• Korean Journal of Microbiology
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• v.31 no.1
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• pp.72-78
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• 1993

Since the 'promoter/enhancer region of the major immediate early (IE) ~ene of human cytomegalovirus (HCMV) contains the cyclic AMP (cAMP) response element (CRE) consensus sequence, it was reasonable to hypothesize that cAMP might affect HCMV replication. Cyclic AMP modulating drugs such as 8-bromoadenosine 3',5'-cyclic monophosphate (BrA), and papaverine were used to affect the intracellular levels of cAMP, and the effects of the drugs on HCMV replication were studied. While papaverine effectively inhibited HCMV multiplication and DNA synthesis, BrA exerted little effect on the production of infectious HCMV yields. The synthesis of DNA in HCMV-infected cells appeared to be stimulated by BrA In order to understand the effect of cAMP on the expression of HCMV major IE gene, plasmid (pCMVIE/CAT) containing a reporter gene driven by HCMV IE promoter was transfected into either permissive human embryo lung (HEL) cells or nonpermissive cells. PL,Javerine, which has been reported to block the HCMV-induced increase in cAMP, reduced the expression of pCMVIE/CA T in permissive HEL cells. Treatment of transfected cells with BrA increased the expression of HCMV major IE promoter not only in HEL cells, but also in nonpermissive HeLa and Vero cells. Therefore, it seems that the expression of HCMV major IE gene is regulated by cAMP.

• Clean Technology
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• v.20 no.4
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• pp.349-353
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• 2014

Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.38-45
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• 2011

The complexation behavior of the $\alpha$-ketostabilized phosphorus ylides $Ph_3P$=CHC(O) $C_6H_4-X$ (X=Br, Ph) towards the transition metal ions mercury (II) and Silver (I) was investigated. The mercury(II) complex {$HgX_2$ [Y]} 2 ($Y_1$=4-bromo benzoyl methylene triphenyl phosphorane; X=Cl(1), Br(2), I(3), $Y_2$=4-phenyl benzoyl methylene triphenyl phosphorane; X=Cl(4), Br(5), I(6)) have been prepared from the reaction of $Y_1$ and $Y_2$ with $HgX_2$ (X=Cl, Br, I) respectively. Silver complexes [$Ag(Y_2)_2]$ X(X=$BF_4$(7), OTf(8)) of the $\alpha$-keto-stabilized phosphorus ylides ($Y_2$) were obtained by reacting this ylide with AgX (X=$BF_4$, OTf) in $Me_2CO$. The crystal structure of complexes (1) and (4) was discussed. These reactions led to binuclear complexes C-coordination of ylide and trans-like structure of complexes $[Y_1HgCl_2]_2$. $CHCl_3$ (1) and $[Y_2HgCl_2]_2$ (4) is demonstrated by single crystal X-ray analyses. Not only all of complexes have been studied by IR, $^1H$ and $^{31}P$ NMR spectroscopy, but also complexes 1-3 have been characterized by $^{13}$CNMR.

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.318-322
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• 1988

We studied the aquation reaction of s-cis-$[Co(eee)Cl_2]^+$ and s-cis-$[Co(eee)Br_2]^+$ complex ions under the various temperatures and pressures. In these complexes eee is $NH_2-CH_2CH_2-S-CH_2CH_2-NH_2$. The rate law of the aquation reactions of these two complexes obeys $Rate = k_{obsd}$[CO(III)], where rate constants of s-cis-$Co(eee)Cl_2]^+$ and s-cis-$[Co(eee)Br_2]^+$ respectively are $0.687{\times}10^{-4}$ $sec^{-1}$ and $4.10{\times}10^{-4}$ $sec^{-1}$ in condition of 0.1M $HClO_4\;and\;40^{\circ}C$. In the same condition, the activation entropies of s-cis-[Co(eee)$Cl_2$]+ and s-cis-(Co(eee)Br_2$]+ complexes respectively are -15.5 eu and -7.54eu, and the activation volumes are $-4.6cm^3mole^{-1}$ and $-4.2cm^3mole^{-1}$. From these data, we could infer the mechanism of the aquation reaction as the interchange dissociation (Id) mechanism.

