노화에서 뇌기능신경망으로부터 추출한 코어복셀 위계구조의 역동적 변화

학위논문(박사) -- 서울대학교대학원 : 융합과학기술대학원 분자의학 및 바이오제약학과, 2023. 2. 이동수.Many methods were developed to assess the functional intervoxel connectivity to discover and better understand the brain function in individuals. In this study, k-core percolation method was assessed to reveal the dynamic hierarchical structure on resting-state fMRI (rsfMRI) on voxel-level and the feasibility of the method was evaluated by applying it in the aging process. Total 70 individuals were included in this study, 32 individuals from Alzheimers Disease Neuroimaging Initiative (ADNI) and 38 individuals from Seoul National University (SNU). K-core percolation method, a voxel-based approach was applied to reveal the hierarchical structure of voxels in the brain. kmax-core and coreness k values derived from k-core percolation characterizing the time-varying core voxels were visualized on various plots to visualize the dynamic hierarchical structure more intuitively. Independent component analysis (ICA) was carried out to label the associated functional independent components (IC) of the identified voxel. Analysis was done in both static and dynamic studies, and in positive and negative correlations. Coreness k value map overlaid on brain T1 MRI was generated for further evaluation of the distribution of coreness k values. Dynamic hierarchical structure of voxels visualized on various plots revealed time-varying change of kmax-core voxels and coreness k values, reflecting the dynamic change of brain function in an individual, which was not fully reflected on static functional connectivity. Dynamic flow pattern was different in positive and negative correlations, portraying the dynamic brain function in different neuronal networks. Coreness k value map revealed altered distribution of coreness k values in the brain. Asymmetric, unsynchronized distribution was deteriorated in the aging process. This asymmetry detected on dynamic coreness k map was assessed quantitatively by measuring asymmetry index, which revealed distinctive difference between young and aged healthy control group. The difference was more evident on dynamic study than static study. Also, as the age increased, coreness k values from static and dynamic studies decreased in all IC regions, which represents decreased connectivity in aging. Investigation of dynamic functional connectivity with k-core percolation on voxel-level revealed dynamic hierarchical structure of voxels, reflecting the time-varying brain function in individuals. Dynamic functional connectivity is more appropriate to investigate ones brain function, since it contains the time-varying information which is not well reflected on static functional connectivity. With this method, characteristics of dynamic hierarchical structure of an individual can be discovered and have shown possibility of further clinical application.