The leaching of natural colloids from forest surface soils and their role for the P transfer

Soil nanoparticles (d<100nm) and colloids (d<1µm) exert a decisive control on the mobilisation of strongly sorbing compounds such as phosphorus (P). We investigated the nanoparticles and colloids present in forest soil leachates examining their role for the P fixation and for the vertical P transfer in forest soils. Mesocosm experiments with three German forest soils (upper 20 cm) were conducted. The mesocosms were irrigated with artificial rain for 22 months and the nanoparticles and colloids were characterised in the soil leachates with special attention to P. The field flow fractionation (FFF) technique coupled online to UV- and DLS- detectors and inductively coupled plasma mass spectrometry (ICP-MS) or to an organic carbon detector (OCD) enabled a size resolved characterization and quantification of the nanoparticulate and colloidal fractions and their elemental composition (P, Corg, Fe, A, Si, Ca. Mn). To visualise and better characterise the particles present in the leachates, transmission electron microscopy with energy-dispersive x-ray spectroscopy (TEM-EDX) measurements were performed. The translocated particles exhibited sizes up to 350 nm. Using FFF we separated the colloids in three size fractions i) 3-20 nm ii) 20-70 nm and iii) 70-350 nm. The particle fractions showed different chemical compositions. However their composition and characteristics were similar between the three forest sites and comparable to the natural nanoparticles and colloids from soils (“water dispersible colloids”) and streams described in literature. Up to 90% (on average ~45 %) of the leached P was associated with the nanoparticles and colloids. Our qualitative and quantitative analysis of the soil leachates showed that nanoparticles and colloids are crucial vectors controlling the P fluxes in forest ecosystems and could be a significant, but as yet still poorly quantified P loss factor

Novel multiple sclerosis susceptibility loci implicated in epigenetic regulation

We conducted a genome-wide association study (GWAS) on multiple sclerosis (MS) susceptibility in German cohorts with 4888 cases and 10,395 controls. In addition to associations within the major histocompatibility complex (MHC) region, 15 non-MHC loci reached genome-wide significance. Four of these loci are novel MS susceptibility loci. They map to the genes L3MBTL3, MAZ, ERG, and SHMT1. The lead variant at SHMT1 was replicated in an independent Sardinian cohort. Products of the genes L3MBTL3, MAZ, and ERG play important roles in immune cell regulation. SHMT1 encodes a serine hydroxymethyltransferase catalyzing the transfer of a carbon unit to the folate cycle. This reaction is required for regulation of methylation homeostasis, which is important for establishment and maintenance of epigenetic signatures. Our GWAS approach in a defined population with limited genetic substructure detected associations not found in larger, more heterogeneous cohorts, thus providing new clues regarding MS pathogenesis

Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers

"This is the peer reviewed version of the following article: Gottselig, N., W. Amelung, J. W. Kirchner, R. Bol, W. Eugster, S. J. Granger, C. Hernández-Crespo, et al. 2017. Elemental Composition of Natural Nanoparticles and Fine Colloids in European Forest Stream Waters and Their Role as Phosphorus Carriers. Global Biogeochemical Cycles 31 (10). American Geophysical Union (AGU): 1592 1607. doi:10.1002/2017gb005657, which has been published in final form at https://doi.org/10.1002/2017GB005657. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] Biogeochemical cycling of elements largely occurs in dissolved state, but many elements may also be bound to natural nanoparticles (NNP, 1-100 nm) and fine colloids (100-450 nm). We examined the hypothesis that the size and composition of stream water NNP and colloids vary systematically across Europe. To test this hypothesis, 96 stream water samples were simultaneously collected in 26 forested headwater catchments along two transects across Europe. Three size fractions (similar to 1-20 nm, >20-60 nm, and >60 nm) of NNP and fine colloids were identified with Field Flow Fractionation coupled to inductively coupled plasma mass spectrometry and an organic carbon detector. The results showed that NNP and fine colloids constituted between 2 +/- 5% (Si) and 53 +/- 21% (Fe; mean +/- SD) of total element concentrations, indicating a substantial contribution of particles to element transport in these European streams, especially for P and Fe. The particulate contents of Fe, Al, and organic C were correlated to their total element concentrations, but those of particulate Si, Mn, P, and Ca were not. The fine colloidal fractions >60 nm were dominated by clay minerals across all sites. The resulting element patterns of NNP <60 nm changed from North to South Europe from Fe-to Ca-dominated particles, along with associated changes in acidity, forest type, and dominant lithology.The authors gratefully acknowledge the assistance of the following people in locating suitable sampling sites, contacting site operators, performing the sampling, and providing data: A. Avila Castells (Autonomous University of Barcelona), R. Batalla (University of Lleida), P. Blomkvist (Swedish University of Agricultural Sciences), H. Bogena (Julich Research Center), A.K. Boulet (University of Aveiro), D. Estany (University of Lleida), F. Garnier (French National Institute of Agricultural Research), H.J. Hendricks-Franssen (Research Center Julich), L. JacksonBlake (James Hutton Institute, NIVA), T. Laurila (Finnish Meteorological Institute), A. Lindroth (Lund University), M.M. Monerris (Universitat Politecnica de Valencia), M. Ottosson Lofvenius (Swedish University of Agricultural Sciences), I. Taberman (Swedish University of Agricultural Sciences), F. Wendland (Research Center Julich), T. Zetterberg (Swedish University of Agricultural Sciences and The Swedish Environmental Research Institute, IVL) and further unnamed contributors. The Swedish Infrastructure for Ecosystem Science (SITES) and the Swedish Integrated Monitoring, the latter financed by the Swedish Environmental Protection Agency, and ICOS Sweden have supported sampling and provided data for the Swedish sites. J.J.K. gratefully acknowledges the support from CESAM (UID/AMB/50017/2013), funded by the FCT/MCTES (PIDDAC) with cofunding by FEDER through COMPETE. N.G. gratefully acknowledges all those who contributed to organizing and implementing the continental sampling. The raw data can be found at http://hdl.handle.net/2128/14937. This project was partly funded by the German Research Foundation (DFG KL2495/1-1).Gottselig, N.; Amelung, W.; Kirchner, J.; Bol, R.; Eugster, W.; Granger, S.; Hernández Crespo, C.... 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Factors associated with depressive mood at the onset of multiple sclerosis - an analysis of 781 patients of the German NationMS cohort

