• Parasites, Hosts and Diseases
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• v.46 no.1
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• pp.29-32
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• 2008

The aim of this study is to determine the Toxocara seropositive rate among healthy people with eosinophilia. A total of 97 people residing in Seoul who were healthy and whose blood eosinophilia was over 10%, as shown by regular health check-ups in 2004, were subjected to this study. Their sera were tested by immunoblotting and ELISA with the antigen of larval Toxocara canis excretory-secretory (ES) protein. Sixty-five sera were band-positive (67.0%). The seropositve control sera were positive to band sizes of 66 kDa, 56 kDa, 32 kDa, and 13 kDa. In ELISA, 63 sera (65.0%) were positive to T. canis ES protein. There was no significant correlation between the IgG ELISA titer and the level of eosinophilia (r = 0.156, P = 0.156). As there were insufficient data to determine whether there were cross-reactions with other helminthic infections, or whether atopy occurred, further studies are required to verify the cause of the seropositive reactions against T. canis ES antigen. Toxocariasis seropositivity is suggested to be the major cause of eosinophilia, since the Toxocara seroprevalence among Korean rural adults was shown to be approximately 5%.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.935-938
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• 2005

Nucleophilic addition reactions of benzylamines (BA; $XC_6H_4CH_2NH_2$) to $\alpha-cyano-\beta$-phenylacrylamides (CPA; $YC_6H_4CH=C(CN)CONH_2$) have been investigated in acetonitrile at 25.0 ${^{\circ}C}$. The rate is first order with respect to BA and CPA and no base catalysis is observed. The addition of BA to CPA occurs in a single step in which the addition of BA to $C_{\beta}$ of CPA and proton transfer from BA to $C_{\alpha}$ of CPA take place concurrently with a four-membered cyclic transition state structure. The magnitude of the Hammett ($\rho_X$) and Bronsted ($\beta_X$) coefficients are rather small suggesting an early tansition state (TS). The sign and magnitude of the crossinteraction constant, $\rho_XY$ (= −D0.26), is comparable to those found in the normal bond formation processes in the $S_N2$ and addition reactions. The normal kinetic isotope effect ($k_H/k_D\;{\gt}$ 1.0) and relatively low ${\Delta}H^{\neq}$ and large negative ${\Delta}S^{\neq}$ values are also consistent with the mechanism proposed.

• Nuclear Engineering and Technology
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• v.40 no.4
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• pp.299-304
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• 2008

A detection system was set up to measure the neutron generation rate of a recently developed D-D neutron generator. The system is composed of a Si detector, He-3 detector, and electronics for pulse height analysis. The neutron generation rate was measured by counting protons using the Si detector, and the data was crosschecked by counting neutrons with the He-3 detector. The efficiencies of the Si and He-3 detectors were calibrated independently by using a standard alpha particle source $^{241}Am$ and a bare isotopic neutron source $^{252}Cf$, respectively. The effect of the cross-sectional difference between the D(d,p)T and $D(d,n)^3He$ reactions was evaluated for the case of a thick target. The neutron generation rate was theoretically corrected for the anisotropic emission of protons and neutrons in the D-D reactions. The attenuations of neutron on the path to the He-3 detector by the target assembly and vacuum flange of the neutron generator were considered by the Monte Carlo method using the MCNP 4C2 code. As a result, the neutron generation rate based on the Si detector measurement was determined with a relative uncertainty of ${\pm}5%$, and the two rates measured by both detectors corroborated within 20%.

• Carbon letters
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• v.18
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• pp.18-23
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• 2016

Polyacrylonitrile (PAN)-based carbon fibers have high specific strength, elastic modulus, thermal resistance, and thermal conductivity. Due to these properties, they have been increasingly widely used in various spheres including leisure, aviation, aerospace, military, and energy applications. However, if exposed to air at high temperatures, they are oxidized, thus weakening the properties of carbon fibers and carbon composite materials. As such, it is important to understand the oxidation reactions of carbon fibers, which are often used as a reinforcement for composite materials. PAN-based carbon fibers T300 and T700 were isothermally oxidized in air, and microstructural changes caused by oxidation reactions were examined. The results showed a decrease in the rate of oxidation with increasing burn-off for both T300 and T700 fibers. The rate of oxidation of T300 fibers was two times faster than that of T700 fibers. The diameter of T700 fibers decreased linearly with increasing burn-off. The diameter of T300 also decreased with increasing burn-off but at slower rates over time. Cross-sectional observations after oxidation reactions revealed hollow cores in the longitudinal direction for both T300 and T700 fibers. The formation of hollow cores after oxidation can be traced to differences in the fabrication process such as the starting material and final heat treatment temperature.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.4
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• pp.445-449
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• 1998

