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Extra steps have been found with atomic-force microscopy generated on rather flat silicon ͑100͒ surfaces annealed at 1200°C in hydrogen, through a comparison with the surface annealed in argon, which exhibits a typical ͑S a ϩS b ͒ step structure. It is suggested that the extra steps are spontaneously generated due to the relaxation of the strain energy associated with the atomic dimers on the reconstructed surface.

0 Hydrolytic degradation products of cefdinir were studied in acidic (pH 1), neutral (pH 6), and basic (pH 9) solutions. Seven major degradation products were isolated by preparative and/or high-performance liquid chromatography and characterized by UV, IR, 1 H-NMR, and mass spectra. To clarify degradation pathways in each pH solution, kinetic and product analyses during hydrolysis of cefdinir were carried out along with the followup reaction of representative degradation products. Cefdinir was shown to degrade via two major degradation routes: -lactam ringopening and pH-dependent isomerizations (lactonization, epimerization at C-6 or C-7, syn−anti isomerization of N-oxime function).

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An enzyme producing isoprimeverose from xyloglucan fragment oligosaccharides has been purified to the electrophoretically pure state from a commercial enzyme preparation of Aspergillus oryzae (Sanzyme 1000). The purified enzyme showed approximately 1,280-fold increase of the specific activity over the original preparation. The purified enzyme was shown to be an oligomeric protein consisting of two subunits, each of which had a molecular weight of 115,000. The enzyme showed the highest activity at pH 5.0 and 60 degrees C, and was stable in the pH range from 5 to 7 and at up to 50 degrees C. The isoelectric point of this enzyme was pH 3.9. The purified enzyme was highly specific for xyloglucan fragment oligosaccharides and split off isoprimeverose units from the non-reducing end of the backbone of the substrate.