• Journal of Chest Surgery
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• v.31 no.12
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• pp.1165-1171
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• 1998

Background: All currently available mechanical and bioprosthetic valves are associated with various types of deterioration leading to dysfunction and/or valvular complications. Reoperation on prosthetic heart valves is increasingly under consideration for both clinical and prophylactic indications. This review was conducted to determine the factors affecting the risk of reoperation for prosthetic valve replacement. Material and method: From January 1985 to July 1996, 124 patients underwent reoperation on prosthetic heart valves, and 3 patients had a second valve reoperation. The causes of reoperation were prosthetic valve failure(96 cases, 77.4%), prosthetic valve thrombosis(16 cases, 12.9%), prosthetic valve endocarditis(7 cases, 5.6%) and paravalvular leak(5 cases, 4.1%). This article is based on the analysis of the experience with particular emphasis on the preoperative risks affecting the outcome of the reoperation. Result: Overall hospital mortality rate was 8.9%(11/124). Low cardiac output was the most common cause of death(70.6%). Left ventricular systolic dimension(p=0.001), New York Heart Association functional class IV(p=0.003) and serum creatinine level(p=0.007) were the independent risk factors, but age, sex and cardiothoracic ratio did not have any influence on the operative mortality. Follow-up period was ranged from 3 to 141 months (mean, 50.6 months). A late mortality rate was 1.8%. Conclusion: The surgical risk of reoperation on heart valve prostheses in the advanced NYHA class patients is higher, therefore reoperation is recommended before the hemodynamic impairment become severe.

• Journal of Chest Surgery
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• v.37 no.7
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• pp.578-584
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• 2004

Sinus of Valsalva aneurysm is a rare cardiac anomaly and a long-term survival after surgical treatment has not been well established. This study was designed to evaluate the long-term surgical results after the repair of sinus Valsalva aneurysm. Material and Method: From April 1991 to November 2003, 35 patients (23 male, 12 female, mean age 35.2 years, range 11∼64) underwent operation for sinus of Valsalva aneurysm. Twenty six patients (74.3%) were in the New York Heart Association (NYHA) class III∼IV before surgery. In preoperative echocardiogram, mean EF was 63.32 $\pm$ 11.43% and nine patients (25.7%) were in AR grade III∼IV. Direct closure, patch closure of ruptured sinus Valsalva were performed in fourteen patients (46.7%), sixteen patients (53.3%) respectively. Aortic valve replacement, valvuloplasty were performed in five patients (14.3%), three patients (8.6%) respectively. Three patients (8.6%) underwent the Bentall procedure. Concomitant procedures were performed in 15 patients (42.9%), which were closure of VSD and ASD. Mean CPB time and ACC time were 116.79 $\pm$ 38.79 and 81.2 $\pm$ 28.97 minutes. Result: There was no operative mortality. One patient (2.9%) developed complete heart block that required a permanent pacemaker implantation. Three patients (8.6%) required reoperation due to a recurred rupture of the sinus Valsalva aneurysm and developed aortic insufficiency. Mean follow-up time was 58.55 $\pm$ 38.38 months. There was one late death. Actuarial 5 year freedom rate from reoperation was 87.1 $\pm$ 7%. Conclusion: Surgical treatment for sinus of Valsalva aneurysm is safe and has satisfactory long-term results.

• Journal of Environmental Health Sciences
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• v.11 no.2
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• pp.41-54
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• 1985

