Glomerular endothelial cells synthesize collagens but little gelatinase A and B

Mesangial sclerosis is a major feature of progressive renal disease. The mesangium contains mesangial cells and is bounded by the peripheral glomerular basement membrane and endothelial cells. Mesangial cells synthesize and degrade extracellular matrix. Whereas both mesangial and endothelial cells synthesize extracellular matrix components, the degradative pathway, well studied in the former, has not been investigated in endothelial cells. This study examines lines of all three glomerular cell types derived from female B6SJLF1/J mice, as well as mRNA levels for collagens alpha1(I), alpha1(IV), alpha3 (IV), alpha5 (IV), and alpha1 (VI), laminin, tenascin, matrix metalloproteinase-2 (MMP-2), and MMP-9. Type I and IV collagen synthesis was confirmed by enzyme-linked immunosorbent assay. MMP-2 and MMP-9 enzyme activity was measured by zymography. It was found that glomerular endothelial cells are a significant source of collagens, laminin, and tenascin. However, they express only low levels of MMP-2 and no detectable MMP-9. Stimulation with exogenous transforming growth factor-beta1 leads to a significant increase in collagen I, tissue inhibitors of metalloproteinase-1, and MMP-9 in conditioned media. These data suggest that glomerular endothelial cells may play an active role in extracellular matrix remodeling in glomerular disease.     

Real structure of partially ordered crystals

Partial order in crystals is a frequently observed phenomenon in minerals and synthetic materials. The partially ordered structures are characterized by low-dimensional order of the real structure. In the case of 1D structures, the ordered units can be described as rods; 2D structures contain ordered layers. The disorder of the real structures is indicated by prominent diffuse scattering in the diffraction patterns of single crystals. No simple method for the quantitative analysis of the diffuse scattering exists, therefore the determination of essential characteristics of the structures is complicated. However, the determination can be facilitated using a combination of different methods, including electron microscopy, computation and X-ray diffraction.     

Variable bandwidth birefringent filter for stable femtosecondlasers

A design for a birefringent filter is described, which is suitable for tunable femtosecond lasers. Using a single plate, which has a steeply diving optic axis, two-octave tunability is attained with negligible deterioration of the stopband rejection. For a specific wavelength region, it means that the filter's bandwidth can be changed by a factor of four. Another characteristic of the design is that, for the same bandwidth, the proposed plate is five times thicker than a conventional plate in which the optic axis is parallel to the surface. Thus, etalon effects can be avoided. Tuning characteristics of color center lasers utilizing the new filter are also presented     

Femtosecond time domain measurements of group velocity dispersionin diode lasers at 1.5 μm

The authors have measured the group velocity dispersion of bulk V-groove semiconductor lasers and multiple quantum well lasers operating at a wavelength near 1.5 μm. The data yield group velocity dispersions in the range from -0.63 to -0.95 μm^-1 and indicate that material dispersion is the dominant factor in the diodes. Cross-correlation traces of transmitted femtosecond pulses confirm the measured values of dispersion     

Investigations of gas-particle-lance flows at high velocity for the injection of solid in melting baths

For the injection of gas and solid into molten masses using lances the situation at the lance outlet is a boundary condition for the mixing in the melting bath and therefore an important parameter for the energy and mass exchanges which take place there. In the scope of the main research programme of the Deutsche Forschungsgemeinschaft named “Mischung mit Energie-und Stoffumsatz in schmelzmetallurgischen Systemen”, a mathematical model is to be developed at the Institut für Energieverfahrenstechnik der Technischen Universität Clausthal, which should make it possible to calculate the situation at the outlet of a lance operating with gas and solid, using operational and geometrical parameters (pressure at lance intake, amount of solid, length and diameter of lance) which can be freely chosen.