Airborne and dust borne microorganisms in selected Polish libraries and archives

The aims of this work were to quantitatively and qualitatively study culturable fungi and bacteria in the air and settled dust in the storerooms of five Polish libraries and archives as well as to estimate the effect of water intrusion on the microbial air quality indoors. In all studied storerooms, the total bioaerosol concentrations at the workplaces ranged from 100 to 1000 cfu/m³. The most prevalent part of the storerooms’ bioaerosol consisted of bacteria, mainly Staphylococcus spp. and Micrococcus spp., followed by filamentous fungi. In four of the studied premises, fungal aerosol concentrations were below 100 cfu/m³. The only exception was observed in the fifth storeroom, which has been periodically flooded with rainwater and where significantly higher concentrations of fungal aerosol were measured. Among the identified fungal species, those of the genus Penicillium were the most numerous. Moreover, Trichothecium laxicephalum and Alternaria tenuis were present in all of the examined storerooms.     

Two-dimensional point spread matrix of layered metal-dielectric imaging elements

We describe the change of the spatial distribution of the state of polarization occurring during two-dimensional (2D) imaging through a multilayer and in particular through a layered metallic flat lens. Linear or circular polarization of incident light is not preserved due to the difference in the amplitude transfer functions for the TM and TE polarizations. In effect, the transfer function and the point spread function (PSF) that characterize 2D imaging through a multilayer both have a matrix form, and cross-polarization coupling is observed for spatially modulated beams with a linear or circular incident polarization. The PSF in a matrix form is used to characterize the resolution of the superlens for different polarization states. We demonstrate how the 2D PSF may be used to design a simple diffractive nanoelement consisting of two radial slits. The structure assures the separation of nondiffracting radial beams originating from two slits in the mask and exhibits an interesting property of a backward power flow in between the two rings.     

Stabilization of butter with deodorized rosemary extract

 The antioxidative activity of the ethanolic extract of deodorized rosemary (Rosmarinus officinalis L.) in butter was tested. The extract was added at two concentrations, 0.05 and 0.1%, to the cream before churning. The samples of isolated fat were stored at 60°C for 38 days and their peroxide values (PVs) determined periodically. The relative changes in the proton absorption patterns of the butter lipids during storage were monitored by nuclear magnetic resonance (NMR) spectroscopy. The samples treated with 0.05 and 0.1% extract had much longer induction periods than the control. A significant correlation (r = 0.980) was measured between the ratio of aliphatic to olefinic protons (R _ao) and the PVs of the butter fat. The deodorized ethanolic extract was also subjected to TLC separation on silica gel plates and UV spectral analysis. The UV spectrum of the extract had maxima at 286 and 328 nm. Six spots attributed to phenolic compounds were observed on the TLC plate. The extract also exhibited strong antioxidant activity in a β-carotene-linoleate model system. Received: 11 July 1997     

Caffeic Acid Reduces the Viability and Migration Rate of Oral Carcinoma Cells (SCC-25) Exposed to Low Concentrations of Ethanol

Alcohol increases the risk of carcinoma originated from oral epithelium, but the biological effects of ultra-low doses of ethanol on existing carcinoma cells in combination with natural substances are still unclear. A role for ethanol (EtOH), taken in small amounts as an ingredient of some beverages or mouthwashes to change the growth behavior of established squamous cell carcinoma, has still not been examined sufficiently. We designed an in vitro study to determine the effect of caffeic acid (CFA) on viability and migration ability of malignant oral epithelial keratinocytes, exposed to ultra-low concentrations (maximum 100 mmol/L) EtOH. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-dimethyltetrazolium bromide) and LDH (lactate dehydrogenase) assays were used to assess the cytotoxic effect of EtOH/CFA and the viability of squamous carcinoma SCC-25 cells (ATCC CRL-1628, mobile part of the tongue). Tested EtOH concentrations were: 2.5, 5, 10, 25, 50, and 100 mmol/L, along with an equal CFA concentration of 50 μmol/L. Carcinoma cells’ migration was investigated by monolayer “wound” healing assay. We demonstrated that very low concentrations of EtOH ranging between 2.5 and 10 mmol/L may induce the viability of oral squamous cell carcinoma cells, while the results following addition of CFA reveal an antagonistic effect, attenuating pro-proliferative EtOH activity. The migration rate of oral squamous carcinoma cells can be significantly inhibited by the biological activity of caffeic acid.     

