• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.80-88
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• 2023

Ensuring safety in the designing of manufacturing and handling facilities for low-density polyethylene (LDPE) is difficult because there are no standards for the dust explosion characteristics of LDPE. In this study, a dust explosion test was performed on two dust samples collected from a bag filter (LDPE 1) during the LDPE manufacturing process and sedimentary dust (LDPE 2) leaked outside a facility such as a silo, and the LDPE 2 explosion test results were summarized. Particle size analysis showed that the volume-based particle diameter (median) was 95.04 ㎛ and the number density was 0-1 ㎛. The maximum explosion pressure (P_max) was 6.6 bar, and the maximum rate of explosion pressure rise was 366 [bar/s] at 1500 g/m³. Accordingly, the dust explosion index (K_st) was 99.4 bar·m/s, which was confirmed as ST-1 grade. Moreover, the minimum ignition energy and minimum ignition temperature was 10 mJ and 450 ℃, respectively. Currently, manufacturing and handling design is based on the characteristic values of high-density polyethylene (HDPE). However, as the test results show that LDPE 2 dust has a higher risk than HDPE (particle diameter 61.6 ㎛), caution is required when using the HDPE design criteria in the LDPE manufacturing process.

• Journal of the military operations research society of Korea
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• v.36 no.1
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• pp.77-90
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• 2010

Adapting commercial equipments to military operations may provide the advantage of low cost, reduced acquisition time, and technology advancement. On the other hand, it may also offer the opportunity for a reliability and logistics risk because commercial products, standards, and practices may not meet military requirements. In addition to this, commercial vendors have little experience in providing the technical data required to support military deployment logistics. As more companies are equipped with data aquisition systems for their products, considerable amount of field warranty data has been accumulated. Typically, the field data for a given product comprise with the sales volume and the number of the claims for each period. Three types of product data are considered in this study: military designed equipment operating in a military environment, commercial equipment operating in a military environment, and commercial equipment operating in a commercial environment. We construct a estimation model for each type of data and propose an reliability transform method from a commercial environment to a military environment. Parametric methods for estimating the product reliability are proposed based on maximum likelihood criteria and least square criteria. Then a reliability transform procedure for handling different types of data is proposed in a consistent fashion. A case study is investigated to characterize our model based on a real field warranty data set.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.136-143
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• 2018

The rate pressure product (RPP) is expressed as a product of the heart rate and systolic blood pressure as an index indirectly measuring the myocardial oxygen consumption, and it indicates the burden on the myocardium. The aim of this study was to determine the optimal level of RPP for preventing metabolic syndrome in a treadmill exercise test in Korean adults. Metabolic syndrome was the diagnosis of the third executive summary report on the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) criteria. According to the criteria, the metabolic syndrome diagnosis group (MetS, N=25), pre-metabolic syndrome group (Pre-MetS, N=106), and non-risk factor group (Non-MetS, N=65) were classified. The exercise stress test was performed based on the Bruce protocol. The RPP was calculated as (heart rate${\times}$systolic blood pressure)${\div}1,000$. The results showed that the maximum systolic blood pressure was high despite the low daily dose reached in the diagnostic group of metabolic syndrome. The optimal threshold of the RPP at the time of the exercise treadmill test for a metabolic syndrome prediction was $12.56mmHg{\times}beats/min{\times}10^{-3}$ in the first stage of the exercise stress test. The second stage of the exercise test was $16.94mmHg{\times}beats/min{\times}10^{-3}$, and at the third stage of the exercise test was $21.11mmHg{\times}beats/min{\times}10^{-3}$.

• Archives of Plastic Surgery
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• v.49 no.3
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• pp.346-351
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• 2022

Background Postmastectomy breast reconstruction (PMR) increases patient satisfaction, quality of life, and psychosocial well-being. There is scarce data regarding the safety of PMR in chronic anticoagulated patients. Perioperative complications can reduce patient satisfaction; therefore, it is important to elucidate the safety of PMR in these patients. Methods A retrospective case-control study of patients who underwent PMR with implants and were on chronic anticoagulation was performed at our institution. Inclusion criteria were women ≥ 18 years old. Exclusion criteria included autologous reconstructions, lumpectomy, and oncoplastic procedures. Two controls for every one patient on anticoagulation were matched by age, body mass index, radiotherapy, smoking history, type of reconstruction, time of reconstruction, and laterality. Results From 2009 to 2020, 37 breasts (20 patients) underwent PMR with implant-based reconstruction and were on chronic anticoagulation. A total of 74 breasts (40 patients) who had similar demographic characteristics to the cases were defined as the control group. Mean age for the case group was 53.6 years (standard deviation [SD] = 16.1), mean body mass index was 28.6 kg/m² (SD = 5.1), and 2.7% of breasts had radiotherapy before reconstruction and 5.4% after reconstruction. Nine patients were on long-term warfarin, six on apixaban, three on rivaroxaban, one on low-molecular-weight heparin, and one on dabigatran. The indications for anticoagulation were prior thromboembolic events in 50%. Anticoagulated patients had a higher risk of capsular contracture (10.8% vs. 0%, p = 0.005). There were no differences regarding incidence of hematoma (2.7% vs. 1.4%, p = 0.63), thromboembolism (5% vs. 0%, p = 0.16), reconstructive-related complications, or length of hospitalization (1.6 days [SD = 24.2] vs. 1.4 days [SD = 24.2], p = 0.85). Conclusion Postmastectomy implant-based breast reconstruction can be safely performed in patients on chronic anticoagulation with appropriate perioperative management of anticoagulation. This information can be useful for preoperative counseling on these patients.

