Suppressing STAT3 activation impairs bone formation during maxillary expansion and relapse

Objectives: The mid-palatal expansion technique is commonly used to correct maxillary constriction in dental clinics. However, there is a tendency for it to relapse, and the key molecules responsible for modulating bone formation remain elusive. Thus, this study aimed to investigate whether signal transducer and activator of transcription 3 (STAT3) activation contributes to osteoblast-mediated bone formation during palatal expansion and relapse. Methodology: In total, 30 male Wistar rats were randomly allocated into Ctrl (control), E (expansion only), and E+Stattic (expansion plus STAT3-inhibitor, Stattic) groups. Micro-computed tomography, micromorphology staining, and immunohistochemistry of the mid-palatal suture were performed on days 7 and 14. In vitro cyclic tensile stress (10% magnitude, 0.5 Hz frequency, and 24 h duration) was applied to rat primary osteoblasts and Stattic was administered for STAT3 inhibition. The role of STAT3 in mechanical loading-induced osteoblasts was confirmed by alkaline phosphatase (ALP), alizarin red staining, and western blots. Results: The E group showed greater arch width than the E+Stattic group after expansion. The differences between the two groups remained significant after relapse. We found active bone formation in the E group with increased expression of ALP, COL-I, and Runx2, although the expression of osteogenesis-related factors was downregulated in the E+stattic group. After STAT3 inhibition, expansive force-induced bone resorption was attenuated, as TRAP staining demonstrated. Furthermore, the administration of Stattic in vitro partially suppressed tensile stress-enhanced osteogenic markers in osteoblasts. Conclusions: STAT3 inactivation reduced osteoblast-mediated bone formation during palatal expansion and post-expansion relapse, thus it may be a potential therapeutic target to treat force-induced bone formation

The analysis of the suction/injection on the MHD Maxwell fluid past a stretching plate in the presence of nanoparticles by Lie group method

In this paper, the magnetohydrodynamic (MHD) Maxwell fluid past a stretching plate with suction/ injection in the presence of nanoparticles is investigated. The Lie symmetry group transformations are used to convert the boundary layer equations into non-linear ordinary differential equations. The dimensionless governing equations are solved numerically using Bvp4c with MATLAB, which is a collocation method equivalent to the fourth order mono-implicit Runge-Kutta method. The effects of some physical parameters, such as the elastic parameter K, the Hartmann number M, the Prandtl number Pr, the Brownian motion Nb, the thermophoresis parameter Nt and the Lewis number Le, on the velocity, temperature and nanoparticle fraction are studied numerically especially when suction and injection at the sheet are considered

On the process of filtration of fractional viscoelastic liquid food

In the process of filtration, fluid impurities precipitate/accumulate; this results in an uneven inner wall of the filter, consequently leading to non-uniform suction/injection. The Riemannian-Liouville fractional derivative model is used to investigate viscoelastic incompressible liquid food flowing through a permeable plate and to generalize Fick's law. Moreover, we consider steady-state mass balance during ultrafiltration on a plate surface, and a fractional-order concentration boundary condition is established, thereby rendering the problem real and complex. The governing equation is numerically solved using the finite difference algorithm. The effects of the fractional constitutive models, generalized Reynolds number, generalized Schmidt number, and permeability parameter on the velocity and concentration fields are compared. The results show that an increase in fractional-order α in the momentum equation leads to a decrease in the horizontal velocity. Anomalous diffusion described by the fractional derivative model weakens the mass transfer; therefore, the concentration decreases with increasing fractional derivative γ in the concentration equation.</p

Perturbation solutions for a micropolar fluid flow in a semi-infinite expanding or contracting pipe with large injection or suction through porous wall

We investigate an unsteady incompressible laminar micropolar flow in a semi-infinite porous pipe with large injection or suction through a deforming pipe wall. Using suitable similarity transformations, the governing partial differential are transformed into a coupled nonlinear singular boundary value problem. For large injection, the asymptotic solutions are constructed using the Lighthill method, which eliminates singularity of solution in the high order derivative. For large suction, a series expansion matching method is used. Analytical solutions are validated against the numerical solutions obtained by Bvp4c

Interference of Heavy Aerosol Loading on the VIIRS Aerosol Optical Depth (AOD) Retrieval Algorithm

Aerosol optical depth (AOD) has been widely used in climate research, atmospheric environmental observations, and other applications. However, high AOD retrieval remains challenging over heavily polluted regions, such as the North China Plain (NCP). The Visible Infrared Imaging Radiometer Suite (VIIRS), which was designed as a successor to the Moderate Resolution Imaging Spectroradiometer (MODIS), will undertake the aerosol observations mission in the coming years. Using the VIIRS AOD retrieval algorithm as an example, we analyzed the influence of heavy aerosol loading through the 6SV radiative transfer model (RTM) with a focus on three aspects: cloud masking, ephemeral water body tests, and data quality estimation. First, certain pixels were mistakenly screened out as clouds and ephemeral water bodies because of heavy aerosols, resulting in the loss of AOD retrievals. Second, the greenness of the surface could not be accurately identified by the top of atmosphere (TOA) index, and the quality of the aggregation data may be artificially high. Thus, the AOD retrieval algorithm did not perform satisfactorily, indicated by the low availability of data coverage (at least 37.97% of all data records were missing according to ground-based observations) and overestimation of the data quality (high-quality data increased from 63.42% to 80.97% according to radiative simulations). To resolve these problems, the implementation of a spatial variability cloud mask method and surficial index are suggested in order to improve the algorithm