• Steel and Composite Structures
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• v.50 no.6
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• pp.675-688
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• 2024

Cold-formed steel (CFS) is prone to buckling failure under loading. Lightweight concrete (LC) made of lightweight aggregate has light weight and excellent thermal insulation performance. However, concrete is brittle in nature which is why different materials have been used to improve this inherent behavior of concrete. The distortional buckling (DB) performance of cold-formed steel-lightweight concrete (CFS-LC) composite columns was investigated in this paper. Firstly, the compressive strength test of foam concrete (FC) and ceramsite concrete (CC) was carried out. The performance of the CFS-LC members was investigated. The test results indicated that the concrete-filled can effectively control the DB of the members. Secondly, finite element (FE) models of each test specimen were developed and validated with the experimental tests followed by extensive parametric studies using numerical analysis based on the validated FE models. The results show that the thickness of the steel and the strength of the concrete-filled were the main factors on the DB and bearing capacity of the members. Finally, the bearing capacity of the test specimens was calculated by using current codes. The results showed that the design results of the AIJ-1997 specification were closer to the experimental and FE values, while other results of specifications were conservative.

• The Korean Journal of Community Living Science
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• v.18 no.1
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• pp.161-175
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• 2007

It is important for young adults to establish good dietary behavior for healthy life. The prevalence of obesity in college students has increased gradually. The obesity is one of the most prevalent health problems in S. Korea. Moreover, obesity is closely related with the disease such as cardiovascular disease, diabetes mellitus. The purpose of this study was to evaluate health practice, serum components and nutrient intake of the college students according to Body Mass Index (BMI) level. 400 male and female freshmen students in 4 year university located near to Seoul metropolitan area were surveyed respectively through the health check-up procedure for college entrance in February. Survey was carried out for them by questionnaires, including a 24-hour dietary recall and anthropometric measurements. Blood samples were obtained while fasting. Nutrient intake was expressed by DDS(Dietary Diversity Score by 5 food groups) and DVS(Dietary Variety Score). Nutrition level was analyzed by Can-Pro (Korea Nutrition Association). And for the quantity intake, percentage ratio against daily requirement(by KDRIs) and MAR(Mean Adequacy Ratio) were calculated. Underweight group($BMI<18.5kg/m^2$), normal weight group($18.5) and overweight group($BMI<23.0 kg/m^2$) were 18.5%, 61.2% and 19.3% respectively. Nutrient intake levels and food intake status were not significantly different among three groups. The mean nutrient adequacy ratio (MAR) was not significantly different by BMI status. Nutrient intakes of calcium, iron, and riboflavin were especially low for all the students. Overweight group showed high blood pressure(120.9/79.3 mmHg) compared with the underweight group (116.4/ 75.8mmHg) but the difference was not significant. The serum triglyceride level in overweight group (94,0mg%) was higher than that in normal (70.9mg%) or underweight group(70.8mg%)(p<0.05). HDL-cholesterol level in overweight (43.8 mg%) group was not significantly different from that in underweight group (45.9mg%). BMI was positively correlated with blood pressure, hemoglobin, and the intake of total fat and cholesterol. But it was negatively correlated with HDL-cholesterol level. With these results overweight group is closely related with the cardiovascular disease risks, such as high blood pressure and high triglycerides and cholesterol. Thus, a health intervention program including weight control is required for young adults.

• The Journal of Pediatrics of Korean Medicine
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• v.14 no.1
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• pp.9-38
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• 2000

It has been widely said in Korea that early administrations of Cervi cornu parvum (deer antler) to febrile infants affect brain functions. Traditional Oriental Medicine states that the head is easily affected by fever and only an excess of heat causes headaches. Traditional Oriental Medicine also states that Cervi cornu parvum cannot be used in febrile conditions. With the aim of investigating different febrile response to LPS, experiments using intravenous injection of LPS have been carried out on Cervi comu parvum(CCP) and Soahbohyul - tang combined with Cervi comu parvum(SB-CCP) administered rabbits. Experiments were also conducted to evaluate the effects of early administration of CCP on learning and memory in 3 week old rats with LPS fever. These were evaluated by using the Morris water maze and the radial arm maze. Changes in body weight were also observed during this period. The results of these experiments are as follows. 1. In the experiments with febrile rabbits, the CCP and SB-CCP administered group showed statistically significant reductions of fever (p<0.05). 2. In the experiments with febrile rabbits, CCP and SB-CCP administered rabbits resulted in the tendency of lower body temperatures and shorter fever periods than the control group. 3. There were no differences of mean body weight and fever patterns among the 4 groups in the experiments on young rats with LPS fever. 4. There was no statistical difference of mean response latencies among the rats in Group I (DDW administered), GroupIII (CCP administered), and groupIV (SB-CCP administered) in the Morris water maze. However, Group Ⅱ (the scopolamine administered group) showed delayed latencies on the second day of the first session (p<0.05), and the second and third day of the second session (p< 0.05). 5. There were no statistical differences of mean response latencies among the rats in Group I, III and Ⅳ in the radial arm maze, but Group Ⅱ showed delayed latencies on the first and third day of the first session (p<0.05). 6. There was no influence from the administration of CCP and SB-CCP on the general behavior of the rats in Irwin´s test. These results suggest that Cervi cornu parvum and Soahbohyul - tang combined with Cervi comu parvum have anti-pyretic actions on LPS fever. The results also suggest that these drugs have no influence on learning and memory in young rats with LPS fever in the Morris water maze and the radial arm maze.

• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.717-726
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• 2007

If conventional reinforcements are used for high-strength concrete (HSC) structures, a large amount of the reinforcement must be required to compensate for the brittleness of HSC and make the best use of HSC. This raises some structural problems such as steel congestion and an increase in self-weight. Therefore, alternative reinforcing materials and methods for HSC structures are needed. In this study, four full-scale beam specimens constructed with HSC (100 MPa) were tested to investigate the effect of the different shear reinforcements on the shear behavior. These four specimens were reinforced for shear stirrups with normal and high strength steels, headed bars, and carbon fiber-reinforced polymer (CFRP) bars, respectively. In addition, steel fibers were added to the HSC in the two of the specimens to observe their beneficial effects. The use of high strength steels resulted in the improvement of the shear capacity since the shear resistance provided by the shear reinforcements and the bond strength were increased. The specimen reinforced with headed bars also showed a superior performance to the conventional steel reinforced specimen due to the considerably high anchorage strength of headed bar. CFRP bars used in this research, however, seemed to be inadequate for shear reinforcement because of the inferior bond capacity. The presence of the steel fibers in concrete led to remarkable improvement in the ductility of the specimens as well as in the overall cracks control capability.

• Korean Journal of Community Nutrition
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• v.14 no.3
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• pp.266-276
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• 2009

The purpose of this study was to implement and evaluate the nutrition education program for elementary school children Subjects were 5th graders (n = 142) of an elementary school in Seoul, and 138 children completed four sessions of nutrition education during March-April, 2008. One group pretest-posttest design was used to evaluate the program effectiveness. Anthropometric measurements and measurements on nutrition knowledge, eating attitudes and eating behavior were done before and after education. Data were analyzed using paired t-test, t-test and ${\chi}^2-test$. After completing nutrition education, body mass index (from 19.3 to 18.9), fat mass (from 10.9 kg to 10.1 kg), percent body fat (from 25% to 23.3%) of subjects decreased significantly (p < 0.001). Percentages of overweight or obese children were 24.6% at pretest and decreased to 20.3% at posttest, although it did not reach statistical significance. Total score of nutrition knowledge increased significantly from 11.9 (59.5/100) at pretest to 14.7 (73.5/100) at posttest (p < 0.001). After nutrition education, percentages of correct answers increased significantly in 10 knowledge items out of 20 items. These included items such as desirable weight control, energy requirements for boys, food groups, snack, and function of fat and balanced meals (p < 0.001). Total score of eating attitudes increased significantly from 35.1 to 36.9 (p < 0.001). Attitude of applying nutrition knowledge to daily life (p < 0.001), interest toward nutrition and health (p < 0.001), attitude of moderating food intake (p < 0.01), and attitude toward eating habit and future health (p < 0.05) were significantly different between pretest and posttest. Total score of eating behaviors increased significantly from 46.7 (possible score: 20-60) to 49.5 by nutrition education (p < 0.001). Improvement in eight eating behaviors were noticed after nutrition education. These included eating meals slowly, eat protein foods (p < 0.001), eating breakfast, eating meals regularly, eating meals with diverse foods, having dairy foods, eating foods using plant oils (p < 0.01), and having grains (p < 0.05). Subjects evaluated quite positively in attractiveness of program, understanding of program contents, helpfulness of program in improving nutrition knowledge and meal management. Study results show that the nutrition education program was effective in improving nutrition knowledge, eating attitudes and changing eating behaviors of children. This program can be used in nutrition education of children at school or at public health centers.

• Biomolecules & Therapeutics
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• v.12 no.1
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• pp.34-42
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• 2004

The aim of this study is to investigate anti-stress effect of Scutellaria baicalensis(SB). The experiments were performed with the use of young (9 weeks of age) male rats of SD strain and the male ICR mice (20-25 g) at the time of first treatment with SB. Animals of the normal group were not exposed to any stress and the control group were exposed to stress. The rats of the Ginseng, Diazepam(BZ) and SB supplementary group were orally administered once a day 100 mg of red ginseng extract, 5 mg of BZ or 100 mg of SB extract/kg body weight and they were exposed to stress. The mice of the Ginseng, BZ and SB supplementary group were given water containing 200 mg of red ginseng extract, 10 mg of BZ or SB extract/100 ml potable water and exposed to stress. Animals were given supplements for 7 days without stress, and then were given supplement for 5 days with restraining and electroshock stress. We recorded stress related behavioral changes of the experimental animals by stressing them using the Etho-vision system and measured levels of blood corticosterone and IL-2. SB supplementation partially blocked the stress effect on locomotion in the rats and mice, and also partially blocked stress-induced behavioral changes such as freezing, burrowing, grooming, smelling, and rearing behavior in the rats and smelling, grooming, tailing, and rearing in the mice. in elevated plus maze test, the staying time of the stressed rats and mice in the open area decreased while it increased in the closed area. But these changes also partially were blocked by SB-supplementation. SB-supplementation decreased levels of the blood corticosterone which was increased by stress in the rats but did not significantly increase levels of blood interleukin 2 which was decreased by stress in mice.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.205-211
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• 2009

