• Title/Summary/Keyword: center loss

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An Experimental Guide to Predictable Fuel Cell Operations by Controlling External Gas Supply (외부 유입 가스 조절을 통한 연료전지 구동 성능 안정화)

  • Jang, Hansaem;Park, Youngeun;Lee, Jaeyoung
    • Applied Chemistry for Engineering
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    • v.29 no.5
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    • pp.626-629
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    • 2018
  • Fuel cell is one of the promising electrochemical technologies enabling power production with various fuel sources such as hydrogen, hydrocarbon and even solid carbon. However, its long-term performance is often unstable and unpredictable. In this work, we observed that gasification-driven hydrocarbons were the culprit of unpredictability. Therefore, we controlled the presence of hydrocarbons with the help of external gas supply, i.e. argon and carbon dioxide, and suggested the optimal amount of carbon dioxide required for predictable fuel cell operations. Our optimization strategy was based upon the following observations; carbon dioxide can work as both an inert gas and a fuel precursor, depending on its amount present in the reactor. When deficient, the carbon dioxide cannot fully promote the reverse Boudouard reaction that produces carbon monoxide fuel. When overly present, the carbon dioxide works as an inert gas that causes fuel loss. In addition, the excessive carbon monoxide may result in coking on the catalyst surface, leading to the decrease in the power performance.

QoS of MPEG-2 Video under Cell Loss Condition (셀손실에 따른 MPEG-2 비디오의 서비스 품질)

  • Han, Jong-Seok;Choi, Jae-Hyoung;Kim, Jee-Joong
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.8
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    • pp.30-38
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    • 1999
  • On providing MPEG-2 video service through the ATM network, it is necessary for network provider to have the ATM QoS objectives in order to guarantee quality of service required by end users at the application layer. In this paper, the degradation of QoS caused by cell losses at application layer is assessed quantitatively by GIQ model considering AAL layer and is evaluated qualitatively by MOS from the viewpoint of the end users in order to analyze the relation between CLR and QoS of MPEG-2 video. From the simulation and empirical results, we know that CLR and $GIQ_{mean}$ for guaranteeing QoS of MOS grade 5(Excellent) are $CLR{\le}4{\times}10^7$ & $GIQ_{mean}{\ge}99.4%$ and those for guaranteeing QoS of MOS grade 4(Good) are $CLR{\le}2{\times}10^6$ & $GIQ_{mean}{\ge}99.705%$.

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Effectiveness of a 5-year Community Oral Health Program for the Elderly in Korea

  • Song, Eun-Joo;Hwang, Soo-Jeong
    • Journal of dental hygiene science
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    • v.17 no.3
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    • pp.202-208
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    • 2017
  • Korea has been running the community oral health program for the elderly, including topical fluoride application and scaling. The aim of this study was to compare the subjective and objective oral health status of 345 participants according to the number of participants in the program and of 37 participants before and after the 5-year program. The survey consisted of an interview questionnaire and oral examinations. Analysis of variance was used to compare the variables of the 345 participants according to the numbers of participants. Paired t-test was used to compare the oral health statuses before and after the 5-year program in 37 subjects. There was no difference in subjective oral health status according to the number of participants in the oral health program in the elderly, including subjective health status, subjective oral health status, satisfaction with oral health, concern about oral health, need of dental treatment, oral pain, tooth sensitivity, subjective periodontal health, and subjective symptoms of periodontitis. The community periodontal index (CPI) of the 1 time participants was significantly higher than that of 3 times, 4 times or 5 times participants in the upper center, lower left, lower center, and lower right areas. There was a significant improvement in CPI from $2.59{\pm}1.14$ to $1.41{\pm}1.54$ (p<0.001) and positive oral behavioral change (daily tooth brushing frequency from $2.27{\pm}0.73$ to $2.54{\pm}0.90$) before and 5 years after the program. However, the program did not prevent tooth loss as the numbers of the remaining teeth significantly reduced from $23.77{\pm}1.84$ to $21.95{\pm}2.03$ over 5 years. We showed that running the community oral health program for the elderly for more than three years might have positive effects on the periodontal health of participants.

