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This paper proposes a new event‐triggered robust control system for robot manipulators, based on two event‐triggered mechanisms (ETMs), which lead to intermittent communication not only for the sensor‐to‐controller channel but also for the controller‐to‐actuator channel. The proposed control system enjoys the advantage of requiring fewer resources of data communication and less signal updating of the control actuators. The control performance of the proposed control system is analyzed based on the Lyapunov approach. Furthermore, the absence of the Zeno behavior in the triggering sequence is proved rigorously. Finally, experiments are carried out on a two‐link robot manipulator system to support the theoretical results. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a progressive autoimmune disease. Due to local infiltration and damage to the joints, activated CD4+ T cells play a crucial role in the progression of RA. However, the exact regulatory mechanisms are perplexing, which makes the effective management of RA frustrating. This study aimed to investigate the effect of mitochondria fission on the polarization and migration of CD4+ T cells as well as the regulatory mechanism of NAR, so as to provide enlightenment on therapeutic targets and novel strategies for the treatment of RA. In this study, a collagen-induced arthritis (CIA) model was established, and rats were randomly given saline or naringenin (NAR, 10 mg/kg, 20 mg/kg, 50 mg/kg, i.p.) once a day, before being euthanized on the 42nd day of primary immunization. The pain-like behavior, articular index scores, account of synovial-infiltrated CD4+ T cells, and inflammatory factors were investigated in each group. In vitro, spleen CD4+ T lymphocytes were derived from each group. In addition, mitochondrial division inhibitor 1 (Mdivi-1) or NAR was added to the cell medium containing C-X-C motif chemokine ligand 12 (CXCL12) in order to induce CD4+ T lymphocytes, respectively. The polarization capacity of CD4+ T cells was evaluated through the immunofluorescence intensity of the F-actin and myosin light chain phosphorylated at Ser19 (pMLC S19), and the mitochondrial distribution was determined by co-localization analysis of the translocase of outer mitochondrial membrane 20 (TOM20, the mitochondrial marker) and intercellular adhesion molecule 1 (ICAM1, the uropod marker). The mitochondrial fission was investigated by detecting dynamin-related protein 1 (Drp1) and mitochondrial fission protein 1 (Fis1) using Western blot and immunofluorescence. This study revealed that high-dose NAR (50 mg/kg, i.p.) alleviated pain-like behavior and articular index scores, reduced the serum level of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α), and accounted for CD4+ T lymphocytes that infiltrated into the synovial membrane of the CIA group. Meanwhile, NAR (50 mg/kg, i.p.) suppressed the polarization of spleen CD4+ T lymphocytes, reduced the redistribution of mitochondria in the uropod, and inhibited the expression of Drp1 and Fis1 in the CIA model. Furthermore, the in vitro experiments confirmed that NAR reduced mitochondrial fission, which in turn inhibited the CXCL12-induced polarization and migration of CD4+ T lymphocytes. Our results demonstrated that the flavonoid NAR was a promising drug for the treatment of RA, which could effectively interfere with mitochondrial fission, thus inhibiting the polarization and migration of CD4+ T cells in the synovial membrane. [ABSTRACT FROM AUTHOR]

High-speed machining provides an efficient approach for machining Inconel 718 with high quality and high efficiency. For high-speed milling of Inconel 718 curved surface, the geometrical characteristics are changing continuously leading to a sharp fluctuation of cutting force, which will aggravate the tool wear. As the wear mechanism of coated cutting tool is seriously affected by the cutting tool geometrical parameters, suitable geometrical parameters of cutting tool should be selected to avoid the cutting tool from being worn out very quickly. In this study, the influence of cutting tool geometrical parameters on tool wear in high-speed milling of Inconel 718 curved surface is investigated with coated cutting tool, and the cutting force in milling process is also analyzed. The results show that the cutting force variation can manifest the tool wear degree, and the failure type of coated cutting tool in plane milling and curved surface milling after the same cutting length is different. Furthermore, the cutting tool geometrical parameters seriously affect the tool wear and the tool life in high-speed milling of Inconel 718 curved surface. Concretely, the small rake angle has greater strength and has superiority, the relief angle increasing can enhance the tool life, and the tool life is decreased with the increasing of helix angle for the cutting tool, whose helix angle is larger than 30°. This study provides a theoretical basis for cutting tool wear mechanism and cutting tool geometrical parameter selection in high-speed milling of Inconel 718 curved surface, so as to guarantee the machining efficiency in high-speed milling of Inconel 718 curved surface. [ABSTRACT FROM AUTHOR]

