• Parasites, Hosts and Diseases
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• 제61권1호
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• pp.53-59
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• 2023

Head louse infestation is a significant public health problem across the world, particularly among preschool and primary schoolchildren. This study investigated the trends of head louse infestation in the Republic of Korea over a 9-year period (2011-2019), targeting primary schoolchildren in 3 areas of Seoul, 4 other large cities, and 9 provinces. A survey was administered annually by the health staff of each regional office (n= 16) of the Korea Association of Health Promotion (KAHP). The branch offices of KAHP examined a total of 51,508 primary schoolchildren, comprising 26,532 boys and 24,976 girls. Over the 9-year survey, a total of 1,107 (2.1%) schoolchildren tested positive for adults and/or nits of Pediculus humanus capitis. The prevalence was 2.8% (133/4,727) in 2011-2012 and gradually decreased to 0.8% (49/6,461) in 2019 (P< 0.05). Head lice were found more frequently in girls (3.0%; 746/24,976) than in boys (1.4%; 361/26,532) (P< 0.05). In terms of geographic localities, the highest infestation rate, 4.7% (average prevalence over 9 years), was observed in southern Seoul (Gangnam branch of KAHP), whereas the lowest infestation rate, 0.7%, was seen in Gyeongsang (north and south provinces) and western Seoul. Although the prevalence decreased significantly during the 9-year period, head louse infestation remains a health and hygiene issue among primary schoolchildren in the Republic of Korea. Regular surveys along with health education are needed to further improve children's hair hygiene.

• 한방재활의학과학회지
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• 제18권2호
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• pp.17-31
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• 2008

Objectives : This study was carried out to investigate the effects of Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) on the monosodium iodoacetate-induced osteoarthritis in rats. Methods : Osteoarthritis was induced by injection of monosodium iodoacetate intraarticularly in both knee joints. Arthritic rats were divided into control and treated group. Control group were taken distilled water for 20days. Treated group were taken extracts of Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) by orally for the same duration. Normal group were injected normal saline and taken distilled water. Body weights were measured at 0, 5th, 10th, 15th, 20th day after injection. At the end of the experiment, gross and histopathological examination on the articular cartilages of the knee joints were performed. Proteoglycan contents of articular cartilages were analyzed by safranine O staining method. The contents of $TNF-{\alpha}$, $IL-1{\beta}$ and IL-6 in synovial fluids were analyzed by ELISA method. Results : 1. Body weights of the treated group were significantly increased compared with control at 20days after injection. 2. Grossly, the severity of osteoarthritis in the treated group were alleviated compared with control. 3. Histopathologically, degenerative and necrotic lesion of articular cartilages in the treated group were alleviated compared with those of the control and histopathological scores of treated group were significantly decreased compared with control. 4. PG contents in articular cartilages of the treated group were significantly increased compared with control. 5. $TNF-{\alpha}$ contents in synovial fluids of the treated group were significantly decreased compared with control. Conclusions : According to above results, Samgi-eum($S{\bar{a}}nq{\grave{i}}-y{\check{i}}n$) has anti-arthritic effects on the monosodium iodoacetate-induced osteoarthritis in rats. And it is related with reduced secretion of $TNF-{\alpha}$ from osteoarthritic chondrocytes and synovial membranes.

• Journal of Species Research
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• 제6권spc호
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• pp.67-70
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• 2017

Three ciliate species, Australocirrus australis (Foissner, 1995) Kumar and Foissner, 2015, Rimaleptus longitrichus ($Vd^{\prime}a{\check{c}}n{\acute{y}}$ and Foissner, 2008) $Vd^{\prime}a{\check{c}}n{\acute{y}}$ and Foissner, 2012, and Frontonia subtropica Pan et al., 2013, that were previously unreported in Korea were collected from terrestrial and marine habitats in Korea. Using live observation and protargol impregnation, the three species were identified using a combination of the following characteristics: Australocirrus australis, the distance between the anterior pretransverse cirrus and the anteriormost transverse cirrus (0.6-2.1% of body length) and the arrangement of the transverse cirri (oblique row); Rimaleptus longitrichus, the arrange of contractile vacuoles and longitudinal ciliary rows anteriorly spaced; Frontonia subtropica, number of somatic kineties (approximately 115 rows) and vestibular kineties (5 rows).

