883 research outputs found
Cu–Ni nanoalloy phase diagram – Prediction and experiment
The Cu-Ni nanoalloy phase diagram respecting the nanoparticle size as an extra variable was calculated by the CALPHAD method. The samples of the Cu-Ni nanoalloys were prepared by the solvothermal synthesis from metal precursors. The samples were characterized by means of dynamic light scattering (DLS), infrared spectroscopy (IR), inductively coupled plasma optical emission spectroscopy (ICP/OES), transmission electron microscopy (TEM, HRTEM), and differential scanning calorimetry (DSC). The nanoparticle size, chemical composition, and Cu-Ni nanoparticles melting temperature depression were obtained. The experimental temperatures of melting of nanoparticles were in good agreement with the theoretical CALPHAD predictions considering surface energy.Fázový diagram nanoslitiny Cu-Ni respektující velikost nanočástic jako další proměnné byl vypočten metodou CALPHAD. Vzorky Cu-Ni nanoslitin byly připraveny solvotermální syntézou z prekurzorů kovů. Tyto vzorky byly charakterizovány pomocí dynamického rozptylu světla (DLS), infračervené spektroskopie (IR) s indukčně vázanou plazmou a optickou emisní spektroskopií (ICP / OES), transmisní elektronovou mikroskopií (TEM, HRTEM) a diferenciální skenovací kalorimetrií (DSC). Velikost nanočástic, chemické složení a Cu-Ni deprese teploty tání nanočástic byly získány experimentálně a v dobré shodě s teoretickou předpovědí metodou CALPHAD s uvážením povrchové energie nanočástic
Macrotroponins cause discrepancy in high-sensitivity examination
Aim. We present two cases with clearly discrepant results of clinical examination and cardiac troponin I (cTnI) and cardiac troponin T (cTnT) concentrations. In similar cases with discrepant results, the possibility of interference should be considered. Methods. Due to the suspicion of the presence of macrotroponin I in both of the presented cases, the patients were invited to our laboratory and both cTnI (Architect i1000, Abbott) and cTnT (Cobas 8000, Roche) concentrations were analysed. The samples were treated by preincubation in a heterophilic antibodies blocking tube (HBT) and analysed. Precipitation with polyethylene glycol solution (PEG) and molecular weight separation by gel filtration on Sephadex G100 was performed and concentrations of cTnI were analysed. Results. In the same blood sample, the cTnT and cTnI concentrations were 7 and 1782 ng/L, respectively, in Case 1, and 6 and 96 ng/L, respectively, in Case 2. Incubation of samples in HBT had no significant effect. CTnI concentrations after precipitation with PEG - presented as the percentage of initial concentrations - were 7.4% in Case 1 (and 26.8% in the control sample) and 1.4% in Case 2 (and 56.0% in the control sample). These results indicate a significant decrease in both cases, supporting presence of macrotroponin I. Finally, analyses of cTnI concentrations after gel filtration also supported the presence of macrotroponin I. Conclusion. The present cases show that the presence of macrotroponin can lead to unnecessary investigation of the patient. When the possibility of interference is suspected, cooperation with laboratory staff to help with interpretation or to perform more detailed analysis is crucial
Clinical and duplex ultrasound evaluation of lower extremities varicose veins - a practical guideline.
Lower extremities varicose veins are among the most frequent diseases in the general population. They can cause complaints with a deterioration of the quality of life and are associated with potentially threatening clinical conditions such as chronic venous ulceration, haemorrhage from ruptured varicose veins, and venous thromboembolism. An accurate diagnostic work-up is crucial to confirm the presence and the extension of the venous problem, in order to obtain an optimal management of the condition. In the past years, great efforts have been made to reach an international consensus on the terminology, the symptomatology, the classification, and the duplex ultrasound examination of lower extremities varicose veins. Mainly guided by these consensus documents, the present article describes the diagnostic work-up of lower extremities varicose veins, based on a careful medical history, physical examination, and duplex ultrasound examination
Thermodynamic assessment and experimental study of the Al-Ag-Ga phase diagram
Ternary Al-Ag-Ga system was assessed both theoretically using thermodynamic calculations of phase equilibria based on CALPHAD method and experimentally using differential thermal analysis (DTA), scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS) and X-ray powder diffraction (XRD) analysis. The calculated phase transition temperatures, isothermal sections at 300 and 500 degrees C and liquidus surface projection were experimentally validated by experimental study of selected long-term annealed alloy samples with overall compositions along four vertical sections Al-Ag80Ga20, Al-Ag60Ga40, Ag-Al80Ga20 and Ag-Al60Ga40
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