The influence of magnetic nanoparticle concentration with dextran polymers in agar gel on heating efficiency in magnetic hyperthermia

The article presents the results of research on the effect of magnetic hyperthermia performed on agar gel samples containing magnetite nanoparticles coated with dextran polymers for different molar weight M (150 kDa, 70 kDa, and 40 kDa). Regardless of the difference in molar dextran weights, these samples differed in a mass concentration of nanoparticles in the ferrogel C 0 (1.602 mg/cm 3, 2.506 mg/cm 3, 3.311 mg/cm 3, and 4.218 mg/cm 3). In the case of the highest magnetic field value H (20 kA·m −1), the specific loss power SPL reaches 70 W·g −1 for nanoparticles with 150 kDa dextran at a concentration of nanoparticles C 0 = 1.602 mg/cm 3. An oscillating magnetic field with an amplitude up to 20 kA·m −1 and a frequency of 357 kHz was used in the study

Effect of Nb doping on structural, optical and photocatalytic properties of flame-made TiO2 nanopowder

TiO2:Nb nanopowders within a dopant concentration in the range of 0.1-15at.% were prepared by one-step flame spray synthesis. Effect of niobium doping on structural, optical and photocatalytic properties of titanium dioxide nanopowders was studied. Morphology and structure were investigated by means of Brunauer-Emmett-Teller isotherm, X-ray diffraction and transmission electron microscopy. Diffuse reflectance and the resulting band gap energy were determined by diffuse reflectance spectroscopy. Photocatalytic activity of the investigated nanopowders was revised for the photodecomposition of methylene blue (MB), methyl orange (MO) and 4-chlorophenol under UVA and VIS light irradiation. Commercial TiO2-P25 nanopowder was used as a reference. The specific surface area of the powders was ranging from 42.9m2/g for TiO2:0.1at.% Nb to 90.0m2/g for TiO2:15at.% Nb. TiO2:Nb particles were nanosized, spherically shaped and polycrystalline. Anatase was the predominant phase in all samples. The anatase-related transition was at 3.31eV and rutile-related one at 3.14eV. TiO2:Nb nanopowders exhibited additional absorption in the visible range. In comparison to TiO2-P25, improved photocatalytic activity of TiO2:Nb was observed for the degradation of MB and MO under both UVA and VIS irradiation, where low doping level (Nb < 1at.%) was the most effective. Niobium doping affected structural, optical and photocatalytic properties of TiO2. Low dopant level enhanced photocatalytic performance under UVA and VIS irradiation. Therefore, TiO2:Nb (Nb < 1at.%) can be proposed as an efficient selective solar light photocatalys

Integracja gospodarcza i handel: rywalizacja i współpraca we współczesnym świecie

Praca recenzowana / Peer-reviewed paperW niniejszej publikacja podjęto próbę przedstawienia charakterystycznych dla współczesnego świata zmian zachodzących w zakresie stosunków politycznych i gospodarczych. Książka przeznaczona jest dla czytelnika zainteresowanego problematyką współczesnych stosunków międzynarodowych, a przede wszystkim studentów kierunków ekonomicznych, socjologicznych i politologicznych. Publikacja powinna umożliwić czytelnikowi poznanie mechanizmu współczesnych politycznych i ekonomicznych relacji w skali międzynarodowej

