• Journal of Chest Surgery
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• v.13 no.4
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• pp.490-494
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• 1980

Myasthenia gravis is a neuromuscular disorder manifested by fatigability and weakness of voluntary muscles. The basic defect in the myasthenia is reduction of available acetylcholine receptors at neuromuscuiar junctions by an autoimmune attack. Removal of the thymus gland now play an Important role in the management of this disease. We have two experiences of thymectomy for myasthenic patients. The 31-year-old housewife(J.H) was admitted to the Taegu Presbyterian Medical Center because of bilateral ptosis, mastication and swallowing difficulties. The presence of thymoma was strongly suggested by roentgenographic studies. A 99.8 gm thymoma was removed completely by total thymectomy. On the 2nd postoperative day respiratory failure developed. Tracheostomy was performed and ventilatory assist was given for 3 days. The patient was completely recovered with antichollestrase drug only. C.N. was 17-year-old girl who has the symptoms of bilateral ptosis and diplopia for 3 years. Tensilon test was positive and antichollnestrase was given for several months, but the patient showed no improvement. After thymectomy she was free from myasthenic symptoms with out anticholinestrase drug.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.35-41
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• 1995

Fracture Mechanics does work for concrete, provided that a finite nonlinear zone at fracture front is being considered. The development of model for fracture process zone is most important to describe fracture phenomena in concrete. The fracture process zone is a region ahead of a traction-free crack, in which two major mechanisms, microcracking and bridging, play important rules. The toughness due to bridging is dominant compared to toughness induced by microcracking, so that the bridging is dominant mechanism governing the fracture process of concrete. In this paper the bridging zone, which is a part of extended macrocrack with stresses transmitted by aggregates in concrete, is model led by a Dugdale-Barenblatt type model with linear tension-softening curve. Two finite element techniques are shown for the model of fracture process zone in concrete.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.3 no.2
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• pp.129-133
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• 2017

Since carbon-fluorine (C-F) bonds play a key role to improve bioavailability and lipophilicity, they have found commonly in pharmaceuticals, radiopharmaceuticals, agrochemicals, and material science. Advances on the efficient method to introduce fluorine to complex organic molecules are mainly results of development of fluorination reagents and transition metal catalysts. In this mini-review, we want to emphasize two representative nucleophilic fluorinating reagents regarding carbon-fluorine bond formation, which were developed in the mid-2000s.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.545-548
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• 2001

Microbiologically influenced corrosion (MIC) of metal is common in the natural environment and sulfate reducing bacteria are representative microorganisms for MIC. We found that biofilm fomlation by SRB on the metal surface might be controlled by quorum sensing, which is a cell density dependent regulation of cell metabolism. As cell free culture fluids (spent media) of Desulfovibrio vulgaris and D. desulfuricans were tested for quontrn sensing related test strains, it was found that spent media of two SRB induced increased luminescence of Vibrio harveyi BB886 (sensor 1+, sensor 2-) and BB170 (sensor 1-, sensor 2+). Quorum activities of D. vulgaris and D. desulfuricans appeared to be parallel to growth patterns, i.e., it was low in the lag phase, highly increased in the exponential phase, and reached maximum in the stationary phase. Interestingly, however, luminescence of V. harveyi BB886 and BB170 induced by a unit cell mass of the SHB showed a maximal peak in the late lag phase. Hence, it was suspected that quorum sensing of these two SHB play unknown roles in shifting cells from dormant to growth stages.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.468-471
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• 2002

The present study was undertaken to Investigate the effects of low temperature and salicylic acid (SA) on chilling tolerance In acclimated and nonacclimated cucumber seedlings. Acclimation significantly affected survival and shoot dry weights. Injuries of acclimated seedlings at the third leaf stage were on the average smaller by half than those of the nonacclimated ones. Chilling caused a large increase in free proline levels, regardless of acclimation status. Exogenous treatment with SA resulted in improvement in growth and survival of acclimated, chilled seedlings, indicating SA and acclimation have common effects. Cycloheximide treatment In the presence of SA restored acclimation-induced chilling tolerance. An elevated proline level was observed in cold-treated and SA- treated plants and the level was more pronounced in the light than in the dark at chilled temperature, indicating that endogenous proline may play a role in chilling tolerance.

• Korean Journal of Child Studies
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• v.20 no.3
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• pp.19-32
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• 1999

This study analyzed the relation of children's attachment security and mother-child interaction to children's peer interactions. The subjects were 51 preschoolers, 44 to 57 months of age and their mothers. Attachment was assessed using the Attachment Q-set (Waters, 1987), mother-child interactions at home were observed with the use of the Teaching Strategies Rating Scales (Erickson, Sroufe, Egeland, 1985), and peer interactions were observed during free play time, using the Holloway and Erickson(1988) categories. Pearson correlation and multiple regression showed that attachment security scores were negatively related to dependency toward peers. Mother's "structure and limit setting" and "respect for child's autonomy" were positively related to "helping with peers" and negatively to "asking for help" and "physical attack". The variables accounting for dependency toward peers were mother's hostility and attachment security.

• Korean Journal of Child Studies
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• v.24 no.5
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• pp.77-89
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• 2003

The relationship of communicative intent of infants and the conversation style of mothers were investigated with 20 mothers and their 2- and 3-year old children. They conversed in naturalistic settings while playing with Lego blocks. Cluster analyses revealed 2 maternal styles: a conversation-eliciting and a directive style. Children of conversation-eliciting mothers provided more information than those of directive mothers. Children of directive mother requested more permission than those of conversation-eliciting mothers. Implications of these two maternal styles for children's communicative abilities were discussed.

• Korean Journal of Child Studies
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• v.30 no.2
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• pp.71-95
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• 2009

This study investigated relationships among infant development, teacher's sensitivity, home literacy environment, and infant-teacher interaction in the child care setting. Verbal and behavioral interactions between 30 2-year-old infant-teacher pairs were video-recorded during free play activities; teachers' sensitivity was observed by trained observers; infant development was assessed by teachers; data on the early home literacy environment were gathered through maternal self-reported questionnaires. Data were analyzed by descriptive statistics, t-tests, and correlation analyses. Results indicated that boys showed more naming; girls showed more physical contact with teachers. Infants high in overall developmental level showed more behavioral interaction with teachers. Teacher's sensitivity correlated positively with behavioral imitating and negatively with questioning and nodding. Verbal interaction in the home correlated positively with nodding.

• Radiation Oncology Journal
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• v.33 no.2
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• pp.66-74
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• 2015

Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) induced by ionizing radiation in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against radiation-induced DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity induced by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against radiation without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects induced by ionizing radiation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.252-263
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• 2001

Nematode infections compromise human health and reduce agricultural productivtiy. Experiments that exploit the powerful molecular genetics of the free-living nematode Caenorhabdl - elegans have contributed to our understanding of how the major classes of anthelmintic nema-tocides kill worms and how worms might evolve resistance to these drugs In C. elegans, as in parasites, benzimidixoles interfere with microtubule polyumerization the imidazothiazoles/tetra-hydropyrimidines activate nicotinic acetylcholine receptors, and the macrocyclic la ctones activate qlutamate-gate chloride chanels. Mutant alleles of genes that encode drug targes often confer resistance in C. elegans. Preliminary evidence suggests that alleles of homologous genes in parasites will, in many cases, also play a role in resistance. Thus information acquired from C. elegans can be usefully applied to understand the mechanisms of drug sensitivity and the genetics of resis-tance in parasites.