Nonlinear optical properties of silver colloidal solution by in situ synthesis technique

Yan Deng,Youyi Sun,Pei Wang,Douguo Zhang,Xiaojin Jiao,Hai Ming,Qijing Zhang,Yang Jiao,Xiaoquan Sun 한국물리학회 2008 Current Applied Physics Vol.8 No.1

The silver colloidal solutions were prepared by in situ synthesis technique in the presence of the Polymethyl Methacrylate, which was polymerized by reversible addition-fragmentation transfer. The UV–VIS spectra and transmission electron microscopy had shown the formation of sphere silver nanoparticles with average size of 10 nm. Nonlinear optical properties as a function of silver concentration were studied using Z-scan technique with 13 ns pulse duration at 532 nm. The optical nonlinearity enhancement was observed by increasing the concentration. The third-order nonlinear susceptibility v(3) was measured to 1.045 · 1011 esu when the concentration was 2.13 mg/ml. Besides, the sample was founded to exhibit a shift from saturable absorption to reverse saturable absorption at higher incident laser energy. The reverse saturable absorption was observed to be responsible for the optical limiting characteristics in our experiments. 2007 Published by Elsevier B.V. The silver colloidal solutions were prepared by in situ synthesis technique in the presence of the Polymethyl Methacrylate, which was polymerized by reversible addition-fragmentation transfer. The UV–VIS spectra and transmission electron microscopy had shown the formation of sphere silver nanoparticles with average size of 10 nm. Nonlinear optical properties as a function of silver concentration were studied using Z-scan technique with 13 ns pulse duration at 532 nm. The optical nonlinearity enhancement was observed by increasing the concentration. The third-order nonlinear susceptibility v(3) was measured to 1.045 · 1011 esu when the concentration was 2.13 mg/ml. Besides, the sample was founded to exhibit a shift from saturable absorption to reverse saturable absorption at higher incident laser energy. The reverse saturable absorption was observed to be responsible for the optical limiting characteristics in our experiments. 2007 Published by Elsevier B.V.

Task - based Spectrum Sharing for Cognitive Radio

Kong Hai Xiang,Yan Jiao,Inwhee Joe 한국통신학회 2018 한국통신학회 학술대회논문집 Vol.2018 No.11

Highly Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by Novel Chiral tert-Amino Alcohols

Cong-hai Zhang,Sheng-jiao Yan,Sheng-qiang Pan,Rong Huang,Jun Lin 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

A series of novel chiral tert-amino alcohols 4a-h derived from enantiomerically pure phenylalanine were synthesized efficiently and used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc (diethylzinc-to-aldehyde addition). The use of 10 mol % of the amino alcohols led to the corresponding sec-alcohols with excellent enantioselectivities (up to 100% ee) and high yields.

Highly Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by Novel Chiral tert-Amino Alcohols

Zhang, Cong-Hai,Yan, Sheng-Jiao,Pan, Sheng-Qiang,Huang, Rong,Lin, Jun Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.4

A series of novel chiral tert-amino alcohols 4a-h derived from enantiomerically pure phenylalanine were synthesized efficiently and used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc (diethylzinc-to-aldehyde addition). The use of 10 mol % of the amino alcohols led to the corresponding sec-alcohols with excellent enantioselectivities (up to 100% ee) and high yields.

Biotransformation of natural polyacetylene in red ginseng by Chaetomium globosum

Wang, Bang-Yan,Yang, Xue-Qiong,Hu, Ming,Shi, Li-Jiao,Yin, Hai-Yue,Wu, Ya-Mei,Yang, Ya-Bin,Zhou, Hao,Ding, Zhong-Tao The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.6

Background: Fermentation has been shown to improve the biological properties of plants and herbs. Specifically, fermentation causes decomposition and/or biotransformation of active metabolites into high-value products. Polyacetylenes are a class of polyketides with a pleiotropic profile of bioactivity. Methods: Column chromatography was used to isolate compounds, and extensive NMR experiments were used to determine their structures. The transformation of polyacetylene in red ginseng (RG) and the production of cazaldehyde B induced by the extract of RG were identified by TLC and HPLC analyses. Results: A new metabolite was isolated from RG fermented by Chaetomium globosum, and this new metabolite can be obtained by the biotransformation of polyacetylene in RG. Panaxytriol was found to exhibit the highest antifungal activity against C. globosum compared with other major ingredients in RG. The fungus C. globosum cultured in RG extract can metabolize panaxytriol to Metabolite A to survive, with no antifungal activity against itself. Metabolites A and B showed obvious inhibition against NO production, with ratios of 42.75 ± 1.60 and 63.95 ± 1.45% at 50 µM, respectively. A higher inhibitory rate on NO production was observed for Metabolite B than for a positive drug. Conclusion: Metabolite A is a rare example of natural polyacetylene biotransformation by microbial fermentation. This biotransformation only occurred in fermented RG. The extract of RG also stimulated the production of a new natural product, cazaldehyde B, from C. globosum. The lactone in Metabolite A can decrease the cytotoxicity, which was deemed to be the intrinsic activity of polyacetylene in ginseng.

