A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models wer...A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models were treated with tacrolimus gavage （4 mg/kg per day） for 0, 2, 4 and 6 weeks. Specimens were harvested at 6 weeks of intragastric administration. Masson staining revealed that the collagen fiber content and scar area in the nerve anastomosis of the sciatic nerve injury rats were significantly reduced after tacrolimus administration. Hematoxylin-eosin staining showed that tacrolimus significantly increased myelinated nerve fiber density, average axon diameter and myelin sheath thickness. Intragastric administration of tacrolimus also led to a significant increase in the recovery rate of gastrocnemius muscle wet weight and the sciatic functional index after sciatic nerve injury. The above indices were most significantly improved at 6 weeks after of tacrolimus gavage. The myelinated nerve fiber density in the nerve anastomosis and the sciatic nerve functions had a significant negative correlation with the scar area, as detected by Spearman＇s rank correlation analysis. These findings indicate that tacrolimus can promote peripheral nerve regeneration and accelerate the recovery of neurological function through the reduction of scar formation.展开更多
Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancien...Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancient uplift slope of the middle of Sichuan. With the exploration and development of high temperature and high pressure carbonate reservoir, a large number of challenges and problems, such as long isolation section, active oil-gas show, large temperature difference, prone to super retarding cement slurry and gas channeling at flare position, have been encountered in the cementing of 177.8 mm hang-liner. In order to solve these problems, numerous measures and methods have been put into use for reducing the safety risk of cementing and improving cementing quality. The large temperature difference channeling cement slurry system, effective anti-pollution spacer and high-pressure packer type liner hanger were developed and applied for field tests in the early stage of development. In addition, equilibrium pressure cementing technology, optimizing of centralizer placement and plasma column structure, improvement of pump displacement and hold pressure while waiting on cement were used to ensure nice displacement efficiency and cementing quality. As Moxi X well for example, the cementing quality factor of merit was 40.29% and the qualification rate was up to 78.87% after adopting the cementing measures and methods above. The cementing quality was much higher than previous level and provided technical support for Gaoshiti-Moxi area.展开更多
Methane hydrate preparation is an effective method to store and transport methane.In promoters to facilitate methane hydrate formation,homogeneous surfactant solutions,sodium dodecyl sulfate(SDS)in particular,are more...Methane hydrate preparation is an effective method to store and transport methane.In promoters to facilitate methane hydrate formation,homogeneous surfactant solutions,sodium dodecyl sulfate(SDS)in particular,are more favorable than heterogeneous particles,thanks to their faster reaction rate,more storage capacity,and higher stability.Foaming,however,could not be avoided during hydrate dissociation with the presence of SDS.This paper investigated the ability of five fluorinated surfactants:potassium perfluorobutane sulfonate(PBS),potassium perfluorohexyl sulfonate(PHS),potassium perfluorooctane sulfonate(POS),ammonium perfluorooctane sulfonate(AOS),and tetraethylammonium perfluorooctyl sulfonate(TOS)to promote methane hydrate formation.It was found that both PBS and PHS achieve a storage capacity of 150(V/V,the volume of methane that can be stored by one volume of water)within 30 min,more than that of SDS.Cationic ions and the carbon chain length were then discussed on their effects during the formation.It was concluded that PBS,PHS,and POS produced no foam during hydrate dissociation,making them promising promoters in large-scale application.展开更多
基金supported by the National Natural Science Foundation of China, No. 81171694
文摘A sciatic nerve transection and repair model was established in Sprague-Dawley rats by transecting the tendon of obturator internus muscle in the greater sciatic foramen and suturing with nylon sutures. The models were treated with tacrolimus gavage （4 mg/kg per day） for 0, 2, 4 and 6 weeks. Specimens were harvested at 6 weeks of intragastric administration. Masson staining revealed that the collagen fiber content and scar area in the nerve anastomosis of the sciatic nerve injury rats were significantly reduced after tacrolimus administration. Hematoxylin-eosin staining showed that tacrolimus significantly increased myelinated nerve fiber density, average axon diameter and myelin sheath thickness. Intragastric administration of tacrolimus also led to a significant increase in the recovery rate of gastrocnemius muscle wet weight and the sciatic functional index after sciatic nerve injury. The above indices were most significantly improved at 6 weeks after of tacrolimus gavage. The myelinated nerve fiber density in the nerve anastomosis and the sciatic nerve functions had a significant negative correlation with the scar area, as detected by Spearman＇s rank correlation analysis. These findings indicate that tacrolimus can promote peripheral nerve regeneration and accelerate the recovery of neurological function through the reduction of scar formation.
文摘Gaoshiti-Moxi structure belt of An-Yue Sinian gas reservoir, which was China’s largest monomer Marine carbonate gas reservoir up to now, located in vying-dragon female temple structure group that belong to the ancient uplift slope of the middle of Sichuan. With the exploration and development of high temperature and high pressure carbonate reservoir, a large number of challenges and problems, such as long isolation section, active oil-gas show, large temperature difference, prone to super retarding cement slurry and gas channeling at flare position, have been encountered in the cementing of 177.8 mm hang-liner. In order to solve these problems, numerous measures and methods have been put into use for reducing the safety risk of cementing and improving cementing quality. The large temperature difference channeling cement slurry system, effective anti-pollution spacer and high-pressure packer type liner hanger were developed and applied for field tests in the early stage of development. In addition, equilibrium pressure cementing technology, optimizing of centralizer placement and plasma column structure, improvement of pump displacement and hold pressure while waiting on cement were used to ensure nice displacement efficiency and cementing quality. As Moxi X well for example, the cementing quality factor of merit was 40.29% and the qualification rate was up to 78.87% after adopting the cementing measures and methods above. The cementing quality was much higher than previous level and provided technical support for Gaoshiti-Moxi area.
基金This work was financially supported by the Key R&D Project of Shandong Province(No.2017GSF16106)DICP&QIBEBT Unite Fund(No.:DICP&QIBEBT UN201807)Strategic Priority Research Program of the Chinese Academy of Science(No.XDA 21060400).
文摘Methane hydrate preparation is an effective method to store and transport methane.In promoters to facilitate methane hydrate formation,homogeneous surfactant solutions,sodium dodecyl sulfate(SDS)in particular,are more favorable than heterogeneous particles,thanks to their faster reaction rate,more storage capacity,and higher stability.Foaming,however,could not be avoided during hydrate dissociation with the presence of SDS.This paper investigated the ability of five fluorinated surfactants:potassium perfluorobutane sulfonate(PBS),potassium perfluorohexyl sulfonate(PHS),potassium perfluorooctane sulfonate(POS),ammonium perfluorooctane sulfonate(AOS),and tetraethylammonium perfluorooctyl sulfonate(TOS)to promote methane hydrate formation.It was found that both PBS and PHS achieve a storage capacity of 150(V/V,the volume of methane that can be stored by one volume of water)within 30 min,more than that of SDS.Cationic ions and the carbon chain length were then discussed on their effects during the formation.It was concluded that PBS,PHS,and POS produced no foam during hydrate dissociation,making them promising promoters in large-scale application.
