In order to study the spread of an epidemic over a region as a function of time, we introduce an entropy ratio describing the uniformity of infections over various states and their districts, and an entropy concentration coefficient C=1-U. The latter is a multiplicative version of the Kullback-Leibler distance, with values between 0 and 1. For product measures and self-similar phenomena, it does not depend on the measurement level. Hence, is an alternative to Gini's concentration coefficient for measures with variation on different levels. Simple examples concern population density and gross domestic product. Application to time series patterns is indicated with a Markov chain. For the Covid-19 pandemic, entropy ratios indicate a homogeneous distribution of infections and the potential of local action when compared to measures for a whole region.
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http://dx.doi.org/10.3390/e22111315 | DOI Listing |
JDR Clin Trans Res
March 2025
Center of Excellence in Genomics and Precision Dentistry, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.
Introduction: Bisphenol A (BPA), known for its endocrine-disrupting properties, is a concern when leaching from dental sealants. This study investigates the systemic BPA exposure following the placement of Bis-GMA-based dental sealants in Thai primary school students.
Objectives: The main objective was to evaluate the changes in urinary BPA concentrations after the application of Bis-GMA dental sealants in a cohort of Thai students.
Foods
February 2025
National Reference Laboratory of Veterinary Drug Residues (HZAU) and MOA Key Laboratory for Detection of Veterinary Drug Residues, Huazhong Agricultural University, Wuhan 430070, China.
Pyrethroids are one of the most commonly used insecticides worldwide in agriculture, public health, and household products. To monitor the presence of pyrethroids in the environment and in food, a broad-spectrum monoclonal antibody (mAb), CL/CN-1D2, was prepared. This mAb demonstrates a 50% inhibitory concentration (IC50) for different pyrethroids: cypermethrin (129.
View Article and Find Full Text PDFMaterials (Basel)
March 2025
School of Chemical Engineering and Technology, Tianjin University, Tianjin 300350, China.
To enhance oil and gas recovery, a novel hydrophobic terpolymer was synthesized via free radical polymerization. The terpolymer consists of acrylamide, acrylic acid, and hydrophobic monomers, and is used as a hydraulic fracturing fluid thickener for freshwater environments. Hydrophobic groups were introduced into terpolymer to improve its tackiness and temperature resistance.
View Article and Find Full Text PDFMaterials (Basel)
March 2025
College of Materials Science and Engineering, Hohai University, Changzhou 213022, China.
S355 steels are widely used in various applications. However, they may be affected by hydrogen, which can induce hydrogen-induced cracking (HIC). The effects of the quenching temperature () on the microstructure variation and HIC susceptibility of S355 steel was investigated by microstructural characterization, hydrogen permeation (HP) test, slow strain rate tensile (SSRT) test, hydrogen microprint technique (HMT) test, and hydrogen-charged cracking test.
View Article and Find Full Text PDFMaterials (Basel)
March 2025
School of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318, China.
At present, the improvement of anti-wear performance of piston rings remains a challenge. In this article, Ni-SiC composite coatings fabricated at 3, 9, and 15 g/L SiC were denoted as NSc-3, NSc-9, and NSc-15 coatings. Meanwhile, the influence of SiC concentration on the surface morphology, phase structure, microhardness, and anti-wear performance of electrodeposited Ni-SiC composite coatings were investigated utilizing scanning electron microscopy, X-ray diffraction, a microhardness tester, and a friction-wear tester, respectively.
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