Hippocampal morphological change is one of the main hallmarks of Alzheimer’s disease(AD).However,whether hippocampal radiomic features are robust as predictors of progression from mild cognitive impairment(MCI)to AD ...Hippocampal morphological change is one of the main hallmarks of Alzheimer’s disease(AD).However,whether hippocampal radiomic features are robust as predictors of progression from mild cognitive impairment(MCI)to AD dementia and whether these features provide any neurobiological foundation remains unclear.The primary aim of this study was to verify whether hippocampal radiomic features can serve as robust magnetic resonance imaging(MRI)markers for AD.Multivariate classifier-based support vector machine(SVM)analysis provided individual-level predictions for distinguishing AD patients(n=261)from normal controls(NCs;n=231)with an accuracy of 88.21%and intersite crossvalidation.Further analyses of a large,independent the Alzheimer’s Disease Neuroimaging Initiative(ADNI)dataset(n=1228)reinforced these findings.In MCI groups,a systemic analysis demonstrated that the identified features were significantly associated with clinical features(e.g.,apolipoprotein E(APOE)genotype,polygenic risk scores,cerebrospinal fluid(CSF)Ab,CSF Tau),and longitudinal changes in cognition ability;more importantly,the radiomic features had a consistently altered pattern with changes in the MMSE scores over 5 years of follow-up.These comprehensive results suggest that hippocampal radiomic features can serve as robust biomarkers for clinical application in AD/MCI,and further provide evidence for predicting whether an MCI subject would convert to AD based on the radiomics of the hippocampus.The results of this study are expected to have a substantial impact on the early diagnosis of AD/MCI.展开更多
A medium resolution spectral imager （MERSI） on-board the first spacecraft of the second generation of Chinas polar-orbit meteorological satellites FY-3A, is a MODIS-like sensor with 20 bands covering visible to ther...A medium resolution spectral imager （MERSI） on-board the first spacecraft of the second generation of Chinas polar-orbit meteorological satellites FY-3A, is a MODIS-like sensor with 20 bands covering visible to thermal infrared spectral region. FY-3A/MERSI is capable of making continuous global observations, and ocean color application is one of its main targets. The objective is to provide information about the ocean color products of FY-3A/MERSI, including sensor calibration, ocean color algorithms, ocean color prod- ucts validation and applications. Although there is a visible on-board calibration device, it cannot realize the on-board absolute radiometric calibration in the reflective solar bands. A multisite vicarious calibration method is developed, and used for monitoring the in-flight response change and providing post-launch cal- ibration coefficients updating. FY-3A/MERSI ocean color products consist of the water-leaving reflectance retrieved from an atmospheric correction algorithm, a chlorophyll a concentration （CHL1） and a pigment concentration （PIG1） from global empirical models, the chlorophyll a concentration （CHL2）, a total sus- pended mater concentration （TSM） and the absorption coefficient of CDOM and NAP （YS443） from Chi- na＇s regional empirical models. The atmospheric correction algorithm based on lookup tables and ocean color components concentration estimation models are described. By comparison with in situ data, the FY-3A/MERSI ocean color products have been validated and preliminary results are presented. Some suc- cessful ocean color applications such as algae bloom monitoring and coastal suspended sediment variation have demonstrated the usefulness of FY-3A/MERSI ocean color products.展开更多
Cooperation of multi-domain massively parallel processor systems in computing grid environment provides new opportunities for multisite job scheduling. At the same time, in the area of co-allocation, heterogeneity, ne...Cooperation of multi-domain massively parallel processor systems in computing grid environment provides new opportunities for multisite job scheduling. At the same time, in the area of co-allocation, heterogeneity, network adaptability and scalability raise the challenge for the international design of multisite job scheduling models and algorithms. It presents multisite job scheduling schema through the introduction of multisite job scheduling model and the performance model under the grid environment. It introduces two job multisite and cooperative scheduling models and algorithms with the core of the optimal and greedy-heuristic resource selection strategies. Meanwhile, compared with single and multisite cooperative scheduling models and algorithms introduced by Sabin, Yahyapour and other persons, the validity and advance of the scheduling model and the performance model herein are proved.展开更多
