RNA secondary structure design

We consider the inverse-folding problem for RNA secondary structures: for a given (pseudo-knot-free) secondary structure find a sequence that has that structure as its ground state. If such a sequence exists, the structure is called designable. We implemented a branch-and-bound algorithm that is able to do an exhaustive search within the sequence space, i.e., gives an exact answer whether such a sequence exists. The bound required by the branch-and-bound algorithm are calculated by a dynamic programming algorithm. We consider different alphabet sizes and an ensemble of random structures, which we want to design. We find that for two letters almost none of these structures are designable. The designability improves for the three-letter case, but still a significant fraction of structures is undesignable. This changes when we look at the natural four-letter case with two pairs of complementary bases: undesignable structures are the exception, although they still exist. Finally, we also study the relation between designability and the algorithmic complexity of the branch-and-bound algorithm. Within the ensemble of structures, a high average degree of undesignability is correlated to a long time to prove that a given structure is (un-)designable. In the four-letter case, where the designability is high everywhere, the algorithmic complexity is highest in the region of naturally occurring RNA.Comment: 11 pages, 10 figure

Successful interdisciplinary treatment of a rare cause of acute myocardial ischaemia from intermittent tumour-associated obstruction of the left main coronary artery: a case report

Background A papillary fibroelastoma of the aortic valve has been reported as a rare cause of myocardial ischaemia. An advanced combined interventional and surgical approach leading to sufficient therapy for the patient is presented in this case report. Case summary A 56-year-old female patient presented in an emergency room of a hospital with an acute coronary syndrome. Over 1.5 years, recurrent stable angina had been known in the patient and significant coronary artery disease has already been ruled out in a previous coronary angiogram. The patient was immediately transferred to the catheter laboratory due to cardiogenic shock where a drug-eluting stent was implanted to, firstly, recanalize the left main coronary artery (LMCA) and, secondly, to protect the left main ostium from obstruction by an echocardiographic-proven mass. During subsequent deterioration of haemodynamics caused by decreasing left ventricular function and acute severe mitral insufficiency, firstly an intra-aortic balloon pump and secondly a veno-arterial extracorporeal membrane oxygenation was established through the femoral vessels. The patient was transferred to our cardiac surgery unit and was successfully operated utilizing a valve-sparing technique by extracting the tumour mass from the left coronary cusp and extracting the stent carefully from the LMCA. Histology revealed a papillary fibroelastoma. Conclusion A papillary fibroelastoma of the aortic valve with intermittent obstruction of the coronary arteries requires surgical therapy. Interventional recanalization and extracorporeal support might be useful strategies to ensure the patient's safety as a bridge to surgery

Quasi-homogenous photocatalysis of quantum-sized Fe-doped TiO2_{2} in optically transparent aqueous dispersions

In this study, the preparation of anatase TiO2 nanocrystals via a facile non-aqueous sol–gel route and their characterization are reported. The 3–4 nm particles are readily dispersable in aqueous media and show excellent photoreactivity in terms of rhodamine B degradation. The catalytic performance can be further increased considerably by doping with iron and UV-light irradiation as a pre-treatment. The effect of surface ligands (blocked adsorption sites, surface defects etc.) on the photoreactivity was thoroughly probed using thermogravimetric analysis combined with mass spectrometry. Photoelectrochemical characterization of thin-film electrodes made from the same TiO2 nanocrystals showed the opposite trend to the catalytic experiments, that is, a strong decrease in photocurrent and quantum efficiency upon doping due to introduction of shallow defect states

Occupational medical prophylaxis for the musculoskeletal system: A function-oriented system for physical examination of the locomotor system in occupational medicine (fokus(C))

Occupational physicians are very often confronted with questions as to the fitness of the postural and locomotor systems, especially the spinal column. Occupational medical assessment and advice can be required by patients with acute symptoms, at routine check-ups, by persons who have problems doing certain jobs, and for expert medical reports as to the fitness of persons with chronic disorders or after operations. Therefore, for occupational medical purposes a physical examination must aim primarily to investigate functions and not structures or radiologic evidence. The physical examination should be structured systematically and according to regions of the body and, together with a specific (pain) anamnesis should provide a basis for the medical assessment

Öffentliches Haftungsrecht: Ökonomisierung – Europäisierung – Dogmatisierung

Das Staatshaftungsrecht, das besser Öffentliches Haftungsrecht hieße, ist ein verrufenes Rechtsgebiet, chaotisch und zersplittert, ein »Flickenteppich« und ein »Durcheinander« zugleich. Diese Abhandlung sinnt auf Abhilfe. Sie schlägt eine neue Dogmatik vor, die das Öffentliche Haftungsrecht zu systematisieren sucht und der ein ökonomisch informierter und unionsrechtlich inspirierter Einheitsanspruch zu Grunde liegt. Der Einheitsanspruch berücksichtigt die Konvergenzen, die im herkömmlichen Staatshaftungsrecht zu beobachten sind, und nimmt Vorwürfe der Sach- und Zeitwidrigkeit auf, die gegen das überkommene Staatshaftungsrecht erhoben werden. Die Schrift wurde in Münster mit dem Habilitationspreis der Juristischen Studiengesellschaft und dem Nachwuchsförderpreis der Universitätsgesellschaft ausgezeichnet

Mineralogy and Provenance of Quaternary Sediments in the Gaxun Nur Basin, Northwestern Inner Mongolia, China

Abstract HKT-ISTP 2013 B