Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Silicon dioxide and titanium dioxide particles found in human tissues
    Peters, Ruud J.B. ; Oomen, Agnes G. ; Bemmel, Greet van; Vliet, Loes van; Undas, Anna K. ; Munniks, Sandra ; Bleys, Ronald L.A.W. ; Tromp, Peter C. ; Brand, Walter ; Lee, Martijn van der - \ 2020
    Nanotoxicology 14 (2020)3. - ISSN 1743-5390 - p. 420 - 432.
    human tissue - nanoparticle - silica - Silicon dioxide - single particle ICP-MS - titanium dioxide

    Silicon dioxide (silica, SiO2, SAS) and titanium dioxide (TiO2) are produced in high volumes and applied in many consumer and food products. As a consequence, there is a potential human exposure and subsequent systemic uptake of these particles. In this study we show the characterization and quantification of both total silicon (Si) and titanium (Ti), and particulate SiO2 and TiO2 in postmortem tissue samples from 15 deceased persons. Included tissues are liver, spleen, kidney and the intestinal tissues jejunum and ileum. Low-level analysis was enabled by the use of fully validated sample digestion methods combined with (single particle) inductively coupled plasma high resolution mass spectrometry techniques (spICP-HRMS). The results show a total-Si concentration ranging from <2 to 191 mg Si/kg (median values of 5.8 (liver), 9.5 (spleen), 7.7 (kidney), 6.8 (jejunum), 7.6 (ileum) mg Si/kg) while the particulate SiO2 ranged from <0.2 to 25 mg Si/kg (median values of 0.4 (liver), 1.0 (spleen), 0.4 (kidney), 0.7 (jejunum, 0.6 (ileum) mg Si/kg), explaining about 10% of the total-Si concentration. Particle sizes ranged from 150 to 850 nm with a mode of 270 nm. For total-Ti the results show concentrations ranging from <0.01 to 2.0 mg Ti/kg (median values of 0.02 (liver), 0.04 (spleen), 0.05 (kidney), 0.13 (jejunum), 0.26 (ileum) mg Ti/kg) while particulate TiO2 concentrations ranged from 0.01 to 1.8 mg Ti/kg (median values of 0.02 (liver), 0.02 (spleen), 0.03 (kidney), 0.08 (jejunum), 0.25 (ileum) mg Ti/kg). In general, the particulate TiO2 explained 80% of the total-Ti concentration. This indicates that most Ti in these organ tissues is particulate material. The detected particles comprise primary particles, aggregates and agglomerates, and were in the range of 50–500 nm with a mode in the range of 100–160 nm. About 17% of the detected TiO2 particles had a size <100 nm. The presence of SiO2 and TiO2 particles in liver tissue was confirmed by scanning electron microscopy with energy dispersive X-ray spectrometry.

    Development and Validation of a Method for the Detection of Titanium Dioxide Particles in Human Tissue with Single Particle ICP-MS
    Peters, Ruud ; Undas, Anna ; Memelink, Joost ; Bemmel, Greet Van; Munniks, Sandra ; Bouwmeester, Hans ; Nobels, Peter ; Schuurmans, Wobbe ; Lee, Martijn Van Der - \ 2018
    Current Trends in Analytical and Bioanalytical Chemistry 2 (2018)1. - ISSN 2642-4266
    Human biomonitoring studies to determine total titanium (total-Ti) and titanium dioxide (TiO2) particles require very sensitive inductively coupled plasma high resolution mass spectrometry (ICP-HRMS) methods. The result of such studies can only be reliably when used in a risk assessment if the analytical methods are fully validated, as reported here for human liver and spleen. For total-Ti an acidic HNO3/HF digestion was applied, followed by ICP-HRMS analysis of the acidic digests. For TiO2 particles a two-step digestion procedure was developed. In the first step the formaldehyde-fixed tissue was depolymerized and in the second step an enzymatic digestion was performed. Sample digests were analyzed with ICP-HRMS operated in single particle mode to detect TiO2 particles. Both methods were validated according to NEN 7777 using a scheme of duplicate analysis over an eight day period. Detection limits for total-Ti and TiO2 particles were 0.01 and 0.005 mg Ti/kg with a particle size quantification limit of 85 nm for TiO2 particles. Repeatability and reproducibility were 24% and 31% for the total titanium concentration, 22% and 39% for the particle titanium concentration, and 29% and 24% for the titanium dioxide particle size. In total 30 human tissue samples were analyzed with the developed and validated method. The results show a total-Ti content in the range of 0.02-0.09 mg Ti/kg in liver and 0.02-0.4 mg Ti/kg in spleen. The concentrations of particle TiO2 ranged from 0.01-0.08 mg Ti/kg in liver and from 0.01-0.1 mg Ti/kg in spleen. On the average, particle TiO2 explained up to 67% of the total-Ti concentrations. The detected TiO2 particles had a particle size range of 85 to 720 nm.
