• The Journal of the Acoustical Society of Korea
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• v.31 no.3
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• pp.151-160
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• 2012

In medical ultrasound imaging, elasticity imaging helps to diagnose tumors such as cancer. This paper is concerned with the application of acoustic radiation force to soft tissue of interest to implement elasticity imaging. In order to reduce the data acquisition time, instead of relying on transmit focusing, a plane wave of burst type is transmitted to apply the acoustic radiation force simultaneously to an entire imaging region to be observed. A homogeneous phantom experiment confirms that increasing the transmit excitation duration instead of employing transmit focusing generates a high enough acoustic radiation force to obtain elasticity images. It is found, however, that a different displacement versus time characteristic is observed unlike the case of using a conventional focused acoustic radiation force. Experimental results obtained through the use of an ultrasound phantom and a bovine liver show that lesions can be correctly differentiated.

• Archives of Plastic Surgery
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• v.42 no.4
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• pp.446-452
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• 2015

Background Various techniques are used for performing breast reduction. Wise-pattern and vertical scar techniques are the most commonly employed approaches. However, a vertical scar in the mid-lower breast is prominent and aesthetically less pleasant. In contrast, a semicircular horizontal approach does not leave a vertical scar in the mid breast and transverse scars can be hidden in the inframammary fold. In this paper, we describe the experiences and results of semicircular horizontal breast reductions performed by a single surgeon. Methods Between September 1996 and October 2013, our senior author used this technique in 38 cases in the US and at our institution. We used a superiorly based semicircular incision, where the upper skin paddle was pulled down to the inframammary fold with the nipple-areola complex pulled through the keyhole. Results The average total reduction per breast was 584 g, ranging from 286 to 794 g. The inferior longitudinal pedicle was used in all the cases. The average reduction of the distance from the sternal notch to the nipple was 13 cm (range, 11-15 cm). The mean decrease in the bra cup size was 1.7 cup sizes (range, a decrease of 1 to 3). We obtained very satisfactory results with a less noticeable scar, no complication such as necrosis of the nipple or the skin flap, wound infection, aseptic necrosis of the breast tissue, or wound dehiscence. One patient had a small hematoma that resolved spontaneously. Conclusions This technique is straightforward and easy to learn, and offers a safe, effective, and predictable way for treating mammary hypertrophy.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.317-328
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• 2017

This paper presents design and specific absorption rate analysis of a 2.4 GHz wearable patch antenna on a conventional and electromagnetic bandgap (EBG) ground planes, under normal and bent conditions. Wearable materials are used in the design of the antenna and EBG surfaces. A woven fabric (Zelt) is used as a conductive material and a 3 mm thicker Wash Cotton is used as a substrate. The dielectric constant and tangent loss of the substrate are 1.51 and 0.02 respectively. The volume of the proposed antenna is $113{\times}96.4{\times}3mm^3$. The metamaterial surface is used as a high impedance surface which shields the body from the hazards of electromagnetic radiations to reduce the Specific Absorption Rate (SAR). For on-body analysis a three layer model (containing skin, fats and muscles) of human arm is used. Antenna employing the EBG ground plane gives safe value of SAR (i.e. 1.77W/kg<2W/kg), when worn on human arm. This value is obtained using the safe limit of 2 W/kg, averaged over 10g of tissue, specified by the International Commission of Non Ionization Radiation Protection (ICNIRP). The SAR is reduced by 83.82 % as compare to the conventional antenna (8.16 W/kg>2W/kg). The efficiency of the EBG based antenna is improved from 52 to 74 %, relative to the conventional counterpart. The proposed antenna can be used in wearable electronics and smart clothing.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.1
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• pp.70-84
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• 1996

This paper reports marginal bone loss around osseointegrated implants after loading in partially edentulous patients in dental hospital, Yonsei University. Two types of implants($Br{\aa}nemark^{TM},\;IMZ^{TM}$) were used. Through the digital measurement on periapical radiograph around 37 implants in human subjects, marginal bone loss was observed for 24 months after delivery of prostheses. The results were as follows; 1. According to experimental periods marginal bone loss in total implants was 1.775 mm at 12 months, 1.921 mm at 24 months after delivery of prostheses(p<0.05). 2. Marginal bone loss in the $Br{\aa}nemark$ implants was 1.831 mm at 12 months, 1.833 mm at 24 months after delivery of prostheses(p<0.05). 3. Marginal bone loss in the IMZ implants was 1.578 mm at 12 months, 2.907 mm at 23 months after delivery of prostheses(p<0.05). 4. During the first year after loading, the IMZ implants showed less marginal bone loss than the $Br{\aa}nemark$ implants but, during the next the $Br{\aa}nemark$ implants showed less than the IMZ implants(p>0.05). These results indicate that marginal bone loss around osseointegrated implants occurs within the first 12 months after delivery of prostheses and stabilizes thereafter, so it is necessary to be careful of using dental implants for the first year after delivery of prostheses.

