OPTIS—An Einstein Mission for Improved Tests of Special and General Relativity

The mission OPTIS aims at improving tests of the foundations of Special and General Relativity by up to three orders of magnitude. The individual tests concern the isotropy and constancy of the speed of light, the time dilation (or Doppler effect), the universality of the gravitational redshift with various combinations of high precision clocks. Furthermore, laser tracking and a laser link allows a strongly improved measurement of the gravitomagnetic Lense–Thirring effect, of the gravitoelectric Einstein perigee advance, of the gravitational redshift, and a search for deviations from Newtonian gravity.For this mission, technologies are required which have been used recently to carry through the most precise tests of Special Relativity. The precision of these tests can be further increased under space conditions thanks to longer integration times, larger changes in the orbital velocity, and larger differences of the gravitational potential. Furthermore, very precise laser tracking and linking of satellites is a well established technique and will provide, in combination with the active drag–free control system, very accurate orbit data. The core technologies for OPTIS are optical cavities, highly stabilized lasers, capacitive gravitational reference sensors, drag–free control, ion clocks, frequency combs, and laser tracking systems. These technologies are also key technologies for other future missions.     

Dust Coulomb balls: three-dimensional plasma crystals

First experimental investigations of spherical three-dimensional plasma crystals consisting of hundreds or thousands of micrometer-sized polymer particles suspended in a radio-frequency gas discharge are described. These "Coulomb balls" are not subject to the formation of dust-free regions (voids) and have an unusual structure of nested crystalline shells. While small systems are in a solid phase, large systems show melting effects.     

Vitrification of human spermatozoa without cryoprotectants

The aim of our study was to investigate the effects of vitrification (cooling rate approximately 10000(C/min) without cryoprotectants on swim-up prepared human spermatozoa in comparison to standard conventional freezing with cryoprotectants. Motility, morphology, rate of viability and acrosome reaction of spermatozoa were evaluated. The described method of cryopreservation of human spermatozoa by direct plunging into liquid nitrogen slush without cryoprotectants was effective and could be recommended for routine IVF.     

Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to reveal the substrate specificity of the peptidyl-cysteine decarboxylase EpiD

The microbial flavoenzyme EpiD catalyzes the oxidative decarboxylation of peptidyl-cysteines to peptidyl-aminoenethiols. These unusual C-terminally modified peptides are intermediates in the biosynthesis of the tetracyclic peptide antibiotic epidermin, which belongs to the lantibiotics family. The peptide SFNSYCC represents the C-terminal partial sequence of the natural precursor peptide EpiA. EpiA is posttranslationally modified to form finally the lantibiotic epidermin. The substrate specificity of EpiD was investigated using high-resolution mass spectrometry and the heptapeptide library SFNSXCC. The enzymatic conversion of particular peptides can be observed by a mass loss of m/z 46. In contrast to the previously used triple quadrupole instrument, electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) was able to resolve and detect all precursor and converted peptides with identical nominal masses in a single measurement, avoiding the necessity to investigate single peptides. Furthermore, a new substrate SFNSCCC of the enzyme EpiD was detected within the reaction mixture.     

Efficient control of the diastereoselectivity and regioselectivity in the singlet-oxygen ene reaction of chiral oxazolidine-substituted alkenes by a remote urea NH functionality: comparison with dimethyldioxirane and m-chloroperbenzoic acid epoxidations

The singlet-oxygen ene reaction and the epoxidation by DMD of chiral oxazolidine-substituted alkenes, equipped with a free urea NH functionality and a conformationally fixed double bond, proceed in high like diastereoselectivity (up to >95:5); also a high regioselectivity was found for the (1)O(2) ene reaction. Capping of the free NH functionality by methylation erases this like selectivity for both oxidants and significantly reduces the regioselectivity in the ene reaction. These data demonstrate effective hydrogen bonding between the remote urea NH functionality and the oxidant that favors the like attack on the C-C double bond. For (1)O(2), the hydrogen bonding in the exciplex results in preferred hydrogen abstraction from the alkyl group cis to the directing urea functionality.     

Magnetic resonance cholangiopancreatography (MRCP) of intraductal papillary-mucinous neoplasm (IPMN) of the pancreas: case report.

The intraductal papillary-mucinous neoplasm (IPMN) is the rarest of the cystic pancreatic tumors. Endoscopic retrograde cholangiopancreatography (ERCP) is currently the gold standard for evaluating IPMN's and can demonstrate dilatation of the main duct or side branches, mural nodules, filling defects, and communication between the tumor and the main pancreatic duct. Recent literature has shown that MRCP may be more sensitive and specific in the diagnosis of IPMN In this case report, we present a patient with IPMN of the pancreas where MRCP was superior to ERCP in characterizing the tumor.     

3D Simulation of Point Defect Migration in Ferroelectrics

Electric fatigue in functional materials involves a set of phenomena which lead to the degradation of materials with an increasing number of electrical cycles. Ionic and electronic charge carriers, later 0 as point defects, interact with each other and with microstructural elements in the bulk and with interfaces, which can lead to degradation, or finally to mechanical damage and dissociation reactions, see e.g. [1]. With this in mind, efforts are made to calculate the fields caused by point defects to simulate their interaction as well as to verify the used material parameters. Here, a material with linear electro mechanical coupling is used. The applied methods are integral transforms (Radon Transform) and a combination of Difference Methods and a Fast Fourier Transform to obtain solutions in an infinite domain and under periodic boundary conditions, respectively. The point defect interaction is studied within the framework of material or configurational forces. These forces are used in combination with reasonable kinetic laws to simulate defect migration, cf. [2]. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

A series of diarylsubstituted oximes as potential substrate for new aldose reductase inhibitors

In the course of our research aimed at the discovery of new compounds acting as aldose reductase inhibitors, we tested a series of some (E)‐ and (Z)‐ω‐[[(aryldiazinylmethylene)amino]oxy]alkanoic acids, which were found to have moderate in vitro inhibitory activity. On this basis we have now prepared several new derivatives modified both at the length of the chain and at its terminal carboxylic group, together with compounds carrying various substituents at the phenyl ring. This paper describes their synthesis and biological properties.