Clinical treatment of mast cell tumor in dog

ShinHo Lee(ShinHo Lee),Chung Hui Kim(Chung Hui Kim),Jae-Hyeon Cho(Jae-Hyeon Cho) 한국예방수의학회 2023 예방수의학회지 Vol.47 No.2

A 11-year-old sexually intact female dog was presented because of a misshapen left elbow with a large mass. The masses on the elbow were diagnosed as high-grade canine mast cell tumor (cMCT) based on the cytological examination using fine-needle aspiration. Cytologically, the mass revealed moderate numbers of eosinophils, anisocytosis, anisokaryosis, and aberrant mitotic figures. The degree of cytologic dysplasia is diagnosed as moderate to severe. The blood analysis revealed low hematocrit and electrolytes. After examining the metastasis and surgical scope with radiographs and ultrasound, surgery was performed to removal the mass. Histopathologically, the mass revealed partially cytoplasmic granules, anisokaryosis of the nucleus, and mitotic counts. Scattered inflammatory cells and necrotic tissues were observed in the tumor. In this study, we found high-grade cMCT and treated the patient through a surgical approach.

Structural and Optical Properties of ZnO Films Grown on Sapphire Substrates Subjected to Substrate Temperature

Shinho Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.3

We present the eect of substrate temperature on the structural and the optical properties of ZnO films grown on sapphire substrates by using pulsed laser deposition. Growing at higher substrate temperature results in an increase in the surface roughness and the size of the grains. The optimum c-axis orientation of the ZnO films occurs at a substrate temperature of 700 C. The decay time, obtained from a least-squares fit of the data to a single exponential, shows a rapid increase in the substrate temperature from 400 C to 500 C and falls gradually as the substrate temperature approaches 700 C. These results are due to variations in the nature of defects and strain with changing substrate temperature.

Optically Excited Terahertz Emission from Low-Temperature-Grown GaAs

Shinho Cho 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.48 No.6

We report on optically excited terahertz emission from low-temperature (LT)-grown GaAs. We have used 70 fs titanium-sapphire laser pulses with wavelengths of 800 nm to generate THz radiation pulses. The LT-GaAs layers are grown on semi-insulating GaAs substrates with GaAs buffer layers. The THz emission from the LT-GaAs surface is strong. No significant variation in the intensity of the THz emission is observed over several azimuthal angles between the polarization of the excitation laser pulse and the crystallographic orientation of the LT-GaAs. The refractive index, which is measured by detecting the THz signal passing through the LT-GaAs in the transmission configuration, is found to be 3.5 in the THz region.

Structural and Optical Properties of Sm-doped BaMoO4 Phosphor Thin Films Deposited by Radio-Frequency Magnetron Sputtering

Shinho Cho 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.8

BaMoO4:Sm^3+ phosphor thin films were prepared using radio-frequency magnetron sputtering at several growth temperatures, followed by rapid thermal annealing. All the phosphor thin films revealed tetragonal structures with preferential (112) orientation. The emission and the excitation intensities, transmittances, and band gap energies of the phosphor thin films were found to depend significantly on the growth temperature. The excitation spectrum consisted of a strong broad band centered at 261 nm in the range 210 - 310 nm arising from charge transfer transitions between O^-2 and Sm^3+ and three weak bands, one each at 370, 406, and 475 nm. The emission spectra of the phosphor thin films under excitation at 267 nm showed six emission bands located at 451, 558, 595, 640, 700, and 762 nm, respectively which were due to the typical 4f-4f transitions of Sm^3+ ions. The highest emission intensity of the BaMoO4:Sm^3+ phosphor thin film was achieved at a growth temperature of 400 °C, where the optical band gap was 4.70 eV and the color chromaticity coordinate was (0.492, 0.353). These results suggest that the BaMoO4:Sm^3+ phosphor thin film is a promising candidate for application in red-light-emitting devices.

Luminescent Properties of LaBO₃:RE³⁺ (RE=Tb, Ce) Phosphors for White Light Emitting Diodes

Cho, Shinho Korea Photovoltaic Society 2014 Current Photovoltaic Research Vol.2 No.2

$Tb^{3+}$ - or $Ce^{3+}$-doped $LaBO_3$ phosphors were synthesized by a solid-state reaction process with different concentrations of activator ions. The XRD spectra showed the monoclinic $LaBO_3$ pattern with the main peak occurring at (014) plane, irrespective of the kind of activator ions. The crystallite size was determined by using the Scherrer formula, and the maximum was obtained with an activator concentration of 0.05 mol for both phosphors. The emission spectra of $LaBO_3$ phosphors doped with $Tb^{3+}$ ions under excitation at 269 nm exhibited three major emission bands at 488, 544, and 587 nm. The strongest emission was green at 544 nm owing to the $^5D_4-^7F_5$ transition at a $Tb^{3+}$ ion concentration of 0.05 mol. For the $Ce^{3+}$-doped $LaBO_3$ phosphors, one strong blue band centered at 469 nm and weak multipeaks were observed. These results suggest that the optimum green and blue emission can be realized by controlling the concentration and type of activator ions incorporated in the host crystal.

