흡습 거동 분석을 통한 점토 나노입자 강화 고분자 나노복합재료의 분산 안정성 향상에 관한 연구

To begin with, nanomaterials are widely used as reinforcing materials with specific functionalities, because they have a characteristic broad particle surface area and excellent properties in small amounts. However, the use of nanomaterial fabrication technology has many limitations, such as the arrangement and dispersion of nanomaterials for use in composite materials and for the use of general structural materials. In order to overcome these limitations, researches on the physical and chemical surface treatment of nanomaterial based reinforcing materials and the development of mechanical techniques have been actively carried out. However, from the macro perspective, fiber reinforced plastics (FRP) composites such as shipbuilding, aerospace, automobiles, still have many technical limitations to their use for commercial purposes. In addition, since the conventional nanotechnology has a high price and a complicated molding process, it has a disadvantage in that the production efficiency is inferior to the use of other materials and methods. Particularly, mass production of nanomaterials is difficult to control the structure such as particular particle size and length, and it is not easy to ensure uniformity of physical and chemical properties when working with these materials in a commercial environment. Therefore, it is necessary to study the nanomaterial pretreatment method and the process of stabilization through a uniform dispersion with the polymer matrix, and it is required to develop nanomaterials for medium and large parts structural materials that exhibit uniform characteristics which can be used for a variety of other applications in other industries. In this context, this study aims to establish the basis of a suitable manufacturing process of nanocomposite materials for general structure by applying FRP composites to applicable top-down processes, that will serve to control the grain and porosity of existing nanomaterials to below a few hundreds of nanometers, and therefore to significantly improve their properties. In this study, halloysite nanotube/epoxy (HNT/EP) matrix glass fiber reinforced plastic (GFRP) and basalt fiber reinforced plastic (BFRP) nanocomposites were prepared by separating crystalloid-HNT (C-HNT) and amorphous-HNT (A-HNT) according to the crystallinity of HNT and the state of dispersion of HNT, which was evaluated at the interface of laminates. The state of dispersion of the laminate nanocomposites fabricated in a flat plate shape was analyzed by dividing a total of eight (A―H) columns in the direction of the air outlet in the vacuum molding. The evaluation of the uniform dispersion was performed at 70。C, and the tendency and the deviation of the moisture absorption rate when immersed in distilled water for 336 h. Based on these studies, the reliability of the state of dispersion criterion of nanomaterials was suitably evaluated. As a result, the material design criteria for uniform dispersibility were obtained through a review of the identified moisture absorption characteristics. The effect of HNT on the interfacial bonding strength between EP and fiber reinforcements (GF, BF) was different depending on the notation of crystallinity that was found. In this regard, it is shown that moisture was important for controlling cohesion between HNTs. In the curing system, HNT was shown to have promoted the curing reaction, and the curing reaction caused the resin to develop properties related to shrinkage. The resin shrinkage affected the mobility of HNT and was a major factor involved in the re-aggregation. In addition, A-HNT has a strong bonding force with EP, which is relatively uniformly dispersed in EP compared with C-HNT, but also has a strong influence on the bonding strength of the interlaminar interface of laminates or weak bonds with the resulting fiber reinforcements. In other words, the crystallinity of HNT is closely related to the dispersibility of this material. In this study, the effect of HNT content and structure on the dispersion stability in GFRP and BFRP was investigated using the structural water characteristics of HNT.List of Tables ⅲ List of Figures ⅴ Abstract ⅺ 1. Introduction 1 1.1 Trends of nanomaterial technology in advanced composites 1 1.2 Objectives of study 8 2. Literature review 11 2.1 Polymer matrix nanocomposites 11 2.1.1 Thermoset polymer composites 11 2.1.2 Nano-modification 15 2.2 Halloysite nanotubes based polymer nanocomposites 18 2.2.1 Halloysite nanotubes and crystallinity 18 2.2.2 Dispersion uniformity of halloysite nanotubes as fillers 21 2.3 Environment degradation of nano-structural materials 28 2.3.1 Hygrothermal behavior of polymer composites 28 2.3.2 Nanomaterials and environmental effect 30 3. Experimental works 30 3.1 Halloysite nanotubes-FRP composites 33 3.2 Experimental procedure 38 3.2.1 Surface modification by thermal treatment 38 3.2.2 Nano-FRP manufacturing process 39 3.3 Evaluation and analysis 41 3.3.1 Structural property 41 3.3.2 Thermal property 42 3.3.3 Environmental degradation property 44 3.3.4 Mechanical property 45 3.3.5 Microscopic observation 46 4. Results and discussion 48 4.1 Morphology effect 48 4.2 Thermal analysis 53 4.3 Moisture absorption behavior 63 4.4 Mechanical property 96 4.4.1 Tensile strength 96 4.4.2 Fracture behavior analysis 112 4.5 Dispersibility 124 5. Proposal for various applications 137 5.1 High functional structural materials 137 6. Conclusions 141 Acknowledgement 144 References 145Docto

