sp^(2)碳连接的二维聚合物

二维多孔聚合物具有光学各向异性、高的电子迁移率、可逆的氧化还原等众多特性,因此它们作为关键材料用于气体吸附与分离、燃料电池膜、超级电容器等领域。这类二维多孔聚合物通常可分为二维金属-有机骨架、二维共价有机骨架、石墨化氮化碳、石墨炔和三明治型多孔聚合物纳米片。其中,sp2杂化碳(Csp2)连接的二维多孔聚合物是新兴的研究领域。与C―N、B―O和C≡C键连接的二维多孔聚合物相比,Csp2-二维聚合物因其高的电子迁移率和可调的带隙而具有独特的光电性质、高的化学/光稳定性和可调的电化学性质。此外,Csp2-二维多孔聚合物是制备过渡金属单原子的2D多孔碳材料的重要前驱体之一。总结了Csp2-二维多孔聚合物的可控合成方法,并讨论了它们在光电器件、气体分离、发光传感和成像、电化学能源存储和光催化等领域的应用情况。

Synthesis of poly[methyl(3,3,3-trifluoropropyl)siloxane]-b-poly(ethylene oxide) block copolymers

A series of new amphiphilic poly[methyl（3,3,3-trifluoropropyl）siloxane]-b-poly（ethylene oxide） （PMTFPS-b-PEO） diblock copolymers with different ratios of hydrophobic segment to hydrophilic segment were prepared by coupling reactions of end-functlonal PMTFPS and PEO homopolymers. Copolymers were shown to be well defined and narrow molecular weight distribution （MWD） （1.07-1.3） by characterizations such as gel permeation chromatography （GPC） and ^1H-nudear magnetic resonance （^1H-NMR）.

Synthesis and Solution Properties of Hydrophobic Associating Polymers

Acrylamide/2-acrylamido alkane sulfonic acid hydrophobic associating copolymers were synthesized by micellar copolymerization. Effects of hydrophobe content, polymer concentration, salinity and surfactant on rheological behavior of copolymers were investigated and the conformation of polymers in solution was studied by means of environmental scanning electronic microscopy and dynamic light scattering. The experimental results showed that in the dilute regime the hydrophobic parts could interact intramolecularly, while in the regime where the polymer concentration was higher than the critical association concentration, intermolecular hydrophobic association became predominant. Within the limit of the solubility, the critical association concentration of the polymer decreased with the increase of the salinity. The experimental results of the solution conformation indicated the presence of the three-dimensional network structure in deionized water and the size of the mesh in the network varied with the polymer concentration. In NaCl solution, above the critical association concentration, an increase in polymer concentration enhanced the intermolecular association and also enlarged the hydrodynamic radius. It would result in the improvement of the thickening power of polymers.

Self-assembly of Polyaniline： Mechanism Study

Anisotropic polyaniline （PAni） plates decorated with self-aligned nanofiber arrays were synthesized under the hydrothermaI conditions. The formation mechanism of the self-assembled structures was investigated by studying the effect on PAni micro-structure with additive electrolyte in reaction system, and numerical simulation for dependence of systematic electrostatic energy on cross angles of self-assembled nanofiber arrays in grid textured PAni plates. It is proposed that the electrostatic interaction based on ionic doping charges plays an important role in the formation of the self-assembled PAni structures.

聚集诱导发光聚合物

聚集诱导发光(AIE)的研究已经成为化学和材料等领域的一个前沿.目前,AIE领域的研究重点主要集中于小分子方面,而具有良好成膜性和协同放大效应的AIE聚合物的研究仍有待进一步发展.其制备方法,构效关系以及相对于小分子的性能和应用独特性还有待进一步体现.该专论较系统性地总结了AIE聚合物的制备方法,介绍了AIE聚合物的构效关系及在传感和生物医药等领域的应用,并对AIE聚合物的未来发展进行了展望.

Clinicopathological Features of Non-familial Colorectal Cancer with High-frequency Microsatellite Instability

Objective To explore the clinicopathological features of non-familial colorectal cancer with high-frequency microsatellite instability (MSI-H). Methods One hundred and fifty patients with colorectal cancer who had no family history were enrolled in this study from June 2006 to June 2008. Five standard microsatellite loci including BAT25, BAT26, D2S123, D5S346, and D17S250 were amplified with immunofluorescent polymerase chain reaction. The patient information including age, sex, and tumor location was recorded. Pathological features including differentiation, mucinous differentiation, histological heterogeneity, and Crohn's-like reaction were observed under light microscope. The presence of tumor-infiltrating lymphocytes (TLs, CD4+ and CD8+) was detected by means of immunohistochemistry. A regression equation was obtained by stepwise logistic regression analysis to evaluate the relationship between MSI-H phenotype in colorectal cancer ands pathological features. Results MSI-H phenotype occurred in 13.33% of the 150 patients with non-familial colorectal cancer. Poor differentiation, histological heterogeneity, Crohn's-like reaction, and presence of TLs were found to be independent factors to identify MSI-H non-familial colorectal cancer. Logistic regression equation showed an overall sensitivity of 70.0%, specificity of 99.2%, and accuracy of 95.3% in identifying MSI-H non-familial colorectal cancer. Conclusion MSI-H non-familial colorectal cancer manifests specific pathological features, which may be relied upon for effective identification of that disease.

