Hepatic encephalopathy （HE） is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestat...Hepatic encephalopathy （HE） is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging （MRI） techniques provide a non-invasive means of assessment of changes in brain volume （coregistered MRI） and impaired brain function （fMRI）, while proton magnetic resonance spectroscopy （^1H MRS） detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.展开更多
In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establi...In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future.展开更多
Computer forensics and identification for traditional Chinese painting arts have caught the attention of various fields. Rice paper＇s feature extraction and analysis methods are of high significance for the rice pape...Computer forensics and identification for traditional Chinese painting arts have caught the attention of various fields. Rice paper＇s feature extraction and analysis methods are of high significance for the rice paper is an important carrier of traditional Chinese painting arts. In this paper, rice paper＇s morphological feature analysis is done using multi spectral imaging technology. The multispectral imaging system is utilized to acquire rice paper＇s spectral images in different wave- length channels, and then those spectral images are measured using texture parameter statistics to acquire sensitive bands for rice paper＇s feature. The mathematical morphology and grayscale statistical principle are utilized to establish a rice paper＇s morphological feature analytical model which is used to acquire rice paper＇ s one-dimensional vector. For the purpose of eval- uating these feature vectors＇ accuracy, they are entered into the support vector machine（SVM） classifier for detection and classification. The results show that the rice paper＇s feature is out loud in the spectral band 550 nm, and the average classifi- cation accuracy of feature vectors output from the analytical model is 96 %. The results indicate that the rice paper＇s feature analytical model can extract most of rice paper＇s features with accuracy and efficiency.展开更多
Single-molecule tip-enhanced Raman spectroscopy(TERS)has emerged as an important technique for structural analysis at sub-molecular scale.Here in this work,we report a TERS study of an isolated free-base porphyrin mol...Single-molecule tip-enhanced Raman spectroscopy(TERS)has emerged as an important technique for structural analysis at sub-molecular scale.Here in this work,we report a TERS study of an isolated free-base porphyrin molecule adsorbed on the Ag(100)surface at cryogenic temperature(~7 K).Site-dependent TERS spectra reveal distinct local vibrational information for the chemical constituents within a single molecule.Moreover,distinct spatial features among different Raman peaks can be resolved from the TERS mapping images.These images are found to associate with related vibrational modes,enabling to resolve the mode associated with N-H bonds at the sub-nanometer level.This study will provide deep insights into the symmetry of adsorption configurations and local vibrational information within a single molecule.展开更多
In this work,electron energy spectroscopic mapping of surface plasmon of Ag nanostructures on highly oriented pyrolytic graphite is reported.Benefitting from the angular dispersive feature of the present scanning prob...In this work,electron energy spectroscopic mapping of surface plasmon of Ag nanostructures on highly oriented pyrolytic graphite is reported.Benefitting from the angular dispersive feature of the present scanning probe electron energy spectrometer,a multi-channel detection mode is developed.By scanning along one direction,the two-dimensional intensity distribution of Ag surface plasmon excitation due to the collision of electron emitted from the tip can be obtained in parallel.The spectroscopic spatial resolution is determined to be around 80 nm.展开更多
Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging...Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer(MODIS) Normalized Difference Vegetation Index(NDVI) data and meteorological data(temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase(especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass.展开更多
基金Supported by grants from BUPA, the Royal College of Physicians of London and Paddington Charitable Trust, St Mary's,London. The European Association for the Study of the Liver, the British Medical Research Council (G9900178)Philips Medical Systems (Cleveland, Ohio, USA) and the United Kingdom Department of Health provided support for some of the studies outlined
文摘Hepatic encephalopathy （HE） is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting. The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging （MRI） techniques provide a non-invasive means of assessment of changes in brain volume （coregistered MRI） and impaired brain function （fMRI）, while proton magnetic resonance spectroscopy （^1H MRS） detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.
基金supported by the National Key Research and Development Program of China(No.2016YFA0200602,No.2017YFA0303500,and No.2018YFA0208702)the National Natural Science Foundation of China(No.21573211,No.21633007,No.21803067,and No.91950207)+1 种基金the Anhui Initiative in Quantum Information Technologies(AHY090200)the USTC-NSRL Joint Funds(UN2018LHJJ).
文摘In recent decades,materials science has experienced rapid development and posed increasingly high requirements for the characterizations of structures,properties,and performances.Herein,we report on our recent establishment of a multi-domain(energy,space,time)highresolution platform for integrated spectroscopy and microscopy characterizations,offering an unprecedented way to analyze materials in terms of spectral(energy)and spatial mapping as well as temporal evolution.We present several proof-of-principle results collected on this platform,including in-situ Raman imaging(high-resolution Raman,polarization Raman,low-wavenumber Raman),time-resolved photoluminescence imaging,and photoelectrical performance imaging.It can be envisioned that our newly established platform would be very powerful and effective in the multi-domain high-resolution characterizations of various materials of photoelectrochemical importance in the near future.
