Enantiomers Self-Sort into Separate Counter-Twisted Ribbons of the Liquid Crystal─Antiferrochirality and Parachirality.

The recently discovered orthorhombic liquid crystal (LC) phase of symmetry is proving to be widespread. In this work, a chiral hydroxybutyrate linkage is inserted into the molecular core of hexacatenar rodlike compounds, containing a thienylfluorenone fluorophore. In addition to more usual tools, the methods used include grazing-incidence X-ray scattering, modulated differential scanning calorimetry (DSC), flash DSC with rates up to 6000 K/s, and chiro-optical spectroscopies using Mueller matrix method, plus conformational mapping.

Fast-Scanning Chip-Calorimetry Measurement of Crystallization Kinetics of Poly(Glycolic Acid).

We report fast-scanning chip-calorimetry measurement of isothermal crystallization kinetics of poly(glycolic acid) (PGA) in a broad temperature range. We observed that PGA crystallization could be suppressed by cooling rates beyond -100 K s and, after fast cooling, by heating rates beyond 50 K s. In addition, the parabolic curve of crystallization half-time versus crystallization temperature shows that PGA crystallizes the fastest at 130 °C with the minimum crystallization half-time of 4.

Aptamer-based polyhedral oligomeric silsesquioxane (POSS)-containing hybrid affinity monolith prepared via a "one-pot" process for selective extraction of ochratoxin A.

A novel aptamer-based polyhedral oligomeric silsesquioxane (POSS)-containing hybrid affinity monolith has been prepared with a facile "one-pot" process simultaneously via "free radical polymerization" and "thiol-ene" click reaction, and used for on-line selective extraction and practical analysis to trace ochratoxin A (OTA). By using the ternary porogenic mixture composed of water/DMF/PEG, a homogeneous polymerization mixture with POSS chemicals, acrylate-based monomers and aptamer aqueous solution was obtained, and the copolymerization of POSS chemicals, polymer monomers and aptamer aqueous solution was systematically studied. Characterizations such as the morphology, FT-IR and fluorescence spectra, mechanical stability, dynamic binding capacity, cross-reactivity and selectivity of the resultant affinity monolith were also evaluated.

An aptamer@AuNP-modified POSS-polyethylenimine hybrid affinity monolith with a high aptamer coverage density for sensitive and selective recognition of ochratoxin A.

A novel hybrid affinity monolith with a high aptamer coverage density was developed via a highly efficient modification of aptamer@gold nanoparticles (Apt@AuNPs) on a well-controlled 3D skeletal POSS-polyethylenimine (PEI) matrix. The effects of amine reagents and the skeletal structures of the hybrid monoliths on the modification efficiency of Apt@AuNPs were studied, and the resultant Apt@AuNPs@POSS-PEI1200 monolith was proposed with a high coverage density of aptamer of up to 1413 pmol μL, which is 4-5 times more than the coverage density when modified with Apt@AuNPs that was reported previously. Characterization including morphology, spectra analysis, mechanical stability, binding capacity and specificity studies was also carried out.

Quinine-modified polymer monolithic column with reversed-phase /strong anion-exchange mixed-mode for pressurized capillary electrochromatography.

Via the facile ring-opening reaction of epoxy groups with quinine, a novel polymer monolith with quaternary ammonium for reversed-phase/strong anion-exchange mixed-mode has been fabricated for pressurized capillary electrochromatography (pCEC). Optimization on the preparation of quinine-modified monoliths has been investigated, and characteristics including morphology, permeability, mechanical stability, reproducibility, and column performance have been also studied. Active quaternary ammonium groups were conveniently produced to generate cationic action sites and stable anodic electroosmotic flow.

Sensitive turn-on fluorescent detection of melamine based on fluorescence resonance energy transfer.

We here report a novel fluorescent method for the detection of melamine based on the high fluorescence quenching ability of gold nanoparticles. The fluorescence was significantly quenched via fluorescence resonance energy transfer when fluorescein molecules were attached to the surface of gold nanoparticles by electrostatic interaction. Upon addition of melamine, the fluorescence was enhanced due to the competitive adsorption of gold nanoparticles between melamine and fluorescein.

[Isolation and characterisation of Spiroplasma sp. from Phytomia zonata (Diptera: Syrphidae)].

Objective: To obtain the spiroplasma resources and characterize the spiroplasmas from insects in China, as well as study the taxonomy of spiroplasma based on biological characteristics.

Methods: We determined morphology by using dark field and transmission electron microscopy. The biological characteristics of the spiroplasmas were studied by using conventional culture-dependent method and phylogenetic analysis based on 16S rDNA.

[Advances in classification and biodiversity of spiroplasmas--a review].

Spiroplasma spp. are helical, motile bacteria that lack cell wall and flagellum, and are enclosed within a single membrane with their genomes ranging from approximately 0.78-2.

[Isolation and biological characteristics of Spiroplasmas from flower surface].

Objective: To obtain the spiroplasma resources and investigate the characteristics of the spiroplasmas on the surface of flowers in China.

Methods: The spiroplasma morphology was examined by dark-field microscope and transmission electron microscopy. The biological characteristics of the spiroplasmas were investigated by using conventional culture-dependent method and phylogenetic analysis based on 16S rRNA gene and ITS (16-23S rDNA intergenic space) sequence comparisons.