A lectin-coupled,multiple reaction monitoring based quantitative analysis of human plasma glycoproteins by mass spectrometry

Aberrant protein glycosylation may be closely associated with cancer pathology. To measure the abundance of protein glycoforms with a specific glycan structure in plasma samples, we developed a lectin-coupled multiple reaction monitoring (MRM)-based mass spectrometric method. It was confirmed that the method could provide reproducible results with precision sufficient to distinguish differences in the abundance of protein glycoforms between individuals. Plasma samples prepared from hepatocellular carcinoma (HCC) patients without immuno-depletion of highly abundant plasma proteins were fractionated by use of fucose-specific aleuria aurantia lectin (AAL) immobilized on magnetic beads by use of a biotin–streptavidin conjugate. The lectin-captured fractions were digested by trypsin and profiled by tandem mass spectrometry. From the proteomic profiling data, target glycoproteins were selected and analyzed quantitatively by MRM-based analysis. The reproducibility of MRM-based quantification of the selected target proteins was reliable, with precision (CV; ≤14% for batch-to-batch replicates and ≤19% for replicates over three days) sufficient to distinguish differences in the abundance of AAL-captured glycoforms between individual plasma samples. This lectin-coupled, MRM-based method, measuring only lectin-captured glycoforms of a target protein rather than total target protein, is a tool for monitoring differences between individuals by measuring the abundance of aberrant glycoforms of a target protein related to a disease. This method may be further applied to rapid verification of biomarker candidates involved in aberrant protein glycosylation in human plasma.     

Highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites: Pt-free, highly efficient, and durable counter electrodes for dye-sensitized solar cells

We report the preparation of highly interconnected ordered mesoporous carbon-carbon nanotube nanocomposites which show Pt-like dye-sensitized solar cell (DSSC) efficiency and remarkable long-term durability as DSSC counter electrodes.     

Isobutene Polymerization Using [CuII(NCMe)6]2+ with Non‐Coordinating Anions as Catalysts

Cu^II compounds coordinated octahedrally with nitriles and associated with bulky, non‐coordinating counter ions can be applied in the polymerization of isobutene at 30 °C. High yields and a high content of terminal double bonds are reached in the resulting highly reactive polyisobutylenes, while the molecular masses are moderate. Two of the coordinating nitriles are more weakly coordinated than the other four, as can be concluded from an exemplary X‐ray structure and from vibrational spectra, thus providing easily accessible sites for substrate coordination.

     

Analysis of coherent gradient sensing (CGS) by fourier optics

A coherent laser beam reflected or transmitted from a deforming plate specimen acquires an optical path difference (phase change) which is related to the deformation and stress field. The optical method of Coherent Gradient Sensing (CGS) uses two parallel grating plates to displace (shear) and recombine the distorted light beam emerging from the specimen. Fringes are produced on the image plane by the interference of the shifted and unshifted beams. The fringe pattern is related to the spatial difference of the phase in the shearing direction. If the shearing distance is small enough, the spatial difference of the phase approximates to its gradient. Each fringe in the image represents a locus of equal gradient component of the phase in the shearing direction. The technique is interpreted by means of wave optics, using the Fraunhofer approximation and the paraxial theory of lenses. The assumptions made in earlier analyses have been removed here. A more precise analysis based on Fourier optics is presented. The simplicity of the optical setup and variable resolution of the technique have led to its frequent use in the area of solid mechanics, including fracture mechanics. Some examples are discussed in the second half of this paper.     

Trp-Lys-Tyr-Met-Val-Met stimulates phagocytosis via phospho-lipase D-dependent signaling in mouse dendritic cells

Dendritic cells (DCs) play a key role in activating the immune response against invading pathogens as well as dying cells or tumors. Although the immune response can be initiated by the phagocytic activity by DCs, the molecular mechanism involved in this process has not been fully investigated. Trp-Lys-Tyr-Met-Val-Met-NH(2) (WKYMVM) stimulates the activation of phospholipase D (PLD) via Ca(2+) increase and protein kinase C activation in mouse DC cell line, DC2.4. WKYMVM stimulates the phagocytic activity, which is inhibited in the presence of N-butanol but not t-butanol in DC2.4 cells. Furthermore, the addition of phosphatidic acid, an enzymatic product of PLD activity, enhanced the phagocytic activity in DC2.4 cells. Since at least two of formyl peptide receptor (FPR) family (FPR1 and FPR2) are expressed in DC2.4 as well as in mouse bone marrow-derived dendritic cells, this study suggests that the activation of FPR family by WKYMVM stimulates the PLD activity resulting in phagocytic activity in DC2.4 cells.     

