Radial Center Research Articles

Corrected unwrapping method based on the tangential and radial distortion centre for the panoramic annular image

A novel corrected unwrapping method is proposed for panoramic annular images based on the catadioptric panoramic imaging system. The method is comprised of four key steps. Firstly, the distortion centre parameters on the panoramic annular image are determined, including the tangential distortion centre by using the least-square fitting (LSF) method and the radial distortion centre by extracting feature points. Secondly, the affine transformation relation between panoramic annular image and cylindrical panoramic image is constructed based on the centre parameters and the geometric properties of panoramic image. Then the annular image pixels are replicated into the cylindrical panoramic image by means of the bilinear interpolation. Finally, the frame aspect ratio for the final image unwrapping is corrected. The motivation for developing this technique is to solve the distortion problem from the centre deviation, and ultimately to promotes its adoption in pipe non-destructive testing systems. Experimental results have proved the feasibility, validity and higher accuracy of the unwrapping method.

Thickness inhomogeneity in hardness and microstructure of copper after the compressive stage in high-pressure torsion

Distinction between plastic deformation occuring in compression and compression-torsion stages is important for understanding the properties and microstructures of materials processed by high-pressure torsion (HPT). In the present study, remarkable through-thickness inhomogeneities of hardness and microstructure were found in the samples processed by compression stage of HPT. Three regions on the radial direction plane of compressed disks were defined to display the inhomogeneity: edge zone (high hardness), radial medium zone (uniform hardness) and center zone (low hardness near the surface and high hardness in the thickness central plane). A low hardness region in the center near the surface was detected and found to stretch along the upper and bottom surfaces of the disks compressed by low pressure. This low hardness region was also found to decrease with increasing the pressure. Not only the hardness but also the microstructure through-thickness inhomogeneity is attributed to stress and strain distribution in the disk as well as to a huge friction between the anvil and the disk during processing.

Insucesso da Técnica Radial em Centro com Alto Volume de Procedimentos

Failure of the Transradial Approach in a High-Volume Center background: The mechanisms and predictors of failed transradial approach in centers dedicated to this technique are not well characterized and were the main objective of this analysis. methods: 6,808 consecutive patients undergoing transradial coronary procedures by operators with utilization rate greater than 90% were included. Simple and multiple logistic regression models were used to identify the predictors of failed transradial approach. Results: Transradial failure rate was 1.7%. Vascular complications were observed in 5%, with a prevalence of asymptomatic arterial occlusion and subcutaneous hematomas. Predictors of failure were female gender (OR = 1.87; 95% CI 1.29-2.71; p = 0.01), age > 70 years (OR = 1.78; 95% CI 1.06-2.98; p = 0.03) and presence of chronic peripheral arterial disease (OR = 5.71; 95% CI 2.40-13.54; p < 0.01). Conclusions: In a high-volume radial center, failure rate was < 2% and variables associated with technical failure were female gender, advanced age and peripheral arterial disease. DesCRIPToRs: Radial artery. Percutaneous coronary intervention. Hemorrhage. Ischemia.

Wall loss of atomic nitrogen determined by ionization threshold mass spectrometry

In the afterglow of an inductively coupled N2 plasma, relative N atom densities are measured by ionization threshold mass spectrometry as a function of time in order to determine the wall loss time twN from the exponential decay curves. The procedure is performed with two mass spectrometers on different positions in the plasma chamber. twN is determined for various pressures, i.e., for 3.0, 5.0, 7.5, and 10 Pa. For this conditions also the internal plasma parameters electron density ne and electron temperature Te are determined with the Langmuir probe and the rotational temperature TrotN2 of N2 is determined with the optical emission spectroscopy. For TrotN2, a procedure is presented to evaluate the spectrum of the transition υ′=0→υ″=2 of the second positive system (C3Πu→B3Πg) of N2. With this method, a gas temperature of 610 K is determined. For both mass spectrometers, an increase of the wall loss times of atomic nitrogen with increasing pressure is observed. The wall loss time measured with the first mass spectrometer in the radial center of the cylindrical plasma vessel increases linearly from 0.31 ms for 3 Pa to 0.82 ms for 10 Pa. The wall loss time measured with the second mass spectrometer (further away from the discharge) is about 4 times higher. A model is applied to describe the measured twN. The main loss mechanism of atomic nitrogen for the considered pressure is diffusion to the wall. The surface loss probability βN of atomic nitrogen on stainless steel was derived from twN and is found to be 1 for the present conditions. The difference in wall loss times measured with the mass spectrometers on different positions in the plasma chamber is attributed to the different diffusion lengths.

