• 한국입자에어로졸학회지
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• 제6권3호
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• pp.107-121
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• 2010

나노기술이 인체, 보건, 환경 등에 영향을 미칠 수 있다는 의혹은 제품이 시장에서 확산되는데 주요한 걸림돌이 되고 있다. 제품이 사용되는 실제상황에서는 물리적, 화학적, 생물학적인 상호작용이 복잡하게 일어나기 때문에 나노제품의 건강, 보건, 환경 영향에 대한 연구는 쉽지 않고 진척이 느리다. 나노입자가 환경에 노출된 후 시간에 따라 어떻게 변화하는지, 나노기술이 인간이나 동물 등의 생명을 지닌 유기체에 어떠한 영향은 미칠지, 공기, 물, 토양 등의 환경 시스템에 미치는 영향이 어떠할 지에 대한 지속적인 연구가 필요하다. 본 논고에서는 나노기술의 잠재적인 영향에 대응하기 위한 국내외 정책 동향을 정리하였다. 미국, 유럽, 일본 등 나노기술 선진국 등의 나노기술 안전성을 확보하기 위해 지속적으로 노력하고 있고, 국내 정부 부서도 최근 나노기술에 관련된 EHS 문제를 해결하기 위해 다양한 정책적 지원을 확충하고 있다. 나노기술 안전성 확보는 나노기술 산업화를 앞당기기 위한 국제 공조가 요구되는 분야이기 때문에, OECD와 ISO는 서로 협력하고 있는데, OECD에서 전체 위해성평가를 담당하고 ISO에서 기반이 되는 독성 평가 방법과 노출 평가 방법 등을 개발한다. 두 국제기구는 나노기술 안전성 문제를 빠른 시간에 해결하기 위해 긴밀한 관계를 유지하고 있다. 마지막으로 국내의 에어로졸 기술을 나노기술 안전성 연구에 적용한 연구 결과를 정리하였고, 나노기술 안전성을 확보하기 위해 필요한 에어로졸 연구 방향에 대해 정리하였다. 최근 한국은 나노안전성 분야 중 은나노 입자에 대한 흡입독성연구를 수행하여 국제적으로 사용되는 데이터를 제공하였고, 나노기술 안전성에 관련된 국제 표준을 주도하여 개발하고 있다. 그렇지만, 이와 같은 성과는 국가 주도의 치밀한 연구 로드맵에 의한 결과라기보다는 제품화를 진행하고자 하는 회사와 독성전문가 등의 다학제적인 연구의 결과이기 때문에 단기적인 연구성과로 끝날 수 있다. 나노기술의 상용화를 위해서는 나노제품의 EHS 영향에 대해 규명해야 하고, 신기술의 채용 뿐 아니라 소비자들에게 친환경 제품으로 다가설 수 있도록 장기적인 연구기획 및 수행이 필요하다. 높은 성능의 나노제품을 개발하는데 그치는 것이 아니라 나노제품의 인체영향, 환경영향에 대한 의혹을 풀 수 있도록 다양한 분야의 연구자들의 협력이 필요하다.

• Journal of Korean Neurosurgical Society
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• 제30권11호
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• pp.1300-1307
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• 2001

Purposes : This study reports the possible causes of seizure recurrence in patients underwent previous epilepsy surgery, and surgical strategy for resection of the additional epileptogenic zone locating at the distant area to the site of first resection. Methods : A total of 10 patients with previous surgery due to intractable epilepsy were studied. Five of these underwent standard temporal lobectomy, four extratemporal resection, and one corticoamygdalectomy. Seizure outcome of these were class III-IV. Evaluation methods for reoperation included MRI, 3D-surface rendering of MRI, PET, prologned video-EEG recording with surface electrodes and subdural grid electrodes. Additional resection was done in the frontal lobe in two, in the temporal lobe in three, in the parietal lobe in two, and in the supplementary sensori-motor area in two. Tumor in the superior frontal gyrus in the left hemisphere was removed in one patient. Extent of resection was decided based on the results of ictal subdural grid EEGs and MRI findings. Awake anesthesia and electrocortical stimulation were performed in the two patients for defining the eloquent area. Results : Histopathologic findings revealed extratemporal cortical dysplasia in six, hippocampal sclerosis and cortical dysplasia of the temporal neocortex in one, neuronal gliosis in two, and meningioma in one. Previous pathology of the five patients with cortical dysplasia in the second operation was hippocampal sclerosis plus cortical dysplasia of the temporal neocortex. After reoperation, seizure outcomes were class I in six, class II in three, class III in one at the mean follow-up period of 17.5 months. Characteristically, patients in class II-III after reoperation showed histopathologic findings of hippocampal sclerosis plus temporal neocortical cortical dysplasia plus extratemporal cortical dysplasia. Conclusions : Seizure recurrence after epilepsy surgery was related with the presence of an additional epileptogenic zone distant to the site of first operation, and the majority of the histopathology of the surgical specimens was cortical dysplasia. In particular, hippocampal sclerosis plus temporal neocortical cortical dysplasia was highly related with seizure recurrence in patients with previous operation. In these patients, multimodal evaluation methods were necessary in defining the additional epileptogenic zone.

