• Title/Summary/Keyword: Observed Variables

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The Association between Pulmonary Function Test Result and Combustible Cigarette Smoking or Electrical Cigarette Smoking in Korean Adults : Using the 2014-2019 Korean national health and nutrition examination survey data (한국 성인에서 일반담배 또는 가열 전자담배를 이용한 흡연 형태와 폐 기능 검사 결과와의 관련성: 2014-2019년도 국민건강영양조사 자료를 이용하여)

  • Il-hwan Kim;Il-Hyun Lee;Sae-Ron Shin
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.1
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    • pp.27-39
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    • 2024
  • Purpose : Smoking is a major factor in chronic obstructive pulmonary disease (COPD), but the effect of electrical cigarette smoking on COPD development is still uncertain. This study aimed to compare the functions of airways and lungs exposed to combustible cigarettes and electrical cigarettes based on the pulmonary function test (PFT) results from the Korean National Health and Nutrition Examination Survey (NHANES). Methods : This study used data from 8,942 participants with PFT results out of 47,309 total subjects from the 6th to 8th Korean NHANES (2014-2015, 2016-2018, and 2019, respectively). Individuals with diseases such as cancer, ex-smokers, and dual tobacco users were excluded. The PFT results were analyzed according to the COPD diagnostic criteria. After adjusting for confounding variables, a complex sample generalized linear model ANOVA test was performed to investigate the association between PFT results and combustible smoker or electrical cigarette user groups. Results : In an analysis based on the obstructive ventilatory disorders (forced expiratory volume in 1 second[FEV1]/forced vital capacity[FVC]<.7), combustible cigarette smokers showed a 3.46 times higher risk of COPD compared to non-smokers, while electrical cigarette smokers exhibited no significant difference in terms of COPD-related risks compared to non-smokers. FEV1 showed a negative relation with combustible cigarette smokers as reported elsewhere (B=-.07, p<.001). FEV1/FVC was negatively related to both combustible cigarette smokers (B=-.03, p<.001) and electrical cigarette smokers (B=-.02, p<.001). Conclusion : FEV1/FVC decreases were observed in the long-term exposure to both combustible and electrical cigarettes. The lower FEV1 in the combustible cigarette group implies the worsening of the severity of COPD, suggesting more damage to the airways and lungs in the short term. Therefore, the temporary electrical cigarettes use for the transition period in order to smoking cessation potentially aids to reduce the harmful effect of combustible cigarettes in COPD development.

Brain Metabolic Network Redistribution in Patients with White Matter Hyperintensities on MRI Analyzed with an Individualized Index Derived from 18F-FDG-PET/MRI

  • Jie Ma;Xu-Yun Hua;Mou-Xiong Zheng;Jia-Jia Wu;Bei-Bei Huo;Xiang-Xin Xing;Xin Gao;Han Zhang;Jian-Guang Xu
    • Korean Journal of Radiology
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    • v.23 no.10
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    • pp.986-997
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    • 2022
  • Objective: Whether metabolic redistribution occurs in patients with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) is unknown. This study aimed 1) to propose a measure of the brain metabolic network for an individual patient and preliminarily apply it to identify impaired metabolic networks in patients with WMHs, and 2) to explore the clinical and imaging features of metabolic redistribution in patients with WMHs. Materials and Methods: This study included 50 patients with WMHs and 70 healthy controls (HCs) who underwent 18F-fluorodeoxyglucose-positron emission tomography/MRI. Various global property parameters according to graph theory and an individual parameter of brain metabolic network called "individual contribution index" were obtained. Parameter values were compared between the WMH and HC groups. The performance of the parameters in discriminating between the two groups was assessed using the area under the receiver operating characteristic curve (AUC). The correlation between the individual contribution index and Fazekas score was assessed, and the interaction between age and individual contribution index was determined. A generalized linear model was fitted with the individual contribution index as the dependent variable and the mean standardized uptake value (SUVmean) of nodes in the whole-brain network or seven classic functional networks as independent variables to determine their association. Results: The means ± standard deviations of the individual contribution index were (0.697 ± 10.9) × 10-3 and (0.0967 ± 0.0545) × 10-3 in the WMH and HC groups, respectively (p < 0.001). The AUC of the individual contribution index was 0.864 (95% confidence interval, 0.785-0.943). A positive correlation was identified between the individual contribution index and the Fazekas scores in patients with WMHs (r = 0.57, p < 0.001). Age and individual contribution index demonstrated a significant interaction effect on the Fazekas score. A significant direct association was observed between the individual contribution index and the SUVmean of the limbic network (p < 0.001). Conclusion: The individual contribution index may demonstrate the redistribution of the brain metabolic network in patients with WMHs.

