• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.21-31
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• 2006

The objectives of this study were to analyze trends of temporal water quality and trophic state in Andong and Imha reservoirs using chemical dataset during 1993 ${\sim}$ 2004, obtained from the Ministry of Environment, Korea. According to long-term limnological analyses, Suspended solids (SS) in Imha Reservoir were 2 ${\sim}$ 8 fold2 greater, than those in SS of Andong Reservoir, and the high solids increased total phosphorus (TP) and biological oxygen demand ($BOD_5$) and decreased the transparency, measured as Secchi depth (SD). Chlorophyll-a (CHL-a) increased little or decreased slightly in the both reservoirs during the high solids, resulting in reduced yields of CHL-a : TP ratios. The deviation analysis of Trophic State Index (TSI) in Imha Reservoir showed that about 70% of TSI (CHL-a)-TSI (SD) and TSI (CHL-a)-TSI(TP) values were less than zero and the lowest values were-60, indicating that influence of inorganic solids (or non-volatile solids) on phytoplankton growth was evident in Imha Reservoir and the impact was greater than that of Andong Reservoir. Inorganic solids in Imha Reservoir resulted in light limitation on phytoplankton growth and thus contributed variations in the relations among three parameters of trophic state index. Especially, seasonal data analysis of nutrients in both reservoirs showed that during the postmonsoon, mean TP concentration was Imha Reservoir greater in than that in Andong Reservoir. The higher TP concentrantion was mainly attributed to increases of inorganic solids from soil erosions and nonpoint source inputs within the watershed. The high inorganic turbidity in Imha Reservoir should be reduced for the conservation of water quality for, especially a tap water supply.

• Clinical and Experimental Pediatrics
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• v.46 no.5
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• pp.459-466
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• 2003

Purpose : AOM is the most common bacterial URI in children. The bacteriology and antibiotic Tx of AOM in children has been studied in many countries. But, there is few study of causative pathogens and antibiotic Tx of AOM in our country. In this aspect, we performed prospective clinical study to confirm the causative pathogens and assess the clinical responses of cefprozil in AOM patients. Methods : Thirty three AOM patients enrolled in this study. Tympanocentesis for isolation of causative pathogens were performed before Tx of cefprozil. The study patients received cefprozil with dose of 15 mg/kg/bid.po/day for 10-12 days, and initially assessed the clinical response at 4-5 days after receiving cefprozil and finally at the end visit. In vitro susceptibility tests of cefprozil to isolated pathogens were done by disc diffusion method, and in vitro susceptibility tests of cefaclor and cefixime to isolated pathogens were simultaneously performed. Results : Bacterial pathogens[S. pneumoniae(10), H. influenzae(5), S. aureus(2), M. catarrhalis(1) and Group A stretococcus(1)] were isolated from 19 patients. Clinically, all patients had history of abrupt high fever except one. Tympanic perforation was dominant in pathogens isolated cases, and otalgia was significantly developed in non-pathogens isolated cases. The ages of pathogens isolated cases were usually below 2 years. Eighty four point nine percent of the patients including two cases with isolation of intermediate resistant S. pneumoniae were clinically improved. Antimicrobial in vitro activity to S. pneumoniae of cefprozil were superior than that of cefacor and cefixime. Conclusion : We confirm that bacteria has the causative role in about 60% cases, and S. pneumoniae is the most common pathogen. Clinically, there were some differences in symptoms, signs and ages between pathogens isolated and non-pathogens isolated cases. The clinical responses of cefprozil in our patients revealed similar outcomes to other countries. And we reconfirm that cefprozil may be clinically effective in cases of AOM due to intermediate resistant S. pneumoniae.

• Journal of Chest Surgery
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• v.29 no.7
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• pp.689-699
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• 1996

An animal experiment was designed for the evaluation of in vivo performance of the newly developed electrohydraulic type ventricular assist device and its influence on the left ventricular function during pal- satile left ventricular assist. Eight adult sheep were incorporated into the study and data were collected from seven sheep. Total as- sist time ranged from 69 minutes to 7 days. The performance of the device was satisfactory both in asyn- chr nous and synchronous mode within the range of given native heart rate. More than 4 liters of device output could be reached within the range of normal left atral pressure without development of negative pressure in the left atrium. Moderate to severe degree of hemolysis was noted as evidenced by significant increase of plasma free hemoglobin level after 3 days of left ventricular support along with the presence of the small amount of thrombi around the floating disc type polymer valve apparatus reflecting that further study and refinement of the device need to be done in regard of biocompatibility and thromboresistance. The hemodynamics showed increase in heart rate (p < 0.05), cardiac output and left ventricular minute work (p < 0.05) after placement of the device at the flow rate of 2.0∼2.5 Llmin. The left atrial pressure, left ventricular pressure and LV dpldt were decreased after the device placement(p < 0.05). The endocardial viability ratio and oxygen contents of the mixed ven us blood and coronary venous blood were all increased (p < 0.05) after the device placement suggesting effective unloading of the left ventricle was accomplished. The myocardial perfusion was thought improved in synchronous counterpulsation as suggested by sig- nificant increase in endocardial viability ratio and coronary venous blood oxygen content in synchronous assist mode comparing with asynchronous mode.