• The Journal of Internal Korean Medicine
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• v.44 no.3
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• pp.387-401
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• 2023

Objective: This study was conducted to investigate the preventive effect of herbal medicines on restenosis after percutaneous coronary intervention (PCI) by reviewing randomized controlled trials (RCTs). Methods: RCTs were searched for herbal medicine treatment after PCI using eight online databases (PubMed, CNKI, Wanfang, J-STAGE, OASIS, ScienceON, KTKP, and KISS). Studies that confirmed restenosis through coronary angiography at follow-up were selected according to the inclusion and exclusion criteria. The primary outcome was the restenosis rate, and the secondary outcome was the angina recurrence rate. Data were extracted from the final selected studies according to the research methodology and then analyzed with Review Manager 5.4.1. Study quality was assessed using Cochrane's risk-of-bias (RoB) tool. Results: Of the 252 papers obtained through the primary search, nine studies that met the selection criteria were finally selected. In these nine studies, herbal medicine combined with western medicine was used for the experimental group, and western medicine treatment was used alone for the control group. The meta-analysis result revealed that the restenosis rate and angina recurrence rate were significantly lower in the experimental group than in the control group (RR=0.34, 95% CI: 0.22-0.53, p<0.00001, I²=0% and RR=0.47, 95% CI: 0.29-0.78, p=0.004, I²=0%, respectively). Furthermore, the quality of studies assessed by Cochrane's RoB was low. Conclusions: This study showed that the combined treatment of herbal medicine and western medicine was effective in preventing restenosis and angina after PCI. As the number of papers included in this study was small, a large number of high-quality clinical studies should be considered in the future.

• Asian Oncology Nursing
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• v.1 no.1
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• pp.5-17
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• 2001

It is known that aggressive treatment of chemotherapy, radiation and autogenous stem cell transplantation is effective for prevention of recurrence in the high-risk breast cancer patients. It was assumed that this procedure takes a longer time and decreases the quality of life more than the standard adjuvant chemotherapy. However, there are few studies comparing the quality of life of patients having bone marrow transplantation and adjuvant chemotherapy. Most of the studies were focused on the quality of life in one point of time, such as only during the early treatment stage, only overall quality of life rather than specific dimensions of the quality of life. The purposes of this study are 1) to identify the difference of the quality of life between two different treatment patterns, adjuvant chemotherapy and autogenous stem cell transplantation: 2) to identify the mostly affected dimension and the periods of time affected by the treatment patterns; and 3) to identify the trajectories of quality of life in each treatment pattern. This is a time series design that measures 4 different points of times. At the beginning of the study, 19 patients were placed in the chemotherapy group and 12 in the group of auto-peripheral blood stem cell transplantation. The inclusion criterion was the advanced disease stage of 3 or over with metastasis of more than 5 lymph nodes. The exclusion criteria were 1) anyone who has metastasis to other organ; 2) anyone who had psychological problems. Ferrell's Quality of Life Scale for Cancer Survivors 41 items on a 10 point scale was used. The QOL-CS includes 4 dimensions, which were labeled physical, psychological, social, and spiritual. The Cronbach‘s alpha of this scale was 0.89. Mann-Whitney U test and Friedman test were used to test each hypothesis. In comparison of the two groups, the quality of life of the bone marrow transplantation group dramatically increased at the 3rd and 6th month after transplantation, while the chemotherapy groups results stayed lower. The most affected dimension of the quality of life at the end of the treatment was the physical dimension. However, it and increased along with time, while the psychological dimension values remained low over the long-term period. Intensive nursing care is needed during the entire period of chemotherapy in all patients having chemotherapy, and is also required for right after cases of bone marrow transplantation.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.1
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• pp.44-53
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• 2018

The WHtR (waist to height ratio) and ABSI (a body shape index) are indicators that reflect abdominal obesity. This study examined the insulin resistance and metabolic syndrome prediction ability of ABSI and WHtR. In this study, 4,395 people aged 20 years or older, who underwent physical examinations at a General Hospital in Gyeonggi-do from January 2017 to September 2017 were assessed on a cross section survey. Metabolic syndrome was defined according to the criteria of the AHA/NHLBI. Insulin resistance was judged to be insulin resistance when the HOMA-IR value was 3.0 or more. Both men and women showed a stronger correlation between WHtR and the metabolic risk factors than ABSI. The AUC value of WHtR and ABSI was 0.849 and 0.676, respectively (p<0.001). The AUC value of WHtR and ABSI for predicting insulin resistance was 0.818 and 0.641, respectively (p<0.001). In conclusion, the ABSI has low predictive power of insulin resistance and metabolic syndrome whereas the WHtR has good predictive power for metabolic syndrome and insulin resistance.

