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To investigate the effect of overnight orthokeratology (OOK) on the ocular surface and dry eye-related cytokines in children.A non-randomized, prospective pilot study was conducted including sixty myopes treated with OOK and sixty age-matched spectacle wearing participants. The following tests were performed before and after 1, 3, 6 and 12 months: ocular surface disease index (OSDI), noninvasive tear breakup time (NITBUT), tear meniscus height (TMH), corneal fluorescein staining (CFS), meiboscore using noncontact meibography. Then the concentrations of interleukin-17A (IL-17A), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) in tear samples were detected with a multiplex immunobead assay at different time points.All parameters had no statistical differences between the two groups prior to treatment. No adverse events were observed except trace to moderate corneal staining and allergic conjunctivitis in the treatment group. NITBUT significantly decreased after 6 and 12 months OOK wearing (P = 0.003 and P = 0.001, respectively). After wearing OOK there was a significant increase in CFS at each follow-up time point compared with baseline (P = 0.023, P = 0.016, P = 0.001, and P 0.001at 1, 3, 6, and 12 months, respectively). The upper meiboscore and the total meiboscore increased gradually and peaked at 12 months of OOK (both P 0.001). The concentration of the three cytokines in the treatment group significantly increased after OOK wearing. These increases occurred at different time points: IL-17A increased significantly 3 months after OOK, IL-6 at 6 months, and PGE2 at 12 months (all P 0.001). However, there were no significant changes in the above parameters in the control group. There were no significant differences in the OSDI or TMH at any follow-up time point compared to baseline in both groups (both P 0.05).Short-term OOK may reduce the stability of the tear film and increase damage to the corneal epithelium. Long-term OOK could induce ocular inflammation through the disruption of meibomian glands.

To explore the role of the corneal sensory nerves in Pseudomonas aeruginosa (P. aeruginosa) keratitis, the synergistic effect between the sensory neurons and macrophages in calcitonin gene-related peptide (CGRP) release, and the functional mechanisms of CGRP-mediated transformation of macrophages to the M2 phenotype.Corneal nerve loss, macrophage recruitment, and CGRP expression were evaluated. To explore the synergistic effect between the sensory neurons and macrophages, RAW 264.7 cells were challenged with lipopolysaccharide (LPS), then trigeminal ganglion (TG) sensory neurons were isolated and co-incubated with macrophages, and CGRP expression was tested. To investigate the biological function of cornea neuron-initiated immune responses mediated by CGRP, BIBN 4096BS was used to inhibit CGRP in vivo and α-CGRP was used to simulate CGRP in vitro. The expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-10), M1 (CD80/CD86), M2 (CD163/CD206) macrophage markers, and signal transducers (PI3K/AKT) were detected.P. aeruginosa infection induced corneal nerve loss, macrophage recruitment, and CGRP up-expression. CGRP was co-localized with macrophages. Co-culture showed that sensory neurons and macrophages can mediate CGRP release. More CGRP was released when the two types of cells were combined to respond to LPS. BIBN 4096BS promoted pro-inflammatory cytokines and inhibited the anti-inflammatory cytokines and signal transducers, while, α-CGRP inhibited the pro-inflammatory cytokines and M1 markers and promoted the anti-inflammatory cytokine, M2 markers, and signal transducers.P. aeruginosa infection induces corneal sensory neuron activation, macrophage recruitment, and CGRP up-expression. The synergistic effect between the sensory neurons and macrophages promotes CGRP release. CGRP inhibits corneal inflammation and promotes the transformation of macrophages to the M2 phenotype through the PI3K/AKT signaling pathway.

Background Global climate change could have potential impact on enterovirus (EV)-induced infectious diseases. However, the environmental factors promoting acute hemorrhagic conjunctivitis (AHC) circulation remain inconclusive. This study aimed to quantify the relationship between the environment and AHC. Methods We retrieved the monthly counts and incidence of AHC, meteorological variables and air quality in mainland China between 2013 and 2018. Exposure risks were evaluated by multivariate distributed lag nonlinear models. Results A total of 219,599 AHC cases were reported in 31 provinces of China, predominantly in southern and central China, seasonally increased in summer. AHC incidence increased by 7% between 2013 and 2018, from 2.6873 to 2.7570 per 100,000 people. A moderate positive correlation was seen between AHC and monthly mean temperature, relative humidity (RH) and precipitation. Each unit increment was associated with a relative risk for AHC of 1.058 at 17°-32 °C at lag 0 months, 1.017 at 65–71% RH at lag 1.4 months, and 1.039 at 400–569 mm at lag 2.4 months. By contrast, a negative correlation was seen between monthly ambient NO2 and AHC. Conclusion Long-term exposure to higher mean temperature, RH and precipitation were associated with an increased risk of AHC. The general public, especially susceptible populations, should pay close attention to weather changes and take protective measures in advance to any AHC outbreak as the above situations occur.

