• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.415-417
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• 2003

CsI 형광체는 X선에 대한 분해능 및 변환효율이 우수한 물질이다. 최근 대면적 평판형 X선 영상검출기의 변환층으로 이용하기 위해 CsI 형광체의 대면적 제조에 대한 연구가 활발히 진행되고 있다. 본 논문은 진공 열증착법을 이용하여 증착속도(3, 3.8, $4.5\;{\mu}m/min$)에 따라 $20\;{\mu}m$ 두께의 CsI 필름을 제조하였고, XRD 및 SEM 분석을 통해 CsI 필름의 기하학적 구조를 조사하였다. 증착된 CsI 필름은 증착속도에 관계없이 복잡한 다결정 구조를 가지며, $3\;{\mu}m/min$의 증착속도에서 약 $1\;{\mu}m$ 크기로 needle-like 한 columnar structure를 가졌다. As results, about 3um/min evaporation rate formed as good geometry characteristics CsI layer.

• Journal of the Korean Vacuum Society
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• v.4 no.S2
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• pp.64-68
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• 1995

Silicon films were deposited at $430^{\circ}C$ by remote plasma chemical vapor deposition(RPECVD) with a gas mixture of $Si_2H_6/SiF_4/H_2$. The silicon films deposited without and with $SiF_4$ were characterized using atomic force microscopy(AFM), transmission electron microscopy(TEM) and X-ray diffraction(XRD). Both silicon films have the same rugged surface morphology, but, the silicon film deposited with $SiF_4$ exhibits more rugged. The silicon film deposited without $SiF_4$ is amorphous, whereas the silicon film deposited with $SiF_4$ is polycrystalline with very small needle-like grains which are perpendicular to the substrate and uniformly distributed in the thickness of the film. The silicon film deposited with $SiF_4$ was found to have a preferred orientation along the growth direction with the<110> of the film parallel to the <111> of the substrate. The effect of $SiF_4$ during RPECVD was discussed.

• Korean Journal of Metals and Materials
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• v.48 no.9
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• pp.861-866
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• 2010

Tetrapod-shaped ZnO crystals were synthesized through a simple oxidation of metallic Zn powder in air without the presence of any catalysts or substrates. X-ray diffraction data revealed that the ZnO crystals had wurtzite structure. It is supposed that the growth of the tetrapod proceeded in a vapor-solid growth mechanism. As the amount of the source powder increased, the size of the tetrapod decreased. The tip morphology of the tetrapod changed from a needle-like shape to a spherical shape with the oxidation time. ZnO crystals with rod shape were fabricated via the oxidation of Zn and Sn mixture. Sn played an important role in the formation of ZnO crystals with different morphology by affecting the growth mode of ZnO crystals. The cathodoluminescent properties were measured for the samples. The strongest green emission was observed for the rod-shaped ZnO crystals, suggesting that the crystals had the high density of oxygen vacancies.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.251-254
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• 2004

Hybrid rockets have many advantages over solid and liquid rockets. Hybrid rockets put forth high $I_{sp}$ like liquid rockets in spite of simple structure and low cost. As oxidizer flow rate is increased, thrust of hybrid rocket is increased accordingly. In this study, lab-scale hybrid rocket is designed, fabricated and tested. This system consists of lab-scale hybrid rocket motor, ignition system, flow system and data aquisition system. In order to control oxidizer flow rate, we construct flow rate control system by using needle valve and stepping motor.

• Journal of Veterinary Clinics
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• v.39 no.2
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• pp.75-80
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• 2022

An 11-year-old male Rex rabbit (Oryctolagus cuniculus) had a rectal prolapse induced by a polypoid mass. The mass was highly vascularized with a cauliflower-like appearance. Anorectal papilloma was suspected, and fine needle aspiration cytology showed eosinophilic inflammation. After surgical removal of the polyp, postoperative care was given, such as systemic antibiotics and analgesics. In the re-examination, the rabbit was resolved, and there were no complications. Histopathological examination of the removed polyp indicated chronic eosinophilic proctitis to be the cause of the inflammatory condition of the protruding rectal polyp.

