• 대한의용생체공학회:의공학회지
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• 제31권4호
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• pp.328-334
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• 2010

Over the past few years, a considerable number of methods have been proposed and applied for the classification of photoplethysmography (PPG). Most of the previous studies, however, focused on the qualitative description of the pulse type according to specific disease and thus provided ambiguous criteria to interpreters. In order to screen out this problem, we present a quantitative method for the pulse type classification including the second derivative of photoplethysmography (SDPTG). In the PPG signal, we have classified the signal as 4 types using the position and the presence of the dicrotic wave. In addition, we have categorized the SDPTG signal as 7 types using the position and the presence of "c" and "d" wave and the sign of "c" wave. In order to check the efficacy of the proposed pulse type classification rule, we collected pulse signals from 155 subjects with different ages and sex. From the correlation analysis, Class 1(p<0.01) and Class 2(p<0.01) in the PPG signal are significantly correlated with ages. In a similar manner Class A(p<0.01), Class C(p<0.05), Class D(p<0.01), and Class F(p<0.01) in the SDPTG signal are considerably correlated with the ages. From these observations, and some earlier ones [4], [5], we can conclude that since the newly proposed method has objectivity and clarity in pulse type classification, this method can be used as an alternative of previous classification rules including similar age-related characteristics.

• Journal of Nutrition and Health
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• 제28권4호
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• pp.331-344
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• 1995

The process of breast feeding was investigated from the 36th week of pregnancy to 12 weeks postnatal, in order to analyze the factors affecting breast feeding duration and provide the basic data on an education program for successful breast feeding. The general characteristics of study group had no marked effects on the breastfeeding duration. The young and highly condition during pregnancy and the degree of morning sickness affected the practice of breastfeeding. In the study of prenatal sociobehavioral factors, intended duration affected the breastfeeding duration, and the maternal perception that breastfeeding is good for weight loss after delivery as well as infant formula milk is not as good as breast milk, led to successful breast feeding. Among the postnatal biological factors, the duration of gestation affected the breast feeding. Among the postnatal biological factors, the duration of gestation affected the breastiffeding outcome. In the case of early parturition, breastfeeding rate was low. Among the postnatal biocultural factors, time of first feed, milk volume and maternal perception of infant's sucking ability affected the bresatfeeding duration. From these result, it is suggested that an education program such as participation of nursing class to the pregnant women should be provided for successful breastfeeding.

• Molecules and Cells
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• 제39권12호
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• pp.855-861
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• 2016

Ginsenosides, which are the active materials of ginseng, have biological functions that include anti-osteoporotic effects. Aqueous ginseng extract inhibits osteoclast differentiation induced by receptor activator of NF-${\kappa}B$ ligand (RANKL). Aqueous ginseng extract produces chromatography peaks characteristic of ginsenosides. Among these peaks, ginsenoside Re is a major component. However, the preventive effects of ginsenoside Re against osteoclast differentiation are not known. We studied the effect of ginsenoside Re on osteoclast differentiation, RANKL-induced tartrate-resistant acid phosphatase (TRAP) activity, and formation of multinucleated osteoclasts in vitro. Ginsenoside Re hampered osteoclast differentiation in a dose-dependent manner. In an in vivo zebrafish model, aqueous ginseng extract and ginsenoside Re had anti-osteoclastogenesis effects. These findings suggest that both aqueous ginseng extract and ginsenoside Re prevent bone resorption by inhibiting osteoclast differentiation. Ginsenoside Re could be important for promoting bone health.

• 과학기술학연구
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• 제8권1호
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• pp.131-158
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• 2008

생물학결정론은 경험연구에 의해서 사실로 입증된 과학진리가 아니라 서유럽 백인중심의 가부장제 자본주의 지배질서와 억압구조의 실상을 은폐하거나 재생산하는 이데올로기에 지나지 않음을 드러내려는 의도에서 인간존재의 특수성을 문화인류학적으로 고찰한 결과는, 인간은 생물학적 유전요인에 의해서 태어나는 것이 아니라 사회문화적 환경요인에 의해서 만들어지는 존재라는 것이었다. 그리고 생물학결정론의 사회맥락에 대한 분석결과로 밝혀진 것은, 골상학과 사회진화론에서 사회생물학과 IQ옹호론에 이르는 생물학결정론 자체가 사회모순의 분출로 기존의 지배질서가 위태로워진 위기상황으로부터 벗어나기 위한 타개책으로 등장하였다는 점이다. 이로 인해 생물학결정론은 태생적으로 불평등한 사회구조를 은폐하고 재생산하는 인종차별주의와 자민족우월주의, 계급차등주의와 남성중심주의의 정당화기제로 작동할 수밖에 없는 문제를 안고 있는 것이다. 그러므로 생명과학이 인류의 희망이 되고자 한다면, 생물학결정론은 반드시 극복해야만 하는 문제로 불평등한 사회구조의 변혁이 선행되지 않고는 해결할 수 없는 난제 중의 난제이다.

