• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.516-521
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• 2011

The basilar membrane, an important functional part of the cochlea, is responsible for spectral separation of vibration signals transmitted from the stapes. In current study, scaled-up polymer membranes designed by mimicking the human basilar membrane were used for investigation of the frequency-separation characteristic. Displacement field formed on each polymer membrane was acquired by Laser Doppler scanning vibrometer and post-processed frequency-wise. The locations of the maximum displacement along the centerline were identified and collected for individual frequency range to produce the frequency-position map of individual polymer membrane. The influences of the membrane thickness and material properties on the variation of the frequency separability were discussed.

• Elastomers and Composites
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• v.44 no.2
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• pp.98-105
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• 2009

The cochlea of the inner ear has two core components, basilar membrane and hair cells. The basilar membrane disperses incoming sound waves by their frequencies. The hair cells are on the basilar membrane, and they are the sensory receptors generating bioelectric signals. In this paper, a biomimetic technology using ZnO piezoelectric nano-pillar was studied as the part of developing process for artificial cochlea and novel artificial mechanosensory system mimicking human auditory senses. In particular, ZnO piezoelectric nano-pillar was fabricated by both low and high temperature growth methods. ZnO piezoelectric nano-pillars were grown on solid (high temperature growth) and flexible (low temperature growth) substrates. The substrates were patterned prior to ZnO nano-pillar growth so that we can selectively grow ZnO nano-pillar on the substrates. A multi-physical simulation was also conducted to understand the behavior of ZnO nano-pillar. The simulation results show electric potential, von Mises stress, and deformation in the ZnO nano-pillar. Both the experimental and computational works help characterize and optimize ZnO nano-pillar.

• Childhood Kidney Diseases
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• v.6 no.1
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• pp.48-55
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• 2002

Purpose: Thin glomerular basement membrane nephropathy (TGBMN) is recognized as the leading cause of microscopic hematuria in both children and adults. However thinning of glomerular basement membrane (TCBM) has been found in healthy adult and also is known to be associated with various renal diseases such as Alport syndronh, IgA nephropathy and mesangial proliferative glomerulonephritis. The association of TGBM with minimal change nephrotic syndrome (MCNS) has been very rare so that the present study was undertaken to determine the relationship between TGBM and MCNS. Methods: The study population consisted of 49 children with biopsy- proven MCNS who have been admitted to the pediatric department of Kyungpook University Hospital during the past 5 years from 1997 to 2001. Group I consisted of 8 children associated with TGBM and Group II 41 children without TCBM. Various parameters such as age of illness, duration from discovery of illness to the time of biopsy, family history of hematuria and other laboratory tests were compared between these two groups and the following results were obtained. Results: Age distribution showed slightly older age in Group I ($7.1{\pm}3.5$ years) compared to Group II ($4.8{\pm}2.9$ years). However this was not statistically different (P=0.056). Family history of hematuria was noted in 2 cases in Group II. Though statistically not significant, hematuria was seen in 2 out of 8 cases ($25\%$) in MCNS children with TGBM, compared to 7 out of 41 cases ($17\%$) with MCNS children without TGBM. Other parameters such as BUN, creatinine, 24 hours urine protein excretion, serum protein, albumin, cholesterol, and T4/T8 ratio, showed no difference. Also renal biopsy finding showed no significant difference and the thickness of glomerular basement membrane in Croup I was $188{\pm}30nm$. Conclusion: TGBM was found in 8 out of 49 children with MCNS ($16.3\%$). And this high frequency of occurrence indicates that these association is not an incidental findings. Typical clinical findings of TCBMN was not noted in all of the 8 children with MCNS associated with TGBM, suggesting that thinning of glomerular basement membrane (TCBN) is secondary to rather than the cause of MCNS. (J Korean Soc Pediatr Nephrol 2002;6: 48-55)

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.38-38
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• 2001