Hematite(α-Fe_(2)O_(3))constitutes one of the most promising photoanode materials for oxygen evolution reaction(OER).Recent research on Fe_(2)O_(3)have found a fast OER rate dependence on surface hole density,suggest...Hematite(α-Fe_(2)O_(3))constitutes one of the most promising photoanode materials for oxygen evolution reaction(OER).Recent research on Fe_(2)O_(3)have found a fast OER rate dependence on surface hole density,suggesting a multisite reaction pathway.However,the effect of heteroatom in Fe_(2)O_(3)on the multisite mechanism is still poorly understood.Herein we synthesized Fe_(2)O_(3)on Ti substrates(Fe_(2)O_(3)/Ti)to study the oxygen intermediates of OER by light-dark electrochemical scans.We identified the Fe-OH species disappeared and Ti-OH intermediates appeared on Fe_(2)O_(3)/Ti when pH=11‒14,which significantly improved the OER performance of Fe_(2)O_(3)/Ti.Combined with the density functional theory calculations,we propose that Ti atom acts as cocatalyst site and captures proton from neighboring Fe-OH species under highly alkaline condition,thereby promoting the coupling of Fe=O and reducing the energy barrier of the non-electrochemical step.Our work provides a new insight into the role of heteroatom in OER multisite mechanism based on clarifying the reaction intermediates.展开更多
Alkaline hydrogen evolution reaction(HER)offers a near-zero-emission approach to advance hydrogen energy.However,the activity limited by the multiple reaction steps involving H_(2)O molecules transfer,absorption,and a...Alkaline hydrogen evolution reaction(HER)offers a near-zero-emission approach to advance hydrogen energy.However,the activity limited by the multiple reaction steps involving H_(2)O molecules transfer,absorption,and activation still unqualified the thresholds of economic viability.Herein,we proposed a multisite complementary strategy that incorporates hydrophilic Mo and electrophilic V into Ni-based catalysts to divide the distinct steps on atomically dispersive sites and thus realize sequential regulation of the HER process.The Isotopic labeled in situ Raman spectroscopy describes 4-coordinated hydrogen bonded H_(2)O to be free H_(2)O passing the inner Helmholtz plane in the vicinity of the catalysts under the action of hydrophilic Mo sites.Furthermore,potential-dependent electrochemical impedance spectroscopy(EIS)reveals that electrophilic V sites with abundant 3d empty orbitals could activate the lone-pair electrons in the free H_(2)O molecules to produce more protic hydrogen,and dimerize into H_(2) at the Ni sites.By the sequential management of reactive H_(2)O molecules,NiMoV oxides multisite catalysts surpass Pt/C hydrogen evolution activity(49 mV@10 mA∙cm^(-2) over 140 h).Profoundly,this study provides a tangible model to deepen the comprehension of the catalyst–electrolyte interface and create efficient catalysts for diverse reactions.展开更多
Several monocentric studies have noted alterations in spontaneous brain activity in Alzheimer's disease (AD), although there is no consensus on the altered amplitude of low-frequency fluctuations in AD patients. T...Several monocentric studies have noted alterations in spontaneous brain activity in Alzheimer's disease (AD), although there is no consensus on the altered amplitude of low-frequency fluctuations in AD patients. The main aim of the present study was to identify a reliable and reproducible abnormal brain activity pattern in AD. The amplitude of local brain activity (AM), which can provide fast mapping of spontaneous brain activity across the whole brain, was evaluated based on multisite rs-fMRI data for 688 subjects (215 normal controls (NCs), 221 amnestic mild cognitive impairment (aMCI) 252 AD). Two-sample t-tests were used to detect group differences between AD patients and NCs from the same site. Differences in the AM maps were statistically analyzed via the Stouffer's meta-analysis. Consistent regions of lower spontaneous brain activity in the default mode network and increased activity in the bilateral hippocampus/parahippocampus, thalamus, caudate nucleus, orbital part of the middle frontal gyrus and left fusiform were observed in the AD patients compared with those in NCs. Significant correlations (P?<?0.05, Bonferroni corrected) between the normalized amplitude index and Mini-Mental State Examination scores were found in the identified brain regions, which indicates that the altered brain activity was associated with cognitive decline in the patients. Multivariate analysis and leave-one-site-out cross-validation led to a 78.49% prediction accuracy for single-patient classification. The altered activity patterns of the identified brain regions were largely correlated with the FDG-PET results from another independent study. These results emphasized the impaired brain activity to provide a robust and reproducible imaging signature of AD.展开更多
