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This study explored the association between cerebral metabolic rates of glucose (CMRGlc) and the severity of Vascular Parkinsonism (VP) and Parkinson's disease (PD). A cross-sectional study was performed to compare CMRGlc in normal subjects vs. VP and PD patients. Twelve normal subjects, 22 VP, and 11 PD patients were evaluated with the H&Y and MMSE, and underwent 18F-FDG measurements. Pearson's correlations were used to identify potential associations between the severity of VP/PD and CMRGlc. A pronounced reduction of CMRGlc in the frontal lobe and caudate putamen was detected in patients with VP and PD when compared with normal subjects. The VP patients displayed a slight CMRGlc decrease in the caudate putamen and frontal lobe in comparison with PD patients. These decreases in CMRGlc in the frontal lobe and caudate putamen were significantly correlated with the VP patients' H&Y, UPDRS II, UPDRS III, MMSE, cardiovascular, and attention/memory scores. Similarly, significant correlations were observed in patients with PD. This is the first clinical study finding strong evidence for an association between low cerebral glucose metabolism and the severity of VP and PD. Our findings suggest that these changes in glucose metabolism in the frontal lobe and caudate putamen may underlie the pathophysiological mechanisms of VP and PD. As the scramble to find imaging biomarkers or predictors of the disease intensifies, a better understanding of the roles of cerebral glucose metabolism may give us insight into the pathogenesis of VP and PD. [ABSTRACT FROM AUTHOR]

Human pharyngeal squamous cell carcinoma (HNSCC) are highly invasive and proliferative and exhibit a poor five-year survival rate, mainly due to poor understanding of HNSCC pathogenesis mechanisms, preventing efficient treatment. Ubiquitin-specific peptidase 22 (USP22) is an important component of cell cycle regulation, as it indirectly affects chromatin structure via histone ubiquitination and regulates activation of gene transcription. In previous studies, silencing of USP22 significantly inhibited tumor cell proliferation. To investigate the expression levels and the role of USP22 in the carcinogenesis of human pharyngeal squamous cell carcinoma, pharyngeal squamous cell carcinoma and adjacent normal tissue samples were collected from four patients. Six pharyngeal squamous cell carcinoma cell lines (SAS, CAL-33, FaDu, HSC-4, UTSCC-5 and UTSCC-8) were also included in this study. The USP22 mRNA and protein expression levels in the patient and cell-line samples were evaluated using quantitative polymerase chain reaction and western blotting analyses. Subsequently, stable USP22 gene silencing in cells was achieved using lentiviral-delivered small interfering RNA (siRNA), and an MTT assay was used to evaluate tumor cell proliferation. Expression levels of cell cycle-associated proteins following USP22 knockdown were assessed using western blot analysis. The results revealed that USP22 was upregulated in pharyngeal squamous cell carcinoma. USP22 knockdown, using lentivirus-delivered siRNA, increased the expression levels of cell cycle proteins P21 and P27, but reduced the levels of phosphorylated retinoblastoma protein, resulting in the inhibition of FaDu cell growth and proliferation. In conclusion, USP22 is involved in the carcinogenesis of human pharyngeal squamous cell carcinoma through regulating tumor cell growth and proliferation. [ABSTRACT FROM AUTHOR]

The self-assembly behavior of azobenzene-based triblock copolymers poly(ethylene oxide)-block-polystyrene-block-poly[6-(4-methoxy-40-oxy-azobenzene) hexyl methacrylate] (PEO-b-PS-b-PMMAZO) and their mixtures with PS or PMMAZO homopolymers was studied by means of transmission electron microscopy, scanning electron microscopy, laser light scattering and UV-vis spectrophotometry. It was found that pure block copolymers self-assembled into spherical micelles with core-shell structures. The addition of PS or PMMAZO homopolymers can not only increase the aggregate size but also have a significant influence on the photo-isomerization behavior and photo-deformation behavior of the aggregate. The photo-isomerization study revealed that a complete trans-cis or cis-trans isomerization of azobenzene chromophores can be acquired when irradiated with UV or visible light for polymers both in organic solutions and in micelles. The photo-isomerization rate of azobenzene chromophores increases when PS homopolymers were incorporated into micelles, while with the addition of PMMAZO homopolymers, it decreases. The photo-induced elongation of the aggregates by irradiation of a linearly polarized laser was observed for all the samples, and the deformation degree increases with the weight fraction of azobenzene groups in the parent copolymers, as well as the PMMAZO content for the mixture micelles. [ABSTRACT FROM AUTHOR]

Using real-space self-consistent field theory, we explored hierarchical microstructures self-assembled from A(BC)nmultiblock copolymers. The multiblock copolymers were classified into two types in terms of relative magnitude of A/B and A/C interaction strengths: one is that χABNis less than or equal to χACN, and the other is that χABNis greater than χACN. For both cases, the multiblock copolymers can self-assemble into hierarchically ordered microstructures with two different length scales. For χABN≤ χACN, various hierarchical microstructures, such as cylinders-in-lamellae∥, lamellae-in-lamella∥, cylinders-in-cylinder∥, and spheres-in-sphere∥, were observed. In these microphases, the small-length-scale structures and the large-length-scale structures are packed in the doubly parallel forms. It was found the number of internal small-length-scale structures can be tailored by tuning the number of BC block and the interaction strength between A and BC blocks. For χABN> χACN, in addition to the parallel packed hierarchical structures, the multiblock copolymers can self-organize into perpendicular packed hierarchical structures, in which the structures with small periods are arranged perpendicular to structures with large periods. These perpendicular packed hierarchical structures were found to be only stable at higher value of χBCN. [ABSTRACT FROM AUTHOR]

The article discusses results of a study that examines the synthesized N-allylcarbazole containing chromium tricarbonyl. The hydrosilylation of the complex with polymethyldrosiloxane is discussed. The techniques used to characterize both the complex and the polymer were cited, including nuclear magnetic resonance (NMR), gel permeation chromatography and elemental analysis. The study showed the amorphous nature of the polymer and its ability to form excellent homogeneous optical transparency films.