• Journal of Chest Surgery
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• v.30 no.10
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• pp.979-985
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• 1997

Between October 1991 and May 1995, 256 "New Duromedics Valve"(Edward TEKNA Bileaflet Valve) were implanted in 208 adult patients(171 mitral, 82 aortic and 3 tricuspid) with age ranging from 18 years to 70 years(mean 48.2$\pm$ 11.6 years). Postoperative complication rates were 12.2%, but there was none valve related one. Overall early mortality rate were 1.4%(1.6% for MVR, 2.1% for DVR, and none for AVR or TVR) respectively. Follow-up was 99% completed ranging in duration from 2 months to 46 months. There were 6 valve-related late complications(2.9%) with 2 patients with upper gastrointestinal bleeding, 2 with cerebral thxomtioembolism, 1 with valve thrombosis and 1 with valve endocarditis. Freedom from these valve-related major complications were 89.9% at 40 months. There were 5 late deaths(2.4%). one of these late deaths was considered valve-related. Overall actuarial survival rates at 40 months were 95.5%, 96.8% for mitral, 97.1% for aortic, 100% for tricuspid, and 92.0% for double valve replacement respectively. Preoperative New York Heart Association functional class were 2.9, and 1.3 in post-operative state. We have been trying to keep the international normalized ratio(INR) with range of 2.5 to 3.0. The INR of 4 patients of 5 with anticoagulant ralated complications was beyond the range. To reduce the rate of anticoagulant related complications, we felt very strongly that the INR should be kept between 2.5 and 3.0. In our cases, there was no structural failure or significant hemolysis in the absence of periprosthetic leak. This experience encourages us to continue using the "New Duromedics Valve".omedics Valve".uot;.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.123-132
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• 1982

These experiments were conducted to investigate the enzymatic characteristics of the purified $\alpha$-amylase (F-2A) of Bacillus circulans F-2 and the digestion rate of various starches. 1. The molecular weight was estimated to be 93000 by SDS-polyacrylamide disc gel electrophoresis. The isoelectric point was about pH 5.0. The optimum pH for the enzyme action was 6.0-6.5 and the stable pH ranged pH 5.5-12.0. The optimum temperature was 6$0^{\circ}C$, and the purified $\alpha$-amylase was stable below 4$0^{\circ}C$. 2. The purified $\alpha$-amylase was activated by Mn$^{＋＋}$ and Co$^{＋＋}$, whereas it was inhibited by Ag$^{＋}$, HT$^{＋＋}$, Cu$^{＋＋}$ and Pb$^{＋＋}$. 3. The purified $\alpha$-amylase is considered to have no sulfhydryl residue essential for its catalytic activity. 4. Michaelis constant (Km) was 1.704 mg/$m\ell$. Activation energy between 25-4$0^{\circ}C$ was 12.297 Kcal/mole, and between 40-6$0^{\circ}C$, it was 7.831 Kcal/mole. 5. The hydrolysis product from soluble starch, amylose and amylopectin in the early stage of hydrolysis was G$_{6}$, and as hydrolysis proceeds, G$_4$and G$_2$appeared. 6. Products from each oligosaccarides are as follows: G$_4$longrightarrow G$_2$＋ G$_2$,G$_3$ ＋G$_1$,G$_{5}$longrightarrow G$_4$＋G$_1$,G$_{6}$longrightarrowG$_4$＋ G$_2$,G$_{7}$ G$_4$,G$_{8}$longrightarrow G$_4$＋G$_4$, 7. On raw potato starch, raw sago starch and raw yam starch, the purified enzyme exhibited a remarkably high digestion rate than Porcine pancreatic amylase and Streptococcus bovis amylase.

