Expression of pendrin in benign and malignant human thyroid tissues

The Pendred syndrome gene (PDS) encodes a transmembrane protein, pendrin, which is expressed in follicular thyroid cells and participates in the apical iodide transport. Pendrin expression has been studied in various thyroid neoplasms by means of immunohistochemistry (IHC), Western blot and RT–quantitative real-time PCR. The expression was related to the functional activity of the thyroid tissue. Follicular cells of normal, nodular goitre and Graves' disease tissues express pendrin at the apical pole of the thyrocytes. In follicular adenomas, pendrin was detected in cell membranes and cytoplasm simultaneously in 10 out of 15 cases. Pendrin protein was detected in 73.3 and 76.7% of the follicular (FTC) and papillary (PTC) thyroid carcinomas, respectively, where pendrin was solely localised inside the cytoplasm. An extensive intracellular immunostaining of pendrin was observed in six out of 11 (54.5%) of positive FTCs and 19 out of 23 (82%) of PTCs. Focal reactivity was detected in one follicular- and three papillary carcinomas, whereas pendrin protein was absent in three of 15 FTC and four of 30 PTC; mRNA of pendrin was detected in 92.4% of thyroid tumours. The relative mRNA expression of pendrin was lower in cancers than in normal thyroid tissues (P<0.001). The pendrin protein level was found to parallel its mRNA expression, which was not, however, related to the tumour size and tumour stage. In conclusion, pendrin is expressed in the majority of differentiated thyroid tumours with high individual variability but its targeting to the apical cell membrane is affected

NrCAM, a neuronal system cell-adhesion molecule, is induced in papillary thyroid carcinomas

NrCAM (neuron-glia-related cell-adhesion molecule) is primarily, although not solely, expressed in the nervous system. In the present study, NrCAM expression was analysed in a series (46) of papillary thyroid carcinomas (PTCs) and paired normal tissues (NT). Quantitative reverse transcriptase (QRT)-PCR revealed that NrCAM expression was upregulated in all PTCs compared to normal thyroid, whatever the stage or size of the primary tumour. NrCAM transcript levels were 1.3- to 30.7-fold higher in PTCs than in NT. Immunohistochemistry (IHC) confirmed that the expression of NrCAM was considerably higher in tumours (score 2+/3+) than in adjacent normal paratumoural thyroid tissue. The NrCAM protein was detected in all but three (93.3%) PTC samples, and it was mainly cytoplasmic; in some cases there was additional membranous localisation – basolateral and partly apical. In the normal thyroid and tissues surrounding tumours, focal NrCAM immunolabelling was seen only in follicles containing tall cells, where staining was restricted to the apical pole of thyrocytes. Western blot analysis corroborated the QRT–PCR and IHC results, showing higher NrCAM protein levels in PTCs than in paired NT. The level of overexpression of the NrCAM mRNA in tumourous tissue appeared to be independent of the primary tumour stage (pT) or the size of the PTC. These data provide the first evidence that NrCAM is overexpressed in human PTCs at the mRNA and protein levels, whatever the tumour stage. Thus, the induction and upregulation of NrCAM expression could be implicated in the pathogenesis and behaviour of papillary thyroid cancers

Practical example of effective detection and location of partial discharges by the acoustic emission method in an electric power transformer

W artykule przedstawiono przykład diagnostyki transformatora elektro-energetycznego pod kątem oceny stanu technicznego papierowo - olejowego układu izolacyjnego zagrożonego występowaniem wyładowań niezupełnych (WNZ). Badania przeprowadzono podczas normalnej pracy jednostki transformatorowej, rejestrując w 36 punktach na powierzchni kadzi sygnały emisji akustycznej (EA) pochodzącej od zjawisk fizycznych występujących wewnątrz transformatora. Zarejestrowane sygnały poddano analizie w dziedzinie czasowej, częstotliwościowej i czasowo - częstotliwościowej. Wynikiem badań była detekcja i lokalizacja miejsca występowania wyładowań elektrycznych oraz wskazanie prawdopodobnej przyczyny i miejsca ich powstawania.Three measurement methods: gas chromatography method (DGA), electrical method and AE method are used in the assessment of the technical condition of paper-oil insulation of high-power transformers exposed to the occurrence of partial discharges (PDs). The acoustic method of PD detection is used as a supplementary one to the two others, mainly the gas chromatography method which does not make it possible to locate the place of the insulation system defect appearance. The basic advantage of the AE method, compared with the electrical one, is the possibility of its application during regular operation of power appliances [2, 3]. The paper presents the measurement results of the AE signals accompanying regular operation of a power transformer of 270 MVA. In order to assess the intensity of the AE signals measured on the object under study, coming from physical phenomena taking place inside a tub, three analyses were performed: in the time, frequency and time-frequency domains. Registration of the AE signals, the distributions of which is shown in Fig. 2, was carried out at 36 measurement points. An exemplary waveform of the AE signals registered is shown in Fig. 3, while the results of the analysis in the time domain are listed in Tables 1 and 2. In order to assess the waveforms registered more accurately, the analysis in the frequency domain was carried out and amplitude spectra were determined, an example of which is presented in Fig. 4. The time-frequency analysis was performed by using a short-time Fourier transform (STFT) determining two-dimensional spectrograms of the power density spectrum (Fig. 5). The assessment of the technical condition of the transformer under study made it possible to detect and locate areas in which PDs occurred. Damage of magnetic screens is a probable cause of their occurrence

