Cavity-Induced Optical Nonreciprocity Based on Degenerate Two-Level Atoms.

We developed and experimentally realized a scheme of optical nonreciprocity (ONR) by using degenerate two-level atoms embedded in an optical ring cavity. For the degenerate transition Fg = 4 ↔ Fe = 3, we first studied the cavity-transmission property in different coupling field configurations and verified that under the strong-coupling regime, the single-dark-state peak formed by electromagnetically induced transparency (EIT) showed ONR. The stable ground-state Zeeman coherence for Λ-chains involved in the degenerate two-level system was found to be important in the formation of intracavity EIT. However, different from the three-level atom-cavity system, in the degenerate two-level system, the ONR effect based on intracavity EIT occurred only at a low probe intensity, because the cavity-atom coupling strength was weakened in the counter-propagating probe and coupling field configuration. Furthermore, ONR transmission with a high contrast and linewidth-narrowing was experimentally demonstrated.

Dual targeting total saponins of Pulsatilla of natural polymer crosslinked gel beads with multiple therapeutic effects for ulcerative colitis.

Oral colon targeted drug delivery system (OCTDDS) is desirable for the treatment of ulcerative colitis (UC). In this study, we designed a partially oxidized sodium alginate-chitosan crosslinked microsphere for UC treatment. Dissipative particle dynamics (DPD) was used to study the formation and enzyme response of gel beads from a molecular perspective. The formed gel beads have a narrow particle size distribution, a compact structure, low cytotoxicity and great colon targeting in vitro and in vivo. Animal experiments demonstrated that gel beads promoted colonic epithelial barrier integrity, decreased the level of pro-inflammatory factors, accelerated the recovery of intestinal microbial homeostasis in UC rats and restored the intestinal metabolic disorders. In conclusion, our gel bead is a promising approach for the treatment of UC and significant for the researches on the pathogenesis and treatment mechanism of UC.

[Determination of rosmarinic acid in seeds and its processed products of Perilla frutescens var. typica and Perilla frutescens var. acuta].

OBJECTIVE: To determine the content of rosmarinic acid in seeds and its processed products of Perilla frutescens var. typica (PFT), Perilla frutescens var. acuta (PFA) and Perilla frutescens var. acuta form. discolor (PFAD). METHODS: The content of rosmarinic acid was determined by RP-HPLC with Welch C18 (250 mm x 4.6 mm, 5 microm) column, using methanol-phosphonic acid solution (39:61) as mobile phase at flow rate of 1.0 mL/min. UV detection wavelength was set at 330 nm and column temperature was set at 28 degrees C. RESULTS: The content of rosmarinic acid in roasted seeds of PFT is higher than in its seeds, but that of PFA and PFAD are lower; The content of rosmarinic acid in seeds of PFT, PFA and PFAD decline after the seeds are honey-pocessed and made into frost-like powder, and that of honey-processed one decline by a larger margin. CONCLUSION: The content of rosmarinic acid in seeds of PFT, PFA and PFAD are prone to decline by heat-processing.