Reversible Coordinative Chain Transfer Polymerization of Butadiene Using a Neodymium Phosphonate Catalyst

Zhengwei Tang,Aimin Liang,Handong Liang,Jiangwei Zhao,Lin Xu,Jie Zhang 한국고분자학회 2019 Macromolecular Research Vol.27 No.8

This study involves an investigation of the chain transfer reaction of butadiene (Bd) polymerization, under the neodymium tris[bis(2-ethylhexyl)phosphate] (Nd)/diisobutyl aluminum hydride (Al)/ethylaluminum sesquichloride (Cl)/Bd catalytic system. The results show that the chain transfer reaction itself is reversible. Only chain propagation and chain exchange reactions occurred during the later period of polymerization, and there was a linear relationship between the molecular weight and the conversion rate. All polymer chains showed sufficient reactivity to propagate by reacting with the monomer. The degree of the chain transfer reaction can be determined by the amount of Al, and the molecular weight in the synthetic polybutadiene can be accurately designed by the formula Mn=54·Bd/Nd/(0.67Al/Nd-7.17). The catalyst-polymerized butadiene afforded products featuring a relatively narrow molecular weight distribution and a high cis-1,4 stereospecificity. One of these products, polybutadiene rubber, showed narrow distribution in the sample, and exhibited good physical and mechanical properties, low abrasion, and low rolling resistance.

Transrectal Real-time Tissue Elastography - An Effective Way to Distinguish Benign and Malignant Prostate Tumors

Zhang, Yan,Tang, Jie,Liang, Hai-Dong,Lv, Fa-Qin,Song, Zhi-Gang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: To investigate the relationship between extracellular matrix parameters and texture of prostatic lesions evaluated by transrectal real-time tissue elastography (TRTE). Methods: 120 patients suspicious for prostate cancer underwent TRTE. Targeted biopsies were carried out after 12-core systematic biopsy. Epithelia were stained with hematoxylin-eosin, and Victoria blue and Ponceau S were used to stain elastic-collagen fibers, and picric acid-sirius red for visualization of collagen type I (Col1) and III (Col3). Smooth muscles were visualized by immunohistochemistry. All image analyses were performed in a blind manner using Image Pro Plus 6.0, and the area ratios of epithelium, elastic fibers, collagen fibers and Col1/Col3 were determined. Results: 42 patients with typical elastograms were included in the final data analysis. Significant differences were detected between the benign and malignant groups in the area ratios of epithelium (P = 0.01), smooth muscles and Col1/Col3 (P = 0.04, P = 0.02, respectively). There were no significant differences in the area ratios of epithelium, smooth muscle and elastic fibers between the stiff and soft lesion groups. The area ratio of Col1 was ($0.05{\pm}0.03$) in the stiff group, and ($0.02{\pm}0.01$) in the soft group (P= 0.00). However, the area ratio of Col3 was ($0.03{\pm}0.02$) in the stiff group, and ($0.05{\pm}0.04$) in the soft group (P = 0.16). Col1/Col3 in the stiff group ($1.99{\pm}1.59$) was greater than in the soft group ($0.71{\pm}0.64$) (P = 0.01). Conclusions: Tissue hardness of prostatic tumors was mainly dependent on the Col1 content, Col1/Col3 being higher in malignant than in benign lesions, so the prostate tissue texture can be used as a target for distinguishing between the two with TRTE.

Characterization and Antioxidant Activity of Released Exopolysaccharide from Potential Probiotic Leuconostoc mesenteroides LM187

( Qing Zhang ),( Jie Wang ),( Qing Sun ),( Shu-ming Zhang ),( Xiang-yang Sun ),( Chan-yuan Li ),( Miao-xin Zheng ),( Wen-liang Xiang ),( Jie Tang ) 한국미생물 · 생명공학회 2021 Journal of microbiology and biotechnology Vol.31 No.8

A released exopolysaccharide (rEPS)-producing strain (LM187) with good acid resistance, bile salt resistance, and cholesterol-lowering properties was isolated from Sichuan paocai and identified as Leuconostoc mesenteroides subsp. mesenteroides. The purified rEPS, designated as rEPS414, had a uniform molecular weight of 7.757 × 10⁵ Da. Analysis of the monosaccharide composition revealed that the molecule was mainly composed of glucose. The Fourier transform-infrared spectrum showed that rEPS414 contained both α-type and β-type glycosidic bonds. ¹H and ¹³C nuclear magnetic resonance spectra analysis showed that the purified rEPS contained arabinose, galactose, and rhamnose, but less uronic acid. Scanning electron microscopy demonstrated that the exopolysaccharide displayed a large number of scattered, fluffy, porous cellular network flake structures. In addition, rEPS414 exhibited strong in vitro antioxidant activity. These results showed that strain LM187 and its rEPS are promising probiotics with broad prospects in industry.

