• Macromolecular Research
• /
• v.12 no.3
• /
• pp.316-321
• /
• 2004

We have performed copolymerizations of ethylene with 1-hexene using various ansa-metallocene compounds in the presence of the non-coordinative [CPh$_3$][B(C$\_$6/F$\_$5/)$_4$ion pair as a cocatalyst. The metallocenes chosen for this study are isospecific metallocene diamide compounds, rac-(EBI)Zr(NMe$_2$)$_2$ [1, EBI = ethylene-l ,2-bis(1-indenyl)], rac-(EBI)Hf(NMe$_2$)$_2$ (2), rac-(EBI)Zr(NC$_4$H$\_$8/)$_2$ (3), and rac-(CH$_3$)$_3$Si(1-C$\_$5/H$_2$-2-CH$_3$-4-$\^$t/C$_4$H$\_$9/)2 Zr(NMe$_2$)$_2$ (4), and syndiospecific metallocene dimethyl compounds, ethylidene(cyclopentadienyl)(9-fluorenyl) ZrMe$_2$ [5, Et(Flu)(Cp )ZrMe$_2$] and isopropylidence (cyclopentadienyl)(9-fluorenyl)ZrMe$_2$ [6, iPr(Flu)(Cp)ZrMe$_2$]. The copolymerization rate decreased in the order 4 ＞1-3＞2 ＞5＞6. The reactivity of I -hexene decreased in the order 2 ＞6＞1- 3-5＞ 4. We characterized the microstructure of the resulting poly(ethylene-co-l-hexene) by $\^$l3/C NMR spectroscopy and investigated various other properties of the copolymers in detail.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.12
• /
• pp.2449-2453
• /
• 2007

L-[18F]FMAU ([18F]1b) was prepared from the precursor 2-O-[(trifluoromethyl)-sulfonyl]-1,3,5-tri-Obenzoyl- α-L-ribofuranose, by coupling the radioactive fluoro-sugar with the corresponding silylated thymine in 4 steps. The final products, including the α and β anomers, were purified using reverse phase HPLC with an appropriate solvent (5% CH3CN/H2O) at a flow rate of 3.0 mL/min. The total elapsed time of synthesis was about 180-200 min from EOB. The α/β anomeric ratio of the compounds was about 1:9, and the radiochemical purity of the product (β-form) was >98% with decay-corrected yields of 25-35%. All radioactive samples were confirmed using co-injection with pure non-radioactive analogues in every step. In the cellular uptake in vitro test of herpes simplex virus-thymidine kinase (HSV1-TK) gene expressed cells, the percent uptake of injected dose (%ID) of L- and D-FMAU was 37.28 and 65.86, respectively after 240 min incubation. However, the relative uptake (MCA-TK/MCA cellular uptake ratio) of L-FMAU was higher than that of D-FMAU (%ID of L-FMAU, 0.36 and D-FMAU, 0.93 after 240 min incubation in MCA cells). This means that L-FMAU will show better specific HSV1-TK gene expressed cell uptake for selective HSV1-TK gene imaging.

• Journal of Food Hygiene and Safety
• /
• v.21 no.3
• /
• pp.153-158
• /
• 2006

The contamination levels of 3-MCPD(3-Monochloropropane-1,2-diol) and 1,3-DCP(1,3-Dichloro-2-Propanol) in soy sauce, sauces was monitored. 105 samples were collected from June 2005 to August 2005 in Gyeonggi-do. 3-MCPD and 1,3-DCP were analyzed by GCMSD. As results, the detection range of 3-MCPD concentration was between 0.02 mg/kg and 0.27 mg/kg in soy sauce. However any samples were not detected with 1,3-DCP. The contaminated rates of 3-MCPD in soy sauce was 17.1%. Soy sauce is the representative vegetable protein hydrolyzed food. The reliable analytical method f3r the toxic 3-MCPD and 1,3-DCP in Soy sauce has been studied. The derivatization studies of 3-MCPD and 1,3-DCP were performed mainly as Silylation with BSA(N,O-Bis(trimethylsilyl)-acetamide). The retention times of derivative, BSA-MCPD, BSA-DCP were 11.30 and 10.12 minutes.

