research Project, in a novel 2-day research cruise where schoolchildren actively participated. Two transects of total length 2.36 km were carried out. A relevant marine litter protocol was developed where marine litter was categorized into six different categories according to their material type and where possible, the source of the items was identified. Plastics (55 %) and metals (36 %) had the biggest share among the recorded marine litter items. Marine litter proved to be an ideal theme in order to enhance the environmental awareness of schoolchildren.

Q-Speciation and Network Structure Evolution in Invert Calcium Silicate Glasses.

Binary silicate glasses in the system CaO-SiO2 are synthesized over an extended composition range (42 mol % ≤ CaO ≤ 61 mol %), using container-less aerodynamic levitation techniques and CO2-laser heating. The compositional evolution of Q speciation in these glasses is quantified using (29)Si and (17)O magic angle spinning nuclear magnetic resonance spectroscopy. The results indicate progressive depolymerization of the silicate network upon addition of CaO and significant deviation of the Q speciation from the binary model. The equilibrium constants for the various Q species disproportionation reactions for these glasses are found to be similar to (much smaller than) those characteristic of Li (Mg)-silicate glasses, consistent with the corresponding trends in the field strengths of these modifier cations. Increasing CaO concentration results in an increase in the packing density and structural rigidity of these glasses and consequently in their glass transition temperature Tg. This apparent role reversal of conventional network-modifying cations in invert alkaline-earth silicate glasses are compared and contrasted with that in their alkali silicate counterparts.

Sputum and BAL Clara cell secretory protein and surfactant protein D levels in asthma.

Clara cell secretory protein (CC16) is associated with Th2 modulation. Surfactant protein D (SPD) plays an important role in surfactant homeostasis and eosinophil chemotaxis. We measured CC16 and SPD in sputum supernatants of 84 asthmatic patients and 12 healthy controls. In 22 asthmatics, we additionally measured CC16 and SPD levels in BAL and assessed smooth muscle area (SMA), reticular basement membrane (RBM) thickness, and epithelial detachment (ED) in bronchial biopsies. Induced sputum CC16 and SPD were significantly higher in patients with severe asthma (SRA) compared to mild-moderate and healthy controls. BAL CC16 and SPD levels were also higher in SRA compared to mild-moderate asthma. CC16 BAL levels correlated with ED, while SPD BAL levels correlated with SMA and RBM. Severity represented a significant covariate for these associations. CC16 and SPD levels are upregulated in SRA and correlate with remodeling indices, suggesting a possible role of these biomarkers in the remodeling process.

A comparative study of marine litter on the seafloor of coastal areas in the Eastern Mediterranean and Black Seas.

In the present work, abundance, spatial distribution and qualitative composition, of benthic marine litter, were investigated in five study areas from the Eastern Mediterranean and Black Seas (Saronikos, Patras and Echinades Gulfs; Limassol Gulf; Constanta Bay). Surveys were performed using the monitoring protocol proposed by the Technical Group for Marine Litter. Densities ranged from 24items/km(2) to 1211items/km(2), with the Saronikos Gulf being the most affected area. Plastics were predominant in all study areas ranging from 45.2% to 95%. Metals and Glass/Ceramics reached maximum values of 21.9% and of 22.4%. The size distribution of litter items showed that ⩾50% fall into medium size categories (10×10cm, 20×20cm) along with an elevated percentage of small-sized (<5×5cm) plastic litter items. The comparative analysis of the data highlighted the dependence of the marine litter problem on many local factors (human sources and oceanographic conditions) and the urgent need for specific actions.

Uranium and other natural radionuclides in the sediments of a Mediterranean fjord-like embayment, Amvrakikos Gulf (Ionian Sea), Greece.

