Παρασκευή, 5 Φεβρουαρίου 2016

Cutaneous Cellular Pseudoglandular Schwannoma: An Unusual Histopathologic Variant.

Cellular schwannoma and pseudoglandular schwannoma are both previously described rare variants of schwannoma. The authors present an unusual case of a cellular spindle cell neoplasm with prominent gland-like structures, having features of both variants. The nature of this lesion was confirmed by histology and immunohistochemistry, with diffuse and strong S100 and membranous collagen type IV staining. The gland-like structures were lined by S100 + cells and contained proteinaceous, mucicarmine-negative material, supporting a degenerative, not true glandular, phenomenon. This is the first case of a cutaneous schwannoma demonstrating both marked cellularity and pseudoglandular formation, which the authors have designated cutaneous cellular pseudoglandular schwannoma. Recognition of this extremely rare variant will help avoid diagnostic confusion and overtreatment of this benign entity. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Demens påvirker humoren

Sansen for slapstick-humor øker hos pasienter med demens.

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Hypoxic markers in non-small cell lung cancer (NSCLC) – A review

Surgery, chemotherapy and radiotherapy have been the main pillars of cancer treatment. Some of the recent improvements in survival of other cancers can be attributed to novel treatment therapies. Such therapies mostly target specific molecules involved in cancer progression and metastasis. Development and clinical introduction of targeted therapies involve identification of new and potentially important molecules in cancer progression. The next important step is to evaluate its prognostic value. Prognostication by molecular markers is also important as this may identify subgroups of patients in need for additional treatment or not, which was not possible with the traditional clinic-pathological prognosticators. Hypoxic markers have been widely explored in the recent past for their prognostic efficacy in non-small cell lung cancer.

The present review article will enlighten importance of hypoxic markers with special reference to non-small cell lung carcinoma.

L'articolo Hypoxic markers in non-small cell lung cancer (NSCLC) – A review sembra essere il primo su European Review.



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Is the effect of topical intranasal steroids on obstructive adenoids transient or long-lasting? Case series and systematic review of literature

Research Articles
M A Bitar, J Nassar, R Dana
The Journal of Laryngology & Otology,FirstView Article(s), 6 pages

Abstract
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Transoral robotic resection of a large schwannoma in the retropharyngeal space

Rapid Communication
A Gungadeen, R Lisseter, J Manickavasagam, V Paleri
The Journal of Laryngology & Otology,FirstView Article(s), 3 pages

Abstract
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Women who survive breast or thyroid cancer are more likely to develop the other type later

The incidence of differentiated thyroid cancer, which includes papillary and follicular cancers, has increased nearly threefold in the United States over the past three decades, and breast cancer is the most commonly diagnosed malignancy in...

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Researchers identify striking genomic signature shared by 5 types of cancer

National Institutes of Health researchers have identified a striking signature in tumour DNA that occurs in five different types of cancer. They also found evidence that this methylation signature may be present in many more types of cancer. The...

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Increased expression of FGF1-mediated signaling molecules in adipose tissue of obese mice

Abstract

Fibroblast growth factors (FGFs) are pleiotropic growth factors that control cell proliferation, migration, and differentiation. Herein, we evaluated whether visceral adiposity of mice is accompanied by the alteration of signaling molecules mediated by fibroblast growth factor receptor 1 (FGFR1) induced by using two different male C57BL/6J mice models of obesity namely high-fat diet (HFD)-induced obesity for 12 weeks or mice with genetic deletion of leptin (ob/ob). Both HFD-fed and ob/ob mice exhibited significantly higher messenger RNA (mRNA) levels of FGF1, cyclin D (cycD), transcription factor E2F1, peroxisome proliferator-activated receptor-gamma 2 (PPAR-γ2), CCAAT-enhancer-binding protein alpha (C/EBPα), and adipocyte protein 2 (aP2) genes in their epididymal adipose tissues compared to those of the normal diet (ND)-fed and lean control mice, respectively. In addition, immunoblot analyses of the epididymal adipose tissues revealed that both mice exposed to HFD and ob/ob mice exhibited elevated phosphorylation of FGFR1, extracellular-signal-regulated kinase (ERK), and retinoblastoma (Rb) proteins. These data support the notion that FGF1-mediated signaling represents an important signaling cascade related to adipogenesis, at least partially, among other known signaling pathways. These new findings regarding the molecular mechanisms controlling adipose tissue plasticity provide a novel insight about the functional network with potential therapeutic application against obesity.



