441 results on '"Yong Bum, Park"'
Search Results
52. Does repeated pleural culture increase the diagnostic yield of Mycobacterium tuberculosis from tuberculous pleural effusion in HIV-negative individuals?
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Yousang Ko, Jinkyung Song, Suh-Young Lee, Jin-Wook Moon, Eun-Kyung Mo, Ji Young Park, Joo-Hee Kim, Sunghoon Park, Yong Il Hwang, Seung Hun Jang, Byung Woo Jhun, Yun Su Sim, Tae Rim Shin, Dong-Gyu Kim, Ji Young Hong, Chang Youl Lee, Myung Goo Lee, Cheol-Hong Kim, In Gyu Hyun, and Yong Bum Park
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Medicine ,Science - Abstract
Despite recent advances in methods for culturing Mycobacterium tuberculosis (MTB), the diagnostic yield of tuberculous pleural effusion (TBPE) remains unsatisfactory. However, unlike repeated sputum cultures of pulmonary tuberculosis, little is known about the role of repeated pleural cultures. We examined whether repeated pleural cultures are associated with increased MTB yield from TBPE.A multicenter, retrospective cohort study was performed from January 2012 to December 2015 in South Korea. Patients were categorized into two groups: single- or repeated-culture groups. The diagnostic yield of MTB and clinical, radiological, and pleural fluid characteristics were evaluated.Among the 329 patients with TBPE, 77 (23.4%) had repeated cultures and 252 (76.5%) had a single culture. Pleural culture was performed twice in all 77 patients in the repeated-culture group at a 1-day interval (inter-quartile range, 1.0-2.0). In the repeated-culture group, the yield of MTB from the first culture was 31.2%, which was similar to that in the single-culture group (31.2% vs. 29.8%, P = 0.887). However, the yield of MTB from the second culture (10/77, 13.0%) was more than that from the first. These results may be attributable to the insufficient immune clearance for MTB invasion into the pleural space between the first and second cultures. Over time, the yield of the second cultures decreased from 17.4% to 6.7% and then 6.3%. Finally, the overall yield of MTB in the repeated- and single-culture groups was 44.2% and 29.8% respectively (P < 0.001).The results showed that repeated pleural cultures increased MTB yield from TBPE in human immunodeficiency virus-negative individuals. Furthermore, repeated cultures may increase yield when carried out for two consecutive days.
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- 2017
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53. The safety and efficacy of CKD-497 in patients with acute upper respiratory tract infection and bronchitis symptoms: a multicenter, double-blind, double-dummy, randomized, controlled, phase II clinical trial
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Shin Jung Park, Seung Won Ra, Yong Bum Park, Yun Young Lim, Chang Youl Lee, Deog Kyeom Kim, Jeong Woong Park, Chin Kook Rhee, Hyoung Kyu Yoon, Kwang Ha Yoo, and Sun Young Kim
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,business.industry ,Phlegm ,Phases of clinical research ,medicine.disease ,Placebo ,Clinical trial ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Internal medicine ,medicine ,Clinical endpoint ,Bronchitis ,Original Article ,030212 general & internal medicine ,medicine.symptom ,Adverse effect ,business ,Acute respiratory tract infection - Abstract
BACKGROUND: Acute upper respiratory tract infection (AURI) together with acute bronchitis is the most common illness worldwide. Botanical medicines used as expectorants and antitussives have proven to be effective while also having excellent safety margins. We aimed at evaluating the efficacy and safety of a new botanical drug, CKD-497, in patients with AURI and acute bronchitis. METHODS: In this phase 2 study, 225 patients were enrolled and randomly assigned to one of four treatment groups: placebo (n=55), Synatura(®) (n=49), CKD-497 200 mg (n=68), or CKD-497 300 mg (n=53). The study drugs were administered three times daily over the course of 7 days. Primary endpoint was the change in the bronchitis severity score (BSS) from baseline to day 7. Secondary endpoint was evaluated based on clinical response rates on days 4 and 7. A safety analysis was also performed. RESULTS: Between baseline and day 7, the mean BSS scores decreased significantly in each group (P
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- 2021
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54. Reasons why patients with tuberculosis in South Korea stop anti-TB treatment: a cross-sectional study
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J S Kim, Jong Koo Lee, A Y Shin, J Min, Yong Bum Park, Seong Yong Lim, H W Kim, M. J. Park, S-S Lee, H-K Koo, and J S Park
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Pulmonary and Respiratory Medicine ,Pediatrics ,medicine.medical_specialty ,Tuberculosis ,Hospitals, Public ,business.industry ,Cross-sectional study ,MEDLINE ,medicine.disease ,Cross-Sectional Studies ,Infectious Diseases ,Republic of Korea ,Humans ,Medicine ,business ,Adverse effect ,Tb treatment ,Aged - Abstract
BACKGROUND: As there had been no reduction in the TB burden in South Korea since 2000, a public-private mix (PPM) strategy was launched in 2011. The purpose of this study was to investigate the reasons for lost to follow-up (LTFU) among TB patients and their clinical characteristics.METHOD: A multicentre, cross-sectional study based on in-depth interviews with patients and their families by TB specialist nurses was conducted. Patients who were reported with a final outcome of LTFU in 2015–2017 at all PPM hospitals across the country were enrolled. Enrolled patients were classified into six subgroups by age and three major reasons for LTFU (adverse effects, refusal of treatment, marginalisation) and their clinical features were compared.RESULTS: Among 780 patients, those who were lost to follow-up due to adverse effects accounted for the largest proportion (n = 387). LTFU in those aged n = 189) and those aged n = 108) were related to having smear-positive TB and a previous history of unfavourable outcomes.CONCLUSION: To reduce LTFU in South Korea, comprehensive strategies, including management of adverse effects, systematic counselling and education, should be implemented.
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- 2020
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55. Clinical Characteristics of Chronic Obstructive Pulmonary Disease in Female Patients: Findings from a KOCOSS Cohort
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Jae Ha Lee, Joon Young Choi, Hyoung Kyu Yoon, Yong Bum Park, Ki Suck Jung, Soo-Jung Um, Seoung Ju Park, Yee Hyung Kim, Shin Young Kim, and Kwang Ha Yoo
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medicine.medical_specialty ,COPD ,Bronchiectasis ,business.industry ,Respiratory infection ,General Medicine ,medicine.disease ,respiratory tract diseases ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Internal medicine ,Cohort ,Medicine ,030212 general & internal medicine ,business ,Depression (differential diagnoses) ,Asthma ,Cohort study - Abstract
Purpose The prevalence of chronic obstructive pulmonary disease (COPD) in females has increased, changing the concept of COPD as a disease mostly limited to males. In this study, the clinical characteristics of COPD in females were investigated. Patients and methods The study was based on a multicenter cohort of COPD patients recruited from 54 medical centers in South Korea. Sex-based differences in general characteristics, exposure risk factors, depression scores, results of pulmonary function tests, COPD exacerbation, symptom scores, and radiologic findings were evaluated. Sex-related differences in the annual FEV1 change over 5 years were analyzed in a linear mixed model. Results Of the 2515 patients enrolled in this study, 8.1% were female. Female patients who had a higher BMI and a lower level of education were less likely to be smokers, were more exposed to passive smoking/biomass, and were more depressed compared to males. The rates of bronchiectasis, previous childhood respiratory infection, and asthma were higher in females. Female patients also had more symptoms and a poorer exercise capacity than males, but no significant differences were observed in terms of exacerbations. Radiologic findings revealed that male patients had worse emphysema, and female patients had worse bronchiectasis, as determined based on chest X-ray and computed tomography findings. On pulmonary function tests, female patients had less obstruction and less annual FEV1 loss over 5 years. Conclusion This study revealed differences in the clinical parameters between male and female patients with COPD, including general characteristics, disease characteristics, and clinical outcomes.
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- 2020
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56. P‐185: Flexible Organic Light‐Emitting Diodes with Improved Outcoupling Efficiency
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Yong-Bum Park, L. Jay Guo, and Changyeong Jeong
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Materials science ,business.industry ,OLED ,Optoelectronics ,business - Published
- 2020
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57. 62‐4: Ultrathin Cu‐Ag Anode for High Light Outcoupling Efficiency by Eliminating Waveguide Mode in OLED
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Changyeong Jeong, Yong-Bum Park, and L. J. Guo
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Materials science ,business.industry ,OLED ,Optoelectronics ,Waveguide mode ,business ,Anti reflective ,Anode - Published
- 2020
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58. ASSOCIATION OF N-TERMINAL (NT)-PRO HORMONE BNP (NT-PROBNP) WITH AIRFLOW LIMITATION AND EXACERBATION IN COPD
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KIM HEY SOO, JI YE JUNG, HYEON KYEONG BAE, HYE RAN GWON, SOL KIM, EUN YOUNG KIM, WOO KYUNG RYU, EUN GI JUNG, HYUN WOO JI, KI-SUCK JUNG, KWANG HA YOO, CHIN KOO RHEE, and YONG BUM PARK
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Pulmonary and Respiratory Medicine ,Cardiology and Cardiovascular Medicine ,Critical Care and Intensive Care Medicine - Published
- 2022
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59. Early Bactericidal Activity of Delpazolid (LCB01-0371) in Patients with Pulmonary Tuberculosis
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Ju Sang Kim, Yong-hyun Kim, Sang Haak Lee, Yee Hyung Kim, Jin-woo Kim, Ji Young Kang, Sung Kyoung Kim, Seung Joon Kim, Yun-Seong Kang, Tae-hyung Kim, Jeongha Mok, Min Kwang Byun, Hye Jung Park, Joon-sung Joh, Yong Bum Park, Hyeong-Seok Lim, Hongjo Choi, Seung Heon Lee, Hyejin Kim, Jeongseong Yang, Hyunji Kim, Xianlin Shen, Abdullah Alsultan, InSook Cho, Lawrence Geiter, and Tae Sun Shim
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Adult ,Pharmacology ,Antitubercular Agents ,Sputum ,Mycobacterium tuberculosis ,Middle Aged ,Pyrazinamide ,Young Adult ,Infectious Diseases ,Isoniazid ,Humans ,Drug Therapy, Combination ,Pharmacology (medical) ,Tuberculosis, Pulmonary ,Oxazolidinones ,Aged - Abstract
Delpazolid, an oxazolidinone, has been studied in non-clinical studies of efficacy and toxicity and Phase 1 clinical studies. Delpazolid has in vitro activity against Gram-positive bacteria, including Mycobacterium tuberculosis .
