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Corneal myofibroblasts play a crucial role in the process of corneal scarring. Potassium has been documented to reduce skin scar tissue formation. Herein, we investigated the ability of potassium to prevent corneal fibrosis in cell culture and in vivo. Corneal fibroblasts (CFs) were isolated from the corneal limbus and treated with TGF-β1 to transform into corneal myofibroblasts. Corneal myofibroblast markers were detected by quantitative real-time PCR, Western blot, and immunofluorescence. The contractive functions of corneal myofibroblast were evaluated by the scratch assay and the collagen gel contraction assay. RNA sequencing in corneal fibroblasts was performed to explore the mechanisms underlying hyperosmolar potassium treatment. GO and KEGG analysis were performed to explore the underlying mechanism by hyperosmolar potassium treatment. The ATP detection assay assessed the level of cell metabolism. KCl eye drops four times per day were administered to mice models of corneal injury to evaluate the ability to prevent corneal scar formation. Corneal opacity area was evaluated by Image J software. Treatment with hyperosmolar potassium could suppress corneal myofibroblast transformation and collagen I synthesis induced by TGF-β1 in cell culture. Hyperosmolar potassium could inhibit wound healing and gel contraction in CFs. RNA sequencing results suggested that genes involved in the metabolic pathway were downregulated after KCl treatment. ATP levels were significantly decreased in the KCl group compared with the control group. Hyperosmolar potassium could prevent corneal myofibroblast transformation after corneal injury and corneal scar formation in mice. Potassium can suppress corneal myofibroblast transformation and collagen I protein synthesis. Moreover, given that KCl eye drops can prevent corneal scar formation, it has been suggested to have huge prospects as a novel treatment approach during clinical practice. [ABSTRACT FROM AUTHOR]

A microcapsule containing a silane coupling agent was prepared by spray drying. The optimal encapsulating condition was determined by employing a response surface methodology with a central composite design. The effect of emulsion’s solid content and oil concentration, inlet air temperature, and atomizer speed on properties of microcapsule were investigated. The resulting microcapsule containing silane coupling agent and possessing an unbroken surface and a good shape under optimized conditions exhibited an encapsulation efficiency of 82.7%, average size of 21.3 µm, and moisture content of 0.93%. The experimental results agree well with the model prediction, with a relative error below 5.0%. [ABSTRACT FROM PUBLISHER]

The article discusses the U.S. pivot towards the Asia-Pacific, which according to Chinese officials and analysts, is a strategy to contain China despite of the claim of the U.S. that it does not focus on a particular country. The origins and the evolution of this U.S. pivot is examined based on a study conducted by the Office of Net Assessment (ONA). An analysis of the Asian security and Sino-American relations, the rational for the pivot and China's role in the Asia-Pacific strategy of the U.S. is also discussed.

Biomonitoring data provide evidence of human exposure to environmental chemicals by quantifying the chemical or its metabolite in a biological matrix. To better understand the correlation between biomonitoring data and environmental exposure, physiologically based pharmacokinetic (PBPK) modeling can be of use. The objective of this study was to use a combined PBPK model with an exposure model for showering to estimate the intake concentrations of chloroform based on measured blood and exhaled breath concentrations of chloroform. First, the predictive ability of the combined model was evaluated with three published studies describing exhaled breath and blood concentrations in people exposed to chloroform under controlled showering events. Following that, a plausible exposure regimen was defined combining inhalation, ingestion, and dermal exposures associated with residential use of water containing typical concentrations of chloroform to simulate blood and exhaled breath concentrations of chloroform. Simulation results showed that inhalation and dermal exposure could contribute substantially to total chloroform exposure. Next, sensitivity analysis and Monte Carlo analysis were performed to investigate the sources of variability in model output. The variability in exposure conditions (e.g., shower duration) was shown to contribute more than the variability in pharmacokinetics (e.g., body weight) to the predicted variability in blood and exhaled breath concentrations of chloroform. Lastly, the model was used in a reverse dosimetry approach to estimate distributions of exposure consistent with concentrations of chloroform measured in human blood and exhaled breath. [ABSTRACT FROM AUTHOR]