This study was conducted for the improvement of milk quality and milk hygiene in public health point of view. Investigation of mastiris infection rate, isolation and identification of causative microorganisms in CMT positive milk, investigation of milk contamination level by measuring the bacteria and soma tic cell counts and investigation of dairy management in farms were performed on 1.605 quarters milk of 434 cows of 20 dairy farms in Gyunggi-area from September 1983 to March 1984. The results were summarized as follows 1. Sixteen (3.7%) of 434 cows were found to be infected with clinical mastiris. 234 (53.9%) of 434 cows and 608(37.9%) of 1, 605 quarters were found to be infected with subclinical mastiris. 2. The causative microorganisms isolated were Staphylococcus aureus (38.3%), Staphylococcus epidermidis(21.0%), Micrococci(13.6%), Streptococcus spp. (12.3%), E. coli (7.4%), Fungus & Yeast (1.6%) and others (5.8%). 3. Total numbers of bacteria were $9.2{\times}10^6$ to $1.21{\times}10^7/ml$(av. $1.805{\times} 10^7/ml$), numbers of coliform bacteria were $4.1{\times} 10^5$ to $9.4{\times} 10^5$/ml(av. $7.05{\times} 10^5$/ml) and somatic cell counts were $4.8{\times} 10^5$ to $1.52{\times} 10^6$ cells/ml (av. $9.5{\times} 10^5$cells/ml) in bulk milk. 4. As comparing with CMT score of +, ++ and +++, somatic cell counts were $3.4{\times} 10^5$ to $1.64{\times} 10^6$ cells/ml (av. $6.41{\times} 10^5$cells/ml), $5.4{\times} 10^5$ to $2.75{\times} 10^6$ cells/ml(av. $1.762{\times} 10^6$cells/ml) and $1.97{\times} 10^6$ to $9.75{\times} 10^6$ cells/ml(av. $7.781{\times} 10^6$cells/ml), respectively. 5. In investigation on dairy management, performance of dry cow therapy, teat dipping after milking, disinfection of milking machine at every milking, replacement of milk liner within 6months and opportunity of acquirement for the mastiris control techniques by dairy education were 65%, 40%, 45%, 55% and 50% in 20 dairy farms, respectively.

• Journal of Aquaculture
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• v.6 no.3
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• pp.173-186
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• 1993

In order to substitute soybean meal for fish meal, the protein requirement of fleshy shrimp was examined and then the effect of soybean meal supplemented with cuttlefish oil was studied. Different contents of protein in prepared diet had significant effects on the survival rate and growth of fleshy shrimp (P<0.05). With regard to protein content ranging from $25\%\;to\;50\%,\;40\%$ protein showed the best survival rate and fastest growth. The percent survival rates of fleshy shrimp fed diets containing protein levels of 25, 30, 35, 40, 45 and $50(\%)$ were $74.0^d,\; 82.0^{cd},\;91.0^b,\;97.0^a,\;93.0^{ab},\;and\;88.0^{bc}\%(P< 0.05).$ The optimum protein requirements for postlarvae (13-84 mg) and juvenile (0.9-8.1g) were calculated by the broken line method as $40.4\%\;and\;39.9\%$. When soybean meal was substituted $(up\;to\;76\%)$ for fish meal in the prepared diet, the performance' gradually suffered with the increase of soybean meal content, but when cuttlefish oil was added to soybean meal, survival rates were improved with $2.5\%$ cuttlefish oil supplement.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.48-54
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• 2007

Bacillus polyfermenticus SCD (B. polyfermenticus SCD) has been appropriately used for the therapy of long-term intestinal disorders, because live strains in the form of active endospores can successfully reach the target intestine in humans. B. polyfermenticus SCD produces the most antibiotic-related materials. In the present study, B. polyfermenticus SCD was fermented with soybeans (BPFS) and its probiotic properties were investigated. B. polyfermenticus SCD and BPFS showed a broad spectrum of antimicrobial activity against pathogenic Gram-positive (Streptococcus parauberis, Streptococcus iniae, Lactococcus garviae) and Gram-negative (Flexibacter tractuosus, Vibrio harveyi, Vibrio vulnificus, Vibrio ordalii) bacteria and moulds (Aspergillus niger, Aspergillus oryzae). Sebastes schlegeli were used to examine survival rate and cleanup action by BPFS. Bacterial infection resulted in a mortality of up to 99% in the commercial fodder fed groups. BPFS both enhanced the growth rate of fry by improving their appetite and had cleaned by decreased eutrophication. Therefore, it seems appropriate that BPFS should be developed as an antibiotic replacement, favorable fodder additive, and antifungal material in fish farming systems.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1433-1438
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• 2002

