ANGA Mechanical Seals (Poland)

Flow Mediated Skin Fluorescence (FMSF) is a new non-invasive diagnostic method for assessing vascular circulation and/or metabolic regulation. The method measures stimulation of the circulation in response to post-occlusive reactive hyperemia (PORH). It analyzes the dynamical changes in NADH fluorescence emitted from skin tissue, providing information on mitochondrial metabolic status and intracellular oxygen delivery through the circulatory system. Assessment of the vascular state using the FMSF technique is based on three parameters: flowmotion (FM) under normoxia conditions, hypoxia sensitivity (HS), and hyperemic response (HRmax). The functioning of mitochondria can be assessed by analyzing the ischemic response (IRmax), hypoxia sensitivity (HS), and the basal level of NADH fluorescence. There is a close relationship between the functioning of mitochondria and the vascular system. Despite these interactions, mitochondrial and vascular regulatory function can be monitored separately as well as simultaneously by the FMSF technique. Uniquely, this approach delivers information on both mitochondrial and vascular function based on a single measurement.

Mitochondrial dysfunction has been linked to psoriasis, and may be an important underlying factor contributing to this disease. However, a precise methodology for assessing mitochondrial dysfunction has yet to be developed. One promising approach is to measure NADH autofluorescence from affected skin areas. In this study, we show that Flow Mediated Skin Fluorescence (FMSF) can be used for non-invasive assessment of mitochondrial dysfunction in psoriasis. The fluorescence level at baseline and the half-time of ischemic growth (t1/2) derived from the FMSF traces can be used for non-invasive assessment of NADH/NAD+ redox imbalance in psoriatic lesions compared to unaffected skin. These results are supported by analysis of the key FMSF parameters, Reactive Hyperemia Response (RHR) and Hypoxia Sensitivity (HS). This method not only contributes to understanding of the biochemical processes involved in the etiopathogenesis of psoriasis, but also provides a basis for identifying new drug targets and improving the treatment process.

Keywords: flow mediated skin fluorescence; FMSF technique; NADH fluorescence, microcirculation, flowmotion, reactive hyperemia response, RHR, hypoxia sensitivity, HS, normoxia oscillatory index, NOI

The paper presents a study of surface condition of stationary and rotary rings of a gas-lubricated face seal before and after 25 hours of operation on a test bench, with 75 cycles of start-ups and stops of the drive. For evaluation of surface conditions, flatness deviation and a selected 2D and 3D roughness parameters were measured. Profiles of the roughness, material ratio curves, topography, and surface maps in colour before and after 25 hours of operations were presented. It has been found that wear of the end faces of the saling rings differs between sintered silicon carbide and carbon graphite. In the case of the stationary ring made of sintered silicon carbide with a hardness of 3000 HV, there is a slight increase in values of almost all (except Sp) measured 3D amplitude parameters: Sa, Sq, Sv, St. In the case of the rotary ring made of carbon graphite with hardness of about 115 HR a noticeable reduction in values of these parameters was found. Changes In 2D and 3D roughness parameters of end faces of the stationary and rotary rings allow confirming the al most contact-free character of the face seal operation.