Changes of the Structural and Mechanical Properties on Nanocomposites based on Halloysite Nanotubes with the Optimization of Dispersion by Ultrasonic Waves

Nanoparticle refers to a particle within the scope of a hundred nanometers and nanoparticles have a wide specific surface area. By controlling their size or using nanoparticles of various types, the properties of material can be improved with only a small amount of particulate filler. Halloysite is a naturally occurring aluminosilicate in the form of nanotubes, also known as halloysite nanotubes (HNTs). The HNTs are odorless, white particles with the chemical formula H4Al2O9Si2·2H2O. Halloysite nanotubes are readily obtainable and are much cheaper than other tubular nanoparticles such as carbon nanotubes. There HNTs have been considered as a functionally effective material capable of mechanically strengthening resins by restrictive matrix dislocation movement. Especially, there are studies showing that adding HNTs to plastics improves tensile strength, impact resistance, fire retardancy and gives the added advantage of improved cycling time in production by injection molding. In this study, samples consisted of nanocomposites manufactured by adding HNTs to unsaturated polyester resin (UP). Herein, the contents of HNTs were 0.5, 1 and 3 wt.%. The purpose was to analyze the mechanical properties of nanocomposites on a function of HNTs content and through this, to find the optimal conditions for developing UP matrix HNT reinforced nanocomposites. The HNTs used in this study were treated by heat. Heat-treated HNTs were divided into 4 groups: untreated HNT (UTHNT), 300 (300HTHNT), 500 (500HTHNT), 700 (700HTHNT) and 1000 (1000HTHNT) heat-treated HNT, according to treating temperatures. To achieve a uniform distribution of nanoparticles in the matrix, the factors optimized for dispersion were considered and a suitable process environment for materials to be used was adopted by dividing these factors into constants and variables. The ultrasonic homogenization is used in the production of nano-size materials, dispersions and emulsions, because of the potential in deagglomeration. Ultrasonic homogenization is an easy way to separate particle aggregate, and obtain homogeneous phase. Ultrasonication was carried out by varying some parameters. The operating time and the volume of the sample were maintained at fixed values, namely 300 s and 18 ml, respectively. The output power was divided into two cases, at 45W and 60W. Finally we established the optimal dispersion condition of HNTs using ultrasonication, and the reinforcement effect of HNTs was studied by X-ray diffraction and evaluation of mechanical properties of nanocomposites such as impact strength and tensile strength. Also, the structural changes of HNT by heat treatment at various temperatures were evaluated.1. Introduction 1.1 Nanocomposites 1.2 Halloysite Nanotube (HNT) as an Eco-friendly Material 1.3 Effective Dispersion of Nanofillers in Nanocomposites 2. Experimental Work 2.1 Materials and Methods 2.1.1 Preparation of UP/HNT Nanocomposites 2.1.2 Heat Treatment of HNTs at Different Temperatures 2.1.3 HNT Dispersion by Ultrasonic Homogenization 2.2 Characterization of UP/HNT Nanocomposites 2.2.1 X-ray Diffraction 2.2.2 Transmission Electron Microscopy (TEM) 2.2.3 Impact Test 2.2.4 Tensile Test 3. Results and Discussion 3.1 Observation of Structural Changes by X-ray Diffraction and TEM Imaging 3.2 Changes in Mechanical Properties 3.2.1 Impact Properties 3.2.2 Tensile Properties 3.2.3 Considerations on the Effects of Nanoparticle Dispersion on Mechanical Strength 4. Conclusion Reference Acknowledgmen

Is fasting beneficial for hospitalized patients with inflammatory bowel diseases?

