Controlled Synthesis of Branched Polystyrene via Free Radical Polymerization of Novel Chain Transfer Monomer

Cui-Ping Li,Jia-Qiang Wang,Jun Lin,Yan Shi,Zhi-Feng Fu 한국고분자학회 2011 Macromolecular Research Vol.19 No.8

The free radical polymerization of styrene was carried out in the presence of a new found chain transfer monomer, p-vinyl benzene sulfonyl chloride (VBSC), which possesses both a chain transfer group and a polymerizable double bond. Branched polystyrene was formed during the polymerization, as indicated by multi-peaks gel permeation chromatography (GPC) curves of the products, the increase in the number-average molecular weight and molecular weight distribution along with monomer conversions. The structure of the obtained polystyrene was analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. The results showed that with increasing VBSC in the feed, the degree of branching and VBSC unit in the copolymer increased and a shortest polystyrene arm arose from the highest VBSC content in the feed, suggesting that the composition and structure of the branched polystyrenes could be tuned by the amount of VBSC in the feed. By tracing the structure change in the copolymer at various stages of polymerization, the main polymerization process can be regarded as the copolymerization of VBSC with styrene first and then chain transfer to polymeric radical to form branched polystyrene. This strategy is facile and less expensive than the other method.

Radiosensitivity Enhancement by Arsenic Trioxide in Conjunction with Hyperthermia in the EC-1 Esophageal Carcinoma Cell Line

Cui, Yan-Hui,Liang, Hai-Jun,Zhang, Qing-Qin,Li, Si-Qing,Li, Xiao-Rui,Huo, Xiao-Qing,Yang, Qing-Hui,Li, Wei-Wei,Gu, Jian-Fa,Hua, Qin-Liang,Lu, Ping,Miao, Zhan-Hui Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Objective: To explore the effect on radiosensitivity of arsenic trioxide ($As_20_3$) in conjunction with hyperthermia on the esophageal carcinoma EC-1 cell line. Method: Inhibition of EC-1 cell proliferation at different concentrations of $As_20_3$ was assessed using the methyl thiazolyl blue colorimetric method (MTT method), with calculation of $IC_{50}$ value and choice of 20% of the $IC_{50}$ as the experimental drug concentration. Blank control, $As_20_3$, hyperthermia, radiotherapy group, $As_20_3$ + hyperthermia, $As_20_3$ + radiotherapy, hyperthermia + radiotherapy and $As_20_3$ + hyperthermia + radiotherapy groups were established, and the cell survival fraction (SF) was calculated from flat panel colony forming analysis, and fitted by the 'multitarget click mathematical model'. Flow cytometry (FCM) was used to detect changes in cell apoptosis and the cell cycle. Results: $As_20_3$ exerted inhibitory effects on proliferation of esophageal carcinoma EC-1 cells, with an $IC_{50}$ of 18.7 ${\mu}mol/L$. After joint therapy of $As_20_3$ + hyperthermia + radiotherapy, the results of FCM showed that cells could be arrested in the $G_2$/M phase, and as the ratio of cells in $G_0/G_1$ and S phases decreased, cell death became more pronounced. Conclusion: $As_20_3$ and hyperthermia exert radiosensitivity effects on esophageal carcinoma EC-1 cells, with synergy in combination. Mechanistically, $As_20_3$ and hyperthermia mainly influence the cell cycle distribution of EC-1 esophageal carcinoma cells, decreasing the repair of sublethal damage and inducing apoptosis, thereby enhancing the killing effects of radioactive rays.

