Tunable surface plasmon-polaritons based on quantum coherence.

Tunable surface plasmons on the interface of a multilevel atomic medium with a cross coupling of the electric and magnetic components of a plasmonic field are investigated. The strong chirality resulting from the quantum coherence leads to some exciting properties of the surface plasmons. Compared to the traditional chiral-metal interface, surface plasmonic mode can still be found at the interface between such atomic media and a dielectric even when both the permittivity and the permeability of the medium are positive. This is in contrast to the conventional plasmonic systems where the signs of the permittivities or permeabilities on the two sides of the interface are opposite. We call this phenomenon an electromagnetically induced plasmon. Additionally, as the chirality and effective refractive index of the atomic medium are dependent on the intensity and phase of the controlling field, we can conveniently manipulate the properties of the surface plasmons.

[Establishment of zebrafish model for non-alcoholic steatohepatitis].

Objective: To establish overfed zebrafish model for non-alcoholic steatohepatitis. Methods: The wild-type zebrafish was fed 3 times a day with normal diet. Body length, weight, and triglyceride levels were measured after 20 days of feeding. The changes in expression of genes associated with cholesterol metabolism, lipid metabolism, endoplasmic reticulum stress, and inflammation were detected by quantitative PCR. Liver tissue sections were stained with H&E. Statistical analyses between groups were compared using t-test. Results: The body length (0.71±0.014) cm and body weight (44.83±1.833) mg of model group were higher than that of control group (0.50±0.009) cm and body weight (19.33±2.753) mg (total (body length) = 12.36, total (body weight) = 7.71, P < 0.01). Triglyceride content in the model group was (59.15 ± 0.5612) µmol / L, higher than the control group (16.71 ± 0.3562) µmol / L (t = 63.84, P < 0.001). Quantitative PCR results showed that the expression of genes related to cholesterol synthesis in the model group was higher than that in the control group (P < 0.01). The expression levels of lipid production and lipid oxidation related factors in the model group were higher than the control group. The difference between the two groups was statistically significant (P < 0.05). The expression of inflammation-related factors in the model group was higher than that in the control group (P < 0.001), and the expression of genes related to endoplasmic reticulum stress in the model group was higher than that to control group (P<0.001). Liver H&E staining showed that the model group had pathological changes such as large bulla and vesicles compared to the control group. Conclusion: A continuous 3 times 20 days of normal diet can simulate the disease characteristics of human non-alcoholic steatohepatitis in a zebrafish.

[Establishment and evaluation of a mouse model of nonalcoholic steatohepatitis-related hepatocellular carcinoma].

OBJECTIVE: To establish an apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) double-knockout (ApoE(-/-)/LDLR(-/-)) mouse model of nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) induced by high-fat and high-cholesterol (HFHC) diet. METHODS: ApoE(-/-) knockout mice were crossed with LDLR(-/-) knockout mice to obtain ApoE(-/-)/LDLR(-/-) mice. The ApoE(-/-)/LDLR(-/-) mice mated with each other, and the offspring were injected with low-dose streptozotocin (STZ) at 2-3 days after birth. Some mice were fed with HFHC diet after weaning as the model group (n = 15), and some mice were fed with normal diet as the control group (n = 15). Mice were sacrificed at the end of weeks 10, 16, and 20 (5 mice at each time point). The body weight was measured. Liver tissue and blood were collected to measure biochemical parameters, evaluate the pathological changes in the liver tissue by HE staining, oil red O staining, and Masson staining, and detect the expression of glypican-3 (a marker of HCC) by immunohistochemical staining. RESULTS: The model group had significantly higher levels of fasting blood glucose and total cholesterol than the control group (P < 0.01). Serum levels of alanine aminotransferase, aspartate aminotransferase, and total triglyceride gradually increased with time in the model group; at week 20, there were significant differences in above three indices between the two groups (P < 0.05). HE staining showed that compared with the control group at the corresponding time point, the model group developed sequential histological changes: NASH at week 10, dysplastic nodules at week 16, and early HCC at week 20. Oil red O staining showed that in the model group, the degree of liver steatosis increased within 10 weeks and gradually decreased later. Masson staining demonstrated that the model group developed pathological changes: mild perisinusoidal fibrosis at week 16 and bridging fibrosis around tumors at week 20. HE staining, oil red O staining, and Masson staining showed that no histological or pathological changes were found in the control group. Glypican-3 was detected in the nodules at week 16 and in the cytoplasm of HCC cells at week 20 in the model group. CONCLUSION: The mouse model of NASH-related HCC can be developed by giving STZ injection to neonatal ApoE(-/-)/LDLR(-/-) mice and feeding them with HFHC diet after weaning for 20 weeks. Early HCC may develop directly from NASH.