Analysis of influence of current transformer incorrect ground connections in Aron circuit on power measurement results

W pracy przedstawiono wpływ błędnego połączenia obwodów wtórnych przekładników prądowych na działanie i wskazania układu pomiarowo-rozliczeniowego energii elektrycznej. Uziemienie końców uzwojeń stron wtórnych przekładników prądowych zamiast początków skutkuje zmianą rozpływu prądów w torach prądowych licznika. Przeanalizowano sposób określenia współczynnika korek-cyjnego dla błędnie połączonego układu oraz wielkości mających wpływ na jego wartość.Influence of incorrect connection of current transformer secondary circuits in Aron circuit on the operation of 3-phase electronic meas-uring and billing system of electrical energy in this paper has been described. Grounding the ends of secondary windings of current transformers instead of beginnings ones causes the current flow change in the measuring system, what was never reported before. Such a mistake connection can happen during the energy meter installation, and is difficult to the detection. It results in significant change of measurement results, lowering the cost of energy to be paid. The explanation of the grounding connection influence into measurement results is given in the paper. The correction factor for long time working incorrectly grounded system is calculated

Measurements of running light power losses of electric energy meters used in SMART GRID systems

W artykule przedstawiono informacje dotyczące inteligentnych sieci elektroenergetycznych oraz inteligentnych systemów pomiarowych ze szczególnym uwzględnieniem zalet wynikających z ich wdrażania oraz obaw powstających na etapie projektowania i wyboru podzespołów. Zasadniczą częścią pracy są badania strat własnych wybranych urządzeń pomiarowych stosowanych w systemach smart grid, co umożliwia ich ocenę i klasyfikację. Zaprezentowano oryginalne układy pomiarowe składowych prądów wejściowych liczników dołączanych do sieci bez obciążenia, co z kolei umożliwia obliczenie mocy czynnej, biernej i pozornej strat własnych liczników. W pomiarach uwzględniono zarówno klasyczne indukcyjne liczniki energii jak i liczniki elektroniczne z różnymi modemami komunikacyjnymi.Information on the smart grid and smart metering systems with particular emphasis on the benefits resulting from their implementation are shortly summarized in the Chapter 1. The essential part of the work are measurements of running light power loss of some chosen measuring devices, both 1-phase and 3-phase, used in smart grid systems, allowing for their assessment and classification. The essential idea of the measuring circuit consists in the measurement of real and imaginary compo-nents of small current consumed by the voltage circuit of the meter under test, while its current circuit is broken (Chap. 2). This is a normal condition of the energy meter connected to the power line, but without load. The current components to be measured are fixed in relation to the respective phase voltage. The measurements are easily and precisely performed by lock-in amplifier instrument (Figs. 2, 3). Original measuring circuits for input current compo-nents of meter voltage circuit under tests are presented. The measuring results allow to calculate the active, reactive, and apparent power losses in the meter voltage circuit. For the measurements and analysis both the common induction energy meters and modern electronic meters of various communication modems were taken into consideration (Tabs. 1, 2)

Diagnostics of technical condition of power transformer magnetic circuit with use of a modified vibroacoustic method