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- 2022
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60. Microorganisms Causing Community-Acquired Acute Bronchitis: The Role of Bacterial Infection.
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Ji Young Park, Sunghoon Park, Sun Hwa Lee, Myung Goo Lee, Yong Bum Park, Kil Chan Oh, Jae-Myung Lee, Do Il Kim, Ki-Hyun Seo, Kyeong-Cheol Shin, Kwang Ha Yoo, Yongchun Ko, Seung Hun Jang, Ki-Suck Jung, and Yong Il Hwang
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Medicine ,Science - Abstract
Although acute bronchitis is quite common, there is relatively limited information regarding the microorganisms that are involved in this illness.We performed a prospective study of acute bronchitis at 31 hospitals and clinics in Korea from July 2011 to June 2012. Sputum specimens were collected for polymerase chain reaction (PCR) and culture of microorganisms.Of the 811 enrolled patients, 291 had acceptable sputum specimens that were included for analysis of the etiologic distribution. With multiplex PCR testing, viruses were identified in 36.1% (105/291), most commonly rhinovirus (25.8%) and coronavirus (3.8%). Typical bacteria were isolated in 126/291 (43.3%) patients. Among these patients Haemophilus influenzae (n = 39) and Streptococcus pneumoniae (n = 30) were isolated most commonly; atypical bacteria were identified in 44 (15.1%) patients. Bacteria-only, virus-only, and mixed infections (bacteria plus virus) accounted for 36.7% (98/291), 17.2% (50/291), and 18.9% (55/291) of infections, respectively. In particular, 52.4% of patients with viral infection had a concurrent bacterial infection, and rhinovirus was the most common virus in mixed infections (40/55). Additionally, infections with typical bacteria were more common in patients with chronic lung disease (p = 0.029), and typical bacterial infections showed a trend towards a higher prevalence with older age (p = 0.001).Bacteria were associated with almost half of community-acquired acute bronchitis cases. Additional studies are required to further illuminate the role of bacteria and to identify patient groups most likely to benefit from antibiotic treatment.
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- 2016
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61. Optimized optical/electrical/mechanical properties of ultrathin metal films for flexible transparent conductor applications: review [Invited]
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Yong-Bum Park, Sangeon Lee, Mustafa Tobah, Taigao Ma, and L. Jay Guo
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Electronic, Optical and Magnetic Materials - Abstract
Transparent conductors are essential for high-performance optoelectronic devices. Recently, ultrathin metal films have received great attention as emerging transparent conductors to replace status quo indium tin oxide (ITO) due to their excellent optoelectrical properties with mechanical flexibility. Understanding an ultrathin metal film's optoelectrical properties with respect to thickness scaling is the prerequisite for the design of high-performance metal film-based transparent conductors. This review paper aims to focus on the evolution of ultrathin metal film’s optical properties as thickness scales. Such evolution of optical properties will be associated with electrical properties by exploring various resistivity scattering models aiming to better understand a film’s intrinsic physical property at an extremely thin scale and provide a guideline for enhancing the film’s intrinsic optoelectrical properties for transparent conductor application. Next, optical design considerations to enhance transparency at visible and near-infrared range are discussed including recent reinforcement learning methods as a potential strategy for transparent conductor design. Then, mechanical flexibility of various ITO-replacement electrodes is discussed as well as the mechanism for the metal film-based transparent conductor's excellent endurance against mechanical stress. Lastly, some of the unique benefits of using a metal film transparent conductor for optoelectronic device application are discussed.
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- 2023
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62. Serological Changes in Anti
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Changwhan, Kim, Jin-Wook, Moon, Yong-Bum, Park, and Yousang, Ko
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Chronic pulmonary aspergillosis (CPA) is an important infection to understand in survivors of pulmonary tuberculosis (PTB). However, limited data are available regarding CPA development and its predisposing factors following PTB. We investigated the development of, and the predisposing factors for, CPA following the completion of PTB treatment. A total of 345 patients, with newly diagnosed culture-positive PTB (between January 2015 and December 2018), were included. Enrolled cases were categorized into four groups (persistently seronegative, seroconversion, seroreversion, and persistently seropositive) according to serological changes in their anti
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- 2021
63. Escalation Time to Open Triple Combination Therapy from the Initiation of LAMA versus ICS/LABA in COPD Management: Findings from Comparing the Incidence of Tiotropium and ICS/LABA in Real-World Use in South Korea (CITRUS) Study
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Ye Jin Lee, Chin Kook Rhee, Yong Il Hwang, Kwang Ha Yoo, So Eun Lee, Doik Lee, Yong Bum Park, and Youlim Kim
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long-acting muscarinic receptor antagonist ,Medicine (miscellaneous) ,Medicine ,inhaled corticosteroids ,long-acting β2-agonists ,chronic obstructive pulmonary disease ,Article ,hormones, hormone substitutes, and hormone antagonists - Abstract
Background: bronchodilators are the key treatment for chronic obstructive pulmonary disease (COPD), however, inhaled corticosteroids (ICSs)/long-acting β2-agonists (LABA) are widely prescribed. We compared the escalation time to open triple combination therapy between long-acting muscarinic receptor antagonists (LAMA) and ICS/LABA in COPD management. Methods: this retrospective study included COPD patients selected from the National Health Insurance Service of South Korea from January 2005 to April 2015. The primary outcome was the escalation time to triple therapy in patients who initially received LAMA or ICS/LABA. Other outcomes included risk factors predisposing escalation to triple combination therapy. Results: a total of 2444 patients were assigned to the LAMA or ICS/LABA groups. The incidences of triple combination therapy in the LAMA and ICS/LABA groups were 81.0 and 139.8 per 1000 person-years, respectively (p < 0.001); the median times to triple therapy escalation were 281 and 207 days, respectively (p = 0.03). Treatment with ICS/LABA showed a higher risk of triple therapy escalation compared to LAMA (hazard ratio (HR), 1.601; 95% confidence interval (CI), 1.402–1.829). The associated risk factor was male sex. (HR, 1.564; 95% CI, 1.352–1.809). Conclusions: the initiation of COPD treatment with LAMA is associated with a reduced escalation time to triple therapy compared with ICS/LABA.
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- 2021
64. The Influences of Majors' Choice Motivation on Golf Learning
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Yong-Bum Park and Jin-Young Hong
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- 2020
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65. Comparison of clinical efficacy and safety between indacaterol and tiotropium in COPD: meta-analysis of randomized controlled trials.
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Jung Soo Kim, Jinkyeong Park, Seong Yong Lim, Yeon-Mok Oh, Kwang Ha Yoo, Yong Bum Park, Seung Soo Sheen, Min-Ji Kim, K C Carriere, Ji Ye Jung, and Hye Yun Park
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Medicine ,Science - Abstract
Two once-daily inhaled bronchodilators, indacaterol and tiotropium, are widely used as first-line therapy in stable COPD patients. This study was performed to compare the clinical efficacy and safety between indacaterol and tiotropium in patients with moderate-to-severe COPD. MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched to identify all published randomized controlled trials (RCTs). The primary outcome was trough forced expiratory volume in 1 second (FEV1) at week 12. Four RCTs were eligible for inclusion (three RCTs with moderate-to-severe COPD patients and one RCT with only severe COPD patients). Trough FEV₁ at weeks 12 and 26 were not significantly different between indacaterol and tiotropium by the standardized mean difference with 0.014 (95% CI, -0.036, 0.063, I²= 23.5%) and with 0.037 (95% CI, -0.059 to 0.133, I²= 0%) along with differences in means of 0.003L and 0.014L, respectively. Indacaterol and tiotropium also showed similar St. George's Respiratory Questionnaire (SGRQ) total scores and percentages of patients with SGRQ improvement (≥ 4 units) at week 26. The incidences of nasopharyngitis, serious cardiovascular events, and serious adverse events were not different between indacaterol and tiotropium, while those of cough (OR = 1.68, P < 0.001, and RR = 1.63) and COPD worsening (OR = 1.18, P = 0.003, and RR = 1.12) were higher for indacaterol than tiotropium. However, when one study with only severe COPD patients was removed from the meta-analysis, the difference in the incidence of COPD worsening between indacaterol and tiotropium became non-significant (OR = 1.13, P = 0.204, and RR = 1.09). The clinical efficacy and serious adverse events between indacaterol and tiotropium were equivocal in patients with moderate-to-severe COPD. Cough is a common complaint associated with indacaterol, and COPD worsening needs to be carefully monitored in severe COPD patients when treated with indacaterol.