Rhizospheric fungi of Panax notoginseng: diversity and antagonism to host phytopathogens

Cui-Ping Miao,Qi-Li Mi,Xin-Guo Qiao,You-Kun Zheng,You-Wei Chen,Li-Hua Xu,Hui-Lin Guan,Li-Xing Zhao 고려인삼학회 2016 Journal of Ginseng Research Vol.40 No.2

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

Removal of High Density Impulse Noise of Aerial Insulator Image

Cui Kebin,Li Baoshu,Yuan Jinsha,Wang Ping 보안공학연구지원센터(IJSIP) 2014 International Journal of Signal Processing, Image Vol.7 No.6

Aiming at the impulse noise generated in capturing the images of insulator on power lines, a denoising method based on peer groups is proposed. The center pixel variance σcenter is defined, the minimum of neighborhood variance and center σmin is treated as threshold σmin and the peer group is determined by comparing the relation between absolute value of gray value difference and σmin . According to the size of peer group and its complement set, center pixel is estimated when noisy pixels exist in the neighborhood window. Otherwise, the size of window is adjusted adaptively and center pixel is estimated on the basis of mean value of non-noisy pixels within adjusted window. The experimental results show that the method can get a higher peak signal to noise ratio, IEF and SSIM when there is high density impulse noise in an image.

Controlled Synthesis of Branched Polystyrene via RAFT Technique in the Presence of Chain Transfer Monomer p-Vinyl Benzene Sulfonyl Chloride

Cui-Ping Li,Jia-Qiang Wang,Yan Shi,Zan Liu,Jun Lin,Zhi-Feng Fu 한국고분자학회 2012 Macromolecular Research Vol.20 No.8

Branched polystyrene was first obtained via a reversible addition-fragmentation chain transfer (RAFT)process in the presence of chain transfer monomer p-vinyl benzene sulfonyl chloride (VBSC) in benzene at 60 oC with 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate as the RAFT agent and 2,2-azobisisobutyronitrile as an initiator. During the RAFT polymerization, VBSC played the role of branching agent. It could not only copolymerized but also acted as a chain transfer agent due to the polymerizable vinyl group and sulfonyl chloride chain transfer group in the VBSC. Gel permeation chromatography (GPC) traces demonstrated that the number-average molecular weights and molecular weight distributions increased along with monomer conversion. Compared with the RAFT process without VBSC, the resulting polymers had broad molecular weight distributions and the sulfonyl functionality of the resultant polymer at the branching point, indicating the formation of branched polystyrene. The structure of the obtained polystyrene was further analyzed by proton nuclear magnetic resonance (1H NMR) spectroscopy. The findings indicated that the branched polystyrene was mainly formed via the RAFT copolymerization of VBSC and styrene firstly to form polystyrene bearing pendant sulfonyl chloride group, and then the pendant sulfonyl chloride group acted as the chain transfer agent to generate the branched structure. In addition, the degree of branching and VBSC unit in copolymer increased along with the VBSC in the feed, implying that composition and structure of the branched polystyrenes could be tuned by the amount of VBSC in the feed.

cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria

Li-qun Peng,Ping Li,Qiu-li Zhang,Lan Hong,Li-ping Liu,Xun Cui,Bai-ri Cui 대한생리학회-대한약리학회 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.1

Adenosine 3 ,5 -cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the Na⁺-K⁺-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain (3.0 μmol/L) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabainincreased atrial dynamics was blocked by KB-R7943 (3.0 μmol/L), an inhibitor for reverse mode of Na⁺-Ca²⁺ exchangers (NCX), but did not by L-type Ca²⁺ channel blocker nifedipine (1.0 μmol/L) or protein kinase A (PKA) selective inhibitor H-89 (3.0 μmol/L). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline (100.0 μmol/L), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP (0.5 μmol/L) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 (30 μmol/L), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

Investigation on Chain Transfer Reaction of Benzene Sulfonyl Chloride in Styrene Radical Polymerization

Cui Ping Li,Zhi Feng Fu,Yan Shi 한국고분자학회 2009 Macromolecular Research Vol.17 No.8

cAMP induction by ouabain promotes endothelin-1 secretion via MAPK/ERK signaling in beating rabbit atria

Peng, Li-qun,Li, Ping,Zhang, Qiu-li,Hong, Lan,Liu, Li-ping,Cui, Xun,Cui, Bai-ri The Korean Society of Pharmacology 2016 The Korean Journal of Physiology & Pharmacology Vol.20 No.1