快速Hermite径向基函数曲面重构

In this paper, a fast method with compactly supported radial basis functions (CSRBFs) is presented for Hermite surface interpolation or approximation from scattered points. By constructing a hierarchy of the given points, a global surface reconstruction is achieved in a coarse-to- ne way which overcome the problems resulted from using CSRBFs. Moreover, we design a radial basis function center selection approach based on approximat- ing errors, to reduce the interpolating points on each level, which make the Hermite radial basis function implicits to be able to deal with point clouds more than one million of points. The experiments demonstrate our method is also suitable for handling extremely nonuniform or noisy point clouds.

CORONARY ANGIOGRAPHY AND PCI COMPLICATIONS - PROSPECTIVE SINGLE CENTRE STUDY

Percutaneous coronary intervention (PCI) is increasingly employed in the treatment of patients with symptomatic coronary disease. However both coronary angiography and PCI are invasive procedures with a risk of complications. The majority of data pertaining to such complications are based on retrospective analyses and these may underestimate the real-world frequency of complications. Trans-radial radial access has been shown to be associated with lower rate of bleeding complications in patients undergoing PCI. However there has been some concern that high volume radial centres may experience higher complication rates in those patients that undergo PCI via femoral access. We prospectively collected data on complications following all diagnostic coronary angiography and PCI procedures performed in a high volume radial centre over a 12 month period. Data on all patients undergoing diagnostic coronary angiography and PCI procedures were included within this study. All in-procedure complications were recorded during the case and confirmed by the interventional cardiologist. A dedicated pro-forma recording all post-procedure complications was completed by a cardiology nurse designated to the care of the patient. Monthly reports of all procedures undertaken in the institution were generated and cross-checked to ensure 100% completion rate. In the event that forms were not completed, staff performed chart reviews and obtained the data by review of physician and nursing records. In the case of uncertainty, independent review was undertaken by a cardiologist. Over the 12 month period 3222 consecutive procedures were undertaken. We will report the rate of complications including access site bleeding will be compared in patients undergoing transfemoral and transradial cases and also with respect to peri-procedural pharmacotherapy received. Data on the complications post catheterisation and percutaneous coronary intervention procedures is usually collected retrospectively or from selected patients recruited in clinical trials. We will report prospectively collected outcome from an unselected cohort of patients undergoing diagnostic angiography and PCI within a high volume radial centre.

TCT-850 Patients undergoing PCI via the femoral artery in a default radial centre have very high BARC bleeding rates and subsequent bleeding 30 day and 1 year mortality

Increasingly the trans-radial route (TR) is preferred over the trans-femoral route (TF) for PCI. However even in high volume default TR centres a small cohort of patients are required to undergo TF PCI. We examined the demographics, procedural and bleeding outcomes of patients undergoing PCI via the

Spiral symmetry centroid detection

Radial symmetry detection is a hot topic in computer vision owing to its importance in understanding the image structure and content. A major generalisation to the problem is presented and single image spiral symmetric centroid detection is studied. Since radial symmetry is just a particular case in the model of spiral symmetry, spiral symmetry detection is more challenging and general. For this new problem, a fast and effective voting-based solution is proposed, which can reliably detect both the classical radial symmetric centre and the more general spiral symmetric centroid. Extensive experiments validate the generality and practicability of the proposed approach.

Discovery of the antigraviton verified by the rotation curve of NGC 6503

Using special relativity theory, it was discovered that to each graviton, there coexists its antiparticle, an antigraviton. Building on this discovery and quantum theory, a new quantum gravity theory (QGT) was invented, providing equations of the gravitational potential, the graviton wavelength, and the circular speed, without the dark matter hypothesis (DMH). According to this QGT, the gravitational scale-length of a spiral galaxy depends on its mass distribution, being approximately equal to 1.5708 times the radius of its “radial center of mass”. Also Newtonian gravity theory (NGT) is of limited validity: if the radius is less than the gravitational scale-length, NGT is exact; but if the radius is greater than the gravitational scale-length, it becomes inadequate, and is surpassed by QGT. When the theoretical rotation curve was compared with the rotation curve of the galaxy NGC6503, the QGT was verified within the rms error of the measured rotation speeds, 3.0 percent. It was also demonstrated how two formulas of general relativity theory (Schwarzschild metric, gravitational time dilation) may be revised by the QGT, and thus be upgraded to formulas of quantum general relativity theory. It is suggested the so-called “dark matter” problem can be solved by discarding the DMH and adopting our new QGT. Keywords: Cosmology: Theory, Dark Matter, Galaxies: Kinematics and Dynamics, Galaxies: Individual (NGC6503), Gravitation, Large-Scale Structure of Universe.

