• Korean Journal of Clinical Laboratory Science
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• v.56 no.3
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• pp.273-276
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• 2024

Spontaneous echo contrast is a swirling, smoke-like echographic pattern observed in B-mode ultrasound imaging, typically arising in areas of blood stasis or low-flow states. This hemodynamic disturbance generates low shear stress due to sluggish flow, leading to endothelial dysfunction and facilitating the activation of fibrinogen, a coagulation factor. Consequently, blood cells, including erythrocytes, readily aggregate, forming a spontaneous echo contrast, a precursor to thrombus formation. Spontaneous echo contrast is primarily found in the left atrium of patients with left atrial enlargement or the left atrial appendage of patients with atrial fibrillation. While less common, it can also be observed in the carotid arteries. This case report presents the imaging findings of spontaneous echo contrast detected during carotid duplex ultrasonography in a patient with metastatic cancer and discusses its clinical implications.

• Korean Journal of Ichthyology
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• v.22 no.2
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• pp.96-104
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• 2010

During an artificial breeding as a part of restoration of the endangered Korean bitterling Acheilognathus signifer, a small number of individuals exhibiting oculocutaneous albinism were produced. We compared the pigmentation and morphology of normal and albinic bitterlings by histological examination of skin samples obtained from 10 regions on the body, fins, and eyes. There were no differences in morphometry and in general morphology of skin between them. In normal bitterlings, pigment cells were better developed in the dorsal region, the upper part of caudal peduncle region, the choroid-retinal epithelium and iris than in other areas. In the albinic bitterling, however, pigment cells were present only in three parts of the dorsal region, the caudal and dorsal fin, which had few melanin cells. Albinic bitterlings also displayed deficient pigmentation in the choroid-retina pigment epithelium and iris. Although they had different pigmentation aspects in distribution and development between normal and albinic bitterlings, melanin cells were mainly present in the dorsal regions of the skin and eyes where are exposed directly to light.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.109.2-109.2
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• 2016

현민지브이티(Genesis)는 중소기업청 중소기업개발지원사업의 일환으로 진행된 2014년도 구매조건부 신제품 개발사업에 선정되어 '극저온 G-M냉동기를 이용한 대용량 Cold Trap개발'과제를 수행하면서 32인치 급으로 수분에 대해서 30,000[L/s] 이상의 배기속도를 가지는 대형 CWP를 개발하고 있다. 1차년도(2015년) 목표는 80K에서 200W급 단단 G-M극저온 냉동기를 개발하는 것이고, 2차년도(2016년) 목표는 이를 장착하여 30,000[L/s]의 물 배기속도 능력을 갖춘 32인치(800mm)급 직부형(appendage) CWP를 개발하는 것이다. 여기에서 가장 큰 문제점은 CWP 시스템의 물 배기속도를 실제로 측정하는 것이다. 왜냐하면 지금까지는 물(H2O)이 가진 독특한 물리적 특성으로 인해 배기속도 측정에 많은 어려움이 있어 이론적으로 계산한 값을 사용해 왔다. (심지어 크라이오 펌프 제조사 조차도 실험하지 않고 이론적인 계산 값을 일반적으로 사용한다.) 그러나 최근 본 과제 외에 물 배기속도 측정에 관한 요구사례와 일부 크라이오 펌프 제조사에서 수행하고 있다는 보고가 있는 바, 실제 물배기속도 시스템을 구축하여 이론과 실제 사이의 차이와 측정의 어려움 등에 관해 규명하고자 하였다. 물 배기속도 측정 방법은 크게 2가지로 나눌 수 있다. 첫째, 시스템으로 흘리는 물의 양을 Liquid MFC를 이용하여 먼저 측정한 후 Vaporizer로 보내어 기화 시키며 배기속도를 측정하는 방법. 둘째, 물을 Vaporizer로 먼저 기화시킨 후에 High Temp. MFM으로 기체 유량을 측정하며 배기속도를 측정하는 방법이 그것이다. 이에 국내 최초로 두 가지 방법 모두를 사용하여 표준화 된 물 배기속도 측정 설비를 구축하였고, 20인치(500mm) 크라이오 펌프와 인라인(inline)형 CWP 모델에 대한 물 배기속도 측정을 성공적으로 완료할 수 있었다. 향후 본 시험 방법과 결과를 토대로 32인치(800mm) 직부형 CWP 모델에 대한 물 배기속도 측정시험을 수행하고자 한다.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.329-332
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• 2008

Purpose: Microcystic adnexal carcinoma is a rare malignant appendage tumor, first described by Goldstein et al in 1982. Here, we present our experience in treatment of a case on the lower lip. Methods: A 52-year-old female with an asymptomatic nodule on the chin, previously misdiagnosed as trichoadenoma by needle aspiration biopsy, was treated by wide excision combined with multiple circumferential frozen biopsies. Results: Pathological examination revealed typical features of microcystic adnexal carcinoma, such as basaloid and squamous cells forming nests and cord-like patterns, horn cysts, and minimal cytologic atypia. The patient has been followed up for 6 months. No sign of recurrence is noted to date. Conclusion: Differentiation from other benign adnexal neoplasms is important for its appropriate treatment. Differentiation can be difficult histologically because it is difficult to acquire an adequate biopsy due to its invasiveness, and clinically due to its asymptomatic and slow growing features. Complete excision is the key treatment, but it may not always be the best solution considering the huge defect that may result and the low incidence of metastasis & deaths owing to the tumor. We add this case to the approximately 300 cases reported worldwide with a review of literature.

