Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc. In this paper, three possib...Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc. In this paper, three possible reaction mechanisms are investigated and the results indicate that if the acetyl group directly transfers from the donor to the acceptor, the high activation energies will make it hard to obtain the target products. When using histidine to mediate the acetylation process, these energies will drop in the 15-45 kJ/mol range. If the histidine residue is protonated, the corresponding energies will be decreased by about 35-87 kJ/mol. The calculations predict an enzymatic acetylation mechanism that undergoes a thiolate-imidazolium pair, which agrees with the experimental results very well.展开更多
目的探讨不同类型人工辅助咳嗽(manually assisted coughing,MAC)技术对脑干卒中患者咳嗽功能、痰液清除能力及肺功能的影响,为卒中后咳嗽功能障碍的康复干预提供临床依据。方法采用前瞻性随机对照设计,连续纳入2023年5月—2024年5月于...目的探讨不同类型人工辅助咳嗽(manually assisted coughing,MAC)技术对脑干卒中患者咳嗽功能、痰液清除能力及肺功能的影响,为卒中后咳嗽功能障碍的康复干预提供临床依据。方法采用前瞻性随机对照设计,连续纳入2023年5月—2024年5月于北京小汤山医院运动康复科住院的脑干卒中患者,将其随机分为膈肌刺激组、气管刺激组和舌根刺激组。3组患者均接受常规康复治疗及呼吸训练,在此基础上,各组分别接受膈肌刺激、气管刺激或舌根刺激干预,每日2次,每次30 min,每周5 d,持续2周。干预前、后采用便携式肺功能检测仪测量峰值咳嗽流量(peak cough flow,PCF),检测24 h痰液量,通过运动心肺功能测试系统检测用力肺活量(forced vital capacity,FVC)、第1秒用力呼气容积(forced expiratory volume in one second,FEV1)、呼气流量峰值(peak expiratory flow,PEF)等静态肺功能指标,并使用超声评估吸气末膈肌厚度(diaphragm thickness at the end of inspiration,TEI)、呼气末膈肌厚度(diaphragm thickness at the end of expiration,TEE)、膈肌厚度分数(diaphragm thickness fraction,DTF)、膈肌移动度(diaphragmatic mobility,DM)等膈肌参数。记录干预后肺炎发生率。结果共纳入33例脑干卒中患者,每组11例。干预后,3组患者的PCF、FVC、FEV1、PEF、TEI、TEE及DTF较干预前均显著提高(均P<0.05),24 h痰液量显著降低(P<0.05)。干预后组间两两比较显示,舌根刺激组的24 h痰液量改善效果优于膈肌刺激组[(35.64±10.71)mL vs.(46.09±9.52)mL,P=0.025];舌根刺激组与气管刺激组的FVC、FEV1、PEF均优于膈肌刺激组(均P<0.05)。干预后3组在PCF、TEI、TEE、DTF等方面的差异均无统计学意义。干预后膈肌刺激组的肺炎发生率为36.4%,气管刺激组为18.2%,舌根刺激组为9.1%,组间差异无统计学意义(P=0.439)。结论膈肌刺激、气管刺激和舌根刺激3种MAC技术均可有效改善脑干卒中患者的咳嗽功能、肺功能及痰液清除能力,其中舌根刺激在诱发咳嗽反射和改善排痰方面的效果更佳。展开更多
In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univari...In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univariate approach experiments,and then central composite design(CCD).The optimal extraction conditions were as follows:methanol concentration of 65%,microwave power of 200 W,and extraction time of 260 s.A high performance liquid chromatography–diode array detector(HPLC–DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus.Chromatographic separation was carried out on an Agilent Zorbax Extend-C_(18) column(4.6 mm×150 mm,3.5 μm).Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water(A)and acetonitrile(B):40%-70% B at 0-8 min,70%-100% B at 8–9 min,100% B for 2 min,and then equilibrated with 40% B for 2 min.展开更多
The ring opening of β-sultam v/a an H2O-assisted ammonolysis process was studied by using Density Functional Theory（DFT） method at the B3LYP/6-31G level as a further step in the theoretical investigation of the amm...The ring opening of β-sultam v/a an H2O-assisted ammonolysis process was studied by using Density Functional Theory（DFT） method at the B3LYP/6-31G level as a further step in the theoretical investigation of the ammonolysis reaction of β-sultams. The calculated pathways are analogous to those previously described for the non-assisted ammonolysis reaction. Solvent effects were assessed by using the polarized continuum model（PCM） method. The results show that mode 1 and pathway a in channel Ⅱ are the most favorable ones in both the cases. The energy barrier of the cleavage of C-S bonds producing P1 is the highest among all the energy barriers. The presence of a solvent in the continuum model disfavors the reaction, whereas the participation of water in the ammonolysis reaction plays a positive role and reduces the active energy greatly. The relative energies of all the transition states in the assisted ammonolysis are 20-80 kJ/mol lower than those for the non-assisted reaction.展开更多
