This letter presents a novel approach for the Synthetic Aperture Radar (SAR) stereo imaging based on the Capon spectrum estimation technique. In order to deal with nonuniform sampling space and lead to super resolutio...This letter presents a novel approach for the Synthetic Aperture Radar (SAR) stereo imaging based on the Capon spectrum estimation technique. In order to deal with nonuniform sampling space and lead to super resolution in the elevation direction, Capon approach is used to focus the SAR data on a certain height. Results obtained on simulated data demonstrate the feasibility of the Capon based algorithm. Compared with the classical Fast Fourier Transform (FFT), the Capon based algo-rithm shows better resolution quality.展开更多
Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidenc...Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidence displays a persistent increase in developing countries.However,the pathogenesis of CD is poorly understood,with some studies emphasizing the link between CD and the intestinal microbiota.Specifically,studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD.Furthermore,investigations have shown whitematter lesions and neurologic deficits in patients with IBD.Based on these findings,brain activity changes in CD patients have been detected by blood oxygenation level dependent functional magnetic resonance imaging(BOLD-f MRI).BOLD-f MRI functions by detecting a local increase in relative blood oxygenation that results from neurotransmitter activity and thus reflects local neuronal firing rates.Therefore,biochemical concentrations of neurotransmitters or metabolites may change in corresponding brain regions of CD patients.To further study this phenomenon,brain changes of CD patients can be detected non-invasively,effectively and accurately by BOLD-f MRI combined with magnetic resonance spectroscopy(MRS).This approach can further shed light on the mechanisms of the occurrence and development of neurological CD.Overall,this paper reviews the current status and prospects on fMRI and MRS for evaluation of patients with CD based on the brain-gut-enteric microbiota axis.展开更多
文摘This letter presents a novel approach for the Synthetic Aperture Radar (SAR) stereo imaging based on the Capon spectrum estimation technique. In order to deal with nonuniform sampling space and lead to super resolution in the elevation direction, Capon approach is used to focus the SAR data on a certain height. Results obtained on simulated data demonstrate the feasibility of the Capon based algorithm. Compared with the classical Fast Fourier Transform (FFT), the Capon based algo-rithm shows better resolution quality.
基金the National Natural Science Foundation of China,No.81473506the Natural Science Foundation of Zhejiang Province,No.LY17H290009the Ministry of Construction,Zhejiang Province,No.WKJ-ZJ-1531
文摘Crohn’s disease(CD)is a chronic,non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease(IBD).CD is prone to relapse,and its incidence displays a persistent increase in developing countries.However,the pathogenesis of CD is poorly understood,with some studies emphasizing the link between CD and the intestinal microbiota.Specifically,studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD.Furthermore,investigations have shown whitematter lesions and neurologic deficits in patients with IBD.Based on these findings,brain activity changes in CD patients have been detected by blood oxygenation level dependent functional magnetic resonance imaging(BOLD-f MRI).BOLD-f MRI functions by detecting a local increase in relative blood oxygenation that results from neurotransmitter activity and thus reflects local neuronal firing rates.Therefore,biochemical concentrations of neurotransmitters or metabolites may change in corresponding brain regions of CD patients.To further study this phenomenon,brain changes of CD patients can be detected non-invasively,effectively and accurately by BOLD-f MRI combined with magnetic resonance spectroscopy(MRS).This approach can further shed light on the mechanisms of the occurrence and development of neurological CD.Overall,this paper reviews the current status and prospects on fMRI and MRS for evaluation of patients with CD based on the brain-gut-enteric microbiota axis.
