• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 1999년도 제8차 추계학술대회 및 정기총회
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• pp.48-48
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• 1999

• Bulletin of the Korean Chemical Society
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• 제16권3호
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• pp.232-237
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• 1995

The absorption spectra of holmium nitrate and erbium nitrate and the difference absorption spectra of their complexes with crown ethers were measured in acetonitrile. The crown ethers used in this study are 12-crown-4 and 15-crown-5. The oscillator strengths for the 4f→4f multiplet-to-multiplet transitions are empirically determined from the absorption spectra in combination with the difference spectra. The intensity parameters Ωλ (λ=2, 4, 6) for the systems are also evaluated by applying the Judd-Ofelt theorem to the observed oscillator strengths. The values of the intensity parameters are compared and discussed to investigate the sensitivity of the intensity parameters to the ligand environment.

• Biomolecules & Therapeutics
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• 제5권3호
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• pp.233-238
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• 1997

The distribution and excretion of radioactivity were examined after intraportal administration of sup 166/Ho-chitosan complex at a dose of 1 mcitg (10 mg chitosan/kg) to rats. Whole body macroautoluminographs showed that the radioactivity after an administration was concentrated in liver and perfused primarily to organs including kidney, spleen, and bone marrow, then to muscle and brain. Similar profiles were observed from 2 hr to 168 hr after the administration. The relative percentage of radioactivity in bone and spinal column increased with time, suggesting that free $^{166}$ Ho, released from chitosan complex deposited in the liver, selectively binds to these tissues. $^{166}$ Ho-chitosan complex administered intraportally was excreted less than 4% through urine (2.7$\pm$0.8%) and feces (0.65 $\pm$ 0.4%) up to seven days. These results demonstrate that the radio-activity of $_{166}$ Ho-chitusan complex when administered intraportally, mainly localizes in liver without affec-ting other tissues and organs. Considering the short half life of $^{166}$ Ho and the localization to the liver, $^{166}$ Ho-chitosan complex might be a useful agent in the treatment of hepatic carcinoma.

• Childhood Kidney Diseases
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• 제22권2호
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• pp.71-74
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• 2018

Endoscopic subureteral injection for treatment of vesicoureteral reflux (VUR) is known to be safe and efficient due to its minimal invasive nature. Being non-migratory, non-antigenic, and biocompatible, Macroplastique (Polydimethylsiloxane) is likely to be stable over time. A 5-year-old boy with a past history of subureteral administration of Macroplastique for unilateral Grade V VUR 4 years ago presented with recurrent gross and microscopic hematuria, along with suprapubic pain. On computed tomography (CT) abdomen, calcified material, suspected to be a stone, was visualized in the bladder. On diagnostic cystoscopy, calcification was seen around the orifice site where Macroplastique injection had been performed. We removed the calcific material by Holmium laser. Endoscopic subureteric implantation has several advantages, but nevertheless, vigilance is needed to detect long-term complications, especially in patients with gross or microscopic hematuria.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1999년도 춘계학술대회
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• pp.53-61
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• 1999

Radiation therapy has been used for the cancer treatment and radiation synovectomy$\^$1-3)/. There are two kinds of radiation therapy; the external radiation therapy and the internal radiation therapy. Hitherto, the external radiation therapy has been widely used, but for the lack of its selectivity it requires strong radiation dose and causes the irritation and damage of the normal tissue or organ. Therefore many researchers give their interests to the internal radiation therapy in which the radioactive materials are injected directly into the target organ or tissue. Many ${\beta}$-emitting radionuclides have been studied for the application of the internal radiation theraily. Among them, Holmium-166 has the many beneficial physical characteristics for the internal radiation therapy such as appropriate half life (26.8hr), high ${\beta}$ energy (max. 1.85 MeV(51%), 1.77 MeV (48%), mean 0.67MeV), and low ${\gamma}$ energy (0.081MeV) easily detected by ${\gamma}$-camera. In the internal radiation therapy, the administered radioactive materials should be retained in the target long enough to increase the therapeutic effects and avoid the damage in the normal tissue or organ. For this purpose, radionuclides are used as complex form with carriers. Carriers should have a high affinity with radionuclides in vivo and in vitro, so the complex can be evenly distributed in the lesion but can not be leaked out from the lesion.

• Current Optics and Photonics
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• 제2권4호
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• pp.356-360
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• 2018

We demonstrate continuous-wave operation of an all-fiber thulium-holmium codoped laser operating at a wavelength of 1706.3 nm. To realize laser operation in the short-wavelength region of the emission-band edge of thulium in silica fiber, we employ fiber Bragg gratings having resonant reflection at a wavelength around 1700 nm as a wavelength-selective mirror in an all-fiber cavity scheme. We first examine the performance of the laser by adjusting the central wavelength of the in-band pump source. Although a pump source possessing a longer wavelength is observed to provide reduced laser threshold power and increased slope efficiency, because of the characteristics of spectral response in the gain fiber, we find that the optimal pump wavelength is 1565 nm to obtain maximum laser output power for a given system. We further explore the properties of the laser by varying the fiber gain length from 1 m to 1.4 m, for the purpose of power scaling. It is revealed that the laser shows optimal performance in terms of output power and slope efficiency at a gain length of 1.3 m, where we obtain a maximum output power of 249 mW for an applied pump power of 2.1 W. A maximum slope efficiency is also estimated to be 23% under these conditions.