BACKGROUND: Chronic pancreatitis shows alterations in the trypsinogen gene (protease serine 1, PRSS1) in some individuals. The conversion of trypsinogen to trypsin in the pancreas is believed to be one of the causes o...BACKGROUND: Chronic pancreatitis shows alterations in the trypsinogen gene (protease serine 1, PRSS1) in some individuals. The conversion of trypsinogen to trypsin in the pancreas is believed to be one of the causes of pancreatitis. This study was to identify the mutation of the PRSS1 gene in a Chinese patient with chronic pancreatitis and to analyze the clinical features of the disease. METHODS: In 6 patients with chronic pancreatitis and 120 normal controls, PRSS1 genes were amplified by the polymerase chain reaction and the products were analyzed by sequencing. RESULTS: Multisite mutations of PRSS1 were found in a patient with chronic pancreatitis. C to A mutation occurred in exon 3 of PRSS1, and T to A mutation in the same exon. These mutations were not found in normal controls or the patients with chronic pancreatitis. CONCLUSION: These are novel mutations in PRSS1.展开更多
Using acrylamide as hydrogen bonding functional monomer and (5R)-5-benzylhydantoin as template, a molecularly imprinted polymer was prepared in a polar solvent, which exhibited good enantiomeric recognition properties...Using acrylamide as hydrogen bonding functional monomer and (5R)-5-benzylhydantoin as template, a molecularly imprinted polymer was prepared in a polar solvent, which exhibited good enantiomeric recognition properties. The binding characteristics and selectivity of the polymer were evaluated by batch methods. Scatchard analysis showed that two classes of binding sites were produced in the polymer matrix and their dissociation constants were calculated to be 3.5 × 10?5mol/L and 4.3 × 10?4 mol/L, respectively, by utilizing the model of multiple independent classes of binding sites. These results were more reasonable than those obtained by Scatchard analysis, which was in agreement with the prediction of the binding characteristics of the polymer by exploring the effect of acrylamide on UV spectra of (5R)-5-benzylhydantoin. The substrate and enantio-selectivity of the polymer was investigated. Finally, the study of effect of water on the chiral separation factor of the polymer further proved that the hydrogen bonding interactions played an important role in the recognition of the acrylamide-based molecularly imprinted polymers.展开更多
基金partially supported by the National Key Research and Development Program of China (2016YFC1305904)the National Natural Science Foundation of China (81871438, 81901101, 61633018, 81571062, 81400890, 81871398)+10 种基金the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB32020200)the Beijing Municipal Science & Technology Commission (Z171100000117001, Z171100000117002)the Primary Research & Development Plan of Shandong Province (2017GGX10112)the Open Project Program of the National Laboratory of Pattern Recognition (NLPR) (201900021)Data collection and sharing for this project was funded by the Alzheimer’s Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904)DOD ADNI (Department of Defense award number W81XWH-12-2-0012)funded by the National Institute on Agingthe National Institute of Biomedical Imaging and Bioengineeringgenerous contributions from Abb Vie, Alzheimer’s AssociationAlzheimer’s Drug Discovery FoundationThe Canadian Institutes of Health Research provide funds to support ADNI clinical sites in Canada。
文摘Hippocampal morphological change is one of the main hallmarks of Alzheimer’s disease(AD).However,whether hippocampal radiomic features are robust as predictors of progression from mild cognitive impairment(MCI)to AD dementia and whether these features provide any neurobiological foundation remains unclear.The primary aim of this study was to verify whether hippocampal radiomic features can serve as robust magnetic resonance imaging(MRI)markers for AD.Multivariate classifier-based support vector machine(SVM)analysis provided individual-level predictions for distinguishing AD patients(n=261)from normal controls(NCs;n=231)with an accuracy of 88.21%and intersite crossvalidation.Further analyses of a large,independent the Alzheimer’s Disease Neuroimaging Initiative(ADNI)dataset(n=1228)reinforced these findings.In MCI groups,a systemic analysis demonstrated that the identified features were significantly associated with clinical features(e.g.,apolipoprotein E(APOE)genotype,polygenic risk scores,cerebrospinal fluid(CSF)Ab,CSF Tau),and longitudinal changes in cognition ability;more importantly,the radiomic features had a consistently altered pattern with changes in the MMSE scores over 5 years of follow-up.These comprehensive results suggest that hippocampal radiomic features can serve as robust biomarkers for clinical application in AD/MCI,and further provide evidence for predicting whether an MCI subject would convert to AD based on the radiomics of the hippocampus.The results of this study are expected to have a substantial impact on the early diagnosis of AD/MCI.