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- 2015
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66. Metabolic Syndrome in Early Chronic Obstructive Pulmonary Disease: Gender Differences and Impact on Exacerbation and Medical Costs
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Seong Yong Lim, Chin Kook Rhee, Hye Sook Choi, Yong Bum Park, and Kwang Ha Yoo
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COPD ,medicine.medical_specialty ,Exacerbation ,business.industry ,Confounding ,Pulmonary disease ,General Medicine ,medicine.disease ,Comorbidity ,Obstructive lung disease ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Internal medicine ,Medicine ,030212 general & internal medicine ,Metabolic syndrome ,business - Abstract
Background Metabolic syndrome (MetS) is a well-known comorbidity of chronic obstructive pulmonary disease (COPD). However, their interrelationship, particularly in early COPD, remains unclear. Therefore, we aimed to assess the prevalence and clinical characteristics of MetS in patients with early COPD, and to explore the impact of MetS on the frequency of COPD exacerbations and associated medical costs. Patients and methods We retrospectively enrolled 43,874 subjects from the KNHANES, including 2164 patients with early COPD (≥40 years old), recorded smoking history, and Global Initiative for Chronic Obstructive Lung Disease spirometric grade I or II, with data linked to the NHI database. We extracted and analyzed data regarding health-care utilization and medical costs for 5 years (2007 to 2012). Results Among 2164 patients with early COPD, the prevalence of MetS was 31.2%, and it was higher in women than in men (35.1% vs. 26.6%; P
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- 2019
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67. The Effect of Participating in University Sports Clubs on a Student’s Stress Management and Adjustment to University Life
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Ki-Hoon Moon and Yong-Bum Park
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Medical education ,Stress management ,Psychology - Published
- 2019
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68. The Difficulty Of Improving Quality Of Life In COPD Patients With Depression And Associated Factors
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Hyoung Kyu Yoon, Won Yeon Lee, Yong Bum Park, Ki Suck Jung, Tae Hyung Kim, An-Soo Jang, Jeong Uk Lim, Kwang Ha Yoo, Chin Kook Rhee, and Chan Kwon Park
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medicine.medical_specialty ,COPD ,business.industry ,General Medicine ,medicine.disease ,Comorbidity ,Pulmonary function testing ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Quality of life ,Internal medicine ,Cohort ,Medicine ,Mass index ,Observational study ,030212 general & internal medicine ,business ,Depression (differential diagnoses) - Abstract
Objectives Depression is a major comorbidity that affects clinical outcomes in patients with chronic obstructive pulmonary disease (COPD). COPD patients with depression are hospitalized more frequently, and show more acute exacerbations, decreased physical and social activities, and higher mortality compared to their non-depressed counterparts. In the present study, we investigated the clinical impact of depressive symptoms and associated clinical factors in Korean patients with COPD by evaluating multicenter cohort data. Materials and methods Patients with COPD enrolled in the Korean COPD Subtype Study, a multicenter observational study, from December 2011 to October 2014 were selected for evaluation. The initial evaluation of all patients included pulmonary function tests, 6 min walk distance (6MWD), the COPD Assessment Test (CAT), and the COPD-specific version of the St. George's Respiratory Questionnaire (SGRQ-C). Significant depression was defined as a Beck Depression Inventory-II (BDI-II) score ≥17. Results Among the 270 study patients, 19.6% had significant depression. The depressed group showed a higher proportion of females (41.4%), lower body mass index (BMI), and lower education level compared to the non-depressed group (p = 0.002, p = 0.008, and p = 0.019, respectively). The depressed group had significantly higher CAT and SGRQ-C scores, as well as a lower 6MWD, compared to the non-depressed group based on 6 month-interval serial measurements over 3 years. The total SGRQ-C score and the symptoms, activity, and impact domain scores were significant predictors of depression (area under curves [AUCs] of 0.699 [0.613-0.786], 0.670 [0.581-0.758], 0.680 [0.589-0.770], and 0.689 [0.603-0.776], respectively). From CAT score domains, sleep and energy scores were significant predictors of depression (AUCs of 0.619 [0.522-0.715] and 0.595 [0.504-0.685], respectively). SGRQ-C score, low BMI, and decreased 6MWD were significantly associated with depression in a multivariable analysis. Conclusion A considerable proportion of patients with COPD had depression, and a high SGRQ-C score, low BMI, and low 6MWD were significantly associated with depression. As improving quality of life in this subgroup is difficult, physicians should be more active in screening patients with significant depression.
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- 2019
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69. Effect of Biologic Aging of Implants on Osseointegration in the Dog.
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Byung-Moon Hwang, Yong Bum Park, and Jae Hoon Lee
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DENTAL implants ,OSSEOINTEGRATED dental implants ,CUSPIDS ,AGING ,MATERIALS testing ,TEETH injuries ,TEETH injury treatment ,ANIMAL experimentation ,BONE marrow ,DENTAL acid etching ,WOUND healing ,OSSEOINTEGRATION - Abstract
The objective of this preclinical study was to investigate the effect of biologic aging of implants on osseointegration in the canine. According to multiple comparisons, there was a significant difference in bone-to-implant contact (BIC) between control implants placed 6 months after manufacture and 2-week-old implants (P = .016), and between control and newly prepared implants with acid-etching (P = .019). However, there was no significant difference in BIC between newly prepared implants with acid-etching and 2-week-old implants. In all groups, BIC at 12 weeks was significantly higher than at week 4 (P < .05). There were no significant differences in bone volume (BV) regardless of area and time. Biologic aging of implants might affect osseointegration in the bone marrow zone at 4 weeks of healing. Although implant aging did not greatly affect BIC and BV at 12 weeks of healing in this study, further research is required to determine an appropriate period of biologic aging of implants that yields significant clinical effects. [ABSTRACT FROM AUTHOR]
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- 2019
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70. Comparing pneumonia incidence in COPD patients treated with or without inhaled corticosteroid
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Kwang Ha Yoo, Youlim Kim, Kyung Yoon Jung, Yong Bum Park, So Eun Lee, Yong Il Hwang, and Chin Kook Rhee
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medicine.medical_specialty ,Pneumonia ,business.industry ,medicine.drug_class ,Copd patients ,Internal medicine ,Incidence (epidemiology) ,Medicine ,Corticosteroid ,business ,medicine.disease - Published
- 2021
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71. The Long-term Efficacy of Domiciliary Noninvasive Positive-Pressure Ventilation in Chronic Obstructive Pulmonary Disease: A Meta-Analysis of Randomized Controlled Trials
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Chin Kook Rhee, Kwang Ha Yoo, So Young Park, Yong Il Hwang, Dong Ah Park, Yun Su Sim, Hye Yun Park, Yong Bum Park, and Jinkyeong Park
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,COPD ,RC705-779 ,Exacerbation ,business.industry ,Mortality rate ,Noninvasive Positive-Pressure Ventilation ,Chronic Obstructive Pulmonary Disease ,medicine.disease ,Confidence interval ,law.invention ,Diseases of the respiratory system ,Infectious Diseases ,Randomized controlled trial ,Quality of life ,law ,Internal medicine ,Meta-analysis ,Relative risk ,medicine ,Original Article ,Mortality ,business - Abstract
We aimed to evaluate the long-term use or effects of domiciliary non-invasive positive pressure ventilation (NIPPV) used to treat patients with chronic obstructive pulmonary disease (COPD). Databases were searched to identify randomized controlled trials (RCTs) of COPD with NIPPV for longer than 1 year. The primary outcome as mortality rates were accessed in this meta-analysis. The eight trials included in this study comprised data from 913 patients. The mortality rates for the NIPPV and control groups were 29% (118/414) and 36% (151/419); this difference was statistically significant (risk ratio (RR): 0.79, 95% confidence interval (CI): 0.65-0.95). Mortality rates were reduced with NIPPV in four trials that included stable COPD patients. There was no difference in admission, acute exacerbation and quality of life (QOL) between the NIPPV and control groups. There was no significant difference in withdrawal rates between the two groups (RR 0.99, 95% CI 0.72-1.36, p = 0.94). Maintaining long-term nocturnal NIPPV for more than 1 year in COPD patients, especially stable status COPD patients, leads to a decrease in the mortality rate, and the withdrawal rate is not high compared to long term oxygen treatments.
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- 2021
72. The current status of chronic obstructive pulmonary disease awareness, treatments, and plans for improvement in South Korea: a narrative review
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Kwang Ha Yoo and Yong Bum Park
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Pulmonary and Respiratory Medicine ,COPD ,Government ,Coping (psychology) ,medicine.medical_specialty ,Tuberculosis ,business.industry ,Pulmonary disease ,Disease ,medicine.disease ,Pulmonary function testing ,respiratory tract diseases ,Review Article on Current Epidemiology and Policies of COPD Worldwide ,Agency (sociology) ,medicine ,business ,Intensive care medicine - Abstract
The prevalence of chronic obstructive pulmonary disease (COPD) is high in South Korea which has remained virtually unchanged over the past few years. Other challenges related to COPD in South Korea include a low level of awareness of COPD, underutilization of pulmonary function tests (PFTs) and a low level of inhaler use. Continued efforts have been made to raise awareness of COPD in the general public and promote screening tests for the early detection of COPD patients for high-risk patients, which should be the primary object for better management of the disease. The Korean Academy of Tuberculosis and Respiratory Diseases (KATRD) and the Korea Disease Control and Prevention Agency (KDCA) have been working in tandem on numerous projects to resolve these issues. As the fruit of these efforts, a couple of projects are currently being carried out to add PFTs into the National Health Examination (NHE) of Korea as part of screening tests and improve the quality of COPD treatments in primary care settings. Raising public awareness of a chronic disease such as COPD requires collective efforts of academic societies and government. In addition, personalized education programs that are tailored to individual COPD patients is a necessity to raise adherence of treatment and self-management of COPD. The aim of this manuscript is to report the current status of COPD management in South Korea in hopes that it will help better treat and manage COPD in other nations coping with similar challenges.