The study was carried out to evaluate leucaena seeds as a protein replacement of mustard seed cake (MSC) in the concentrate mixture of growing lambs. Fifteen owing male lambs (Local${\times}$Corridale) with an average body weight of 16.3 kg were allocated into three dietary treatments (T1, T2, and T3) with five animals in each group. Animals were offered dry mixed grass, berseem hay and concentrate mixture to meet their nutrient requirements. In concentrate mixture of T1, (Control) MSC was used as protein source, while in T2 and T3 groups, 25 and 50% of MSC was replaced by leucaena leucocephala seeds. On completion of three months (90 days) of feeding, a digestion cum-metabolism trial was conducted to determine DMI, nutrient utilization, and nitrogen balance. Changes in body weight were recorded at 15 day internals and eating patterns were recorded for 3 consecutive days at the end of the feeding trial. MSC had higher CP contents than leucaena seeds (27.0%). Mimosine contents in leucaena seeds were 1.1 compared to 0.2 and 0.4% in concentrate mixture of T2 and T3 group, respectively. Dry matter intake varied non-significantly ($79.3{\pm}1.2$ to $83.4{\pm}1.3g/kg$ $w^{0.75}$) across the dietary treatments. Digestibility of DM and cell wall polysaccharides (NDF, ADF. Cellulose and hemicellulose) were comparable, however CP digestibility was relatively lower in leucaena luecocephala seeds based groups (T2 $45.5{\pm}1.7$ and T3 $46.7{\pm}3.5$) compared to MSC supplemented group (T1 $47.7{\pm}0.9%$). The growth rate of lambs was non-significantly higher in T1 ($79.2{\pm}5.4$) compared to T2 ($73.8{\pm}8.8$) and T3 ($73.9{\pm}7.0$), respectively. The animals were in positive nitrogen balance and N-balance varied from 1.8 to 2.9 g/d across treatment groups. The eating rate (% of total offered) of concentrate up-to 15 min was relatively higher in T1 (82.4) than T2 (74.2) and T3 (77.8%). However no effect of leucaena seeds was recorded on total DMI of animals. The results of the study revealed that the inclusion of up to 50% leucaena seeds, as protein source in concentrate mixture of lambs had no adverse effect on DMI, nutrient utilization, eating patterns, nitrogen balance and growth performance of lambs.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.10
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• pp.1389-1393
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• 2001

A study was carried out to investigate the nutritive value and utilization of three grass species, batiki grass (lschaemum aristatum var. indicum), guinea grass (Panicum maximum) and signal grass (Bracharia decumbens) by growing goats. Eighteen growing crossbred goats $(Anglo-Nubian{\times}Fiji\;local)$ of between 9-11 months of age and pre-trial average live weight of $9.50{\pm}1.60kg$ were divided on the basis of weight to three treatment groups in a completely randomized design. The grasses constituted the diets and they were harvested fresh and chopped into pieces before they were offered to the goats. Chemical composition of the grasses, DMI, body weight gain (BWG) and apparent nutrient digestibility coefficients were measured. The grasses had similar DM content. The CP content of the grasses was in the range of 8.3-11.2%. Crude fiber (CF) content was between 30.9-35.2%. Ether extract (EE) was low with a range of 1.2-1.8%. Nitrogen free extract (NFE) was similar (40.9%) for batiki and guinea grasses, while signal grass had more NFE content (51.1%). The grasses are good sources of minerals (ash). OM content was higher in signal grass while guinea and batiki grasses had similar OM content. The goats on signal grass had higher DMI than those on batiki and guinea grasses (p<0.05). The goats on batiki grass had lower average BWG (p<0.05) than those on guinea and signal grasses. Nutrients digestibility were significantly (p<0.05) higher in the goats on signal grass compared to those on guinea and batiki grasses. The goats on guinea grass were better (p<0.05) in the digestibility of CP, OM, NFE and ME than those on batiki grass. However, goats on batiki were significantly better (p<0.05) in digestibility of CF than those on guinea grass. Signal and guinea grasses had more DCP than batiki grass. DE was lower in batiki grass (p<0.05) than in guinea and signal grasses. There was no significant difference (p>0.05) between batiki and guinea grasses in TON. Data obtained in this experiment demonstrated that signal grass is better than guinea and signal in the nutrition of growing goats in the tropical environment of Samoa. It had the highest nutritive value, better apparent digestibility coefficients which have better growth rate and feed efficiency. In ranking, signal grass was better than guinea and batiki grasses, while guinea grass was better than batiki in nutritive value in the parameters measured. For future pasture establishment in Samoa, signal grass is recommended for consideration because of its higher nutritive value as a replacement for batiki, the most predominant grass.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.373-377
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• 1997

