Age dependent accumulation of cadmium in the human ovary

In an eight years old boy we operated an intramedullary astrocytoma grade I and reimplanted the laminae C4-7 en bloc. A good stability was achieved. Ten years later only one segment remained intact, the others showing spontaneous fusion as a major draw back. This is possibly due to subperiostal dissection and bracing. No spinal stenosis occurred. An overuse of the remaining disc C4/5 might lead to a secondary degenerative stenosis. The operation is simple and might avoid swan neck deformity in children after large decompression of dorsal structures.     

Resolution correction in EELS

Correction for inelastically scattered electrons is important in determining intensities in elastic peak electron spectroscopy (EPES), e.g. for obtaining information on inelastic mean free paths in the material, relevant parameters in quantitative applications of electron spectroscopy. The spectral shape of electron energy loss spectra depends more strongly on the spectrometer function in the elastic peak region, than in the continuous energy part. Therefore the resolution correction of the EELS spectra results in a considerable change of the spectral shape. The importance and the role of this correction is demonstrated in the case of REELS of Ni sample comparing the shapes of EELS spectra measured at different energy resolutions using different type spectrometers : (1) home-made HSA (ESA 31). Debrecen ; (2) home-made HSA (Clermont Ferrand) ; (3) CMA MAC2 by CAMECA-RIBER and a HSA (Lyon) ; (4) CMA OPC105 type by RIBER (Budapest).     

Corrosion behaviour of duplex stainless steels containing minor ruthenium additions in reducing acid media

The dissolution behaviour, as well as the time, potential and concentration dependence of HSO _– ⁴ SO _2t- ⁴ and Cl^– accumulations measured by an in situ radiotracer method on surface oxide-layers of duplex stainless steels containing various amounts of ruthenium as additive are presented and discussed. Several independent techniques, such as mass loss tests, potentiodynamic responses, radiotracer and ICP methods, were used to characterize the complex features of the passivation phenomena of steels modified with ruthenium. The experimental results reveal that the interaction of bisulfate/sulfate ions with passive oxide layer is stronger than those of chloride ions on the stainless steels studied. Both the extent and the strong character of bisulfate/sulfate accumulation are more likely related to the redistribution of the main alloying components (Cr, Ni, Mo) as well as the Ru in the surface oxide-film formed on steels passivated spontaneously in dilute HCl and H₂SO₄. It is found that the ruthenium additions to the base duplex stainless steel significantly increase the corrosion resistance in reducing acid environments. There is evidence of anodic inhibition and this seems to be responsible for the observed increased corrosion resistance of the duplex stainless steels with small ruthenium additions.     

On the simultaneous role of Cr in the passivity of stainless steel and in the sorption of HSO4 and Cl ions in the passive film

The sorption behaviour of HSO⁻₄ and Cl⁻ ions on stainless steel is discussed in the light of recent theories of passivity attributing a significant role to the Cr content and the state of Cr species in the passive layer. It is shown through experimental evidences that a link between the formation of Cr³⁺ species in the passive film and HSO⁻₄ sorption can be formulated.     

Simultaneous extraction of oil and antinutritional compounds from flaxseed

A two-phase solvent extraction process, developed in our laboratory for rapeseed, was used to simultaneously extract oil and toxic, antinutritional components from flaxseed to produce a meal suitable for animal feed. The most effective solvent systems consisted of hexane in combination with a solution of methanol that contained 10% (vol/vol) water and 2.5–5% (w/w) ammonia, or methanol that contained 10% water (vol/vol) and 0.08% (w/w) NaOH. The treatments were carried out both at laboratory and semipilot-plant scales. The success of the test with a pilot-scale Karr liquid-liquid extraction column suggested that this process could be readily carried out on an industrial scale. The resulting flax meal had a high protein content (40–47%) and low levels of cyanogenic glycosides (reduced by 90–100% from the starting material). The methanol-ammonia extraction reduced the total polyphenol content by ≈20%. The oil extraction efficiency of the Karr column was high, resulting in meal residual oil contents of ≈1%.     

Photopolymers for rapid prototyping

Rapid prototyping by means of stereolithography using different types of photopolymers has gained increasing interest because cellular structures can be built at a high resolution with sub-μm feature sizes. Structures made with digital light processing and microstereolithography and rapid prototyping based on two-photon absorption photopolymerization techniques are presented. Soluble photopolymers were developed to substitute crosslinked photopolymers as mold materials and to extend the variety of materials which can be cast. With these molds, the processing of ‘bio-inspired’ ceramic composites with a controlled architecture from a macroscopic scale down to the nanometer range is possible. Another example is the development of biophotopolymers that are based on commercially available reactive diluents and modified gelatin for the fabrication of cellular bone replacement materials. Biocompatibility was investigated by seeding with osteoblast-like cells.     

The role of specimen-induced spherical aberration in confocal microscopy

We present an overview of recent theories for describing specimen-induced spherical aberration in confocal microscopy. One of these theories is used to compute numerically the role of spherical aberration in general confocal, and especially in biological confocal, microscopy for a variety of three-layer specimen structures. In particular, we study the effect of specimen-induced spherical aberration on the maximum value of the overall confocal point spread function, the accompanying focal shift and the size of the optical probe in both fluorescence and brightfield confocal microscopy.