• Journal of Veterinary Science
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• v.23 no.6
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• pp.68.1-68.8
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• 2022

Background: Studies on anesthetized dogs regarding pulse pressure variation (PPV) are increasing. The influence of respiratory rate (RR) on PPV, in mechanically ventilated dogs, has not been clearly identified. Objectives: This study evaluated the influence of RR on PPV in mechanically ventilated healthy dogs after hemorrhage. Methods: Five healthy adult Beagle dogs were premedicated with intravenous (IV) acepromazine (0.01 mg/kg). Anesthesia was induced with alfaxalone (3 mg/kg IV) and maintained with isoflurane in 100% oxygen. The right dorsal pedal artery was cannulated with a 22-gauge catheter for blood removal, and the left dorsal pedal artery was cannulated and connected to a transducer system for arterial blood pressure monitoring. The PPV was automatically calculated using a multi-parameter monitor and recorded. Hemorrhage was induced by withdrawing 30% of blood (24 mL/kg) over 30 min. Mechanical ventilation was provided with a tidal volume of 10 mL/kg and a 1:2 inspiration-to-expiration ratio at an initial RR of 15 breaths/min (baseline). Thereafter, RR was changed to 20, 30, and 40 breaths/min according to the casting lots, and the PPV was recorded at each RR. After data collection, the blood was transfused at a rate of 10 mL/kg/h, and the PPV was recorded at the baseline ventilator setting. Results: The data of PPV were analyzed using the Friedman test followed by the Wilcoxon signed-rank test (p < 0.05). Hemorrhage significantly increased PPV from 11% to 25% at 15 breaths/min. An increase in RR significantly decreased PPV from 25 (baseline) to 17%, 10%, and 10% at 20, 30, and 40 breaths/min, respectively (all p < 0.05). Conclusions: The PPV is a dynamic parameter that can predict a dog's hemorrhagic condition, but PPV can be decreased in dogs under high RR. Therefore, careful interpretation may be required when using the PPV parameter particularly in the dogs with hyperventilation.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.343-352
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• 2022

Pig slaughterhouses harbor high humidity because of the necessary cleaning that takes place simultaneously with slaughter, which facilitates the existence of mold. Due to the enclosed space, there are several limitations to the control of mold growth with respect to cleaning, ventilation, and drying. In this study, the prevalence of fungi was investigated in four pig slaughterhouses in Korea. Four fungi (Aspergillus niger, Penicillium commune, Penicillium oxalicum, and Cladosporium cladosporioides) were detected with the highest frequency. These four strains were subjected to various treatments to reduce their growth. The fungi were inoculated onto stainless steel (SS) chips and treated with ultraviolet (UV)-C irradiation and hot water. Individual treatments with UV-C (15, 30, 90, 150, 300, and 600 mJ/cm²), and hot water (60, 65, 70, and 83℃) were performed to sanitize the SS chips. Simultaneous cleaning with 60℃ hot water and more than 150 mJ/cm² of UV-C reduced the fungal incidence by > 6.5 Log from 6.6-7.0 Log CFU/cm² (initial count). Our results demonstrate that a combined treatment of UV-C and hot water is the most economical and convenient way to prevent microbiological contamination of small tools (such as knives and sharpeners) and steel surfaces in slaughterhouses.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.2
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• pp.111-116
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• 2023

We provided general anesthesia management to a patient with advanced atrioventricular block, which was discovered in the remote period after open-heart surgery. A 21-year-old man with Noonan syndrome was scheduled to undergo excision of a median intramandibular tumor. At 2 months of age, the patient underwent endocardial repair for congenital heart disease. During our preoperative examination, an atrioventricular block was detected, which had not been previously noted. Emergency drugs were administered, and a transcutaneous pacemaker was placed. During anesthesia induction, mask ventilation was easy, and intubation was performed smoothly using a video laryngoscope. The transcutaneous pacemaker was activated in demand mode at a pacing rate of 50 cycles/min approximately throughout the anesthesia time, and the hemodynamic status remained stable. The effect of intraoperatively administered atropine was brief, lasting only a few seconds. Although body movements due to thoracoabdominal muscle spasm were observed during pacemaker activation, they did not interfere with surgery. In postoperative patients with congenital heart disease, an atrioventricular block may be identified in the remote period, and preoperative evaluation should be based on this possibility. In addition, during anesthesia management, it is important to prepare multiple measures to maintain hemodynamic status.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.14-23
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• 2017

