• Clinical and Experimental Pediatrics
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• 제57권3호
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• pp.101-109
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• 2014

The use of glucocorticoids (GCs) in the perinatal period is suspected of being associated with adverse effects on long-term neurodevelopmental outcomes for preterm infants. Repeated administration of antenatal GCs to mothers at risk of preterm birth may adversely affect fetal growth and head circumference. Fetal exposure to excess GCs during critical periods of brain development may profoundly modify the limbic system (primarily the hippocampus), resulting in long-term effects on cognition, behavior, memory, co-ordination of the autonomic nervous system, and regulation of the endocrine system later in adult life. Postnatal GC treatment for chronic lung disease in premature infants, particularly involving the use of dexamethasone, has been shown to induce neurodevelopmental impairment and increases the risk of cerebral palsy. In contrast to studies involving postnatal dexamethasone, long-term follow-up studies for hydrocortisone therapy have not revealed adverse effects on neurodevelopmental outcomes. In experimental studies on animals, GCs has been shown to impair neurogenesis, and induce neuronal apoptosis in the immature brains of newborn animals. A recent study has demonstrated that dexamethasone-induced hypomyelination may result from the apoptotic degeneration of oligodendrocyte progenitors in the immature brain. Thus, based on clinical and experimental studies, there is enough evidence to advice caution regarding the use of GCs in the perinatal period; and moreover, the potential long-term effects of GCs on brain development need to be determined.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.118-125
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• 2012

Heat shock proteins (Hsps) play a key role in the cellular defense response to diverse environmental stresses. Here, the role of Hsp genes in the acquisition of thermotolerance in the cyanobacterium Microcystis aeruginosa NIES-298 was investigated. Twelve Hsp-related genes were examined to observe their modulated expression patterns at different temperatures (10, 15, 25, and $35^{\circ}C$) over different exposure periods. HspA and HtpG transcripts showed an up-regulation of expression at low temperatures (10 and $15^{\circ}C$) and high temperature ($35^{\circ}C$), compared with the control ($25^{\circ}C$). To examine their effects upon thermotolerance, we purified recombinant HspA and HtpG proteins. During a thermotolerance study at $54^{\circ}C$, the HspA-transformed bacteria showed increased thermotolerance compared with the control. HtpG also played a role in the defense response to acute heat stress within 30 min. These findings provide a better understanding of cellular protection mechanisms against heat stress in cyanobacteria.

• 한국산업보건학회지
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• 제9권2호
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• pp.52-65
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• 1999

This study was performed to evaluate the hand-arm vibration of the steel processing factory workers. Measurement, evaluation and as sessment were based on the International Standard(ISO 5349). The frequency weighted accelerations of the various hand-held tools and total exposure time were measured to assess the periods for the white finger symptom to occur. As a result, it was found that the air angle grinder and the air baby grinder are more harmful than other hand-held tools. It was also found that using various vibratory tools together is more harmful than using a single tool.

• Reproductive and Developmental Biology
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• 제28권4호
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• pp.235-240
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• 2004

In vitro maturation of denuded porcine immature oocytes can be enhanced by co-incubation with spermatozoa even before fertilization. This study was to determine whether the addition of spermatozoa into the culture medium could influence the nuclear maturation of porcine cumulus-enclosed germinal vesicle (GV) oocytes. Cumulus-oocyte complexes (COCs) were collected from follicles of 3- to 5-mm diameter. Porcine COCs were cultured in tissue culture medium containing spermatozoa. After 48 h culture, oocytes were examined for evidence of GV breakdown, metaphase I, anaphase-telophase I, and metaphase II. The proportion of oocytes reaching at metaphase II was significantly (P < 0.05) increased in the oocytes cultured in media containing spermatozoa compared to those in media without spermatozoa (52.3% vs 12.5%). No difference in the percentage of metaphase II was observed among the different periods of spermatozoa exposure and among the spermatozoa from different species. The proportion of oocytes reaching metaphase II was significantly different between high and low concentrations of spermatozoa. The present study suggests that manunalian spermatozoa contain a substance(s) that improves nuclear in vitro maturation of porcine cumulus-enclosed GV oocytes. Enhancing effect of spermatozoa for in vitro maturation of oocytes is a highly dose-dependent.

