The application of coordinate transformation matrix into the multi-degree of freedom vibration control

This paper describes the application of the coordinate transformation matrices into the multi-degree of freedom vibration control. An example with an aluminum beam supported by dual actuators is used to derive how to create both the input transformation matrix and the output transformation matrix. In order to achieve the synchronous movement of the dual actuators, the direct actuator control test and 2DOF control test have been performed. By comparing with the results of the direct actuator control test without using the transformation matrix, the 2DOF control test proves that the transformation matrix is a powerful tool for a significant improvement in test control accuracy

Study on multi-axis sine vibration test control techniques

This paper describes several key aspects about multi-axis sine vibration test control techniques including the identification of the system frequency response function, synchronization of the input and output signals, the generation of the sinewave, the control algorithm, etc. A multi-axis sine vibration controller is developed based on these key techniques and the major framework of the controller is introduced. Finally, a dual axial experiment is carried out by the controller. The test results show the feasibility of the control algorithm and the good control strategy of the multi-axis sine vibration controller in which the key techniques are realized

Evidence for a Novel, Caspase-8-Independent, Fas Death Domain-Mediated Apoptotic Pathway

Certain caspase-8 null cell lines demonstrate resistance to Fas-induced apoptosis, indicating that the Fas/FasL apoptotic pathway may be caspase-8-dependent. Some reports, however, have shown that Fas induces cell death independent of caspase-8. Here we provide evidence for an alternative, caspase-8-independent, Fas death domain-mediated apoptotic pathway. Murine 12B1-D1 cells express procaspase-3, -8, and -9, which were activated upon the dimerization of Fas death domain. Bid was cleaved and mitochondrial transmembrane potential was disrupted in this apoptotic process. All apoptotic events were completely blocked by the broad-spectrum caspase inhibitor Z-VAD-FMK, but not by other peptide caspase inhibitors. Cyclosporin A (CsA), which inhibits mitochondrial transition pore permeability, blocked neither pore permeability disruption nor caspase activation. However, CsA plus caspase-8 inhibitor blocked all apoptotic events of 12B1-D1 induced by Fas death domain dimerization. Our data therefore suggest that there is a novel, caspase-8-independent, Z-VAD-FMK-inhibitable, apoptotic pathway in 12B1-D1 cells that targets mitochondria directly

A whole row automatic pick-up device using air force to blow out vegetable plug seedlings

Aim of study: To develop a whole row automatic pick-up device using air force to blow out plug seedlings, to avoid the damage to seedlings that the current way of seedling picking by needle insertion induces.Area of study: Jiangsu Province, China.Material and methods: We designed a pick-up device which mainly consists of a seedling transporting device, a seedling air loosening device, a seedling clamping device and an automatic control system. The damage rate of seedling was significantly reduced and the success rate of seedling picking was increased by using the new seedling air loosening method and the new designed end-effectors. A prototype of the new pick-up device was produced according to the calculation results, and the performance tests were arranged under actual production conditions in an indoor laboratory.Main results: The calculation showed that when the diameter of the blowhole in air nozzle is 3.5 mm, and the air pressure is between 0.146 MPa and 0.315 MPa, the seedlings can be blown out successfully. Besides, the clamping strain test showed that the new designed end-effector can meet the requirements of seedling picking. The orthogonal test showed that both the air pressure and water content significantly affected the success ratio. The success ratio reached 96.64% when air pressure was 0.4 MPa, water content was 55%-60% and airflow rate was 100%, what meets the current requirements of transplanting.Research highlights: This research can provide some references for the automatic transplanting technology

The application of improved signal summing method into the spacecraft force limited vibration test

This paper provides an improved signal summing method for the spacecraft force limited vibration test system with eight force transducers. The key point for this method is to change the combination way of the signals coming out of the eight force transducers while the formulas inside the signal conditioning amplifier have been used skillfully. This method had been successfully adopted in the spacecraft force limited vibration test and the accuracy requirements of key force and moment signals have been met. And this method has been proved to be a very powerful tool for providing the critical force and moment data used to determine the force limited profile during the spacecraft dynamic test

Health monitoring device design and application for large synchronously excited multi-shaker vibration test facility

There are different kinds of equipments distributed in different locations for a large complicated multi-shaker vibration test facility, so it is challenging to monitor the real state of test facility thoroughly during its operation. Long-term operation of this test facility will lead to the degradation of reliability and malfunction, and sometimes the emergency stop of the whole test system that threatens the safety of the spacecraft seriously. This paper presents in detail the design and application of a set of health monitoring device for a large multi-shaker vibration test facility which is capable of monitoring the operation state in real time and predicting the potential malfunction of the whole test facility to ensure the reliability of this large test system and safety of the spacecraft during its environmental vibration test

