Chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor promotes sciatic nerve repair

A chemically extracted acellular allogeneic nerve graft can reduce postoperative immune rejection, similar to an autologous nerve graft, and can guide neural regeneration. However, it remains poorly understood whether a chemically extracted acellular allogeneic nerve graft combined with neurotrophic factors provides a good local environment for neural regeneration. This study investigated the repair of injured rat sciatic nerve using a chemically extracted acellular allogeneic nerve graft combined with ciliary neurotrophic factor. An autologous nerve anastomosis group and a chemical acellular allogeneic nerve bridging group were prepared as controls. At 8 weeks after repair, sciatic functional index, evoked potential amplitude of the soleus muscle, triceps wet weight recovery rate, total number of myelinated nerve fibers and myelin sheath thickness were measured. For these indices, values in the three groups showed the autologous nerve anastomosis group 〉 chemically extracted acellular nerve graft ＋ ciliary neurotrophic factor group 〉 chemical acellular allogeneic nerve bridging group. These results suggest that chemically extracted acellular nerve grafts combined with ciliary neurotrophic factor can repair sciatic nerve defects, and that this repair is inferior to autologous nerve anastomosis, but superior to chemically extracted acellular allogeneic nerve bridging alone.

Combining acellular nerve allografts with brainderived neurotrophic factor transfected bone marrow mesenchymal stem cells restores sciatic nerve injury better than either intervention alone

In this study, we chemically extracted acellular nerve allografts from bilateral sciatic nerves, and repaired 10-mm sciatic nerve defects in rats using these grafts and brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells. Experiments were performed in three groups： the acellular nerve allograft bridging group, acellular nerve allograft ＋ bone marrow mesenchymal stem cells group, and the acellular nerve allograft ＋ brain-derived neurotrophic factor transfected bone marrow mesenchyrnal stem cells group. Results showed that at 8 weeks after bridging, sciatic functional index, triceps wet weight recovery rate, myelin thickness, and number of myelinated nerve fibers were significantly changed in the three groups. Variations were the largest in the acellular nerve allograft ＋ brain-derived neurotrophic factor transfected bone marrow mesenchymal stem cells group compared with the other two groups. Experimental findings suggest that chemically extracted acellular nerve allograft combined nerve factor and mesenchymal stem cells can promote the restoration of sciatic nerve defects. The repair effect seen is better than the single application of acellular nerve allograft or acellular nerve allograft combined mesenchymal stem cell transplantation.

Preparation of Aminated Lignin through Etherification and Amination

A new method for the preparation of aminated lignin （AEL） through etherification and amination reaction was presented. Chlorine atoms were ？rstly introduced into lignin through its etheri？cation with epichlorohydrin. Then, hydrophilic amine groups were grafted to the modi？ed lignin structure through amination with ethylenediamine to obtain AEL. Subsequent acidi？cation of AEL led to the ionized aminated lignin （IAEL）. The results of our analyses showed that the nitrogen content of AEL was 6.9%. Foaming and emulsifying experiments indicated that AEL had better foamability and emulsifying properties than IAEL. Surface tension tests showed that AEL and IAEL had similar critical micelle concentration （CMC）. However, IAEL had lower surface tension （36.33 mN/m） than AEL （42.89 mN/m） at CMC. These results demonstrate the promising applicability of AEL as an emulsi？er and that of IAEL as feedstock in the production of detergent and dispersant.

Synthesis of Humin-based Carbon Quantum Dots and Luminescent Properties

The unique properties of carbon quantum dots （CQDs） make them promising materials in many ？elds. Herein, we present a facile method for the preparation of photo-luminescent CQDs using humins as the carbon precursor for the purpose of providing a high value-added solution for this “biomass conversion process waste”. The structure of the CQDs was analyzed, and the effects of reaction temperature and time on the CQDs’ ？uorescence were investigated. The results showed that humins were effectively carbonized during the reaction. The ？uorescence intensity of humin-based CQDs initially increased with reaction temperature and time, and subsequently decreased beyond 200℃ and 4 h. Polyaromatic structures and hydrophilic groups such as O-H, C-O, -COOH and C==O groups exist in the CQDs. The humin-based CQDs have the dimension of 3~7 nm with an average size of about 5.5 nm. The highest emission intensity of blue/cyan ？uorescence light at 440 nm is achieved on the excitation with UV light at the wavelength of 330 nm.

Aerosol light absorption in a coastal city in Southeast China:Temporal variations and implications for brown carbon

