在过去的十多年中,伴随着量子化学理论与计算机硬件、软件的不断发展,量子化学计算核磁共振参数(quantum chemical calculation of nuclear magnetic resonance parameters,qcc-NMR)的方法也日趋成熟,这些方法往往在较小的计算成本下就...在过去的十多年中,伴随着量子化学理论与计算机硬件、软件的不断发展,量子化学计算核磁共振参数(quantum chemical calculation of nuclear magnetic resonance parameters,qcc-NMR)的方法也日趋成熟,这些方法往往在较小的计算成本下就可以获得比较理想的计算精度,且对于NMR参数计算结果的分析也从最初的简单统计学方法逐渐发展为基于更为复杂的统计学原理或人工神经网络的方法,这些进展都促使qcc-NMR这一工具在天然产物研究中得到了越来越广泛的应用,从而对传统的NMR技术、质谱,以及各种光谱技术做出了重要补充.本文对qcc-NMR在天然产物结构鉴定中的应用进行了综述,并对近年来的一些应用实例进行了较为详细的分析.展开更多
By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using rese...By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.展开更多
The interaction between N, N′-bis（dimethyldodecyl）-1,6-hexanediammoniumdibromide （G12-6-12） and cetyltrimethylammonium bromide （CTAB） in D20 aqueous medium has been investigated by NMR at 298 K. The G12-6-12 an...The interaction between N, N′-bis（dimethyldodecyl）-1,6-hexanediammoniumdibromide （G12-6-12） and cetyltrimethylammonium bromide （CTAB） in D20 aqueous medium has been investigated by NMR at 298 K. The G12-6-12 and CTAB are about 0.773 and measured critical micelle concentration （cmc） of 0.668 mmol/L, respectively. The cmc^＊ （cmc of mixture） values are less than CMC^＊ （cmc of ideally mixed solution） in the mixed system, and the interaction parameter βM〈0 at different molar fractions α of G12-6-12 in the mixed systems, but just when α≤0.3, cmc^＊ values are much smaller than CMC^＊, and βM satisfies the relation of ｜βM｜〉｜ln（cmc1/cmc2）｜ （cmcl： cmc of pure G12-6-12 and cmc2： cmc Of pure CTAB）. The results indicate that there exists synergism between G12-6-12 and CTAB, and they can form mixed micelles, which is further proven by 2D NOESY and self-diffusion coefficient D experiments. There are intermolecular cross peaks between G12-6-12 and CTAB in 2D NOESY, and the radius of micelles in mixed solution is bigger than that in G12-6-12 pure solution in D experiments, indicating there are mixed micelles. However, when α〉0.3, we find that cmc^＊≈CMC^＊, βM≈0, obviously, the two surfactants are almost ideal mixing fitting the pseudo-phase separation model and regular solution theory.展开更多
