Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationsh...Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationship of AFL and AF？ Whether there are some differences in clinical course and mechanism between the new onset LAFL and the with a history of AFL remained unclear. The aim of this study was to assess the impacts of circumferential ablation on the occurrence of arrhythmias in follow-up in 2 groups： （1） patients with a history of AFL and AF, and （2） patients with new onset LAFL. Methods Data from 465 patients who had circumferential pulmonary vein ablation （CPVA） or segmental pulmonary vein ablation （SPVA） were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation were included from analysis. Forty-one patients constituted the history of AFL group （group 1, aged 57±13 years, 7 females） and twenty-eight patients constituted the new onset LAFL group （group 2, aged 55±12 years, 6 females）, bipolar recordings were obtained from the tricuspid annulus, coronary sinus, interatrial septum and left atrium. Target sites were identified by early, fragmented or double potentials and by concealed entrainment. Linear lesions were created between target sites and nearby anatomical barriers （1） typical atrial flutter （cycle length, 242± 39 ms）. cavotricuspid isthmus ablation was performed. （2） new onset LAFL （cycle length, 282±153 ms）. 20 episodes of AAFs were documented in 20/28 （71.4%） patients. Target sites were identified around pulmonary veins （n=10）, gap in linear lesion （n=7）, left atrial roof lines （1 case）. For those cases the ablation line between PV and mitral annulus was performed. Patients in Group 2 had larger left atria, incidence of AFL pre-CPVA, and lower ejection fraction. Results There was no significant difference in post-CPVA AF recurrence between Groups 1 and 2, but AFL incidence after CPVA was higher in Group 2 （33% vs 4%, P 〈 0.0001）. Ablation of AFL in group 1 patients resulted in an 88% acute success rate （group2, 86%） and 12% （group2,17%） recurrence over a mean follow-up of 287 ±101 days.Condusions In patients with a history of atrial flutter, post-CPVA AF recurrence is similar to patients with new onset LAFL. However, LAFL is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with LAFL, mitral Isthmus ablation is needed and can be performed effectively. Its eleetrophysiologieal eonse-quenees could be considered analogus to the results achieved by eavotrieuspid isthmus ablation.展开更多
A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a po...A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely de-graded into H2 and CO2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H2 and CO2 by the aqueous phase reforming process.展开更多
A novel method for the one pot synthesis of N-alkyl arylamines from nitro aromatic compounds and alcohols is proposed through the combination of the aqueous-phase reforming of alcohol for hydrogen production, the redu...A novel method for the one pot synthesis of N-alkyl arylamines from nitro aromatic compounds and alcohols is proposed through the combination of the aqueous-phase reforming of alcohol for hydrogen production, the reduction of nitro aromatic compounds for the synthesis of aromatic amine and the N-alkylation of aromatic amine for the production of N-alkyl arylamine over an identical catalyst under the same conditions of temperature and pressure in a single reactor. In this process, hydrogen generated from the aqueous-phase reforming of alcohols was used in-situ for the hydrogenation of nitro aromatic compounds for aromatic amine synthesis, followed by N-alkylation of aromatic amine with alcohols to form the corresponding N-alkyl arylamines at a low partial pressure of hydrogen. For the system composed of nitrobenzene and ethanol, under the conditions of 413 K and PN2 = 1 MPa, the conversion degrees of nitrobenzene and aniline were 100%, the selectivity to N-ethylaniline and N, N-diethylaniline were 85.9% and 0%-4%, respectivity, after reaction for 8 h at the volumetric ratio of nitrobenzene:ethanol:water = 10:60:0. The selectivity for N, N-diethylaniline production is much lower than that through the traditional method. In this process, hydrogen and aromatic amines generated from the aqueous-phase reforming of alcohols and hydrogenation of nitro aromatic compounds, respectively, could be promptly removed from the surface of the catalyst due to the occurrence of in-situ hydrogenation and N-alkylation reactions. Thus, this may be a potential approach to increase the selectivity to N-alkyl arylamine.展开更多
