• Title/Summary/Keyword: Single gamma

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The Development of Gamma Energy Identifying Algorithm for Compact Radiation Sensors Using Stepwise Refinement Technique

  • Yoo, Hyunjun;Kim, Yewon;Kim, Hyunduk;Yi, Yun;Cho, Gyuseong
    • Journal of Radiation Protection and Research
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    • v.42 no.2
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    • pp.91-97
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    • 2017
  • Background: A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. Materials and Methods: The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. Results and Discussion: The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under $10^4$ ($/0.09cm^2$ of the scintillator surface). Conclusion: Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

Association Study of Single-Nucleotide Polymorphisms of STAT2/STAT3/IFN-γ Genes in Cervical Cancer in Southern Chinese Han Women

  • Yuan, Yuan;Fan, Jie-Lin;Yao, Fang-Ling;Wang, Kang-Tao;Yu, Ying;Carlson, Jennifer;Li, Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.8
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    • pp.3117-3120
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    • 2015
  • Objective: Interferon-${\gamma}$ (IFN-${\gamma}$) and signal transducers and activators of transcription (STATs) each play an important role in carcinogenesis associated with viral infection. Cervical cancer is almost invariably associated with infection by human papillomavirus (HPV), and previous studies suggested that dysregulation of the signal pathway involved in IFN-${\gamma}$ and STATs is associated. Our objective was to evaluate the association of SNPs in STAT2, STAT3, and IFN-${\gamma}$ with cervical cancer susceptibility in Chinese Han women in Hunan province. Materials and Methods: Genomic DNA was extracted from peripheral blood samples of 234 cervical cancer patients and 216 healthy female controls. STAT2 and STAT3 genotyping was performed using polymerase chain reaction-restriction enzyme (PCR-RE) analysis. IFN-${\gamma}$ genotyping was detected by PCR-amplification of specific allele (PASA). Results: For STAT2 rs2066807 polymorphisms, there was no significant difference of genotype distribution (P=0.827) and allele frequencies (P=0.830, OR=1.09, 95% CI: 0.51-2.31) between cases and controls. For STAT3 rs957970 polymorphisms, there was no significant difference of genotype distribution (P=0.455) and allele frequencies (P=0.560, OR=0.92, 95% CI: 0.71-1.20) between cases and controls. For IFN-${\gamma}$ +874A/T polymorphisms, there was no significant difference of genotype distribution (P=0.652) and allele frequencies (P=0.527, OR=1.12, 95% CI: 0.79-1.59) between cases and controls. Conclusion: These results suggest that polymorphisms in STAT2, STAT3 and IFN-${\gamma}$ genes are not likely to be strong predictors of cervical cancer in Han women in southern China.

Identification of ${\gamma}-Glutamylamine$ Cyclotransferase, as the Preform Enzyme at the Dormant Stage, From Soybean (Glycine max) Seeds

  • Kang, Hyeog;Park, Sung-Joon;Cho, Young-Dong
    • BMB Reports
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    • v.30 no.6
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    • pp.438-442
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    • 1997
  • ${\gamma}-Glutamylamine$ cyclotransferase was purified to homogeneity from soybean (Glycine max) seeds. To our knowledge, it is the first purification of the enzyme from plant origins. The molecular weight of the enzyme estimated by Sephacryl S-300 gel filtration and SDS-PAGE was 27,000, indicating that the enzyme is a monomer. The optimal pH for activity was 8.6. The Km value for ${\gamma}-glutamyldansylcadaverine$ was 11 ${\mu}M$. The enzymatic activity was substantially inhibited by the addition of p-chloromercuribenzoate and partially inhibited by the $Cu^{2+}$ ion. However, neither other modification reagents nor other divalent metal ions affected the enzymatic activity. The comparison between the enzymatic activities of seed extracts treated with cycloheximide and control extracts, and the detection of the same single protein band by western blot analysis at the dormant stage without inhibition with distilled water indicate that ${\gamma}-Glutamylamine$ cyclotransferase is already present at the dormant stage and gradually activated during germination in soybean seeds.

