ABSTRACT
Epigenetic modification pertains to the alteration of genetic-expression, which could be transferred to the next generations, without any alteration in the fundamental DNA sequence. Epigenetic modification could include various processes such as DNA methylation, histone alteration, non-coding RNAs (ncRNAs), and chromatin adjustment are among its primary operations. Osteoporosis is a metabolic disorder that bones become more fragile due to the decrease in mineral density, which could result in a higher risk of fracturing. Recently, as the investigation of the causal pathology of osteoporosis has been progressed, remarkable improvement has been made in epigenetic research. Recent literatures have illustrated that epigenetics is estimated to be one of the most contributing factors to the emergence and progression of osteoporosis. This dissertation primarily focuses on indicating the research progresses of epigenetic mechanisms and also the regulation of bone metabolism and the pathogenesis of osteoporosis in light of the significance of epigenetic mechanisms. In addition, it aims to provide new intelligence for the treatment of diseases related to bone metabolism.
ABSTRACT
Liquid crystal (LC) based geometric phase optical elements are widely used to effectively change the wavefront or propagation direction of light. Using photoalignment, the liquid crystal can be aligned according to the designed pattern, leading to components such as gratings, lenses or general wavefront shaping devices. The functionality and efficiency of the component is strongly influenced by how well the LC follows the imposed alignment pattern. Next to a considerable tilting of the LC at the air interface, we report on the observation of symmetry breaking in polymerized LC polarization gratings. By carefully analyzing the experimental and numerical data for gratings with different periods, we conclude that the non-negligible homeotropic anchoring strength at the air interface is responsible for the tilt angle and the symmetry breaking. The role of anchoring strength at the photoaligned and air interface and other parameters are investigated.
ABSTRACT
PURPOSE: This study aimed to determine whether the natural antioxidant resveratrol (RSV) prevents type 2 diabetes mellitus (T2DM)-induced cognitive impairment and to explore whether redox-associated factor nuclear factor erythroid 2-related factor 2 (Nrf2) plays a critical role in the neuroprotective effect of RSV. MATERIALS AND METHODS: We established a T2DM model with 8-week-old male ICR mice by administration of a high-fat diet for 2 months and low-dose streptozotocin for 3 days. Then, diabetic and age-matched control mice were treated with or without RSV for 4 months every other day and subjected to the Morris water maze test. After the mice were euthanized, whole brains were sectioned for Nissl staining and immunofluorescence labeling. Hippocampal sections were observed by transmission electron microscopy to evaluate the ultrastructure of synapses. Inflammatory factors, oxidative stress-related indexes, and Nrf2 and downstream target gene expression were analyzed in hippocampal tissues by quantitative real-time PCR, Western blotting, and associated quantitative kits. RESULTS: In the Morris water maze test, compared to control mice, T2DM mice showed learning and memory impairments, but RSV treatment prevented the learning and memory decline in T2DM mice. Similarly, RSV prevented T2DM-induced hippocampal neuron destruction and synaptic ultrastructural damage. The expression levels of inflammatory factors and oxidative stress-related indicators were increased in the T2DM group compared with the control group but were decreased significantly by RSV treatment in the T2DM group. Additionally, the expression of Nrf2 and its downstream target genes was decreased in the T2DM group compared with the control group and was significantly increased by RSV treatment in the T2DM group. CONCLUSION: RSV prevented T2DM-induced cognitive impairment through anti-inflammatory and antioxidant activities. This effect was accompanied by the upregulation of Nrf2 transcriptional activity and the increased expression of downstream antioxidant genes.
ABSTRACT
Nanocage structures derived from decasulfonated ß-cyclodextrin (SCD) intercalated ZnAl- and MgAl- layered double hydroxides (LDHs) were prepared through calcination-rehydration reactions. The ZnAl- and MgAl-LDH layers revealed different basal spacings (1.51 nm for SCD-ZnAl-LDH and 1.61 nm for SCD-MgAl-LDH) when contacting SCD, while producing similar monolayer and vertical SCD orientations with cavity axis perpendicular to the LDH layer. The structures of the SCD-LDH and carboxymethyl-ß-cyclodextrin (CMCD)-LDH intercalates were fully analyzed and compared, and a structural model for the SCD-LDH was proposed. The thermal stability of SCD after intercalation was remarkably enhanced, with decomposition temperature increased by 230 °C. The adsorption property of the SCD-LDH composites for phenol compounds (the effects of adsorption time and phenol concentration on adsorption) was investigated completely. The monolayer arrangement of the interlayer SCD did not affect the adsorption efficiency toward organic compounds, which verified the highly swelling ability of the layered compounds in solvents. Both composites illustrated preferential adsorptive efficiency for 2,3-dimethylphenol (DMP) in comparison with other two phenols of hydroquinone (HQ) and tert-butyl-phenol (TBP), resulting from appropriate hydrophobicity and steric hindrance of DMP. For the two phenols of HQ and TBP, SCD-MgAl-LDH gave better adsorption capacity compared with SCD-ZnAl-LDH. The double-confinement effect due to the combination of the parent LDH host and intercalated secondary host may impose high selectivity for guests. This kind of nanocage structure may have potential applications as adsorbents, synergistic agents, and storage vessels for particular guests.
