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Oligonucleotides are being employed for gene-silencing activity by a variety of mechanisms, including antisense, ribozyme, and siRNA. In the present studies, we designed novel oligonucleotides complementary to targeted mRNAs and studied the effect of 3'-end exposure and oligonucleotide length on gene-silencing activity. We synthesized both oligoribonucleotides (RNAs) and oligodeoxynucleotides (DNAs) with phosphorothioate backbones, consisting of two identical segments complementary to the targeted mRNA attached through their 5'-ends, thereby containing two accessible 3'-ends; these compounds are referred to as gene-silencing oligonucleotides (GSOs). RNA and/or DNA GSOs targeted to MyD88, VEGF, and TLR9 mRNAs had more potent gene-silencing activity than did antisense phosphorothioate oligonucleotides (PS-oligos) in cell-based assays and in vivo. Of the different lengths of GSOs evaluated, 19-mer long RNA and DNA GSOs had the best gene-silencing activity both in vitro and in vivo. These results suggest that GSOs are novel agents for gene silencing that can be delivered systemically with broader applicability.

Bifunctional heterostructures composed of gold nanorods and hematite nanoparticle aggregates are prepared facilely through the hydrothermal decomposition of ferric acetylacetonate on the surface of the nanorods. The gold nanorod in the heterostructure is partially coated with the hematite nanoparticle aggregates. The hematite coating is porous. These heterostructures exhibit both plasmonic and superparamagnetic properties. They are well-dispersed in aqueous solutions. Such heterostructures will be potentially useful for many biotechnological applications.

The structure and miscibility of polyimide PBPI-E/PTI-E blends were studied by wide- and small-angle X-ray scattering and dynamic mechanical analysis, where PBPI-E is a biphenyl-dianhydride-based polyimide, and PTI-E is a polyimide from 4,4'-thiodiphthalic anhydride and 4,4'-oxydianiline. The results obtained show that there exists a paracrystalline structure in the blends with high content of PBPI-E, but this does not affect the miscibility of the blends. The blends are miscible over the entire composition range, since only one T(g) was observed for each blend. Meanwhile, the segregation of PTI-E during crystallization of PBPI-E in the blends is interlamellar.

Single-stranded oligoribonucleotides (ORNs) stimulate innate immune responses through TLR7 and TLR8. Specific linkages and chemical modifications incorporated into synthetic ORN can greatly enhance nuclease stability, selectivity, and potency. In the present study, we have synthesized 15 ORN containing different sequence compositions and chemical modifications and studied their TLR7- and TLR8-mediated immune response profiles in HEK293 cells expressing human TLR7 or TLR8, human PBMCs, mDCs and pDCs, non-human primate (NHP) PBMCs, and in vivo in mice and NHPs. Based on the results obtained, eight of the ORNs containing specific chemical modifications induced immune responses through both TLR7 and TLR8, including activation of NF-κB in TLR7- and TLR8-transfected cell lines; induction of IFN-α, IL-6, TNF-α, IL-12, and IP-10 in human PBMCs; IFN-α induction in human pDCs; CD80 upregulation in human pDCs and mDCs; IL-12 induction following acute administration in mice; IFN-α, IP-10, IL-6, and IL-12 induction in NHP PBMCs; and IFN-α, IP-10, and IL-6 induction following acute administration in NHPs. Seven of the ORNs show selectivity for TLR8-induced responses; they specifically activate only TLR8-transfected cell lines, induce cytokines other than IFN-α in human and NHP PBMCs, activate mDCs more than pDCs, and do not induce IL-12 acutely in mice, consistent with the lack of functional TLR8 in mice. The novel TLR8-selective ORNs also induce cytokines other than IFN-α acutely in NHPs. In conclusion, we have designed and synthesized novel ORNs with varying sequence compositions and chemical modifications, which selectively act as agonists of TLR8 or dual agonists of TLR7 and TLR8.

