• Korean Journal of Veterinary Pathology
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• v.5 no.1
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• pp.9-16
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• 2001

To investigate the effects of safflower seed supplementation diet on the hepatic injury of rats administered with carbon tetrachloride (CCI$_4$), histopathological changes were assessed following acute and chronic administration in rats. In acute cases, all rats in group fed with 10% safflower seed supplementation diet survived despite the administration of lethal doses of $CCl_4$. However, most rats in group fed with control diet died. The hepatic injuries of survived rats, in the histopathological findings, were mild compared to those of dead rats. In the chronic cases, livers of group 2 fed with control diet were more progressive in fatty changes and centrilobular necrosis than those of group 3 fed with 20%safflower seed diet. However, after six weeks, livers of group 2 and 3 showed severe necrosis and mild fibrosis at the same time. Group 5 fed with 10% safflower seed supplementation diet and water containing 0.05% phenobarbital sodium showed mild fatty changes and necrosis compared with group 4 fed with control diet and water containing 0.05% phenobarbital sodium at sixth week. At 8 to 10 wee71s after the administration of $CCl_4$, severe fibrosis. fatty changes and marked necrosis were observed in group 4, but hepatic injuries were less severe in group 5. The present results suggested that safflower seed has some protective effect in hepatic lesions and consequently delay the progression of hepatic fibrosis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.33 no.4
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• pp.44-54
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• 2020

Objectives : In the present study, we investigated whether or not an herb mixture including Lycii fructus(HML) has attenuation effects on light stress in rats. Methods : Light stress was induced by exposure to 300 lx of constant lifht for 24 h and 1mg/kg of caffeine was injected into the rat. Rats were orally treated with distilled water of HML for 21 days at 100mg/kg/d. The changes of mortality rate, clinical signs, body, blood chemistry, melatonin and IL-2 expression were analyzed after experiment. Results : Normal weight changes were observed in all treatment groups. In addition, no changes were observed in dead animals and general symptoms. At the time of autopsy, the appearance of all groups and gross examination of major organs were observed, and no gross findings were observed. Blood biochemical tests showed that total cholesterol and HDL cholesterol levels were statistically significantly decreased in the group treated with HML compared to the stress-induced group. Melatonin was measured in the blood, but there was no significant difference in the group treated with HML compared to the group with stress-induced group, but it tended to increase. IL-2 was measured in the blood, no significant change was observed in the group treated with HML compared to the stress-induced group. Conclusions : According to the above results, HML maybe help with hematological changes expressed by caffeine and light-induced stress.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.141-148
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• 2003

This paper presents a rotating ann test for assessment of an underwater hybrid navigation system for a semi-autonomous underwater vehicle. The navigation system consists of an inertial measurement unit (IMU), an ultra-short baseline (USBL) acoustic navigation sensor and a doppler velocity log (DVL) accompanying a magnetic compass. The errors of inertial measurement units increase with time due to the bias errors of gyros and accelerometers. A navigational system model is derived to include the error model of the USBL acoustic navigation sensor and the scale effect and bias errors of the DVL, of which the state equation composed of the navigation states and sensor parameters is 25 in the order. The conventional extended Kalman filter was used to propagate the error covariance, update the measurement errors and correct the state equation when the measurements are available. The rotating ann tests are conducted in the Ocean Engineering Basin of KRISO, KORDI to generate circular motion in laboratory, where the USBL system was absent in the basin. The hybrid underwater navigation system shows good tracking performance against the circular planar motion. Additionally this paper checked the effects of the sampling ratio of the navigation system and the possibility of the dead reckoning with the DVL and the magnetic compass to estimate the position of the vehicle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.96-102
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• 2007

Welding deformation causes critical problems under construction and in use of steel structures by varying the magnitude of the steel structures and deteriorating mechanic strength. Existing method to construct steel structures in civil engineering needs preassembly process for a part of or the whole structures on a broad space to examine the size of structures inevitably varied in the process of welding (assembly process). It leads to waste of time, space and human efforts, worry of safety accidents with the characteristic of the work to be performed on a high place, and non-efficiency and non-economy by using such supplementary equipments as crane. This paper, to remove the needless preassembly process by pre-estimating welding deformation produced under construction of large steel structures, devises a method modeling welded part for applying the equivalence load method and examines the effects of welding sequence and self weight on welding deformation by the method.

