• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1345-1348
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• 2010

Highly monodisperse polystyrene (PS) nanospheres were fabricated by surfactant-free emulsion polymerization in water using styrene, 2,2'-azobis(2-methyl propionamidine) dihydrochloride (AIBA), and poly(vinyl pyrrolidone) (PVP). The size and distribution of the PS nanospheres were systematically investigated in terms of initiator concentration, stabilizer concentration, reaction temperature, reaction time, and reactant concentration. With increasing AIBA initiator concentration, PS particle sizes are raised proportionally, and can be controlled from 120 to 380 nm. Particle sizes were reduced with increasing PVP concentration. This decrease occurs because a high PVP concentration leads to a large number of primary nuclei in the early stage of polymerization. When the reaction temperature increased, the sizes of the PS particles decrease slightly. The particles grew quickly during the initial reaction stage (1-3 h) and the growth rate became steady-state after 6 h. The PS sizes approximately doubled when the reactant (styrene, PVP, azo-initiator) concentrations were increased by a factor of eight.

• The Journal of Korean Physical Therapy
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• v.10 no.2
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• pp.41-55
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• 1998

An analysis of 87 stroke Patients who were enrolled in 7 hospitals in cities of Pusan, Taegu, Kumi, and Andong from January 1 to May 31, 1998 was conducted using the modified Barthel Index(BI) and the adapted PULSES profile index(PS) to evaluate their function. Patients were examined at the following intervals : Initial assessment, one month after initial, at discharge, and ore month after discharge. The mean BI score of patients initial assessment was 26.32. and that of PS was 17.34. There were statistically significant between initial score and one month after initial (16.61 : p<0.001), at discharge(33.51 : p<0,001), one month after discharge(43,56 : p<0.001). PS scores were also improved significantly(-2.1, -3. 94, and -5.52(p<0.001), and BI score between discharge and one month after discharge wag significant improvement(10.06 : p <0.001) and in PS score(-1,57 : p<0.001). Age and BI scone were significantly associated with the improved in BI score between initial and discharge (T3-T1)(p<0.05). Below age forty and the lower initial BI score showed significantly higher improvement(T3-T1) after physical therapy(p<0.05). Initial BI score, BI score at discharge, and religion were significantly associated with the improvement of BI score between initial and one month after discharge(T4-T1)(p<0.05). The lower initial BI score, the high. BI score at discharge, and the religious showed significantly higher improvement(T4-T1)(p<0.05). BI score at discharge and religion were significantly associated with the improvement of BI score between at discharge and one month after discharge(T4-T3)(p<0.05). The lower BI score at discharge, the religious showed significantly higher improvement(T4-T3)(p<0.05) Initial PS score were significantly associated with the improved in PS score between initial and discharge(T3-T1)(p<0.05). The higher initial PS score showed significantly hier improvement(T3-T1)(p<0.05). Initial PS score, Bi score at discharge, and patient's attitude for physical therapy after discharge were significantly associated with the improvement of PS score between initial and one month after discharge(T4- T1)(p <0.05). The higher initial PS scorer the lower PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T1)(p<0.05). PS score at discharge, Patient's attitude for Physical therapy after discharge were significantly associated with the improvement of PS score between discharge and one month after discharge(T4-T3)(p<0.05). The higher PS score at discharge, patient's positive attitude for physical therapy after discharge showed significantly higher improvement(T4-T3)(p<0.05). In conclusion, Initial BI score, BI score at discharge, age, and religion were significantly associated with BI score improvement. initial PS score, BI score discharge, and patient's attitude for physical therapy after discharge were significantly associated with PS score improvement in stroke patients.

• Korean Journal of Pharmacognosy
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• v.3 no.4
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• pp.211-213
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• 1972

전보에서 저자들은 인삼의 anti-inflammatory activity를 추적하여 Panax saponin A 및 C 로 명명된 dammalene계 glycoside를 분리하였고 A에 대해서는 이미 그 화학구조를 밝혀 보고한바 있다. 본보에서는 Panax saponin C(PS-C)의 부분 화학구조를 밝혀 보고코자 한다. PS-C는 산분해하면 panaxatriol 1 mol, glucose 2 mol 및 rhamnose 1 mol을 생성하고, acetylation하면 dodeca-acetate를 형성한다. 따라서 protopanaxtriol의 20[s]-수산기는 glycoside 결합에 참여하고있다. PS-C는 6 mol의 $HIO_4$를 소모하고 permethylate에 대한 methanolysis product를 GLC로 분석한 결과 2, 3, 4-trimethoxy-methyl-rhamnoside 1 mol과 $2,\;3,\;4,\;6-tetramethoxy-{\alpha}-methyl\;glucosied\;2\;mol$이 생성되므로 PS-C 중에 존재하는 3 mol의 sugar는 oligoside 결합에 의하지 않고 monoside결합에 의하여 연결되어 있고 glucose는 ${\beta}-glycoside$ 결합을 하고 있음을 의미한다.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.73-74
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• 2003

