• 대한수의학회지
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• 제43권4호
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• pp.633-639
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• 2003

We investigated the effect of green tea and its fractions of alcohol and polysaccharide on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of gamma-irradiation. Jejunal crypts were protected by pretreatment of green tea (i.p.: 50 mg/kg of body weight, at 12 and 36 hours before irradiation., p.o.: 1.25% water extract, for 7days before irradiation, p<0.01) and alcohol and polysaccharide fractions showed no significant modifying effects. Green tea and its fractions administration before irradiation (i.p. at 12 and 36hours before irradiation) resulted in an increase of the formation of endogenous spleen colony (p<0.05). The frequency of radiation-induced apoptosis in intestinal crypt cells was also reduced by pretreatment of green tea (i.p. at 12 and 36 hours before irradiation, p<0.05., p.o. for 7days before irradiation, p<0.001) and its fractions (p<0.001). These results indicated that green tea might be a useful radioprotector, especially since it is a relatively nontoxic natural product. Further studies are needed to characterize better the promotion nature of green tea and its components.

• 한국정보시스템학회지:정보시스템연구
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• 제22권4호
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• pp.85-115
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• 2013

Digital knowledge and information goods as experience goods have some unique characteristics such as close to zero reproduction and distribution cost, high price volatility, and low price acceptability. For the reasons, the pricing policies of digital knowledge goods are very difficult and complicate. Also, most consumers of digital goods have experienced cognitive dissonance after buying decision. The purpose of this paper is to investigate what factors affect the price acceptability level and cognitive dissonance of digital knowledge goods buyers. This paper suggest a structural model that was established by the cognitive dissonance theory and S-O-R(Stimulus-Organization-Response) model. The model is consisted of four exogenous variables and three endogenous variables. The empirical test and statistical analysis suggest following results and practical implications. The variables such as product involvement and perception of price fairness that have positive roles to price acceptability have strong influence on the all the three endogenous variables. But the variables such as sale proneness and price mavenism that have negative roles to price acceptability have little influence on the all the three endogenous variables. In the model, the payment intention was very important mediating variable between exogenous variables and two dependent variables, ie. price acceptability and cognitive dissonance. These results imply that the digital knowledge portals must have some differentiated pricing policies to the customers who have price consciousness and price mavenism. Also, they need some special promotions to whom have positive attitude to the value of digital goods.

• International Journal of Oral Biology
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• 제42권3호
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• pp.99-106
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• 2017

Type1 diabetes mellitus (DM) is generally known to be caused by destruction of insulin-producing pancreatic ${\beta}$ cells or an immune-related problem. Polydipsia is a representative symptom of DM, and it has been reported that this condition is closely related to xerostomia and is considered that hyposalivation from the salivary gland results in this phenomenon. Although various studies have reported that induction of diabetes reduces endogenous stem cells in other organs (heart, brain etc.), diabetes-related changes in endogenous stem cells in the salivary gland have not yet been well established. Therefore, in this study, to verify the change in salivary gland stem cells after diabetes, salivary gland tissues in the control and diabetes-induced groups were processed by histochemistry (Masson's trichrome staining) for morphological analysis, TUNEL assay for cell death, and immunohistochemistry (Ki-67 and c-Kit) for cell proliferation and maturation. Diabetes induced by STZ leads to vacuolization, apoptosis, and reduction in proliferating cells/salivary gland stem cells in salivary glands of rats. This result suggests that diabetes may be associated with reduction in salivary gland function such as degeneration and inhibition of regeneration in the salivary gland.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.197-199
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• 1991

The role of estrogen in calcium metabolism has not been well documented. To further investigate the effects of endogenous estrogen on the calcium regulating hormones in women, we correlated the changes of estrogen level with those of calcium regulating hormones during ovulation induction in 12 hypogonadal and 8 normally menstruating women. During ovulation induction, the serum leveles of estradiol rose from 40.0 to 831.0pg/ml. There were no significant changes in the serum leveles of total calcium, inorganic phosphorus, parathyroid hormone, calcitonin. However, 1, $25-(OH)_2D_3$ rose significantly from 31.0 to 47.2pg.ml as the endogenous $E_2$ increaed (p<0.005).

• Journal of Plant Biology
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• 제38권3호
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• pp.227-234
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• 1995

Exogenous putrescine of 0.5 mM or higher concentratons applied during a 16 h inductive dark period could elevate putrescine content in cotyledons of Pharbitis nil Choisy cv. Violet, a short-day plant, resulting in complete blocking of photoperiodic floral induction. Titers of putrescine, spermidine and spermine in the cotyledons were traced throughout a 16 h dark period. While non-induced cotyledons under continous light slightly increased levels of polyamines, induced tissue maintaiend its putrescine, spermidine and spermine levels as low as 66.4%, 60.9% and 84.9% of non-induced levels respecitvely. Endogenous polyamines kept at lower levels in the inductive dark period were found to upsurge by a night break treatment of 10 min light in the middle of the dark and consequently the inductive dark effect was canceled. Elevation of polyamine titers could also be induced by 100 $\mu$L/L ethylene treatment which completely suppressed floral induction. Compared to untreated cotyledons, ehtylene-treated tissues increased putrescine content by as much as 136.5% in 12 h and spermidine level by up to 130.1% in 8 h. Ethylene-treated cotyledons not only increased endogenous polyamine content but also liberate ethylene in the second half of the inductive dark period accumulating up to three to fourfold level supporting a hypothesis that ethylene-treated tissues are stimulated to produce ethylene which in turn accelerates polyamine biosynthesis in the tissues. It is postulated that substantially low polyamine titers in the inductive dark period would be one of the necessary factors controlling photoperiodic induction of flowering in Pharbitis nil and the inhibitory effects of night break and exogenous ethylene treatment may be atributed to their action to stimulate endogenous polyamine production.

