Publications by authors named "Rabea Sietmann"

Objective: Many dental diseases are attributable to biofilms. The screening of antimicrobial substances, in particular, requires a high sample throughput and a realistic model, the evaluation must be as quick and as simple as possible. For this purpose, a colorimetric assay of the tetrazolium salt XTT (sodium 3'-[1-[(phenylamino)-carbony]-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene-sulfonic acid hydrate) converted by saliva biofilms is recommended.

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Unlabelled: Platelets play a dominant role in the pathogenesis of bleeding disorders and cardiovascular pathology (e.g., myocardial infarction).

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Aim: Dental biofilms play a major role in the pathogenesis of peri-implant mucositis. Biofilm reduction is a pre-requisite for a successful therapy of peri-implant mucosal lesions. In this study, we evaluated the effect of three different plasma devices on the reduction of Streptococcus mutans (S.

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Plasma medicine and also decontamination of bacteria with physical plasmas is a promising new field of life science with huge interest especially for medical applications. Despite numerous successful applications of low temperature gas plasmas in medicine and decontamination, the fundamental nature of the interactions between plasma and microorganisms is to a large extent unknown. A detailed knowledge of these interactions is essential for the development of new as well as for the enhancement of established plasma-treatment procedures.

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Knowledge on absolute protein concentrations is mandatory for the simulation of biological processes in the context of systems biology. A novel approach for the absolute quantification of proteins at a global scale has been developed and its applicability demonstrated using glucose starvation of the Gram-positive model bacterium Bacillus subtilis and the pathogen Staphylococcus aureus as proof-of-principle examples. Absolute intracellular protein concentrations were initially determined for a preselected set of anchor proteins by employing a targeted mass spectrometric method and isotopically labeled internal standard peptides.

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Purpose: To determine the surface characteristics of porcine corneal lenticules after Femtosecond Lenticule Extraction.

Methods: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used to create refractive corneal lenticules on 10 freshly isolated porcine eyes. The surface regularity on the corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system.

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Background: To determine the surface characteristics of human corneal lenticules after femtosecond laser surgery for myopia.

Methods: The Carl Zeiss Meditec AG VisuMax® femtosecond laser system was used for refractive correction called Femtosecond Lenticule Extraction on 24 myopic eyes. The surface regularity on the refractive corneal lenticules recovered was evaluated by assessing scanning electron microscopy images using an established scoring system.

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Background: Pseudomonas aeruginosa is commonly associated with contact lens (CL) -related eye infections, for which bacterial adhesion and biofilm formation upon hydrogel CLs is a specific risk factor. Whilst P. aeruginosa has been widely used as a model organism for initial biofilm formation on CLs, in-vitro models that closely reproduce in-vivo conditions have rarely been presented.

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In this paper we demonstrate that the anodic, bioelectrocatalytic performance of wastewater inoculum based, mixed culture microbial biofilms can be considerably improved by using a consecutive, purely electrochemical selection and biofilm acclimatization procedure. The procedure may represent an alternative to a repetitive mechanical biofilm removal, re-suspension and electrochemically facilitated biofilm formation. By using the proposed technique, the bioelectrocatalytic current density was increased from the primary to the secondary biofilm from 250 microAcm(-2) to about 500 microAcm(-2); and the power density of respective microbial fuel cells could be increased from 686 mWm(-2) to 1487 mWm(-2).

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Aromatic organic compounds that are present in the environment can have toxic effects or provide carbon sources for bacteria. We report here the global response of Bacillus subtilis 168 to phenol and catechol using proteome and transcriptome analyses. Phenol induced the HrcA, sigmaB and CtsR heat-shock regulons as well as the Spx disulfide stress regulon.

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The yeast Trichosporon mucoides and the filamentous fungus Paecilomyces lilacinus as biphenyl oxidizing organisms are able to oxidize chlorinated biphenyl derivatives. Initial oxidation of derivatives chlorinated at C4 position started at the non-halogenated ring and went on up to ring cleavage. The products formed were mono- and dihydroxylated 4-chlorobiphenyls, muconic acid derivatives 2-hydroxy-4-(4-chlorophenyl)-muconic acid and 2-hydroxy-5-(4-chlorophenyl)-muconic acid as well as the corresponding lactones 4-(4-chlorophenyl)-2-pyrone-6-carboxylic acid and 3-(4-chlorophenyl)-2-pyrone-6-carboxylic acid.

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The biotransformation of biphenyl, dibenzofuran, and diphenyl ether by 24 strains belonging to 18 species of the genus Trichosporon was investigated to assess the taxonomic relevance of this property at species and genus level. With the exceptions of T. brassicae and T.

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