Composition and Antioxidant Activity of Water-Soluble Polysaccharides from Tuber indicum

Qiang Luo,Jie Zhang,Liang Yan,Yuanlin Tang,Xiang Ding,Zhirong Yang,Qun Sun 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.12

Crude water-soluble Chinese truffle Tuber indicum polysaccharide (TIP) was extracted from the fruiting bodies with water and then successively purified by DEAE–cellulose 52 and Sephadex G-100 column chromatography,yielding two major polysaccharide fractions: TIP1-1 and TIP2-1. High-performance gel permeation chromatography analysis showed that the average molecular sizes of TIP1-1 and TIP2-1 were approximately 1.75×10⁴Da and 5.73×10³ Da, respectively. Monosaccharide component analysis by gas chromatography indicated that TIP1-1 was composed of mannose,glucose, galactose, and rhamannose in the respective molar ratio of 3.93:1.24:0.75:1.26 and that TIP2-1 contained mannose,glucose, and arabinose in the respective molar ratio of 5.27:1.44:0.43. The antioxidant activity analyses revealed that TIP1-1and TIP2-1 possessed considerable antioxidant activity. Compared with TIP1-1, which has a higher molecular weight and contains no uronic acid, TIP2-1 exhibited a protective effect on PC12 cells injured by H₂O₂and a higher scavenging activity against free radicals. The relative effects of the lower molecular size, the presence of uronic acid, and the antioxidant activity of TIP2-1 appear to be significant. Accordingly, the Chinese truffle T. indicum might serve as an effective antioxidative healthcare food and source of natural antioxidants.

Designing Co7Fe3@TiO2 Core–Shell Nanospheres for Electromagnetic Wave Absorption in S and C Bands

Na Chen,Jian‑Tang Jiang,Zhen‑Jie Guan,Shao‑Jiu Yan,Liang Zhen,Cheng‑Yan Xu 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

Ferromagnetic-dielectric nanocomposites have attracted extensive interests for its high electromagnetic wave absorption(EMA) performance due to the synergetic effects between different components. Herein, we report the design of core–shellstructured Co7Fe3@TiO2 composite particles, which are subsequently annealed in H2/Ar atmosphere to further improve itsEMA performance. The introducing of TiO2dielectric shell together with hydrogen annealing contributes greatly to theelectromagnetic properties due to the increased conductivity and enhanced ferromagnetic resonance. Excellent EMA performanceis achieved in S (2–4 GHz) and C (4–8 GHz) bands in coatings using Co7Fe3@TiO2 as absorbents. Apart from thehigh EMA efficiency, the location of EMA band can be tailored in a wide range through regulating the coating thickness. Specifically, an effective absorption band of 2.0 GHz in C band at a thickness of 2.62 mm, and an effective absorption bandof 1.7 GHz are achieved in S band at thicknesses of 4.0–5.0 mm. The excellent electromagnetic properties are ascribed tothe effective complementary between dielectric loss and ferromagnetic loss.

Effect of a Single Bout of Exercise on Autophagy Regulation in Skeletal Muscle of High-Fat High-Sucrose Diet-Fed Mice

Didi Zhang,이지현,곽성은,신형은,Yan-Jie Zhang,문효열,신동미,성제경,Liang Tang,송욱 대한비만학회 2019 The Korean journal of obesity Vol.28 No.3