Perioperative pain relief is essential in veterinary practice. However, the cat is one of the most poorly understood species regarding pain control management. Ovariohysterectomy(OHE) produces considerable postoperative pain in cats. Practitioners are often reluctant to administer analgesics due to lack of familiarity with available drugs, concern about side effects, or frustration with the need for record keeping of controlled substances. The purpose of this study was to determine if intraperitoneal administration of bupivacaine can provide relief of pain following OHE in cats. Twelve healthy female cats were randomly divided into two groups. OHE was performed under general inhalation anesthesia. Just prior to complete closure of the linea alba, 6 cats in SAL group received 0.88 ml/kg 0.9% saline, 6 cats in BUP group received 4.4 mg/kg 0.75% bupivacaine diluted to an equivalent volume with saline in the intraperitoneal space. Cats were scored at 0, 1, 2, 4, 8, 12 and 24 hours post-extubation by one observer. Cats were evaluated using a visual analogue scale(VAS) and composite pain scale(CPS) that included physiologic variables. There were no significant differences in body weight, anesthesia time, surgery time, and incision length between the two groups. Cats in the BUP group had significantly(p<0.05) lower VAS-pain scores than cats in the SAL group at 4, 8, 12 hours after surgery. Cats in the BUP group had significantly lower CPS scores than cats in the SAL group at 8, 12 hours after surgery. No adverse side effects were observed. These results support that the intraperitoneal administration of bupivacaine following OHE can be used for the prevention of postoperative pain and pain-induced behavioral changes in cats.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7549-7554
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• 2015

The aim of this study was to develop gastric retentive bi-layered tablet using floating drug delivery technique. Metformin was selected as a model drug due to its narrow absorption window as well as very highly water solubility. These properties of metformin led to be difficult controlling the drug release. The bi-layered tablet was prepared with bi-layered compression machine to minimize interference between floating part and controlling part. The tablet weight, appearance and hardness were evaluated after compression process. The times of 'time to floating' and 'Floating duration' were tested for floating ability and drug release study was also carried out to understand drug release behavior. Furthermore, the drug release of bi-layered tablet was compared with marketed metformin tablet with sustained release pattern (Glucopharge XR$^{(R)}$).The floating ability and drug release behaviors were well controlled by changing amounts of $NaHCO_3$ (floating substance) and hydroxypropyl methylcellulose (HPMC; release control material). Bi-layered tablet had 13s of time to float, over 10h of floating duration and very similar drug release behavior compared with Glucopharge XR$^{(R)}$($f_2$: 89.6). Consequently, the bi-layered tablet with floating ability was successfully prepared and these properties can maximize the efficacy of metformin.

• Polymer(Korea)
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• v.37 no.6
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• pp.702-710
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• 2013

Zaltoprofen loaded polyoxalate (POX) microspheres were prepared by an emulsion solvent-evaporation/extraction method like oil-in-water (O/W) for sustained release of zaltoprofen. The influence of several preparation parameters such as fabrication temperature, stirring speed, intensity of the sonication, initial drug ratio, molecular weight ($M_w$) of POX, concentration of POX and concentration of emulsifier has been investigated on the zaltoprofen release profiles. Physicochemical properties and morphology of zaltoprofen loaded POX microspheres were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and Fourier transform infrared (FTIR). Through the analyzed results, it was demonstrated that the characteristics of the microspheres greatly affected by the prepared condition. The releases behavior of zaltoprofen was investigated for 10 days in vitro. It was confirmed that the release behavior of zaltoprofen can be controlled by the manufacturing factor of solvent-evaporation/extraction method.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.4
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• pp.381-390
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• 2023

In this study, the mechanical performance of concrete exposed to chloride ion penetration was investigated. And a compressive stress-strain model was presented. CaCl₂ solution was added when mixing concrete to simulate long-term chloride ion penetration, and the concentration of chlorine ions was set to 0, 1, 2, and 4 % based on the weight of the binder. To investigate the compressive stress-strain curve after the peak stress of concrete, the compressive strength was measured by displacement control. When the chlorine ion concentration was 1 %, peak stress increased, but when the chlorine ion concentration was 2 % or more, peak stress decreased. In the case of peak strain, no trend according to chloride ion concentration was observed at 7 days. At 28 days, peak strain decreased as the chloride ion concentration increased. A compressive stress-strain curve model based on the Popovics model was presented using changes in peak stress and peak strain at 28 days. Microstructure analyses were performed to investigate the cause of the decrease in mechanical performance as the concentration of chlorine ions increased. It was confirmed that as the concentration of chlorine ion increased, Friedel's salt increased and portlandite decreased.