BACKGROUND/AIMS: Patients with inflammatory bowel disease (IBD) are usually hospitalized because of aggravated gastrointestinal symptoms. Many clinicians empirically advise these patients to fast once they are admitted. However, there has been no evidence that maintaining a complete bowel rest improves the disease course. Therefore, we aimed to investigate the effects of fasting on disease course in admitted patients with IBD or intestinal Behçet's disease. METHODS: A total of 222 patients with IBD or intestinal Behçet's disease, who were admitted for disease-related symptoms, were retrospectively analyzed. We divided them into 2 groups: fasting group (allowed to take sips of water but no food at the time of admission) and dietary group (received liquid, soft, or general diet). RESULTS: On admission, 124 patients (55.9%) started fasting and 98 patients (44.1%) started diet immediately. Among patients hospitalized through the emergency room, a significantly higher proportion underwent fasting (63.7% vs. 21.4%, P<0.001); however, 96.0% of the patients experienced dietary changes. Corticosteroid use (P<0.001; hazard ratio, 2.445; 95% confidence interval, 1.506-3.969) was significantly associated with a reduction in the disease activity score, although there was no significant difference between the fasting group and the dietary group in disease activity reduction (P=0.111) on multivariate analysis. CONCLUSIONS: In terms of disease activity reduction, there was no significant difference between the fasting and dietary groups in admitted patients with IBD, suggesting that imprudent fasting is not helpful in improving the disease course. Therefore, peroral diet should not be avoided unless not tolerated by the patient.ope

