• Korean Journal of Ecology and Environment
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• 제41권3호
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• pp.382-394
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• 2008

The objective of this study was to analyze temporal trends of water chemistry and spatial heterogeneity between the dam site (Daecheong Reservoir, S1) and the downstream (S2$\sim$S4) using water quality dataset (obtained from the Ministry of Environment, Korea) during 2000$\sim$2007. Water quality, based on eight physical and chemical parameters, varied largely depending on the years, sampling sites, and the discharge volume. Conductivity and nutrients (TN and TP) showed a decreasing trend in the downstream (S4) rather than the dam site during the monsoon. Spatial variation increased toward downstream (S4) from Daecheong Reservoir (S1). Also, BOD and COD increased toward downstream. Because of input of nutrient and pollutant nearby S1, lentic ecosystem in monsoon, BOD and COD were slightly increased. whereas relatively decreased in S4, lotic ecosystem in monsoon, by dilution effect of nutrient and pollutant by discharge from upper dam, S1. Spatial variation of SS increased toward downstream (S4) by the side of Daecheong Reservoir (S1). Based on the dataset, efficient water quality management in the point source tributary streams is required for better water quality of downstream. Monthly characteristics of DO showed the lowest value in the monsoon that tend to increase water temperature. DO was lowest in October at S1 because turbid water, input to the Daecheong Reservoir in the monsoon affect to the postmonsoon period. In contrast, water temperature increased toward summer monsoon, in spite of some differences showed between S1 and S4 environment. Overall, the characteristics of water quality in downstream region have close correlation with discharge amount of Daecheong Reservoir. Thus, those characteristics can explain that discharge control of upper dam mainly affect to the water quality variation in downstream reach.

• The Korean Society of Law and Medicine
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• 제16권1호
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• pp.155-190
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• 2015

The court sentenced meaningful decisions related to the medical service in 2014. The court assumed the negligence of medical staff in the accident if being broken while using the medical equipment for not an original purpose at the time of surgery and ruled that the compensation for damage can be recognized in recognition of the causal relationship between the explanation duty violation and side effect's happening when unproven surgery on safety is implemented regarding the duty of explanation, that in the case of cosmetic surgery, the subject on the duty of explanation needs to be expanded compared to the general medical practice and that the duty of explanation cannot be accepted for the range that cannot be expectable. Also, the court has provided the requirement and limitation of self-determination exercise in case of the crash between patient's self-determination and doctor's duty of care and has ruled that as automobile insurance contract is a contract with the insurance company to pay regarding liability for car accidents, treating patients and taking the insurance money is not illegal activity even for the unlicensed hospital violating the medical law while established. The judgment stating the opinion that medical practitioners cannot be punished according to the medical law prohibiting the receiving of rebate in case that medical practitioners did not receive benefit while the medical institution itself gained an unfair economic benefit also stands out. And the court has ruled that even if the medical institution who received a business suspension is closed, the suspension is still effective in case that the same operator opens a new medical institution in the same place, ruled on the requirement to conduct a medical service outside of the medical institution that the doctor opened and ruled that the administrative penalty cannot be conducted prior to the conviction on charge of violating the medical law.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제25권2호
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• pp.51-55
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• 2015

The present research is focused on the effect of porous graphite what is influenced on the 4H-SiC crystal growth by PVT method. We expect that it produces more C-rich and a change of temperature gradient for polytype stability of 4H-SiC crystal as adding the porous graphite in the growth cell. The SiC seeds and high purity SiC source materials were placed on opposite side in a sealed graphite crucible which was surrounded by graphite insulator. The growth temperature was around $2100{\sim}2300^{\circ}C$ and the growth pressure was 10~30 Torr of an argon pressure with 5~15 % nitrogen. 2 inch $4^{\circ}$ off-axis 4H-SiC with C-face (000-1) was used as a seed material. The porous graphite plate was inserted on SiC powder source to produce a more C-rich for polytype stability of 4H-SiC crystal and uniform radial temperature gradient. While in case of the conventional crucible, various polytypes such as 6H-, 15R-SiC were observed on SiC wafers, only 4H-SiC polytype was observed on SiC wafers prepared in porous graphite inserted crucible. The defect level such as MP and EP density of SiC crystal grown in the conventional crucible was observed to be higher than that of porous graphite inserted crucible. The better crystal quality of SiC grown using porous graphite plate was also confirmed by rocking curve measurement and Raman spectra analysis.