• Applied Microscopy
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• v.35 no.1
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• pp.41-56
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• 2005

Present study was performed to observe the tegumental ultrastructures by the developmental stages which derived from the experimental life cycle of Spirometra erinacei in laboratory conditions. In SEM view, coracidium was spherical in shape with numerous cilia, and its surface was covered with long cilia, tuberclelike projections with millet-like processes, and small holes. The body surface of procercoid was covered with numerous pointed microtriches except that of frontal pit with stout spine-like ones. However that of cercomer was covered with somewhat sparse blunt-tiped microtriches. Plerocercoids of 3 days old resembled the mature procercoid in shape, and their frontal pits were covered with numerous stout spine-like microtriches. However frontal pit and body surface in more than 5 days old ones were covered with conoid microtriches. On the surface of adult scolex, hairly long filamentous and stout short microtriches were mixedly distributed. Filamentous microtriches were more densely distributed in the anterior portion than in the posterior of scolex. The neck and immature proglottid were covered with only stout short conoid microtriches. In TEM view of coracidia, embryophore and oncosphere were obviously distinguished. The embryophore contained numerous glycogen particles, mitochondria and lipid granules. The cilia on the surface of embryophore rooted in the coracidial sheath, and consisted of 9 pairs of microtubules and 2 core complex. The oncosphere was covered with a thin and unarmed tegument, and was multi-nucleated. The protoplasmic layer of procercoid and plerocercoid consisted of disc-shaped bodies, vacuoles and mitochondria. Their tegumental cells commonly retained a nucleus, granular endoplasmic reticulums and secretory granules. The protoplasmic layer of plerocercoid was more compacted than that of procercoid. From the above results, it was confirmed that the tegumental ultrastructures are something different according to the developmental stages of S. erinacei.

• Magazine of the Korean Society of Agricultural Engineers
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• v.13 no.1
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• pp.2162-2176
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• 1971

From the ancient times our forefathers settled down in this peninsular and cultivated the hills and waste-lands into fields. Instead of fertilizing the lands they moved to find other fertile lands and lived a feudal life of agriculture and various machines played a main role in the land reclamation. The best method of land clearing, the time and efficiency in the operation and the effect of growing crops should sysematically analized prior to the time of 3rd Five-year Economic Development(1972-1976) in order to cultivated 210,000 ha of waste-land or the modernization of our country. The present study was investigated to find out a new working-system of mechanical land clearing and development of fertile soil. The results are as follows: 1) The land reclamation in natural slope is much more encourageable in land clearing and farming when the slope is below ten grades than bench terrace. 2) Weeds were mixed with soil in the land clearing work in order to supply organic materials and to make soil swollen instead of burning of just removing. 3) The equipments such as bulldozers, harrows, power tillers and so on should be prepared in order to do a systematic work in the land clearing. 4) The work of pulling-up roots is dependent upon the forms of roots spreading under the ground. The work of the pulling-up the straight roots was most difficult. 5) The land clearing work of the wrinkled style blocks was easy in pulling up roots and in the time of first plowing. The harrowing work could also be simply done. 6) The amount of soil carried was $240m^3/10a$, 15.6% increased amount from the standard block, while the required time of clearing work was 2 hours 15 minutes 45 seconds/10a, the one third of time required for the standard block. 7) The time disc harrowing work increased 50%, or 15 minutes/10a compared to the harrowing work required in the cultivated soil. 8) The time of rotary tilling increased 2.4 times or 1 hour 47 minutes 43 seconds/10a compared to the time required in the cultivated soil. 9) The reclamed land should be fertilized according to the soil quality, especially added fertilizer should be more than 1,200kg/10a, limes 20kg/10a. In order to produce added fertilizer grass fields should be needed. 10) The experiment of pasture growing is now progressing and therefore the effect of land clearing and the degree of developed soil will be investigated before long.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.846-853
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• 2003