Background: Autophagy maintains metabolic homeostasis of muscles, and its impairment may cause muscle dysfunction. Exercise can improve muscle dysfunction induced by long-term high-fat diet. This study aimed to explore the association of autophagy with impaired muscle dysfunction in obese conditions and investigate its relationship with exercise-induced muscle function improvement. Methods: Male C57BL/6 mice (n=24) were randomly assigned to four groups: low-fat diet+plain water feeding sedentary (CON) group, low-fat diet+plain water feeding exercise (CON+EX) group, high-fat high-sucrose (HFHS) diet-fed sedentary group, and HFHS diet-fed exercise (HFHS+EX) group, and subjected to a single bout of exhaustive exercise. Results: HFHS diet resulted in shorter hanging time, reduced grip force, and lower exhaustion time and distance, and decreased lean mass per body weight. Moreover, in the soleus, which is chosen as a representative red (oxidative) muscle, LC3II/LC3I ratio, P62, and Bnip3 levels were altered following the HFHS diet, and were negatively correlated with muscle performance parameters; exercise significantly decreased the LC3II/LC3 ratio while P62 increased with HFHS diet. Autophagy-related protein changes were not found in the white (glycolytic) gastrocnemius. Conclusion: The study revealed that 20-week HFHS diet causes a significant increase in body weight and fat mass, along with a decrease in muscle function. Autophagy-related LC3 and P62 protein expression was negatively correlated with muscle function, and they were reduced when a single bout of exercise stimulated the soleus of obese mice. However, no change of autophagy-related proteins was seen in the gastrocnemius.

A NEW CORE – SHELL HYBRID NANOSTRUCTURES OF GOLD NANOROD FOR ENHANCING FLUORESCENCE AND APPLICATION IN DUAL-COLOR IMAGING

LU ZHANG,Peihui Yang,YAN-JIE GUO,JIAN-JUN LUO,GUI-MIN SUN,ZHI-HONG LIANG,YAN-JUAN TANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.3

A novel core – shell hybrid nanostructure was constructed by employing gold nanorod (AuNR)combined with rhodamine B (RB) as a core and silica as a shell. The poly(sodium 4-styr-enesulfonate) (PSS), a negatively charged polyelectrolyte, played the role of linker to electro-statically trap RB on AuNRs. Due to the °uorescence spectral overlap between RB and AuNRs at560 nm, the red °uorescence and enhanced green °uorescence of the hybrid nanostructures wereobserved obviously, which is capable for dual-color labeling. To reduce toxic side e®ects ofAuNRs, silica was coated on AuNRs as a shell to fabricate the novel core – shell hybrid nano-structure function as a dual-color labeling for cancer-cell imaging. The fabricated compositestructures were characterized by transmission electron microscopy (TEM), absorption spectrum,°uorescence spectrum, zeta potential measurements and laser scanning confocal microscope(LSCM). The experiment results con¯rmed that the obtained hybrid nanostructures providedexcellent photostability, biocompatibility and active surface for further biological functionali-zation. The novel composite structures may have great potential application in cell multicolorlabeling and imaging instead of traditional °uorescent dyes.

Subdivision of Nasopharyngeal Carcinoma Patients with Bone-Only Metastasis at Diagnosis for Prediction of Survival and Treatment Guidance

Xue-Song Sun,Yu-Jing Liang,Sai-Lan Liu,Qiu-Yan Chen,Shan-Shan Guo,Yue-Feng Wen,Li-Ting Liu,Hao-Jun Xie,Qing-Nan Tang,Xiao-Yun Li,Jin-Jie Yan,Lin-Quan Tang,Hai-Qiang Mai 대한암학회 2019 Cancer Research and Treatment Vol.51 No.4

Purpose The purpose of this study was to subdivide M1 stage nasopharyngeal carcinoma (NPC) patients with bone-only metastases for prognosis prediction while identifying the treatment effect of locoregional radiotherapy (LRRT) and metastasis radiotherapy (MRT) among patients with different risk. Materials and Methods From November 2006 to October 2016, a total of 226 patients with bone-only metastasic NPC were retrospectively enrolled. All patients developed distant lesions before receiving treatment. All potential prognostic factors were considered and the correlation of the M1 subdivisions with overall survival (OS) was determined by Cox regression hazards model. Kaplan-Meier curves were used to appraise survival condition and log-rank testing was used to compare the differences. Results The median follow-up time was 33.9 months (range, 3 to 126 months). According to multivariate Cox proportional hazard analysis, the number of metastatic lesions and Epstein-Barr virus (EBV) DNA status after palliative chemotherapy (PCT) were independent prognostic factors for OS. Thus, we subdivided patients into three risk groups according to these two factors. Systemic chemotherapy combined with LRRT may benefit patients in low- and intermediate-risk groups but not in the high-risk group. Further aggressive MRT based on systemic chemotherapy showed no survival benefit in any risk group. Conclusion The stratification of NPC patients with bone-only metastasis based on EBV DNA after PCT and the number of metastatic lesions provided promising prognostic value and could aid clinicians in person-specific treatment.

