• 대한바이러스학회지
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• 제29권2호
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• pp.75-86
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• 1999

Rotaviruses belong to Reoviridae causes diarrhea in human beings as well as domestic animals. This study was conducted to see what type of human rotaviruses are distributed in Seoul and Kyung-gi province. Twenty two of 81 patients showed rotavirus positive with diagnostic kit and RNA electropherosis. We isolated all of rotaviruses from the patients. Electropherotypes of 22 isolates showed 4:2:3:2 pattern whereas those migration patterns were long type. All of those isolates belonged to group A. Twenty out of 22 isolates reacted with monoclonal antibodies specific to G1, P1A and subgroup II, whereas rest of them, A-29 and K-30 reacted with subgroup I specific monoclonal antibody. The nucleotide sequence of an isolate K-21 showed $98{\sim}100%$ and $90{\sim}96%$ homologies with those of Wa and KU strain, respectively.

• Communications for Statistical Applications and Methods
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• 제24권6호
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• pp.561-581
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• 2017

Bayesian statistics can play a key role in the design and analysis of clinical trials and this has been demonstrated for medical device trials. By 1995 Bayesian statistics had been well developed and the revolution in computing powers and Markov chain Monte Carlo development made calculation of posterior distributions within computational reach. The Food and Drug Administration (FDA) initiative of Bayesian statistics in medical device clinical trials, which began almost 20 years ago, is reviewed in detail along with some of the key decisions that were made along the way. Both Bayesian hierarchical modeling using data from previous studies and Bayesian adaptive designs, usually with a non-informative prior, are discussed. The leveraging of prior study data has been accomplished through Bayesian hierarchical modeling. An enormous advantage of Bayesian adaptive designs is achieved when it is accompanied by modeling of the primary endpoint to produce the predictive posterior distribution. Simulations are crucial to providing the operating characteristics of the Bayesian design, especially for a complex adaptive design. The 2010 FDA Bayesian guidance for medical device trials addressed both approaches as well as exchangeability, Type I error, and sample size. Treatment response adaptive randomization using the famous extracorporeal membrane oxygenation example is discussed. An interesting real example of a Bayesian analysis using a failed trial with an interesting subgroup as prior information is presented. The implications of the likelihood principle are considered. A recent exciting area using Bayesian hierarchical modeling has been the pediatric extrapolation using adult data in clinical trials. Historical control information from previous trials is an underused area that lends itself easily to Bayesian methods. The future including recent trends, decision theoretic trials, Bayesian benefit-risk, virtual patients, and the appalling lack of penetration of Bayesian clinical trials in the medical literature are discussed.

• The Korean Journal of Ecology
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• 제18권1호
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• pp.121-136
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• 1995

The forest vegetation on Mt. Ch’ongnyang was investigated for phytosociological analysis of the vegetation types and interspecific association. The forest was classified into seven vegetation units; A: Quercus Mongolica community, A-1: Group of Quercus variabilis, A-1-a: Subgroup of Pinus densiflora, A-1-b: Typical subgroup, A-2: Group of Aconitum trilobum, A-3: Group of Quercus dentata, B: Zelkova serrata communty. The group of Quercus variabilis was distributed on southeast- and southwest-facing slopes in 400~830 m above the sea level, and organic matter in the soil was 3.36~4.67％. The group of Aconitum trilobum was distributed on northeast- and northwest-facing slopes in 650~830 m above the sea level, and organic matter in the soil was 7.18％. The group of Quercus dentata was distributed on southwest-facing solpes in the vicinity of 810 m above the sea level, and organic matter in the soil was 9.7％. The Zelkova serrata community was distributed in the vicinity of ravines, and organic matter in the soil was 7.6％. The contents of Mg and Ca, and electric conductivity in the Zelkova serrata community were relatively high, 11.82 me/100mg, and 11.27 me/100mg, 102.2 μ mos/cm, respectively. In the results of polar ordination, environmental gradient of axis Ⅰ and axis Ⅱwere correlated with moisture, inclination and azimuth, respectively. Group of Quercus variabilis has occurred in xeric, group of Aconitum trilobum in submesic, and the Zelrova serrata community in mesic sites. In the meantime the interspecific association analysis based on chi-square yielded three species groupings with high positive affinity(p<0.01), i.e.group Ⅰ consisted of 18 species, including Acer pseudo-sieboldianum, Ansliaea acerifolia, Aconitum trilobum and group Ⅲ consisted of 19 species, in cluding Zelrova serrata, Oplismenus undulatifolius, Acer truncatum var. barbinerve, respectively.