Comparative Study on Volatile Flavor Compounds of Traditional Chinese-type Soy Sauces Prepared with Soybean and Defatted Soy Meal

Xian-Li Gao,Hai-Feng Zhao,Mou-Ming Zhao,Chun Cui,Jiao-Yan Ren 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.6

Volatile extracts obtained from traditional Chinese-type soy sauces prepared with soybean (SSSB) and defatted soy meal (SSDSM) by solid phase microextraction (SPME) and direct solvent extraction (DSE) were analyzed by gas chromatography-mass spectrometry (GC-MS). The volatile flavor compounds and relative contents of different chemical classes detected in SSSB and SSDSM were compared for their differences. Results showed that significant differences in both constituents of volatile flavor compounds and relative contents of different chemical classes were observed for both kinds of soy sauces. A total of 152 and 131 compounds were identified in SSSB and SSDSM, respectively, and 102 volatile flavor compounds were common in both kinds of soy sauces. Moreover, relative contents of acids, aldehydes, esters, furan(one)s, miscellaneous compounds, phenols, pyrazines, pyrrol(idinon)es, and sulfur-containing compounds in both kinds of soy sauces were all significantly different.

Changes in Volatile Aroma Compounds of Traditional Chinese-type Soy Sauce During Moromi Fermentation and Heat Treatment

Xian-Li Gao,Chun Cui,Hai-Feng Zhao,Mou-Ming Zhao,Lan Yang,Jiao-Yan Ren 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.4

Considering the important influence of longtime (150 day) moromi fermentation and heat treatment on the aroma formation of traditional Chinese-type soy sauce (TCSS), volatile compounds in samples taken from different stages of moromi fermentation and heat treatment were analyzed by solid phase microextraction coupled with gas chromatography-mass spectrometry. Results showed that a total of 76 volatile compounds were identified in all the samples, and most of the volatile compounds were common. During 150 day of moromi fermentation, relative contents of acids, alcohols, aldehydes and ketones, esters,and furan(one)s along with all the sensory attributes of acidic, alcoholic, fruity, caramel-like, smoky, and malty changed greatly. Notably, relative contents of alcohols,aldehydes and ketones along with the sensory intensities of alcoholic, caramel-like, and smoky of heated sample (80℃/60 min) decreased markedly, whereas there were slight increases in relative contents of furan(one)s, phenols,and sulfur-containing compounds of it. Long-time moromi fermentation and heat treatment have significant influence on the formation and relative contents of volatile compounds in TCSS, whereas changes in volatile compounds and their relative contents of the samples were responsible for the differences in sensory attributes.

Case-control study on the fibroblast growth factor receptor 2 gene Polymorphisms associated with breast cancer in in Chinese Han women

Chun-Lian Liu,Xiao-Ping Hu,Wei-Dong Guo,Li Yang,Jie Dang,Hai-Yan Jiao 한국유방암학회 2013 Journal of breast cancer Vol.16 No.4

Purpose: Genetic variation in fibroblast growth factor receptor 2(FGFR2) is a newly described risk factor for breast cancer. Thisstudy aimed to evaluate the association of four single nucleotidepolymorphisms (SNPs) in FGFR2 with breast cancer in Han Chinesewomen. Methods: Two hundred three women with breastcancer and 200 breast cancer-free age-matched controls wereselected. Four SNPs (rs2981579, rs1219648, rs2420946, andrs2981582) and their haplotypes were analyzed to test for theirassociation with breast cancer susceptibility. The presence ofthe four FGFR2 SNPs was determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Results:A statistically significant difference was observed in thefrequency of rs2981582 in the FGFR2 gene (p<0.05) betweencase and control groups. In subjects stratified by menopausalstatus, rs2981582 TT, rs2420946 AA, and rs1219648 CC weresignificantly associated with the risk of breast cancer in postmenopausalsubjects, but no significant associations betweenthese four SNPs and the risk of breast cancer were identified inpremenopausal subjects. Further, there was no significant associationbetween hormone receptor status (estrogen receptor andprogesterone receptor) and breast cancer risk. Six common (>3%) haplotypes were identified. Three of these haplotypes,CGTC (odds ratio [OR], 0.613; 95% confidence interval [CI],0.457-0.82; p=0.001), TGTC (OR, 6.561; 95% CI, 2.064-20.854;p<0.001), and CATC (OR, 12.645; 95% CI, 1.742-91.799; p=0.001) were significantly associated with breast cancer risk. Conclusion:Our findings indicated that the SNP rs2981582 and haplotypesCGTC, TGTC, and CATC in FGFR2 may be associatedwith an increased risk of breast cancer in Han Chinese women.