• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.476-487
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• 2001

In this study, three tree species (Populus euramericana, Kalopanax pictus and Quercus serrata) exhibiting different levels of shade tolerance were employed to investigate photosynthetic responses to the lower light condition on forest floors. Chlorophyll contents, spectral properties and photosynthetic characteristics were examined by using the tree species grown under high light intensity (PPFD $920{\mu}mol\;m^{-2}s^{-1}$) or low light intensity (PPFD $80{\mu}mol\;m^{-2}s^{-1}$). Plants grown under the low light intensity tended to have reduced leaf area, chlorophyll content per unit leaf area, light absorption and respiration in the shade intolerant tree species of P. euramericana. However, the shade tolerant species K. pictus and Q. serrata showed increased leaf area, chlorophyll content and net apparent quantum yield. Therefore, light absorption and light utilization efficiency were improved under the low light intensity. Also shade tolerant species maintained activities of photosystems and $CO_2$ fixation systems with little changes in low light intensity condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.226-234
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• 2017

The physical properties of lightweight foamed concrete mixed with EPS waste and flame resistant EPS waste were investigated. For this purpose, the main variables considered were a cement content of 300 and $400kgf/m^3$ and an EPS replacement ratio of 0, 10, 20, 30, and 40% by the volume ratio of the foam. The water-cement ratio and the dilution concentration were fixed to 0.5 and 10% respectively. The test results showed that the apparent density meets degrees 0.5 and 0.6 of KS F4039, and they showed little difference between the two mixes of Type A and Type B, regardless of the unit cement content. The bending strength obtained through the compressive strength also met the degree of KS F 4039. The thermal conductivity was 1~3% higher for the mixes of EPS than the case of flame resistant EPS, but both mixes met the 0.4 degree of KS F4039. The absorption ratio showed the values above 20% with a 1~3% difference for the two mixes, which mean further studies will be needed to reduce the absorption ratio.

• Journal of Pharmaceutical Investigation
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• v.24 no.2
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• pp.95-104
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• 1994

Inclusion complexes of ketoconazole(KT) with ${\alpha}^_$, ${\beta}^_$cyclodextrin(CD) and $dimethy1-{\beta}-cyclodextrin$ (CD) and $dimethy1-{\beta}-cyclodextrin(DM{\beta}CD)$ as nasal absorption enhancer were prepared in 1: 2 molar ratios by freeze-drying and solvent evaporation methods. In order to compare with the intrinsic absorptivity of KT in the jejunum(J) and the nasal cavity(N), the in situ simultaneous perfusion method was employed. The in situ recirculation study revealed that KT-CD inclusion complexes with the greater stability constant and the faster dissolution rate proportionally increased the absorption of KT in the J and N of rats. The rank order of apparent KT permeability$(P_{app}\;:\;cm/sec\;{\time}\;1O^{-5}{\pm}S.E.)$, corrected by surface area of absorption, was $5.10{\pm}0.3(N,\; KT-DM{\beta}CD)$ )> $4.13{\pm}0.4(N,\;KT-{\beta}-CD)$ )> $3.52{\pm}0.2(N,\;KT-{\alpha}-CD)$ )> $2.76{\pm}0.3(J,\; KT-DM{\beta}CD)$ )> $2.61{\pm}0.5(J,\;KT-{\beta}-CD)$ )> $2.42{\pm}0.4(J,\;KT-{\alpha}-CD)$ at pH 4.0. The in crease in permeability of $KT-DM{\beta}CD$ inclusion complex was 2.6 folds in the J and 4.5 folds in the N when the perfusing solution was changed from the buffer(pH 4.0) to saline. The absorption rate of $KT-DM{\beta}CD$ inclusion complex after nasal administration was more rapid than those of ketoconazole alone and $KT-DM{\beta}CD$ inclusion complex after oral administration to rats. In comparision with an oral administration of ketoconazole suspension in corn oil, the relative bioavailability was calculated 137.3% for the oral and 195.0% for nasal $KT-DM{\beta}CD$ inclusion complex in rats. The present results suggest that $KT-DM{\beta}CD$ inclusion complex may serve as a potential nasal absorption enhancer for the nasal delivery of ketoconazole.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.E1
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• pp.17-24
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• 2001

For the purpose of collecting fog droplets as a function of size a new sampling method was developed in this study. Formation of 100$\pm$10㎛ thickness of polymeric water absorbent film (PWAF) on a nuclepore filter could be successfully realized. Also applicability of particle induced X-ray emission (PIXE) method to the chemical analysis of size-segregated fog droplets collected on PWAF was examined experimentally with synthetic fog droplets generated from a nebulizer. Absorption capacity of S-PAAS polymeric water absorbent shows marked decreases in the range less than 1 wt% and slight decrease between 1 and 3.5 wt% of every salt concentration. Dependency of absorption capacity on pH shows the maximum at pH 7. No apparent peak which can influence the quantitative analysis of elements dissolved and suspended in fog droplets was found at PIXE spectrum of PWAF blank. PWAF kept the original shape without rupture under the PIXE analytical conditions of beam intensity for 10 to 60 nA and irradiation time of 4∼5 min. It should be said that the proposed new technique in the work is helpful to get more detailed information of fog droplets, to clarify the fog formation processes, and to develop a model of acid deposition process.

