The prevalence of obesity and obesity related comorbidities including diabetes and nonalcoholic fatty liver disease (NAFLD) has been rising globally. Nonalcoholic fatty liver disease is emerging as a common liver dise...The prevalence of obesity and obesity related comorbidities including diabetes and nonalcoholic fatty liver disease (NAFLD) has been rising globally. Nonalcoholic fatty liver disease is emerging as a common liver disease among adults which can lead to the eventua development of complications including cirrhosis and hepatocellular carcinoma. With the rise of obesity in children, the development of detection methods for the presence of NAFLD is becoming imperative. Although the gold standard for diagnosis is liver biopsy, practica issues limit pediatric use and warrant development of noninvasive or minimally invasive screening tools for the detection and staging of NAFLD. A variety of diagnostic methods have been studied including use aminotransferases, imaging studies and serologic markers which have some population-based limitations. Additional factors such as gender and ethnicity may also play a role in the screening of NAFLD in pediatric population studies.展开更多
The correlation of serum arylesterase(PON1) activity on phenylacetate determined by an integrated method to clas-sical biochemical indexes of liver damage was investigated for the use of PON1 activity to evaluate live...The correlation of serum arylesterase(PON1) activity on phenylacetate determined by an integrated method to clas-sical biochemical indexes of liver damage was investigated for the use of PON1 activity to evaluate liver damage.PON1 reaction curve as absorbance at 270 nm for 0.20 mmol/L phenylacetate hydrolysis was analyzed by the integrated method to determine maximal PON1 reaction rate.Classical biochemical indexes of liver damage were determined routinely.The 95% confidence threshold of PON1 activity in sera from healthy individuals was 2.12 mkat/L [(4.73±1.31) mkat/L,n=105].PON1 activity in clinical sera was closely correlated to serum albumin,total protein and the ratio of albumin to globulins,but was weakly correlated to both direct and total bilirubin in serum.There were no correlations of PON1 activity to γ-glutamyltransferase,alkaline phos-phatase,alanine aminotransferase and aspartate aminotransferase.Among 127 clinical sera with PON1 activity>2.12 mkat/L,there were 92% healthy individuals examined by albumin,90% healthy individuals examined by total protein,88% healthy individuals examined by total bilirubin,86% healthy individuals examined by direct bilirubin and 64% healthy individuals examined by the ratio of albumin to globulins,respectively.In each group of healthy individuals judged by classical biochemical indexes of close correlation to PON1 activity,percentage of healthy individuals examined by PON1 activity was always >80%.These results suggested PON1 activity on phenylacetate estimated by the integrated method was also suitable for the evaluation of liver damage.展开更多
用量子化学ONIOM(B3LYP/6-311++G(3df,3pd):UFF)∥ONIOM(B3LYP/6-31+G(d,p):UFF)方法,研究α-Ala在SWBNNT(9,9)与水复合环境的手性转变。分子结构计算表明:反应物S型α-Ala和中间体INT1在SWBNNT(9,9)与水复合环境,与单体相比,氢转移断的...用量子化学ONIOM(B3LYP/6-311++G(3df,3pd):UFF)∥ONIOM(B3LYP/6-31+G(d,p):UFF)方法,研究α-Ala在SWBNNT(9,9)与水复合环境的手性转变。分子结构计算表明:反应物S型α-Ala和中间体INT1在SWBNNT(9,9)与水复合环境,与单体相比,氢转移断的O-H和C-H键都略长,H与其要转移到的目标原子O的距离均短很多。反应通道研究发现:在SWBNNT(9,9)与水复合环境下,α-Ala手性转变有4条路径,每条路径上氢转移都能以1个或2个水分子为媒介实现。势能面计算发现:手性转变反应的最高能垒来自H从手性C向羰基O转移的过渡态;在氨基先异构接着羧基H转移和H从手性C向羰基O转移顺次实现的路径,并以2H2O为氢转移媒介时最高能垒被降到最小值153.8 k J·mol-1。比只在SWBNNT(9,9)内的302.7 k J·mol-1明显降低,比只在水环境的167.8 k J·mol-1也有所降低。结果表明:SWBNNT(9,9)与水复合环境,对α-Ala手性转变有较好的催化作用。展开更多
采用组合的量子化学ONIOM(our own n-layered integrated molecule orbit and molecule mechanics)(B3LYP/6-31++G(d,p):UFF)方法,研究了限域在SWBNNT(9,9)内α-丙氨酸的分子结构和手性转变通道.为得到高水平的能量,在ONIOM(B3LYP/6-311...采用组合的量子化学ONIOM(our own n-layered integrated molecule orbit and molecule mechanics)(B3LYP/6-31++G(d,p):UFF)方法,研究了限域在SWBNNT(9,9)内α-丙氨酸的分子结构和手性转变通道.为得到高水平的能量,在ONIOM(B3LYP/6-311++G(3df,3pd):UFF)水平,计算了各个包结物的单点能.分子结构分析表明:与单体α-丙氨酸相比,受限在SWBNNT(9,9)内时,骨架碳氮原子间的键长不同程度地缩短,骨架碳原子的键角及骨架碳氮原子的二面角略有增大.反应路径研究发现:α-丙氨酸分子在SWBNNT(9,9)内的手性转变有两条同单体情况大致相同的反应通道,不存在单体情况的含有羰基H和甲基H协同转移过程的反应通道.手性转变反应过程的势能面计算发现:与单体α-丙氨酸手性转变反应过程的主要能垒相比较,在纸外面的氢从手性碳直接到羰基氧的过渡态产生的能垒,从326.5kJ·mol-1降到319.7kJ·mol-1;氢首先在羧基内转移,而后手性碳的氢在纸面外转移到羰基,这两个过程的能垒从198.0kJ·mol-1和320.3kJ·mol-1降到135.5kJ·mol-1和302.7kJ·mol-1.结果表明:限域在SWBNNT(9,9)内的α-丙氨酸,其手性转变过程中不同的氢转移反应能垒被不同程度地降低.展开更多
文摘The prevalence of obesity and obesity related comorbidities including diabetes and nonalcoholic fatty liver disease (NAFLD) has been rising globally. Nonalcoholic fatty liver disease is emerging as a common liver disease among adults which can lead to the eventua development of complications including cirrhosis and hepatocellular carcinoma. With the rise of obesity in children, the development of detection methods for the presence of NAFLD is becoming imperative. Although the gold standard for diagnosis is liver biopsy, practica issues limit pediatric use and warrant development of noninvasive or minimally invasive screening tools for the detection and staging of NAFLD. A variety of diagnostic methods have been studied including use aminotransferases, imaging studies and serologic markers which have some population-based limitations. Additional factors such as gender and ethnicity may also play a role in the screening of NAFLD in pediatric population studies.