Familial form of Alzheimer's disease (FAD) is caused by mutations in presenilin-1 and presenilin-2 (PS2). PS1 and PS2 mutation are known to similar effects on the production of amyloid $\beta$ peptide (A$\beta$) and cause of cell death in the Alzheimer's brain. The importance of the alternation of calcium homeostasis in the neuronal cell death by PS1 mutation in a variety of experimental system has been demonstrated. (omitted)

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.11
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• pp.924-927
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• 2017

This paper presents a 6~18 GHz 8-bit true time delay (TTD) circuit. The unit delay circuit is based on m-derived filter with relatively constant group delay. The designed 8-bit TTD is implemented with two single-pole double-throw (SPDT) switches and seven double- pole double-throw (DPDT) switches. The reflection characteristics are improved by using inductors. The designed 8-bit TTD was fabricated using $0.18{\mu}m$ CMOS. The measured delay control range was 250 ps with 1 ps of delay resolution. The measured RMS group delay error was less than 11 ps at 6~18 GHz. The measured input/output return losses are better than 10 dB. The chip consumes zero power at 1.8 V supply. The chip size is $2.36{\times}1.04mm^2$.

• Microbiology and Biotechnology Letters
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• v.33 no.2
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• pp.117-122
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• 2005

Beijerinckia indica was cultured in mineral salts medium (MSM) medium with various carbon and nitrogen sources to improve the production yield of heteropolysaccharide-7 (PS-7). At high C/N ratio, the high concentration of PS-7 was produced until 40 h of the culture, whereas most of the glucose as a carbon source was used for the cell growth at low C/N ratio. However, at the high C/N ratio, PS-7 accumulation stopped at 48 h of the culture due to the increasing viscosity of the culture broth would inhibit the cell growth. Therefore, the optimized value of C/N ratio was 33.3 (20 g/L glucose, 7.5 mM $NH_{4}NO_3$) for the high production of PS-7. In the culture with various carbon sources, B. indica effectively used the hexoses or glucose-generating sugars for PS-7 formation. Especially, sucrose was the best carbon source for the high production of PS-7 (6.96 g/L) with a high viscosity (40772 cp). In the culture of B. indica with MSM medium containing 20 g/L glucose and 7.5 mM $NH_{4}NO_3$ in a 51 fermentor, the highest cell concentration was 2.5 g/L and the highest concentration of PS-7 was 7.5 g/L (35174 cp). The additional nitrogen sources of 7.5 mM $NH_{4}NO_3$, glutamine and glutamate at 12 h of the culture after exhaustion of a nitrogen source regulated the metabolism of carbon sources, therefore the nitrogen sources could control PS-7 synthesis.

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.1-7
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• 1999

A fungus, Penicillium sp. PS-113, isolated from soil showed the high phosphate-solubilizing activity in patato dextrose broth-rock phosphate to produce free phosphates to the culture broth with the concentrations of 585 ppm against rock phosphate. In this medium, the optimum temperature and initial pH to solubilize rock phosphate were 30$^{\circ}C$ and pH 7.5, respectively. In order to make the mass production of the conidia from this fungus, we cultured in on various solid-based media like barley, corn, wheat, rice, rice bran, and compost. As a result, the fungus highly produced conidia ranging from 2.1 to $5.1{\times}10_9$ conidia/g${\cdot}$media on these solid media except compost-based medium, which was 0 times less than others. Effects of inoculation of the phosphate solubilizing fungus as a biofertilizer were studied in perlite-based pot cropped with Zea mays Suwon 19. Inoculation of Penicillium sp. PS-113 increased in plant height (1.4 times), plant weight (5.2~8.1 times) and root length (1.1~1.2 times) at 60-day cultivation, compared to Hogland solution either without $NH_4H_2PO_4$ or displace $NH_4H_2PO_4$ to powdered rock phosphate, a phosphorus source for plant growth.