A novel process for holographic polymer dispersed liquid crystal system via simultaneous photo-polymerization and siloxane network formation

Formation of transmission holographic polymer dispersed liquid crystal gratings was studied for matrix components of trimethylolpropane triacrylate:trimethoxysilylmethyl methacrylate:1-vinyl-2-pyrrolidone (reactive diluent) in the range from 80:10:10,wt% to 10:80:10,wt% and E7 as nematic liquid crystal under the irradiation with Nd-YAG laser (532,nm). The optimum concentration of E7 in the recording solution was 35,wt% (65,wt% of matrix components) in presence of small amounts of radical photo-initiator system (Rose Bengal 0.05,wt%, NPG 0.1,wt%). When the concentration of methacrylate in matrix components was low (< 30%), gratings with apparently high diffraction efficiency could be fabricated both for trimethoxysilylmethyl methacrylate (cross-linkable by hydrolysis) and trimethylsilylmethyl methacrylate (non-cross-linkable by hydrolysis), although transiently high initial diffraction efficiency was observed by the non-equilibrium initial photo-polymerization of cross-linking components. Distinct difference was seen at higher concentration (> 50,wt%) of the methacrylates. Contrary to that gratings with reasonably high and stable diffraction efficiency were successfully fabricated with trimethoxysilylmethyl methacrylate, gratings with only low diffraction efficiency were obtained for non-cross-linkable trimethylsilylmethyl methacrylate. With higher concentration of photo-sensitizer and photo-initiator (0.2,wt%; 1.0,wt%), and shorter irradiation time, gratings with high diffraction efficiency could be fabricated only for the photo-initiator system of 3,3′-carbonylbis(7-diethylaminocoumarin) and diphenyliodonium hexafluorophosphate with shorter induction period (∼174,s). Grating with diffraction efficiency of 72% was obtained with trimethoxysilylpropyl acrylate (80,wt% in the matrix component) and 35,wt% E7. By increasing the concentration of diphenyliodonium hexafluorophosphate to 2,wt%, diffraction efficiency increased to 85% and induction period was shortened to 129,s, and low volume shrinkage of 8% was attained via simultaneous radical cross-linking of trimethylolpropane triacrylate and siloxane network formation of trimethoxysilyl groups of trimethoxysilylmethyl acrylate by atmospheric moisture catalyzed by cationic species produced from the initiator system. In SEM morphology, although gratings formed with high concentration of trimethoxysilylpropyl acrylate had some cracks in polymer matrix, the largest grating spacing indicating the lowest volume shrinkage and very regular and well-defined gratings were observed.     

Indium-mediated consecutive 1,2-shift reaction and regioselective allylation of vinyl epoxides

Allyl indium, prepared from allyl bromide and indium metal in aprotic solvent, reacts with terminal vinyl epoxides at room temperature to afford various bishomoallyl alcohols in moderate to high yields via consecutive 1,2-shift reaction and regioselective allylation.     

Covalent fixed multicyclic polystyrene conformers

Covalent fixed multicyclic polystyrene conformers were synthesized from inconvertible polystyrene conformers based on p‐tert‐butylthiacalix[4]arene by azidation and subsequent click coupling. Selective 1D NOESY analyses confirmed that the spatial structures of star polystyrene precursors and multicyclic polystyrenes were preserved during the azidation and click coupling processes. The conformation of star polymers affected degree of decrease in the hydrodynamic volume after cyclization but had little effect on glass transition behavior. The rigid core of star polymer increased the T_g but in the case of multicyclic polymer, this influence of core structure was reduced. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 4020–4026