Erhöhung der Dauerhaftigkeit von Wasserbauwerken durch faserbewehrte, zementgebundene Komposite

Sehr viele Infrastrukturbauwerke haben bereits eine hohe Nutzungsdauer hinter sich und müssen instandgesetzt oder neu errichtet werden. Im Zuge der aktuellen Bestrebungen, mit möglichst geringen Materialeinsätzen die notwendige Bauwerkssicherheit zu erzeugen, rücken dünne Instandsetzungsschichten immer häufiger in den Fokus der Planenden. Aufgrund fehlender Beispielbauten und Umsetzungsrichtlinien werden solche Lösungen jedoch oft nicht ausgeführt. Im hier vorgestellten Beispiel wird anhand einer über 100 Jahre alten Schleuse die Möglichkeit einer Sanierung mit dünnen Schichten aus hochduktilem Beton (engl.: strain-hardening cement-based composites, SHCC) und Textilbeton (engl.: textile reinforced concrete, TRC) vorgestellt sowie Ergebnisse aus dem nunmehr dreijährigen Bauwerksmonitoring dargelegt

Mitochondria Targeted Protein-Ruthenium Photosensitizer for Efficient Photodynamic Applications

Organelle-targeted photosensitization represents a promising approach in photodynamic therapy where the design of the active photosensitizer (PS) is very crucial. In this work, we developed a macromolecular PS with multiple copies of mitochondria-targeting groups and ruthenium complexes that displays highest phototoxicity toward several cancerous cell lines. In particular, enhanced anticancer activity was demonstrated in acute myeloid leukemia cell lines, where significant impairment of proliferation and clonogenicity occurs. Finally, attractive two-photon absorbing properties further underlined the great significance of this PS for mitochondria targeted PDT applications in deep tissue cancer therapy

Expression of cell cycle regulators and frequency of TP53 mutations in high risk gastrointestinal stromal tumors prior to adjuvant imatinib treatment

Despite of multitude investigations no reliable prognostic immunohistochemical biomarkers in GIST have been established so far with added value to predict the recurrence risk of high risk GIST besides mitotic count, primary location and size. In this study, we analyzed the prognostic relevance of eight cell cycle and apoptosis modulators and of TP53 mutations for prognosis in GIST with high risk of recurrence prior to adjuvant treatment with imatinib. In total, 400 patients with high risk for GIST recurrence were randomly assigned for adjuvant imatinib either for one or for three years following laparotomy. 320 primary tumor samples with available tumor tissue were immunohistochemically analyzed prior to treatment for the expression of cell cycle regulators and apoptosis modulators cyclin D1, p21, p16, CDK4, E2F1, MDM2, p53 and p-RB1. TP53 mutational analysis was possible in 245 cases. A high expression of CDK4 was observed in 32.8% of all cases and was associated with a favorable recurrence free survival (RFS), whereas high expression of MDM2 (12.2%) or p53 (35.3%) was associated with a shorter RFS. These results were independent from the primary KIT or PDGFRA mutation. In GISTs with higher mitotic counts was a significantly increased expression of cyclin D1, p53 and E2F1. The expression of p16 and E2F1 significantly correlated to a non-gastric localization. Furthermore, we observed a significant higher expression of p21 and E2F1 in KIT mutant GISTs compared to PDGFRA mutant and wt GISTs. The overall frequency of TP53 mutations was low (n = 8; 3.5%) and could not be predicted by the immunohistochemical expression of p53. In summary, mutation analysis in TP53 plays a minor role in the subgroup of high-risk GIST before adjuvant treatment with imatinib. Strong expression of MDM2 and p53 correlated with a shorter recurrence free survival, whereas a strong expression of CDK4 correlated to a better recurrence free survival.Peer reviewe

Recommendations of RILEM TC 260-RSC for using superabsorbent polymers (SAP) for improving freeze–thaw resistance of cement-based materials