The distribution of the natural radionuclides ((238)U, (232)Th, (226)Ra, (40)K) and the artificial (137)Cs was studied in sediment cores collected from Amvrakikos Gulf, a seasonal anoxic marine basin, using γ-ray spectrometry. The activity of radionuclides, along with the concentrations of Fe and Mn, were also studied in relation to the total organic carbon and the granulometric fractions of the sediments. The results obtained revealed higher (238)U activity concentrations in all the examined sediment samples compared to the world and Greek average values for soil. The high activity values of (238)U are attributed, besides the lattice-held fraction, to phosphate fertilizer inputs in the Gulf via major rivers and/or to alteration processes of phosphate ores located mainly in the drainage basin of the river Louros. The elevated activity values of (40)K could be attributed to the mineralogical composition of the sediments and to phosphate fertilizers containing potassium. Organic matter seems to be a more efficient sorbent for U than clay minerals and amorphous Fe and Mn-oxyhydroxides. Scanning electron microscopy, together with qualitative analysis of some smectites, reveals the occurrence of U, suggesting a limited absorption of U onto clay minerals. The applied BCR sequential extraction procedure revealed that U was found mainly in the refractory phase or associated with organic matter and to a lesser extent as surface-coating oxides, with the exception of one sediment core which is characterized by high content of fresh marine organic matter and presents high percentage of U in the exchangeable fraction.

Structural characteristics of novel Ca-Mg orthosilicate and suborthosilicate glasses: results from 29Si and 17O NMR spectroscopy.

The structural characteristics of novel alkaline-earth suborthosilicate glasses along the compositional join (1 - x)(Ca(0.5)Mg(0.5)O) - xSiO(2) with 0.28 ≤ x ≤ 0.33 are investigated using high resolution (29)Si and (17)O nuclear magnetic resonance spectroscopy. The structures of these glasses consist of isolated Q(0) and Q(1) anionic species and Mg(2+) and Ca(2+) countercations that are held together by Coulombic interactions. The concentration of the Q(1) species rapidly decreases with decreasing SiO(2) content and becomes undetectable in the glass with x = 28 mol %. The compositional variation of the physical properties of these glasses such as glass transition temperature and density can be attributed to the Q-speciation in the structure. The NBOs are associated with a random distribution of the alkaline-earth cations in their nearest neighbor coordination shell. The resulting random packing of dissimilar Ca-NBO and Mg-NBO coordination polyhedra may give rise to structural and topological frustration responsible for the unusual glass-forming ability of these suborthosilicate liquids with extremely low SiO(2) contents. Finally, the composition and the formation of Q(1) species necessitate the formation of free O(2-) ions in the structure of these glasses that are only bonded to Mg(2+) and Ca(2+) cations. The (17)O NMR results presented in this study allow for direct observation of such oxygen species.

Short-range structure of invert glasses along the pseudo-binary join MgSiO3-Mg2SiO4: results from 29Si and 25Mg MAS NMR spectroscopy.

The short-range structure of "invert" glasses along the pseudobinary join MgSiO(3)-Mg(2)SiO(4) has been studied using (29)Si and (25)Mg MAS NMR spectroscopy. The results indicate a progressive compositional evolution in Q speciation that approximately follows a statistical distribution. The Mg(2)SiO(4) glass shows an abrupt deviation from this trend with the presence of nearly 40% of the Si atoms as (Si(2)O(7))(6-) dimers, i.e., Q(1) species. Mg(2+) ions are present in predominantly octahedral coordination in all glasses. When taken together, these results indicate that glasses with MgO contents between 50 and 60 mol % are characterized by a structure consisting primarily of at least three types of Q species and MgO(6) octahedra. On the other hand, the structure of glasses with >60 mol % MgO appears to consist of Q(0) and Q(1) species with structural connectivity being primarily provided by the MgO(6) octahedra. The possible consequences of such compositional evolution of structure on the ability of glass formation in this system are discussed.

Glass formation and structure in the MgSiO(3)-Mg(2)SiO(4) pseudobinary system: From degraded networks to ioniclike glasses.