• 한국철도학회논문집
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• 제16권5호
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• pp.386-393
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• 2013

본 연구에서는 궤도 하부 노반상에서 다짐도 확인 및 강화노반 두께 결정을 위하여 사용되는 변형계수 $E_{v2}$ 측정방법의 적절성과 측정값의 유효성을 검토하였다. 이를 위하여 반복평판재하시험(RPBT)을 실시하고 평판직하부에서 발생하는 압축변형률을 파악하였다. 동일 흙노반재료에 대한 공진주시험으로부터 획득된 전단탄성계수감소곡선과 $E_{v2}$를 비교하였다. 실 현장 RPBT의 발생변형률 수준과 변형계수의 크기가 합리적인지를 분석하기 위하여 응력조건과 대표 평균변형률계수($I_z$) 보정에 의해 반복평판재하시험 변형계수($E_{v2}$)를 재평가하였다. PLAXIS 프로그램을 이용하여 깊이에 따른 변형률 영향계수($I_z$)를 재산정하여 반복평판재하시험 결과($E_{v2}$) 해석에 미치는 변형률 영향계수의 영향을 분석하였으며 ABAQUS를 이용하여 3D궤도구조에서 노반이 받는 변형률수준을 확인하였다. 궤도하부구조가 경험하는 변형률수준에서의 변형계수 $E_{v2}$를 획득하기 위해서는 노반의 비선형성을 구현할 수 있도록 현 반복평판재하시험의 하중단계를 세분화할 필요성을 확인하였다.

• Geomechanics and Engineering
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• 제23권2호
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• pp.151-163
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• 2020

Grouting method is an effective way of reinforcing cracked rock masses and plugging water gushing. Current grouting diffusion models are generally developed for horizontal cracks, which is contradictory to the fact that the crack generally occurs in rock masses with irregular spatial distribution characteristics in real underground environments. To solve this problem, this study selected a cement-sodium silicate slurry (C-S slurry) generally used in engineering as a fast-curing grouting material and regarded the C-S slurry as a Bingham fluid with time-varying viscosity for analysis. Based on the theory of fluid mechanics, and by simultaneously considering the deadweight of slurry and characteristics of non-uniform spatial distribution of viscosity of fast-curing grouts, a theoretical model of slurry diffusion in an oblique crack in rock masses at constant grouting rate was established. Moreover, the viscosity and pressure distribution equations in the slurry diffusion zone were deduced, thus quantifying the relationship between grouting pressure, grouting time, and slurry diffusion distance. On this basis, by using a 3-d finite element program in multi-field coupled software Comsol, the numerical simulation results were compared with theoretical calculation values, further verifying the effectiveness of the theoretical model. In addition, through the analysis of two engineering case studies, the theoretical calculations and measured slurry diffusion radius were compared, to evaluate the application effects of the model in engineering practice. Finally, by using the established theoretical model, the influence of cracking in rock masses on the diffusion characteristics of slurry was analysed. The results demonstrate that the inclination angle of the crack in rock masses and azimuth angle of slurry diffusion affect slurry diffusion characteristics. More attention should be paid to the actual grouting process. The results can provide references for determining grouting parameters of fast-curing grouts in engineering practice.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.1003-1010
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• 2008

The objective of the present study was to identify differences in the expression levels of liver proteins between healthy and ketotic cows, establish a liver metabolic interrelationship of ketosis and elucidate the metabolic characteristics of the liver during ketosis. Liver samples from 8 healthy multiparous Hostein cows and 8 ketotic cows were pooled by health status and the proteins were separated by two-dimensional-electrophoresis (2D-E). Statistical analysis of gels was performed using PDQuest software 8.0. The differences in the expression levels of liver proteins (p<0.05) between ketotic and healthy cows were identified by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF-TOF) tandem mass spectrometry. Five enzymes/proteins were identified as being differentially expressed in the livers of ketotic cows: expression of 3-hydroxyacyl-CoA dehydrogenase type-2 (HCDH), acetyl-coenzyme A acetyltransferase 2 (ACAT) and elongation factor Tu (EF-Tu) were down-regulated, whereas that of alpha-enolase and creatine kinase were up-regulated. On the basis of this evidence, it could be presumed that the decreased expression of HCDH, which is caused by high concentrations of acetyl-CoA in hepatic cells, in the livers of ketotic cows, implies reduced fatty acid ??oxidation. The resultant high concentrations of acetyl-CoA and acetoacetyl CoA would depress the level of ACAT and generate more ??hydroxybutyric acid; high concentrations of acetyl-CoA would also accelerate the Krebs Cycle and produce more ATP, which is stored as phosphocreatine, as a consequence of increased expression of creatine kinase. The low expression level of elongation factor Tu in the livers of ketotic cows indicates decreased levels of protein synthesis due to the limited availability of amino acids, because the most glucogenic amino acids sustain the glyconeogenesis pathway; thus increasing the level of alpha-enolase. Decreased protein synthesis also promotes the conversion of amino acids to oxaloacetate, which drives the Krebs Cycle under conditions of high levels of acetyl-CoA. It is concluded that the livers of ketotic cows possess high concentrations of acetyl-CoA, which through negative feedback inhibited fatty acid oxidation; show decreased fatty acid oxidation, ketogenesis and protein synthesis; and increased gluconeogenesis and energy production.