W publikacji scharakteryzowano zaproponowaną metodykę, tzw. zmodyfikowaną metodę wibroakustyczną, oraz przedstawiono rezultaty badań uzyskane na dwóch transformatorach, jednostce typu TR 16000/110 i TORb 25000/110. Ocenę efektywności opracowanej metodyki pomiarowo – diagnostycznej przeprowadzono poprzez korelację wyników analizy czasowo – częstotliwościowej zarejestrowanych wibracji z rezultatami badań chromatograficznych (DGA) oleju elektroizolacyjnego pobranego z kadzi monitorowanych urządzeń. Analizę zarejestrowanych drgań wykonano z wykorzystaniem przekształceń STFT, CWT i DWT.The subject of the paper concerns evaluation of the technical condition of the power transformer magnetic circuit by measuring and analyzing vibrations recorded during switching on the transformer. This paper presents the results of technical verification of the noninvasive method used for diagnostics of transformer cores. The research on application of this method has been performed at the Institute of Power Engineering of the Opole University of Technology for several years. The paper characterizes the proposed methodology, the so-called modified vibroacoustic method, and presents the results obtained on two tested transformers, type TR 16000/110 and TORb 25000/110. Evaluation of the effectiveness of the developed methodology of diagnostic measurements was performed by correlation analysis of the time-frequency vibrations recorded with the results of chromatographic studies (DGA) of oil taken from the transformer tank. The recorded vibrations were analyzed using the transformation STFT (Short Time Fourier Transform), CWT (Continuous Wavelet Transform) and DWT (Discrete Wavelet Transform). On the basis of the results given in this paper as well as the currently conducted research work, it was found that there is a real possibility of using the developed method for noninvasive assessment of technical condition of mechanical construction of power transformer cores in operating conditions

Diagnostics of technical condition of power transformers with use of the Acoustic Emission Method

Tematyka artykułu dotyczy wykonanych przez pracowników Politechniki Opolskiej badań związanych z detekcją, oceną intensywności i lokalizacją wyładowań niezupełnych metodą emisji akustycznej w trzech transformatorach elektroenergetycznych o mocach 125, 160 i 400 MVA. Rezultatem przeprowadzonych prac było sformułowanie rekomendacji technicznych dotyczących aktualnego stanu technicznego badanych jednostek. Analizę zarejestrowanych impulsów akustycznych przeprowadzono w dziedzinie czasu, częstotliwości i czasowo-częstotliwościowej.An important part of a comprehensive evaluation of the technical condition of power transformers is detection, assessment of the intensity and location of partial discharges (PDs), that may occur in their paper-oil insulation systems. Modern monitoring techniques are increasingly using the acoustic emission (AE) method, which combines the features of the gas chromatography and electricity methods, to evaluate the electrical discharge. The paper presents investigations performed by a team of the Opole University of Technology dealing with the detection, evaluation, intensity and location of PDs by means of the AE method for three transformers of 125, 160 and 400 MVA power. The result of this work was formulation of technical recommendations for the current technical condition of units. The analysis of the recorded pulses EA was conducted in the time, frequency and time-frequency domain. The paper generally characterizes the possibility of the AE method, and the used measuring system (Fig. 1). There are given the technical parameters of the energy object under study (Figs. 2, 7 and 11). The results of detection, assessment of the intensity and location of electrical discharges in transformers diagnosed are shown in Figs. 3, 5, 6, 9, 10, 13, 14 and Tables 1-4

Repeatability Estimation for Vibration Measurement Results of Power Transformer Core

The subject matter of this paper refers to the diagnostics of a transformer core, based on measurements and analysis of vibroacoustic signals registered during their normal operation. The paper presents results of the research aimed to evaluate the repeatability of vibration measurements for power transformer core. Recording of vibroacoustic signals was performed under laboratory conditions on dry-insulated transformers. The study concerned evaluation of changes in vibroacoustic indicators of the transformer core during operation with a turned and loosened core. Conclusions from the measurement results were drawn on the basis of the parametric test of significance derived from the variance analysis for many means of single classification basing on the Fisher-Snedecor F-distribution

Hunting in Poland as part of the sustained development of rural areas

Due to state ownership of both free game and most forests in Poland, large hunting districts and low number of hunters, hunting in Polish hunting grounds provides an opportunity to encounter many animal species, often in their almost natural environment. The qualities of Poland’s fauna and flora as well as Poland’s accession to the EU and the resulting ease of movement have contributed to the development of hunt tourism. As a consequence, there has been a rise in the demand for services offered by rural areas inhabitants, which in turn should make local communities recognize the need to preserve the natural environment