• Journal of Nutrition and Health
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• v.28 no.11
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• pp.1049-1055
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• 1995

This study was designed to investigate the effects of calcium supplementation on calcium metabolism in seven healthy college women, aged from 19 to 21 years old. For this purpose, metabolic studies were conducted for two weeks. During the first week, the subjects ate experimental diet which nutrients composition was similar to their usual intake. And during the consecutive second week, they ate the same experimental diet supplemented with 500mg of calcium daily. The results were summarized as follows ; 1) Fecal excretion of calcium increased significantly (P<0.05), but urinary excretion of that did not show any change after supplementary intake of calcium. 2) Mean apparent calcium absorption was 28.5% and retention was 182mg/day when subjects ate the experimental diet without calcium supplementation. Calcium retention was significantly ate the experimental diet without calcium supplementation. Calcium retention was decreased to 24.1% by additional intake of calcium. 3) Phosphorus balance did not show any change after additional intake of calcium. 4) Serum calcium level was also not changed by additional intake of calcium. 5) Serum calcium level increased significantly(P<0.05) but serum phosphorus level did not show any change after additional intake of calcium. The above results showed that supplementation of 500mg calcium daily can be helpful to increase calcium retention as well as the peak bone mass in young women eating usual Korean diets.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.579-582
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• 2003

Norfloxacin, that inhibits the action of topoisomerase Ⅱ, binds to wide variety of DNA. The binding mode of this drug to double- and super-coiled DNA (ds- and scDNA) is compared in this study by various spectroscopic methods, including absorption, fluorescence, and circular dichroism(CD) spectroscopy. Hypochromism in the absorption band, negative and positive induced CD bands (respectively in 240-260 nm and 270-300 nm region) are apparent for the norfloxacin that bound to both the dsDNA and scDNA. A decrease in fluorescence is also noticed in the presence of both DNAs. Since the spectroscopic characteristics are the same for both complexes, it is imperative that the binding mode of the norfloxacin is similar in ds- and scDNA. In the presence of $Mg^{2+}$, which is a cofactor in the topoisomerase Ⅱ action, the fluorescence intensity of the scDNA-norfloxacin complex increased and the resulting fluorescence intensity and shape was identical to that in the absence of scDNA. Therefore, the addition of an excess amount of $Mg^{2+}$ may result in the extrusion of norfloxacin from scDNA.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.89-98
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• 2014

In this study, soybean is used to produce soymilk according to various extracting methods and heating time. Specifically, the soy slurry is being filtered before being heated, or heated before being filtered. Following that the soymilk produced is freeze-dried to be powdered, and then, the quality characteristics of the powdered soymilk are mutually compared to determine the applicability of various food additives. The freeze-dried soymilk powder shows 2.03~6.35% of moisture content, and in terms of unit quantity, retained more proteins, which suggests that the ratio of protein extraction is higher than any other nutrients. Accordingly, the protein coefficient is significantly higher in soymilk powder being heated and processed than in raw soybeans. In particular, protein coefficient is the highest in the soymilk which is heated for 20 minutes before being filtered (SHBF20). The longer the heating time was, the trypsin inhibitor (TI) tended to be far less active. Such an inactivation seems to be more apparent in the "SHAF" soymilk powder than "SHBF" soymilk powder. Because protein had to be denaturated by heating for soymilk, the nitrogen solubility index (NSI) of soymilk powder is decreased considerably, while the protein digestibility, water absorption, emulsification and foaming activity all increase. Oil absorption tends to decrease slightly. As discussed above, the soymilk heated for 10 minutes after being filtered (SHAF10) and the soymilk heated for 20 minutes before being filtered (SHBF20) show optimum processing conditions for soymilk powder.

• Advances in concrete construction
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• v.13 no.3
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• pp.243-254
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• 2022

Reinforced concrete (RC) deep beams are critical structural elements used in offshore pile caps, rectangular cross-section water tanks, silo structures, transfer beams in high-rise buildings, and bent caps. As a result of the low shear span ratio to effective depth (a/d) in deep beams, arch action occurs, which leads to shear failure. Several studies have been carried out to improve the shear resistance of RC deep beams and avoid brittle fracture behavior in recent years. This study was performed to investigate the behavior of RC deep beams numerically and experimentally with different reinforcement arrangements. Deep beams with four different reinforcement arrangements were produced and tested under monotonic static loading in the study's scope. The horizontal and vertical shear reinforcement members were changed in the test specimens to obtain the effects of different reinforcement arrangements. However, the rebars used for tension and the vertical shear reinforcement ratio were constant. In addition, the behavior of each deep beam was obtained numerically with commercial finite element analysis (FEA) software ABAQUS, and the findings were compared with the experimental results. The results showed that the reinforcements placed diagonally significantly increased the load-carrying and energy absorption capacities of RC deep beams. Moreover, an apparent plastic plateau was seen in the load-displacement curves of these test specimens in question (DE-2 and DE-3). This finding also indicated that diagonally located reinforcements improve displacement ductility. Also, the numerical results showed that the FEM method could be used to accurately predict RC deep beams'behavior with different reinforcement arrangements.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.3
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• pp.251-258
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• 1983