• 동서간호학연구지
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• 제13권2호
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• pp.138-146
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• 2007

Introduction: The purpose of this study was to examine relationships among stroke patients' activities of daily living(ADL), depression, and quality of life(QOL). Methods: Data were collected by questionnaires from 251 stroke patients at 5 hospitals and 2 public health centers in Seoul and Kyonggi-Do. The following Questionnaires were utilized for this study: Functional independence measure(FIM) from Grange, Hamilton, and Sherwin(1986), the Korean CES-D scale from Randloff(1977), and quality of life scale from Bang, Hwal-Lan(1991). Results: Data were analyzed using the pearson correlation, t-test, and ANOVA with SPSS/WIN 12.0. The results of this study were as follow; The subjects consisted of 110 fern ales and 141 m ales. The mean score of activity of daily living was 87.2(range 18-126). Age, family history, comorbidity, paralysis site, and duration after diagnosis were significantly associated with activity of daily living. The mean score of depression was 23.8(range 11-44). Age, gender, education, and job were significantly associated with depression. The mean score of quality of life scale was 3.0(range 1-5). Gender, religion, education, job, economic status, and duration after diagnosis were significantly associated with quality of life. Relationships among activity daily living, depression, and quality of life scale: The activity of daily living had a negative relationship with depression score. The activity of daily living had a positive relationship with QOL score. The depression had a negative relationship with QOL score. Conclusion: Based on these results, it is necessary to run rehabilitation programs to improve stroke patients' ADL, depression. Also, it research for of identifying stroke patients' quality of life according to rehabilitation program.

• 한국지진공학회논문집
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• 제24권6호
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• pp.253-266
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• 2020

The extended slip-weakening model was investigated by using a compiled set of source-spectrum-related parameters, i.e. seismic moment M_o, S-wave velocity V_s, corner-frequency f_c, and source-controlled high-cut frequency fmax, for 113 shallow crustal earthquakes (focal depth less than 25 km, M_W 3.0~7.5) that occurred in Japan from 1987 to 2016. The investigation was focused on the characteristics of stress drop, radiation energy-to-seismic moment ratio, radiation efficiency, and fracture energy release rate, G_c. The scaling relationships of those source parameters were also investigated and compared with those in previous studies, which were based on generally used singular models with the dimensionless numbers corresponding to f_c given by Brune and Madariaga. The results showed that the stress drop from the singular model with Madariaga's dimensionless number was equivalent to the breakdown stress drop, as well as Brune's effective stress, rather than to static stress drop as has been usually assumed. The scale dependence of stress drop showed a different tendency in accordance with the size category of the earthquakes, which may be divided into small-moderate earthquakes and moderate-large earthquakes by comparing to M_o = 10¹⁷~10¹⁸ Nm. The scale dependence was quite similar to that shown by Kanamori and Rivera. The scale dependence was not because of a poor dynamic range of recorded signals or missing data as asserted by Ide and Beroza, but rather it was because of the scale dependent V_r-induced local similarity of spectrum as shown in a previous study by the authors. The energy release rate G_c with respect to breakdown distance D_c from the extended slip-weakening model coincided with that given by Ellsworth and Beroza in a study on the rupture nucleation phase; and the empirical relationship given by Abercrombie and Rice can represent the results from the extended slip-weakening model, the results from laboratory stick-slip experiments by Ohnaka, and the results given by Ellsworth and Beroza simultaneously. Also the energy flux into the breakdown zone was well correlated with the breakdown stress drop, ${\tilde{e}}$ and peak slip velocity of the fault faces. Consequently, the investigation results indicate the appropriateness of the extended slip-weakening model.