Epidemiologic Analysis of Burns in Military Hospital

  • Choi, Jangkyu;Park, Sejin;Kim, Hyun Chul
    • Journal of Trauma and Injury
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    • v.30 no.4
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    • pp.145-157
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    • 2017
  • Purpose: We accessed epidemioloy of 908 acute burns (7 years) in the military, of injuries and propose proper educational programs to suit community. Methods: We surveyed burn demographics, circumstances of injuries, size, result of treatment. Results: The mean age was 20.6 years. The flame burns (FB) (325, 35.8%) were most common, followed scald (SB) (305, 33.6%), contact (CB) (219, 24.1%), electric (EB) (45, 5.0%) and chemical burns (ChB) (14, 1.5%). The more occurred during winter (29.7%). SB had mean 3.9% total body surface area (TBSA). The 251 (82.3%) had superficial burns by spillage of hot water/food on lower limbs (45.6%), feet (33.8%) in summer (34.8%), treated with simple dressing (92.8%). Morbidity rate was 5.6%; post traumatic stress disease (PTSD) (0.7%). FB had large wound (9.3% TBSA). The 209 (64.3%) had superficial burns by ignition to flammable oils (31.7%) and bomb powders (29.2%) on head/neck (60.3%), hands (58.6%) in summer (31.7%), autumn (30.2%). They underwent simple dressing (83.4%) and skin graft (16.0%). Morbidity rate was 18.8%; PTSD (10.5%), inhalation injuries (4.0%), corneal injury (3.7%), amputations (0.9%), and mortality rate (1.2%). CB had small (1.1% TBSA), deep burns (78.5%) by hotpack (80.4%) on lower limbs (80.4%). The more (59.8%) underwent skin graft. EB had 6.8% TBSA. The 29 (64.4%) had superficial burns by touching to high tension cable (71.1%) on hand (71.1%), upper limbs (24.4%) in autumn (46.8%). They underwent simple dressing (71.1%) and skin graft (24.4%). They showed high morbidity rate (40.0%); loss of consciousness (13.3%), nerve injuries (11.1%), neuropathy (8.9%), amputations (2.2%), and mortality rate (2.2%). Conclusions: The cook should wear apron over the boots during work. The lighter or smoking should be strictly prohibited during work with flammable liquids or bomb powders. Don't directly apply hotpack to skin for a long time. Use insulating glove during electric work. Keep to the basic can prevent severe injury and proper education is important.

Implant supported fixed prosthesis for complete edentulous maxilla with severe alveolar ridge resorption: A case report (치조골 흡수가 심한 상악 완전 무치악 환자에서 임플란트 고정성 보철물을 이용한 수복 증례)

  • Choi, Yoon-Ji;Lee, Ji-Hyoun;Jhin, Min-Ju
    • The Journal of Korean Academy of Prosthodontics
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    • v.54 no.2
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    • pp.152-159
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    • 2016
  • Implant fixed prosthesis for the complete edentulous maxilla provides significant benefits in the aspects of functions and esthetics compared with the conventional denture. Implant supported fixed prosthesis are totally supported by implant, and thus stabilizes the prosthesis to the maximum degree as possible. Also, the improved retention and stability of fixed prosthesis enhance patients' psychological and psychosocial health. This clinical presentation describes a maxillary full arch implant-supported fixed prosthesis in complete maxillary edentulous patient who showed vertical and horizontal alveolar bone resorption in the anterior ridge. To rehabilitate the esthetics and proper lip support, the zirconia framework was fabricated and the pink porcelain was veneered to reproduce the natural gingival tissue. After 9 months of follow up, the restorations were maintained without complications and the patient was satisfied with the restoration both functionally and esthetically.