Between January, 1991 and May 1995, mitral valve repair was undertaken on 32 patients under 15 years for congenital mitral regurgitation. Mean age was 24.0$\pm$26.1 months(range 3 months to 15 years), 16 patients were male and 16 patients were female associated cardiac anomalies were found in 26 patients (81%), and ventricular septal defects were noted in 18 patients(56%). In regards to pathologic findings, there were annular dilatation(n:7), leaflet prolapse(n=18), cleft leaflet(n=5) and restricted valve motion (n=2). The method of repair consisted of annuloplasty(Modif ed Devega type) in 14, repair of redundunt leaflet in 6, closure of cleft in 5, triangular resection in 2 and splitting of papillary muscle in one. There was no operative mortality and two late deaths occurred as a result of heart failure and sepsis. Tro patients required replacement of the mitral valve after 3 months and 7 months respectivehy because of recurrent mitral regurgitation. Actuarial survival was 92.5% at 46 months and actuarial freedom from reoperation was 95% at 12 months and 92.5% at 46 months. Actuarial freedom from valve repair failure was 68% at 12 months and 61.8% at 46 months. Although valve repair failure rate was high, we believe that mitral valve repair should be of rcrred to children because of low mortality and low reoperation rate.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.62-62
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• 2018

Pt is still considered as one of the most active electrocatalysts for ORR in alkaline fuel cells. However, the high cost and scarcity of Pt hamper the widespread commercialization of fuel cells. As a strong candidate for the replacement of Pt catalyst, silver (Ag) has been extensively studied due to its high activity, abundance, and low cost. Ag is more stable than Pt in the pH range of 8~14 as the equilibrium potential of Ag/Ag+ being ${\approx}200mV$ higher than that of Pt/PtO. However, Ag is the overall catalytic activity of Ag for oxygen reduction reaction(ORR) is still not comparable to Pt catalyst since the surface Ag atoms are approximately 10 times less active than Pt atoms. Therefore, further enhancement in the ORR activity of Ag catalysts is necessary to be competitive with current cutting-edge Pt-based catalysts. We demonstrate the architectural design of Ag catalysts, synthesized using plasma discharge in liquid phase, for enhanced ORR kinetics in alkaline media. An attractive feature of this work is that the plasma status controlled via electric-field could form the Ag nanowires or dendrites without any chemical agents. The plasma reactor was made of a Teflon vessel with an inner diameter of 80 mm and a height of 80 mm, where a pair of tungsten(W) electrodes with a diameter of 2 mm was placed horizontally. The stock solutions were made by dissolving the 5-mM AgNO3 in DI water. For the synthesis of Agnanowires, the electricfield of 3.6kVcm-1 in a 200-ml AgNO3 aqueous solution was applied across the electrodes using a bipolar pulsed power supply(Kurita, Seisakusyo Co. Ltd). The repetition rate and pulse width were fixed at 30kHz and 2.0 us, respectively. The plasma discharge was carried out for a fixed reaction time of 60 min. In case of Ag nanodendrites, the electric field of 32kVcm-1 in a 200-ml AgNO3 aqueous solution was applied and other conditions were identical to the plasma discharge in water in terms of electrode configuration, repetition rate and discharge time. Using SEM and STEM, morphology of Ag nanowires and dendrites were investigated. With 3.6 kV/cm, Ag nanowire was obtained, while Ag dendrite was constructed with 32 kV/cm. The average diameter and legth of Ag nanowireses were 50 nm and 3.5 um, and thoes values of Ag dendrites were 40 nm and 3.0 um. As a results of XPS analysis, the surface defects in the Ag nanowires facilitated O2 incorporation into the surface region via the interaction between the oxygen and the electron cloud of the adjacent Ag atoms. The catalytic activity of Ag for oxygen reduction reaction(ORR) showed that the catalytic ORR activity of Ag nanowires are much better than Ag nanodendrites, and electron transfer number of Ag nanowires is similar to that of Pt (${\approx}4$).

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.109-112
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• 2008

In this study, Assessment of bond property of HSC with the rate of Blust-furnace(0, 12, and 25 percent by weight cement) and Evaluation of the relationship of the compressive strength coefficient (${\beta}$) between compressive strength with 40${\sim}$120MPa were performed. Design and Test of Bond specimens were carried out based on the ASTM C-234. Test results are follows, most specimens showed that the splitting failure in all specimens, except for B-40 series which showed that the pull-out failure. For the B-40 Series, the relation of compressive strength versus bond stress has well converged that of the proposed equation with the variation(${\beta}$=2/3) in UCB/E.E.R.C-83. The crack strength of concrete in splitting was proportioned to the compressive strength of concrete, and was the highest on the contents of blast furnace slag to 12 percent by weight of cement in each series, except for B-60 series. In the relation of admixture replacement rate versus maximum bond stress, The maximum bond stress was the highest in 12 percent by weight of cement according to less than 40MPa, and was the highest in 25 percent by weight of cement according to 80MPa.