This recommendation is focused on application of superabsorbent polymers (SAP) for the improvement of the resistance of cement-based materials to freeze—thaw attack with or without deicing salts. A simple approach to the determination of the amount and properties of SAP as well as methods to verify SAP effectiveness for frost resistance protection are presented

Staphylococcus aureus Panton-Valentine Leukocidin Is a Very Potent Cytotoxic Factor for Human Neutrophils

The role of the pore-forming Staphylococcus aureus toxin Panton-Valentine leukocidin (PVL) in severe necrotizing diseases is debated due to conflicting data from epidemiological studies of community-associated methicillin-resistant S. aureus (CA-MRSA) infections and various murine disease-models. In this study, we used neutrophils isolated from different species to evaluate the cytotoxic effect of PVL in comparison to other staphylococcal cytolytic components. Furthermore, to study the impact of PVL we expressed it heterologously in a non-virulent staphylococcal species and examined pvl-positive and pvl-negative clinical isolates as well as the strain USA300 and its pvl-negative mutant. We demonstrate that PVL induces rapid activation and cell death in human and rabbit neutrophils, but not in murine or simian cells. By contrast, the phenol-soluble modulins (PSMs), a newly identified group of cytolytic staphylococcal components, lack species-specificity. In general, after phagocytosis of bacteria different pvl-positive and pvl-negative staphylococcal strains, expressing a variety of other virulence factors (such as surface proteins), induced cell death in neutrophils, which is most likely associated with the physiological clearing function of these cells. However, the release of PVL by staphylococcal strains caused rapid and premature cell death, which is different from the physiological (and programmed) cell death of neutrophils following phagocytosis and degradation of virulent bacteria. Taken together, our results question the value of infection-models in mice and non-human primates to elucidate the impact of PVL. Our data clearly demonstrate that PVL acts differentially on neutrophils of various species and suggests that PVL has an important cytotoxic role in human neutrophils, which has major implications for the pathogenesis of CA-MRSA infections

The glycoprotein-hormones activin A and inhibin A interfere with dendritic cell maturation

<p>Abstract</p> <p>Background</p> <p>Pregnancy represents an exclusive situation in which the immune and the endocrine system cooperate to prevent rejection of the embryo by the maternal immune system. While immature dendritic cells (iDC) in the early pregnancy decidua presumably contribute to the establishment of peripheral tolerance, glycoprotein-hormones of the transforming growth factor beta (TGF-beta) family including activin A (ActA) and inhibin A (InA) are candidates that could direct the differentiation of DCs into a tolerance-inducing phenotype.</p> <p>Methods</p> <p>To test this hypothesis we generated iDCs from peripheral-blood-monocytes and exposed them to TGF-beta1, ActA, as well as InA and Dexamethasone (Dex) as controls.</p> <p>Results</p> <p>Both glycoprotein-hormones prevented up-regulation of HLA-DR during cytokine-induced DC maturation similar to Dex but did not influence the expression of CD 40, CD 83 and CD 86. Visualization of the F-actin cytoskeleton confirmed that the DCs retained a partially immature phenotype under these conditions. The T-cell stimulatory capacity of DCs was reduced after ActA and InA exposure while the secretion of cytokines and chemokines was unaffected.</p> <p>Conclusion</p> <p>These findings suggest that ActA and InA interfere with selected aspects of DC maturation and may thereby help preventing activation of allogenic T-cells by the embryo. Thus, we have identified two novel members of the TGF-beta superfamily that could promote the generation of tolerance-inducing DCs.</p

UPGRADING THE CONCEPT OF UHPFRC FOR HIGH DURABILITY IN THE CRACKED STATE: THE CONCEPT OF ULTRA HIGH DURABILITY CONCRETE (UHDC) IN THE APPROACH OF THE H2020 PROJECT RESHEALIENCE

