Automatically Welded Tubular X‐Joints for Jacket Substructures: Prediction of the Technical Fatigue Crack Location

To increase the competitiveness of jacket substructures compared to monopiles a changeover from an individual towards a serial jacket production based on automated manufactured tubular joints combined with standardized pipes has to be achieved. Therefore, this paper addresses fatigue tests of automatically welded tubular X-joints focusing on the location of the technical fatigue crack. The detected location of the technical crack is compared to numerical investigations predicting the most fatigue prone notch considering the structural stress approach as well as the notch stress approach. Besides, the welding process of the automated manufactured tubular X-joints is presented

Tajixanthonhydrat und dessen Verwendung zur Behandlung von Tumorerkrankungen

Es werden Tajixanthonhydrat sowie Tajixanthonhydrat-Derivate der allgemeinen Formel I $F1 beschrieben sowie ein Verfahren zu ihrer Herstellung. Tajixanthonhydrat besitzt u. a. eine ausgeprägte Biofilm-inhibierende Wirkung gegen Staphylococcus epidermidis

Forced exercise-induced osteoarthritis is attenuated in mice lacking the small leucine-rich proteoglycan decorin

Objective Interterritorial regions of articular cartilage matrix are rich in decorin, a small leucine-rich proteoglycan and important structural protein, also involved in many signalling events. Decorin sequesters transforming growth factor P (TGFP3), thereby regulating its activity. Here, we analysed whether increased bioavailability of TGF3 in decorin-deficient (Dcn(-/-)) cartilage leads to changes in biomechanical properties and resistance to osteoarthritis (OA). Methods Unchallenged knee cartilage was analysed by atomic force microscopy (AFM) and immunohistochemistry. Active transforming growth factor beta-1 (TGF beta 1) content within cultured chondrocyte supernatants was measured by ELISA. Quantitative realtime (RT)-PCR was used to analyse mRNA expression of glycosaminoglycan (GAG)-modifying enzymes in C28/12 cells following TGFf31 treatment. In addition, OA was induced in Dcn(-/-) and wild-type (WT) mice via forced exercise on a treadmill. Results AFM analysis revealed a strikingly higher compressive stiffness in Dcn(-/-) than in WT cartilage. This was accompanied by increased negative charge and enhanced sulfation of GAG chains, but not by alterations in the levels of collagens or proteoglycan core proteins. In addition, decorin-deficient chondrocytes were shown to release more active TGF beta 1. Increased TGF beta signalling led to enhanced Chstl 1 sulfotransferase expression inducing an increased negative charge density of cartilage matrix. These negative charges might attract more water resulting in augmented compressive stiffness of the tissue. Therefore, decorin-deficient mice developed significantly less OA after forced exercise than WT mice. Conclusions Our study demonstrates that the disruption of decorin -restricted TGF beta signalling leads to higher stiffness of articular cartilage matrix, rendering joints more resistant to OA. Therefore, the loss of an important structural component can improve cartilage homeostasis

The importance of growth kinetic analysis in determining bacterial susceptibility against antibiotics and silver nanoparticles

Routine antibiotics susceptibility testing still relies on standardized cultivation-based analyses, including measurement of inhibition zones in conventional agar diffusion tests and endpoint turbidity-based measurements. Here, we demonstrate that common off-line monitoring and endpoint determination after 18-24 h could be insufficient for reliable growth-dependent evaluation of antibiotic susceptibility. Different minimal inhibitory concentrations were obtained in 20- and 48 h microdilution plate tests using an Enterococcus faecium clinical isolate (strain UKI-MB07) as a model organism. Hence, we used an on-line kinetic assay for simultaneous cultivation and time-resolved growth analysis in a 96-well format instead of off-line susceptibility testing. Growth of the Enterococcus test organism was delayed up to 30 h in the presence of 0.25 μg mL of vancomycin and 8 μg mL of fosfomycin, after which pronounced growth was observed. Despite the delayed onset of growth, treatment with fosfomycin, daptomycin, fusidic acid, cefoxitin, or gentamicin resulted in higher maximum growth rates and/or higher final optical density values compared with antibiotic-free controls, indicating that growth stimulation and hormetic effects may occur with extended exposure to sublethal antibiotic concentrations. Whereas neither maximum growth rate nor final cell density correlated with antibiotic concentration, the lag phase duration for some antibiotics was a more meaningful indicator of dose-dependent growth inhibition. Our results also reveal that non-temporal growth profiles are only of limited value for cultivation-based antimicrobial silver nanoparticle susceptibility testing. The exposure to Ag(0) nanoparticles led to plasma membrane damage in a concentration-dependent manner and induced oxidative stress in Enterococcus faecium UKI-MB07, as shown by intracellular ROS accumulation

New communesin derivatives from the fungus Penicillium sp. derived from the Mediterranean sponge Axinella verrucosa

The ethyl acetate extract of Penicillium sp., derived from the Mediterranean sponge Axinella verrucosa, yielded the known compound communesin B (1) and its new congeners communesins C (2) and D (3), as well as the known compounds griseofulvin, dechlorogriseofulvin, and oxaline. All structures were unambiguously established by 1D and 2D NMR and MS data. In several bioassays performed on different leukemia cell lines, the communesins exhibited moderate antiproliferative activity

Anthraquinones and betaenone derivatives from the sponge-associated fungus Microsphaeropsis species : novel inhibitors of protein kinases

An undescribed fungus of the genus Microsphaeropsis, isolated from the Mediterranean sponge Aplysina aerophoba, produces two new betaenone derivatives (1, 2) and three new 1,3,6, 8-tetrahydroxyanthraquinone congeners (5-7). The structures of the compounds were established on the basis of NMR spectroscopic and mass spectrometric data and by CD spectroscopy. This is the first report wherein the (1)H and (13)C NMR data of the betaenone congeners are fully and unambiguously assigned on the basis of two-dimensional NMR spectroscopy. Furthermore, we describe the first elucidation of the absolute configuration of 1-(2'-anthraquinonyl)ethanols such as 5 and 6, by quantum chemical calculation of their circular dichroism (CD) and comparison with experimentally measured spectra. Moreover, it was shown that compounds 1, 5, 6, and 7 are inhibitors of PKC-epsilon, CDK4, and EGF receptor tyrosine kinases