Propositional dynamic logic of context-free programs and fixpoint logic with chop

This paper compares propositional dynamic logic of non-regular programs and fixpoint logic with chop. It identifies a fragment of the latter which is equi-expressive to the former. This relationship transfers several decidability and complexity results between the two logics.     

Subsampling in testing autocovariance for periodically correlated time series

Abstract. The main purpose of this article was to describe the asymptotic properties of subsampling procedure applied to nonstationary, periodically correlated time series. We present the conditions under which the subsampling version for the estimator of Fourier coefficient of autocovariance function is consistent. Our result provides new tools in statistical inference methods for nonstationary, periodically correlated time series. For example, it enables to construct consistent subsampling test which successfully distinguishes the period of the series.     

Low power current-mode binary-tree asynchronous Min/Max circuit

A novel, current-mode, binary-tree, asynchronous Min/Max circuit for application in nonlinear filters as well as in analog artificial neural networks is proposed. The relatively high precision above 99% can be achieved by eliminating the copying of the input signals from one layer to the other in the tree. In the proposed solution, the input signals are always directly copied to particular layers using separate signal paths. This makes the precision almost independent on the number of the layers i.e. the number of the inputs. The circuit is a flexible solution. The power dissipation, as well as data rate can be scaled up and down in a wide range. For an average value of the input currents of 20 μA and data rate of 11 MHz the circuit dissipates 505 μW, while for the signals of 200 nA and data rate of 500 kHz the power dissipation is reduced to 1 μW. The prototype circuit with four inputs, realized in the CMOS 0.18 μm technology, occupies the area of 1800 μm².     

Dyes based on the 6,7‐dichloro‐5,8‐quinolinedione skeleton as new type II photoinitiators for radical polymerisation

Several dyes based on the 6,7‐dichloro‐5,8‐quinolinedione skeleton have been synthesised and characterised by proton nuclear magnetic resonance spectroscopy and electron ionisation mass spectrometry. The spectroscopic and electrochemical properties of these dyes were investigated. Photoredox pairs consisting of the synthesised dyes and commercially available hydrogen donors (2‐mercaptobenzoxazole, 2‐mercaptobenzothiazole, 2‐mercaptobenzimidazole, and 2,5‐dimercapto‐1,3,4‐thiadiazole) were tested for use as effective initiator systems for radical polymerisation of trimethylolpropane triacrylate with visible light. The efficiencies of these initiator systems are discussed in terms of the free energy change for the electron transfer process from the dye to the hydrogen donor.     

Acrylic pressure‐sensitive adhesive for transdermal drug delivery systems

This article describes the development in the area of resin‐free acrylic pressure‐sensitive adhesive (PSA) based on 2‐ethylhexyl acrylate, methyl acrylate, acrylic acid, N‐vinyl caprolactam, and pregnancy transdermal drug delivery systems, and shows the variety of polymer composition, residue monomers content, quality control of peel adhesion level and repeating during the time, biocompatibility of the acrylic PSA layer, and efficacy in clinical medicine. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Studies of a mixing process induced by a transverse rotating magnetic field

This study reports on research results in the field of a mixing process under the action of a transverse rotating magnetic field (TRMF). The main objective of this paper is to present the effect of this type of a magnetic field on the mixing time. The proposed dimensional analysis of Navier–Stokes equation including the Lorentz force allows describing the analyzed process by means of the relationships basing on the dimensionless numbers (the mixing time number, the magnetic Taylor number, and the rotational Reynolds number). The possibility of using the magnetic particles (Fe₃O₄) as active micro-stirrers under the influence of a TRMF for active enhancement of a mixing process was considered. Moreover, the effect of a particle content on homogenization efficiency by applying a TRMF was also investigated. The obtained experimental results suggest that the mixing time under the TRMF and MDF conditions may be worked out by using the relation between the mentioned mixing time number and the modified Reynolds number (particle Reynolds number). Important conclusions referring to the discussion of experimental studies of a mixing process are also specified.