• Applied Microscopy
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• v.25 no.2
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• pp.11-19
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• 1995

This research was undertaken to determine the effect of cyclophosphamide(CP) on the Leydig cells and macrophages in the interstitial tissue of the mice(ICR strain). To evaluate how this drug could affect the these cells, during administration(200mg/kg) 1 time to 3 times at intervals of 48hrs. In the Leydig cells of the control and 1 time treated group, a number of microperoxisomes were observed interspersed among the network of smooth endoplasmic reticulum(SER) in cellular regions where the SER predominantes. Microperoxisomes were also founded in close proximity to the cell membrane. The interstitial tissue were exhibited degenerating Leydig cells but macrophages wer containd greatly increased numbers of cytoplasmic inclusion body and secondary lysosomes. In the 1 time treated group. A very small number of Leydig cells were observed, from 2 to 3 time group, but macrophages were more increased than 1 time group in number. CP thus offers a valuable opportunity to study further the interaction between Leydig cells and macrophages in the interstitial tissue. These alteration could be direct mediated by toxic effect of the drug on the interstitial tissue.

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.265-270
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• 1991

Theoretical calculations on the stabilization energies of framework atoms in hydrolyses Co(Ⅱ )-exchanged zeolite A were made using some potential energy functions and optimization program. The protons which are produced by hydrolysis of $[Co(H_2O)_n]^{2+}$ ion in large cavity showed a tendency to attack the framework oxygen atom O(1) preferentially, and the oxygen atom O(4) within OH- ion was coordinated at Al atom. The weakness of bonds between T(Si, Al) and oxygen by attack of proton and too large coordination number around small aluminum atom will make the framework of Co(Ⅱ)-exchanged zeolite A more unstable. The stabilization energy of $Co_4Na_4$-A framework (- 361.57 kcal/mol) was less than that of thermally stable zeolite A($Na_{12-}$A: - 419.68 kcal/mol) and greater than that of extremely unstable Ba(Ⅱ)-exchanged zeolite A($Ba_{6-}$A: - 324.01 kcal/mol). All the data of powder X-ray diffraction, infrared and Raman spectroscopy of Co(Ⅱ)-exchanged zeolite A showed the evidence of instability of its framework in agreement with the theoretical calculation. Three different groups of water molecules are found in hydrated Co(Ⅱ )-exchanged zeolite A; W(Ⅰ) group of water molecules having only hydrogen-bonds, W(Ⅱ) group water coordinated to $Na^+$ ion, ans W(Ⅲ) group water coordinated to Co(Ⅱ) ion. The averaged interaction energy of each water group shows the decreasing order of W(Ⅲ)>W(Ⅱ)>W(Ⅰ).

• The Journal of Korean Medicine
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• v.19 no.1
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• pp.179-204
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• 1998

