高シリカ型ゼオライト膜の合成と分離プロセスへの応用 [論文要旨及び審査の要旨]

関西大

高シリカ型ゼオライト膜の合成と分離プロセスへの応用

関西大

Rapid determination of multidrug resistance-associated protein in cancer cells by capillary electrophoresis immunoassay

The adenosine triphosphate (ATP) binding-cassette (ABC) transporters are a superfamily of cellular proteins that have been partly implicated as a cause of multidrug resistance (MDR) in cancer cells. The ABC superfamily consists of P-glycoprotein, multidrug resistance-associated proteins (MRP) and breast cancer-related proteins, of which MRP is of particular interest because of its ability to efflux a broader range of substrates. Since MRP1 is the most prominent member of the MRP family, a simple technique is needed for its quantification. We developed a simple, fast (total analysis time of 3 h) capillary electrophoresis immunoassay (CEIA) for the quantification of MRP1 in cancer cells. MRP1 antibody was labeled with fluorescein isothiocyanate. The labeled antibody was incubated with the cell lysate for a fixed interval (1 h), after which the cell lysate mixture was directly injected into the capillary to separate the complex of MRP1 and its antibody from free antibody. The noncompetitive CEIA method had a limit of detection of 0.2 nM and a good linear range (1.7-14.9 x 10(4) cells), and was fairly reproducible (RSD < 10%). The results showed that two cell lines. A549 and RDES, expressed MRP1 in the absence of doxorubicin (DOX), with A549 registering a higher expression. Compared to DOX-free cancer cells, there was an acceleration of MRP1 expression during the 12 h-exposure to DOX, after which the level of expression remained nearly constant as the intracellular accumulation of DOX decreased. The results obtained in this work indicate that the developed CEIA method is useful for relative quantification of MRPs in cancer cells

Transverse effects in multifrequency Raman generation

The theory of ultrabroadband multifrequency Raman generation is extended, for the first time, to allow for beam-propagation effects in one and two transverse dimensions. We show that a complex transverse structure develops even when diffraction is neglected. In the general case, we examine how the ultrabroadband multifrequency Raman generation process is affected by the intensity, phase quality, and width of the input beams, and by the length of the Raman medium. The evolution of power spectra, intensity profiles, and global characteristics of the multifrequency beams are investigated and explained. In the two-dimensional transverse case, bandwidths comparable to the optical carrier frequency, spanning the whole visible spectrum and beyond, are still achievable

Synthesis and gas permeation properties of chabazite-type titanosilicate membranes synthesized using nano-sized seed crystals

Chabazite (CHA)-type zeolite membranes have received considerable attention regarding their high permeance and separation performance. A recent report detailing a unique preparation procedure for a CHA-type titanosilicate (Ti-CHA) zeolite—in which titanium heteroatoms were incorporated into the zeolite framework by substitution of aluminum—demonstrates excellent physico-chemical properties when compared with conventional aluminosilicate CHA-type zeolites. In this study, the synthesis of Ti-CHA zeolite membranes (Ti-CHA membrane) was investigated. The Ti-CHA membrane was synthesized on an alumina support via a secondary growth method using Ti-CHA zeolite seed crystals. The Ti-CHA membrane properties were studied as a function of seed crystal size. The average particle diameter was observed to reduce from 2.3 μm to 450 nm by increasing the loading of Ti-CHA into the synthesis gel. Regardless of the seed crystal particle size, the presence of CHA-type zeolites on the alumina support was confirmed by x-ray diffraction. UV-Vis demonstrated the incorporation of titanium heteroatoms into the zeolite framework. The results indicated the successful synthesis of the Ti-CHA membrane regardless of the seed crystal particle size. Additionally, the membrane thickness decreased by using the seed crystal. Single gas permeation tests showed that the thinnest Ti-CHA membrane prepared in this study exhibited a relatively high CO2 permeance of 1.5×10−6 mol m−2 s−1 Pa−1, compared with that of previously reported CHA-type zeolite membranes. The influence of moisture on the separation performance of the Ti-CHA membrane was evaluated in the presence of gas mixtures composed of CO2, methane and H2O ranging from 0.1 to 5 vol.%. In the presence of 1 vol.% H2O, the CO2 permeance and selectivity were only marginally reduced as a result of the highly hydrophobic pore structure.This work was partially supported by Kansai University Fund for Supporting Young Scholars, 2018

Band-modulation of MgZnO/ZnO Metal-semiconductor-metal Photodetectors

Magnesium (Mg) diffusion behavior on the band modulation of MgxZn1-xO/ZnO metal-semiconductor-metal photodetectors (MSM-PDs) was studied. As the annealing temperature increases, Mg atoms diffuse from MgxZn1-xO into the underlying ZnO layer, which modulates the detection band of the fabricated MSM-PDs from two distinct bands into one band. For the annealing temperature lower than 900 ºC, two detection bands were achieved located in the wavelength region of 280–320 nm and 360–400 nm, attributed to the absorption of the MgxZn1-xO and the ZnO layer, respectively. When the annealing temperature is raised to 900 ºC, the MgxZn1-xO/ZnO bi- layer becomes homogenized into a single MgxZn1-xO layer, leading to only one detection band with a wavelength region of 280–340 nm. In the photoluminescence measurement, the as-deposited MgxZn1-xO/ZnO bi-layer demonstrates two distinct emission peaks located at about 340 and 400 nm for the absorption of the MgxZn1-xO and ZnO layers, whereas only one emission peak of 355 nm was observed in the 900 ºC-annealed MgxZn1-xO/ZnO bi-layer

The effect of nanoparticle size on thermal diffusivity of gold nano-fluid measured using thermal lens technique

A dual beam mode-mismatched thermal lens method has been employed to investigate the dependence of thermal diffusivity of gold nanofluid on nanoparticles sizes. The samples were prepared at various sizes by utilizing the gamma radiation method. In the dual beam mode-mismatched thermal lens a diode laser (532 nm) was used as an excitation beam and a He-Ne laser with the beam output at 632.8 nm was used as a probe beam. Thermal diffusivity of gold nano-fluid increased with the increasing particle sizes ranging from 10.4 to 29.6 nm. [DOI: http://dx.doi.org/10.2971/jeos.2013.13026

The advancement of blood cell research by optical tweezers

Demonstration of the light radiation pressure on a microscopic level by A. Ashkin led to the invention of optical tweezers (OT). Applied in the studies of living systems, OT have become a preferable instrument for the noninvasive study of microobjects, allowing manipulation and measurement of the mechanical properties of molecules, organelles, and cells. In the present paper, we overview OT applications in hemorheological research, placing emphasis on red blood cells but also discussing OT applications for the investigation of the biomechanics of leukocytes and platelets. Blood properties have always served as a primary parameter in medical diagnostics due to the interconnection with the physiological state of an organism. Despite blood testing being a well-established procedure of conventional medicine, there are still many complex processes that must be unraveled to improve our understanding and contribute to future medicine. OT are advancing single-cell research, promising new insights into individual cell characteristics compared to the traditional approaches. We review the fundamental and practical findings revealed in blood research through the optical manipulation, stretching, guiding, immobilization, and inter-/intracellular force measurements of single blood cells