• 제목/요약/키워드: subtractive

검색결과 289건 처리시간 0.04초

Performance Evaluation of Multi-User Detectors Employing Subtractive Interference Cancellation Schemes for a DS-CDMA System (감산형 간섭제거기법을 적용한 DS-CDMA 다중사용자 검파기의 성능분석)

  • Seo, Jung-Wook;Kim, Young-Chul;Oh, Chang-Heon;Ko, Bong-Jin;Cho, Sung-Joon
    • Journal of Advanced Navigation Technology
    • /
    • 제6권1호
    • /
    • pp.17-26
    • /
    • 2002
  • In this paper, we have analyzed the BER (Bit Error Rate) performance of multi-user detectors employing SIC(Successive Interference Cancellation) and PIC (Parallel Interference Cancellation) which are the representative schemes in the subtractive interference cancellation. We have considered the MUD structure employing HIC (Hybrid Interference Cancellation) which combines SIC with PIC scheme, and then analyzed the BER performance. We have evaluated the BER performance of SIC and HIC schemes which execute the soft decision to generate the tentative data bit for the purpose of the interference cancellation in MAI and noise environments. Through the numerical analysis and computer simulation, it is shown that HIC can remove the effect of MAI more efficiently than the others, that improve the BER performance and increase the capacity of DS-CDMA systems regardless of the power control conditions. The reason is that the SIC scheme in front of HIC can solve the near-far problem caused by the imperfect power control and PIC scheme in the rear of it can improve the performance much more.

  • PDF

Detection of Differentially Expressed Genes in Glioblastoma by Suppression Subtractive Hybridization

  • Yu, Na-Mi;Ahn, Jung-Yong;Choi, Eun-Jin;Hong, Yong-Kil;Kim, Tai-Gyu;Kim, Chang-Hyun;Lee, Kyu-Sung;Kim, Dong-Seok;Kim, Jin-Kyeoung
    • Journal of Korean Neurosurgical Society
    • /
    • 제37권6호
    • /
    • pp.443-448
    • /
    • 2005
  • Objective: A variety of genetic alterations in human glioblastoma comprises signal transduction and cell cycle arrest control of cellular processes. Subtractive hybridization is potentially a faster method for identifying differentially expressed genes associated with a particular disease state. Using the technique of subtraction, we isolated novel genes that are overexpressed in glioblastoma tissue as compared to normal brain tissue. Methods: We evaluated the differential expression of genes in each of hybridizing tester and driver cDNAs to digested 130 clones. After sequencing of 130 clones and homology search, this study performed to determine mRNA expression of the unknown gene, "clone 47", in brain tissue, glioblasoma, and several cancer cell lines by reverse transcription-polymerase chain reaction (RT-PCR). To test the time course for Go-phase arrest, serum stimulation and expression at various times for RT-PCR performed. Results: We identified 23 novel genes by BLAST of the digested 130 clones. The expressions of "clone 47" mRNA of glioblastoma and several cancer lines were significantly higher than normal brain tissues and several normal cell lines. We confirmed the mRNA expression of "clone 47" was up-regulation for $0.5{\sim}1hr$ of WI-38 cell differentiation. Conclusion: The novel gene, "Clone 47" is upregulated in glioblastoma tissue and several cancer cell lines. This gene is time dependent activation during time course of serum stimulation. This result suggests that "clone 47" playa role in brain tumorigenesis and the activation of this "clone 47" may be necessary for the development of cancer.

Identification of Genes Involved in Primordial-primary Follicle Transition by Suppression Subtractive Hybridization

