10 research outputs found
Point-of-care testing for the detection of SARS-CoV-2: a systematic review and meta-analysis
Objective: To evaluate the diagnostic accuracy of the Food and Drug Administration Emergency Use Authorization (FDA-EUA) authorized point-of-care tests (POCTs) for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
Materials and methods: A systematic literature search was conducted using the PubMed, Embase, and Web of Science databases for articles published till August 10, 2020. We included studies providing information regarding diagnostic test accuracy of FDA-EUA POCTs for SARS-CoV-2 detection. The methodologic quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The review protocol is registered in the International Prospective Register of Systematic Reviews (protocol number CRD42020202248).
Results: We included 26 studies describing a total of 3242 samples. The summary sensitivity and specificity were 0.94 [95% confidence interval (CI): 0.88-0.97] and 1.00 (95% CI: 0.99-1.00), respectively. The area under the summary receiver operating characteristic curve was 1.00 (95% CI: 0.99-1.00). A pooled analysis based on the index test revealed a summary sensitivity and specificity of Cepheid Xpert Xpress SARS-CoV-2 [0.99 (95% CI: 0.97-1.00) and 0.99 (95% CI: 0.94-1.00, respectively)] and ID NOW COVID-19 [0.78 (95% CI: 0.74-0.82) and 1.00 (95% CI: 0.98-1.00), respectively].
Conclusions: FDA-EUA POCTs, especially molecular assays, have high sensitivity, specificity, and overall diagnostic accuracy for detecting SARS-CoV-2. If approved, FDA-EUA POCTs can provide a rapid and practical way to identify infected individuals early on and help to limit the strain on the healthcare system. However, more high-quality clinical data are required to support our results.ope
Cannabidiol for Treating Lennox-Gastaut Syndrome and Dravet Syndrome in Korea
Background: For the first time in Korea, we aimed to study the efficacy and safety of cannabidiol (CBD), which is emerging as a new alternative in treating epileptic encephalopathies.
Methods: This study was conducted retrospectively with patients between the ages of 2-18 years diagnosed with Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) were enrolled from March to October 2019, who visited outpatient unit at 3 and 6 months to evaluate medication efficacy and safety based on caregiver reporting. Additional evaluations, such as electroencephalogram and blood tests, were conducted at each period also. CBD was administered orally at a starting dose of 5 mg/kg/day, and was maintained at 10 mg/kg/day.
Results: We analyzed 34 patients in the LGS group and 10 patients in the DS group between the ages of 1.2-15.8 years. In the 3-month evaluation, the overall reduction of seizure frequency in the LGS group was 52.9% (>50% reduction in 32.3% of the cases), and 29.4% in the 6-month evaluation (more than 50% reduction in 20.6%). In DS group, the reduction of seizure frequency by more than 50% was 30% and 20% in the 3-month and 6-month evaluation, respectively. Good outcomes were defined as the reduction of seizure frequency by more than 50% and similar results were observed in both LGS and DS groups. Adverse events were reported in 36.3% of total patients of which most common adverse events were gastrointestinal problems. However, no life-threatening adverse event was reported in both LGS and DS during the observation period.
Conclusion: In this first Korean study, CBD was safe and tolerable for use and could be expected to potentially reduce the seizure frequency in pediatric patients with LGS or DS.ope
Effects of Cannabidiol on Adaptive Behavior and Quality of Life in Pediatric Patients With Treatment-Resistant Epilepsy
Background and purpose: Data regarding the effects of cannabidiol (CBD) on the quality of life (QOL) are currently inadequate. We assessed the QOL of pediatric patients with epilepsy who were treated with CBD.
Methods: This prospective, open-label study included pediatric and adolescent patients (aged 2-18 years) with Dravet syndrome or Lennox-Gastaut syndrome. Oral CBD was administered at 10 mg/kg/day. The Korean version of the Quality Of Life in Childhood Epilepsy (QOLCE) questionnaire was administered when CBD treatment began and again after 6 months. Adaptive behavior was measured using the Korean versions of the Child Behavior Checklist (K-CBCL) and the second edition of the Vineland Adaptive Behavior Scales (Vineland-II).
