Greyscale generation for optically driving liquid crystal display

It is very difficult to display greyscale for an optically driving liquid crystal display (ODLCD) because the driving unit and display unit are separate, and there are no electronics in the display part of ODLCD. In this paper, two greyscale generation methods are proposed to achieve this goal. Six and nine grey levels are separately achieved through the two methods.     

Identification and Functional Characterization of an α-Amylase with Broad Temperature and pH Stability from Paenibacillus sp.

Amylases are important industrial enzymes that have been applied widely in the food, detergent, and pulp industries and fermentation processes. In the present study, a gene encoding an alpha-amylase from the genomic DNA library of Paenibacillus sp. was identified and characterized. The amylase gene designated amy1 was shown to consist of 1,980 bp and shared sequence identity towards α-amylase genes from other Bacillus sp. The deduced amino acid sequence for Amy1 indicated 80 % sequence identity with other Bacillus strains. Heterologous expression of recombinant Amy1 in Escherichia coli BL21(DE3) facilitated the recovery of this protein in soluble form. Enzyme kinetic data revealed Amy1 to have a K _m of 23.83 mg/mL and K _cat of 48.74 min^?1 and K _cat /K _m of 2 min^?1 mg^?1 mL^?1 for starch. The activity of this protein was found to be enhanced by Mn²⁺, and furthermore, Amy1 remained active at a broad pH range (4–10) and temperature (30–90 °C). The ability of Amy1 to act on food waste under broad temperature and pH conditions, together with its ability to produce simple sugars, shows many advantages for further application in the food industry.     

One‐step synthesis of block copolymers using a hydroxyl‐functionalized trithiocarbonate RAFT agent as a dual initiator for RAFT polymerization and ROP

A range of well‐defined block copolymers were synthesized using 4‐cyano‐4‐(dodecylsulfanylthiocarbonyl)sulfanylpentanol (CDP) as a dual initiator for reversible addition‐fragmentation chain transfer (RAFT) polymerization and ring‐opening polymerization (ROP) in a one‐step process. Styrene, (meth)acrylate, and acrylamide monomers were polymerized in a controlled manner for one block composed of vinyl monomers, and δ‐valerolactone (VL), ε‐caprolactone (CL), trimethylene carbonate (TMC), and L ‐lactide (LA) were used for the other block composed of cyclic monomers. Diphenyl phosphate was used as a catalyst for the ROP of VL, CL, and TMC, and 4‐dimethyamino pyridine for the ROP of LA. These catalysts did not interfere with RAFT polymerization and the synthesis of various block copolymers proceeded in a controlled manner. CDP was found to be a very useful dual initiator for a one‐step synthesis of various block copolymers by a combination of RAFT polymerization and ROP. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Tailor‐Made Hole‐Conducting Coadsorbents for Highly Efficient Organic Dye‐Sensitized Solar Cells

The Y‐shaped, low molecular mass, hole‐conductor (HC), acidic coadsorbents 4‐{3,7‐bis[4‐(2‐ethylhexyloxy)phenyl]‐10H‐phenothiazin‐10‐yl}benzoic acid ( PTZ1 ) and 4‐{3,7‐bis[4‐(2‐ethylhexyloxy)phenyl]‐10H‐phenothiazin‐10‐yl}biphenyl‐4‐carboxylic acid ( PTZ2 ) were developed. Owing to their tuned and negative‐shifted HOMO levels (vs. NHE), they were used as HC coadsorbents in dye‐sensitized solar cells (DSSCs) to improve cell performance through desired cascade‐type hole‐transfer processes. Their detailed functions as HC coadsorbents in DSSCs were investigated to obtain evidence for the desired cascade‐type hole‐transfer processes. They have multiple functions, such as preventing π–π stacking of dye molecules, harvesting light of shorter wavelengths, and faster dye regeneration. By using PTZ2 as the tailor‐made HC coadsorbent on the TiO₂ surface with the organic dye NKX2677, an extremely high conversion efficiency of 8.95 % was achieved under 100 mW cm^?2 AM 1.5G simulated light (short‐circuit current J_SC=16.56 mA cm^?2, open‐circuit voltage V_OC=740 mV, and fill factor of 73 %). Moreover, J_SC was increased by 13 %, V_OC by 27 % and power‐conversion efficiency by 49 % in comparison to an NKX2677‐based DSSC without an HC coadsorbent. This is due to the HC coadsorbent having a HOMO energy level well matched to that of the NKX‐2677 dye to induce the desired cascade‐type hole‐transfer processes, which are associated with a slower charge recombination, fast dye regeneration, effective screening of liquid electrolytes, and an induced negative shift of the quasi‐Fermi level of the electrode. Thus, this new class of Y‐shaped, low molecular weight, organic, HC coadsorbents based on phenothiazine carboxylic acid derivatives hold promise for highly efficient organic DSSCs.     