Replication of the Association between Copy Number Variation on 8p23.1 and Autism by Using ASD-specific BAC Array

  • Woo, Jung-Hoon;Yang, Song-Ju;Yim, Seon-Hee;Hu, Hae-Jin;Shin, Myung-Ju;Oh, Eun-Hee;Kang, Hyun-Woong;Park, Seon-Yang;Chung, Yeun-Jun
    • Genomics & Informatics
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    • v.8 no.1
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    • pp.19-27
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    • 2010
  • To discover genetic markers for autism spectrum disorder (ASD), we previously applied genome-wide BAC array comparative genomic hybridization (array-CGH) to 28 autistic patients and 62 normal controls in Korean population, and identified that chromosomal losses on 8p23.1 and on 17p11.2 are significantly associated with autism. In this study, we developed an 8.5K ASD-specific BAC array covering 27 previously reported ASD-associated CNV loci including ours and examined whether the associations would be replicated in 8 ASD patient cell lines of four different ethnic groups and 10 Korean normal controls. As a result, a CNV-loss on 8p23.1 was found to be significantly more frequent in patients regardless of ethnicity (p<0.0001). This CNV region contains two coding genes, DEFA1 and DEFA3, which are members of DEFENSIN gene family. Two other CNVs on 17p11.2 and Xp22.31 were also distributed differently between ASDs and controls, but not significant (p=0.069 and 0.092, respectively). All the other loci did not show significant association. When these evidences are considered, the association between ASD and CNV of DEFENSIN gene seems worthy of further exploration to elucidate the pathogenesis of ASD. Validation studies with a larger sample size will be required to verify its biological implication.

Can the Serum Level of Myostatin be Considered as an Informative Factor for Cachexia Prevention in Patients with Medullary Thyroid Cancer?

  • Hedayati, Mehdi;Nozhat, Zahra;Hannani, Masoomeh
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.119-123
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    • 2016
  • Thyroid cancer, the most common endocrine neoplasia, consists of four main types of carcinomas: papillary, follicular, and anaplastic, all with thyroid follicular origin, and medullary thyroid cancer (MTC) related to para-follicular cells. Cronic diseases such as diverse cancers may be associated with cachexia, especially at advanced stage. Cancer-induced cachexia is associated with diminished quality of life, functional performance, reduced response to antitumor therapy, and increased morbidity and mortality. Myostatin (Mst) is one of the outstanding molecules in the skeletal muscle loss process in cancer and it may be released by both skeletal muscle and cachexia-inducing tumors. Recently changes in serum levels of Mst have been identified as an important factor of cancer-induced cachexia. The goal of this study was to assessserum Mst levels in MTC patients. In this descriptive and case-control study, 90 participants were selected, comprising 45 MTC patients (20 males, $29{\pm}13.9years$, 25 females, $29{\pm}14.5years$) and 45 control individuals (25 males, $23.1{\pm}11.6years$, 20 females, $31.5{\pm}14.4years$). Serum Mst was determined using an ELISA kit and body mass index (BMI) was calculated by weight and height measurements. The Kolmogorov Simonov test showed a normal distribution for log transformed Mst serum levels in both case and control groups. Geometric means were 5.9 and 8.2 ng/ml respectively, and a significant difference was found according to the independent t-test results (P<0.01). There was also a significant difference mean of Mst between females in control and MTC groups, but not for the males. Pearson correlation test showed no correlation between age and BMI with Mst serum levels. The findings of this study support the hypothesis that Mst serum levels may have a potential ability for early diagnosis of cachexia in MTC patients, especially in females.