그동안 뇌 기능을 보다 더 잘 이해하고 분석하기 위해 다양한 분석 방법들이 개발되었다. 이 연구에서는 K코어추출법이라는 방식을 적용하여 휴지기 뇌기능자기공명영상에서 역동적 위계 구조를 복셀 단위에서 밝혀내고자 하였다. 그리고 이 분석방법이 임상 분야에서도 적용 가능한지 알아보고자 노화 과정에 적용하여 분석해 보았다. 총 70명을 대상으로 연구가 진행되었는데, 인지 기능이 정상인 대상들을 ADNI에서 32명 그리고 서울대학교에서 38명의 데이터를 받아 분석을 진행하였다. K코어추출법이라는 방법은 복셀 단위로 분석하는 방법으로, 뇌에서 복셀의 위계 구조를 밝혀내기 위해 사용하였다. K코어추출법으로 구한 K최상위코어값, K코어값의 시간에 따른 변화를 히스토그램, 깃발 플롯, 뇌 그림 등의 다양한 방법으로 시각화하였다. 추출된 복셀은 독립 요소 분석법을 적용하여 기능적으로 뇌의 어느 요소에 해당하는지 확인하였다. 이러한 분석은 정적, 동적 연구에 사용되었고 또한 양성, 음성 상관 연구에도 사용되었다. K코어값은 뇌 T1 자기공명영상에 얹어서 뇌 내의 분포에 관해서도 분석을 진행하였다. 복셀의 역동적 위계 구조는 시간에 따라 변화하는 K최상위코어값과 K코어값을 동영상으로 만든 히스토그램, 깃발 플롯, 뇌 그림 등으로 시각화하였는데 각 개인의 동적인 뇌 기능 변화가 그림으로 잘 표현되었다. 이러한 동적인 기능적 연결성은 정적인 기능적 연결성에는 담기지 못한 시간에 따른 뇌 기능의 변화에 대한 정보가 담겨 있었다. 또한, 시간에 따른 역동적 변화는 양성, 음성 상관에 따라서 다르게 나타나 신경계 네트워크에 따라 그 변화도 다르게 나타남을 보였다. K코어값 분포도에서는 뇌에서 K코어값의 분포가 나이가 든 군에서 비대칭적으로 나타나는 것을 발견할 수 있었는데, 이는 노화가 진행됨에 따라 악화되는 경향이 있었다. K코어값 분포도에서 발견한 비대칭적 분포는 비대칭 척도를 이용하여 정량화하였다. 그 결과, 젊은 정상군과 나이가 든 정상군에서 차이가 있다는 것을 확인할 수 있었고 그 차이는 정적인 기능적 연결성보다는 동적인 기능적 연결성에서 더 뚜렷하게 나타나는 것을 볼 수 있었다. 또한, 나이가 들어감에 따라 모든 영역에서 정적, 동적인 K코어값 모두 감소하였는데 이는 노화가 진행되면서 뇌의 기능적 연결성이 떨어지는 것을 나타낸다고 볼 수 있다. K코어추출법으로 복셀 단위로 동적인 기능적 연결성을 분석하였을 때 뇌의 역동적인 위계 구조를 밝혀냈고 이는 시간에 따라 변화하는 각 개인의 뇌 기능을 잘 반영하였다. 정적 기능적 연결성에는 담지 못하는 시간에 따른 정보를 담는다는 점에서 개인의 뇌 기능을 연구할 때 역동적 기능적 연결성을 연구하는 것이 더 적합하다고 볼 수 있다. 이러한 K코어추출법으로 뇌 기능의 역동적인 위계 구조를 밝혀내고, 노화에 적용해서 분석한 것처럼 앞으로 임상에서 다른 분야에도 적용하여 뇌 기능을 연구하는 데에 활용할 수 있을 것으로 기대된다.I. Introduction 1 1-1. Dynamic functional brain connectivity in rsfMRI 1 1-2. k-core percolation 3 1-3. Functional connectivity in aging process 5 II. Purpose 7 III. Materials and methods 8 3-1. Data preprocessing 8 3-2. Sliding-window analysis 10 3-3. Application of k-core percolation 11 3-4. Quantitative analysis of asymmetry index 13 3-5. Voxel-based analysis of coreness k values 14 IV. Results 15 4-1. Generation of dynamic hierarchical structure 15 4-2. Visual assessment of hierarchical structure 17 4-3. Visual assessment of coreness k value map 23 4-4. Quantitative assessment with asymmetry index 31 4-5. Correlation of age and coreness k values 37 4-6. Coreness k values in gender and aging 37 4-7. Validation of coreness k values in young group 40 V. Discussion 42 VI. Conclusion 51 VII. References 52 VIII. Supplementary figures and movies 61 IX. 국문초록 76박