Thin film field-effect phototransistors (FETs) can be developed from bandgap-tunable, solution-processed, few-layer reduced graphene oxide (FRGO) films. Large-area FRGO films with tunable bandgaps ranging from 2.2 eV to 0.5 eV can be achieved readily by solution-processing technique such as spin-coating. The electronic and optoelectronic properties of FRGO FETs are found to be closely related to their bandgap energy. The resulting phototransistor has great application potential in the field of photodetection.

Plasmon-based photothermal therapy is one of the most intriguing applications of noble metal nanostructures. The photothermal conversion efficiency is an essential parameter in practically realizing this application. The effects of the plasmon resonance wavelength, particle volume, shell coating, and assembly on the photothermal conversion efficiencies of Au nanocrystals are systematically studied by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance. The temperature of Au nanocrystal solutions reaches the maximum at ∼75 °C when the plasmon resonance wavelength of Au nanocrystals is equal to the illumination laser wavelength. For Au nanocrystals with similar shapes, the larger the nanocrystal, the smaller the photothermal conversion efficiency becomes. The photothermal conversion can also be controlled by shell coating and assembly through the change in the plasmon resonance energy of Au nanocrystals. Moreover, coating Au nanocrystals with semiconductor materials that have band gap energies smaller than the illumination laser energy can improve the photothermal conversion efficiency owing to the presence of an additional light absorption channel.

A series of polyimides with different structures have been synthesized and studied by dynamic mechanical analysis. The results obtained indicate that the beta relaxation in polyimides is related to the rotation of rigid segment(s) of p-phenylene and imide groups around 'hinges' such as -O-, -CH2- and so on in diamines. It is noticed that two kinds of polyimides both with [GRAPHICS] imide groups have verv weak beta relaxation below the glass transition temperature. This phenomenon is due to the fact that the configuration of chains with the above imide groups hinders the rotation of the rigid segments in the chains.

Tumor necrosis factor, alpha-induced protein 1 (TNFAIP1) is an immediate-early response gene of endothelium induced by TNF alpha. However, little is really known concerning the TNFAIP1 expression regulation. To better understand how TNFAIP1 expression is regulated, we functionally characterized the promoter region of human TNFAIP1 gene. Deletion mutation analysis, gel electrophoretic mobility shift, and site-directed mutagenesis assays allowed the identification of one functional Sp1-binding site within the human TNFAIP1 core promoter region. Moreover, chromatin immunoprecipitation analysis indicated that Sp1 was associated in vivo with the TNFAIP1 promoter. Further, Sp1 overexpression enhanced TNFAIP1 promoter activity. These findings suggest that Sp1 is implicated in the control of basal TNFAIP1 gene expression. Accordingly, Sp1 is supposed to be involved in the elevation of TNFAIP1 in response to TNF alpha induction, and thus participate in inflammation-associated angiogenesis.

Gold nanocubes, nanobranches, and nanospheres were prepared in high yields using a seeded growth method in the presence of cationic surfactants. The resultant Au nanostructures are encapsulated with a surfactant bilayer and positively charged. The nanocubes are single-crystalline and enclosed with low-index facets. The nanobranches and nanospheres are multiply twinned. Each nanobranch possesses a varying number of sharp tips, which expose high-index facets. Glutathione was used to induce the assembly of the Au nanostructures, including both monocomponent (nanocubes and nanobranches) and bicomponent (nanocube-nanosphere and nanobranch-nanosphere) systems. The assembly was observed to occur predominantly at the vertices of the nanocubes and the sharp tips of the nanobranches. This curvature-directed assembly can be attributed to the preferential bonding of glutathione to the highly curved sites of the Au nanostructures. The fact that the curvature-directed assembly occurs for both the single-crystalline nanocubes and the multiply twinned nanobranches strongly suggests that the preferential bonding of glutathione to the curved sites is due to the less ordered surfactant bilayer at the curved sites than on the flat surfaces.

