DNA combining and photocleaving properties of photosensitizer-encapsulated silica nanoparticles

Abstract  

Based on theoretical predictions, water-soluble silica nanoparticle encapsulated hypocrellin A (HA) was prepared, and its photosensitization activity was evaluated. The encapsulated HA showed not only very good water solubility, but also much stronger singlet oxygen generation ability than free HA. Investigations on binding interactions with DNA showed promising results as well. These findings suggest that HA carrier can exert photodynamic action via photosensitization.     

Sonophysically‐Exfoliated Individual Multi‐Walled Carbon Nanotubes in Water Solution

We report the sonophysically‐exfoliated methods access to the preparation of homogeneous‐free multi‐walled carbon nanotubes (MWCNTs) in water solution. Highly stable, uniform, individual MWCNTs are entirely performed through sodium dodecylsulfate surfactants by means of a tip sinicator. HRTEM images show that the crystalline finger walls of individual CNTs are apparently observed. Raman spectrum of MWCNTs shows that the so‐called G'‐band, associated with metallic electronic structure, was significantly observed at 2644 cm^?1 with full‐width at half‐maximum of 262 cm^?1, indicating that the sonication physical methods do not alter their electric properties. Owing to its easy‐to‐use procedure and low cost of implementation, this approach could lead to the commercial viability of the large‐scale MWCNTs processing.     

Two New Triterpenoids from the Stems of Schisandra bicolor

Two new triterpenoids, schisanbilactones A and B ( 1 and 2 , resp.), and a new natural product, 1‐chloro‐3‐phenylhex‐5‐en‐3‐ol ( 3 ), as well as a known triterpenoid, kadsulactone A ( 4 ), were isolated from the stems of Schisandra bicolor. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D‐NMR techniques.     

Effects of film structure on electrochromic properties of the multilayer films containing polyoxometalates

Multilayer films of tungstophosphate anion (P₂W₁₈) and poly(allylamine hydrochloride) (PAH) were fabricated on quartz and ITO substrates by layer-by-layer self-assembly method. These films were characterized by UV–vis spectroscopy, cyclic voltammetry (CV), chronoamperometric (CA), chronocoulometry (CC) and atomic force microscopy (AFM). The effects of film structure on multilayer electrochromic properties were investigated. The electrochromic responses of the composite films were related to the surface coverage of anion and multilayer thickness. It was found that higher concentration of polycation and anion, or adding salt to the polycation solution used for multilayer film preparation led to thicker and denser film structure which improved optical contrast and coloration efficiency whereas prolonged response time.     

Reactions of pyridyl side chain functionalized cyclopentadiene with ruthenium carbonyl

Abstract  

Reactions of the pyridyl side-chain-functionalized cyclopentadiene [C₅H₅CR₂(CH₂C₅H₄N)] [R ₂ = Et₂ (1), (CH₂)₄ (2)] with Ru₃(CO)₁₂ in refluxing xylene gave the new intramolecular C–H activated trinuclear product [μ-(C₅H₃N)CH₂C(C₂H₅)₂(C₅H₄)Ru(CO)]₂Ru(CO)₂ (3) and the normal dinuclear metal complex [(C₅H₄N)CH₂C(CH₂)₄(C₅H₄)Ru(CO)]₂(μ-CO)₂ (4). The structures of the trinuclear complex 3 and dinuclear complex 4 were characterized by elemental analysis, IR spectra, ¹H-NMR and X-ray diffraction.     

Nonparametric M-estimation for Functional Stationary Ergodic Data

Acta Mathematicae Applicatae Sinica, English Series - This paper considers a nonparametric M-estimator of a regression function for functional stationary ergodic data. More precisely, in the...     

N-硫代酰基硫乙酸功能化三乙撑四胺交联PVC树脂的制备及对Hg~(2+)的吸附

以聚氯乙烯为原料依次与四乙烯五胺、CS_2和ClCH_2COONa反应合成了一种新的含N、O、S的N-硫代酰基硫乙酸功能化三乙撑四胺交联聚氯乙烯螯合树脂,树脂结构经红外分析和元素分析表征. 探讨了在不同pH值、Hg~(2+)初始浓度、吸附温度和时间等条件下合成树脂对Hg~(2+)的吸附性能. 结果表明,螯合树脂对Hg~(2+)有较快的吸附速率,pH值约为2.0时,树脂对Hg~(2+)的吸附效果最好,随温度升高吸附量逐渐增大. 温度在35 ℃、Hg~(2+)起始浓度为17.66 mmol/L时,树脂对Hg~(2+)的吸附量可达3.330 mmol/g. 树脂对Hg~(2+)的吸附符合Langmuir和Freundlich等温式. 用0.2 mol/L HNO3-10%硫脲对吸附后的树脂进行洗脱,脱附率达99.20%.     

Azobenzene‐Functionalized Metal–Organic Polyhedra for the Optically Responsive Capture and Release of Guest Molecules

Stimuli‐responsive metal–organic polyhedra (srMOPs) functionalized with azobenzene showed UV‐irradiation‐induced isomerization from the insoluble trans‐srMOP to the soluble cis‐srMOP, whereas irradiation with blue light reversed this process. Guest molecules were trapped and released upon cis‐to‐trans and trans‐to‐cis isomerization of the srMOPs, respectively. This study provides a new direction in the ever‐diversifying field of MOPs, while laying the groundwork for a new class of optically responsive materials.     

Simultaneous In Situ Quantification of Two Cellular Lipid Pools Using Orthogonal Fluorescent Sensors

Lipids regulate a wide range of biological activities. Since their local concentrations are tightly controlled in a spatiotemporally specific manner, the simultaneous quantification of multiple lipids is essential for elucidation of the complex mechanisms of biological regulation. Here, we report a new method for the simultaneous in situ quantification of two lipid pools in mammalian cells using orthogonal fluorescent sensors. The sensors were prepared by incorporating two environmentally sensitive fluorophores with minimal spectral overlap separately into engineered lipid‐binding proteins. Dual ratiometric analysis of imaging data allowed accurate, spatiotemporally resolved quantification of two different lipids on the same leaflet of the plasma membrane or a single lipid on two opposite leaflets of the plasma membrane of live mammalian cells. This new imaging technology should serve as a powerful tool for systems‐level investigation of lipid‐mediated cell signaling and regulation.     

A turn-on fluorescence-sensing technique for glucose determination based on graphene oxide–DNA interaction

Graphene is a two-dimensional carbon nanomaterial one atom thick. Interactions between graphene oxide (GO) and ssDNA containing different numbers of bases have been proved to be remarkably different. In this paper we propose a novel approach for turn-on fluorescence sensing determination of glucose. Hydrogen peroxide (H₂O₂) is produced by glucose oxidase-catalysed oxidation of glucose. In the presence of ferrous iron (Fe²⁺) the hydroxyl radical (?OH) is generated from H₂O₂ by the Fenton reaction. This attacks FAM-labelled long ssDNA causing irreversible cleavage, as a result of the oxidative effect of ?OH, producing an FAM-linked DNA fragment. Because of the weak interaction between GO and short FAM-linked DNA fragments, restoration of DNA fluorescence can be achieved by addition of glucose. Due to the excellent fluorescence quenching efficiency of GO and the specific catalysis of glucose oxidase, the sensitivity and selectivity of this method for GO-DNA sensing are extremely high. The linear range is from 0.5 to 10 μmol L^?1 and the detection limit for glucose is 0.1 μmol L^?1. The method has been successfully used for analysis of glucose in human serum. Figure

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