The purpose of this research was to investigate the efficacy of Goiwhasan extract powder on the gastric injuries, antiulcer, gastrointestinal tract and blood hemostasis. Animals were used through this studies mice and rats. All animals were divided into 3 groups, contol group(no treatment), sample Ⅰ group(375mg/kg administration), sample Ⅱ group(750mg/kg administration). The gastric injuries and ulcer have been made by using pyloric ligation, indomethacin, HCI-ethanol, acetic acid and then The histological observation was followed. In the gastrointestinal tract, gastric juice secretion, gastric acidity, pepsin output, blood gastrin and secretin level, transport potentials in the small and large intestine were checked. And studies on blood hemostasis were performed on normal hemostatic activities and plasma prothrombin time, plasma recalcification time, plasma fibrinogen levels in the hypoprothrombinemic mice induced by warfarin. The results were as follows: 1. The antigastric ulcer effects on the pyloric ligation, indomethacin, HCl-ethanol, acetic acid induced gastric injuries were shown in Sample Ⅱ group(p<0.05). 2. Through the morphologic examination on the acetic acid induced ulcer, Sample Ⅰ group showed mild regeneration of epithelium and slight decrease of periulcer edema then that of Control group, while Sample Ⅱ group showed more retraction of round ulcer site, remarkable loss of swelling and edema then that of Control group, and revealing the regenerated epithelium in the surrounding ulcer site. Thus it was noted that both Sample groups have antigastriculcer effects on the experimentally induced gastric ulcer. 3. The inhibitory effects on gastric juice were noted in both Sample Ⅰ group(p<0.05) and Sample Ⅱ group(p<0.01). However, only Sample Ⅱ group showed the inhibitory effects on total acidity and pepsin output(p<0.05). 4. The significant inhibition of blood gastrin level showed at 30 min.(P<0.05) and 90 min.(P<0.05) after starting medication in only Sample Ⅱ group, but significance of blood secretin level in both groups was not recognized. 5. Any significant changes in barium sulfate transport in the small intestine of mice was not recognized in both groups, but the significantly inhibitory effect in large intestine was recognized in both Sample Ⅰ group(p<0.05) and Sample Ⅱ group(p<0.001). 6. In hemostatic effect on both normal mice and hypoprothrombinemic mice induced by warfarin, the significantly shortening effect on coagulation time was seen in only Sample Ⅱ group(p<0.01). 7. On plasma prothrombin time in hypoprothrombinemic rat induced by warfarin, Sample Ⅱ group have shortened the prothrombin time significantly(p<0.001). 8. On plasma reclcification time in hypoprothrombinemic rat induced by warfarin, the recalcification time have been shortened significantly in both Sample Ⅰ group(p<0.05) and Sample Ⅱ group(p<0.01). 9. On plasma fibrinogen levels in hypoprothrombinemic rat induced by warfarin, the fibrinogen contents in Sample Ⅱ have been decreased significantly(p<0.01). Overall the above results suggest that Goiwhasan has an therapeutic efficacy on antigastric ulcer and blood hemostasis. Further studies would be needed on the interaction of its herbal medicine and its mechanism in the future.

• The Journal of Information Systems
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• v.29 no.2
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• pp.265-286
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• 2020

Purpose Among various psychosocial factors, negative social comparison, attention blocking to stimuli, and cognitive interference via information overload are considered most critical in hindering the effective performance improvement of computer-based idea generation. Given that the effect of negative social comparison along with a plausible solution based on the notion of performance feedback and goal setting has been successfully addressed, this study focused on the remaining issues of "attention blocking to stimuli and cognitive interference via information overload" and attempted to find a way to alleviate the effect of such process losses on performance. Design/methodology/approach A 2 × 4 between-subjects design was used, crossing cognitive ability (high and low) and personality (extroversion and introversion). Five subjects per each treatment were randomly selected to make the sample size equal. The group simulator was used to measure individual-level performance. The dependent variables were the quantity of and quality score of ideas. The manner by which these performance measures were operationalized was consistent with prior studies. An additional analysis using the number of diverse ideas was also conducted. Findings Three arguments were made in this study: (1) high cognitive individuals would perform better than low cognitive individuals, (2) extraverted individuals would perform better than introverted individuals, and (3) cognitive ability and personality would interact such that individuals in Q1 would have the highest performance. Cognitive ability had an effect on quality not quantity. Personality had an effect on both quantity and quality. An interaction between cognitive ability and personality was not found due to small sample size despite the use of the group simulator.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.795-804
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• 2007