This experiment was carried out to investigate the capability of production of artificial milk for leaf protein concentrate (LPC). Chloroplastic protein and cytoplasmic protein were extracted from leaves of Dystaenia takeshimana Nakai and LPC was extracted from leaves of Italian ryegrass to increase the functional properties of LPC as a level of milk casein. One gram of chloroplastic protein and cytoplasmic protein and 1g of LPC were succinylated by addition of succinic anhydride 0.1, 0.25, and 1g respectively. Their functional properties were investigated in this experiment. The results obtained were summarized as follows: 1. The non-succinylated LPC showed a higher value in bulk density than the chloroplastic protein, the cytoplasmic protein and LPC succinylated by addition of succinic anhydride 0.1, 0.25, and 1g respectively. Nevertheless, succinylation had an enhancing effect as indicated by the rises as the degrees of succinylation was increased. 2. Although solubility of non-succinylated LPC was lower than that of milk casein, succinylation caused an effective increase in the solubility of the protein and LPC. 3. Water absorption and fat absorption of succinylated LPC were twice to eight times higher than those of milk casein. Fat absorption was not influenced to the extent by succinylation as the water absorption. Excessive succinylation resulted in the decrease of both water absorption and fat absorption. 4. Emulsifying activity and emulsion stability were increased in proportion to the succinylated degree of LPC. More than 10% increase in the amount of succinic anhydride resulted in an apparent increase in emulsifying activity and emulsion stability. Besides, the succinylated LPC showed more excellent functional properties in emulsifying activity and emulsion stability than milk.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.584-589
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• 2001

Isopropryl 2-(1-3-dithiethane-2-ylidene)-2 [N-(4-methyl-thiazole-2-yl) carbamoyl] acetate (YH439) is currently under phase ll clinical trials by the Yuhan Research Center for use as a hepatoprotective agent. Unfortunately, the oral bioavailbility of YH439, which is sparingly soluble in water (i.e., $0.3{\;}\mu\textrm{g}/ml{\;}or{\;}0.91{$\mu}M$ at room temperature), reportedly, is negligibleregardless of the dose administered to rats in the 10-300 mg/kg range. The bioavailability of the compound increased up to 24%, when administered in the form of a micellar solution ($700{\;}\mu\textrm{g}/ml$or 2.1 mM for YH439) at a dose of 10 mg/kg, suggesting that its limited solubility is associated with its negligible bioavailability. In order to obtain additional informmation concerning the bioavailability of YH439, the mechanism(s) involved in gastrointestinal (Gl) absorption were investigated in the present study. For this purpose, the transport of YH430 across a Caco-2 cell monolayer was measured in a $Transwell^{\circledR}$. A permeability of $4.07{\times}10^{-5}{\;}cm/s$ was obtained for the absorptive (i.e., apical to basolateral direction) transport of $0.42{\mu}M$ YH439, implicating that the in vivo Cl absorption is nearly complete. The absorptive transport exhibited a slight concentration-dependency with an intrinsic clearance ($CL_{i}$) of $0.38{\mu}L/{\textrm{cm}^2}/sec$, which accounted for 28.1% of the total intrinsic clearance (i.e., $CL_i$ plus the intrinsic clearance for the linear component) of the transport. Thus, saturation of the absorption process appears to be a minor factor in limiting the bioavailability of the compound. The apparent permeability of YH439 from the basolateral to the apical direction (i.e., efflux, $6.67{\times}10^{-5}{\;}cm/s$) was comparable to that for absorptive transport, but, interestingly, a more distinct concentration-dependency was observed for this transport. However, the efflux does not appear to influence the bioavailability of the compound, as evidenced by the sufficiently high permeability in the absorption direction. Rather, a reportedly extensive first-pass hepatic metabolism appears to be a principal factor in limiting the bioavailability. In this respect, reducing the first-pass metabolism by some means would lead to a higher bioavailability of the compound. Thus, elevation of the absorption rate of YH439 becomes a necessity. From a practical point of view, increasing the concentration of YH439 in the Cl fluid appears to be a feasible way to increase the absorption rate, because the compound is primarily absorbed via a linear mechanism. In summary, the solubilization of YH439, as previously demonstrated for a micellar solution of the compound, appears to be a practical way to increase the oral bioavailability of YH439.