• Bulletin of the Korean Chemical Society
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• 제16권11호
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• pp.1122-1125
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• 1995

Three inherently chiral calix[4]arenes 3-5 were synthesized as racemate starting from the ethylation at 1.3-distal hydroxy groups of calix[4]arene 2 which has two phenyl groups at upper rim in AABB fashion, and then two remaining hydroxy groups were acetylated by treatment with acetyl chloride in the presence of NaH to produce calix[4]arene 4. Treatment of 4 with AlCl3 under Fries rearrangement conditions, only one acetyl group was rearranged to the para-position to afford calix[4]arene 5 with AABC substitution pattern at the upper rim of calix. The structure of chiral calix[4]arenes were confirmed based on NMR and massspectra.

• 한국환경과학회지
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• 제21권12호
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• pp.1455-1462
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• 2012

The vertical distributions of nitrifying bacteria in aerobic fixed biofilm were investigated to evaluate the relationship between nitrification performance and microbial community at different HRT. Fluorescent in situ hybridization (FISH) and portable ion selective microelectrode system were adopted to analyze microbial communities and ions profiles according to the biofilm depth. Cilia media packed MLE (Modified Ludzack-Ettinger) like reactor composed of anoxic, aerobic I/II was operated with synthetic wastewater having COD 200 mg/L and $NH_4{^+}$-N mg/L at HRT of 6 hrs and 4 hrs. Total biofilm thickness of aerobic I, II reactor at 4 hrs condition was over two times than that of 6 hrs condition due to the sufficient substrate supply at 4 hrs condition (6 hrs; aerobic I 380 ${\mu}m$ and II 400 ${\mu}m$, 4 hrs; aerobic I 830 ${\mu}m$ and II 1040 ${\mu}m$). As deepen the biofilm detection point, the ratio of ammonia oxidizing bacteria (AOB) was decreased while the ratio of nitrite oxidizing bacteria (NOB) was maintained similar distribution at both HRT condition. The ratio of AOB was higher at 4 hrs than 6 hrs condition and $NH_4{^+}$-N removal efficiency was also higher at 4 hrs with 89.2% than 65.4% of 6 hrs. However, the ratio of NOB was decreased when HRT was reduced from 6 hrs to 4 hrs and $NO_2{^-}$-N accumulation was observed at 4 hrs condition. Therefore, it is considered that insufficient HRT condition could supply sufficient substrate and enrichment of AOB in all depth of fixed biofilm but cause decrease of NOB and nitrite accumulation.

• 한국식물병리학회지
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• 제10권2호
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• pp.123-128
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• 1994

Incidence of blast caused by Pyricularia grisea Sacc. on 21 leading cultivars and elite lines of rice was investigated in different locations such as Icheon, Chuncheon, Jecheon, and Naju during three years from 1991 to 1993. Disease index of leaf blast of Dongjinbyeo was high in the blast nursery with range 4 to 9 at Naju, but low at other locations with range 1 to 4. Percentages of diseased leaf area of Joryungbyeo and Daelipbyeo 1 were 4.3 and 12%, respectively in the fields at Jecheon in 1993, but were much lower in the other locations during three years. The incidences of leaf blast of Daelipbyeo 1 were 0.3 and 12.0% at Chuncheon and Jecheon, respectively in 1993, but no disease occurred at Naju during three years. Percentage of diseased panicles of Joryungbyeo was 100% at Icheon and Jecheon in 1993, 92.4% in Suweon 390 at Icheon on 1991 and 100% in Jinbu 15 at Jecheon on 1993. Race distribution of rice blast fungus at Icheon and Jecheon was more varied than that of the other locations.

• 소성∙가공
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• 제19권4호
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• pp.230-235
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• 2010

Titanium alloy sheets have excellent specific strength and corrosion resistance as well as good performance at high temperature. Recently, titanium alloys are widely employed not only for aerospace parts but also for bio prothesis and motorcycle. However, the database is insufficient in the titanium alloy for press forming process. In this study, the effect of temperature on the forming limit diagram was investigated for Ti-6Al-4V titanium alloy sheet through the Hecker‘s punch stretching test at elevated temperature. Experimental results obtained in this study can provide a database for the development of press forming process at elevated temperature of Ti-6Al-4V titanium alloy sheet. From the experimental studies it can be concluded that the formability of Ti-6Al-4V titanium alloy sheet is governed by the ductile failure for the testing temperature. The formability of Ti-6Al-4V titanium alloy sheet at $700^{\circ}C$ increases about 7 times compared with that at room temperature.