目的:分析前列腺多参数核磁共振检查第2版前列腺影像报告与数据系统(prostate imaging-reporting and data system version 2,PI-RADS V2)中低评分患者的临床特征。方法:回顾性分析2015年7月—2019年7月在上海交通大学附属仁济医院行经...目的:分析前列腺多参数核磁共振检查第2版前列腺影像报告与数据系统(prostate imaging-reporting and data system version 2,PI-RADS V2)中低评分患者的临床特征。方法:回顾性分析2015年7月—2019年7月在上海交通大学附属仁济医院行经会阴前列腺穿刺活检,并且术前行多参数核磁共振检查的2588例患者的临床资料,患者年龄25~91岁,平均(67.6±7.9)岁;PSA中位数11.49(7.49,20.74)ng/mL,其中983例PSA位于灰区(4~10ng/mL)。2588例患者中,PI-RADS V2评分2分302例(11.7%),3分238例(9.2%),4分1842例(71.2%),5分206例(7.9%)。采用logistic单因素和卡方检验对中低PI-RADS V2评分(≤3分)患者的临床特征进行分析。结果:2588例经会阴前列腺穿刺活检者中有1259(48.6%)例患者穿刺病理为前列腺癌(prostate cancer,PCa),以PI-RADS V2评分>3分为界,PI-RADS V2中低评分者占6.6%(83/1259),临床分期均≤cT2cN0M0期,其中48.2%(40/83)为临床无显著意义前列腺癌(clinically insignificant prostate cancer,ciPCa)。以PI-RADS V2评分>3分为穿刺指征,可使17.7%(457/2588)的患者避免不必要的穿刺,而且漏诊83例中所有患者均为局限性PCa,其中ciPCa占48.2%;在PSA值位于灰区的983例患者中,穿刺阳性率为33.9%(333/983),以PI-RADS V2评分>3分为穿刺指征,可使20.3%(200/983)的患者避免不必要的穿刺,而且漏诊26例中所有患者均为局限性PCa,其中ciPCa患者占69.2%(18/26)。结论:多参数核磁共振检查对评估患者是否需要进行前列腺穿刺具有指导意义,在PI-RADS V2≤3分的患者中,仍有部分患者穿刺病理为PCa,但是相对于PI-RADS高评分者其临床分期及Gleason评分明显偏低,其中ciPCa占大部分;而对于PSA值位于灰区的患者,采用PIRADS V2对患者进行评估可大幅减少不必要的前列腺穿刺。展开更多
前列腺癌是英国男性肿瘤中发病率最高的恶性肿瘤[1],伦敦大学医学院(University College London Hospital,UCLH)是英国最大的前列腺癌诊疗中心。笔者结合自己2017至2018年在该医院泌尿外科前列腺癌机器人手术组和局部治疗组的工作经验,...前列腺癌是英国男性肿瘤中发病率最高的恶性肿瘤[1],伦敦大学医学院(University College London Hospital,UCLH)是英国最大的前列腺癌诊疗中心。笔者结合自己2017至2018年在该医院泌尿外科前列腺癌机器人手术组和局部治疗组的工作经验,介绍前列腺癌患者在英国的诊疗路径。一、NHS免费医疗制度和违规(Breach)制度英国的国民保健服务体系(National Health Service,NHS)是在二战后1948年建立,是英国国民评价第一的政府系统[2]。展开更多
文摘在过去的十多年中,伴随着量子化学理论与计算机硬件、软件的不断发展,量子化学计算核磁共振参数(quantum chemical calculation of nuclear magnetic resonance parameters,qcc-NMR)的方法也日趋成熟,这些方法往往在较小的计算成本下就可以获得比较理想的计算精度,且对于NMR参数计算结果的分析也从最初的简单统计学方法逐渐发展为基于更为复杂的统计学原理或人工神经网络的方法,这些进展都促使qcc-NMR这一工具在天然产物研究中得到了越来越广泛的应用,从而对传统的NMR技术、质谱,以及各种光谱技术做出了重要补充.本文对qcc-NMR在天然产物结构鉴定中的应用进行了综述,并对近年来的一些应用实例进行了较为详细的分析.
文摘By analyzing hundreds of capillary pressure curves, the controlling factors of shape and type of capillary pressure curves are found and a novel method is presented to construct capillary pressure curves by using reservoir permeability and a synthesized index. The accuracy of this new method is verified by mercury-injection experiments. Considering the limited quantity of capillary pressure data, a new method is developed to extract the Swanson parameter from the NMR T2 distribution and estimate reservoir permeability. Integrating with NMR total porosity, reservoir capillary pressure curves can be constructed to evaluate reservoir pore structure in the intervals with NMR log data. An in-situ example of evaluating reservoir pore structure using the capillary pressure curves by this new method is presented. The result shows that it accurately detects the change in reservoir pore structure as a function of depth.
