289 research outputs found

    Wase baksteen gedateerd. Natuurwetenschappelijk dateringsonderzoek in de Sint-Andreas- en Sint-Gislenuskerk in Belsele (Sint-Niklaas)

    Get PDF
    De nauwkeurige datering van middeleeuwse gebouwen is vaak problematisch. Gedateerde geschreven bronnen over de bouwgeschiedenis zijn niet voorhanden of vatbaar voor diverse interpretaties. Vormelijke kenmerken staan niet altijd garant voor een nauwkeurige en gefundeerde datering. Ook bouwmaterialen en constructietechnieken kunnen soms niet meer bieden dan grove chronologische aanwijzingen. Sinds enkele decennia wordt in toenemende mate gebruik gemaakt van natuurwetenschappelijke technieken voor de absolute datering van middeleeuwse gebouwen. In dit onderzoek werd de parochiekerk Sint-Andreas- en Sint-Gislenus in Belsele (Sint-Niklaas) onderworpen aan verschillende natuurwetenschappelijke dateringstechnieken, zoals onder meer 14C-datering, thermoluminescentie (TL), optisch gestimuleerde luminescentie (OSL) en archeomagnetische analyse (AM). Het onderzoek focuste op de in baksteen gebouwde lichtbeuk van het middenschip en de bijbehorende dakkap, traditioneel gedateerd in het tweede kwart van de 13de eeuw. Voor Vlaanderen alvast een unieke en waardevolle gevalstudie

    An integrated palaeoenvironmental investigation of a 6200 year old peat sequence from Ile de la Possession, Iles Crozet, sub-Antarctica

    No full text
    International audienceA 6200 year old peat sequence, cored in a volcanic crater on the sub-Antarctic Ile de la Possession (Iles Crozet), has been investigated, based on a multi-proxy approach. The methods applied are macrobotanical (mosses, seeds and fruits) and diatom analyses, complemented by geochemical (Rock-Eval6) and rock magnetic measurements. The chronology of the core is based on 5 radiocarbon dates. When combining all the proxy data the following changes could be inferred. From the onset of the peat formation (6200 cal yr BP) until ca. 5550 cal yr BP, biological production was high and climatic conditions must have been relatively warm. At ca. 5550 cal yr BP a shift to low biological production occurred, lasting until ca. 4600 cal yr BP. During this period the organic matter is well preserved, pointing to a cold and/or wet environment. At ca. 4600 cal yr BP, biological production increased again. From ca. 4600 cal yr BP until ca. 4100 cal yr BP a “hollow and hummock” micro topography developed at the peat surface, resulting in the presence of a mixture of wetter and drier species in the macrobotanical record. After ca. 4100 cal yr BP, the wet species disappear and a generally drier, acidic bog came into existence. A major shift in all the proxy data is observed at ca. 2800 cal yr BP, pointing to wetter and especially windier climatic conditions on the island probably caused by an intensification and/or latitudinal shift of the southern westerly belt. Caused by a stronger wind regime, erosion of the peat surface occurred at that time and a lake was formed in the peat deposits of the crater, which is still present today

    Thalidomide, dexamethasone and lovastatin with autologous stem cell transplantation as a salvage immunomodulatory therapy in patients with relapsed and refractory multiple myeloma

    Get PDF
    The treatment of patients with multiple myeloma usually includes many drugs including thalidomide, lenalidomide and bortezomib. Lovastatin and other inhibitors of HMG-CoA reductase demonstrated to exhibit antineoplasmatic and proapoptotic properties in numerous in vitro studies involving myeloma cell lines. We treated 91 patients with relapsed or refractory multiple myeloma with thalidomide, dexamethasone and lovastatin (TDL group, 49 patients) or thalidomide and dexamethasone (TD group, 42 patients). A clinical response defined of at least 50% reduction of monoclonal band has been observed in 32% of TD patients and 44% of TDL patients. Prolongation of overall survival and progression-free survival in the TDL group as compared with the TD group has been documented. The TDL regimen was safe and well tolerated. The incidence of side effects was comparable in both groups. Plasma cells have been cultured in vitro with thalidomide and lovastatin to assess the impact of both drugs on the apoptosis rate of plasma cells. In vitro experiments revealed that the combination of thalidomide and lovastatin induced higher apoptosis rate than apoptosis induced by each drug alone. Our results suggest that the addition of lovastatin to the TD regimen may improve the response rate in patients with relapsed or refractory myeloma