In high-density high-rise cities such as Hong Kong, buildings account for nearly 90% of energy consumption and 61% of carbon emissions. Therefore, it is important to study the design of buildings, especially high-rise buildings, to achieve lower carbon emissions in the city. The carbon emissions of a building consist of embodied carbon from the production of construction materials and operational carbon from energy consumption during daily operation (e.g., air-conditioning and lighting). An integrated analysis of both types of carbon emissions can strengthen the design of low carbon buildings, but most of the previous studies concentrated mainly on either embodied or operational carbon. Therefore, the primary objective of this study is to develop a holistic methodology framework considering both embodied and operational carbon, in order to enhance the sustainable design of low carbon high-rise buildings. The framework will be based on the building information modeling (BIM) technology because BIM can be integrated with simulation systems and digital models of different disciplines, thereby enabling a holistic design and assessment of low carbon buildings. Structural analysis program is first coupled with BIM to validate the structural performance of a building design. The amounts of construction materials and embodied carbon are then quantified by a BIM-based program using the Dynamo programming interface. Operational carbon is quantified by energy simulation software based on the green building extensible Markup Language (gbXML) file from BIM. Computational fluid dynamics (CFD) will be applied to analyze the ambient wind effect on indoor temperature and operational carbon. The BIM-based framework serves as a decision support tool to compare and explore more environmentally-sustainable design options to help reduce the carbon emissions in buildings.

• Safety and Health at Work
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• v.15 no.1
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• pp.87-95
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• 2024

Background: This study focuses on assessing occupational risk for the health hazards encountered during maintenance works (MW) in semiconductor fabrication (FAB) facilities. Objectives: The objectives of this study include: 1) identifying the primary health hazards during MW in semiconductor FAB facilities; 2) reviewing the methods used in evaluating the likelihood and severity of health hazards through occupational health risk assessment (OHRA); and 3) suggesting variables for the categorization of likelihood of exposures to health hazards and the severity of health effects associated with MW in FAB facilities. Methods: A literature review was undertaken on OHRA methodology and health hazards resulting from MW in FAB facilities. Based on this review, approaches for categorizing the exposure to health hazards and the severity of health effects related to MW were recommended. Results: Maintenance workers in FAB facilities face exposure to hazards such as debris, machinery entanglement, and airborne particles laden with various chemical components. The level of engineering and administrative control measures is suggested to assess the likelihood of simultaneous chemical and dust exposure. Qualitative key factors for mixed exposure estimation during MW include the presence of safe operational protocols, the use of air-jet machines, the presence and effectiveness of local exhaust ventilation system, chamber post-purge and cooling, and proper respirator use. Using the risk (R) and hazard (H) codes of the Globally Harmonized System alongside carcinogenic, mutagenic, or reprotoxic classifications aid in categorizing health effect severity for OHRA. Conclusion: Further research is needed to apply our proposed variables in OHRA for MW in FAB facilities and subsequently validate the findings.

• Tuberculosis and Respiratory Diseases
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• v.87 no.3
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• pp.319-328
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• 2024

Background: Although inhaled corticosteroids (ICS) is reportedly associated with a higher risk of pneumonia in chronic obstructive pulmonary disease (COPD), the clinical implications of ICS have not been sufficiently verified to determine their effect on the prognosis of pneumonia. Methods: The electronic health records of patients hospitalized for pneumonia with underlying COPD were retrospectively reviewed. Pneumonia was confirmed using chest radiography or computed tomography. The clinical outcomes of pneumonia in patients with COPD who received ICS and those who received long-acting bronchodilators other than ICS were compared. Results: Among the 255 hospitalized patients, 89 met the inclusion criteria. The numbers of ICS and non-ICS users were 46 and 43, respectively. The CURB-65 (confusion, uremia, respiratory rate, blood pressure, age ≥65 years) scores at the initial presentation of pneumonia were comparable between the two groups. The proportions of patients with multilobar infiltration, pleural effusion, and complicated pneumonia in the radiological studies did not vary between the two groups. Additionally, the defervescence time, proportion of mechanical ventilation, intensive care unit admission, length of hospital stays, and mortality rate at 30 and 90 days were not significantly different between the two groups. ICS use and blood eosinophils count were not associated with all pneumonia outcomes and mortality in multivariate analyses. Conclusion: The clinical outcomes of pneumonia following ICS use in patients with COPD did not differ from those in patients treated without ICS. Thus, ICS may not contribute to the severity and outcomes of pneumonia in patients with COPD.

• Journal of Bio-Environment Control
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• v.20 no.1
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• pp.1-7
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• 2011

The objective of the present study is to identify the applicability of a low pressure fogging system for cooling commercial tomato greenhouse. In particular, the cooling system in this experiment utilizes low pressure spray nozzles which were developed in Korea recently. The experimental result that the temperature in fog-cooled greenhouse was lower than the non-cooled greenhouse showed the cooling effect by the low pressure fogging system. But because the relative humidity in fog-cooled greenhouse was comparatively low, the satisfactory cooling effect could be acquired by narrowing the space of fog nozzles and extending fogging time to supply more fog spray quantity. The variation of temperature distribution in fog-cooled greenhouse along timelag was insignificant during short time, but that was great during long period of day. This result showed the variation of temperature along timelag was slight by fog cooling but great by other factors like radiation, ventilation, air flow, etc. The advanced operation technology of fog system was required to reduce the variation of temperature along time lag. We plan to suggest the advanced installation and operation technology of low pressure fogging system for cooling commercial tomato greenhouse by further experiments in near future.

