7 research outputs found
The use of CA125, human epididymis protein 4 (HE4), risk of ovarian malignancy algorithm (ROMA), risk of malignancy index (RMI) and subjective assessment (SA) in preoperative diagnosing of ovarian tumors
Objectives: To compare utility of CA125, human epididymis protein 4 (HE4), risk of ovarian malignancy algorithm (ROMA), risk of malignancy index (RMI) and subjective assessment (SA) in preoperative diagnosis of ovarian tumors. Material and methods: Research was conducted among 456 patients qualified for surgery due to ovarian tumor. Preoperatively, CA125 and HE4 serum levels were estimated, and transvaginal ultrasound was performed. ROMA and RMI values and SA qualifications were obtained. Results were compared with pathomorphological findings. Results: Receiver Operating Characteristic (ROC)-Area Under Curve (AUC) values for CA125, HE4, ROMA, RMI and SA in preoperative diagnosis of malignant lesions were 0.819, 0.909, 0.911, 0.895 and 0.895, respectively. Combinations of biochemical and sonographic methods increased sensitivity in diagnosis of ovarian tumors. Combinations utilizing serum HE4 concentrations were most useful. Conclusions: CA125, HE4, ROMA, RMI and SA proved to be useful in preoperative diagnosis of ovarian tumors. HE4 and ROMA occurred to be the most useful. Ultrasonographic methods are considerably useful in diagnosis of ovarian tumors. RMI and SA present similar overall diagnostic value
Nickel Nanowires: Synthesis, Characterization and Application as Effective Catalysts for the Reduction of Nitroarenes
We have demonstrated a convenient method of synthesizing nickel nanowires (NiNWs), which could be easily tuned to produce materials with a carefully defined nanostructure. By varying the concentration of the Ni precursor, pH of the medium or reaction temperature, we directly affected the diameter of the formed product as well as the yield of the process. The obtained material consisted of straight bundles of NiNWs, which revealed powerful catalytic action for the reduction of nitroarenes to appropriate amine derivatives. A selection of substrates were employed and all of them were successfully converted into the corresponding aromatic amine despite the presence of different substituents on the aromatic ring with high yields, even in large scale reactions. The results showed that NiNW-based catalysts could constitute efficient catalytic systems for the synthesis of aryl amines at industrial levels
Shrinkage and mechanical properties of drying oil paints
[EN] Understanding how the evolving molecular composition of an oil paint layer on its transition to an aged solid film affects its dimensional change and mechanical properties is fundamental to the assessment of material durability and more broadly risk of degradation of oil paintings. Tensile properties-modulus of elasticity and strain at break-as well as cumulative shrinkage were determined for a selection of oil paints from Mecklenburg¿s Paint Reference Collection now after approximately 30 years of drying. The oil paints were found to get stiffer and more brittle with diminishing plastic deformation and increasingly elastic behaviour. For some paints, the increases in stiffness and decreases in the strain at break were dramatic during the late stage of drying. The observations modify the current physical model of paintings in which the mismatch in the response of glue-based ground layer and unrestrained wood or canvas support to variations in relative humidity (RH) has been identified as the worst-case condition for the fracturing of the entire pictorial layer. This study demonstrated that some paints were more brittle than the glue-based ground layer and as a consequence more vulnerable to cracking. The shrinkage of paints due to molecular relocation and/or evaporation of organic medium as they dry and age was measured. This shrinkage can exceed their strain at break and lead to fracturing of the oil paint layer if it is restrained by a dimensionally stable substrate. Consequently, after long-term drying, the cumulative shrinkage can cause oil paints to crack even in absence of fluctuations in RH or temperature. An example of cracking developed in an oil paint layer on the top of an undamaged ground layer in a historic panel painting was made evident by the X-ray microtomography.This work was funded by the European Union's Horizon 2020 research and innovation program under grant agreement No. 814624 and the statutory research fund of the Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences. Lukasz Bratasz's work was financed by the Polish National Agency for Academic Exchange, project Polish Returns [Grant PPN/PPO/2018/1/00004/U/00001].Janas, A.; Mecklenburg, M.; Fuster-López, L.; Kozlowski, R.; Kékicheff, P.; Favier, D.; Andersen, CK.... (2022). Shrinkage and mechanical properties of drying oil paints. Heritage Science. 10(1):1-10. https://doi.org/10.1186/s40494-022-00814-211010
Mechanical properties and moisture-related dimensional change of canvas paintings¿canvas and glue sizing.
[EN] Understanding canvas paintings as physical systems is fundamental to develop evidence-based environmental specifications for museums. A number of tests were carried out to determine mechanical properties of canvas, canvas sized with animal glue and animal glue-based ground layer (gesso) as a function of relative humidity (RH). The mechanical properties of the canvas samples tested exhibited an anisotropy dependent on the measurement direction, being the stiffness corresponding to the weft direction greater than the warp and diagonal ones. Sizing the canvas with a layer of animal glue significantly increased its modulus of elasticity while the anisotropy of mechanical properties was kept in the composite material. The application of an animal glue-based ground layer on sized canvas increased the elasticity modulus of the system by another order of magnitude (similar to 2 GPa) whereas the anisotropy of the material disappeared. The measurements were carried out in a wide range of RH from 30 to 90%. An increase in RH caused a decrease in the material stiffness. Cracking of the gesso layer, which is often responsible for the formation of cracks in paintings, was observed at strains of the order of a few thousandths. Swelling of glue sizing dominated the moisture-induced swelling of the composite material in the less stiff warp direction, completely overriding the shrinkage of the untreated canvas. In contrast, the swelling of the composite material in the stiffer weft direction was much smaller than for pure glue alone, being clearly affected by the textile.This work was funded by the European Union's Horizon 2020 research and innovation program under grant agreement No. 814624 and the statutory research fund of the Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences. Lukasz Bratasz's work was financed by the Polish National Agency for Academic Exchange, project Polish Returns [Grant PPN/PPO/2018/1/00004/U/00001]Janas, A.; Fuster-López, L.; Andersen, CK.; Vicente-Escuder, Á.; Kozlowski, R.; Poznanska, K.; Gajda, A.... (2022). Mechanical properties and moisture-related dimensional change of canvas paintings¿canvas and glue sizing. Heritage Science. 10(1):1-10. https://doi.org/10.1186/s40494-022-00794-311010
European XFEL RF Gun Commissioning and LLRF Linac Installation
The European x-ray free electron laser (XFEL) is based on a 17.5 GeV super conducting pulsed linac and is scheduled to deliver its first beam in 2016. The first component of its accelerator chain, the RF gun, was installed in fall of 2013 and its commissioning is underway. This contribution gives an update on the low level radio frequency (LLRF) system development and installation for the XFEL. In particular, the installation, performance and conditioning results of the RF gun are presented. The subsequent steps toward LLRF components mass-production, testing and installation for the XFEL linac are also explained
LLRF Commissioning of the European XFEL RF Gun and Its First Linac RF Station
The European X-ray free electron laser (XFEL) at the Deutsches Elektronen-Synchrotron (DESY), Hamburg Germany is in its construction phase. Approximately a third of the super-conductive cryomodules have been produced and tested. The RF gun is installed since 2013; periods of commissioning are regularly scheduled between installation phases of the rest of the injector. The first linac, L1, consisting of 4 cryomodules powered by one 10 MW klystron is installed and being commissioned. This contribution reports on the installation and preparation work of the low-level radio frequency system (LLRF) to perform the commissioning of the XFEL first components. The commissioning plans, schedule and first results are presented