• Journal of Periodontal and Implant Science
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• 제27권4호
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• pp.751-765
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• 1997

Periodontal disease is a bacterially causal by disease, To remove plaque and bacteria, it has been necessary to prescribe chemical drug to patient to subjugate therapeutic unvalue by mechanical scaling. As a patient on a high dosage of the antibiotics to maintain the effective concentration may produce unfavorable side effects, this decase demands the Slow-release local drug delivery system. The object of the experiment is to study on the slow-release local drug delivery effects of calcium sulfate compounded with tetracycline that mainly used in periodontal disease. Experimental groups were divided into four classes as follow: Group 1 10% tetracycline compounded modified calcium sulfate paste. Group 2 : compounded and hardened 10% tetracycline and calcium sulfate. Group 3 : compounded 10% tetracycline and calcium sulfate, used Just before hardened. Group 4 : tetracycline-ethylene vinyl acetate fiber. In the four groups, release concentration, it's durability and the period of absorption by times are observed and concluded as follow: 1. An effective concentration($4{\mu}g/ml$) remained until 5 weeks in group 1, 9 days in group 2, 7 days in group 3, 15 days in group 4. 2. It was fully fused at 11.8 days average in group 2 and 14.8 days average in group 3. . There were no statistically significant results in tetracycline concentration until a week in group 2 and 3(p<0.05) These results suggest that tetracycline loaded calcium sulfate release sufficient tetracycline and fused in $11{\sim}14$ days, so calcium sulfate is useful carrier as slow release local drug delivery system.

• The korean journal of orthodontics
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• 제33권3호
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• pp.169-183
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• 2003

Tooth movement by orthodontic force effects great tissue changes within the periodontium, especially by shifting the blood flow in the pressure side and resulting in a hypoxic state of low oxygen tension. The aim of this study is to elucidate the possible mechanism of apoptosis in response to hypoxia in MC3T3El osteoblasts, the main cells in bone remodeling during orthodontic tooth movement. MC3T3El osteoblasts under hypoxic conditions ($2\%$ orygen) resulted in apoptosis in a time-dependent manner as estimated by DNA fragmentation assay and nuclear morphology stained with fluorescent dye, Hoechst 33258. Pretreatment with Z-VAD-FMK, a pancaspase inhibitor, or Z-DEVD-CHO, a specific caspase-3 inhibitor, completely suppressed the DNA ladder in response to hypoxia. An increase in caspase-3-like protease (DEVDase) activity was observed during apoptosis, but no caspase-1 activity (YVADase) was detected. To confirm what caspases are involved in apoptosis, Western blot analysis was performed using anti-caspase-3 or -6 antibodies. The 10-kDa protein, corresponding to the active products of caspase-3, and the 10-kDa protein of the active protein of caspase-6 were generated in hypoxia-challenged cells in which the processing of the full length form of caspase-3 and -6 was evident. While a time course similar to this caspase-3 and -6 activation was evident, hypoxic stress caused the cleavage of lamin A, which was typical of caspase-6 activity. In addition, the stress elicited the release of cytochrome c into the cytosol during apoptosis. Furthermore, we observed that pre-treatment with SB203580, a selective p38 mitogen activated protein kinase inhibitor, attenuated the hypoxia-induced apoptosis. The addition of SB203S80 suppressed caspase-3 and -6-like protease activity by hypoxia up to $50\%$. In contrast, PD98059 had no effect on the hypoxia-induced apoptosis. To confirm the involvement of MAP kinase, JNK/SAPK, ERK, or p38 kinase assay was performed. Although p38 MAPK was activated in response to hypoxic treatment, the other MAPK -JNK/SAPK or ERK- was either only modestly activated or not at all. These results suggest that p38 MAPK is involved in hypoxia-induced apoptosis in MC3T3El osteoblasts.

