Metal‐ and solvent‐free,clickable synthesis and postpolymerization functionalization of poly(triazole)s

In this study, a series of linear poly(triazole)s (PTAs) were successfully synthesized by the metal‐ and solvent‐free, thermal click polymerization of diazide and dialkyne (A₂ + B₂) monomers. All click polymerizations proceeded smoothly at 80 °C in an open atmosphere without protection from oxygen and moisture. After being polymerized for 36 h, the crude polymer was further fractionated into three fractions using a multistep precipitation method. By selectively choosing precipitating agents, this process produced poly(triazole) fractions with low polydispersity index (<1.30). The resulting PTAs are soluble in common organic solvents and stable at a temperature up to 320 °C. Furthermore, the methyl benzoate moieties in the main chain can serve as useful building blocks for further postpolymerization functionalization, yielding 1,2,4‐triazole derivatives. This functionalization strategy offers potential for the development of novel triazole‐based materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

A facile method to synthesize high‐molecular‐weight biobased polyesters from 2,5‐furandicarboxylic acid and long‐chain diols

In this study, biobased furan dicarboxylate polyesters have been prepared using 2,5‐furandicarboxylic acid (FDCA) and diols with high number of methylene groups (long‐chain diols), namely, 8, 9, 10, and 12. Because of the high boiling points of these diols, a modified procedure of the well‐known melt polycondensation was applied in this work. According to this, the dimethyl ester of FDCA (DMFD) reacted in the first transesterification stage with the corresponding diols forming bis‐hydroxy‐alkylene furan dicarboxylates (BHFD). In the second stage, the BHFD reacted with DMFD again at temperatures of 150–170 °C (for 4–5 h), and in the final stage, the temperature was raised to 210–230 °C (vacuum was applied for 2–3 h). The molecular weight of the polyesters and the content of oligomers, as was verified by gel permeation chromatography analysis, depend on the polycondensation time and temperature. The chemical structure of the polyesters was verified from ¹H NMR spectroscopy. All the polymers were found to be semicrystalline, with melting temperatures from 69 to 140 °C depending on the diol used. In addition, the mechanical properties also varied with the type of diol. The higher values were observed for poly(octylene 2,5‐furanoate), whereas the lowest values were observed for poly(dodecylene 2,5‐furanoate) with the higher number of methylene groups in its repeating unit. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2617–2632     

The effect of electron irradiation on the optical properties of the natural armenian zeolite-clinoptilolite

Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were carried out in the 400–5400 cm⁻¹ range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally treated ones. A decrease in the intensity of IR absorption bands at 3550 cm⁻¹ and 3650 cm⁻¹ was found after irradiation.     

Polyfluorene derivatives pending iridium complexes: Improved optoelectronic properties by introducing D‐A units and altering pendent mode

To study influence of the donor(D)‐acceptor(A) units and pendent mode of phosphorescent moiety on the opto‐electronic properties for its resulting copolymers, two D‐A‐based polyfluorene derivatives ( P 1 and P 2) pending the red‐emitting iridium bi(phenylisoquilonato) (picolinato) [Ir(Piq)₂(pic)] unit and a polyfluorene derivative ( P 3) only pending Ir(Piq)₂(pic) unit were synthesized and characterized, in which the donor of carbazole, the acceptor of oxadiazole are grafted into the C‐9 position of fluorene, the Ir(Piq)₂(pic) unit is pended into either the C‐9 position for P 1 and P 3 or the end for P 2 of fluorene by unconjugated linkage, respectively. Their opto‐electronic properties were significantly influenced by the D‐A units and pendent mode of the Ir(Piq)₂(pic) unit. In the polymer light‐emitting devices with a configuration of ITO/PEDOT/polymers/LiF/Al, the P 1 showed best electroluminescent properties than the P 2 and P 3. The maximum current efficiency of 0.72 cd/A and the highest luminance of 1398 cd/m 2 were obtained in the P 1‐based device, which are 1.3 and 1.5 times higher than those in the P 2‐based device, respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Analytical solutions of N‐person games

The possibility of analytical solutions of N‐person games is presented. A simple formula provides valuable information about the outcomes of such games with linear payoff functions and Pavlovian agents. Experiments performed with our simulation tool for the multiagent stag hunt dilemma game are presented. For the case of Pavlovian agents the game has nontrivial but remarkably regular solutions. If both payoff functions are linear and the real solutions of Eq. (2) are both positive, then the analytical solutions are remarkably accurate. © 2012 Wiley Periodicals, Inc. Complexity, 2012     

Is CLIA 2003 the quality alliance envisioned between manufacturers,laboratory professionals,and regulatory agencies?

