• Journal of the Korean Vacuum Society
• /
• v.17 no.3
• /
• pp.220-225
• /
• 2008

In this research, the P(VDF-TrFE) copolymer thin films were prepared by the physical vapor deposition and studied to their piezoelectric properties. In the case of a specimen produced by varying the deposition temperature from $260^{\circ}C$ to $300^{\circ}C$, its piezoelectric coefficient($d_{33}$) increased from 32.3pC/N to 36.28pC/N, and piezoelectric voltage coefficient($g_{33}$) from $793{\times}10^{-3}V{\cdot}m/N$ to $910.5{\times}10^{-3}V{\cdot}m/N$. On the basis of these experimental results, we concluded that the P(VDF-TrFE) copolymer thin film prepared at $300^{\circ}C$ showed the optimum piezoelectric properties. At the deposition temperature of $320^{\circ}C$, its piezoelectric coefficient(d33) decreased 25.3 pC/N and piezoelectric voltage coefficient($g_{33}$) $680{\times}10^{-3}V{\cdot}m/N$.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.12
• /
• pp.1904-1915
• /
• 2019

Resistant starch (RS) is metabolized by gut microbiota and involved in the production of short-chain fatty acids, which are related to a variety of physiological and health effects. Therefore, the availability of RS as a prebiotic is a topic of interest, and research on gut bacteria that can decompose RS is also important. The objectives in this study were 1) to isolate a human gut bacterium having strong degradation activity on non-gelatinized RS, 2) to characterize its RS-degrading characteristics, and 3) to investigate its probiotic effects, including a growth stimulation effect on other gut bacteria and an immunomodulatory effect. Bifidobacterium adolescentis P2P3 showing very strong RS granule utilization activity was isolated. It can attach to RS granules and form them into clusters. It also utilizes high-amylose corn starch granules up to 63.3%, and efficiently decomposes other various types of commercial RS without gelatinization. In a coculture experiment, Bacteroides thetaiotaomicron ATCC 29148, isolated from human feces, was able to grow using carbon sources generated from RS granules by B. adolescentis P2P3. In addition, B. adolescentis P2P3 demonstrated the ability to stimulate secretion of Th1 type cytokines from mouse macrophages in vitro that was not shown in other B. adolescentis. These results suggested that B. adolescentis P2P3 is a useful probiotic candidate, having immunomodulatory activity as well as the ability to feed other gut bacteria using RS as a prebiotic.

• Bulletin of the Korean Chemical Society
• /
• v.23 no.2
• /
• pp.291-294
• /
• 2002

The reactions of triplet oxygen atom with halomethanes as a potential fire extinguisher were studied by a discharge flow-chemiluminescence imaging method. The experiments were carried out under second order conditions. The bimolecular atom-molecule reaction rate constants were determined in terms of the initial rate method. The initial concentration of oxygen atom was also determined under second order rate law instead of the pseudo-first order conditions with $[O(^3P)]_0{\ll}[sample]_0$. The second order conditions were more reliable than pseudo-first order conditions for the determinations of rate constants. The rate constants of the reactions $CF_3I\;+\;O(^3P)$, $CH_3PI\;+\'O(^3P)$, and $CHBrCl_2\;+\;O(^3P)$ were determined to be $5.0\;{\times}\;10^{-12}$ , $1.1\;×\;0^{-11}$ , and $1.9\;{\times}\;10^{-14}cm^3molecule^{-1}s^{-1}$, respectively.

