• Safety and Health at Work
• /
• v.2 no.4
• /
• pp.365-374
• /
• 2011

Objectives: This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance. Methods: The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared. Results: There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-${\alpha}$, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs exposure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530). Conclusion: This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.65 no.7
• /
• pp.1186-1192
• /
• 2016

This paper proposes techniques to diagnose short-circuit faults of both the diodes and power FET in switching mode power supply (SMPS) by using a simple analog tester. The diodes in full-bridge rectifier, power FET, switching transformer, and some sensors are modelled with resistor. The total resistance value measured at the input terminal of a SMPS is analyzed when the short-circuit faults of diodes in a full bridge rectifier or power FET are occurred. The short-circuit faults of one or two diodes in a full bridge rectifier, power FET, and both the diodes in a full bridge rectifier and power FET can be detected by a range of total resistance, which is measured by the analog tester. Through experiments, the theoretical analysis for total resistance under short-circuit faults can be verified.

• International Journal of Internet, Broadcasting and Communication
• /
• v.16 no.1
• /
• pp.148-155
• /
• 2024

We are designed was to find an efficient warm-up method for resistance training for muscle hypertrophy, and 10 males with at least 3 years of resistance training experience were selected as subjects. The 75% 1RM was measured directly based on the pre-measured bench press 1RM. After that, the main experiment of 75% 1RM bench press according to the three warm-up methods was conducted one week apart, and all experiments were randomized and cross-over. Performance according to the warm-up method (3) was measured by total exercise volume, and physiological changes were determined by myocardial workload. All post-measurement data were analyzed using SPSS.22.0 and analyzed using repeated measures one-way ANOVA and contrast comparisons were made using the deviation method. The results showed that the method of gradually increasing the number of repetitions by performing the same intensity as the intensity of the main exercise in the form of muscle hypertrophy, but at submaximal repetitions, showed the highest performance.

• Parasites, Hosts and Diseases
• /
• v.37 no.1
• /
• pp.33-37
• /
• 1999

An age-dependent aspect of resistance to Cryptosporidium muris (strain MCR) infection was monitored in Syrian golden hamsters. Mesocricetus auratus. at 1-, 5- and 10-week of age and in ICR mice, Mus musculus, at 3-, 12-, and 15-week of age orally inoculated with a single dose of $2{\times}10^6$ oocysts. respectively. The prepatent periods for both animals were similar, independent of age, but the patency was significantly longer in younger hamsters (P<0.001) and a long tendency in younger mice. Hamsters infected at 1-week of age excreted about 10 times higher oocysts than those at 5- and 10-week of age. However, the total oocyst output was similar among mice of different ages. There was a good correlation between the length of the patency and the total oocyst output in hamsters (R=0.9646), but not in mice (R=0.456l). The immunogenicity of the parasite to homologous challenge infections was very strong in hamsters and relatively strong in mice. These results indicate that acquired resistance to C. muris infection is age-related and the innate resistance is independent of age of hamsters, and that both innate and acquired resistance, on the contrary, are irrespective of age of mice.

• Korean Journal of Veterinary Research
• /
• v.45 no.2
• /
• pp.179-183
• /
• 2005

Epidemiological characteristics of a total of 48 swine herd with diarrhea or a history of diarrhea in Gyeongsang-do between 1999 and 2000 were performed to evaluate the prevalence of Salmonella spp., their serotypes and antibiotic resistance patterns with respect to the different stages of swine production system. A total of 139 Salmonella spp. (21%) were isolated from 662 fecal samples and the overall herd prevalence of Salmonella spp. ranged from 12.5% to 88%. The average prevalence of Salmonella spp. from swine stages of suckling/nursery, grow/finisher and sow stage were 25.7%, 19.2% and 18.4%, respectively. Ten serotypes of Salmonella spp. were identified with a predominance of S. Typhimurium, S. Derby and S. Agona. Twenty-five isolates (18%) were found to be untypable. One hundred and two Salmonella isolates (73.4%) resistant to more than 1 antibiotic were characterized by 24 diverse resistance patterns, and their frequency of antibiotic resistance was highest in grow/finisher stage (83.3%). Resistance to tetracycline (TE; 67.6%), sulfamethoxazole (SU; 46.8%) and streptomycin (ST; 28%) was most common and the most common resistance patterns were TE SU (31.4%), TE (21.6%) and TE SU ST (20.6%) in order.