A theoretical approach combining self-consistent-field theory (SCFT) for fluids and density functional theory (DFT) for particles was applied to investigate the self-assembly behavior of amphiphilic diblock copolymer/nanoparticle mixture in dilute solution. Two kinds of hydrophobic nanoparticles are studied:  one is that the particles are selective to hydrophobic blocks but are incompatible with hydrophilic blocks, and the other is that the particles are nonselective to hydrophobic and hydrophilic blocks. For both cases, the self-association of amphiphilic block copolymer/nanoparticle mixture is observed, and the nanoparticles are spatially organized in the clusters. The aggregate morphologies can be tuned by the particle radius and particle volume fraction. For the selective particles, the aggregate morphologies of amphiphilic block copolymer/nanoparticle mixture can experience a transition from vesicles to mixture of circlelike and rod micelles as the particle radius and/or particle volume fraction increase. For the nonselective nanoparticles, the large compound micelles are produced instead of the vesicles. The large compound micelles transform to the mixture of large compound micelles and circlelike micelles with an increase in particle volume fraction and/or radius. The distribution of nanoparticles in the clusters is also affected by the particle radius and volume fraction. For both cases, when the values of nanoparticle radius and/or volume fraction are small, the nanoparticles are almost uniformly distributed in the cores of micelles. However, the particles tend to localize near the interfaces between the core and shell with increasing particle volume fraction and/or radius. [ABSTRACT FROM AUTHOR]

The effect of an external electrical field on phase behaviors is reported for polymer dispersed liquid crystal films of 4′‐pentyl‐4‐biphenylcarbonitrile/poly(methyl methacrylate) binary mixtures with various polymer molecular weights. The experimental results show that increasing the molecular weight of the polymer or the electrical field intensity can give rise to an increase in the phase‐transition temperature and a widening of the binary phase region. The lattice theory, regarding a binary system consisting of a rigid nematic liquid crystal and a random polymer, has been extended to the case in which an external electrical field is present. A comparison of the theoretical predictions with the experimental results has been carried out, and satisfactory agreement has been found. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1898–1906, 2007 [ABSTRACT FROM AUTHOR]

Coarse-grained molecular dynamic simulations are performed for lyotropic liquid-crystalline (LC) solutions of semiflexible rod-like molecules, which are realized by harmonic-stretching potential and angle-bending potential. The phase behavior and molecular dynamic information are investigated. When the concentration of rod-like molecules increases, the solution transits from isotropic to binary phase and then to anisotropic phase. The influences of chain length, temperature, solvent solubility, and chain rigidity are studied. The simulation for the phase behavior successfully reproduces the predictions of Flory lattice theory on the rod-like molecule solution. The decrement of the chain rigidity increases the concentration of phase transition, and the apparent persistence length is increases by molecular alignments with LC formations at higher concentrations. [ABSTRACT FROM AUTHOR]

Morphologies and bridging properties of graft copolymers in the bulk state were studied by using a real-space algorithm of self-consistent field theory in two dimensions. The phase transition from cylindrical to lamellar phase can be triggered by changing the position of graft points and the number of branches. The fraction of bridged conformation, fbridge, shows a tendency to decrease with increasing the length of free end blocks, 1, and the number of branches, m. The value of fbridgehas a discontinuous drop when the transition from cylindrical to lamellar phase takes place. The relationship between mand the number of bridged chains per unit area, nb, which is associated with the mechanical properties of copolymers, was also examined. It was found that nbincreases with increasing min the cylindrical phase. However, in the lamellar phase, nbdecreases when mincreases. It is proposed that the position of graft points and the number of branches are two important parameters for material design. [ABSTRACT FROM AUTHOR]

The homogeneous hydrolysis method was proposed to synthesize nano-TiO2 with mixed crystal of anatase and rutile. It is remarkable that the crystal-form-controllable nanosize TiO2 was obtained by the addition of toluene-p-sulfonic acid (TSA). Two processes of the rutile phase formation were proposed. TiO2 was pure anatase crystalline in the absence of TSA. The sample with 0.2 mole ratio of TSA was mixed crystal of anatase and rutile, and characterized that the size of nanocrystalline was 19.5 nm for rutile and 13.5 nm for anatase, the specific surface area was 72.7 m2/g, and the energy of band gap was 2.83 eV. And the mechanism of the development of rutile nano-TiO2 was presented in homogeneous hydrolysis system with TSA. [ABSTRACT FROM AUTHOR]

We report here a discovery that amphiphilic polypeptide block copolymers and polypeptide homopolymers are able to aggregate together into super-helical structures of rods and rings, in which polypeptide chains form the core and PEG chains form the shell. [ABSTRACT FROM AUTHOR]