• Journal of Veterinary Science
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• v.23 no.5
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• pp.78.1-78.13
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• 2022

Background: Florfenicol might be ineffective for treating Staphylococcus aureus small colony variants (SCVs) mastitis. Objectives: In this study, florfenicol-loaded chitosan (CS)-sodium tripolyphosphate (TPP) composite nanogels were prepared to allow targeted delivery to SCV infected sites. Methods: The formulation screening, the characteristics, in vitro release, antibacterial activity, therapeutic efficacy, and biosafety of the florfenicol composite nanogels were studied. Results: The optimized formulation was obtained when the CS and TPP were 10 and 5 mg/mL, respectively. The encapsulation efficiency, loading capacity, size, polydispersity index, and zeta potential of the optimized florfenicol composite nanogels were 87.3% ± 2.7%, 5.8% ± 1.4%, 280.3 ± 1.5 nm, 0.15 ± 0.03, and 36.3 ± 1.4 mv, respectively. Optical and scanning electron microscopy showed that spherical particles with a relatively uniform distribution and drugs might be incorporated in cross-linked polymeric networks. The in vitro release study showed that the florfenicol composite nanogels exhibited a biphasic pattern with the sustained release of 72.2% ± 1.8% at 48 h in pH 5.5 phosphate-buffered saline. The minimal inhibitory concentrations of commercial florfenicol solution and florfenicol composite nanogels against SCVs were 1 and 0.25 ㎍/mL, respectively. The time-killing curves and live-dead bacterial staining showed that the florfenicol composite nanogels were concentration-dependent. Furthermore, the florfenicol composite nanogels displayed good therapeutic efficacy against SCVs mastitis. Biological safety studies showed that the florfenicol composite nanogels might be a biocompatible preparation because of their non-toxic effects on the renal tissue and liver. Conclusions: Florfenicol composite nanogels might improve the treatment of SCV infections.

• Journal of Ecology and Environment
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• v.46 no.1
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• pp.85-98
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• 2022

Background: Korean white pine (Pinus koraiensis) is a major commercial species, and the importance of the oak trees (Quercus spp.) is increasing due to various factors such as environmental and ecological values. However, more information is required to clearly understand the growth characteristics of these species especially regarding thinning intensity. This study was performed to provide the basic information to develop the silvicultural guideline and field manual by analyzing tree and stand characteristics in line with thinning intensity in the Korean white pine plantation and oak-dominated natural deciduous forest. Results: Diameter at breast height (DBH) and volume changes by the thinning intensity in the Korean white pine plantation were significantly different from those in the oak-dominated deciduous natural forest. In particular, DBH distribution in the pine stand appeared that there were more large diameter trees as the thinning intensity was higher. DBH periodic annual increment (PAI) of the pine stand was higher as the thinning intensity was stronger and the growth period was shorter. This trend was similarly shown in the natural deciduous forest, but the amount of PAI was smaller than in pine stand. The volume PAI after thinning was not decreased over time. In each stand type, the PAI tended to be lower as stand density was higher. The volume PAI in the pine stand was significantly higher than that in the oak-dominated natural deciduous forest. Dead trees occurred the most in the unthinned plots of each stand type, and those were higher in the natural deciduous forest. Ingrowth trees were observed only in the natural deciduous forest, and its distribution was the lowest in unthinned plots; Korean white pine as ingrowth occurred the most frequently among many tree species. Conclusions: Different effects of thinning treatment on DBH and volume PAI, mortality, and ingrowth were observed for each stand. With respect to forest growth, Korean white pine plantation was superior to the oak-dominated natural deciduous forest. The results of this study offer fundamental information for the development of silvicultural guidelines for Korean white pine plantations and oak-dominated natural deciduous forests in Korea.

• Research in Plant Disease
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• v.17 no.2
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• pp.177-183
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• 2011

Four-year-old seedlings of Pinus thunbergii, Pinus densiflora and Pinus rigida were inoculated with Fusarium circinatum isolate (FT-7), the pitch canker fungus, from P. thunbergii, to evaluate the effects of the pathogen on disease development and gas exchange rate. Needle dehydration was evident on 2 of 10 seedlings of P. thunbergii and P. rigida at 18 and 21 days after inoculation, respectively, while no symptoms were observed in P. densiflora seedlings throughout the experiment. Gas exchange stopped completely in 4 of 5 measured seedlings of P. thunbergii and 2 of 5 measured seedlings of P. rigida at 25 days after inoculation, and in the remaining 3 seedlings of P. rigida at 39 days after inoculation. Disease development in P. thunbergii seedlings was faster than that in P. rigida seedlings. By the time, the experiment was ended at 78 days after inoculation, 9 of 10 seedlings of P. rigida and 8 of 10 seedlings of P. thunbergii seedlings treated with FT-7 was almost dead, but all seedlings of P. densiflora were still healthy. We suggest that P. densiflora is resistant to F. circinatum in the current study, and gas exchange rate of the species after inoculation does not differ significantly compared to that of untreated control.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.659-672
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• 1997