Purpose : Pneumoccocus is one of the most important causes of invasive infection through the childhood period and the prevelance of antibiotics resistance of pneumococcus is increasing worldwide. A 7-valent conjugate vaccine has been developed. It is important to know the prevalence of each serotype of pneumococci in the countries where the vaccine is used to estimate the coverage rate by the vaccine. Methods : One hundred and twenty seven strains of clinical isolates and 72 strains from healthy carriers recovered from Korean children during the period from 1997 to 2002 were subjected to determination of serotype by Quellung reaction and penicillin susceptibility with oxacillin disc diffusion test. Results : Forty-three per cent of clinical isolates were obtained from children under two years of age. Thirty strains(24%) were isolated from normally sterile body fluids. The frequent serotypes were 19F, 19A, 23F, 6A, 6B and 9V. Fifty-six per cent of the clinical isolates were represented in the current 7-valent protein conjugate pneumococccal vaccine, and 84% when the cross-reactive serotypes were included. Frequent serotypes of strains isolated from one to five year-old healthy children were 19F, 14, 11A, 23F, 18C, and 19A. Seventy-one per cent of the carrier strains were included in the 7-valent vaccine. Ninety-three per cent of the clinical isolates and 86% of carrier strains were not susceptible to penicilline. Conclusion : Fifty-six to 84% of pneumococci recovered from Korean children are covered by the current 7-valent protein conjugate pneumococcal vaccine and the prevalence of penicillin resistance was very high.

• Restorative Dentistry and Endodontics
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• v.33 no.6
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• pp.526-536
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• 2008

The purpose of this study was to compare the effect of various dentin bonding systems on microtensile bond strength of immediate dentin sealing (IDS) and delayed dentin sealing (DDS). Eighteen extracted permanent molars were used in this study. The teeth for DDS group were restored with a provisional restorations, and immersed in saline solution for 1 week, and divided into 3 subgroups according to various dentin bonding adhesives; SB subgroup (3 step total-etch adhesive), SE subgroup (2 step self-etch adhesive), XE subgroup (1 step self-etch adhesive). In IDS group, the teeth were divided into 3 subgroups, and applied with bonding adhesives as in DDS group. The teeth were restored with provisional restorations, and immersed in saline solution for 1 week. Indirect composite disc was cemented with resin cement, and all specimens were subjected to microtensile bond strength. The data were statistically analyzed with oneway ANOVA and Student t-test. The results were as follows: 1. The IDS group showed significantly higher ${\mu}TBS$ than DDS group in 3 step total-etch and 2 step selfetch adhesive (p < 0.05). 2. In IDS and DDS group, 3 step total-etch adhesive showed the highest ${\mu}TBS$ value, followed by 2 step self-etch, and 1 step self-etch adhesive. In IDS group, the ${\mu}TBS$ value for 1 step self-etch adhesive was significantly different from those of the other subgroups (p < 0.05), and in DDS group, there were statistical differences in all subgroup (p < 0.05). 3. Failure modes of tested dentin bonding adhesives were mostly mixed failure and only 1 step self-etch adhesive showed adhesive failure.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.519-526
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• 1992

The gene coding for urease of alkalophilic Bacillus pasteurii had been cloned in Escherichia coli previously. The urease protein was purified 63.1-fold by TEAE-cellulose, DEAE-Sephadex A-50, Sephadex G-150 and Sephadex G-200 chromatographies with a 7.3% yield from the sonicated fluid of the E. coli HB1Ol(pBUll) encoding B. pasteurii urease gene. The ureases of E. coli (pBUll) and B. pasteurii possessed as a $K_m$ for urea, 42.1 mM and 40.4 mM, respectively. They hydrolyzed urea with $V_{max}$ of 86.9$\mu$mol/min and 160$\mu$mol/min, respectively. Both ureases were composed with four subunits (Mrs 67,000) and a subunit (Mr 20,000). The molecular weight of both native enzymes was Mr 280,OOO$pm$10,000 determined by gel filtration chromatography and Coomassie blue staining of the subunits. The optimal reaction pH of both ureases were pH 7.5. The ureases were stabled in pH 5.5-10.5. The optimal reaction temperature of both ureases were $60^{\circ}C$, and the ureases were stable for an hour at $50^{\circ}C$, 40min at $60^{\circ}C$ and 10 min at $70^{\circ}C$ The activity of both enzymes were inhibited completely by $Ag^{2+}$, $Hg^{2+}$, $Zn^{2+}$, $Cu^{2+}$, and were inhibited 60% by CoH, 30% by $Fe^{2+}$ and 10% by $Pb^{2+}$. However it was increased by the addition of $Sn^{2+}$, $Mn^{2+}$, $Mg^{2+}$ at concentration of $1{\times}10^{-3}$M. Both ureases were inhibited completely by p-CMB and acetohydroxamic acid. The urease expressed in E. coli (pBU11) was inhibited 70% by SDS. The urease of B. pasteurii was inhibited 40% by hydroxyurea, whereas the recombinant urease of E. coli strain was inhibited 17%. Both enzymes were not inhibited by cyclohexanediaminetetraacetic acid (CDTA) and ethylendiaminetetraacetic acid (EDTA).