• Nuclear Engineering and Technology
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• 제51권3호
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• pp.792-799
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• 2019

The present study aims to investigate the fluorination of thorium oxide ($ThO_2$) by ammonium hydrogen difluoride ($NH_4HF_2$). Fluorination was performed at room temperature by mixing $ThO_2$ and $NH_4HF_2$ at different molar ratios, which was then left to react for 20 days. Next, the mixtures were analyzed using X-ray diffraction (XRD) at the intervals of 5, 10, 15, and 20 days, followed by the heating of the mixtures at $450-750^{\circ}C$ with argon gas flow. The characterization of $ThF_4$ was established using X-ray diffraction (XRD) and scanning electron microscopy-dispersion X-ray spectroscopy (SEM-EDX). In this study, ammonium thorium fluoride was synthesized through the fluorination of $ThO_2$ at room temperature. The optimum molar ratio in synthesizing ammonium thorium fluoride was 1.0:5.5 ($ThO_2:NH_4HF_2$) with 5 days reaction time. In addition, the heating of ammonium thorium fluoride at $450^{\circ}C$ was sufficient to produce $ThF_4$. Overall, this study proved that $NH_4HF_2$ is one of the fluorination agents that is capable of synthesizing $ThF_4$.

• 대한간호학회지
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• 제5권1호
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• pp.31-40
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• 1975

A study on public health education curriculums of 14 universities located in Seoul city was carried out from Oct. 15 1974 to Nov. 15 1974. The data were obtained from 11 universities bulletins & 3 universities administration officers. The contentments of public health were obtained by the interview with the teaching professors on the syllabuses. The results were as follows: 1. General Public health topics were taught at 4 universities (28.6%) out of 14 universities & 129 departments (25.3%) out of 509 departments. General public health education were taught at 2 universities (28.6%) out of 7 universities with medical school of the colleges of education 2 collages (18.2%) had the public health education in the curriculums. 2. Academic administration of Public health education by universities 2 hrs for 2 credits were allocated at 2 universities (50%), while 4 hrs for 2 credits at the rest universities (50% ), Pubic health education were taught as an essential general education at 4 universities. Public health education were taught in freshman course at 2 universities in senior course at 2 other universities. Text books on public health education were chosen at 2 universities and at other 2 universities, just references were introduced to students. Contents of public health education. In two universities teaching programs of public health were undertaken & in other two universities no particular leaching programs were undertaken. And contents of tuberculosis, V. D. & communicable disease control Pregnancy & delivery, precaution ok post paestum maternal & child health were taught at 4 universities. Contents of health & college students, alcohol tobacco & coffee, chosen of sports were taught at few university. 3. General public health education instructors: The instructors were consisted of 13 men(81.2%) & 3 women (18.8%) Physicians were 11 (68.8%), nurses 2 (12.5%) & others 3(18.7%) Full time instructors were 7 (43.7%) part time instructors 9 (56.3%) Position & organization instructors belong to ; instructors (75.0%) had the teaching position in universities & research workers & others were 3 (18.8%) & medical practitioner was I(6.2%) 4. Public health & home nursing education by general home economic departments. Home nursing & public health were taught as an compulsory general education program in 10 departments 50.5% & as an alternative major course in 7 departments (35.0%) 2 hrs for 2 credits were allocated at 9 departments (45.0%) while eve. 4hrs for 4credits were 8 departments (40.0%).

• 대한간호학회지
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• 제41권2호
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• pp.157-164
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• 2011

Purpose: This study was performed to identify changes in blood glucose at preoperative fasting time in surgical patients over 60 yr. Methods: Data collection was performed from July, 2008 through July, 2009. Participants consisted of 80 nondiabetic surgical patients. Blood glucose was checked from 3 to 5 times. The 5 times were 2-hr fasting on the pre-operative day (T1, n=80), 8 hr (T2, n=80), 10 hr (T3, n=17), 12 hr (T4, n=34) and 14 hr fasting on the day of the operation (T5, n=29). Results: Of the patients, 27.5% had a blood glucose level of less than 79 mg/dL at T2; 17.6% at T3; 32.4% at T4; and 17.2% at T5. Mean blood glucose levels were 93.8 mg/dL at T1; 88.4 mg/dL at T2; 91.7 mg/dL at T3; 87.4 mg/dL at T4: and 94.1 mg/dL at T5. Blood glucose was the lowest at T2 (p<.001). Conclusion: As 17.6-32.4% of the patients showed the blood glucose level of less than 79 mg/dL at 8-14 hr pre-operative fasting, the authors recommend that surgical patients p>60 yr-of-age be observed for hypoglycemia during pre-operative fasting of more than 10 hr and that surgical patients >60 yr-of-age with risks for hypoglycemia be scheduled for operation within 10 hr preoperative fasting.