• Progress in Medical Physics
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• 제26권1호
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• pp.28-35
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• 2015

In this study, we investigated the effects of an iterative reconstruction algorithm and an automatic exposure control (AEC) technique on image quality and radiation dose through phantom experiments with coronary computed tomography (CT) angiography protocols. We scanned the AAPM CT performance phantom using 320 multi-detector-row CT. At the tube voltages of 80, 100, and 120 kVp, the scanning was repeated with two settings of the AEC technique, i.e., with the target standard deviations (SD) values of 33 (the higher tube current) and 44 (the lower tube current). The scanned projection data were reconstructed also in two ways, with the filtered back projection (FBP) and with the iterative reconstruction technique (AIDR-3D). The image quality was evaluated quantitatively with the noise standard deviation, modulation transfer function, and the contrast to noise ratio (CNR). More specifically, we analyzed the influences of selection of a tube voltage and a reconstruction algorithm on tube current modulation and consequently on radiation dose. Reduction of image noise by the iterative reconstruction algorithm compared with the FBP was revealed eminently, especially with the lower tube current protocols, i.e., it was decreased by 46% and 38%, when the AEC was established with the lower dose (the target SD=44) and the higher dose (the target SD=33), respectively. As a side effect of iterative reconstruction, the spatial resolution was decreased by a degree that could not mar the remarkable gains in terms of noise reduction. Consequently, if coronary CT angiogprahy is scanned and reconstructed using both the automatic exposure control and iterative reconstruction techniques, it is anticipated that, in comparison with a conventional acquisition method, image noise can be reduced significantly with slight decrease in spatial resolution, implying clinical advantages of radiation dose reduction, still being faithful to the ALARA principle.

• Korean Chemical Engineering Research
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• 제49권1호
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• pp.75-82
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• 2011

Five different composition UV-cured poly(urethane acrylate-co-acrylic acid) (PU-co-AA) films have been prepared by reacting isophorone diisocyanate(IPDI), polycaprolactone triol(PCLT), 2-hydroxyethyl acrylate(HEA), and different weight ratio trimethylolpropane triacrylate(TMPTA) and acrylic acid(AA) as diluents, and characterized using a Fourier transform infrared spectroscopy(FT-IR). The adhesion properties onto the stainless steel, morphology, mechanical hardness, and electrical property of UV-cured PU-co-AA films were investigated as a function of acrylic acid(AA) content. All the PU-co-AA films are structure-less and the molecular ordering and packing density decreased with increasing content of AA due to the flexible structure and -COOH side chains in AA. The crosscut test showed that PU-co-AA films without AA and with low content of AA showed 0% adhesion(0B) and the adhesion of PU-co-AA films in the range of 40-50% AA increased dramatically as the content of AA increases. The pull-off measurements showed that the adhesion force of PU-co-AA films to stainless steel substrate varied from 6 to 31 kgf /$cm^2$ and increased linearly with increasing AA content. The mechanical hardness also decreased as the content of AA increases. This may come from relatively linear and flexible structure in AA and low crystallinity in PU-co-AA films with higher content of AA. The higher AA-containing PU-co-AA films showed higher dielectric constant due to the increase of polarization by introducing AA monomer. In conclusion, the physical properties of UV-cured PU-co-AA films are strongly dependent upon the content of AA and the incorporation of AA in polyurethane acrylate is very useful way to increase the adhesion strength of UV-curable polymers on the stainless steel substrate.

