• Journal of the Korea Society of Computer and Information
• /
• v.24 no.3
• /
• pp.175-179
• /
• 2019

This study is a descriptive research of paramedic students who could be exposed to blood and body fluids during the clinical practicum to analyze the risk factors. From June 1 to June 30, 2018, 172 paramedic students who attended the University in Jeolla-do region were analyzed. The collected data were analyzed by using the SPSS WIN 21.0 program. The general characteristics of subjects, the exposure level of blood and body fluids, and etc were obtained for frequency and percentage analysis. The study found that 72.7 percent of students had experience to blood or body fluids exposure during the clinical practicum. Except for any needle injury, 70.4 percent of student were exposed to blood or body fluids. 28.8 percent of them which was the highest percentage of injection injury were exposed during the venous blood draw. 36.5 percent of exposure were related to wound dressings which was the highest percentage related to clinical procedures. 71.2 percent of students mentioned that they did not report this exposure because 68.5 percent students thought that it has no danger. According to the survey on hepatitis B, 50.6% of students had antibodies, but 31.8 percent of students did not confirm that the antibodies were formed. Even though paramedic students do practical training in a hazardous environment with repeated exposure to blood and body fluids due to the nature of job characteristics, the systemic infection control education program is insufficient. In order to prevent exposure and to protect paramedic students who do practical training with patients, it is necessary to make more systematic and active efforts in the continuous monitoring and the preventive education.

• Journal of the Korean Data Analysis Society
• /
• v.20 no.6
• /
• pp.2841-2852
• /
• 2018

This study examines regression modeling method using zero-inflated distribution in relation to estimation of exposure distribution required in advertisement media planning. Exposure distribution is the percentage of audiences that are exposed each time the ad is repeated. Such an exposure distribution plays a very important role in providing basic information necessary for calculating various indicators for quantitatively measuring the advertising effect. Especially, due to the decrease of advertising price and the spread of various media, the frequency of the advertisement or the broadcasting of specific advertisements has been greatly increased compared to the past. As a result, the frequency of exposure is relatively decreasing. In this situation, the number of individuals who are not exposed to the media, that is, are not exposed to advertising structurally is increasing. This research proposes advertising exposure distribution models using a zero-inflated regression model, and conducts a comparative study using actual cases.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.32 no.3
• /
• pp.253-267
• /
• 2022

Objectives: This study was performed to check whether the CRS (Chemical Ranking and Scoring) system is appropriate as a method to determine substances as candidates for substances subject to permission and to apply this system to the selection of candidates for substances subject to permission. Methods: A risk score was obtained by multiplying the hazard score and the exposure score and then ranking them. The hazard sub-indicators are carcinogenicity, germ cell mutagenicity, reproductive toxicity, specific target organ toxicity-repeated exposure, respiratory sensitization and endocrine disrupting chemicals. Exposure sub-indicators are persistence, bioaccumulation and emission volume. Sensitivity analysis was performed for missing values. Correlation analysis and multivariable linear regression analysis were performed among hazard, exposure and risk in order to confirm that CRS was an appropriate method. Results: As a result of the sensitivity analysis on missing values, it was confirmed that the effect on the risk ranking was not sensitive. Correlation and regression analysis confirmed that exposure had a greater effect on risk than hazard. Conclusions: The CRS system, which derives a risk score using a hazard and exposure score, is judged to be appropriate as a method for the selection of preliminary of candidates for substances subject to permission. Benzene, cadmium, nickel, and cobalt were selected as priority candidates for substances subject to permission.

• The Korean Journal of Physiology and Pharmacology
• /
• v.12 no.3
• /
• pp.117-123
• /
• 2008

Although growth associated protein-43 (GAP-43) is known to playa significant role in the regulation of axonal growth and the formation of new neuronal connections in the hippocampus, there is only a few studies on the effects of acute stress on GAP-43 mRNA expression in the hippocampus. Moreover, the effects of repeated citalopram treatment on chronic mild stress (CMS)-induced changes in GAP-43 mRNA expression in the hippocampus have not been explored before. To explore this question, male rats were exposed to acute immobilization stress or CMS. Also, citalopram was given prior to stress everyday during CMS procedures. Acute immobilization stress significantly increased GAP-43 mRNA expression in all subfields of the hippocampus, while CMS significantly decreased GAP-43 mRNA expression in the dentate granule cell layer (GCL). Repeated citalopram treatment decreased GAP-43 mRNA expression in the GCL compared with unstressed controls, but this decrease was not further potentiated by CMS exposure. Similar decreases in GAP-43 mRNA expression were observed in CA1, CA3 and CA4 areas of the hippocampus only after repeated citalopram treatment in CMS-exposed rats. This result indicates that GAP-43 mRNA expression in the hippocampus may differently respond to acute and chronic stress, and that repeated citalopram treatment does not change CMS-induced decreases in GAP-43 mRNA expression in the GCL.