• Korean Journal of Pharmacognosy
• /
• v.44 no.4
• /
• pp.336-343
• /
• 2013

In a continuation of investigation on Cordyceps militaris, thirteen compounds were isolated from the $CH_2Cl_2$ and n-BuOH-soluble fraction of C. militaris. They were identified as twelve diketopiperazines such as cyclo($\small{L}$-Gly-$\small{L}$-Pro) (1), cyclo($\small{L}$-Ala-$\small{L}$-Pro) (2), cyclo($\small{L}$-Ser-$\small{L}$-Pro) (3), cyclo($\small{L}$-Val-$\small{L}$-Pro) (4), cyclo($\small{L}$-Thr-$\small{L}$-Pro) (5), cyclo($\small{L}$-Pro-$\small{L}$-Pro) (6), cyclo($\small{L}$-Thr-$\small{L}$-Leu) (7), cyclo($\small{L}$-Tyr-$\small{L}$-Ala) (8), cyclo($\small{L}$-Phe-$\small{L}$-Ser) (9), cyclo($\small{L}$-Phe-$\small{L}$-Pro) (10), cyclo($\small{L}$-Tyr-$\small{L}$-Pro) (11) and brevianamide F (13), and an amino acid, tryptophan (12). Their structures were identified on the basis of chemical evidences and spectroscopic analysis including 1D-NMR ($^1H$, $^{13}C$), 2D-NMR (HSQC, HMBC) and MS spectral data. Among the isolated compounds, compounds 1, 2, 6-11 are first reported from C. militaris.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.06a
• /
• pp.198.1-198.1
• /
• 2010

The goal of this study is to measure and compare the performance of solar heat pump for room and hot water heating. To accomplish the goal, solar heat pump with alumium roll bond type evaporator and indoor heat exchanger(condenser) was built and fully instrumented with thermocouples and pressure transducers etc. The test results showed that the COP(coefficient of performance) of HFC-134a($CF_3CH_2F$) were higher than those of CFC-12($CF_2Cl_2$). One "stratospherically safe" new refrigerant is 1,1,1,2-tetrafluoroethane(HFC-134a), which is thermodynamically similar to CFC-12 and considered to be a potential direct replacement for CFC-12 in air-conditioning and refrigeration applications. The solar heat pump system for room heating was designed to show the best efficiency that the room temperature make $18{\sim}20^{\circ}C$ and $23{\sim}25^{\circ}C$ in the southern part of South Korea during November, December, and January.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.10
• /
• pp.2889-2894
• /
• 2013

A new complex [$Ni(phen)(C_9H_8Br_2NO_3)_2{\cdot}2CH_3OH{\cdot}2H_2O$] [phen: 1,10-phenanthroline $C_9H_8Br_2NO_3$: 3,5-dibromo-L-tyrosine] was synthesized and characterized by IR, elemental analysis and single crystal X-ray diffraction. X-ray crystallography shows that Ni(II) ion is six-coordinated. The Ni(II) ion coordinates with four nitrogen atoms and two oxygen atoms from three ligands, forming a mononuclear Ni(II) complex. The crystal crystallizes in the Orthorhombic system, space group $P2_12_12$ with a = 12.9546 ${\AA}$, b = 14.9822 ${\AA}$, c = 9.9705 ${\AA}$, V = 1935.2 ${\AA}$, Z = 1, F(000) = 1008, S = 0.969, ${\rho}_{calcd}=1.742g{\cdot}cm^{-3}$, ${\mu}=4.688mm^{-1}$, $R_1$ = 0.0529 and $wR_2$ = 0.0738 for 3424 observed reflections (I > $2{\sigma}(I)$). Theoretical study of the title complex was carried out by density functional theory (DFT) method and the B3LYP method employing the $6-3l+G^*$ basis set. The energy gap between HOMO and LUMO indicates that this complex is prone to interact with DNA. CCDC: 908041.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.1
• /
• pp.79-86
• /
• 2008

This paper presents to improve of isolation characteristics between personal communication service(PCS) antenna In mobile terminal and 2-channel multi input multi output(MIMO) antenna in the wireless broadband Internet(WiBro) band. In order to improve the isolation between each channel antenna, the proposed PCS antenna with an air space of 3 mm height is located on the projected ground plane($25{\times}12mm$) which is very small space$(0.19{\lambda})$ between the 2-channel WiBro-MIMO antenna. The proposed PCS antenna structure is a modified planar inverted F antenna (PIFA) of spiral type with shorting strip line(6${\times}$4 mm). The calculated Isolation values between the proposed PIFA with 3-dimensional structure and the MIMO antenna at Wibro band are about -20dB below and agree well with the measurement. Measured return loss, bandwidth, and gain o# the proposed antenna are -20dB at 1.8GHz, 110MHz(1.76${\sim}$1.87 GHz) band at -10dB below, and 0.05dBi, respectively, Moreover, we confirm that the proposed PCS antenna has no influence on performance and characteristics of the conversional 2-channel WiBro-MIMO antenna.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.3
• /
• pp.340-350
• /
• 2007

