• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.20 no.1
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• pp.29-40
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• 2010

This study was aimed at investigating the gene expression profile in basal ganglia of cadmium exposed rat based on cDNA array analysis. For cDNA array analysis, adult Sprague-Dawley male rats (350 ${\pm}$ 25 g) were intraperitoneally injected with 2.0 mg/kg body weight/day of CdCl2 (0.3 ml) for 5 days. For doserelated gene expression analysis rats were intraperitoneally injected with 0.0, 0.1, 0.3, 1.0 mg/kg body weight/day of CdCl$_2$ for 5 days. Control rats were injected with equal volume of saline. Cadmium concentration of brain was analyzed by atomic absorption spectrophotometer. For cDNA array, RNA samples were extracted from basal ganglia and reverse-transcribed in the presence of [${\alpha}$32P]-dATP. Membrane sets of the Atlas Rat 1.2 array II and Toxicology array 1.2 (Clontech, Palo Alto, CA) were hybridized with cDNA probe sets. RT-PCR was employed to validate the relative gene expression patterns obtained from the cDNA array. Northern blot hybridization methods were employed to assess the dose-related gene expression. Among the 2352 cDNAs, 671 genes were detected in both array sets and 63 genes of 38 classes showed significant (more than two fold) changes in expression. Thirty five of these genes were up-regulated and twenty eight were down-regulated in the cadmium exposed group. According to the dose-related gene expression analysis, heat shock 27 kDa protein (HSP27), neurodegeneration-associated protein 1 (Neurodap 1) genes were significantly up-regulated and melatonin receptor 1a (Mel1a), Kinesin family member 3C (KIF3C), novel kinesinrelated protein (KIF1D) genes were significantly downregulated even in the low-dose of cadmium exposed group (0.1 mg/kg body weight/day). Conclusions Sixty three genes detected in this study can give some more useful informations about the cadmium-induced neurotoxicity in the basal ganglia. As well as, HSP27, Neurodap1, Mel1a, KIF3C and KIF1D genes may be useful for the study of the cadmium-induced neurotoxicity because these genes showed dramatic changes of mRNA levels in response to the low dose of cadmium exposure.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.311-322
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• 2015

Objective : The purpose of this study was to investigate the effects of landing height and knee joint muscle fatigue on the movement of the lower extremity during cutting after landing. Method : Subjects included 29 adults (age: $20.83{\pm}1.56years$, height: $172.42{\pm}9.51cm$, weight: $65.07{\pm}10.18kg$). The subjects were asked to stand on their dominant lower limb on jump stands that were 30 and 40 cm in height and jump from each stand to land with the dominant lower limb on a force plate making a side step cutting move at a $45^{\circ}$ angle with the non-dominant lower limb. The fatigue level at 30% of the knee extension peak torque using an isokinetic dynamometer. Results : The results showed that the difference of landing height increased maximum range of motion and angular velocity of hip, knee, and ankle joints in the sagittal plane, and in the angular velocity of motion of the hip joint in the sagittal plane. The maximum range of motion of the knee joint in the sagittal plane and the frontal plane decreased on landing from both heights after the fatigue exercise. The angular velocity of the hip joint in the sagittal plane, and the maximum range of motion of the hip joint in the transverse plane decreased for both landing heights after the fatigue exercise. The angular velocity of the hip joint in the frontal plane decreased for the 30 cm landing height after the fatigue exercise. On the other hand, the angular velocity and maximum range of motion of the ankle joint in the sagittal plane for both landing heights, and the angular velocity and maximum range of motion of the ankle joint in the frontal plane increased on landing from the 40 cm height after the fatigue exercise. Conclusion : Different landing heights of 30 and 40 cm and 30% fatigue of peak torque of knee extensor found a forefoot and stiff landing strategy, when cutting after landing. These results might be due to decline in the shock absorption capability of the knee joint and the movement capability related to cutting while increasing the contribution of the ankle joint, which may cause increased ankle joint injuries.

• Archives of Reconstructive Microsurgery
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• v.3 no.1
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• pp.24-31
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• 1994

The heel, with its specialized fat for shock absorption at heel strike and large surface area for balance and weight bearing, is a important component of normal ambulation. Despite of distinguished improvement in the field of microsurgical free flaps, the choice of reconstruction of the heel has been remained controversial. We reviewed 22 cases of the heel reconstruction using vascularized free flaps from January, 1980 through May, 1993 at the Department of Orthopedic Surgery of Korea University Hospital. The results were as follows: 1. The etiology was traumatic in 21 cases, and chronic ulceration due to burn in 1. 2. The arteries used in free flaps were 11 dorsalis pedis arteries, 2 deep circumflex iliac arteries, 2 supeficial iliac arteries, 2 branches of lateral femoral circumflex iliac arteries, 2 radial arteries, and 3 thorcodorsal arteries. 3. The mean size of the vascularized bone was $4.5cm{\times}3.5cm$, and that of skin flap was $12.1cm{\times}9.2cm$. 4. Of the 22 cases, 19 had a successful outcome and 3 in failure, the causes of failure were thrombosis and infection.

