Wpływ składu surowcowego dzianin lewo-prawych platerowanych na ich właściwości antymikrobowe

This paper deals with the determination of the antimicrobial efficiency of plain plated weft knits antimicrobial treated with commercial silver chloride (AgCl (iSys Ag, Germany)) dispersed in a reactive organic-inorganic binder (iSys MTX, Germany). Antimicrobial treatment was performed by the exhaustion method. The morphology of untreated and antimicrobial treated knits was analysed using Scanning Electron Microscopy (SEM) to confirm the presence of silver particles on the fibre surface. The antimicrobial activity was estimated using the Agar diffusion Test (according to standard EN ISO 20645:2004 (qualitative method)) and antibacterial finishes in a Textile Materials Test (according to the AATCC 100–1999 standard (quantitative method)). Two strains of bacteria - E. coli and S. aureus were used in this research. The results obtained proved that the fibre type and raw composition have an important influence on the relationship between the fibre surface and antimicrobial effect of the material formation and optimal antimicrobial efficiency obtained. It was found that pure fibre cotton and man-made bamboo knits had the highest antimicrobial activity for both types of bacteria (E. coli and S. aureus). Meanwhile knits of 100% polyester fibre and blended knits containing polyester fibre had an insufficient effect on the bacterial growth. It was also established that antimicrobial treated knits with the same fibre composition and very similar total linear density of folded yarns but with a different number of folded yarns in the structure have different antimicrobial activity. This is because the higher number of folded yarns in the knitted loop has a larger surface area and, herewith, larger antimicrobial acting area.W artykule oceniano właściwości antymikrobowe dzianin lewo-prawych platerowanych nasycanych komercyjnym chlorkiem srebra. Chlorek srebra tworzył zawiesinę w reaktywnym organiczno nieorganicznym związku (iSysMTX). Morfologię dzianin przed i po obróbce badano za pomocą SEM dla potwierdzenia obecności cząstek srebra na powierzchni włókien. Antymikrobową aktywność oceniano jakościowo stosując dyfuzyjny test z użyciem agaru oraz ilościowo badając zaimpregnowany materiał włókienniczy. Stosowano dwa szczepy bakterii E.coli i S.aureus. Stwierdzono że antymikrobowe właściwości zależą od typu włókna i składu surowcowego. Okazało się, ze najlepsze właściwości antymikrobowe posiadają dzianiny z czystych włókien bawełnianych oraz włókien chemicznych z surowca bambusowego. Natomiast dzianiny wykonane z 100% włókien poliestrowych i mieszanek mają gorsze właściwości antybakteryjne. W przypadku dzianin wykonanych z włókien o porównywalnej masie liniowej jednorodnych lub skręconych z kilku przędz to te ostatnie ze względu na zwiększoną powierzchnię mają lepsze właściwości antymikrobowe

Intra-Individual Reaction Time Variability in Mild Cognitive Impairment and Alzheimer’s Disease: Gender, Processing Load and Speed Factors

Compared to cognitively healthy ageing (CH), intra-individual variability in reaction time (IIV(RT)), a behavioural marker of neurological integrity, is commonly reported to increase in both Alzheimer’s disease (AD) and mild cognitive impairment (MCI). It varies in MCI with respect to whether it represents the pro-dromal stages of dementia or not; being greatest in those most likely to convert. Abnormal IIV(RT) in MCI therefore represents a potential measure of underlying functional integrity that may serve to differentiate MCI from CH and to help identify those patients for whom MCI is the result of a progressive pathological process. As the clinical approach to MCI is increasingly stratified with respect to gender, we investigated whether this factor could influence study outcome. The influence of RT(SPEED) and processing load upon IIV(RT) was also examined. Under low processing load conditions, IIV(RT) was significantly increased in both MCI and AD compared to CH. However, correcting for an individual’s processing speed abolished this effect in MCI but not in AD, indicating that the increased IIV(RT) in MCI and AD may result from different factors. In MCI but not in CH, IIV(RT) was significantly greater for females. Increasing task processing load by adding distracting information, although increasing overall IIV(RT), failed to improve the differentiation between CH and both MCI and AD, and in MCI resulted in a reduction in the influence of gender upon study outcome. The outcome of studies investigating IIV(RT) in MCI and AD compared to CH therefore appear influenced by the gender of the participants, by task-related processing load and processing speed