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991.
Biodegradable Spheres Protect Traumatically Injured Spinal Cord by Alleviating the Glutamate‐Induced Excitotoxicity 下载免费PDF全文
Dongfei Liu Jian Chen Tao Jiang Wei Li Yao Huang Xiyi Lu Zehua Liu Weixia Zhang Zheng Zhou Qirui Ding Hélder A. Santos Guoyong Yin Jin Fan 《Advanced materials (Deerfield Beach, Fla.)》2018,30(14)
New treatment strategies for spinal cord injury with good therapeutic efficacy are actively pursued. Here, acetalated dextran (AcDX), a biodegradable polymer obtained by modifying vicinal diols of dextran, is demonstrated to protect the traumatically injured spinal cord. To facilitate its administration, AcDX is formulated into microspheres (≈7.2 µm in diameter) by the droplet microfluidic technique. Intrathecally injected AcDX microspheres effectively reduce the traumatic lesion volume and inflammatory response in the injured spinal cord, protect the spinal cord neurons from apoptosis, and ultimately, recover the locomotor function of injured rats. The neuroprotective feature of AcDX microspheres is achieved by sequestering glutamate and calcium ions in cerebrospinal fluid. The scavenging of glutamate and calcium ion reduces the influx of calcium ions into neurons and inhibits the formation of reactive oxygen species. Consequently, AcDX microspheres attenuate the expression of proapoptotic proteins, Calpain, and Bax, and enhance the expression of antiapoptotic protein Bcl‐2. Overall, AcDX microspheres protect traumatically injured spinal cord by alleviating the glutamate‐induced excitotoxicity. This study opens an exciting perspective toward the application of neuroprotective AcDX for the treatment of severe neurological diseases. 相似文献
992.
993.
《国际聚合物材料杂志》2012,61(2):91-94
In recent years, nano/micro wires have attracted considerable attention because of their extraordinary physical properties and enormous potential for applications in numerous fields of research and technology. Among the methods widely used to create nanowires, electrochemical deposition in the pores of ion-track polymer membranes have turned out to be very suitable. This method may also be used to synthesize nano/micro structures on the substrate itself to prevent post-synthesis manipulations. For this, the polycarbonate layer is spin coated on the semiconducting substrate and then irradiated with heavy ions. Chemical etching of these latent tracks leads to the formation of nano-/micro-size pores. After depositing metal in these pores, the polycarbonate templates are removed by dissolving them in dichloromethane, leading to the formation of nanowires standing on the substrate itself. Using this technique, we have studied VI characteristics of metallic nano/micro wires grown on the silicon substrate. These nano/micro structures show Schottky behavior when forward biased and ohmic behavior when reversed biased. 相似文献
994.
《国际聚合物材料杂志》2012,61(9):499-501
The authors studied the formation of a wafer-scale network of connected colloidal beads by reactive ion etching. The dimensions of the connections have been studied as a function of etching time for colloidal beads of different sizes, and could be well controlled. The authors have found that the nano-network forms and disappears for the same time of etching independent of the diameter of the polystyrene beads. With recent interest of connected colloidal networks in various optical sensing applications, such as photonic crystals, as surface-enhanced Raman scattering substrates, the studies have potential uses in the development of wafer-scale nanophotonic sensors. 相似文献
995.
A commercial crosslinked ionic polymer AV‐17 containing ? N(CH3)3Cl groups was used. The common compounds of Bi(III) and Al(III); Bi(III) and Cr(III); Bi(III) and Fe(III); Bi(III) and FeOOH and of three components—Bi(III), Fe(III), and Cr(III); Bi(III), FeOOH, and Cr(III) were obtained in the AV‐17 polymer phase and investigated using scanning electron microscopy, powder X‐ray diffraction, thermogravimetric analysis, and Fourier‐transform infrared spectroscopy. It was shown that metal‐containing compounds were concentrated on the surface of the polymer granules. The compounds were in the crystalline (BiOCl) or amorphous (jarosites and oxihydroxides) state. The morphology and composition of the metal‐containing ultra dispersed particles were different on the surface and in the volume of the polymer granule. Most of the metal‐containing compounds were in the form of pseudo spherical particles, but compounds containing Bi(III) and FeOOH in the volume of AV‐17 granule, were in the form of clew of nanometer fibers. Thermogravimetric analysis (in an N2 atmosphere) in the range 24–1000°C of the metallic compounds containing polymer was also carried out. The metal‐containing polymer samples were stable up to 120°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
996.
《国际聚合物材料杂志》2012,61(2-3):513-518
Abstract The calculation of complexes R n BF3-n . HF (there is R = CH3 and C2H5) has been carried out by the quantum-chemical semi-empirical MNDO method in Dewar and Teel parameterization. The geometrical and electronic structure of these complexes was obtained. On an example of simple H-acids we estimated their acid strength. We found that irrespective of the ligand surrounding of B atom the complexes R n BF3-n HF have rather high acid strength (pK a = 17.9 14.9). 相似文献
997.
998.
《Advanced Powder Technology》2014,25(5):1534-1540
SnO2/CoSn composites have been prepared by hydrolysis accompanied by carbothermal reduction. With the addition of cobalt, SnO2/CoSn nanoparticles self-assemble to form nano-micro-structure cluster even microparticles. The nano-micro-structure cluster not only shortens lithium-ion diffusion and electron transportation route, but also cohere together to form compact defense. This preserves the integrity of the structure and the capacity from fading during cycling. It exhibits the improved charge capacity of 627.3 mA h/g in the first cycle and 421.9 mA h/g after 50 cycles at 100 mA/g. It paves the way for practical applications of tin-based anodes. 相似文献
999.
N. Rodriguez A. Portavoce J. Delalleau C. Grosjean C. Girardeaux 《Thin solid films》2010,518(17):5022-5027
Arsenic (As) and phosphorus (P) implantations are concurrently used to create the n-zones of recent microelectronic device pn-junctions. We studied the As-P codiffusion effect on the junction depths during the dopant activation process. As diffusion is accelerated during codiffusion. The acceleration magnitude depends on As concentration and varies during annealing time. Contrasting with usual transient-enhanced-diffusion phenomena, a time delay can be observed before As diffusion acceleration occurs. P diffusion shows no specific modification due to codiffusion. Its diffusion behavior can be understood considering the usual Fermi level and electrical effects linked to the time evolution of the two dopant distributions. The behavior of As during codiffusion is discussed using finite element simulations. 相似文献
1000.