BACKGROUND: Depression has a major impact on the disease burden of multiple sclerosis (MS). Analyses of overlapping MS and depression risk factors [smoking, vitamin D (25-OH-VD) and Epstein-Barr virus (EBV) infection] and sex, age, disease characteristics and neuroimaging features associated with depressive symptoms in early MS are scarce. OBJECTIVES: To assess an association of MS risk factors with depressive symptoms within the German NationMS cohort. DESIGN: Cross-sectional analysis within a multicenter observational study. METHODS: Baseline data of n = 781 adults with newly diagnosed clinically isolated syndrome or relapsing-remitting MS qualified for analysis. Global and region-specific magnetic resonance imaging (MRI)-volumetry parameters were available for n = 327 patients. Association of demographic factors, MS characteristics and risk factors [sex, age, smoking, disease course, presence of current relapse, expanded disability status scale (EDSS) score, fatigue (fatigue scale motor cognition), 25-OH-VD serum concentration, EBV nuclear antigen-1 IgG (EBNA1-IgG) serum levels] and depressive symptoms (Beck Depression Inventory-II, BDI-II) was tested as a primary outcome by multivariable linear regression. Non-parametric correlation and group comparison were performed for associations of MRI parameters and depressive symptoms. RESULTS: Mean age was 34.3 years (95% confidence interval: 33.6-35.0). The female-to-male ratio was 2.3:1. At least minimal depressive symptoms (BDI-II > 8) were present in n = 256 (32.8%), 25-OH-VD deficiency (<20 ng/ml) in n = 398 (51.0%), n = 246 (31.5%) participants were smokers. Presence of current relapse [coefficient (c) = 1.48, p = 0.016], more severe fatigue (c = 0.26, p < 0.0001), lower 25-OH-VD (c = -0.03, p = 0.034) and smoking (c = 0.35, p = 0.008) were associated with higher BDI-II scores. Sex, age, disease course, EDSS, month of visit, EBNA1-IgG levels and brain volumes at baseline were not. CONCLUSION: Depressive symptoms need to be assessed in early MS. Patients during relapse seem especially vulnerable to depressive symptoms. Contributing factors such as fatigue, vitamin D deficiency and smoking, could specifically be targeted in future interventions and should be investigated in prospective studies

Chapter 12. Separation Systems Coupled to ICP-MS for the Analysis of Metal-based Nanoparticles and Colloids

A broad range of separation systems have been established in elemental speciation analysis online with sensitive elemental detection by inductively coupled plasma mass spectrometry (ICP-MS) for low molecular mass species but also for macroproteins. The classical techniques size exclusion chromatography, reversed phase chromatography and capillary electrophoresis have been successfully applied for characterisation of metal-containing nanoparticles and colloids. In addition, special separation techniques for characterisation of particulate elemental species including nanopollutants have been established online with ICP-MS: hydrodynamic chromatography and field flow fractionation. The separation principles of these techniques along with advantages and limitations for metal-based (nano)particles are briefly summarised and discussed in this chapter. The performance, flexibility, challenges and drawbacks are highlighted based on examples of recent applications covering a broad range of particle compositions, particle sizes and sample matrices. Suitable calibration strategies, mass balance issues and recoveries are addressed in individual sections for quality control

Review on metal speciation analysis in cerebrospinal fluid-current methods and results: A review.

The large number of patients suffering from neurodegenerative diseases like Alzheimer&#39;s disease and Parkinson&#39;s disease motivates many research groups worldwide to investigate pathogenic factors and molecular mechanisms of these diseases. Recent studies and reviews indicate that metals are involved in these neurodegenerative processes in case their homeostasis in the brain is disturbed. Important is that the focus of these recent studies is on essential metals like Fe, Cu, Zn and Mn, but not on the well-known neurotoxic metals like Hg and Pb. Key issues for understanding metal induced neurotoxic effects are the transport processes across the neural barriers, the metal binding forms (species) and their interactions with neuronal structures. Total metal concentrations in cerebrospinal fluid were published in several studies for controls and patients, but the amount of reliable data sets is not yet sufficient for clear definition of normal and elevated levels. The need for more detailed information on metal species in CSF is highlighted in this review. However, studies on element speciation analysis, that means identification and quantification of the various binding forms of metals in cerebrospinal fluid, are rare. The major reasons therefore are difficulties in accessing cerebrospinal fluid samples, the non-covalent nature of many metal species of interest and their rather low concentrations. In spite of this, several applications demonstrate the potential of hyphenated techniques as additional diagnostic tools for cerebrospinal fluid analysis. This review shows the importance of trace element analysis and more specifically of element speciation in cerebrospinal fluid for an improved understanding of pathologic mechanisms promoting neuro-degeneration. Respective analytical techniques are also highlighted. Additionally, biochemical assays for selected high molecular mass metal species are summarized and critically discussed. Moreover additional potential techniques like direct non-invasive methods as well as mathematical modelling approaches are considered. Data on total concentrations of numerous elements in CSF as well as speciation information of elements such as Al, As, Ca, Cd, Cu, Fe, Mg, Mn, Hg, Pb, Se and Zn in CSF are summarized