Results: This study included 41 patients (11 with Dravet syndrome and 30 with Lennox-Gastaut syndrome), of which 25 were male. The median age was 4.1 years. After 6 months, 26.8% (11/41) of patients experienced a ≥50% reduction in the number of seizures. The total score for the QOLCE questionnaire did not change from baseline to after 6 months of CBD treatment (85.71±39.65 vs. 83.12±48.01, respectively; p=0.630). The score in the motor skills domain of Vineland-II reduced from 48.67±13.43 at baseline to 45.18±14.08 after 6 months of treatment (p=0.005). No other Vineland-II scores and no K-CBCL scores had changed after 6 months of CBD treatment.
Conclusions: CBD is an efficacious antiseizure drug used to treat Dravet syndrome and Lennox-Gastaut syndrome. However, it did not improve the patient QOL in our study, possibly because all of our patients had profound intellectual disabilities.ope
Using the lactate-to-albumin ratio to predict mortality in patients with sepsis or septic shock: a systematic review and meta-analysis
Objective: This study aimed to investigate whether the lactate-to-albumin ratio (LAR) can predict mortality in patients with sepsis or septic shock.
Patients and methods: A systematic search of the PubMed, EMBASE, Web of Science, and Google Scholar databases was conducted on December 16, 2021, for relevant articles that provided the predictive performance of LAR for mortality in patients with sepsis or septic shock.
Results: Eight studies encompassing a total of 4,723 patients were included in this paper. The pooled sensitivity, specificity, and diagnostic odds ratio of the LAR for predicting mortality were 0.71 (95% confidence interval [CI]: 0.54-0.84), 0.68 (95% CI: 0.58-0.76) and 5.23 (95% CI: 2.62-10.45), respectively. The area under the summary receiver operating characteristic curve was 0.74 (95% CI: 0.70-0.78).
Conclusions: The current evidence suggests that LAR is moderately predictive of mortality among patients with sepsis or septic shock and may be beneficial to identify high-risk patients.ope
Prognostic Factors for Absence Epilepsy in Childhood
Purpose: Childhood absence epilepsy (CAE) is a common form of idiopathic generalized epilepsy
with onset middle childhood and has typically a good prognosis, but remission rates vary. We
aimed to analyze unfavorable prognostic factors in children initially diagnosed with CAE.
Methods: We retrospectively reviewed 48 patients under 13 years of age who were diagnosed
with CAE at the Severance Children’s Hospital, Seoul, Korea. We analyzed clinical information in cluding comorbidity through neuropsychological test.
Results: Thirteen of the 48 patients (27%) showed an unfavorable prognosis, with clinical sei zures or seizure waves on electroencephalogram persistent even after 12 months of anticonvul sant therapy. The mean age at absence seizure onset was 6.51±2.36 years. The most commonly
used antiepileptic drug (AED) was ethosuximide, and the median duration of initial AEDs was
25.63±24.41 months. The presence of comorbidity and clinical absence seizures after 6 months
of AEDs correlated with an unfavorable prognosis. Motor seizures were the most unfavorable
prognostic factor during follow-up.
Conclusion: This study shows that clinical absence seizures after 6 months of AED, comorbidity,
and motor seizure are the most important predictive factors of an unfavorable prognosis for ab sence epilepsy in childhood. This study suggests that when these factors are observed, early in tervention needs to be considered.ope
Development of Risk Analysis and Coal Production Forecasting Models Applicable to Longwall Mines
학위논문 (박사)-- 서울대학교 대학원 : 에너지시스템공학부, 2017. 2. 전석원.롱월 광산은 지하 공간에서 작업이 이루어진다는 점과 대규모 자동화 기계장비를 사용한다는 점에서 채탄 작업을 진행하는 동안 수많은 리스크에 노출되게 된다.
