MONITORING SYSTEM FOR UNDER-WATER PIPE LINE

The growing interest in new under-water pipe lines for the delivery of natural gas (in Baltic Sea, Mediterranean region, Caspian Sea, Black Sea, etc.) needs a new instruments for the monitoring of leakage and/or possible destruction of the pipes, which could not only disturb fragile ecological systems of Baltic and other seas, but also can lead to the technological catastrophes. We plan to develop a prototype of the system consisting of pervaporation membrane and gas sensors. Overall system will be immersed into water and will be fabricated in two versions: as a stationary instrument dipped into sea water and as an instrument towed along the pipe line. Micromachined metal oxide semiconductor gas sensors used for the detection of methane concentrations is designed and fabricated using “nano-on-micro” approach. Overall system is optimized from the point of view of minimum power consumption, which is necessary to assure its long term operation under autonomous conditions

WNT4 Expression in Primary and Secondary Kidney Diseases: Dependence on Staging

Background/Aims: WNT4 protein is important for kidney development. Its expression was found to be altered in experimental models of chronic kidney disease (CKD). However, the expression of the WNT4 gene has yet not been studied in human renal biopsy samples from patients with broad spectrum of glomerular disease and at different stages of CKD. Thus, the aim of the study was to assess the WNT4 gene expression in renal biopsies of 98 patients using the real-time PCR technique. Materials: In order to assess the relative amounts of mRNA, in samples of patients with manifestation of different renal diseases and separately at different stages of CKD, by QPCR, total RNA was isolated from human kidney tissues collected during renal biopsies. Results of blood and urine samples assessment were used to calculate the correlations of biochemical parameters with WNT4 gene expression in both studied groups. Results: After pathomorphological evaluation, 49 patients were selected as presenting the most common cases in the studied group. Among the patients who developed focal segmental glomerulosclerosis (FSGS; n = 13), IgA nephropathy (IgAN; n = 10), IgAN with morphological presentation of focal segmental glomerulosclerosis (IgAN/FSGS; n = 8), membranous nephropathy (MN; n = 12), and lupus nephritis (LN; n = 6) were included in the analysis. We found that the level of WNT4 mRNA was higher in kidney specimens obtained from patients with MN as compared to those diagnosed with LN or IgAN. A correlation between WNT4 gene expression and serum albumin and cholesterol levels was observed in patients with FSGS, while WNT4 mRNA levels correlated with plasma sodium in patients diagnosed with LN. After consideration of 98 patients, based on the KDIGO classification of CKD, 20 patients were classified as CKD1 stage, 23 as stage 2, 13 as stage 3a, 11 as stage 3b, 13 as stage 4, and 18 as stage 5. WNT4 gene expression was lower in the CKD patients in stage 2 as compared to CKD 3a. Correlations of WNT4 mRNA level at different stages of CKD with indices of kidney function and lipid metabolism such as serum levels of HDL and LDL cholesterol, TG, urea, creatinine, sodium, and potassium were also found. Conclusions: Our results suggest that altered WNT4 gene expression in patients with different types of glomerular diseases and patients at different stages of CKD may play a role in kidney tissue disorganization as well as disease development and progression

MONITORING SYSTEMS FOR UNDERWATER PIPELINES

The system for methane detection, under development by our group, consists of gas sensor and pervaporation membrane. The gas sensor was designed and fabricated using ‘nano-on-micro’ approach. The membrane covers the sensor and preferentially transport detected component. Two kinds of hydrophobic membranes were investigated: titania membranes modified by grafting process and polimeric membranes made from polidimethoxysilane (PDMS). Hydrophobic properties of the ceramic membranes were obtained by surface modification with fluorinated silanes (C6F13C2H4Si(OEt)3 and C12F25C2H4Si(OEt)3). Modified ceramic membranes properties were estimated using contact angle measurements. The highest contact angle value (148º) was obtained for membrane modified C12, whereas for membrane modified C6 the highest value was 135º. PDMS membranes of different thickness (in range 75-195 μm) were formed. PDMS permeability properties were examined by water pervaporation. The permeability coefficient of water through PDMS membrane was equal 7,34•10-15 mol/m Pa s. It was proved that water transport is inversly proportional to membrane thickness. Results for PDMS membranes were compared with results obtained for commertial membrane. Moreover, selective commercial membrane properties were tested by pervaporation in water-ethanol sytsem (1-10wt.% of ethanol). The membrane transported selectively ethanol (enrichment factor was in range 4-15)