• Korean Journal of Microbiology
• /
• v.37 no.4
• /
• pp.253-258
• /
• 2001

A Bacillus circulans KCTC3004 $\beta$-1,3-glucanase gene contained in a recombinant plasmid pLM460 derived from subcloning the original recombinant plasmid pLM530 was trasferred into a new shuttle vector plasmid pLMS1180 by ligating linearized DNAs of pLM460 and pUB110. B. subtilis RM125 and B. megaterium ATCC14945 transformed with pLMS1180 produced the $\beta$-1,3-glucanase substantially. Most of the enzyme was produced during the exponential growth period. The maxium activities of the $\beta$-1,3-glucanase produced by the Bacillus transformants were compared with that of the B. circulans gene donor strain. The B. subtilis RM125 (pLM1180) enzyme showed the activity 14 times higher than that of the gene donor cells, followed by the B. megaterium ATCC14945 (pLMS 1180) enzyme with activity 5 times higher than that of the gene donor cells. While E. coli secreted about 7% of the produced enzyme, B. subtilis excreted the enzyme into the medium wholly and B. megaterium about 97% of the total product. The SDS-PAGE of this enzyme produced in E. coli (pLMS1180), B subtilis (pLMS1180) or B. megaterium (pLMS1180) indicated a molecular weight of 38,000. The enzymes overproduced in three different host cells hydrolyzed laminarin to produce mainly laminaribiose, laminaritriose, and laminarioligosaccharides. The plasmid pLMS1180 was stable in B. megaterium, E. coli, but was unstable in B. subtilis.

• Applied Chemistry for Engineering
• /
• v.29 no.3
• /
• pp.336-341
• /
• 2018

In general, the synthesis of poly(3-hexylthiophene)(P3HT)-based block copolymers requires at least a 4-5 step process. To control the molecular weight, molecular weight distribution, and block ratio, the reaction conversion and time should be monitored. In addition, the reaction scale usually limited to several mg to g was difficult to increase due to the limitations of living radical polymerizations. In this study, we synthesized P3HT-b-poly(4-vinylprydine) (P3HT-b-P4VP) with a final product quantity of > 19 g via a 2-step synthetic method with an anionic polymerization. In this method, the molecular weight and molecular weight distribution of P3HT-b-P4VP can be well controlled without monitoring the reaction conversion. We also studied physical properties of P3HT-b-P4VP depending on different solvent systems, which were investigated by UV-vis spectroscopy, atomic force microscopy, and ultraviolet photoelectron spectroscopy.

• Journal of East-West Nursing Research
• /
• v.5 no.1
• /
• pp.50-64
• /
• 2000

The purpose of this study was to investigate the correlation of family support, self-esteem and life-satisfaction in homeless persons and to provide basic data to help them attain a better quality of life. From Jul. 1 to Oct. 10, 2000, 235 homeless persons, registered at the noninstitutionalized homeless and institutionalized homeless in Seoul, were accepted as subjects for the study. The instruments used for this study were a Family support scale of Park, Jee Won, life-satisfaction scale of Wood, Wylie & Sheafer and Rosenberg's Self-esteem Scale. The reliability of the scales were tested by Cronbach's Alpha. The collected data Were analyzed by the SPSS program using unpaired t-test and Pearson's Correlation Coefficients. The results were as follows : 1. There Was a statistically significant difference in the level of demographic between family support groups : age(t=2.74, P=.001), education background(f=5.48, P=.001), connection of family (t=2.29, P=.05), present illness(t=2.04, P=.05). 2. There Was a statistically significant difference in the level of demographic between self-esteem groups : education background(t=3.24, P=.05), connect of family (t=3.38, P=.001), types of disease(t=2.12, P=.05), job related to income (t=2.12, P=.05). 3. There Was a statistically significant difference in the level of demographic between life-satisfaction groups : education background(t=3.39, P=.05), connect of family(t=2.10, P=.01), smoking(t=2.38, P=.01), disease(t=1.92, P=.05), emotion states(t= 6.12, P=.001). 4. There was a positive correlation between family support and self-esteem for the homeless and it was statistically significant (r=.267, p=.001). 5. There was a positive correlation between family support and life-satisfaction for the homeless and it was statistically significant(r=.299, p=.001). 6. There was a positive correlation between life-satisfaction and self-esteem for the homeless and it was statistically significant(r=.179, p=.01).