Surface Modification of Carbon Nanotube by Poly(ethylene glycol) for the Preparation of Poly(vinyl alcohol) Nanocomposite

Herein, PEGylated multi-walled carbon nanotube (MWNT) was prepared for the successive fabrication of poly(vinyl alcohol) PVA/MWNT nanocomposite film by solution casting. The surface modified MWNT showed a good colloidal stability in a polar solvent, i.e., water. Also, the PEGylated MWNT had an improved dispersion stability in aqueous PVA solution. The mixture of PEGylated MWNT and PVA dissolved in water was film casted and the dispersion uniformity and corresponding improvement of electrical conductivity were investigated. The electrical conductivity of PVA/modified MWNT composite film was three-fold higher than that of PVA/pristine MWNT composite film due to the much improved distribution uniformity of modified MWNT in PVA matrix.     

Targeted resequencing of candidate genes reveals novel variants associated with severe Beh?et's uveitis

Behçet''s disease (BD) is a chronic systemic inflammatory disorder characterized by four major manifestations: recurrent uveitis, oral and genital ulcers and skin lesions. To identify some pathogenic variants associated with severe Behçet''s uveitis, we used targeted and massively parallel sequencing methods to explore the genetic diversity of target regions. A solution-based target enrichment kit was designed to capture whole-exonic regions of 132 candidate genes. Using a multiplexing strategy, 32 samples from patients with a severe type of Behçet''s uveitis were sequenced with a Genome Analyzer IIx. We compared the frequency of each variant with that of 59 normal Korean controls, and selected five rare and eight common single-nucleotide variants as the candidates for a replication study. The selected variants were genotyped in 61 cases and 320 controls and, as a result, two rare and seven common variants showed significant associations with severe Behçet''s uveitis (P<0.05). Some of these, including rs199955684 in KIR3DL3, rs1801133 in MTHFR, rs1051790 in MICA and rs1051456 in KIR2DL4, were predicted to be damaging by either the PolyPhen-2 or SIFT prediction program. Variants on FCGR3A (rs396991) and ICAM1 (rs5498) have been previously reported as susceptibility loci of this disease, and those on IFNAR1, MTFHR and MICA also replicated the previous reports at the gene level. The KIR3DL3 and KIR2DL4 genes are novel susceptibility genes that have not been reported in association with BD. In conclusion, this study showed that target enrichment and next-generation sequencing technologies can provide valuable information on the genetic predisposition for Behçet''s uveitis.     

Synthesis and Transistor Properties of Asymmetric Oligothiophenes: Relationship between Molecular Structure and Device Performance