• Animal Bioscience
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• 제37권5호
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• pp.852-861
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• 2024

Objective: The present study aimed to investigate the effect of β-nicotinamide mononucleotide (NMN) supplementation on ram sperm quality during storage at 4℃ in vitro. Methods: Tris-citric acid-glucose solution containing different doses of NMN (0, 30, 60, 90, and 120 µM) was used to dilute semen collected from rams and it was stored at 4℃. Sperm motility, plasma membrane integrity as well as acrosome integrity were evaluated at 0, 24, and 48 h time points after storage at 4℃. In addition, sperm mitochondrial activity, lipid peroxidation (LPO), malondialdehyde (MDA) content, reactive oxygen species (ROS) content, glutathione (GSH) content, superoxide dismutase (SOD) activity, and apoptosis were measured at 48 h time point after storage at 4℃. Results: Results demonstrate that the values obtained for sperm motility, acrosome integrity, and plasma membrane integrity in the NMN treatments were significantly higher than control (p<0.05). The addition of 60 µM NMN significantly improved ram sperm mitochondrial activity and reduced LPO, MDA content, and ROS content compared to control (p<0.05). Interestingly, sperm GSH content and SOD activity for the 60 µM NMN treatment were much higher than those observed for control. NMN treatment also decreased the level of Cleaved-Caspase 3, Cleaved-Caspase 9, and Bax while increasing Bcl-2 level in sperm at 48 h time point after storage at 4℃. Conclusion: Ram sperm quality can be maintained during storage at 4℃ with the addition of NMN at 60 µM to the semen extender. NMN also reduces oxidative stress and apoptosis. Overall, these findings suggest that NMN is efficient in improving the viability of ram sperm during storage at 4℃ in vitro.

• 한국축산식품학회지
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• 제31권4호
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• pp.551-556
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• 2011

본 연구는 표준균주 C. sakazakii(CAFM2)와 4개의 야생균주(EB 1, EB 5, EB 7, EB 41)를 사용하여 pH를 조정한 산성 환경에서의 저항성을 살펴보았다. C. sakazakii는 pH 4.5 TSB에서 5시간, 10시간 동안 적응한 경우, pH 4.5 TSB에서 적응하지 않은 경우와 비교하여 EB 7을 제외한 모든 균주가 pH 2.5 TSB에서의 D값이 유의적으로 높게 나타났다(p<0.05). 따라서 약산성 환경에서 적응한 균주는 강산성 환경에서의 저항성이 증가하였다. C. sakazakii는 pH 4.5 TSB에서 배양한 경우, pH 7.2 TSB에서 배양한 경우와 비교하여 모든 균주가 pH 2.5 TSB에서의 D값이 유의적으로 높게 나타났다(p<0.05). 따라서 약산성 환경에서 배양한 균주는 강산성 환경에서의 저항성이 증가하였다. 본 연구를 통해 C. sakazakii는 약산성 환경에 적응한 경우 강산성 환경에서의 저항성이 증가하는 것으로 나타났다. 이러한 acid adaptation response는 C. sakazakii와 관련된 식품 가공 산업에서의 hurdle technology를 적용하는데 있어서 안전성 확보와 관련된 시사점을 제공할 수 있을 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1489-1492
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• 2016

Background: Although there are no biomarkers that are routinely used in endometrial cancer (EC) management, many studies have found that serum human epididymis protein 4 (HE4) is superior to cancer antigen 125 (CA125) in the detection of EC. The correlation of HE4 with two prognostic factors for EC, primary tumor diameter (PTD) and depth of myometrial invasion (DMI) may be useful in identifying EC patients at high risk of lymphatic dissemination. Objective: To evaluate the correlation of serum HE4 with PTD and DMI in patients with EC. Materials and Methods: A cross-sectional study was conducted on 70 EC patients who were scheduled for elective surgery at Rajavithi Hospital between 1st September 2013 and 30th May 2014. Preoperative serum levels of HE4 and CA125 were investigated, and then gross measurement of PTD was taken and postoperative pathologic slides were reviewed for DMI including histologic types, grading and staging. Results: Preoperative serum HE4 levels were strongly correlated with PTD (r=0.65, p<0.001) and moderately correlated with DMI (r=0.46, p<0.001). Moreover, serum HE4 levels were significantly elevated in EC patients with PTD >2 cm (p<0.001) and DMI > 50% (p=0.004). The performance of serum HE4 in identifying EC patients at low risk and high risk of lymph node metastasis was significantly better than that of CA125 (AUC 0.88 vs. 0.65, p=0.003). At an optimal cut-off value of 70 pM/L, serum HE4 had a sensitivity of 83.3% and a specificity of 80.0%. Conclusions: In EC patients, preoperative serum HE4 is significantly correlated with PTD and DMI. Serum HE4 levels could be useful in identifying endometrial cancer patients at high risk of lymphatic spread who would benefit from systemic lymphadenectomy at the cut-off value of 70 pM/L.