• Toxicological Research
• /
• v.20 no.2
• /
• pp.143-151
• /
• 2004

This study was to investigate single and repeated-dose toxicities of CJ-11555, an anticirrhotic agent, in Sprague-Dawley (SO) rats. In single-dose oral toxicity study, the test article were administered once by gavage to males and females at dose levels of 0 and 2,000 mg/kg. No dead animals and abnormal necropsy findings were found in control and CJ-11555 treated group. Therefore, the approximate lethal dose of CJ-11555 was considered to be higher than 2,000 mg/kg in rats. In the 4-week repeated oral toxicity study, the test article was administered once daily by gavage to male and female rats at dose levels of 0, 10, 50 and 200 mg/kg/day for 4-weeks. In clinical signs, yellow-colored urine and yellow hair coat were observed in the 50 and 200 mg/kg male and female groups. In hematology, erythrocyte count and hemoglobin were significantly decreased in the 200mg/kg male and female groups. In serum biochemistry, total cholesterol was significantly increased and aspartate aminotransferase (AST) was significantly decreased in the 50 or 200 mg/kg male and female groups. In histopathological examinations, centrilobular hepatocellular hypertrophy in the liver, congestion and pigmentation in the spleen, hyaline droplets in the kidney were observed in the 50 and 200 mg/kg male and female groups. In toxicokinetic study, CJ-11555 was dose-dependent in systemic exposure and showed better absorption in female with minimum accumulation after multidosing. Based on these results, it was concluded that the 4-week repeated oral dose of CJ-11555 resulted in the suppression of AST activity and centrilobular hepatocellular hypertrophy in both sexes at a dose level of 50 or 200 mg/kg/day. The target organ was estimated to be liver, spleen and male's kidney. The no-observed-adverse-effect level (NOAEL) for CJ-11555 in rats following gavage for at least 4-week is 10 mg/kg/day.

• Biomolecules & Therapeutics
• /
• v.19 no.1
• /
• pp.45-51
• /
• 2011

These experiments were designed to use typical makers from behaviors and molecular basis in addicted animals of morphine and cocaine. Morphine has been widely abused with a high physical dependence liability. Morphine withdrawal activates the intracellular cAMP signaling pathway and further leads to changes in the expression of the cAMP response element binding protein (CREB), which may be important to the development and expression of morphine dependence. From these experiments, repeated morphine (10 mg/kg, twice per day for 7 days) developed physical dependence. Withdrawal signs were precipitated by naloxone and also increased the expression of the CREB. In addition, repeated exposure of cocaine (15 mg/kg) to mice develops locomotor sensitization and produced lasting behavioral sensitivity. Cocaine- and amphetamine-regulated transcript peptide (CART) peptide was up-regulated by repeated administration of cocaine in the striatum. Therefore, repeated morphine induced the development of physical dependence and increased pCREB. In addition, repeated cocaine induced locomotor sensitization and over-expressed CART peptide. In conclusion, the development of physical dependence and pCREB for morphine, and locomotor sensitization and CART peptide over-expression for cocaine would be useful markers to predict the abuse potential of opioid analgesics and pychostimulant drugs in animals, respectively.

• Environmental Analysis Health and Toxicology
• /
• v.16 no.4
• /
• pp.211-221
• /
• 2001

The purpose of this study was to investigate the acute (4 hours) and repeated-dose (6 hours a day, 5 days a week, 4 weeks) toxic effects of 1-hexene on Sprague-Dawley (SD) rats which were treated by inhalation. The results were as follows; 1. The median lethal concentration(LC$_{50}$) was estimated 52,694 ppm (confidence limit 95％; 49,494~55,447 ppm) in acute inhalation. Abnormal clinical signs related to the 1-Hexene were not observed with the acute inhalation dose. Cross findings of necropsy revealed on evidence of specific toxicity related to the 1-hexene. II. By repeated inhalation exposure the body weight of male were more or less reduced by the dose of 2,500 ppm and 5,000 ppm compared with control group. However there were no significant variation hematology and blood biochemistry for the exposed rats compared with the control rats. Abnormal clinical signs and gross findings of necropsy related to the 1-hexene were not shown. In conclusion when we exposed 1-hexene to SD rats for 4 weeks, 5 days per week, 6 hours per day, the Lowest observed effect level (LOEL) was over 2,500 ppm and Non observed effect level (NOEL) was below 500 ppm.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.10a
• /
• pp.83-87
• /
• 2002

