• 대한세포병리학회지
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• 제5권1호
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• pp.28-34
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• 1994

Aspiration biopsy cytology is a convenient, easy and non-invasive method for diagnosis of tumors. The results and cytologic features of carcinoma in various organs have been reported frequently, however, those of soft tissue sarcoma are relatively rare to find. Here we describe fine needle aspiration cytologic features of various soft tissue sarcomas and discuss cytologic differential points. The material is 6 cases of soft tissue sarcoma that were confirmed by histologic examination. They are composed of 2 cases of dermatofibrosarcoma protuberans and one case of malignant fibrous histiocytoma, synovial sarcoma, alveolar soft pan sarcoma, and malignant schwannoma respectively.

• 대한기계학회논문집A
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• 제41권1호
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• pp.41-48
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• 2017

최근 에너지, 바이오공학, 전자공학 등 다양한 분야에서 초미세 고분자섬유의 활용이 증대되고 있다. 이러한 고분자 섬유의 제작방법의 하나로서 전기방사법은 타 공정에 비해 공정장치가 간단하고 재료의 선택에 제한이 적은 등 다양한 장점을 가져 활발하게 사용되고 있다. 그러나 전기방사공정은 미세한 고분자 섬유가 전기장이 부가된 공기층을 통과하면서 높은 불안정성을 가지기 때문에 전기방사공정을 통해 제작되는 섬유매트의 형상 및 기하학적 특성의 조절이 어려운 단점을 가지고 있다. 본 연구에서는 서로 다른 두 가지 용매를 이용하여 섬유의 직경을 나노섬유와 마이크로섬유로 제작할 수 있음을 보였으며, 이를 조합하여 기계적 특성과 공극률을 조절할 수 있는 하이브리드 섬유매트를 제작할 수 있음을 보였다. 또한 제작된 매트를 이용하여 기계적 특성과 공극률이 조절될 수 있음을 확인하였다.

• 대한방사선기술학회지:방사선기술과학
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• 제28권4호
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• pp.301-306
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• 2005

목 적 : 일부지역에서 실시되고 있는 유방촬영술에 대한 유방팬톰영상을 분석하여 화질관리의 실태를 알아보고져 한다. 대상과 방법 : 2005년 5월에서 6월까지 2개월간 일부지역의 47개 병원에 설치된 유방촬영기기를 대상으로 실험하였으며 유방팬톰영상의 분석은 확대경을 이용하여 영상에서 보이는 섬유소, 작은 석회화그룹, 종괴의 개수를 세어 점수로 기록 평가하였다. 유방팬톰영상평가시험의 평가기준에 의해서 섬유소 4개 이상, 작은 석회화그룹 3개 이상, 종괴 3개 이상이 보인 경우를 합격으로 분류하였다. 결 과 : 유방팬톰영상 47예 중 합격이 33예(70.3%), 불합격이 14예(29.7%)였으며 합격한 경우에 사용한 관전압 범위는 $23{\sim}30\;kVp$, 관전류량 범위는 $20{\sim}60\;mAs$, 사진농도 범위는 $0.48{\sim}1.77$로 나타났으며 격자를 사용한 경우는 31예(91%)로 나타났다. 결 론 : 일부지역에서 실시되고 있는 유방촬영술의 영상에서 약 70.3%가 유방팬톰영상평가 시험에 합격한 것으로 나타났다. 적절한 범위의 관전압, 관전류, 격자 사용으로 적절한 사진농도를 얻어 시험기준에 합격된 우수한 화질의 유방영상을 얻어야 한다.

• Applied Microscopy
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• 제15권1호
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• pp.71-85
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• 1985

The ultrastructure on the dorsal vessel of 5-day-old cabbage butterfly, Pieris rapae L., was carried out using the transmission and scanning electron microscope. The results are as follows. 1) The aorta. The aorta is simple tubular type and consists of the inner and outer membrane of the myocardium and thick myocardium is located between them. However the inner membrane with $0.26{\mu}m$ thickness and outer membrane with $0.08{\mu}m$ are composed of fibrous materials, the former is composed of low and high densed fibrous materials and the latter appears homogeneous layer. The myocardium consists of typical striated muscles. The sarcomere with $1.6{\mu}m$ length and in cross section, each thick filaments are surrounded by $7{\sim}8$ thin filaments. The intercalated disc is joining the end of the two muscle cells, desmosomes and septate junctions are appeared between the neighboring muscle cells. 2) The heart. The heart composing of myocardium enclosed by its inner and outer membrane as the aorta has a series of well formed segmental chamber. The arrangement of myofilaments, cell adhensions and membrane elements are observed as same as at the aorta. The inner membrane of the heart is deeply invaginated into the myocardium than the outer membrane and a lot of well developed mitochondria with rod shape are aggregated in the folds. The longitudinally and transversely oriented tubule system formed by invagnation of the sarcolemma into the muscle bundle is built up dyad with the sarcoplasmic reticulum as the aorta. The slit is formed by deeply invagination of the inner membrane of myocadium toward the muscle layer and then the inner and outer membrane of myocardium are fused. Therefore, the ostium is formed between the myocardium and situated at the lateral side of the myocardium.

