A rapid assay for miRNA maturation by using unmodified pre-miRNA

Without labeling RNA: A new rapid assay for micro-RNA maturation was developed. The assay depends on the cleavage of unmodified pre-miRNAs and the subsequent amplification of the mature miRNA by rolling circle amplification (see accompanying scheme).     

Comparison of test images obtained from various configurations of scanning near-field optical microscopes

The characteristics of a few experimental near-field optical microscopes, located in different laboratories, have been compared on the basis of their ability to image a well-defined submicrometer test object.     

Comparative study by electrophysiology of olfactory responses in bumblebees (Bombus hypnorum andBombus terrestris)

Electrophysiological data (EAG) were recorded on adult bumblebees stimulated with floral and/or pheromonal pure odorants at different concentrations. The responses of queen, worker, and male bees are compared and the sensitivities of these insects to the pure odorants tested are discussed.     

Polymers with terminally cyanobiphenyl-substituted side chains

Summary Two acrylate side chain polymers in which the mesogenic moiety is a 4-cyano-biphenyl-4-yl group have been synthesized and characterized by d.s.c., optical microscopy and X-ray diffraction. If the mesogenic moiety is linked to the polymer backbone by a -O-CO-(CH₂)-₅ group, the resultant polymer is nematic. For a -O-(CH₂)-₆ group, the unusual NS_AN_re sequence is observed. X-ray diffraction has shown that the S_A phase has a partially bilayer structure : the molecules are arranged in an antiparallel, overlapping interdigitated structure with a layer spacing of about 1.4 times the length of the side chains. Monolayer fluctuations are also observed in this S_A phase.     

Accepting Zeno words: a way toward timed refinements

Timed models were introduced to describe the behaviors of real-time systems and they were usually required to produce only executions with divergent sequences of times. However, when some physical phenomena are represented by convergent executions, Zeno words appear in a natural way. Moreover, time can progress if such an infinite execution can be followed by other ones. Therefore, in a first part, we extend the definition of timed automata, allowing to generate sequences of infinite convergent executions, while keeping good properties for the verification of systems: emptiness is still decidable. In a second part, we define a new notion of refinement for timed systems, in which actions are replaced by recognizable Zeno (timed) languages. We study the properties of these timed refinements and we prove that the class of transfinite timed languages is the closure of the usual one (languages accepted by Muller or Büchi timed automata) under refinement. Received: 16 October 1998 / 8 March 2000     

Towards a low‐cost high‐quality carbon‐nanotube field‐emission display

Abstract— We have developed field‐emission‐display technology driven by chemical‐vapor‐deposition‐grown carbon‐nanotube emitters incorporated in a simple, low‐cost device structure. Here, we report on frit‐sealed test displays with a brightness of 3000 cd/m² at 3 kV and a lifetime of 9000 hours with only 45% degradation. We also demonstrate the scalability of the technology with a uniform high‐brightness 6‐in. QVGA that displays video images with a switching voltage of 40 V.     

Influence of protein and mineral composition on the formation of whey protein heat-induced microgels

The aim of the present study was to investigate the effect of the initial protein and mineral composition on the formation of whey protein microgels at a protein concentration of 4 wt%. As a model system, both demineralized α-lactalbumin (α-la) and β-lactoglobulin (β-lg) were mixed at 20/80, 50/50 and 80/20 α-la/β-lg ratios and heated (85 °C, 15 min) in the pH range 5.7–6.2. Pure dispersions of α-la were not forming microgels but rather precipitates (12%) and a majority of soluble aggregates (83%). Upon mixing with β-lg, microgels were only obtained for the 20/80 ratio at pH 5.7 or for pure β-lg at pH 5.8. Interestingly, the latter ratio was close to the natural composition occurring in most of the commercial whey protein isolates (WPIs). For higher ratios, particles were more or less aggregated and not spherical. As for α-la alone, most of the denatured proteins formed soluble aggregates. These results might be explained by the fact that α-la reduced the hydrophobic attractive forces involved in microgel formation, shifting the equilibrium towards the soluble aggregates pathway. This assumption was confirmed by the very low surface hydrophobicity of the soluble aggregates determined by ANS binding experiments. The conversion yield from native protein into microgels was about 51% for the 20/80 α-la/β-lg model mixture, whereas it was higher (70–85%) for commercial WPIs under similar experimental conditions. To test the possible effect of the initial mineral composition of the commercial WPIs, these products were demineralized and their ability to form microgels was tested again. After demineralisation, WPIs behaved very similarly to the 20/80 α-la/β-lg model system, the yield of conversion into microgels dropping to about 65% at pH 5.7. It was therefore concluded that in addition to the α-la/β-lg mixing ratio that was controlling hydrophobic interactions between denatured proteins that was accounting for about 50% of the microgel conversion yield, the initial mineral composition of WPIs contributed to another 20–35% yield as it was modulating the repulsive forces between the denatured proteins, promoting aggregation.     

The Saccharomyces cerevisiae MFS Superfamily SGE1 Gene Confers Resistance to Cationic Dyes

A gene from Saccharomyces cerevisiae whose overexpression confers resistance to 10-N-nonyl acridine orange (NAO) has been isolated. This cationic dye binds acidic phospholipids and more specifically cardiolipin (Petit, J. M., Maftah, A., Ratinaud, M. H. and Julien, R. Eur. J. Biochem. 209 , 267–273, 1992). The isolated gene was found to be identical to SGE1, a partial multicopy suppressor of the gal11 mutation (Amakasu, H., Suzuki, Y., Nishizawa, M. and Fukasawa, T. Genetics 134 , 675–683, 1993), that also confers crystal violet resistance to a supersensitive strain (Ehrenhofer-Murray, A. E., Wurgler, F. E. and Sengstag, C. Mol. Gen. Genet. 244 , 287–294, 1994). The data presented in this paper show that the SGE1 gene product, a member of the major facilitator superfamily, confers a pleiotropic drug-resistance phenotype when present in high copy number. The results also demonstrate that Sge1p acts as an extrusion permease whose specificity seems restricted to dye molecules possessing a large unsaturated domain that stabilizes a permanent positive charge such as NAO, crystal violet, ethidium bromide or malachite green. © 1997 John Wiley & Sons, Ltd.