A series of glasses xMgO-(1-x)SiO(2) with compositions from enstatite MgSiO(3) (x=0.5) to forsterite Mg(2)SiO(4) (x=0.667) in mole fraction intervals of x approximately 0.02 have been prepared by containerless levitation techniques and CO(2) laser heating. Polarized and depolarized Raman spectra measured at ambient conditions for all these glasses show systematic and smooth band intensity changes with composition. Analysis of the Raman band contours in terms of vibrations due to different oxygen bridged SiO(4) tetrahedra (Q(i), species analysis) undoubtedly shows that bridging oxygens are present in all glasses studied even in the limit of the forsterite composition where bridged Si(2)O(7) (6-) ionic dimers are formed. Furthermore the relative amounts of the Q(i) species change smoothly with composition while at high MgO content "free" oxygens are present presumably forming Mg-O-Mg bridges, which contribute to the glass stability at these compositions. Raman spectra measurements at different temperature below T(g) show small alterations in the Q(i) species in the MgSiO(3) region while no changes were observed in the Mg(2)SiO(4) region. The Boson peak frequency is practically invariant on both composition and temperature and this is in contrast to the systematics followed by most silicate glasses. It is suggested that at compositions near the forsterite ioniclike glasses are formed arising from a very fragile liquid.

In situ measurements of the D(1) and D(2) Raman band intensities of vitreous and molten silica in the 77-2150 K temperature range.

In situ quantitative Raman spectra of vitreous and molten silica were measured from LN(2) temperatures up to above melting and used to calculate the intensities of the two 'defect peaks' D(1) and D(2) associated with the corresponding four- and three-membered ring structures. The D(1) intensity decreases with increasing temperature while the D(2) intensity appears to be invariant to temperature. The data are in disagreement with the quenching/fictive temperature experiments and show definitely no abrupt intensity changes at any temperature.

Dynamic light scattering study on phase separation of a protein-water mixture: application on cold cataract development in the ocular lens.

We present a detailed dynamic light scattering study of the phase separation in the ocular lens emerging during cold cataract development. Cold cataract is a phase separation effect that proceeds via spinodal decomposition of the lens cytoplasm with cooling. The intensity autocorrelation functions of the lens protein content are analyzed with the aid of two methods, providing information on the populations and dynamics of the scattering elements associated with cold cataract. It is found that the temperature dependence of many measurable parameters changes appreciably at the characteristic temperature approximately 16+/-1 degrees C which is associated with the onset of cold cataract. By extending the temperature range of this work to previously inaccessible regimes, i.e., well below the phase separation or coexistence curve at Tcc, we have been able to accurately determine the temperature dependence of the collective and self-diffusion coefficients of proteins near the spinodal. The analysis showed that the dynamics of proteins bears some resemblance to the dynamics of structural glasses, where the apparent activation energy for particle diffusion increases below Tcc, indicating a highly cooperative motion. Application of ideas developed for studying the critical dynamics of binary protein-solvent mixtures, as well as the use of a modified Arrhenius equation, enabled us to estimate the spinodal temperature Tsp of the lens nucleus. The applicability of dynamic light scattering as a noninvasive, early-diagnostic tool for ocular diseases is also demonstrated in light of the findings of the present paper.

Dynamics of proteins: light scattering study of dilute and dense colloidal suspensions of eye lens homogenates.