High-flow nasal oxygenation for anesthetic management

High-flow nasal oxygenation (HFNO) is a promising new technique for anesthesiologists. The use of HFNO during the induction of anesthesia and during upper airway surgeries has been initiated, and its applications have been rapidly growing ever since. The advantages of this technique include its easy set-up, high tolerability, and its abilities to produce positive airway pressure and a high fraction of inspired oxygen and to influence the clearance of carbon dioxide to some extent. HFNO, via a nasal cannula, can provide oxygen both to patients who can breathe spontaneously and to those who are apneic; further, this technique does not interfere with bag-mask ventilation, attempts at laryngoscopy for tracheal intubation, and surgical procedures conducted in the airway. In this review, we describe the techniques associated with HFNO and the advantages and disadvantages of HFNO based on the current state of knowledge.ope

(A) Study on the Speed Control of the Diesel Engine with a Digital Governor

A Study on the Speed Control of the Diesel Engine with a Digital Governor The marine propulsion diesel engine with mechanical-hydraulic governor has been widely used to control the engine speed. But these days, marine propulsion disesel engine tends to become slower in speed and longer in stroke for higher engine efficiency, so it leads to difficulty for the mechanical-hydraulic governor to regulate the speed of high power engine with long stroke and low speed, because of the jiggling caused by rough fluctuation of rotating torque and the hunting by long dead time occurred in fuel combustion process. To cope with these difficulties, engine manufacturers highly reco- mmend to adopt digital governor for the longer stroke and slower speed engine. Most of the digital governors adopt the feedback control method in which the only engine rpm-signal is used, but it does not work effectively when the load variation occurs. In this paper, the author considers the perturbation of engine parameters as the modeling uncetrainties and designs not only the robust speed controller but fuzzy speed controller for the engine. Through the computer simulation, the performances of both controlle- rs are compared and reviewed