이러한 롱월 광산에서의 리스크 분석은 일반적으로 정성적 리스크 분석이 주를 이루고 있으며, 최근 다양한 분석 방법들의 개발⋅보급으로 리스크 발생 가능성이나 피해정도를 수치적으로 제시하는 정량적 리스크 분석에 대한 연구가 증가하고 있는 추세이다. 하지만, 대부분 특정 사건에 대한 리스크 분석에 국한되어 있으며, 프로젝트 전반에 대한 포괄적이고 정량적인 리스크 분석에 대한 연구는 아직까지 미흡한 실정이다.
따라서 본 연구에서는 이러한 한계를 극복하기 위하여 우선, 롱월 광산에서 발생 가능한 리스크를 천반 붕락, 반팽, 롱월 막장 붕괴, 채탄 장비의 폐색 또는 고장, 운반 장비의 폐색 또는 고장, 롱월 패널 재배치 작업 지연, 지반 침하, 자연발화 등 총 8가지로 분류하고, 리스크는 위험요소가 발생할 확률과 그로 인한 피해정도(영향)의 곱이라는 리스크 정의를 바탕으로 결함수분석을 통해 리스크의 발생 확률을 분석하고, 계층분석적 의사결정방법을 통해 리스크의 영향도를 분석한 뒤, 이를 종합적으로 고려하여 리스크 레벨을 평가할 수 있는 정량적 리스크 분석 모델을 개발하였다.
개발된 리스크 분석 모델은 호주의 스프링베일 광산과 앙구스플레이스 광산에 적용하여 모델의 적합성을 검증하였다. 검증은 리스크 분석 모델에 의해 산정된 리스크 레벨과 상기 두개 광산에서 최근 5년간 발생한 리스크들로 인한 다운타임과의 상관관계 분석을 통해 이루어졌다. 그 결과 스프링베일 광산과 앙구스플레이스 광산의 리스크 레벨과 다운타임 사이의 결정계수와 평균 제곱근 오차가 각각 0.955, 2.664와 0.965, 1.795로 나타나 리스크 분석 모델의 적합성이 매우 우수한 것으로 확인되었다.
또한, 일반적으로 롱월 광산에서 생산계획을 수립할 때 패널별 생산량은 패널의 길이, 폭, 높이를 고려하여 산정하게 되는데, 실제 생산을 하다 보면 지질 조건의 변화로 인해 예상했던 생산량과 실제 생산량에 차이가 발생하게 된다. 하지만, 생산계획 수립 시 이러한 생산량의 차이를 반영할 수 있는 정량적인 기준이 없어 설계 당시 공학자의 주관적 판단에 의해 생산 가능 물량을 산정하고 있다.
본 연구에서는 이러한 문제점을 보완하기 위해 암반공학 시스템과 다중 선형 회귀분석을 이용하여 지질 조건을 고려한 패널별 생산량 예측 모델을 개발하였다. 암반공학 시스템을 이용한 예측 모델에는 탄층 두께변화, 탄층 두께, 탄층 경사, 천반상태, 바닥상태, 탄층 깊이 등 6개의 매개변수를 활용하였으며, 다중선형 회귀분석을 이용한 예측 모델에는 피어슨 상관계수와 다중 공선성 분석을 통해 상관성 낮은 탄층 두께와 높은 분산팽창지수를 보이는 탄층 두께변화를 제외한 4개의 매개변수를 활용하여 예측 모델을 개발하였다.
예측 모델의 개발 및 검증에는 호주의 스프링베일 광산과 앙구스플레이스 광산에서 확보한 31개의 패널 자료를 활용하였으며, 24개의 패널 자료를 활용하여 예측 모델을 개발하고, 예측 모델에 사용되지 않은 7개의 패널 자료를 활용하여 예측 모델을 검증하였다. 그 결과 암반공학 시스템을 이용한 예측 모델은 결정계수 0.777, 평균 제곱근 오차 0.905의 결과를 얻었으며, 다중 선형 회귀분석을 이용한 예측 모델은 결정계수 0.759, 평균 제곱근 오차 1.149의 결과를 얻어 지질조건을 고려한 예측 모델을 통해서 실제 생산량에 가까운 생산량을 예측할 수 있는 것으로 확인되었다.Longwall mines have been exposed many risks due to working in the underground and using the large-scale automation machinery equipments.