Aberrant methylation of the 3q25 tumor suppressor gene PTX3 in human esophageal squamous cell carcinoma

AIM:To identify the novel methylation-silenced gene pentraxin 3(PTX3) in esophageal squamous cell carcinoma(ESCC).METHODS:PTX3 mRNA expression was examined in six human ESCC cell lines,one human immortalized normal esophageal epithelial cell line,primary ESCC tumor tissue,and paired adjacent nontumor tissue using reverse transcription polymerase chain reaction(RTPCR).Semi-quantitative immunohistochemistry was used to examine cellular localisation and protein levels.Methylation specific PCR and bisulphite genomic sequencing were employed to investigate the methylation of the candidate gene.RESULTS:In the majority of ESCC cell lines,we found that PTX3 expression was down-regulated due to gene promoter hypermethylation,which was further confirmed by bisulphite genomic sequencing.Demethylation treatment with 5-aza-2'-deoxycytidine restored PTX3 mRNA expression in ESCC cell lines.Methylation was more common in tumor tissues(85%) than in adjacent nontumor tissues(25%)(P < 0.01).CONCLUSION:PTX3 is down-regulated through promoter hypermethylation in ESCC,and could potentially serve as a biomarker of ESCC.

In-situ electropolymerized bipolar organic cathode for stable and high-rate lithium-ion batteries

To address the dissolution issue and enhance the electrochemical performance of organic electrode materials,herein, a bipolar organic cathode was prepared by in-situ electropolymerization of amino-phenyl carbazole naphthalene diimide(APCNDI). APCNDI is composed of n-type 1,4,5,8-naphthalene tetracarboxylic diimide that stores Li cations and p-type carbazole groups which react with anions and serve as polymerization sites. Electropolymerization completely eliminated the dissolution problem of APCNDI, and the electropolymerized cathode demonstrated a bipolar reaction with excellent electrochemical performance, stable cycling performance with a capacity retention of 92 mA h g;after1000 cycles, and a superior rate performance of 72 mA h g;at 10 A g;. The bipolar feature and reactions of APCNDI were systematically investigated and verified by multiple characterization techniques. Our findings provide a novel strategy for the design and fabrication of electrodes for high-performance organic batteries.

An accurate,high-speed,portable bifunctional electrical detector for COVID-19

Coronavirus disease 2019(COVID-19),caused by SARS-CoV-2,has rapidly spread and caused a severe global pandemic.Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2,accurate and rapid diagnosis of COVID-19 has been the most crucial measure to control this pandemic.Here,we developed a portable bifunctional electrical detector based on graphene fieldeffect transistors for SARS-CoV-2 through either nucleic acid hybridization or antigen-antibody protein interaction,with ultra-low limits of detection of~0.1 and~1 fg mL^(−1) in phosphate buffer saline,respectively.We validated our method by assessment of RNA extracts from the oropharyngeal swabs of ten COVID-19 patients and eight healthy subjects,and the IgM/IgG antibodies from serum specimens of six COVID-19 patients and three healthy subjects.Here we show that the diagnostic results are in excellent agreement with the findings of polymerase chain reaction-based optical methods;they also exhibit rapid detection speed(~10 min for nucleic acid detection and~5 min for immunoassay).Therefore,our assay provides an efficient,accurate tool for high-throughput point-of-care testing.

Dynamics of the Manakov Solitons in Biased Guest-Host Photorefractive Polymer

In the biased guest-host photorefractive polymer, the Manakov equations can be used to describe the op- tical soliton propagation and interaction. Hereby for such equations, via the Hirota method and syrnbolic computation, analytic soliton solutions in the bright-dark and dark-dark forms are obtained. Based on the choice of photorefrac- rive polymer parameter and incident-optical-beam parameter, the bright-dark and dark-dark solitons as well as their interaction can occur in the polymer when the total intensity is much lower than the background illumination, and our analysis indicates that the incident light with different polarization directions influence little on the soliton propagation. ~, representing the soliton intensity far away from the soliton center, determines the appearance of bright or dark soliton under the background illumination. Through the graphic and asymptotic analysis on the two-soliton solutions along with the different ~, we find that there exist the elastic and inelastic interactions between the bright-dark solitons, while the interactions between the dark-dark solitons are always elastic.