• Korean Journal of Mathematics
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• 제28권3호
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• pp.639-647
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• 2020

A simple type of Cohen's transformation consists of a polynomial and a linear fractional transformation. We study the effectiveness of Cohen transformation to find N-polynomials over finite fields.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1669-1680
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• 2010

The phase-shifted version of the multichannel quantum-defect theory (MQDT) was reformulated by disentangling the interloper spectrum from the perturbed dense Rydberg series for a systems involving 2 closed and more than 1 open channel. The theory was applied successfully to Martins and Zimmermann's photoionization spectra of the Rydberg series Cu I $3d^9\;4s(^1D_2)\;nd^2G_{9/2}$ perturbed by the interloper, $3d^9\;4p^2\;^4F_{9/2}$, for which Cohen's 4 channel QDT had failed. The zero surface graphic of the perturbed Fano's asymmetry parameter q of the autoionization spectrum of dense Rydberg series by the interloper was determined by only two parameters for this system. It was used as a map to trace the transformation route of the 3 channel autoionization spectra to the 4 channel spectra when the channel coupling of the closed channels with a newly added open channel was turned on progressively.

• 한국자기공명학회논문지
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• 제2권2호
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• pp.85-105
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• 1998

Prions cause neurodegenerative diseases in animals and humans. The scrapie prion protein (PrPSc) is the major-possibly only-component of the infectious prion and is generated from the cellular isoform (PrPC) by a conformational change. Limited proteolysis of PrPSc produces an polypeptide comprised primarily of residues 90 to 231, which retains infectivity. The three-dimensional structure of rPrP(90-231), a recombinant protein resembling PrPC with the Syrian hamster (SHa) sequence, was solved using multidimensional NMR. Low-resolution structures of rPrP(90-231), synthetic peptides up to 56 residues, a longer (29-231, full-length) protein with SHa sequence, and a short here further structure refinement of rPrP(90-231) and dynamic features of the protein. Consideration of these features in the context of published data suggests regions of conformational heterogeneity, structural elements involved in the PrPC\longrightarrowPrPSc transformation, and possible structural features related to a species barrier to transmission of prion diseases.

• Asian Pacific Journal of Cancer Prevention
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• 제14권7호
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• pp.4151-4155
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• 2013

Background: To compare response evaluation criteria in solid tumours (RECIST) and volumetric evaluation (VE) for colorectal cancer with liver-limited metastasis. Patients and Methods: VE of liver metastases was performed by manual contouring before and after chemotherapy on 45 pairs of computed tomography (CT) images in 36 patients who suffered from metastatic colorectal cancer (mCRC) with liver metastasis only. Cohen kappa was used to compare the agreement between VE and RECIST. Pearson correlation was performed for their comparison after cubic root transformation of the aggregate tumor volumes. Logistic regression was done to identify clinical and radiographic factors to account for the difference which may be predictive in overall response (OR). Results: There were 16 partial response (PR), 23 stable disease (SD) and 6 progressive disease (PD) cases with VE, and 14 PR, 23 SD and 8 PD with RECIST. VE demonstrated good agreement with RECIST (${\chi}$=0.779). Discordant objective responses were noted in 6 pairs of comparisons (13.3%). Pearson correlation also showed excellent correlation between VE and RECIST ($r^2$=0.966, p<0.001). Subgroup analysis showed that VE was in slightly better agreement with RECIST for enlarging lesions than for shrinking lesions ($r^2$=0.935 and $r^2$=0.780 respectively). No factor was found predictive of the difference in OR between VE and RECIST. Conclusions: VE exhibited good agreement with RECIST. It might be more useful than RECIST in evaluation shrinking lesions in cases of numerous and conglomerate liver metastases.