• Title/Summary/Keyword: Medical products

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Development of Conductive Polycaprolactone (PCL)-resin based on Reduced Graphene Oxide(rGO)/Polypyrrole (Ppy) composite for 3D-printing application (3D 프린팅 응용을 위한 환원그래핀/폴리피롤 복합체 기반의 전도성 폴리카프로락톤 레진의 개발)

  • Jeong, Hyeon Taek;Jung, Hwa Yong;Cho, Young Kwang;Kim, Chang Hyeon;Kim, Yong Ryeol
    • Journal of the Korean Applied Science and Technology
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    • v.35 no.3
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    • pp.935-939
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    • 2018
  • 3D Printing technology is developing in various prototypes for medical treatment, food, fashion as well as machinery and equipment parts production. 3D printing technology is also able to fully be utilized to other industries in terms of developing its technology which has been reported in many field of areas. 3D printing technology is expected to be used in various applications related to $4^{th}$ industrial revolution such as finished products and parts even it is still carried out in the prototype model. In this study, we have investigated and developed conductive resin for 3d printing application based on reduced graphene oxide(rGO)/Polypyrrole(Ppy) composite and polycaprolactone(PCL) as a biodegradable polymer. The electrical properties and surface morphology of the conductive PCL resin based on therGO/Ppy composite were analyzed by 4point-probe and scanning electron microscope(SEM). The conductive PCL resin based on rGO/Ppy composite is expected to be applicable not only 3D printing, but also electronic materials in other industrial fields.

The Performance Evaluation and Analysis of Next Generation Wireless LAN with OFDM (OFDM을 적용한 차세대 무선 LAN의 성능 평가 및 분석)

  • Han, Kyung-Su;Youn, Hee-Sang
    • Journal of Advanced Navigation Technology
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    • v.6 no.1
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    • pp.37-43
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    • 2002
  • This paper describes the performance evaluation and analysis of Wireless Local Area Network (W-LAN) in the 5 GHz ISM-band in compliance with IEEE 802.11a. At present, most W-LAN products are based on 2.4 GHz band, but low speed (11Mbps) has the limitation to serve systems demanding high-speed data transmission. To solve this problem, it is necessary to design next generation W-LAN system with 54Mbps in the 5GHz. It is sure that implementation of next generation W-LAN will bring competitive advantages. In particular, it will support telecommunications for high-speed mobile environments as well as for fixed places such as a school zone, a lecture room, a hospital and other premises. A few simulation methods are applied to more accurate and reliable performance analysis of next generation W-LAN. To verify if continuous data service is supported for a high-speed mobile notebook, multi-path fading channels between wireless Access Point (AP) and wireless Network Interface Card (NIC) are modeled. In addition, low interference is analyzed via convolutional codes and Orthogonal Frequency-Division Multiplexing (OFDM). Also, to obtain reliable Bit Error Rate (BER), a single tap Least Mean Square (LMS) equalizer is applied. Given the above simulation, next generation W-LAN is an ideal solution for continuous data transmission in high-speed mobile environments.

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The Effects of Soy Milk Supplement on Isoflavone Concentration of Breast Milk, Plasma and Urine from Breast Feeding Woman (수유부에서 두유 보충이 모유, 혈액 및 뇨 중 Isoflavone 농도에 미치는 영향)

  • 이현주;장영은;이혜옥;김정숙;김승보;조여원
    • Journal of Nutrition and Health
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    • v.36 no.7
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    • pp.736-742
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    • 2003
  • Soybeans have been a major protein source for many centuries in Korea. Soybeans contain phytochemicals which are isoflavones, biochemically active component. Isoflavone is a kind of phytoestrogen, structurally and functionally similar to estrogen. It has been reported that the breast milk and blood of breast feeding mothers who consume soy products contain isoflavones. This study was conducted to investigate the effects of soy milk supplement on the isoflavones (daidzein, genistein) concentration of breast milk, plasma and urine from breast feeding woman. Seventeen healthy women who delivered at Kyung Hee Medical Center were recruited. For the first 2 weeks after delivery, seventeen women ingested 400 ml (isoflavone 43.2 mg) of soy milk on the given time starting from the day of giving birth. For the next 2 weeks, soy milk ingestion was withdrawn. Dietary intake and anthropometric data were checked and breast milk, blood, and 24 hr urine samples were collected on the day of giving birth, the 14th (the last day of the supplement phase) and 28th (the last day of the withdrawal phase) day, respectively. HPLC analysis was used to measure the concentration of isoflavones. Dietary intakes of the subjects were inadequate for the Korean RDA regardless of soy milk supplementation. Especially, intakes of vit A, calcium, and iron were very low. The Anthropometric data such as LBM, TBW, PIBW, BMI checked on the day of 14th decreased and maintained their levels by the 28th day. Daidzein concentration in breast milk was not affected by soy milk supplementation. However, genistein concentration decreased by the 28th day (14th day: 0.89 $\pm$ 0.10 $\mu$g/ml, 28th day : 0.48 $\pm$ 0.07 $\mu$g/ml) (p < 0.05). Plasma daidzein and genistein concentrations were not changed by the 14th day and decreased by the 28th day (14th day: 49.64 $\pm$ 3.30 ng/ml, 26.72 $\pm$ 2.90 ng/ml, 28th day: 38.30 $\pm$ 4.40 ng/ml, 6.51 $\pm$ 0.50 ng/ml, respectively) (p < 0.05). Twenty four hour urine concentrations of daidzein and genistein significantly increased by the 14th day and decreased by the 28th day (14th day: 5.80 :t 0.3 mg/d, 4.17 $\pm$ 0.2 mg/d, 28th day: 6.72 $\pm$ 0.4 mg/d, 5.09 $\pm$ 0.5 mg/d, respectively) (p < 0.001). The rate of urinary recovery of daidzein was greater than that of genistein. The results of this study indicate that the supplement of dietary soy milk to the lactating women elevates the contents of isoflavone in the breast milk.

