• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.4
• /
• pp.381-385
• /
• 2007

Bone is a dynamic organ that bone remodeling occurs throughout life and involves the process in which the bone matrix is broken down through resorption by osteoclasts and then built back again through bone formation by osteoblasts. Usually these two processes balance each other and a stable level of bone mass is maintained. We here discuss transcription factors involved in regulating the osteoblast differentiation pathway. Runx2 is a transcription factor which is essential in skeletal development by regulating osteoblast differentiation and chondrocyte maturation. Its companion subunit, Cbf${\beta}$ is needed for an early step in osteoblast differentiation pathway. Whereas Osterix(Osx) is a new identified osteoblast-specific transcription factor which is required for the differentiation of preosteoblasts into more mature and functional osteoblasts. We also discuss other transcription factors, Msx1 and 2, Dlx5 and 6, Twist, and Sp3 that affect skeletal patterning and development. Understanding the characteristics of mice in which these transcription factors are inactivated should help define their role in bone physiology and pathology of bone defects.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.7 no.4
• /
• pp.117-122
• /
• 1998

Glass fiber epoxy composite material is widely used in the structures of aircrafts, robots and other machines because of their high specific strength, high specific stiffness and high damping. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joint must be provided, which require precise machining. In this paper, the machinability of the glass fiber epoxy composite material was experimentally investigated. The results can be summarized as follows : 1. The entrance of hole is very good manufacturing existing, but exit come to occur sever surface exfoliation. 2. The cutting force in drilling of the glass fiber epoxy composite material is decreased as the drilling speed increased. 3. If the glass fiber epoxy composite material is drilling by the standard twist drill, then the hole recommand cutting condition is spindle speed 400∼600rpm, feed 40∼50mm/min.

• Wind and Structures
• /
• v.16 no.3
• /
• pp.241-248
• /
• 2013

The wind turbine blade is a very important part of the rotor. Extraction of energy from wind depends on the design of blade. In this work, the analysis is done on a blade of length 38.95 m which is designed for V82-1.65 MW horizontal axis wind turbine (supplied by Vestas). The airfoil taken for the blade is NACA 634-221 which is same from root to tip. The analysis of designed blade is done in flap-wise loading. Two shapes of the spar are taken, one of them is of square shape and the other one is combination of square and cross shape. The blade and spar are of the same composite material. The Finite element analysis of designed blade is done in ANSYS. This work is focused on the two segments of blade, root segment and transition segment. Result obtained from ANSYS is compared with the experimental work.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.8
• /
• pp.4635-4639
• /
• 2013

Multi-drug resistance (MDR) is an essential aspect of human lung cancer chemotherapy failure. Recent studies have shown that vinorelbine is involved in underlying processes in human tumors, reversing the MDR inseveral types of cancer cells. However, the roles and potential mechanism are not fully clear. In this study, we explored effects of vinorelbine in multi-drug resistance reversal of human lung cancer A549/DDP cells. We found that vinorelbine increased drug sensitivity to cisplatin and intracellular accumulation of rhodamine-123, while decreasing expression of P-glycoprotein (P-gp), multi-drug resistance-associated protein (MRP1) and glutathione-S-transferase ${\pi}$ (GST-${\pi}$) in A549/DDP cells. At the same time, we also established downregulation of p-Akt and decreased transcriptional activation of NF-${\kappa}B$ and twist after vinorelbine treatment. The results indicated that vinorelbine might be used as a potential therapeutic strategy in human lung cancer.

• Fashion & Textile Research Journal
• /
• v.4 no.4
• /
• pp.399-404
• /
• 2002

The purpose of this study was to develop the rain melange fabrics with using the pulsar interlacing unit. The properties of the pulsar interlaced yarns (PI yarn) which were textured with the several texturing conditions were analyzed and compared with the regular interlaced yarn (IT yarn) and with normally composited yarn (CP yarn). The results were as follows : The PI yarn which has the best rain random melange effect could be obtained with following texturing condition; 3 kg/$cm^2$ of interlacing air pressure, 1.6 mm diameter of interlacing nozzle and 500 m/min of yarn speed. When IT yarn was compared with CP yarn, IT yarn had higher denier and tenacity than those of CP yarn and had lower elongation and shrinkage than those of CP yarn.

• Design & Manufacturing
• /
• v.2 no.1
• /
• pp.11-14
• /
• 2008

we can save a development cost and time as computer was used in tool and die design of car fields in die manufacture process. Dimension accuracy errors such as springback, springgo, overcrown and twist were reduced product accuracy and caused trouble to assembly each parts of car. In this paper, CADCEUS was used to modify and optimize results of deflection for a tail gate panel of car parts in order to reduce dimension accuracy errors by springback in sheet metal forming. As CADCEUS was used to apply for a tail gate panel, the time for quality to improve was reduced to 30%.

• The Journal of Korean Physical Therapy
• /
• v.5 no.1
• /
• pp.89-94
• /
• 1993

Liking is a common activity in many of occupations and daily living, Lifting has been studied for many years. In this article, based on the existing literatures on lifting, mechanism of back support and proper posture during lifting are described. These mechanisms include the intra-abdominal pressure mechanism, the thoracolumbar fascia mechanism, and posterior ligamentous system. Proper posture for lifting are in the squat style, the lumbar spine is aligned in its normal lordosis and the pelvis is aligned in an anterior tilt. Keep the load close to the body and avoid twist white lifting.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.10
• /
• pp.203-208
• /
• 1998

Carbon fiber epoxy composite materials are widely used in the structures of aircrafts, robots and other machines because of their high specific strength, high specific stiffness and high damping. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joints must be provided, which require precise machining. In this paper, the machinability characterisitcs of the drilling operation of the carbon fiber epoxy composite materials was experimentally investigated. The experimental results are as follows 1.The entrance of hole is very good manufacturing existing, but exit come to occur sever surface exfoliation. 2. The cutting force in drilling of the carbon fiber epoxy composite materials is decreased as the drilling speed increased. 3.The hole of the carbon fiber epoxy composite materials is not good manufacturing by use of the standard twist, therefore, the new drill designed in order to accurate hole.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.426-429
• /
• 2005

The fringe-field switching (FFS) mode associated with a transition from a homogenously aligned to twist deformation require rubbing process. In this devices, $1^o$ of misalignment in an azimuthal direction could cause voltage-dependent transmittance (V-T) to be different from that in a normal area and consequently results in a rubbing mura. According to our studies, the single domain FFS cells are much more sensitive to the rubbing mura than the dual domain FFS cell. Moreover, the FFS cells with negative LC are much more sensitive to the rubbing mura than the FFS cells with positive LC.

• Macromolecular Research
• /
• v.10 no.1
• /
• pp.44-48
• /
• 2002

The supermolecular structures of poly(ethylene terephthalate) (PET), poly(ethylene 2,6-naphthalate) (PEN), and their blend were investigated with optical microscopy and small angle light scattering. With increasing the crystallization temperature, incomplete spherulitic texture was developed for the PET samples. At a high crystallization temperature of 220 $^{\circ}C$, the light scattering pattern represented a random collection of uncorrelated lamellae. The general morphological appearances for the PEN samples were similar to that of the PET. A notable feature was that the spherulites of the PEN formed at 200 $^{\circ}C$ showed regular concentric bands arising from a regular twist in the radiating lamellae. The spherulitic morphology of the PET/PEN blend was largely influenced by the changes of the sequence distribution in polymer chains determined by the level of transesterifcation. The increased sequential irregularity in the polymer chains via transesterification caused a morphological transition from a regular folded crystallite to a tilted lamellar crystallite.