• Journal of the Korean Physical Society
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• 제80권
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• pp.516-525
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• 2022

This study is to assess the clinical use of commercial PerFRACTION^TM for patient-specific quality assurance of volumetric-modulated arc therapy. Forty-six pretreatment verification plans for patients treated using a TrueBeam STx linear accelerator for lesions in various treatment sites such as brain, head and neck (H&N), prostate, and lung were included in this study. All pretreatment verification plans were generated using the Eclipse treatment planning system (TPS). Dose distributions obtained from electronic portal imaging device (EPID), ArcCHECK^TM, and two-dimensional (2D)/three-dimensional (3D) PerFRACTION^TM were then compared with the dose distribution calculated from the Eclipse TPS. In addition, the correlation between the plan complexity (the modulation complexity score and the leaf travel modulation complexity score) and the gamma passing rates (GPRs) of each quality assurance (QA) system was evaluated by calculating Spearman's rank correlation coefficient (r_s) with the corresponding p-values. The gamma passing rates of 46 patients analyzed with the 2D/3D PerFRACTION^TM using the 2%/2 mm and 3%/3 mm criteria showed almost similar trends to those analyzed with the Portal dose imaging prediction (PDIP) and ArcCHECK^TM except for those analyzed with ArcCHECK^TM using the 2%/2 mm criterion. Most of weak or moderate correlations between GPRs and plan complexity were observed for all QA systems. The trend of mean rs between GPRs using PDIP and 2D/3D PerFRACTION^TM for both criteria and plan complexity indices as in the GPRs analysis was significantly similar for brain, prostate, and lung cases with lower complexity compared to H&N case. Furthermore, the trend of mean rs for 2D/3D PerFRACTION^TM for H&N case with high complexity was similar to that of ArcCHECK^TM and slightly lower correlation was observed than that of PDIP. This work showed that the performance of 2D/3D PerFRACTION^TM for pretreatment patient-specific QA was almost comparable to that of PDIP, although there was small difference from ArcCHECK^TM for some cases. Thus, we found that the PerFRACTION^TM is a suitable QA system for pretreatment patient-specific QA in a variety of treatment sites.

• 대한수학회지
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• 제55권6호
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• pp.1529-1540
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• 2018

The matrix equation $X^p+A^*XA=Q$ has been studied to find the positive definite solution in several researches. In this paper, we consider fixed-point iteration and Newton's method for finding the matrix p-th root. From these two considerations, we will use the Newton-Schulz algorithm (N.S.A). We will show the residual relation and the local convergence of the fixed-point iteration. The local convergence guarantees the convergence of N.S.A. We also show numerical experiments and easily check that the N.S. algorithm reduce the CPU-time significantly.

• Parasites, Hosts and Diseases
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• 제61권3호
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• pp.317-324
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• 2023

Standard- and large-sized eggs of Trichuris trichiura were found in the feces of schoolchildren in Yangon, Myanmar during epidemiological surveys and mass deworming with albendazole in 2017-2019. The standard-sized eggs were identified as those of T. trichiura, but it was necessary to exclude the possibility of the large-sized eggs belonging to Trichuris vulpis, a dog whipworm. We conducted morphological and molecular studies to determine the species of the 2 types of Trichuris eggs. Individual eggs of both sizes were isolated from Kato-Katz fecal smears (n=20) and mechanically destroyed using a 23G injection needle. Nuclear DNA was extracted, and the 18S rRNA region was sequenced in 15 standard-sized eggs and 15 large-sized eggs. The average size of standard-sized eggs (T. trichiura) was 55.2×26.1 ㎛ (range: 51.7-57.6×21.3-28.0 ㎛; n=97), whereas the size of large-sized eggs was 69.3×32.0 ㎛ (range: 65.1-76.4×30.1-34.5 ㎛; n=20), slightly smaller than the known size of T. vulpis. Regarding standard-sized eggs, the 18S rRNA nucleotide sequences exhibited 100% homology with T. trichiura deposited in GenBank and 88.6-90.5% homology with T. vulpis. Regarding large-sized eggs, the nucleotide sequences showed 99.8-100% homology with T. trichiura in GenBank and 89.6-90.7% homology with T. vulpis. Both standard- and large-sized eggs of Trichuris spp. found in Myanmar schoolchildren during 2017-2019 were morphologically and molecularly confirmed to belong to T. trichiura. The conversion of eggs from smaller to large sizes might be due to anthelmintic treatments with albendazole.