Statement of problem. Nano-scale calcium-phosphate coating on the anodizing titanium surface using ion beam-assisted deposition (IBAD) has been recently introduced to improve the early osseointegration. However, not much is known about their surface characteristics that have influence on tissue-implant interaction. Purpose. This study was aimed to investigate microtopography, surface roughness, surface composition, and wettability of the titanium surface modified by the anodic oxidation and calcium phosphate coating using IBAD. Material and methods. Commercially pure titanium disks were used as substrates. The experiment was composed of four groups. Group MA surfaces represented machined surface. Group AN was anodized surface. Group CaP/AN was anodic oxidized and calcium phosphate coated surfaces. Group SLA surfaces were sandblasted and acid etched surfaces. The prepared titanium discs were examined as follows. The surface morphology of the discs was examined using SEM. The surface roughness was measured by a confocal laser scanning microscope. Phase components were analyzed using thin-film x-ray diffraction. Wettability analyses were performed by contact angle measurement with distilled water, formamide, bromonaphtalene and surface free energy calculation. Results. (1) The four groups showed specific microtopography respectively. Anodized and calcium phosphate coated specimens showed multiple micropores and tiny homogeneously distributed crystalline particles. (2) The order of surface roughness values were, from the lowest to the highest, machined group, anodized group, anodized and calcium phosphate deposited group, and sandblasted and acid etched group. (3) Anodized and calcium phosphate deposited group was found to have titanium and titanium anatase oxides and exhibited calcium phosphorous crystalline structures. (4) Surface wettability was increased in the order of calcium phosphate deposited group, machined group, anodized group, sandblasted and acid etched group. Conclusion. After ion beam-assisted deposition on anodized titanium, the microporous structure remained on the surface and many small calcium phosphorous crystals were formed on the porous surface. Nanoscale calcium phosphorous deposition induced roughness on the microporous surface but hydrophobicity was increased.

• Macromolecular Research
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• v.15 no.6
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• pp.547-552
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• 2007

Water soluble polymer, poly(vinyl pyrrolidone) was chosen to conjugate with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(succinyl) (N-succinyl DPPE) to make a new drug delivery system. PVP with an amine group (amino-PVP) was polymerized by free radical polymerization. The amine group of amino-PVP was conjugated with the carboxylic group of N-succinyl DPPE. The resultant conjugate could form nanoparticles in the aqueous solution; these nanoparticles were termed a lipid-polymer system. The critical aggregation concentration was measured with pyrene to give a value of $1{\times}10^{-3}g/L$. The particle size of the lipid-polymer system, as measured by DLS, AFM and TEM, was about 70 nm. Lipophilic component in the inner part of the lipid-polymer system could derive the physical interaction with hydrophobic drugs. Griseofulvin was used as a model drug in this study. The loading efficiency and release profile of the drug were measured by HPLC. The loading efficiency was about 54%. The release behavior was sustained for a prolonged time of 12 days. The proposed lipid-polymer system with biodegradable and biocompatible properties has promising potential as a passive-targeting drug delivery carrier because of its small particle size.

• Journal of Educational Research in Mathematics
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• v.15 no.1
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• pp.75-105
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• 2005

This study explored a mathematical modeling flow and the effect of interactions among students and between a student and Excel on modeling in a small group modeling environment with Excel. This is a case study of three 8th graders' modeling activity using Excel during their extra lessons. The conclusions drawn from this study are as follows: First, small group modeling using Excel was formed by formulating 4∼10 modeling cycles in each task. Students mainly formed tables and graphs and refined and simplified these models. Second, students mainly formed tables, algebraic formulas and graphs and refined tables considering each variable in detail by obtaining new data with inserting rows. In tables, students mainly explored many expected cases by changing the values of the parameters. In Graphs, students mainly identified a solution or confirmed the solution founded in a table. Meanwhile, students sometimes constructed graphs without a purpose and explored the problem situations by graphs mainly as related with searching a solution, identifying solutions that are found in the tables. Thus, the teacher's intervention is needed to help students use diverse representations properly in problem situations and explore floatingly and interactively using multi-representations that are connected numerically, symbolically and graphically. Sometimes students also perform unnecessary activities in producing data by dragging, searching a solution by 'trial and error' and exploring 'what if' modeling. It is considered that these unnecessary activities were caused by over-reliance on the Excel environment. Thus, the teacher's intervention is needed to complement the Excel environment and the paper-and-pencil environment properly.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.340-347
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• 2006

