Methane coupling in microwave plasma under atmospheric pressure

Methane coupling in microwave plasma under atmospheric pressure has been investigated.The effects of molar ratio n（CH4）/n（H2）,flow rate and microwave power on the reaction have been studied.（1）With the decrease of n（CH4）/n（H2）ratio,methane conversion,C2 hydrocarbon yield,energy yield and space-time yield of acetylene increased,but the yield of carbon deposit decreased.（2）With the increase of microwave power,energy yield of acetylene decreased,but space-time yield of acetylene increased.（3）With the increase of flow rate,energy yield and space-time yield of acetylene increased first and then decreased.Finally,under the reaction conditions of CH4 flow rate of 700 mL/min,n（CH4）/n（H2）ratio of 1/4 and microwave power of 400 W,the energy yield and space-time yield of acetylene could reach 0.337 mmol/kJ and 12.3 mol/（s m3）,respectively.The reaction mechanism of methane coupling in microwave plasma has been investigated based on the thermodynamics of chemical reaction.Interestingly,the acetylene yield of methane coupling in microwave plasma was much higher than the maximum thermodynamic yield of acetylene.This phenomenon was tentatively explained from non-expansion work in the microwave plasma system.

Partial function prediction of sulfate-reducing bacterial community from the rhizospheres of two typical coastal wetland plants in China

Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.

A cross-linked polyacrylamide electrolyte with high ionic conductivity for compressible supercapacitors with wide temperature tolerance

The development of compressible supercapacitors (SCs) that is tolerant to wide temperature range has been severely hindered due to the poor ionic conductivity and absence of extra functions in conventional polymer electrolytes.Herein,a highly conductive and compressible hydrogel polyelectrolyte has been prepared from polyacrylamide cross-linked by methacrylated graphene oxide (MGO-PAM) and the polyelectrolyte can maintain its excellent elasticity at-30 ℃ as well as its original shape at 100 ℃.As a result,the SC based on the MGO-PAM polyelectrolyte outperformed those fabricated with the conventional poly(vinyl alcohol)(PVA)/H2SO4 electrolyte over a wide temperature window between-30 and 100 ℃.Meanwhile,the device shows an excellent cycling stability (capacitance retention of 93.3% after 8,000 cycles at-30 ℃ and 76.5 % after 4,000 cycles under 100 ℃) and a reversible compressibility (a high capacitance retention of 94.1% under 80% compression).Therefore,the MGO-PAM polyelectrolyte enables the fabrication of compressible SCs with a wide operating temperature,rendering new insights for developing next-generation robust and multifunctional energy-storage devices.

Strontium modulates osteogenic activity of bone cement composed of bioactive borosilicate glass particles by activating Wnt/β-catenin signaling pathway

There is a need for synthetic grafts to reconstruct large bone defects using minimal invasive surgery.Our previous study showed that incorporation of Sr into bioactive borate glass cement enhanced the osteogenic capacity in vivo.However,the amount of Sr in the cement to provide an optimal combination of physicochemical properties and capacity to stimulate bone regeneration and the underlying molecular mechanism of this stimulation is yet to be determined.In this study,bone cements composed of bioactive borosilicate glass particles substituted with varying amounts of Sr(0 mol%to 12 mol%SrO)were created and evaluated in vitro and in vivo.The setting time of the cement increased with Sr substitution of the glass.Upon immersion in PBS,the cement degraded and converted more slowly to HA(hydroxyapatite)with increasing Sr substitution.The released Sr2+modulated the proliferation,differentiation,and mineralization of hBMSCs(human bone marrow mesenchymal stem cells)in vitro.Osteogenic characteristics were optimally enhanced with cement(designated BG6Sr)composed of particles substituted with 6mol%SrO.When implanted in rabbit femoral condyle defects,BG6Sr cement supported better peri-implant bone formation and bone-implant contact,comparing to cements substituted with 0mol%or 9mol%SrO.The underlying mechanism is involved in the activation of Wnt/β-catenin signaling pathway in osteogenic differentiation of hBMSCs.These results indicate that BG6Sr cement has a promising combination of physicochemical properties and biological performance for minimally invasive healing of bone defects.

Corrigendum to“Strontium modulates osteogenic activity of bone cement composed of bioactive borosilicate glass particles by activating Wnt/β-catenin signaling pathway”[Bioact.Mater.5(2020)334-347]

The authors regret that the printed version of the above article contained a number of errors which were not identified during the proofing stage.The correct and final version follows.The authors would like to apologies for any inconvenience caused.The authors regret:1.“…and the underlying molecular mechanism of this simulation is yet to be determined”,Page 335,needs to be corrected to“and the underlying molecular mechanism of this stimulation is yet to be determined”.

Device-assisted enteroscopy-based stricturotomy for small bowel strictures associated with Crohn’s disease(with video)

Introduction Bowel stricture is a common complication in patients with Crohn’s disease(CD),which often requires surgery[1,2].Notably,25%of patients develop at least one small bowel stricture[3].Endoscopic intervention has emerged as a feasible and minimally invasive adjunct or alternative to surgery.However,endoscopic intervention for small bowel strictures poses a technical challenge for gastroenterologists.Deep small bowel strictures beyond the terminal ileum are only accessible to device-assisted enteroscopy,including balloon-assisted enteroscopy(BAE).BAE-based endoscopic balloon dilation(EBD)has been reported to be safe and effective for small bowel strictures from CD[4].