응급실에 내원한 호흡기질환 노인에게 제공한 퇴원계육중재가 간호서비스만족도, 재입원율 및 퇴원준비도에 미치는 효과

학위논문 (석사)-- 서울대학교 대학원 : 간호학과, 2013. 8. 박연환.국 문 초 록 호흡기질환은 노인에서 발생율이 매우 높은 만성질환으로 잦은 입원과 퇴원을 반복하게 한다. 이로 인해 의료비가 증가되고 노인의 삶의 질이 저하되며 생명의 위협까지 받게 된다. 감염에 취약하고 자가 관리 능력이 저하된 노인은 호흡기감염으로 인한 갑작스런 호흡곤란 등의 이유로 응급실을 경유한 입원이 많고 준비없이 퇴원을 하게 되기도 한다. 따라서 응급실 퇴원 시 노인의 상황에 맞는 적절한 퇴원교육중재를 제공한다면 호흡기질환을 관리하는 데 도움이 될 것이다. 본 연구는 응급실에 내원한 호흡기질환 노인에게 적용한 퇴원교육중재가 간호서비스만족도와 재입원율, 퇴원준비도에 영향을 미치는지 알고자 시도하였다. 본 연구는 비동등성 대조군 전후시차 설계로 사전조사에서 실험군 25명, 대조군 25명, 사후조사에서 실험군 21명, 대조군 19명이었다. 실험군의 문헌고찰과 연구자의 임상경험을 토대로 건강상태사정, 교육, 상담, 지지로 구성된 퇴원교육중재는 2009년 2월 16일부터 2009년 5월 27일까지 실험군 25명에게 각기 이루어졌다. 간호서비스만족도는 CSQ8(Client Satisfaction Questionnaire)로, 재입원율은 시기와 횟수, 재입원 이용기관을 파악하였으며, 퇴원준비도에 관해서는 질환에 대한 이해와 자가 관리로 나누어 0-100점까지 점수로 측정하였다. 수집된 자료는 SPSS 17.0으로 분석하였다. 호흡기질환 노인에게 퇴원교육중재를 제공한 결과 4주후에 측정한 간호서비스만족도와 퇴원준비도의 자가 관리는 실험군이 대조군보다 통계적으로 유의하게 높았다. 그러나 재입원율과 퇴원준비도의 질환에 대한 이해에서는 유의한 차이가 없었다. 결론적으로 퇴원교육중재는 호흡기 질환 노인의 간호서비스만족도와 퇴원준비도의 일부에는 효과가 있었으나 재입원율 감소에는 기여하지 못하였다. 향후 교육내용의 수정, 결과변수의 보완, 장기간의 사후조사와 큰 표본수를 가지고 중재의 효과를 명확하게 확인하는 반복연구가 필요하다. 주요어 : 퇴원교육중재, 노인, 호흡기질환, 간호서비스만족도, 재입원율, 퇴원준비도Effects of discharge planning on Patient satisfaction of nursing services, readmission rate and preparedness to discharge in older patients admitted to the emergency department for pulmonary disease. Hyeon Ju Kim College of Nursing Seoul National University Directed by Professor Yeon-Hwan Park, Ph.D., R. N. The purpose of this study was to examine the effects of discharge planning on patient satisfaction, readmission rate and preparedness to discharge in elderly admitted to the emergency department for pulmonary disease. A quasi-experimental intervention study design was used. There were 40 adults subjects over the aged of 65 admitted to the emergency department for pulmonary disease. They were divided into two groups: an intervention group of 21 patients and a control group of 19 patients. The period for the discharge planning program intervention was 3 months and 10days from Feb. 16th to May 27th. Data were collected from medical records, physical measurements and a questionnaire. The questionnaire was designed to obtain information on demographics, characteristics related to satisfaction with the discharge planning program, readmission, and preparedness to discharge. To analyze the data, descriptive statistics, Pearsons chi-sqaure test, Fishers exact test, Wilcoxon rank sum test, and independent sample t-test for homogeneity and Pearsons chi-sqaure test, Wilcoxon rank sum test and independent sample t-test for hypothesis examination were used with the software package SPSS version 17.0. There was a high degree of patient satisfaction with nursing services and a significant effect on self-care at home after intervention of the discharge planning program intervention. No significant effect on readmission rate and the patient's understanding of disease(preparedness to discharge) were observed between the intervention group and the control group. The results from this study suggested that a discharge planning program intervention can provide satisfaction to older patients admitted to the emergency department for pulmonary disease although no significant effects on readmission rate and preparedness to discharge(patient's understanding of disease)were observed. To clarify the effects of discharge planning on older patients admitted to the emergency department for pulmonary disease, a larger sampling population, better instruments for various measures, a new manual on discharge planning and frequent follow-up are necessary. Key words : discharge planning, older adults, pulmonary disease, patient satisfaction with nursing services, readmission, preparedness목 차 Ⅰ 서론 ………………………………………………………… 1 1. 연구의 필요성 …………………………………………… 1 2. 연구의 목적 ……………………………………………… 4 3. 용어의 정의 ……………………………………………… 4 Ⅱ 문헌고찰 …………………………………………………… 6 1. 호흡기 질환 노인의 퇴원 후 추후관리 ……………… 6 2. 퇴원계획중재 …………………………………………… 10 Ⅲ 연구의 개념적 기틀 ……………………………………… 17 1. 연구의 개념적 기틀 ………………………………… 17 2. 연구 가설 ……………………………………………… 19 Ⅳ 연구방법 …………………………………………………… 20 1. 연구설계 ……………………………………………… 20 2. 연구대상 ……………………………………………… 21 3. 응급실 호흡기질환 노인대상의 퇴원교육중재 … 24 4. 연구도구 ……………………………………………… 28 5. 자료수집절차 ……………………………………… 30 6. 자료분석방법 ……………………………………… 33 Ⅴ 연구 결과 ………………………………………………… 34 1. 실험군, 대조군의 동질성 검정 …………………… 34 2. 가설검정 …………………………………………… 40 Ⅵ 논의 ……………………………………………………… 44 Ⅶ 결론 및 제언 …………………………………………… 50 참고문헌 ……………………………………………………… 52 부록 ……………………………………………………… 63 1. 동의서 …………………………………………………… 63 2. 자료수집도구 …………………………………………… 64 3. 호흡기질환 노인의 응급실에서 퇴원 시 교육자료 … 71 Absract ………………………………………………… 86Maste

A Two-Step Approach to Overcoming Data Imbalance in the Development of an Electrocardiography Data Quality Assessment Algorithm: A Real-World Data Challenge