The present work is devoted to establishing the ultrashort pulse laser ablation generalized thermoelastic model with spatio-temporal nonlocal effect and investigating the transient responses of the process of silicon ablated by the picosecond pulse laser. The research is divided into three cases. 1) The solid silicon before the target surface melting is studied, and the transient responses of the final state of this case are taken as the initial conditions of the Case Two. 2) The liquid silicon after the target surface melting is researched, and the heat flux taken away by vaporization is considered in the boundary condition. 3) The solid silicon after the target surface melting is discussed, and the moving solid-liquid interface is regarded as the coordinate origin. The coupled governing equations containing spatial nonlocal parameter, time delay factor, and kernel function are established and solved by the Laplace transform together with its numerical inversion. The melting time and depth of target are emphatically discussed. The temperature, displacement and stress with different laser intensity, spatial nonlocal parameter, time delay factor, kernel function as well as time are obtained and illustrated graphically. [ABSTRACT FROM AUTHOR]

This letter proposes a novel control technique called as voltage mode-capacitor current ripple hybrid control (VCHC) strategy for single-inductor dual-output (SIDO) buck converter in inductor current continue conduction mode (CCM). The proposed strategy aims to reduce the cross regulation which is a key technical drawback of SIDO CCM buck converter. A small-signal model is also developed to investigate the frequency-domain responses of the proposed converter. The bode plots based on the small-signal model show that the proposed control strategy significantly reduces the cross regulation and improves transient performance compared with the one with voltage mode-inductor current ripple hybrid control. Finally, simulation and experiment results verify the effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

The pharmacokinetics of octamethylcyclotetrasiloxane (D4), a highly lipophilic and well-metabolized volatile cyclic siloxane, are more complex than those of other volatile hydrocarbons. The purpose of the present study was to evaluate rate constants for saturable metabolism in the body, to estimate possible presystemic D4 clearance by respiratory-tract tissues, and to assess rate constants for uptake of D4 after oral dosing. These experiments provided the opportunity to refine current physiologically based pharmacokinetic (PBPK) models for D4 and to independently estimate key model parameters by sensitive inhalation methods. The PBPK model could only be fitted to gas uptake results when metabolic capacity was included in the respiratory-tract epithelium. The model simulations were highly sensitive to the parameter for total percent of whole-body metabolism allocated to the respiratory tract, with optimal fits observed with this value equal to 5%. Oral uptake of D4 was evaluated using both closed and open chamber concentration time-course studies after intubation of D4 in corn oil. Conclusions from the oral uptake studies were also verified by comparison with independent data sets for blood concentrations of D4 after oral dosing. The pharmacokinetic (PK) analysis of uptake from the gut and release from blood into chamber air results for oral doses from 10 to 300 mg D4/kg body weight were consistent with a combination of prolonged and slow uptake of D4 from the gastrointestinal tract and of reduced absorption at higher doses, as well as the extrahepatic clearance of D4 in pulmonary tissues. These closed chamber gas uptake studies provide a valuable confirmation of the conclusions reached in other pharmacokinetic studies and have uncovered a situation where closed chamber loss is highly sensitive to respiratory-tract clearance. This sensitivity largely arises from the unusual characteristics of D4: high-affinity metabolic clearance and low blood:air partitioning. [ABSTRACT FROM AUTHOR]

Steady-state cross-regulation is a critical issue for dual-output dc-dc converters. The effect of leakage inductance on steady-state cross-regulation of dual-output LLC resonant converter is analysed in this Letter. It is revealed that a proportional relation between leakage inductance and load resistance of dual-output LLC resonant converter ensures zero steady-state cross-regulation. Furthermore, the variations of steady-state cross-regulation with regards to leakage inductance and load resistance are concluded. Finally, experimental results are provided to verify the theoretical analysis. [ABSTRACT FROM AUTHOR]

As the initial effort in a multi-step uncertainty analysis of a biologically based cancer model for formaldehyde, a Markov chain Monte Carlo (MCMC) analysis was performed for a compartmental model that predicts DNA-protein cross-links (DPX) produced by formaldehyde exposure. The Bayesian approach represented by the MCMC analysis integrates existing knowledge of the model parameters with observed, formaldehyde-DPX-specific data, providing a statistically sound basis for estimating model output uncertainty. Uncertainty and variability were evaluated through a hierarchical structure, where interindividual variability was considered for all model parameters and that variability was assumed to be uncertain on population levels. The uncertainty of the population mean and that of the population variance were significantly reduced through the MCMC analysis. Our investigation highlights several issues that must be dealt with in many real-world analyses (e.g., issues of parameters' nonidentifiability due to limited data) while demonstrating the feasibility of conducting a comprehensive quantitative uncertainty evaluation. The current analysis can be viewed as a case study, for a relatively simple model, illustrating some of the constraints that analysts will face when applying Bayesian approaches to biologically or physiologically based models of increasing complexity. [ABSTRACT FROM AUTHOR]