• The korean journal of orthodontics
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• v.31 no.5 s.88
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• pp.499-504
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• 2001

Transverse skeletal deficiency is a common clincal problem associated with narrow basal and dentoalveolar bone. The clinical characteristics of transverse deficiency presents with anterior crowding and posterior buccal crossbite. Orthodontic expansion, using lip bumper and functional devices, was recommanded for younger ages. However, expansion of lower anterior area in older Patients is unstable and tends to relapse toward the original dimension. Distraction osteogenesis is a unique form of clincal tissue engineering and biologic process of new bone formation between bone segments that are gradually separately by incremental traction. Distraction osteogenesis was considered that great potential for correcting transverse mandibular deficiencies. In this Paper, a case of treated transverse deficiency patients with distraction osteogenesis using tooth-borne and tooth & bone-borne distractor is presented.

• Bioinformatics and Biosystems
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• v.1 no.1
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• pp.67-72
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• 2006

The aim of this paper is to discuss the effect of missing values in detecting differentially expressed genes in a cDNA microarray experiment in the context of a one sample problem. We conducted a cDNA micro array experiment to detect differentially expressed genes for the metastasis of colorectal cancer based on twenty patients who underwent liver resection due to liver metastasis from colorectal cancer. Total RNAs from metastatic liver tumor and adjacent normal liver tissue from a single patient were labeled with cy5 and cy3, respectively, and competitively hybridized to a cDNA microarray with 7775 human genes. We used $M=log_2(R/G)$ for the signal evaluation, where Rand G denoted the fluorescent intensities of Cy5 and Cy3 dyes, respectively. The statistical problem comprises a one sample test of testing E(M)=0 for each gene and involves multiple tests. The twenty cDNA microarray data would comprise a matrix of dimension 7775 by 20, if there were no missing values. However, missing values occur for various reasons. For each gene, the no missing proportion (NMP) was defined to be the proportion of non-missing values out of twenty. In detecting differentially expressed (DE) genes, we used the genes whose NMP is greater than or equal to 0.4 and then sequentially increased NMP by 0.1 for investigating its effect on the detection of DE genes. For each fixed NMP, we imputed the missing values with K-nearest neighbor method (K=10) and applied the nonparametric t-test of Dudoit et al. (2002), SAM by Tusher et al. (2001) and empirical Bayes procedure by $L\ddot{o}nnstedt$ and Speed (2002) to find out the effect of missing values in the final outcome. These three procedures yielded substantially agreeable result in detecting DE genes. Of these three procedures we used SAM for exploring the acceptable NMP level. The result showed that the optimum no missing proportion (NMP) found in this data set turned out to be 80%. It is more desirable to find the optimum level of NMP for each data set by applying the method described in this note, when the plot of (NMP, Number of overlapping genes) shows a turning point.

• Korean Journal of Pharmacognosy
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• v.41 no.2
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• pp.73-88
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• 2010

Traditionally, the root of Lithospermum erythrorhizon Sieb. et Zucc(L.E) has been used as efficacious therapy for inflammation, burns, frostbite and skin ailments (e.g eczema and psoriasis). It contains isohexenylnaphthoquinone derivatives (shikonin and its esters) and furylhydroquinones (shikonofurans) in lipophilic fractions and caffeic acid oligomers (rosmarinic acid, lithospermic acid B) in polar fractions. Recently, new preparative isolation and analysis procedures of shikonin along with its oligomers from the extract of L. erythrorhizon by the combination of high-speed counter-current chromatography with high-performance liquid chromatography-diode array detection have also been introduced. Although there have been many reports on the wound healing, antiinflammatory, and anticancer effects, the research on the effects of anti-atopic dermatitis of the root of L. erythrorhizon were relatively scarce. However, in recent years, new information gathered from research efforts, on the anti-atopic dermatitis properties of the extract or constituents of L. erythrorhizon has been accumulated. In this paper, the findings and advance on the in vitro and in vivo activities of L. erythrorhizon and its constituents especially focused on antiinflammatory and anti-atopic dermatitis effects are summarized. The phytochemical constituents of L. erythrorhizon or its tissue cultures are also presented. Although there are few to verify or refute its activity in human, one result of clinical study of the extract of L. erythrorhizon on the atopic dermatitis patients was introduced to assess the possibility of its clinical use. The reported mechanisms of action and in vivo pharmacological studies in different animal models for the various types of extracts or constituents of L. erythrorhizon are supportive of its therapeutic potential or dietary supplement, however, more evidence from clinically relevant models, as well as systemic studies on the active constituents or the various types of standardized extracts at the cellular and molecular level, are required.

