Ersatzteillager Mensch? Tissue Engineering

The increased expectation of life of the people in the developed nations has enhanced the needs for permanent or temporal substitutions of deseased, injured, or aged organs and tissues. This is one of the great challenges the medicine presently faces. The regenerative medicine comprises developments and applications in the fields of implants, cell‐based therapies and tissue engineering.     

Simultaneous determination of L-693,612, a topical carbonic anhydrase inhibitor, and two potential metabolites in human whole blood by ion-pair high-performance liquid chromatography

A method for the simultaneous determination of a topical carbonic anhydrase inhibitor, L-693,612, and two of its potential metabolites in human whole blood is described. The analytes are isolated from the matrix via liquid-liquid extraction with a mixture of toluene, ethyl acetate and isopropanol (49:50:1, v/v/v). The analytes are then back extracted into dilute phosphoric acid prior to injection into the HPLC system. A cyano column (Zorbax SB-CN, 150 × 4.6 mm) with a mobile phase of phosphoric acid(0.085%)-acetonitrile (73.5:26.5) containing 10 mM sodium decane sulfonate and adjusted to pH 3 is used for the analysis. Detection is based on UV absorbance at 252 nm. The assay was found to be linear in the concentration range of 5–500 ng/ml for each analyte when 1-ml aliquots of whole blood were extracted.     

Coherent production ofρ − mesons in charged current antineutrino-neon interactions in BEBC

Coherent production ofρ ^? mesons in charged current antineutrino interactions on neon nuclei is studied in the BEBC bubble chamber exposed to the CERN SPS wide band beam. The cross section is measured to be (95±25)·10^?40 cm² per neon nucleus, averaged over the beam energy spectrum. The distributions of kinematical variables and the absolute value of the cross section are in agreement with theoretical predictions based on the CVC hypothesis and the vector meson dominance model.     

Brillouin scattering of vitreous silica under high pressure

The pressure dependence of Brillouin spectra of vitreous silica exhibits a maximum in the hypersonic absorption and a minimum in the sound velocity at about 2 GPa almost independent of temperature. The results are discussed on the basis of relaxing defects residing in double-well potentials with a Gaussian distribution of barrier heights and a Lorentzian distribution in the asymmetry. Our analysis suggests that both the distribution functions are strongly changed at higher pressures. It is striking that a phase boundary between α-quartz and coesite exists just at the pressure where absorption and sound velocity of vitreous silica pass their extremum. This might be a hint that a corresponding structural change also occurs in the glass.     

Anomalous dynamics in the Ising chain

We analyze a 1D Ising system with anomalous distributions of nearest neighbor interactions and show that the single-spin-flip dynamics exhibit breakdown of dynamic scaling. The results are obtained by a real-space numerical method applied to the exact equations of motion and they may be explained by domain wall motion arguments reformulated in terms of extreme value statistics.     

Diameters of airborne latex spheres measured with a cylindrical aerosol centrifuge

Accurate diameters for eight different sizes of airborne Dow polystyrene latex spheres were obtained from measurements with a Cylindrical Aerosol Centrifuge by using the internal calibration of the instrument. Differences of up to 10% were observed between nominal and measured diameters. A comparison with electron microscopic sizing techniques is included.     

Conduction and valence band density of states of SnS2: Theory and experiment

The band structure of SnS₂ has been investigated over a wide energy range by pseudopotential band structure calculations and synchrotron radiation photoemission spectroscopy techniques. A good correspondence has been found between energy positions of the theoretical density of states features and structure in the constant initial state (CIS) and energy distribution curves (EDC's) for the conduction and the valence bands respectively. In the energy region between — 8 eV and 15 eV from the top of the valence band we observe four valence band and six conduction band peaks.     

Evidence for higher twist effects in fast π− production by antineutrinos in neon

Evidence for a significant higher twist contribution to highz π^? production in antineutrino scattering is presented. In events withW>3 GeV andQ ²>1 GeV² in our data, it accounts for (51 ±8)% of all π^? withz above 0.5. It is consistent with thez?Q ² correlations of Berger's higher twist prediction. The data are inconclusive concerning the predictedy?z correlation andp _T dependence. Thez ?Q ² correlation is not adequately described by the Lund Monte-Carlo.     

The α-AlB12 structure

The crystal structure of α-AlB₁₂, reported recently by Higashi, Sakurai, and Atoda is confirmed by an independent investigation of a different crystal. The space group is P4₁2₁2 (or P4₃2₁2) and our lattice parameters are a = 10.161(7)Å, c = 14.283(8)Å. The structure was partially solved by Patterson methods, when the full structure was communicated to us by Higashi et al. Utilizing 2393 reflections, our structure refinement yields an R value of 2.6% with very low standard deviations for structural parameters (0.0001 for atomic coordinates of boron atoms). Within the standard deviations there is excellent agreement with all parameters determined by Higashi et al. It is found, nevertheless, that the structural parameters of α-AlB₁₂ do not serve to account for the reported Debye-Scherrer patterns of “BeB₆,” “LiB₆,” or β-tetragonal boron, all of which have the same cell dimensions and space group as α-AlB₁₂.