Generally, risk analysis in longwall mines is mainly performed by qualitative risk analysis and recently, as various analytical methods have been developed and introduced, researches on quantitative risk analysis, which present numerically likelihood of occurrence or consequence, is increasing.
However, most of them are limited for specific events and research on comprehensive and quantitative risk analysis for the overall project is insufficient.
In this study, to overcome this limitation, firstly, the risks that can occur in longwall mines are classified into 8 itemsroof fall, floor heave, collapse of longwall face, jammed or broken of coal extraction equipments, jammed or broken of coal transportation equipments, delay of longwall relocation, subsidence and spontaneous combustion. And then a quantitative risk analysis model has been developed using fault tree analysis (FTA) and analytic hierarchy process (AHP) based on the definition of Risk= likelihood×consequence. In this model, FTA is used to calculate the risk probability and AHP is used to evaluate the risk impact.
The developed risk analysis model is validated by applying it to Springvale and Angus Place coal mines in Australia. The validations are done by correlation analysis between the risk levels calculated by the risk analysis model and the downtime occurrences caused by the risks in the two coal mines over the past 5 years.
In conclusion, the coefficient of determination (R2) and root mean square error (RMSE) of Springvale (R2=0.955, RMSE=2.664) and Angus Place (R2=0.965, RMSE=1.795) coal mines have been obtained. These indicate that the risk levels evaluated by risk analysis model closely coincide with the downtime occurrences.
Also, generally, when planning the production in the longwall mine, the production of panel is calculated considering the length, width and height of panel. But there is a difference between the expected and the actual production due to the geological conditions. However there is no quantitative criterion that can reflect the difference in production when making the production plan, and therefore it is calculated by the subjective judgement of the engineers.
In this study, in order to minimize the errors caused by personal judgement, the production forecasting models considering geological conditions have been developed using rock engineering systems (RES) and multiple linear regression analysis.
The RES based model uses 6 parameters (variation in seam thickness, seam thickness, dip of seam, roof quality, floor quality and depth of seam). And in the multiple linear regression based model, 4 parameters except variation in seam thickness (high variation index factor) and seam thickness (low correlation) are used through Pearson correlation coefficient and multi-collinearity analysis.
For the development and validation of the production forecasting models, 31 panel data sets are used from the Springvale and Angus Place coal mine. The production forecasting models are developed using 24 panel data sets and validated the suitability of the forecasting models by using 7 panel data sets not used in the forecasting models.
In conclusion, the coefficient of determination (R2) and root mean square error (RMSE) for the RES based model (R2=0.777, RMSE=0.905) and the multiple linear regression based model (R2=0.759, RMSE=1.149) have been obtained. These indicate that the production can be forecasted close to actual production through the forecasting models considering geological conditions.1. 서론 1
2. 리스크 관리 개요 6