    The effects of pH variations on silver nanoparticles during human in vitro digestion as input for computational modelling approaches
    Undas, A.K. ; Bouwmeester, H. ; Rijkers, Deborah ; Bemmel, M.E.M. van; Munniks, S.M. ; Zande, M. van der - \ 2018
    Detection of nanoparticles in Dutch surface waters
    Peters, Ruud J.B. ; Bemmel, Greet van; Milani, Nino B.L. ; Hertog, Gerco C.T. den; Undas, Anna K. ; Lee, Martijn van der; Bouwmeester, Hans - \ 2018
    Science of the Total Environment 621 (2018). - ISSN 0048-9697 - p. 210 - 218.
    Cerium dioxide - Environmental - Nanoparticles - Silver - Single-particle ICP-MS - Titanium dioxide

    Nano-enabled consumer products are a likely source of nanoparticles in the environment and a number of studies have shown the release of nanoparticles from commercial products. Predicted environmental concentrations have been calculated but there is a need for real measurement data to validate these calculations. However, the detection of engineered nanoparticles in environmental matrices is challenging because of the low predicted environmental concentrations which may be in the ng/L range. In this study nanosized Ag, CeO2 and TiO2 have been measured in multiple surface water samples collected along the rivers Meuse and IJssel in the Netherlands using single-particle ICP-MS as measurement technique. Validation of the analytical method showed its capability to quantitatively determine nanoparticles at low concentrations. Concentration mass detection limits for Ag, CeO2 and TiO2 were 0.1 ng/L, 0.05 ng/L and 10 ng/L respectively. Size detection limits for Ag, CeO2 and TiO2 were 14, 10 and 100 nm. The results of the study confirm the presence of nano-sized Ag and CeO2 particles and micro-sized TiO2 particles in these surface waters. n-Ag was present in all samples in concentrations ranging from 0.3 to 2.5 ng/L with an average concentration of 0.8 ng/L and an average particle size of 15 nm. n-CeO2 was found in all samples with concentrations ranging from 0.4 to 5.2 ng/L with an average concentration of 2.7 ng/L and an average particle size of 19 nm. Finally, μ-TiO2 was found in all samples with a concentration ranging from 0.2 to 8.1 μg/L with an average concentration of 3.1 μg/L and an average particle size of 300 nm. The particle sizes that were found are comparable with the particle sizes that are used in nanomaterial applications and consumer products. The nanoparticle concentrations confirm the predicted environmental concentrations values in water for all three nanoparticles.

    Transfer Study of Silver Nanoparticles in Poultry Production
    Gallocchio, Federica ; Biancotto, Giancarlo ; Cibin, Veronica ; Losasso, Carmen ; Belluco, Simone ; Peters, Ruud ; Bemmel, Greet van; Cascio, Claudia ; Weigel, Stefan ; Tromp, Peter C. ; Gobbo, Federica ; Catania, Salvatore ; Ricci, Antonia - \ 2017
    Journal of Agricultural and Food Chemistry 65 (2017)18. - ISSN 0021-8561 - p. 3767 - 3774.
