Evaluating the Effects of Pulsed Electrical Stimulation on the Mechanical Behavior and Microstructure of Medulla Oblongata Tissues.

The development of remote surgery hinges on comprehending the mechanical properties of the tissue at the surgical site. Understanding the mechanical behavior of the medulla oblongata tissue is instrumental for precisely determining the remote surgery implementation site. Additionally, exploring this tissue's response under electric fields can inform the creation of electrical stimulation therapy regimens. This could potentially reduce the extent of medulla oblongata tissue damage from mechanical compression. Various types of pulsed electric fields were integrated into a custom-built indentation device for this study. Experimental findings suggested that applying pulsed electric fields amplified the shear modulus of the medulla oblongata tissue. In the electric field, the elasticity and viscosity of the tissue increased. The most significant influence was noted from the low-frequency pulsed electric field, while the burst pulsed electric field had a minimal impact. At the microstructural scale, the application of an electric field led to the concentration of myelin in areas distant from the surface layer in the medulla oblongata, and the orderly structure of proteoglycans became disordered. The alterations observed in the myelin and proteoglycans under an electric field were considered to be the fundamental causes of the changes in the mechanical behavior of the medulla oblongata tissue. Moreover, cell polarization and extracellular matrix cavitation were observed, with transmission electron microscopy results pointing to laminar separation within the myelin at the ultrastructure scale. This study thoroughly explored the impact of electric field application on the mechanical behavior and microstructure of the medulla oblongata tissue, delving into the underlying mechanisms. This investigation delved into the changes and mechanisms in the mechanical behavior and microstructure of medulla oblongata tissue under the influence of electric fields. Furthermore, this study could serve as a reference for the development of electrical stimulation regimens in the central nervous system. The acquired mechanical behavior data could provide valuable baseline information to aid in the evolution of remote surgery techniques involving the medulla oblongata tissue.

Mechanical behavior and microstructure of porcine brain tissues under pulsed electric fields.

Pulsed electric fields are extensively utilized in clinical treatments, such as subthalamic deep brain stimulation, where electric field loading is in direct contact with brain tissue. However, the alterations in brain tissue's mechanical properties and microstructure due to changes in electric field parameters have not received adequate attention. In this study, the mechanical properties and microstructure of the brain tissue under pulsed electric fields were focused on. Herein, a custom indentation device was equipped with a module for electric field loading. Parameters such as pulse amplitude and frequency were adjusted. The results demonstrated that following an indentation process lasting 5 s and reaching a depth of 1000 µm, and a relaxation process of 175 s, the average shear modulus of brain tissue was reduced, and viscosity decreased. At the same amplitude, high-frequency pulsed electric fields had a smaller effect on brain tissue than low-frequency ones. Furthermore, pulsed electric fields induced cell polarization and reduced the proteoglycan concentration in brain tissue. As pulse frequency increased, cell polarization diminished, and proteoglycan concentration decreased significantly. High-frequency pulsed electric fields applied to brain tissue were found to reduce impedance fluctuation amplitude. This study revealed the effect of pulsed electric fields on the mechanical properties and microstructure of ex vivo brain tissue, providing essential information to promote the advancement of brain tissue electrotherapy in clinical settings.

Analysis of traditional Chinese medicine syndrome types and frequency changes of CD8+ and CD25+ T cells in metabolic-related fatty liver disease.

This study aimed to observe and analyze the changes in traditional Chinese medicine (TCM) syndrome types and CD8+ and CD25+T cell frequencies of metabolic-related fatty liver disease. For this purpose, 100 patients with metabolic-related fatty liver disease and their TCM syndrome types who were screened for medical treatment were collected. Flow cytometry was used to detect the changes in the frequency of CD8+ and CD25+T cells in the peripheral blood of patients, as well as liver function, fasting blood glucose, and lipid index. The frequency differences of CD8+ and CD25+T cells in patients with different syndrome types were compared. To use partial correlation analysis to determine the correlation between CD8+, CD25+T cell frequencies and TCM syndrome types in patients. Results showed that a total of 30 cases of liver stagnation and spleen deficiency syndrome, 25 cases of phlegm turbidity internal obstruction syndrome, 20 cases of dampness heat stasis syndrome, and 25 cases of phlegm stasis mutual accumulation syndrome were included in the 100 MAFLD patients. There was statistical significance (P<0.01) in the comparison of ALT, AST, GGT, TC, TG, HDL-C, LDL-C, FPG, HOMA-IR, CD8+CD25+, CD8+CD25-, CD8-CD25+, and CD8-CD25- among patients with different TCM syndrome types. There is a positive correlation between TCM syndrome types and patients' CD8+CD25+, CD8+CD25-, and CD8-CD25+, while there is a negative correlation between them (P<0.05). From the chord diagram, the relationship between CD8+CD25+ and TCM syndrome types is the closest. The ROC curve was used to analyze and determine that the relevant standard for CD8+CD25+ in liver depression and spleen deficiency syndrome is <4.90%; The relevant standard for phlegm turbidity internal obstruction syndrome is 4.90%~7.88%; Damp heat stasis syndrome is 7.88%~8.20%; The syndrome of phlegm and blood stasis accumulation is more than 8.20%. The TCM syndrome types of metabolic-related fatty liver disease will vary with the frequency of CD8+ and CD25+T cells. In conclusion, TCM syndrome types are closely related to the severity of the patient's condition and immune function, providing a new perspective and means for understanding the pathogenesis of metabolic-related fatty liver disease and evaluating the condition.

The Shortest Duration Constrained Hidden Markov Model: Data denoise and forecast optimization on the country-product matrix for the Fitness-Complexity Algorithm.

The Economic Fitness Index describes industrial completeness and comprehensively reflects product diversification with competitiveness and product complexity in production globalization. The Fitness-Complexity Algorithm offers a scientific approach to predicting GDP and obtains fruitful results. As a recursion algorithm, the non-linear iteration processes give novel insights into product complexity and country fitness without noise data. However, the Country-Product Matrix and Revealed Comparative Advantage data have abnormal noises which contradict the relative stability of product diversity and the transformation of global production. The data noise entering the iteration algorithm, combined with positively related Fitness and Complexity, will be amplified in each recursion step. We introduce the Shortest Duration Constrained Hidden Markov Model (SDC-HMM) to denoise the Country-Product Matrix for the first time. After the country-product matrix test, the country case test, the noise estimation test and the panel regression test of national economic fitness indicators to predict GDP growth, we show that the SDC-HMM could reduce abnormal noise by about 25% and identify change points. This article provides intra-sample predictions that theoretically confirm that the SDC-HMM can improve the effectiveness of economic fitness indicators in interpreting economic growth.