• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.492-497
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• 2016

The intermediate product resulting from the radical degradation experiment of PCE and the atomic charge gained through Gaussian03W were compared against each other. The result was that the ratio of PCE radical degradation was almost 98% or higher after the 9 hr point in reaction time. The reaction speed constant was $0.16hr^{-1}$ and it followed the first reaction. We could see that at each location of the PCE molecule, dechlorination happened at a point where the negative atomic charge was the greatest. Moreover, the intermediate product of PCE radical degradation that was confirmed in the experiment and literature coincided exactly with the intermediate product in the atomic charge calculation. Therefore, when the atomic charge is calculated, the radical degradation pathway of the organic chlorine compound could be forecast.

• Bulletin of the Korean Chemical Society
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• v.29 no.5
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• pp.1018-1024
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• 2008

Photolysis of 2-(pentamethyldisilanyloxy)phenylpentamethyldisilane 1 in methanol provides five photoproducts 3, 4, 5, 6, and 7. Compounds 3 and 4 were probably formed from the methanol addition reactions of silene intermediate 2 and the formation of 5, 6, and 7 can best be explained by the nucleophilic attack of methanol to silicon atom in pentamethyldisilanyloxy or pentamethyldisilanyl group of the photoexcited state of 1. Irradiation of 1 in n-hexane gives a photoproduct 6 via silyl radical intermediate 8 and a novel intramolecular cyclization photoproduct 11 via silene 9 and silyl radical intermediate 10. Irradiation of 1 in deaerated methylene chloride in the presence of acetone affords a novel photoproduct 11 and phenol 7 but the expected photoproducts from the reaction of the silene intermediate with acetone were not obtained.

• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.857-866
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• 2001

Efficient syntheses of PGI2 analogue 2a and its epimer 3 have been accomplished. Using aryl iodide 6 as the common intermediate, either radical or palladium-assisted tandem alkene insertion strategies have been employed for construction of the benzoprostacyclin framework.

• Journal of the Korean Chemical Society
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• v.24 no.3
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• pp.250-258
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• 1980

Various radicals may add to isonitriles to give imidoyl radcals RN=CR'. This may be also generated via abstraction of imidoyl hydrogen from imine in the following manner: RN=CR' ＋ R"${\cdot}{\rightarrow}$ RN=CR' ＋ R"-H Imidoyl radicals would be stabilized via two pathways, ${\beta}$-cleavage and atom transfer reactions. ${\beta}$-Cleavage may occur in two directions depending upon structure of the radicals. Cyanide transfer and the "so-called" normal ${\beta}$-cleavage are the two modes of ${\beta}$-cleavage. Addition of t-butoxy radical to t-butyl isocyanide 7 generates an imidoyl radical t-Bu-N=C-O-Bu-t, which undergoes ${\beta}$-cleavage to give t-butyl isocyanate and t-butyl radical. Addition of phenyl radical to 7 forms the intermediate radical t-Bu-N=$C-C_6H_5$, which decomposes to give benzonitrile and t-butyl radical. The t-butyl radical generated from the ${\beta}$-cleavage adds to 7 giving the radical t-Bu-N=C-Bu-t, which cleaves only to pivalonitrile and t-butyl radical, inducing radical chain isomerization. Trimethylsilyl radical adds to 7 to give the intermediate t-Bu-N=$C-Si(CH_3)_3$, which collapses to $(CH_3)_3$SiCN and a t-butyl radical.

• Bulletin of the Korean Chemical Society
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• v.10 no.4
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• pp.374-377
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• 1989

Photolysis of dichlorodiphenylmethane in glassy 2-MeTHF at 77K results in the formation of diphenylcarbene and the diphenylchloromethyl radical, which were detected by their flourescence emission and excitation spectra. The relative yield of the carbene to radical is shown to vary dramatically as a function of irradiation time. The photolability of the radical is also demonstated. These results were interpreted in terms of a two step mechanism, where the diphenylchloromethyl radical is an intermediate in the formation of diphenylcarbene.

