• Title/Summary/Keyword: Potential Problem

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Effect of Mating Delay and Mating Duration on Reproductive Performance of Antheraea mylitta

  • Rath, S. S.;Narain, Raj;Singh, M. K.;Suryanarayana, N.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.2
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    • pp.113-119
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    • 2007
  • Tropical tasar silkmoth Antheraea mylilta D. is an economically important insect. The wild nature and above all unsynchronized emergence of moths lead to impairment in reproductive activity. The mating in moths is low (64%-70%), leaving about 30-36% of potential females unused for seed (= egg) production. Delay in mating adversely affects the reproductive performance such as mating behaviour, fecundity and fertility. Females are more severely affected by mating delay than males. Therefore, a study was under taken to develop a method to overcome the problem so that the production of layings can be increased to meet the ever increasing demand. It was revealed from the study that out of 16 possible age combinations (from the age groups of day 0 to day 3), female and male of day 0 (4-8 hours old) excel in their reproductive performance than others (with 94.4% mating success, 284 fecundity and 91.5% hatching). Reproductive performance declined significantly even if one of the parents was older. When either of the mating pair was 1 day old, the mating declined by 28%; fecundity by 32.8%; and hatching by 40.8%. The insemination of eupyrene sperm was declined by 35.2% when both the parents are 1 day old. Mating duration of 8 hours resulted in insemination of $8.3{\times}10^5$ eupyrene sperms, which was declined by 31.6%, 48% and 55% upon lowering of mating duration to 6 hr, 4 hr and 2 hr were maintained respectively.

Graphene formation on 3C-SiC ultrathin film on Si substrates

  • Miyamoto, Yu;Handa, Hiroyuki;Fukidome, Hirokazu;Suemitsu, Maki
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.9-10
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    • 2010
  • Since the discovery of graphene by mechanical exfoliation from graphite[1], various fabrication methods are available today such as chemical exfoliation, epitaxial graphene on SiC substrates, etc. In view of industrialization, the mechanical exfoliation method may not be an option. Epitaxial graphene on SiC substrates, in this respect, is by far more practical because the method consists of conventional thermal treatments familiar to semiconductor industry. Still, the use of the SiC substrate itself, and hence the incompatibility with the Si technology, lessens the importance of this technology in its future industrialization. In this context, we have tackled the problem of forming graphene on Si substrates (GOS). Our strategy is to form an ultrathin (~80 nm) SiC layer on top of a Si substrate, and to graphitize the top SiC layers by a vacuum annealing. We have actually succeeded in forming the GOS structure [2,3,4]. Raman-scattering microscopy indicates presence of few-layer graphene (FLG) formed on our annealed SiC/Si heterostructure, with the G ($1580\;cm^{-1}$) and the G'($2700\;cm^{-1}$) bands, both related to ideal graphene, clearly observed. Presence of the D ($1350\;cm^{-1}$) band indicates presence of defects in our GOS films, whose elimination remains as a challenge in the future. To obtain qualified graphene films on Si substrate, formation of qualified SiC films is crucial in the first place, and is achieved by tuning the growth parameters into a process window[5]. With a potential for forming graphene films on large-scale Si wafers, GOS is a powerful candidate as a key technology in bringing graphene into silicon technology.

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Optimizing the Plasma Deposition Process Parameters of Antistiction Layers Using a DOE (Design of Experiment) (실험 계획법을 이용한 점착방지막용 플라즈마 증착 공정변수의 최적화 연구)

  • Cha Nam-Goo;Park Chang-Hwa;Cho Min-Soo;Park Jin-Goo;Jeong Jun-Ho;Lee Eung-Sug
    • Korean Journal of Materials Research
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    • v.15 no.11
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    • pp.705-710
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    • 2005
  • NIL (nanoimprint lithography) technique has demonstrated a high potential for wafer size definition of nanometer as well as micrometer size patterns. During the replication process by NIL, the stiction between the stamp and the polymer is one of major problems. This stiction problem is moi·e important in small sized patterns. An antistiction layer prevents this stiction ana insures a clean demolding process. In this paper, we were using a TCP (transfer coupled plasma) equipment and $C_4F_8$ as a precursor to make a Teflon-like antistiction layer. This antistiction layer was deposited on a 6 inch silicon wafer to have nanometer scale thicknesses. The thickness of deposited antistiction layer was measured by ellipsometry. To optimize the process factor such as table height (TH), substrate temperature (ST), working pressure (WP) and plasma power (PP), we were using a design of experimental (DOE) method. The table of full factorial arrays was set by the 4 factors and 2 levels. Using this table, experiments were organized to achieve 2 responses such as deposition rate and non-uniformity. It was investigated that the main effects and interaction effects between parameters. Deposition rate was in proportion to table height, working pressure and plasma power. Non-uniformity was in proportion to substrate temperature and working pressure. Using a response optimization, we were able to get the optimized deposition condition at desired deposition rate and an experimental deposition rate showed similar results.