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IJERPH, Vol. 13, Pages 196: Advancing Sustainability through Urban Green Space: Cultural Ecosystem Services, Equity, and Social Determinants of Health

Urban green spaces provide an array of benefits, or ecosystem services, that support our physical, psychological, and social health. In many cases, however, these benefits are not equitably distributed across diverse urban populations. In this paper, we explore relationships between cultural ecosystem services provided by urban green space and the social determinants of health outlined in the United States Healthy People 2020 initiative. Specifically, we: (1) explore connections between cultural ecosystem services and social determinants of health; (2) examine cultural ecosystem services as nature-based health amenities to promote social equity; and (3) recommend areas for future research examining links between urban green space and public health within the context of environmental justice.

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IJERPH, Vol. 13, Pages 194: Prevalence of Residential Dampness and Mold Exposure in a University Student Population

The impact of residential dampness or mold on respiratory health is well established but few studies have focused on university students. This study aims to: (a) describe the prevalence of exposure to residential dampness or mold in university students according to socio-geographic factors and (b) identify associated housing characteristics. A web survey was conducted in 2014 among the 26,676 students registered at the Université de Sherbrooke (QC, Canada). Residential dampness and mold being closely intertwined, they were considered as a single exposure and assessed using a validated questionnaire. Exposure was compared according to socio-geographic and housing characteristics using chi-square tests and logistic regressions. Among the 2097 participants included in the study (response rate: 8.1%), over 80% were tenants. Residential exposure to dampness or mold was frequent (36.0%, 95% CI: 33.9–38.1). Marked differences for this exposure were noted according to home ownership (39.7% vs. 25.5% among tenants and owners respectively; OR = 1.92%, 95% CI: 1.54–2.38). Campus affiliation, household composition and the number of residents per building were associated with exposure to dampness or mold (p < 0.01), while sex and age were not. Exposure was also associated with older buildings, and buildings in need of renovations and lacking proper ventilation (p < 0.001). This study highlights the potential risk of university students suffering from mold-related health effects given their frequent exposure to this agent. Further research is needed to fully evaluate the mold-related health impact in this at risk group.

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IARC Metings: Epigenetics and Environmental Origins of Cancer, 11-12 June 2016

birth-of-dna_Epigenetics.jpgThe International Agency for Research on Cancer (IARC) is pleased to announce a meeting on Epigenetics and Environmental Origins of Cancer, which will take place at IARC on 11-12 June 2016. The goals of this meeting are to evaluate recent scientific knowledge in the area, to determine future research needs, and to assess the implications of such studies in cancer causation and prevention. The meeting is a satellite event to the IARC 50th anniversary conference on Global Cancer: Occurrence, Causes, and Avenues to Prevention.

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Parkinson’s disease diagnosis is preceded by increased risk of falls, study finds

People with Parkinson’s disease have a higher risk of falls that cause injury or hip fracture for many years before their condition is diagnosed, a study shows.1 Reporting in PLOS Medicine, the...
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Better training is needed on fetal alcohol disorders, says BMA

Training programmes on the prevention, diagnosis, and management of fetal alcohol syndromes should be implemented for UK healthcare professionals and included in undergraduate curriculums to resolve...
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Validierung von SleepMinder® zur Erfassung der Schlafqualität bei Patienten mit OSAS

Zusammenfassung

Hintergrund

Die kardiorespiratorische Polysomnographie (PSG) ist der Goldstandard der Diagnostik schlafbezogener Atemstörungen (SBAS) und stellt aufgrund des großen Zeit- und Kostenaufwands den letzten Schritt einer Stufendiagnostik dar.