文摘Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationship of AFL and AF？ Whether there are some differences in clinical course and mechanism between the new onset LAFL and the with a history of AFL remained unclear. The aim of this study was to assess the impacts of circumferential ablation on the occurrence of arrhythmias in follow-up in 2 groups： （1） patients with a history of AFL and AF, and （2） patients with new onset LAFL. Methods Data from 465 patients who had circumferential pulmonary vein ablation （CPVA） or segmental pulmonary vein ablation （SPVA） were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation were included from analysis. Forty-one patients constituted the history of AFL group （group 1, aged 57±13 years, 7 females） and twenty-eight patients constituted the new onset LAFL group （group 2, aged 55±12 years, 6 females）, bipolar recordings were obtained from the tricuspid annulus, coronary sinus, interatrial septum and left atrium. Target sites were identified by early, fragmented or double potentials and by concealed entrainment. Linear lesions were created between target sites and nearby anatomical barriers （1） typical atrial flutter （cycle length, 242± 39 ms）. cavotricuspid isthmus ablation was performed. （2） new onset LAFL （cycle length, 282±153 ms）. 20 episodes of AAFs were documented in 20/28 （71.4%） patients. Target sites were identified around pulmonary veins （n=10）, gap in linear lesion （n=7）, left atrial roof lines （1 case）. For those cases the ablation line between PV and mitral annulus was performed. Patients in Group 2 had larger left atria, incidence of AFL pre-CPVA, and lower ejection fraction. Results There was no significant difference in post-CPVA AF recurrence between Groups 1 and 2, but AFL incidence after CPVA was higher in Group 2 （33% vs 4%, P 〈 0.0001）. Ablation of AFL in group 1 patients resulted in an 88% acute success rate （group2, 86%） and 12% （group2,17%） recurrence over a mean follow-up of 287 ±101 days.Condusions In patients with a history of atrial flutter, post-CPVA AF recurrence is similar to patients with new onset LAFL. However, LAFL is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with LAFL, mitral Isthmus ablation is needed and can be performed effectively. Its eleetrophysiologieal eonse-quenees could be considered analogus to the results achieved by eavotrieuspid isthmus ablation.
基金the Program for New Century Excellent Talents in University (Grant No. NCET-04-0557)the Specialized Research Fund for the Doctoral Program of High Education (Grant No. SRFDP-20060337001)
文摘A resource recycling technique of hydrogen production from the catalytic degradation of organics in wastewater by aqueous phase reforming (APR) has been proposed. It is worthy of noting that this technique may be a potential way for the purification of refractory and highly toxic organics in water for hydrogen production. Hazardous organics (such as phenol, aniline, nitrobenzene, tetrahydrofuran (THF), toluene, N,N-dimethylformamide (DMF) and cyclohexanol) in water could be completely de-graded into H2 and CO2 with high selectivity over Raney Ni, and Sn-modified Raney Ni (Sn-Raney-Ni) or Pd/C catalyst under mild conditions. The experimental results operated in tubular and autoclave reactors, indicated that the degradation degree of organics and H2 selectivity could reach 100% under the optimal reaction conditions. The Sn-Raney-Ni (Sn/Ni=0.06) and Pd/C catalysts show better catalytic performances than the Raney Ni catalyst for the degradation of organics in water into H2 and CO2 by the aqueous phase reforming process.
基金Supported by the Program for New Century Excellent Talents in University (Grant No. NCET-04-0557)the Specialized Research Fund for the Doctoral Program of High Education (Grant No. SRFDP-20060337001)
文摘A novel method for the one pot synthesis of N-alkyl arylamines from nitro aromatic compounds and alcohols is proposed through the combination of the aqueous-phase reforming of alcohol for hydrogen production, the reduction of nitro aromatic compounds for the synthesis of aromatic amine and the N-alkylation of aromatic amine for the production of N-alkyl arylamine over an identical catalyst under the same conditions of temperature and pressure in a single reactor. In this process, hydrogen generated from the aqueous-phase reforming of alcohols was used in-situ for the hydrogenation of nitro aromatic compounds for aromatic amine synthesis, followed by N-alkylation of aromatic amine with alcohols to form the corresponding N-alkyl arylamines at a low partial pressure of hydrogen. For the system composed of nitrobenzene and ethanol, under the conditions of 413 K and PN2 = 1 MPa, the conversion degrees of nitrobenzene and aniline were 100%, the selectivity to N-ethylaniline and N, N-diethylaniline were 85.9% and 0%-4%, respectivity, after reaction for 8 h at the volumetric ratio of nitrobenzene:ethanol:water = 10:60:0. The selectivity for N, N-diethylaniline production is much lower than that through the traditional method. In this process, hydrogen and aromatic amines generated from the aqueous-phase reforming of alcohols and hydrogenation of nitro aromatic compounds, respectively, could be promptly removed from the surface of the catalyst due to the occurrence of in-situ hydrogenation and N-alkylation reactions. Thus, this may be a potential approach to increase the selectivity to N-alkyl arylamine.
