• Tuberculosis and Respiratory Diseases
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• v.45 no.6
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• pp.1223-1235
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• 1998

Background and Objective : Although prone positioning has been reported to improve gas exchange, prone positioning alone does not seem to be sufficient to increase systemic oxygen transport in an acute lung injury. The objective of this study was to investigate whether the combined therapy of low dose nitric oxide (NO) inhalation and prone positioning has an additive effect on the oxygenation and hemodynamics in patients with severe ARDS. Patients and Methods : Twelve patients with ARDS were included. Prone positioning alone, later combined with nitric oxide inhalation (5~10 ppm) from the supine position (baseline) were performed with serial measurement of gas exchange, respiratory mechanics and hemodynamic at sequential time points. The patient was regarded as a responder to prone positioning if an increase in $PaO_2/FiO_2$ of more than 20 mm Hg at 30 min or 120 min intervals after prone positioning was observed compared to that of the baseline. The same criterion was applied during nitric oxide inhalation. Results : Eight patients (66.5%) responded to prone positioning and ten patients (83.3%) including the eight just mentioned responded to the addition of NO inhalation. The $AaDO_2$ level also decreased promptly with the combination of prone positioning and NO inhalation compared to that of prone positioning alone ($191{\pm}109$ mm Hg vs. $256{\pm}137$ mm Hg, P<0.05). Hemodynamic parameters and lung compliance did not change significantly during prone positioning only. Following the addition of NO inhalation to prone positioning, the mean pulmonary artery pressure and pulmonary artery occlusion pressure decreased and cardiac output, stroke volume and oxygen delivery increased (P < 0.05) compared to those of prone 120 min. Conclusion : These findings indicate that NO inhalation would provide additional improvement in oxygenation and oxygen transport to mechanically ventilated patients with ARDS who are in a prone position.

• Journal of Radiation Protection and Research
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• v.39 no.1
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• pp.7-13
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• 2014

Phosphate rock, phosphogypsum, and products in phosphate processing facility contain naturally occurring radioactive materials (NORM). Therefore, they may give rise to enhanced radiation dose to workers due to inhalation of airborne particulates. Internal dose due to particle inhalation varies depending on particle properties. The objective of the present study was to characterize particle properties at the largest phosphate processing facility in Korea. A cascade impactor was employed to sample airborne particulates at various processing areas in the plant. The collected samples were used for characterization of particle size distribution, particle concentration in the air, and shape analysis. Aerodynamic diameters of airborne particulates ranged 0.03-100 ${\mu}m$ with the highest concentration at the particle size range of 4.7-5.8 ${\mu}m$ (geometric mean = 5.22 ${\mu}m$) or 5.8-9.0 ${\mu}m$ (geometric mean = 7.22 ${\mu}m$). Particle concentrations in the air varied widely by sampling area up to more than two orders of magnitude. The large variation resulted from the variability of mechanical operations and building ventilations. The airborne particulates appeared as spheroids or rough spherical fragments across all sampling areas and sampled size intervals. Average mass densities of phosphate rocks, phosphogypsums, and fertilizers were 3.1-3.4, 2.1-2.6, and 1.7 $gcm^{-3}$, respectively. Radioactivity concentration of uranium series in phosphate rocks varied with country of origin, ranging 94-866 $Bqkg^{-1}$. Among the uranium series, uranium was mostly concentrated on products, including phosphoric acid or fertilizers whereas radium was concentrated on byproducts or phosphogypsum. No significant radioactivity of $^{226}Ra$ and $^{228}Ra$ were found in fertilizer. However, $^{40}K$ concentration in fertilizer was up to 5,000 Bq $g^{-1}$. The database established in this study can be used for the accurate risk assessment of workers due to inhalation of airborne particles containing NORM. In addition, the findings can be used as a basic data for development of safety standard and guide and for practical radiation safety management at the facility.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.18 no.3
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• pp.224-238
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• 2008