The objective of this study was to determine whether peroxisome proliferator-activated receptor ${\gamma}$(PPAR${\gamma}$ is involved in the regulation of weaning to estrus of primiparous sows. Twelve sows composed of 6 groups of 2 full-sibs in a similar age (325.2 d), body weight (BW; 152.4 kg) and backfat thickness (BFT; 27.0 mm) at start of lactation, were allocated to accept 31 MJ (restricted group, R-group) or 53 MJ (control group, C-group) DE/d treatment, respectively. The experimental results indicated that the low energy intake resulted in excessive losses of BW and BFT during lactation in R-group sows, which may be related to decrease of serum 15-deoxy-${\Delta}^{12,14}$-prostaglandin $J_2$ (15d-$PGJ_2$), a ligand of PPAR${\gamma}$ The obvious peak and the frequency of LH, FSH and estradiol ($E_2$) were only observed in C-group sows. Except for $E_2$ at d 1 and 2, serum FSH, LH and $E_2$ concentrations in R-group were lower than those in C-group sows after weaning. However, the serum progesterone ($P_4$) level in R-group sows was always more than that in C-group. The expression abundances of PPAR${\gamma}$and GnRH receptor (GnRH-R) in pituitary, FSH receptor (FSH-R), LH receptor (LH-R), estrogen receptor (ES-R) and aromatase in ovary of anestrous sows were lower than those of estrous sows. Neither the BFT nor the BW was associated with the mRNA abundance of PPAR${\gamma}$in hypothalamus during lactation. Expressions of PPAR${\gamma}$in pituitary and ovary were affected evidently by the BFT changes and only by the loss of BW of sows during and after lactation. Furthermore, PPAR${\gamma}$mRNA level in ovary was significantly related to the expression abundances of GnRH-R, FSH-R, ES-R and aromatase, and GnRH-R was obviously associated with PPAR${\gamma}$expression in pituitary. However, PPAR${\gamma}$expression in hypothalamus likely has no effects on these genes expression and no obvious difference for all sows. Not serum $E_2$ or $P_4$ alone but the ratios of $E_2$ to $P_4$ and 15d-$PGJ_2$ to $P_4$, and serum FSH and LH were evidently related to PPAR${\gamma}$expression in pituitary and ovary. It is concluded that PPAR${\gamma}$is associated with body conditions, reproduction hormones and their receptor expression, which affected the functions of pituitary and ovary and ultimately the estrus after weaning of primiparous sows.

• Korean journal of applied entomology
• /
• v.30 no.1
• /
• pp.18-28
• /
• 1991

The optimal pH of the extraction buffer was 7.5 considiering AChE stability and its buffer capacity when AChE was isolated and extracted from the housefly(Musca domesitca L.)and three other insect species with 0.01 M sodium phosphate buffer. Also, the optimal pH of the reaction buffer was 7.5 considering enzyme activity and its buffer capacity when AChE activity was measured with the substrate in 0.1 M sodium phosphate buffer. The Potter Elvehjem type homogenizer with Teflon pestle was used to homgenize the tissues. When preparing a AChE suspension by centrifuging the homogenate, 700 g supernatant of adult head for the housefly, 700 g supernatnat of 5th instar nymphal whole body for the brown planthopper, lipid-eliminated 10,000 g supernatant of 5th instar larval whole body for the diamondback moth, and 700 g supernatant of 4th instar larval head for the tobacco cutworm were considered satisfactory as enzyme sources in view of mass preparation, extraction efficiency and stability of enzyme activity during evaluation. When AChE suspensions of 4 insect species were stored at $-18^{\circ}C$, more than 90% of activity was maintained up to 3 weeks. Km values of AChEs of the housefly, the brown planthopper, and the diamondback moth were 0.042, 0.037 and 0.043 mM, respectively and AChE-specific substrate inhibition was observed at high concentration. Km value of the tobacco cutworm ChE was 1.15 mM and BuChE characteristics was observed, though further study is needed. The optimal substrate concentration for the AChE inhibition tests was 0.5 mM for the housfly, the brown planthopper, and the diamondback moth and 12 mM for the tobacco cutworm.

