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Statistical Issues in the Articles Published in the Journal of Veterinary Clinics (한국임상수의학회지에 발표된 논문의 통계분석 검토)

  • Pak, Son-Il;Oh, Tae-Ho
    • Journal of Veterinary Clinics
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    • v.27 no.2
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    • pp.170-174
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    • 2010
  • With the ease availability of statistical software and powerful computers the application of statistical methods in domestic veterinary journals is on the increase. In parallel with this benefit, statistical errors are not uncommon even in renowned scientific and medical journals. These errors may lead to misinterpretation of the data, thereby, subjected to faulty conclusions. A systematic review of articles published in 8 issues of the Journal of Veterinary Clinics during 2006-2007 was performed to assess the statistical methodology and reporting. Ninety-four (72.9%) articles of the 129 original articles screened included any inferential statistical analysis in the article, including comparison of 3 or more groups (53 or 56.4%), comparison of independent 2 groups (40 or 42.6%), and paired t-test (9 or 9.6%) in order. Of the 94 articles in which statistical analysis was done 62 (or 66.0%) had at least 1 statistical error. Errors included failure to apply or incorrectly applying independent Student's t-test for paired data or vice versa, inappropriate use of t-test for more than 3 groups and failure in chi-square test to consider continuity-correction for small expected frequencies. The common errors in ANOVA were failure to validate assumption of the test, inappropriate post-hoc multiple-comparison and incorrect assumption of independence of data in repeated measures design. Reporting errors included failure to state statistical methods and failure to state specific test if more than 1 test was done. It is suggested that an editorial effort would be necessary to achieve the improvement of appropriate statistical procedures through the publication of statistical guidelines to author(s).

MICROLEAKAGE OF CURRENT DENTIN BONDING SYSTEMS (복합레진 수복시 복합용기 및 단일용기 상아질 접착제의 미세변연누출에 관한 연구)

  • Ryu, Ju-Hee;Park, Dong-Sung;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.24 no.1
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    • pp.55-66
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    • 1999
  • The purpose of this study was to evaluate the microleakage of 5 current dentin bonding systems which are composed of 2 multi-bottle systems(Scotchbond Multi-Purpose, All Bond2) and 3 one-bottle systems(Single bond, One-Step, Prime & Bond). In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of sixty extracted human premolars and molars on cementum margin. The experimental teeth were randomly divided into six groups of 10 samples (20 surfaces) each, Group 1 : Scotchbond Multi-Purpose ; Group 2 : All Bond 2 ; Group 3 : Single Bond ; Group 4 : One-Step ; Group 5 : Prime & Bond ; Group 6 : no bonding agent(control). The bonding agent and composite resin were applied for each group following the manufacturer's instructions. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 60 teeth were placed in 2% Methylene blue dye for 24 hours, then rinsed with tab water. The specimen were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen were then observed with a stereomicroscope at ${\times}20$. The results of study were statistically analyzed using the Student-Newmann-Keul's Methods and the Mann-Whitney Rank Sum Test. The resin/dentin interfaces were examined under Scanning Electron Microscopy. The results of this study were as follows. 1. None of the dentin bonding systems used in this study showed significant difference in leakage values at both the enamel and the dentin margins (P>0.05). 2. In all groups except the control, leakage value seen at the enamel margin was significantly lower than that seen at the dentin margin (P<0.05). 3. Compared to the control group, all the groups treated with dentin bonding systems showed significantly lower leakage value at both enamel and dentin margins (P<0.05). 4. In the SEM view, gaps were observed in the composite resin / dentin interface in group 6 where no dentin bonding agent was used, and in all the other groups (group 1, 2, 3, 4, 5) composite resin, hybrid layer, and dentin were seen to be closely adhering to each other where there were no leakages. Well-developed resin tags 3~100${\mu}m$ in length infiltrated dentinal tubules past the hybrid layer and a hybrid layer 1~5${\mu}m$ thick had developed between the dentinal surface and the composite resin surface.