Ziel

Das Ziel war die Bestimmung der diagnostische Aussagekraft von SleepMinder® (Resmed Sensor Technologies, Dublin, Irland) bei der Erkennung von Schlafdauer (engl. Total Sleep Time [TST]) und Schlafeffizienz (SE).

Material und Methoden

SleepMinder® ist ein kontaktloses Screeninggerät zur Analyse respiratorischer Ereignisse und der Schlafqualität, basierend auf dem Prinzip der Reflexion leistungsarmer Radiowellen. In einem Kollektiv von 57 Patienten mit Verdacht auf SBAS wurde simultan zu einer PSG eine Messung mit SleepMinder® durchgeführt und die diagnostische Aussagekraft der durch SleepMinder® erhaltenen Ergebnisse ermittelt. Zusätzlich wurde der Einfluss von periodischen Beinbewegungen (PLM) auf die klinische Güte von SleepMinder® untersucht.

Ergebnisse

SleepMinder® überschätzt im Vergleich zur PSG die TST, wobei kein statistisch signifikanter Unterschied beim Vergleich zwischen Gruppe 1 (Apnoe-Hypopnoe-Index [AHI] < 15/h) und Gruppe 2 (AHI ≥ 15/h) bestand. Gruppe 1 zeigte eine Abweichung von 5 % und Gruppe 2 eine von 6 % beim Vergleich der mittels SleepMinder® und PSG bestimmten TST. Bei 51 % der Patienten trat eine Abweichung < 10 % auf, bei 70 % der Patienten < 20 % und bei 9 % der Patienten ≥ 30 %. Die mittlere Abweichung lag bei 24 min. Für den Vergleich von SEPSG und SESleepMinder® ergab sich eine Abweichung von 1 % in Gruppe 1 und von 7 % in Gruppe 2 (p = n. s.). Auch hier fand sich kein statistisch signifikanter Unterschied zwischen den untersuchten Gruppen. Bei 49 % der Patienten zeigte sich eine Abweichung < 10 %, bei 67 % der Patienten < 20 % und bei 7 % der Patienten ≥ 30 %. Die mittlere Abweichung lag bei 2 %.

Diskussion

Die Möglichkeit durch SleepMinder® TST und SE mit moderater Genauigkeit zu schätzen kann beim Screening zur Bestimmung von SBAS eine nützliche Zusatzfunktion sein, um zu entscheiden, ob bspw. ein geringer AHI darauf zurückzuführen ist, dass der Patient während der Nacht kaum geschlafen hat.



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Mountain bike injuries: Which modality is best?

2016_02_04_12_36_31_56_Mountain_biking_2New international research on musculoskeletal trauma of the neck, torso, and...


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Worldwide trends in incidence in occupational allergy and asthma.

Purpose of review: Recent improvements in the methods for analyzing trends in occupational health surveillance and the prospect of future improvements in the collecting and sharing of electronic data alongside increasing availability of linked datasets make this a good time to review the existing literature on trends in occupational allergy and asthma (OAA). Recent findings: There is a notable lack of reports of recent trends in OAA in the academic literature and much of the published work comes from European countries. The incidence of OAA appears to be declining based on physician-reporting or recognized compensation claims for the countries with published data. However, we need to be cautious in interpreting this as a decline in the 'true' incidence of OAA. Few of the studies adjusted appropriately for changes in the population at risk and one of the most robust study designs showed no change in the incidence of allergic contact dermatitis in contrast to the other studies. Summary: Many existing datasets have the potential to be used to examine trends, and studies from Canada show the potential of using linked databases for surveillance. We hope that this review will encourage improvements in the analysis, and more dissemination, of trends. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Uptake and toxicity of nano-ZnO in the plant-feeding nematode, Xiphinema vuittenezi : the role of dissolved zinc and nanoparticle-specific effects