    chicken - nanomaterials - silver - silver nanoparticles - spICP-MS - transfer

    Silver nanoparticles (AgNPs) are of interest due to their antimicrobial activity and are seen as potential candidates to replace antibiotics in animal husbandry. A few studies have focused on this new application, but they lack any considerations about residual accumulation of AgNPs in edible animal tissues and animal products. In this research, a 22 day in vivo study was carried out by oral administration of 20 nm spherical PVP coated AgNPs to hens. Six doses of approximately 1 mg kg-1 of AgNPs-PVP each were administered to animals throughout the experimentation. Atomic absorption spectroscopy (AAS) was used for quantitative determination of residual total Ag in different organs and matrices. The analyses showed that Ag accumulates in livers (concentration ranging from 141 μg kg-1 to 269 μg kg-1) and yolks (concentration ranging from 20 μg kg-1 to 49 μg kg-1) but not in muscles, kidneys, and albumen belonging to hens of the treated group (tG2). Ag was not detected in animals of the control group (uG1) (i.e., total Ag < LOD = 10 μg kg-1). Single particle inductively coupled plasma mass spectrometry (spICP-MS) and scanning electron microscopy with energy dispersive X-ray detection (SEM-EDX) were employed to elucidate the presence of AgNPs in livers and yolks belonging to tG2 animals. spICP-MS highlighted that part of residual Ag found in livers (about 5-20%) is in NP form with an average dimension of approximately 20 nm. SEM-EDX technique confirmed the presence of AgNPs only in livers of treated animals. The results show that feeding AgNPs to hens may become a source of consumer exposure to AgNPs. As far as we know this is the first study showing transfer of AgNPs or reaction products thereof from animal feed to animal products.

    Hybrid imaging labels : Providing the link between mass spectrometry-based molecular pathology and theranostics
    Buckle, Tessa ; Wal, Steffen Van Der; Malderen, Stijn J.M. Van; Müller, Larissa ; Kuil, Joeri ; Unen, Vincent Van ; Peters, Ruud J.B. ; Bemmel, Greet van; McDonnell, Liam A. ; Velders, Aldrik H. ; Koning, Frits ; Vanhaeke, Frank ; Leeuwen, Fijs W.B. Van - \ 2017
    Theranostics 7 (2017)3. - ISSN 1838-7640 - p. 624 - 633.
    Bimodal - Fluorescence - LA-ICP-MS imaging - Mass cytometry - Mass spectrometry - Molecular imaging - Molecular pathology - Radioisotopes - SPECT
    Development of theranostic concepts that include inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) imaging can be hindered by the lack of a direct comparison to more standardly used methods for in vitro and in vivo evaluation; e.g. fluorescence or nuclear medicine. In this study a bimodal (or rather, hybrid) tracer that contains both a fluorescent dye and a chelate was used to evaluate the existence of a direct link between mass spectrometry (MS) and in vitro and in vivo molecular imaging findings using fluorescence and radioisotopes. At the same time, the hybrid label was used to determine whether the use of a single isotope label would allow for MS-based diagnostics. Methods: A hybrid label that contained both a DTPA chelate (that was coordinated with either 165Ho or 111In) and a Cy5 fluorescent dye was coupled to the chemokine receptor 4 (CXCR4) targeting peptide Ac-TZ14011 (hybrid-Cy5-Ac-TZ4011). This receptor targeting tracer was used to 1) validate the efficacy of (165Ho-based) mass-cytometry in determining the receptor affinity via comparison with fluorescence-based flow cytometry (Cy5), 2) evaluate the microscopic binding pattern of the tracer in tumor cells using both fluorescence confocal imaging (Cy5) and LA-ICP-MS-imaging (165Ho), 3) compare in vivo biodistribution patterns obtained with ICP-MS (165Ho) and radiodetection (111In) after intravenous administration of hybrid-Cy5-Ac-TZ4011 in tumor-bearing mice. Finally, LA-ICP-MS-imaging (165Ho) was linked to fluorescence-based analysis of excised tissue samples (Cy5). Results: Analysis with both mass-cytometry and flow cytometry revealed a similar receptor affinity, respectively 352 ± 141 nM and 245 ± 65 nM (p = 0.08), but with a much lower detection sensitivity for the first modality. In vitro LA-ICP-MS imaging (165Ho) enabled clear discrimination between CXCR4 positive and negative cells, but fluorescence microscopy was required to determine the intracellular distribution. In vivo biodistribution patterns obtained with ICP-MS (165Ho) and radiodetection (111In) of the hybrid peptide were shown to be similar. Assessment of tracer distribution in excised tissues revealed the location of tracer uptake with both LA-ICP-MS-imaging and fluorescence imaging.