• Korean Journal of Applied Biomechanics
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• v.31 no.4
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• pp.276-282
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• 2021

Objective: To investigate effects of Fibular Repositioning Taping (FRT) on lower extremity joint stiffness and angle during drop-landing. Method: Twenty-eight participants (14 healthy, 14 with chronic ankle instability [CAI]) performed drop-landings from a 60 cm box; three were performed prior to tape application and three were performed post-FRT. Three-dimensional kinematic and kinetic data were collected using an infrared optical camera system (Vicon Motion Systems Ltd. Oxford, UK) and force-plate (AMTI, Watertown, MA). Joint stiffness and sagittal angle of the ankle, knee, and hip were analyzed. Results: The hip [Healthy: p<.05; M ± SD: 29.43 ± 11.27 (pre), 33.04 ± 12.03 (post); CAI: p<.05; M ± SD: 31.45 ± 9.70 (pre), 32.29 ± 9.85 (post)] and knee [Healthy: p<.05; M ± SD: 53.44 ± 8.09 (pre), 55.13 ± 8.36 (post); CAI: p<.05; M ± SD: 53.12 ± 8.35 (pre), 55.55 ± 9.81 (post)] joints demonstrated significant increases in sagittal angle after FRT. A significant decrease in joint angle was found at the ankle [Healthy: p<.05; M ± SD: 56.10 ± 3.71 (pre), 54.09 ± 4.31 (post); CAI: p<.05; M ± SD: 52.80 ± 6.04 (pre), 49.86 ± 10.08 (post)]. A significant decrease in hip [Healthy: p<.05; M ± SD: 1549.16 ± 517.53 (pre), 1272.48 ± 646.73 (post); CAI: p<.05; M ± SD: 1300.42 ± 595.55 (pre), 1158.27 ± 550.58 (post)] and knee [Healthy: p<.05; M ± SD: 270.12 ± 54.07 (pre), 239.13 ± 64.70 (post); CAI: p<.05; M ± SD: 241.58 ± 93.48 (pre), 214.63 ± 101.00 (post)] joint stiffness was found post-FRT application, while no difference was found at the ankle [Healthy: p>.05; M ± SD: 57.29 ± 17.04 (pre), 59.37 ± 18.30 (post); CAI: p>.05; M ± SD: 69.15 ± 17.63 (pre), 77.24 ± 35.05 (post)]. Conclusion FRT application decreased joint angle at the ankle without altering ankle joint stiffness. In contrast, decreased joint stiffness and increased joint angle was found at the hip and knee following FRT. Thus, participants utilize an altered shock absorption mechanism during drop-landings following FRT. When compared to previous research, the joint kinematics and stiffness of the lower extremity appear to be different following FRT versus traditional ankle taping.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.2
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• pp.133-142
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• 2022

The purpose of this study is to develop an impact crusher with a radial rotating plate installed at the bottom, which is a shock absorber that can produce high-quality recycled coarse aggregate for concrete and to verify the effect of improving the quality performance of recycled coarse aggregate and its applicability through concrete tests. As a result, it showed improved quality in all items such as absolute dry density, absorption rate, abrasion resistance, Particle shape judgment rate, amount lost in the 0.08 mm sieve passing test, alkali aggregate reaction, clay mass, stability, and impurity content, and it was found to meet the criteria of recycled aggregate quality standards. In addition, the air volume and slump of concrete to which recycled coarse aggregate is applied meet all domestic standards. According to the test results of the compressive strength characteristics by age of concrete according to the mixing ratio of the recycled coarse aggregate, it was confirmed that the mixing ratio of the recycled coarse aggregate was applicable up to 60 %.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.513-523
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• 2017

We evaluated the viability of phytoplankton along the salinity gradient in the flood and ebb tides of spring tide of February and the ebb tide of neap tide of March 2017 in the Seomjin River Estuary. Additional laboratory experiments were also conducted to determine the reason of the pH changes along the salinity gradient using the field natural sample in February. In field, saltwater was well mixed at downstream vertically and the salinity gradient was horizontally appeared toward upstream of freshwater zone. There were strong negative correlations between salinity and nutrient (nitrate + nitrite R=0.99, p<0.001, and silicate R=0.98, p<0.001), implying that those two nutrients of freshwater origin were gradually diluted with mixing the saltwater. On the other hands, relatively high phosphate concentration was kept in the stations of saltwater over 15 psu, indicating that it was caused by resuspended sediments of Gwangyang Bay and downstream by tidal water mixing.Among phytoplankton community structure in winter, Eucampia zodiacus have occupied to be c.a. 70 % in the most stations. Based on the field survey results for survivability of phytoplankton by phytoPAM instrument, there was positive correlations between salinity and chlorophyll a (R=0.82, p<0.001) and, salinity and active chlorophyll a (R=0.80, p<0.001), implying that the dominant marine diatom species may have significantly damaged in low salinity conditions of upstream. Also, maximum mortality rate of phytoplankton caused by low salinity shock was appered to be 75% in the upstream station. In particular, the pH in spring tides of February had tended to increase with high phytoplankton accmulated stations, suggesting that it was related with absorption of $CO_2$ by the photosynthesis of dominant diatom. In laboratory experiments, phytoplankton mass-mortality caused by low salinity shock was also occurred, which is confirmed with reducing the photosynthetic electron transport activity. Following the phytoplankton mass-mortality, bacteria abundance was significantly increased in 24 hours. As a result, the mass-proliferating bacteria can produce the $CO_2$ in the process of biodegradation of diatoms, which can lead to pH decrease. Therefore, marine phytoplankton species was greatly damaged in freshwater mixing area, depending on along the salinity gradient that was considered to be an important role in elevating and reducing of pH in Seomjin River Estuary.

