CSTR中以果糖、丙酮为底物的B-Z反应体系研究

对果糖 (Fru) 丙酮 (Act) BrO 3 Mn2 + H2 SO4体系在CSTR中出现的动力学行为进行研究 。

Perfecting HER catalysts via defects:Recent advances and perspectives

Defect engineering has become a promising approach to improve the performance of hydrogen evolution reaction(HER)catalysts.Non-noble transition metal-based catalysts(TMCs)have shown significant promise as effective alternatives to traditional platinum-group catalysts,attracting considerable attention.However,the industrial application of TMCs in electrocatalytic hydrogen production necessitates further optimization to boost both catalytic activity and stability.This review comprehensively examines the types,fabrication methods,and characterization techniques of various defects that enhance catalytic HER activity.Key advancements include optimizing defect concentration and distribution,coupling heteroatoms with vacancies,and leveraging the synergy between bond lengths and defects.In-depth discussions highlight the electronic structure and catalytic mechanisms elucidated through in-situ characterization and density functional theory calculations.Additionally,future directions are identified,exploring novel defect types,emphasizing precision synthesis methods,industrial-scale preparation techniques,and strategies to enhance structural stability and understanding the in-depth catalytic mechanism.This review aims to inspire further research and development in defect-engineered HER catalysts,providing pathways for high efficiency and cost-effectiveness in hydrogen production.

Transformation of carbon dioxide into valuable chemicals over bifunctional metallosalen catalysts bearing quaternary phosphonium salts

The chemical transformation of CO2under mild conditions remains a great challenge because of itsexceptional kinetic and thermodynamic stability.Two important reactions in the transformation ofCO2are the N‐formylation reaction of amines using hydrosilanes and CO2,and the cycloaddition ofCO2to epoxides.Here,we report the high efficiency of bifunctional metallosalen complexes bearingquaternary phosphonium salts in catalyzing both of these reactions under solvent‐free,mild conditionswithout the need for co‐catalysts.The catalysts’bifunctionality is attributed to an intramolecularcooperative process between the metal center and the halogen anion.Depending on the reaction,this activates CO2by permitting either the synergistic activation of Si–H bond via metal–hydrogen coordinative bond(M–H)or the dual activation of epoxide via metal–oxygen coordinativebond(M–O).The one‐component catalysts are also shown to be easily recovered and reusedfive times without significant loss of activity or selectivity.The current results are combined withprevious work in the area to propose the relevant reaction mechanisms.

Impact of homogeneous pathologic response to preoperative chemotherapy in patients with multiple colorectal liver metastases

AIM To analyze the homogeneity of pathologic response to preoperative chemotherapy(PRPC) after chemotherapy in patients with multiple liver metastases(LM).METHODS From September 2011 to August 2014,patients with at least two LM undergoing preoperative chemotherapy prior to resection were included in this retrospective,single-center study. The endpoints were PRPC homogeneity(according to both the Rubbia-Brandt and MD Anderson classifications),the impact of PRPC on the MDT decision,factors associated with homogeneous PRPC and overall survival of patients with vs. without homogeneous PRPC.RESULTS seventy-three patients with a total of 88 liver resections(including 15 two-stage procedures) were included in the study. The homogeneous PRPC rate was 55% according to the Rubbia-Brandt classification and 53% according to the MD Anderson classification. The MDT decision was modified by the PRPC in only 2.7% of patients(n = 2). CONCLUSION The PRPC was homogeneous in only one half of patients and had very little influence on the MDT decision.

Bacteriocinogeny in experimental pigs treated with indomethacin and Escherichia coli Nissle

AIM： To evaluate bacteriocinogeny in short-term highdose indomethacin administration with or without probiotic Escherichia coli Nissle 1917 （EcN） in experimental pigs.METHODS： Twenty-four pigs entered the study： Group A （controls）, Group B （probiotics alone）, Group C （indomethacin alone） and Group D （probiotics and indomethacin）. EcN （3.5 × 10^10 bacteria/d for 14 d） and/or indomethacin （15 mg/kg per day for 10 d） were administrated orally. Anal smears before and smears from the small and large intestine were taken from all animals. Bacteriocin production was determined with 6 different indicator strains; all strains were polymerase chain reaction tested for the presence of 29 individual bacteriocinencoding determinants. RESULTS： The general microbiota profile was rather uniform in all animals but there was a broad diversity in coliform bacteria （parallel genotypes A, B1, B2 and D found）. In total, 637 bacterial strains were tested, mostly Escherichia coli （E. coli. There was a higher incidence of non-E：, coli strains among samples taken from the jejunum and ileum compared to that of the colon and rectum indicating predominance of E. coil strains in the large intestine. Bacteriocinogeny was found in 24/77 （31%） before and in 155/560 （28%） isolated bacteria at the end of the study. Altogether, 13 individual bacteriocin types （out of 29 tested） were identified among investigated strains. Incidence of four E. coli genotypes was equally distributed in all groups of E. coil strains, with majority of genotype A （ranging from 81% to 88%）. The following types of bacteriocins were most commonly revealed： colicins Ia/Ib （44%）, microcin V （18%）, colicin E1 （16%） and microcin H47 （6%）. There was a difference in bacteriocinogeny between control group A （52/149, 35%） and groups with treatment at the end of the study： B： 31/122 （25%, P = 0.120）; C： 43/155 （28%, P = 0.222）; D： 29/134 （22%, P = 0.020）. There was a significantly lower prevalence of colicin Ib, microcins H47 and V （probiotics group, P 〈 0.001）, colicin E1 and microcin H47 （indomethacin group, P 〈 0.001） and microcins H47 and V （probiotics and indomethacin group, P = 0.025） compared to controis. Escherichia fergusonil （E. fergusoniO was identi-fled in 6 animals （6/11 isolates from the rectum）. One strain was non-colicinogenic, while all other strains of E. fergusonii solely produced colicin El. All animals started and remained methanogenic despite the fact that EcN is a substantial hydrogen producer. There was an increase in breath methane （after the treatment） in 5/6 pigs from the indomethacin group （C）. CONCLUSION： EcN did not exert long-term liveabilib/ in the porcine intestine, All experimental pigs remained methanogenic, Indomethacin and EcN administered together might produce the worst impact on bacteriocinogeny.

Experimental Study of Premixed Stoichiometric Ethylene/Oxygen/Argon Flame

A comprehensive experimental study of the premixed ethylene/oxygen/argon flame at 2.667 kPa with a stoichiometric equivalence ratio （Ф=1） was performed with the tunable synchrotron photoionization and molecular-beam sampling mass spectrometry techniques. The isomers of most observed species in the flame were unambiguously identified by measurements of the photoionization etticiency spectra, e.g. C3H4, C2H4O and C4H4. The mole fraction profiles of species up to C7H8 were measured by scanning the burner position at the selected photon energies near ionization thresholds, and the flame temperature profile was obtained by using Pt/Pt-13%Rh thermocouple. Compared with the previous studies, a lot of new flame species： C3H2, C3H3, C3H5, C2H6O, C4H2, C4H4, C4H6, C3H4O, C3H6O, C3H8O, C5H6, C4H8O and C7H8, were observed. A series of free radicals in the flame are detected to be CH3, C2H3, C2H5, HCO, C3H3 and C3H5. Based on the experimental work, a reduced reaction mechanism was developed including 40 species and 223 reactions. Modeling and measurements agree well for the major species and most intermediates. A detailed kinetic model is desired for this flame.