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DEHP, DEP and DBP Exposure Analysis using Urinary Metabolites of Gyonggi Province University Students

  • Lee, JangWoo;Kho, YoungLim;Kim, SungKyoon;Choi, Kyungho;Hwang, SeongHee;Jeong, Jeeyeon;Kim, Pangyi
    • Journal of Environmental Health Sciences
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    • v.39 no.5
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    • pp.408-417
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    • 2013
  • Objectives: Phthalates are used as plasticizers in polyvinyl chloride (PVC) plastics. As phthalate plasticizers are not chemically bound to the PVC, they can leach, migrate or evaporate into indoor air and atmosphere, foodstuffs, other materials, etc. Therefore, humans are exposed through ingestion, inhalation, and dermal exposure over their entire lifetime, including during intrauterine development. In particular, university students have a great number of opportunities to contact products including phthalates during campus life (food packaging, body care products, cosmetic, lotions, aftershave, perfume etc.). The purpose of this study was to examine levels of phthalate exposure as undergraduate students begin to use pharmaceuticals and personal care products including phthalates. Methods: Phthalate metabolites, mono-ethyl phthalate (MEP), mono-n-butyl phthalate (MnBP), mono-isobutyl phthalate (MiBP), mono-2- ethylhexyl phthalate (MEHP), {(mono-(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP}, and mono-(2-ethlyl-5-oxohexyl) phthalate (MEOHP} were examined. 80 urine samples collected from university students were analyzed using LC/MS/MS(API 4000, Applied Bioscience) with on-line enrichment and columnswitching techniques. This study was carried out at Y university located in Gyonggi Province from 2008 to 2011. Results: The detection limit of phthalate metabolites were 0.03 ng/mL for MEP, 0.11 ng/mL for MnBP, 0.08 ng/mL for MiBP, 0.93 ng/mL for MEHP, 0.19 ng/mL for MEOHP and 0.16ng/mL for MEHHP. MnBP showed the highest urinary levels (median: 31.6 ug/L, 24.8 ug/g creatinine (cr)). Concentrations were also high for MEHHP (median: 24.1 ug/L, 19.0 ug/g cr), followed by MEOHP (median: 22.8 ug/L, 17.9 ug/g cr). In individual cases, the maximum level reached up to 348 ug/L, and 291 ug/g cr, respectively. The urinary and creatinine adjusted levels of MEP were lower than those for DBP and DEHP metabolites, but were higher in 95th percentiles. As a result, the mean daily DEP intake value was 2.3 ${\mu}g/kg$ bw/day, 3.5 ${\mu}g/kg$ bw/day for DEHP and 4.9 ${\mu}g/kg$ bw/day for DBP. Conclusion: These students' phthalate exposure levels were below the international safe level set by the EU, but higher than the 2012 KFDA survey of the age group from 3 to 18.

Evaluation of Cancer Detection Efficiency by Means of Hybrid and Inverse Filter in Chest Radiography (디지털 흉부 방사선 영상에서 Hybrid Filter와 Inverse Filter를 적용한 종양의 검출능 평가)

  • Kim, Youn-Young;Kim, Tae-Young;Kim, Hyun-Ji;Park, Min-Seock;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.36 no.4
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    • pp.319-326
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    • 2013
  • The purpose of this study is to evaluate usefulness of Hybrid image and Inverse image about detection of tumor shadow in chest radiography using ROC analysis. Original images of 60 cases are selected from Standards digital image date base issued by the Japanese Society of Radiological Technology. Through computer language of C, Inverse images of 60 cases and Hybrid image of 30 cases are made. The continues reading experiment was conducted. In the case of inverse image were observed by 5 radiographer and 2 radiologist. In the case of In case of Hybrid image were observed by 3 student radiographer and 2 experienced radiographer. ROC curve are constructed using ROCKIT Program made by Metz. In Inverse image, a Az of average ROC curve was increases from 0.742 of original image to 0.775 of inverse image. In normal cases, the effect of the detrimental is same to that of the beneficial, however In abnormal cases, the beneficial effect is greater than detrimental effect. However in Hybrid image, a Az of average ROC curve was decreases from 0.5253 of original image to 0.4868 of Hybrid image. In Normal cases, the effect of the detrimental is greater than that of the Beneficial, however In abnormal cases, the Beneficial effect is greater than detrimental effect. The inverse image can be more positively considered for the detecting of tumor than the hybrid image.

