• 한국분말재료학회지
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• 제8권4호
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• pp.258-267
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• 2001

In this work, the conventional transient liquid phase(TLP) bonding was modified. An attempt was made of using a liquid phase sintered alloy, which will be a liquid phase coexisting with a solid phase at the bonding temperature, as an interlayer for bonding metals. With an aim of revealing the fundamental features of this modified TLP bonding, the kinetics concerned with the growth of solid particles and the isothermal solidification process in Fe-1.16wt%B and Fe-4.5wt%P interlayers for the bonding pure iron, as well as the morphological change of the solid particle, were investigated.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제8권2호
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• pp.145-152
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• 2001

Posner [Proc. Amer. Math. Soc. 8 (1957), 1093-1100] defined a derivation on prime rings and Herstein [Canad, Math. Bull. 21 (1978), 369-370] derived commutative property of prime ring with derivations. Recently, Bergen [Canad. Math. Bull. 26 (1983), 267-227], Bell and Daif [Acta. Math. Hunger. 66 (1995), 337-343] studied derivations in primes and semiprime rings. Also, in near-ring theory, Bell and Mason [Near-Rungs and Near-Fields (pp. 31-35), Proceedings of the conference held at the University of Tubingen, 1985. Noth-Holland, Amsterdam, 1987; Math. J. Okayama Univ. 34 (1992), 135-144] and Cho [Pusan Kyongnam Math. J. 12 (1996), no. 1, 63-69] researched derivations in prime and semiprime near-rings. In this paper, Posner, Bell and Mason＇s results are extended in prime near-rings with some conditions.

• Journal of Preventive Medicine and Public Health
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• 제30권2호
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• pp.267-278
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• 1997

The purpose of this study was to investigate the incidence rate of hepatitis B in the military service and to examine the effect of the asymptomatic hepatitis B surface antigen(HBsAG) carries on the incidence of hepatitis B. The subject were 223,270 men who were conscripted to the Korean Army from 1991 to 1994. According to the conscripted year, four conscription cohort were constructed. At the screening examination for military service no test for hepatitis B were performed in 1991 and 1992. In 1993, a screening test for hepatitis B were performed and those who were confirmed as HBsAg positive o. showed high titers $(\geqq100IU)$ of nm glutamic-pyruvic transaminase(SGPT) were excluded from conscription. In 1994, the criteria for conscription was changed and those who were HBsAg positive were not excluded from conscription. Only those who showed $\geq$ SGPT 100IU were excluded. The main results were as follows ; 1. The positive rate of HBsAg is 5.5% in the conscripted men. 2. The incidence rates of the hepatitis B in 1991 and 1992 conscription cohort were 9.96 and 8.10 per ten thousand person-year, respectively. The incidence rate of the hepatitis B was 1.34 per ten thousand person-year in 1993 conscription cohort which was confirmed as HBsAg negative at the screning test, and 7.41 per ten thousand person-year in 1994 conscription cohort which included the HBsAg positive. 3. The incidence rate of hepatitis B was 99.98 per ten thousand person-year in HBsAg positive group and 2.25 per ten thousand person-year in HBsAg negative group. The incidence rate of the group with high SGPT and HBsAg positive was 255 times higher than that of normal population. 4. The incidence of hepatitis B in HBsAg negative group did not increase even though the probability of personal contact with HBsAg positive had been increased. from the above results, the men who have high SGPT with HBsAg positive should be excluded from military service, and it can not be said that asymptomatic HBsAg carriers influence on the hepatitis B incidence among the HBsAg negative through personal contact.

• 한국레이저가공학회지
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• 제8권3호
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• pp.5-10
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• 2005

[ $InxGa_{1-x}P/GaAs$ ] structures were grown by chemical beam epitaxy(CBE), Pure phosphine($PH_3$) gases were used as group V sources. for the group III sources, TEGa, TmIn were used. $InxGa_{1-x}P$ epilayer was grown on SI-GaAs substrate and has a 1-${\mu}m$ thick. We have investigated the characteristics of $InxGa_{1-x}P$ by the photoreflectance(PR) spectroscopy, The PR spectrum of $InxGa_{1-x}P$ shows third-derivative feature whose Peaks Provide energy gap. The energy gap of $InxGa_{1-x}P$ has deduced composition x. From temperature dependance of PR spectra, temperature coefficient is $dEg/dT=-3.773{\times}10^{-4}$ eV/K, and Varshni coefficients $\alpha$ and $\beta$ values obtained $4{\times}10^4$ eV/K and 267 K respectively. Also, interaction $\alpha$B was 19.4 meV using the Bose-Einstein temperature relation, and $\Theta$ value related the average phonon frequency were 101.4 K. In particular, shoulder peak related to defects observed in PR signal that measured in temperature 82 K.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2353-2358
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• 2014

