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[en] Chronic social stress and/or pharmacological treatments differentially modulate the expression of c-Fos, a marker of neuronal activity, in subregions of the rat brain. Here, we examined the effect of the atypical antipsychotic Clozapine (Clz) (20 mg/kg/day for 3 weeks) on the neuronal activation pattern of c-Fos protein expression in stress-relevant brain subregions of adult male Wistar rats exposed to chronic social isolation (CSIS: 3 weeks), an animal model of depression and schizophrenia, and controls. The protein expression of c-Fos was also used to map neuronal populations in brain subregions activated by CSIS alone. Subregions which showed significantly increased c-Fos protein expression following CSIS included the retrosplenial cortex (RSC), (subregions:RSC granular cortex, c region (RSGc) and dysgranular (RSD)), dentate gyrus, dorsal (DGd), paraventricular thalamic nucleus, posterior part (PVP), lateral (LA)/basolateral (BL) complex of amygdala, caudate putamen (CPu) and accumbens nucleus, shell (AcbSh). Increases in c-Fos protein expression in the RSGc, RSD, DGd, PVP, LA/BL complex of amygdala and striatum (CPu, Acb Core (AcbC) and AcbSh) following Clz treatment in controls were found. Clz applied simultaneously with CSIS modulated neuronal activity in CPu, AcbC and AcbSh subregions compared to CSIS alone, increasing c-Fos protein expression. Furthermore, Clz revealed synergistic effects with CSIS in the CA1d and PVP. These identified neural circuits reflect brain subregions activated following CSIS and/or Clz administration. These data further contribute to the understanding of the effectiveness of Clz in the modulation of brain subregion activation in response to CSIS. © 2019
[en] This research is focused on improving the efficiency of the anion exchange process for purifying plutonium. While initially focused on plutonium, the technology could also be applied to other ion-exchange processes. Work in FY17 focused on the improvement and optimization of porous foam columns that were initially developed in FY16. These foam columns were surface functionalized with poly(4-vinylpyridine) (PVP) to provide the Pu specific anion-exchange sites. Two different polymerization methods were explored for maximizing the surface functionalization with the PVP. The open-celled polymeric foams have large open pores and large surface areas available for sorption. The fluid passes through the large open pores of this material, allowing convection to be the dominant mechanism by which mass transport takes place. These materials generally have very low densities, open-celled structures with high cell interconnectivity, small cell sizes, uniform cell size distributions, and high structural integrity. These porous foam columns provide advantages over the typical porous resin beads by eliminating the slow diffusion through resin beads, making the anion-exchange sites easily accessible on the foam surfaces. The best performing samples exceeded the Pu capacity of the commercially available resin, and also offered the advantage of sharper elution profiles, resulting in a more concentrated product, with less loss of material to the dilute heads and tails cuts. An alternate approach to improving the efficiency of this process was also explored through the development of a microchannel array system for performing the anion exchange.
[en] Ternary complexes of bismuth nanoparticles with β-cyclodextrin and polyvinylpyrrolidone are studied via UV and visible spectroscopy and dynamic light scattering. It is shown that, depending on the ratio of the concentrations of β-cyclodextrin to polyvinylpyrrolidone in a synthetic medium, bismuth nanoparticles can be stabilized sterically either by distributing polyvinylpyrrolidone molecules over the surface of a complex of nanoparticles with β-cyclodextrin or by forming inclusion complexes of nanoparticles in the hydrophobic cavity of β-cyclodextrin as a result of associated β-cyclodextrin molecules being pushed apart by polyvinylpyrrolidone molecules. The conditions are determined for the formation of ternary complexes that are aggregatively stable for 20 days and are characterized by a unimodal particle size distribution.
[en] Highlights: • A highly selective morphology formation of Cu-Ni nanocrystals is developed. • Nanocrystals evolve from nanoplates to nanowires with increasing PVP amount. • Nanoplates/nanowires are well dispersed and have high crystallinity and uniformity. • A mechanism is proposed for the formation of Cu-Ni nanocrystals. • Nanoplates/nanowires show better catalytic activities than conventional catalyst.
