Restoration and preservation of the reinforced concrete poles of fence at the former Auschwitz concentration and extermination camp

AbstractThe objective of this study was to assess the present state of the reinforced concrete poles of fence at the former Auschwitz I and Auschwitz II-Birkenau concentration and extermination camp. The poles were subjected to renovation about 10 years ago. After this time some deficiencies of applied renovation method were noticed. Cracks appeared between fresh and original part of concrete cover. Analysis of the reasons of these failures was performed and a modification of used restoration method was proposed to overcome this deficiency. The modification consists in application of sacrificial anodes mounted outside the pole, in soil and inside the concrete cover

Inhibition of Proliferation and Induction of Apoptosis in Multiple Myeloma Cell Lines by CD137 Ligand Signaling

BACKGROUND: Multiple myeloma (MM) is a malignancy of terminally-differentiated plasma cells, and the second most prevalent blood cancer. At present there is no cure for MM, and the average prognosis is only three to five years. Current treatments such as chemotherapy are able to prolong a patient's life but rarely prevent relapse of the disease. Even hematopoietic stem cell transplants and novel drug combinations are often not curative, underscoring the need for a continued search for novel therapeutics. CD137 and its ligand are members of the Tumor Necrosis Factor (TNF) receptor and TNF superfamilies, respectively. Since CD137 ligand cross-linking enhances proliferation and survival of healthy B cells we hypothesized that it would also act as a growth stimulus for B cell cancers. METHODOLOGY/PRINCIPAL FINDINGS: Proliferation and survival of B cell lymphoma cell lines were not affected or slightly enhanced by CD137 ligand agonists in vitro. But surprisingly, they had the opposite effects on MM cells, where CD137 ligand signals inhibited proliferation and induced cell death by apoptosis. Furthermore, secretion of the pro-inflammatory cytokines, IL-6 and IL-8 were also enhanced in MM but not in non-MM cell lines in response to CD137 ligand agonists. The secretion of these cytokines in response to CD137 ligand signaling was consistent with the observed activation of the classical NF-kappaB pathway. We hypothesize that the induction of this pathway results in activation-induced cell death, and that this is the underlying mechanism of CD137-induced MM cell death and growth arrest. CONCLUSIONS/SIGNIFICANCE: These data point to a hitherto unrecognized role of CD137 and CD137 ligand in MM cell biology. The selective inhibition of proliferation and induction of cell death in MM cells by CD137 ligand agonists may also warrant a closer evaluation of their therapeutic potential

The influence of UV light on performance of poly(methyl methacrylate) in regard to dye-sensitised solar cells

Low - cost production and simplicity of the process as well as comparable efficiencies make Dye - Sensitised Solar Cells (DSSC) competitive among commercial solar technologies. Excellent transparency and weatherability make the poly(methyl methacrylate) (PMMA) polymer a possible substitute of transparent, conductive glass commonly used in Dye-Sensitised Solar Cells. In the presented investigation thin PMMA film was applied. UV-C irradiation in range of 200-280nm was used to accelerate polymer degradation. Combination of Electrochemical Impedance Spectroscopy (EIS) and Atomic Force Microscopy (AFM) were used in order to provide information about photodegradation of the polymer coating as well as durability of PMMA film. AFM allowed evaluation of the photodegradation of PMMA coating and indicated possible local defects. The data gained using EIS technique confirmed that the PMMA deteriorated over a period of 141 hours of irradiation with UV-

Investigation of morphological and electrical properties of the PMMA coating upon exposure to UV irradiation based on AFM studies

The objective of study was to investigate the influence of UV irradiation on morphological changes of a polymeric surface and its electrical properties. In the presented investigation thin poly(methyl methacrylate)(PMMA) film was applied onto iron substrate by solution casting method. UV-C irradiation in range of 200–280nm was used as a deteriorative factor to induce polymer degradation. Atomic force microscopy (AFM) method was employed to study surface topography of the PMMA coatings before and after exposure to UV-illumination. Photo-induced changes in the polymer surface taking form of microcracks were illustrated by AFM images. In order to support results obtained with AFM method, electrochemical impedance spectroscopy (EIS) measurements were conducted. The authors chose this technique to confirm whether the changes on UV-exposed PMMA surface observed on AFM images could indicate potential sites of the polymer coating long before serious damage could occur. Both methods EIS and AFM were used in order to provide information about durability of PMMA fil