    Oral intake of added titanium dioxide and its nanofraction from food products, food supplements and toothpaste by the Dutch population
    Rompelberg, Cathy ; Heringa, Minne B. ; Donkersgoed, Gerda van; Drijvers, José ; Roos, Agnes ; Westenbrink, Susanne ; Peters, R.J.B. ; Bemmel, M.E.M. van; Brand, Walter ; Oomen, Agnes G. - \ 2016
    National Institute for Public Health and the Environment
    food supplements - foodproducts - TiO 2 intake - Dutch population - Titanium dioxide - TiO 2 NPs - TiO 2 NPs ranges - bw - TiO 2 - TiO 2 ranges
    Titanium dioxide (TiO2) is commonly applied to enhance the white colour and brightness of food products. TiO2 is also used as white pigment in other products such as toothpaste. A small fraction of the pigment is known to be present as nanoparticles (NPs). Recent studies with TiO2 NPs indicate that these particles can have toxic effects. In this paper, we aimed to estimate the oral intake of TiO2 and its NPs from food, food supplements and toothpaste in the Dutch population aged 2 to over 70 years by combining data on food consumption and supplement intake with concentrations of Ti and TiO2 NPs in food products and supplements. For children aged 2–6 years, additional intake via ingestion of toothpaste was estimated. The mean long-term intake to TiO2 ranges from 0.06 mg/kg bw/day in elderly (70+), 0.17 mg/kg bw/day for 7–69-year-old people, to 0.67 mg/kg bw/day in children (2–6 year old). The estimated mean intake of TiO2 NPs ranges from 0.19 μg/kg bw/day in elderly, 0.55 μg/kg bw/day for 7–69-year-old people, to 2.16 μg/kg bw/day in young children. Ninety-fifth percentile (P95) values are 0.74, 1.61 and 4.16 μg/kg bw/day, respectively. The products contributing most to the TiO2 intake are toothpaste (in young children only), candy, coffee creamer, fine bakery wares and sauces. In a separate publication, the results are used to evaluate whether the presence of TiO2 NPs in these products can pose a human health risk.
    Dalende bodems, stijgende kosten : mogelijke maatregelen tegen veenbodemdaling in het landelijk en stedelijk gebied: beleidsstudie
    Born, G.J. van den; Kragt, F. ; Henkens, D. ; Rijken, B. ; Bemmel, B. van; Sluis, S. van der; Polman, N. ; Bos, Ernst Jenno ; Kuhlman, Tom ; Kwakernaak, C. ; Akker, J. van den; Diogo, V. ; Koomen, E. ; Lange, G. de; Bakel, J. van; Brinke, W.B.M. ten - \ 2016
    Den Haag : Planbureau voor de Leefomgeving (PBL-publicatie 1064) - 92
    Het doel van deze studie is om bodemdaling, de gevolgen van bodemdaling en het effect van mogelijke maatregelen in de Nederlandse laagveengebieden op een transparante manier in beeld te brengen. Dat doen we voor zowel het landelijk als stedelijk gebied. Deze studie laat de handelingsopties voor bestuurders zien voor afgewogen keuzes in het landelijk en stedelijk gebied ten aanzien van dilemma’s in de laagveengebieden die nu al op hun bord liggen of mogelijk in de toekomst zullen gaan spelen. Daarvoor kijken we naar een breed scala van effecten van bodemdaling, zoals de effecten op de landbouw en voedselproductie, het waterbeheer, het klimaat (CO2-emissie), natuur en landschap, en de bebouwde omgeving inclusief de infrastructuur. We geven een beeld van de orde van grootte van de problemen die door bodemdaling worden veroorzaakt en geven inzicht in de kosten en baten van bodemdaling. We kijken daarbij naar de gevolgen voor natuur, klimaat, landbouw, (water)beheer, wonen en infrastructuur.
    Oral intake of added titanium dioxide and its nanofraction from food products, food supplements and toothpaste by the Dutch population
    Rompelberg, Cathy ; Heringa, Minne B. ; Donkersgoed, Gerda van; Drijvers, José ; Roos, Agnes ; Westenbrink, Susanne ; Peters, Ruud ; Bemmel, Greet van; Brand, Walter ; Oomen, Agnes G. - \ 2016
    Nanotoxicology 10 (2016)10. - ISSN 1743-5390 - p. 1404 - 1414.
