The virtue of the multifunctional triazene linkers in the efficient solid-phase synthesis of heterocycle libraries.

With the implementation of combinatorial chemistry into the modern drug discovery process, the approach to novel diverse heterocycle libraries is an indispensable requirement. Triazenes, which are concealed diazonium salts, can be used to link functionalized arenes and amines to generate various heterocyclic structures, namely, benzoannelated nitrogen heterocycles, upon cleavage from the resin. Since triazene anchors are stable toward various reagents and perform well under a range of reaction conditions, these multifunctional linkers are well suited for automated solid-phase syntheses and the syntheses of complex organic molecules, such as natural products, on solid supports.

Carrier-wave Rabi flopping: role of the carrier-envelope phase.

Recently, a dependence of Rabi flopping on the carrier-envelope phase of the exciting laser pulses was predicted theoretically [Phys. Rev. Lett.

Risk reduction in craniofacial surgery using computer-based modeling and intraoperative immersion.

We present a two-stage concept for risk reduction in craniofacial surgery, consisting of preoperative risk modeling and intraoperative risk reduction. Preoperatively it is important to find and to visualize risk sources in order to minimize them. Our risk model is composed by superimposition of an isotropic risk potential and an anisotropic tissue field constituent.

3D structure from endoscopic images.

Endoscopy is an important procedure for the diagnostic and therapy of various pathologies. In 2000, the Institute for Process Control and Robotics/Universität Karlsruhe (TH) has developed a basic framework for reconstructing 3D models from image sequences. The framework is able to realise automatic navigation for new colonoscopes with own driving system and on the other hand to offer a virtual 3D endoscopic view during bad visibility conditions caused by e.

Realtime textured 3D-models for medical applications.

Realistic visualisation becomes more and more important in medicine. Whenever a patient individual 3D-model was generated the aim is to visualise the model as realistic as possible. We use 3D-models in our diagnostic and therapeutic tools for intraoperative visualisation of e.

A new, accurate and easy to implement camera and video projector model.

In 2000, the Institute for Process Control and Robotics/Universität Karlsruhe (TH) has developed a prototype system for projector based augmented reality consisting of a state-of-the-art PC, two CCD cameras and a video projector which is used for registration and projection of surgical planning data. Tracking, registration as well as projection require an accurate calibration process for cameras and video projectors. We have developed a new, flexible, plain and easy to implement model, which can both be used for calibration of cameras and video projectors.

Interactive simulation of the teeth cleaning process using volumetric prototypes.

In this paper, an interactive simulation system for teeth cleaning is presented. This simulation system offers assistance for optimizing design and manufacturing of new toothbrushes. Data acquisition and pre-processing techniques for the model generation are shown and the mathematical method for modelling of the elastic behaviour of the toothbrushes parts is explained.

Volumetric implant-planning based on Symmetry Considerations.

Symmetry Considerations can be used not only to plan the desired shape of reconstructured bone structures, but also to generate prototypes for soft tissue implants. The poster describes a system which allows to calculate a symmetry plane in the facial area automatically and computes proposals for implants or transplants. The system presented has been used to calculate soft tissue implants and a replacement for parts of the lower jaw.

Evaluation of INPRES--Intraoperative Presentation of surgical planning and simulation results.

In this paper we present fundamental results of the first evaluation of INPRES in a laboratory environment. While the system itself--an HMD-based approach for intraoperative augmented reality in head and neck surgery--has been described elsewhere several times, this paper will focus on methods and outcome of recently accomplished test procedures.

A VR-system supporting symmetry related cranio-maxillofacial surgery.

The reconstruction of patients with large deformations in the facial area should consider functional aspects as well as aesthetical ones. In this paper, an integrated virtual reality system which allows bone manipulation, osteotomy planning, calculation of implants for soft tissue and bones combined with the calculation of the post-operative appearance is presented. It is a valuable tool for a wide range of cranio-maxillofacial surgeries.

A new protocol for the one-pot synthesis of symmetrical biaryls.

Biaryls play an important role in modern organic chemistry. Although a large number of protocols for the synthesis of symmetrical and unsymmetrical biaryls already exist, most of them are not generally applicable. In our studies toward the total synthesis of the secalonic acids, we were interested in bis(pinacolato)diboron as a reagent for transforming haloarenes into arylboronic esters.

Ortho-chalcogenostannates as ligands: syntheses, crystal structures, electronic properties, and magnetism of novel compounds containing ternary anionic substructures [M4(mu4-Se)(SnSe4)4]10- (M=Mn, Zn, Cd, Hg), 3(infinity)[[Hg4(mu4-Se)(SnSe4)3]6-], or 1(infinity)[[HgSnSe4]2-].

By reaction of K4[SnSe4].1.5 MeOH with CdCl2 or Hg(OAc)2 in water/methanol it was possible to prepare single crystals of four novel compounds that contain ternary anionic coordination oligomers and polymers: [K10(H2O)16(MeOH)(0.