[en] The helical micro/nanofiber arrays of polyvinylpyrrolidone (PVP) were successfully prepared by Near-field electrospinning(NFES) with different concentrations of PVP and different voltages by a gradient of per 0.5 kV from 1 kV to 2.2 kV. It is found that the morphology of the arrayed fibers evolved with regularity with the increase of the working voltage, and the uniformity of the fiber arrays also increased. The formation mechanism of the arrayed helical micro/nanofibers was analyzed. This may be a cost-effective method for the large-scale production of morphologically controllable spiral fibers, which opens up an effective way for the precise and controlled deposition of electrospun helical fibers and the integration of single or array spiral fibers with functional devices. (paper)
[en] Pb(Zr0.52Ti0.48)O3 nanocrystals were synthesized by a hydrothermal method. The poly(vinyl pyrrolidone) (PVP) was used as the surfactant to control growth of the Pb(Zr0.52Ti0.48)O3 nanocrystals. The effect of PVP concentration, reaction temperature and time on morphologies and crystallinity of Pb(Zr0.52Ti0.48)O3 nanocrystals were investigated. The tetragonal PbZr0.52Ti0.48O3 grains were obtained, as they were prepared at 200 °C for 4 h with PVP concentration from 0.1 to 10.0 g/L. With increasing the PVP concentration from 0.1 to 10.0 g/L, the size of PbZr0.52Ti0.48O3 grains decreased. When the PbZr0.52Ti0.48O3 grains were prepared at 200 °C for 12 h with PVP concentration of 6.0 g/L, the PbZr0.52Ti0.48O3 nanocrystals with average diameter of 30 nm were formed.
[en] Highlights: • The branched MoS2 nanowires were facile synthesized. • The PVP played an important role in forming the branched MoS2 nanowires. • The growth mechanism of branched MoS2 nanowires was proposed. - Abstract: In this work, the branched MoS2 nanowires are synthesized by a facile and feasible reflux method. It is clearly that the MoS2 nanowires interconnect with each other, forming regular branched network. In this fabrication, the polyvinyl pyrrolidone (PVP) is used as surfactant which is critical for the formation of branched MoS2 wires. Without the PVP, only MoS2 nanoparticles can be obtained.
[en] Colorimetric solid-phase extraction (C-SPE) has been previously explored as a means to monitor the iodine-based disinfectant used in the water systems on board the space shuttle. This same disinfectant is baselined for eventual deployment in the US water recovery system planned for node 3 of the International Space Station (ISS). With C-SPE, the I2 concentration is determined from the diffuse reflectance spectrum (DRS) of the yellow iodine-poly(vinylpyrrolidone) (PVP) complex using the Kubelka-Munk function. However, the solution chemistry of iodine is very complex and results in a variety of inorganic species (e.g., I-, I2, I3-, HOI) that have very different biocidal capabilities. Thus, the nature of the interaction of iodine with PVP, and more specifically, the identity of the iodine species involved in the interaction, requires more elucidation. This paper reports the findings from a series of detailed experiments conducted to elicit a more complete understanding of the iodine-PVP system employed in C-SPE. The results indicate that I2, one of the two dominant biocidal forms of iodine, is the species responsible for the analytical signal in our C-SPE platform. These findings lay the ground work for the planned development of a multiplexed iodine determination and speciation platform for in-flight analysis of spacecraft water samples
[en] Objective: To study and compare the clinical efficacy between the percutaneous vertebroplasty (PVP) and conservative treatment in the treatment of osteoporotic vertebral compression fracture (OVCF) in spine. Methods: 60 cases of OVCF were treated with PVP or conservative treatment Among them, 30 cases were performed with PVP and 30 cases were conservative treated. The clinical efficacy in 2 week and 3 months between the two groups were analysed. Results: The efficacy of PVP was better than conservative treatment in 2 weeks. The equal efficacy appeared in 3 months. Conclusion: PVP and conservative treatment all are effective ways in treating OVCF. PVP can release the pain more efficacy than conservative treatment in 2 weeks. (authors)