Background: Ventricular assist devices are now used as a bridge to recovery/decision/transplant or as destination therapy in end-stage heart failure. Continued improvements in technology and pump design have made impl...Background: Ventricular assist devices are now used as a bridge to recovery/decision/transplant or as destination therapy in end-stage heart failure. Continued improvements in technology and pump design have made implantation an easier process with reduced operative risks and pump-related adverse events. Considering the beneficial effects of these devices in the clinical setting, it seemed logical to address the long-term effect of the continuous flow pumps on diastolic dysfunction. Methods: This study addresses the effect of HeartMate IITM(HMII) support for 284+/-97 days on echocardiographic parameters of diastolic function. Data from fifteen patients was retrospectively studied status post left ventricular assist device (LVAD) implantation. The data at approximately 1-year post implantation was compared with that obtained prior to implantation. Statistical analyses were performed using the Microsoft Excel Program/MSExcel Stats. Echocardiographic measurements were carried out in accordance with the American Society of Echocardiography guidelines. Results: Of all the echocardiographic parameters assessed only E/Ea and calculated left atrial pressure (LAP) showed a statistically significant decrease. Two parameters that showed a trend towards significance are Ea (septal) and global functional index (p = 0.05). Conclusions: Continuous Flow LVAD support appears to improve diastolic dysfunction. This study has limitations in that we used a single type of continuous flow device (HeartMate IITM) and was conducted as a retrospective analysis. Further studies with larger populations and longer support are required to validate this finding.展开更多
The radial basis function networks were applied to bacterial classification based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOF-MS) data. The classification of bacteri...The radial basis function networks were applied to bacterial classification based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOF-MS) data. The classification of bacteria cultured at different time was discussed and the effect of the network parameters on the classification was investigated. The cross-validation method was used to test the trained networks. The correctness of the classification of different bacteria investigated changes in a wide range from 61.5% to 92.8%. Owing to the complexity of biological effects in bacterial growth, the more rigid control of bacterial culture conditions seems to be a critical factor for improving the rate of correctness for bacterial classification.展开更多
We investigate the time-modulated electronic and spin transport properties through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm（A-B） interferometer. By using the Keldysh non-equilibrium Gree...We investigate the time-modulated electronic and spin transport properties through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm（A-B） interferometer. By using the Keldysh non-equilibrium Green＇s function technique, the photon-assisted spin-dependent average current is analyzed. The T-shaped three-quantum-dot molecule A-B interferometer exhibits excellent controllability in the average current resonance spectra by adjusting the interdot coupling strength, Rashba spin-orbit coupling strength, magnetic flux, and amplitude of the time-dependent external field.Efficient spin filtering and multiple electron-photon pump functions are exploited in the multi-quantum-dot molecule A-B interferometer by a time-modulated external field.展开更多
基金the National Natural Scientific Foundation of China(No.20603030)the Youth Natural Science Foundation of Ludong University(No.042902)+1 种基金the Post-doctor Research Foundation of Shandong Province(No.200601007)the Youth Natural Science Foundation of Shandong Provincial Education Department(No.200139)
文摘Arylamine N-acetyltransferases （NATs, EC 2.3.1.5） catalyze the N-acetylation of primary arylamines, and play a key role in the biotransformation and metabolism of drugs, carcinogens, etc. In this paper, three possible reaction mechanisms are investigated and the results indicate that if the acetyl group directly transfers from the donor to the acceptor, the high activation energies will make it hard to obtain the target products. When using histidine to mediate the acetylation process, these energies will drop in the 15-45 kJ/mol range. If the histidine residue is protonated, the corresponding energies will be decreased by about 35-87 kJ/mol. The calculations predict an enzymatic acetylation mechanism that undergoes a thiolate-imidazolium pair, which agrees with the experimental results very well.