• Korean Journal of Clinical Pharmacy
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• v.27 no.2
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• pp.92-98
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• 2017

Background: Nebulized colistimethate is increasingly used, because there are problems such as renal dysfunction and low distribution within the lungs when colistimethate is administered intravenously. This study was designed to compare and analyze the changes in renal function by of nebulized colistimethate treatment for its safe administration. Methods: This study retrospectively reviewed the electronic medical records of adult patients above 19 years old, receiving only the nebulized colistimethate at least 4 days in Yonsei university health system from Nov 2014 to Aug 2015. Acute kidney injury (AKI) was determined by using the RIFLE criteria (Risk, Injury, Failure, Loss and End-stage renal disease) according to serum creatinine (SCr) levels before and after use of nebulized colistimethate. Results: 48 patients were included our study and their SCr increased significantly after nebulized colistimethate treatment ($SCr_0$ vs. $SCr_1$; $0.85{\pm}0.80$ vs. $1.00{\pm}0.82mg/dL$, n=48, p<0.001), but the changes were in normal range according to the standards at Yonsei university health $system^a$. Among 48 patients, 38 patients were in the non-AKI group (79.2%), and 10 patients developed AKI (20.8%). Within the AKI group, 2 patients were in the Injury group (20%) and the other 8 in the Risk group (80%). Conclusion: There was no significant difference in age, dosage and duration of treatment between AKI group and non-AKI group (p>0.05). The study has a significance in that it reviewed the safety of nebulized colistimethate only treatment to national patients, analyzing its nephrotoxicity. It has confirmed that nebulized colistimethate is a safer method than intravenous injection, and requires to establish a guideline for the use of nebulized colistimethate in further studies with broader patient groups. $^a$ : SCr Male 0.68-1.19 mg/dL, Female 0.49-0.91 mg/dL.

• Journal of Korean Academy of Rural Health Nursing
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• v.7 no.1
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• pp.5-17
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• 2012

Purpose: The objectives of this study were to investigate the prevalence of the metabolic syndrome (MetS) and to identify associated factors with MetS among rural residents. Methods: Data were collected from 1,196 subjects over aged 30 years by a self-administered questionnaire, physical measurement, and blood test in a rural area. The prevalence of MetS was determined by the criteria of the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) and 2005 the Korean society for the study of obesity. Results: The prevalence of MetS was 40.5% for men, 49.2% for women. The prevalence of risk factors of MetS was 57.4% for elevated blood pressure, 49.0% for low HDL-cholesterol, and 48.6% for abdominal obesity. Unemployment and higher Body mass index (BMI) were associated factors for MetS regardless of gender. And higher age and physical inactivity in women only increased the odds of the MetS. Especially, BMI was a strong risk factor of MetS in both men and women. Conclusion: The prevalence of metabolic syndrome was higher in a rural area. Therefore, health care providers should develop lifestyle modification program to increase physical activity level and to prevent the obesity among rural residents in order to decrease the prevalence of MetS.

• Journal of Dental Anesthesia and Pain Medicine
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• v.21 no.5
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• pp.379-396
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• 2021

Background: Trigeminal neuralgia (TN) is characterized by brief, unilateral, sharp, stabbing, and shooting pain of the fifth cranial nerve. The objective of this systematic review with meta-analysis was to determine the effect of medications compared to placebo in adult patients with TN. Methods: Review authors identified randomized placebo-controlled trials (RCTs) from PubMed, Web of Science, Cochrane, and EMBASE up to February 2021. We assessed the inclusion and exclusion criteria as well as the risk of bias of the studies based on the Cochrane Handbook. A total of 324 unduplicated references were scanned independently and reduced to eight relevant RCTs, with 89 patients included. Medications investigated included oral carbamazepine, subcutaneous sumatriptan, lidocaine (intranasal, 8% spray on the oral mucosa or intravenous), buprenorphine (ganglionic local opioid analgesia), and oral Nav1.7, a selective sodium channel blocker. Results: Meta-analyses showed that overall patients receiving lidocaine reported a significantly lower post-treatment intensity of pain -3.8 points on a 0-10 scale (95% Cl = -4.653 to -2.873; P < 0.001). Patients who received lidocaine were 8.62 times more likely to have pain improvement than patients on placebo (P < 0.001). In one RCT, patients receiving oral carbamazepine showed a significant improvement in pain intensity of -32% compared to the placebo (P < 0.001). In one trial, patients receiving 3 mg subcutaneous sumatriptan had a significantly lower intensity of pain on average -6.1 points on a scale of 0-10 compared to placebo (P < 0.001) and a significant improvement in pain intensity of -75% compared to the improvement in the placebo group (P < 0.001). Patients who received subcutaneous sumatriptan were 10 times more likely to have pain improvement than those who received placebo (P = 0.001) in one study. Due to the unclear/high risk of bias and small sample size, the quality of the evidence for lidocaine in the treatment of TN was low. Conclusion: Further studies are needed for carbamazepine, sumatriptan, buprenorphine, and oral Nav1.7 sodium channel blockers, as only one study reported outcomes.