• The Journal of Korean Medicine
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• v.29 no.1
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• pp.95-105
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• 2008

Objectives : Although herbal medicines containing flavonoids have been reported to exert anti-tumor activities, it has not been explored whether Hwang-Jeong (Polygonati sibirici Rhizoma, PsR) exerts anti-tumor activity in human glioma. The present study was therefore undertaken to examine the effect of PsR on cell viability and to determine its underlying mechanism in A172 human glioma cells. Methods : Cell viability was estimated by MTT assay. Reactive oxygen species generation and mitochondrial membrane potential were measured by the fluorescence dyes. The phosphorylation of kinases was evaluated by western blot analysis and caspase activity was estimated using colorimetric assay kit. Results : PsR resulted in loss of cell viability in a dose- and time-dependent manner. PsR did not increase reactive oxygen species (ROS) generation and the PsR-induced cell death was also not affected by antioxidants, suggesting that ROS generation is not involved in loss of cell viability. Western blot analysis showed that PsR treatment caused rapid reduction in phosphorylation of extracellular signal-regulated kinase (ERK) without changes in p38 and Jun-NH2-terminal kinase (JNK). U0126, an inhibitor of ERK, increased the PsR-induced cell death, but inhibitors of p38 and JNK did not affect the cell death. PsR induced depolarization of mitochondrial membrane potential. Caspase activity was not stimulated by PsR and caspase inhibitors did not prevent the PsR-induced cell death. Conclusion : Taken together, these findings suggest that PsR results in human glioma cell death through caspaseindependent mechanisms involving down-regulation of ERK.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1535-1540
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• 2004

Six dry Holstein cows were used to evaluate the effect of dietary neutral detergent fiber (NDF) concentration and particle size (PS) on chewing activity. Treatments were arranged in a 3$\times$3 factorial design; total mixed rations contained three NDF concentrations (26, 32, 38%) and three PS (1.0, 1.5, 2.0 cm). NDF levels and particle sizes of diets were adjusted by formulating rate and cutting length of alfalfa hay and rice straw. Cows were fed twice daily at 90% of ad libitum feed intake throughout the experiment. Chewing activity was positively associated with NDF concentration, but not significantly affected by PS of diet. Eating time per unit of NDF intake was affected by PS rather than NDF concentration of diet. Time spent ruminating per unit DM or NDF intake increased with increasing NDF concentration of diet, but was not affected by PS. As the PS of diet increased, the eating time per day increased, but the rumination time decreased. In addition, as the number of rumination bolues decreased the rumination duration increased as well as the chews per bolus. The regression equation induced from relationships of NDF concentrations (NDF, %) and particle sizes (PS, cm) of diet on roughage value index (RVI, min of chewing time/kg DMI) was as follows. RVI=-19.672+1.44$\times$NDF+5.196$\times$PS, ($R^{2}$=0.81).

• Toxicological Research
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• v.25 no.4
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• pp.175-180
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• 2009

Lead (Pb) is a ubiquitously occurring environmental heavy metal which is widely used in industry and human life. Possibly due to a global industrial expansion, recent studies have revealed the prevalent human exposure to Pb and increased risk of Pb toxicity. Once ingested by human, 95% of absorbed Pb is accumulated into erythrocytes and erythrocytes are known to be a prime target for Pb toxicity. Most of the studies were however, focused on $Pb^{2+}$ whereas the effects of $Pb^{4+}$, another major form of Pb on erythrocytes are poorly understood yet. In this study, we investigated and compared the effects of $Pb^{4+}$, $Pb^{2+}$ and other heavy metals on procoagulant activation of erythrocytes, an important factor for the participation of erythrocytes in thrombotic events in an effort to address the cardiovascular toxicity of $Pb^{4+}$. Freshly isolated erythrocytes from human were incubated with $Pb^{4+}$, $Pb^{2+}$, $Cd^{2+}$ and $Ag^+$ and the exposure of phosphatidylserine (PS), key marker for procoagulant activation was measured using flow cytometry. As a result, while $Cd^{2+}$ and $Ag^+$ did not affect PS exposure, $Pb^{4+}$ and $Pb^{2+}$ induced significantly PS exposure in a dose-dependent manner. Of a particular note, $Pb^{4+}$ induced PS exposure with a similar potency with $Pb^{2+}$. PS bearing microvesicle (MV), another important contributor to procoagulant activation was also generated by $Pb^{4+}$. These PS exposure and MV generation by $Pb^{4+}$ were well in line with the shape change of erythrocyte from normal discocytes to MV shedding echinocytes following $Pb^{4+}$ treatment. Meanwhile, nonspecific hemolysis was not observed suggesting the specificity of $Pb^{4+}$-induced PS exposure and MV generation. These results indicated that $Pb^{4+}$ could induce procoagulant activation of erythrocytes through PS exposure and MV generation, suggesting that $Pb^{4+}$ exposure might ultimately lead to increased thrombotic events.