    Food additive E 171 - long-term dietary intake - nanomaterial - probabilistic modelling - TiO

    Titanium dioxide (TiO2) is commonly applied to enhance the white colour and brightness of food products. TiO2 is also used as white pigment in other products such as toothpaste. A small fraction of the pigment is known to be present as nanoparticles (NPs). Recent studies with TiO2 NPs indicate that these particles can have toxic effects. In this paper, we aimed to estimate the oral intake of TiO2 and its NPs from food, food supplements and toothpaste in the Dutch population aged 2 to over 70 years by combining data on food consumption and supplement intake with concentrations of Ti and TiO2 NPs in food products and supplements. For children aged 2–6 years, additional intake via ingestion of toothpaste was estimated. The mean long-term intake to TiO2 ranges from 0.06 mg/kg bw/day in elderly (70+), 0.17 mg/kg bw/day for 7–69-year-old people, to 0.67 mg/kg bw/day in children (2–6 year old). The estimated mean intake of TiO2 NPs ranges from 0.19 μg/kg bw/day in elderly, 0.55 μg/kg bw/day for 7–69-year-old people, to 2.16 μg/kg bw/day in young children. Ninety-fifth percentile (P95) values are 0.74, 1.61 and 4.16 μg/kg bw/day, respectively. The products contributing most to the TiO2 intake are toothpaste (in young children only), candy, coffee creamer, fine bakery wares and sauces. In a separate publication, the results are used to evaluate whether the presence of TiO2 NPs in these products can pose a human health risk.

    Physicochemical characterization of titanium dioxide pigments using various techniques for size determination and asymmetric flow field flow fractionation hyphenated with inductively coupled plasma mass spectrometry
    Helsper, Hans ; Peters, Ruud J.B. ; Bemmel, Greet van; Herrera Rivera, Zahira ; Wagner, Stephan ; Kammer, Frank von der; Tromp, Peter C. ; Hofmann, Thilo ; Weigel, Stefan - \ 2016
    Analytical and Bioanalytical Chemistry 408 (2016)24. - ISSN 1618-2642 - p. 6679 - 6691.
    Asymmetric flow field flow fractionation - Inductively coupled plasma mass spectrometry - Nanomaterials - Size distribution - Titanium dioxide - Zirconium

    Seven commercial titanium dioxide pigments and two other well-defined TiO2 materials (TiMs) were physicochemically characterised using asymmetric flow field flow fractionation (aF4) for separation, various techniques to determine size distribution and inductively coupled plasma mass spectrometry (ICPMS) for chemical characterization. The aF4-ICPMS conditions were optimised and validated for linearity, limit of detection, recovery, repeatability and reproducibility, all indicating good performance. Multi-element detection with aF4-ICPMS showed that some commercial pigments contained zirconium co-eluting with titanium in aF4. The other two TiMs, NM103 and NM104, contained aluminium as integral part of the titanium peak eluting in aF4. The materials were characterised using various size determination techniques: retention time in aF4, aF4 hyphenated with multi-angle laser light spectrometry (MALS), single particle ICPMS (spICPMS), scanning electron microscopy (SEM) and particle tracking analysis (PTA). PTA appeared inappropriate. For the other techniques, size distribution patterns were quite similar, i.e. high polydispersity with diameters from 20 to >700 nm, a modal peak between 200 and 500 nm and a shoulder at 600 nm. Number-based size distribution techniques as spICPMS and SEM showed smaller modal diameters than aF4-UV, from which mass-based diameters are calculated. With aF4-MALS calculated, light-scattering-based “diameters of gyration” (Øg) are similar to hydrodynamic diameters (Øh) from aF4-UV analyses and diameters observed with SEM, but much larger than with spICPMS. A Øg/Øh ratio of about 1 indicates that the TiMs are oblate spheres or fractal aggregates. SEM observations confirm the latter structure. The rationale for differences in modal peak diameter is discussed.