Autoregulation of canonical Wnt signaling controls midbrain development.

After the primary anterior-posterior patterning of the neural plate, a subset of wnt signaling molecules including Xwnt-1, Xwnt-2b, Xwnt-3A, Xwnt-8b are still expressed in the developing brain in a region spanning from the posterior part of the diencephalon to the mesencephalon/metencephalon boundary. In this expression field, they are colocalized with the HMG-box transcription factor XTcf-4. Using antisense morpholino loss-of-function strategies, we demonstrate that the expression of this transcription factor depends on Xwnt-2b, which itself is under the control of XTcf-4.

Effect of an industrial waste water on the nitrification in fixed-bed biofilm reactors--use of fluorescence in-situ hybridization (FISH).

The influence of an industrial waste water containing partly toxic and poorly biodegradable substances on an autotrophic biocenosis was investigated. Nitrifying bacteria were identified using fluorescently-labeled oligonucleotide probes and epifluorescence microscopy. Industrial waste water was used untreated and after ozonation to simulate the effects of indirect discharge to municipal waste water treatment plants.

Syntheses of the 47 electron clusters [(Cp*Fe)3(mu3-X)2] (X = S, Se) and the First Fe/Sn/Se Heterocubane Cluster [(CpFe)3(SnCl3)(mu3-Se)4] x DME by the use of chalcogenostannate salts.

By reacting 1-aminoethylammonium (H2NCH2CH2NH3+ = enH+) salts of [Sn2E6]4- anions (E = S, Se), [enH]4[Sn2S6] (1) and [enH]4[Sn2Se6] x en (2), with FeCl2/LiCp, three novel (partly) oxidized, Cp* ligated iron chalcogenide clusters were synthesized. Two of them, [(CpFe)3(mu3-S)2] (3) and [(Cp*Fe)3(mu3-Se)2] (4), contain formally 47 valence electrons. [(Cp*Fe)3(SnCl3)(mu3-Se)4] x DME (5) represents the first known mixed metal Fe/Sn/Se heterocubane type cluster.

The rapid yellowing of spruce at a mountain site in the Central Black Forest (Germany). Combined effects of Mg deficiency and ozone on biochemical, physiological and structural properties of the chloroplasts.

Biochemical, physiological and ultrastructural changes of the chloroplasts were examined in the course of the rapid yellowing process of spruce (Picea abies (L.) Karst.) at a Mg-deficient and ozone polluted mountain site (Schöllkopf mountain, Central Black Forest, Germany, 840 m a.

Two metalloid Ga22 clusters containing a novel Ga22 core with an icosahedral Ga12 center.

In addition to the two so far known types of metalloid Ga(22) clusters a new type is presented in two compounds containing the anions [Ga(22)Br[N(SiMe(3))(2)](10)Br(10)](3-) (1) and [Ga(22)Br(2)[N(SiMe(3))(2)](10)Br(10)](2-) (2). In both anions 10 Ga atoms of the icosahedral Ga(12) core are directly connected to further Ga atoms. The two remaining Ga atoms (top and bottom) of the Ga(12) icosahedron are bonded to one (1) and two Br atoms (2), respectively.

Application of magnetic resonance imaging to the investigation of the diffusivity of 1,1,1,2-tetrafluorethane in two polymers.

In order to evaluate the suitability of a polymer as a sealing material for certain working fluids used in process plants, information about the fluid diffusivity into the polymer or the polymer permeability to the fluid is a prerequisite. The fluid of interest in the present work is 1,1,1,2-tetrafluorethane, CH(2)FCF(3), a partly fluorinated hydrocarbon (HFC) commonly known as refrigerant R134a. HFCs are increasingly used in refrigeration, air conditioning, and heat pump applications as substitutes for the chlorofluorocarbons (CFCs) or hydrochlorofluorocarbons (HCFCs) that are believed to be responsible for ozone depletion in the stratosphere.

Planar system for magnetic induction conductivity measurement using a sensor matrix.

In this study the performance of an axial gradiometer sensor for magnetic induction tomography was investigated and the results of measurements to determine the precision and sensitivity of the sensor were undertaken. In the first part of the study a single gradiometer sensor was used and the noise and drift were measured for two excitation current values at a single frequency of 600 kHz. The variations of the real and imaginary received signal components with conductivity were then obtained for samples with 0-5 S m(-1).

Ultrafiltration of nonionic surfactants and dissolved organic matter.

A brownwater sample with a high content of humic substances (HS) was fractionated by multistage ultrafiltration (mst-UF) into five fractions with nominal molecular weights ranging from >30 to <1 kDa. Fractions were characterized with respect to molecular size distribution and structure. Size exclusion chromatography with online DOC detection revealed that mst-UF yielded fractions with decreasing Mp (molecular weight at peak maximum) and polydispersities from nominally large to small mst-UF fractions.