The Study of Driving Fatigue using HRV Analysis (HRV 분석을 이용한 운전피로도에 관한 연구)

  • 성홍모;차동익;김선웅;박세진;김철중;윤영로
    • Journal of Biomedical Engineering Research
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    • v.24 no.1
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    • pp.1-8
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    • 2003
  • The job of long distance driving is likely to be fatiguing and requires long period alertness and attention, which make considerable demands of the driver. Driving fatigue contributes to driver related with accidents and fatalities. In this study, we investigated the relationship between the number of hours of driving and driving fatigue using heart rate variability(HRV) signal. With a more traditional measure of overall variability (standard deviation, mean, spectral values of heart rate). Nonlinear characteristics of HRV signal were analyzed using Approximate Entropy (ApEn) and Poincare plot. Five subjects drive the four passenger vehicle twice. All experiment number was 40. The test route was about 300Km continuous long highway circuit and driving time was about 3 hours. During the driving, measures of electrocardiogram(ECG) were performed at intervals of 30min. HRV signal, derived from the ECG, was analyzed using time, frequency domain parameters and nonlinear characteristic. The significance of differences on the response to driving fatigue was determined by Student's t-test. Differences were considered significant when a p value < 0.05 was observed. In the results, mean heart rate(HRmean) decreased consistently with driving time, standard deviation of RR intervals(SDRR), standard deviation of the successive difference of the RR intervals(SDSD) increased until 90min. Hereafter, they were almost unchanging until the end of the test. Normalized low frequency component $(LF_{norm})$, ratio of low to high frequency component (LF/HF) increased. We used the Approximate Entropy(ApEn), Poincare plot method to describe the nonlinear characteristics of HRV signal. Nonlinear characteristics of HRV signals decreased with driving time. Statistical significant is appeared after 60 min in all parameters.

The Effect of Social Supports, Psychological Behaviors, and Stress on the Depression Symptoms of College Students -Validation of Casual Model using Covariance Structure Analysis- (대학생의 사회적지지, 심리적 행동특성 및 스트레스가 우울수준에 미치는 영향 -공분산구조분석에 의한 인과모델의 검증-)

  • Park, Ui-Su;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.209-218
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    • 2017
  • This study examined the influence of social support (social support from family, social support from friends), psychological behavioral characteristics (self-esteem, interpersonal dependency, locus of control), and stress on the depression levels of college students. The study subjects were 546 college students in D city. The survey was conducted using a self-administered questionnaire in October 2015. As a result, the depression levels were significantly higher in the group showing lower family and friends' social support, self-esteem, and locus of control, while it was significantly higher in the group showing higher interpersonal dependency and stress. The depression levels of the subjects showed a negative correlation with family and friends' social support, self-esteem, and locus of control, but a positive correlation with interpersonal dependency and stress. Covariance structure analysis revealed an increase in the depression levels of college students when the awareness of the stress source was higher, and when the awareness of social support or psychological behavioral characteristics was lower. These results suggest that the depression levels of college students would be increased when the social support and psychological behavioral characteristics are low, and when stress is high. In particular, it was influenced much more by stress than other factors. Therefore, to decrease the depression levels of college students, it would be necessary to put efforts to understand their main stress sources and then reduce them.

Breast Cancer Clustering in Kanagawa, Japan: A Geographic Analysis

  • Katayama, Kayoko;Yokoyama, Kazuhito;Yako-Suketomo, Hiroko;Okamoto, Naoyuki;Tango, Toshiro;Inaba, Yutaka
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.1
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    • pp.455-460
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    • 2014
  • Background: The purpose of the present study was to determine geographic clustering of breast cancer incidence in Kanagawa Prefecture, using cancer registry data. The study also aimed at examining the association between socio-economic factors and any identified cluster. Materials and Methods: Incidence data were collected for women who were first diagnosed with breast cancer during the period from January to December 2006 in Kanagawa. The data consisted of 2,326 incidence cases extracted from the total of 34,323 Kanagawa Cancer Registration data issued in 2011. To adjust for differences in age distribution, the standardized mortality ratio (SMR) and the standardized incidence ratio (SIR) of breast cancer were calculated for each of 56 municipalities (e.g., city, special ward, town, and village) in Kanagawa by an indirect method using Kanagawa female population data. Spatial scan statistics were used to detect any area of elevated risk as a cluster for breast cancer deaths and/or incidences. The Student t-test was performed to examine differences in socio-economic variables, viz, persons per household, total fertility rate, age at first marriage for women, and marriage rate, between cluster and other regions. Results: There was a statistically significant cluster of breast cancer incidence (p=0.001) composed of 11 municipalities in southeastern area of Kanagawa Prefecture, whose SIR was 35 percent higher than that of the remainder of Kanagawa Prefecture. In this cluster, average value of age at first-marriage for women was significantly higher than in the rest of Kanagawa (p=0.017). No statistically significant clusters of breast cancer deaths were detected (p=0.53). Conclusions: There was a statistically significant cluster of high breast cancer incidence in southeastern area of Kanagawa Prefecture. It was suggested that the cluster region was related to the tendency to marry later. This study methodology will be helpful in the analysis of geographical disparities in cancer deaths and incidence.