Thermal response induced from nonlinear temperature distribution in composite box gilder bridges depends on several variables(environmental conditions, physical and material properties, location and orientation of bridge, and cross-section geometry). In this paper, parametric study are conducted in order to find the effects of variations of seasons, location and orientation of bridge, sectional geometry and some material properties on the axial deformation, curvature and stresses in composite box girder bridge. A two-dimensional transient finite element model to conduct this parametric studies is briefly presented. Firstly, the effects of the parameters on the diurnal variation of curvature are considered, and for the time of maximum curvature, on the distribution of temperature and stresses of composite box girder sectional are considered. Finally, some considerations about the influence of the parameters on the daily maximum values of axial deformation, curvature and stresses are carried out. The influence of thermal effect on structures is important as much as the influence of live or dead load in some cases. In the design of steel composite bridges, the thermal stresses calculated on the supposition that the temperature difference between the concrete slab and steel girder is $10^{\circ}C$ and the temperature distributions are uniform in concrete slab and steel girder can be underestimated.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.137-145
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• 2012

Aggregatibacter actinomycetemcomitans is the most important etiologic agent of aggressive periodontitis and can interact with endothelial cells. Monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) are chemokines, playing important roles in periodontal pathogenesis. In our current study, the effects of A. actinomycetemcomitans on the production of MCP-1 and IL-8 by human umbilical vein endothelial cells (HUVEC) were investigated. A. actinomycetemcomitans strongly induced the gene expression and protein release of both MCP-1 and IL-8 in a dose- and time-dependent manner. Dead A. actinomycetemcomitans cells were as effective as live bacteria in this induction. Treatment of HUVEC with cytochalasin D, an inhibitor of endocytosis, did not affect the mRNA up-regulation of MCP-1 and IL-8 by A. actinomycetemcomitans. However, genistein, an inhibitor of protein tyrosine kinases, substantially inhibited the MCP-1 and IL-8 production by A. actinomycetemcomitans, whereas pharmacological inhibition of each of three members of mitogen-activated protein (MAP) kinase family had little effect. Furthermore, gel shift assays showed that A. actinomycetemcomitans induces a biphasic activation (early at 1-2 h and late at 8-16 h) of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and an early brief activation (0.5-2 h) of activator protein-1 (AP-1). Activation of canonical NF-${\kappa}B$ pathway ($I{\kappa}B$ kinase activation and $I{\kappa}B-{\alpha}$ degradation) was also demonstrated in these experiments. Although lipopolysaccharide from A. actinomycetemcomitans also induced NF-${\kappa}B$ activation, this activation profile over time differed from that of live A. actinomycetemcomitans. These results suggest that the expression of MCP-1 and IL-8 is potently increased by A. actinomycetemcomitans in endothelial cells, and that the viability of A. actinomycetemcomitans and bacterial internalization are not required for this effect, whereas the activation of protein tyrosine kinase(s), NF-${\kappa}B$, and AP-1 appears to play important roles. The secretion of high levels of MCP-1 and IL-8 resulting from interactions of A. actinomycetemcomitans with endothelial cells may thus contribute to the pathogenesis of aggressive periodontitis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5111-5116
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• 2013

Background: Early in the 21st century, cancers are the second cause of death worldwide. Colon cancer is third most common cancer and one of the few amenable to early diagnosis and treatment. Evaluation of factors affecting this cancer is important to increase survival time. Some of these factors affecting all diseases including cancer are social determinants of health. According to the importance of this disease and relation with these factors, this study was conducted to assess the relationship between social determinants of health and colon cancer survival. Materials and Methods: This was a cross-sectional, descriptive study for patients with colon cancer registered in the Cancer Research Center of Shahid Beheshti University of Medical Science, from April 2005 to November 2006, performed using questionnaires filled by telephone interview with patients (if patients had died, with family members). Data was analyzed with SPSS software (version 19) for descriptive analysis and STATA software for survival analysis including log rank test and three step Cox Proportional Hazard regression. Results: Five hundred fifty nine patients with ages ranging from 23 to 88 years with mean${\pm}$standard deviation of $63{\pm}11.8$ years were included in the study. The five year survival was 68.3%( 387 patients were alive and 172 patients were dead by the end of the study). The Cox proportional hazard regression showed 5-year survival was related to age (HR=0.53, p=0.042 for>50 years versus<50 years old) in first step, gender (HR=0.60, p=0.006 for female versus male) in second step, job (HR=1.7, p=0.001 for manual versus non manual jobs), region of residency (HR=3.49, p=0.018 for west versus south regions), parents in childhood (HR=2.87, p=0.012 for having both parents versus not having), anatomical cancer location (HR=2.16, p<0.033 for colon versus rectal cancer) and complete treatment (HR=5.96, p<0.001 for incomplete versus complete treatment). Conclusions: Social determinants of health such as job, city region residency and having parents during childhood have significant effects in 5-year survival of colon cancer and it may be better to consider these factors in addition to developing cancer treatment and to focus on these determinants of health in long-time planning.