Characterization of two plasma membrane protein 3 genes (PutPMP3) from the alkali grass, Puccinellia tenuiflora, and functional comparison of the rice homologues, OsLti6a/b from rice

  • Chang-Qing, Zhang;Shunsaku, Nishiuchi;Shenkui, Liu;Tetsuo, Takano
    • BMB Reports
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    • v.41 no.6
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    • pp.448-454
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    • 2008
  • Two full-length cDNAs, PutPMP3-1 and PutPMP3-2, encoding PMP3 family proteins were isolated from Puccinellia tenuiflora, a monocotyledonous halophyte. Expression of both genes was induced by low temperature, salt stress, dehydration, ABA, and $NaHCO_3$. Transcripts of PutPMP3-2 were more strongly induced by these stresses relative to those of PutPMP3-1, particularly under low temperature and dehydration conditions. Expression of PutPMP3-1 and PutPMP3-2 in yeast mutants lacking the PMP3 gene can functionally complement the membrane hyper-polarization and salt sensitivity phenotypes resulting from PMP3 deletion. To compare the functions of PutPMP3-1 and PutPMP3-2, the orthologous genes in rice (OsLti6a and OsLti6b) were isolated. Both OsLti6a and OsLti6b could functionally complement the loss of PMP3 in yeast. PutPMP3-2 and OsLti6a were more effective in reversing membrane hyperpolarization than PutPMP3-1 and OsLti6b. However, the four yeast transformants each showed similar levels of salt tolerance. These results imply that these PMP3 family members don't function identically under different stress tolerance conditions.

Oxygen Consumption and Blood Physiology of Olive Flounder Paralichthys olivaceus Subjected to Salinity Changes (염분 변화에 따른 넙치(Paralichthys olivaceus)의 산소 소비율과 혈액 성상)

  • Oh, Sung-Yong;Jeong, Yu Kyung;Lee, Geun Su;Kang, Pil Jun;Park, Hye Mi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.4
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    • pp.620-627
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    • 2020
  • Oxygen consumption and blood physiology of olive flounder Paralichthys olivaceus (mean body weight 106.6±6.8 g, mean±SD) was investigated at salinities of 34.0 (control), 33.7, 33.3, 32.6, 31.3, 28.6, 23.1, 12.2 and 0.0 psu at 20.0℃, respectively. Stepwise salinity changes (34.0→33.7→33.3→32.6→31.3→28.6→23.1→12.2→0.0 psu) with an interval of 24 h for each salinity induced a significant (P<0.05) increase of oxygen consumption rate (OCR) in fish exposed from 31.3 to 0.0 psu compared to that of control fish. The maximum OCR was found in fish exposed to 23.1 psu, which was accompanied by 36.2% higher energy consumption than the control fish. Fish exposed to each salinity for 24 h induced a significant decrease of blood plasma Na+ in 0.0 psu and Cl- in 12.2 and 0.0 psu (P<0.05), and increase of plasma glutamic oxaloacetic transaminase (GOT) in 0.0 psu compared to the control fish (P<0.05). The results of this experiment show that P. olivaceus exposed to concentrations below 31.3 psu requires more energy costs to adapt to salinity changes than 34.0 psu under our experimental conditions.

PERFORATION OF THE TEMPOROMANDIBULAR JOINT MENISCUS: DIAGNOSED BY MAGNETIC RESONANCE IMAGING (MAGNETIC RESONANCE IMAGING을 이용한 악관절 원판 천공 진단)

  • Kim, Houng-Gon;Dolan, Eward;Vogler, James B.;Nokes, Steven R.
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.11 no.2
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    • pp.11-18
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    • 1989
  • Advancement of surgical techniques has made it necessary to accurately diagnose internal derangements. Arthrography and computerized tomography have been used to diagnose the majority of temporomandibular joint disorders, however, these methods have had their disadvantages. Magnetic resonance imaging utilizing surface coils has greatly improved the ability to diagnose meniscus abnormalities without using intrarticular injections or ionizing radiation. Ninety-two patients (184 joints) were evaluated by means of magnetic resonance imaging(MRI). Thirty-one patients (39 joints) were diagnosed as having meniscus perforation. Retrospective review of fifteen patients (20 joints) with a perforated meniscus diagnosed by magnetic resonance imaging pre-operatively demonstrated a sixty-five percent correlation between the radiographic diagnosis and the surgical findings.

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