• Radiation Oncology Journal
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• 제11권1호
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• pp.97-102
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• 1993

A retrospective analysis of various characteristics in 32 limited stage small cell lung cancer patients treated at the Department of Therapeutic Radiology in Kangnam St. Mary's Hospital, Catholic University Medical College from April 1983 to September 1991, was carried out to identify factors which had prognostic significance for survival from initiation of radiation therapy. There were 26 men and 6 women. Median age was 63 years (range: 24-78 years). The follow up duration was 1.5 to 44 months (median: 9 months). External radiation therapy was done with daily 160-180 cGy,5 fraction/week, total of 1000-6660 cGy (median: 4500 cGy) to the mediastinum by 6 MV linear accelerator. Of 32 Patients, 27 ($84.4{\%}$) patients were treated with combined modality (chemotherapy plus radiation therapy), and 5 ($15.6{\%}$) patients were treated with radiation therapy only. Complete responders were 12 patients ($37.5{\%}$), partial responders were 11 ($34.4{\%}$), and no responders were 9($28.1{\%}$). Karnofsky performance status over 70 (p<0.04), chemotherapy regimen (CAV, PV, and CAV+PV) (p<0.04),6 or more cycles of chemotherapy (p<0.007), radiation therapy over 4500 cGy (p<0.03), and radiation therapy responder (CR+PR) (p<0.003) showed a significantly favorable influence on 1 year survival rate. Age (p=0.545), sex (p=0.666), presence of superior vena cava syndrome (p=0.719), prophylactic cranial irradiation (p=0.217), and radiation therapy duration (p=0.491) had no effect on survival. Radiation induced side effects were transient esophagitis in 11 ($34{\%}$), general weakness in 9($28{\%}$), gastrointestinal symptoms in terms of nausea, vomiting and indigestion in 5 ($15{\%}$) and leukopenia in 1 ($3{\%}$).

• Journal of Hospice and Palliative Care
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• 제10권4호
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• pp.184-189
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• 2007

Purpose: This study was to explore barriers to effective pain management in general population. Methods: Total 163 Participants completed the Barrier Questionnaire-II (BQ-II), a 27-item on a six point scale, from May to June in 2007. BQ-II consisted of four subscales which were 1) physical effects (PE) addressing beliefs that side effects of analgesics are inevitable and concerns about tolerance, fatalism (Fa) addressing fatalistic beliefs about cancer pain and its management, Communication (Co) addressing the beliefs of 'good patient' and concerns of distracting physician from underlying disease, and harmful effects (HE) addressing fear of addiction and harmful effect to immune system of pain medicine. Results: The BQ-II total had an internal consistency of 0.877 in this study. HE was the biggest barrier (3.03) followed by PE (2.73), Fa (2.15), and Co (1.71). Items appeared as great concerns were 'there is a danger of becoming addicted to pain medication'(3.58), 'using pain medicine blocks your ability to know if you have any new pain' (3.18), 'pain medicine is very addictive' (3.09), 'when you use pain medicine your body becomes used to its effects and pretty soon it won't work any more' (3.09), and 'drowsiness from pain medicine is difficult to control' (3.09). Only 12 respondents (7.4%) reported that they took any type of pain education, however, those who took pain education represented significantly lower barriers to pain management than who did not (P=.029). Conclusion: This result suggests the strategies for public education to surmount cancer pain.

• Journal of Life Science
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• 제29권12호
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• pp.1337-1344
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• 2019

Osteoporosis is characterized by a reduction in bone mass and typically manifests as an increase in fractures. Because this disease is common in elderly populations and lifespans are rapidly increasing, the incidence of osteoporosis has also grown. Most drugs currently used for osteoporosis treatment target osteoclasts in the bone tissue to prevent absorption. However, these medications also cause certain side effects and, furthermore, cannot increase bone mass. Thus, in order to control osteoporosis, regenerative medicine that utilizes adult stem cells and osteoblasts has been extensively studied. Statins, also known as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, are cholesterol-lowering drugs that have been widely prescribed for cardiovascular diseases. Interestingly, recent studies have reported the beneficial effects of various statins on bone formation via the activation of osteoblasts. Thus, the current study investigated the effects of seven statin-family drugs on osteoblast activity during osteogenic differentiation using adult stem cells from human periosteal tissue. Specifically, statin effects on alkaline phosphatase activity, an early marker of bone cell differentiation, and on calcium deposit, a late marker of bone cell differentiation, were assessed. The results demonstrate that some statins (for example, pitavastatin and pravastatin) have a weak but positive effect on bone formation, and the findings therefore suggest that statin treatments can be a novel modulator for osteogenic differentiation and regenerative medicine using periosteal stem cells.