Abstract

Nanoparticulate ZnO is one of the most commonly applied nanomaterials. As ZnO is more soluble than many other oxide nanoparticles, its toxicity beyond the nanoparticle-specific effects can be attributed to the dissolved ionic zinc. The investigation of uptake and toxicity of nano-ZnO in the plant-feeding nematode, Xiphinema vuittenezi, which was used in previous studies as a biological model organism, was aimed. The establishment of the role of dissolved zinc and nanoparticle-specific effects in the toxicity was also the objective of our study. Zn uptake was found to be significantly higher for bulk and nano-ZnO than for ZnSO4 solution; however, treatments caused loss of potassium in the worms in a dissolved-zinc-dependent manner. The toxicity was the lowest for bulk ZnO, and it was very similar for nano-ZnO and ZnSO4 solution. Accordingly, the toxicity of ZnO nanoparticles is a combination of dissolved-zinc-caused toxicity and nanoparticle-specific effects.



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Treatment of real industrial wastewater using the combined approach of advanced oxidation followed by aerobic oxidation

Abstract

Fenton oxidation and ultrasound-based pretreatment have been applied to improve the treatment of real industrial wastewater based on the use of biological oxidation. The effect of operating parameters such as Fe2+ loading, contact time, initial pH, and hydrogen peroxide loading on the extent of chemical oxygen demand (COD) reduction and change in biochemical oxygen demand (BOD5)/COD ratio has been investigated. The optimum operating conditions established for the pretreatment were initial pH of 3.0, Fe2+ loading of 2.0, and 2.5 g L−1 for the US/Fenton/stirring and Fenton approach, respectively, and temperature of 25 °C with initial H2O2 loading of 1.5 g L−1. The use of pretreatment resulted in a significant increase in the BOD5/COD ratio confirming the production of easily digestible intermediates. The effect of the type of sludge in the aerobic biodegradation was also investigated based on the use of primary activated sludge (PAS), modified activated sludge (MAS), and activated sludge (AS). Enhanced removal of the pollutants as well as higher biomass yield was observed for MAS as compared to PAS and AS. The use of US/Fenton/stirring pretreatment under the optimized conditions followed by biological oxidation using MAS resulted in maximum COD removal at 97.9 %. The required hydraulic retention time for the combined oxidation system was also significantly lower as compared to only biological oxidation operation. Kinetic studies revealed that the reduction in the COD followed a first-order kinetic model for advanced oxidation and pseudo first-order model for biodegradation. The study clearly established the utility of the combined technology for the effective treatment of real industrial wastewater.



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Short-term effects of atmospheric particulate matter on myocardial infarction: a cumulative meta-analysis

Abstract

Atmospheric particulate matter (PM) is hypothesized to increase the risk of myocardial infarction (MI). However, the epidemiological evidence is inconsistent. We identified 33 studies with more than 4 million MI patients and applied meta-analysis and meta-regression to assess the available evidence. Twenty-five studies presented the effects of the PM level on hospitalization for MI patients, while eight studies showed the effects on mortality. An increase in PM10 was associated with hospitalization and mortality in myocardial infarction patients (RR per 10 μg/m3 = 1.011, 95 % CI 1.006–1.016; RR per 10 μg/m3 = 1.008, 95 % CI 1.004–1.012, respectively); PM2.5 also increased the risk of hospitalization and mortality in MI patients (RR per 10 μg/m3 = 1.024, 95 % CI 1.007–1.041 for hospitalization and RR per 10 μg/m3 = 1.012, 95 % CI 1.010–1.015 for mortality). The results of the cumulative meta-analysis indicated that PM10 and PM2.5 were associated with myocardial infarctionwith the addition of new studies each year. In conclusion, short-term exposure to high PM10 and PM2.5 levels revealed to increase risk of hospitalization and mortality for myocardial infarction. Policy support of pollution control and individual protection was strongly recommended.



