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Advancing Column Generation by a Novel Variable Fixing Method In the paper titled “DeLuxing: Deep Lagrangian Underestimate Fixing for Column-Generation-Based Exact Methods,” Dr. Yu Yang introduces DeLuxing—an innovative variable-fixing technique that significantly advances column-generation-based exact methods for solving large-scale optimization problems, particularly vehicle routing problems (VRPs). DeLuxing leverages a novel linear programming formulation with a small subset of the enumerated variables, which is theoretically guaranteed to yield qualified dual solutions for computing Lagrangian underestimates. By eliminating over 75% of the unnecessary variables, DeLuxing drastically boosts computational efficiency, doubling the size of CMTVRPTW (capacitated multitrip vehicle routing problem with time windows) instances that can be solved optimally. Additionally, this breakthrough accelerates top VRP solvers like RouteOpt by up to 71%. The core concept underpinning DeLuxing extends to broader contexts such as variable type relaxation and cutting plane addition, achieving an additional 25% speedup for difficult instances. 

Mounting concerns regarding per‐/poly‐fluoroalkyl substances (PFAS) on human health are focusing attention on trace‐level PFAS detection in aqueous environments. Here, we report a readily prepared small molecule, 2,6‐bis(3,5‐diethyl‐1H‐pyrrol‐2‐yl)pyridine (receptor 1), that displays high binding affinities (logKa< = 4.9–6.2) and produces a strong “turn‐on” emission response when exposed to representative PFAS in hexanes. The hydrophobic nature of 1 , and its strong affinity for various PFAS, allowed hexanes solutions of 1 to be used as “turn‐on” emission sensors for dilute aqueous solutions of long‐chain (≥C8) PFAS under acidic conditions (pH 2) by liquid‐phase extraction (LPE). In the case of perfluorooctanoic acid (PFOA), the response was rapid (under 10 min) and sensitive. Limits of detection (LOD) as low as 250 ppt were readily achievable by direct naked‐eye observation. LOD as low as 40 and 100 ppt, respectively, could be reached for deionized and tap water solutions of PFOA using a smartphone color‐scanning application. Little change in the sensitivity was seen in the presence of a range of inorganic and organic species that could act as potential interferants. Support for the present findings came from UV–vis absorbance, fluorescence, 1