A review of studies on gut microbiota and levodopa metabolism

Parkinson’s disease (PD) is the second most common neurodegenerative disease globally. Levodopa (L-dopa) has been the cornerstone for treating Parkinson’s since the 1960s. However, complications such as “wearing-off” and dyskinesia inevitably appear with disease progression. With the further development of microbiomics in recent years, It has been recognized that gut microbiota plays a crucial role in Parkinson’s disease pathogenesis. However, Little is known about the impact of gut microbiota in PD treatment, especially in levodopa metabolism. This review examines the possible mechanisms of gut microbiota, such as Helicobacter pylori, Enterobacter faecalis, and Clostridium sporogenes, affecting L-dopa absorption. Furthermore, we review the current status of gut microbiota intervention strategies, providing new insights into the treatment of PD

Development of a Novel Double-Ring Deployable Mesh Antenna

This paper addresses a type of deployable mesh antenna consisting of the double-ring deployable truss edge frame and the cable net reflector. The structural design concept of the deployable antennas is presented. The deployable truss is designed and the geometric relationship of each strut length is formulated. Two types of radial truss elements are described and compared. The joint pattern and the active cables of the final design concept are determined. The pattern of the cable net is the three-orientation grid. Two connection schemes between the reflector and the deployable edge frame are investigated. The design parameters and the shape adjustment mechanism of this cable net are determined. The measurement test technologies of the antennas on the ground including test facilities, deployment test, and measurement and adjustment test are proposed. The antenna patterns are analyzed based on the real surfaces of the reflector obtained by the reflective surface accuracy measurement. The tests and analytic results indicated that the accuracy of the reflective surface is high and is suitable for low-frequency communication

Deployment simulation of inflatable structures based on improved spring-mass system

p. 2337-2353Inflatable membrane antenna structures are applied in spaceflight missions broadly. Fold and deployment simulation of inflatable antenna is the key technology of structure analysis. The simulation method of membrane deployable structure is mentioned based on improved spring-mass system. During structure development, self-contact or collision of membrane film may occur easily. The distinguish rule of self-contact elements is advanced and penalty function method is used to solve this difficult problem. Finite different method is used to solve the motion of system. Membrane inflatable tube is one of most important members for spatial inflatable structure. These time history of inflatable pressure and other gas parameter of each tube part are analyzed. The tube between two hinges is equal to cantilever beams and the moment tending to straighten the tube is obtained. This deployable moment is equal to drive forces which subjected to the spring-mass system. Numerical examples are presented to show that analyze method can simulate the 3D deployment motion of inflatable tube. Compared to the experiment result from the reference, the validity of the method is shown and the analysis precision is high. Then initial state and fold state of main members of inflatable antenna are described, which include inflatable tube, inflatable torus and reflector etc. Deployable drive forces and deployable process order of each part are analyzed. The antenna model like IAE antenna is analyzed and simulated by the fore mentioned system. Each state during deployment process and velocity and acceleration of each node are obtained. The example is used to validate the simulation method and the fold scheme of inflatable antenna.Xu, Y.; Guan, F. (2010). Deployment simulation of inflatable structures based on improved spring-mass system. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/728

Nonlinear Vibration Study Based on Uncertainty Analysis in MEMS Resonant Accelerometer

This paper aims to develop a resonant accelerometer for high-sensitivity detection and to investigate the nonlinear vibration of the MEMS resonant accelerometer driven by electrostatic comb fingers. First, a nonlinear vibration model of the resonator with comb fingers in a MEMS resonant accelerometer is established. Then, the nonlinear and nonlinear stiffness coefficients are calculated and analyzed with the Galérkin principle. The linear natural frequency, tracking error, and nonlinear frequency offset are obtained by multi-scale method. Finally, to further analyze the nonlinear vibration, a sample-based stochastic model is established, and the uncertainty analysis method is applied. It is concluded from the results that nonlinear vibration can be reduced by reducing the resonant beam length and increasing the resonant beam width and thickness. In addition, the resonant beam length and thickness have more significant effects, while the resonant beam width and the single concentrated mass of comb fingers have little effect, which are verified by experiments. The results of this research have proved that uncertainty analysis is an effective approach in nonlinear vibration analysis and instructional in practical resonant accelerometer design