Continuously acquired biosignals from patient monitors contain significant amounts of unusable data. During the development of a decision support system based on continuously acquired biosignals, we developed machine and deep learning algorithms to automatically classify the quality of ECG data. A total of 31,127 twenty-s ECG segments of 250 Hz were used as the training/validation dataset. Data quality was categorized into three classes: acceptable, unacceptable, and uncertain. In the training/validation dataset, 29,606 segments (95%) were in the acceptable class. Two one-step, three-class approaches and two two-step binary sequential approaches were developed using random forest (RF) and two-dimensional convolutional neural network (2D CNN) classifiers. Four approaches were tested on 9779 test samples from another hospital. On the test dataset, the two-step 2D CNN approach showed the best overall accuracy (0.85), and the one-step, three-class 2D CNN approach showed the worst overall accuracy (0.54). The most important parameter, precision in the acceptable class, was greater than 0.9 for all approaches, but recall in the acceptable class was better for the two-step approaches: one-step (0.77) vs. two-step RF (0.89) and one-step (0.51) vs. two-step 2D CNN (0.94) (p < 0.001 for both comparisons). For the ECG quality classification, where substantial data imbalance exists, the 2-step approaches showed more robust performance than the one-step approach. This algorithm can be used as a preprocessing step in artificial intelligence research using continuously acquired biosignals.ope

Recommendations for Anesthesia in Patients Suspected of COVID-19 Coronavirus Infection

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Guidelines for the control and prevention of coronavirus disease (COVID-19) transmission in surgical and anesthetic settings

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Application of high-flow nasal oxygenation as a rescue therapy in difficult videolaryngoscopic intubation

In difficult airway situations, the next step of the airway management method is selected according to the prior presence of difficulties in mask ventilation and endotracheal intubation. It is important for the practitioner to be calm, quick in judgment, and take action in cases of difficult intubation. Recently, high-flow nasal oxygenation has been rapidly introduced into the anesthesiology field. This technique could extend the safe apnea time to desaturation. Especially, it maintains adequate oxygenation even in apnea and allows time for intubation or alternative airway management. We report two cases in which high-flow nasal oxygenation was implemented in the middle of the induction process after quick judgment by clinicians. High-flow nasal oxygenation was successfully used to assist in prolonging the safe apnea time during delicate airway securing attempts.ope

Development of diagnostic methods and surveillance of Rift valley fever in Republic of Korea