• Reproductive and Developmental Biology
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• v.29 no.3
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• pp.163-168
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• 2005

The aim of this study was to investigate the changes in insulin-like growth factor-I (IGF-I) and growth hormone (GH) in serum, the quantitation of spermato-genesis and the comparable relationships among these measurements during pubertal period in New Zealand White male rabbits. To investigate the age-related testicular changes in DNA contents of spermatogenic cells, the fine-needle testicular biopsies from males aged 10 to 28 wks were evaluated by flow cytometry(FCM). Body weight increased significantly between the ages of 12 and 20 wks (P<0.05) and reached 3.4 kg at 28 wks of age. The highest serum IGF-I level (451.3ng/mL) was observed at 20wks of age (P<0.05) and thereafter remained stable at low levels. Serum GH level at 18 wks of age was 183.3 pg/mL which was significantly higher compared to the other ages (P<0.05), and the rising time in serum GH tend to be somewhat earlier than that of IGF-I. The relative percentage of It-cells in testicular cell compartments was $48.2\%$ at the age of 18 wks which significantly increased than those of 16-wk-old (P<0.05) and thereafter increased with the advance of age to $68\%$. The percentage of 2C-cells in testis was $26.8\%$ at 18 wks of age which was significantly lower than $54.3\%$ at 16 wks old (P<0.05). The percentage of 4C-cells was constantly maintained $2\~6\%$ except the $9.9\%$ at 18 wks of age. In conclusion, the results suggest that the puberty onset occurred at about the 18 wks of age and that the IGF-I and GH in serum during the pubertal period showed the age/growth-specific changes and these changes might be related to the spermatogenesis. The DNA FCM combined with fine-needle testicular biopsy could offer a very sensitive method to monitor the quantitative spermatogenic events related to the puberty onset.

• Applied Microscopy
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• v.37 no.3
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• pp.147-156
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• 2007

The dorsal lingual papillae of Myotis macrodactylus were investigated morphologically using scanning electron microscopy. Three types of lingual papillae from Myotis macrodactylus were recognized. The filiform(Fi) papillae were distributed over the entire dorsal surface of the tongue, and they could be classified into 5 types of papillae by the shape, size and number of the protrusion. Type I was distributed on dorsal surface of the apex in the anterior region of the tongue, has a crow-like shape with ten to fifteen formed projections. Type II was located in the medial portion of the anterior region of the tongue, has an eight to ten spin-like protrusion. Type III was distributed on the medial portion of the tongue, has a scale-like papille with five to seven protrusion. Type IV was distributed on the both lateral portion of the posterior region of the tongue, has a small conical papillae, does not have needle projection. Type V have not needle projection, a large of conical papillae, on the both lateral portion of the posterior region of the tongue. Most Fu(Fungiform) papillae were distributed the both lateral region or medial portion of the posterior region of the tongue, has a round or oval shape with $40{\sim}45$ papillae. The small $(65{\mu}m)$, meddle $(75{\mu}m)$ and large $(120{\mu}m)$ fungiform papillae were distributed on dorsal surface of the apex in the anterior, the both lateral portions and medial portion of the posterior region of the tongue, respectively. Two large oval vallate (V) papillae are located in the medial portion of the posterior region of the tongue. In conclusion, the morphology of lingual papillae is useful to determine species relationship among Myotis species. It suggests that the difference of types and number of lingual papillae caused by the difference of food habit.