Impact of Additional Preoperative Computed Tomography Imaging on Staging, Surgery, and Postsurgical Survival in Patients With Papillary Thyroid Carcinoma

  • So Yeong Jeong;Sae Rom Chung;Jung Hwan Baek;Young Jun Choi;Sehee Kim;Tae-Yon Sung;Dong Eun Song;Tae Yong Kim;Jeong Hyun Lee
    • Korean Journal of Radiology
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    • v.24 no.12
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    • pp.1284-1292
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    • 2023
  • Objective: We investigated the impacts of computed tomography (CT) added to ultrasound (US) for preoperative evaluation of patients with papillary thyroid carcinoma (PTC) on staging, surgical extent, and postsurgical survival. Materials and Methods: Consecutive patients who underwent surgery for PTC between January 2015 and December 2015 were retrospectively identified. Of them, 584 had undergone preoperative additional thyroid CT imaging (CT + US group), and 859 had not (US group). Inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) were used to adjust for 14 variables and balance the two groups. Changes in nodal staging and surgical extent caused by CT were recorded. The recurrence-free survival and distant metastasis-free survival after surgery were compared between the two groups. Results: In the CT + US group, discordant nodal staging results between CT and US were observed in 94 of 584 patients (16.1%). Of them, CT accurately diagnosed nodal staging in 54 patients (57.4%), while the US provided incorrect nodal staging. Ten patients (1.7%) had a change in the extent of surgery based on CT findings. Postsurgical recurrence developed in 3.6% (31 of 859) of the CT + US group and 2.9% (17 of 584) of the US group during the median follow-up of 59 months. After adjustment using IPTW (580 vs. 861 patients), the CT + US group showed significantly higher recurrence-free survival rates than the US group (hazard ratio [HR], 0.52 [95% confidence interval {CI}, 0.29-0.96]; P = 0.037). PSM analysis (535 patients in each group) showed similar HR without statistical significance (HR, 0.60 [95% CI, 0.31-1.17]; P = 0.134). For distant metastasis-free survival, HRs after IPTW and PSM were 0.75 (95% CI, 0.17-3.36; P = 0.71) and 0.87 (95% CI, 0.20-3.80; P = 0.851), respectively. Conclusion: The addition of CT imaging for preoperative evaluation changed nodal staging and surgical extent and might improve recurrence-free survival in patients with PTC.

Effects of dietary supplementation of polysaccharide from Agaricus blazei Murr on productive performance, egg quality, blood metabolites, intestinal morphology and microbiota of Korean quail

  • Liang Hong;Zheng Ma;Xueyi Jing;Hua Yang;Jifei Ma;Lei Pu;Jianbin Zhang
    • Animal Bioscience
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    • v.37 no.8
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    • pp.1452-1462
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    • 2024
  • Objective: This study aimed to investigate the effects of dietary supplementation with Agaricus blazei polysaccharide (ABP) at varying concentrations on the performance, egg quality, blood biochemistry, intestinal morphology, and microflora of quail. Methods: The study involved a total of 2,700 Korean quails, which were randomly divided into three groups. The measured variables encompassed productive performance, egg parameters, carcass parameters, serum metabolites, immune response parameters, antioxidative properties, and gut microbiome. Results: The addition of ABP did not have a significant effect on average daily feed intake. However, it was found to increase the average daily egg weight and egg production rate, reduce the feed-egg ratio. There were no significant impacts on egg quality measures such as egg shape index, egg yolk index and color, egg yolk and protein content. However, ABP supplementation significantly increased the Hough unit (p<0.01) and decreased the rate of unqualified eggs (p<0.01). Regarding serum parameters, the inclusion led to an increase in total protein concentration (p<0.05) and a reduction in low-density lipoprotein cholesterol (p<0.05). There were no significant effects observed on immune indicators such as immunoglobulin A (IgA) and IgM. ABP supplementation increased the levels of serum antioxidant indicators, including glutathione peroxidase, total superoxide dismutase (p<0.05), and total antioxidant capacity colorimeter (p<0.05). Furthermore, ABP supplementation significantly elevated the intramuscular fatty acid content in quail meat. Additionally, ABP supplementation demonstrated a significant improvement in the diversity of gut microbiota and induced alterations in the composition of the gut microbiota. Conclusion: The findings of this study indicate that dietary supplementation of ABP enhanced production performance and antioxidant capacity while increasing the levels of polyunsaturated fatty acids in quail muscle.