시간적 측면을 중심으로

학위논문(박사) -- 서울대학교대학원 : 음악대학 음악과, 2022. 8. 서정은장형준.본 논문은 벨러 버르토크(1881-1945) 《두 대의 피아노와 타악기를 위한 소나타》(1937)의 작품 분석과 연주자적 해석에 관한 연구이다. 이 곡은 버르토크의 대표적인 실내악 작품 중 하나로, 서양음악의 전통적 형식 안에서 동유럽 민속음악의 특징적 리듬들을 내재하고 있다. 버르토크는 여러 해에 걸친 민속음악 연구를 통해 음계, 리듬 등 민속적 요소들을 그의 음악에 접목하였으며, 다른 악기들을 통한 타악기적 효과를 추구하여 독창적인 방식으로 20세기 현대 음악에 새로운 방향을 제시하였다. 특히 《두 대의 피아노와 타악기를 위한 소나타》는 다양한 템포 변화, 동유럽 민속음악 리듬의 적용, 불규칙한 리듬 패턴의 전개 그리고 복합적인 리듬 구조 같은 시간적 변화를 선보이고 있다. 이에 따른 연구의 필요성이 제기되는바, 본 연구에서는 《두 대의 피아노와 타악기를 위한 소나타》를 템포, 박절, 리듬 등 포함하는 시간적 관점에 주목하여 분석하고, 버르토크의 연주를 포함한 세 그룹의 음원을 통해 피아니스트 관점에서 연주자의 해석을 고찰 및 필자의 해석을 제언한다. 예비적 고찰로서 제Ⅱ장에서는 그의 생애와 시기별 작품 개요를 살펴본 후, 그가 직접 채보 및 연구한 동유럽 민요들과 리듬(파를란도-루바토, 엄격 리듬, 부점 리듬, 불가리안 리듬)들에 대한 정의를 이해하고 그의 작품들에 적용된 예시를 살펴본다. 본격적인 작품 분석을 논의하는 Ⅲ장에서는 먼저 전반적인 구조를 살펴본 후, 시간적 측면으로 다음과 같이 4가지 관점으로 분석한다. 첫째, 악장별 템포의 흐름을 이해하기 위해 메트로놈 표기가 변화되는 부분들을 파악한다. 둘째, Ⅱ장에서 살펴본 동유럽 민속음악 리듬이 이 작품에서 어떻게 적용되고 발전해 나가는지 살펴본다. 셋째, 불규칙한 리듬 패턴들이 전개되는 부분들을 몇 가지 형태로 구분하여 분석한다. 넷째, 폴리미터 구조 안에서 박절의 불일치가 나타나는 부분들을 논의한다. 이러한 이론적 작품 분석에 기반하여 Ⅳ장에서는 버르토크 연주를 포함한 세 그룹의 연주 음원을 분석하고 연주자의 관점에서 해석을 제언한다. 먼저 세 음원의 전반적인 템포 해석을 파악하기 위해 악장별 각 섹션의 평균 템포를 계산하여 그들의 연주 경향을 파악한다. 그리고 작품 분석에서 살펴본 동유럽 민속음악 리듬이 적용된 부분들에 대해 세 그룹의 연주를 고찰하고 필자의 해석을 제시한다. 마지막으로는 불규칙한 리듬 패턴이 전개되는 패시지 중 피아니스트 관점에서 난해하게 여겨질 수 있는 부분에 대해 필자의 해석을 제안한다. 본 연구를 통해 연주자들이《두 대의 피아노와 타악기를 위한 소나타》를 보다 심층적으로 이해하고 실질적으로 연주에 도움받기를 기대한다.This thesis presents an analysis of Sonata for Two Pianos and Percussion (1937) by Béla Bartók (1881-1945) and interpretations of different performances. This piece is one of Bartók's representative chamber music works and contains rhythms from Eastern European folk music within the traditional form of Western music. Through years of research on folk music, Bartók applied folk elements such as scale and rhythm to his music; while pursuing percussion effects through other instruments, presenting a new and original direction for contemporary music in the 20th century. In particular, Sonata for Two Pianos and Percussion shows temporal changes such as the frequent use of tempo changes, the use of Eastern European folk rhythms, irregular rhythm patterns, and multiple rhythmic structures. Therefore, this thesis analyzes Sonata for Two Pianos and Percussion in terms of the temporal aspects specifically tempo, meter, and rhythm and through recordings from three groups, including Bartók's performance, examining the performers’ interpretations as well as the author’s interpretation of the work as a pianist. Chapter II examines Bartók’s life and provides an outline of his works by period, exploring the concepts of Eastern European folk songs and folk rhythms (i.e., Parlando-rubato, Rigid rhythm, Dotted rhythm, and Bulgarian rhythm) that he studied, and analyzing his works to which these folk song rhythms are applied. Chapter III analyzes the overall structure of each movement from the following four perspectives in terms of temporal aspects. First, in order to understand the flow of the tempo in each movement, the parts where metronome changes are identified. Second, the chapter examines how the Eastern European folk music rhythms are applied and developed in this work. Third, the parts characterized by irregular rhythm patterns are classified into several forms and then analyzed. Fourth, the chapter discusses the parts where inconsistencies in the beats appear in the polymeter structure. Based on the theoretical analysis of the work, Chapter IV analyzes the recordings of three groups, including Bartók's performance, and proposes interpretations from the perspective of a performer. First, to understand the overall tempo interpretation of the three recordings, the average tempo of each section for each movement is calculated and the corresponding performance trends are identified. Second, the chapter examines the performances of the three groups of recordings and presents the author’s interpretation of the parts to which Eastern European folk music rhythms are applied based on the analysis described in chapter Ⅲ. Third, for the interpretation of irregular rhythm patterns, the author’s interpretation is presented, relying on an analysis of parts which can be considered as difficult to perform. By examining and interpreting Sonata for Two Pianos and Percussion from a temporal perspective, it is expected that performers will be able to understand the work in more depth, through this example of practical guidance for their performances.Ⅰ. 서론 1 Ⅱ. 벨러 버르토크의 음악 세계 6 1. 작곡가의 생애 6 2. 시기별 작품 개요 15 2.1. 제1기 (1907-25) 15 2.2. 제2기 (1926-45) 17 3. 버르토크의 채보 연구와 동유럽 민속음악 리듬 20 3.1. 버르토크의 민속음악 채보 연구 20 3.1.1. 헝가리 민요 23 (1) 옛 양식(Old Style) 23 (2) 새로운 양식(New Style) 26 (3) 혼합 양식(Mixed Style) 29 3.1.2. 슬로바키아 민요 31 3.1.3. 루마니아 민요 35 3.2. 동유럽 민속음악에서 나타나는 리듬 39 3.2.1 파를란도-루바토(Parlando-rubato) 40 3.2.2. 엄격 리듬(Rigid Rhythm) 44 3.2.3. 부점 리듬(Dotted Rhythm) 47 3.2.4. 불가리안 리듬(Bulgarian Rhythm) 52 3.2.5. 베르분코시(verbunkos)&차르다시(csrds) 56 Ⅲ.두 대의 피아노와 타악기를 위한 소나타 작품 연구 60 1. 작품 개요 60 2. 작품 구조 개괄 67 2.1. 1악장 68 2.2. 2악장 84 2.3. 3악장 91 3. 시간적 측면에서의 분석 104 3.1. 템포와 박자 104 3.1.1. 1악장 107 3.1.2. 2악장 117 3.1.3. 3악장 124 3.2. 작품에 적용된 동유럽 민속음악 리듬 130 3.2.1. 파를란도-루바토(Parlando-rubato) 130 3.2.2. 엄격 리듬(Rigid Rhythm) 137 3.2.3. 부점 리듬(Dotted Rhythm) 139 3.2.4. 불가리안 리듬(Bulgarian Rhythm) 140 3.3. 불규칙한 리듬 패턴의 전개 방식 143 3.3.1. 불규칙한 프레이징 구조 143 3.3.2. 기보된 것과 다르게 인지되는 부분 146 3.3.3. 스트레토(stretto) 기법 148 3.3.4. 박절적 불협화(Metrical Dissonance) 152 3.4. 폴리미터(Polymeter) 구조 155 3.4.1. 그룹 불협화(Grouping Dissonance)가 동반된 폴리미터 155 3.4.2. 그룹 및 변위 불협화(Displacement Dissonance)가 동반된 폴리미터 157 3.4.3. 서로 다른 단위 박에 의한 폴리미터 160 Ⅳ.두 대의 피아노와 타악기를 위한 소나타의 연주 분석과 해석적 고찰 162 1. 템포에 관한 해석 166 1.1. 1악장 166 1.2. 2악장 170 1.3. 3악장 173 2. 동유럽 민속음악 요소가 드러나는 패시지 176 2.1. 파를란도-루바토(Parlando-rubato) 177 2.1.1. 성부 간의 모방적 전개 178 2.1.2. 시간적 측면에서의 프레이징 해석 183 2.1.3. 연주 분석을 통한 해석 제언 195 2.2. 부점 리듬(Dotted Rhythm) 199 2.2.1. 음원을 통한 연주 분석 199 2.2.2. 연주 분석을 통한 해석 제언 205 2.3. 불가리안 리듬(Bulgarian Rhythm) 206 2.3.1. 음원을 통한 연주 분석 206 2.3.2. 연주 분석을 통한 해석 제언 209 3. 불규칙한 패턴의 해석에 대한 패시지 211 3.1. 기보된 것과 다르게 인지되는 부분 211 3.1.1. 음원을 통한 연주 분석 212 3.1.2. 연주 분석을 통한 해석 제언 218 3.2. 박절적 불협화(Metrical Dissonance) 219 3.2.1. 음원을 통한 연주 분석 220 3.2.2. 연주 분석을 통한 해석 제언 223 Ⅴ. 결론 224 참고문헌 228 Abstract 236박