2.1 리스크 정의 및 관련 개념 6
2.1.1 리스크 정의 6
2.1.2 리스크 관련 개념 9
2.2 리스크 관리 10
2.2.1 리스크 관리 계획 수립 13
2.2.2 리스크 식별 13
2.2.3 정성적 리스크 분석 수행 14
2.2.4 정량적 리스크 분석 수행 14
2.2.5 리스크 대응 계획 수립 15
2.2.6 리스크 모니터링 및 통제 15
2.3 자원개발 프로젝트에서의 리스크 분석 사례 17
2.3.1 정성적 리스크 분석 사례 17
2.3.2 정량적 리스크 분석 사례 21
2.4 리스크 분석 방법 선정 29
2.4.1 리스크 분석 방법 비교 29
2.3.2 리스크 분석 방법 선정 31
3. 롱월 광산에서 고려되어야 할 리스크 요인 32
3.1 롱월 채탄 개요 32
3.1.1 패널 굴진 34
3.1.2 롱월 채탄 37
3.1.3 석탄 운반 40
3.2 지질 조건에 따른 리스크 요인 41
3.2.1 암반역학적 특성에 따른 리스크 요인 42
3.2.2 지층 특성에 따른 리스크 요인 50
3.3 설계 조건에 따른 리스크 요인 54
3.3.1 패널 설계 54
3.3.2 채준갱도 개설 방법 55
3.3.3 필라 설계 57
3.3.4 채탄기 설계 60
3.3.5 천반지지대 설계 63
3.3.6 AFC 설계 65
3.4 생산관리 조건에 따른 리스크 요인 67
3.4.1 광산 안전 관련 리스크 요인 68
3.4.2 장비 관련 리스크 요인 80
3.4.3 광산 운영 관련 리스크 요인 81
4. 롱월 광산에 적용 가능한 리스크 분석 모델 개발 84
4.1 결함수분석을 통한 리스크 발생 확률 분석 84
4.1.1 결함수분석 개요 84
4.1.2 지반 관련 리스크 선정 89
4.1.3 롱월 장비 관련 리스크 선정 97
4.1.4 환경 관련 리스크 선정 103
4.1.5 리스크 발생 확률 분석 110
4.2 계층분석적 의사결정방법을 통한 리스크 영향도 분석 113
4.2.1 계층분석적 의사결정방법 개요 113
4.2.2 계층분석적 의사결정방법의 절차 및 방법 114
4.2.3 리스크 영향도 분석 120
4.3 리스크 분석모델의 현장 적용 123
4.3.1 호주 스프링베일 유연탄 광산 123
4.3.2 호주 앙구스플레이스 유연탄 광산 141
4.3.3 현장 적용 사례에 대한 비교 분석 157
5. 지질 조건을 고려한 생산량 예측 모델 개발 159
5.1 암반공학시스템을 이용한 예측 모델 개발 159
5.1.1 암반공학 시스템 개요 159
5.1.2 예측 모델 개발 절차 및 방법 161
5.1.3 예측 모델 개발 171
5.2 다중 선형 회귀분석을 이용한 예측 모델 개발 174
5.2.1 회귀분석 개요 174
5.2.2 변수들 간의 상관관계 분석 177
5.2.3 예측 모델 개발 183
5.3 예측 모델의 현장 적용 186
6. 결 론 191
참고문헌 196
Appendix A. Overview of longwall equipments 207
Appendix B. Questionnaire sheet 217
Appendix C. Results of questionnaire 250
Abstract 259Docto
Potential role of stress-induced gluconeogenesis in disease aggravation and mortality in pyruvate dehydrogenase deficiency: A case-based hypothesis
Pyruvate dehydrogenase (PDH) deficiency is an inherited metabolic disorder caused by a defect in any subunit of the pyruvate dehydrogenase complex (PDHC), which has an essential role in glucose metabolism. The causes of disease progression in PDH deficiency are not fully understood yet. Based on repeated observations of a patient with PDH deficiency at our center, we hypothesized that stress-induced gluconeogenesis contributes to rapid exacerbation of the disease. This link has not been established previously.restrictio
Paediatric Trauma Score as a non-imaging tool for predicting intracranial haemorrhage in patients with traumatic brain injury
To identify a useful non-imaging tool to screen paediatric patients with traumatic brain injury for intracranial haemorrhage (ICH). We retrospectively analysed patients aged < 15 years who visited the emergency department with head trauma between January 2015 and September 2020. We divided patients into two groups (ICH and non-ICH) and compared their demographic and clinical factors. Among 85 patients, 21 and 64 were in the ICH and non-ICH groups, respectively. Age (p = 0.002), Pediatric trauma score (PTS; p < 0.001), seizure (p = 0.042), and fracture (p < 0.001) differed significantly between the two groups. Factors differing significantly between the groups were as follows: age (odds ratio, 0.84, p = 0.004), seizure (4.83, p = 0.013), PTS (0.15, p < 0.001), and fracture (69.3, p < 0.001). Factors with meaningful cut-off values were age (cut-off [sensitivity, specificity], 6.5 [0.688, 0.714], p = 0.003) and PTS [10.5 (0.906, 0.81), p < 0.001]. Based on the previously known value for critical injury (≤ 8 points) and the cut-off value of the PTS identified in this study (≤ 10 points), we divided patients into low-risk, medium-risk, and high-risk groups; their probabilities of ICH (95% confidence intervals) were 0.16-12.74%, 35.86-89.14%, and 100%, respectively. PTS was the only factor that differed significantly between mild and severe ICH cases (p = 0.012). PTS is a useful screening tool with a high predictability for ICH and can help reduce radiation exposure when used to screen patient groups before performing imaging studies.ope
