Optical investigations and photoactive solar energy applications of new synthesized Schiff base liquid crystal derivatives

New homologues series of liquid crystalline materials namely, (E)-3-methoxy-4-[(p-tolylimino)methyl]phenyl 4-alkloxybenzoates (I-n), were designed and evaluated for their mesomorphic and optical behavior. The prepared series constitutes three members that differ from each other by the terminally attached alkoxy chain group, these vary between 6 and 12 carbons. A laterally OCH3 group is incorporated into the central benzene ring in meta position with respect to the ester moiety. Mesomorphic characterizations of the prepared derivatives are conducted using differential scanning-calorimetry (DSC), polarized optical-microscopy (POM). Molecular structures were elucidated by elemental analyses and NMR spectroscopy. DSC and POM investigations revealed that all the synthesized derivatives are purely nematogenic exhibiting only nematic (N) mesophase, except for the longest chain derivative (I-12) that is dimorphic possesses smectic A and N phases. Moreover, all members of the group have a wide mesomorphic range with high thermal nematic stability. A comparative study was established between the present derivative (I-6) and their previously prepared isomer. The results indicated that the location exchange of the polar compact group (CH3) influences the N mesophase stability and range. The electrical measurements revealed that all synthesized series I-n show Ohmic behaviors with effective electric resistances in the GΩ range. Under white light illumination, the effective electric conductivity for the compound I-8 is five times that obtained in dark conditions. This derivative also showed two direct optical band gaps in the UV and visible light range. In addition, I-6 has band energy gaps of values 1.07 and 2.79 eV, which are suitable for solar energy applications.

Assessment of synovial fluid and serum cytokine levels in children with septic arthritis

Acute septic arthritis (ASA) is a common orthopedic infection of children which may produce devastating sequelae and chronic morbidity. Improved understanding of the intra-articular inflammatory response in ASA may identify cytokine targets with diagnostic or therapeutic potential, though no detailed investigations to this end have been performed. Given this, we used a multiplex cytokine assay for assessment of levels of 40 different cytokines in the synovial fluid and blood of children with ASA. Twelve children (8 controls undergoing orthopedic surgery for non-infectious conditions and 4 with ASA) were prospectively enrolled. Blood and synovial fluid were collected intraoperatively from each subject, and the levels of 40 cytokines were determined using a multiplex assay. Cytokines were organized by function and structure into 12 groups for analysis. The Benjamini-Hochberg method was used to control for type 1 errors, with an a priori false discovery rate of 10%. Subjects with ASA were younger than controls (mean age 8.0 vs 13.1 years, p=0.0400). Significant elevations were seen in interleukins (IL) with chemokine properties, IL-6 and those in the common-γ chain group in the blood and synovial fluid of children with ASA compared with controls, while significant elevations in 5 additional cytokine groups were seen in synovial fluid from children with ASA compared with controls, most notably IL-6 (median 8294.3 vs 10.7 pg/mL, p=0.0066). Our pilot study is the first to describe in detail the cytokine response in children with ASA, and highlights the need for additional study.

A Structural Investigation on Polystyrene with Cyclohexene Mid-Chain Group: Thermal Stability and Self-Assembly Kinetics in Nonpolar and Polar Aprotic Solutions

This study was focused on cyclohexene (CH) mid-chain functional polymer of polystyrene (PSt-CH-PSt) because of its potential application in nanotechnology and its possible usage in hierarchical structures. Molecular and nano scale structural characterizations and thermal behavior of the powder form PSt-CH-PSt functional polymer were carried out by FTIR, SAXS, XRD and DSC methods. Solutions of PSt-CH-PSt in tetrahydrofuran and chloroform were also investigated by SAXS and FTIR. The stable one type nano particles which have oblate core-shell shape were determined in powder form and in solution of PSt-CH-PSt. The self-assembly kinetics of the polymer indicate that the mid chain part location in oblate core shell aggregations may be controlled by polar aprotic THF and nonpolar CLF solvent effects. Exponential decreasing in oblate shell volumes of PSt-CH-PSt nano globules in THF as a function of temperature was also determined by SAXS.

