• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.983-985
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• 2013

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.265-266
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• 2003

• The Journal of Korean Society for Radiation Therapy
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• v.13 no.1
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• pp.1-13
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• 2001

I. Purpose This study is performed to encourage cancer patients to identify, relieve and effectively overcome the stress caused by radiotherapy, by analyzing stress reactions and coping patterns of cancer patients who perceived stress due to radiotherapy. II. Materials & Methods The study group was composed of 85 cancer patients of the age 20 or higher who were undergoing radiotherapy in four hospitals located in Seoul and Kyonggi-do. The survey questionnaire was used, which had 161 questions inquiring respondents of general status, perceived stress, stress reactions and coping patterns. The surveyed data were analyzed by a SAS program, which employed descriptive statistics. Pearson Correlation Coefficient, t-test, ANOVA and Stepwised Multiple Regression. III. Results The stress perception and reaction rates were low in cancer patients comparing to patients of the other study. In the coping patterns. the problem-focused coping patterns were significantly higher than emotion-focused coping patterns. The statistically meaningful differences were observed in the stress perception and reactions depending on the time of diagnosis and perceived health level. As for the problem-focused coping patterns, significant differences were found depending on age, marital status, education, income and the number of family members as well as perceived health level of patients. The level of perceived stress and that of stress reactions was found to have positively significant correlation(r=.764, p<.001) while the perceived stress and the problem-focused coping patterns was correlated negatively (r=-.288, p<.01). The stress reactions and the problem-focused coping patterns was found to have negatively significant correlation(r=-.289, p<.01). IV. Conclusion The problem-focused coping behavior, which cooperated with doctors, technologists, nurses and families of cancer patients, is advisable for the cancer patients to overcome uncertainty and uneasiness by effectively release the stress.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1199-1203
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• 2010

Second-order rate constants ($k_N$) have been measured spectrophotometrically for Michael-type reactions of 1-(X-substituted phenyl)-2-propyn-1-ones (2a-f) with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ value increases as the incoming amine becomes more basic and the substituent X changes form an electron-donating group (EDG) to an electron-withdrawing group (EWG). The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.48 - 0.51. The Hammett plots for the reactions of 2a-f exhibit poor correlations but the corresponding Yukawa-Tsuno plots result in much better linear correlations with ${\rho}$ = 1.57 and r = 0.46 for the reactions with piperidine while ${\rho}$ = 1.72 and r = 0.39 for those with morpholine. The amines employed in this study are less reactive in MeCN than in water for reactions with substrates possessing an EDG, although they are ca. 8 pKa units more basic in the aprotic solvent. This indicates that the transition state (TS) is significantly more destabilized than the ground state (GS) in the aprotic solvent. It has been concluded that the reactions proceed through a stepwise mechanism with a partially charged TS, since such TS would be destabilized in the aprotic solvent due to the electronic repulsion between the negative-dipole end of MeCN and the negative charge of the TS. The fact that primary deuterium kinetic effect is absent supports a stepwise mechanism in which proton transfer occurs after the rate-determining step.

• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2955-2959
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• 2011

Second-order rate constants for nucleophilic substitution reactions of 2,4-dinitrophenyl benzenesulfonate 1a with a series of alicyclic secondary amines in MeCN have been measured spectrophotometrically and compared with those reported previously for the corresponding reactions performed in aqueous medium to investigate the effect of medium on reactivity and reaction mechanism. The amines employed in this study are found to be more reactive in the aprotic solvent than in $H_2O$. The reactions of 1a in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{nuc}$ = 0.58, which contrasts to the curved Br${\o}$nsted-type plot reported previously for the corresponding reactions performed in the aqueous medium (i.e., ${\beta}_2$ = 0.86 and ${\beta}_1$ = 0.38). Accordingly, it has been concluded that the reaction mechanism changes from a stepwise mechanism to a concerted pathway upon changing the medium from $H_2O$ to MeCN. Reactions of Y-substituted phenyl benzenesulfonates 1a-c with piperidine in MeCN result in a linear Br${\o}$nsted-type plot with ${\beta}_{lg}$ = -1.31, indicating that expulsion of the leaving group is significantly more advanced than bond formation in the transition state. The trigonal bipyramidal intermediate ($TBPy^{\pm}$) proposed previously for the reactions in $H_2O$ would be highly unstable in MeCN due to strong repulsion between the negative charge in $TBPy^{\pm}$ and the negative dipole end of MeCN. Thus, destabilization of $TBPy^{\pm}$ in MeCN has been concluded to change the reaction mechanism from a stepwise mechanism to a concerted pathway.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2023-2028
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• 2013

A kinetic study is reported for the nucleophilic substitution reactions of phenyl Y-substituted-phenyl carbonates (5a-5k) with piperidine in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The plots of $k_{obsd}$ vs. [piperidine] for the reactions of substrates possessing a strong electron-withdrawing group (EWG) in the leaving group (i.e., 5a-5i) are linear and pass through the origin. In contrast, the plots for the reactions of substrates bearing a weak EWG or no substituent (i.e., 5j or 5k) curve upward, indicating that the electronic nature of the substituent Y in the leaving group governs the reaction mechanism. Thus, it has been suggested that the reactions of 5a-5i proceed through a stepwise mechanism with a zwitterionic tetrahedral intermediate (i.e., $T^{\pm}$) while those of 5j and 5k proceed through a stepwise mechanism with two intermediates (i.e., $T^{\pm}$ and its deprotonated form $T^-$). The slope of the Br${\o}$nsted-type plot for the second-order rate constants (i.e., $k_N$ or $Kk_2$) changes from -0.41 to -1.89 as the leaving-group basicity increases, indicating that a change in the rate-determining step (RDS) occurs. The reactions of 5a-5k with piperidine result in larger $k_1$ values than the corresponding reactions with ethylamine.

