The adsorption and decomposition mechanisms of methylamine catalyzed by Pt4 cluster supported on ruffle(110) titania[namely, Pt4/TiO2-R(110)] were investigated via density functional theory slab calculations with ...The adsorption and decomposition mechanisms of methylamine catalyzed by Pt4 cluster supported on ruffle(110) titania[namely, Pt4/TiO2-R(110)] were investigated via density functional theory slab calculations with Hubbard corrections(DFT+U). The adsorption energies under the most stable configuration of the possible species and the energy barriers of the possible elementary reactions involved in methylamine decomposition were obtained. Through systematic calculations for the reaction mechanism of methylamine decomposition on the PtVTiO2-R(110), the most possible decomposition path is CHaNH2→CH2NH2+H→CH2NH+2H→CHNH+3H→HCN+4H→CN+5H, which is similar to that of methylamine dissociation catalyzed by Pt(100) surface.展开更多
AIM To evaluate the short-term and long-term outcomes following laparoscopic vs open surgery for pathological T4(pT 4) colorectal cancer.METHODS We retrospectively analyzed the short-and long-term outcomes of proven p...AIM To evaluate the short-term and long-term outcomes following laparoscopic vs open surgery for pathological T4(pT 4) colorectal cancer.METHODS We retrospectively analyzed the short-and long-term outcomes of proven p T4 colorectal cancer patients who underwent complete resection by laparoscopic or open surgery from 2006 to 2015 at Guangdong General Hospital.RESULTS A total of 211 p T4 colorectal cancer patients were included in this analysis, including 101 cases in thelaparoscopy(LAP) group and 110 cases in the open surgery(OPEN) group [including 15(12.9%) cases of conversion to open surgery]. Clinical information(age, gender, body mass index, comorbidities, American Society of Anesthesiologists score, etc.) did not differ between the two groups. In terms of blood loss, postoperative complications and rate of recovery, the LAP group performed significantly more favorably(P < 0.05). With regard to p T4 a/b and combined organ resection, there were significantly more cases in the OPEN group(P < 0.05). The 3-and 5-year overall survival rates were 74.9% and 60.5%, respectively, for the LAP group and 62.4% and 46.5%, respectively, for the OPEN group(P = 0.060). The 3-and 5-year disease-free survival rates were 68.0% and 57.3%, respectively, for the LAP group and 55.8% and 39.8%, respectively, for the OPEN group(P = 0.053). Multivariate analysis showed that ⅢB/ⅢC stage, lymph node status, and CA19-9 were significant predictors of overall survival. PT4 a/b, ⅢC stage, histological subtypes, CA19-9, and adjuvant chemotherapy were independent factors affecting disease-free survival.CONCLUSION Laparoscopy is safely used in the treatment of p T4 colorectal cancer while offering advantages of minimal invasiveness and faster recovery. Laparoscopy is able to achieve good oncologic outcomes similar to those of open surgery. We recommend that laparoscopy be carried out in experienced centers. It is still required to screen the appropriate cases for laparoscopic surgery, optimize the preoperative diagnosis process, and reduce the conversion rate. Multi-center, prospective, and large-sample studies are required to assess these issues.展开更多