• Journal of Chest Surgery
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• v.36 no.10
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• pp.754-758
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• 2003

Backgroun: Thymectomy was known as an effective treatment modality of myasthenia gravis. In this paper, we analyzed the result of thymectomy and the factors affecting the postoperative system improvement. Material and Method: We analyzed the medical records of 50 patients who received the thymectomy for myasthenia gravis from January 1997 to December 2001. Result: 39 patients showed sympton improvement. The effect of thymectomy as a treatment is 78%. There was no statistically significant correlation between postoperative improvement and Sex, Age, the Weight of thymic tissue, preoperative symptom duration, and preoperative mestinon dosage. However, the thymic pathology and low grade preoperative symptoms were affecting the postoperative prognosis. Conclusion: Thymic hyperplasia showed good prognosis compared to thymoma. Low grade preoperative symptoms (Group I or IIA) also showed good prognosis. So, early thymectomy is recommendable for the good treatment results of myasthenia gravis.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.7-19
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• 1988

The object of this paper was to investigate the histopatological changes on dog's pulp under cavitation by irradiation of the $CO_2$ laser. The subjects were derived from four dogs, and irradiated 113.23 J/$mm^2$, 283.09 J/$mm^2$, 566.08 J/$mm^2$ in Group I, II, and III respectively. The dogs were sacrificed immediately, 24 hour, 72 hour and 1 week after $CO_2$ laser treatment. For light microscopic examination, routine H-E and PAS stains were employed. For electron microscopic observation, the teeth were fixed in 1% paraformaldehyde and 1% glutaraldehyde, decalcified teeth in 10% EDTA were stained by uranyl acetate and lead citrate. The observation was made with a Hitachi H-500 model electron microscope. The following results were obtained in this study: 1. At the early stage of the experimental sub-groups-immediately, 24 hour, 72 hour samples of Group I, II and III-coagulation necrosis and hyperemia were observed in odontoblastic and subodontoblastic pulpal layer. 2. At the 1 week sub-group of Group I, II, regenerative hyperplasia of the odontoblasts without coagulation necrosis were revealed, in addition to thickened predentin. On he other hand coagulation necrosis and atrophic change accompanying with hyperplasia were found at the 1 week sub-group of Group III. 3. Ultrastructurally, the odontoblasts appeared nuclear degeneration, vacuolar change of cytoplasmic organelles and rupture of plasma membrane at the early stage of the experimental period of all groups. 4. Under spectrohelioscopic examination, regenerative odontobalsts were seen at the 1 week specimens of Group I, II and III. 5. The pulpal response occured at 113-566 J/$mm^2$. The pathologic change of pulp tissue occured at the early experimental period but regeneration of odontoblasts could be seen after 1 week.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.99-117
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• 1991

The purpose of this study is to evaluate the effects of dentin bonding agents on the fibroblasts cultivated from human pulp tissue. The fibroblasts were cultured in DMEM/10%FBS medium. Whatman filter paper discs (6mm diameter) soaked with $2{\mu}l$ of dentin bonding agents were placed on a millipore filter (pore size $0.22{\mu}m$) contained in a 50mm Petri dish, and then, exposed for 10 minutes, 30 minutes, 1 hour, 6 hours, 12 hours, 24 hours, 4 days and 7 days in $37.^{\circ}C$, 5% $CO_2$ incubator. The results of the experiments were analyzed by counting the cells and measuring the protein contents at 1 day, 4 days and 7 days. The results of this study were as follows: l. CLEARFIL NEW BOND, LITE-FIL BOND, GLUMA 3 Primer and GLUMA 4 Sealer showed cytotoxicity compared to the control group in the cell counts and the protein contents. 2. GLUMA 4 Sealer showed the least cytotoxicity among the three dentin bonding agents. 3. The results of the cell count were simialr to the results of protein content measurement. 4. LITE-FIL BOND exhibited marked cytotoxicity during 1 day, but, the cytotoxicity was slightly reduced after 4 and 7 days. 5. In GLUMA 3 Primer group, it was not possible to count the cell numbers and measure the protein contents, but the degeneration of cells was observed under the inverted phase-contrast microscope.