Spermatogonial stem cells은 sperrnatogenesis에서 중요한 역할을 하며, 곡세정관의 기저막에 위치하고 있는 것으로 알려져 있다. 그러나, 그 동안 이 세포에 특이하게 발현되는 marker가 거의 알려져 있지 않아 spermatogonial stem cell의 연구에 많은 어려움을 가져왔다. 최근 일반적인 stem cell이 갖는 특성 중, 기저막과 상호작용을 하는 surface protein으로 integrin이 존재한다는 사실을 이용하여, anti-$\alpha$$_{6}$/ 또는 anti-$\beta$$_1$ integrin항체로 germ cell을 선발하여 정소에 이식한 결과, 높은 효율로 이식세포유래의 정자발생이 가능하다는 결과가 보고되었다 (Shinohara et al., 1999). 한편, 항암제의 일종인 busulfan을 마우스에 투여(40mg/kg)한 후 4-5주가 경과하면 세정관의 기저막에 위치하는 spermatogonia를 제외하고 대부분의 생식세포는 소멸한다 본 실험의 목적은 이러한 사실들을 이용하여 spermatogonial stem cell의 특성을 밝히고, 이 생식세포를 보다 간편하고 손쉽게 선발할 수 있는 시스템을 확립하는데 있다. Busulfan처리 후 5주가 경과된 마우스와 정상적인 13주령의 마우스 testis로부터 세포를 분리한 후 FITC-conjugated anti-IgG를 이용한 면역형광법으로 측정.분석한 결과, 형광표식된 세포비율이 대조군과 비교하여 busulfan을 처리한 경우에서 유의적인 증가를 보였다.(17$\pm$3.8%. 0.7$\pm$0.3% busulfan vs control). 또한, IgG와 결합한 단백질이 존재하는 이들 세포들은 곡세정관의 기저막을 따라 위치하며, 단백질과 복합체를 형성한 IgG는 anti-Ig $G_{2a}$와 반응하지 않는다는 사실을 관찰했다. 이러한 IgG 복합체를 형성한 세포들의 특성을 이용하여, IgG와 반응을 하지 않는 것으로 확인된 이차 항체인 an1i-Ig $G_{2}$와 일차 항체인 anti-$\alpha$$_{6}$ 또는 anti-$\beta$$_1$ integrin항체를 이용하여 측정.분석하였다. Busulfan을 처리한 마우스 정소에서 분리한 세포를 다시 laminin으로 코팅된 dish에서 선발.회수해서, anti-lgG, anti-$\alpha$$_{6}$ 또는 anti-$\beta$$_1$ integrin항체로 각각 표식된 세포비율을 비교하였다. Laminin으로부터 선발.회수한 세포에서는 IgG복합체가 $\alpha$$_{6}$ 또 는 $\beta$$_1$integrin과 거의 같은 수준에서 높은 비율로 표식되었다. 결론적으로, busulfan에 의해 유도된 IgG와 결합가능한 단백질은 $\alpha$$_{6}$나 $\beta$$_1$ integrin과 마찬가지로 immunoglobulin G를 이용하여 spermatogonial stem cell의 선발을 가능하게 했다. 따라서, busulfan처리시 IgG는 미분화된 정조세포의 선발을 위한 하나의 marker로서 사용가능함을 시사한다.다.

• Korean journal of applied entomology
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• v.34 no.3
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• pp.266-277
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• 1995

The adult brown planthopper possesses tow oval shaped compound eyes which, on their ventral borders, curve around the base of the antennae. Compound eye of the adult brown planthopper is recognised apposition eye which each ommatidium is optically isolated from it surroundings, the rhabdoms receiving light only from their own corneal lens. Each ommatidium possesses its own dioptric apparatus formed from the cuticular cornea and an underlying crystalline cone. The retinula cells lying immediately beneath the crystalline cone have their individual rhabdomeres tightly opposed to form one central, closed rhbdom. The rhabdom stretches from the spex of the crystalline cone nearly to the basement membrane and is approximately 110~120 $\mu\textrm{m}$ in length. The crystalline cone is surrounded by a pair of primary pigment cells an these in turn are surrounded by accessory pigment cells. Accessory pigment cells extend beyond the crystalline cone surrounding the retinular cells in the distal region of the eye. The crystalline cone is surrounded by the distal-most regions of the retinula cells show the presence of seven cells and sections taken proximally in the last quarter of the omatidium before the basement membrane is reached, reveal the presence of a small, eighth retinula cell which also contributes to the central rhabdom. Each ommatidium has a central rhabdom formed from the modified inner border of all of the retinula cells. Th rhabdom consists of micrvilli arising from the inner wall of each retinula cell. In cross section th microvilli exhibit a characteristic honeycomb appearance. Pigment cells comprise the primary pigment cells enveloping the crystalline cone, the accessory pigment cells extending from the inner surface of the comea to the basement membrane and the small pigment cells of the basement membrane.

• Childhood Kidney Diseases
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• v.5 no.1
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• pp.1-8
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• 2001

Purpose : Clinical manifestations and pathologic findings of thin glumerular basement membrane disease, recognized as a common underlying disease of benign, familaiar and asymptomatic hematuria has not been reported systemically in Korera. We analyzed clinical and pathologic findings of patients who were diagnosed as thin glomerular basement membrane disease Methods : We analyzed clinical and pathologic findings of twenty-six patients who were diagnosed as thin glomerular basement membrane disease by renal biopsy among who complained asymptomatic hematuria from 1990 to 2000. Results : The subjects were aged 9.4${\pm}$3.2 (3.0-15.8) years-old at onset of hematuria, and 11.1${\pm}$2.2 (4.7-16.3) years-old at renal biopsy. Sexual discrepancy was more common in girls (eight boys and eighteen girls). A family history of hematuria was found in 8 patients(30.7$\%$). Major clinical manifestation on admission was microscopic hematuria according to the findings of 3case(11.5$\%$) of gross hematuria, 23cases(88.5$\%$9) of microscopic hematuria, and 1 case(3.8$\%$) of proteinuria. Microscopic hematuria persisted in all cases. Kidney biopsy showed few changes by light microscopy, but IgM, C3 and fibrinogen deposit in mesangium was found by immunofluorescent microscopy in a few cases. Electron microscopic findings have revealed thinning of the glomerular basement membrane varied from 180.9${\pm}$35.8nm. Conclusion : Thin glomerular basement membrane disease might be a common cause of microscopic hematuria of children and family history was revealed in about 30$\%$. Clinical progression was good in majorities.(J. Korean Soc Pediatr Nephrol 5 : 1-8, 2001)

