• Korean Journal of Radiology
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• v.20 no.1
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• pp.58-68
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• 2019

Objective: To compare digital breast tomosynthesis (DBT) and conventional full-field digital mammography (FFDM) in the detectability of breast cancers in patients with dense breast tissue, and to determine the influencing factors in the detection of breast cancers using the two techniques. Materials and Methods: Three blinded radiologists independently graded cancer detectability of 300 breast cancers (288 women with dense breasts) on DBT and conventional FFDM images, retrospectively. Hormone status, histologic grade, T stage, and breast cancer subtype were recorded to identify factors affecting cancer detectability. The Wilcoxon signed-rank test was used to compare cancer detectability by DBT and conventional FFDM. Fisher's exact tests were used to determine differences in cancer characteristics between detectability groups. Kruskal-Wallis tests were used to determine whether the detectability score differed according to cancer characteristics. Results: Forty breast cancers (13.3%) were detectable only with DBT; 191 (63.7%) breast cancers were detected with both FFDM and DBT, and 69 (23%) were not detected with either. Cancer detectability scores were significantly higher for DBT than for conventional FFDM (median score, 6; range, 0-6; p < 0.001). The DBT-only cancer group had more invasive lobular-type breast cancers (22.5%) than the other two groups (i.e., cancer detected on both types of image [both-detected group], 5.2%; cancer not detected on either type of image [both-non-detected group], 7.3%), and less detectability of ductal carcinoma in situ (5% vs. 16.8% [both-detected group] vs. 27.5% [both-non-detected group]). Low-grade cancers were more often detected in the DBT-only group than in the both-detected group (22.5% vs. 10%, p = 0.026). Human epidermal growth factor receptor-2 (HER-2)-negative cancers were more often detected in the DBT-only group than in the both-detected group (92.3% vs. 70.5%, p = 0.004). Cancers surrounded by mostly glandular tissue were detected less often in the DBT only group than in the both-non-detected group (10% vs. 31.9%, p = 0.016). DBT cancer detectability scores were significantly associated with cancer type (p = 0.012), histologic grade (p = 0.013), T and N stage (p = 0.001, p = 0.024), proportion of glandular tissue surrounding lesions (p = 0.013), and lesion type (p < 0.001). Conclusion: Invasive lobular, low-grade, or HER-2-negative cancer is more detectable with DBT than with conventional FFDM in patients with dense breasts, but cancers surrounded by mostly glandular tissue might be missed with both techniques.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1199-1203
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• 2010

Second-order rate constants ($k_N$) have been measured spectrophotometrically for Michael-type reactions of 1-(X-substituted phenyl)-2-propyn-1-ones (2a-f) with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ value increases as the incoming amine becomes more basic and the substituent X changes form an electron-donating group (EDG) to an electron-withdrawing group (EWG). The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.48 - 0.51. The Hammett plots for the reactions of 2a-f exhibit poor correlations but the corresponding Yukawa-Tsuno plots result in much better linear correlations with ${\rho}$ = 1.57 and r = 0.46 for the reactions with piperidine while ${\rho}$ = 1.72 and r = 0.39 for those with morpholine. The amines employed in this study are less reactive in MeCN than in water for reactions with substrates possessing an EDG, although they are ca. 8 pKa units more basic in the aprotic solvent. This indicates that the transition state (TS) is significantly more destabilized than the ground state (GS) in the aprotic solvent. It has been concluded that the reactions proceed through a stepwise mechanism with a partially charged TS, since such TS would be destabilized in the aprotic solvent due to the electronic repulsion between the negative-dipole end of MeCN and the negative charge of the TS. The fact that primary deuterium kinetic effect is absent supports a stepwise mechanism in which proton transfer occurs after the rate-determining step.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.224-224
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• 2002

Chitin-degrading marine bacterial strain 98CJ11027 was isolated from bryozoa from the coastal area of Cheju Island, Korea, and identified as a member of the genus Vibrio. The molecular mass of the main extracellular chitinase (chitinase I), purified from strain 98CJ11027, was estimated to be 98 kDa. The optimal condition for chitinase I activity is pH 6.0 and 45℃. The activity was inhibited by $Fe^+2$ and$Cu^+2$. Chitinase I displayed the hydrolysis type of chitobiosidase and catalyzed reversed hydrolysis leading to the synthesis of tetraacetylchitotetraose.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.3
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• pp.278-290
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• 1991

