CircRNA and Stroke: New Insight of Potential Biomarkers and Therapeutic Targets.

Stroke, the second-largest cause of death and the leading cause of disability globally, presents significant challenges in terms of prognosis and treatment. Identifying reliable prognosis biomarkers and treatment targets is crucial to address these challenges. Circular RNA (circRNA) has emerged as a promising research biomarkers and therapeutic targets because of its tissue specificity and conservation. However, the potential role of circRNA in stroke prognosis and treatment remains largely unexplored. This review briefly elucidate the mechanism underlying circRNA's involvement in stroke pathophysiology. Additionally, this review summarizes the impact of circRNA on different forms of strokes, including ischemic stroke and hemorrhagic stroke. And, this article discusses the positive effects of circRNA on promoting cerebrovascular repair and regeneration, maintaining the integrity of the blood-brain barrier (BBB), and reducing neuronal injury and immune inflammatory response. In conclusion, the significance of circRNA as a potential prognostic biomarker and a viable therapeutic target was underscored.

A microfluidic generator of dynamic shear stress and biochemical signals based on autonomously oscillatory flow.

Biological cells in vivo typically reside in a dynamic flowing microenvironment with extensive biomechanical and biochemical cues varying in time and space. These dynamic biomechanical and biochemical signals together act to regulate cellular behaviors and functions. Microfluidic technology is an important experimental platform for mimicking extracellular flowing microenvironment in vitro. However, most existing microfluidic chips for generating dynamic shear stress and biochemical signals require expensive, large peripheral pumps and external control systems, unsuitable for being placed inside cell incubators to conduct cell biology experiments. This study has developed a microfluidic generator of dynamic shear stress and biochemical signals based on autonomously oscillatory flow. Further, based on the lumped-parameter and distributed-parameter models of multiscale fluid dynamics, the oscillatory flow field and the concentration field of biochemical factors has been simulated at the cell culture region within the designed microfluidic chip. Using the constructed experimental system, the feasibility of the designed microfluidic chip has been validated by simulating biochemical factors with red dye. The simulation results demonstrate that dynamic shear stress and biochemical signals with adjustable period and amplitude can be generated at the cell culture chamber within the microfluidic chip. The amplitudes of dynamic shear stress and biochemical signals is proportional to the pressure difference and inversely proportional to the flow resistance, while their periods are correlated positively with the flow capacity and the flow resistance. The experimental results reveal the feasibility of the designed microfluidic chip. Conclusively, the proposed microfluidic generator based on autonomously oscillatory flow can generate dynamic shear stress and biochemical signals without peripheral pumps and external control systems. In addition to reducing the experimental cost, due to the tiny volume, it is beneficial to be integrated into cell incubators for cell biology experiments. Thus, the proposed microfluidic chip provides a novel experimental platform for cell biology investigations.

A microfluidic system for precisely reproducing physiological blood pressure and wall shear stress to endothelial cells.

To reproduce hemodynamic stress microenvironments of endothelial cells in vitro is of vital significance, by which one could exploit the quantitative impact of hemodynamic stresses on endothelial function and seek innovative approaches to prevent circulatory system diseases. Although microfluidic technology has been regarded as an effective method to create physiological microenvironments, a microfluidic system to precisely reproduce physiological arterial hemodynamic stress microenvironments has not been reported yet. In this paper, a novel microfluidic chip consisting of a cell culture chamber with on-chip afterload components designed by the principle of input impedance to mimic the global hemodynamic behaviors is proposed. An external feedback control system is developed to accurately generate the input pressure waveform. A lumped parameter hemodynamic model (LPHM) is built to represent the input impedance to mimic the on-chip global hemodynamic behaviors. Sensitivity analysis of the model parameters is also elaborated. The performance of reproducing physiological blood pressure and wall shear stress is validated by both numerical characterization and flow experiment. Investigation of intracellular calcium ion dynamics in human umbilical vein endothelial cells is finally conducted to demonstrate the biological applicability of the proposed microfluidic system.

Optimization and mechanisms of biosorption process of Zn(II) on rape straw powders in aqueous solution.

The different part powders of rape straw as adsorbents were performed to remove zinc ions from aqueous solution in this work. The various factors on influencing removal efficiency of Zn(II) were investigated, and the operational conditions were optimized using the Box-Behnken design of response surface methodology (RSM). Under the optimum conditions obtained, the removal rates of Zn(II) were attained to 100.00%, 78.02%, and 17.00% by straw pith core, seedpods, and shell of rape straw, respectively. Equilibrium and kinetic models were applied to evaluate the adsorption behaviors of Zn(II) on the adsorbents. The equilibrium data were best described by the Langmuir isotherm model, which indicated that the adsorption behaviors were favorably monolayer adsorption processes. The biosorption capacities of Zn(II) were 34.66 mg g-1, 36.41 mg g-1, and 36.74 mg g-1 of rape straw pith core; 23.33 mg g-1, 23.85 mg g-1, and 24.30 mg g-1 of seedpods; and 11.19 mg g-1, 11.23 mg g-1, and 11.27 mg g-1 of shell, respectively, at the various temperatures of 20 °C, 30 °C, and 40 °C based on Langmuir isotherm equation. The pseudo-second-order kinetic model was well to determine the adsorption kinetics, which suggested that ion exchange were occurred during adsorption processes of Zn(II). The characteristics of adsorbents before and after adsorption of Zn(II) were measured using the methods of scanning electron microscope (SEM), zeta potential classes, energy dispersive spectrometer (EDS), and Fourier transform infrared spectroscopy (FT-IR), respectively. The results provided evidences for the adsorption mechanisms of Zn(II) including electrostatic attraction, ion exchange, and functional group involvement on the three part powders of rape straw in aqueous water.

[Biomechanical research in treating unstable Pilon fracture with anatomic plate of distal tibia].

OBJECTIVE: To investigate the mechanical characteristics of new anatomic plate of distal tibia from view of biomechanics. METHODS: Twelve fresh adult moist ankle specimens were randomly divided into four block groups (every group had 3 specimens), 3 tibial specimens as a normal control (normal group N), 9 specimens were resulted in unstable distal tibial Pilon fracture. Using steel plate fixation with a new anatomic distal tibial plate (group A), reconstruction plate (group B), clover plate (group C). Group B and group C as control group to test the remote axial compressive strength, remote axial stiffness, reversing biomechanical properties, contacted characteristics of the tibial astragaloid articular surface. RESULTS: The remote axial compressive strength, remote axial stiffness, reversing biomechanical properties, contacted characteristics of tibial astragaloid articular surface the in distal tibial Pilon fracture instability of group A were near normal group N (P>0.05). Group A was best than group B and C (P<0.05). CONCLUSION: The new anatomic plate of distal tibia was relatively strong, which can reach effective and stable fixation for unstable distal tibial Pilon fracture.