• Child Health Nursing Research
• /
• v.5 no.1
• /
• pp.70-83
• /
• 1999

The birth of a premature infant is distressing for its parents. The parents of a premature infant experience stress according to the infant's physical appearance and behavior, the environment of the neonatal intensive care unit (NICU) , and the alteration in the parental role. Especially, a mother of a premature infant feels distressed even after the discharge of the infant : therefore, she has difficulties in maternal role performance. The main purpose of this study is to identify the effects of the planned infant care information program in order to lower the stress level for mothers of premature infants caused by the birth and hospitalization in NICU of premature infants, to reduce the maternal role strain, and to promote the maternal role performance after the infants' discharge. This study employed two methods of research at the same time : quasi -experimental non-equivalent pre and post test to compare : non-equivalent post test to compare. The total number of subjects was 19 who were assigned to the research program : 12 mothers of premature infants at the NICU at the Ch university hospital and 7 at the NICU at the Y general hospital located in Chounju city. The data were collected for 79 days from August 18 to November 5, 1998. The questionnaire method was applied for the data collection, and the measures used in this study were Parental Stressor Scale : NICU(Miles, 1993), the Maternal Role Strain Measures ( Hobbs, 1968 ; Steffensmeier, 1982) , and Self Confidence Scale (Pharis, 1978). Research procedure is as follows : after preliminary examination, the experimental subjects, the mothers of premature infants at the Nl CU at Ch university hospital were provided with slide films and information developed by the researcher based on existing documents and data. It took two 60-minute sessions a week for two weeks, and the mothers' stress level was measured using the same instrument twice one week and two week after the infants' hospitalization. The stress level of the contrast subjects, the mothers at Y general hospital was measured during the same period. The experimental subjects were provided with booklets on matters that require attention after the infants' discharge and on developmental project, and they were educated to play the maternal role in person for 2-3 hours a week : breast-feeding, burping a baby, and changing diapers. One week after the infants' discharge, the maternal role strain and the maternal role performance were examined in two groups of the subjects. The analysis of collected data was done using descriptive statistics including real numbers, percentages, averages, and standard deviations. Mann-Whitney test ; x² test ; Repeated Measures Analysis of Variance ; ANCOVA Spearman's rho correlation coefficients. The results on this study were as follows. (1) The examination of the same quality showed that there were no differences in the general and obstetrical characters between the two groups. However, in terms of the characters of premature infants. just right after their birth, the infants at the contrast group weighed more than those at the experimental group(U=16.5, p=.02), and the former was in mother's womb longer than the latter(U=15.5, p=.02). (2) The stress level of the mothers provided with the plannned nursing intervention program became lower as time passed compared to the others'(F=16.61, p=.00) Even when the influence of weight at birth and the length of gestation was removed among the premature infants' characters, the mothers' stress levels made a statistical difference 2 weeks after the infants' hospitalization depending on treatment (F=8.00, p=.01) (3) The maternal role strain of the mothers provided with the planned nursing intervention program was lower than the others'(U=2.0, p=.00). Even when the influence of weight at birth and the length of gestation was removed among the premature infants' characters, the maternal role strain levels made a statistical difference 2 weeks after the infants' hospitalization, depending on treatment(F=14.72, p=.00). (4) The maternal role performance level of the mothers provided with the planned nursing program was higher than the others'(U=.0, p=.00). Even when the influence of weight at birth and the length of gestation was removed among the premature infants' characters, the mothers' stress levels made a statistical difference 2 weeks after the infants' hospitalization, depending on treatment(F=8.00, p=.01). (5) The correlation between a mother's stress level 2 weeks after her infant's hospitalization, the maternal role strain and the maternal role performance were compared : the stress and the maternal role strain were statistically irrelevant to each other(r=.33, p=.12) : the stress was found to be in inverse proportion to the maternal role performance(r=-.53, p=.02). The maternal role strain was in inverse proportion to the maternal role performance as well(r=-.50, p=.00). In conclusion, for the mothers provided with the planned nursing intervention program, their stress level was getting lower as time passed during the infants' hospitalization, their maternal role strain reduced when they took care of their infants after their discharge, and their maternal role performance level was high compared to the other mothers. Besides, the lower the stress level of mothers of premature infants was during the infants' hospitalization, the higher the maternal role performance after their discharge was. The lower maternal role strain was, the higher the maternal role performance was as well. These results of the study suggested that the nursing intervention program for the mothers of premature infants developed by the researcher would be effectively applied to nursing practice, and it would be a foundation for the development of this kind of program.