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- 2021
73. Tackling light trapping in organic light-emitting diodes by complete elimination of waveguide modes
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Yong-Bum Park, L. Jay Guo, and Changyeong Jeong
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Permittivity ,Multidisciplinary ,Materials science ,Fabrication ,business.industry ,Physics::Instrumentation and Detectors ,Astrophysics::High Energy Astrophysical Phenomena ,Organic Chemistry ,Physics::Optics ,SciAdv r-articles ,Optics ,Anode ,OLED ,Optoelectronics ,Quantum efficiency ,Prism ,business ,Nonlinear Sciences::Pattern Formation and Solitons ,Decoupling (electronics) ,Research Articles ,Diode ,Research Article - Abstract
Efficiency improvement of organic light-emitting diodes was achieve by complete elimination of waveguide modes., Conventional waveguide mode decoupling methods for organic light-emitting diodes (OLEDs) are typically not scalable and increase fabrication complexity/cost. Indium-tin-oxide–free transparent anode technologies showed efficiency improvement without affecting other device properties. However, previous works lack rigorous analysis to understand the efficiency improvement. Here, we introduced an ultrathin silver (Ag) film as transparent electrode and conducted systematic modal analysis of OLEDs and report that waveguide mode can be completely eliminated by designing an OLED structure that is below the cutoff thickness of waveguide modes. We also experimentally verified the waveguide mode removal in organic waveguides with the help of index-matching fluid and prism. The negative permittivity, extremely thin thickness (~5 nanometers), and highly conductive properties achieved by a uniform copper-seeded Ag film can suppress waveguide mode formation, enhancing external quantum efficiency without compromising any other characteristics of OLEDs, which paves the way for cost-effective high-efficiency OLEDs in current display industry.
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- 2021
74. Assessing the Escalation Time to Open Triple Therapy from Initiation of LAMA vs ICS/LABA in COPD Management; Findings from Comparing the Incidence of Tiotropium and ICS/LABA in Real-World Use in South Korea (CITRUS Study)
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Chin Kook Rhee, Youlim Kim, Kwang-Ha Yoo, Yong Bum Park, Yong-Il Hwang, and S.E. Lee
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medicine.medical_specialty ,COPD ,biology ,business.industry ,Internal medicine ,Ics laba ,Incidence (epidemiology) ,medicine ,Lama ,medicine.disease ,business ,biology.organism_classification - Published
- 2021
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75. Impact of Previous Occupational Exposure on Outcomes of Chronic Obstructive Pulmonary Disease
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Youlim Kim, Tai Sun Park, Tae-Hyung Kim, Chin Kook Rhee, Changhwan Kim, Jae Seung Lee, Woo Jin Kim, Seong Yong Lim, Yong Bum Park, Kwang Ha Yoo, Sang-Do Lee, Yeon-Mok Oh, and Ji-Yong Moon
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Medicine (miscellaneous) ,occupational exposure ,chronic obstructive pulmonary disease ,acute exacerbation ,lung function - Abstract
Occupational exposures have been regarded as a risk factor for the development of chronic obstructive pulmonary disease (COPD). However, there is little knowledge regarding the effect of occupational exposure on the treatment outcomes of COPD. Therefore, the aim of this study was to evaluate the question of whether occupational exposure can have a potential impact on COPD outcomes. Methods: Information regarding self-reported occupational exposure for 312 patients with COPD from the Korean Obstructive Lung Disease (KOLD) Cohort were included. A comparison of the rate of acute exacerbation, annual lung function change, and quality of life according to the presence or absence of occupational exposure was performed. Results: Seventy-six patients (24.4%) had experienced occupational exposure; chemical materials were most common. At enrollment, a higher COPD-specific version of the St. George Respiratory Questionnaire total score (39.7 ± 18.8 vs. 33.1 ± 17.6, p = 0.005) and a higher exacerbation history in the past year (30.3% vs. 17.5%, p = 0.017) were observed for patients with occupational exposure compared to those without occupational exposure. Furthermore, in the follow-up period, after adjusting for potential confounders, a higher frequency of acute exacerbation (odd ratio, 1.418; 95% confidence interval, 1.027–1.956; p = 0.033) and a more rapid decline in forced expiratory volume in 1 s (p = 0.009) was observed for COPD patients with occupational exposure compared to those without occupational exposure. Conclusions: In the KOLD cohort, worse outcomes in terms of exacerbation rate and change in lung function were observed for COPD patients with occupational exposure compared to those without occupational exposure. These findings suggest that occupational exposure not only is a risk factor for COPD but also might have a prognostic impact on COPD.
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- 2022
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76. Predicting long-term mortality with two different criteria of exercise-induced desaturation in COPD
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Yong Bum Park, Yousang Ko, Chin Kook Rhee, Changhwan Kim, Seong Yong Lim, Joon Beom Seo, Jae Seung Lee, Yeon-Mok Oh, Ji Yong Moon, Jin Hwa Lee, Sang Do Lee, and Kwang Ha Yoo
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Pulmonary and Respiratory Medicine ,Male ,Risk ,medicine.medical_specialty ,Time Factors ,Walk Test ,Cohort Studies ,03 medical and health sciences ,Pulmonary Disease, Chronic Obstructive ,0302 clinical medicine ,Predictive Value of Tests ,Internal medicine ,Surveys and Questionnaires ,Republic of Korea ,Medicine ,Humans ,030212 general & internal medicine ,Exercise ,Aged ,Proportional Hazards Models ,COPD ,Exercise Tolerance ,business.industry ,Proportional hazards model ,Middle Aged ,medicine.disease ,Predictive value ,Obstructive lung disease ,Oxygen ,Increased risk ,030228 respiratory system ,Walk test ,Cohort ,Long term mortality ,Female ,business ,Follow-Up Studies - Abstract
Background There are few reports on exercise-induced desaturation (EID) as a predictor of mortality in chronic obstructive pulmonary disease (COPD). However, the definitions of EID vary in published reports. The main purpose was to evaluate the association between EID and long-term mortality by applying two criteria of EID. Methods A total of 507 subjects were selected from the Korean Obstructive Lung Disease cohort. EID was assessed using the 6-min walk test (6MWT) and defined using two different criteria [1]: post-6MWT oxygen saturation (SpO2) of ≤88% (criterion A) and [2] post-6MWT SpO2 Results The prevalence of EID was 5.1% based on criterion A and 13.0% based on criterion B. Regardless of the criteria used, mortality was higher in the EID group than in the non-EID group (A: 50 vs. 11.4%, B: 33.3 vs. 10.4%) during up to 161 months of follow-up. COPD patients without EID survived significantly longer than those with EID (A: 143.5 vs. 92.9, B: 144.8 vs. 115.2 months). Multivariate Cox regression analysis revealed that COPD patients with EID had a 2.4-fold increased risk of death by criterion A (adjusted HR 2.375; 95% CI: 1.217–4.637; P = 0.011). The risk of death increased in COPD patients with EID by criterion B, but the difference was not statistically significant. Conclusions COPD patients with EID demonstrated significantly higher long-term mortality than those without EID. The EID criterion A has a better predictive value for mortality in COPD.
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- 2021
77. Enhanced light outcoupling from OLEDs by suppressing guided modes formation using an ultrathin flexible transparent conductor
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Yong-Bum Park, Changyeong Jeong, and L. Jay Guo
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010302 applied physics ,Materials science ,Fabrication ,business.industry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Conductor ,Indium tin oxide ,0103 physical sciences ,OLED ,Optoelectronics ,Quantum efficiency ,Prism ,0210 nano-technology ,business ,Electrical efficiency ,Decoupling (electronics) - Abstract
All previous waveguide mode decoupling methods used to increase external quantum efficiency (EQE) and power efficiency of OLEDs are complex in structure and not scalable in fabrication. Here, we introduce a novel yet simple approach of using an ultrathin (~ 5 nm) copper-seeded silver (Cu-Ag) film to completely eliminate waveguide modes and enhance outcoupling efficiency of OLEDs. We experimentally verified waveguide mode elimination in the organic waveguides using index matching fluid and prism. In essence, the OLED structure can be designed to below the cutoff thickness of waveguide modes using the ultrathin Cu- Ag electrode, leading to a theoretical maximum EQE of 76.1% without compromising other characteristics of OLEDs. This EQE is higher than any other theoretically expected values reported previously without increasing fabrication steps/complexity.
