Corrugated-Diaphragm Based Fiber Laser Hydrophone with Sub-100 µPa/Hz1/2 Resolution.

In this work, a beat-frequency encoded fiber laser hydrophone is developed for high-resolution acoustic detection by using an elastic corrugated diaphragm. The diaphragm is center-supported by the fiber. Incident acoustic waves deform the diaphragm and induce a concentrated lateral load on the laser cavity. The acoustically induced perturbation changes local optical phases and frequency-modulates the radio-frequency beat signal between two orthogonal lasing modes of the cavity. Theoretical analysis reveals that a higher corrugation-depth/thickness ratio or larger diaphragm area can provide higher transduction efficiency. The experimentally achieved average sensitivity in beat-frequency variation is 185.7 kHz/Pa over a bandwidth of 1 kHz. The detection capability can be enhanced by shortening the cavity length to enhance the signal-to-noise ratio. The minimum detectable acoustic pressure reaches 74 µPa/Hz1/2 at 1 kHz, which is comparable to the zeroth order sea noise.

Therapeutic effects of topical doxycycline in a benzalkonium chloride-induced mouse dry eye model.

PURPOSE: We investigated the therapeutic effects and underlying mechanisms of topical doxycycline in a benzalkonium chloride (BAC)-induced mouse dry eye model. METHODS: Eye drops containing 0.025%, 0.1% doxycycline or solvent were administered to a BAC-induced dry eye model four times daily. The clinical evaluations, including tear break-up time (BUT), fluorescein staining, inflammatory index, and tear volume, were performed on days 0, 1, 4, 7, and 10. Global specimens were collected on day 10 and processed for immunofluorescent staining, TUNEL, and periodic acid-Schiff assay. The levels of inflammatory mediators in the corneas were determined by real-time PCR. The total and phosphorylated nuclear factor-κB (NF-κB) were detected by Western blot. RESULTS: Both 0.025% and 0.1% doxycycline treatments resulted in increased BUT, lower fluorescein staining scores, and inflammatory index on days 4, 7, and 10, while no significant change in tear volume was observed. The 0.1% doxycycline-treated group showed more improvements in decreasing fluorescein staining scores, increasing Ki-67-positive cells, and decreasing TUNEL- and keratin-10-positive cells than other groups. The mucin-filled goblet cells in conjunctivas were increased, and the expression of CD11b and levels of matrix metalloproteinase-9, IL-1ß, IL-6, TNF-α, macrophage inflammatory protein-2, and cytokine-induced neutrophil chemoattractant in corneas were decreased in both doxycycline-treated groups. In addition, doxycycline significantly reduced the phosphorylation of NF-κB activated in the BAC-treated corneas. CONCLUSIONS: Topical doxycycline showed clinical improvements and alleviated ocular surface inflammation on BAC-induced mouse dry eye, suggesting a potential as an anti-inflammatory agent in the clinical treatment of dry eye.

[Emphasizing the clinical investigation of dry eye].

In the past twenty years, with the rapid development of dry eye research in China, significant progresses have been achieved and there has been a remarkable improvement in diagnostic rate and clinical outcomes. Publication and popularization of the clinical diagnosis and treatment recommendations for dry eye from consensus of expert advice provides criteria for clinical work of dry eye. There has still been a significant gap between our research and world's advanced level in dry eye, therefore clinical investigations of high level will be intensively promoted to reveal the epidemiologic and clinical characteristics of dry eye populations in China, and establish the diagnostic criteria for Chinese patients, develop the clinical research on dry eye drugs and home-made clinical devices. Based on evidence-based research evidences, criteria for diagnosis and treatment of dry eye will be established and the clinical investigation of dry eye will be developed to reach the world's advanced level.

Pericytes are correlated with the permeability of rat corneal neovascular vessels induced by alkali burn.

BACKGROUND: Corneal neovascular leakage can lead to edema and secondary scarring. Previous studies have shown that pericytes play a key role in maturation of angiogenesis. The present studies investigate the relationship between vascular permeability and pericyte coverage of endothelial cells in rat corneal neovascular induced by alkali burns. METHODS: Corneal neovascular vessels induced by alkali burns was performed in Sprague-Dawley rats. Corneas were excised on 1, 2, 3, 5, 7 and 10 days after cauterization. The vascular permeability rate was measured by the Evans blue method. The microvessel pericyte coverage index (MPI) was applied to quantify the pericyte coverage through double immunofluorescent staining of frozen sections of corneas with CD31 as the endothelial and alpha-smooth muscle actin (alpha-SMA) as the pericyte markers. The correlation between permeability rate and MPI was analyzed. Pericyte coverage was confirmed ultrastructually using transmission electron microscopy. RESULTS: The vascular permeability rate was (1.14 +/- 0.17), (0.24 +/- 0.08), (0.29 +/- 0.16), (0.14 +/- 0.10), (0.09 +/- 0.06) and (0.05 +/- 0.04) microg x ml(-1) x mm(-2) respectively on 1, 2, 3, 5, 7 and 10 days after cauterization. The MPI was 0, 16.07%, 11.95%, 43.84%, 73.97% and 86.21% respectively at the above mentioned time points. The correlation coefficient between MPI and the permeability rate was -0.943 (P = 0.005). CONCLUSIONS: Pericyte recruitment was significantly correlated with the permeability of corneal neovascularization induced by alkali burns in rats. Therapeutic strategies aiming at anti-leakage should be most effective if they promote pericytes proliferation in the course of corneal neovascularization.