• Journal of the Korean Applied Science and Technology
• /
• v.35 no.1
• /
• pp.131-140
• /
• 2018

This study is a descriptive research study for analyzing the relevance among stress, anxiety, and ego-resilience in nursing college students before clinical practice. The survey was conducted targeting the second-year students in a K college who were anticipating their first clinical practice. The survey result showed that female students showed higher stress levels than male students (t=-5.51, p<.001) before clinical practice. Female students also showed higher anxiety levels than male students (t=-3.30, p=.001) before clinical practice. The students showed higher anxiety levels before clinical practice as they felt more strongly that they were in bad health (F=3.27, p=.041), as their personality was less outgoing (t=-3.32, p=.001), and as they had a lower satisfaction level in their major (F=7.25, p=.001). The students showed higher ego-resilience levels before clinical practice as they felt more strongly that they were in good health (F=3.74, p=.026) and as their personality was more outgoing (F=3.19, p=.002). The stress and anxiety levels before clinical practice also had a positive correlation (r=.211, p=.010) and the ego-resilience and anxiety before clinical practice had a negative correlation (r=-.313, p<.001). Based on the finding, it is necessary to develop the competence improvement program that can reduce the anxiety of nursing college students before clinical practice in order to improve their ego-resilience.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.10C
• /
• pp.959-964
• /
• 2007

In this paper, for a positive integer M and a prime p such that $M|p^n-1$, families of M-ary sequences using the M-ary Sidel'nikov sequences with period $p^n-1$ are constructed. The family has its maximum magnitude of correlation values upper bounded by $3\sqrt{p^{n}}+6$ and the family size is $(M-1)^2(2^{n-1}-1)$+M-1 for p=2 or $(M-1)^2(p^n-3)/2+M(M-1)/2$ for an odd prime p.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.15 no.2
• /
• pp.293-301
• /
• 2009

Purpose: This study was conducted to investigate the relationship between self-esteem and coping skills among middle school students. Method: The participants were 674 students in three middle schools in GyeongGi-Do. The data were collected from June 10 to 20, 2005. The instruments used were the Rosenberg Self-esteem Scale and the Ways of Coping Checklist. The data were analyzed using the SPSS-Win 12.0 program. Result: Self-esteem showed a significant positive correlation with positive coping skills (r= .162. p= .000). As for the positive coping skills, there was a significant difference by grade (F= 4.69, p= .010), relationship with parent (F=4.036, p= .02), and relationship with siblings (F=3.902, p= .02). As for the negative coping skills, there was a significant difference by grade (F=3.05, p= .04), condition of living with parents (F=3.559, p= .02), economic status (F=3.736, p= .02), relationship with sibling (F=3.408, p= .03), and troubling matters (F=5.422, p= .005). Conclusion: Positive coping skills may be effective for adjustment because they positively related to self-esteem. Self-esteem and coping skills should be considered when an adolescent's mental health enhancement program is designed.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.6
• /
• pp.2495-2499
• /
• 2015

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is an important serine/threonine protein kinase and a member of the MAPK family. MEKK3 can effectively activate the MEK/ERK signaling pathway and promote an autocrine growth loop critical for tumor genesis, cell proliferation, terminal differentiation, apoptosis and survival. To explore the relationship between MEKK3 and cell apoptosis, clinicopathology and prognosis, we characterize the expression of MEKK3, pERK and FoxP3 in the renal clear cell carcinoma (RCCC). Protein expression was detected by tissue microarray and immunochemistry in 46 cases of RCCC and 28 control cases. Expression levels of CD3+,CD3+CD4+,CD3+CD8+,CD4+CD25+, CD4+CD25+ FoxP3+ were assessed by flow cytometry and analyzed for their association with pathological factors, correlation and prognosis in RCCC. Expression of MEKK3, pERK and FoxP3 was significantly up-regulated in RCCC as compared to control levels (p<0.01), associated with pathological grade (p<0.05)and clinical stage (p<0.05). CD4+CD25+ Foxp3+ Treg cells were also significantly increased in RCCC patients (p<0.05). Cox multivariate regression analysis showed that MEKK3, pERK expression and patholigical stage were independent prognostic factors in patients with RCCC (p<0.05). MEKK3 can be used as an important marker of early diagnosis and prognostic evaluation in RCCC. It may be associated with imbalance of anti-tumor immunity and overexpression of pERK. Expression of MEKK3 and pERK are significantly increased in RCCC, with protein expression and clinical stage acting as independent prognostic factors.