Effect of the Organic Functional Group on the Grafting Ability of Trialkoxysilanes onto Graphene Oxide: A Combined NMR, XRD, and ESR Study

The functional properties displayed by graphene oxide (GO)-polymer nanocomposites are strongly affected by the dispersion ability of GO sheets in the polymeric matrix, which can be largely improved by functionalization with organosilanes. The grafting to GO of organosilanes with the general formula RSi(OCH3)3 is generally explained by the condensation reactions of silanols with GO reactive groups. In this study, the influence of the organic group on the RSi(OCH3)3 grafting ability was analyzed in depth, taking into account the interactions of the R end chain group with GO oxidized groups. Model systems composed of commercial graphene oxide reacted with 3-aminopropyltrimethoxysilane (APTMS), 3-mercaptopropyltrimethoxysilane (MPTMS), and 3-methacryloxypropyltrimethoxysilane, (MaPTMS), respectively, were characterized by natural abundance 13C, 15N and 29Si solid state nuclear magnetic resonance (NMR), x-ray diffraction (XRD), and electron spin resonance (ESR). The silane organic tail significantly impacts the grafting, both in terms of the degree of functionalization and direct interaction with GO reactive sites. Both the NMR and XRD proved that this is particularly relevant for APTMS and to a lower extent for MPTMS. Moreover, the epoxy functional groups on the GO sheets appeared to be the preferential anchoring sites for the silane condensation reaction. The characterization approach was applied to the GO samples prepared by the nitric acid etching of graphene and functionalized with the same organosilanes, which were used as a filler in acrylic coatings obtained by cataphoresis, making it possible to correlate the structural properties and the corrosion protection ability of the layers.

RETAIL STORE IMAGE: A STUDY OF THE MATAHARI DEPARTMENT STORE (AT BANDUNG INDONESIA)

Purpose: Retail industry currently in Indonesia is less profitable. However, there is still a retail stores chain group that Matahari endures and this is absolutely not autonomous purchasing by the customers. The objective of the study is to identify the qualities of stores and to assess their impacts on the consumer purchasing decision. This is most significant for sellers in today's unstable market and is worried about sellers' essential to take into account the effect of selling store image and its relation to purchaser reliability. Methodology: The used method in the research is casual research method. Data is analysing through descriptive analysis method and multiple linear regression. The data is processed through SPSS software. Main Findings: Based on interviews conducted by respondents, one of the store brands in Matahari's department store is the Executive, which is a store brand that sells clothes, and trousers with expensive price, so if the customer uses the brand product Executive, they will feel proud. Because the customer has a good view of the product of the Executive brand, and the Executive product is sold in Matahari department store, the customer's assessment of the department store of the Matahari becomes good. Implications/Applications: The results of the research can be used by Matahari department store in developing their marketing strategies in order to promote brand image.

Efficient uptake of perrhenate/pertechnenate from aqueous solutions by the bifunctional anion-exchange resin

In this work, batch experiments were carried out to explore the sorption properties for perrhenate (ReO4−, a surrogate for TcO4−) by two types of commercial bifunctional anion-exchange resins (Purolite A530E and A532E). It is found that these two bifunctional anion-exchange resins could rapidly remove ReO4− from aqueous solution within 150 min and the maximum sorption capacity for ReO4− reached as high as 707 and 446 mg/g for Purolite A530E and A532E, respectively. The sorption properties were independent of pH over a wide range from 1 to 13. More importantly, both Purolite A530E and A532E exhibited excellent selectivity for the removal of ReO4− in the presence of large excess of NO3− and SO42−. Finally, the removal percentage of ReO4− by these two resins could be >90% and 80%, respectively, from the Hanford low-level waste melter off-gas scrubber simulant stream. Such high selectivity of Purolite A530E and A532E for the removal of ReO4− might be due to the presence of the long-chain group of –[N(Hexyl)3]+, which favored hydrophobic and large anions such as ReO4−/TcO4− rather than NO3−.

Polypentagonal ice-like water networks emerge solely in an activity-improved variant of ice-binding protein

Polypentagonal water networks were recently observed in a protein capable of binding to ice crystals, or ice-binding protein (IBP). To examine such water networks and clarify their role in ice-binding, we determined X-ray crystal structures of a 65-residue defective isoform of a Zoarcidae-derived IBP (wild type, WT) and its five single mutants (A20L, A20G, A20T, A20V, and A20I). Polypentagonal water networks composed of ∼50 semiclathrate waters were observed solely on the strongest A20I mutant, which appeared to include a tetrahedral water cluster exhibiting a perfect position match to the (101¯0) first prism plane of a single ice crystal. Inclusion of another symmetrical water cluster in the polypentagonal network showed a perfect complementarity to the waters constructing the (202¯1) pyramidal ice plane. The order of ice-binding strength was A20L < A20G < WT < A20T < A20V < A20I, where the top three mutants capable of binding to the first prism and the pyramidal ice planes commonly contained a bifurcated γ-CH3 group. These results suggest that a fine-tuning of the surface of Zoarcidae-derived IBP assisted by a side-chain group regulates the holding property of its polypentagonal water network, the function of which is to freeze the host protein to specific ice planes.