    NOEnet–Use of NOE networks for NMR resonance assignment of proteins with known 3D structure

    Get PDF
    Motivation: A prerequisite for any protein study by NMR is the assignment of the resonances from the 15N−1H HSQC spectrum to their corresponding atoms of the protein backbone. Usually, this assignment is obtained by analyzing triple resonance NMR experiments. An alternative assignment strategy exploits the information given by an already available 3D structure of the same or a homologous protein. Up to now, the algorithms that have been developed around the structure-based assignment strategy have the important drawbacks that they cannot guarantee a high assignment accuracy near to 100%

    Significance of Frequencies, Compositions, and/or Antileukemic Activity of (DC-stimulated) Invariant NKT, NK and CIK Cells on the Outcome of Patients With AML, ALL and CLL

    Get PDF
    Invariant natural killer T (iNKT)/natural killer (NK)/cytokine-induced killer (CIK) cells are important for immune surveillance. (I) Novel combinations of antibody 6B11 (targeting the V alpha 24-J alpha 18-invariant T-cell receptor) with CD4/CD8/CD1d/V alpha 24 for iNKT subset detection and "T/NK cell-like"-iNKT subsets were defined. Compared with healthy peripheral blood mononuclear cells (MNC) (significantly) lower proportions of iNKT cells (6B11 (+)/6B11 (+)CD3 (+)/6B11 (+)CD161(+)), NK cells (CD3(-)CD56(+)/CD3(-)CD161(+)), and CIK cells (CD3(+)CD56(+)/CD3(+)CD161(+)) were found in peripheral blood MNC from acute myeloid (AML)/acute myeloid, lymphoid (ALL)/chronic lymphoid leukemia (CLL) patients in acute disease stages. Subtyping of iNKT cells revealed (significantly) higher proportions of CD3(+) T cells and CD161(+) NK cells in AML/ALL/CLL expressing 6B11 compared with healthy MNC. Prognostic evaluations showed higher proportions of iNKT/NK/CIK cells in favorable AML subgroups (younger age, primary, no extramedullary disease, achievement/maintenance of complete remission) or adult ALL and CLL patients. (II) iNKT/NK/CIK cell frequencies increased after (vs. before) mixed lymphocyte cultures of T-cell-enriched immune reactive cells stimulated with MNC/whole blood with or without pretreatment with "cocktails" (dendritic cells generating methods/kits inducing blasts' conversion to leukemia-derived dendritic cells from AML patients). Individual "cocktails" leading to "highest" iNKT cell frequencies could be defined. Antileukemic blast lytic activity correlated significantly with frequencies of iNKT/NK/CIK cells. In summary healthy MNC show significantly more iNKT/NK/CIK cells compared with AML/ALL/CLL MNC, a shift in the iNKT cell composition is seen in healthy versus leukemic samples and iNKT/NK/CIK cell-proportions in AML/ALL/CLL MNC samples correlate with prognosis. "Cocktail"-treated AML blasts lead to higher iNKT/NK/CIK cell frequencies and samples with antileukemic activity show significantly higher frequencies of iNKT/NK/CIK cells. Proportions of iNKT/NK/CIK cells should regularly be evaluated in AML/ALL/CLL diagnosis panels for quantitative/prognostic estimation of individual patients' anti leukemic potential and their role in dendritic cells/leukemia-derived dendritic cells triggered immune surveillance
    • 

    corecore