• 생명과학회지
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• 제6권2호
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• pp.111-119
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• 1996

The production of interleukin-1(IL-1)and nitric oxide(NO) by cultured fibroblast cells of human nasal turbinate was revealed by biological assay respectively. The cells were incubated for various periods of time in the presence of staphyloccocal toxic shock syndrome toxin-1(TSST-1) and house dust mite(Dermatophagoides farinae, HDM), and the culture supernatants were harvested. There was a little difference in the activities of IL-1beta and the amount of NO produced by the cells when stimulated with 0.002-0.1$\mu$g/ml of TSSTO-1 and 0.02-1$\mu$g/ml of HDM. The shapes of the time course curves for the production of IL-1beta and NO by the cells were different. Groups stimulated with TSST-1 or HDM produced more IL-beta in 2 h than no exposure group(Control). A certain mixed group(TSST-1, 10ng+mite, 100 ng) continued to produce IL-1beta highly throughout the entire incubation period. The cells stimulated with TSST-1 or HDM produced more NO in 2 h and 6 h than that produced in the end of incubation(48 h). Also, the mixed groups were generally similar. There results suggest that induction of IL-1beta by a certain mixed condition(TSST-1+mite) in fibroblast cell in vivo may play a role in inflammation.

• 한국식품과학회지
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• 제26권5호
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• pp.585-589
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• 1994

시험관 내에서 T-2 toxin이 병아리 비장세포의 blastogenesis에 미치는 영향을 살펴본 결과, B-cell mitogen인 lipopolysaccharide 및 T-cell mitogen인 concanavalin A 자극에 대해 T-2 toxin의 농도가 증가함에 따라 억제정도가 증가하는 경향을 나타내었다. 노출시기를 달리하여 T-2 toxin을 투여한 병아리의 비장세포에서 mitogen 자극에 내한 반응을 안아 본 결과, 부화하기 전과 후에 계속 T-2 toxin에 노출시킨 실험군은 가장 영향을 많이 받은 것으로 나타났고 부화전 혹은 부화후 어느 한 시기에만 T-2 toxin에 노출된 실험군은 비교적 영향을 적게 받는 것으로 나타났다.

• The Korean Journal of Pain
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• 제8권2호
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• pp.347-349
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• 1995

A 43 year old man who suffered from right facial palsy was treated successfully with the application of both magnetic resonance diagnostic analyser(MRA) and drug therapy. Treatment of facial palsy is generally composed of stellate ganglion block(SGB), drug therapy and operative intervention. Short periods of exposure to appropriate magnetic resonance can beneficially modulate the balance of autonomic nervous system that are responsible for sympathetic overflow. It was concluded that recovery of facial palsy by application of both MRA and drug therapy was effective in patient who refused SGB.

• The Korean Journal of Pain
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• 제6권2호
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• pp.280-283
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• 1993

Idiopathic hyperhidrosis is a physically and emotionally distressing symptom, which lacks a precise definition. Although operative and nonoperative methods have been shown to be effective in the treatment of idiopathic hyperhidrosis, limitations, cautions and complications are inherent in their extended use. The purpose of this report is to describe the theraputetic effects of magnetic resonance for managing idiopathic hyperhidrosis. A 28 years old woman had been suffering from profuse sweating on both planter and palmar sides for 15 years. We successfully treated this symptom with the 6 magnetic resonance treatments without any complications. Now she lives well in a condition of normal sweating after the applications. It suggest that short daily periods of exposure to appropriate magnetic resonance can beneficially modulate the balance of autonomic nervous system that are responsible for sympathetic overflow, and that there is an effective window of induced electrical magnetism in which sympathetic function can be controlled in the absence of side effects.

• International Journal of Concrete Structures and Materials
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• 제3권1호
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• pp.25-32
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• 2009

A non-destructive testing (NDT) method for evaluating physical properties of concrete including the compressive strength is highly desirable. This paper presents such an NDT method based on measurement of electromagnetic (EM) properties of the material. Experiments are carried out on cement mortar with different water/cement (W/C) ratios. Their EM properties including the conductivity and the dielectric constant are measured at different exposure conditions and curing periods over a wide frequency range of the EM wave. The compressive strength of these specimens is also tested. It is found that both the conductivity and the dielectric constant increase as the W/C ratio decreases and the curing period increases, which lead strength development in the specimens. A linear correlation is observed between the averaged EM properties over the 5 to 20 GHz frequency range and the measured compressive strength, demonstrating the effectiveness of the EM property-based NDT method in evaluating strength of OPC mortar.

• 한국지반신소재학회논문집
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• 제3권1호
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• pp.37-42
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• 2004

보강토 옹벽시스템에서, 부직포 지오텍스타일은 블럭이 시공될 때 보강토체의 전면에 노출, 포설되어 있다. 임시구조물에 보강토 옹벽이 적용될 때 지오텍스타일은 시공기간 중 일광에 노출되게 된다. 이 기간 중, 자외선에 의해 부직포 지오텍스타일의 분해가 발생하게 된다. 따라서 현장시공의 관점에서 부직포 지오텍스타일의 자외선 저항성이 명확하게 평가되어야만 한다. 본 연구에서는 실험실 및 현장시험을 수행하여 KOESWall 시스템에 사용되는 부직포 지오텍스타일의 자외선 저항성이 평가되었고, 그 결과를 SEM 사진과 인장특성으로 나타내었다.