Experimental and numerical study on the structural behavior of Multi-Cell Beams reinforced with metallic and non-metallic materials

  • Yousry B.I. Shaheen;Ghada M. Hekal;Ahmed K. Fadel;Ashraf M. Mahmoud
    • Structural Engineering and Mechanics
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    • v.90 no.6
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    • pp.611-633
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    • 2024
  • This study intends to investigate the response of multi-cell (MC) beams to flexural loads in which the primary reinforcement is composed of both metallic and non-metallic materials. "Multi-cell" describes beam sections with multiple longitudinal voids separated by thin webs. Seven reinforced concrete MC beams measuring 300×200×1800 mm were tested under flexural loadings until failure. Two series of beams are formed, depending on the type of main reinforcement that is being used. A control RC beam with no openings and six MC beams are found in these two series. Series one and two are reinforced with metallic and non-metallic main reinforcement, respectively, in order to maintain a constant reinforcement ratio. The first crack, ultimate load, deflection, ductility index, energy absorption, strain characteristics, crack pattern, and failure mode were among the structural parameters of the beams under investigation that were documented. The primary variables that vary are the kind of reinforcing materials that are utilized, as well as the kind and quantity of mesh layers. The outcomes of this study that looked at the experimental and numerical performance of ferrocement reinforced concrete MC beams are presented in this article. Nonlinear finite element analysis (NLFEA) was performed with ANSYS-16.0 software to demonstrate the behavior of composite MC beams with holes. A parametric study is also carried out to investigate the factors, such as opening size, that can most strongly affect the mechanical behavior of the suggested model. The experimental and numerical results obtained demonstrate that the FE simulations generated an acceptable degree of experimental value estimation. It's also important to demonstrate that, when compared to the control beam, the MC beam reinforced with geogrid mesh (MCGB) decreases its strength capacity by a maximum of 73.33%. In contrast, the minimum strength reduction value of 16.71% is observed in the MC beams reinforced with carbon reinforcing bars (MCCR). The findings of the experiments on MC beams with openings demonstrate that the presence of openings has a significant impact on the behavior of the beams, as there is a decrease in both the ultimate load and maximum deflection.

Spectral moment analysis of distortion errors in alveolar fricatives in Korean children (치조 마찰음 왜곡 오류 유무에 따른 아동 발화 적률분석 비교)

  • Yunju Han;Do Hyung Kim;Ja Eun Hwang;Dae-Hyun Jang;Jae Won Kim
    • Phonetics and Speech Sciences
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    • v.16 no.1
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    • pp.33-40
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    • 2024
  • This study investigated acoustic features in spectral moment analysis, comparing accurate articulations with distortions of alveolar fricatives such as dentalization, palatalization, and lateralization. A retrospective analysis was conducted on speech samples from 61 children (mean age: 5.6±1.5 years, 19 females, 42 males) using the Assessment of Phonology & Articulation for Children (APAC) and Urimal-test of Articulation and Phonology I (U-TAP I). Spectral moment analysis was applied to 169 speech samples. The results revealed that the center of gravity of accurate articulations was higher than that of palatalization, while palatalization was lower than dentalization. The variance of dentalization was higher than that of both accurate articulations and palatalization. The skewness of dentalization was higher than that of accurate articulations, and the skewness of palatalization was higher than that of accurate articulations. The kurtosis of palatalization was higher than that of both accurate articulations and dentalization. No significant differences were observed for the position of fricatives (initial, medial) and tense type (plain, tense) across all variables of spectral moment analysis for each distortion type. This study confirmed distinct patterns in center of gravity, variance, skewness, and kurtosis depending on the type of alveolar fricative distortion. The objective values provided in this study will serve as foundational data for diagnosing alveolar fricative distortions in children with speech sound disorders.