• Korean Journal of Materials Research
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• v.14 no.9
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• pp.607-613
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• 2004

This study was to investigate the surface properties of electrochemically oxidized Ti-6Al-7Nb alloy by anodic spark discharge technique. Anodizing was performed at current density 30 $mA/cm^2$ up to 300 V in electrolyte solutions containing $DL-{\alpha}$-glycerophosphate disodium salt hydrate($DL-{\alpha}$-GP) and calcium acetate (CA). Hydrothermal treatment was done at $300^{\circ}C$ for 2 hrs to produce a thin outermost layer of hydroxyapatite (HA). The bioactivity was evaluated from HA formation on the surfaces in a Hanks' solution with pH 7.4 at $36.5^{\circ}C$ for 30 days. The size of micropores and the thickness of oxide film increased and complicated multilayer by increasing the spark forming voltage. Needle-like HA crystals were observed on anodic oxide film after the hydrothermal treatment at $300^{\circ}C$ for 2 hrs. When increasing $DL-{\alpha}$-GP in electrolyte composition, the precipitated HA crystals showed the shape of thick and shorter rod. However, when increasing CA, the more fine needle shape HA crystals were appeared. The bioactivity in Hanks' solution was accelerated when the oxide films composed with strong anatase peak with presence of rutile peak. The increase of amount of Ca and P was observed in groups having bioactivity in Hanks' solution. The Ca/P ratio of the precipitated HA layer was equivalent to that of HA crystal and it was closer to 1.67 as increasing the immersion time in Hanks' solution.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.215-220
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• 2007

This study was conducted to examine the establishment of bovine ES-like cells having pluripotency. The hatched blastocysts derived from culture of in vitro fertilized embryos for 10 to 12 days dissociated mechanically into ICM-and trophectoderm-rich clumps using needle, and cultured onto mitotically-inactivated MEF feeder layer. The primary colonies originated from ICM cells were detached mechanically 7 days after seeding and subsequent subculture was conducted at intervals of every 5 to 7 days. Two ES -like cell lines were established and maintained over 40 passages. Self-renewal of the established lines was confirmed by examining the alkaline phosphatase activity, stem cell-specific marker profiles including SSEA isotopes, Oct-4 and STAT3. Moreover, the established cell lines could produce anchorage-independent embryoid bodies (EBs) with gradual decrease of Oct-4 transcript level in time-dependent manner.

• Tuberculosis and Respiratory Diseases
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• v.56 no.1
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• pp.18-28
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• 2004

Background : Many diseases like lung cancer and tuberculosis can involve cervical lymph node. Fine needle aspiration cytology(FNAC) was known as a useful screening test for the evaluation of enlarged lymph node. But the usefulness and limitations of FNAC according to disease category or physical characteristics of lymph node were not yet fully established. Methods : Retrospective analysis of three hundred forty two adult patients who performed FNAC due to enlarged cervical lymph nodes at the Seoul Municipal Boramae Hospital during the period from January 1999 to December 2002 and final diagnosis could be made by surgical biopsy, microbiology or clinical observation. Results : Among the 342 cases, 176(51.5 %) were finally diagnosed as benign nature ncluding reactive hyperplasia, Kikuchi's disease and acute suppuration. Eighty eight(25.7 %) were diagnosed as tuberculous lymphadenitis, 66(19.3 %) as metastasis, and 12(3.5 %) as lymphoma. Tuberculosis, metastasis, and lymphoma all showed significantly larger diameter, longer duration of lymph node enlargement. There were higher frequency of supraclavicular involvement in the cases of tuberculosis and metastasis. The overall diagnostic sensitivity of FNAC was 88.0 %, and 88.6 % in benign nature lesion, 77.3 % in tuberculosis, 90.1% in metastasis and 58.3 % in lymphoma. The diagnosis of tuberculosis was made by FNAC in 68 cases (77.3 %) among 88 cases. Lung cancer(43.9 percent) was most frequent cause of cervical lymph node metastasis. Diagnostic sensitivity of FNAC was significantly lower in the supraclavicular than other cervical lymph node(80 % vs. 91.3 %) and not correlated with disease nature, node size or number. Conclusion : Though FNAC was a reliable screening test for enlarged cervical lymph node enlargement, the diagnostic sensitivity was low in the case of lymphoma or when the enlarged lymph node was located at the supraclavicular area.