• Clinical and Experimental Pediatrics
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• 제64권7호
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• pp.341-346
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• 2021

Background: The results differ among published studies regarding exposure to meconium and the risk of developing autism spectrum disorders (ASDs). Purpose: The present study pooled all of the epidemiologic studies retrieved from broader databases on the association between meconium exposure and risk of developing ASD in children. Methods: The Web of Science, PubMed, Scopus, and Google Scholar databases were searched without language restrictions for articles published between their inception to February 20, 2020, using relevant keywords. The pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated as random-effect estimates of the associations among studies. A subgroup analysis was conducted to explore any potential sources of heterogeneity among studies. Results: The pooled estimate of OR reported a weakly significant association between meconium exposure and ASD development in children (OR, 1.13; 95% CI, 1.03-1.24). There was low heterogeneity among the articles reporting risk for ASD among children (I²=19.3%; P=0.259). The results of subgroup analysis based on meconium exposure showed a significant association between a meconium-stained neonate and ASD development (OR, 1.18; 95% CI, 1.11-1.24). Couclusion: Meconium exposure was weakly associated with an increased risk of ASD. However, more evidence based on large prospective cohort studies is required to provide conclusive evidence about whether meconium exposure is associated with an increased risk of ASD development.

• Safety and Health at Work
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• 제13권3호
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• pp.269-278
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• 2022

Background: PTSD (Post-traumatic stress disorder, PTSD) had a great impact on health care workers during the COVID-19 (Corona Virus Disease 2019, COVID-19). Better knowledge of the prevalence of PTSD and its risk factors is a major public health problem. This study was conducted to assess the prevalence and important risk factors of PTSD among medical staff during the COVID-19. Methods: The databases were searched for studies published during the COVID-19, and a PRISMA (preferred reporting items for systematic review and meta-analysis) compliant systematic review (PROSPERO-CRD 42021278970) was carried out to identify articles from multiple databases reporting the prevalence of PTSD outcomes among medical staff. Proportion random effect analysis, I² statistic, quality assessment, subgroup analysis, and sensitivity analysis were carried out. Results: A total of 28 cross-sectional studies and the PTSD results of doctors and nurses were summarized from 14 and 27 studies: the prevalences were 31% (95% CI [confidence interval, CI]: 21%-40%) and 38% (95% CI: 30%-45%) in doctors and nurses, respectively. The results also showed seven risks (p < 0.05): long working hours, isolation wards, COVID-19 symptoms, nurses, women, fear of infection, and pre-existing mental illness. Two factors were of borderline significance: higher professional titles and married. Conclusion: Health care workers have a higher prevalence of PTSD during COVID-19. Health departments should provide targeted preventive measures for medical staff away from PTSD.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.114.1-114
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• 2003

A new isolate of rod-shaped virus was identified from grafted cactus, Gymnocalycium mihanovichii grafted onto Hylocereus trigonus, in Korea. The virus proved to be a new Tobamovirus and called previously as Tobamovirus-Ca for which we suggest the name Cactus mild mottle virus(CMMoV), because it produced systemic mild mosaic symptoms on its original host. CMMoV is distantly related to known species of the genus Tobamovirus on the basis of host range, serological and sequence analyses. Western blot analysis showed that CMMoV is serologically unrelated to Summons' Opuntia virus which is the only known species of the genus found in cactus plants. The 3'-terminal 2,910 nucleotides have been sequenced for the virus. The coat protein (CP) and movement protein (MP) genes encode 161 and 306 amino acids residues, respectively. The nucleotide and amino acid sequences of the CP were 39.6 ％ to 49.2 ％ and 26.4 ％ to 40.3 ％ identical to other tobamoviruses, respectively. The MP and 3' noncoding region shared 16.3 ％ to 23.3 ％ and 44.6 ％ to 63.4 ％ identities, respectively, with the members of the genus. Phylogenetic tree analysis of the CP gene revealed that CMMoV clusters with members of subgroup I of Tobamovirus. CMMoV particles contained genomic RNA along with two subgenomic RNAs, and this characteristics is common in the members of the subgroup II. This is the first information of sequence and comparative analysis of a Tobamovirus that infects cactus.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1034-1043
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• 2021

