Fluorescence modulation of an aggregation-induced emission active ligand via rigidification in a coordination polymer and its application in singlet oxygen sensing

A new Zn(II)-based coordination polymer (CP) having the formula [Zn(L)(2,2'-bpy)] (1) was synthesized using ZnCl2, 3,3'-(anthracene-9,10-diyl)diacrylic acid ligand (H2L), and 2,2'-bipyridine (2,2'-bpy) in DMF under solvothermal conditions. Here, the anthracene-based dicarboxylic acid ligand shows aggregation-induced emission (AIE) activity in an ethanol/hexane medium. Single-crystal X-diffraction analysis reveals that the one-dimensional (1D) zigzag chainlike structure of 1 is assembled from tetrahedrally coordinated Zn2+ ions interconnected by 2,2'-bpy and ditopic anthracene-based ligand molecules. The crystal structure analysis reveals that the ditopic anthracene-based flexible ligand adopts a twisted conformation in the CP crystal compared to its free state. Because of the twisted conformation of the ATE active ligand in the CP crystal, a large (similar to 80 nm) hypsochromic shift was observed in the emission spectrum with a drastic color change compared to the free state of ligand. The origin of these rare fluorescence properties is ascribed to the twisted diacrylic acid ligand conformation and rigidity in the CP crystal. An unprecedented response was observed toward singlet oxygen (O-1(2)) by 1 via a fluorescence turn-off mechanism. The presence of the anthracene moiety is the main influential factor for O-1(2) sensing, which undergoes [4 + 2] cycloaddition reaction with O-1(2), producing a nonemissive 9,10-endoperoxide product. The unique photoluminescence properties along with tunable fluorescence responses indicate that incorporating an AIE active anthracene core into the CP crystal is a beneficial strategy to develop new fluorescent materials with significant sensing ability

A binary particle swarm optimization approach for power system security enhancement

Improvement of power system security manages the errand of making healing move against conceivable system overloads in the framework following the events of contingencies. Generation re-dispatching is answer for the evacuation of line overloads. The issue is the minimization of different goals viz. minimization of fuel cost, minimization of line loadings and minimization of overall severity index. Binary particle swarm optimization (BPSO) method was utilized to take care of optimal power flow issue with different targets under system contingencies. The inspiration to introduce BPSO gets from the way that, in rivalry with other meta-heuristics, BPSO has demonstrated to be a champ by and large, putting a technique as a genuine alternative when one needs to take care of a complex optimization problem. The positioning is assessed utilizing fuzzy logic. Simulation Results on IEEE-14 and IEEE-30 bus systems are presented with different objectives

Case report: Pregnancy After Vitrification of Biopsied Human Blastocysts Previously Frozen by the Slow Method

Pre-implantation genetic screening (PGS) with trophectoderm biopsy is an extremely powerful technique for the determination of embryos with a high implantation potential. Patients with cryopreserved embryos seeking PGS have had limited access to this treatment due to the need to thaw, biopsy, and refreeze these embryos. This is especially true for patients with embryos cryopreserved by the slow freeze technique due to the low survival rate after thawing. In this case report, we describe the application of refreezing with the vitrification technique to embryos thawed with the slow technique and biopsied for PGS. The patient had a total of 8 blastocysts thawed, biopsied, and refrozen with vitrification. Next Generation Sequencing (NGS) of these embryos revealed that 4 blastocysts were euploid. The patients achieved a pregnancy on the the first frozen embryo transfer procedure that terminated after 11 days. The second frozen embryo transfer procedure resulted in the live birth of a 3800g boy, demonstrating that thaw, biopsy, and refreeze are applicable to human reproduction even in cases where embryos have been cryopreserved by the slow techniqu

Corona and Electric Field Distribution Analysis in 400 kV Line Insulators

The performance of insulator strings in transmission lines can be improved by corona rings owing to their electric field grading property. The insulation performance of the string depends on the corona ring parameter settings. In this study, the design of a corona ring for a 400 kV non-ceramic overhead line insulator is presented. Two parameters were altered during the investigation, ring measurement (R) and ring tube breadth (r) while maintaining a constant ring height (h). Based on electric field distribution, the proposed composite insulators were compared with glass insulators. Simulation studies were performed for the insulator strings, including corona rings with different design parameters. The corona discharge and optimal configuration results were analyzed, and it was found that the electric field was lower with composite insulators

Effects of Y incorporation in TaON gate dielectric on electrical performance of GaAs metal-oxide-semiconductor capacitor

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