Математическое моделирование системы отслеживания шва в сварке электронным пучком

В ходе исследований разработана математическая модель системы отслеживания шва в сварке электронным пучком. Экспериментально доказана эффективность применения данной модели к любой электронно-сварочной установке. Для простейшего детектора излучения (пластины-детектора) без использования физических фильтров были получены электронные изображения сварных швов, отличающиеся высокой четкостью. Эмпирически доказана независимость сканирования от механических характеристик электронно-сварочной установки. Доказано, что отсутствие источников электронов с необходимой мощностью пучка не является препятствием для получения достаточного качества измерений.In the course of research, a mathematical model of the tracking system of a weld in electron beam welding was developed. The effectiveness of applying this model to any electronic welding installation has been experimentally proven. For the simplest radiation detector (detector plate) without the use of physical filters, electronic images of welds, which are distinguished by high definition, were obtained. Empirically proven independence of the scan from the mechanical characteristics of the electronic welding installation. It is proved that the absence of electron sources with the necessary beam power is not an obstacle to obtaining a sufficient measurement quality

The Investigation of Bovine Viral Diarrhoea Virus Antigens with Immunofluorescence and Immunohistochemical Methods in Bovine Abortions

The investigation of bovine viral diarrhoea virus (BVDV) in bovine abortions in Erzurum, Turkey was undertaken with immunofluorescence, immunohistochemistry and histopathological methods. For this purpose, tissue sections from 56 aborted foetuses were examined. At the end of the study, histopathological lesions were observed in 17(30.36%) samples. Hyperaemia in sinusoids and central veins, degeneration and necrosis of some hepatocytes and cellular infiltration in portal areas were main histopathological changes in liver. In brain sections, hyperaemia, degeneration and necrosis of neurons, spongiosis and vasculitis, especially in BVDV positive sections, were prominent. In addition, there was interstitial or catarrhal pneumonia in lung sections. Positive immunofluorescence staining was detected in 8(14.28%) foetal tissues by direct immunofluorescence method. In immunohistochemical staining, 6(10.71%) samples were found positive. Antigenic localisations were observed in the cytoplasm of neuronal cells, neuroglia and leptomeninges in brain; hepatocytes cytoplasm of the liver; apical portion of bronchiolar epithelium and alveolar macrophages of lung sections. It is concluded that BVDV is an effective factor for the cattle abortion in Erzurum, Turkey. (C) 2015 PVJ. All rights reserve

PET/CT in lung cancer: Influence of contrast medium on quantitative and clinical assessment

OBJECTIVES: To evaluate the influence of intravenous contrast medium and different contrast medium phases on attenuation correction, PET image quality and clinical staging in combined PET/CT in patients with a suspicion of lung cancer. METHODS: Sixty patients with a suspicion of lung cancer were prospectively enrolled for combined (18)F-FDG-PET/CT examination. PET images were reconstructed with non-enhanced and arterial and venous phase contrast CT. Maximum and mean standardised uptake values (SUVmax and SUVmean) and contrast enhancement (HU) were determined in the subclavian vein, ascending aorta, abdominal aorta, inferior vena cava, portal vein, liver and kidney and lung tumour. PET data were evaluated visually for clinical staging and image quality. RESULTS: SUVmax was significantly increased between contrast and non-contrast PET/CT at all anatomic sites (all P < 0.001). SUVmax was significantly increased for arterial PET/CT compared to venous PET/CT in the arteries (all P < 0.001). Venous PET/CT resulted in significantly higher SUVmax values compared to arterial PET/CT in the parenchymatous organs (all P < 0.05). Visual clinical evaluation of malignant lesions showed no differences between contrast and non-contrast PET/CT (P = 1.0). CONCLUSIONS: Contrast enhanced CT is suitable for attenuation correction in combined PET/CT in lung cancer; it affects neither the clinical assessment nor image quality of the PET images. KEY POINTS : * Positron emission tomography combined with computed tomography is now a mainstream investigation * There has been debate about whether CT contrast agents affect PET results * Contrast-enhanced CT is satisfactory for attenuation correction in lung cancer PET/CT * Multiphase CT does not affect PET; additional unenhanced CT is unnecessary * For quantitative follow-up PET analysis, an identical PET/CT protocol is required