• Bulletin of the Korean Chemical Society
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• v.24 no.5
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• pp.583-592
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• 2003

The gas phase identity nucleophilic substitution reactions of halide anions (X = F, Cl, Br) with cyclopentadienyl halides (1) are investigated at the B3LYP/6-311+G**, MP2/6-311+G** and G2(+)MP2 levels involving five reaction pathways: σ-attack $S_N2$, β-$S_N$2'-syn, β-$S_N$2'-anti, γ-$S_N$2'-syn and γ-$S_N$2'-anti paths. In addition, the halide exchange reactions at the saturated analogue, cyclopentyl halides (2), and the monohapto circumambulatory halide rearrangements in 1 are also studied at the same three levels of theory. In the σ-attack $S_N2$ transition state for 1 weak positive charge develops in the ring with X = F while negative charge develops with X = Cl and Br leading to a higher energy barrier with X = F but to lower energy barriers with X = Cl and Br than for the corresponding reactions of 2. The π-attack β-$S_N$2' transition states are stabilized by the strong $n_C-{\pi}^{*}_{C=C}$ charge transfer interactions, whereas the π-attack γ-$S_N$2' transition states are stabilized by the strong $n_C-{\sigma}^{*}_{C-X}$ interactions. For all types of reaction paths, the energy barriers are lower with X = F than Cl and Br due to the greater bond energy gain in the partial C-X bond formation with X = F. The β-$S_N$2' paths are favored over the γ-$S_N$2' paths only with X = F and the reverse holds with X = Cl and Br. The σ-attack $S_N2$ reaction provides the lowest energy barrier with X = Cl and Br, but that with X = F is the highest energy barrier path. Activation energies for the circumambulatory rearrangement processes are much higher (by more than 18 kcal $mol^{-1}$) than those for the corresponding $S_N2$ reaction path. Overall the gas-phase halide exchanges are predicted to proceed by the σ-attack $S_N2$ path with X = Cl and Br but by the β-$S_N$2'-anti path with X = F. The barriers to the gas-phase halide exchanges increase in the order X = F < Br < Cl, which is the same as that found for the gas-phase identity methyl transfer reactions.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.405-410
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• 2022

In brachytherapy, a radiation source is inserted into the body to kill tumor tissue. Therefore, it is important to accurately measure the location of the source and the dose distribution. In this study, a dosimeter that can be used for brachytherapy was developed using CsPbBr₃ which is cheaper than the existing detector materials and has a simpler manufacturing process. The CsPbBr₃ dosimeter performance was evaluated by analyzing reproducibility, linearity, and distance dependence in ¹⁹²Ir source. As a result of reproducibility evaluation, the RSD was 1.36%, which satisfies the standard value of 1.5%. As a result of the linearity evaluation, the R² value was 0.9993, which satisfies the standard R² of 0.9990. The distance dependence evaluation showed a signal value that decreased exponentially as the distance increased. The evaluation results show that the CsPbBr₃ dosimeter satisfies the evaluation criteria and can be used as a brachytherapy quality assurance dosimeter.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.395-403
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• 2022

In this study, we identified that the fermentation of Korean indigenous probiotics and red ginseng produced ginsenoside compound K (CK) from major ginsenosides. Based on whole genome sequencing of 19 probiotics species, β-glucosidase, α-arabinofuranosidase, β-xylosidase, and α-rhamnosidase related to bioconversion of ginsenosides are identified in the genome of 19 species, 3 species, 6 species, and 8 species, respectively. Among the 19 probiotics species, Bifidobacterium longum CBT BG7 converted from ginsenoside Rb1 to CK, and both B. breve CBT BR3 and B. lactis CBT BL3 converted ginsenoside Rb1 to Rd. The final concentration and yield of ginsenoside F2 and CK were higher in the fermentation with the nondisrupted cells than with disrupted cells. The combination of both CBT BG7 and BL3, and CBT BG7 and BR3 showed higher amounts of F2 than CBT BG7 only. CBT BG7 with adding α-amylase increased the amounts of F2. In this study, we identified that the fermentation of both Korean indigenous probiotic bacteria CBT BG7, BR3 and BL3, and red gingseng is able to produce CK, a bioactive compound that promotes health benefits.

• Journal of Korean Foot and Ankle Society
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• v.26 no.1
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• pp.40-47
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• 2022