文摘目的探讨不同类型人工辅助咳嗽(manually assisted coughing,MAC)技术对脑干卒中患者咳嗽功能、痰液清除能力及肺功能的影响,为卒中后咳嗽功能障碍的康复干预提供临床依据。方法采用前瞻性随机对照设计,连续纳入2023年5月—2024年5月于北京小汤山医院运动康复科住院的脑干卒中患者,将其随机分为膈肌刺激组、气管刺激组和舌根刺激组。3组患者均接受常规康复治疗及呼吸训练,在此基础上,各组分别接受膈肌刺激、气管刺激或舌根刺激干预,每日2次,每次30 min,每周5 d,持续2周。干预前、后采用便携式肺功能检测仪测量峰值咳嗽流量(peak cough flow,PCF),检测24 h痰液量,通过运动心肺功能测试系统检测用力肺活量(forced vital capacity,FVC)、第1秒用力呼气容积(forced expiratory volume in one second,FEV1)、呼气流量峰值(peak expiratory flow,PEF)等静态肺功能指标,并使用超声评估吸气末膈肌厚度(diaphragm thickness at the end of inspiration,TEI)、呼气末膈肌厚度(diaphragm thickness at the end of expiration,TEE)、膈肌厚度分数(diaphragm thickness fraction,DTF)、膈肌移动度(diaphragmatic mobility,DM)等膈肌参数。记录干预后肺炎发生率。结果共纳入33例脑干卒中患者,每组11例。干预后,3组患者的PCF、FVC、FEV1、PEF、TEI、TEE及DTF较干预前均显著提高(均P<0.05),24 h痰液量显著降低(P<0.05)。干预后组间两两比较显示,舌根刺激组的24 h痰液量改善效果优于膈肌刺激组[(35.64±10.71)mL vs.(46.09±9.52)mL,P=0.025];舌根刺激组与气管刺激组的FVC、FEV1、PEF均优于膈肌刺激组(均P<0.05)。干预后3组在PCF、TEI、TEE、DTF等方面的差异均无统计学意义。干预后膈肌刺激组的肺炎发生率为36.4%,气管刺激组为18.2%,舌根刺激组为9.1%,组间差异无统计学意义(P=0.439)。结论膈肌刺激、气管刺激和舌根刺激3种MAC技术均可有效改善脑干卒中患者的咳嗽功能、肺功能及痰液清除能力,其中舌根刺激在诱发咳嗽反射和改善排痰方面的效果更佳。
基金partially supported by grants from the Science and Technology Development Fund of Macao(FDCT059/2011/A3)the University of Macao(MYRG085 to Jing Zhao and MYRG201400041 to LSP,respectively)
文摘In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univariate approach experiments,and then central composite design(CCD).The optimal extraction conditions were as follows:methanol concentration of 65%,microwave power of 200 W,and extraction time of 260 s.A high performance liquid chromatography–diode array detector(HPLC–DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus.Chromatographic separation was carried out on an Agilent Zorbax Extend-C_(18) column(4.6 mm×150 mm,3.5 μm).Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water(A)and acetonitrile(B):40%-70% B at 0-8 min,70%-100% B at 8–9 min,100% B for 2 min,and then equilibrated with 40% B for 2 min.