• Advances in concrete construction
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• 제13권 2호
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• pp.123-132
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• 2022

This paper aims to adapt Multilinear regression (MLR) to predict the strength and toughness of SIFCON containing various pozzolanic materials. Slurry Infiltrated Fibrous Concrete (SIFCON) is one of the most common terms used in concrete manufacturing, known for its benefits such as high ductility, toughness and high ultimate strength. Assessment of compressive strength (CS.), flexural strength (F.S.), splitting tensile strength (STS), dynamic elasticity modulus (DME) and impact energy (I.E.) using the experimental approach is too costly. It is time-consuming, and a slight error can lead to a repeat of the test and, to solve this, alternative methods are used to predict the strength and toughness properties of SIFCON. In the present study, the experimentally investigated SIFCON data about various mix proportions are used to predict the strength and toughness properties using regression analysis-multilinear regression (MLR) models. The input parameters used in regression models are cement, fibre, fly ash, Metakaolin, fine aggregate, blast furnace slag, bottom ash, water-cement ratio, and the strength and toughness properties of SIFCON at 28 days is the output parameter. The models are developed and validated using data obtained from the experimental investigation. The investigations were done on 36 SIFCON mixes, and specimens were cast and tested after 28 days of curing. The MLR model yields correlation between predicted and actual values of the compressive strength (C.S.), flexural strength, splitting tensile strength, dynamic modulus of elasticity and impact energy. R-squared values for the relationship between observed and predicted compressive strength are 0.9548, flexural strength 0.9058, split tensile strength 0.9047, dynamic modulus of elasticity 0.8611 for impact energy 0.8366. This examination shows that the MLR model can predict the strength and toughness properties of SIFCON.

• Applied Microscopy
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• 제41권2호
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• pp.99-107
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• 2011

한국산 다람쥐 정자의 형태적 특징을 알아보기 위하여 광학현미경과 주사 및 투과 전자현미경으로 관찰하였다. 다람쥐 정자머리의 모양은 주걱 모양의 형태를 취하고 있었다. 정자의 전체 길이는 67.8 ${\mu}m$이었으며, 머리의 길이는 7.8 ${\mu}m$, 꼬리는 60.0 ${\mu}m$이었다. 꼬리는 경부(1.0 ${\mu}m$), 중편부(8.0 ${\mu}m$), 주편부(48.5 ${\mu}m$) 그리고 미부(2.5 ${\mu}m$)로 각각 구성되어져 있었다. 특히, 본 연구에서 정자의 중편부도 짧지만 미부의 길이는 다른 설치류 종보다도 매우 짧은 것이 특징적이다. 첨체 후 덮개는 핵의 약 1/5을 점유하고 있으며, 적도절은 핵 상단의 첨체 후 덮개와 첨체 덮개사이에 위치하고 있었다. 9개의 분절주들은 미토콘드리아에 의해 둘러싸여져 있었다. 중편부의 미토콘드리아의 회전수는 26개 이었다. 한 개의 분절주는 10~12개의 마디로 구성되어져 있었으며, 이들 경부의 각각의 분절주는 중편부의 9개의 외측치밀 섬유와 제각기 결합되어 있었다. 특히 경부의 분절주와 분절주 사이에는 수많은 satellite 섬유와 흡사한 물질들이 존재하고 있었다. 중편부의 9개의 외측 치밀 섬유는 Nos. 1, 5, 6의 섬유가 다른 섬유들(2, 3, 4, 7, 8, 9) 보다도 크다. 섬유초와 종 지주는 주편부에는 존재하고 있었으며, 미부에는 섬유초와 종 지주는 존재하지 않았다. 이상의 결과에서 볼 때, 정자두부와 꼬리의 구조적인 특징들은 정자의 진화와 더불어 종을 분류하는데 있어서 매우 중요한 정보를 제공하리라 여겨진다.

