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Number of results: 9
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Abstract

The aim of this study was to measure serum neopterin and C-reactive protein (CRP) concen- trations in female dogs with mammary tumours and evaluate the association between the values of these indicators and some clinical characteristics of the tumour. Fifty three female dogs were used for this study, including 43 dogs with mammary gland tumours (10 benign and 33 malignant) and 10 healthy controls. The concentrations of neopterin and CRP were determined using the ELISA technique and commercial ELISA kits. The mean serum neopterin concentration in fe- male dogs with mammary tumours was lower than in healthy dogs, but significant difference was not found. Similarly, there were no significant differences in neopterin concentrations in female dogs based on tumour size, tumour ulceration and metastasis. The mean CRP concentration was significantly higher (p<0.05) in dogs with malignant tumours compared to dogs with benign tu- mours and control. Furthermore, serum CRP concentration was significantly higher (p<0.05) in dogs with metastatic malignant tumours compared to dogs with non-metastatic mammary tu- mours. The CRP concentration was significantly lower (p<0.05) in dogs with tumours less than 3 cm compared to those with larger tumours, and significantly higher in dogs with ulcerated tu- mours compared to those without ulceration. Our findings suggest that the neoplastic process in the mammary gland does not cause significant changes in serum neopterin concentrations in dogs. Higher concentrations of serum CRP in dogs with advanced stages of malignant tumours may suggest that CRP could be a potential prognostic marker in canine malignant mammary tu- mours, but this hypothesis needs further study.
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Abstract

The results of experimental test of nine thickset reinforced concrete slabs in punching are presented in the this paper. The aim of the tests was verifi cation of the Eurocode EC 2 procedure, by which the ultimate shear stresses vRd,c depend on the slenderness of the slab. Besides of the performed tests results, the analysis of the foreign investigation of the fundaments is also included. The test results, as well as other tests, show the correctness of the function assumed in Eurocode 2, which gives correlation between ultimate stresses vRd,c and shear slenderness.
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Abstract

The study presents a durability analysis of dies used in the first operation of producing a valve-type forging from high nickel steel assigned to be applied in motor truck engines. The analyzed process of producing exhaust valves is realized in the forward extrusion technology and next through forging in closed dies. It is difficult to master, mainly due to the increased adhesion of the charge material (high nickel steel) to the tool’s substrate. The mean durability of tools made of tool steel W360, subjected to thermal treatment and nitriding, equals about 1000 forgings. In order to perform a thorough analysis, complex investigations were carried out, which included: a macroscopic analysis combined with laser scanning, numerical modelling by FEM, microstructural tests on a scanning electron microscopy and light microscopy (metallographic), as well as hardness tests. The preliminary results showed the presence of traces of abrasive wear, fatigue cracks as well as traces of adhesive wear and plastic deformation on the surface of the dies. Also, the effect of the forging material being stuck to the tool surface was observed, caused by the excessive friction in the forging’s contact with the tool and the presence of intermetallic phases in the nickel-chromium steel. The obtained results demonstrated numerous tool cracks, excessive friction, especially in the area of sectional reduction, as well as sticking of the forging material, which, with insufficient control of the tribological conditions, may be the cause of premature wear of the dies.
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Abstract

Calretinin (CR), a calcium-binding protein from EF-hand family, is localised in non-pyramidal GABA-ergic interneurons of the hippocampus. CR takes part in maintaining calcium binding homeostasis, which suggests its neuroprotective role. Hippocampal neurons contain membrane transient receptor potential vanilloid 1 (TRPV1) which binds to capsaicin (CAP) contained in habanero pepper fruits. Few in vivo studies have revealed the effect of CAP on interneurons containing CR. The aim of the present study was to investigate the CR immunoreac- tivity in interneurons of the hippocampal CA1 field and dentate gyrus (DG) in adult rats after intragastric admin- istration of the habanero pepper fruits. Wistar rats received a peanut oil – control group (C), and oil suspension of habanero pepper fruits at doses of 0.025 g dm/kg b.w. – group I and 0.08 g dm/kg b.w. – group II for 28 days. After euthanasia, the brains were collected and embedded in paraffin blocks using a routine histological tech- nique. Frontal hippocampal sections were immunohistochemically stained for CR by using a peroxidase-antiper- oxidase method. CR immunoreactive (CR-IR) interneurons were morphologically and morphometrically ana- lyzed under a light microscope. The results showed similar shapes and distribution of cells in both areas of the brain in group C and I of animals. However, CR-IR interneurons in the hippocampal CA1 field and in DG were occasionally observed in the group II of rats. The results of morphometric studies did not reveal statistically significant differences in the surface area and shape index of cells between examined brain regions from groups I and II compared to group C. Only in group II of rats, an increase in the digital immunostaining intensity of CR-IR interneurons was found in DG. Low number of CR-IR interneurons in the hippocampal CA1 field and in the DG, under the influence of a large dose of habanero pepper fruits containing CAP, may be caused by the activation of TRPV1 receptors and the increase in Ca2+ ions in these cells. This phenomenon may ultimately lead to neuronal death and may disturb neuronal conduction.
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Abstract

The present paper describe the issue of tool materials wear in a high temperature conditions. The investigations were performed at the cast steel tool material at the tribological contact to the structural steel. The investigations aim was to determine the role of microstructure in a tribological properties between the structural steel and tool material. The results of such investigation could be referenced to the industry conditions and could answer about the problems of tool materials wear. The observations of the wear mechanisms were referred to the microstructure of the mill rolls. The laboratory tests ware aimed at evaluating the thermal treatment modification effect on the cast steels properties. A significant role of the morphology of ledeburitic cementite and secondary cementite on the tribological properties was exhibited. The investigations assumed the presence of an austenitic matrix with primary and secondary cementite. Influence of varying morphology carbides was described. in the cast steel microstructure. The investigation results make possible to point to a direction of carbide morphology change with the purpose of obtaining the assumed properties of hot operation tools.
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