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Growth of ${\gamma}-6Bi_2O_3{\cdot}GeO_2$ Single Crystals by EFG Method (EFG법에 의한 ${\gamma}-6Bi_2O_3{\cdot}GeO_2$)

  • ;;Kei-Miyamoto
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.1 no.2
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    • pp.34-45
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    • 1991
  • The fundamental conditions for growing $r-6Bi_2O_3{\cdot}GeO_2$ (BGO) single crystal plates by EFG (Edge -defined Film-fed Growth) method, were investigated and the characterization, quality test were carried out for obtained BGO single crystal plates. The optimum growing conditions determined in this study were as follows: ${\cdot}$ temperature gradient: 22^{\circ}C/cm

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The Effect of Heat Treatment on the Martensitic Transformation in an Cu-Al-Ni Single Crystal (Cu-Al-Ni계 단결정 합금의 마르텐사이트 변태특성에 미치는 열처리의 영향)

  • Kim, Y.S.;Jang, W.Y.
    • Journal of the Korean Society for Heat Treatment
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    • v.13 no.3
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    • pp.177-182
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    • 2000
  • The effects of betatizing and aging temperatures on the martensitic transformation characteristics in an Cu-13.4wt%Al-4.2wt%Ni single crystal have been studied. Microstructures show that the specimen betatized above $800^{\circ}C$ has only ${{\beta}_1}^{\prime}$ martensite while the specimen betatized of below $700^{\circ}C$ has two phases i.e., ${{\beta}_1}^{\prime}+{\gamma}_2$ When betatizing temperature increase from $600^{\circ}C$ upto $900^{\circ}C$, Ms and As temperatures decrease due to the dissolution of which ${\gamma}_2$ phase depletes Al content in the matrix thereafter makes the both Ms and As temperatures significantly increased. Ms and As temperatures of the specimen aged at $200^{\circ}C$ are relatively stable but those of the specimen aged at $300^{\circ}C$ are shifted rapidly with aging time, especially within the first 30min.

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CHARACTERISTICS EVALUATION AND GROWTH OF $BI_4GE_3O_{12}$ SINGLE CRYSTAL BY CZOCHRALSKI METHOD

  • Cho, Yun-Ho;Kim, Yong-Kyun;Lee, Woo-Gyo;Kang, Byoung-Hwi;Kim, Jong-Kyung;Lee, Dong-Hoon;Park, Jae-Woo
    • Journal of Radiation Protection and Research
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    • v.34 no.2
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    • pp.83-86
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    • 2009
  • The single crystal scintillator of bismuth germinate ($Bi_4Ge_3O_{12}$:BGO) was successfully grown by the conventional Czochraski technique. The characteristics of the grown BGO were evaluated and presented on the excitation, emission responses and energy spectra of the $\gamma$-rays from $^{241}Am$, $^{133}Ba$, $^{57}Co$, $^{22}Na$, $^{137}Cs$ and $^{54}Mn$ radio-isotopes. The energy resolution of grown BGO, $\Delta$E/E, was estimated to be 12.1% at 662 keV of $\gamma$-ray for $^{137}Cs$ nuclide. Compared to the commercial BGO crystal, we confirmed that the grown BGO has a good performance and is comparable to reference one.

Retardation of Fatigue Crack Propagation by Single Overloading (단일과대하중에 의한 피로균열전파의 지연거동)

  • 김상철;함경춘;강동명
    • Journal of the Korean Society of Safety
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    • v.7 no.1
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    • pp.20-29
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    • 1992
  • Effects of strain hardening exponents on the retardation behavior of fatigue crack propagation are experimentally investigated. The retardation of fatigue crack propagation seems to be induced by the crack closure at crack tip. The phenomenon of crack closure becomes remarkable with the increment of strain hardening exponent and magnitude of percent peak load. The ratio of crack growth increment(a$\_$d//w$\_$d/) is influenced by a single overloading (a$\_$d/) and estimated plastic zone size (W$\_$d/=2r$\_$y/) is increased according with the increasing of strain ha.dening exponents. The number of retarded crack growth cycles were (N$\_$d/) decreased as the baseline stress intensity factor .ange( K$\_$b/) was increased. Within the limitation of these experimental results obtained under the single overload, an empirical relation between crack retardation ratio (Nd/N*), strain hardening exponent (n) and percent peak load (%PL) has been proposed as; Nd/N*= exp [PL $.$ PL$.$A(n)+B(n) ] where, A(n)=${\alpha}$n+${\beta}$, B(n)=${\gamma}$n+$\delta$, PL=%PL/100 and ${\alpha}$=0.78, ${\beta}$=0.54, ${\gamma}$=0.58 and $\delta$=-0.01, It is interesting to note that all these constants are identical for materials such as aluminum(A3203), steel(S4SC), steel(SS41) and stainless steel(SUS316) used in this experimental study.

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