A series of three thiophene–naphthalene‐based asymmetric oligomers—5‐decyl‐2,2′:5′,2′′:5′′,2′′′‐quaterthiophene (DtT), 5‐decyl‐5′′‐(naphthalen‐2‐yl)‐2,2′:5′,2′′‐terthiophene (D3TN), and 5‐(4‐decylphenyl)‐5′‐(naphthalen‐2‐yl)‐2,2′‐bithiophene (DP2TN)—was synthesized by Suzuki cross‐coupling reactions. The long alkyl side chains improved both the solubility of the oligomers in solvents and their tendency to self‐assemble. UV/Vis absorption measurements suggested that DtT, D3TN, and DP2TN form H‐type aggregates with a face‐to‐face packing structure. In addition, the three oligomers were found to adopt vertically aligned crystalline structures in films deposited on substrates, as revealed by grazing‐incidence wide‐angle X‐ray scattering. These oligomers were used as the active layers of p‐type organic field‐effect transistors, and the resulting devices showed field‐effect mobilities of 3.3×10^?3 cm² V^?1 s^?1 for DtT, 1.6×10^?2 cm² V^?1 s^?1 for D3TN, and 3.7×10^?2 cm² V^?1 s^?1 for DP2TN. The differences in transistor performances were attributed to the degree of π overlap and the morphological differences determined by the molecular structures.     

Insight into the Origin of the Positive Effects of Imidazolium Salt on Electrocatalytic Activity: Ionic Carbon Nanotubes as Metal‐Free Electrocatalysts for Oxygen Reduction Reaction

We report remarkable metal‐free electrocatalytic activities of the imidazolium salt‐functionalized ionic multi‐walled carbon nanotubes (IM‐f‐MWCNTs) in the oxygen reduction reaction (ORR). The electrocatalytic activity can be attributed to the induced polarization of the π‐electrons of CNTs, thus accelerating interfacial electron transfer. The zwitterionic MWCNTs functionalized with poly(vinylimidazolium sulfonate) have a more positive surface charge and exhibit a better electrocatalytic activity than the poly(vinylbutylimidazolium chloride)‐functionalized MWCNTs. The IM‐f‐MWCNTs showed better fuel selectivity than the commercial Pt/C electrocatalyst.     

Surface anchoring mode‐dependent hydrolysis reactions of hydrazone groups on gold examined by pH‐dependent Raman spectroscopy

We conducted a comparative study of the pH‐dependent anchoring behaviors of 3‐methyl‐2‐benzothiazolinone hydrazone (3M2BH) and benzophenone hydrazone (BPH) on gold nanoparticles (AuNPs) by means of interfacial Raman spectroscopy. We found that several bands of 3M2BH in the highly alkaline pH region disappeared as the colloidal conditions became more neutral and acidic. The vibrational band at 919, 1174, and 1222 cm⁻¹ at pH 10.0 disappeared below pH 9.2, which may be because of the hydrolysis reactions that cleave the labile N―NH₂ group of 3M2BH, indicating a rather perpendicular orientation via the sulfur atom at the surfaces. A fairly high transition pH value was assumed to be because of the interaction of the N―NH₂ group in the vicinity of the surfaces. Several characteristic bands, including 1584 and 1617 cm⁻¹, also exhibited different intensities, suggesting that the adsorbates on Au surfaces underwent structural transformations of the N―NH₂ group after the pH value became neutral or acidic. These changes were not observed for BPH, presumably because of the direct and robust binding of the hydrazone onto Au surfaces. Our results revealed that the pH‐dependent cleavage reactions may vary depending on the surface anchoring modes of the adsorbates. Copyright © 2015 John Wiley & Sons, Ltd.     

Hydrothermal synthesis of a nano-rod mercury(ii) metal-ligand coordination compound

A novel nano-rod mercury(II) coordination compound [Hg (BINH)I₂] (1), (BINH is the abbreviation of benzylideneisonicotinohydrazide) is synthesized by a hydrothermal method that produces the coordination compound at a nanosize level. The new nanostructure is characterized by scanning electron microscopy, powder X-ray diffraction, elemental analysis, and IR spectroscopy. Compound 1 was structurally characterized by single crystal X-ray diffraction and the single-crystal structure of this complex shows that each mercury(II) center is four-coordinated with two N-donor atoms from tow BINH ligands and tow iodo anions. Self-assembly of this complexes is pereformed by CH?I and π-π stacking interactions. The supramolecular features in these complexes are controlled by weak directional intermolecular interactions.