A Study on Equitable Pricing Models for E-journals through an Analysis of the Current Pricing Systems (전자저널의 가격모형과 가격책정 현황에 관한 연구)

  • 신은자
    • Journal of the Korean Society for Library and Information Science
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    • v.35 no.2
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    • pp.151-170
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    • 2001
  • Pricing for e-journals has become more complex than before-certainly much more complex than print pricing has ever been. E-journals charge either a fiat fee based on print, user, library size, usage, and combination. A survey of publisher's pricing structure found that print based model is popular followed by user based model. The current pricing situation is far from equitable and can be improved if publishers can be coerced to change their pricing practices. This study focus on a number of possible pricing models that may supplement and/or possibly replace the current print based model. With the possibility that its pricing will eventually be based strictly according to usage, may lead to the most equitable pricing model as well as the most efficient use of society's resources. Libraries can alleviate the pricing problem by encouraging library organizations and university consortia to exploit their potential monopoly power into a bilateral monopoly situation.

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Scenarios for Effective Fire Fighting Operations during Tunnel Fires (도로터널 화재시 효과적인 소방활동전략 수립을 위한 시나리오 연구)

  • Kim, Hak kuen;Lee, Ji-hee
    • Fire Science and Engineering
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    • v.31 no.5
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    • pp.107-116
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    • 2017
  • Fires in tunnels are an international concern and fatal accidental fires in tunnels seem to occur on annual. They have the potential to become much worse int the future as more and longer tunnels are constructed and as traffic densities increase. This is a serious problem. The main purpose of this study is to develop operational procedures for fire brigades in road tunnel fires. This study discussed the past to see what can be learned from the incidents that have already done in tunnels. 73 cases of road tunnel fires domestic and outside of Korea were investigated and classified into 4 incident categories. Among them, 4 tunnel fires are highlighted, focusing on the activities of fire brigades and operation. Regarding the establishment of the strategies for fire fighting, 6 kinds of fire scenario curves have been deducted with regard to the relation between intervention time and heat release rate. It made the choice from the defensive or aggressive fire fighting activities depending on two criteria i.e. response limit and maximum response time. Road Tunnel Classification models can be useful when a fire brigade evaluates fire risk levels in the tunnels under its jurisdiction from the firefighting point of view and sets up preventive measures.

An HTML5 based AAC Board Making System (HTML5기반 보완·대체 의사소통 판 제작 및 활용 시스템)

  • Jang, Yujin;Hong, Ki-Hyung
    • KIISE Transactions on Computing Practices
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    • v.21 no.5
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    • pp.365-372
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    • 2015
  • Augmentative and Alternative Communication(AAC) is the widespread supporting plan to solve the communication problem of the people with communication disorder. AAC means various types of non-verbal communication methods that are used to augment or substitute the communications of using speech. With the increasing number of potential Korean AAC users, the demands for AAC are also increasing. In spite of the increasing demands, AAC is not being actively and practically used. In this paper, we implemented a web-based AAC board making system, where the board-makers (special educators and speech therapists) can create and share the customized boards to help the board-users (people with communication disorder). The web-based AAC board making system contributes to the application of AAC in many societies, such as hospitals, schools, companies, or anywhere the AAC intervention is needed.

Vaneomycin-Resistant Enteroeocci (VRE) Treatment Options (Vaneomycin-Resistant Enteroeocci (VRE) 약물치료방법)

  • Kim, Myo Kyoung
    • Korean Journal of Clinical Pharmacy
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    • v.9 no.1
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    • pp.1-14
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    • 1999
  • Vancomycin-resistant Enterococci (VRE) have recently emerged in Korean hospitals, as well as in those of other countries. VRE have been partially attributed to the overuse and misuse of vancomycin. The mecbanisms of VRE resistance are related to VanA, VanB, and VanC. Both VanA and VanB produce abnormal ligase enzymes to form D-ala-D-lactate termini in E. faecium and E. faecalis, instead of D-ala-D-ala termini. Meanwhile, Van C produces D-ser-D-ala termini in E. gallinarum and E. casseliflavus. These abnormal termini have a low affinity to vancomycin. As a result, VRE avoid the activity of vancomycin by these mechanisms. Unfortunately, there is no approved therapy for the treatment of VRE. Thus, available but uncommonly prescribed antibiotics (due to their toxicity or unproven efficacy) may become possible options. They include chloramphenicol, novobiocin, fosfomycin, and bacitracin. The combination therapy of available agents may also be the other options. They include high doses of a penicillin- or ampicillin-aminoglycoside combination, high doses of an ampicillin/sulbactam and aminoglyoosidcs combination, an ampicillin and vancomycin combination, and a ciprofloxacin, aminoglycosides, and rifampin combination. With respect to the near future, many types of investigational agents will most likely expand their treatment options for VRE. Teicoplanin, a glycopeptide, can be used for VanB- and VanC-related VRE. LY333328, a new generation of glycopeptide, is effective in treating VanA as well as VanB and VanC. RP59500 (quinupristin/dalfopristin), a streptogramin, is effective in treating vancomycin-resistant E. faecium. New generation quinolones (especially clinatloxacin) are potential options for the treatment of VRE, even though they cannot work as effectively against VRE as they can against Staphylococci. Both glycylcyclines (a new generation of tetracyclines) and ketolides (a new generation of macrolides) show good activity against Enterococci, regardless of vancomycin susceptibility. Oxazolidinones (i. e. eperezolid and 1inezolid) and everninomicins (i. e. SCH27899) are new groups of antibiotics, which also demonstrate good activity against VRE. It is imperative that clinical pharmacists take the responsibility of investigating new treatment options for VRE in order to combat this growing problem throughout the world.