Prediction of the sop tissue changes following hard tissue movements is very important in the preoperative analysis of surgical changes of the patient who have orthognathic surgery. This study examined post operative changes of the mid-facial sop tissues in Koreans depending upon two major positional changes of the maxilla following Le Fort - I type osteotomy for orthognathic purposes. Sixty patients(41 males and 19 females) of Koreans were selected and divided into two groups according to directional change of movement of anterior bony structures of the Maxilla as follows : Group I (44 patients) was mooed anteriorly and/or inferiorly, and Group II (16 patients) was mooed posteriorly and/or superioly. Postoperative changes of the sop tissue measurements following hard tissue changes were examined on pre - and post - operative cephalometrics by means of computerized digitation methods and the ratios of changes were analysed. The results were obtained as follows : 1. In Group I, all of the sop tissue measures except the Pn was closely followed by the changes of the hard tissue measures in the horizontal plane, but the Sn and the Cm were only correlated to the vertical changes(p<0.001). In group II, all of the sop tissue measures excluding of the N' and the Pn were significantly correlated to the hard tissue measures in horizontal plane(p<0.001), but the Ls and Stm were only correlated relatively to the vertical changes of the ANS(p<0.01). 2. Predictable ratio of the Sn was 66% of the ANS or 56% of the A in the horizontal plane and 89% of the A in the vertical plane in Group I. In Group II, the Sn was predictable as 85% of the ANS or 70% of the A in the horizontal plane but was not predictable in vertical plane. 3. Predictable ratio of the Cm was 28% of the ANS or 50% of the A in the horizontal plane and 56% of the ANS or 36% of the A in the vertical plane in Group I. In Group II, the Cm was predictable horizontally as 74% of the A. Predictable ratio of the Pn was 30% of the ANS or 38% of the A in horizontal plane in Group I, but it was not predictable both horizontally and vertically in Group II. 4. Predictable ratio of the Ls was 52% of the Pr in Group I and 77% in Group II in the horizontal plane. The Stm was predictable as 34% of the pr or 22% of the I in the horizontal plane in Group I, and was also predictable as 55% of the pr or 68% of the I horizontally and 21% of the pr or 65% of the I vertically in Group II. 5. All ratios of change in the thickness. length and area of the upper lip following maxillary movement were statiscally correlated, however, mangitudes of them were meaningful clinically.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1378-1380
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• 2001

Ohmic contacts have been fabricated on p-type 4H-SiC using Pt/Ti. Low resistivitf Ohmic contacts of Pt/Ti to p-type 4H-SiC were investigated. Specific contact resistances were measured using the transmission line model method, and the physical properties of the contacts were examined using x-ray diffraction, scanning electron microscopy. Ohmic behavior with linear current-voltage characteristics was observed following anneals at $900^{\circ}C$ for 90sec at a pressure of $3.4{\times}10^{-5}$ Torr. The Pt/Si/Ti films was measured lower value of the specific contact resistance by the annealing process, and the contact resistances were improved more than one order compared to Ti contact the annealed sample. Scanning electron microscopy shows that the Pt layer effectively reduce the oxidation of Ti films. And results are obtained as $4.6{\times}10^{-4}$ ohm/$cm^2$ for a Pt/Ti metal structure after a vacuum annealing at $900^{\circ}C$ for 90sec. Titanium has a relatively high melting point, thus Ti-based metal contacts were attempted in this study.

• Journal of the Korean Magnetic Resonance Society
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• v.9 no.2
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• pp.74-92
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• 2005

The high resolution solution structure of MCP-3 was determined using multinuclear, multidimensional NMR spectroscopy with an expressed and $^{13}C-\;and\;^{15}N-labeled$ protein. The MCP-3 has a typical chemokine fold including 3 anti-parallel $\beta-sheets$, and a C-terminal helix, but it exists as a monomer in solution under the conditions where the structure was determined (2 mM, pH 5.1 at $30^{\circ}C$). Based on the structure and the amino acid sequence compared to other chemokines we propose that Ile20 and Leu25 in MCP-3 play key roles in the formation of N-loop (residues between the $2^{nd}$ cysteine and the I sheet) which has been implicated as a determinant of chemokine specificity. Additional receptor binding surface is supplied by the 40s loop (residues between the 2 and the 3 sheet) and the binding interface of the acidic N-terminal region of chemokine receptor to MCP-3 would resemble the dimerization interface of CC type dimer.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.202-210
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• 2024

