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141.
Tomasz Chmielewski Marcin Chmielewski Anna Pitkowska Agnieszka Grabias Beata Skowroska Piotr Siwek 《Materials》2021,14(12)
The article presents the results of research on the structural evolution of the composite Fe-Al-based coating deposited by arc spray with initial low participation of in situ intermetallic phases. The arc spraying process was carried out by simultaneously melting two different electrode wires, aluminum and low alloy steel (98.6 wt.% of Fe). The aim of the research was to reach protective coatings with a composite structure consisting of a significant participation of FexAly as intermetallic phases reinforcement. Initially, synthesis of intermetallic phases took place in situ during the spraying process. In the next step, participation of FexAly fraction was increased through the annealing process, with three temperature values, 700 °C, 800 °C, and 900 °C. Phase structure evolution of the Fe-Al arc-sprayed coating, stimulated by annealing, has been described by means of SEM images taken with a QBSD backscattered electron detector and by XRD and conversion electron Mössbauer spectroscopy (CEMS) investigations. Microhardness distribution of the investigated annealed coatings has been presented. 相似文献
142.
Aleksandra Kolano-Burian Przemyslaw Zackiewicz Agnieszka Grabias Anna Wojcik Wojciech Maziarz Maciej Szlezynger Patryk Wlodarczyk Maciej Kowalczyk Lukasz Hawelek 《Materials》2021,14(12)
In the present work, we investigated in detail the thermal/crystallization behavior and magnetic properties of materials with Fe84.5-xCoxNb5B8.5P2 (x = 0, 5, 10, 15 and 20 at.%) composition. The amorphous ribbons were manufactured on a semi-industrial scale by the melt-spinning technique. The subsequent nanocrystallization processes were carried out under different conditions (with/without magnetic field). The comprehensive studies have been carried out using differential scanning calorimetry, X-ray diffractometry, transmission electron microscopy, hysteresis loop analyses, vibrating sample magnetometry and Mössbauer spectroscopy. Moreover, the frequency (up to 300 kHz) dependence of power losses and permeability at a magnetic induction up to 0.9 T was investigated. On the basis of some of the results obtained, we calculated the values of the activation energies and the induced magnetic anisotropies. The X-ray diffraction results confirm the surface crystallization effect previously observed for phosphorous-containing alloys. The in situ microscopic observations of crystallization describe this process in detail in accordance with the calorimetry results. Furthermore, the effect of Co content on the phase composition and the influence of annealing in an external magnetic field on magnetic properties, including the orientation of the magnetic spins, have been studied using various magnetic techniques. Finally, nanocrystalline Fe64.5Co20Nb5B8.5P2 cores were prepared after transverse thermo-magnetic heat treatment and installed in industrially available portable heating equipment. 相似文献
143.
Micha Jakubczak Ewa Karwowska Anita Rozmysowska-Wojciechowska Mateusz Petrus Jarosaw Wo
niak Joanna Mitrzak Agnieszka M. Jastrzbska 《Materials》2021,14(1)
Point-of-use (POU) water treatment systems and devices play an essential role in limited access to sanitary safe water resources. The filtering materials applied in POU systems must effectively eliminate contaminants, be readily produced and stable, and avoid secondary contamination of the treated water. We report an innovative, 2D Ti3C2/Al2O3/Ag/Cu nanocomposite-modified filtration material with the application potential for POU water treatment. The material is characterized by improved filtration velocity relative to an unmodified reference material, effective elimination of microorganisms, and self-disinfecting potential, which afforded the collection of 99.6% of bacteria in the filter. The effect was obtained with nanocomposite levels as low as 1%. Surface oxidation of the modified material increased its antimicrobial efficiency. No secondary release of the nanocomposites into the filtrate was observed and confirmed the stability of the material and its suitability for practical application in water treatment. 相似文献
144.
145.
An effective method for levulinic acid esters synthesis by the enzymatic Fischer esterification of levulinic acid using a lipase B from Candida antarctica (CALB) immobilized on the advanced material consisting of multi-wall carbon nanotubes (MWCNTs) and a hydrophobic polymer—polytetrafluoroethylene (Teflon, PTFE)—as a heterogeneous biocatalyst, was developed. An active phase of the biocatalyst was obtained by immobilization via interfacial activation on the surface of the hybrid material MWCNTs/PTFE (immobilization yield: 6%, activity of CALB: 5000 U∙L∙kg−1, enzyme loading: 22.5 wt.%). The catalytic activity of the obtained biocatalyst and the effects of the selected reaction parameters, including the agitation speed, the amount of PTFE in the CALB/MWCNT-PTFE biocatalyst, the amount of CALB/MWCNT-PTFE, the type of organic solvent, n-butanol excess, were tested in the esterification of levulinic acid by n-butanol. The results showed that the use of a two-fold excess of levulinic acid to n-butanol, 22.5 wt.% of CALB on MWCNT-PTFE (0.10 wt.%) and cyclohexane as a solvent at 20 °C allowed one to obtain n-butyl levulinate with a high yield (99%) and selectivity (>99%) after 45 min. The catalyst retained its activity and stability after three cycles, and then started to lose activity until dropping to a 69% yield of ester in the sixth reaction run. The presented method has opened the new possibilities for environmentally friendly synthesis of levulinate esters. 相似文献
146.