  • Park, Chang-Eun;Yoon, Se-Jin;Jeon, Eun-Hyun;Kim, Young-Hoon;Lee, Sook-Hwan;Lee, Kyung-Ah
    • Proceedings of the Korean Society of Embryo Transfer Conference
    • /
    • 한국수정란이식학회 2002년도 국제심포지엄
    • /
    • pp.98-98
    • /
    • 2002
  • Recruitment of primordial follicles(PMF) is crucial for female fertility. however, factors and mechanisms that regulate this process is poorly understood. The present study was conducted to obtain an inclusive view of the gene expression and to identify novel factors and their pathways of regulating PMF arrest and/or growth initiation. Ovaries from one-day neonatal(consists of oocyte and PMF) and five-day old(consists of PMF and primary follicles, PRIF) mice were collected, either total RNA or mRNA was isolated, and suppression subtractive hybridization(SSH) was used to isolate and clone genes that differentially expressed in day 1 and day 5 ovaries. Confirmation that some of these genes are differentially expressed in PMF and/or in PRIF was accomplished by using laser captured microdissection(LCM), RT-PCR. in situ hybridization(ISH) and/or immunohistochemistry(IHC). In toto, 357 clones were sequenced and analyzed by BLAST and RIKEN program. Sequences of 330 clones significantly matched database entries while 27 clones were novel. Forty-two and 47 different genes were identified as differentially expressed in day 1 and day 5 ovaries, respectively, while 7 genes were expressed in both stages of ovaries. Day 5-subtracted library included several genes known as markers far growing follicles, such as ZP2, MATER, and fetuin. Among the genes with assigned functions, 23.8% was associated with cell cycle/apoptosis regulation, 7.1% with cellular structure, 11.9% with metabolism, 26.2% with signal transduction, and 31.0% with gene/protein expression in day 1; while 10.6%, 17.0%, 23.5%, 25.5%, and 23.4% in day 5, respectively. Genes such as GDF-8, Lats2, Septin2, and Weel were the highly expressed genes in PMF, while HSP84, Laminin2, MATER, MTi7, PTP, and Wrn were highly expressed genes in PRIF. We have successfully discovered list of genes expressed in day 1 and day 5 ovaries and confirmed that some of them are differentially expressed in PMF and/or PRIF. Gene expression profile from the present study would provide insight for the future study on the mechanism(s) involved in primordial-primary follicular transition. This work was Supported by Korean Health 21 RND Project, Ministry of Health and Welfare, Korea (01-PJ10-PG6-01GN13-0002).

  • PDF

Isolation of cDNA Encoding Low Temperature-inducible L-asparaginase from Soybean (Glycin max) (저온 스트레스에 발현이 유도되는 콩의 L-asparaginase 유전자의 분리)

  • Park, Seong-Whan;Kim, Kee-Young;Chen, Liang;Lee, Jai-Heon
    • Journal of Plant Biotechnology
    • /
    • 제29권2호
    • /
    • pp.99-104
    • /
    • 2002
  • Suppression subtractive hybridization (SSH) was used to isolate wound-induced cDNAs from wounded soybean. One of low-temperature-inducible cDNA, slti182 showed high homology with genes encoding 1-asparaginase. The full length cDNA of slti182, deginated GmASP1, is 1258 bp long and contains an open reading frame consisted of 326 amino acids. CmASP1 protein showed the highest identity (84%) with putative asparaginase from A. thaliana (AB012247), but it showed only 55% identity with another isoform of A. tathaliana (Z34884). The expression of GmASP1 during low temperature stress started to increase 3 hours after treatment, reached the maximum at 6 hour, and then decreased to the initial level at 48 hours. The amount of GmASP1 transcripts increased again when low-temperature-treated plants were transferred to room temperature, The present study suggests that GmASP1 may function to accelerate the protein synthesis which is important in the early response to low temperature.

Comparison analysis of fracture load and flexural strength of provisional restorative resins fabricated by different methods (제작방법에 따른 임시 수복용 레진의 파절강도 및 굴곡강도에 관한 연구)

  • Cho, Won-Tak;Choi, Jae-Won
    • The Journal of Korean Academy of Prosthodontics
    • /
    • 제57권3호
    • /
    • pp.225-231
    • /
    • 2019
  • Purpose: This study was undertaken to compare fracture and flexural strength of provisional restorative resins fabricated by additive manufacturing, subtractive manufacturing, and conventional direct technique. Materials and methods: Five types of provisional restorative resin made with different methods were investigated: Stereolithography apparatus (SLA) 3D printer (S3Z), two digital light processing (DLP) 3D printer (D3Z, D3P), milling method (MIL), conventional method (CON). For fracture strength test, premolar shaped specimens were prepared by each method and stored in distilled water at $37^{\circ}C$ for 24 hours. Compressive load was measured using a universal testing machine (UTM). For flexural strength test, rectangular bar specimens ($25{\times}2{\times}2mm$) were prepared by each method according to ISO 10477 and flexural strength was measured by UTM. Results: Fracture strengths of the S3Z, D3Z, and D3P groups fabricated by additive manufacturing were not significantly different from those of MIL and CON groups (P>.05/10=.005). On the other hand, the flexural strengths of S3Z, D3P, and MIL groups were significantly higher than that of CON group (P<.05), but the flexural strength of D3Z group was significantly lower than that of CON group (P<.05). Conclusion: Within the limitation of our study, provisional restorative resins made from additive manufacturing showed clinically comparable fracture and flexural strength as those made by subtractive manufacturing and conventional method.

Identification of Differentially Expressed Genes by Methylmercury in Neuroblastoma cell line using suppression subtractive hybridization (SSH) and cDNA Microarray

  • Kim, Youn-Jung;Chang, Suk-Tai;Yun, Hye-Jung;Ryu, Jae-Chun
    • Proceedings of the PSK Conference
    • /
    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
    • /
    • pp.189.2-190
    • /
    • 2003
  • Methylmercury (MeHg), one of the heavy metal compounds. can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. (omitted)

  • PDF