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Sorption and degradation of selected organic UV filters (BM-DBM, 4-MBC, and OD-PABA) in laboratory water-sediment systems

Abstract

Organic UV filters that have been widely used in sunscreens and other personal care products have drawn much public concern because of their widespread contamination in the environment and their potential ecological risks to ecosystems. We selected three UV filters with high frequency of detection in the environment, namely butyl methoxy dibenzoylmethane (BM-DBM), ethylhexyl dimethyl p-aminobenzoate (OD-PABA), and 4-methylbenzylidene camphor (4-MBC), to investigate the sorption and degradation behaviors of these compounds in lab-scale water-sediment systems set up with natural water and sediment samples collected from different rivers and lakes (i.e., Yangtze River, Qinhuai River, Xuanwu Lake, and Mochou Lake) in Nanjing, East China. The sorption isotherms of these UV filters were well described by the Freundlich equation (C s= K f  × C w n ). The sorption of three UV filters in four sediments was all linear or close to it, with n values between 0.92 and 1.13. A moderate to strong sorption affinity was observed for these compounds, and the sorption appears to be irreversible. For the combined sorption and degradation studies, sorption was found to be a primary mechanism for the disappearance of these UV filters from the water phase, and biotransformation appears to be the predominant factor for the degradation of the target compounds in the water-sediment systems. All three UV filters were found to be slightly resistant to the microbes in these systems, with DT50total and DT90total values—the disappearance time (DT) describes the time in which the initial total mass of the UV filters in the whole system is reduced by 50 and 90 %—ranging between 18 and 31 days and 68 and 101 days, respectively.



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Optimization of a combined electrocoagulation-electroflotation reactor

Abstract

This work studies the efficiency of an electroflotation process for the separation of the solids produced during the electrocoagulation treatment of three different types of wastewater: kaolin suspension, coloured organic solution and oil-in-water emulsion. Additionally, a combined electrocoagulation-electroflotation reactor is designed and optimized taking into account the effect of current density, residence time, pollutant concentration and the ratio floated/settled solids. To do this, an experimental design with response surface methodology (RSM) has been used. Results show that electroflotation is a good alternative to the removal of oil microdrops and dyes, but it is not recommended for the separation of solids formed during electrocoagulation of colloid suspensions due to its high density. It has been found that the use of aluminium leads to better results than the use of iron in the treatment of oil-in-water emulsions and coloured solutions. In these cases, the use of a combined electrocoagulation-electroflotation reactor is recommended and the effect of the main inputs has been studied.



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Microglial cells (BV-2) internalize titanium dioxide (TiO 2 ) nanoparticles: toxicity and cellular responses

Abstract

Because of their whitening and photocatalytic effects, titanium dioxide nanoparticles (TiO2-NPs) are widely used in daily life. These NPs can be found in paints, plastics, papers, sunscreens, foods, medicines (pills), toothpastes, and cosmetics. However, the biological effect of TiO2-NPs on the human body, especially on the central nervous system, is still unclear. Many studies have demonstrated that the brain is one of the target organs in acute or chronic TiO2-NPs toxicity. The present study aimed to investigate the effect of TiO2-NPs at different concentrations (0.1 to 200 μg/mL) on murine microglial cells (BV-2) to assess their activity on cell growth and viability, as well as their neurotoxicity. Different parameters were measured: cell viability, cell proliferation and DNA content (SubG1 peak), mitochondrial depolarization, overproduction of reactive oxygen species (especially superoxide anions), and ultrastructural changes. Results showed that TiO2-NPs induced some cytotoxic effects with a slight inhibition of cell growth. Thus, at high concentrations, TiO2-NPs were not only able to inhibit cell adhesion but also enhanced cytoplasmic membrane permeability to propidium iodide associated with a loss of mitochondrial transmembrane potential and an overproduction of superoxide anions. No induction of apoptosis based on the presence of a SubG1 peak was detected. The microscopic observations also indicated that small groups of nanosized particles and micron-sized aggregates were engulfed by the BV-2 cells and sequestered as intracytoplasmic aggregates after 24-h exposure to TiO2-NPs. Altogether, our data show that the accumulation TiO2-NPs in microglial BV-2 cells favors mitochondrial dysfunctions and oxidative stress.