The aim of this study is to confirm the physicochemical property and hazard of thinner (012), which is a diluent of enamel paint used for floor coating for waterproofing and oil painting for the outer wall. The literatures of physicochemical property and hazard of thinner were surveyed and its physicochemical property were evaluated. And then, the inhalation toxicity of thinner affecting the central nervous system and reproductive organs in rats were examined by subchronic (6 h./day. 5 days/ week for 13 weeks) inhalation test. 1) According to the 13-week subchronic inhalation test, there were no significant changes in clinical test and body weight. However, a significant evidence of toxicity was observed in the hematological test and organ weight such as heart, kidney, liver and brain (p<0.01) in the 200 ppm and 1,000 ppm exposure groups in a dose response manner. In the histopathology analysis, there were no significant evidence of toxicity. Therefore, thinner was not classified as an organ targeted toxic agent. In case of Harmfulness, it could be classified as a chronic toxic agent 3($500 ppm/4hr, rat). 2) The reproductive toxicity such as extension of the period of estrous cycle, reduction of serum estradiol concentration and increase of frequency of the abnormal sperm was observed in the 1,000 ppm exposed animals. 3) The result of the physicochemical property of the test material showed that the specific gravity was 0.793, boiling point $155.8^{\circ}C$, steam pressure 2.1 kPa, ignition point $34.5^{\circ}C$, and spontaneous ignition point $280^{\circ}C$. The endothermic and exothermic values were 371.4 J/g and 159.1 J/g. respectively. The explosion limit was 214 mg/l. These data showed that thinner could be classified as an explosion agent level 1.2 and ignitive liquid agent 3 ($23-60^{\circ}C$) according to the notification No. 2008-1 of the Labor Ministry, "Classifying Standard of Chemical Materials."

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.270-276
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• 1994

Background: The measurement of nonspecific bronchial hyperreactivity is valuable for diagnosis and management of bronchial asthma. Methacholine or histamine is used for the pharmacologic provocation test. Usually a methacholine bronchial provocation test is performed by a dosing technique with counted number of breaths. A dosimeter is indispensable in the dosing technique. Recently a timed tidal breathing technique which dose not need an expensive dosimeter was introduced. We measured the degree of nonspecific bronchial hyperreactivity to histamine using a simple timed tidal breathing technique. Method: Forty two healthy volunteers, 12 patients with bronchial asthma(BA), 10 patients with rhinitis(RH) and 10 patients with upper respiratory infection(URI) participated in the study. The subject's nose was clipped and inhalation continued during tidal breathing for 2 minutes via a face mask. $FEV_1$ was measured at 30 seconds, 90 seconds after inhalation and inhalation of next solution was continued until there was a fall in $FEV_1$ of 20%. Histamine PC20 was defined as the concentration at 20% fall of $FEV_1$ and it was obtained from the log dose-response curve by linear interpolation. Results: Inhalation of serial dilution of histamine could be performed in all patients without significant side effects. The geometric mean${\pm}$standard deviation of histamine PC20 in healthy volunteers is $8.27{\pm}2.22mg/ml$, BA group $0.33{\pm}3.02mg/ml$, RH group $0.85{\pm}3.24mg/ml$, and URI group $1.47{\pm}1.98mg/ml$. Conclusion: Histamine bronchial provocation test using timed tidal breath method is a simple and suitable tool for management of patients with bronchial hyperreactivity.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.132-135
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• 2004

In this study, we investigated the effect of threshold on a delivered dose in organ with internal motion by respiration. With mathematic model for 3D dose calculation reported by Lujan et al., we had calculated the position of organ as a function of time in previous study. This result presented that the variation of organ is within 2 mm from initial exhale position to the organ position during operating 1 s. Gating threshold, in this study, is determined to the moving region of target during 1s at a primary position of exhale. This period of gating threshold is 50% of the duty cycle in a half breathing cycle which is period from the top position of exhalation to the bottom position of inhalation. Radiation fields were then delivered under three conditions; 1) existent of moving target in the region of threshold(1sec, 1.5sec), 2) existent of moving target out of the region of threshold, 3) non-moving target. The non-moving target delivery represents a dose different induced due to internal organ motion.

• Nuclear Engineering and Technology
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• v.54 no.4
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• pp.1431-1438
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• 2022

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 93, 77, 92 and 938 Bq kg^-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y^-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10^-3, 4.26×10^-3, 0.62×10^-3, and 25.61×10^-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.235-238
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• 2006

Exogenous lipoid pneumonia (ELP) is an uncommon condition resulting from aspiration or inhalation of vegetable, animal or mineral oil. It results in foreign body type inflammatory reaction of the lung and can show various clinical presentations from asymptomatic incidental finding to severe pneumonia leading to acute respiratory failure. Although many cases have been reported, severe ELP requiring steroid or whole lung lavage for treatment is rare. We report a case of 51-year old man with esophageal cancer who developed severe ELP following ingestion of large dose shark oil (Squalene) and successfully treated with prednisolone.