Purpose: We aimed to detect the expression of HIF-1${\alpha}$, VEGF, HPSE-1 and CD31 in SKOV3 xenografts in nude mice treated with different doses of ionizing radiation, trying to explore the possible mechanism of hypoxia and radioresistance. Methods: Nude mice bearing SKOV3 xenografts were randomly divided into 4 groups: Group A (control group, no ionizing radiation), Group B (treated with low dose of ionizing radiation: 50cGy), Group C (treated with high dose of ionizing radiation: 300cGy), Group D ( combined ionizing radiation, treated with ionizing radiation from low dose to high dose : 50cGy first and 300cGy after 6h interval). The mRNA levels of HIF-1 and VEGF in each group were detected by real time polymerase chain reaction, while HPSE-1 expression was measured by ELISA. The microvessel density (MVD) and hypoxic cells were determined through immunohistochemical (IHC) staining of CD31 and HIF-1a. Results: Significant differences of HIF-1${\alpha}$ mRNA level could be found among the 4 groups (F=74.164, P<0.001): Group C>Group A>Group D> Group B. The mRNA level of VEGF in Group C was significantly higher than in the other three groups (t=-5.267, P=0.000), while no significant difference was observed among Group A, B and D (t=1.528, 1.588; P=0.205, 0.222). In addition, the MVD was shown to be the highest in Group C (t=6.253, P=0.000), whereas the HPSE-1 level in Group A was lower than in Group B (t=14.066, P=0.000) and higher than in Group C (t=-21.919, P=0.000), and similar with Group D (t=-2.066, P=0.058). Through IHC staining of HIF-1a, the expression of hypoxic cells in Group A was (++), Group B was (+), Group C was (+++) and Group D was (+). Conclusion: Ionizing radiation with lowerdoses might improve tumor hypoxia through inhibiting the expression of HIF-1 and HPSE-1, whereas higherdoses worsen tumor hypoxic conditions by up-regulating HIF-1${\alpha}$, HPSE-1, VEGF and CD31 levels. A protocol of low-dose ionizing radiation followed by a high-dose irradiation might at least partly improve tumor hypoxia and enhance radiosensitivity.

• 한국임상수의학회지
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• 제15권2호
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• pp.267-273
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• 1998

The study was carried out to investigate the changes of total WBC, neutrophil, lymphocyte, monocite, eosinophil in the horses'blood of 3 groups which randomly assigned 3 heads to each group. In group A(daily therapy), each horse was iniected, intramuscularly, 100 mg of prednisolone acetate/day for 3 days, consecutively. In group B(alternate-day therapy), each horse was injected, 100 mg of prednisolone acetate/day 4 times on alternate days, intramuscularly. In control group, each horse was injected, intramuscularly, the equivalent volumes/day of saline solution fur 3 days, consecutively. The results were summarized as fellows: 1. Total WBC counts in group A rapidly increased until day 4th, which the counts reached the $maximum(13.10{\pm}0.13{\times}10^{3}/{\mu}l$)(p<0.05), and decreased into control group range until day loth. In group B rapidly increased until day 1st, and gradually increased until day 71% which the counts reached the maximum ($12f3{\pm} 0.20$)0<0.05), and decreased into control group range until day 16th. 2. Neutrophil counts in group A rapidly increased until day 4HL which the coun% reached the maxi um($10.85{\pm} 0.08$)0<0.05), and decreased into control group range until day loth. In group B rapidly increased until day 1st and slowly increased until day 7th, which the counts reached the maximum$(9.76{\pm}0.22)0<0.05)$, and decreased into control group range until day 16th. 3. Lymphocyte counts in group A and B rapidly decreased until day 4th, which the counts reached the minimum(2.14{\pm}0.12 and 2.09{\pm}0.20$, respectively) (p<0.05), and increased into control group range until day 10th. Group A and B, however, had no significant effects each other on Iymphocyte counts during the study. 4. Monocite and eosinophil counts in group A and B remained in the range of control group during the study. Eosinophil in group A and B slightly decreased on day 4th, significantly%<0.05), but we could not generally be reliable the result because of severe standard deviations. In conclusion, we fecund that group A had more rapidly increase and decrease than group B on hematologic counts of WBC, but group B had longer period than group A on the hematologic effects of WBC, and found not differences between daily therapy and alternate-day therapy.

