Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of inc...
详细信息
Simultaneous rest perfusion/fatty-acid metabolism studies have the potential to replace sequential rest/stress perfusion studies for the assessment of cardiac function. Simultaneous acquisition has the benefits of increased signal and lack of need for patient stress, but is complicated by cross-talk between the two radionuclide signals. We consider a simultaneous rest Tc-99m-sestamibi/I-123-BMIPP imaging protocol in place of the commonly used sequential rest/stress Tc-99m-sestamibi protocol. The theoretical precision with which the severity of a cardiac defect and the transmural extent of infarct can be measured is computed for simultaneous and sequential SPECT imaging, and their performance is compared for discriminating (1) degrees of defect severity and (2) sub-endocardial from transmural defects. We consider cardiac infarcts for which reduced perfusion and metabolism are observed. From an information perspective, simultaneous imaging is found to yield comparable or improved performance compared with sequential imaging for discriminating both severity of defect and transmural extent of infarct, for three defects of differing location and size.
Background Coronary artery ectasia (CAE) is a rare finding in coronary angiography and associated with poor clinical outcomes. Unlike atherosclerosis, diabetes mellitus (DM) is not commonly associated with CAE. This s...
详细信息
Background Coronary artery ectasia (CAE) is a rare finding in coronary angiography and associated with poor clinical outcomes. Unlike atherosclerosis, diabetes mellitus (DM) is not commonly associated with CAE. This study aims to investigate the effect of type 2 diabetes mellitus (DM2) on coronary artery ectasia, especially the differences in angiographic characteristics and clinical outcomes. Methods Patients with angiographically confirmed CAE from 2009 to 2015 were included. Quantitative coronary angiography (QCA) was performed to measure the diameter and length of the dilated lesion. The primary endpoint was the maximum diameter and maximum length of the dilated lesion at baseline coronary angiography. The secondary endpoint was 5-year major adverse cardiovascular events (MACE), which was a component of cardiovascular death and nonfatal myocardial infarction (MI). Propensity score weighting (PSW) and propensity score matching (PSM) were used to balance covariates. Kaplan-Meier method and Cox regression were performed to assess the clinical outcomes. Results A total of 1128 patients were included and 258 were combined with DM2. In the DM2 group, the maximum diameter of dilated lesion was significantly lower (5.26 mm vs. 5.47 mm, P = 0.004) and the maximum length of the dilated lesion was significantly shorter (25.20 mm vs. 31.34 mm, P = 0.002). This reduction in dilated lesion diameter (5.26 mm vs. 5.41 mm, P = 0.050 in PSW;5.26 mm vs. 5.46 mm, P = 0.007 in PSM, respectively) and length (25.17 mm vs. 30.17 mm, P = 0.010 in PSW;25.20 mm vs. 30.81 mm, P = 0.012 in PSM, respectively) was consistently observed in the propensity score analysis. A total of 27 cardiovascular deaths and 41 myocardial infarctions occurred at 5-year follow-up. Compared with non-DM group, there were similar risks of MACE (6.02% vs. 6.27%;HR 0.96, 95% CI 0.54-1.71, P = 0.894), cardiovascular death (2.05% vs. 2.61%;HR 0.78, 95% CI 0.29-2.05, P = 0.605) and MI (4.07% vs. 3.72%;HR 1.11, 95% CI
: Several methods for establishing cross-links between Protein Data Bank (PDB) structures or Structural Classification of Proteins (SCOP) domains and Swiss-Prot + TrEMBL sequences (or vice versa) rely on database anno...
: Several methods for establishing cross-links between Protein Data Bank (PDB) structures or Structural Classification of Proteins (SCOP) domains and Swiss-Prot + TrEMBL sequences (or vice versa) rely on database annotations. Alternatively, sequence alignment procedures can be used. In this study, we describe Seq2Struct, a web resource for the identification of sequence-structure links. The resource consists of an exhaustive collection of annotated links between Swiss-Prot + TrEMBL and PDB + SCOP database entries. Links are based on pre-established highly reliable thresholds and stored in a relational database, which has been enhanced using annotations derived from Swiss-Prot, PDB, SCOP, GOA and DSSP databases. The Seq2Struct database contents, supported by a WWW web interface, can be queried both online and downloaded.
Most services rely on a real‐time transaction between provider andcustomer. The nature of this interaction determines an immediate qualityperception of the service by the user. In the long term, thesecumulative quali...
详细信息
Most services rely on a real‐time transaction between provider andcustomer. The nature of this interaction determines an immediate qualityperception of the service by the user. In the long term, thesecumulative quality perceptions may significantly affect the overallviability of the service and success of the provider firm. A transactionmatrix is developed that allows placement of any service deliveryprocess with respect to the technology and people interfacecharacteristics. Selective repositioning within the matrix is shown toinfluence performance and productivity. A prescription for management ispresented to allow use of the transaction model in strategic planningand tactical decision making.
Recent developments of backside treatment for the backside-illuminated scientific charge-coupled device (CCD) imagers have shown near-theoretical efficiency even at the short wavelength region of the spectrum. By usin...
详细信息
Recent developments of backside treatment for the backside-illuminated scientific charge-coupled device (CCD) imagers have shown near-theoretical efficiency even at the short wavelength region of the spectrum. By using a scanning electron microscope (SEM), we report here, for the first time, performance comparisons of backside-treated and untreated CCDs to an electron flux varying from 1 to 100 pA and beam energy ranging from less than 1 keV up to 20 keV. We describe the theoretical analysis, the SEM testing procedure, and the quantum efficiency measurement results. It is shown, for example, that the average quantum efficiency increases from less than 1% for an untreated CCD to nearly 40% for a backside-treated CCD at a beam energy of 1 keV.
暂无评论