    Characterization of Titanium Dioxide Nanoparticles in Food Products: Analytical Methods To Define Nanoparticles
    Peters, R.J.B. ; Bemmel, M.E.M. van; Herrera-Rivera, Z. ; Helsper, J.P.F.G. ; Marvin, H.J.P. ; Weigel, S. ; Tromp, P.C. ; Oomen, A.G. ; Rietveld, A.G. ; Bouwmeester, H. - \ 2014
    Journal of Agricultural and Food Chemistry 62 (2014)27. - ISSN 0021-8561 - p. 6285 - 6293.
    field-flow fractionation - plasma-mass spectrometry - efficiency - exposure - tio2
    Titanium dioxide (TiO2) is a common food additive used to enhance the white color, brightness, and sometimes flavor of a variety of food products. In this study 7 food grade TiO2 materials (E171), 24 food products, and 3 personal care products were investigated for their TiO2 content and the number-based size distribution of TiO2 particles present in these products. Three principally different methods have been used to determine the number-based size distribution of TiO2 particles: electron microscopy, asymmetric flow field-flow fractionation combined with inductively coupled mass spectrometry, and single-particle inductively coupled mass spectrometry. The results show that all E171 materials have similar size distributions with primary particle sizes in the range of 60–300 nm. Depending on the analytical method used, 10–15% of the particles in these materials had sizes below 100 nm. In 24 of the 27 foods and personal care products detectable amounts of titanium were found ranging from 0.02 to 9.0 mg TiO2/g product. The number-based size distributions for TiO2 particles in the food and personal care products showed that 5–10% of the particles in these products had sizes below 100 nm, comparable to that found in the E171 materials. Comparable size distributions were found using the three principally different analytical methods. Although the applied methods are considered state of the art, they showed practical size limits for TiO2 particles in the range of 20–50 nm, which may introduce a significant bias in the size distribution because particles
    Development and validation of single particle ICP-MS for sizing and quatitative determination of nano-silver in chicken meat
    Peters, R.J.B. ; Herrera Rivera, Z.E. ; Bemmel, G. van; Marvin, H.J.P. ; Weigel, S. ; Bouwmeester, H. - \ 2014
    Analytical and Bioanalytical Chemistry 406 (2014)16. - ISSN 1618-2642 - p. 3875 - 3885.
    plasma-mass spectrometry - engineered nanoparticles - growth-performance - microbial profile - broiler-chickens - food - quantification - nutraceuticals - nanotechnology - nanomaterials
    The application of nanomaterials is leading to innovative developments in industry, agriculture, consumer products, and food and related sectors. However, due to the special properties of these materials there are concerns about their safety, especially because of our limited knowledge of human health effects and the fact that constantly new nanomaterials and applications thereof are being produced. The development of analytical techniques is a key element to understand the benefits as well as the risks of the application of such materials. In this study, a method is developed and validated for sizing and quantifying nano-silver in chicken meat using single particle inductive coupled plasma mass spectrometry (ICP-MS). Samples are processed using an enzymatic digestion followed by dilution of the digest and instrumental analysis of the diluted digest using single particle ICP-MS. Validation of the method in the concentration of 5-25 mg/kg 60-nm silver nanoparticles showed good performance with respect to trueness (98-99% for size, 91-101% for concentration), repeatability (
    Deltascenario’s voor 2050 en 2100 : nadere uitwerking 2012-2013
    Bruggemann, W. ; Dammers, E. ; Born, G.J. van den; Rijkens, B. ; Bemmel, B. van; Bouwman, A. ; Nabielek, K. ; Beersma, J. ; Hurk, B. van den; Polman, N.B.P. ; Linderhof, V.G.M. ; Folmer, C. ; Huizinga, F. ; Hommes, S. ; Linde, A. te; Didde, R. ; Roukema, M. - \ 2013
    Delft : Deltares - 65
    klimaatverandering - economische groei - economische ontwikkeling - scenario-analyse - overstromingen - risicoanalyse - climatic change - economic growth - economic development - scenario analysis - floods - risk analysis
    Planbureau voor de Leefomgeving (PBL), Centraal Planbureau (CPB), KNMI en Wageningen UR, LEI publiceren onder leiding van Deltares de ‘Deltascenario’s voor 2050 en 2100 – nadere uitwerking 2012-2013’. Deze scenario’s bouwen voort op de in 2011 gepubliceerde Deltascenario’s. Ze zijn gebaseerd op meer óf minder economische groei in combinatie met matige óf grote klimaatverandering. De vier scenario’s hebben de namen: RUST (resultaat van matige klimaatverandering en lage groei van economie en bevolking); DRUK (matige klimaatverandering, sterke groei); WARM (snelle klimaatverandering, lage groei); STOOM (snelle klimaatverandering, sterke groei). Aan de hand van elk van de uitgewerkte scenario’s toont het consortium voor welke uitdagingen Nederland in de toekomst kan komen te staan als het gaat om zoetwatervoorziening, de ruimtelijke inrichting van stad en land en bescherming tegen overstromingen.