New metal oxide nanoparticles for gas sensors

Tyt. z ekranu tytułowego.Promotor: Mieczysław Rękas, Artur Braun.Niepublikowana praca doktorska.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2013.Zawiera bibliogr.Dostępna także w wersji drukowanej.Tryb dostępu: Internet.Semiconductor metal oxide, MOx, based gas sensors, review of research on metal oxide based gas sensors, gas sensing semiconductor metal oxide nanoparticles, technology from the perspective of nanotechnology, metal oxide nanoparticles for gas sensing application, electronic structure, optical properties of semiconductor metal oxides, non-stoichiometry, surface properties of MOx vs. electrical properties, gas sensing behavior, defect chemistry of Fe2O3, general model, basic principles of the interaction of gas molecules with the semiconductor metal oxides, electronic band structure of n-type and p-type semiconductor MOx upon oxidizing, acceptor type, reducing, donor type, gas molecules, interaction of oxygen gas molecules with n-type semiconductor metal oxides, interaction of reducing gas molecules with n-type semiconductor metal oxides, interaction of ammonia gas molecules with n-type semiconductor metal oxides, influence of the crystallite/grain size on the sensing mechanism, effect of the water vapor molecules on the conductivity of semiconductor metal oxides, flame spray synthesis of metal oxide nanoparticles, experimental methods, determination of the crystal structure, morphology, XRD, BET, TEM, characterization of the surface chemical composition and stoichiometry, XPS, resonant EBS, investigation of the electronic structure, NEXAFS, in-situ observation of the chemical interaction of the oxygen and hydrogen molecules at the surface and the electronic structure of the metal oxides, AP-XPS, AP-NEXAFS, determination of the optical band gap, DRS, investigation of the nature of the electrical transport properties, EIS, evaluation of the gas sensing performance towards hydrogen and ammonia detection, DC measurements, un-modified and Ti-modified Fe2O3 nanoparticles, crystal structure, morphology, band gap, DRS optical measurements, chemical composition, electronic structure, XPS, resonant EBS, effect of oxidizing, reducing processing conditions on the chemical composition, electronic structure of Fe2O3 nanoparticles, effect of Ti-modification on the chemical composition, electronic structure of Fe2O3 nanoparticles, electronic structure under UHV conditions - NEXAFS, in-situ observations of the surface chemistry, electronic structure of Fe2O3 nanoparticles -AP-XPS, in-situ observations of the surface chemistry and electronic structure of Fe2O3 nanoparticles - AP-NEXAFS, electrical properties - EIS, gas sensing performance, TiO2, ZnO, SnO2 nanoparticles, crystal structure, morphology, band gap - DRS optical measurements, chemical composition, electronic structure - XPS, resonant EBS, effect of oxidizing, reducing processing conditions on the chemical composition, electronic structure of MOx nanoparticles, tungsten trioxide WO3, crystal structure, morphology, band gap - DRS optical measurements, chemical composition and electronic structure - XPS, resonant EBS, effect of oxidizing and reducing processing conditions on the chemical composition, electronic structure of WO3 nanoparticles, electronic structure under UHV conditions - NEXAFS, impedance behavior under H2, NH3, effect of temperatur

New metal oxide nanoparticles for gas sensors ph.d. thesis /

Tyt. z ekranu tytułowego.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2013.Zawiera bibliogr.Dostępna także w wersji drukowanej.Tryb dostępu: Internet.Semiconductor metal oxide, MOx, based gas sensors, review of research on metal oxide based gas sensors, gas sensing semiconductor metal oxide nanoparticles, technology from the perspective of nanotechnology, metal oxide nanoparticles for gas sensing application, electronic structure, optical properties of semiconductor metal oxides, non-stoichiometry, surface properties of MOx vs. electrical properties, gas sensing behavior, defect chemistry of Fe2O3, general model, basic principles of the interaction of gas molecules with the semiconductor metal oxides, electronic band structure of n-type and p-type semiconductor MOx upon oxidizing, acceptor type, reducing, donor type, gas molecules, interaction of oxygen gas molecules with n-type semiconductor metal oxides, interaction of reducing gas molecules with n-type semiconductor metal oxides, interaction of ammonia gas molecules with n-type semiconductor metal oxides, influence of the crystallite/grain size on the sensing mechanism, effect of the water vapor molecules on the conductivity of semiconductor metal oxides, flame spray synthesis of metal oxide nanoparticles, experimental methods, determination of the crystal structure, morphology, XRD, BET, TEM, characterization of the surface chemical composition and stoichiometry, XPS, resonant EBS, investigation of the electronic structure, NEXAFS, in-situ observation of the chemical interaction of the oxygen and hydrogen molecules at the surface and the electronic structure of the metal oxides, AP-XPS, AP-NEXAFS, determination of the optical band gap, DRS, investigation of the nature of the electrical transport properties, EIS, evaluation of the gas sensing performance towards hydrogen and ammonia detection, DC measurements, un-modified and Ti-modified Fe2O3 nanoparticles, crystal structure, morphology, band gap, DRS optical measurements, chemical composition, electronic structure, XPS, resonant EBS, effect of oxidizing, reducing processing conditions on the chemical composition, electronic structure of Fe2O3 nanoparticles, effect of Ti-modification on the chemical composition, electronic structure of Fe2O3 nanoparticles, electronic structure under UHV conditions - NEXAFS, in-situ observations of the surface chemistry, electronic structure of Fe2O3 nanoparticles -AP-XPS, in-situ observations of the surface chemistry and electronic structure of Fe2O3 nanoparticles - AP-NEXAFS, electrical properties - EIS, gas sensing performance, TiO2, ZnO, SnO2 nanoparticles, crystal structure, morphology, band gap - DRS optical measurements, chemical composition, electronic structure - XPS, resonant EBS, effect of oxidizing, reducing processing conditions on the chemical composition, electronic structure of MOx nanoparticles, tungsten trioxide WO3, crystal structure, morphology, band gap - DRS optical measurements, chemical composition and electronic structure - XPS, resonant EBS, effect of oxidizing and reducing processing conditions on the chemical composition, electronic structure of WO3 nanoparticles, electronic structure under UHV conditions - NEXAFS, impedance behavior under H2, NH3, effect of temperatur