Current solutions for new concrete constructions in Extremely Aggressive Exposures, as recommended and enforced by design codes, are not taking into account new cement-based construction materials, such as Ultra High Performance Fibre Reinforced Concrete, neither new constituents specifically conceived to improve the concrete durability, because of the lack of standards and technical awareness by most designers and contractors. The H2020 ReSHEALience project will upgrade to the concept of Ultra High Durability Concrete (UHDC), combining nano-scale constituents (nano-cellulose, alumina nanofibers) and self-healing promoters (crystalline admixtures). The paper will present the approach pursued in the project together with a synopsis of the results of ongoing research

Erhöhung der Dauerhaftigkeit von Wasserbauwerken durch faserbewehrte, zementgebundene Komposite

Sehr viele Infrastrukturbauwerke haben bereits eine hohe Nutzungsdauer hinter sich und müssen instandgesetzt oder neu errichtet werden. Im Zuge der aktuellen Bestrebungen, mit möglichst geringen Materialeinsätzen die notwendige Bauwerkssicherheit zu erzeugen, rücken dünne Instandsetzungsschichten immer häufiger in den Fokus der Planenden. Aufgrund fehlender Beispielbauten und Umsetzungsrichtlinien werden solche Lösungen jedoch oft nicht ausgeführt. Im hier vorgestellten Beispiel wird anhand einer über 100 Jahre alten Schleuse die Möglichkeit einer Sanierung mit dünnen Schichten aus hochduktilem Beton (engl.: strain-hardening cement-based composites, SHCC) und Textilbeton (engl.: textile reinforced concrete, TRC) vorgestellt sowie Ergebnisse aus dem nunmehr dreijährigen Bauwerksmonitoring dargelegt

Erhöhung der Dauerhaftigkeit von Wasserbauwerken durch faserbewehrte, zementgebundene Komposite

Sehr viele Infrastrukturbauwerke haben bereits eine hohe Nutzungsdauer hinter sich und müssen instandgesetzt oder neu errichtet werden. Im Zuge der aktuellen Bestrebungen, mit möglichst geringen Materialeinsätzen die notwendige Bauwerkssicherheit zu erzeugen, rücken dünne Instandsetzungsschichten immer häufiger in den Fokus der Planenden. Aufgrund fehlender Beispielbauten und Umsetzungsrichtlinien werden solche Lösungen jedoch oft nicht ausgeführt. Im hier vorgestellten Beispiel wird anhand einer über 100 Jahre alten Schleuse die Möglichkeit einer Sanierung mit dünnen Schichten aus hochduktilem Beton (engl.: strain-hardening cement-based composites, SHCC) und Textilbeton (engl.: textile reinforced concrete, TRC) vorgestellt sowie Ergebnisse aus dem nunmehr dreijährigen Bauwerksmonitoring dargelegt

Floating breakwater pontoon pilot cast with carbon textile reinforcement-based ultra high durability concrete: Materials development and testing, and implementation in the North Atlantic (Irelands west coast)

A floating unit with three pontoons made of epoxy-coated carbon textile reinforced, ultra-high durability concrete (ECF UHDC), mineral impregnated carbon fibre-reinforced UHDC (MCF UHDC) and, as references, steel-reinforced concretes has been designed and installed in the Northern Atlantic. While marine structures with steel reinforcement require large cover depths, which cause problems in size, cost, environmental friendliness and short service life, carbon textile reinforced concrete (TRC) cannot suffer from chloride-induced corrosion of a metal reinforcement. In the EU H2020 project “ReSHEALience” (rethinking coastal defence and green-energy service infrastructures through enhanced-durability highperformance cement-based materials), TRCs have been modified with functional admixtures from consortium partners. A mineral self-healing promoter and alumina nano-fibers have, among others, been implemented to boost high-performance concretes towards UHDCs. Resulting composite variants have been applied in a full-scale floating unit that has been launched in the harbor of Galway at the Irish West Coast in June 2020. Such a floating body is a representation of breakwaters installed to reduce wave impacts to the coast. Besides, TRC-based UHDC can be applied as strengthening and repair layer on concrete structures to enhance their service life in general