Analysis of the Result and Merit of Computed Tomography Guided Percutaneous Needle Aspiration Biopsy of Focal Lung Lesion (CT 유도하 국소적 폐질환의 경피적 흡입생검의 장점과 결과 분석)

  • Chang, You-Song;Cho, Kil-Ho;Byun, Woo-Mock;Hwang, Mi-Soo;Park, Bok-Hwan
    • Journal of Yeungnam Medical Science
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    • v.10 no.1
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    • pp.127-134
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    • 1993
  • Percutaneous needle biopsy of pulmonary lesion with use of fluoroscopic guidance is well established as a diagnostic tool but limited by the small size and inaccessibility of certain lesions. However, percutaneous needle biopsy has been used increasingly in relation to advance and the safty of smaller biopsy needle and new imaging modalities such as ultrasound and CT. CT, because of its characteristics of high resolution, allows tissue sampling with considerable safety from area that heretofore could not be visualized under fluoroscopy. The authors summarized 44 pulmonary lesions that underwent CT-guided transthoracic biopsy with fine-needle over a 14 month period and analyzed the sensitivity of PTNB. CT-guided PTNB was done with 20 gauge or 22 gauge Westcott biopoy needle(Manan medical products, USA). A diagnosis was made in 27 of 44 cases(61%) including malignany in 19 of 24 cases and benignancy in 8 of 20 cases. The pulmonary mass lesions were located at the peripheral zone of the lung field in 33 cases and at the central zone in 11 cases. Complications were observed in 2 cases which were pneumothorax and hemoptysis each but specific therapy was not required. The sensitivity of PTNB by one session was 61%(27/44). The sensitivity of malignancy was 79%(19/24) and benignancy was 40%(8/20). These results suggest the usefulness of PTNB using fine needles be increased in earlier diagnosis and improved staging of pulmonary nodular lesions without significant complications.

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Purification and Properties of ${\gamma}-Cyclodextrinase$ from Bacillus megaterium(KFCC 11855) (Bacillus megaterium이 생산하는 ${\gamma}-cyclodextrinase$의 정제와 특성에 관한 연구)

  • Oh, Beyoung-Taek;Cha, Youn-Soo;Kim, Yong-Hwi
    • Applied Biological Chemistry
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    • v.38 no.1
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    • pp.42-48
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    • 1995
  • The experiment was carried out to purify and to investigate the properties of the cyclodextrinase produced from Bacillus megaterium KFCC 11855. The enzyme was partially purified with $(NH_4)_2SO_4$ and chromatography on DEAE-trisacryl, Ultrogel AcA 34, DEAE-trisacryl and Ultrogel HA. The optimum temperature and pH of the purified enzyme were $60^{\circ}C$ and 6.0, respectively. The enzyme was stable at the temperature of $45^{\circ}C$ below and at the pH range of $6.0{\sim}9.0$, respectively. The Km value for ${\gamma}-cyclodextrin$ was 0.903 mM. The enzyme activity was increased by $Mg^{2+}$ and $Mn^{2+}$, but decreased by $Hg^{2+}$ and $Cu^{2+}$. The enzyme degraded ${\gamma}-cyclodextrin$ but not ${\alpha}-cyclodextrin$. The degree of ${\beta}-CD$ degradation by the enzyme was very low. The decomposed products of ${\gamma}-cyclodextrin$ by the enzyme were mainly glucose, maltose and a little amount of maltotriose.

