• The korean journal of orthodontics
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• v.53 no.5
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• pp.298-306
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• 2023

Objective: Pain following the insertion of separators and archwires varies with age, sex, race, ethnicity, threshold, and health status. This study aimed to evaluate the characteristics of pain in orthodontic patients after the insertion of elastomeric separators, its effects on daily life, and its association with age and sex in a population not previously studied in this regard. Methods: A cross-sectional study of 130 patients undergoing orthodontic treatment included collecting data on demographics, pain experienced following the placement of separators, time of onset, duration, characteristics, change in dietary pattern or chewing side, intake of analgesics, and severity of pain on the Wong Baker's scale. The results are reported as counts and percentages. Associations between sex and age were evaluated using Pearson's chi-square test. Results: Among the 130 patients, 56.2% were 9-20 years old, 63.8% experienced pain following the insertion of separators, 22.9% had their first episode of pain at 4 hours, 56.6% experienced intermittent pain, and 37.3% experienced discomfort; 18.1% males and 81.9% females experienced pain following the insertion of separators. Pearson's chi-square test showed a significant association between pain and sex (P = 0.04). Most patients (37.3%) reported "hurts little more" for pain intensity on Wong Baker's scale and 21.7% reported all four quadrants as sites of pain. Conclusions: The pain experienced after separator insertion was associated with sex and age. Females experienced more pain than males and patients between the age range of 21 and 36 years suffered more pain during mastication than between 9 and 20 years old.

• Korean Circulation Journal
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• v.53 no.9
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• pp.635-644
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• 2023

Background and Objectives: The History, Electrocardiography, Age, Risk factors, and Troponin (HEART) pathway was developed to identify patients at low risk of a major adverse cardiac event (MACE) among patients presenting with chest pain to the emergency department. Methods: We modified the HEART pathway by replacing the Korean cut-off of 25 kg/m² with the conventional threshold of 30 kg/m² in the definition of obesity among risk factors. The primary outcome was a MACE within 30 days, which included acute myocardial infarction, primary coronary intervention, coronary artery bypass grafting, and all-cause death. Results: Of the 1,304 patients prospectively enrolled, MACE occurred in 320 (24.5%). The modified HEART pathway identified 37.3% of patients as low-risk compared with 38.3% using the HEART pathway. Of the 500 patients classified as low-risk with HEART pathway, 8 (1.6%) experienced MACE, and of the 486 low-risk patients with modified HEART pathway, 4 (0.8%) experienced MACE. The modified HEART pathway had a sensitivity of 98.8%, a negative predictive value (NPV) of 99.2%, a specificity of 49.0%, and a positive predictive value (PPV) of 38.6%, compared with the original HEART pathway, with a sensitivity of 97.5%, a NPV of 98.4%, a specificity of 50.0%, and a PPV of 38.8%. Conclusions: When applied to Korean population, modified HEART pathway could identify patients safe for early discharge more accurately by using body mass index cut-off levels suggested for Koreans.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.315-323
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• 2023

The brassica leaf beetle, Phaedon brassicae Baly (Coleoptera: Chrysomelidae), is one of the important pests infesting cruciferous vegetables. In order to understand the biological characteristics of the insect, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of P. brassicae at four constant temperatures of 15, 20, 25 and 27.5℃ for immature life stage and five constant different temperatures of 10, 15, 20, 25 and 27.5℃ for adult stage. Eggs and larvae successfully developed next life stage at temperature tested. The development period of egg, larva, and pupa decreased as temperature increased. Lower developmental threshold (LDT) and thermal constant (K) were calculated using linear regression as 8.7℃ and 344.73DD, respectively. Lower and higher threshold temperature (TL and TH) from egg to adult emergence were estimated by Briere function as 5.3℃ and 40.4℃, respectively. Adults produced eggs at the temperature range between 10℃ and 27.5℃, and showed an estimated maximum number, ca. 627.5 eggs at 21.7℃. Adult oviposition models including aging rate, age-specific survival rate, age-specific cumulative oviposition, and temperature-dependent fecundity were constructed. Temperature-dependent development models and adult oviposition models would be useful components to understand the population dynamics of P. brassicae and to establish the strategy of integrated pest management in cruciferous crops.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.235-245
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• 2011

