14 research outputs found

    Effect of Cesium and Phosphate Addition to Mo/V/W Mixed Oxide Catalysts for the Gas Phase Oxidation of Methacrolein to Methacrylic Acid

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    The present study investigates modified Mo/V/W mixed oxides as a possible alternative for state of the art heteropoly acid catalysts (HPA) in the partial oxidation of methacrolein (MAC) to methacrylic acid (MAA). Even though HPAs show an excellent activity and MAA selectivity, their long-term stability is unsatisfying, rendering the catalyst inoperable after runtimes of roughly 6 months. Mo/V/W mixed oxides consisting of M1 and a hexagonal (Mo,V,W)Ox_{x}-phase (h-phase) in varying proportions were modified by impregnation with aqueous solutions containing cesium and phosphate ions. All samples were characterized with respect to specific surface area, crystallinity, elemental and phase composition. The catalytic performance in the oxidation of MAC to MAA was investigated using a continuously operated reaction unit with tubular fixed bed reactor. Impregnation with cesium and phosphate ions and subsequent heating triggers the transformation of the mixed oxide into a Keggin-type HPA, whereby the h-phase is more reactive than M1. The transformation into HPA is accompanied by a change in the catalytic properties, i.e., the selectivity to MAA is considerably improved. Compared to HPA synthesized directly, however, the HPA samples obtained by transformation of mixed oxides exhibit no advantages, be it with respect to activity, MAA selectivity or stability

    DoH!Bots Team Description for RoboCup 2007

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    The DoH!Bots (Dortmund Humanoid Robots) is a team of researchers and students from Dortmund University. Our group took part in the humanoid league for the first time at RoboCup 2006, as part of the team BreDoBrothers which was a cooperation with Bremen University. This year both groups want to compet

    A Murine Model for Inducing and Manipulating Hair Follicle Regression (Catagen): Effects of Dexamethasone and Cyclosporin A

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    Most cases of hair loss are based on premature induction of follicle regression (catagen). Deciphering the unknown regulation of catagen is therefore clinically important, but catagen is also an excellent model for organ involution by rapid terminal differentiation and for epithelial cell death (apoptosis). We here report an assay for the controlled pharmacologic induction and manipulation of catagen follicles. Dexamethasone-21-acetate (0.1%) was applied once daily to depilation-induced, growing follicles (anagen VI) on the backs of C57 B1-6 mice. Characteristic catagen-associated changes in skin color were photodocumented and assessed by morphometric histology. Topical dexamethasone induced catagen-like follicles significantly earlier, more homogeneously, and also more extensively than vehicle. This process was inhibited by high intraperitoneal doses of cyclosporin A. In addition to its clinical relevance as a screening assay for catagen-blocking drugs, this simple murine model is an attractive tool for dissecting the molecular, cellular, and developmental biology of catagen

    Cisplatin and vindesine combination chemotherapy in advanced malignant melanoma: an EORTC phase II study

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    Sixty-one evaluable patients with measurable advanced malignant melanoma received 4-week courses of a combination of cisplatin 100 mg/m2 as a 24-hr i.v. infusion on day 1 and vindesine 3 mg/m2 as an i.v. bolus on days 1, 8, 15 for two courses and every other week thereafter. Two patients achieved complete response for 46 and 81+ weeks respectively, eleven patients achieved partial response for a median of 17 weeks (range 8-26) and three patients had no change for 24 weeks or more. The overall response rate of 21% did not seem to be affected by prior chemotherapy or site of indicator lesions, soft tissue vs visceral. Myelosuppression, consisting essentially of leucopenia, required dose schedule modifications in 41% of the first two courses and 12% of the remaining courses, but never produced major complications. Non-hematologic toxic effects were prominent, especially nausea and vomiting, which were universal. Alopecia was seen in 71% of the patients, neuromuscular manifestations in 39%, diarrhea in 30%, renal impairment in 25%, mucositis in 12%, ototoxicity in 7% and phlebitis in 3%. These results do not suggest striking additive or synergistic antitumor activity of cisplatin and vindesine in advanced malignant melanoma, at least with the method of drug administration selected for this trial. © 1982.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    GermanTeam 2005 The German National RoboCup Team

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    The GermanTeam participates as a national team in the Sony Legged Robot League. It consists of students and researchers from the following four universities
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