Clinical Course of Hepatitis B Viral Infection in Patients Undergoing Anti-Tumor Necrosis Factor α Therapy for Inflammatory Bowel Disease

Background/aims: Little is known about the clinical course of hepatitis B virus (HBV)-infected patients undergoing anti-tumor necrosis factor α (TNF-α) therapy for inflammatory bowel disease (IBD). We aimed to investigate the clinical course of HBV infection and IBD and to analyze liver dysfunction risks in patients undergoing anti-TNF-α therapy. Methods: This retrospective multinational study involved multiple centers in Korea, China, Taiwan, and Japan. We enrolled IBD patients with chronic or resolved HBV infection, who received anti-TNF-α therapy. The patients' medical records were reviewed, and data were collected using a web-based case report form. Results: Overall, 191 patients (77 ulcerative colitis and 114 Crohn's disease) were included, 28.3% of whom received prophylactic antivirals. During a median follow-up duration of 32.4 months, 7.3% of patients experienced liver dysfunction due to HBV reactivation. Among patients with chronic HBV infection, the proportion experiencing liver dysfunction was significantly higher in the non-prophylaxis group (26% vs 8%, p=0.02). Liver dysfunction occurred in one patient with resolved HBV infection. Antiviral prophylaxis was independently associated with an 84% reduction in liver dysfunction risk in patients with chronic HBV infection (odds ratio, 0.16; 95% confidence interval, 0.04 to 0.66; p=0.01). The clinical course of IBD was not associated with liver dysfunction or the administration of antiviral prophylaxis. Conclusions: Liver dysfunction due to HBV reactivation can occur in HBV-infected IBD patients treated with anti-TNF-α agents. Careful monitoring is needed in these patients, and antivirals should be administered, especially to those with chronic HBV infection.ope