Objective: The purpose of this meta-analysis was to investigate the pooled agreements of the coronary artery calcium (CAC) severities assessed by electrocardiogram (ECG)-gated and non-ECG-gated CT and evaluate the impact of the scan parameters. Materials and Methods: PubMed, EMBASE, and the Cochrane library were systematically searched. A modified Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to evaluate the quality of the studies. Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and the correlation coefficient of the CAC scores or the weighted kappa for the categorization of the CAC severities detected by the two modalities. The heterogeneity among the studies was also assessed. Subgroup analyses were performed based on factors that could affect the measurement of the CAC score and severity: slice thickness, reconstruction kernel, and radiation dose for non-ECG-gated CT. Results: A total of 4000 patients from 16 studies were included. The pooled bias was 62.60, 95% LOA were -36.19 to 161.40, and the pooled correlation coefficient was 0.94 (95% confidence interval [CI] = 0.89-0.97) for the CAC score. The pooled weighted kappa of the CAC severity was 0.85 (95% CI = 0.79-0.91). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, the agreement between the CAC categorizations was better when the two CT examinations had reconstructions based on the same slice thickness and kernel. Conclusion: The pooled agreement of the CAC severities assessed by the ECG-gated and non-ECG-gated CT was excellent; however, it was significantly affected by scan parameters, such as slice thickness and the reconstruction kernel.

• Korean Journal of Radiology
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• 제21권4호
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• pp.450-461
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• 2020

Objective: We performed a meta-analysis to evaluate the agreement of cardiac computed tomography (CT) with cardiac magnetic resonance imaging (CMRI) in the assessment of right ventricle (RV) volume and functional parameters. Materials and Methods: PubMed, EMBASE, and Cochrane library were systematically searched for studies that compared CT with CMRI as the reference standard for measurement of the following RV parameters: end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), or ejection fraction (EF). Meta-analytic methods were utilized to determine the pooled weighted bias, limits of agreement (LOA), and correlation coefficient (r) between CT and CMRI. Heterogeneity was also assessed. Subgroup analyses were performed based on the probable factors affecting measurement of RV volume: CT contrast protocol, number of CT slices, CT reconstruction interval, CT volumetry, and segmentation methods. Results: A total of 766 patients from 20 studies were included. Pooled bias and LOA were 3.1 mL (-5.7 to 11.8 mL), 3.6 mL (-4.0 to 11.2 mL), -0.4 mL (5.7 to 5.0 mL), and -1.8% (-5.7 to 2.2%) for EDV, ESV, SV, and EF, respectively. Pooled correlation coefficients were very strong for the RV parameters (r = 0.87-0.93). Heterogeneity was observed in the studies (I² > 50%, p < 0.1). In the subgroup analysis, an RV-dedicated contrast protocol, ≥ 64 CT slices, CT volumetry with the Simpson's method, and inclusion of the papillary muscle and trabeculation had a lower pooled bias and narrower LOA. Conclusion: Cardiac CT accurately measures RV volume and function, with an acceptable range of bias and LOA and strong correlation with CMRI findings. The RV-dedicated CT contrast protocol, ≥ 64 CT slices, and use of the same CT volumetry method as CMRI can improve agreement with CMRI.

