X-ray absorption near edge structure and Mössbauer spectroscopy in study of iron valence states in tissues

X-ray absorption near edge structure Fe K-edge spectra and $\text{}^{57}$Fe Mössbauer spectra of selected standard compounds were recorded at room temperature. Valence and spin states of Fe in these samples known from Mössbauer spectroscopy were correlated with the shapes of X-ray absorption near edge structure spectra in search of possible application of X-ray absorption near edge structure spectroscopy as analytical tool determining local electronic states of iron in tissues. As an example, the X-ray absorption near edge structure spectra of healthy and cancerous tissues of prostate are shown, suggesting Fe$\text{}^{3+}$ in cancerous tissues

Macro-GH - a clinical entity causing a diagnostic challenge - a case report.

AIM: Presentation of a new case of a patient with macro-GH, that may interfere with different GH assays leading to false-positive results in serum samples. CASE PRESENTATION: A 61-year-old female was referred with a pituitary macroadenoma and elevated growth hormone levels The laboratory tests showed increased fasting GH level, measured by a sandwich chemiluminescence immunoassay (LIAISON® XL) without suppression on oral glucose tolerance test and normal IGF-1. The patient did not have the typical signs and symptoms of acromegaly. The patient underwent a transsphenoidal resection of a pituitary tumor, showing only α-subunit immunostaining. Postoperative GH levels remained elevated. An interference in the determination of GH level was suspected. GH was analyzed by three different immunoassays, UniCel DxI 600, Cobas e411 and hGH-IRMA. Heterophilic antibodies and rheumatoid factor were not detected in serum sample. GH recovery after precipitation with 25% polyethylene glycol (PEG) was 12%. Size-exclusion chromatography confirmed the presence of macro-GH in serum sample. CONCLUSION: If results of laboratory tests are not consistent with the clinical findings, the presence of an interference within immunochemical assays could be suspected. To identify interference caused by the macro-GH, the PEG method and size-exclusion chromatography should be used

Corticotropinoma as the underlying cause of intermittent Cushing’s syndrome in a patient previously diagnosed with primary pigmented nodular adrenocortical disease

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High-energy-resolution grazing emission X-ray fluorescence applied to the characterization of thin Al films on Si

The grazing emission X-ray fluorescence (GEXRF) technique was applied to the analysis of different Al films, with nominal thicknesses in the range of 1 nm to 150 nm, on Si wafers. In GEXRF the sample volume from which the fluorescence intensity is detected is restricted to a near-surface region whose thickness can be tuned by varying the observation angle. This is possible because of the refraction of the fluorescence X-rays and the quite long emission paths within the probed sample. By recording the X-ray fluorescence signal for different shallow emission angles, defined relatively to the flat, smooth sample surface, the deposited Al surface layers of the different samples could be well characterized in terms of layer thickness, layer density, oxidation and surface roughness. The advantages offered by synchrotron radiation and the employed wavelength-dispersive detection setup were profited from. The GEXRF results retrieved were confirmed by complementary measurements. The experimental setup, the principles and advantages of GEXRF and the analysis of the recorded angular intensity profiles will be discussed in details

Evaluation of different analytical approaches using total reflection X-ray fluorescence systems for multielemental analysis of human tissues with different adipose content

Publisher Copyright: © 2022 The AuthorsElemental content plays an important role in biological processes, and so, the multielemental analysis of human tissue samples is required in biomedical research. Still, the small amount of available biological samples and the adipose content of the samples can be major setbacks for the accurate determination of elemental content. In this study, we explored the potential of several analytical approaches combined with total reflection X-ray fluorescence spectrometry (TXRF) for multielemental analysis of human tissues with different adipose content (colon, heart, liver, lung, muscle, intestine, skin, stomach, uterus, bladder and aorta). The capabilities and limitations of different sample treatment procedures (suspension and acidic digestion) and two TXRF systems with different anode configurations (Mo and W X-ray tubes) have been evaluated for such purpose. Results showed that for tissues with a higher fat content (e.g., skin, and intestine) the best strategy was the acidic digestion of the sample before TXRF analysis. However, for other tissues, acceptable results were obtained by suspending 20 mg of powdered material in 1 mL of 2 M nitric acid. A further enhancement of the limits of detection and accuracy of the results was achieved if using Mo-TXRF systems, especially for the determination of low Z elements (e.g., K, and Ca) and of elements present at low concentrations (e.g., Cu) in the human tissues. Finally, results by TXRF analysis were compared with those obtained with μ-EDXRF and ICP-OES, and a good agreement was obtained.publishersversionpublishe

Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

Various 3-dimensional nano-scaled periodic structures with different configurations and periods deposited on the surface of silicon and silica substrates were investigated by means of the grazing incidence and grazing emission X-ray fluorescence techniques. Apart from the characteristics which are typical for particle- and layer-like samples, the measured angular intensity profiles show additional periodicity-related features. The latter could be explained by a novel theoretical approach based on simple geometrical optics (GO) considerations. The new GO-based calculations were found to yield results in good agreement with experiment, also in cases where other theoretical approaches are not valid, e.g., periodic particle distributions with an increased surface coverage

Research into ultrasonic and hydrodynamic cavitation phenomena in a hydraulic system

У статті описано процеси ультразвукової кавітації в гідравлічному резервуарі та гідродинамічної кавітації у шестеренному насосі. Виникнення зазначених процесів підтверджено експериментальними дослідженнями при використанні резервуара і насоса з прозорої пластмаси. Доведено, що кавітаційна система, створена за оригінальним проектом, є корисною для генерування явища ультразвукової кавітації. Також показано, що метод PIV-візуалізації, який полягає в спеціальному освітленні прозорих об'єктів і записи структури потоку крізь ці об'єкти за допомогою швидкісної відеокамери, при вивченні явища кавітації досить ефективний. Візуально встановлено взаємодію ультразвуку та гідродинамічної кавітації. У свою чергу, виникнення ультразвукової кавітації в резервуарі викликає дегазацію масла, що подається в насос, яке зменшує гидродинамическую кавітацію у внутрішніх каналах і зазорах. Це свідчить про позитивний вплив ультразвукової кавітації на роботу насоса та гідравлічної системи в цілому. Представлена робота є прикладом ефективної співпраці між дослідниками Вроцлавського університету науки і технологій (Польська Республіка) і Національного технічного університету України “Київського політехнічного інституту імені Ігоря Сікорського”.The article describes the course of the ultrasonic cavitation in a hydraulic tank and the hydrodynamic cavitation in a gear pump. The course of those phenomena was confirmed in experimental tests carried out with the use of a tank and a pump made of transparent plastics. It has been proved that the oscillator-cavitation system made according to the original project is useful to in-duce the phenomenon of ultrasonic cavitation. It has also been shown that the PIV visualization method, consisting in a special sys-tem of illuminating transparent objects and recording the flow through those objects with a fast camera, is useful for the studying of the cavitation phenomena. A visible interaction between the ultrasonic and the hydrodynamic cavitation was observed. The induction of ultrasonic cavitation in the tank causes degassing of the oil, and the degassed oil supplying the pump reduces the hydrodynamic cavitation in its internal channels and clearances. This is an example of beneficial effects of the ultrasonic cavitation on the operation of a pump and a hy-draulic system. The presented work is an example of effective co-operation between the communities of Wroclaw University of Science and Technol-ogy and Igor Sikorsky Kiyv Politechnic Institute, National Technical University of Ukraine.В статье описываются процессы ультразвуковой кавитации в гидравлическом резервуаре и гидродинамической кавитации в шестеренном насосе. Возникновение указанных процессов подтверждено экспериментальными исследованиями при использовании резервуара и насоса из прозрачной пластмассы. Доказано, что кавитационная система, созданная по оригинальному проекту, полезна для генерирования явления ультразвуковой кавитации. Также показано, что метод PIV-визуализации, который заключается в специальном освещении прозрачных объектов и записи структуры потока через эти объекты с помощью скоростной видео камеры, при изучении явления кавитации весьма эффективен. Визуально установлено взаимодействие ультразвука и гидродинамической кавитации. В свою очередь, возникновение ультразвуковой кавитации в резервуаре вызывает дегазацию масла, подаваемого в насос, которое уменьшает гидродинамическую к авитацию во внутренних каналах и зазорах. Это свидетельствует о положительном воздействииу льтразвуковой кавитации на работу насоса и гидравлической системы в целом. Представленная работа является примером эффективного сотрудничества между исследователями Вроцлавского университета науки и технологий (Польская Республика) и Национального технического университета Украины “Киевского политехнического института имени Игоря Сикорского”