The metabolic evolution model of transportation demand for comprehensive transportation systems is put forward on the basis of a metabolic theory of ecology. In the model, the growth rates or changing rates of transpo...The metabolic evolution model of transportation demand for comprehensive transportation systems is put forward on the basis of a metabolic theory of ecology. In the model, the growth rates or changing rates of transportation volumes for the various transportation modes of a city are determined not only by the GDP per capita which reflects the size of the city itself, but also by the relationship of competition and cooperation among transportation modes. The results of empirical analysis for Chinese cities show that the allometric growth exponent in the equation for the variation rate of passenger demand volume on rail is greater than the predicted value of 1/4 in metabolic ecology, whereas the allometric growth relationship is not so evident in the equation for the variation rate of passenger demand volume on road. The changing rate of road transportation is thus mainly affected by the relationship of competition and cooperation among transportation modes for Chinese cities.展开更多
Objective To evaluate metabolic abnormalities in patients with mesial temporal lobe epilepsy （MTLE） with proton magnetic resonance spectroscopy （MRS） using a 3.0T MR scanner. Methods Sixty-three patients （32 wom...Objective To evaluate metabolic abnormalities in patients with mesial temporal lobe epilepsy （MTLE） with proton magnetic resonance spectroscopy （MRS） using a 3.0T MR scanner. Methods Sixty-three patients （32 women and 31 men） with diagnosed MTLE underwent diagnostic MR imaging （MRI） and proton MRS using a 3.0T MR scanner. The clinical history and interictal epileptiform discharges （IEDs） were recorded. Sixteen healthy volunteers served as control. The results of proton MRS were compared with the findings of electroencephalogram and structural MRI findings. Results Twenty-seven of the 63 patients with MTLE showed unilateral hippocampal sclerosis, and 9 showed bilateral hippocampal sclerosis. The concentration ratio of N-acytelaspartate （NAA） / [ creatine （ Cr ） ＋ choline （Cho） ] in the hippocampal region of MTLE patients （0. 64±0. 07） was significantly lower than control （0. 80±0. 05, P = 0.023）. In the patients with unilateral hippocampal sclerosis, NAA/（Cr ＋ Cho） in the hippocampal region ipsilateral to the sclerotic hippocampus （0.56±0.06） was significantly lower than the ratio in the contralateral hippocampal region （0.69±0.07, P 〈 0. 001 ）. There was significant difference in hippocampal NAA/（ Cr ＋ Cho） between the refractory patients and the non-refractory patients （0. 64±0. 05 vs.0.71±0. 07, P =0. 04）. Forty-five patients were lateralized by IEDs, while 49 patients were lateralized by metabolite ratio. And lateralization determined by proton MRS and IEDs was concordant in 33 patients. Conclusions MRS as a noninvasive tool adds helpful metabolite information to routine MRI in evaluation of MTLE. The method is well established and should be a routine clinical application in the investigation of epilepsy.展开更多
AIM To gain knowledge of xanthelasma,a large populationbased study was conducted. METHODS Patients who underwent upper gastrointestinal endoscopy at the First Affiliated Hospital,College of Medicine,Zhejiang Universit...AIM To gain knowledge of xanthelasma,a large populationbased study was conducted. METHODS Patients who underwent upper gastrointestinal endoscopy at the First Affiliated Hospital,College of Medicine,Zhejiang University,Hangzhou,China during Jan 2009 to Nov 2016 were included. General characteristics as well as clinical data were collected,including blood routine,serum biochemical analysis,endoscopic findinds,histological evaluation and comorbiditie. Statistical analyses was performed using SPSS 20.0 software for Windows(IBM Inc.,Chicago,IL,United States) using Student's t-test,Mann-Whitney U test,χ2 test,univariable and multivariable logistic analysis. 2-tailed P value less than 0.05 was considered to be statistically significant. RESULTS A total of 176006 endoscopies were retrieved and we included 1370 xanthelasma participants(703 men,667 women) in this study. Prevalence of xanthelasma was 0.78% with average age of 56.6 ± 11.2 years. Chief complaint of xanthelasma consisted abdominal pain (24.2%),up-abdominal discomfort(14.1%),abdominal distention(10.1%),dyspepsia(9.1%),et al. Most xanthelasma occurred as single lesion in gastric antrum. Xanthelasma patients witnessed higher Helicobacter pylori(H. pylori) infection rate,more of other gastric lesions including atrophy,intestinal metaplasia and dysplasia(P < 0.01). In xanthelasma patients,serum carcinoembryonic antigen,triglyceride,fasting glucose,neutrophil,neutrophil-to-lymphocyte ratio were significantly higher,and high density lipoprotein-cholesterol,lymphocyte was lower(P < 0.05). Xanthelasma accompanied with more fatty liver disease and hepatic cyst,but fewer gallbladder polyp(P < 0.05). In logistic regression,it revealed that fasting plasma glucose(OR = 3.347,1.170-9.575,P < 0.05),neutrophil(OR = 1.617,1.003-2.605,P < 0.05),and carcinoembryonic antigen(OR = 2.011,1.236-3.271,P < 0.01) were all independent risk factors in xanthelasma. CONCLUSION Current study described a large xanthelasma cohort in Chinese population,revealed its relationship with H. pylori infection,carcinogenesis,metabolic dysfunction and inflammation as well.展开更多
Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of comb...Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of combinatorial biosynthesis provides the possibility to produce "unnatural" natural drugs, which has achieved initial success. This paper provides an overview for the strategies of combinatorial biosynthesis in producing the structural and functional diversity of polyketides, including the redesign of metabolic flow, polyketide synthase(PKS) engineering, and PKS post-translational modification. Although encouraging progress has been made in the last decade, challenges still exist regarding the rational combinatorial biosynthesis of polyketides. In this review, the perspectives of polyketide combinatorial biosynthesis are also discussed.展开更多
Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,whic...Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,which are two processes underlying recognition. Methods:Participants saw a series of pictures with either blue or red background,and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition,participants remained awake until the posttest;in the sleep condition,participants slept for 1 h until awakened and asked to remain awake until the posttest. Results:Daytime sleep contributed to retention of source memory rather than item memory in females,whereas males undergoing daytime sleep had a trend towards increased familiarity. For females,however,neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion:The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies,as well as with different electrophysiological changes during daytime sleep.展开更多
基金The Ph.D.Programs Foundation of Ministry of Education of China(No.20060286005)China Postdoctoral Science Foundation(No.20070411018)
文摘The metabolic evolution model of transportation demand for comprehensive transportation systems is put forward on the basis of a metabolic theory of ecology. In the model, the growth rates or changing rates of transportation volumes for the various transportation modes of a city are determined not only by the GDP per capita which reflects the size of the city itself, but also by the relationship of competition and cooperation among transportation modes. The results of empirical analysis for Chinese cities show that the allometric growth exponent in the equation for the variation rate of passenger demand volume on rail is greater than the predicted value of 1/4 in metabolic ecology, whereas the allometric growth relationship is not so evident in the equation for the variation rate of passenger demand volume on road. The changing rate of road transportation is thus mainly affected by the relationship of competition and cooperation among transportation modes for Chinese cities.
文摘Objective To evaluate metabolic abnormalities in patients with mesial temporal lobe epilepsy （MTLE） with proton magnetic resonance spectroscopy （MRS） using a 3.0T MR scanner. Methods Sixty-three patients （32 women and 31 men） with diagnosed MTLE underwent diagnostic MR imaging （MRI） and proton MRS using a 3.0T MR scanner. The clinical history and interictal epileptiform discharges （IEDs） were recorded. Sixteen healthy volunteers served as control. The results of proton MRS were compared with the findings of electroencephalogram and structural MRI findings. Results Twenty-seven of the 63 patients with MTLE showed unilateral hippocampal sclerosis, and 9 showed bilateral hippocampal sclerosis. The concentration ratio of N-acytelaspartate （NAA） / [ creatine （ Cr ） ＋ choline （Cho） ] in the hippocampal region of MTLE patients （0. 64±0. 07） was significantly lower than control （0. 80±0. 05, P = 0.023）. In the patients with unilateral hippocampal sclerosis, NAA/（Cr ＋ Cho） in the hippocampal region ipsilateral to the sclerotic hippocampus （0.56±0.06） was significantly lower than the ratio in the contralateral hippocampal region （0.69±0.07, P 〈 0. 001 ）. There was significant difference in hippocampal NAA/（ Cr ＋ Cho） between the refractory patients and the non-refractory patients （0. 64±0. 05 vs.0.71±0. 07, P =0. 04）. Forty-five patients were lateralized by IEDs, while 49 patients were lateralized by metabolite ratio. And lateralization determined by proton MRS and IEDs was concordant in 33 patients. Conclusions MRS as a noninvasive tool adds helpful metabolite information to routine MRI in evaluation of MTLE. The method is well established and should be a routine clinical application in the investigation of epilepsy.