基金The National Basic Research Program (973 Program) of China under contract No.2010CB950803National Meteorological Special Project of China under contract No.GYHY200906036
文摘A medium resolution spectral imager （MERSI） on-board the first spacecraft of the second generation of Chinas polar-orbit meteorological satellites FY-3A, is a MODIS-like sensor with 20 bands covering visible to thermal infrared spectral region. FY-3A/MERSI is capable of making continuous global observations, and ocean color application is one of its main targets. The objective is to provide information about the ocean color products of FY-3A/MERSI, including sensor calibration, ocean color algorithms, ocean color prod- ucts validation and applications. Although there is a visible on-board calibration device, it cannot realize the on-board absolute radiometric calibration in the reflective solar bands. A multisite vicarious calibration method is developed, and used for monitoring the in-flight response change and providing post-launch cal- ibration coefficients updating. FY-3A/MERSI ocean color products consist of the water-leaving reflectance retrieved from an atmospheric correction algorithm, a chlorophyll a concentration （CHL1） and a pigment concentration （PIG1） from global empirical models, the chlorophyll a concentration （CHL2）, a total sus- pended mater concentration （TSM） and the absorption coefficient of CDOM and NAP （YS443） from Chi- na＇s regional empirical models. The atmospheric correction algorithm based on lookup tables and ocean color components concentration estimation models are described. By comparison with in situ data, the FY-3A/MERSI ocean color products have been validated and preliminary results are presented. Some suc- cessful ocean color applications such as algae bloom monitoring and coastal suspended sediment variation have demonstrated the usefulness of FY-3A/MERSI ocean color products.
基金This work was supported in part by the National Natural Science Foundation of China （Grant No. 90412001） the National Grand Fundamental Research 973 Program of China （Grant No. G2005CB321806）.
文摘Cooperation of multi-domain massively parallel processor systems in computing grid environment provides new opportunities for multisite job scheduling. At the same time, in the area of co-allocation, heterogeneity, network adaptability and scalability raise the challenge for the international design of multisite job scheduling models and algorithms. It presents multisite job scheduling schema through the introduction of multisite job scheduling model and the performance model under the grid environment. It introduces two job multisite and cooperative scheduling models and algorithms with the core of the optimal and greedy-heuristic resource selection strategies. Meanwhile, compared with single and multisite cooperative scheduling models and algorithms introduced by Sabin, Yahyapour and other persons, the validity and advance of the scheduling model and the performance model herein are proved.
文摘Hematite(α-Fe_(2)O_(3))constitutes one of the most promising photoanode materials for oxygen evolution reaction(OER).Recent research on Fe_(2)O_(3)have found a fast OER rate dependence on surface hole density,suggesting a multisite reaction pathway.However,the effect of heteroatom in Fe_(2)O_(3)on the multisite mechanism is still poorly understood.Herein we synthesized Fe_(2)O_(3)on Ti substrates(Fe_(2)O_(3)/Ti)to study the oxygen intermediates of OER by light-dark electrochemical scans.We identified the Fe-OH species disappeared and Ti-OH intermediates appeared on Fe_(2)O_(3)/Ti when pH=11‒14,which significantly improved the OER performance of Fe_(2)O_(3)/Ti.Combined with the density functional theory calculations,we propose that Ti atom acts as cocatalyst site and captures proton from neighboring Fe-OH species under highly alkaline condition,thereby promoting the coupling of Fe=O and reducing the energy barrier of the non-electrochemical step.Our work provides a new insight into the role of heteroatom in OER multisite mechanism based on clarifying the reaction intermediates.
文摘Alkaline hydrogen evolution reaction(HER)offers a near-zero-emission approach to advance hydrogen energy.However,the activity limited by the multiple reaction steps involving H_(2)O molecules transfer,absorption,and activation still unqualified the thresholds of economic viability.Herein,we proposed a multisite complementary strategy that incorporates hydrophilic Mo and electrophilic V into Ni-based catalysts to divide the distinct steps on atomically dispersive sites and thus realize sequential regulation of the HER process.The Isotopic labeled in situ Raman spectroscopy describes 4-coordinated hydrogen bonded H_(2)O to be free H_(2)O passing the inner Helmholtz plane in the vicinity of the catalysts under the action of hydrophilic Mo sites.Furthermore,potential-dependent electrochemical impedance spectroscopy(EIS)reveals that electrophilic V sites with abundant 3d empty orbitals could activate the lone-pair electrons in the free H_(2)O molecules to produce more protic hydrogen,and dimerize into H_(2) at the Ni sites.By the sequential management of reactive H_(2)O molecules,NiMoV oxides multisite catalysts surpass Pt/C hydrogen evolution activity(49 mV@10 mA∙cm^(-2) over 140 h).Profoundly,this study provides a tangible model to deepen the comprehension of the catalyst–electrolyte interface and create efficient catalysts for diverse reactions.
