Chemical analysis of Penstemon campanulatus (Cav.) Willd.--antimicrobial activities

A new iridoid glucoside named 10-isovaleroyl-dihydropenstemide (1), along with nine known compounds was isolated from the aerial part of Penstemon campanulatus (Cav.) Willd. The known compounds include three iridoid glucosides, one phenylpropanoid glucoside, one monoterpene glucoside, one monoterpene lactone and three flavonoids. Their structures were elucidated on the basis of spectral evidence. Additionally four phenolic acids as well as a fatty acid were determined through GC-MS analysis. All isolated compounds and the crude extracts were assayed for their antimicrobial activities against six Gram positive and negative bacteria, as well as against three human pathogenic fungi.     

The presence of androgen receptors in the epididymis and prostate of the stallion and cryptorchid horse--a preliminary study

Distribution of androgen receptors (ARs) in the epididymal duct and prostate of three entire stallions and one bilaterally cryptorchid horse was studied immunohistochemically using a polyclonal rabbit antiserum against the ARs. In both the healthy stallions and the cryptorchid, the epithelial cells of the epididymides showed nuclear staining for ARs. The intensity of AR-staining in the principal cells of the epididymis was stronger than that of the basal cells. In the prostate, the glandular secretory cells were moderately stained whereas the basal cells expressed weak AR-staining. Immunostaining for ARs in the reproductive tissues of the cryptorchid horse was always stronger than in those of the stallions. Our results demonstrate for the first time the AR localisation to equine epididymal and prostatic cells, which are directly regulated by androgens.     

The critical rotational speed of circular saw: simple measurement method and its practical implementations

Operation safety during sawing operations as well as dimensional accuracy and surface roughness depend on circular saw dynamic features among other factors such as circular saw blade accuracy and static/dynamic properties of the machine tool. Manufacturers of saw blades have an obligation to mark tools with a value stating the maximum allowed rotational speed for each saw. However, in some cases the value indicated on the saw corresponds to the critical rotational speed or is dangerously close to this critical value. Saw operation at the critical rotational speed is inadvisable and may result in serious injury or depreciation of product quality. This report outlines a simple methodology for evaluation of circular saw critical rotational speed. The assessment was conducted with a camera vision technique on the basis of an impulse test. Results are compared with theoretically calculated critical rotational speeds and the marks on saw blades.     

Chemical composition and nutritive value of husked and naked oats grain

11 samples of oats from the 2005 crop of the field experiment carried out in RSD Lipnik were examined. Naked grain oats were represented by a standard Polar cultivar and 5 strains (STH 6102, STH 6856, STH 7146, STH 7256, STH 1692), whereas husked grains were represented by a standard Bohun cultivar and 4 strains (STH 684, STH 688, STH 729, STH 840). The examined naked grain oats differ considerably from husked grain oats in their chemical composition. A statistically significantly higher content of protein (P ≤ 0.05), a higher level of fat (P ≤ 0.01) and a lower value of crude fibre (P ≤ 0.01) were observed in the grains of naked oats compared with the husked grains. The protein of oats is characterised by a favourable amino acid composition of high quality protein which can be confirmed by the EAAI values. The first amino acid limiting the nutritive value of protein was lysine in nearly all oat samples. The characteristic feature of the Polar cultivar was isoleucine deficit. The positive nutritive values for oat grains, in particular those for naked oat grains, make it possible to use them as food for humans and feed for monogastric animals.