The relationship between diverticulosis and colorectal neoplasia: A meta-analysis

BACKGROUND/AIMS: Diverticulosis and colorectal neoplasia share epidemiological trends and risk factors which are common in Western countries and incidences increase with age. However, the data on an association between diverticulosis and colorectal neoplasia are conflicting. Thus, we performed a meta-analysis to evaluate whether diverticulosis is associated with colorectal neoplasia. METHODS: A systematic literature search of PubMed, EMBASE, Cochrane Library, Web of Science, and SCOPUS was conducted to identify studies that investigated the association between diverticulosis and advanced colorectal neoplasia (advanced adenoma, colorectal cancer), adenomas, or polyps. The demographic characteristics of patients, including age, gender, indication for colonoscopy, confounding factors, and outcomes of colorectal neoplasia were assessed. RESULTS: We identified 29 cross-sectional studies (N = 450,953) that investigated the association between diverticulosis and colorectal neoplasia. The meta-analysis found that diverticulosis was not associated with advanced colorectal neoplasia (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.63-1.50). Although there was a positive correlation between diverticulosis and adenomas (OR 1.47, 95% CI 1.18-1.84) and diverticulosis and polyps (OR 1.95, 95% CI 1.15-3.31), diverticulosis did not increase the risk of adenomas (OR 1.34, 95% CI 0.87-2.06) in patients who underwent screening colonoscopy. Moreover, all the increased risk of colorectal neoplasia in patients with diverticulosis was observed in published studies only, and not in unpublished ones. CONCLUSIONS: This meta-analysis demonstrated that diverticulosis is not associated with an increased risk of advanced colorectal neoplasia. Although diverticulosis was associated with a higher risk of polyps and adenomas, the risk was not increased in screening populations. Moreover, the increased risk of colorectal neoplasia in patients with diverticulosis was observed only in published studies and not in unpublished ones.ope

Diagnosis of Bleeding Meckel's Diverticulum in Adults

Background and aims: Various modalities have been used to diagnose Meckel's diverticulum (MD) in practice, but with their diagnostic accuracy deemed to be unsatisfactory for clinical practice. Moreover, the usefulness of these modalities has not been evaluated for the diagnosis of bleeding MD in adults, due to the relative rarity of this condition. Therefore, the aim of our multicenter study was to determine the most accurate modality for the preoperative diagnosis of bleeding MD in adults. Methods: We conducted a retrospective analysis of the diagnostic accuracy for small bowel bleeding associated with MD of different modalities in patients ≥18 years old who underwent assessment for MD, with confirmation at the time of explorative surgery. Diagnostic accuracy of the different modalities was evaluated against the diagnosis obtained using technetium-99m pertechnetate scintigraphy (also known as Meckel's scan), considered to be the gold standard for the diagnosis of bleeding MD in pediatrics. Results: Thirty-five adults were identified with bleeding in MD over the study period, between 2005 and 2012. Among these patients, only 24 (68.6%) were diagnosed with MD preoperatively. The mean (95% confidence interval) diagnostic accuracy of selected modalities was as follows: Meckel's scan, 21.4% (5.7%-51.2%); capsule endoscopy, 35.7% (14.0%-64.4%); balloon-assisted enteroscopy (BAE), 85.0% (61.1%-96.0%); angiography, 0.0% (0.0%-80.2%); computed tomography, 31.8% (14.7%-54.9%); and small-bowel follow-through, 62.5% (25.9%-90.0%). The diagnostic accuracy was significantly higher for BAE than for Meckel's scan (P = 0.001). Conclusions: Among available diagnostic modalities, BAE provides the highest accuracy for the diagnosis of bleeding MD in adults and, therefore, should be considered as the preferred modality for preoperative diagnosis.ope

