Learn More
A deformation of the algebra of diffeomorphisms is constructed for canonically deformed spaces with constant deformation parameter θ. The algebraic relations remain the same, whereas the comultiplication rule (Leibniz rule) is different from the undeformed one. Based on this deformed algebra a covariant tensor calculus is constructed and all the concepts(More)
We study a deformation of infinitesimal diffeomorphisms of a smooth manifold. The deformation is based on a general twist. This leads to a differential geometry on a noncommutative algebra of functions whose product is a star-product. The class of noncommutative spaces studied is very rich. Non-anticommutative superspaces are also briefly considered. The(More)
PURPOSE There is a growing amount of data suggesting that carcinomas of the right and left colon should be considered as different tumor entities. Using the data and analysis compiled in the German multicentered study "Colon/Rectum Cancer," we aimed to clarify whether the existing differences influence clinical and histological parameters, the perioperative(More)
Gauge theories on a space-time that is deformed by the Moyal-Weyl product are constructed by twisting the coproduct for gauge transformations. This way a deformed Leibniz rule is obtained, which is used to construct gauge invariant quantities. The connection will be enveloping algebra valued in a particular representation of the Lie algebra. This gives rise(More)
BACKGROUND Poor treatment results obtained with palliative chemotherapy for advanced gastric cancer indicate the need for new effective and well-tolerated regimens. PATIENTS AND METHODS Forty-three patients with locally advanced or metastatic gastric cancer were enrolled in a phase II study to evaluate the efficacy and safety of combination chemotherapy(More)
Collaborative filtering aims at helping users find items they should appreciate from huge catalogues. In that field, we can distinguish user-based, item-based and model-based approaches. For each of them, many options play a crucial role for their performances, and in particular the similarity function defined between users or items, the number of neighbors(More)
INTRODUCTION An adequate approach to surgically induced sepsis needs an early and targeted antibiotic therapy in addition to focus sanitation. The PCR-based LightCycler Septifast test can detect 90 % of the sepsis-associated microoganisms (e. g., Gram-positive, Gram-negative bacteria, fungi) within only a few hours. PATIENTS AND METHODS A systematic(More)
BACKGROUND Colorectal cancer (CRC) is one of the most common malignancies in the Western world. Histopathologically, adenocarcinomas are mostly diagnosed. Mucinous and signet-ring cell subtypes occur with a very low incidence. However, these subtypes differ remarkably in terms of clinical, histological and molecular biological characteristics. The aim of(More)
BACKGROUND The open abdomen (OA) is a severe disease pattern accompanied by high morbidity and mortality. It is either result of a surgical dis-ease or approach. The aim of this review article is to provide a systematic overview on the options of a temporary closure of the abdominal wall including early and late consequences in the treatment of an open(More)