Tuning the Dynamic Fragility of Acrylic Polymers by Small Molecules: The Interplay of Hydrogen Bonding Strength

High-<i>T</i>_g polymers exhibit high fragilities in general. Here, we report for the first time that small molecules with double phenolic end groups are effective to independently mediate the dynamic fragility (<i>m</i>) and glass transition temperature (<i>T</i>_g) of acrylic polymers. Broad band dielectric spectrometer (BDS), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimeter (DSC) measurements showed that the addition of small molecules with a concentration lower than 30 wt % leads to a narrower relaxation time distribution of the intermolecular cooperative rearrangement motion because of the formation of hydrogen bonding networks. These acrylic polymers exhibited a significant decrease in <i>m</i> while showing a linear increase in <i>T</i>_g by changing the loading of the small molecules. Further experimental results demonstrated that <i>m</i> decreases monotonically with intermolecular hydrogen bonding strength for a given host polymer matrix. The <i>m</i>/<i>T</i>_g value diminishes with increasing small molecule content, whereas the value remains slightly changed by the copolymerization of different amounts of styrene on the acrylate chains. These results demonstrate that the compelling opposite change in <i>m</i> and <i>T</i>_g in the small molecule-loaded system is dominated by enthalpic intermolecular interactions. A distinct reduction of <i>m</i> in relation with small molecules was observed in poly­(butyl methacrylate), where a methyl group attached to the same C atom of the hydrogen bonding ester group. The impact difference of size, number, and steric hindrance of phenolic groups in small molecules, as well as the chemical structure of polymers, on the mixture’s fragility and <i>T</i>_g was discussed based on the generalized entropy theory of glass formation

Expression profile of <i>FASN</i> gene and association of its polymorphisms with intramuscular fat content in Hu sheep

The content of intramuscular fat (IMF) is one of the most important factors that has a large impact on meat quality, and it is an effective way to improve IMF according to marker-assisted selection (MAS). Fatty-acid synthase (FASN) is a key gene in meat lipid deposition and fatty acid composition. Thus, this study was conducted to investigate the expression profile of FASN in mRNA and protein levels using real-time quantitative PCR (RT-qPCR) and western-blot methods. In addition, single nucleotide polymorphisms (SNPs) within FASN in 921 Hu rams with IMF content records were investigated using DNA-pooling sequencing and improved multiple ligase detection reaction (iMLDR) methods. Consequently, the highest mRNA expression level of FASN was observed in the perinephric fat, and the lowest in the liver among the 11 tissues analyzed, while no significant difference was found in mRNA and protein expression levels in longissimus dorsi among individuals with different IMF contents. A total of 10 putative SNPs were identified within FASN, and 9 of them can be genotyped by iMLDR method. Notably, two SNPs were significantly associated with IMF content, including NC_040262.1: g.5157 A > G in intron 5 (p = 0.046) and NC_040262.1: g.9413 T > C in intron 16 (p = 0.041), which supply molecular markers for improving meat quality in sheep breeding.</p

MOESM3 of Serum IFN-Îł levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis

Additional file 3: Figure S1. IFN-Îł increases IDO expression of MSC in vitro

MOESM1 of Serum IFN-Îł levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis

Additional file 1: Table S1. Clinical and demographic characteristics of the patients enrolled in the study

MOESM2 of Serum IFN-Îł levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis

Additional file 2. Source and preparation of MSCs

Supplementary document for High-speed 4 × 4 silicon photonic electro-optic switch, operating at the 2 μm waveband - 6608040.pdf

Supplemental documen