• Proceedings of the KIEE Conference
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• 1984.07a
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• pp.99-102
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• 1984

• Applied Microscopy
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• v.34 no.3
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• pp.199-209
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• 2004

The migut epitheluim of the last instar larva in the mosquito larvae, Anopheles sinensis was observed with electron microscopes. The midgut epitheluim of the mosquito larva is composed of a single-layered columnar absorptive cells, regenerative cells and secretory granular cells. The free surface of the columnar absorptive cells has a regular array of microvilli 'brush border', while cell membranes close to the basal lamina are extrmely infolded and a lot of mitochondria are concentrated in those processes. The columnar absorptive cells also contain cell organelles expected to be found in absorptive cell. Midgut regenerative cells which are positioned basally in the epithelium form the groups, which are called 'nidi', composed of 1 or $2{\sim}3$ cells, they show darker appearance than the columnar absoptive cells. The secretory granular cells contain numerous electron dense granules, $200{\sim}400$ nm in diameter. The cone shaped secretory granular cells are located in the basal portion of the midgut epitheluim. The epithelium is surrounded by the subepithelial space and muscle bundles. The subepithelial space, which is filled with fibrous connective tissue, is innervated by many axon cells and tracheoles.

• Applied Microscopy
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• v.35 no.3
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• pp.177-186
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• 2005

The foregut epithelium of the last instar larva in the scarab beetle, Allomyrina dichotoma was observed with electron microscopes. The foregut epithelium of the scarab beetle larva is composed of a single-layered squamous absorptive cell. The luminal surface of the epithelium is covered with cuticular intima. The free surface of the squamous cell has a irregular array of microvilli 'brush border', while cell membrans close to the basal lamina are infolded and a lot of mitochondria are concentrated in those processes. The cytoplasm in the epithelial cells is well developed nucleus, mitochondria. And the basal region of cell contains large lipid-, protein droplets and numerous glycogen granules. The basal lamina is located between the basal membrane and muscle bundle, providing barrier between the epithelium and the hemolymph. The epithelium is surround by the subepithelial space and muscles. The subepithelial space, which is composed of fibrous connective tissue is innervated by many tracheoles and axon.

• Proceedings of the KAIS Fall Conference
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• 2000.10a
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• pp.243-244
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• 2000

Serum albumin은 혈청 단백질 중 50-60%를 차지한다. 알부민은 순환계 내에서 삼투압을 유지시켜 세포내외의 체액을 유지 및 지용성 물질치 이동에 관여한다. 신사구체와 기저막의 투과성이 증가하거나 세뇨관의 흡수감소 등으로 단백질의 요배설량이 하루에 150mmg 이상되는 단백뇨는 신장내의 병변이 있음을 나타내는 중요한 지표이다. 이러한 단백뇨는 크게 사구체성 단백뇨, 세뇨관성 단백뇨, 혼합성 단백뇨로 나눌수 있는데 이중 사구체 기저막의 손상으로 발생되는 사구체성 단백뇨는 알부민과 같은 고분자량의 단백질이 소변 내로 배설되는 현상이다. 일반적으로 알부민이 정상치 이상으로 소변을 통하여 배설되는 것을 'microalbuminuria'라고 하며 당뇨병으로 인한 신장병변을 예견하는데 중요한 지표로 알려져 있다. Microalbuminuria는 방사 면역확산법, 방사성 면역측정법, 면역혼탁측정법, 비탁측정법, 효소결합면역측정법(ELISA) 등으로 검출할 수 있으나 최근에는 안전하면서도 민감도가 높고 측정이 용이한 방법인 ELISA를 이용한 면역분석방법이 많이 사용되고 있다. 면역특이성이 떨어지는 다세포군 항체를 사용한 방법의 문제점을 극복하기 위해서 세포융합기술을 이용한 단세포군항체를 생산하는 세포주를 개발하였고 그 특성을 규명하였다. 따라서 본 연구에서 세포융합기술을 도입하여 개발된 인간 혈청 알부민에 대한 단세포군항체는 glycohemoglobin에 대한 단세포군항체와 더불어 당뇨병의 진행 정도를 진단할 수 있는 키트의 원료로 사용될 수 있다.