한국인 만성 변비 환자에서 프루칼로프라이드의 안전성과 유효성: 시판 후 조사

Background/aims: Constipation is a common gastrointestinal disorder. Prucalopride is a dihydrobenzofurancarboxamide derivative with gastrointestinal prokinetic activities and is recommended as an appropriate choice in patients unresponsive to laxatives. This study assessed the safety and efficacy of prucalopride in Korean patients with chronic constipation, in whom laxatives were ineffective. Methods: This prospective, non-interventional post-marketing surveillance of prucalopride was conducted from 2012 to 2018 at 28 hospitals in Korea. Adults who received prucalopride for the symptomatic treatment of chronic constipation were included. The patients received 2 mg of prucalopride once daily or 1 mg once daily in patients older than 65 years. The baseline characteristics, adverse events (AEs), and seven-point scale of Clinical Global Impression-Improvement were collected. Results: Of 601 patients, 67.7% were female, and the mean age was 62.3 years. Three hundred patients (49.9%) were older than 65 years. At the baseline, 70.0% of patients reported less than two instances of spontaneous complete bowel movements per week. AEs were reported in 107 patients (17.7%), including headache (3.2%) and diarrhea (2.8%). Seven serious AEs (SAEs) were reported in five patients (0.8%). The SAEs were resolved without complications; there were no cases of death. All SAEs were assessed as 'unlikely' causality with prucalopride. In 72.7% of patients, chronic constipation was improved by the prucalopride treatment during the study period. Conclusions: This study demonstrated the promising safety and efficacy profile of prucalopride in clinical practice. Thus, prucalopride should be considered in patients with chronic constipation when bowel symptoms are refractory to simple laxatives.ope

Nationwide Multicenter Study for Overlaps of Common Functional Gastrointestinal Disorders in Korean Patients With Constipation

Background/aims: In spite of increased concerns about the overlaps among the various functional gastrointestinal disorders (FGIDs), studies for the overlap between constipation and other common FGIDs are rare. Therefore, we investigated the patterns of overlaps between constipation and other common FGIDs. Methods: This study was designed as a prospective nationwide multi-center questionnaire study using Rome III questionnaires for functional dyspepsia (FD), irritable bowel syndrome (IBS), and functional constipation (FC), as well as various questionnaires about patients' information, degree of symptoms, and quality of life. For the evaluation of gastroesophageal reflux disease (GERD), GERD-Q was used. Results: From 19 centers, 759 patients with constipation were enrolled. The proportions of FC and IBS subtypes of constipation (IBS-C) were 59.4% and 40.6%, respectively. Among them, 492 (64.8%) showed no overlap. One hundred and thirty-six patients (17.9%) presented overlapping GERD, and 80 patients (10.5%) presented overlapping FD. Fifty one (6.7%) of patients were overlapped by both GERD and FD. Coincidental herniated nucleus pulposus (HNP) (P = 0.026) or pulmonary diseases (P = 0.034), reduced fiber intake (P = 0.013), and laxative use (P < 0.001) independently affected the rate of overlaps. These overlapping conditions negatively affected the constipation-associated quality of life, general quality of life, and degree of constipation. Conclusions: The overlap of GERD or FD was common in patients with constipation. Coincidental HNP or pulmonary diseases, reduced fiber intake, and laxatives use were found to be independent associated factors for overlapping common FGIDs in Korean patients with constipation.ope

Treatment of inflammatory bowel disease in Asia: the results of a multinational web-based survey in the 2(nd) Asian Organization of Crohn's and Colitis (AOCC) meeting in Seoul

Background/aims: Inflammatory bowel disease (IBD) management guidelines have been released from Western countries, but no adequate data on the application of these guidelines in Asian countries and no surveys on the treatment of IBD in real practice exist. Since there is a growing need for a customized consensus for IBD treatment in Asian countries, Asian Organization of Crohn's and Colitis performed a multinational survey of medical doctors who treat IBD patients in Asian countries. Methods: A questionnaire was developed between August 2013 and November 2013. It was composed of 4 domains: personal information, IBD diagnosis, IBD treatment, and quality of IBD care. Upon completion of the questionnaire, a web-based survey was conducted between 17 March 2014 and 12 May 2014. Results: In total, 353 medical doctors treating IBD from ten Asian countries responded to the survey. This survey data suggested a difference in available medical treatments (budesonide, tacrolimus) among Asian countries. Therapeutic strategies regarding refractory IBD (acute severe ulcerative colitis [UC] refractory to intravenous steroids and refractory Crohn's disease [CD]) and active UC were coincident, however, induction therapies for mild to moderate inflammatory small bowel CD are different among Asian countries. Conclusions: This survey demonstrated that current therapeutic approaches and clinical management of IBD vary among Asian countries. Based on these results and discussions, we hope that optimal management guidelines for Asian IBD patients will be developed.ope