학위논문 (박사)-- 서울대학교 대학원 : 수의학과, 2017. 2. 유한상.Rift Valley fever (RVF) is an acute mosquito-borne viral zoonotic disease that affects mainly domestic ruminants and humans. This disease causes abortions in pregnant animals, and it has a high mortality rate in newborn animals. RVF virus (RVFV) was first identified in Kenya in 1931 and was reported to be endemic in Africa but has recently spread to the Arabian Peninsula. With increasing climate change and global movement in animals and animal products, there is great concern that the disease might be spreaded worldwide to regions such as Europe, Asia and the Americas. Therefore, early detection and surveillance are important for preventing the introduction of RVF in non-endemic or disease free countries. Although RVF has not been reported in the Republic of Korea (ROK), the possibility of RVFV introduction will be increasing because transmissible mosquito vectors are present and direct flights to Africa were added in 2012. Thus diagnostic methods were developed and conducted a surveillance study to detect RVFV in mosquito vectors. In the first study, a new quantatitative real time RT-PCR (qRT-PCR) assay was developed that can safely and cost-effectively differentiate infected from vaccinated animals (DIVA) with possible application in RVF-free countries. The new qRT-PCR assay targeting the S segment (NSs and N gene) was tested with synthesized standard RNA and MP-12 strain viruses. The detection limit of the new qRT-PCR assay was 1 copy/µl of NSs and N, and was able to differentiate the Smithburn strain from the Clone 13 vaccine strain. No cross reactivity with other vector-borne viruses was observed, a factor which is especially important in the ROK, was observed. To examine the performance of the new qRT-PCR, intra-and inter-assay variability data were analyzed and showed high reproducibility. These results indicate that the new qRT-PCR can be used as a safe and cost-effective DIVA diagnostic test in RVF-free countries including ROK. In second study, a monoclonal antibody-based competitive ELISA was developed for the detection of antibodies to RVFV in goat and cattle. The recombinant N protein of RVFV was expressed in E. coli with six-histidine tag and the purified N protein was used for detecting antigen with competitive monoclonal antibody against RVFV antibodies. The competitive ELISA (C-ELISA) could detect antibodies at 9-11 days after inoculation in goat and cattle with the sensitivity of 94.7 % (virus neutralization titer >32) and specificity of 99.7%, respectively. In addition, C-ELISA did not show any cross-reactivity with positive sera against Arboviruses such as Akabane, Aino, Chuzan, Ibaraki, and Bovine ephemeral fever virus which are prevalent viral agents in ruminant animals throughout Southeast Asia. The results in present study indicate that C-ELISA is a simple, rapid and convenient sero-diagnostic method for RVFV in goat and cattle. In third study, a surveillance study was conducted to detect RVFV in mosquito vectors collected around the airport and harbor from 2012 to 2013. A total of 36,734 mosquitoes were collected and tested by real time RT-PCR. A total of 1,837 mosquito pools were used, and all were confirmed to be negative. This is the first report in the ROK concerning RVFV surveillance in mosquito vectors, and continuous surveillance should be conducted for the early warning of RVFV introduction. In final study, a serological surveillance was conducted to detect antibodies against RVFV. A total of 2,382 serum samples from goats and cattle were randomly collected from nine areas in ROK from 2011 to 2013. These samples were tested for antibodies against RVFV, using commercial ELISA kits. None of the goats and cattle was positive for antibodies against RVFV. This finding suggests that this disease is not present in ROK, and furthermore presents the evidence of the RVFV-free status of this country. Taken together, the results of this study have important meaning in animal and public health because RVF is transboundary disease and zoonosis. Furthermore, continuous surveillance and regulatory activities need to be undertaken to maintain this status.General introduction 1 Literature Review 4 Vector borne disease 4 Definition 4 Mosquito vector 7 Surveillance 8 Rift Valley Fever 10 Etiology and Epidemiology 11 Transmission and vector 12 Clinical signs and diagnosis 13 Prevention and control 14 One health 16 Concept 16 One health in ROK 17 Chapter I Development of a quantitative real time RT-PCR to differentiate Rift Valley Fever virus from Clone 13 vaccine strain 19 Abstract 19 Introduction 21 Materials and Methods 24 Results 29 Discussion 31 Chapter II Competitive ELISA for the Detection of Antibodies to Rift Valley Fever Virus in Goat and Cattle 42 Abstract 42 Introduction 44 Materials and Methods 46 Results 52 Discussion 55 Chapter III Surveillance of Rift Valley Fever virus in mosquito vectors of the Republic of Korea 66 Abstract 66 Introduction 68 Materials and Methods 70 Results 72 Discussion 73 Chapter IV Serological surveillance studies confirm the Rift Valley Fever virus free status in Republic of Korea 79 Abstract 79 Introduction 81 Materials and Methods 83 Results 84 Discussion 85 General conclusions 91 References 93 국문초록 106Docto

Airway management in a patient with an intratracheal tumor near the carina by a two-stage operation

In patients with intratracheal tumors, airway management while maintaining oxygenation and providing surgical access to the airway can be challenging. Here, we present a case of a two-stage operation to remove an intratracheal tumor causing partial obstruction near the carina. In the otorhinolaryngology department, a biopsy was performed during apnea under high-flow nasal oxygenation support. A few days later, a thoracic surgeon performed tracheal resection after sternotomy under general anesthesia. Mechanical ventilation was performed by inserting a sterile endotracheal tube in the resected distal part of the trachea in the surgical field for tracheal end-to-end anastomosis. Airway was successfully secured through close communication between teams of anesthesiologists and surgeons.ope