Protective association of Klotho rs495392 gene polymorphism against hepatic steatosis in non-alcoholic fatty liver disease patients

Wen-Yue Liu,Xiaofang Zhang,Gang Li,Liang-Jie Tang,Pei-Wu Zhu,Rafael S. Rios,Kenneth I. Zheng,Hong-Lei Ma,Xiao-Dong Wang,Qiuwei Pan,Robert J. de Knegt,Luca Valenti,Mohsen Ghanbari,Ming-Hua Zheng 대한간학회 2022 Clinical and Molecular Hepatology(대한간학회지) Vol.28 No.2

Background/Aims: Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic dysfunction. Among the multiple factors, genetic variation acts as important modifiers. Klotho, an enzyme encoded by the klotho (KL) gene in human, has been implicated in the pathogenesis of metabolic dysfunctions. However, the impact of variants in KL on NAFLD risk remains poorly understood. The aim of this study was to investigate the impact of KL rs495392 C>A polymorphism on the histological severity of NAFLD. Methods: We evaluated the impact of the KL rs495392 polymorphism on liver histology in 531 Chinese with NAFLD and replicated that in the population-based Rotterdam Study cohort. The interactions between the rs495392, vitamin D, and patatin-like phospholipase domain containing 3 (PNPLA3) rs738409 polymorphism were also analyzed. Results: Carriage of the rs495392 A allele had a protective effect on steatosis severity (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.42–0.89; P=0.010) in Chinese patients. After adjustment for potential confounders, the A allele remained significant with a protective effect (OR, 0.66; 95% CI, 0.45–0.98; P=0.040). The effect on hepatic steatosis was confirmed in the Rotterdam Study cohort. Additional analysis showed the association between serum vitamin D levels and NAFLD specifically in rs495392 A allele carriers, but not in non-carriers. Moreover, we found that the rs495392 A allele attenuated the detrimental impact of PNPLA3 rs738409 G allele on the risk of severe hepatic steatosis. Conclusions: The KL rs495392 polymorphism has a protective effect against hepatic steatosis in patients with NAFLD.

Patterns of Failure and Survival Trends in 3,808 Patients with Stage II Nasopharyngeal Carcinoma Diagnosed from 1990 to 2012: A Large-Scale Retrospective Cohort Study

Xue-Song Sun,Di-Han Liu,Sai-Lan Liu,Qiu-Yan Chen,Shan-Shan Guo,Yue-Feng Wen,Li-Ting Liu,Hao-Jun Xie,Qing-Nan Tang,Yu-Jing Liang,Xiao-Yun Li,Jin-Jie Yan,Ming-Huang Hong,Jun Ma,Lin-Quan Tang,Hai-Qiang M 대한암학회 2019 Cancer Research and Treatment Vol.51 No.4

Purpose The purpose of this study was to investigate the survival trends and patterns of failure in patients with stage II nasopharyngeal carcinoma (NPC) treated with radiotherapy (RT) and chemotherapy over the last 20 years. Materials and Methods Thirty-eight hundred and eight patients diagnosed with stage II NPC between January 1990 and December 2012 were involved in this retrospective cohort study. All patients were treated with RT. According to the main imaging techniques and RT technology, we categorized these patients into four calendar periods: 1990-1996, 1997-2002, 2003-2007, and 2008-2012. Overall survival (OS), progression-free survival (PFS), locoregional relapse-free survival (LRFS), and distant metastasis–free survival (DMFS) were served as the clinical outcome. Results After a median follow-up period of 84.7 months, we observed increasing trends in survival and disease control. The 3- and 5-year OS rates increased from 87.1% and 78.7% in the first calendar period to 97.4% and 94.5% in the last calendar period, respectively (p < 0.001). Additionally, significant increasing trends could be seen in the PFS and LRFS during the four calendar periods. In the subgroup analysis, the LRFS in patients older than 50 years at diagnosis showed greater improvement than younger patients. However, the rate of distant metastasis was stable and relatively low, as the 5-year DMFS ranged from 90.5% to 94.7% among the four calendar periods. Conclusion The survival rates in patients with stage II NPC showed increasing trends from 1990 to 2012. The advance of RT provided excellent locoregional control and enhanced OS.