Establishment of a gnotobiotic pig model of Clostridioides difficile infection and disease

Clostridioides difficile (C. difficile) is a gram-positive, spore-forming, anaerobic bacterium known to be the most common cause of hospital-acquired and antibiotic-associated diarrhea. C. difficile infection rates are on the rise worldwide and treatment options are limited, indicating a clear need for novel therapeutics. Gnotobiotic piglets are an excellent model to reproduce the acute pseudomembranous colitis (PMC) caused by C. difficile due to their physiological similarities to humans and high susceptibility to infection. Here, we established a gnotobiotic pig model of C. difficile infection and disease using a hypervirulent strain. C. difficile-infected pigs displayed classic signs of C. difficile infection, including severe diarrhea and weight loss. Inoculated pigs had severe gross and microscopic intestinal lesions. C. difficile infection caused an increase in pro-inflammatory cytokines in samples of serum, large intestinal contents, and pleural effusion. C. difficile spores and toxins were detected in the feces of inoculated animals as tested by anaerobic culture and cytotoxicity assays. Successful establishment of this model is key for future work as therapeutics can be evaluated in an environment that accurately mimics what happens in humans. The model is especially suitable for evaluating potential prophylactics and therapeutics, including vaccines and passive immune strategies.Instituto de VirologíaFil: Nyblade, Charlotte. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Parreño, Gladys Viviana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Virología e Innovaciones Tecnológicas; ArgentinaFil: Parreño, Gladys Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Parreño, Gladys Viviana. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Zhou, Peng. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Hensley, Casey. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Oakes, Vanessa. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Mahsoub, Hassan M. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Mahsoub, Hassan M. Virginia Polytechnic Institute and State University. Center for Emerging, Zoonotic, and Arthropod‑Borne Pathogens; Estados UnidosFil: Kiley, Kelsey. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Frazier, Maggie. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Frazier, Annie. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Zhang, Yongrong. University of Maryland at Baltimore. Department of Microbial Pathogenesis; Estados UnidosFil: Feng, Hanping. University of Maryland at Baltimore. Department of Microbial Pathogenesis; Estados UnidosFil: Yuan, Lijuan. Virginia Polytechnic Institute and State University. Virginia-Maryland College of Veterinary Medicine. Department of Biomedical Sciences and Pathobiology; Estados UnidosFil: Yuan, Lijuan. Virginia Polytechnic Institute and State University. Center for Emerging, Zoonotic, and Arthropod‑Borne Pathogens; Estados Unido

Immunological consequences of apoptosis in a tumor system

Cell lines genetically deficient in caspase-8 have been shown to be resistant to Fas-induced apoptosis, indicating that this pathway may be caspase-8-dependent. Some reports, however, have shown that Fas can induce cell death independent of caspase-8. In this study, we provide evidence for an alternative, caspase-8-independent, Fas death domain-mediated apoptotic pathway in the BCR-ABL positive leukemia cell line, 12B1-D1. Our data suggest that there is a novel, caspase-8-independent, Z-VAD-FMK inhibitable, apoptotic pathway in 12B1-D1 cells that targets mitochondria directly. In attempting to develop effective anti-cancer immunotherapies the relative ability of apoptotic cells to induce an immune response remains an important but controversial consideration. Apoptotic tumor cells can theoretically be a suitable antigen source for stimulation of anti-tumor responses. HSPs can act as danger signals to the immune system. We, therefore, hypothesize that the immunogenicity of apoptotic cell may be enhanced if endogenous HSP expression is induced, or an exogenous source of HSPs is present. To induce endogenous HSPs expression, the engineered 12B1-D1 cells are heat stressed before the induction of apoptosis by AP20187. These stressed apoptotic 12B1-D1 cells express HSP60 and HSP72 on their surface. Vaccination of mice with stressed apoptotic 12B1-D1 cells, but not non-stressed ones, elicits a potent cell-mediated anti-tumor immunity that significantly retards tumor progression. We have further demonstrated that, stressed apoptotic cells had higher abilities to upregulate the co-stimulatory molecules on the surface of DC, to stimulate DC to secrete proinflammatory cytokines, and to enhance their immunostimulatory functions. We further explored whether the immunogenicity of non-stressed apoptotic cell can be enhanced if an exogenous source of HSPs is present at the vaccination site. We used liver derived chaperone proteins co-injected with non-stressed apoptotic tumors to mice. Reproducibly this resulted in the generation of a durable and specific T-cell-mediated anti-tumor immunity. In summary, we have demonstrated that apoptotic tumor cells can be either immunogenic or non-immunogenic and DC may play a key role in determining the immunological consequences of apoptotic tumor cells. We have further demonstrated that normal tissue (liver) MCC may function as a danger signal for the immune system. These may provide new insights for combining immunotherapy with conventional therapies for treatment of cancers