• Investigative Magnetic Resonance Imaging
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• 제16권1호
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• pp.16-24
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• 2012

목적: Dixon 정량 화학적 변위 자기공명영상(QCSI)의 척추 골수 지방함량과 이중에너지 방사선 흡수법 (DXA)를 통한 BMD 값과의 상관성을 알아본다. 대상과 방법: QCSI와 간의 화학적 변위영상을 포함한 전신 자기공명영상(MRI)과 요추의 DXA를 시행한 68명의 건강한 사람들[평균연령, 50.7세; 범위, 25-76세; 남/여=36/32]을 대상으로 후향적 연구를 시행하였다. 성별과 T-score에 따라 정상(남/여=27/23)과 골감소증(남/여=9/9)집단으로 나누고, MRI로 척추골수와 간의 지방함량을 측정하였다. 각 집단의 나이, 체질량지수(BMI), 골수 지방함량과 간의 지방함량을 비교하였고, 여성에서는 폐경 전후 각 변수들의 비교를 추가하여 Spearman's 상관계수로 평가하였다. 결과: 남성의 나이, BMI, 척추 골수와 간의 지방함량은 정상과 골감소증 집단 사이에 큰 차이를 보이지 않았다. 여성에서는, 골감소증 집단의 평균 나이가 정상집단에 비해 높았고(p=0.01), 폐경된 경우가 많았으나[폐경 전, 26.1%(6/23); 후, 77.8%(7/9); p<0.05], 다른 변수들은 유의한 차이를 보이지 않았다. 골수 지방함량과의 비교에 있어 여성의 나이는 유일한 의미 있는 변수였다(r=0.43, p<0.05). 결론: Dixon QCSI를 통한 척추 골수 지방함량의 측정은 남녀 모두에 있어 DXA BMD 감소를 정확히 반영하지는 않는다.

• Pediatric Infection and Vaccine
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• 제23권2호
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• pp.109-116
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• 2016

목적: 최근 관찰연구들에서 낮은 혈중 25(OH)D 농도가 호흡기 감염과 관련이 있다는 결과들이 보고되고 있다. 하지만, 소아의 무작위 대조 연구에서 비타민 D의 투여가 호흡기 감염을 예방하는 효과에 대해서는 아직 논란의 여지가 있다. 이번 연구는 비타민 D 보충 요법이 호흡기 감염 예방에 미치는 영향을 체계적 문헌고찰과 메타분석을 통하여 알아보고자 한다. 방법: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trial을 이용하여 소아의 호흡기 감염 예방을 위해 비타민 D 보충을 실험한 무작위 대조 연구들이 분석 대상에 포함되었다. 문헌의 비뚤림 위험도를 평가하기 위해 코크란 연합의 질 평가 방법(Cochrane Collaboration's tool for assessing the risk of bias)을 사용하였다. 연구별로 상대위험도와 95% 신뢰구간을 추출한 후, Review Manager 5.3을 이용하여 메타분석을 시행하였다. 결과: 총 7편의 무작위 대조 연구들이 메타분석 대상에 포함되었다. 임의효과모형을 사용하여 산출된 전체 비타민 D 보충군에서 상대적 위험도는 0.82 (95% CI: 0.69-0.98)이었고, 이질성에 대한 $I^2=62%$ 이었다. 연구 간의 이질성 원인을 파악하기 위해 시행한 하위 집단 분석에서 추적 관찰 기간이 1년 미만인 경우, 대상군의 나이가 5세 이상인 경우, 대상군이 환자인 경우, 비타민 D 투여 요법이 매일 요법인 경우 이질성이 감소하였다. 깔때기 그림에서 출판 비뚤림의 가능성을 시사하는 비대칭 소견을 보였다. 결론: 메타분석 결과는 소아에서 비타민 D 보충요법이 호흡기 감염을 예방하는 데 효과가 있을 수 있음을 보여준다. 하지만, 이번 연구에서는 분석대상에 포함된 연구들이 적고, 연구들 간에 이질성이 존재하며, 출판 비뚤림이 존재할 가능성이 있어 결과를 주의해서 해석할 필요가 있다.