Synthesis of Metal-Organic Frameworks Derived Composite Nanomaterials and their Properties

Metal-organic frameworks(MOFs)are a new class of crystalline porous materials with periodic network structures,which are formed by self-assembly between metal ions and bridging organic linkers.Due to high surface areas,large pore volumes,and tunable surface properties,MOFs present promising application in gas storage and separation,drug delivery,heterogeneous catalysis,etc.Recently,MOFs are found to

Effect of inferior vena cava respiratory variability-guided fluid therapy after laparoscopic hepatectomy:a randomized controlled clinical trial

Background:After major liver resection,the volume status of patients is still undetermined.However,few concerns have been raised about postoperative fluid management.We aimed to compare gut function recovery and short-term prognosis of the patients after laparoscopic liver resection(LLR)with or without inferior vena cava(IVC)respiratory variability-directed fluid therapy in the anesthesia intensive care unit(AICU).Methods:This randomized controlled clinical trial enrolled 70 patients undergoing LLR.The IVC respiratory variability was used to optimize fluid management of the intervention group in AICU,while the standard practice of fluid management was used for the control group.The primary outcome was the time to flatus after surgery.The secondary outcomes included other indicators of gut function recovery after surgery,postoperative length of hospital stay(LOS),liver and kidney function,the severity of oxidative stress,and the incidence of severe complications associated with hepatectomy.Results:Compared with patients receiving standard fluid management,patients in the intervention group had a shorter time to anal exhaust after surgery(1.5±0.6 days vs.2.0±0.8 days)and lower C-reactive protein activity(21.4[95%confidence interval(CI):11.9-36.7]mg/L vs.44.8[95%CI:26.9-63.1]mg/L)24 h after surgery.There were no significant differences in the time to defecation,serum concentrations of D-lactic acid,malondialdehyde,renal function,and frequency of severe postoperative complications as well as the LOS between the groups.Conclusion:Postoperative IVC respiratory variability-directed fluid therapy in AICU was facilitated in bowel movement but elicited a negligible beneficial effect on the short-term prognosis of patients undergoing LLR.Trial Registration:ChiCTR-INR-17013093.

N-doped carbon shell encapsulated PtZn intermetallic nanopartides as highly efficient catalysts for fuel cells

The high cost and poor durability of Pt nanoparticles(NPs)have always been great challenges to the commercialization of proton exchange membrane fuel cells(PEMFCs).Pt-based intermetallic NPs with a highly ordered structure are considered as promising catalysts for PEMFCs due to their high catalytic activity and stability.Here,we reported a facile method to synthesize N-doped carbon encapsulated PtZn intermetallic(PtZn@NC)NPs via the pyrolysis of Pt@Zn-based zeolitic imidazolate framework-8(Pt@ZIF-8)composites.The catalyst obtained at 800℃(10%-PtZn@NC-800)was found to exhibit a half-wave potential(Ev2)up to 0.912 V versus reversible hydrogen electrode(RHE)for the cathodic oxygen reduction reaction in an acidic medium,which shifted by 26 mV positively compared to the benchmark Pt/C catalyst.Besides,the mass activity and specific activity of 10%-PtZn@NC-800 at 0.9 V versus RHE were nearly 3 and 5 times as great as that of commercial Pt/C,respectively.It is worth noting that the PtZn@NC showed excel Ient stability in oxygen reducti on reacti on(ORR)with just 1 mV of the Ev2 loss after 5,000 cycles,which is superior to that of most reported PtM catalysts(especially those disordered solid solutions).Furthermore,such N-doped carb on shell encapsulated PtZn intermetallic NPs showed significa ntly enha need performances towards the anodic oxidation reaction of organic small molecules(such as methanol and formic acid).The synergistic effects of the N doped carbon encapsulation structure and intermetallic NPs are responsible for outstanding performances of the catalysts.This work provides us a new engineering strategy to acquire highly active and stable multifunctional catalysts for PEMFCs.