2,885 research outputs found
Opinion dynamics on directed small-world networks
In this paper, we investigate the self-affirmation effect on formation of
public opinion in a directed small-world social network. The system presents a
non-equilibrium phase transition from a consensus state to a disordered state
with coexistence of opinions. The dynamical behaviors are very sensitive to the
density of long-range interactions and the strength of self-affirmation. When
the long-range interactions are sparse and individual generally does not insist
on his/her opinion, the system will display a continuous phase transition, in
the opposite case with high self-affirmation strength and dense long-range
interactions, the system does not display a phase transition. Between those two
extreme cases, the system undergoes a discontinuous phase transition.Comment: 6 pages, 5 figure
Neuroprotective effects of bis(7)-tacrine against glutamate-induced retinal ganglion cells damage
<p>Abstract</p> <p>Background</p> <p>Glutamate-mediated excitotoxicity, primarily through N-methyl-D-aspartate (NMDA) receptors, may be an important cause of retinal ganglion cells (RGCs) death in glaucoma and several other retinal diseases. Bis(7)-tacrine is a noncompetitive NMDA receptors antagonist that can prevent glutamate-induced hippocampal neurons damage. We tested the effects of bis(7)-tacrine against glutamate-induced rat RGCs damage in vitro and in vivo.</p> <p>Results</p> <p>In cultured neonatal rats RGCs, the MTT assay showed that glutamate induced a concentration- and time-dependent toxicity. Bis(7)-tacrine and memantine prevented glutamate-induced cell death in a concentration-dependent manner with IC50 values of 0.028 μM and 0.834 μM, respectively. The anti-apoptosis effects of bis(7)-tacrine were confirmed by annexin V-FITC/PI staining. In vivo, TUNEL analysis and retrograde labeling analysis found that pretreatment with bis(7)-tacrine(0.2 mg/kg) induced a significant neuroprotective effect against glutamate-induced RGCs damage.</p> <p>Conclusions</p> <p>Our results showed that bis(7)-tacrine had neuroprotective effects against glutamate-induced RGCs damage in vitro and in vivo, possibly through the drug's anti-NMDA receptor effects. These findings make bis(7)-tacrine potentially useful for treating a variety of ischemic or traumatic retinopathies inclusive of glaucoma.</p
Developing a novel rabbit model of atherosclerotic plaque rupture and thrombosis by cold-induced endothelial injury
<p>Abstract</p> <p>Background</p> <p>It is widely believed that atherosclerotic plaque rupture and subsequent thrombosis leads to acute coronary events and stroke. However, study of the mechanism and treatment of human plaque rupture is hampered by lack of a suitable animal model. Our aim was to develop a novel animal model of atherosclerotic plaque rupture to facilitate the study of human plaque disruption and thrombosis.</p> <p>Methods</p> <p>28 healthy male New Zealand white rabbits were randomly divided into two groups: rabbits in group A (n = 12) were only fed a high-fat diet for eight weeks; rabbits in group B (n = 16) underwent cold-induced endothelial injury with liquid nitrogen, then were given a high-fat diet for eight weeks. After completion of the preparatory regimen, triggering of plaque rupture was attempted by local injection of liquid nitrogen in both groups.</p> <p>Results</p> <p>All rabbits in group B had disrupted plaques or rupture-driven occlusive thrombus formation, but none in group A showed any effects. More importantly, the cold-induced plaques in our model were reminiscent of human atherosclerotic plaques in terms of architecture, cellular composition, growth characteristics, and patterns of lipid accumulation.</p> <p>Conclusion</p> <p>We successfully developed a novel rabbit model of atherosclerotic plaque rupture and thrombosis, which is simple, fast, inexpensive, and reproducible, and has a low mortality and a high yield of triggering. This model will allow us to better understand the mechanism of human plaque rupture and also to develop plaque-stabilizing therapies.</p
Thermal Analysis and Characterization of Polystyrene Initiated by Benzoyl Peroxide
PresentationBased on the complexity of the polystyrene polymerization mechanism initiated by benzoyl peroxide (BPO), the thermal risk of the reaction process was estimated using thermal analysis and characterization. The polymerization process was thermally analysed using an adiabatic rate calorimeter and differential scanning calorimeter. The results demonstrated that the onset reaction temperature, adiabatic temperature rise, and maximum temperature of the synthesis reaction of BPO-initiated polymerization were lower than those of thermos initiated polymerization. Moreover, nuclear magnetic resonance imaging, gel permeation chromatography, and Fourier transform infrared spectrometry were used to characterize the polymerization products obtained under the two initiation conditions. The polystyrene obtained using the two initiation methods had the same hydrogen structure; however, their molecular weight and distribution uniformity differed considerably, and the BPO-initiated process was discovered to include the effects of the thermos initiated process. Moreover, the free radicals produced by BPO decomposition participated in the chain reaction of polystyrene polymerization, accelerated instantaneous grain growth, and promoted the formation of short- chain polystyrene. In summary, the BPO-initiated polymerization process exhibited the desired thermal safety characteristics and has potential for practical use
Control of absorption of monolayer MoS thin-film transistor in one-dimensional defective photonic crystal
The light absorption and transmission of monolayer MoS in a
one-dimensional defective photonic crystal (d-1DPC) is theoretically
investigated. The study shows that the strong interference effect decreases
photon density in particular areas of the microcavity. The d-1DPC can reduce
light absorption of monolayer MoS and enhance light transmission. The
impact of monolayer MoS light absorption on the localization effect of
photon is investigated when monolayer MoS and the organic light-emitting
diode are located in the same microcavity. However, monolayer MoS does
not reduce the localization effect of light by regulating the position of
monolayer MoS in the microcavity.Comment: 5pages,5figure
Obstacles Existed in the Labor Union’s Endeavors to Protect the Employees’ Rights and Some Wayouts
With deepened economy reformation in China, labor relation becomes more and more complicated, and labor relation conflicts are sharpened increasingly. The interior employees’ rights are encroached frequently and the number of labor conflicts climbs dramatically. However, the impacts of the labor union, with protecting employees’ rights as its basic function, are far from meeting the employees’ satisfaction. This article analyses the labor union’s functions and its right-protection measures. The existing problems are discussed and some countermeasures are put forward. Key Words: Labor Union, Function, Obstacle, Countermeasure Résumé A cause de la contradiction de la relation de travail de plus en plus intense, les droits et les intérêts légals des ouvriers et employés tenant le bas du pavé sont à maintes reprises violés et les litiges de travail montent en flèche. Cependant, le rôle réel que joue le syndicat dont la fonction fondamentale consiste à sauvegarder les droits et les intérêrs des ouvriers et employés est loin de répondre à leurs demandes. L’auteur analyse dans cet article les fonctions et les moyens de sauvegarde des droits du syndicat, examine les problèmes existants dans ce domaine et propose des contre‐mesures. Mots-clés: le syndicat ,la fonction, les obstacles, les contre‐mesures 摘 要 由於勞動關係矛盾日益尖銳,處於弱者地位的職工合法權益屢遭侵犯,勞動爭議急劇上升。但以維護職工合法權益爲其基本職責的工會所發揮的實際作用卻遠不能滿足職工的要求。本文分析了工會的職能和維權手段,探討了工會在維權方面所存在的問題,提出了相應的對策。關鍵詞: 工會;職能;障礙;對
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