• 한국양식학회지
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• 제17권4호
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• pp.262-267
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• 2004

Physiological responses (oxygen consumption, ammonia excretion, hemoglobin, red blood cell and white blood cell) of cultured eel, Anguilla japonica to vibration stress were studied in an indoor experimental system. Vibration of 76-93 dB (V) from an electric vibrator was provided in 15-minute intervals during daytime (0800-1800) over a ten day period. Oxygen consumption before the beginning of the experiment (0 day) was 83.9 mg $O_2$$.$kg$^{-1}$ ㆍhr$^{-1}$ . After 1, 5 and 10 days of stress respiration rate decreased by 37.5, 53.7 and 70.5%, respectively. Ammonia excretion showed a similar pattern to that of oxygen consumption. Ammonia excretion decreased by 80.1 % following 10 days of vibration stress. Blood hemoglobin concentration also decreased at 1, 3 and 10th day were 29.4% on day 1,83.9% on day 3 and 87.9% by day 10, while red blood cell counts at day 1 and day 10th were 59.8% and 84.7% lower than initial counts, respectively. The white blood cell count increased by 191.2% at day 7, dropping to 41.5% at day 10. Physiological activity was reduced by 50% following 3.4 days of vibration stress.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.267-267
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• 1994

In order to obtain insight into the mechanism by which DNA containing a thymine photo-dimer is recognized by the excision repair enzyme, T$_4$ endonuclease V, we have taken NMR study of this protein and its complex with oligonucleotides. The conformations of five different DNA duplexes DNA I : d(GCGGATGGCG).d(CGCCTACCGC), DNA II d(GCGGTTGGCG) .d(CGCCAACCGC), DNA III : d(GCGGT ^ TGGCG) .d(CGCCAACCGC), DNA IV d(GCGGGCGGCG).d(CGCCCGCCGC) and DNA V d(GCGGCCGGCG) . d(CGCCGGCCGC) were studied by $^1$H NMR. The NMR spectra of these five DNA duplexes in the absence of the enzyme clearly show that the formation of a thymine dimer within the DNA induces only a minor distortion in the structure, and that the overall structure of B type DNA is retained. The photo-dimer formation is found to cause a large change in chemical shifts at the GC7 base pair, which is located at the 3'-side of the thymine dimer, accompanied by the major conformational change at the thymine dimer site. The binding of a mutant T$_4$ endonuclease V (E23Q), which is unable to digest DNA containing a thymine dimer, to the DNA duplex d(GCGGT ^ TGGCG)ㆍd(CGCCAACCGC) causes a large down-field shift in the imino proton resonance of GC7. Therefore, this position is thought to be either the crucial point of the interaction wi th T$_4$ endonuclease V, or the si to of a conformational change in the DNA caused by the binding of T$_4$ endonuclease V. Usually, it is very difficult to assign NMR peaks in DNA * protein complex because of severe peak overlaps. In order to overcome these peak overlaps, we used a method of deuterium incorporation.

• Journal of Plant Biology
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• 제36권3호
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• pp.267-273
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• 1993

Promoters of the chlorophyll a/b bidning protein genes, cab1, and cab2, of Arabidopsis thaliana were studied for their functions in differential expression during greening of etiolated shoots. The etiolated shoots were derived from leaves of transgenic tobacco plants with the cab-CAT (chloramphenicol acetyltransferase) translational fusions, and CAT activity was measured to monitor the activities of the cab promoters. Cab1 promoter activity increased rapidly and showed saturation after about 24 hours of greening, but that of cab2 increased with about 2 day-lag period and showed saturation after 6 days. Cab1 promoter activity was more sensitive to levulinic acid (LA) compared with cab2 activity. Cab2 promoter activity was inhibited more sensitively by chloramphynicol (CAP) than by inhibitors of Chl formation. Cab1 promoter activity was, however, inhibited less sensitively by CAP than by LA. The treatment of abscisic acid (ABA) did not block Chl synthesis so significantly as LA treatment did, and cab2 promoter activity was much less sensitive to ABA compared with that of cab1. These results suggest that cab1 expression is strongly related with Chl formation, possibly with $\delta$-aminolevulinic acid accumulation, and cab2 expression is suppressed more by the blockage of translation of Chl a-apoproteins than by the blockage of Chl a accumulation.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.267-273
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• 2013

Multiplex RT-PCR was used to detect respiratory viruses in 5,318 clinical samples referred to the laboratory of a tertiary teaching hospital from December 2006 to November 2010. The acquired data were analyzed with respect to types, ratio, and co-infection trends of infected respiratory viruses. Trends in respiratory viral infection according to sex, age, and period of infection were also analyzed. Of the 5,318 submitted clinical samples, 3,350 (63.0%) specimens were positive for at least one respiratory virus. The infection rates were 15.8% for human rhinovirus, 14.4% for human respiratory syncytial virus A, 9.7% for human respiratory syncytial virus B, 10.1% for human adenovirus, 5.4% for influenza A virus, 1.7% for influenza B virus, 4.7% for human metapneumovirus, 2.3% for human coronavirus OC43, 1.9% for human coronavirus 229E/NL63, 3.7% for human parainfluenza virus (HPIV)-1, 1.1% for HPIV-2, and 5.3% for HPIV-3. The co-infection analysis showed 17.1% of double infections, 1.8% of triple infections. The median age of virus-positive patients was 1.3 years old, and the 91.5% of virus-positive patients were under 10 years old. Human respiratory syncytial virus was the most common virus in children < 5 years of age and the influenza A virus was most prevalent virus in children over 5 years of age. These results help in elucidating the tendency of respiratory viral infections.