Temperature-related parameters of Panonychus citri (McGregor) (Acarina: Tetranychidae) development were estimated and a stage-structured matrix model was developed. The lower threshold temperatures were estimated as $8.4^{\circ}C$ for eggs, $9.9^{\circ}C$ for larvae, $9.2^{\circ}C$ for protonymphs, and $10.9^{\circ}C$ for deutonymphs. Thermal constants were 113.6, 29.1, 29.8, and 33.4 degree days for eggs, larvae, protonymphs, and deutonymphs, respectively. Non-linear development models were established for each stage of P. citri. In addition, temperature-dependent total fecundity, age-specific oviposition rate, and age-specific survival rate models were developed for the construction of an oviposition model. P. citri age was categorized into five stages to construct a matrix model: eggs, larvae, protonymphs, deutonymphs and adults. For the elements in the projection matrix, transition probabilities from an age class to the next age class or the probabilities of remaining in an age class were obtained from development rate function of each stage (age classes). Also, the fecundity coefficients of adult population were expressed as the products of adult longevity completion rate (1/longevity) by temperature-dependent total fecundity. To evaluate the predictability of the matrix model, model outputs were compared with actual field data in a cool early season and hot mid to late season in 2004. The model outputs closely matched the actual field patterns within 30 d after the model was run in both the early and mid to late seasons. Therefore, the developed matrix model can be used to estimate the population density of P. citri for a period of 30 d in citrus orchards.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.269-274
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• 2006

Temperature-dependent development studies of two aphid species, A. egomae and A. gossypii occurring in green perilla greenhouse were conducted at $15{\sim}35^{\circ}C$, and 16:8 (L:D h) of light period in the laboratory. The mortality of two aphid species was high in young stages (1st and 2nd). In A. egomae, the mortalitiy increased with increasing and decreasing temperature: the mortalitie at $15^{\circ}C$ and $35^{\circ}C$ were 22.3% and 15.6%, respectively. While the mortalities of A. gossypii increased with increasing temperature: the mortality at $35^{\circ}C$ was 50.0%. The developmental periods of A. egomae and A. gossypii ranged from 20.8days to 5.4days and from 22.6days to 9.1days at $15^{\circ}C$ to $30^{\circ}C$ of temperature resion, respectively, and were 7.2days and 10.7days at $35^{\circ}C$ for each species. The lower developmental threshold temperatures for total nymphs of A. egoame and A. gossypii were $9.9^{\circ}C$ and $4.9^{\circ}C$, respectively and an effective degree-days (DD) for the developmental completion of total nymph were 108.0 DD for.A. egomae and 221.2DD for A. gossypii. In green perilla greenhouse, the occurrence period of A. gossypii was earlier about 15 days than that of A. egomae. When the occurrence period of two aphid species was estimated by degree-days based on lower threshold temperatures, A. gossypii occurred earlier than A. egomae in the field. A. gossypii occurred from early April and showed dominant position to late May compared with A. egomae Whereas, A egomae started to occur from mid April and then were abundant after late May followed by abrupt population crash around late July.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.328-333
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• 1998

To obtain basic information for establishing a pest control strategy for insect pest management system, changes in the population densities of the black-tipped sawfly(Acantholyda posticalis posticalis Matsumura) and damage patterns in tree growth were investigated in national forests in Hoigok-ri, Kapyung-gun, Kyunggi-do, where the pest control measures were taken. The results obtained were as follows ; 1. The larval density in the soil of the forests where the insecticides were applied have been kept below economic threshold for about 7 years. The density was the highest in the middle of slopes and similar to the level of the early stage of the insect outbreak. 2. After the pest control by insecticides, reduction in tree height and diameter growth lasted for 2-3 years in trees defoliated by over 70%. 3. The diameter growth of the trees damaged by black-tipped sawfly recovered faster in upper stem than in the lower. 4. volume growth of the trees defoliated over 70% by the insect decreased for three to four years. The volume loss of trees defoliated by 70% and 90% was 19.6% and 54.0%, respectively. 5. Maintaining the rate of defoliation below 50%, which is the economic threshold, by chemical control measures had an effect of reducing the tree volume loss by $40m^2/ha$ as compared with a stand defoliated by 90%.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.241-247
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• 2015