• 대한의용생체공학회:의공학회지
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• 제14권4호
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• pp.365-370
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• 1993

Of the assumptions commonly used in continuous infection model, the least likely to be even approximately true in large population, is that of homogeneous mixing. In this paper, We investigate a model for the spread of infection amongst a population which is divided into classes, such that the individuals of each class mix homogeneously amongst themselves, but mix to a lesser degree with individuals of other class. The stochastic model in this form is intractable and approximations are made, yielding results in reasonable agreement with simulation trials.

• ALGAE
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• 제20권3호
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• pp.197-205
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• 2005

Temporal variability in lake phytoplankton is controlled by a complex between hydrological and chemical factors, and biological interactions. We explored annual change of phytoplankton in Lake Daecheong, using phytoplankton analysis data from 1997 to 2002 (except 2000). The standing crop of phytoplankton was ranged from 3.5 x 10 to 1.5 x 106 cells mL$^{-1}$ and the highest mean value was at site 1. The class composition ratios of phytoplankton standing crop were divided into three classes. From January to March, diatoms showed a dominance (68.1-77.7%). From April to June, diatoms were mixed with cryptomonad etc. or blue-green algae. From July to October, blue-green algae showed a dominance (54.7-84.0%). In the case of green algae, the class composition ratios were below 10%. But green algae appeared all the year round.

• Journal of Species Research
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• 제13권2호
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• pp.142-146
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• 2024

The purpose of this study was to isolate and identify wild yeasts from soil collected in Daegu City and Cheongyang County, Republic of Korea. Among 11 strains isolated in this study, nine strains were previously reported and two strains were unreported in Republic of Korea. To identify wild yeast strains, pairwise sequence comparisons of the D1/D2 region of the 26S rRNA gene sequence were done using Basic Local Alignment Search Tool (BLAST). The cell morphologies were observed by phase contrast microscope and assimilation test are done using API 20C AUX kit. All strains were assigned to the phylum Basidiomycota. Of the two unrecorded yeast strains, CY-9-10C belongs to the genus Mrakia (family Mrakiaceae, order Cystofilobasidiales, class Tremellomycetes) and PG3-4-10C belongs to the genus Slooffia (family Chrysozymaceae, order Microbotryomycetes incertae sedis, class Microbotryomycetes). Both strains had oval-shaped and polar budding cells. This research described the morphological and biochemical properties of the two unreported yeast species that had not officially reported in Korea.

• BMB Reports
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• 제32권6호
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• pp.541-546
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• 1999

When we compared the chitinase activity of various plant sources using colorimetric or active gel-staining assay methods, the specific activity of pumpkin leaves was the highest among the samples we analyzed. The highly active chitinase from pumpkin leaves (designated PL-ChtIII) was purified to homogeneity using affinity chitin gel and HPLC Mono-Q anion-exchange cloumn chromatographies. In contrast to other members of the class III chitinase family, PL-ChtIII showed a strong binding affinity to the regenerated chitin gel column. The apparent molecular weight of PL-ChtIII was estimated to be 29 kDa on SDS-PAGE gel, while its optimum pH and temperature were shown to be pH 6.0 and $60^{\circ}C$, respectively. Analyzing the reaction products of PL-ChtIII with swollen chitin as substrate, the dimer and tetramer of N-acetylglucosamine were produced as major products in the first hour of the enzymatic reaction along with a small amount of monomers and trimers. As the reaction time increased, dimeric N-acetylglucosamine became the predominant form of reaction product.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1992년도 추계학술대회
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• pp.117-122
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• 1992

In systems in which inductive coupling between a pancake-shaped coil on the surface of the body and a similar coil within the body is utilized for the transfort of electromagnetic energy, the minimization of temperature rise in the tissue is intimately related to the achievement of minimum losses in the region of the implanted coil. The new class of amplifiers, named "class E", for inverter is defined and is illustrated by a detailed description and a set of desist equations for one simple member of the class. For TET circuit the authors measured 65 to 76 percent efficiency at 1985kHz at 30 to 50 W output from IRF250 MOSFET transistor.

• Journal of Species Research
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• 제10권3호
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• pp.217-226
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• 2021

During a project aiming to comprehensively investigate indigenous prokaryotic species in Korea, a total of 20 bacterial strains phylogenetically belonging to the the class Bacilli of the phylum Firmicutes were isolated from various environmental sources such as soil, air, tidal flat, sea water, grain, wetland, breast milk and healthy human urine. Phylogenetic analysis based on 16S rRNA gene sequences revealed that 20 bacterial strains showed the high sequence similarities (≥98.7%) to the closest type strains and formed robust phylogenetic clades with closely related species of validly published names in the class Bacilli of the phylum Firmicutes. In the present study, we report 20 species of 13 genera of seven families of two orders of one class in the phylum Firmicutes, which have not been previously reported in Korea. Morphological, biochemical, and physiological characteristics, isolation sources, and NIBR deposit numbers of these unrecorded bacterial species are described in the species descriptions.