• Parasites, Hosts and Diseases
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• v.32 no.1
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• pp.53-56
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• 1994

A case of gastric anisaklasis due to the larva of Pseunotewqnova decipiens was confirmed by gastroendoscoplc examination In April 23, 1991. The patient, residing In Pusan, was a 42-year-old housewife, who complained of severe epigastric pawn and recalled that the symptom suddenly attacked her about 6 hours after eating raw Sebqstes inermis. In the gastroendoscopic examination performed about 9 hours after the onset of the symptom, a long whitish nematode larva penetrating the gastric mucosa in the greater curvature of mid-body was found and removed with a biopsy forcep. The nematode was $29.73{\times}0.94mm$ in size, had an intestinal cecum reaching over mfd-level of the ventnculus and was identified as the 4th stage larva of f decfpiens.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.130-133
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• 2004

Leaf blight and fruit rot of sweet persimmon (cv. Fuyu) caused by Pestalotia diospyri were observed during the growing season and postharvest such as storage and transport, respectively. Typical symptoms on leaves developed with small brown spots and were later reddish brown colors. In the storage fruit, the white mycelial mats formed between fruit and calyx. The pathogenic fungus was isolated from infected fruits and cultured on potato dextrose agar (PDA). Colony color of the fungus was white at first on PDA. Conidia were ovoid or fusiform, 5 cells, middle 3 cells were olive, upper and lower 2 cells were colorless, and their size were $16{\sim}22\;{\times}\;6{\sim}8\;{\mu}m$. They had were $2{\sim}3$ appendage at basal cell and size $9{\sim}18\;{\mu}m$. Based on the cultural and mycological characteristics and pathogenicity test on host plants and fruits, the fungus was identified as Pestalotia diospyri Syd.&P. Syd. This is the first report on the leaf blight and fruit rot of sweet persimmon caused by Pestalotia diospyri in Korea.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.63-71
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• 2003

This paper presents a robust slewing control of a flexible space structure based on sliding surface design. A sliding surface is designed for a single-axis rest-to-rest slewing in view of target angle, target angular velocity, and root monent of the flexible appendage. In comparison with the Lypunov control law, both controllers guarantee the stability and command tracking capabilities for nominal system. It is also shown that the designed control law provides further robustness to internal/external uncertainties. Extending the results of a single-axis maneuver, a sliding mode control law was sought for an arbitrary three-axis maneuver. Quaternion was used to determine the attitude of a space structure and sliding surfaces were designed for each axis, thereby a robust control law was derived considering the coupling effects between each rotational axis during the maneuver. Several numerical examples were demonstrated to show the effectiveness of the designed control law.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.335-339
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• 2012

An unrecorded species, Carex benkei T. Shimizu, was found in Is. Jaewondo, Jaewon-ri, Imja-myeon, Sinan-gun, Jeollanam-do and Dongbaik-dongsan, Seonheul-ri, Jocheon-eup, Jeju-si, Is. Jeju-do, South Korea. C. benkei is closely related to C. transversa Boott and C. brownii Tuck., and C. benkei is distingushied from the pistillate scales length, excluding the awn, similar to the achene and the beak of the achene with an annular appendage. A new Korean name, 'Gin-Hwa-Sal-Sa-Cho', was given based on its long pistillate scales excluding the awn compared with Carex transversa Boott. We provide here its redescription, illustrations, photographs, and a key to species of the sect. Confertiflorae Franch. ex Ohwi.

• Archives of Craniofacial Surgery
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• v.18 no.1
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• pp.50-53
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• 2017

Trichilemmal cysts are common fluid-filled growths that arise from the isthmus of the hair follicle. They can form rapidly multiplying trichilemmal tumors-, also called proliferating trichilemmal cysts, which are typically benign. Rarely, proliferating trichilemmal cysts can become cancerous. Here we report the case of a patient who experienced this series of changes. The 27-year-old male patient had been observed to have a $1{\times}1cm$ cyst 7 years ago. Eight months prior to presentation at our institution, incision and drainage was performed at his local clinic. However, the size of the mass had gradually increased. At our clinic, he presented with a $5{\times}4cm$ hard mass that had recurred on the posterior side of his neck. The tumor was removed without safety margin, and the skin defect was covered with a split-thickness skin graft. The pathologic diagnosis was a benign proliferating trichilemmal cyst. The mass recurred after 4months, at which point, a wide excision (1.3-cm safety margin) and split-thickness skin graft were performed. The biopsy revealed a trichilemmal carcinoma arising from a proliferating trichilemmal cyst. This clinical experience suggests that clinicians should consider the possibility of malignant changes when diagnosing and treating trichilemmal cysts.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.23-31
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• 2010

The flow around a remotely-operated vehicle (ROV) has been investigated numerically to improve the resistant performance by modifying the hull form of the ROV. In the case of the base hull form considered in this study, form drag rather than friction drag was the dominant component of total drag. Subsequently, the surfaces that were most susceptible to local pressure effects were modified to give them a more streamlined shape. Eleven different hull forms were chosen to undergo surface modification for drag reduction. In addition, four different boat-tail appendages with different slant angles were installed at the stern to reduce the wake vortices that are induced by the local regions of very low pressure. Consequently, a total of 11 different hull forms for drag reduction were considered. The final hull form, which combined the hull for which surface modification resulted in the lowest drag with a boat-tail appendage with a 15-degree slant angle, resulted in a drag reduction of 20%.