• Korean Journal of Cognitive Science
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• v.22 no.1
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• pp.39-55
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• 2011

People tend to overestimate their emotional reactions to events such as physical handicap and buying a new car in the future. Students overestimate their reactions to a future grade as compared to their reactions after receiving the grade. Impact bias refers to people's tendency to overestimate the intensity and the duration of emotional reactions to a future event. The present study explored whether impact bias occurs to risky objects such as nuclear energy, genetically engineered food, and mobile phone. Participants were asked to predict their emotional reactions at three time points, that is, at the present, a week after, and a year after. They predicted their reactions before and after two debiasing tasks. The present study demonstrated a different pattern of impact bias at three time points: A largest bias was observed a week after the present. A defocalism manipulation has eliminated the impact bias whereas an adaptation manipulation has not. Several points were discussed regarding the difference between the previous and the present work.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.spc
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• pp.33-39
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• 2009

The practice of supplying nutrients for paddy soil with sustaining human health and ecological soundness is to utilize indicators considering soil chemical reactions. The long-term basis experiment of fertilizer and amendment of paddy soil and an experiment of yield response of soil types on nitrogen level from 2000 till 2002were used to search indicators of nutrient supplying capacity related to soil chemical reactions. Chemical reactions of paddy soil was composed of dissociating and/or adsorbing nutrients and of decomposing soil organic matter (SOM) into $H^+$, $e^-$, $CO_2$ in paddy soil. The indicators of nutrient supplying capacity, which were established by considering soil chemical reactions, were SOM or soil protein for nitrogen and available phosphate for phosphorus and cation exchangeable capacity (CEC) and exchangeable potassium for potassium. Korea has used fertilizer recommendation equations established with the indicators of nutrient supplying capacity for paddy soil.

• Journal of Oral Medicine and Pain
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• v.25 no.4
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• pp.355-364
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• 2000

This study was to find dental materials causing hypersensitivity reactions by carrying out patch tests in the patients with oral mucosal lesions to investigate the possibility of hypersensitivity reactions in etiology of oral mucosal lesions. 31 patients (female 26, male 5, age range 24-72 years) with oral mucosal lesions were classified as patient group, and 41 volunteers (female 24, male 17, age range 23-40 years) without oral mucosal lesion, systemic disease and history of allergy as control group. The obtained results were as follows: 1. There were various dental restorations in most of patient group and control group, 29(94%) in 31 patient group, 35(85%) in 41 control group. 2. Among sites of oral mucosal lesions, buccal mucosa was the most common site with 60%, followed by gingiva with 24%, tongue with 16%. Lesions in contact with restorations were highly 90% in tongue and 89% in buccal mucosa, but comparatively lower 53% in gingiva. 3. The ratio of positive reactions to the patch test in patient group was significantly higher than the control group (p<0.05). 4. Dental materials causing positive reactions to the patch test were mainly mercury(19%), potassium dichromate(16%), cobalt chloride(16%) in patient group, cobalt chloride(17%) in control group. 5. In 20 patients with lichen planus, 8 patients(40%) showed positive reactions to the patch test.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.155-166
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• 1992

In dentistry, precious metal alloys are, mainly due to economic factors, increasingly displaced by alternatives containing Ni-Cr-Co. There are some reports where hypersensitive reactions to Ni-Cr-Co alloys are presented and discussed. The reactions reported vary from mucosa contact stomatitis to generalized dermatitis without any oral mucosal reaction. The purpose of this study was to investigate the incidence of nickel, chrome, cobalt and copper, and to know whether subjects with positive skin reaction to nickel would also demonstrate adverse intraoral reaction to a non-precious metal nickel. The patch tests were performed in 81 subjects(male 39, female 42) and nickel sulfate 5% aq., potassium bichromate 0.5% at., cobalt chloride 2% aq., & copper sulfate 1% aq., were used for test allergens. And then the intraoral tests were performed in 16 subjects, 8 subjects with positive allergic skin reaction to nickel and 8 subjects with negative allergic skin reaction. A pure metallic nickel plate was attached to the buccal side of the upper second premolar. The results are as follows : 1. The frequency of nickel sensitivity was 9.9% (2 men, 6 women), cobalt was 4.9% (1 man, 3 women), and chrome was 2.5% (2 men) respectively and there was no positive reaction to copper 2. The positive reactions were 8 of 23 (34.8%) with a history of jewelry allergic reactions and 3 of 58 (5.1%) without a history of jewelry allergic reactions. 3. Three of 8 subjects with positive skin reaction. gave reactions to the metal plates.