The Clinical Laboratory Improvement Amendments of 1988 (CLIA88) had a groundbreaking effect on laboratory professionals, instrument and reagent manufacturers, and regulators in the United States, and by association, worldwide. CLIA88 defined new levels of responsibility for all three of these stakeholders in modern laboratory testing. As a result, we envisioned a CLIA-driven approach to regulations, which in effect, created a three-member quality alliance. In 2003, the long awaited CLIA updates to the quality control and quality assurance requirements were published. The revisions in CLIA 2003 will herald an era in which manufactures take responsibility for meeting new standards of quality (improved accuracy and precision or reduced total allowable error) in the clinical laboratory and, especially, at point of care where testing is performed by non-laboratorians. The European (Bureau International des Poids ed Mesures) efforts at traceability, the National Committee of Clinical Laboratory Standards efforts at estimating total allowable error, and the new CLIA 2003 quality systems approach for quality requirements return to the fundamental concepts of accuracy to assess the efficacy of clinical laboratory testing.Presented at the 8th Conference on Quality in the Spotlight, 17–18 March 2003, Antwerp, Belgium     

Surface morphology and in vitro release performance of double-walled PLLA/PLGA microspheres entrapping a highly water-soluble drug

Double-walled microspheres trapping gentamicin sulphate were prepared from poly(l-lactic acid) (PLLA) and poly(l-lactic-co-glycolic acid) (PLGA) as a delivery system for highly hydrophilic antibiotics. The surface and cross-section morphology of the microspheres were characterized by SEM and FTIR. The diameters of the microspheres were ranging from about 50 μm to 700 μm. A low initial burst was achieved. The encapsulation efficiency was more than 70% and the cumulative drug release was about 40% for 30 days. The results indicated that the double-walled microspheres were able to achieve higher encapsulation efficiency and lower initial burst for highly water-soluble drugs.     

Counting SL2（F2^s） Representations of Torus Knot Groups

In this paper,we count the number of SL2(F2^s)-representations of torus knot groups up to a conjugacy.For the finite field F2^s with character 2,the counting method is similar to that in out previous work[1].Explicit formulae of the effective counting are given in this paper.Twisted Alexander polynomials related to those reprsentations are discussed.     

Effect of energy addition on MR $\rightarrow$ RR transition

A combined computational and experimental study was performed to investigate the effect of a single laser energy pulse on the transition from a Mach Reflection (MR) to a Regular Reflection (RR) in the Dual Solution Domain (DSD). The freestream Mach number is 3.45 and two oblique shock waves are formed by two symmetric 2003_Article_198_TeX2GIFEqu2.gif" alt="$22^\circ$" align="middle" border="0"> wedges. These conditions correspond to a point midway within the DSD wherein either an MR or an RR is possible. A steady MR was first obtained experimentally and numerically, then a single laser pulse was deposited above the horizontal center plane. In the experiment, the laser beam was focused resulting in a deposition volume of approximately 3 mm³, while in the simulation, the laser pulse was modeled as an initial variation of the temperature and pressure using Gaussian profile. A grid refinement study was conducted to assess the accuracy of the numerical simulations. For the steady MR, the simulation showed the variation of Mach stem height along the span due to side effects. The predicted spanwise averaged Mach stem height was 1.96 mm within 2% of the experimental value of 2 mm. The experiment showed that the Mach stem height decreased to 30% of its original height due to the interaction with the thermal spot generated by the laser pulse and then returned to its original height by 2003_Article_198_TeX2GIFEqu3.gif" alt="$300\;\mu$" align="middle" border="0"> s. That the Mach stem returned to its original height was most likely due to freestream turbulence in the wind tunnel. The numerical simulation successfully predicted the reverse transition from a stable MR to a stable RR and the stable RR persisted across the span. This study showed the capability of a laser energy pulse to control the reverse transition of MR 2003_Article_198_TeX2GIFEqu4.gif" alt="$\rightarrow$" align="middle" border="0"> RR within the Dual Solution Domain.