Sickmann A Reinders J Wagner Y Joppich C Zahedi R Meyer HE Schönfisch B Perschil I Chacinska A Guiard B Rehling P Pfanner N Meisinger C 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(23):13207-13212
We performed a comprehensive approach to determine the proteome of Saccharomyces cerevisiae mitochondria. The proteins of highly pure yeast mitochondria were separated by several independent methods and analyzed by tandem MS. From >20 million MS spectra, 750 different proteins were identified, indicating an involvement of mitochondria in numerous cellular processes. All known components of the oxidative phosphorylation machinery, the tricarboxylic acid cycle, and the stable mitochondria-encoded proteins were found. Based on the mitochondrial proteins described in the literature so far, we calculate that the identified proteins represent approximately 90% of all mitochondrial proteins. The function of a quarter of the identified proteins is unknown. The mitochondrial proteome will provide an important database for the analysis of new mitochondrial and mitochondria-associated functions and the characterization of mitochondrial diseases. 相似文献
147.
148.
Lubiński A Lewicka-Nowak E Zienciuk A Królak T Kempa M Pazdyga A Raczak G Swiatecka G 《Kardiologia polska》2005,63(3):234-41; discussion 242-3
INTRODUCTION: The reduction of defibrillation threshold (DFT) in patients treated with an implantable cardioverter-defibrillator increases patients' safety and prolongs ICD battery life. AIM: To evaluate the possibility of reducing the defibrillation threshold in ICDs with an active can and an additional atrial defibrillation coil instead of the typical intracardiac single-coil lead. METHOD: This study involved 138 patients (36 F and 102 M, mean age 54+/-15 years) including 62 subjects with dual-coil defibrillation lead (group A) and 76 ones with single-coil defibrillation lead (group B). No statistically significant differences with respect to age, left ventricular function, main disease or exacerbation of heart failure according to the NYHA functional class were observed between groups. The defibrillation threshold was measured using the DFT+ protocol. RESULTS: No significant differences between groups were identified with respect to pacing and sensing parameters. The comparison of DFT values between the two studied groups revealed significant improvement (by 14% mean) of defibrillation efficacy in group A. In group A, the mean DFT was 9.8+/-4.6 J (3-20 J) and mean defibrillation resistance - 45+/-7 W (32-73 W), whereas in group B: 11.45+/-5.25 J (3-28 J) and 72+/-12.8 W (38-106 W), respectively. In 93% of patients from group A, DFT was below 15 J, in comparison to 81% of patients from group B (p=0.046). The odds ratio of a higher defibrillation threshold (?15 J) in group A vs. group B was 0.3 (95% confidence interval: 0.09-0.98). The DFT reduction associated with modified ICD system use was independent of following clinical parameters: patient age, gender, main disease, end-diastolic left ventricular diameter, left ventricular ejection fraction, NYHA functional class and concomitant treatment with antiarrhythmic agents. CONCLUSIONS: Modification of the electric field during defibrillation, achieved with the use of active-can ICDs with dual-coil defibrillation leads, allows a reduction of DFT by 14%. At the same time, it reduces the risk of a higher (> or =15 J) DFT by three times compared to patients with a standard single-coil defibrillation lead. 相似文献
149.
Holowiecki J Krawczyk-Kulis M Giebel S Jagoda K Stella-Holowiecka B Piatkowska-Jakubas B Paluszewska M Seferynska I Lewandowski K Kielbinski M Czyz A Balana-Nowak A Król M Skotnicki AB Jedrzejczak WW Warzocha K Lange A Hellmann A 《British journal of haematology》2008,142(2):227-237
The treatment of adults with Philadelphia-negative acute lymphoblastic leukaemia (ALL) depends on the presence of risk factors including age, white blood cell count, immunophenotype and time to complete remission. In recent years, status of minimal residual disease (MRD) has been postulated as an additional risk criterion. This study prospectively evaluated the significance of MRD. Patients were treated with a uniform Polish Adult Leukemia Group (PALG) 4-2002 protocol. MRD status was assessed after induction and consolidation by multiparametric flow cytometry. Out of 132 patients included (age, 17–60 years), 116 patients were suitable for analysis. MRD level ≥0·1% of bone marrow cells after induction was found to be a strong and independent predictor for relapse in the whole study population ( P < 0·0001), as well as in the standard risk (SR, P = 0·0003) and high-risk ( P = 0·008) groups. The impact of MRD after consolidation on outcome was not significant. The combination of MRD status with conventional risk stratification system identified a subgroup of patients allocated to the SR group with MRD <0·1% after induction who had a very low risk of relapse of 9% at 3 years as opposed to 71% in the remaining subjects ( P = 0·001). We conclude that MRD evaluation after induction should be considered with conventional risk criteria for treatment decisions in adult ALL. 相似文献
150.
Paweł Śledziński Joanna Zeyland Ryszard Slomski Agnieszka Nowak-Terpiłowska 《Journal of child & adolescent substance abuse》2019,28(2):65-72
Marijuana is recently a subject of a global debate due to potential medical application of cannabis products and the progressive legalization of its recreational use. This situation leads to the need for access to comprehensive and reliable information about the effects of marijuana intake. Our review presents the actual state of knowledge regarding acute and chronic health effects generated by recreational marijuana use. Marijuana smoking can lead to structural and functional alterations in the central nervous system. These effects are especially significant and dangerous at the prenatal, child, and adolescence periods. In contrary to a common myth, cannabis does exhibit an addictive potency, albeit not a strong one. We discuss the “cannabis gateway hypothesis,” which suggests that marijuana use can be the first step before trying more dangerous drugs. However, drawing significant conclusions is difficult due to the strong impact of confounders and often unclear relationships among studied factors, especially in the socioeconomic context. Moreover, we point to the need for the unbiased assessment of the harm generated by marijuana in comparison with other drugs. 相似文献