Three pairs of polyimide/polyimide blends (50/50 wt%) with different molecular structures were prepared by two ways, i.e. mixing of the polyamic acid precursors with subsequent imidization, and direct solution mixing of the polyimides. The blends were studied with DMA technique. The results obtained show that all the blends prepared with these two different ways are miscible, as there existed only one glass transition temperature (Tg) for all the blends. It is suggested that the miscibility of these polyimide/polyimide blends is a result of the strong inter-molecular charge-transfer interaction between the chains of their components.

The toughening effect of the separate phases of ethylene/propylene block copolymers and their blends was studied by scanning electron microscopy (SEM). The results obtained show that the interfacial adhesion between separate phases and the isotactic polypropene (iPP) matrix in ethylene/propylene block copolymers is strong at room temperature, but poor at low temperature; specimens exhibit tearing of separate phases during fracture at room temperature, but interfacial fracture between separate phases and the iPP matrix at low temperature. From the characteristics of fractographs of ethylene/propylene block copolymers and their blends, it could be concluded that the separate phases improve the toughness of specimens in several ways: they promote the plastic deformation of the iPP, and they can be deformed and fractured themselves during the fracture process. However, it was shown that the plastic deformation processes, such as multiple-crazing, shear yielding, etc. of the matrix are the dominant mechanisms of energy absorption in highly toughened ethylene/propylene block copolymers and their blends. The deformation and fracture of separate phases are only of secondary importance.

Fractal behaviour of ramified domains in the late stage of spinodal phase separation in a binary polymer blend of poly(vinyl acetate) with poly(methyl methacrylate) was investigated by optical microscopic method. In the late stage of the spinodal decomposition, the fractal dimension D is about 1.64. It implies that some anomalous properties of irregular structure probably may be explained by fractal concepts.

Characterization, morphology and thermal properties of commercial ethylene-propylene block copolymers have been studied by 13 C nuclear magnetic resonance (n.m.r.) spectroscopy, differential scanning calorimetry (d.s.c.), dynamic mechanical analysis (d.m.a.) and scanning electron microscopy (SEM). The results obtained show that there exists some ethylene-propylene random copolymer in the block copolymers extractable by n-heptane. The possibility of forming PP-b-PE diblock copolymer is questionable on the basis of the effects of residual propene and the chain-transfer reaction in the sequential copolymerization. A difference in the thermal properties between commercial ethylene-propylene block copolymers and PP/PE blends was noticed, which cannot be used to identify PP-b-PE diblock copolymer. The multiphase structure has been confirmed by d.m.a. and SEM, with ethylene-propylene random copolymer and polyethylene forming the domains in the matrix of polypropylene.

Phosphate sorption capacities of 15 Chinese fly ashes were determined and related to their composition. The data of P sorption were best fitted to Langmuir equation, and the calculated sorption maxima of phosphate ( Q m ) ranged from 5.51 to 42.55 mg/g. The Q m value showed a significantly positive correlation with total Ca content ( r = 0.9836 ** ) and total Fe content ( r = 0.8049 ** ), but negative correlation with total Si and total Al content. Correlation coefficients of CaO ( r = 0.9647 ** ) and CaSO 4 ( r = 0.9399 ** ) were much greater than that of CaCO 3 ( r = 0.6361 * ). Correlation coefficients of Q m with Fe 2 O 3d and Al 2 O 3d were much higher than those of total Fe and total Al contents, respectively. Fractionation of P sorbed by fly ash revealed that loosely bound P fraction and/or Ca + Mg-P fraction were the dominant form of immobilized phosphate. Ca content was strongly correlated with the Ca + Mg-P fraction instead of Mg content, whereas Fe content was highly correlated with Fe–Al-P fraction compared with Al content. The loosely bound P was correlated well with both Ca and Fe content. The greatest removal of phosphate occurred at alkaline conditions for high calcium fly ash, at neutral pH levels for medium calcium fly ash, while low calcium fly ash immobilized little phosphate at all pH values. This behavior was explained by the reaction of phosphate with Ca and Fe related components. It was concluded that P immobilization by fly ash was governed by Ca ingredient (especially CaO and CaSO 4 ) and Fe ingredient (especially Fe 2 O 3d ).