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Seasonal variability of mercury concentration in soils, buds and leaves of Acer platanoides and Tilia platyphyllos in central Poland

Abstract

In this paper, we present the results of mercury concentration in soils, buds and leaves of maple (Acer platanoidesAp) and linden (Tilia platyphyllosTp) collected in four periods of the growing season of trees, i.e. in April (IV), June (VI), August (VIII) and November (IX) in 2013, from the area of Poznań city (Poland). The highest average concentration of mercury for 88 samples was determined in soils and it equaled 65.8 ± 41.7 ng g−1 (range 14.5–238.9 ng g−1); lower average concentration was found in Ap samples (n = 66): 55.4 ± 18.1 ng g−1 (range 26.5–106.9 ng g−1); in Tp samples 50.4 ± 15.8 ng g−1 (range 23.1–88.7 ng g−1) and in 22 samples of Tp buds 40.8 ± 22.7 ng g−1 (range 12.4–98.7 ng g−1) and Ap buds 28.2 ± 13.6 ng g−1 (range 8.0–59.5 ng g−1). Based on the obtained results, it was observed that the highest concentration of mercury in soils occurred in the centre of Poznań city (95.5 ± 39.1 ng g−1), and it was two times higher than the concentration of mercury in other parts of the city. Similar dependencies were not observed for the leaf samples of Ap and Tp. It was found that mercury concentrations in the soil and leaves of maple and linden were different depending on the period of the growing season (April to November). Mercury content in the examined samples was higher in the first two research periods (April IV, June VI), and then, in the following periods, the accumulation of mercury decreased both in soil and leaf samples of the two tree species. There was no correlation found between mercury concentration in leaves and mercury concentration in soils during the four research periods (April–November). When considering the transfer coefficient, it was observed that the main source of mercury in leaves is the mercury coming from the atmosphere.



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Determination of the distribution and speciation of selenium in an argillaceous sample using chemical extractions and post-extractions analyses: application to the hydrogeological experimental site of Poitiers

Abstract

To better understand selenium’s dynamics in environmental systems, the present study aims to investigate selenium speciation and distribution in black argillaceous sediments, partially fulfilling karstic cavities into the Hydrogeological Experimental Site of Poitiers. These sediments are suspected to be responsible for selenium concentrations exceeding the European Framework Directive’s drinking water limit value (10 μg L−1) in some specific wells. A combination of a sequential extractions scheme and single parallel extractions was thus applied on a representative argillaceous sample. Impacts of the extractions on mineral dissolution and organic matter mobilization were followed by quantifying major cations and total organic carbon (TOC) in the aqueous extracts. The nature of the released organic matter was characterized using thermochemolysis coupled with gas chromatography–mass spectrometry (GC-MS). About 10 % of selenium from the black argillaceous studied matrix could be defined as ‘easily mobilizable’ when the majority (around 70 %) revealed associated with the aliphatic and alkaline-soluble organic matter’s fraction (about 20 %). In these fractions, selenium speciation was moreover dominated by oxidized species including a mixture of SeVI (20–30 %) and SeIV (70–80 %) in the ‘easily mobilizable’ fraction, while only SeIV was detected in alkaline-soluble organic matter fraction.



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Enhanced photochemical decomposition of environmentally persistent perfluorooctanoate by coexisting ferric ion and oxalate

Abstract

Perfluorooctanoic acid (PFOA), an environmentally persistent pollutant, was found to be quickly decomposed under 254 nm UV irradiation in the presence of ferric ion and oxalic acid. To understand the PFOA decomposition mechanism by this process, the effects of reaction atmosphere and concentrations of ferric ions and oxalic acids on PFOA decomposition were investigated, as well as decomposition intermediates. PFOA mainly decomposes via two pathways: (i) photochemical oxidation via Fe(III)-PFOA complexes and (ii) one-electron reduction caused by carboxylate anion radical (CO2•−), which was generated by photolysis of ferrioxalate complexes. Under excess oxalic acid, PFOA decomposition was accelerated, and its corresponding half-life was shortened from 114 to 34 min as ferric concentration increased from 7 to 80 μM. Besides fluoride ions, six shorter chain perfluorinated carboxylic acids (PFCAs) bearing C2-C7 were identified as main intermediates. The presence of O2 promoted the redox recycling of Fe3+/Fe2+ and thus avoided the exhaustion of the Fe(III).