Novel tempered resin bonded ferro-silicon nitride-corundum refractories containing 0 wt.%, 15 wt.% and 25 wt.% ferro-silicon nitride were prepared respectively. Creep tests were performed under a load of 0.2 MPa at a temperature of 1300 °C for 50 hours in air. The results showed that creep performance was significantly improved by the addition of ferro-silicon nitride. Ferro-silicon nitride-corundum containing 15 wt.% ferro-silicon nitride initially presented a steady-state stage and was able to remain stable from the beginning of the holding time until 50 hours of creep testing. All the specimens exhibited cold crushing strength more than 100 MPa both before and after creep testing. Phase composition and microstructure were analyzed following the creep experiments. The results showed that Si 2 N 2 O and O’-sialon crystals formed in situ during creep testing, in addition to the conversion of α-Si 3 N 4 to β-Si 3 N 4 . Liquid Fe 3 Si from the ferro-silicon nitride component accelerated the formation of the O’-sialon and prolonged the growth of β-Si 3 N 4 , which improved the creep performance significantly. Fe 3 Si liquid migrated into the pores, and some Fe 3 Si coexisted with residual carbon from the resin, which filled a part of pores and protected the specimens from severe oxidation.

Commercial silicon powders are nitrided at constant temperatures (1453 K; 1513 K; 1633 K; 1693 K). The X-ray diffraction results show that small amounts of Si3N4 and Si2N2O are formed as the nitridation products in the samples. Fibroid and short columnar Si3N4 are detected in the samples. The formation mechanisms of Si3N4 and Si2N2O are analyzed. During the initial stage of silicon powder nitridation, Si on the outside of sample captures slight amount of O2 in N2 atmosphere, forming a thin film of SiO2 on the surface which seals the residual silicon inside. And the oxygen partial pressure between the SiO2 film and free silicon is decreasing gradually, so passive oxidation transforms to active oxidation and metastable SiO(g) is produced. When the SiO(g) partial pressure is high enough, the SiO2 film will crack, and N2 is infiltrated into the central section of the sample through cracks, generating Si2N2O and short columnar Si3N4 in situ. At the same time, metastable SiO(g) reacts with N2 and form fibroid Si3N4. In the regions where the oxygen partial pressure is high, Si3N4 is oxidized into Si2N2O.

Objectives To investigate the effects of neutrophil extracellular traps (NETs) on angiogenesis in vitro and in vivo and the regulatory role of mammalian target of rapamycin (mTOR) activity in it. Methods The regulatory role of mTOR in NETs formation was explored. In vitro, human neutrophils were pretreated with rapamycin. NETs formation was measured using immunofluorescence staining of NETs markers, SYTOX Green and PicoGreen after NaOH stimulation. In vivo, mice were treated with rapamycin, and NETs formation in cornea was measured using immunofluorescence staining 7 days after alkali burn. Then, the effects of NETs on angiogenesis were investigated. In vitro, human neutrophils were treated with DNase I or rapamycin. NETs were isolated after NaOH stimulation and the isolated NETs were co-culture with human umbilical vein endothelial cells (HUVECs). HUVECs migration, proliferation, and inflammatory activation were measured. In vivo, mice were injected subconjunctivally with supernatant containing NETs. Corneal neovascularization was visualized by immunofluorescence staining. Results NETs structures can be observed in NaOH-stimulated neutrophils and alkali-burned mouse cornea compared with normal group. Treated with rapamycin enhanced NETs formation in response to NaOH management compared with DMSO control in vitro and in vivo. NETs increased the migration, proliferation and inflammatory activation of HUVECs, and subconjunctival injection of NETs promoted inflammatory and angiogenic response in corneal alkali burn model. Conclusions NETs formation can be triggered by NaOH stimulation. mTOR activity has a negative regulatory effect on NETs formation. NETs promoted angiogenic responses and inflammatory activation of HUVECs and increased corneal neovascularization and inflammatory response.

The temperatures may have influence on the spread of COVID-19, However, we believe that government regulation and cooperation of public play a more important role.

The semi-analytical solution of transient responses and the bounded control strategy to minimize the transient responses for seismic-excited hysteretic structures are investigated in this manuscript, the hysteretic behavior is described by Duhem model while the seismic excitations by random processes with Kanai–Tajimi spectrum. The averaged Fokker–Planck–Kolmogorov equation with respect to the probability density of amplitude response is firstly derived by utilizing the stochastic averaging technique based on the generalized harmonic functions. The probability density is approximately expressed as a series expansion in terms of a set of specified basis functions with time-dependent coefficients which are determined through the Galerkin procedure. The quasi-optimal bounded control strategy to minimize the transient response is proposed based on the averaged system with respect to amplitude response and an appropriate performance index. The quasi-optimal control is derived from the minimum condition in the dynamic programming equation. The application and effectiveness of the proposed analytical procedure and control strategy are illustrated through one representative example.

Reliability of first-passage type for wideband noise-excited viscoelastic systems and the quasi-optimal bounded control strategy for maximizing system reliability are investigated. The viscoelastic term is approximately replaced by equivalent damping and stiffness separately. By using the stochastic averaging method based on the generalized harmonic functions, the averaged Ito stochastic differential equation is obtained for the system amplitude. The associated backward Kolmogorov equation is derived and solved to obtain the system reliability. By applying the dynamic programming principle to the averaged system, the quasi-optimal bounded control is devised by maximizing system reliability. The application of the proposed analytical procedures and the effectiveness of the control strategy are illustrated through one example.