• 한국지역사회생활과학회지
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• 제27권4호
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• pp.891-906
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• 2016

This study examined the working site environment of Korean native cattle raising farmers and their actual condition of wearing personal protective equipment as part of preventing disasters during agricultural work. To this end, 160 Korean cattle raising farmers were surveyed and a site visit was performed on 10 farms. According to an examination of the cattle breeding environment, the major harmful factors were in the following order: fine dust (12.8%), organic feed dust (10.3%), contact with cattle (9.7%), manure (8.2%), germs and viruses (8.1%), harmful gases (7.4), contact with obstacles (6.7), and temperature (6.6%). The current status of the rate of wearing protection was in the order of gloves (20.9%), working hats (19.7%), boots (19.6%), masks (10.9%), protective clothing (8.9%), and specialized working clothing (6.6%). Nevertheless, most Korean cattle raising farmers recognized the risks when they did not wear protective equipment and the need for wearing protectors, but they mostly did not wear personal protective equipment due to a lack of knowledge on the selection of appropriate personal protective equipment and the discomfort they experience when they put on protectors. Even when they put on protective equipment, 38% was inappropriate for the farming work environment. Given the research results, improvements on and the development of specialized working clothing and personal protective equipment to protect farmers from harmful and dangerous materials from the cattle nurturing environment is necessary. Overall, based on the study data, objectified data collection, a determination of the necessary performance elements of personal protective equipment, and R&D will be needed through an on-site current status investigation.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4632-4640
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• 2015

본 연구의 목적은 국내 증가하고 있는 중국, 베트남을 비롯한 결혼이주여성을 대상으로 이들의 산전관리 교육요구도를 파악함으로써 향후 이들을 위한 산전관리 교육 프로그램의 기초자료를 제공하고자 수행되었다. 자료수집은 D시 1개의 다문화센터를 이용하는 71명의 결혼이주여성을 대상으로 2014년 3월부터 2015년 4월까지 수행되었다. 산전관리 교육요구도는 불임, 남녀생식구조, 산전교육, 예방접종, 건강문제 관리방법 등의 내용을 포함한 18개의 문항으로 구성되었다. 결혼이주여성은 신생아 안전관리 및 응급대처법, 예방접종, 건강문제관리, 신생아 정상발달과정, 신생아 관리법 등 주로 신생아 발달과정을 이해하고 이들의 건강문제를 해결하기 위한 것에 교육요구도가 높은 것으로 나타났다. 또한, 결혼이주여성의 국적에 따른 산전관리 교육요구도는 유의한 차이가 없는 것으로 나타났고, 이들 세부항목 중 불임에 대한 교육요구도에서 베트남 출신 결혼이주여성이 중국과 기타 국적 출신의 결혼이주여성보다 높은 것으로 나타났다 (F=5.53, p<.05). 따라서, 향후 결혼이주여성을 위한 산전관리 프로그램을 개발 할 시 신생아 성장발달 과정과 이들 간호방법이 가장 우선시 되어 프로그램 내용을 개발할 것을 제안한다.

• 대한지역사회영양학회지
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• 제20권5호
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• pp.362-374
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• 2015

Objectives: This study was performed to investigate the effects of overestimation of their own body shape on weight control behaviors, mental condition, physical activity, dietary behavior, health-related quality of life, and nutritional status among young Korean females. Methods: A total of 1,514 women aged 20-39 years who are not pregnant and lactating among those who participated in the Fifth Korea National Health and Nutrition Examination Survey (2010~2011), were analyzed and grouped into underestimation (n=120), normal estimation (NE, n=840), and overestimation (OE, n=554), based on their body perception compared to actual percent ideal body weights. Variables were compared between OE group and NE group. Results: The subjects in OE group were significantly younger (29.5 vs. 30.5 years, respectively p < 0.05) and had lower body mass index (20.9 vs. 22.2 respectively, p < 0.01), health-related quality of life measured by EQ-5D (EuroQol-5 Dimension)(0.97 vs. 0.98 respectively, p < 0.05), nutrition adequacy ratio (NAR) of protein (0.91 vs. 0.93 respectively, p < 0.05), phosphorous (0.93 vs. 0.96 respectively, p < 0.05), and iron (0.70 vs. 0.75 respectively, p < 0.01), and index of nutrition quality (INQ) of iron (0.84 vs. 0.89 respectively, p < 0.05) compared to those in the NE group. The results of logistic regression showed that unmarried status (OR 1.32; 1.01~1.72) and severely underweight/underweight status (OR 1.94; 1.01~3.75)/(OR 1.81; 1.34~2.45) were significantly related to the probability of overestimation by the subjects. Significantly more women in OE group practiced fasting, skipping meals, and taking prescribed pills to lose body weights and had skipped breakfast compared to those in the NE group. Conclusions: The results of this study suggested that the Korean young women's distorted perception of own body shape may be associated with undesirable weight control behavior, low quality of life, and lower nutritional status. Therefore, nutrition education for this group should include information on correct body shape perception and its importance.