Traditional 1D vector based FDA algorithm is popular used in face image retrieval. In FDA, data is represented by 1D vector, which is converted from image matrix. Usually, this conversion makes the number of examples less than that of data dimension, which will give rise to small sample problem. To overcome this problem, 2D matrix based algorithm is proposed, in which the within-class scatter matrix is derived directly from matrix. In the existing matrix based algorithms, IMPCA and GLRAM don’t utilize discriminant information between classes. Although TDLDA goes further, yet it is solved by iterative steps. Here we propose a new matrix based technique: IMFDA. It not only takes the advantage of discriminant information between classes, but also can be solved as a generalized eigenvalue problem. Experiments on ORL face database show that the new algorithm is more efficient than IMPCA, GLRAM and TDLDA with lower test error and shorter running time.

Eight oligonucleotide duplexes have been prepared with four pairs of selected complementary pairs of native/analogue heterocyclic bases incorporated at a selected test site. The base pairs vary in the nature of their functionality in the minor groove. Each pair has a minor groove purine amino group present or absent, and correspondingly has a minor grove pyrimidine carbonyl present or absent. Loss of duplex stability is most notable when the minor groove pyrimidine carbonyl is absent although in other respects normal Watson-Crick hydrogen bonding is maintained in these sequences. These differences in stability are discussed in terms of possible variations in minor groove hydration.

The criteria of polymer-polymer miscibility determined by viscometry are reviewed, and a new criterion is proposed based on the classical Huggins equation and the Huggins coefficient K(m) in the blends. It was found that, in a ternary (polymer-A)-(polymer-B)-solvent system, [GRAPHICS] In the absence of strong specific interaction forces between molecules that would encourage aggregation and at sufficiently low concentration, the above equation can be written thus: [GRAPHICS] This equation can be used to determine the miscibility of polymer blends, when: alpha greater-than-or-equal-to 0 miscible, alpha < 0 immiscible. It is found that the new criterion is reasonable and suitable to predict polymer-polymer miscibility by the viscometry method.

A hexagonal mesoporous aluminophosphate with high thermal stability (JLU-50) is successfully synthesized from the assembly of preformed aluminophosphate precursors with a cationic surfactant cetylt...

In this paper, a cheap porous acrylic ion-exchange resin was introduced as a carbon source and metal ion supporter for the fabrication of Sn–C composites, which were used as anode materials for lithium ion batteries. The porous structure of the ion-exchange resin could be well preserved in the Sn–C composite, and Sn ions could be easily reduced to Sn nanoparticles. The as-prepared Sn–C composite showed high specific capacity and stable cycle performance. However, the large surface area and exposed metal nanoparticles of the porous Sn–C composites resulted in a low initial coulomb efficiency and led to potential safety problems. To remove these disadvantages, a surface carbon encapsulation process was applied to the porous Sn–C composite through a chemical vapour deposition process. The covered Sn–C composite showed an enclosed porous structure and all previously exposed Sn nanoparticles were perfectly encapsulated by amorphous carbon. The covered Sn–C composite also showed greatly improved chemical stability and a high initial coulomb efficiency over 80%.

Highly sensitive near-infrared (NIR) phototransistors based on poly(3-hexylthiophene) (P3HT) and lead sulfide quantum dots (PbS QDs) were fabricated by a solution process. The phototransistors show high responsivity up to 2 × 104 A W−1 under NIR illumination with wavelength of 895 nm, which is much bigger than that of the photodetectors based on PbS QDs or organic semiconductors only. The sensing mechanism is attributed to the photo-induced electrons generated in the PbS QDs, which increase the threshold voltage of the transistor. These phototransistors may find promising applications as infrared sensors for their high responsivity, easy fabrication, low cost and flexibility.