文摘The interaction between N, N′-bis（dimethyldodecyl）-1,6-hexanediammoniumdibromide （G12-6-12） and cetyltrimethylammonium bromide （CTAB） in D20 aqueous medium has been investigated by NMR at 298 K. The G12-6-12 and CTAB are about 0.773 and measured critical micelle concentration （cmc） of 0.668 mmol/L, respectively. The cmc^＊ （cmc of mixture） values are less than CMC^＊ （cmc of ideally mixed solution） in the mixed system, and the interaction parameter βM〈0 at different molar fractions α of G12-6-12 in the mixed systems, but just when α≤0.3, cmc^＊ values are much smaller than CMC^＊, and βM satisfies the relation of ｜βM｜〉｜ln（cmc1/cmc2）｜ （cmcl： cmc of pure G12-6-12 and cmc2： cmc Of pure CTAB）. The results indicate that there exists synergism between G12-6-12 and CTAB, and they can form mixed micelles, which is further proven by 2D NOESY and self-diffusion coefficient D experiments. There are intermolecular cross peaks between G12-6-12 and CTAB in 2D NOESY, and the radius of micelles in mixed solution is bigger than that in G12-6-12 pure solution in D experiments, indicating there are mixed micelles. However, when α〉0.3, we find that cmc^＊≈CMC^＊, βM≈0, obviously, the two surfactants are almost ideal mixing fitting the pseudo-phase separation model and regular solution theory.
文摘目的:分析前列腺多参数核磁共振检查第2版前列腺影像报告与数据系统(prostate imaging-reporting and data system version 2,PI-RADS V2)中低评分患者的临床特征。方法:回顾性分析2015年7月—2019年7月在上海交通大学附属仁济医院行经会阴前列腺穿刺活检,并且术前行多参数核磁共振检查的2588例患者的临床资料,患者年龄25~91岁,平均(67.6±7.9)岁;PSA中位数11.49(7.49,20.74)ng/mL,其中983例PSA位于灰区(4~10ng/mL)。2588例患者中,PI-RADS V2评分2分302例(11.7%),3分238例(9.2%),4分1842例(71.2%),5分206例(7.9%)。采用logistic单因素和卡方检验对中低PI-RADS V2评分(≤3分)患者的临床特征进行分析。结果:2588例经会阴前列腺穿刺活检者中有1259(48.6%)例患者穿刺病理为前列腺癌(prostate cancer,PCa),以PI-RADS V2评分>3分为界,PI-RADS V2中低评分者占6.6%(83/1259),临床分期均≤cT2cN0M0期,其中48.2%(40/83)为临床无显著意义前列腺癌(clinically insignificant prostate cancer,ciPCa)。以PI-RADS V2评分>3分为穿刺指征,可使17.7%(457/2588)的患者避免不必要的穿刺,而且漏诊83例中所有患者均为局限性PCa,其中ciPCa占48.2%;在PSA值位于灰区的983例患者中,穿刺阳性率为33.9%(333/983),以PI-RADS V2评分>3分为穿刺指征,可使20.3%(200/983)的患者避免不必要的穿刺,而且漏诊26例中所有患者均为局限性PCa,其中ciPCa患者占69.2%(18/26)。结论:多参数核磁共振检查对评估患者是否需要进行前列腺穿刺具有指导意义,在PI-RADS V2≤3分的患者中,仍有部分患者穿刺病理为PCa,但是相对于PI-RADS高评分者其临床分期及Gleason评分明显偏低,其中ciPCa占大部分;而对于PSA值位于灰区的患者,采用PIRADS V2对患者进行评估可大幅减少不必要的前列腺穿刺。
文摘前列腺癌是英国男性肿瘤中发病率最高的恶性肿瘤[1],伦敦大学医学院(University College London Hospital,UCLH)是英国最大的前列腺癌诊疗中心。笔者结合自己2017至2018年在该医院泌尿外科前列腺癌机器人手术组和局部治疗组的工作经验,介绍前列腺癌患者在英国的诊疗路径。一、NHS免费医疗制度和违规(Breach)制度英国的国民保健服务体系(National Health Service,NHS)是在二战后1948年建立,是英国国民评价第一的政府系统[2]。