    Zeepaarden Greenpeace brengen levens in gevaar
    Bemmel, N. van; Lindeboom, H.J. - \ 2011
    De Volkskrant (2011).
    Inventarisatie van compensatiegebied voor de steenuil rond "de Waalsprong", gemeente Nijmegen
    Jagers op Akkerhuis, G.A.J.M. - \ 2008
    Wageningen : Alterra (Alterra-rapport 1782) - 33
    stedelijke planning - uilen - habitats - inventarisaties - natuurcompensatie - betuwe - urban planning - owls - habitats - inventories - nature compensation - betuwe
    In dit rapport worden de resultaten gepresenteerd van inventarisatie van alternatieve gebieden voor de roofvogel steenuil. Als mogelijke steenuilhabitats komen ter sprake: Valburg, Homoet, zuidkant van Arnhem, Bemmel, Lingewaard en Ooijpolder
    Selection and optimization of proteolytically stable llama single-domain antibody fragments for oral immunotherapy
    Harmsen, M.M. ; Solt-Smits, C.B. van; Zijderveld-van Bemmel, A.M. van; Niewold, T.A. ; Zijderveld, F.G. van - \ 2006
    Applied Microbiology and Biotechnology 72 (2006)3. - ISSN 0175-7598 - p. 544 - 551.
    infectious intestinal-diseases - chicken egg antibodies - in-vitro evolution - escherichia-coli - saccharomyces-cerevisiae - ribonuclease-a - stability - affinity - prophylaxis - expression
    We previously demonstrated that oral application of the recombinant single-domain antibody fragment (VHH) clone K609, directed against Escherichia coli F4 fimbriae, reduced E. coli-induced diarrhoea in piglets, but only at high VHH doses. We have now shown that a large portion of the orally applied K609 VHH is proteolytically degraded in the stomach. Stringent selection for proteolytic stability identified seven VHHs with 7- to 138-fold increased stability after in vitro incubation in gastric fluid. By DNA shuffling we obtained four clones with a further 1.5- to 3-fold increased in vitro stability. These VHHs differed by at most ten amino acid residues from each other and K609 that were scattered over the VHH sequence and did not overlap with predicted protease cleavage sites. The most stable clone, K922, retained 41% activity after incubation in gastric fluid and 90% in jejunal fluid. Oral application of K922 to piglets confirmed its improved proteolytic stability. In addition, K922 bound to F4 fimbriae with higher affinity and inhibited fimbrial adhesion at lower VHH concentrations. K922 is thus a promising candidate for prevention of piglet diarrhoea. Furthermore, our findings could guide selection and improvement by genetic engineering of other recombinant antibody fragments for oral use.
    Gaafheid van bodem en reliëf gemeente Lingewaal en gemeente Geldermalsen; kennisinstrument bij de relatie cultuurhistorie en ruimtelijke ontwikkelingen
    Weijschedé, T.J. ; Exaltus, R.P. ; Koomen, A.J.M. ; Bemmel, B. van - \ 2006
    Wageningen : Alterra (Alterra-rapport 1249) - 82
    geomorfologie - fysiografische elementen - verstoord land - bodemstructuur (soil fabric) - bodemmorfologische kenmerken - cultureel erfgoed - landinrichting - instrumentatie - nederland - informatiesystemen - topologie - betuwe - geomorphology - physiographic features - disturbed land - soil fabric - soil morphological features - cultural heritage - land development - instrumentation - netherlands - information systems - topology - betuwe
    Dit project betreft een kennisproject dat als doelstelling heeft om nieuwe, breed toepasbare kennis te ontwikkelen over cultuurhistorische waarden in samenhang met de gaafheid van bodem en reliëf. Dit heeft voor de gemeenten Lingewaal en Geldermalsen een reëel (kaart)beeld opgeleverd van de gaafheid van bodem en reliëf en de aanwezigheid hierin en samenhang hiermee met archeologische, cultuurhistorische en aardkundige waarden. Deze informatie is gebundeld in een webportaal
    Nieuwe inzichten verankeren via goed ondernemerschap
    Noorduyn, L. - \ 2005
    Syscope Magazine 2005 (2005)7. - p. 3 - 4.
