91 research outputs found

    Effects of transplanted GDNF gene modified marrow stromal cells on focal cerebral ischemia in rats

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    Objective: To evaluate the therapeutic effect of transplanted glial cell derived neurotrophic factor (GDNF) modified marrow stromal cells (MSCs) on an experimental ischemic brain injury based on the behavioral, morphological, and immunohistochemical observations. Methods: The MSCs from four-week newborn rats were cultured in vitro. The cerebral ischemia and reperfusion model was established in adult Sprague–Dawley (SD) rats by using the suture method. Three days after model establishment, the animals were injected with prepared MSCs via their caudal veins. The animals were then divided into a sham-operation group, ischemia group, MSCs transplantation group, or GDNF+ MSCs transplantation group and were scored for their neurobehavioral manifestations at 3, 14, and 28 days after the transplantation was performed. At this time, the survival condition of intracerebral transplanted cells was measured by laser confocal microscopy while the effect of transplantation on the Generic Digital Beam Former (GDNF) expression in the ischemic brain tissue was evaluated. Results: The MSCs cells transfected with GDNF gene were characterized by green fluorescence. Three days after the transplantation, the animals that underwent the cell transplantation showed significantly better behavioral data than the controls. Fourteen days after transplantation, the animals transplanted with GDNF gene modified MSCs were better than those transplanted with common MSCs. As compared with common MSCs transplantation, GDNF+MSCs transplantation was significantly more effective in reducing apoptotic cell volume and enhancing Bcl-2 expression, which was favorable for the ischemic brain injury. Conclusions: Transplanted GDNF modified MSCs can improve the nervous function and have a protective effect on the ischemic brain injury through reducing apoptotic cell volume and enhancing the expression of anti-apoptotic gene Bcl-2

    Disturbance observer-based adaptive sliding mode synchronization control for uncertain chaotic systems

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    The synchronization control problem of a class of chaotic systems with unknown uncertainties and outside perturbation is addressed in this article by employing an innovative adaptive sliding mode controller (SM, SMC) constructed using a disturbance observer (DO). For the synchronous error system, the external disturbances estimated by the disturbance observer cannot be measured directly. If the appropriate gain matrix is chosen, the DO can approximate the unknown external disturbances well. Then a continuous adaptive SM controller based on the DO's output is designed by using adaptive techniques and the system dimensional expansion method. The Duffing-Holmes chaotic system is finally selected to numerically test the efficiency of the suggested strategy

    Functional similarities between pigeon \u27milk\u27 and mammalian milk : induction of immune gene expression and modification of the microbiota

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    Pigeon ‘milk’ and mammalian milk have functional similarities in terms of nutritional benefit and delivery of immunoglobulins to the young. Mammalian milk has been clearly shown to aid in the development of the immune system and microbiota of the young, but similar effects have not yet been attributed to pigeon ‘milk’. Therefore, using a chicken model, we investigated the effect of pigeon ‘milk’ on immune gene expression in the Gut Associated Lymphoid Tissue (GALT) and on the composition of the caecal microbiota. Chickens fed pigeon ‘milk’ had a faster rate of growth and a better feed conversion ratio than control chickens. There was significantly enhanced expression of immune-related gene pathways and interferon-stimulated genes in the GALT of pigeon ‘milk’-fed chickens. These pathways include the innate immune response, regulation of cytokine production and regulation of B cell activation and proliferation. The caecal microbiota of pigeon ‘milk’-fed chickens was significantly more diverse than control chickens, and appears to be affected by prebiotics in pigeon ‘milk’, as well as being directly seeded by bacteria present in pigeon ‘milk’. Our results demonstrate that pigeon ‘milk’ has further modes of action which make it functionally similar to mammalian milk. We hypothesise that pigeon ‘lactation’ and mammalian lactation evolved independently but resulted in similarly functional products

    The Research of University Librarians Participating in the Guidance of University Students’ Discipline Competition

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    The discipline competition of college students is an important part of innovation and entrepreneurship education, and is increasingly valued. As an important teaching auxiliary department, university libraries have a large number of library resources and a sufficient number of teachers, and should actively participate in the guidance of discipline competitions. To this end, we should determine the scope of the subject competition, establish a team of instructors, choose the suitable students participating in the competition, optimize the layout of the library to facilitate students to participate in the competition, strengthen the cooperation between schools and enterprises, and establish the database of the subject competition of excellent entries in the school
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