Soyasaponins $A_1$, DDMP-conjugated group B soyasaponins ${\alpha}g\;and\;{\beta}g$, non-DDMP counterpart soyasaponin I, II+III, and DDMP moiety were quantified in the large-, midium-, and small-seed soybean varieties. Protein contents were ranged from 38.1% to 41.8%, and oil contents were ranged from 15.5% to 18.9%, respectively. Oil contents in the large-seed varieties were significantly higher than those of medium- and small-seed varieties. Among detected soyasaponin peaks, ${\beta}g$ was a major soyasaponin in DDMP-conjugated group B soyasaponins followed by soyasaponin I, DDMP moiety and $A_1$. Soyasaponin concentration among different seed size soybean varieties. The soyasaponin concentration of mediumseed ($4014.5{\mu}g/g$) was slightly higher than those of largeseed ($3755.0{\mu}g/g$) and small-seed varieties ($3620.3{\mu}g/g$), however, the differences was statistically not significant. The composition rates of soyasaponins in the large-size seeds were 9.4% of soyasaponin $A_1$, 26.5% of DDMP-conjugated soyasaponins, 49.9% of non-DDMP counterpart soyasaponins, and 14.2% of DDMP moiety, respectively. Similar results were observed in the composition ratios of middle- and small-size seeds. Oil content and C:N ratio showed the significant positive correlations with total soyasaponin concentration, while the 100-seed weight, fiber, and ash contents showed the negative correlations with total soyasaponin but statistically not significant. It was noted that protein contents didn't have any relationship with group A, group B, DDMP moiety, and total soyasaponin. This fact suggested that protein contents are not affects the variation of soyasaponin concentration.

• YAKHAK HOEJI
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• v.49 no.5
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• pp.380-385
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• 2005

The aim of this study is to investigate the effects of verapamil on the pharmacokinetics of tamoxifen following oral administration of tamoxifen with verapamil to rats. Tamoxifen (10 mg/kg) was administered orally in the presence or absence of verapamil (1, 3 or 6 mg/kg). Compared to the control group (given tamoxifen alone), the presence of verapamil significantly (p<0.05 by 1 mg/kg, p<0.01 by 3 and 6 mg/kg) increased the areas under the plasma concentration-time curve (AUC) and the peak concentrations ($C_{max}$) of tamoxifen. Consequently, the relative bioavailability ($RB\%$) of tamoxifen with verapamil was 1.6-2.1 fold higher than that of the control. But the time to reach peak concentration ($T_{max}$) and the terminal half-life ($t_{1/2}$) of tamoxifen were not altered significantly in the presence of verapamil. The increased AUC and $C_{max}$ of tamox­ifen in the presence of verapamil might be associated with the inhibition by verapamil of the P-glycoprotein and the first­pass metabolizing enzyme CYP3A4 in small intestinal mucosa. The drug interaction should be taken into consideration when tamoxifen is used to the patient with verapamil in the clinical setting.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.476-476
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• 2011

Introduction of CNTs into a metal matrix has been considered to improve the mechanical properties of the metal matrix. However, the binding energy between metals and pristine CNTs wall is known to be so small that the interfacial slip between CNTs and the matrix occurs at a relatively low external stress. The interfacial strength between CNT and metal matrix is thus one of the key factors for successful development of the CNT/metal composites. Defective or functionalized CNT has been considered to enhance the interfacial strength of nanocomposites. In the present work, we design the various realistic hybrid structures of the single wall CNT/Cu complexes and characterize the interaction between single wall CNTs and Cu nano-particle and Cu13 cluster using first principle calculations. The characteristics of functionalized CNTs with various surface functional groups, such as -COOH, -OH, and -O interacting with Cu are investigated. We found that the binding energy can be enhanced by the surface functional group including oxygen since the oxygen atom can mediate and reinforce the interaction between carbon and Cu. These results strongly support the recent experimental work which suggested the oxygen on the interface playing an important role in the excellent mechanical properties of the CNT/Cu composite.