• 대한수학회보
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• 제50권6호
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• pp.1863-1871
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• 2013

For a ring R with an automorphism ${\sigma}$, an n-additive mapping ${\Delta}:R{\times}R{\times}{\cdots}{\times}R{\rightarrow}R$ is called a skew n-derivation with respect to ${\sigma}$ if it is always a ${\sigma}$-derivation of R for each argument. Namely, if n - 1 of the arguments are fixed, then ${\Delta}$ is a ${\sigma}$-derivation on the remaining argument. In this short note, from Bre$\check{s}$ar Theorems, we prove that a skew n-derivation ($n{\geq}3$) on a semiprime ring R must map into the center of R.

• 대한전자공학회논문지SD
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• 제47권5호
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• pp.31-40
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• 2010

본 논문에서는 IEEE 802.11n 무선 랜 표준용 LDPC 복호기 프로세서를 설계하였다. 설계된 프로세서는 IEEE 802.11n 표준의 블록길이 1,944와 부호화율 1/2의 패리티 검사 행렬을 지원하며, 하드웨어 감소를 위해 최소합 알고리듬과 layered 구조를 적용하였다. 최소합 알고리듬의 특징을 이용한 검사노드 메모리 최소화 방법을 고안하여 적용하였으며, 이를 통해 기존방법의 메모리 크기의 25%만을 사용하여 구현하였다. 설계된 프로세서를 $0.35-{\mu}m$ CMOS 셀 라이브러리로 합성한 결과, 200,400 게이트와 19,400 비트의 메모리로 구현되었으며, 80 MHz@2.5V로 동작하여 약 135 Mbps의 성능을 갖는다. 설계된 회로는 FPGA 구현을 통해 하드웨어 동작 검증과 복호성능을 분석하였으며, 이를 통해 설계된 LDPC 복호기의 유용성을 입증하였다.

• 대한의생명과학회지
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• 제23권2호
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• pp.73-79
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• 2017

Pulse pressure is an independent risk factor for cardiovascular disease. The aim of the present study was to assess the association between pulse pressure and metabolic syndrome in Korean men. The study subjects were 8,439 adults aged 40 to 64 years, who underwent health screening examination from January 2012 to December 2014 at the Health Promotion Center of one hospital in Gyeonggi-do for general health check-up. They include the metabolic syndrome absent group (Absent, n=3,078), the pre-metabolic syndrome group (Pre-MetS, n=4,242) and the metabolic syndrome group (MetS, n=1,119). Progressive increase in pulse pressure was demonstrated for increasing components of the metabolic syndrome (P<0.001). The pulse pressure according to the degree of the metabolic syndrome was higher in the pre-MetS and MetS groups compared to the Absent group (P<0.001). Systolic and diastolic blood pressure, total cholesterol, triglyceride, fasting glucose, and abdominal obesity positively correlated with pulse pressure (P<0.001).

• Journal of Species Research
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• 제1권2호
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• pp.218-223
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• 2012

While preparing a floristic study of Korean hepatics, we discovered four unrecorded species collected from Mt. Geumo, Donggang river, Mt. Deokhang, and Mt. Naebyeon in Korea. Plagiochila shangaica Steph., Porella stephaniana (C. Massal.) S. Hatt., Porella chinensis (Steph.) S. Hatt., Solenostoma horikawanum (Amakawa) V$\acute{a}\check{n}$a, Hentschel & J. Heinrichs are reported for the first time in Korea here.