Ultrafast and Irreversibly Thermochromic SiO2 -PC/PEG Double Layer for Green Thermal Printing.

Traditional thermochromic photonic crystal (PC) usually has a slow and reversible thermal response, which limits its application in thermal printing. Here, the authors develop a thermochromic "SiO2 -PC/PEG" double layer structure with a responding time of milliseconds for fast thermal printing. Controlled by the print-head, the polyethylene glycol (PEG) melts, infiltrates, and solidifies within the interparticle voids, which instantly and irreversibly changes the refractive index and produces the PC pattern. Multicolor printing can be realized by tuning the size and type of colloidal particles. Resolution as high as 300 DPI is achieved to print the high-resolution patterns and then the grayscale patterns based on the control of pixel densities. Different from fiber thermal paper, the "SiO2 -PC/PEG" film has no toxic bisphenol A and possesses superior light stability for keeping the images longer. It is fully compatible with the commercial printer, which provides a mature solution for fast and convenient preparation of PC patterns.

Metal-Organic Framework-Coated Photonic Crystals for High-Performance Thin-Layer Chromatography.

Traditional SiO2 gel-based thin-layer chromatography (TLC) is unable to separate substances with close structures, and its detection requires dyeing when the sample has neither fluorescence nor ultraviolet (UV) absorption signals. Here, high-performance TLC was developed based on metal-organic framework-coated photonic crystal (MOF/PC) films. Using the MIL-100/PC as the TLC plate, the cresol isomers can now be separated in a 2 cm development distance due to the enhanced adsorption-desorption and the good selectivity from the micropores. Meanwhile, the cresol changes the refractive index of MOF/PC, which produces color changes for sample recognition. Compared to the traditional TLC, the MOF/PC TLC shows much higher selectivity toward the analytes, which fully compensates its limited plate numbers and ensures a high-resolution separation. It also provides a convenient solution for chemical analysis as the detection based on structural color change does not require UV irradiation or dyeing treatment.

Dityrosine administration induces dysfunction of insulin secretion accompanied by diminished thyroid hormones T3 function in pancreas of mice.

Oxidized tyrosine products are commonly found in food with high protein content and have been demonstrated to cause damage of liver and kidney in our previous studies. Dityrosine (Dityr) is a typical oxidized tyrosine product. Due to its structural homology with thyroid hormones T3, we assumed that one of the endocrine systems most likely considered in connection with its disruption by Dityr may be the T3 action. T3 plays important roles in insulin synthesis, and thyroid hormone resistance (RTH) is associated with the impairment of glucose metabolism. Therefore, this study determined whether Dityr exposure impaired T3 function in pancreas leading to glucose metabolism disruption. After 10-week gavage with Dityr, mice exhibited impaired glucose tolerance and disturbed energy metabolism. The elevated free THs content in plasma, the up-regulation of THs synthesis-specific genes expressions in thyroid glands, and the increased thyroid follicles histology shapes and areas indicated that Dityr enhanced the THs synthesis in thyroid glands. In addition, Dityr-induced RTH, which reflected as elevated plasma free THs in the presence of unsuppressed thyroid stimulating hormone. The mRNA downregulation of membrane transporter of T3 (MCT8) and co-activator factors (RXRα, Src-1), together with the decreased protein level of thyroid hormone receptor ß1 (TRß1) in pancreas illustrated that the activation ability of T3 to downstream gene involved in insulin synthesis was suppressed by Dityr. In MIN-6 cell experiment, T3 improved glucose-stimulated insulin secretion by upregulating mRNA levels of insulin synthesis-related genes (Ins2, MafA, Pdx1) and T3 action-related genes, as well as increasing protein level of TRß1. These data suggest that Dityr suppress T3-regulated insulin synthesis stimulated by glucose via an indirect way of decreasing sensibility to T3 in pancreas. All these findings indicate that Dityr can disrupt THs function in pancreas leading to glucose metabolism disorder.

Dietary oxidized tyrosine (O-Tyr) stimulates TGF-ß1-induced extracellular matrix production via the JNK/p38 signaling pathway in rat kidneys.

Oxidized tyrosine (O-Tyr) products have been detected in commercial food and have been demonstrated to induce liver injury in our previous study, but the precise mechanisms of the impact induced by dietary O-Tyr are still unclear. Kidney plays an important role in the metabolism of protein. Accumulation of O-Tyr products, especially the dityrosine (Dityr) and advanced oxidation protein products (AOPPs), in vivo was shown to be associated with many kidney diseases. Therefore, this study determined whether chronic exposure to dietary O-Tyr impaired renal function in rats. After O-Tyr treatment for 24 weeks, rats exhibited oxidative stress and protein oxidation in the kidneys, accompanied with inflammatory reaction and renal dysfunction. Elevated extracellular matrix (ECM) contents and the histological examination (HE and Masson stain) results indicated renal fibrosis. The Real-time PCR and Western blotting assay showed that O-Tyr activated phosphorylation of JNK/p38 and up-regulated the expression of transforming growth factor-ß1 (TGF-ß1) and Smad 2/3. These results suggest that dietary O-Tyr could induce oxidative stress, inflammation and renal fibrosis through JNK/p38/TGF-ß1 signaling pathway. Dityr (accounting for 22 % of the total O-Tyr material) may be responsible for the O-Tyr-induced injury. This study also provides a modified procedure for separation and purification of Dityr, the main oxidized product in O-Tyr.

Dityrosine administration induces novel object recognition deficits in young adulthood mice.

Dietary modifications have been shown to contribute to the physical and mental diseases. Oxidative modifications of protein can be easily found in protein-rich food such as meat and milk products. Previous studies mainly focus on the consequences of lipid oxidation products intake in vivo, but the effects of protein oxidation products consumption have been largely neglected. Oxidants have been shown to play an important role in aging and neurodegenerative diseases. Dityrosine is the oxidated product of tyrosine residues in protein which is considered as a biomarker for oxidative stress, but the potential deleterious effects of dityrosine are unknown. In the present study, we explored the effects of dityrosine administration on the behavioral aspect. We found that dityrosine-ingested mice displayed impaired memory during novel object recognition test, but no influence to the spatial memory in Morris water maze compared with the saline group. Other aspects of neurobehavioral function such as locomotor activity, anxiety and social behavior were not affected by dityrosine ingestion. Furthermore, we found that dityrosine-ingested mice showed decreased expression level of NMDA receptor subunits Nr1, Nr2a, Nr2b as well as Bdnf, Trkb. Our study suggests that dityrosine exposure impairs hippocampus-dependent nonspatial memory accompanied by modulation of NMDA receptor subunits and Bdnf expression.