Semen quality was compared between the local Katjang and the cross-bred (local Katjang ♀ ${\times}$ German Fawn ♂) bucks. There were on significant genotypic differences in semen characteristics of concentration (first ejaculate : $6.19{\pm}1.30$ -versus $6.33{\pm}1.40{\times}10^9/ml;$second ejaculate: $5.82{\pm}1.10$ - versus $5.68{\pm}1.45{\times}10^9/ml$, for Katjang and the cross-breds, respectively), percentage live (first ejaculate: $77.61{\pm}1.33%$ versus $77.81{\pm}0.53%$; second ejaculate: $81.97{\pm}1.59%$ versus $82.74{\pm}0.96%$, for Katjang and cross-breds, respectively) and percentage of normal sperms (first ejaculate: $12.54{\pm}3.88%$ versus $26.45{\pm}3.83%$; second ejaculate: $38.68{\pm}3.65%$ versus $28.54{\pm}4.38%$, for Katjang and cross-breds, respectively), with the exception of seminal volume and sperm motility. Means of all variables were within the values reported for other goat breeds, In contrast, the differences in semen characteristics between the first and second ejaculations of both genotypes were more distinct, the second ejaculations always had more volume, more normal sperms and better sperm motility but less sperm concentrations. Removing the seminal plasma and replacing it with tris-citrate buffer greatly prolonged the viability of sperms of both genotypes when stored at $5{^{\circ}C}$. Sperm motility seens to be a good indicator of sperm viability. However, the sperms of the corss-bred bucks withstood the washing process better and their swimming abilities were superior ($8.12{\pm}0.46mm/min$) when compared to those of the local Katjang breed ($5.42{\pm}0.49mm/min$). The higher content of calcium ions in their seminal plasma (first ejaculate: $10.5{\pm}0.8$ versus $10.6{\pm}0.8mg/100ml$;second ejaculate: $15.3{\pm}0.8$ versus $16.1{\pm}0.8mg/100ml$, for Katjang and cross-breds, respectively) means that in natural matings the sperms of the cross-breds would be at an advantage compared to those of the local Katjang, since calcium ions reportedly initiate acrosomal reactions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.620-628
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• 1996

To avoid the self-agglutination of Staphylococcus aureus sensitized with rabbit antibody in the absence of antigen, we determined the optimum concentration of rabbit antibody for sensitization. It was analyzed by using three different kinds of S. aureus strains at various concentraions of antibody. The optimized coagglutination test using the S. aureus sensitized with rabbit antibody was applied to the diagnosis of edwardsiellosis in field and in laboratory. The presence of E. tarda as low as $10\;{\mu}g/ml$ was detected by this method. Moreover, it showed good coagglutination results against several different forms of antigens such as FKC, EDTA or heat extracted antigen of E. tarda. E. tarda strains, isolated from the flounders suffering from edwardsiellosis in fields, showed some cross-reactions to the E. tarda 219 analyzed by both agglutination and coagglutination test with rabbit anti-E, tarda 219 antibody. The degree of cross-reactions analyzed was enough to apply the coagglutination test for the diagnosis of edwardsiellosis in field. Thus, even 1,000 fold diluted tissue homogenate of infected flounder naturally contained enough E. tarda as an antigen to show good coagglutination with S. aueus sensitized with rabbit anti-E, tarda 219 antibody. The successful application of this method to the homogenate and heat extract of tissues from naturally or artificially infected flounder or tilapia preyed that coagglutination test was a simple and rapid reliable dignostic technique suitable for using in laboratory and field without any special equipments.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.9-14
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• 1989

Enzyme-linked immunoelectrotransfer blot (EITB) using crude worm antigen of adult Paragonimus westermani was performed for human patients sera to identify the species-specific components. Crude antigen was obtained by homogenizing and centrifuging 24-week old adult worms at 10,000 rpm for 60 minutes in phosphate buffered saline (PBS, PH 7.2) containing: Phenyl methyl sulfonyl auoride (PMSF). Gradient sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) was performed and blotted electrophoretically onto a sheet of nitrocellulose paper. The sheet was cut into strips and exposed to sera diluted 1 : 200 with PBS. SDS-PAGE showed 26 protein bands ranging 229 to 10 kDa. Of them 229, 91, 60, 50, 35∼31, 27, 25, 21, 17, 11 and 10 kDa components showed positive reaction with serum antibody of patients with p. westermani. Sera of patients infected with Clcnorchis sinensis reacted with 35∼31, 19, and 11 kDa bands. Human sera from cysticercosis and diphyllobothriasis cases showed non-specific cross reactions with 229, 35∼31, 27, 25 and 17kDa bands. Protein bands of 91, 60, 21 and 10kDa showed strong positive reaction without cross reactions with sera from other helminthic infections.