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A Case of Pneumatosis Intestinalis in Peritoneal Dialysis Peritonitis (복막투석복막염 환자에서 발생한 창자벽공기증 1예)

  • Jung, Sun-Young;Na, Ji-Hun;Choi, Yun-Jung;Koh, Sung-Ae;Choi, Ku-Hyang;Park, Jong-Won;Do, Jun-Young;Yun, Kyeng-Woo
    • Journal of Yeungnam Medical Science
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    • v.26 no.1
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    • pp.49-55
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    • 2009
  • Peritonitis is a serious problem in patients undergoing peritoneal dialysis. Rarely pneumatosis intestinalis can occur as a complication of this infectious process. Pneumatosis intestinalis is a potential life threatening condition with a challenging management. The mortality of peritoneal dialysis patients with pneumalosis intestinalis secondary to mesenteric ischemia is almost 100%. We describe a rare case of pneumatosis intestinalis in a peritoneal dialysis patient who developed Staphylococcus aureus peritonitis which was initially treated with appropriate antibiotics. Since initial response to therapy was not achieved, an abdominal computerized tomography was done which revealed a pneumatosis intestinalis. A laparotomy was performed and small bowel necrosis was seen. A segmental resection with ileostomy, jejunostomy was done. Though surgical treatment was performed, the patient died in 2 weeks after admission. Pneumocystitis intestinalis in peritoneal dialysis peritonitis is a uncommon complication which requires prompt evaluation to rule out mesenteric ischemia as it carries a high mortality and its management will be surgical.

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A small molecule approach to degrade RAS with EGFR repression is a potential therapy for KRAS mutation-driven colorectal cancer resistance to cetuximab

  • Lee, Sang-Kyu;Cho, Yong-Hee;Cha, Pu-Hyeon;Yoon, Jeong-Soo;Ro, Eun Ji;Jeong, Woo-Jeong;Park, Jieun;Kim, Hyuntae;Kim, Tae Il;Min, Do Sik;Han, Gyoonhee;Choi, Kang-Yell
    • Experimental and Molecular Medicine
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    • v.50 no.11
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    • pp.12.1-12.12
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    • 2018
  • Drugs targeting the epidermal growth factor receptor (EGFR), such as cetuximab and panitumumab, have been prescribed for metastatic colorectal cancer (CRC), but patients harboring KRAS mutations are insensitive to them and do not have an alternative drug to overcome the problem. The levels of ${\beta}$-catenin, EGFR, and RAS, especially mutant KRAS, are increased in CRC patient tissues due to mutations of adenomatous polyposis coli (APC), which occur in 90% of human CRCs. The increases in these proteins by APC loss synergistically promote tumorigenesis. Therefore, we tested KYA1797K, a recently identified small molecule that degrades both ${\beta}$-catenin and Ras via $GSK3{\beta}$ activation, and its capability to suppress the cetuximab resistance of KRAS-mutated CRC cells. KYA1797K suppressed the growth of tumor xenografts induced by CRC cells as well as tumor organoids derived from CRC patients having both APC and KRAS mutations. Lowering the levels of both ${\beta}$-catenin and RAS as well as EGFR via targeting the $Wnt/{\beta}$-catenin pathway is a therapeutic strategy for controlling CRC and other types of cancer with aberrantly activated the $Wnt/{\beta}$-catenin and EGFR-RAS pathways, including those with resistance to EGFR-targeting drugs attributed to KRAS mutations.

Distributed Rainfall-Runoff Modeling Using GIS (GIS를 이용한 분산형 강우-유형 모형의 개발)

  • 김경숙;박종현;윤기준;이상호
    • Korean Journal of Remote Sensing
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    • v.11 no.2
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    • pp.1-16
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    • 1995
  • This study is conducted to eveluate the potential of a GIS to assist an application problem. GIS has been applied to rainfall-runoff modeling over Soyang area. Various rainfall-runoff models have been developed over the years. A distributed rainfall-runoff model is selected because it considers the topographic characteristics over the basin. GIS can handle the spatial data to enhance the modeling. GRASS-a public domain GIS S/W-is used for GIS tools. Digital database is generated, including soil map, vegetation map, digital elevation model, basin and subbasin map, and water stream. The inpu data for the model has been generated and manupulated using GIS. The database, model and GIS are integrated for on-line operation. The inflow hydrographs are tested for the flood of Sept., 1990. This shows the promising results even without the calibration.