Back pain as a manifestation of paraspinal bone cancer in children

Aim: The aim of the study was to retrospectively assess diagnostic difficulties in paraspinal bone cancers as noted in the authors’ centre in 2009–2016. Material and methods: The study was performed in a group of 7 patients aged 3.5–17 years with paraspinal tumours, which constitutes 16.6% (7/42) of all children with bone cancers treated in the authors’ centre. The analysis involved: reported symptoms, time from the onset of the first symptoms to the correct diagnosis, type and stage of cancer, and treatment outcomes. Results: The most common symptom was pain in the lumbosacral region. In all cases, the first symptoms were considered to be the consequences of musculoskeletal system dysfunction. They persisted for 12–28 weeks before cancer was diagnosed. In this period, none of the children had spine radiography or any other diagnostic tests performed. The final diagnosis was determined on the basis of a histopathological examination. The most common were malignant tumours with extensive neoplastic infiltration. Two patients underwent radical surgery, and the remaining children required additional intensive chemotherapy. Moreover, proton therapy was implemented in 1 case. One patient died due to tumour progression, a patient with chondroblastoma is still being treated, and the remaining patients are in remission, but, due to tumour location, the prognosis is uncertain. Conclusions: 1) Cancer must be considered in children with recurrent back pain. 2) Plain radiography should be the basic diagnostic test. 3) Persisting back pain with normal radiography is an indication for magnetic resonance imaging or computed tomography, or for extending the range of imaging. 4) Imaging should be performed prior to rehabilitation for back pain

Effect of Nb doping on structural, optical and photocatalytic properties of flame-made TiO2 nanopowder

TiO2:Nb nanopowders within a dopant concentration in the range of 0.1-15 at.% were prepared by one-step flame spray synthesis. Effect of niobium doping on structural, optical and photocatalytic properties of titanium dioxide nanopowders was studied. Morphology and structure were investigated by means of Brunauer–Emmett–Teller isotherm, X-ray diffraction and transmission electron microscopy. Diffuse reflectance and the resulting band gap energy were determined by diffuse reflectance spectroscopy. Photocatalytic activity of the investigated nanopowders was revised for the photodecomposition of methylene blue (MB), methyl orange (MO) and 4-chlorophenol under UVA and VIS light irradiation. Commercial TiO2-P25 nanopowder was used as a reference. The specific surface area of the powders was ranging from 42.9 m2/g for TiO2:0.1 at.% Nb to 90.0 m2/g for TiO2:15 at.% Nb. TiO2:Nb particles were nanosized, spherically shaped and polycrystalline. Anatase was the predominant phase in all samples. The anatase-related transition was at 3.31 eV and rutile-related one at 3.14 eV. TiO2:Nb nanopowders exhibited additional absorption in the visible range. In comparison to TiO2-P25, improved photocatalytic activity of TiO2:Nb was observed for the degradation of MB and MO under both UVA and VIS irradiation, where low doping level (Nb < 1 at.%) was the most effective. Niobium doping affected structural, optical and photocatalytic properties of TiO2. Low dopant level enhanced photocatalytic performance under UVA and VIS irradiation. Therefore, TiO2:Nb (Nb < 1 at.%) can be proposed as an efficient selective solar light photocatalyst

Exocrine Pancreatic Function in Girls with Anorexia Nervosa

Objectives: To assess pancreatic exocrine function in patients with anorexia nervosa using a breath test with 13C-labeled mixed triglycerides (MTG-BT) and to determine the relationship between the test results and selected biochemical and hormonal parameters. Material and methods: Anthropometric measurements, biochemical and hormonal parameters (serum leptin, soluble leptin receptor (sLR), acylated and desacylated ghrelin, free leptin index (FLI)), and MTG-BT were performed in a group of 31 girls with the restrictive type of AN, as well as 38 healthy girls (C). Results: The average cumulative dose of 13C-triglycerides recovered with exhaled air (%CD) was similar in both study groups, while the average time from 13C-triglycerides administration to peak 13CO2 excretion in expired air (time to peak (TTP)) was significantly longer in patients with AN compared to C. In both groups, %CD correlated negatively with FLI. TTP correlated negatively with sLR and FLI in the AN and with serum insulin and HOMA-IR values in the C. Conclusions: In girls with AN, the pancreatic efficiency of lipase secretion was found to be normal, while the kinetics of this enzyme secretion were disturbed. These changes may result from disorders in the functioning of the adipose–insular and islet–acinar axes