The Effectiveness of Ulmus Davidiana Planch Herbal Acupuncture to Inhibit $NF-{\kappa}B$ Activation on Type II Collagen-induced Arthritis in Mice (유근피(楡根皮) 약침의 $NF-{\kappa}B$ 활성 억제능이 생쥐의 Type II Collagen 유발 관절염에 미치는 영향)

  • Lee, A-Ram;Byun, Hyuk;Park, In-Shik;Jung, Chan-Yung;Kang, Min-Joo;Kim, Eun-Jung;Lee, Seung-Deok;Kim, Kap-Sung
    • Journal of Acupuncture Research
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    • v.24 no.6
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    • pp.15-27
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    • 2007
  • Objectives : The purpose of this study is to investigate the effectiveness of Ulmus davidiana Planch herbal acupuncture(UA) to inhibit nuclear $factor(NF)-{\kappa}B$ activation on type II collagen-induced arthritis (CIA) in mice. Methods : Using an in vitro test, the synoviocytes picked out from the experimental CIA mice were subcultured. The synoviocyte cells were treated with phorbol-12-myristate-13-acetate(PMA) for 1 hour prior to the addition of indicated concentrations($0.4\;-\;1.0mg/m{\ell}$) of UA, and the cells were further incubated for 24 hours. The in vivo test, $NF-{\kappa}B$ p65, inducible nitric oxide synthase(iNOS), cyclooxygenase-2(COX-2), vascular cell adhesion molecule(VCAM)-1 production and apoptosis was observed by immunohistochemical staining. Results : The PMA-induced $I{\kappa}B$ kinase(IKK), iNOS and COX-2 mRNA expression were dose-dependently decreased in UA treated synoviocytes. Using the in vivo test, the number of eosinophils in mice treated with UA noticeably decreased in the the CIA group(P<0.05 using student t test). In mice treated with UA, there was less cartilage erosion. less bone destruction, mild synovial hyperplasia, mild fibrosis, and mild angiogenesis with less MIP-2 production. By immunohistochemical staining, suppression of $NF-{\kappa}B$ p65, iNOS production, inhibition of COX-2 production, inhibition of VCAM-1 production and inducing apoptosis were observed. Conclusions : These results suggest that UA might be applicable to the therapy of RA to suppress $NF-{\kappa}B$ activation.

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Study on the Adolescent Patient′s Stress during Hospitalization (청년기환자의 입원생활에 따르는 긴장에 관한 연구)