In vivo 3D Kinematics of Axis of Rotation in Malunited Monteggia Fracture Dislocation

BACKGROUND: Normal elbow joint kinematics has been widely studied in cadaver, whilst in vivo study, especially of the forearm, is rare. Our study analyses, in vivo, the kinematics of normal forearm and of malunited forearm using a three-dimensional computerized simulation system.METHODS: We examined 8 patients with malunited Monteggia fracture and 4 controls with normal elbow joint. The ulna and radius were reconstructed from CT data placing the forearm in three different positions; full pronation, neutral, and full supination using computer bone models. We analyzed the axis of rotation 3-dimentionally based on the axes during forearm rotation from full pronation to full supination.RESULTS: Axis of rotation of normal forearm was pitch line, with a mean range of 2 mm, from full pronation to full supination, connecting the radial head center proximally and ulnar fovea distally. In normal forearm, the mean range was 1.32 mm at the proximal radioulnar joint and 1.51 mm at the distal radioulnar joint. However in Monteggia fracture patients, this range changed to 7.65 mm at proximal and 4.99 mm at distal radoulnar joint.CONCLUSIONS: During forearm rotation, the axis of rotation was constant in normal elbow joint but unstable in malunited Monteggia fracture patients as seen with radial head instability. Therefore, consideration should be given not only to correcting deformity but also to restoring AOR by 3D kinematics analysis before surgical treatment of such fractures.

The prevalence and outcomes of transradial percutaneous coronary intervention for acute coronary syndrome. Analysis from the single-centre ISACS-TC Registry (International Survey of Acute Coronary Syndrome in Transitional Countries) (2010-12)

The aims were to compare the prevalence and short-term outcomes of transradial (TRA) percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) in dedicated radial centre. This was a single-centre observational study of 3484 consecutively enrolled patients with ACS in a 3-year period (2010–12). There were 1648 patients with ST-elevation myocardial infarction (STEMI) and 1836 with non-ST-elevation ACS (NSTEACS). All patients underwent diagnostic coronary angiography within 24 h (STEMI) or within 72 h (NSTEACS). Percutaneous coronary intervention was performed in 84.9% patients (96.6% with STEMI and 74.9% with NSTEACS). Optimal medical treatment (OMT) only was recommended to 2.2% with STEMI and to 11.1% with NSTEACS. Coronary artery bypass graft (CABG) surgery was performed for 1.7% of STEMI and 14.1% of patients with NSTEACS ( P < 0.0001). Most of the PCI procedures were performed through the wrist access (radial 97% and ulnar artery access 1.3%). There was high overall procedural success 98.5% (STEMI 99% and NSTEACS 97%). At 30 days, cardiovascular mortality was 4.7% in STEMI patients and 1.4% in patients with NSTEACS who were treated by PCI ( P < 0.0001). Major adverse cardiac events defined as a composite of death, myocardial infarction, stroke, and non-CABG major bleeding and major access site complications at 30 days were higher in STEMI vs. NSTEACS patients (7.7 vs. 4.4%; P < 0.0001). Transradial access for PCI in a large cohort of unselected patients with ACS, is safe and feasible when performed by experienced radial operators. Patients with NSTEACS are more frequently treated with OMT and have higher referral rate to CABG in comparison with STEMI patients. There is higher 30 day mortality in patients with STEMI.

Radial Basis Function Process Neural Network Training Based on Generalized FRECHET Distance And GA-SA Hybrid Strategy

For learning problem of Radial Basis Function Process Neural Network (RBF-PNN), an optimization training method based on GA combined with SA is proposed in this paper. Through building generalized Fr\'echet distance to measure similarity between time-varying function samples, the learning problem of radial basis centre functions and connection weights is converted into the training on corresponding discrete sequence coefficients. Network training objective function is constructed according to the least square error criterion, and global optimization solving of network parameters is implemented in feasible solution space by use of global optimization feature of GA and probabilistic jumping property of SA . The experiment results illustrate that the training algorithm improves the network training efficiency and stability.

