Superconducting versus normal conducting cavities

One of the most important issues of high-power hadron linacs is the choice of technology with respect to superconducting or room-temperature operation. The favour for a specific technology depends on several parameters such as the beam energy, beam current, beam power and duty factor. This contribution gives an overview of the comparison between superconducting and normal conducting cavities. This includes basic radiofrequency (RF) parameters, design criteria, limitations, required RF and plug power as well as case studies.Comment: 20 pages, contribution to the CAS - CERN Accelerator School: Course on High Power Hadron Machines; 24 May - 2 Jun 2011, Bilbao, Spai

Frequency Jump at Low Energies

One or more radio-frequency jumps are usually necessary for realizing a >= 100 AMeV/u proton or ion driver linac. Typically, such jumps happen in the range of \b{eta} = 0.2-0.6 between the resonator structures fitting to this \b{eta}-range, e.g. DTL, HWR, CCL or elliptical cavities. We propose to perform the first frequency jump already at low energies (\b{eta} <= 0.1) between two RFQ accelerators, which can bring some unique advantages. First studies have been performed and the results proved that this idea is feasible and promising. Many efforts have been and are being made to address the most critical issue for the jumps i.e. the beam matching at the transition

Synthesis of Octahydroperylene, the Framework of Altertoxin III

Routes to the framework of perylenequinone-derived mycotox- ins of the dihydroanthracene type are described. Starting with anthracene derivatives, attachment of C3 units at positions 9 and 10 and twofold cyclization would furnish the required pentacycle. Heck-type couplings, S$_N$2 additions of enolates, alkynyl and allyl additions turned out to be not successful, while addition of a Grignard reagent prepared from acetal-protected 3-bromopropionaldehyde to anthraflavic acid methyl ester, subsequent acetal cleavage, and Birch reduction furnished octahydroperylene in only four steps

Oxidation of Dithia Compounds: Comparative Experimental and Theoretical Studies on 1,3 Bis(methylthio)propane, Bis(methylthio)methane, and Theoretical Studies on 1,3-Bis(methylthio)propane, Bis(methylthio)methane, and meso-4,6-Dimethyl-1,3-dithiane

1,3-Bis(methylthio)propane, bis(methylthio)methane, and meso-4,6-dimethyl-1,3-dithiane were oxidized with 1–4 equivalents of hydrogen peroxide, meta-chloroperbenzoic acid, sodium periodate, or potassium permanganate, respectively, and the amounts of oxidized substrates (sulfoxides and/or sulfones) were determined by NMR spectroscopy. Sulfanyl groups in the former starting material turned out to behave like independent functions, while a mutual influence of the sulfur functions was verified in the latter compounds. A meaningful investigation was possible in the conformationally constrained dithiane derivative. Oxidation of the dithiane with stoichiometric amounts of periodate led to exclusive formation of bissulfoxides, while hydrogen peroxide and meta-chloroperbenzoic acid yielded the possible products less specifically and permanganate preferentially furnished sulfones. The experimental investigations were supported by calculations on energies and stereoelectronic effects of starting materials, products, and transition states. The unique property of permanganate to exclusively yield sulfones might be due to its special oxidation mechanism, where the sulfur is not only acting as nucleophile, but concomitantly as electrophilic moiety

Fermented mistletoe extract as a multimodal antitumoral agent in gliomas

In Europe, commercially available extracts from the white-berry mistletoe (Viscum album L.) are widely used as a complementary cancer therapy. Mistletoe lectins have been identified as main active components and exhibit cytotoxic effects as well as immunomodulatory activity. Since it is still not elucidated in detail how mistle toe extracts such as ISCADOR communicate their effects, we analyzed the mechanisms that might be responsible for their antitumoral function on a molecular and functional level. ISCADOR-treated glioblastoma (GBM) cells down-regulate central genes involved in glioblastoma progression and malignancy such as the cytokine TGF-β and matrix-metalloproteinases. Using in vitro glioblastoma/immune cell co-cultivation assays as well as measurement of cell migration and invasion, we could demonstrate that in glioblastoma cells, lectin-rich ISCADOR M and ISCADOR Q significantly enforce NK-cell-mediated GBM cell lysis. Beside its immune stimulatory effect, ISCADOR reduces the migratory and invasive potential of glioblastoma cells. In a syngeneic as well as in a xenograft glioblastoma mouse model, both pretreatment of tumor cells and intratumoral therapy of subcutaneously growing glioblastoma cells with ISCADOR Q showed delayed tumor growth. In conclusion, ISCADOR Q, showing multiple positive effects in the treatment of glioblastoma, may be a candidate for concomitant treatment of this cancer