  • 백영주
    • Journal of Korean Academy of Nursing
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    • v.6 no.1
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    • pp.72-79
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    • 1976
  • Contemper nursing literature place much importance on human- centered and individualized care. Nursing research has related stress during hospitalization of adolescent patients to adaptation to a new environment, isolation from friends, limitation due to illness, over protection of parents and communication with member of the medical team. The investigator conducted this study in the hope that an understanding of adolescents responses to hospitalization, their perceptions, the kinds and levels of stress, and the relationships between stressors and individual characteristics would contribute to the improvement of adolescent patient care. The objective of the study was to obtain informations related to the adolescents psychological stress experience during hospitalization, specifically stress from interpersonal relationships and communication, isolation from the family, social or economic problems, illness and from the treatment environment and nursing care. An interview schedule adopted from Holmes and Rahe's Social Readjustment Rating Scale and selected items from Voicer's instrument on stress-producing events was used with 120 adolescent inpatients aged 13 to 18 years three general hospitals in Seoul during Aug. 10, to Sep. 30, 1975. 1. The sample consisted of 66 male and 54 female patients. Sixty-six percent were late adolescents, aged 16 to 18 years: 4% were early adolescents, aged 13 to 15 years. The primary cause for hospitalization was for orthopedic problems (35.8%). More than half of these (54.4%) were due to injury or accident. 2. Stress eclated to illness revealed the highest score (4.97), followed by stress related to treatment environment and nursing care (4.34) , isolation from family and social or economic problems (4.01) and interpersonal relationships and communication (3.96). 3. The perceived indifference of doctors and nurses was a serious cause of stress (mean=4.83). Fellow patients and visitors caused least stress (mean=2.06). 4. Discontinuation of education or unemployment were major stressful events (mean=4.71). Least stressful was isolation from the family (mean=3.47). 5. More than 94% of the respondents expressed fears related to body image (mean=4.97) 6. Within the category of treatment environment and nursing care, items related to restrictions because of treatment, discomfort because of treatment, inadequate explanation from nurses about procedures were rated as severe stress events (mean=4.6). Items related to the ward environment and to having a relative stay with them were seen by the group as less serious events (mean=3.7). 7. Stress related to interpersonal relationships and communication was correlated positively with female patients and those preferring passive activities. (P〈0.05) 8. Stress related to family problems was positively related to female and early adolescent patients (P< 0.05). Stress related to social problems was positively , elated to students and those preferring active pursuits (P< 0.05). 9. There were no correlation between the high stress related to disease and any of the characteristic items. (P> 0.05) 10. Stress related to treatment environment and nursing care was positively related of early adolescent and female and student patients. (P< 0.05) This group of hospitalized adolescents reported high level of stress related to treatment environment and nursing care, due to lack of consideration of normal growth and development and individual characteristics. The findings have important implications for the planning of effective, individualized, comprehensive nursing care of adolescents during hospitalization.

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Cognition of registered nurse on emergency treatment for oral and maxillofacial injury in Jeju province (제주 지역 간호사의 구강 악안면 영역 손상에 대한 응급 처치 인식도)

  • Lee, Byoung-Jin;Song, Hyo-Jeong;Lim, Gil-Chai;Kahm, Se-Hoon;Kim, Sung-Joon
    • The Journal of the Korean dental association
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    • v.50 no.12
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    • pp.763-770
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    • 2012
  • The purposes of this work were to assess the cognition of the registered nurse(RN) on oral and maxillofacial emergency treatment and to compare cognition of the RN with that of the 119 emergency medical technician(EMT). 450 RNs who were working at each of secondary hospitals in Jeju province had responded to the questionnaire. Independent sample t-test and chi-square test were used to assess the state of RN on dental emergency treatment and to compare RN with EMT. The question 'education time on dentistry in formal education' that marked '0 hour' and '1-3 hours' were 73.3% and 20.0%, respectively. The question 'refresher training class on dentistry' that marked '0 hour' and '1-3 hours' were 92.9% and 6.7%, aggregately 99.6%. The results showed low score in the question 'reduction of temporo-mandibular joint(TMJ)'($1.67{\pm}0.857$), 'fixation of dislocated TMJ'($1.70{\pm}0.853$) and 'post-avulsed tooth treatment'($1.78{\pm}0.774$) by 5-point Likert scale. Likewise, the scores were $2.02{\pm}0.806$ in the question 'treatment of maxillofacial trauma', $2.76{\pm}1.061$ in the question 'emergent care of avulsed tooth', $2.70{\pm}1.095$ in the question 'treatment time of avulsed tooth' and $2.79{\pm}1.056$ in the question 'mouth guard', respectively. Compared to EMT, results of RN showed a statistically lower figure(p<0.05) in all items compared except the question 'medicine control', and the question 'doctor care in emergency room' was borderline(p=0.069). From this study, it is necessary for RN and student of nursing science to be educated on the oral and maxillofacial emergency treatment for the initial management of injuries. Authors suggest further co-study and nation-wide research with nursing care.