Neutrophil-to-lymphocyte ratio for the diagnosis of pediatric acute appendicitis: a systematic review and meta-analysis
Objective: Acute appendicitis (AA) is one of the most common surgical emergencies and causes of acute abdominal pain in the pediatric population. However, it can be difficult to diagnose in children. We aimed to provide updated evidence on the diagnostic utility of the neutrophil-to-lymphocyte ratio (NLR) for AA, along with other conventional biomarkers, in pediatric patients.
Materials and methods: We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for eligible articles published up to May 16, 2021.
Results: We included 19 studies comprising a total of 5,974 pediatric cases. The overall sensitivity and specificity of the NLR were 0.82 (95% confidence interval [CI]: 0.79-0.85) and 0.76 (95% CI: 0.69-0.81), respectively. The overall diagnostic odds ratio was 14.34 (95% CI: 9.05-22.73). The area under the summary receiver operating characteristic curve was 0.86 (95% CI: 0.83-0.89). The pooled sensitivity and specificity of other biomarkers were as follows: 0.79 (95% CI: 0.71-0.86) and 0.66 (95% CI: 0.54-0.77) for the white blood cell count, 0.73 (95% CI: 0.69-0.77) and 0.68 (95% CI: 0.55-0.79) for the C-reactive protein level, 0.75 (95% CI: 0.65-0.82) and 0.78 (95% CI: 0.72-0.83) for the absolute neutrophil count, and 0.83 (95% CI: 0.79-0.87) and 0.68 (95% CI: 0.53-0.80) for the neutrophil percentage, respectively.
Conclusions: The NLR has moderate predictive power for AA and can be used as a simple, auxiliary tool for diagnosis. NLR can also help clinicians decide whether to perform imaging testing when the clinical symptoms or physical examination findings are vague.ope
Age-adjusted quick Sequential Organ Failure Assessment score for predicting mortality and disease severity in children with infection: a systematic review and meta-analysis
We assessed the diagnostic accuracy of the age-adjusted quick Sequential Organ Failure Assessment score (qSOFA) for predicting mortality and disease severity in pediatric patients with suspected or confirmed infection. We conducted a systematic search of PubMed, EMBASE, the Cochrane Library, and Web of Science. Eleven studies with a total of 172,569 patients were included in the meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio of the age-adjusted qSOFA for predicting mortality and disease severity were 0.69 (95% confidence interval [CI] 0.53-0.81), 0.71 (95% CI 0.36-0.91), and 6.57 (95% CI 4.46-9.67), respectively. The area under the summary receiver-operating characteristic curve was 0.733. The pooled sensitivity and specificity for predicting mortality were 0.73 (95% CI 0.66-0.79) and 0.63 (95% CI 0.21-0.92), respectively. The pooled sensitivity and specificity for predicting disease severity were 0.73 (95% CI 0.21-0.97) and 0.72 (95% CI 0.11-0.98), respectively. The performance of the age-adjusted qSOFA for predicting mortality and disease severity was better in emergency department patients than in intensive care unit patients. The age-adjusted qSOFA has moderate predictive power and can help in rapidly identifying at-risk children, but its utility may be limited by its insufficient sensitivity.ope