Prognostic Value of Coronary CT Angiography for Predicting Poor Cardiac Outcome in Stroke Patients without Known Cardiac Disease or Chest Pain: The Assessment of Coronary Artery Disease in Stroke Patients Study

  • Sung Hyun Yoon;Eunhee Kim;Yongho Jeon;Sang Yoon Yi;Hee-Joon Bae;Ik-Kyung Jang;Joo Myung Lee;Seung Min Yoo;Charles S. White;Eun Ju Chun
    • Korean Journal of Radiology
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    • v.21 no.9
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    • pp.1055-1064
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    • 2020
  • Objective: To assess the incremental prognostic value of coronary computed tomography angiography (CCTA) in comparison to a clinical risk model (Framingham risk score, FRS) and coronary artery calcium score (CACS) for future cardiac events in ischemic stroke patients without chest pain. Materials and Methods: This retrospective study included 1418 patients with acute stroke who had no previous cardiac disease and underwent CCTA, including CACS. Stenosis degree and plaque types (high-risk, non-calcified, mixed, or calcified plaques) were assessed as CCTA variables. High-risk plaque was defined when at least two of the following characteristics were observed: low-density plaque, positive remodeling, spotty calcification, or napkin-ring sign. We compared the incremental prognostic value of CCTA for major adverse cardiovascular events (MACE) over CACS and FRS. Results: The prevalence of any plaque and obstructive coronary artery disease (CAD) (stenosis ≥ 50%) were 70.7% and 30.2%, respectively. During the median follow-up period of 48 months, 108 patients (7.6%) experienced MACE. Increasing FRS, CACS, and stenosis degree were positively associated with MACE (all p < 0.05). Patients with high-risk plaque type showed the highest incidence of MACE, followed by non-calcified, mixed, and calcified plaque, respectively (log-rank p < 0.001). Among the prediction models for MACE, adding stenosis degree to FRS showed better discrimination and risk reclassification compared to FRS or the FRS + CACS model (all p < 0.05). Furthermore, incorporating plaque type in the prediction model significantly improved reclassification (integrated discrimination improvement, 0.08; p = 0.023) and showed the highest discrimination index (C-statistics, 0.85). However, the addition of CACS on CCTA with FRS did not add to the prediction ability for MACE (p > 0.05). Conclusion: Assessment of stenosis degree and plaque type using CCTA provided additional prognostic value over CACS and FRS to risk stratify stroke patients without prior history of CAD better.

Percutaneous Biliary Metallic Stent Insertion in Patients with Malignant Duodenobiliary Obstruction: Outcomes and Factors Influencing Biliary Stent Patency