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

Rhizospheric fungi of Panax notoginseng: diversity and antagonism to host phytopathogens

Miao, Cui-Ping,Mi, Qi-Li,Qiao, Xin-Guo,Zheng, You-Kun,Chen, You-Wei,Xu, Li-Hua,Guan, Hui-Lin,Zhao, Li-Xing The Korean Society of Ginseng 2016 Journal of Ginseng Research Vol.40 No.2

Background: Rhizospheric fungi play an essential role in the plantesoil ecosystem, affecting plant growth and health. In this study, we evaluated the fungal diversity in the rhizosphere soil of 2-yr-old healthy Panax notoginseng cultivated in Wenshan, China. Methods: Culture-independent Illumina MiSeq and culture-dependent techniques, combining molecular and morphological characteristics, were used to analyze the rhizospheric fungal diversity. A diffusion test was used to challenge the phytopathogens of P. notoginseng. Results: A total of 16,130 paired-end reads of the nuclear ribosomal internal transcribed spacer 2 were generated and clustered into 860 operational taxonomic units at 97% sequence similarity. All the operational taxonomic units were assigned to five phyla and 79 genera. Zygomycota (46.2%) and Ascomycota (37.8%) were the dominant taxa; Mortierella and unclassified Mortierellales accounted for a large proportion (44.9%) at genus level. The relative abundance of Fusarium and Phoma sequenceswas high, accounting for 12.9% and 5.5%, respectively. In total,113 fungal isolates were isolated from rhizosphere soil. They were assigned to five classes, eight orders (except for an Incertae sedis), 26 genera, and 43 species based on morphological characteristics and phylogenetic analysis of the internal transcribed spacer. Fusarium was the most isolated genus with six species (24 isolates, 21.2%). The abundance of Phoma was also relatively high (8.0%). Thirteen isolates displayed antimicrobial activity against at least one test fungus. Conclusion: Our results suggest that diverse fungi including potential pathogenic ones exist in the rhizosphere soil of 2-yr-old P. notoginseng and that antagonistic isolates may be useful for biological control of pathogens.

Effectiveness and Safety of Dabrafenib in the Treatment of 20 Chinese Children with BRAFV600E-Mutated Langerhans Cell Histiocytosis

Ying Yang,Dong Wang,Lei Cui,Hong-Hao Ma,Li Zhang,Hong-Yun Lian,Qing Zhang,Xiao-Xi Zhao,Li-Ping Zhang,Yun-Ze Zhao,Na Li,Tian-You Wang,Zhi-Gang Li,Rui Zhang 대한암학회 2021 Cancer Research and Treatment Vol.53 No.1

Purpose We sought to investigate the effectiveness and safety of dabrafenib in children with BRAFV600E-mutated Langerhans cell histiocytosis (LCH). Materials and Methods A retrospective analysis was performed on 20 children with BRAFV600E-mutated LCH who were treated with dabrafenib. Results The median age at which the patients started taking dabrafenib was 2.3 years old (range, 0.6 to 6.5 years). The ratio of boys to girls was 2.3:1. The median follow-up time was 30.8 months (range, 18.9 to 43.6 months). There were 14 patients (70%) in the risk organ (RO)+ group and six patients (30%) in the RO– group. All patients were initially treated with traditional chemotherapy and then shifted to targeted therapy due to poor control of LCH or intolerance to chemotherapy. The overall objective response rate and the overall disease control rate were 65% and 75%, respectively. During treatment, circulating levels of cell-free BRAFV600E (cfBRAFV600E) became negative in 60% of the patients within a median period of 3.0 months (range, 1.0 to 9.0 months). Grade 2 or 3 adverse effects occurred in five patients. Conclusion Some children with BRAFV600E-mutated LCH may benefit from monotherapy with dabrafenib, especially high-risk patients with concomitant hemophagocytic lymphohistiocytosis and intolerance to chemotherapy. The safety of dabrafenib is notable. A prospective study with a larger sample size is required to determine the optimal dosage and treatment duration.