• Journal of Microbiology
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• 제34권4호
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• pp.374-378
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• 1996

In the aquatic fungus Allomyces macrogynus the effects of $Ca^{2+}$ and cAMP on the intracellular signal transduction of zoospore germination were studied using in vitro protein phosphorylation assay system. An endogenously phosphorylated protein (p50) having molecular weight of 50 kDa on SDS-PAGE was found in soluble fractions of both zoospore and mycelium. In zoospore extract, the endogenous phosphorylation of p50 was weak without any effectors, but was enhanced by $Ca^{2+}$ and even more by cAMP. Phosphorylation of the same protein in mycelial extract was high only in the absence of cAMP. Irrespective of the presence of $Ca^{2+}$ and cAMP, its phosphorylation was antagonistically suppressed in assay of combined zoospore and mycelial extracts. These results suggest that p50 is interconvertible in phosphorylation/dephosphorylation as a novel protein involved in germination of A. macrogynus. The antagonistic effect of cAMP to the phosphorylation of p50s from different developmental stages may be important in the regulation of cellular differentiation.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.35-41
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• 1997

The pancreas is an important organ in the maintenance of zinc homeostasis. Endogenous zinc is con-tinuously secreted via pancreatic exocrine fluid or to a lesser extent in bile. Much of the endogenous secretion must be reabsorbed to sustain zinc homeostasis. The objective of this study was to estimate the relative size of the pancreatic/biliary zinc pool in comparision to the dietary zinc intake, and to study the effect of the phytate and calcium on the zinc homeostasis using a rat model. At the termination of the experiment, pan-creatic/biliary fluid was collected from the rats. Both radioactivity and total zinc were measured and the relative size of the pancreatic/biliary zinc pool was estimated. To determine the effect of phytate and calcium on zinc homeostsis, dietary zinc intake, the amount of zinc in pancreatic.biliary fluid and fecal zinc excretion were measured. The flow rate of pancreatic/biliary fluid, as corrected for tubing constriction, gives the corrected zinc concentration in the pancreatic/biliary fluid was 2.2 times higher than dietary zinc intake. To maintain zinc homeostasis, zinc absorption/reabsorption was very efficient in the current model; 76%, 88% of absorption/reabsorption for low calcium group and high calcium group 81% for phytate group and non-phytate group, respectively.

• 한국지역사회생활과학회지
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• 제25권1호
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• pp.51-64
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• 2014

With a shift in the rural development process toward a bottom-up approach, the need to enhance the endogenous capacity of communities has become the core of rural development. In this regard, scholars have paid close attention to social capital to identify ways to facilitate endogenous rural development but focused mainly on relationships between social capital and local environment. That is, few studies have investigated the relationships between social capital and its various dimensions in the context of rural development initiatives. This study examines the effects of social capital on the problem-solving ability of community residents'rural development initiatives and assesses the types of social capital associated with such initiatives to propose optimal path for improving this ability. To distinguish between major dimensions of social capital, a questionnaire was developed by considering various stages of the rural development process. The survey considered a sample of 59 employees from public rural development institutions. According to the results, four paths were significant at the 5% level. Among these four paths, three set common goals. The effective channel was the path [common goals${\Rightarrow}$network${\Rightarrow}$cooperation${\Rightarrow}$problem-solving ability]. The key factor in improving problem-solving skills, the endogenous ability of community residents to facilitate rural development initiatives. The results suggest that governments should strengthen education and training programs to help residents set their common goals.

• 한국작물학회지
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• 제56권3호
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• pp.250-254
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• 2011

The study was carried out to evaluate the affect of proton beam radiation on production of bulbil and tuber including change of endogenous gibberellins, of Dioscorea opposita Thunb. The yield of bulbils and tubers from non- and irradiated D. opposita Thunb at doses of 5, 10, 15 and 20 Gy were determined. Endogenous gibberellins were also quantified by GC/MS analysis. D. opposita tubers irradiated at 15 Gy produced higher bulbil production than non-irradiated plants. Enlarged bulbil (above size diameter 4 mm) was significantly increased at 15 Gy. Bioactive endogenous $GA_4$ was dominant in bulbils and tubers irradiated with proton beam rather than $GA_1$. Major gibberellins biosynthetic pathways in bulbils and tubers of D. opposita plants were non C-13 hydroxylation route. From the results of this study, 15 Gy proton beam radiation was suggested as an optimal dose that can produce high amounts of bulbil for mass production of D. opposita plant.

• Journal of Microbiology
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• 제43권6호
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• pp.510-515
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• 2005

The growth of red pepper plants was enhanced by treatment with the rhizobacterium, Bacillus cereus MJ-1. Red pepper shoots showed a 1.38-fold increase in fresh weight (fw) and roots showed a 1.28-fold fw gain. This plant growth-promoting rhizobacterium (PGPR) has been reported to produce gibberellins (GAs). Other GAs-producing rhizobacteria, Bacillus macroides CJ-29 and Bacillus pumilus CJ-69, also enhanced the fw of the plants. They were less effective than B. cereus MJ-1, though. The endogenous GAs content of pepper shoots inoculated with MJ-1 was also higher than in shoots inoculated with CJ-29 or CJ-69. When inoculated with MJ-1, bacterial colonization rate of the roots was higher than that of roots inoculated with CJ-29 or CJ-69. These results support the idea that the plant growth-promoting effect of the bacteria also positively related with the efficiency of root colonization by the bacteria. In addition, we identified the major endogenous GAs of the red pepper as originating from both the early C-13 hydroxylation and the early non C-13 hydroxylation pathways, with the latter being the predominant pathway of GA biosynthesis in red pepper shoots.