Light-absorbing carbonaceous aerosols including black carbon(BC) and brown carbon(BrC)play significant roles in atmospheric radiative properties. One-year measurements of aerosol light absorption at multi-wavelength were continuously conducted in Xiamen,southeast of China in 2014 to determine the light absorption properties including absorption coefficients(σabs) and absorption ?ngstr?m exponent(AAE) in the coastal city.Light absorptions of BC and BrC with their contributions to total light absorption were further quantified. Mean σabsat 370 nm and 880 nm were 56.6 ± 34.3 and 16.5 ± 11.2 Mm-1,respectively. σabspresented a double-peaks diurnal pattern with the maximum in the morning and the minimum in the afternoon. σabswas low in warm seasons and high in cold seasons. AAE ranged from 0.26 to 2.58 with the annual mean of 1.46, implying that both fossil fuel combustion and biomass burning influenced aerosol optical properties. σabsof BrC at 370 nm was 24.0 ± 5.7 Mm-1, contributing 42% to the total absorption. The highest AAE(1.52 ± 0.02) and largest BrC contributions(47% ± 4%) in winter suggested the significant influence of biomass burning on aerosol light absorption. Long-distance air masses passing through North China Plain and the Yangtze River Delta led to high AAE and BrC contributions. High AAE value of 1.46 in July indicated that long-range transport of the air pollutants from intense biomass burning in Southeast Asia would affect aerosol light absorption in Southeast China. The study will improve the understanding of light absorption properties of aerosols and the optical impacts of BrC in China.

Halloysite nanotubes loaded with nano silver for the sustained-release of antibacterial polymer nanocomposite scaffolds

It is challenging for antibacterial polymer scaffolds to achieve the drug sustained-release through directly coating or blending.In this work,halloysite nanotubes(HNTs),a natural aluminosilicate nanotube,were utilized as a nano container to load nano silver(Ag)into the lumen through vacuum negativepressure suction&injection and thermal decomposition of silver acetate.Then,the nano Ag loaded HNTs(HNTs@Ag)were introduced to poly-l-lactic acidide)(PLLA)scaffolds prepared by additive manufacturing for the sustained-release of Ag^+.Acting like a’shield’,the tube walls of HNTs not only retarded the erosion of external aqueous solution on internal nano Ag to generate Ag^+but also postponed the generated Ag^+to diffuse outward.The results indicated the PLLA-HNTs@Ag nanocomposite scaffolds achieved a sustained-release of Ag^+over 28 days without obvious initial burst release.Moreover,the scaffolds exhibited a long-lasting antibacterial property without compromising the cytocompatibility.Besides,the degradation properties,biomineralization ability and mechanical properties of the scaffolds were increased.This study suggests the potential application of inorganic nanotubes as drug carrier for the sustained-release of functional polymer nanocomposite scaffolds.

Decavanadate-based Transition Metal Hybrids as Bifunctional Catalysts for Sulfide Oxidation and C-C Bond Construction

The development of bifunctional catalysts has drawn much attention in realizing efficient and feasible catalytic systems to meet the diverse dema nd of pote ntial industrial applications.Desig n of stable and powerful bifun ctional catalysts for various catalysis systems is highly desirable yet largely unmet.Here,three kinds of decavanadate-based transition metal hybrids(DTMH)(i.e.,Co-DTMH,Ni-DTMH and Ag-DTMH)have been successfully synthesized through a pH tuning strategy and further characterized.Specifically,the rare M05N six-coordinated transition metal coordination modes have been detected in Co-DTMH and Ni-DTMH,while Ag atoms in Ag-DTMH exhibited three-and five-coordinated geometries with the tuning of specially selected imidazole ligands.Thus-obtained clusters can serve as powerful bifunctional catalysts for both sulfide oxidation and C-C bond construction.Remarkably,Ag-DTMH dem on st rated excellent heteroge ne ous bifunctional catalytic properties in the selective oxidati on of sulfides and construction of C-C bond(yields up to 99%),which enable successful recycling for three cycles with remained catalytic activities and structure stability.The newly designed decavanadate-based transition metal hybrids with bifunctional property hold high promise in the practical applications like continuous catalysis or flow bed reactions.

Insurance Plan for Service Assurance in Cloud Computing Market with Incomplete Information

Nowadays,cloud computing has been identified as new opportunities for migrating to the expected agility,reuse,and adaptive capabilities that can support the ever changing IT trends and requirements.Unfortunately,the rapid evolution of those technologies also comes with open issues such as security,privacy,integrity,quality of services,and their possible detrimental consequences.In this work,the concept of insurance is introduced to compensate the cloud computing customers when encountering those failures if service providers(SPs)have insurance purchased.Particularly,we consider the situation when the insurer is unable to see the system failure risk levels of the SPs,which is usually seen as an incomplete information market,in contrast with the optimal situation in a complete information market.First,an insurance-based cloud computing architecture is proposed to build a monetary credit system in which the cloud computing SP pays a premium for a certain coverage to the insurer.Subsequently,problem is formulated to solve the optimal insurance plan in complete and incomplete information markets,together with detail analysis of insurance policies in both cases are provided.Furthermore,simulation results show the properties of the two insurance plans and parameters that affect the design of the insurance plan.

海上丝绸之路背景下的中非渔业合作发展研究——以印度洋沿岸非洲国家为例

21世纪是海洋经济时代,沿海各国对海洋经济发展给予了前所未有的重视。目前,国际社会对印度洋海洋资源开发与利用颇为关注。随着我国海上丝绸之路发展战略的提出,本文以印度洋沿岸非洲国家为例,阐述印度洋沿岸非洲国家渔业资源状况,分析中非渔业合作现状及其发展特征,探讨未来中非渔业深度合作发展面临问题并提出举措建议,希望进一步丰富中非海洋经济合作理论,并且为中非经贸交流提供理论借鉴。