  • Ji Hye Kwon;Dong Il Gwon;Jong Woo Kim;Hee Ho Chu;Jin Hyoung Kim;Gi-Young Ko;Hyun-Ki Yoon;Kyu-Bo Sung
    • Korean Journal of Radiology
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    • v.21 no.6
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    • pp.695-706
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    • 2020
  • Objective: To investigate the technical and clinical efficacy of the percutaneous insertion of a biliary metallic stent, and to identify the factors associated with biliary stent dysfunction in patients with malignant duodenobiliary obstruction. Materials and Methods: The medical records of 70 patients (39 men and 31 women; mean age, 63 years; range, 38-90 years) who were treated for malignant duodenobiliary obstruction at our institution between April 2007 and December 2018, were retrospectively reviewed. Variables found significant by univariate log-rank analysis (p < 0.2) were considered as suitable candidates for a multiple Cox's proportional hazard model. Results: The biliary stents were successfully placed in all 70 study patients. Biliary stent insertion with subsequent duodenal stent insertion was performed in 33 patients and duodenal stent insertion with subsequent biliary stent insertion was performed in the other 37 study subjects. The median patient survival and stent patency time were 107 days (95% confidence interval [CI], 78-135 days) and 270 days (95% CI, 95-444 days), respectively. Biliary stent dysfunction was observed in 24 (34.3%) cases. Multiple Cox's proportional hazard analysis revealed that the location of the distal biliary stent was the only independent factor affecting biliary stent patency (hazard ratio, 3.771; 95% CI, 1.157-12.283). The median biliary stent patency was significantly longer in patients in whom the distal end of the biliary stent was beyond the distal end of the duodenal stent (median, 327 days; 95% CI, 249-450 days), rather than within the duodenal stent (median, 170 days; 95% CI, 115-225 days). Conclusion: The percutaneous insertion of the biliary metallic stent appears to be a technically feasible, safe, and effective method of treating malignant duodenobiliary obstruction. In addition, a biliary stent system with a distal end located beyond the distal end of the duodenal stent will contribute towards longer stent patency in these patients.

A study on the relationship between the organizational culture, generational conflict, and organizational commitment of Hotel companies : Focusing on M Generation and Z Generation Differences (호텔기업의 조직문화와 세대 갈등, 조직몰입 간의 관계에 대한 연구 : M세대, Z세대 차이를 중심으로)

  • Kim Myeongyong;Sim Juree;Kang Jungkoo
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.3
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    • pp.643-650
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    • 2024
  • Currently, South Korea is grappling with a paradoxical situation characterized by simultaneous labor shortages and job shortages. Within this context, retirees are citing conflicts with supervisors/colleagues and dissatisfaction with organizational culture as the primary reasons for their departure, with these issues disproportionately affecting the MZ generation. In response, scholars have conducted preliminary studies to understand the relationships between organizational culture and other variables specifically concerning the MZ generation. However, most of these studies are based on a unified theory of the MZ generation, failing to satisfy the practical demands for distinguishing between Generations M and Z. Therefore, this research aims to explore the differences in variable relationships between these two groups within the hospitality industry. Surveys were conducted among 170 individuals from Generation M and 110 from Generation Z, and the data were analyzed using AMOS structural equation modeling. The analysis confirmed that both hierarchical culture and generational conflict significantly define relationships across all generations, with generational conflict adversely affecting organizational commitment. Additionally, while a relationship-oriented culture negatively impacts generational conflict for Generation M, no such effect was observed for Generation Z. This study successfully identifies the differential impacts between Generation M and Generation Z.

A Study on the Differences in Body Condition, Size, and Climate Environment According to Sex of Kaloula borealis (맹꽁이(Kaloula borealis)의 성별에 따른 신체 상태와 크기 및 기후환경 차이에 관한 연구)

  • Il-Nam Kim;Min Seock Do;Sang-Cheol Lee;Yang-Seop Bae
    • Journal of Wetlands Research
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    • v.26 no.2
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    • pp.160-167
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    • 2024
  • The amphibians serve as environmental indicator species warning of threats from pollution and development, and information regarding their body condition and surrounding habitat can be utilized as crucial indicators for assessing ecosystem health. The objective of this study was to investigate the differences in body condition and the climate environments according to the season and sex of Class II endangered Kaloula borealis. A total of 53 surveys were conducted from June to October 2018, targeting frogs inhabiting the Godeok-dong area of Gangdong-gu, Seoul. Using the weight and length of each individual, the body condition index (SMI, Scaled mass index) was calculated. Results showed a total capture of 396 individuals, consisting of 235 males and 161 females. Females exhibited longer SVL and greater weight compared to males, with higher body condition indices. Monthly body condition indices were lower for males in June, while no differences were observed between males and females from July to September. Among the climate environments where females and males appeared, environmental variables related to precipitation and humidity showed differences. These research findings are deemed crucial for providing fundamental information to ascertain suitable habitats for Kaloula borealis and selecting alternative habitats due to developmental impacts in the future.