Anti-cancer activity of Tonglian decoction against esophageal cancer cell proliferation through regulation of the cell cycle and PI3K/Akt signaling pathway

Objective: The purpose of this study was to observe the anti-cancer activity of Tonglian decoction (TD) on esophageal cancer (EC) cells in vitro, and to elucidate the related molecular mechanisms in the cell cycle and PI3K/Akt signaling pathway. Methods: EC9706 cells were cultured in RPMI 1640 medium supplemented with 10% calf serum at 37°C in a 5% CO2 incubator. The cells were treated with rat serum containing TD or the serum of rats administered Xiaoaiping as a positive control drug. Cell proliferation was assessed by methylthiazolyldiphenyl-tetrazolium bromide assays. Cell morphology was observed under a microscope. The cell cycle was examined by flow cytometry. Protein expression in the PI3K/Akt signaling pathway was measured by western blotting. Results: TD mainly inhibited cell proliferation. Concentrations of 50% cell inhibition by rat serum containing TD or Xiaoaiping were 73.6 and 153.8 μL/mL, respectively. TD also influenced cell morphology characterized by small shrunken cells. Cell colonies became small and the cell proliferation rate was slower. In cell cycle analysis, the percentage of cells in S phase was decreased significantly by TD and Xiaoaiping compared with the blank control group (P < .05). Western blotting showed that serum containing TD strongly down-regulated EGFR, PI3K, Akt, p-Akt, and mTOR expression compared with the blank control group (P < .05). Conclusion: TD could inhibit EC9706 carcinoma cell proliferation by blocking the cell cycle progression in S phase. The possible mechanism was inhibition of multiple targets in the PI3K/Akt signaling pathway by TD

Adversarial Multiscale Feature Learning Framework for Overlapping Chromosome Segmentation

Chromosome karyotype analysis is of great clinical importance in the diagnosis and treatment of diseases. Since manual analysis is highly time and effort consuming, computer-assisted automatic chromosome karyotype analysis based on images is routinely used to improve the efficiency and accuracy of the analysis. However, the strip-shaped chromosomes easily overlap each other when imaged, significantly affecting the accuracy of the subsequent analysis and hindering the development of chromosome analysis instruments. In this paper, we present an adversarial, multiscale feature learning framework to improve the accuracy and adaptability of overlapping chromosome segmentation. We first adopt the nested U-shaped network with dense skip connections as the generator to explore the optimal representation of the chromosome images by exploiting multiscale features. Then we use the conditional generative adversarial network (cGAN) to generate images similar to the original ones; the training stability of the network is enhanced by applying the least-square GAN objective. Finally, we replace the common cross-entropy loss with the advanced Lovász-Softmax loss to improve the model’s optimization and accelerate the model’s convergence. Comparing with the established algorithms, the performance of our framework is proven superior by using public datasets in eight evaluation criteria, showing its great potential in overlapping chromosome segmentation

Insights into azalomycin F assembly-line contribute to evolution-guided polyketide synthase engineering and identification of intermodular recognition.

Modular polyketide synthase (PKS) is an ingenious core machine that catalyzes abundant polyketides in nature. Exploring interactions among modules in PKS is very important for understanding the overall biosynthetic process and for engineering PKS assembly-lines. Here, we show that intermodular recognition between the enoylreductase domain ER1/2 inside module 1/2 and the ketosynthase domain KS3 inside module 3 is required for the cross-module enoylreduction in azalomycin F (AZL) biosynthesis. We also show that KS4 of module 4 acts as a gatekeeper facilitating cross-module enoylreduction. Additionally, evidence is provided that module 3 and module 6 in the AZL PKS are evolutionarily homologous, which makes evolution-oriented PKS engineering possible. These results reveal intermodular recognition, furthering understanding of the mechanism of the PKS assembly-line, thus providing different insights into PKS engineering. This also reveals that gene duplication/conversion and subsequent combinations may be a neofunctionalization process in modular PKS assembly-lines, hence providing a different case for supporting the investigation of modular PKS evolution