Purpose: The modified Broström repair (BR) technique has yielded good outcomes in patients with chronic ankle instability. This study compared clinical and radiological outcomes between two groups of patients who underwent modified BR or lateral ligament augmentation using suture tapes (ST). Materials and Methods: Seventy-seven patients (ST group [n=47], BR group [n=30]; body mass index <26.61 kg/m²; mean age, 30.7±11.0 years [range, 17~39 years]; mean follow-up, 34.0±12.0 months [range, 24~59 months]) were retrospectively reviewed between January 2014 and July 2017. The Foot and Ankle Outcome Score (FAOS), American Orthopedic Foot and Ankle Score (AOFAS), Foot and Ankle Ability Measure (FAAM), visual analogue scale (VAS) score, and Sefton grading system were used for clinical assessment. The talar tilt angle and anterior talar translation were measured using the Telos stress device (Telos GmbH, Marburg, Germany) at 150 N for radiological evaluation. Results: FAOS, AOFAS, FAAM, and VAS scores improved in both groups at final follow-up (ST, 91.1±5.2, 93±2, 88.1±4.5, 1.5±0.7 vs. BR, 91.3±5.4, 93±3, 83.3±4.8, 1.2±0.7, respectively; p=0.854, 0.971, <0.001, 0.04, respectively). According to the FAOS, mean sports activity scores for the ST and BR groups at the final follow-up were 90.3±3.2 and 76.6±4.2, respectively, reflecting superior outcomes in the ST group (p<0.001). Sefton grading revealed satisfactory functional outcomes (ST, 91.5% vs. BR, 90.0%). There was significant improvement in the talar tilt angle and anterior talar translation in both the ST and BR groups (7.6°±1.2°, 10.5±1.8 mm vs. 4.9°±1.1°, 7.9±1.5 mm, respectively; p<0.001). Conclusion: The ST group demonstrated comparable clinical but better improvement in mechanical stability and FAOS sports scores than the BR group.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.61-66
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• 2012

Purpose: This study was to compare the cumulative survival rate (CSR) of Br${\aa}$nemark machined surface implants and TiUnite$^{TM}$ imlants and to analyze association between risk factors and the CSR of the implants. Materials and methods: A retrospective study design was used to collect long-term follow-up clinical data from dental records of 156 patients treated with 541 Br${\aa}$nemark machined and TiUnite$^{TM}$ implants at Korea University Guro hospital in South Korea from 1993 through 2008. Machined implant and TiUnite$^{TM}$ implant were compared by CSR. Exposure variables such as gender, systemic disease, location, implant length, diameter, prosthesis type, opposing occlusion type, date of implant placement, type of edentulous space, abutment type, existence of splinting with natural teeth, and existence of cantilever were collected. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR (${\alpha}$=.05). Results: Patient ages ranged from 16 to 75 years old (mean age, 51 years old). Implants were more frequently placed in men than women (94 men versus 63 women). Since 1993, 264 Br${\aa}$nemark machined implants were inserted in 79 patients and since 2001, 277 TiUnite$^{TM}$ implants were inserted in 77 patients. A total survival rate of 86.07% was observed in Br${\aa}$nemark and Nobel Biocare TiUnite$^{TM}$ during 15 years. A survival rate of machined implant during 15 years was 82.89% and that of TiUnite$^{TM}$ implant during 5 years was 98.74%. The implant CSR revealed lower rates association with several risk factors such as, systemic disease, other accompanied surgery, implant location, and Kennedy classification. Conclusion: Clinical performance of Br${\aa}$nemark machined and TiUnite$^{TM}$ implant demonstrated a high level of predictability. In this study, TiUnite$^{TM}$ implant was more successful than machined implant. The implant CSR was associated with several risk factors.

• Journal of the Korean Wood Science and Technology
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• v.14 no.4
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• pp.14-20
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• 1986

These experiments were carried out to determine the ultraviolet absorption spectra of AcBr lignins(acetyl bromide lignin) from 10 hardwood species grown in Mt. Jiri. 1. There were 3 peak positions, at 249nm(max. peak), at 262-266nm(shallow min. peak) and at 270-280nm(lower max. peak). The Bj$\ddot{o}$rkman lignin and lignin sulfonatic acid spectra had shoulders, but the AcBr lignin didn't. 2. Average absorbances of the AcBr lignin at peak positions were 0.457${\pm}$0.0077 at 249nm, 0.297${\pm}$0.0029 at 262-266nm and 0.309${\pm}$0.0067 at 270-280nm. 3. Average absorptivities of the AcBr lignin at peak positions were 25.005${\pm}$0.3825 at 249nm, 16.264${\pm}$0.2347 at 262-266nm and 16.863${\pm}$0.3444 at 270-280nm. 4. AcBr lignin absorptivities in each species were as follows: 16.939${\pm}$0.3735 in Acer pseudo-sieboldianum var. koreanum, 17.411${\pm}$0.2937 in Carpinus laxiflora, 16.579${\pm}$0.4348 in Comus controversa, 16.385${\pm}$0.4140 in Fraxinus rhynchophylla, 16.287${\pm}$0.4156 in Meliosma myriantha, 16.492${\pm}$0.1432 in Platycarya strobilacea, 16.343${\pm}$0.3177 in Prunus sargentii, 17.549${\pm}$0.3253 in Sophora japanica, 18.400${\pm}$0.2925 in Stewartia koreana, 16.245${\pm}$0.4339 in Styrax obassia. 5. As the spectra of AcBr lignin from hardwood showed the unpromounced peak from 270nm to 280nm, it was supposed that thes hardwood lignins were the guaiacyl-syringyl copolymers.