• 대한두경부종양학회지
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• 제20권1호
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• pp.7-12
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• 2004

Background and Objectives: Brain metastasis from well-differentiated thyroid carcinoma is uncommon, and the treatment remains controversial. In this study, we analyzed cases of brain metastasis from well differentiated thyroid carcinoma to determine optimal treatment. Material and Methods: From March 1986 to May 2003, we experienced 13 cases of brain metastases from well-differentiated thyroid carcinomas. There were 6 men and 7 women with a mean age of 62.3 years. The time interval detecting the brain metastasis, treatment methods, outcomes, and the prognostic factors were analyzed. Results: In 11 patients, brain metastasis was found at a mean of 96 months after thyroid surgery (range, 1-204months). In 1 patient, brain metastasis was found simultaneously with the thyroid cancer. In the remaining one, brain metastasis was presented as the first sign. Treatment included gamma knife therapy in 2, external radiation therapy (ExRT) in 2, resection and ExRT in 2, gamma knife therapy and ExRT in 2 and intracranial holmium injection in 1. Three patients received no treatment. The mean survival was 20.5months (1-119 months). Only 2 patients with early detection remained alive after treatment (23months and 119months). The age, sex, primary tumor size, combined organs of distant metastasis and treatment methods did not affect the prognosis. There were noticeable symptomatic improvements in patients who received any kind of treatment for brain metastasis. Conclusion: Early detection and treatment of brain metastasis appears to bring symptomatic relief and improve survival. Therefore, early screening for brain metastasis is recommended for patients with symptoms. However, further study is needed to determine the optimal method of treatment.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.540-545
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• 2008

Since mid 20th century, dental treatments with laser have been introduced and improved a lot. Because early $CO_2$, Nd:YAG, diode, argon, and holmium lasers are used for dealing soft tissue, so it applied just limited field. But, in 1997 the lasers of erbium family that able to dealing soft and hard tissue also were introduced, laser application fields are enlarged. In today, the application fields reach on implantation treatment, so clinicians can use the laser to make holes for implantation, and flap elevation, even though treating peri-implantitis. So our class want to discover the optimal setting of Er:YAG laser when treating peri-implantitis. We observed the surface that initially treated by RBM and TPS passion and laser with varied options of exposure time and power with SEM image. For this we conclude the optimal setting range that does not alter the implant surface structure and report it.

• Nuclear Engineering and Technology
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• 제53권12호
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• pp.4106-4113
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• 2021

Rare earth doped barium tellurite glasses were synthesised and explored for their radiation shielding applications. All the samples showed good thermal stability with values varying between 101 ℃ and 135 ℃ based on dopants. Structural properties showed the dominance of matrix elements compared to rare earth dopants in forming the bridging and non-bridging atoms in the network. Bandgap values varied between 3.30 and 4.05 eV which was found to be monotonic with respective rare earth dopants indicating their modification effect in the network. Various radiation shielding parameters like linear attenuation coefficient, mean free path and half value layer were calculated and each showed the effect of doping. For all samples, LAC values decreased with increase in energy and is attributed to photoelectric mechanism. Thulium doped glasses showed the highest value of 1.18 cm^-1 at 0.245 MeV for 2 mol.% doping, which decreased in the order of erbium, holmium and the base barium tellurite glass, while half value layer and mean free paths showed an opposite trend with least value for 2 mol.% thulium indicating that thulium doped samples are better attenuators compared to undoped and other rare earth doped samples. Studies indicate an increased level of thulium doping in barium tellurite glasses can lead to efficient shielding materials for high energy radiation.

• 한국세라믹학회지
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• 제41권8호
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• pp.618-622
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• 2004

플로라이드, 설파이드 및 셀레나이드 유리에 각각 첨가된 홀뮴 이온의 $^{5}$ I$_{5}$ \$\longrightarrow$$^{5}$ I$_{7}$ 전자천이에 기인하는 1.6$\mu$m 형광의 여기 스펙트럼을 $^{5}$ I$_{5}$ 준위가 위치하는 ∼900nm 대역에서 측정하였다. $^{5}$ $F_{1}$ 준위로의 상향전이가 발생하는 특정 파장대역에서 1.6$\mu$m발광의 여기효율이 감소하는 현상이 플로라이드 및 설파이드 유리에서 관찰되었으나 셀레나이드 유리에서는 $^{5}$ I$_{8}$ \$\longrightarrow$$^{5}$ I$_{5}$ 흡수 스펙트럼과 여기 스펙트럼의 모양이 유사하였으며, 이러한 현상은 각 비정질 유전체 재료의 광학적 비선형성과 단파장쪽 투과단의 차이에 기인한다. 한편, Tb$^{3+}$ , Dy$^{3+}$ , Eu$^{3+}$ 또는 N$d^{3+}$ 이온을 공동 첨가함으로써 $^{5}$ I$_{7}$ 준위의 형광수명을 효과적으로 감소시킬 수 있으나 Eu$^{3+}$ 이온을 제외한 나머지 공동 첨가제는 기저상태 흡수를 통하여 1.6 $\mu$m 대역에서의 흡수 손실을 크게 한다. 따라서 형광수명 감소 효과가 Tb$^{3+}$ 이온보다 크지는 않지만 추가적인 흡수 손실이 없는 Eu$^{3+}$ 이온이 공동 첨가제로 더 적합하다.