Compounds 2 and 4 were obtained from V. officinalis for the first time, and compound 1 is a new triterpenoid compound, which exhibits significantly higher antitumor activity against human hepatoma cell line Bel 7402 in vitro than the blank control.”
“The spin and electric charge of electrons in nanoscale artificial magnetic systems exhibit peculiar behaviors especially in a radio-frequency (rf) region via spin-wave excitations. One of the interesting effects is the rectification of the rf current in nanomagnets. We present a detailed experimental magnetic field dependence of the rectifying spectrum induced by a rf current flowing through the Selleck Smoothened Agonist ferromagnetic
wire and discuss in terms of the quantized spin-wave modes excited by the microwave injection. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3056143]“
“Two new polyketides, 7,8-dihydroxy-3,5,7-trimethyl-8,8a-dihydro-1H-isochromen-6(7H)-one (1) and 6-(hydroxymethyl)-2,2-dimethyl-3,4-dihydro-2H-chromene-3,4-diol
(2), together with a known nitrogen-containing polyketide (cytochalasin-type of metabolites), -cytochalasin (3), have been isolated from the fermentation broth of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from selleckchem the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. The absolute configurations of compound 1 were determined by NOESY analysis and the literature data were compared with circular dichroism (CD) spectroscopy. The cytotoxic effects on MCF-7, NCI-H460 and SF-268
cell lines of all compounds were evaluated by the sulforhodamine B method.”
“Background: Despite the renewed interest in metal-on-metal selleck kinase inhibitor implants in the past two decades, the underlying wear mechanisms and biological effects are still not fully understood.
Methods: This paper first reviews the tribology of metal-on-metal bearings, bringing new insights into the interaction of wear and corrosion, and putting the characteristics and the potential origin of wear particles in perspective with the proposed wear mechanisms. It then summarizes the current knowledge on the biological effects of particles and metal ions in relation to these wear mechanisms.
Results: Tribochemical reactions play an important role in the wear of metal-on-metal joints. The generated tribomaterial, which progressively forms by mechanical mixing of the uppermost nanocrystalline zone of the metal surface with proteins from the synovial fluid, governs the wear rate and influences the corrosive behavior of the bearing. Nanometer-sized wear particles may initially originate from the passivation layer covering the implant surface and then detach from this tribolayer.