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- 2020
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78. Longitudinal Changes in Clinical Features, Management, and Outcomes of Idiopathic Pulmonary Fibrosis. A Nationwide Cohort Study
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Yong Bum Park, Choon-Sik Park, Man Pyo Chung, Jong Sun Park, Soo Taek Uh, Hyejung Shin, Yong Hyun Kim, Jong Wook Shin, Yee Hyung Kim, Sung Woo Park, Jin Woo Song, Jongmin Lee, Sei Hoon Yang, Hong Lyeol Lee, Sang-Heon Kim, Sung Woo Moon, Dong Soon Kim, Young Whan Kim, Moo Suk Park, Sun Mi Choi, Yangjin Jegal, Hongseok Yoo, Sung Hwan Jeong, Bumsu Shin, Hyun Lee, Song Yee Kim, Hye Sook Choi, Hyun Kyung Lee, Jae Ha Lee, Eun Joo Lee, and Tae Hyung Kim
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,business.industry ,Biopsy ,Interstitial lung disease ,MEDLINE ,Clinical epidemiology ,medicine.disease ,Idiopathic Pulmonary Fibrosis ,Respiratory Function Tests ,Cohort Studies ,Idiopathic pulmonary fibrosis ,Internal medicine ,Pulmonary fibrosis ,medicine ,Life expectancy ,Humans ,sense organs ,business ,Lung Diseases, Interstitial ,Cohort study - Abstract
Rationale: In recent decades, diagnosis and treatment recommendations for idiopathic pulmonary fibrosis (IPF) have changed. In Korea, the average life expectancy has increased, unmet healthcare nee...
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- 2020
79. COPD is not associated with a poor prognosis in COVID-19
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Tai Joon An, Youlim Kim, Yong Bum Park, Kyungjoo Kim, Do Yeon Cho, Kwang-Ha Yoo, and Chin Kook Rhee
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Background: Coronavirus disease 2019 (COVID-19) is a worldwide pandemic. The effect of underlying chronic obstructive pulmonary disease (COPD) on COVID-19 is controversial. We set this study to examine the clinical outcomes of COVID-19 according to the underlying COPD.Methods: COVID-19 patients were assessed using nationwide health insurance data. COPD patients were operationally defined. Comorbidities were evaluated by using the modified Charlson Comorbidity Index (mCCI) which excluded the factors of COPD from conventional CCI scores. Baseline characteristics and clinical outcomes of COVID-19, such as mortality, hospital length of stay (LOS), and intensive care unit (ICU) admission, were assessed. Subgroup analysis about the effect of inhaled corticosteroid of COPD patients on COVID-19 was performed.Results: COPD group were older (71.3±11.6 vs. 47.7±19.1, p < 0.001) and have higher CCI scores (2.6±1.9 vs. 0.8±1.3, p < 0.001) than non-COPD group. Mortality was higher in COPD groups than in non-COPD group (22.9% vs. 3.2%, p < 0.001). The ICU admission rate and hospital LOS were not significantly different between the two groups. In univariate analysis, ages, male sex, mCCI, socioeconomic status, and underlying COPD were associated with mortality. In multivariate analysis, underlying COPD was not associated with mortality after adjusted. On the other hand, other variables are still associated with mortality. Older ages (odds ratio [OR] 1.12; 95% confidence interval [CI] 1.11–1.14; p < 0.001), male sex (OR 2.29; 95% CI 1.67–3.12; p < 0.001), higher mCCI (OR 1.30; 95% CI 1.20–1.41; p < 0.001), and medical aid insurance (OR 1.55; 95% CI 1.03–2.32; p = 0.035) were associated with mortality of COVID-19. Underlying COPD was also not associated with hospital LOS and ICU admission rates in the adjusted analyses. In the subgroup analysis, there was no significant difference between the ICS user and nonuser including mortality and hospital LOS. In the adjusted analyses, the use of ICS in COPD patients was not associated with mortality and hospital LOS in COVID-19.Conclusions: Mortality, hospital LOS, and ICU admission rate were not associated with underlying COPD in COVID-19.
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- 2020
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80. Risk factors for early readmission after acute exacerbation of chronic obstructive pulmonary disease
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Chin Kook Rhee, Kwang Ha Yoo, Yong Bum Park, and Yong Suk Jo
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Acute exacerbation of chronic obstructive pulmonary disease ,COPD ,medicine.medical_specialty ,Exacerbation ,Systemic steroid ,business.industry ,medicine.disease ,Pneumonia ,Emergency medicine ,medicine ,Skilled Nursing Facility ,Lung cancer ,business ,Medical expenses - Abstract
Background and Objective: Patients discharged after treatment for acute exacerbation of chronic obstructive pulmonary disease (COPD) are at high risk for readmission. We aimed to identify the prevalence and risk factors for readmission. Methods: We included 16,105 patients who had claimed their medical expenses from May 1, 2014, to May 1, 2016 after discharge from any medical facility in Korea, following treatment for acute exacerbation of COPD. We analysed the potential risk factors for readmission within 30 days of discharge. Results: Readmission rate was 26.4% (3989 patients among 15,101 patients) and over 50% of readmissions occurred within 10 days of discharge. Approximately 57% of readmissions occurred due to respiratory causes. Major causes of readmission were COPD (27%), pneumonia (14.2%) and lung cancer (7.1%), in that order. Patients who were readmitted were male, had more comorbidities, and were less frequently admitted to tertiary hospitals than those who were not readmitted. Risk factors for readmission within 30 days of discharge were male sex, medical aid coverage, longer hospital stay, longer duration of systemic steroid use during hospital stay, high comorbid condition index, and discharge to skilled nursing facility. Conclusions: Readmission occurred in approximately a quarter of patients, and was associated with patient-related and clinical factors. Using these results, we can identify high-risk patients for readmission and precautions are needed to be taken before deciding discharge plan.
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- 2020
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81. Clinical Characteristics of Chronic Obstructive Pulmonary Disease in Female Patients: Findings from a KOCOSS Cohort
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Joon Young, Choi, Shin Young, Kim, Jae Ha, Lee, Yong Bum, Park, Yee Hyung, Kim, Soo-Jung, Um, Ki Suck, Jung, Kwang Ha, Yoo, Seoung Ju, Park, and Hyoung Kyu, Yoon
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Smoking ,respiratory tract diseases ,Cohort Studies ,KOCOSS database ,Pulmonary Disease, Chronic Obstructive ,Pulmonary Emphysema ,Forced Expiratory Volume ,gender difference ,Republic of Korea ,cohort study ,Humans ,COPD ,Female ,Child ,Lung ,Original Research - Abstract
Purpose The prevalence of chronic obstructive pulmonary disease (COPD) in females has increased, changing the concept of COPD as a disease mostly limited to males. In this study, the clinical characteristics of COPD in females were investigated. Patients and Methods The study was based on a multicenter cohort of COPD patients recruited from 54 medical centers in South Korea. Sex-based differences in general characteristics, exposure risk factors, depression scores, results of pulmonary function tests, COPD exacerbation, symptom scores, and radiologic findings were evaluated. Sex-related differences in the annual FEV1 change over 5 years were analyzed in a linear mixed model. Results Of the 2515 patients enrolled in this study, 8.1% were female. Female patients who had a higher BMI and a lower level of education were less likely to be smokers, were more exposed to passive smoking/biomass, and were more depressed compared to males. The rates of bronchiectasis, previous childhood respiratory infection, and asthma were higher in females. Female patients also had more symptoms and a poorer exercise capacity than males, but no significant differences were observed in terms of exacerbations. Radiologic findings revealed that male patients had worse emphysema, and female patients had worse bronchiectasis, as determined based on chest X-ray and computed tomography findings. On pulmonary function tests, female patients had less obstruction and less annual FEV1 loss over 5 years. Conclusion This study revealed differences in the clinical parameters between male and female patients with COPD, including general characteristics, disease characteristics, and clinical outcomes.