Synthesis and Characterization of Mg2SiO4:Tb3+, Eu3+ Phosphors for White Light Generation

Shinho Cho 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.5

The effect of Eu3+ codoping on the structural, morphological, and optical properties of Mg2SiO4:Tb3+ was investigated. The phosphor powders were synthesized by changing the molar concentration of Eu3+ at a fixed Tb3+ content of 5 mol% by using a conventional solid-state reaction. The X-ray diffraction patterns revealed that the crystal structure of all the phosphors, irrespective of the Eu3+ and the Tb3+ contents, showed an orthorhombic structure, and the surface morphology exhibited pebble-like crystalline grains. The emission spectra of Eu3+ and Tb3+-codoped Mg2SiO4 phosphors under an ultraviolet excitation of 252 nm consisted of one intense red band at 619 nm and five weak bands at 448, 488, 598, 658, and 707 nm originating from the transitions of Eu3+, in addition to the several emission bands located at 492, 552, 592, and 628 nm arising from the transitions of Tb3+. As the Eu3+ content was increased, the intensity of the main green emission band at 552 nm decreased markedly and disappeared at 10 mol% Eu3+, when complete energy transfer from Tb3+ to Eu3+ was observed. The results suggest that the emission wavelength and the luminescent intensity of the phosphors can be tuned by modulating the Eu3+ and the Tb3+ contents incorporated into the host matrix.

Photoluminescence Properties of BaMoO4:RE3+ (RE = Eu, Sm, Dy, Tb, Tm) Phosphors

Shinho Cho 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.9

Rare-earth (RE)-activated barium molybdate phosphors for multicolor display applications were synthesized with different activator ions via a solid-state reaction. The effects of the activator ions on the structural, morphological, and optical properties of barium molybdate phosphors were investigated. The XRD spectra of all the phosphors, regardless of the activator ion, exhibited that the main peak of the phosphors occurred at the (112) plane, indicating the tetragonal BaMoO4 structure. The crystalline particles exhibited a tendency to agglomerate with irregular shapes and sizes. The emission spectra of RE-ion-doped BaMoO4 phosphors under ultraviolet excitation consisted of multicolor emissions: blue for Tm3+ activator ions, green for Tb3+ activator ions, yellow for Dy3+ activator ions, reddish orange for Eu3+ activator ions, and red for Sm3+ activator ions. These results suggest that multicolor emission can be realized by incorporating appropriate activator ions into the BaMoO4 host lattice.

Properties of nitrogen and aluminium-codoped ZnO thin films grown with different nitrogen flow ratios for solar cell applications

Shinho Cho 한국물리학회 2010 Current Applied Physics Vol.10 No.3

The nitrogen and aluminium-codoped ZnO (NAZO) thin films are grown by rf magnetron sputtering system with the nitrogen flow ratio changing from 0% to 30%. All of the NAZO films show a strongly c-axis preferred orientation, while the values of the electron concentration are found to decrease with the increase of the nitrogen flow ratio, and they are determined as 1.5–27 × 1019 cm-3. The optical transmittance spectra indicate an average transmittance of about 95% in the visible range, and a red shift of the band gap energy is observed with increasing the nitrogen flow ratio. These results suggest that the nitrogen flow ratio is an important parameter to grow the high-quality NAZO films for the application of solar cells.

Annealing effect on the properties of Eu-doped BaWO₄ thin films grown on glass substrates by RF magnetron sputtering

Shinho CHO 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.8

Luminescent Properties of LaBO₃:RE<SUP>3+</SUP> (RE=Tb, Ce) Phosphors for White Light Emitting Diodes

Shinho Cho 한국태양광발전학회 2014 Current Photovoltaic Research Vol.2 No.2

Tb<SUP>3+</SUP>- or Ce<SUP>3+</SUP>-doped LaBO₃ phosphors were synthesized by a solid-state reaction process with different concentrations of activator ions. The XRD spectra showed the monoclinic LaBO₃ pattern with the main peak occurring at (014) plane, irrespective of the kind of activator ions. The crystallite size was determined by using the Scherrer formula, and the maximum was obtained with an activator concentration of 0.05 mol for both phosphors. The emission spectra of LaBO₃ phosphors doped with Tb<SUP>3+</SUP> ions under excitation at 269 nm exhibited three major emission bands at 488, 544, and 587 nm. The strongest emission was green at 544 nm owing to the <SUP>5</SUP>D₄-<SUP>7</SUP>F5 transition at a Tb<SUP>3+</SUP> ion concentration of 0.05 mol. For the Ce<SUP>3+</SUP>-doped LaBO₃ phosphors, one strong blue band centered at 469 nm and weak multipeaks were observed. These results suggest that the optimum green and blue emission can be realized by controlling the concentration and type of activator ions incorporated in the host crystal.