• Restorative Dentistry and Endodontics
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• 제8권1호
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• pp.7-17
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• 1982

The purpose of this study was to investigate the fine structural modifications of fibroblasts in the coronal region of inflamed human pulps from carious teeth. Six untreated human teeth with large carious lesions and two normal teeth as control were selected from male and female patients between the ages of 20 and 39. The teeth were divided into 4 groups by light microscopic findings: the normal control group, the chronic inflammatory cell-appeared group, the acute and chronic inflammatory cell-appeared group, and the total necrosis group. All tissues were fixed in 2.5% glutaraldehyde in 0.1M sodium cacodylate buffer at pH 7.4 and 1% osmic acid in same buffer. They were embedded in Epon 812. The ultrathin sections were stained conventionally and examined with a AEI Corynth 500 electron microscope. The results were as follows; 1. The fibroblasts of the normal pulps were almost in a quiescent state. 2. The active and the quiescent fibroblasts were found in the pulps of the chronic inflammatory cell-appeared group. Lymphocytes and plasma cells were also seen scattered among these fibroblasts. 3. In the pulps of the acute and chronic inflammatory cell-appeared group, active, degenerative and necrotic fibroblasts were found in the PMN appeared area. And all the fibroblasts in the fibrosis area were active. In the area of chronic inflammatory cellular infiltration, almost all the fibroblasts were active, but seldom were quiescent fibroblasts observed. Some fibroblasts in the pulps of two teeth had large vacuoles that contained banded collagen fibrils. The phagosomes had small beaded vesicles or large lysosome-like varicosity. In two of the teeth, microorganisms were present and two morphological shapes were identified, a rod and a coccus. 4. Vacuolar, vesicular, lamellar, fibrous and myelin structures were observed in the pulp of the total necrosis group, and cocci were also seen.

• Membrane and Water Treatment
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• 제11권3호
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• pp.231-235
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• 2020

Industrialization and modern developments have led to an influx of toxic heavy metals into the aquatic environment, and the accumulation of heavy metals has serious adverse effects on humans. Among the various heavy metal treatment methods, adsorption is very useful and frequently used. Plastic materials, such as polypropylene and polyethylene, have been widely used as filter media due to their mechanical and chemical stability. However, the surface of plastic material is inert and therefore the adsorption capability of heavy metals is very limited. In this study, granular media and fiber media composed of polypropylene and polyethylene are used, and the surface modification was conducted in order to increase adsorption capability toward heavy metals. Oxygen plasma generated hydroxyl groups on the surface of the media to activate the surface, and then acrylic acid was synthesized on the surface. The grafted carboxyl group was confirmed by FT-IR and SEM. Heavy metal adsorption capability of pristine and surface modified adsorbents was also evaluated. Overall, heavy metal adsorption capability was increased by surface modification due to electrostatic interaction between the carboxyl groups and heavy metal ions. Fibrous PP/PE showed lower improvement compared to granular PP media because pore blockage occurred by the surface modification step, thereby inhibiting mass transfer.

• Applied Microscopy
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• 제19권1호
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• pp.59-69
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• 1989

Ultrastructure of the secretory portion of the small ampullate gland in the orb web spider, Nephila clavata, has been investigated using the electron microscope. The secretory portion of this gland comprise two different regions which are a S-shaped storage sac and a long, convoluted tail. By the internal textures of the secretory granules, the sac is subdivided into two regions ; the proximal region near the tail and the distal region near the duct. Commonly single layered connectives cover the basal portion of the sac epithelium, and apical portion of the epithelial cells is occupied by the thick cuticles. Within the epithelial cells of both the proximal and distal region, several types of the secretory granules surrounded by a limiting membrane and had characteristic crystalloid are scattered throughout the cytoplasm. The granular size and its electron densities are not coincide with each other according to the maturation level of the granules. The wall of the tail is composed of single layer of columnar epithelial cells, and their nuclei are found at the basal portion of the cells. Dissimilar to the epithelial cells of the sac, apical cuticles are not found at this portion. In the cytoplasm of these cells, numerous secretory granules, synthesized from the rough endoplasmic reticula commonly and had fine fibrous materials, are found. At the cell surface bordering the lumen, microvilli are seen, arid along the cellular boundaries specialized septate junctions and desmosomes appeared.

• 한국재료학회지
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• 제23권9호
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• pp.495-500
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• 2013

Mo-based thin films are frequently used as back electrode materials because of their low resistivity and high crystallinity in CIGS chalcopyrite solar cells. Mo:Na/Mo bilayer thin films with $1{\mu}m$ thickness were deposited on soda lime glass by varying the thickness of each layer using dc-magnetron sputtering. The effects of the Mo:Na layer on morphology and electrical property in terms of resistivity were systematically investigated. The resistivity increased from $159{\mu}{\Omega}cm$ to $944{\mu}{\Omega}cm$; this seemed to be caused by increased surface defects and low crystallinity as the thickness of Mo:Na layer increased from 100 nm to 500 nm. The surface morphologies of the Mo thin films changed from a somewhat coarse fibrous structures to irregular and fine celled structures with increased surface cracks along the cell boundaries as the thickness of Mo:Na layer increased. Na contents varied drastically from 0.03 % to 0.52 % according to the variation of Mo:Na layer thickness. The change in Na content may be ascribed to changes in surface morphology and crystallinity of the thin films.