Two Optimal Value Functions in Parametric Conic Linear Programming

Journal of Optimization Theory and Applications - We consider the conic linear program given by a closed convex cone in an Euclidean space and a matrix, where vector on the right-hand side of the...     

Carbohydrate-based nanostructured catalysts: applications in organic transformations

The requirement of green and sustainable materials to prepare heterogeneous catalysts has intensified for practical reasons over the past few decades. Carbohydrates are possibly the most plentiful and renewable organic materials in nature with inimitable physiochemical properties, plausible low-cost and large-scale production, and sustainability features could be exploited in the generation of nanostructured heterogeneous catalysts. This review article outlines the organic transformations catalyzed by diverse carbohydrate-based nanostructured catalysts in greener and environmentally friendly processes. Selected examples are highlighted for a variety of organic reactions exploiting the proposed catalysts’ reactivity and reusability, and interactions with the intrinsic nature of the applied carbohydrate supports; advantages and speculated challenges of the introduced catalysts are deliberated as well.     

Scalar curvature,mean curvature and harmonic maps to the circle

Annals of Global Analysis and Geometry - We study harmonic maps from a 3-manifold with boundary to $$\mathbb {S}^1$$ and prove a special case of Gromov dihedral rigidity of three-dimensional cubes...     

Momentum-Kick Model Application to High-Multiplicity pp Collisions at s = 13 $\sqrt {s}=13$ TeV at the LHC

International Journal of Theoretical Physics - In this study, the momentum-kick model is used to understand the ridge behaviour in dihadron Δη–Δφ correlations recently...     

A New Reversible Colorimetric Chemosensor Based on Julolidine Moiety for Detecting F−

Journal of Fluorescence - We synthesized an original reversible colorimetric chemosensor PDJ...     

Supramolecular Tuning Enables Selective Oxygen Reduction Catalyzed by Cobalt Porphyrins for Direct Electrosynthesis of Hydrogen Peroxide

We report a supramolecular strategy for promoting the selective reduction of O₂ for direct electrosynthesis of H₂O₂. We utilized cobalt tetraphenylporphyrin (Co-TPP), an oxygen reduction reaction (ORR) catalyst with highly variable product selectivity, as a building block to assemble the permanently porous supramolecular cage Co-PB-1(6) bearing six Co-TPP subunits connected through twenty-four imine bonds. Reduction of these imine linkers to amines yields the more flexible cage Co-rPB-1(6). Both Co-PB-1(6) and Co-rPB-1(6) cages produce 90–100 % H₂O₂ from electrochemical ORR catalysis in neutral pH water, whereas the Co-TPP monomer gives a 50 % mixture of H₂O₂ and H₂O. Bimolecular pathways have been implicated in facilitating H₂O formation, therefore, we attribute this high H₂O₂ selectivity to site isolation of the discrete molecular units in each supramolecule. The ability to control reaction selectivity in supramolecular structures beyond traditional host–guest interactions offers new opportunities for designing such architectures for a broader range of catalytic applications.     

Solid‐phase microextraction Arrow for the volatile organic compounds in soy sauce

A novel solid‐phase microextraction Arrow was used to separate volatile organic compounds from soy sauce, and the results were verified by using gas chromatography with mass spectrometry. Solid‐phase microextraction Arrow was optimized in terms of three extraction conditions: type of fiber used (polydimethylsiloxane, polyacrylate, carbon wide range/polydimethylsiloxane, and divinylbenzene/polydimethylsiloxane), extraction temperature (40, 50, and 60°C), and extraction time (10, 30, and 60 min). The optimal solid‐phase microextraction Arrow conditions were as follows: type of fiber = polyacrylate, extraction time = 60 min, and extraction temperature = 50°C. Under the optimized conditions, the solid‐phase microextraction Arrow was compared with conventional solid‐phase microextraction to determine extraction yields. The solid‐phase microextraction Arrow yielded 6–42‐fold higher levels than in solid‐phase microextraction for all 21 volatile organic compounds detected in soy sauce due to the larger sorption phase volume. The findings of this study can provide practical guidelines for solid‐phase microextraction Arrow applications in food matrixes by providing analytical methods for volatile organic compounds.     

Reversible Shape‐Morphing and Fluorescence‐Switching in Supramolecular Nanomaterials Consisting of Amphiphilic Cyanostilbene and Cucurbit[7]uril

We demonstrate a reversible shape‐morphing with concurrent fluorescence switching in the nanomaterials which are complexed with cucurbit[7]uril (CB[7]) in water. The cyanostilbene derivative alone forms ribbon‐like two‐dimensional (2D) nanocrystals with bright yellow excimeric emission in water (λ_em=540 nm, Φ_F=42 %). Upon CB[7] addition, however, the ribbon‐like 2D nanocrystals immediately transform to spherical nanoparticles with significant fluorescence quenching and blue‐shifting (λ_em=490 nm, Φ_F=1 %) through the supramolecular complexation of the cyanostilbene and CB[7]. Based on this reversible fluorescence switching and shape morphing, we could demonstrate a novel strategy of turn‐on fluorescence sensing of spermine and also monitoring of lysine decarboxylase activity.     

Indium(III)chloride catalyzed synthesis of novel 1H-pyrazolo[1,2-b]phthalazine-5,10-diones and 1H-pyrazolo[1,2-a]pyridazine-5,8-diones under solvent-free condition

An efficient, inexpensive and environmentally friendly synthesis of novel 3-amino-2-benzoyl-1-aryl-1H-pyrazolo[1,2-b]phthalazine-5,10-dione and 3-amino-2-benzoyl-1-aryl-1H-pyrazolo[1,2-a]pyridazine-5,8-dione derivatives has been developed via one-pot three-component reaction of phthalhydrazide or maleic hydrazide, aldehydes and arylacetonitrile in the presence of catalytic amount of InCl₃ as a Lewis acid catalyst under solvent-free conditions. The most important features of the present protocol are mild reaction conditions, short reaction times, high yields, and a wide range of functional group tolerance.