• Parasites, Hosts and Diseases
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• v.24 no.1
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• pp.25-41
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• 1986

The applicability of micro-ELISA was evaluated in human neuro-cysticercosis using paired samples of serum and CSF. A total of 355 cases who were mostly neurologic patients was subjected. Cystic fluid of C. cellulosae was used as antigen in protein concentration of $2.5{\;}{\mu}g/ml$. Serum was diluted to 1 : 100 and CSF was undiluted in the assay for the specific IgG antibody level. The differential criterion of the positive reaction was the abs. of o. 18 in both samples. The results were summarized as follows: 1. The overall sensitivity of the micro-ELISA in 71 confirmed neurocysticercosis was 90.1% ; the sensitivity by serum was 77.5% and that by CSF was 83.1%. CSF was a more sensitive and valuable material. Most of the false negative cases of neuro-cysticercosis showed far lower level of abs. rather than marginal. 2. The overall specificity of the micro-ELISA in 52 confirmed other neurologic diseases was 88.5%; the specificities by serum and by CSF were 94.2% respectively. Cases of other neurologic diseases did not show false positive reactions in both samples. 3. When serum was assayed, taeniasis(2/18), sparganosis(2/20), paragonimiasis(1/56), clonorchiasis(1/15) and fascioliasis(1/1) cases showed cross reactions. When CSF was assayed, 2 ot 10 neuro-sparganosis showed cross reactions while none of 9 neuro-paragonimiasis showed it. Out of 71 confirmed neuro-cysticercosis cases, 6 and 11 showed cross reactions by serum and CSF to crude extract antigen of sparganum; but no case did show it to crude extract antigen of Paragonimus westermani. 4. Ventricular CSF showed low or negative levels of IgG antibody than lumbar CSF unless the lesion was at the lateral ventricle itself. 5. Out of 4 racemose cysticercosis cases, 3 showed positive reaction in serum while all of 3 examined CSF were positive. The above results indicated that the serological test for detecting the specific IgG antibody by micro-ELISA using paired samples of serum and CSF was very helpful for clinical differentiation of neuro-cysticercosis from neurologic diseases of other causes.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.6
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• pp.396-404
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• 2011

An investigation on the removals of PAH-quinone compounds, which are commonly produced from the biological and/or chemical treatments of PAH-contaminated soils, from the aqueous phase via birnessite (${\delta}-MnO_2$)-mediated oxidative transformation is described. It was demonstrated that acenaphthenequinone (APQ), p-PAH quinone can be removed via birnessite-mediated oxidative-coupling reactions, and anthraquinone (AQ) and 1,4-naphthoquinone (1,4-NPQ), o-PAH quinones were efficiently removed by birnessite-mediated cross-coupling reactions in the presence of catechol (CAT) as a reactive mediator. The removals of PAH-quinone compounds followed pseudo-first-order reactions, and the rate constant (k, $hr^{-1}$) for the removals of 1,4-NPQ under the experiment conditions (1,4-NPQ = 10 mg/L, CAT = 50 mg/L, ${\delta}-MnO_2$ = 1.0 g/L, pH 5, Reaction time = 6~96 hr) was 0.0426, which was about 4 times lower than that of APQ (0.173). With the observed pseudo-first order rate constants with respect to birnessite loadings under the same experimental conditions, the surface-normalized specific rate constant, $K_{surf}$, for 1,4-NPQ was determined to be $8.5{\times}10^{-4}L/m^2{\cdot}hr$. The analysis of the kinetic data with respect to birnessite loading indicated that the cross-coupling reactions of 1,4-NPQ consist of two different reaction steps over time and the results have also been discussed in terms of the reaction mechanisms.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1670-1674
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• 2007

Addition reactions of anilines (XC6H4NH2) to β-nitrostilbene (YC6H4CH=C(NO2)C6H4Y') have been investigated in acetonitrile at 30.0 oC. The magnitude of βX values (=0.11-0.34) indicates relatively earlier transition state for additions with anilines than with benzylamines. The signs of ρY and ρY' are positive with Δρ = ρY?ρY' = 0.04, demonstrating a TS imbalance with a negative charge development on the Cβ in the TS. The signs of cross-interaction constants ρXY (<0), ρXY' (<0) and ρYY' (>0) are consistent with bond forming and breaking processes. The relatively weak normal kinetic isotope effects involving deutarated nucleophiles, kH/kD>1, suggest an early, hydrogen-bonded, 4-member cyclic TS.