Platinum/cerium-zirconium-sulfate(Pt/Ce-Zr-SO_4^(2-)) catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate(SO_4^(2-))addition improv...Platinum/cerium-zirconium-sulfate(Pt/Ce-Zr-SO_4^(2-)) catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate(SO_4^(2-))addition improved the catalytic activity significantly.When using Pt/Ce-Zr-SO_4^(2-) with 10 wt%SO_4^(2-),the temperature for 90%conversion of propene and CO decreased by 75℃ compared with Pt/Ce-Zr.The conversion exceeded 95%at 240℃ even after 0.02%sulfur dioxide poisoning for 20 h.Temperature-programmed desorption of CO and X-ray photoelectron spectroscopy analyses revealed an improvement in Pt dispersion onto the Ce-Zr-SO_4^(2-) support,and the increased number of Pt particles built up more Pt^(-)-(SO_4^(2-))^(-) couples,which resulted in excellent activity.The increased total acidity and new Bronsted acid sites on the surface provided the Pt/Ce-Zr-SO_4^(2-) with good sulfur resistance.展开更多
A variety of spherical and structured activated charcoal supported Pt/Fe3O4 composites with an average particle size of ~100 nm have been synthesized by a self-assembly method using the difference of reduction potenti...A variety of spherical and structured activated charcoal supported Pt/Fe3O4 composites with an average particle size of ~100 nm have been synthesized by a self-assembly method using the difference of reduction potential between Pt (Ⅳ) and Fe (Ⅱ) precursors as driving force. The formed Fe3O4 nanoparticles (NPs) effectively prevent the aggregation of Pt nanocrystallites and promote the dispersion of Pt NPs on the surface of catalyst, which will be favorable for the exposure of Pt active sites for high-efficient adsorption and contact of substrate and hydrogen donor. The electron-enrichment state of Pt NPs donated by Fe304 nanocrystallites is corroborated by XPS measurement, which is responsible for promoting and activating the terminal C=O bond of adsorbed substrate via a vertical configuration. The experimental results show that the activated charcoal supported Pt/Fe3O4 catalyst exhibits 94.8% selectivity towards cinnamyl alcohol by the transfer hydrogenation of einnamaldehyde with Pt loading of 2.46% under the optimum conditions of 120 ℃ for 6 h, and 2-propanol as a hydrogen donor. Additionally, the present study demonstrates that a high-efficient and recyclable catalyst can be rapidly separated from the mixture due to its natural magnetism upon the application of magnetic field.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.21503122, 21346002), the Shanxi Province Science Foundation for Youths, China(No.2014021016-2), the Scientific and Technological Programs in Shanxi Province, China(No. 2015031017), the Industrial and Technological Programs in Datong City, China(No.2015022) and the Foundation of Key Laboratory of Advanced Energy Materials Chemistry of the Ministry of Education of China.
文摘The adsorption and decomposition mechanisms of methylamine catalyzed by Pt4 cluster supported on ruffle(110) titania[namely, Pt4/TiO2-R(110)] were investigated via density functional theory slab calculations with Hubbard corrections(DFT+U). The adsorption energies under the most stable configuration of the possible species and the energy barriers of the possible elementary reactions involved in methylamine decomposition were obtained. Through systematic calculations for the reaction mechanism of methylamine decomposition on the PtVTiO2-R(110), the most possible decomposition path is CHaNH2→CH2NH2+H→CH2NH+2H→CHNH+3H→HCN+4H→CN+5H, which is similar to that of methylamine dissociation catalyzed by Pt(100) surface.