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Spatial-temporal dynamics and sources of total Hg in a hydroelectric reservoir in the Western Amazon, Brazil

Abstract

Damming rivers to construct hydroelectric reservoirs results in a series of impacts on the biogeochemical Hg cycle. For example, modifying the hydrodynamics of a natural watercourse can result in the suspension and transport of Hg deposits in the water column, which represents an exposure risk for biota. The objective of this study was to evaluate the influences of seasonality on the dispersion of total Hg in the Hydroelectric Power Plant (HPP)-Samuel Reservoir (Porto Velho/Brazil). Sampling campaigns were performed during the three following hydrological periods characteristic of the region: low (Oct/2011), ebbing (May/2012), and high (Feb/2013) water. Sediment profiles, suspended particulate matter (SPM), and aquatic macrophytes (Eicchornia crassipes and Oryza spp.) were collected, and their Hg concentrations and isotopic and elemental C and N signatures were determined. The drainage basin significantly influenced the SPM compositions during all the periods, with a small autochthonous influence from the reservoir during the low water. The highest SPM Hg concentrations inside the reservoir were observed during the high water period, suggesting that the hydrodynamics of this environment favor the suspension of fine SPM, which has a higher Hg adsorption capacity. The Hg concentrations in the sediment profiles were ten times lower than those in the SPM, indicating that large particles with low Hg concentrations were deposited to form the bottom sediment. Hg concentrations were higher in aquatic macrophyte roots than in their leaves and appeared to contribute to the formation of SPM during the low water period. In this environment, Hg transport mainly occurs in SPM from the Jamari River drainage basin, which is the primary source of Hg in this environment.



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Degradation and detoxification of the triphenylmethane dye malachite green catalyzed by crude manganese peroxidase from Irpex lacteus F17

Abstract

Malachite green (MG), a recalcitrant, carcinogenic, and mutagenic triphenylmethane dye, was decolorized and detoxified using crude manganese peroxidase (MnP) prepared from the white rot fungus Irpex lacteus F17. In this study, the key factors (pH, temperature, MG, Mn2+, H2O2, MnP) in these processes were investigated. Under optimal conditions, 96 % of 200 mg L−1 of MG was decolorized when 66.32 U L−1 of MnP was added for 1 h. The K m, V max, and k cat values were 109.9 μmol L−1, 152.8 μmol L−1 min−1, and 44.5 s−1, respectively. The decolorization of MG by MnP followed first-order reaction kinetics with a kinetic rate constant of 0.0129 h−1. UV–vis and UPLC analysis revealed degradation of MG. Furthermore, seven different intermediates formed during the MnP treatment of 0.5 h were identified by LC-TOF-MS. These degradation products were generated via two different routes by either N-demethylation of MG or the oxidative cleavage of the C–C double bond in MG. Based on ecotoxicity analyses performed on bacteria and algae, it was confirmed that MG metabolites produced by the MnP-catalyzed system were appreciably less toxic than the parent compound. These studies indicate the potential use of this enzyme system in the clean-up of aquatic and terrestrial environments.