The tracking and contouring errors are inevitable in real computer numerical control contour following because of the reasons such as servo delay and dynamics mismatch. In order to improve the motion accuracy, this paper proposes a synergistic real-time compensation method of tracking and contouring errors for precise parametric curve following of the computer numerical control systems. The tracking error for each individual axis is first compensated, by using the feed-drive models with the consideration of model uncertainties, to enhance the tracking performances of all axes. Further, the contouring error is estimated and compensated to improve the contour accuracy directly, where a high-precision contouring-error estimation algorithm, based on spatial circular approximation of the desired contour neighboring the actual motion position, is presented. Considering that the system structure is coupled after compensation, the stability of the coupled system is analyzed for design of the synergistic compensator. Innovative contributions of this study are that not only the contouring-error can be estimated with a high precision in real time, but also the tracking and contouring performances can be simultaneously improved although there exist modeling errors and disturbances. Simulation and experimental tests demonstrate the effectiveness and advantages of the proposed method. [ABSTRACT FROM AUTHOR]

End-stage patients experience unbearable pain because of refractory symptoms.Palliative sedation is a form of palliative care which relieves patients' agony by lowering their consciousness.Standard palliative sedation can help patients die with dignity.It is distinct from euthanasia and does not alter the survival of patients.Sufficient palliative care is the premise of palliative sedation.Repeated and detailed clinical evaluation,as well as multidisciplinary involvement,is necessary for the standardized implementation of palliative sedation.Here,we proposed the standard process and specifications of palliative sedation in Peking Union Medical College Hospital.Furthermore,we reported a case of palliative sedation for an advanced cancer patient with refractory delirium and living pain to demonstrate its application in clinical practice.

Objective To summarize the palliative care consultations proposed by the Emergency Department of Peking Union Medical College Hospital. Methods A retrospective study was conducted on 22 palliative care consultations in the Emergency Department of Peking Union Medical College Hospital from January 2017 to June 2020. Results A total of 18 patients (6 males and 12 females) received palliative care consultations in the Emergency Department,with the average age of (65±8) years (36-88 years).Specifically,10 and 6 patients received once and twice consultations,respectively,and 2 patients did not complete the consultation.Of the patients receiving palliative care consultations,15 had malignant tumors and 3 had non-neoplastic diseases.The reasons for palliative care consultations included communication (61.1%,11/18) and pain relief (61.1%,11/18).In terms of the place of death,8 patients died in the hospital and 6 patients in other medical institutions. Conclusion There is a clear demand for palliative care consultation in the Emergency Department of Peking Union Medical College Hospital,and the consultation can bring help to both emergency doctors and patients.

Objective To explore the obstacles in palliative care consultation services and put forward the suggestions for improving the services in grade A tertiary hospitals. Methods A semi-structured interview was conducted with 17 medical workers who had requested palliative care consultation services in Peking Union Medical College Hospital. Results The palliative care consultation services were hindered by five obstacle factors including insufficient knowledge of patients and their families about palliative care,unsound understanding of medical workers about palliative care,poor implementation of consultation opinions,limited labor of palliative care team,and poor economic benefits from palliative care.In view of such obstacles,the following suggestions were put forward,which included increasing the acceptance of palliative care by patients and their families,enriching the knowledge of medical staff on palliative care,establishing a new cooperation model between consultation team and medical staff,strengthening the institutional guarantee for the development of palliative care,and establishing and perfecting the laws and policies related to palliative care. Conclusion Although there are many difficulties in the in-hospital palliative care consultation services in grade A tertiary hospitals,the demand and expectation of medical staff for palliative care are still increasing.

Objective To explore the effects of palliative care consultation on medical professionals who have requested it in Peking Union Medical College Hospital. Methods Semi-structured interviews were conducted with 17 medical professionals who had requested palliative care consultation.Results Palliative care consultation had the following positive effects:building a bridge for doctor-patient communication,providing psychological support to reduce the sense of occupational exhaustion for medical professionals,providing technical support for medical professionals to help patients relieve symptoms,helping medical professionals in the multidisciplinary learning of palliative care,adding humanistic care and neglected ethical concerns.Conclusion Palliative care consultation improves the quality of care for dying patients,and the capacity of consultation needs to be enhanced urgently.

Combined with the material characteristics of acupuncture needle, new connection technology and injection moulding technology, and through mechanical test, a new type of magnetic joint for electroacupuncture instrument, with regular appearance and simple manufacturing process, is developed, which can be connected with acupuncture needle in close range. This joint is composed of the inner magnet joint and the outer joint protective sleeve. The new conductive adhesive is used to simplify the manufacturing process. Its advantages include connection with acupuncture needle by magnetic force, being convenient to store when idle and easy to switch to the working state, and quick disconnection in case of emergency. This joint is connected safely and firmly with acupuncture needle by magnetic force, which shortens the operation time, improves the working efficiency, and effectively solves the problems existing in the crocodile clip connector.