基金University-Industry-Science Partnership Project of Guangdong Province and Ministry of Education,China(No.2012B091000155)Strategic Emerging Industries Project of Guangdong Province(No.2011912027)
文摘Computer forensics and identification for traditional Chinese painting arts have caught the attention of various fields. Rice paper＇s feature extraction and analysis methods are of high significance for the rice paper is an important carrier of traditional Chinese painting arts. In this paper, rice paper＇s morphological feature analysis is done using multi spectral imaging technology. The multispectral imaging system is utilized to acquire rice paper＇s spectral images in different wave- length channels, and then those spectral images are measured using texture parameter statistics to acquire sensitive bands for rice paper＇s feature. The mathematical morphology and grayscale statistical principle are utilized to establish a rice paper＇s morphological feature analytical model which is used to acquire rice paper＇ s one-dimensional vector. For the purpose of eval- uating these feature vectors＇ accuracy, they are entered into the support vector machine（SVM） classifier for detection and classification. The results show that the rice paper＇s feature is out loud in the spectral band 550 nm, and the average classifi- cation accuracy of feature vectors output from the analytical model is 96 %. The results indicate that the rice paper＇s feature analytical model can extract most of rice paper＇s features with accuracy and efficiency.
基金supported by the National Key R&D Program of China(No.2016YFA0200600)the National Natural Science Foundation of China,the Chinese Academy of Sciences+1 种基金Anhui Initiative in Quantum Information TechnologiesAtif Ghafoor acknowledges support by the China Scholarship Council
文摘Single-molecule tip-enhanced Raman spectroscopy(TERS)has emerged as an important technique for structural analysis at sub-molecular scale.Here in this work,we report a TERS study of an isolated free-base porphyrin molecule adsorbed on the Ag(100)surface at cryogenic temperature(~7 K).Site-dependent TERS spectra reveal distinct local vibrational information for the chemical constituents within a single molecule.Moreover,distinct spatial features among different Raman peaks can be resolved from the TERS mapping images.These images are found to associate with related vibrational modes,enabling to resolve the mode associated with N-H bonds at the sub-nanometer level.This study will provide deep insights into the symmetry of adsorption configurations and local vibrational information within a single molecule.
基金supported by the National Key Research and Development Program of China(No.2017YFA0303500)the National Natural Science Foundation of China(No.11674302)。
文摘In this work,electron energy spectroscopic mapping of surface plasmon of Ag nanostructures on highly oriented pyrolytic graphite is reported.Benefitting from the angular dispersive feature of the present scanning probe electron energy spectrometer,a multi-channel detection mode is developed.By scanning along one direction,the two-dimensional intensity distribution of Ag surface plasmon excitation due to the collision of electron emitted from the tip can be obtained in parallel.The spectroscopic spatial resolution is determined to be around 80 nm.
基金Under the auspices of National Natural Science Foundation of China(No.41471026,31171451)Strategic Science and Technology Program in the Thirteenth Five-Year Plan of Institute of Geographical Sciences and Natural Resources Research,Chinese Academy of Sciences(No.2012ZD003)
文摘Examining the direct and indirect effects of climatic factors on vegetation growth is critical to understand the complex linkage between climate change and vegetation dynamics. Based on the Moderate Resolution Imaging Spectroradiometer(MODIS) Normalized Difference Vegetation Index(NDVI) data and meteorological data(temperature and precipitation) from 2001 to 2012, the trend of vegetation dynamics were examined in the Ziya-Daqing basins, China. The path analysis was used to obtain the information on the relationships among climatic factors and their effects on vegetation growth. It was found that the trends of growing season NDVI were insignificant in most plain dry land, while the upward trends were significant in forest, grass and dry land in Taihang Mountains. According to the path analysis, in 23% of the basins the inter-annual NDVI variation was dominated by the direct effect of precipitation, in 5% by the direct effects of precipitation and temperature, and in less than 1% by the direct effect of temperature or indirect effects of these two climatic factors. It indicated that precipitation significantly affected the vegetation growth in the whole basins, and this effect was not regulated by temperature. Precipitation increase(especially in July, August and September) was favorable to greenness enhancement. Summer temperature rising showed negative effect on plant productivity enhancement, but temperature rise in April was beneficial for the vegetation growth. When April temperature increases by 1℃, the onset date of greenness for natural vegetation will be 2 days in advance. There was a lag-time effect of precipitation or temperature on monthly NDVI for all land use types except grass.