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Changes in speciation and leaching behaviors of heavy metals in dredged sediment solidified/stabilized with various materials

Abstract

Solidification/stabilization (S/S) of sediments is frequently used to treat contaminants in dredged sediments. In this study, sediment collected from the Pearl River Delta (China) was solidified/stabilized with three different kinds of functional materials: cement, lime and bentonite. Lime primarily acted via induced increases in pH, while cements stabilization occurred through their silicate-based systems and the main function of bentonite was adsorption. The speciation and leaching behaviors of specific heavy metals before and after S/S were analyzed and the results showed that the residual speciation of Cd, Cr, Ni, Pb and Zn increased in all treatments except for Cu, as the exchangeable speciation, carbonate-bound speciation and Fe-Mn-oxide-bound speciation of Cu (all of which could be stabilized) were less than 2 % of the total amount. Pb leaching only decreased when pH increased, while the mobility of Cr and Ni only decreased in response to the silicate-based systems. The leached portion of the Fe-Mn-oxide-bound speciation followed the order Zn > Cu > Ni/Cd > Pb > Cr. The leached portion of organic-matter-bound species was less than 4 % for Cd, Cr, Ni and Pb, but 35.1 % and 20.6 % for Cu and Zn, respectively.



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Biomarkers of oxidative stress and metal accumulation in marsh frog ( Pelophylax ridibundus )

Abstract

To understand the effect of metals on the marsh frog Pelophylax ridibundus and the possible environment-induced changes in oxidative stress enzymes, we determined the concentrations of 18 metals: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, In, Li, Mn, Ni, Pb, Sr, and Zn, in the tissues (liver, skin, and muscle) and water samples collected from different locations in Serbia. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), glutathione S-transferase (GST), acetylcholinesterase (AChE), and changes in concentrations of reduced glutathione (GSH) and sulfhydryl groups (SH) were analyzed in the tissues of the sampled frogs. The concentrations of Al, Cd, Co, Cr, Cu, Fe, Ga, Hg, and Ni were highest in the liver, whereas those of Ba, Ca, Li, Mn, Pb, Sr, and Zn were highest in the skin. Hg correlated positively with liver SOD (in frogs from Danube-Tisza-Danube Canal (DTD)), muscle CAT (DTD), and muscle GST Ponjavica River (PO); Pb demonstrated a strong positive correlation with liver GR in frogs from Mt. Fruška Gora (FG); Cd only exhibited a positive correlation with AChE in the skin of frogs from DTD. In the skin, Zn correlated positively with AChE (DTD), SH groups (PO), and CAT (FG), and negatively with CAT, GST, and SH in the liver of frogs from DTD. Examination of these oxidative stress biomarkers, together with analysis of metal accumulation in the liver and skin of marsh frogs, provides a powerful tool for the assessment of metal pollution.



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The applied indicators of water quality may underestimate the risk of chemical exposure to human population in reservoirs utilized for human supply—Southern Brazil

Abstract

The knowledge concerning associations between chronic chemical exposure and many disorders with complex etiology involving gene–environment interactions is increasing, and new methods must be developed to improve water quality monitoring. The complexity of chemical mixtures in polluted aquatic environments makes the evaluation of toxic potential in those sites difficult, but the use of biomarkers and bioindicators has been recognized as a reliable tool to assess risk of exposure to biota and also the human population. In order to evaluate the use of fish and biomarkers to assess toxic potential and bioavailability of chemicals in human-related hydric resources, an in situ experiment was accomplished in two water reservoirs designated for human supply, which were previously evaluated by the local environmental regulatory agency through a set of physical, chemical, and classical biological parameters. Molecular, biochemical, and morphological biomarkers were performed in caged Oreochromis niloticus kept for 6 months in the studied reservoirs to assess potentially useful biomarkers to evaluate the quality of water for human supply. Chemical analysis of toxic metals in liver and muscle and polycyclic aromatic hydrocarbons (PAHs) in bile was considered to assess the bioavailability of pollutants and highlight human activity impact. The reservoir previously classified by a governmental agency as less impacted presented more risk of exposure to biota. These results were supported by chemical analysis, vitellogenin expression, histopathological findings (gonads, liver, and gills), as well as indicators of neurotoxic effects and oxidative stress in liver. The inclusion of some biomarkers as parameters in regulatory monitoring programs in reservoirs designated for human supply is strongly suggested to evaluate the risks of exposure to the human population. Thus, a revision of the traditional biological and physicochemical analysis utilized to establish the conditions of water quality is necessary.



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