Nowoczesne rozwiązania telefonicznych central abonenckich. Przegląd Zagadnień Łączności, 1963, nr 6 (21)

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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

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

Present possibilities and prospects of the acoustic method application in diagnostics of insulation systems

W artykule zostały scharakteryzowane prowadzone obecnie przez autorów artykuły prace związane z doskonaleniem akustycznej metody pomiaru wyładowań elektrycznych, jakie mogą występować w układach izolacyjnych urządzeń elektroenergetycznych. Szczególną uwagę zwrócono na ekspercki system diagnostyczny wykorzystujący metodę emisji akustycznej do oceny stanu mierzonej izolacji transformatorów energetycznych.The paper characterizes the research work on the improvement of the acoustic method of the measurements of electrical discharges that can occur in insulation systems of power appliances. The utmost attention was directed to the expert diagnostic system using the acoustic emission method for the evaluation of the condition of the power transformer insulation measured

Use of a reflectometer for transformer oil testing

W artykule przedstawiono możliwości wykorzystania reflektometru do badania oleju transformatorowego. Scharakteryzowano metrologiczne właściwości reflektometru optycznego. Przedstawiono przykładowe wyniki pomiarów zmian współczynników Fresnela na końcu włókna światłowodowego dla olejów izolacyjnych o różnym stopniu zestarzenia. W konkluzji określono perspektywy wykorzystania optycznej techniki pomiarowej do określenia stopnia zestarzenia olejów izolacyjnych.In the article, possibilities of using a reflectometer for transformer oil testing have been presented. Metrological properties of the optical reflectometer have been characterized. Exemplary measurement results of Fresnel factor changes at the end of an optical fibre for insulating oil of various ageing degree have been presented. The conclusion points out numerous perspectives of using optical measurement technique to determine the ageing degree of insulation oils

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

Current state of research on mouflon (Ovis musimon) as a basis for management, protection or elimination of this species from Poland

The paper presents the first Polish bibliography on mouflon that includes papers published in the years 1945−2014. Forty seven publications show diversified interest in mouflon depending on its population size. Three different periods of research activity and publishing were distinguished. The first one (1945−1960) called the ‘opening balance' was the time of assessment of mouflon in Poland after the World War 2. At that time, mouflon status as an alien species was not taken into account. After the first unsuccessful attempts of introduction, ‘period of ambivalence' in the research and publishing activity occurred. In years 1961−1990 only nine publications, mainly popular ones, about the biology and occurrence of the species in Poland, and the history of its introduction were published. Along significant increase in number in the early 1990s, there was a significant increase in interest in this species among scientists. Majority of Polish research on mouflon has been published in the ‘renaissance' phase (since 1991). Papers deal with genetic testing, parasitology or telemetry, but knowledge about the role of mouflon in the ecosystem is still insufficient. Preliminary analysis of the number of publications and their subject (figs. 1 and 2) clearly shows that despite its 70−year history in Poland, the mouflon is still little−known species. Well−documented history of the reintroductions and their development is accompanied by almost complete lack of knowledge about the ecology. In terms of hunting management, protection or elimination of this species from Poland, there are currently no any reliable information, which could be useful for decision−makers. Mouflon has been a species of small numbers, not causing severe damage to forests and fields, and apparently not influencing negatively other ungulates in the areas of its occurrence. Not being a source of hunting successes or environmental problems it still remains outside the interest of scientists. At first mouflon was promoted, but later on, sometimes after many years, researchers tried to answer basic matters. Currently priority should be given to the research on i) the genetic condition of all local populations and evaluate their stability, ii) the interaction between mouflon and other wild ungulates, iii) its dietary composition in terms of damage to forests and fields, iv) parasites in isolated populations and v) assessment of the future of the species in Poland in the time of significant increase in wolf population

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

Direct observations of wildlife as an element of the monitoring of large ungulates on the example of moose (Alces alces L.) in the Kampinoski National Park

More than 3000 direct observations of 5900 mooses were used to investigate the sex structure and growth of the population living in the Kampinoski National Park (KNP, central Poland). The study used data collected by the park service since 1998. To confirm the hypothesis that the random observations will accurately describe the population structure the experiment was performed with a theoretical population. It was a collection of 102 numbers (1−39 for females, 40−81 for males, and 82−102 for calves). Sex structure of this population was 1:1 and the growth rate was 0.6 calf/female. To provide the randomness all ‘animals' were mixed and renumbered. Each time we drew 4 numbers (like 4 random moose observed). The drawn numbers were grouped into: males, females and calves. Results of the consecutive draws were accumulated, while sex ratio and growth rate of this hypothetical population were constantly recalculated. Changes in ratios with increasing abundance of ‘recorded' moose were observed. It was assumed that the accuracy of estimates of population structure will increase with the number of observed animals and ultimately the results of the draw will show real sex structure and growth of analyzed population. The draw was repeated three times. Each time the results confirmed the hypothesis. A similar procedure was performed for empirical data from KNP. The documented direct observation of moose throughout the year provides a reliable assessment of the sex structure and population growth. At a constant, daily assessment of gender structure requires longer observation time than evaluation of growth. Application of these traits based on a small empirical material and/or short follow−up time may result in significant errors. The sex structure of moose in KNP is at the level of about 1:2, while growth at 0.8 calf/female. The values of indicators describing these characteristics are higher than previously adopted for the purposes of hunting of moose use in Poland. It would clarify the methodology of recording observations – a clear definition of calf age (0−1 years) and a separate listing of moose treated as an independent one−year age group. It is also strict principle of not combining several separate observations (e.g. summary of the daily observations) as one independent observation. The method of accumulation of direct observation to assess the gender structure and growth should be tested in other deer species