QCM study of microbiological activity during long-term exposure to atmosphere—aluminium colonisation by <Emphasis Type="Italic">Aspergillus Niger</Emphasis>

The study demonstrated a possibility to sense the activity of microorganisms on metals in situ under atmosphere conditions using a quartz crystal microbalance (QCM) as a sensitive mass change detector. Other innovative aspects of the QCM application include long-term monitoring (over month), taking count of the influence of atmospheric pressure and application of Al-glued foil electrodes. The research subject was aluminium colonisation by Aspergillus niger Tiegh., a filamentous ascomycete fungus. The difference between the QCM data for abiotic and biotic samples reflected microbiological activity, which resulted in exponential mass gain during exposure. The increase in mass was due to various phenomena, i.e. development of biomass, secretion of metabolites, water uptake by the colony and microbially induced corrosion. The glued foil method demonstrated a possibility to expand the scope of the QCM studies from evaporated, sputtered or electroplated materials to those, from which thin foils may be produced. Dedicated to Professor Dr. Algirdas Vaškelis on the occasion of his 70th birthday.     

Inorganic chemical approaches to pharmacognosy. VII. X-ray fluorescence spectrometric studies on the inorganic constituents of crude drugs. (5). The relationship between inorganic constituents of plants and the soils on which they are grown

Inorganic constituents of the leaves of several kinds of plants growing on different soil types were investigated using energy-dispersive X-ray fluorescence spectrometry. The results can be summarized as follows: (1) Each plant exhibited a characteristic metals profile, even if they were grown on similar soil types. (2) As we would expect, the metals profile of the plant leaves depends on the inorganic constitution of the soil on which it is grown. However, the degree of the influence of the soil types on the metals profile of the plant differs according to the kind of inorganic element: Ca and Cu are almost independent of the soil types, but the Ti and Fe content is dependent upon the soil types. (3) Sr content of plant leaves is closely related to the ratio of Sr to Ca of the soil on which the plants are grown. (4) This information should be helpful in identifying the producing district or original plant of a crude drug by its metals profile.     

Direct detection of RNAs in living cells using peptide-inserted Renilla luciferase

In this study, non-engineered RNAs were detected in living cells using bioluminescence. Two types of probe were utilized: a peptide inserted RLuc (PI-RLuc) probe and a split-RNA probe. Incorporation of the PI-RLuc and split-RNA probes enabled the direct detection of RNA introduced into living cells.     

Total reactivity of pyridine and quinoline via the reactions of arylbenzoates with hydroxide ion. Apparent substituent constants for some N-heteroaromatic groups

A new set of apparent σ values was evaluated for the aza substitution of all positions in pyridyl and quinolyl groups on the basis of the alkaline hydrolysis of aryl benzoates. The enhanced reactivities of 4-pyridyloxy- and 4-quinolyloxy- groups were first estimated quantitatively.     

RNA detection using peptide-inserted <Emphasis Type="Italic">Renilla</Emphasis> luciferase

A novel complementation system with short peptide-inserted-Renilla luciferase (PI-Rluc) and split-RNA probes was constructed for noninvasive RNA detection. The RNA binding peptides HIV-1 Rev and BIV Tat were used as inserted peptides. They display induced fit conformational changes upon binding to specific RNAs and trigger complementation or discomplementation of Rluc. Split-RNA probes were designed to reform the peptide binding site upon hybridization with arbitrarily selected target RNA. This set of recombinant protein and split-RNA probes enabled a high degree of sensitivity in RNA detection. In this study, we show that the Rluc system is comparable to Fluc, but that its detection limit for arbitrarily selected RNA (at least 100 pM) exceeds that of Fluc by approximately two orders of magnitude.