An approach for the transverse oxidation of Au nanorods has been demonstrated by selectively capping the ends of the nanorods with Ag2O through a hydrothermal reaction. The tight Ag2O capping protects the ends of the nanorods and restricts oxidation to occurring only at the side surfaces. Such transverse oxidation leads to a gradual reduction in the effective diameter of the nanorods, an increase in the effective aspect ratio, and therefore a red shift in the longitudinal plasmon resonance. The red shift in the longitudinal plasmon resonance can reach up to 250 nm and be controlled by varying the oxidation time. In addition, the Ag2O capping and transverse oxidation process is also applicable for Au nanorods with different longitudinal plasmon resonance wavelengths. Furthermore, the transverse oxidation is nonuniform. It produces dimples on the side surfaces of the Au nanorods. Numerical electrodynamic calculations indicate that the oxidized nanorods exhibit stronger electric field intensity enhancements at the dimples for both the longitudinal and transverse plasmon resonances in comparison to the unoxidized nanorods. We believe that this transverse oxidation approach will be beneficial to the design and preparation of Au nanostructures for various biotechnological applications.

This paper shows the applicability of Design of Experiment (DOE) and statistical analysis for bond strength test for specialised concrete/normal concrete bi-layer specimens. Four factors and different levels for each factor are considered in the DOE based on fractional factorial design to decrease the number of tests significantly. The prediction equation is successfully tested for model adequacy checking, Analysis of Variance (ANOVA), analysis of main effects, and estimation of model parameters step by step and, finally, verified with maximum and minimum values.

Core-shell Au nanorod-AgAuS nanostructures were hydrothermally prepared from Au nanorods and metal thiobenzoates and then transformed into Au nanoparticle-decorated sulfide nanostructures.

The electrochromic (EC) property of WO(3) nanoparticles grown on vertically self-aligned ZnO nanorods (ZNRs) is reported. An electrochromic character display based on WO(3) nanoparticle-modified ZnO nanorod arrays on a flexible substrate has been fabricated and demonstrated. The ZNRs were first synthesized on ZnO-seed-coated In(2)O(3):Sn (ITO) glass (1 cm(2) cell) and polyethylene terephthalate (PET) (4 cm(2) cell) substrates by a low temperature hydrothermal method, and then amorphous WO(3) nanoparticles were grown directly on the surface of the ZNRs by the pulsed laser deposition (PLD) method. The ZNR-based EC device shows high transparence, good electrochromic stability and fast switching speed (4.2 and 4 s for coloration and bleaching, respectively, for a 1 cm(2) cell). The good performance of the ZNR electrode-based EC display can be attributed to the large surface area, high crystallinity and good electron transport properties of the ZNR arrays. Its high contrast, fast switching, good memory and flexible characteristics indicate it is a promising candidate for flexible electrochromic displays or electronic paper.

The solvothermal synthesis of CdTe nanocrystals in dimethylformamide using cadmium lactate and sodium hydrogen telluride as precursors and 1-thioglycerol as a stabilizer is described. The resultant nanocrystals can be dispersed in the mixture solution of ammonium hydroxide, water, ethanol, and tetraethyl orthosilicate without aggregation and therefore readily encapsulated in silica submicrospheres without ligand exchange through the Stober process. CdTe nanocrystals of up to three different emission colors are encapsulated in silica spheres at varying emission intensity ratios, allowing for both wavelength and intensity encoding. A two-step growth process is also employed for the preparation of core-shell silica spheres, with differently sized CdTe nanocrystals encapsulated separately in the core and shell regions. Solid core-mesostructured shell silica spheres are further prepared. The mesostructured shell functions as a matrix for both nanocrystals and organic fluorophores. Our preparation approach is highly versatile and efficient. It offers potentials for the creation of optically encoded silica submicrospheres for many optical and biotechnological applications.