基金supported by the National Key Research and Development Program of China (2016YFC1305904, 2016YFC1306300)the National Natural Science Foundation of China (81871438, 61633018, 81571062, 81471120, 61431012, 81430037)+1 种基金the Strategic Priority Research Program (B) of Chinese Academy of Sciences (XDB32020200)the Beijing Municipal Commission of Health and Family Planning (PXM2019_026283_000002)
文摘Several monocentric studies have noted alterations in spontaneous brain activity in Alzheimer's disease (AD), although there is no consensus on the altered amplitude of low-frequency fluctuations in AD patients. The main aim of the present study was to identify a reliable and reproducible abnormal brain activity pattern in AD. The amplitude of local brain activity (AM), which can provide fast mapping of spontaneous brain activity across the whole brain, was evaluated based on multisite rs-fMRI data for 688 subjects (215 normal controls (NCs), 221 amnestic mild cognitive impairment (aMCI) 252 AD). Two-sample t-tests were used to detect group differences between AD patients and NCs from the same site. Differences in the AM maps were statistically analyzed via the Stouffer's meta-analysis. Consistent regions of lower spontaneous brain activity in the default mode network and increased activity in the bilateral hippocampus/parahippocampus, thalamus, caudate nucleus, orbital part of the middle frontal gyrus and left fusiform were observed in the AD patients compared with those in NCs. Significant correlations (P?<?0.05, Bonferroni corrected) between the normalized amplitude index and Mini-Mental State Examination scores were found in the identified brain regions, which indicates that the altered brain activity was associated with cognitive decline in the patients. Multivariate analysis and leave-one-site-out cross-validation led to a 78.49% prediction accuracy for single-patient classification. The altered activity patterns of the identified brain regions were largely correlated with the FDG-PET results from another independent study. These results emphasized the impaired brain activity to provide a robust and reproducible imaging signature of AD.
文摘BACKGROUND: Chronic pancreatitis shows alterations in the trypsinogen gene (protease serine 1, PRSS1) in some individuals. The conversion of trypsinogen to trypsin in the pancreas is believed to be one of the causes of pancreatitis. This study was to identify the mutation of the PRSS1 gene in a Chinese patient with chronic pancreatitis and to analyze the clinical features of the disease. METHODS: In 6 patients with chronic pancreatitis and 120 normal controls, PRSS1 genes were amplified by the polymerase chain reaction and the products were analyzed by sequencing. RESULTS: Multisite mutations of PRSS1 were found in a patient with chronic pancreatitis. C to A mutation occurred in exon 3 of PRSS1, and T to A mutation in the same exon. These mutations were not found in normal controls or the patients with chronic pancreatitis. CONCLUSION: These are novel mutations in PRSS1.
基金Project (NO. 29770511) suported by the National Natural Science Foundation of China.
文摘Using acrylamide as hydrogen bonding functional monomer and (5R)-5-benzylhydantoin as template, a molecularly imprinted polymer was prepared in a polar solvent, which exhibited good enantiomeric recognition properties. The binding characteristics and selectivity of the polymer were evaluated by batch methods. Scatchard analysis showed that two classes of binding sites were produced in the polymer matrix and their dissociation constants were calculated to be 3.5 × 10?5mol/L and 4.3 × 10?4 mol/L, respectively, by utilizing the model of multiple independent classes of binding sites. These results were more reasonable than those obtained by Scatchard analysis, which was in agreement with the prediction of the binding characteristics of the polymer by exploring the effect of acrylamide on UV spectra of (5R)-5-benzylhydantoin. The substrate and enantio-selectivity of the polymer was investigated. Finally, the study of effect of water on the chiral separation factor of the polymer further proved that the hydrogen bonding interactions played an important role in the recognition of the acrylamide-based molecularly imprinted polymers.