基金Project (No. 30200266) supported by the National Natural Science Foundation of China
文摘The correlation of serum arylesterase(PON1) activity on phenylacetate determined by an integrated method to clas-sical biochemical indexes of liver damage was investigated for the use of PON1 activity to evaluate liver damage.PON1 reaction curve as absorbance at 270 nm for 0.20 mmol/L phenylacetate hydrolysis was analyzed by the integrated method to determine maximal PON1 reaction rate.Classical biochemical indexes of liver damage were determined routinely.The 95% confidence threshold of PON1 activity in sera from healthy individuals was 2.12 mkat/L [(4.73±1.31) mkat/L,n=105].PON1 activity in clinical sera was closely correlated to serum albumin,total protein and the ratio of albumin to globulins,but was weakly correlated to both direct and total bilirubin in serum.There were no correlations of PON1 activity to γ-glutamyltransferase,alkaline phos-phatase,alanine aminotransferase and aspartate aminotransferase.Among 127 clinical sera with PON1 activity>2.12 mkat/L,there were 92% healthy individuals examined by albumin,90% healthy individuals examined by total protein,88% healthy individuals examined by total bilirubin,86% healthy individuals examined by direct bilirubin and 64% healthy individuals examined by the ratio of albumin to globulins,respectively.In each group of healthy individuals judged by classical biochemical indexes of close correlation to PON1 activity,percentage of healthy individuals examined by PON1 activity was always >80%.These results suggested PON1 activity on phenylacetate estimated by the integrated method was also suitable for the evaluation of liver damage.
文摘用量子化学ONIOM(B3LYP/6-311++G(3df,3pd):UFF)∥ONIOM(B3LYP/6-31+G(d,p):UFF)方法,研究α-Ala在SWBNNT(9,9)与水复合环境的手性转变。分子结构计算表明:反应物S型α-Ala和中间体INT1在SWBNNT(9,9)与水复合环境,与单体相比,氢转移断的O-H和C-H键都略长,H与其要转移到的目标原子O的距离均短很多。反应通道研究发现:在SWBNNT(9,9)与水复合环境下,α-Ala手性转变有4条路径,每条路径上氢转移都能以1个或2个水分子为媒介实现。势能面计算发现:手性转变反应的最高能垒来自H从手性C向羰基O转移的过渡态;在氨基先异构接着羧基H转移和H从手性C向羰基O转移顺次实现的路径,并以2H2O为氢转移媒介时最高能垒被降到最小值153.8 k J·mol-1。比只在SWBNNT(9,9)内的302.7 k J·mol-1明显降低,比只在水环境的167.8 k J·mol-1也有所降低。结果表明:SWBNNT(9,9)与水复合环境,对α-Ala手性转变有较好的催化作用。
文摘采用组合的量子化学ONIOM(our own n-layered integrated molecule orbit and molecule mechanics)(B3LYP/6-31++G(d,p):UFF)方法,研究了限域在SWBNNT(9,9)内α-丙氨酸的分子结构和手性转变通道.为得到高水平的能量,在ONIOM(B3LYP/6-311++G(3df,3pd):UFF)水平,计算了各个包结物的单点能.分子结构分析表明:与单体α-丙氨酸相比,受限在SWBNNT(9,9)内时,骨架碳氮原子间的键长不同程度地缩短,骨架碳原子的键角及骨架碳氮原子的二面角略有增大.反应路径研究发现:α-丙氨酸分子在SWBNNT(9,9)内的手性转变有两条同单体情况大致相同的反应通道,不存在单体情况的含有羰基H和甲基H协同转移过程的反应通道.手性转变反应过程的势能面计算发现:与单体α-丙氨酸手性转变反应过程的主要能垒相比较,在纸外面的氢从手性碳直接到羰基氧的过渡态产生的能垒,从326.5kJ·mol-1降到319.7kJ·mol-1;氢首先在羧基内转移,而后手性碳的氢在纸面外转移到羰基,这两个过程的能垒从198.0kJ·mol-1和320.3kJ·mol-1降到135.5kJ·mol-1和302.7kJ·mol-1.结果表明:限域在SWBNNT(9,9)内的α-丙氨酸,其手性转变过程中不同的氢转移反应能垒被不同程度地降低.
