Design, analysis, and control of a cable-driven parallel platform with a pneumatic muscle active support

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The neck is an important part of the body that connects the head to the torso, supporting the weight and generating the movement of the head. In this paper, a cable-driven parallel platform with a pneumatic muscle active support (CPPPMS) is presented for imitating human necks, where cable actuators imitate neck muscles and a pneumatic muscle actuator imitates spinal muscles, respectively. Analyzing the stiffness of the mechanism is carried out based on screw theory, and this mechanism is optimized according to the stiffness characteristics. While taking the dynamics of the pneumatic muscle active support into consideration as well as the cable dynamics and the dynamics of the Up-platform, a dynamic modeling approach to the CPPPMS is established. In order to overcome the flexibility and uncertainties amid the dynamic model, a sliding mode controller is investigated for trajectory tracking, and the stability of the control system is verified by a Lyapunov function. Moreover, a PD controller is proposed for a comparative study. The results of the simulation indicate that the sliding mode controller is more effective than the PD controller for the CPPPMS, and the CPPPMS provides feasible performances for operations under the sliding mode control

Emergent Conformal Symmetry at the Multicritical Point of (2+1)D SO(5) Model with Wess-Zumino-Witten Term on Sphere

Novel critical phenomena beyond the Landau-Ginzburg-Wilson paradigm have been long sought after. Among many candidate scenarios, the deconfined quantum critical point (DQCP) constitutes the most fascinating one, and its lattice model realization has been debated over the past two decades. Following the pioneering works with the fuzzy sphere methods [W. Zhu, et al, Phys. Rev. X 13, 021009], we apply the spherical Landau level regularization to study the effective (2+1)D SO(5) non-linear sigma model with a topological term and the potential DQCP therein. Utilizing the state-of-the-art density matrix renormalization group method with explicit $\text{SU(2)}_\text{spin}\times\text{U(1)}_\text{charge}\times\text{U(1)}_\text{angular-momentum}$ symmetry as well as exact diagonalization simulations, we provide a comprehensive phase diagram for the model with a SO(5) continuous transition line -- extension of the previous identified SO(5) multicritical point [arXiv:2307.05307] -- while tuning interaction length. The state-operator correspondence with the conformal tower structure is used to identify the emergent conformal symmetry with the best scaling dimension of relevant primary fields and they match well with the critical exponents obtained from the crossing point analysis of the correlation ratio. Our results thus further support the rich structure of the phase diagram of the SO(5) model.Comment: 7+6 pages, 4 figure

Radix bupleuri Extract Inhibits Hyperplasia of Mammary Gland in Rats

Purpose: To investigate the effect of Radix bupleuri extract (RBE) on hyperplasia of mammary gland (HMG) in rats.Methods: Forty virgin female Wistar rats were randomly divided into control, HMG model, positive control (Rupisanjie capsule, RPSJC), and low-, middle-, and high-dose RBE groups. Estrogen and progestogen were intramuscularly injected into the rats to induce HMG. RPSJC and RBE were administered by intragastric administration. Changes in nipple height were measured; serum estradiol (E2), progesterone (P), prolactin (PRL), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) levels were evaluated; and uterus and ovary indices were calculated. Morphological changes in mammary glands were observed by light microscopy.Results: Compared with HMG model rats, those treated with RBE had significantly decreased nipple height and uterus index (both p < 0.01), and the numbers of mammary gland lobules and secretion were reduced by RBE. The treatment also significantly decreased serum E2, PRL, and FSH levels (all p < 0.01), while serum P and LH levels (p < 0.01) were significantly increased in RBE-treated HMG rats. Histopathologic observation confirmed that high dose of RBE attenuated HMG.Conclusion: The findings suggest that RBE has significant effect of anti hyperplasia of mammary gland.Keywords: Radix Bupleuri, Anti-inflammatory, Anti-hyperplasia, Mammary gland, Nipple height, Uterus inde

Elevated MTSS1 Expression Associated with Metastasis and Poor Prognosis of Residual Hepatitis B-Related Hepatocellular Carcinoma

Background: Hepatectomy generally offers the best chance of long-term survival for patients with hepatocellular carcinoma (HCC). Many studies have shown that hepatectomy accelerates tumor metastasis, but the mechanism remains unclear. Methods: An orthotopic nude mice model with palliative HCC hepatectomy was performed in this study. Metastasis-related genes in tumor following resection were screened; HCC invasion, metastasis, and some molecular alterations were examined in vivo and in vitro. Clinical significance of key gene mRNA expression was also analyzed