This study has been conducted to verify the applicability of FT-NIR (Fourier Transform Near Infrared) to prove coidentity between market agrochemical products and registered prescriptions. The spectrum correlations were investigated on 83 registered samples and there market products, 23 products which had same formulation and active ingredients and 68 products which had different active ingredients. In 83 samples/products, the primary differentiated spectrum correlation values were 95.86~100%, which mean that all samples qualified over 95% threshold. In 23 products which had same active ingredients and formulations, correlation values were 29.09~99.83%. 3 products over 99.0% were proved to have same active/inert ingredients and formulations although they're from different manufacturers. The rest products except the 3 items were under 95%. In 68 products had different active ingredients, correlation values varied from 2.00% to 93.70%. Higher correlation is supposed to come from similarity of inert ingredients despite different active ingredients. They can be decided to unqualify under 95% threshold. So applicability of FT-NIR has been verified on qualitative distinction of coidentity between registered market agrochemicals.

• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.137-146
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• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Korean Journal of Radiology
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• v.2 no.1
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• pp.28-36
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• 2001

Objective: To provide a systematic overview of the effects of various parameters on contrast enhancement within the same population, an animal experiment as well as a computer-aided simulation study was performed. Materials and Methods: In an animal experiment, single-level dynamic CT through the liver was performed at 5-second intervals just after the injection of contrast medium for 3 minutes. Combinations of three different amounts (1, 2, 3 mL/kg), concentrations (150, 200, 300 mgI/mL), and injection rates (0.5, 1, 2 mL/sec) were used. The CT number of the aorta (A), portal vein (P) and liver (L) was measured in each image, and time-attenuation curves for A, P and L were thus obtained. The degree of maximum enhancement (Imax) and time to reach peak enhancement (Tmax) of A, P and L were determined, and times to equilibrium (Teq) were analyzed. In the computed-aided simulation model, a program based on the amount, flow, and diffusion coefficient of body fluid in various compartments of the human body was designed. The input variables were the concentrations, volumes and injection rates of the contrast media used. The program generated the time-attenuation curves of A, P and L, as well as liver-to-hepatocellular carcinoma (HCC) contrast curves. On each curve, we calculated and plotted the optimal temporal window (time period above the lower threshold, which in this experiment was 10 Hounsfield units), the total area under the curve above the lower threshold, and the area within the optimal range. Results: A. Animal Experiment: At a given concentration and injection rate, an increased volume of contrast medium led to increases in Imax A, P and L. In addition, Tmax A, P, L and Teq were prolonged in parallel with increases in injection time The time-attenuation curve shifted upward and to the right. For a given volume and injection rate, an increased concentration of contrast medium increased the degree of aortic, portal and hepatic enhancement, though Tmax A, P and L remained the same. The time-attenuation curve shifted upward. For a given volume and concentration of contrast medium, changes in the injection rate had a prominent effect on aortic enhancement, and that of the portal vein and hepatic parenchyma also showed some increase, though the effect was less prominent. A increased in the rate of contrast injection led to shifting of the time enhancement curve to the left and upward. B. Computer Simulation: At a faster injection rate, there was minimal change in the degree of hepatic attenuation, though the duration of the optimal temporal window decreased. The area between 10 and 30 HU was greatest when contrast media was delivered at a rate of 2 3 mL/sec. Although the total area under the curve increased in proportion to the injection rate, most of this increase was above the upper threshould and thus the temporal window was narrow and the optimal area decreased. Conclusion: Increases in volume, concentration and injection rate all resulted in improved arterial enhancement. If cost was disregarded, increasing the injection volume was the most reliable way of obtaining good quality enhancement. The optimal way of delivering a given amount of contrast medium can be calculated using a computer-based mathematical model.

• Journal of Sericultural and Entomological Science
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• v.52 no.1
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• pp.33-38
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• 2014

This studies by treatment of 25 individual adults of O. laevigatus and Banker plant with different number of eggs of O. laevigatus were conducted to develop new biological control of the western flower thrips (WFT) in chrysanthemum house. In this work, a treatment of 25 individual adults of O. laevigatus, Banker plant with different number of eggs of O. laevigatus and mixed treatment were applied. Initial WFT density per plant were 5 individuals. WFT density was measured every 7days after treatment for 7 weeks. Biological control of WFT by 25 individual adults of O. laevigatus and Banker plant with 25 eggs of O. laevigatus were applied 1 time and resulted in the high control value of thrips 91.8%. The population of WFT was kept under the economic threshold level (1 individual per plant). For the last three years we developed new banker plant system. This system is being developed to improve biological control of WFT on chrysanthemums.