基金Supported by Science Foundation of Health Bureau of Zhejiang Province,No.2017183691(to Chen Y)
文摘AIM To gain knowledge of xanthelasma,a large populationbased study was conducted. METHODS Patients who underwent upper gastrointestinal endoscopy at the First Affiliated Hospital,College of Medicine,Zhejiang University,Hangzhou,China during Jan 2009 to Nov 2016 were included. General characteristics as well as clinical data were collected,including blood routine,serum biochemical analysis,endoscopic findinds,histological evaluation and comorbiditie. Statistical analyses was performed using SPSS 20.0 software for Windows(IBM Inc.,Chicago,IL,United States) using Student's t-test,Mann-Whitney U test,χ2 test,univariable and multivariable logistic analysis. 2-tailed P value less than 0.05 was considered to be statistically significant. RESULTS A total of 176006 endoscopies were retrieved and we included 1370 xanthelasma participants(703 men,667 women) in this study. Prevalence of xanthelasma was 0.78% with average age of 56.6 ± 11.2 years. Chief complaint of xanthelasma consisted abdominal pain (24.2%),up-abdominal discomfort(14.1%),abdominal distention(10.1%),dyspepsia(9.1%),et al. Most xanthelasma occurred as single lesion in gastric antrum. Xanthelasma patients witnessed higher Helicobacter pylori(H. pylori) infection rate,more of other gastric lesions including atrophy,intestinal metaplasia and dysplasia(P < 0.01). In xanthelasma patients,serum carcinoembryonic antigen,triglyceride,fasting glucose,neutrophil,neutrophil-to-lymphocyte ratio were significantly higher,and high density lipoprotein-cholesterol,lymphocyte was lower(P < 0.05). Xanthelasma accompanied with more fatty liver disease and hepatic cyst,but fewer gallbladder polyp(P < 0.05). In logistic regression,it revealed that fasting plasma glucose(OR = 3.347,1.170-9.575,P < 0.05),neutrophil(OR = 1.617,1.003-2.605,P < 0.05),and carcinoembryonic antigen(OR = 2.011,1.236-3.271,P < 0.01) were all independent risk factors in xanthelasma. CONCLUSION Current study described a large xanthelasma cohort in Chinese population,revealed its relationship with H. pylori infection,carcinogenesis,metabolic dysfunction and inflammation as well.
基金supported by the Major Research Plan of Tianjin(No.16YFXTSF00460)
文摘Polyketides have been widely used clinically due to their significant biological activities, but the needed structural and functional diversity cannot be achieved by common chemical synthetic methods. The tool of combinatorial biosynthesis provides the possibility to produce "unnatural" natural drugs, which has achieved initial success. This paper provides an overview for the strategies of combinatorial biosynthesis in producing the structural and functional diversity of polyketides, including the redesign of metabolic flow, polyketide synthase(PKS) engineering, and PKS post-translational modification. Although encouraging progress has been made in the last decade, challenges still exist regarding the rational combinatorial biosynthesis of polyketides. In this review, the perspectives of polyketide combinatorial biosynthesis are also discussed.
基金supported partially by the National Basic Research Program (973) of China (No. 2006CB303101)the National Natural Science Foundation of China (No. 90820305)
文摘Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,which are two processes underlying recognition. Methods:Participants saw a series of pictures with either blue or red background,and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition,participants remained awake until the posttest;in the sleep condition,participants slept for 1 h until awakened and asked to remain awake until the posttest. Results:Daytime sleep contributed to retention of source memory rather than item memory in females,whereas males undergoing daytime sleep had a trend towards increased familiarity. For females,however,neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion:The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies,as well as with different electrophysiological changes during daytime sleep.