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- 2020
82. Exacerbations of Chronic Obstructive Pulmonary Disease Tool to assess the efficacy of acute treatment
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Sun Young Kyung, Sung Soo Jung, Sung Ho Yoon, Ju Sang Kim, Hye Sook Choi, Seung Hun Jang, Yong Bum Park, Kang Hyeon Choe, Kyeong Cheol Shin, and Young Sam Kim
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COPD ,medicine.medical_specialty ,Exacerbation ,business.industry ,Pulmonary disease ,General Medicine ,medicine.disease ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Randomized controlled trial ,Cronbach's alpha ,law ,Internal medicine ,medicine ,Sputum ,In patient ,030212 general & internal medicine ,medicine.symptom ,business ,After treatment - Abstract
Background and objective The Exacerbations of Chronic Obstructive Pulmonary Disease Tool-Patient-Reported Outcomes (EXACT-PRO) has been suggested as a reliable and valid measure for early assessment of COPD exacerbations and perceived recovery. However, there has been no evidence for EXACT-PRO efficacy in assessing recovery from treatment in a randomized controlled trial. The study evaluated the reliability, validity, and responsiveness of EXACT-PRO for the evaluation of the efficacy of acute treatment in patients with COPD exacerbation. Methods In a Phase III randomized controlled study for assessing the efficacy of antibiotic treatment on COPD exacerbation, EXACT-PRO was evaluated in the responders and non-responders. Results A total of 295 patients were analyzed (259 responders and 37 non-responders). Cronbach's α was 0.96 for EXACT total, 0.96 for the breathlessness domain, 0.89 for the cough and sputum domain, and 0.93 for the chest symptoms domain. The EXACT score correlated with the COPD assessment test (CAT) score (r=0.8, P
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- 2019
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83. Longitudinal change of FEV1 and inspiratory capacity: clinical implication and relevance to exacerbation risk in patients with COPD
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Seoung Ju Park, Ki Suck Jung, Kwang Ha Yoo, Yong Suk Jo, Deog Kyeom Kim, Yong Bum Park, Sung Kyoung Kim, and Soo Jung Um
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COPD ,medicine.medical_specialty ,Exacerbation ,business.industry ,Gold standard ,General Medicine ,respiratory system ,medicine.disease ,respiratory tract diseases ,Inspiratory Capacity ,03 medical and health sciences ,0302 clinical medicine ,030228 respiratory system ,Quality of life ,Internal medicine ,medicine ,In patient ,Lung volumes ,030212 general & internal medicine ,business ,Lung function - Abstract
Background and objective FEV1 is the gold standard for assessment of COPD. We compared efficacy of FEV1, inspiratory capacity (IC), and IC to total lung capacity (TLC) ratio in the evaluation of COPD and their association with exacerbation. Methods We analyzed the association of dyspnea severity, quality of life status, and lung function with lung function measurements and exacerbation risk in 982 patients enrolled in the Korea COPD Subgroup Registry and Subtype Research study. Exacerbation and longitudinal lung function change were evaluated in 3 years' follow-up. Results The FEV1, IC, and IC to TLC ratio showed comparable negative correlations with dyspnea severity and quality of life status, and positive correlation with exercise capacity. In patients with >2 events/year, annual rate of change in FEV1 and IC tended to decline more rapidly in those with FEV1 50% (-14.46±19.40 mL/year vs 12.29±9.24 mL/year, P=0.213; -4.75±17.28 mL/year vs -78.05±34.16 mL/year, P=0.056 for FEV1 and IC, respectively), without significance. Conclusion Longitudinal changes in IC and FEV1 were not significantly associated with exacerbation risk.
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- 2019
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84. Solitary Tracheal Papilloma
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Yousang Ko, Yong Bum Park, and Changwhan Kim
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Pulmonary and Respiratory Medicine ,Aged, 80 and over ,medicine.medical_specialty ,Papilloma ,business.industry ,MEDLINE ,Critical Care and Intensive Care Medicine ,medicine.disease ,Dermatology ,Medicine ,Humans ,Female ,Tracheal Neoplasms ,business - Published
- 2020
85. Male current smokers have low awareness and optimistic bias about COPD: field survey results about COPD in Korea
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Tae Hyung Kim, Joo Hun Park, Yong Il Hwang, Joo-Hee Kim, Hyoung Kyu Yoon, Ji Young Park, Chin Kook Rhee, Seung Hun Jang, Yong Bum Park, Kwang Ha Yoo, Sunghoon Park, and Ki-Suck Jung
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Spirometry ,COPD ,medicine.medical_specialty ,Demographics ,medicine.diagnostic_test ,business.industry ,General Medicine ,medicine.disease ,Field survey ,respiratory tract diseases ,Pulmonary function testing ,medicine ,Physical therapy ,Risk factor ,business ,Respiratory health ,Laboratory technicians - Abstract
Background Smoking is a major risk factor for COPD. However, there is low COPD awareness among smokers. We conducted a field survey to investigate COPD awareness, optimistic bias associated with COPD, and COPD prevalence (using handheld spirometry) among current male smokers. Subjects and methods We enrolled currently smoking males aged over 40 years, who completed a self-administered questionnaire. The questionnaire consisted of six parts: 1) baseline demographics, 2) participants' awareness of COPD and pulmonary function tests, 3) presence of COPD-related respiratory symptoms and experience with pulmonary function testing, 4) optimistic bias about COPD, 5) willingness to change attitude toward respiratory health, and 6) preference of media for obtaining health-related information. Pulmonary function was assessed via handheld spirometry by two experienced pulmonary function laboratory technicians after completion of the questionnaire. Results We enrolled 105 participants. Only 24.8% knew of COPD. Awareness of pulmonary function testing was reported by 41.9% of participants, and 30.5% had previously undertaken pulmonary function tests. Among the subjects who had not previously undergone pulmonary function tests, 47% were not aware of their existence. The mean optimistic bias scores were 3.9 and 4.0, respectively, reflecting the general perception, among participants, that they were about as likely to develop COPD as similarly aged smokers and friends, respectively. A total of 40.0% of participants perceived personal COPD risk to be lower than COPD risk among their friends. Abnormal handheld spirometry results were observed in 28.6% of participants. Among the subjects with abnormal handheld spirometry results, 36.7% had FEV1 values
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- 2019
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86. Comparison of clinical efficacy between ultra-LABAs and ultra-LAMAs in COPD: a systemic review with meta-analysis of randomized controlled trials
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Hye Yun Park, Kwang Ha Yoo, Min-Ji Kim, Hyun Lee, Ji Ye Jung, Chin Kook Rhee, Se Yong Kim, Dong Ah Park, Yong Bum Park, Yong Il Hwang, Eun Yeong Cho, and Seonwoo Kim
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,COPD ,biology ,business.industry ,medicine.drug_class ,technology, industry, and agriculture ,MEDLINE ,Muscarinic antagonist ,Odds ratio ,Lama ,biology.organism_classification ,medicine.disease ,law.invention ,Randomized controlled trial ,law ,Internal medicine ,Meta-analysis ,Bronchodilator ,medicine ,Original Article ,business ,medicine.drug - Abstract
Background: A single long-acting bronchodilator, ultra-long acting muscarinic antagonist (ultra-LAMA) or ultra-long acting β2-agonist (ultra-LABA) is preferred for the initial treatment of patients with chronic obstructive pulmonary disease (COPD); however, there are few head-to-head comparative studies between the two. Here, a meta-analysis of randomized controlled trials was performed to compare the clinical efficacy between ultra-LABA and ultra-LAMA in patients with moderate-to-severe COPD. Methods: MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched (to March 1, 2017) to identify all published randomized controlled trials. Results: Of the 12,906 articles found by searching the databases, we obtained data from 10,591 patients with COPD (LABA, n=5,058; LAMA, n=5,533) in seven published studies. Our results showed that COPD exacerbation were significantly lower in patients taking ultra-LAMA than those taking ultra-LABA (odds ratio =0.857, P=0.0008). However, no significant differences were observed between ultra-LAMA and ultra-LABA patients regarding improvement in trough forced expiratory volume in 1 s, the transitional dyspnea index, or St. George’s Respiratory Questionnaire score. Conclusions: This study suggests that COPD exacerbation occurred less often in patients taking an ultra-LAMA than in those taking an ultra-LABA with similar efficacy of lung function and quality of life.
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- 2018
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87. Clinical impacts of the classification by 2017 GOLD guideline comparing previous ones on outcomes of COPD in real-world cohorts
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Snu airway registry investigators, Yon-Mok Oh, Ki Suck Jung, Soo-Jung Um, Eunkyung Kim, Yong Bum Park, Deog Kyeom Kim, Chang Hoon Lee, Kwang Ha Yoo, Sang Do Lee, Ji Hyun Lee, Jin Hwa Song, and Kocoss investigators Kold
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Male ,medicine.medical_specialty ,Time Factors ,Databases, Factual ,Exacerbation ,Health Status ,International Journal of Chronic Obstructive Pulmonary Disease ,Rate ratio ,Risk Assessment ,Severity of Illness Index ,Group A ,Group B ,Decision Support Techniques ,Pulmonary Disease, Chronic Obstructive ,03 medical and health sciences ,0302 clinical medicine ,Predictive Value of Tests ,Risk Factors ,Internal medicine ,Republic of Korea ,Severity of illness ,medicine ,Health Status Indicators ,Humans ,030212 general & internal medicine ,Lung ,Original Research ,pulmonary disease ,Aged ,Aged, 80 and over ,COPD ,business.industry ,chronic obstructive/classification ,chronic obstructive/epidemiology ,General Medicine ,Guideline ,Middle Aged ,Prognosis ,medicine.disease ,030228 respiratory system ,Practice Guidelines as Topic ,Disease Progression ,Female ,chronic obstructive/diagnosis ,business ,Gold classification - Abstract
Jin Hwa Song,1 Chang-Hoon Lee,1 Soo-Jung Um,2 Yong Bum Park,3 Kwang Ha Yoo,4 Ki Suck Jung,5 Sang-Do Lee,6 Yon-Mok Oh,6 Ji Hyun Lee,7 Eun Kyung Kim,7 Deog Kyeom Kim8,9 On behalf of KOLD, KOCOSS, and SNU airway registry investigators 1Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea; 2Division of Respiratory Medicine, Department of Internal Medicine, Dong-A University College of Medicine, Dong-A University Medical Center, Busan, Republic of Korea; 3Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kangdong Sacred Heart Hospital, Seoul, Republic of Korea; 4Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea; 5Division of Pulmonary Medicine, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Hallym University Medical School, Anyang Gyeonggi-do, Republic of Korea; 6Department of Pulmonary and Critical Care Medicine and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul, Republic of Korea; 7Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam Gyeonggi-do, Republic of Korea; 8Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Republic of Korea; 9Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea Purpose: While GOLD classification has been revised, its clinical impacts on outcomes of COPD patients have not been widely evaluated in real-world cohorts.Materials and methods: According to 2007, 2013, and 2017 GOLD classifications, distribution and clinical characteristics of group-shifted patients and the risk of acute exacerbation were analyzed in combined Korean COPD cohorts. Future risk for annual moderate-to-severe exacerbation was estimated as incidence rate ratio (IRR) and compared by groups.Results: Among 1,880 COPD patients, in GOLD 2017 classification, groups B and A were increased to 61.2% and 22.2% of total population, while group C was shrunken to 2.2% and patients with higher risk were decreased (16.6% in GOLD 2017 vs 44.7% in GOLD 2013). The kappa coefficient of agreement of both systems was 0.581 (agreement 71.7%). Groups B and D showed higher IRR of moderate-to-severe exacerbation than group A (IRR 2.4 and 5.3 respectively, P
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- 2018
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88. Heteroepitaxy of Fin-Shaped InGaN Nanoridge Using Molecular Beam Epitaxy
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Yong-Bum Park, Robert Hovden, Reed Yalisove, Jiseok Gim, and Zetian Mi
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010302 applied physics ,Materials science ,Photoluminescence ,business.industry ,Nanowire ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Epitaxy ,01 natural sciences ,Crystal ,Etching (microfabrication) ,0103 physical sciences ,Scanning transmission electron microscopy ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Layer (electronics) ,Molecular beam epitaxy - Abstract
We have demonstrated a well-ordered In-rich single crystalline InGaN nanoridge array grown on GaN/sapphire substrate using the integration of top-down etching and bottom-up molecular beam epitaxy. During the initial growth of InGaN on a patterned GaN/sapphire substrate, a (1011) r-plane predominantly forms, suppressing the growth in [1011] crystal direction and resulting in a triangular InGaN nanoprism. As the growth proceeds further, a narrow (∼50 nm) single-crystal fin-shaped InGaN nanoridge forms atop the InGaN nanoprism structure. The resulting narrow fin-shaped InGaN nanoridge structure shows extremely strong photoluminescence (PL) intensity with a center wavelength at 524–560 nm and narrow distribution compared to the epitaxially grown planar InGaN layer or InGaN nanowire. High-resolution scanning transmission electron microscopy (STEM) combined with an energy-dispersive X-ray (EDS) map reveals that a sharply faceted single-crystal InGaN nanoridge (∼50 nm width) forms along the top of each InGaN n...