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Interaction of Forskolin with the Effect of Oxotremorine on $[^3H]-Acetylcholine$ Release in Rabbit Hippocampus (가토 해마에서 Acetylcholine 유리에 미치는 Oxotremorine 및 Forskolin의 영향)

  • Choi, Bong-Kyu;Kim, Chong-Suhn;Yoon, Young-Bok;Kook, Young-Johng
    • The Korean Journal of Pharmacology
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    • v.27 no.2
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    • pp.89-97
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    • 1991
  • As it has been reported that the depolarization-induced release of acetylcholine(ACh) is diminished by activation of presynaptic muscarinic autoreceptor in rabbit hippocampus and various lines of evidence indicate the involvement of adenylate cyclase system in ACh release, it was attempted to delineate the role of cAMP in the muscarinic autoreceptor-mediated control of ACh release. Slices and synaptosomal preparations from rabbit hippocampus were incubated with $[^3H]-choline$ and the release of the labelled products was evoked either by electrical stimulation or by $high-K^+$, and the influence of various agents on the evoked tritium release was investigated. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from $0.1\;to\;30\;{\mu}M$, increased the $[^3H]-ACh$ release in a dose-dependent manner and also dbcAMP increased the tritium outflow. The responses to oxotremorine, a specific muscarinic agonist, were characterized by decrement of ACh release in dose range of $0.1-30\;{\mu}M$, and the oxotremorine effects were inhibited either by forskolin or by atropine. Glibenclamide, a specific $K^+-channel$ inhibitor, in concentration of $1{\sim}10\;{\mu}M$, decreased the evoked ACh release slightly and inhibited the enhancing effect of evoked ACh-release of a large dose$(10\;{\mu}M)$ of forskolin. These results indicate that the cAMP might play a role in the muscarinic ACh receptor-mediated control of ACh rlease in the rabbit hippocampus and suggest that certain potassium currents may also be participated in the post-receptor mechanism of ACh release.

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Korean Customer Attitudes Towards SNS Shopping

  • Cho, Young-Sang;Heo, Jeong-Yoon;Youn, Myoung-Kil
    • Journal of Distribution Science
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    • v.10 no.8
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    • pp.7-14
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    • 2012
  • As a new format of retailing, social shopping on SNS has rapidly grown in recent. Although there is much literature associated with customer behaviours in the academic world, little attention has been paid to identifying the shopping patterns of SNS shoppers. This paper will, thus, identify how perceived value has an impact on the buying intention of SNS shoppers, after illustrating what kind of factor influences the formation process of perceived value in the Korean marketplace. Given that SNS shoppers are for the most part 20s as well as 30s, the authors handed out questionnaires to them. Furthermore, based on literature review results, the conceptualised research model was developed. Despite lack of literature, the authors developed five constructs like price reduction, quantity- and time-limited message, product ranges, information-sharing, and required number of shoppers. The researchers made a considerable effort to identify the relationship between research concepts and each variable, based on a few research analysis methods such as frequency analysis, the Varimax rotation technique used orthogonal rotation, Cronbach's Alpha, PCA (Principle Component Analysis), and the like. Amongst the 5 variables used to measure the degree of influences on the perceived value as a social shopping characteristic, it has been evident that price cut, required minimum shoppers, product variety, and information-sharing have a positive impact on the perceived value formation processes of SNS customers. Also, this research implies that SNS retailers can differentiate themselves from other retailers by differently using the above factors. From a practitioner's point of view, these factors should be strategically used to increase the social shopping opportunities of SNS users. It is, furthermore, evident that the perceived value formed by the above 4 factors have played an important role in the buying decision process of SNS customers. In a sense, whether customers are aware of higher price cut rates, information-sharing, required minimum shoppers, and product variety has a positive impact on making buying decisions. From a retailer's point of view, online shopping mall operators are able to use blog as well as twitter to improve the buying intention as a marketing tool of social network, because the business activities provided by social shopping retailers, like the rapid, accurate responses to customer requirements, the provision of a variety of information, and the communications between customers are closely related to buying intentions. There are a few research limitations to conduct this empirical research. It was not easy to review prior papers, due to its lack. In spite of the increasing number of SNS shoppers in Korea, little research attention has been paid to this kind of research topic by academicians, because buying products or services through SNS is in its infancy. With regard to research populations, it would be difficult to generalise the research findings in Korea, owing to unbalanced respondent distribution. Considering the above research limitations as well as the growth of social shopping, many authors should pay considerable attention to SNS-related issues in the future, and develop the more sophisticated criteria to measure the characteristics of SNS shoppers.