基金Supported by Natural Science Foundation of Guangdong Province,No.2016A030310328 and No.2016A030313762
文摘AIM To evaluate the short-term and long-term outcomes following laparoscopic vs open surgery for pathological T4(pT 4) colorectal cancer.METHODS We retrospectively analyzed the short-and long-term outcomes of proven p T4 colorectal cancer patients who underwent complete resection by laparoscopic or open surgery from 2006 to 2015 at Guangdong General Hospital.RESULTS A total of 211 p T4 colorectal cancer patients were included in this analysis, including 101 cases in thelaparoscopy(LAP) group and 110 cases in the open surgery(OPEN) group [including 15(12.9%) cases of conversion to open surgery]. Clinical information(age, gender, body mass index, comorbidities, American Society of Anesthesiologists score, etc.) did not differ between the two groups. In terms of blood loss, postoperative complications and rate of recovery, the LAP group performed significantly more favorably(P < 0.05). With regard to p T4 a/b and combined organ resection, there were significantly more cases in the OPEN group(P < 0.05). The 3-and 5-year overall survival rates were 74.9% and 60.5%, respectively, for the LAP group and 62.4% and 46.5%, respectively, for the OPEN group(P = 0.060). The 3-and 5-year disease-free survival rates were 68.0% and 57.3%, respectively, for the LAP group and 55.8% and 39.8%, respectively, for the OPEN group(P = 0.053). Multivariate analysis showed that ⅢB/ⅢC stage, lymph node status, and CA19-9 were significant predictors of overall survival. PT4 a/b, ⅢC stage, histological subtypes, CA19-9, and adjuvant chemotherapy were independent factors affecting disease-free survival.CONCLUSION Laparoscopy is safely used in the treatment of p T4 colorectal cancer while offering advantages of minimal invasiveness and faster recovery. Laparoscopy is able to achieve good oncologic outcomes similar to those of open surgery. We recommend that laparoscopy be carried out in experienced centers. It is still required to screen the appropriate cases for laparoscopic surgery, optimize the preoperative diagnosis process, and reduce the conversion rate. Multi-center, prospective, and large-sample studies are required to assess these issues.
基金supported by the National Natural Science Foundation of China(21506194,21676255)the Provincial Natural Science Foundation of Zhejiang Province(LY16B070011)the Commission of Science and Technology of Zhejiang Province(2017C33106,2017C03007)~~
文摘Platinum/cerium-zirconium-sulfate(Pt/Ce-Zr-SO_4^(2-)) catalysts were prepared by wetness impregnation.Catalytic activities were evaluated from the combustion of propene and CO.Sulfate(SO_4^(2-))addition improved the catalytic activity significantly.When using Pt/Ce-Zr-SO_4^(2-) with 10 wt%SO_4^(2-),the temperature for 90%conversion of propene and CO decreased by 75℃ compared with Pt/Ce-Zr.The conversion exceeded 95%at 240℃ even after 0.02%sulfur dioxide poisoning for 20 h.Temperature-programmed desorption of CO and X-ray photoelectron spectroscopy analyses revealed an improvement in Pt dispersion onto the Ce-Zr-SO_4^(2-) support,and the increased number of Pt particles built up more Pt^(-)-(SO_4^(2-))^(-) couples,which resulted in excellent activity.The increased total acidity and new Bronsted acid sites on the surface provided the Pt/Ce-Zr-SO_4^(2-) with good sulfur resistance.
基金This work is supported by the National Natural Science Foundation of China (No.51372248, No.51432009 and No.51502297), Instrument Developing Project of the Chinese Academy of Sciences (No.yz201421), the CAS/SAFEA International Partnership Program for Creative Research Teams of Chinese Academy of Sciences, China.
文摘A variety of spherical and structured activated charcoal supported Pt/Fe3O4 composites with an average particle size of ~100 nm have been synthesized by a self-assembly method using the difference of reduction potential between Pt (Ⅳ) and Fe (Ⅱ) precursors as driving force. The formed Fe3O4 nanoparticles (NPs) effectively prevent the aggregation of Pt nanocrystallites and promote the dispersion of Pt NPs on the surface of catalyst, which will be favorable for the exposure of Pt active sites for high-efficient adsorption and contact of substrate and hydrogen donor. The electron-enrichment state of Pt NPs donated by Fe304 nanocrystallites is corroborated by XPS measurement, which is responsible for promoting and activating the terminal C=O bond of adsorbed substrate via a vertical configuration. The experimental results show that the activated charcoal supported Pt/Fe3O4 catalyst exhibits 94.8% selectivity towards cinnamyl alcohol by the transfer hydrogenation of einnamaldehyde with Pt loading of 2.46% under the optimum conditions of 120 ℃ for 6 h, and 2-propanol as a hydrogen donor. Additionally, the present study demonstrates that a high-efficient and recyclable catalyst can be rapidly separated from the mixture due to its natural magnetism upon the application of magnetic field.