We report a dynamic light scattering study on protein suspensions of bovine lens homogenates at conditions (pH and ionic strength) similar to the physiological ones. Light scattering data were collected at two temperatures, 20 and 37 degrees C, over a wide range of concentrations from the very dilute limit up to the dense regime approaching the physiological lens concentration. A comparison with experimental data from intact bovine lenses was advanced, revealing differences between dispersions and lenses at similar concentrations. In the dilute regime, two scattering entities were detected and identified with the long-time self-diffusion modes of alpha-crystallins and their aggregates, which naturally exist in lens nucleus. Upon increasing protein concentration, significant changes in time correlation function were observed starting at approximately 75 mg ml(-1), where a new mode originating from collective diffusive motions becomes visible. Self-diffusion coefficients are temperature insensitive, whereas the collective diffusion coefficient depends strongly on temperature revealing a reduction of the net repulsive interparticle forces with decreasing temperature. While there are no rigorous theoretical approaches on particle diffusion properties for multicomponent, nonideal hard sphere polydispersed systems, as the suspensions studied here, a discussion of the volume fraction dependence of the long-time self-diffusion coefficient in the context of existing theoretical approaches was undertaken. This study is purported to provide some insight into the complex light scattering pattern of intact lenses and the interactions between the constituent proteins that are responsible for lens transparency. This would lead to understand basic mechanisms of specific protein interactions that lead to lens opacification (cataract) under pathological conditions.

A rare case of solitary osteochondroma of the dens of the C2 vertebra.

We report an extremely rare case of a 22-year-old man with an asymptomatic osteochondroma of the dens of C2 vertebra accidentally found during a brain CT scan examination.

Natural radionuclides and (137)Cs distributions and their relationship with sedimentological processes in Patras Harbour, Greece.

Surficial and subsurficial sediment samples derived from gravity cores, selected from the harbour of Patras, Greece, were analyzed for grain size, water content, bulk density, specific gravity, organic carbon content and specific activities of natural radionuclides and (137)Cs. The specific activities of (232)Th, (226)Ra, (40)K and (137)Cs were measured radiometrically. The radionuclides (238)U and (232)Th were also analyzed using the INAA. The differences found between the specific activities of the natural radionuclides measured by the two methods are of no statistical significance. The sediment cores selection was based on a detailed bathymetric and marine seismic survey. Through the study of the detailed bathymetric map and the seismic profiles it was shown that ship traffic is highly influential to the harbour bathymetry. The granulometric and geotechnical properties of the sediments and therefore the specific activities of the natural radionuclides and (137)Cs seem to be controlled by the ship traffic. Relationship between radionuclide activity concentrations and granulometric/geotechnical parameters was defined after the treatment of all the analyses using R-mode factor analysis. The natural radionuclide activities are related to the fine fraction and bulk density of the sediments, while (137)Cs is mainly influenced by the organic carbon content. In addition, (238)U and (226)Ra seem to be in close relation with the heavy minerals fraction in coarse-grained sediments with high specific gravity.

Leukotriene E(4) in urine in patients with asthma and COPD--the effect of smoking habit.

Leukotriene E(4) (LTE(4)) is implicated in asthma pathophysiology and possibly in chronic obstructive pulmonary disease (COPD) as one of the causes of persistent bronchoconstriction and mucus hypersecretion. Cigarette smoking stimulates cysteinyl leukotrienes (CysLTs) production. We investigated whether LTE(4) is equally increased in asthma and COPD and whether smoking significantly affects LTE(4) levels. Secondary outcomes involved correlations with inflammatory and functional parameters. We studied 40 patients with COPD [20 smokers], 40 asthmatics [20 smokers] and 30 healthy subjects [15 smokers]. Spirometry (FEV(1)% pred., FEV(1)/FVC) was performed, urine was collected for measurement of LTE(4) and creatinine, induced sputum was collected for differential cell counts and serum for ECP. LTE(4)/creatinine levels (pg/mg) [mean (sd)] were increased in asthmatic patients compared to COPD and controls, [125.6(54.5) vs. 54.5(19) vs. 55.9(18.9)pg/mg, respectively, P<0.0001 for asthma]. Smoking significantly affects LTE(4) levels only in asthmatic patients [164 (48) vs. 87 (26.3), P<0.0001 for smokers]. The only significant correlation was between eosinophils in induced sputum and LTE(4)/creatinine levels in asthmatics. In conclusion, patients with asthma presented higher LTE(4) values compared to normals and patients with COPD. Smoking significantly affects LTE(4) values only in asthmatics indicating a different underlying CysLTs inflammatory process in this condition.