• Bulletin of the Korean Chemical Society
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• v.16 no.3
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• pp.285-287
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• 1995

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.278-284
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• 2016

Commercial Korean domestic and foreign intermediate food materials (IFMs) of blueberry, Aronia, oat, sweet pumpkin, and ginger were purchased to compare their functional properties, including total phenolic content (TPC), total flavonoid content (TFC), total anthocyanin content (TAC), and antioxidant capacity. Each IFM was extracted using 80% (v/v) methanol for the analyses. The TPC (mg gallic acid equivalent/100 g dried sample) and TFC (mg catechin equivalent/100 g dried sample) levels in domestic blueberry (TPC, 2,916 ± 200; TFC, 1,327 ± 31) and sweet pumpkin (TPC, 476 ± 20; TFC, 23 ± 32) IFMs were significantly higher than those in the foreign IFMs. In the case of TAC (mg cyanidin-3-glucoside/100 g dried sample), the level in domestic blueberry IFM (949 ± 57) was significantly higher than that in the foreign product. Among the domestic IFMs, the antioxidant capacities (mg vitamin C equivalent/100 g dried sample) of blueberry, sweet pumpkin, and ginger were 7,057 ± 321, 311 ± 8, and 3,321 ± 109, respectively, being significantly higher than those of their foreign counterparts, based on the ABTS radical scavenging assay. In the DPPH radical scavenging assay, foreign Aronia (12,667 ± 437) and ginger (2,067 ± 99) IFMs showed significantly higher levels of free radical scavenging activity than did the domestic IFMs. These results provide basic information regarding the functional properties of Korean domestic IFMs, compared with their foreign counterparts.

• Macromolecular Research
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• v.15 no.1
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• pp.31-38
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• 2007

Pentamethylcyclopentadienyltitanium trichloride, bis(cyclopentadienyl)titanium dichloride ($Cp_2TiCl_2$), and bis(pentamethylcyclopentadienyl)titanium dichloride were used in the polymerization of styrene without the aid of Group I-III cocatalysts. The properties of the resulting polymer indicated that polymerization was more controlled than in thermal polymerization. The kinetic studies indicated that a lower level of termination is present and that the polymer chain can be extended by adding an additional monomer. To elucidate the mechanism of polymerization, a series of experiments was performed. All results supported the involvement of a radical mechanism in the polymerization using $Cp_2TiCl_2$. The possibility of atom transfer radical polymerization (ATRP) mechanism was investigated by isolating the intermediate species. We could confirm the activation step from the reaction of 1-PEC1 with $Cp_2TiCl$ by detecting the coupling product of the generated active radicals. However, the reversible deactivation reaction competes with other side reactions, and it detection was difficult with our model system.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3373-3376
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• 2014

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5951-5956
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• 2015

Background: To evaluate the rate of pathologic high-risk factors, intermediate-risk factors, and treatment outcomes in early-stage cervical cancer patients undergoing radical hysterectomy and pelvic lymphadenectomy (RHPL). Materials and Methods: Medical records of stage IA-IIA1 cervical cancer patients who underwent RHPL during the 2006 to 2012 time period and patient follow-up data until December 2013 were reviewed. Results: Of 331 patients, 52 women (15.7%) had pathologic high-risk factors and 59 women (17.8%) had intermediate-risk factors without high-risk factors. All studied patients had an initial complete response. At median follow-up time of 40.9 months (range 1-103.3 months) and mean follow-up time of$ 43.3{\pm}25.3$ months, 37 women had disease recurrence and 4 women had died of disease. The most common site of recurrence was the pelvis (64.8%). Five-year and 10-year disease free survival rates were 96.1% and 91.5%, respectively. Five-year and 10-year overall survival rates were 100% and 99.4%, respectively. Independent factors related to recurrence were pelvic node metastasis (odds ratio [OR], 2.670; 95%CI, 1.001-7.119), and >1/3 cervical stromal invasion (OR, 3.763; 95%CI, 1.483-9.549). Conclusions: The rates of pathologic high-risk and intermediate-risk factors should be considered and disclosed when counseling patients regarding primary treatment by RHPL. Oncologic outcomes of primary surgical treatment for early-stage cervical carcinoma were found to be excellent.