文摘The ring opening of β-sultam v/a an H2O-assisted ammonolysis process was studied by using Density Functional Theory（DFT） method at the B3LYP/6-31G level as a further step in the theoretical investigation of the ammonolysis reaction of β-sultams. The calculated pathways are analogous to those previously described for the non-assisted ammonolysis reaction. Solvent effects were assessed by using the polarized continuum model（PCM） method. The results show that mode 1 and pathway a in channel Ⅱ are the most favorable ones in both the cases. The energy barrier of the cleavage of C-S bonds producing P1 is the highest among all the energy barriers. The presence of a solvent in the continuum model disfavors the reaction, whereas the participation of water in the ammonolysis reaction plays a positive role and reduces the active energy greatly. The relative energies of all the transition states in the assisted ammonolysis are 20-80 kJ/mol lower than those for the non-assisted reaction.
文摘Background: Ventricular assist devices are now used as a bridge to recovery/decision/transplant or as destination therapy in end-stage heart failure. Continued improvements in technology and pump design have made implantation an easier process with reduced operative risks and pump-related adverse events. Considering the beneficial effects of these devices in the clinical setting, it seemed logical to address the long-term effect of the continuous flow pumps on diastolic dysfunction. Methods: This study addresses the effect of HeartMate IITM(HMII) support for 284+/-97 days on echocardiographic parameters of diastolic function. Data from fifteen patients was retrospectively studied status post left ventricular assist device (LVAD) implantation. The data at approximately 1-year post implantation was compared with that obtained prior to implantation. Statistical analyses were performed using the Microsoft Excel Program/MSExcel Stats. Echocardiographic measurements were carried out in accordance with the American Society of Echocardiography guidelines. Results: Of all the echocardiographic parameters assessed only E/Ea and calculated left atrial pressure (LAP) showed a statistically significant decrease. Two parameters that showed a trend towards significance are Ea (septal) and global functional index (p = 0.05). Conclusions: Continuous Flow LVAD support appears to improve diastolic dysfunction. This study has limitations in that we used a single type of continuous flow device (HeartMate IITM) and was conducted as a retrospective analysis. Further studies with larger populations and longer support are required to validate this finding.
基金Supported by Foundation for Young Mainstay TeachersEducation Ministry of China.
文摘The radial basis function networks were applied to bacterial classification based on the matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOF-MS) data. The classification of bacteria cultured at different time was discussed and the effect of the network parameters on the classification was investigated. The cross-validation method was used to test the trained networks. The correctness of the classification of different bacteria investigated changes in a wide range from 61.5% to 92.8%. Owing to the complexity of biological effects in bacterial growth, the more rigid control of bacterial culture conditions seems to be a critical factor for improving the rate of correctness for bacterial classification.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11447132 and 11504042)the Natural Science Foundation of Heilongjiang,China(Grant No.A201405)+2 种基金111 Project to Harbin Engineering University,China(Grant No.B13015)Chongqing Science and Technology Commission Project,China(Grant Nos.cstc2014jcyj A00032 and cstc2016jcyj A1158)Scientific Research Project for Advanced Talents of Yangtze Normal University,China(Grant No.2017KYQD09)
文摘We investigate the time-modulated electronic and spin transport properties through two T-shaped three-quantum-dot molecules embedded in an Aharonov-Bohm（A-B） interferometer. By using the Keldysh non-equilibrium Green＇s function technique, the photon-assisted spin-dependent average current is analyzed. The T-shaped three-quantum-dot molecule A-B interferometer exhibits excellent controllability in the average current resonance spectra by adjusting the interdot coupling strength, Rashba spin-orbit coupling strength, magnetic flux, and amplitude of the time-dependent external field.Efficient spin filtering and multiple electron-photon pump functions are exploited in the multi-quantum-dot molecule A-B interferometer by a time-modulated external field.
