The integral <Emphasis Type="Italic">K</Emphasis>-theoretic Novikov conjecture for groups with finite asymptotic dimension

The integral assembly map in algebraic K-theory is split injective for any geometrically finite discrete group with finite asymptotic dimension.     

Selective cap opening in carbon nanotubes driven by laser-induced coherent phonons

We demonstrate the possibility of a selective nonequilibrium cap opening of carbon nanotubes as a response to femtosecond laser excitation. By performing molecular dynamics simulations based on a microscopic electronic model we show that the laser-induced ultrafast structural changes differ dramatically from the thermally induced dimer emission. Ultrafast bond weakening and simultaneous excitation of two coherent phonon modes of different frequencies, localized in the spherical caps and cylindrical nanotube body, are responsible for the selective cap opening.     

New probe of the electronic structure of amorphous materials

Here we show that electrochemical equilibrium voltage curves of amorphous WO3 and TiO2 coatings exhibit fine structure in striking agreement with the density of states in the conduction bands, as obtained by ab initio calculations for the crystalline counterparts. We suggest that localization of the band states is essential for observing the electronic structure. Our highly sensitive electrochemical method opens new vistas for studying the electronic structure of nonmetallic disordered materials that can be intercalated with an ionic species.     

Probeheads and instrumentation for pulse EPR and ENDOR spectroscopy with chirped radio frequency pulses and magnetic field steps

Probeheads and instrumentation for modern X-band pulse EPR and ENDOR experiments with chirped radio-frequency pulses and rapidB ₀-field pulses are described. The resonant frequency, the quality factor and, for the first time, the response of a pulse ENDOR resonator structure to a microwave pulse in the subnanosecond time scale have been calculated. The performance of the probeheads for time-domain chirp ENDOR and electron Zeeman-resolved EPR is demonstrated.     

Metall-Pseudohalogenide. XLIII. Anionische Tricyanmethanid-Komplexe des Palladium (II) und Platin (II)

Metal Pseudohalides. XLIII. Anionic Tricyanomethanide Complexes of Palladium (II) and Platinum (II) The synthesis of homogeneous tricyanmethanido metallates(II) of the type [(C₆H₅)₄E]₂[M{C(CN)₃}₄] (M: Pd, Pt; E: P, As) is reported. I.R., ¹³C-N.M.R., and ESCA investigation are indicating for these complexes relative weak metal-ligand interactions.     

Macroscopic tumor volume of malignant glioma determined by contrast-enhanced magnetic resonance imaging with and without magnetization transfer contrast

The purposes of this study were to compare the conspicuity and lesion volume of contrast-enhancing macroscopic malignant glioma determined by postcontrast magnetic resonance (MR) imaging with and without magnetization transfer (MT) saturation, and to discuss possible implications for radiotherapy planning. Nineteen patients (age 24–60 years) with histologically proven malignant glioma were prospectively examined by MR imaging. After the administration of gadolinium dimeglumine (0.1 mmol/kg body weight), the lesions were imaged with an MT-weighted FLASH (fast, low-angle shot) pulse sequence and with a conventional T₁-weighted spin-echo (SE) sequence without MT saturation. The mean tumor volumes of gliomas measured on MT-weighted FLASH images were significantly (p < .01) larger than those obtained from T₁-weighted SE images (45 ± 15 cm³ vs. 33 ± 10 cm³). The mean contrast-to-noise ratio of enhancing lesions on MT-weighted FLASH was 48 ± 14 compared with 30 ± 14 on SE images, representing a significant (p < .01) improvement. We conclude that the volume of contrast enhancement of malignant glioma identified on MT-weighted FLASH images represents the area of disrupted blood-brain barrier. If this volume of subtle contrast enhancement is caused by tumor infiltration and represents the boost target volume for stereotactic radiosurgery or brachytherapy, MT-weighted FLASH images would be better than T₁-weighted SE images to define these volumes. These improved delineation of areas at highest risk for recurrence following radiation therapy should enhance the efficacy of treatment planning for high-boost therapy.     

Active learning with support vector machines in the drug discovery process

We investigate the following data mining problem from computer-aided drug design: From a large collection of compounds, find those that bind to a target molecule in as few iterations of biochemical testing as possible. In each iteration a comparatively small batch of compounds is screened for binding activity toward this target. We employed the so-called "active learning paradigm" from Machine Learning for selecting the successive batches. Our main selection strategy is based on the maximum margin hyperplane-generated by "Support Vector Machines". This hyperplane separates the current set of active from the inactive compounds and has the largest possible distance from any labeled compound. We perform a thorough comparative study of various other selection strategies on data sets provided by DuPont Pharmaceuticals and show that the strategies based on the maximum margin hyperplane clearly outperform the simpler ones.     

Self assembly,structure and properties of the decanuclear lanthanide ring complex,Dy10(OC2H4OCH3)30

Self assembly produced high yields of the lanthanide ring complex Dy10(OC2H4OCH3)30, the largest lanthanide ring known, characterized by X-ray diffraction methods and by magnetic susceptibility as a function of temperature.