• Molecular & Cellular Toxicology
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• v.4 no.4
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• pp.348-354
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• 2008

Bisphenol A (BPA), an environmental endocrine disrupter, enters the human body continuously in food and drink. Young children are likely to be more vulnerable than adults to chemical exposure due to the immaturities of their organ systems, rapid physical development, and higher ventilation, metabolic rates, and activity levels. The direct effect of BPA on peripheral tissue might also be of importance to the development of insulin resistance. However, the influence that BPA has on insulin signaling molecules in skeletal muscle has not been previously investigated. In this study, we examined the effect of BPA on fasting blood glucose (FBG) in post-weaned Wistar rats and on insulin signaling proteins in C2C12 skeletal muscle cells. Subsequently, we investigated the effects of BPA on insulin-mediated Akt phosphorylation in C2C12 myotubes. In rats, BPA treatment (0.1-1,000 ng/mL for 24 hours) resulted in the increase of FBG and plasma insulin levels, and reduced insulin-mediated Akt phosphorylation. Furthermore, the mRNA expression of insulin receptor (IR) was decreased after 24 hours of BPA treatment in C2C12 cells in a dose-dependent manner, whereas the mRNA levels of other insulin signaling proteins, including insulin receptor substrate-1 (IRS-1) and 5'-AMP-dependent protein kinase (AMPK), were unaffected. Treatment with BPA increased GLUT4 expression and protein tyrosine phosphatase 1B (PTP1B) activity in C2C12 myotubes, but not in protein levels. We conclude that exposure to BPA can induce insulin resistance by decreasing IR gene expression, which is followed by a decrease in insulin- mediated Akt activation and increased PTP1B activity.

• Journal of Environmental Health Sciences
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• v.47 no.5
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• pp.410-424
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• 2021

Background: Subway stations have the characteristics of being located underground and are a representative public-use facility used by an unspecified number of people. As concerns about indoor air quality (IAQ) increase, various management measures are being implemented. However, there are few systematic studies and cases of long-term continuous measurement of underground station air quality. Objectives: The purpose of this study is to analyze changes and factors influencing IAQ in subway stations through real-time continuous long-term measurement using IoT-based IAQ sensing equipment, and to evaluate the IAQ improvement effect of a bio-filter system. Methods: The IAQ of a subway station in Seoul was measured using IoT-based sensing equipment. A bio-filter system was installed after collecting the background concentrations for about five months. Based on the data collected over about 21 months, changes in indoor air quality and influencing factors were analyzed and the reduction effect of the bio-filter system was evaluated. Results: As a result of the analysis, PM₁₀, PM_2.5, and CO₂ increased during rush hour according to the change in the number of passengers, and PM₁₀ and PM_2.5 concentrations were high when a PM warning/watch was issued. There was an effect of improving IAQ with the installation of the bio-filter system. The reduction rate of a new-bio-filter system with improved efficiency was higher than that of the existing bio-filter system. Factors affecting PM_2.5 in the subway station were the outdoor PM_2.5, platform PM_2.5, and the number of passengers. Conclusions: The IAQ in a subway station is affected by passengers, ventilation through the air supply and exhaust, and the spread of particulate matter generated by train operation. Based on these results, it is expected that IAQ can be efficiently improved if a bio-filter system with improved efficiency is developed in consideration of the factors affecting IAQ and proper placement.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.378-384
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• 2019

In the food wastewater treatment facilities, the water quality improvement effect and the greenhouse gas emission amount followed by the change in electricity usage through a change of the aeration tank ventilation system were evaluated. also, the amount of greenhouse gas emission followed by the change in electricity usage through the change of the sludge dewatering, storage, transporting method was also evaluated. The total GHG emission from food wastewater treatment facility improvement were divided into direct emissions from the treatment processes and indirect ones from electricity usage. The water quality improvement effect of wastewater treatment plant was found to be 63.3% for BOD removal rate, 42.0% for COD removal rate, 71.0% for SS removal rate and 39.6% for T-N removal rate. and according to the results of calculating output by applying both direct emissions of greenhouse gas (Scope 1) and the indirect emission (Scope 2) of greenhouse gas followed by changes in power consumption. It was estimated that there was a total of 276.0tCO2eq./yr(7.5%) greenhouse gas reduction effect from 3,668.8tCO2eq./yr before improvement to 3,392.8tCO2eq./yr after improvement. In this result is not due to the effects of water quality improvement of emission source, but because the reduction in electricity use has reduced the amount of greenhouse gas emissions.