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- 2018
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89. Preparation and characterization of durable catalyst via diazonium reaction in PEMFC
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Yong-Bum Park, Myoung-Ki Min, Eunyoung You, and Chanho Pak
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Nitrile ,Chemistry ,General Chemical Engineering ,chemistry.chemical_element ,Proton exchange membrane fuel cell ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Durability ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,Chemical engineering ,Fluorine ,Wetting ,0210 nano-technology ,Platinum - Abstract
The electrochemical catalytic durability can be enhanced by the post treatment of diazonium reaction. The diazonium salts which have fluorine, acid, and nitrile functional groups were grafted on the surface of Pt based catalyst with 1–3 wt%. Pt/GKB6-Dia4F, which was a catalyst with fluorine functional group, showed the excellent properties in durability as well as in mass activity. After the durability test, electrochemical surface area (ECSA) and mass activity of the Pt/GKB6-Dia4F were maintained by 81.9% and 75.3%, respectively. These were higher than those of pristine catalyst, which were 60.8% and 58.9%, respectively. The causes of these enhancements were investigated in the aspect of electrostructure of platinum or wettability of the catalyst. In XPS, the valid Pt4f peak shifts of the treated-catalysts were not detected, but the indisputable changes of the surface properties via diazonium reaction were detected. This indicates that the main factor affecting the catalytic durability is the wettability of the catalyst. Therefore, we conclude that diazonium reaction is an effective method to change the surface property of the catalyst, which can enhance the catalytic durability.
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- 2018
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90. The motive of majors in sports for the major selection and it's effect on academic achievement
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Yong-Bum Park and Jin-Young Hong
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Mathematics education ,Academic achievement ,Psychology ,Selection (genetic algorithm) - Published
- 2018
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91. Miliary Tuberculosis Mimicking Brain Metastasis from Renal Cell Carcinoma
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Yong Bum Park, Jong Seok Bae, Eun-Kyung Mo, Mi-Ri Kang, Yousang Ko, and Yerim Kim
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0301 basic medicine ,Pathology ,medicine.medical_specialty ,Miliary tuberculosis ,Tuberculosis ,business.industry ,Tuberculosis, Miliary ,Neoplasm metastasis ,030106 microbiology ,medicine.disease ,lcsh:RC346-429 ,03 medical and health sciences ,0302 clinical medicine ,Brain neoplasms ,Tuberculoma, Intracranial ,Renal cell carcinoma ,medicine ,Tuberculoma ,030212 general & internal medicine ,business ,lcsh:Neurology. Diseases of the nervous system ,Brain metastasis - Abstract
Background Miliary tuberculosis (TB) can cause diagnostic confusion for clinicians because its radiological appearance can resemble that of metastatic cancer. Case Report Here, we describe the case of a 72-yearold woman with miliary TB mimicking brain metastasis from renal cell carcinoma. The patient visited our clinic because of dysarthria and sluggish speech. A metastatic cancer such as renal cell carcinoma or brain tumor was suspected. However, the patient was diagnosed with miliary TB associated with multiple intracranial tuberculomas and a subsequent paradoxical response to anti-TB therapy. Conclusion Clinicians should be aware that miliary TB can mimic metastatic cancer even in older people, especially in TB-endemic regions.
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- 2018
92. Revised (2018) COPD Clinical Practice Guideline of the Korean Academy of Tuberculosis and Respiratory Disease: A Summary
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Joong Hyun Ahn, Yong Bum Park, Hyoung Kyu Yoon, Yeon-Mok Oh, Jin Hwa Lee, Seong Yong Lim, Kwang Ha Yoo, and Chin Kook Rhee
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Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,COPD ,Tuberculosis ,Exacerbation ,business.industry ,Respiratory disease ,Guideline ,Review ,medicine.disease ,Treatment ,03 medical and health sciences ,Pulmonary Disease, Chronic Obstructive ,0302 clinical medicine ,Infectious Diseases ,Systematic review ,030228 respiratory system ,Family medicine ,Health care ,Epidemiology ,Diagnosis ,medicine ,030212 general & internal medicine ,business - Abstract
Chronic obstructive pulmonary disease (COPD) results in high morbidity and mortality among patients nationally and globally. The Korean clinical practice guideline for COPD was revised in 2018. The guideline was drafted by the members of the Korean Academy of Tuberculosis and Respiratory Diseases as well as the participating members of the Health Insurance Review and Assessment Service, Korean Physicians' Association, and Korea Respiration Trouble Association. The revised guideline encompasses a wide range of topics, including the epidemiology, diagnosis, assessment, monitoring, management, exacerbation, and comorbidities of COPD in Korea. We performed systematic reviews assisted by an expert in meta-analysis to draft a guideline on COPD management. We expect this guideline to facilitate the treatment of patients with respiratory conditions by physicians as well other health care professionals and government personnel in South Korea.
