In order to improve accuracy of electron beam transverse sizes measurement,the vertical and horizontal synchrotron radiation light interferometers have been designed to measure beam transverse sizes for the upgrade pr...In order to improve accuracy of electron beam transverse sizes measurement,the vertical and horizontal synchrotron radiation light interferometers have been designed to measure beam transverse sizes for the upgrade project of Hefei Light Source(HLS II).In this paper,the light intensity distributions of the interferogram are descussed,and parameters of the interferometers are optimized.The interferograms are simulated under MATLAB. Taking integrations of two-dimensional interferogram intensity,normalized one-dimensional interference intensities distribution of the vertical and horizontal interferogram are obtained.The two curves are fitted to compare the beam transverse sizes with the designed sizes,and this verifies the feasibility of this method.Finally,several factors that affect the beam sizes measurement are discussed.展开更多
As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam positio...As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam position monitor based on position-sensitive detector (PSD) has been developed to measure the photon beam position in vertical and horizontal directions at the same time at HLS (Hefei Light Source). The new PBPM based on the PSD has fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, and then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. As the results shown, the resolution of the system is better than 3 mm.展开更多
Background Several small sample-size observational studies evaluated the association of plasma brain natriuretic peptide （BNP） or N-terminal pro-brain natriuretic peptide （NT-proBNP） with atrial fibrillation （AF...Background Several small sample-size observational studies evaluated the association of plasma brain natriuretic peptide （BNP） or N-terminal pro-brain natriuretic peptide （NT-proBNP） with atrial fibrillation （AF）,but the results were contradictory.We aimed to perform a meta-analysis of relevant studies to evaluate the availability of this association.Methods We performed an extensive literature search on PubMed,Web of Science （WOS） and the Cochrane Library databases.Pooled standardized mean difference （SMD） and 95% confidence interval （CI） were calculated to assess the strength of association using random effects models.We performed sensitivity and subgroup analyses to explore the potential sources of heterogeneity.We also estimated publication biases.Statistical analyses were performed using the STATA 12.0 software.Results A total of 11 studies including 777 cases and 870 controls were finally analyzed.Overall,the brain natriuretic peptide/N-terminal pro-brain natriuretic peptide levels were higher in atrial fibrillation patients than controls without atrial fibrillation.Results showed that the SMD in the natriuretic peptide levels between cases and controls was 2.68 units （95%CI 1.76 to 3.60）; test for overall effect z-score=5.7 （P 〈0.001）.There was significant heterogeneity between individual studies （I2=97.8%; P 〈0.001）.Further analysis revealed that differences in the assay of natriuretic peptide possibly account for this heterogeneity.Conclusions Increased BNP/NT-proBNP levels were associated with the presence of atrial fibrillation.This finding indicates that BNP/NT-proBNP may prove to be a biomarker of an underlying predisposition to AF.展开更多
基金Supported by the National Science Foundation of China(10675118,11175173)
文摘In order to improve accuracy of electron beam transverse sizes measurement,the vertical and horizontal synchrotron radiation light interferometers have been designed to measure beam transverse sizes for the upgrade project of Hefei Light Source(HLS II).In this paper,the light intensity distributions of the interferogram are descussed,and parameters of the interferometers are optimized.The interferograms are simulated under MATLAB. Taking integrations of two-dimensional interferogram intensity,normalized one-dimensional interference intensities distribution of the vertical and horizontal interferogram are obtained.The two curves are fitted to compare the beam transverse sizes with the designed sizes,and this verifies the feasibility of this method.Finally,several factors that affect the beam sizes measurement are discussed.
基金Supported by the National Science Foundation of China (10675118, 11175173)
文摘As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam position monitor based on position-sensitive detector (PSD) has been developed to measure the photon beam position in vertical and horizontal directions at the same time at HLS (Hefei Light Source). The new PBPM based on the PSD has fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, and then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. As the results shown, the resolution of the system is better than 3 mm.
文摘Background Several small sample-size observational studies evaluated the association of plasma brain natriuretic peptide （BNP） or N-terminal pro-brain natriuretic peptide （NT-proBNP） with atrial fibrillation （AF）,but the results were contradictory.We aimed to perform a meta-analysis of relevant studies to evaluate the availability of this association.Methods We performed an extensive literature search on PubMed,Web of Science （WOS） and the Cochrane Library databases.Pooled standardized mean difference （SMD） and 95% confidence interval （CI） were calculated to assess the strength of association using random effects models.We performed sensitivity and subgroup analyses to explore the potential sources of heterogeneity.We also estimated publication biases.Statistical analyses were performed using the STATA 12.0 software.Results A total of 11 studies including 777 cases and 870 controls were finally analyzed.Overall,the brain natriuretic peptide/N-terminal pro-brain natriuretic peptide levels were higher in atrial fibrillation patients than controls without atrial fibrillation.Results showed that the SMD in the natriuretic peptide levels between cases and controls was 2.68 units （95%CI 1.76 to 3.60）; test for overall effect z-score=5.7 （P 〈0.001）.There was significant heterogeneity between individual studies （I2=97.8%; P 〈0.001）.Further analysis revealed that differences in the assay of natriuretic peptide possibly account for this heterogeneity.Conclusions Increased BNP/NT-proBNP levels were associated with the presence of atrial fibrillation.This finding indicates that BNP/NT-proBNP may prove to be a biomarker of an underlying predisposition to AF.
