2,378 research outputs found

    Doxycycline inhibits the infiltration of inflammatory cells in rat alkali burn corneas

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    AIM: To investigate the inhibited effect of Doxycycline on the infiltration of inflammatory cells in rat alkali burn corneas. METHODS: Corneas of 32 SD rats were injured with 1mol/L NaOH, then divided into two groups: control and doxycycline-treated. All agents were administered topically 4 times daily. Slit-lamp microscope was performed and inflammatory index was calculated at 3, 7, 14 and 21 days after injury. Then 4 rats were randomly sacrificed and each cornea was divided into two parts, one for histopathology, the other for ICAM-1 ELISA assay. RESULTS:In control group, the inflammatory index and the number of inflammatory cell was higher than the doxycycline-treated dramatically at all time points(P<0.05). Compared with control group, corneal ICAM-1 expression decreased significantly in doxycycline-treated group at all time points(P < 0.05). CONCLUSION:Doxycycline may inhibit inflammatory cell infiltration by down-regulating ICAM-1 expression

    Experimental investigations of stress-gas pressure evolution rules of coal and gas outburst: A case study in Dingji coal mine, China

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    Coal and gas outburst is a potentially fatal risk during the mining of gassy coal seams, which seriously threatens the safe mining of collieries. To understand the outburst mechanism and evolution rules, a new apparatus (LSTT) was developed to conduct simulated experiment. In the context of an outburst accident in Dingji coal mine, the authors launched an authentic outburst experiment to replay the outburst accident. Experimental apparatus, similar criterion, coalā€like materials and gas sources, and experimental design were discussed systematically in this paper. Experimentally, the study analyzed the geoā€stress has significant influence on the outburst evolution. At the driving face, the stress concentration possibly caused gas outburst, under the influence of miningā€induced stress. After the outburst occurred, the stress balance of the coal changed, resulting in the instability of the coal. Furthermore, the elastic energy, gas enthalpy, and gravitational potential energy were released rapidly. The experimental result stated that outburst coal has the sorting characteristics, in line with the field outburst law. The intensity prediction model has been built based on the energy model. Moreover, the factors that impact outburst intensity were analyzed. In the process of coal and gas outburst, the gas enthalpy of gas and the elastic potential of coal are the main energy sources. This study provides guidance for the development of the outburst mechanism and outburst mine management

    The Study of the Composite Material Go/CF/PTFE Tribological Property

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    In this paper, the composite material Go/CF/PTFE tribological property was studied. The test of its mechanical property, and the fabrication of the filled PTEE composite material sample which is based on the technology of cold press molding and sinter molding proved that adding Go and CF moderately to the composite material was an efficient way to improve its mechanical property. Meanwhile the process of friction and wear trial and SEM analysis results of the micro-structure of wear pattern proved that the addition of the Go and CF tremendously improved the anti-wear property and that after the addition the plowing effect which took place on the material surface would turn into a kind of mixed wear effect that includes plowing effect and fatigue wear. Working as pinning and bridging, the Go which distributing uniformly in the matrix was able to improve the resistance and substantially resisted the crack propagation, therefore to a certain degree enhanced the intensity of composite material and prolong its lifespan

    Geometric bionics: Lotus effect helps polystyrene nanotube films get good blood compatibility

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    Various biomaterials have been widely used for manufacturing biomedical applications including artificial organs, medical devices and disposable clinical apparatus, such as vascular prostheses, blood pumps, artificial kidney, artificial hearts, dialyzers and plasma separators, which could be used in contact with blood^1^. However, the research tasks of improving hemocompatibility of biomaterials have been carrying out with the development of biomedical requirements^2^. Since the interactions that lead to surface-induced thrombosis occurring at the blood-biomaterial interface become a reason of familiar current complications with grafts therapy, improvement of the blood compatibility of artificial polymer surfaces is, therefore a major issue in biomaterials science^3^. After decades of focused research, various approaches of modifying biomaterial surfaces through chemical or biochemical methods to improve their hemocompatibility were obtained^1^. In this article, we report that polystyrene nanotube films with morphology similar to the papilla on lotus leaf can be used as blood-contacted biomaterials by virtue of Lotus effect^4^. Clearly, this idea, resulting from geometric bionics that mimicking the structure design of lotus leaf, is very novel technique for preparation of hemocompatible biomaterials
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