• Journal of Veterinary Clinics
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• v.19 no.3
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• pp.333-336
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• 2002

This experiment was carried out to investigate the optimal dose of intravitreal gentamicin that decreases intraocular pressure effectively and minimizes complications in dog. After inhalation anesthesia, gentamicin was injected intravitreally into the left eyes at doses of 10, 15 and 20 mg with 1 mg dexamethasone, respectively. Sterilized isotonic saline and dexamethasone mixture into the right eyes for control. Six dogs were used in each group. Intraocular pressures were measured using applanation tonometer(Mentore, Tono-Pen) until 5 months after injection of gentamicin. Ocular examinations were performed using direct ophthalmoscopy. The ocular volumes of both eyes were measured. Intraocular pressures of eyes injected with 10. 15 and 20 mg of gentamicin were decreased significantly compared with control eyes. Severe corneal opacity and neovascularization occurred in 20 mg treated group. Intraocular hemorrhage was observed in 3 dogs of 20 mg treated group. Ocular volume was significantly decreased(p <0.05) in 20 mg treated group, compared with 10 and 15 mg treated group. It is considered that intravitreal gentamicin injection at dose of 10 mg or 15 mg decrease intraocular pressure effectively and minimize complications such as corneal opacity, hyphema and phthisis bulbus.

• Journal of Dental Anesthesia and Pain Medicine
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• v.16 no.3
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• pp.165-173
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• 2016

Dentists often sedate patients in order to reduce their dental phobia and stress during dental treatment. Sedatives are administered through various routes such as oral, inhalation, and intravenous routes. Intravenous administration has the advantage of rapid onset of action, predictable duration of action, and easy titration. Typically, midazolam, propofol or dexmedetomidine are used as intravenous sedatives. Administration of these sedatives via infusion by using a syringe pump is more effective and successful than infusing them as a bolus. However, during intravenous infusion of sedatives or opioids using a syringe pump, fatal accidents may occur due to the clinician's carelessness. To prevent such risks, smart syringe pumps have been introduced clinically. They allow clinicians to perform effective sedation by using a computer to control the dose of the drug being infused. To ensure patient safety, various alarm features along with a drug library, which provides drug information and prevents excessive infusion by limiting the dose, have been added to smart pumps. In addition, programmed infusion systems and target-controlled infusion systems have also been developed to enable effective administration of sedatives. Patient-controlled infusion, which allows a patient to control his/her level of sedation through self-infusion, has also been developed. Safer and more successful sedation may be achieved by fully utilizing these new features of the smart pump.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.302-311
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• 2018

BACKGROUND: Dithianon (75%) formulation were mixed and sprayed as closely as possible by normal practice on the ten farms located in the Mungeong of South Korea. Patches, cotton gloves, socks, masks, and XAD-2 resin were used for measurement of the potential exposure of dithianon on the applicators wearing standardized whole-body outer and inner dosimeter (WBD). This study has been carried out to determine the dermal and inhalation exposure to dithianon during preparation of spray suspension and application with a power sprayer on a apple orchard. METHODS AND RESULTS: A personal air monitor equipped with an air pump, IOM sampler and cassette, and glass fiber filter was used for inhalation exposure. The field studies were carried out in a apple orchard. The temperature and relative humidity were monitored with a thermometer and a hygrometer. Wind speed was measured using a pocket weather meter. All mean field fortification recoveries were between 85.1% and 99.1% in the level of 100 LOQ (limit of quantification), while the LOQ for dithianon was $0.05{\mu}g/mL$ using HPLC-DAD. The exposure to dithianon on arms of the mixer/loader (0.0794 mg) was higher than other body parts (head, hands, upper body, or legs). The exposure to dithianon on the applicator's legs (3.78 mg) was highest in the body parts. The dermal exposures for mixer/loader and applicator were 10 and 8.10 mg, respectively, from a grape orchard. The inhalation exposure during application was estimated as 0.151 mg, and the ratio of inhalation exposure was 11.2% of the dermal exposure (inner clothes). CONCLUSION: The dermal and inhalation exposure on the applicator appeared to be 4.203 mg - 25.064 mg and $0.529{\mu}g-116.241{\mu}g$, respectively. The total exposures on the agricultural applicators were at the level of 2.596 mg - 25.069 mg to dithianon during treatment for apple orchard. The TER showed 3.421 (>1) when AOEL of dithianon was used as a reference dose for the purpose of risk assessment of the mixing/loading and application.