• Journal of the Korean Society for Library and Information Science
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• v.30 no.1
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• pp.89-123
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• 1996

The world has moved from the Cold War between the east and the west and moved toward the age without idealogy. It places emphasis on economic benefit and welfare of its own nation as its main point With this world trend, in order to sam the competitiveness and the reconciliation of the divided nation the north and the south Korea should be united. Once the north and the south are united, information society will be altered with the huge flow of the civilization. At the same time, the issue of how to operate library policies and system, in which effective acquisition, manipulation, accumulation, and dissemination of information un would be very important. From this point of view, the following conclusions are obtained in this study. Firstly, when building a national library preparing for the national unification. it is essential to introduce 1) the concept of policy and system for information society and 2) that of policy and system which has national-culture as its focus. Secondly, it is essential to prepare the cooperative-structure between libraries prior to the national unification. This kind of cooperation should gradually expand to an extent that allows actual benefits such as building union catalog, inter-library loan system, resource sharing, standardized cataloging rules, and exchange of dissertation... etc. Thirdly, developing the library policies and systems for the national unification must be based on the concept of the mutual cooperation as inter-dependent model rather than on the concept of the incorporation-absorption as a dominant model. The next point the principles of the followings in preparing the library policies should be considered: 1) free-competition, 2) revolution of consciousness through the social education, 3) independence and love for humanity, 4) scientific or reasonable thinking, 5) job responsibility, 6) democratic citizenship, 7) mind far collective life, 8) spirit of public interest 9) globalization In addition, the model of the library systems preparing for thenational unification should include the followings : 1) uniformity of library system and its authority, 2) establishment of research institutes for library policy and system, 3) exchange of library establishment and information resources, 4) building library networks, 5) establishment of education systems for the library and information science and enhancement of its quality, 6) modernizing and developing information technology and its transfer. Finally, the libraries in the north and the south has different concepts, goals, information resources, and the different ways of using them. Considering the practical aspects of the libraries and the reasons for their existence, they must structure the mutual cooperative system so as to minimize the shock when confronting the social changes, so-called the national unification.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.2
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• pp.1-14
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• 2012

The purpose of this study is to derive a desirable riverfront construction plan to me for the activities of citizens through the evaluation and analysis of the urban riverfront space from the perspective of universal design. Therefore, previous studies were examined in order to induce evaluation tools that bhve been grafted from the universal design concept; in addition, a field survey was conducted in Shincheon, Daegu, which was selected as the study target, in order to induce problems and improvement directions from the perspective of universal design. The major results can be summarized as follows. (1) In the 'fairness' aspect, all the items such as installation of integrated functional signage, showing pictures, symbols, foreign language signs, and restroom entrances signage were determined to be 'All Unsuitable' for all sections; and therefore, it is necessary to improve the fairness of usage for everybody. (2) In the 'Functionality(Usability)' aspect, all items such as installation of bicycle paths beside access roads, installation of integrated functional signs, and night light signs were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the functionalities of these facilities. (3) In the 'Convenience' aspect, all items such as the installation of bicycle parking areas, continuous rest facilities, and back and ann support(handles) at resting facilities were determined to be 'All Unsuitable' for many sections; therefore, it is necessary to improve these facilities for the convenience of usage. (4) In the 'Information(Recognizability)' aspect, all items such as showing pictures, symbols, foreign languages and installation of night light signs, and restroom entrances signage were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the recognizability to minimize misunderstandings and confusion. (5) In the 'Safety' aspect, all items such as the installation of safe pedestrian paths in parking areas, using anti-slip and shock absorption materials on restroom floors, and the continuous installation of pedestrian paths that are separate from bicycle paths were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the safety to prevent accidents. (6) In the 'Amenity' aspect, access roads, parking areas, hygiene facilities, convenience facilities, and waterside facilities for many sections were determined to be 'All Unsuitable'; therefore, it is necessary to conduct more concentrated hygiene management. (7) In the 'Accessibility(Mobility)' aspect, all items such as the installation of safe pedestrian paths in parking areas, and continuous pedestrian paths that are separate from bicycle paths were determined to be 'All Unsuitable' for all sections; therefore, it is necessary to improve the accessibility to provide safety and convenience. (8) In the 'Durability' aspect, access roads, parking areas, rest facilities, convenience facilities, fitness facilities, and waterside facilities were determined to be 'All Unsuitable' for many sections, therefore, it is necessary to improve sunken or damaged areas by inspecting facilities by section.