Background: Panax ginseng Meyer polysaccharides exhibit various biological functions, like antagonizing galectin-3-mediated cell adhesion and migration. Galectin-8 (Gal-8), with its linker-joined N- and C-terminal carbohydrate recognition domains (CRDs), is also crucial to these biological processes, and thus plays a role in various pathological disorders. Yet the effect of ginseng-derived polysaccharides in modulating Gal-8 function has remained unclear. Methods: P. ginseng-derived pectin was chromatographically isolated and enzymatically digested to obtain a series of polysaccharides. Biolayer Interferometry (BLI) quantified their binding affinity to Gal-8, and their inhibitory effects on Gal-8 was assessed by hemagglutination, cell migration and T-cell apoptosis. Results: Our ginseng-derived pectin polysaccharides consist mostly of rhamnogalacturonan-I (RG-I) and homogalacturonan (HG). BLI shows that Gal-8 binding rests primarily in RG-I and its β-1,4-galactan side chains, with sub-micromolar K_D values. Both N- and C-terminal Gal-8 CRDs bind RG-I, with binding correlated with Gal-8-mediated function. Conclusion: P. ginseng RG-I pectin β-1,4-galactan side chains are crucial to binding Gal-8 and antagonizing its function. This study enhances our understanding of galectin-sugar interactions, information that may be used in the development of pharmaceutical agents targeting Gal-8.

• Proceedings of the Ginseng society Conference
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• 1993.09a
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• pp.132-137
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• 1993

Several Prosapogenins and sapogenins obtained by acid hydrolysis or alkaline cleavage of Korean red ginseng saponins were separated and identified by spectral and physical methods. Some of these degradation products showed the cytotoxic activities against various cancer cell lines, that is, A549, SK - OV - 3, L121O, P388 and K562. The significant difference of activity between stereoisooers was not approved and the activity was inversely proportional to the number of sugars binding to sapogenins. It was clear that diol type prosapogenins and sapogenins were more cytotoxic than triol type ones.

• Animal Bioscience
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• v.37 no.2
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• pp.274-283
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• 2024

Objective: The aim of the study was to evaluate the physicochemical properties (nutrient composition, pH, water content and activity, sorption properties) and mechanical properties (compression force and energy) of granulated feed mixtures with various inclusion levels of crude fibre concentrates ARBOCEL and VITACEL for broiler chickens, i.e. +0.0% (control group - group C), +0.3%, +0.8%, +1.0%, +1.2%. Methods: The feed mixtures were analyzed for their physicochemical properties (nutrient composition by near-infrared spectroscopy, pH with the use a CP-401 pH meter with an IJ-44C glass electrode, water content was determined with the drying method and activity was determined with the Aqua Lab Series 3, sorption properties was determined with the static method) and mechanical properties (compression force and energy with the use TA-HD plus texture analyzer). The Guggenheim-Anderson-de Boer (GAB) model applied in the study correctly described the sorption properties of the analyzed feed mixtures in terms of water activity. Results: The fibre concentrate type affected the specific surface area of the adsorbent and equilibrium water content in the GAB monolayer (p≤0.05) (significantly statistical). The type and dose of the fibre concentrate influenced the dimensionless C and k parameters of the GAB model related to the properties of the monolayer and multilayers, respectively (p≤0.05). They also affected the pH value of the analyzed feed mixtures (p≤0.05). In addition, crude fibre type influenced water activity (p≤0.05) as well as compression energy (J) and compression force (N) (p≤0.001) (highly significantly statistical) of the feed mixtures. Conclusion: The physicochemical analyses of feed mixtures with various inclusion levels (0.3%, 0.8%, 1.0%, 1.2%) of crude fiber concentrates ARBOCEL or VITACEL demonstrated that both crude fiber types may be used in the feed industry as a feedstuff material to produce starter type mixtures for broiler chickens.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.290-296
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• 2021

Objective: The purpose of this research is to examine the effects of three types of different running shoes with different properties on impact variables (PVRGF and VLR) and the lower extremity joint's dynamic stability variables (LyEs of DPA, IEA, FEA, DPAV, IEAV, and FEAV) during running. Method: The participants in this research were 12 males (Age: 22.0 ± 3.3 years, Height: 177.2 ± 4.1 cm, Weight: 74.3 ± 9.6 kg). One type of N company's running shoes and two types (FA, FB) of F company's running shoes were used. As for the properties of the running shoes, thickness (mm), dwell time (ms), peak acceleration (m/s2), and energy return (%) were measured. The motions running at 3.5 m/s on a treadmill (Instrumented treadmill, Bertec, USA) wearing each type of running shoes were analyzed. Results: Although the VLR of the thick running shoes (FB) was smaller than that of the other running shoes (N, FA), the LyEs of PVGRF and DPA were larger (p<.05). Even though the running shoes' dwell time (i.e., impact absorption time) and peak acceleration showed a positive correlation with the LyEs of DPAV, IEAV, and FEAV, the energy return showed a negative correlation (p<.05). Conclusion: Our results indicated that the running shoes with excellent impact absorption function are predicted to be suitable for running beginners who need to reduce the burden of the lower extremity joint during running. The running shoes with excellent energy return are expected to be suitable for mid-and long-distance running elite athletes or marathoners to whom stability and consistency are essential during running.