• Journal of Nutrition and Health
• /
• v.38 no.7
• /
• pp.553-560
• /
• 2005

The purpose of this study was to examine the lipid peroxidation, plasma antioxidant status and insulin resistance in childhood obesity. To this end, we measured blood lipid profiles, glucose, insulin concentrations, plasma antioxidant vitamins, baseline conjugated diene formation as a measure of LDL oxidation in vivo and TRAP (total radical trapping antioxidant potential) of 93 school children (58 nonobese, 35 overweight-obese). Insulin resistance was estimated by homeostasis model assessment of insulin resistance (HOMA-IR). The overweight-obese children showed significantly higher levels of leptin (p < 0.0001) and triglyceride (p < 0.05) and significantly lower level of plasma Iycopene (p < 0.001) and $\gamma$-tocopherol (p < 0.05) compared with the normal weight children. Furthermore, the levels of TRAP were significantly lower in overweight-obese children (p < 0.05). Significant positive relationships between plasma leptin and conjugated dienes formation (p < 0.005) and inverse relationship between plasma leptin and lipid corrected levels of $\beta$-carotene (p < 0.05), Iycopene (p < 0.05) were observed. Our results showed an increased lipid peroxidation and decreased antioxidant capacity in childhood obesity which could be involved in the atherosclerotic process.

• The Journal of Korean Physical Therapy
• /
• v.36 no.1
• /
• pp.27-32
• /
• 2024

Purpose: This study was conducted to verify the effect of applying a pressure biofeedback unit on walking ability and knee joint function while performing knee joint extensor strengthening exercises using resistance exercise equipment in total knee replacement (TKR) patients. Methods: This study was conducted on twelve patients receiving rehabilitation treatment after being admitted to a rehabilitation hospital post-TKR. Of these, six were allocated to a feedback group with a pressure biofeedback unit, and the other 6 were allocated to a control group without a pressure biofeedback unit. The subjects performed an exercise program for 45 minutes per session, five times a week, for two weeks. Walking ability and knee joint function were evaluated and analyzed before and after exercise. Results: The feedback group showed significantly better improvements in walking speed, gait cycle, step length on the non-operation side, time on the foot on the operation side, K-WOMAC stiffness, and K-WOMAC function than the control group (p<0.05). Conclusion: When strengthening the knee joint extensor muscles using resistance exercise equipment in TKR patients, the provision of a pressure biofeedback unit was found to improve walking ability and knee joint function by inducing concentric-eccentric contraction of the knee joint extensor muscles. Therefore, the study shows that exercise based on the provision of a pressure biofeedback unit should be considered when strengthening knee joint extensor muscles to improve the walking ability and knee joint function of TKR patients in clinical practice.

• Journal of the Korean Society of Safety
• /
• v.33 no.6
• /
• pp.22-27
• /
• 2018

Fire fighters are exposed to the risk of many accidents during fire suppression, especially near the high voltage circuit. In order to prevent and analyze the electric shock accidents, measurement of water resistance is crucial. However, this has been one of the overlooked research areas and it has been very difficult to measure the mixed up resistance components separately. In this paper, we measured a total resistance of apparatus and regarded it as a serial resistance of contact resistance and length dependant resistance. Measuring the resistance by varying the length of water stream, the variable resistance and fixed contact resistance appear, which are used to calculate the both components of resistances. In addition, the resistance of fire hose can be calculated from the parallel circuit which is formed by grounding the fire hose with the resistance of water stream. Results show that we can successfully measure the resistance per unit length of water stream and fire hose, thereby proving that this method is a facile way to measure water and fire hose resistance. However, many experiments are still required to obtain the precise contact resistance of ground under various condition and the resistance between the human body and fire hose.

• The Plant Pathology Journal
• /
• v.24 no.4
• /
• pp.433-438
• /
• 2008

Potato virus X (PVX) resistance in potato is one of the best-characterized resistance models, however little is known in pepper. To evaluate the resistance to PVX in Capsicum annuum, a total of eleven pepper accessions were used for resistance screening against two PVX strains, USA and UK3. None of them were resistant against strain UK3, whereas four resistant genotypes were found against strain USA, three of which were further characterized. Two unlinked dominant genes were identified for both genotypes Bukang and Perennial; resistance in the genotype CV3 seemed to be conferred by two complementary dominant genes. These results demonstrated that the resistance to PVX in C. annuum is different from that in potato. This is the first report on genetic analysis of PVX resistance in C. annuum.

• Journal of Ship and Ocean Technology
• /
• v.1 no.2
• /
• pp.1-10
• /
• 1997

The prediction of the total resistance of a ship is generally based on considering it to be a simple sum of the viscous resistance and the wave resistance. An experimental approach for predicting full-size ship resistance on this basis is practical but obviously has the deficiency that a model has to be built for each prototype of interest and the resulting tank tests are time consuming. On the other hand, purely theoretical calculations of the wave resistance, using, for example, the Michell theory, require relatively little computer time and give an excellent portrayal of the overall variation of the vessel resistance as a function of forward speed. Unfortunately, there are sufficient differences between this theory and the measured results to make this method impractical for design purposes. The proposal examined here is to use a data bank of experimental resistance results to modify the theoretical predictions. It is demonstrated that the technique will produce remarkably accurate resistance predictions and can take into account the effects of the water depth, any restriction of canal or river width, as well as the prismatic coefficient, and other geometric parameters.