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COMPARISON OF BOND STRENGTH OF A FIBER POST CEMENTED WITH VARIOUS RESIN CEMENTS (다양한 레진시멘트로 합착한 섬유포스트의 결합강도 비교)

  • Lee, Hyun-A;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.33 no.6
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    • pp.499-506
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    • 2008
  • The purpose of this study was to compare the push-out strength of a fiber post cemented with various resin cements. Newly extracted 36 human mandibular premolars which had single root canal were selected and their crown portions were removed. The root canal was instrumented using $PROTAPER^{TM}$ system and obturated using continuous wave technique. In each root, a 9-mm deep post space was prepared. #2 translucent fiber post (DT Light post, Bisco Inc., Schaumburg, IL, U.S.A.) was cemented using injection technique with Uni-dose needle tip (Bisco) and six different resin cements. The tested resin cements were Duo-Link (Bisco Inc., Schaumburg, IL, U.S.A.), Variolink II (Ivoclar-Vivadent AG, Schann, Liechtenstein), Panavia F (Kuraray Medical Inc., Okayama, Japan), Multilink Automix (Ivoclar-Vivadent AG, Schann, Liechtenstein), RelyX Unicem (3M ESPE Dental Products, St. Paul, MN, U.S.A.), and Maxcem (Kerr Co., CA, U.S.A.). After storage in distilled water for 24 hours, each root was transversally sectioned into approximately 1-mm thick sections. This procedure resulted in 6 serial sections per root. Push-out test wasperformed using a universal testing machine (EZ Test, Shimadzu Co.) with a crosshead speed of 1 mm/min. The data were analyzed with one-way ANOVA and Tukey HSD (p=0.05). The push-out strength of the groups which cemented fiber post with Panavia F and Multilink Automix were lower than those of the other groups. But, there were no statistically significant difference among groups at a probability level of 0.05.

Utilization of Polyunsaturated Lipids in Red Muscled Fishes 2. Concentration, Refining, and Storage Stability of Polyunsaturated Lipids of Sardine Oil (적색육어류의 고도불포화지질의 이용에 관한 연구 2. 정어리유의 고도불포화지질의 농축${\cdot}$정제 및 저장 안정성)

  • LEE Kang-Ho;LEE Byeong-Ho;JEONG In-Hak;SUH Jae-Soo;CHOI Byeong-Dae;SONG Sung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.5
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    • pp.436-445
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    • 1986
  • As the second part of the studies on the utilization of polyunsaturated lipids in sardine oil as nutritional or medical supplement, the conditions of lipid extration and concentration, refining, and storage stability of EPA-condensed sardine oil were investigated. In extraction of lipids, solvent ratios of chloroform-methanol mixture(2:1 v/v) affected the final content of unsaturated lipid in extracted oil and recovery. Stepwise solvent fractionation method at various low temperatures was effective to concentrate polyenoic acids like EPA and DHA when acetone or acetone-methanol mixture, added in the ratio of 1:5 (v/v) was applied step by step to different temperatures at 0 to $-35^{\circ}C$. Addition of 1 to $5\%$ (v/v) of water to acetone was also benefit to raise EPA content but that resulted in reducing the yield of condensed oil from $65\%\;to\;28\%$. Concentration rate of polyenoic acids by solvent fractionation in lipid-actone solution (1:5, v/v) at 0 to $-30^{\circ}C$ seemed limited to $5{\sim}8\%$ in fatty acid composition depending on the initial content of those polyenoic acids in the sardine oil. During the extraction, concentration, and alkaline treatment, oxidation was rapidly induced but oxidation products could be thoroughly removed on the process of deceleration and peroxide elimination. To stabilize the reactive polyenoic acid condensed oil during the storage, stuffing nitrogen gas was essential to expel dissolved oxygen in oil or to seal the oil from open air, and the addition of antioxidative agents as BHA and tocopherols were greatly helpful to extend the storage life.

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Blood Glucose Measurement and Management System using a Smart Band and an App (스마트 밴드와 앱을 이용한 혈당 측정 및 관리 시스템)

  • Jeon, Yeongjun;Park, Yujin;Kang, SoonJu
    • KIISE Transactions on Computing Practices
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    • v.23 no.6
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    • pp.371-378
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    • 2017
  • In modern society, awareness of diabetes is growing with an increase in the elderly population and an increase in the incidence of diabetes. In particular, diabetic patients can suddenly develop hypoglycemic shock; therefore, it is important to measure blood glucose periodically. However, self-monitoring blood glucose meters are difficult to carry and it is difficult to manage the value. To solve these problems, the blood glucose measurement system has been developed as a sensor attached to the body or as one of the functions of smart devices, but it has not been commercialized. In this paper, we propose a smart band with a blood glucose measurement function. If a user enters a schedule to measure blood glucose level, such as before/after meals, in the app, he/she can receive a measurement alarm from the band. The user can measure the blood glucose level at any time using the band, and the measured value is transmitted and managed by the app including behavior history such as before/after meals and the time. This will help the user to manage, diagnose and prevent health problems. The system has been tested using two medical device-certified products, and each blood glucose measurement value has been confirmed to be more accurate.