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- 2018
93. Comparison of CPI and GAP models in patients with idiopathic pulmonary fibrosis: a nationwide cohort study
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Jin Woo Song, Jin Hwa Lee, Dong Soon Kim, Hyun Kyung Lee, Sung Woo Park, Eun Joo Lee, Jong Wook Shin, Young Whan Kim, Yong Hyun Kim, Song Yee Kim, Choon-Sik Park, Sang Hoon Lee, Man Pyo Chung, Hong Lyeol Lee, Yong Bum Park, Sung Hwan Jeong, Yangin Jegal, Moo Suk Park, Soo Taek Uh, and Jongsun Park
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Male ,medicine.medical_specialty ,Aging ,lcsh:Medicine ,Gastroenterology ,Article ,Cohort Studies ,03 medical and health sciences ,Idiopathic pulmonary fibrosis ,0302 clinical medicine ,DLCO ,Internal medicine ,Republic of Korea ,medicine ,Humans ,In patient ,030212 general & internal medicine ,Stage (cooking) ,lcsh:Science ,Survival analysis ,Aged ,Sex Characteristics ,Multidisciplinary ,Models, Statistical ,business.industry ,lcsh:R ,Area under the curve ,Interstitial lung disease ,respiratory system ,medicine.disease ,Survival Analysis ,Idiopathic Pulmonary Fibrosis ,respiratory tract diseases ,030228 respiratory system ,Female ,lcsh:Q ,business ,Cohort study - Abstract
The clinical course of idiopathic pulmonary fibrosis (IPF) is difficult to predict, partly owing to its heterogeneity. Composite physiologic index (CPI) and gender-age-physiology (GAP) models are easy-to-use predictors of IPF progression. This study aimed to compare the predictive values of these two models. From 2003 to 2007, the Korean Interstitial Lung Disease (ILD) Study Group surveyed ILD patients using the 2002 ATS/ERS criteria. A total of 832 patients with IPF were enrolled in this study. CPI was calculated as follows: 91.0 − (0.65 × %DLCO) − [0.53 × %FVC + [0.34 × %FEV1. GAP stage was calculated based on gender (0–1 points), age (0–2 points), and two physiologic lung function parameters (0–5 points). The two models had similar significant predictive values for patients with IPF (p
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- 2018
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94. Resistivity Scaling Transition in Ultrathin Metal Film at Critical Thickness and Its Implication for the Transparent Conductor Applications
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Yong‐Bum Park, Changyeong Jeong, and L. Jay Guo
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Electronic, Optical and Magnetic Materials - Published
- 2021
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95. Verification effect of Senior Health Yoga Program combined with Recreation
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Su-Wha Bae and Yong-Bum Park
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Medical education ,Psychology ,Recreation - Published
- 2017
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96. Urinary desmosine is associated with emphysema severity and frequent exacerbation in patients with COPD
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Joon Beom Seo, Sang Do Lee, Chin Kook Rhee, Ji Hyun Lee, Jin Hwa Lee, Seong Yong Lim, Yousang Ko, Su Hee Kim, Jae Seung Lee, Changhwan Kim, Yeon-Mok Oh, Yong Bum Park, Hyun Ju Yoo, Kwang Ha Yoo, and Tae Hyung Kim
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Pulmonary and Respiratory Medicine ,COPD ,medicine.medical_specialty ,Exacerbation ,business.industry ,Urinary system ,Urine ,medicine.disease ,Gastroenterology ,Obstructive lung disease ,respiratory tract diseases ,Desmosine ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,030228 respiratory system ,chemistry ,Internal medicine ,Cohort ,Medicine ,030212 general & internal medicine ,business ,Body mass index - Abstract
Background and objective Matrix degradation is a key feature of chronic obstructive pulmonary disease (COPD). Desmosine and isodesmosine (desmosines) are excreted in urine following matrix degradation. The main purpose of this study was to investigate the association between computed tomography (CT) emphysema indices and urinary desmosines in patients with COPD. Methods A total of 152 subjects were selected from the Korean Obstructive Lung Disease cohort. Their urine samples were assayed for desmosines using liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. The cohort was divided into emphysema-dominant (n = 80) and non-emphysema dominant- (n = 72) groups according to the CT emphysema index. Results The level of urinary desmosines was significantly higher in the emphysema-dominant group. Significant differences were also observed between the two groups for body mass index and lung function. Multivariate analysis indicated that a high level of urinary desmosines was a significant independent predictor of emphysema (relative risk: 2.6; 95% CI: 1.11–6.09; P = 0.028). The percentage of frequent exacerbators was significantly higher in the high urinary desmosine group in the first year of follow-up (P = 0.041). The mean number of exacerbations was higher in the high urinary desmosine group, although this difference was not statistically significant (P = 0.067). The changes in emphysema index did not differ between the two urinary desmosine groups over 3 years of follow-up. Conclusion This study indicates that the level of urinary desmosines measured by LC-MS/MS methods is associated with the CT emphysema index. Urinary desmosine can be a useful predictor in identifying frequent exacerbators.
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- 2017
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97. Autophagy Primes Neutrophils for Neutrophil Extracellular Trap Formation during Sepsis
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Eun-Kyung Mo, Ki-Suck Jung, Shin-Yeong Kim, Younsuck Koh, So Hee Park, Suh-Young Lee, Won-Gyun Ahn, Yong Bum Park, Myung Goo Lee, Dong-Keun Song, Hyun-Jung Kim, Myung Jae Park, Shin Kim, Sanjeeb Shrestha, Jun-Kyu Kim, So Young Park, Young-Jin Youn, Chang-Won Hong, and Yousang Ko
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Male ,0301 basic medicine ,Pulmonary and Respiratory Medicine ,Neutrophils ,Fluorescent Antibody Technique ,Stimulation ,Critical Care and Intensive Care Medicine ,Extracellular Traps ,Pathogenesis ,Sepsis ,Mice ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Immune system ,Autophagy ,Animals ,Humans ,Medicine ,Prospective Studies ,Aged ,Mice, Inbred BALB C ,business.industry ,Effector ,Pneumonia ,Neutrophil extracellular traps ,medicine.disease ,Community-Acquired Infections ,Disease Models, Animal ,030104 developmental biology ,chemistry ,030220 oncology & carcinogenesis ,Immunology ,Phorbol ,Female ,business - Abstract
Neutrophils are key effectors in the host's immune response to sepsis. Excessive stimulation or dysregulated neutrophil functions are believed to be responsible for sepsis pathogenesis. However, the mechanisms regulating functional plasticity of neutrophils during sepsis have not been fully determined.We investigated the role of autophagy in neutrophil functions during sepsis in patients with community-acquired pneumonia.Neutrophils were isolated from patients with sepsis and stimulated with phorbol 12-myristate 13-acetate (PMA). The levels of reactive oxygen species generation, neutrophil extracellular trap (NET) formation, and granule release, and the autophagic status were evaluated. The effect of neutrophil autophagy augmentation was further evaluated in a mouse model of sepsis.Neutrophils isolated from patients who survived sepsis showed an increase in autophagy induction, and were primed for NET formation in response to subsequent PMA stimulation. In contrast, neutrophils isolated from patients who did not survive sepsis showed dysregulated autophagy and a decreased response to PMA stimulation. The induction of autophagy primed healthy neutrophils for NET formation and vice versa. In a mouse model of sepsis, the augmentation of autophagy improved survival via a NET-dependent mechanism.These results indicate that neutrophil autophagy primes neutrophils for increased NET formation, which is important for proper neutrophil effector functions during sepsis. Our study provides important insights into the role of autophagy in neutrophils during sepsis.
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- 2017
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98. The Effect of Leisure Commitment and Satisfaction of Screen Golf Users on Participation Intention in Practical Course
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Yong-Bum Park and Seok-Jin Lim
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Medical education ,Psychology ,Course (navigation) - Published
- 2017
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99. Effects of mechanical stretching on average orientation of cellulose and pectin in onion epidermis cell wall: A polarized FT-IR study
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Kabindra Kafle, Christopher M. Lee, Sarah N. Kiemle, Daniel J. Cosgrove, Seong H. Kim, Joshua J. Stapleton, and Yong Bum Park
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0106 biological sciences ,0301 basic medicine ,chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Polymer ,Dichroism ,Polysaccharide ,01 natural sciences ,Cell wall ,Coupling (electronics) ,03 medical and health sciences ,chemistry.chemical_compound ,Crystallography ,Dipole ,Transverse plane ,030104 developmental biology ,chemistry ,Cellulose ,Composite material ,010606 plant biology & botany - Abstract
The organization of polysaccharides in plant cell walls is important for the mechanics of plant cells. Spectral analysis of cell walls by polarized IR can reveal polysaccharide organization, but may be complicated by dipoles not aligned with the backbone. For instance, analysis of uniaxially-aligned cellulose Iβ film revealed that the dipole transition vector of the 1160 cm−1 band involving stretch vibrations of glycosidic C1–O–C4 linkages is approximately at 30° with respect to the backbone of the cellulose chain, because of coupling with C5–O–C1 bonds in the six-membered rings. In the case of homogalacturonan, the dipole transition vector of the ester carbonyl group vibration (νC=O, 1745 cm−1) is expected to be nearly normal to the homogalacturonan backbone. Using this information and the dichroism equation, the change in net orientation of cell wall polymers upon mechanical stretch was determined by polarized IR analysis. Never-dried abaxial outer epidermal cell walls of the second scale of onion bulb were mechanically stretched along longitudinal or transverse directions with respect to the long axis of the cells and then dried while under mechanical stretch. The average orientations of both 1160 and 1745 cm−1 vibration transition dipoles were rotated by ~5° and ~4°, respectively, along the stretch direction from their initial random distributions upon longitudinal strain by 14%; and by ~4° and ~3°, respectively, upon transverse strain by 12%. These results imply that both cellulose microfibrils and pectins in the cell wall are passively realigned along the stretch direction by external mechanical force. The analytical methodology developed here will be useful to study how cell wall polymers might reorganize during cell wall growth and development.
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- 2017
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100. Dependence of Sum Frequency Generation (SFG) Spectral Features on the Mesoscale Arrangement of SFG-Active Crystalline Domains Interspersed in SFG-Inactive Matrix: A Case Study with Cellulose in Uniaxially Aligned Control Samples and Alkali-Treated Secondary Cell Walls of Plants
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Yong Bum Park, Hugh O'Neill, Seong H. Kim, Daisuke Sawada, Christopher M. Lee, Ashutosh Mittal, Mohamadamin Makarem, and Kabindra Kafle
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chemistry.chemical_classification ,Materials science ,Sum-frequency generation ,Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Alkali metal ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Matrix (mathematics) ,chemistry.chemical_compound ,General Energy ,chemistry ,Molecule ,Physical and Theoretical Chemistry ,Cellulose ,0210 nano-technology ,Spectroscopy ,Alkyl - Abstract
Vibrational sum frequency generation (SFG) spectroscopy can selectively detect not only molecules at two-dimensional (2D) interfaces but also noncentrosymmetric domains interspersed in amorphous three-dimensional (3D) matrixes. However, the SFG analysis of 3D systems is more complicated than 2D systems because more variables are involved. One such variable is the distance between SFG-active domains in SFG-inactive matrixes. In this study, we fabricated control samples in which SFG-active cellulose crystals were uniaxially aligned in an amorphous matrix. Assuming uniform separation distances between cellulose crystals, the relative intensities of alkyl (CH) and hydroxyl (OH) SFG peaks of cellulose could be related to the intercrystallite distance. The experimentally measured CH/OH intensity ratio as a function of the intercrystallite distance could be explained reasonably well with a model constructed using the theoretically calculated hyperpolarizabilities of cellulose and the symmetry cancellation princi...
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- 2017
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