    agrarische bedrijfsvoering - ondernemerschap - persoonlijke ontwikkeling - duurzaamheid (sustainability) - managementvaardigheden - kennisoverdracht - systeeminnovatie - farm management - entrepreneurship - personal development - sustainability - management skills - knowledge transfer - system innovation
    André van der Goes, paprikateler in Bemmel heeft de eerste bijeenkomsten van de nieuwe cursus “Kijk …. mijn bedrijf achter de rug”. ‘Met de cursus wil ik eens kritisch naar ons bedrijf kijken en ervaringen uitwisselen met collega’s. Waar zitten bij ons ingesleten gewoontes en waar letten collega’s op bij een goede bedrijfsvoering.’
    Evaluation of two enzyme-linked immunosorbent assays for detecting Salmonella enterica subsp enterica serovar Dublin antibodies in bulk milk
    Veling, J. ; Zijderveld, F.G. van; Bemmel, A. ; Schukken, Y.H. ; Barkema, H.W. - \ 2001
    Clinical and Diagnostic Laboratory Immunology 8 (2001). - ISSN 1071-412X - p. 1049 - 1055.
    Two enzyme-linked immunosorbent assays (ELISAs) for the detecting Salmonella enterica subsp. enterica serovar Dublin antibodies in bulk milk were developed and evaluated for potential use in control programs. The ELISAs were based on either lipopolysacharide (LPS ELISA) or flagellar antigen (GP ELISA). Sensitivity was determined with 79 case herds with a wide range of clinical signs. Specificity was determined with 125 Dutch and 200 Swedish control herds. The relation between antibodies in bulk milk, antibodies in serum, and the level of milk production of individual cows was studied with 61 case herds. The optimal optical density (OD) values of the LPS ELISA and the GP ELISA were determined to be 0.2 and 0.5, respectively. The sensitivities of the LPS ELISA and the GP ELISA were 54 and 63°respectively, with a specificity of 98␏or both ELISAs with samples from the Dutch control herds. The specificities for samples from the Swedish herds were 100␏or the LPS ELISA and 95␏or the GP ELISA. The sensitivity of the combination of tests was 65 hen samples were run in parallel, and the specificity was 100 hen samples were run in series, irrespective of whether the samples came from Dutch or Swedish control herds. The variance (R2) in the OD value for bulk milk samples could be explained by the percentage of seropositive lactating cows in a herd with the LPS ELISA for 51␘f the samples and with the GP ELISA for 72ÐThe variance in the OD value was best explained by the combination of the percentage of seropositive lactating cows in the herd and the mean log10 serum antibody titer for that herd (R2 = 62␏or the LPS ELISA and R2 = 75␏or the GP ELISA). Case herds more often tested negative by the ELISA with bulk milk when the percentage of seropositive lactating cows was less than 5ÐIt is concluded that both ELISAs with bulk milk can be used in control programs to distinguish between infected and noninfected herds. Specificity can be increased by using the two tests in combination. Sensitivity was relatively low for both single tests and both tests combined.
    Evaluation of three newly developed enzyme-linked immunosorbent assays and two agglutination tests for detecting Salmonella enterica subsp enterica serovar Dublin infections in dairy cattle
    Veling, J. ; Zijderveld, F.G. van; Zijderveld van Bemmel, A.M. van; Barkema, H.W. ; Schukken, Y.H. - \ 2000
    Journal of Clinical Microbiology 38 (2000)12. - ISSN 0095-1137 - p. 4402 - 4407.
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