Aerospace industries are widely using honeycomb sandwich structures that it has high specific strength and stiffness, chemical material resistance and fatigue resistance. But, in repairing process of damaged areas, one of the problems is that delamination can be occurred in the sound areas during and/or after the exposure to the elevated curing temperature in case that the repair process is repeated. Therefore, this study was conducted Flatwise tensile, Drum peel and Long beam flexural strength tests to evaluate the degree of degradation of mechanical properties of the honeycomb sandwich structures by affecting thermal aging. As the results, the decrease of mechanical strength was observed at the specific specimen which is exposed over 50hrs at $127^{\circ}C$.

• Korean Journal of Occupational Health Nursing
• /
• v.30 no.3
• /
• pp.132-143
• /
• 2021

Purpose: The study aimed to explore experiences of the posttraumatic growth (PTG) in firefighters with repeated exposure to traumatic events. Methods: Participants were 11 firefighters from two fire departments, who had experienced more than one critical trauma events. Data were collected through personal interviews from August to October 2020 and analyzed by Colaizzi's phenomenological methods. Results: The PTG experiences were derived into four categories: 'growth in self-perception', 'rediscovery of the meaning of life', 'deep interpersonal relationships', and 'discovery of the meaning of work'. Conclusion: These findings could be used as basic information for developing PTG program for firefighters such as logo-therapy, semantic therapy, and self-disclosure intervention using expressive writing and speaking.

• Toxicological Research
• /
• v.23 no.4
• /
• pp.391-403
• /
• 2007

The study was conducted to assess the repeated dose and reproduction and developmental toxicities of acetanilide, an intermediate for drug production, as a part of OECD Screening Information Data Set (SIDS) program. The test agent was administered by gavage at dose levels of 0, 22, 67, 200 and 600 mg/kg to Sprague-Dawley rats (12/group/sex) during pre-mating and mating period for males(up to 30 days) and females and pregnancy and early lactation period for females (up to 39-50 days). At 22 mg/kg, decreases in HGB, HCT (males) and MCHC (females), hyperplasia of spleen red pulp, hyperplasia of femur bone marrow (both sexes) were observed. At 67 mg/kg, salivation (males), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and MCHC (males), increases in MCV (males) and spleen weight (males), hyperplasia of spleen red pulp and femur bone marrow (both sexes) were observed. At 200 mg/kg, decreases in locomotor activity and salivation (both sexes), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and increases in MCV, MCH, BUN, T-BIL (males), enlargement of spleen (both sexes), increased weight of spleen (males), hyperplasia of spleen red pulp and femur bone marrow and extramedullary hematopoiesis of liver (both sexes), atrophy of thymus and corpus luteum hyperplasia of ovary (females) were observed. At 600 mg/kg, decreases in locomotor activity, cyanosis (both sexes), reddish tear, and salivation (males), mortality (4 out of 12 females), decreased body weight (females), reduced food consumption (both sexes), decreases in RBC, HGB, HCT and MCHC and increases in WBC, MCV, MCH, reticulocyte, neutrophil, lymphocyte, monocyte, AST, ALT, BUN, T-BIL, ALB, Ca and A/G ratio (males), enlargement of spleen, increased weights of spleen (both sexes), liver (males), kidney and ovary, decreased weights of thymus (females), hyperplasia of spleen red pulp, hyperplasia of femur bone marrow and extramedullary hematopoiesis of liver (both sexes), and atrophy of thymus and corpus luteum hyperplasia of ovary (females) were observed. Regarding the reproduction and development toxicities, there were no treatment-related changes in precoital time, mating index, fertility index and pregnancy index at all doses tested. At 22 and 67 mg/kg, there were no adverse effects on all the parameters observed. At 200 mg/ kg, decreased body weight of pups (day 4 p.p.) were observed. At 600 mg/kg, decreased body weight of pups (day 0 and 4 p.p.) and viability index (day 4 p.p.), increased incidence of newborns dead or with abnormal clinical signs were observed. The results suggest that the NOAELs for general toxicity are < 22 mg/kg, LOAELs are 22 mg/kg and the NOAELs for reproductive toxicity are 67 mg/kg.