Procedural Volume and Outcomes With Radial or Femoral Access for Coronary Angiography and Intervention

The study sought to evaluate the relationship between procedural volume and outcomes with radial and femoral approach. RIVAL (RadIal Vs. femorAL) was a randomized trial of radial versus femoral access for coronary angiography/intervention (N = 7,021), which overall did not show a difference in primary outcome of death, myocardial infarction, stroke, or non-coronary artery bypass graft major bleeding. In pre-specified subgroup analyses, the hazard ratios for the primary outcome were compared among centers divided by tertiles and among individual operators. A multivariable Cox proportional hazards model was used to determine the independent effect of center and operator volumes after adjusting for other variables. In high-volume radial centers, the primary outcome was reduced with radial versus femoral access (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.28 to 0.87) but not in intermediate- (HR: 1.23; 95% CI: 0.88 to 1.72) or low-volume centers (HR: 0.83; 95% CI: 0.52 to 1.31; interaction p = 0.021). High-volume centers enrolled a higher proportion of ST-segment elevation myocardial infarction (STEMI). After adjustment for STEMI, the benefit of radial access persisted at high-volume radial centers. There was no difference in the primary outcome between radial and femoral access by operator volume: high-volume operators (HR: 0.79; 95% CI: 0.48 to 1.28), intermediate (HR: 0.87; 95% CI: 0.60 to 1.27), and low (HR: 1.10; 95% CI: 0.74 to 1.65; interaction p = 0.536). However, in a multivariable model, overall center volume and radial center volume were independently associated with the primary outcome but not femoral center volume (overall percutaneous coronary intervention volume HR: 0.92, 95% CI: 0.88 to 0.96; radial volume HR: 0.88, 95% CI: 0.80 to 0.97; and femoral volume HR: 1.00, 95% CI: 0.94 to 1.07; p = 0.98). Procedural volume and expertise are important, particularly for radial percutaneous coronary intervention. (A Trial of Trans-radial Versus Trans-femoral Percutaneous Coronary Intervention [PCI] Access Site Approach in Patients With Unstable Angina or Myocardial Infarction Managed With an Invasive Strategy [RIVAL]; NCT01014273).

Risk Score, Causes, and Clinical Impact of Failure of Transradial Approach for Percutaneous Coronary Interventions

To study the causes of and to develop a risk score for failure of transradial approach (TRA) for percutaneous coronary intervention (PCI). TRA-PCI failure has been reported in 5% to 10% of cases. TRA-PCI failure was categorized as primary (clinical reasons) or crossover failure. Multivariate analysis was performed to determine independent predictors of TRA-PCI failure, and an integer risk score was developed. From January to June 2010, TRA-PCI was attempted in 1,609 (97.3%) consecutive patients, whereas 45 (2.7%) had primary TRA-PCI failure. Crossover TRA-PCI failure occurred in 30 (1.8%) patients. Causes of primary TRA-PCI failure included chronic radial artery occlusion (11%), previous coronary artery bypass graft (27%), and cardiogenic shock (20%). Causes for crossover TRA-PCI failure included: inadequate puncture in 17 patients (57%); radial artery spasm in 5 (17%); radial loop in 4 (13%); subclavian tortuosity in 2 (7%); and inadequate guide catheter support in 2 (7%) patients. Female sex (odds ratio [OR]: 3.2; 95% confidence interval [CI]: 1.95 to 5.26, p < 0.0001), previous coronary artery bypass graft (OR: 6.1; 95% CI: 3.63 to 10.05, p < 0.0001), and cardiogenic shock (OR: 11.2; 95% CI: 2.78 to 41.2, p= 0.0011) were independent predictors of TRA-PCI failure. Risk score values from 0 to 7 predicted a TRA-PCI failure rate from 2% to 80%. In a high-volume radial center, 2.7% of patients undergoing PCI are excluded from initial TRA on clinical grounds, whereas crossover to femoral approach is required in only 1.8% of the cases. A new simple clinical risk score is developed to predict TRA-PCI failure.

Influence and Analysis of Temperature Rise to Principal Spindle's Rotating Error Test

The form of principal spindle's dynamic errors is analysed firstly. Scientific test scheme is designed to analyse the influence of rotating speed to rotating errors and decrease temperature rises influence. Principal spindle's radial average errors and asynchronous errors, axial average errors and asynchronous errors, minimum radial separation center of some vertical machine center are all tested with SPN-300 of API. Test method is rise speed-test-stop &amp; cooling-rise speed. Three vertical machine centers are tested and every machine center is tested three times at different rotating speed. The test results and the influences of all errors are analysed at last.

Fast and High-Accuracy Localization for Three-Dimensional Single-Particle Tracking

We report a non-iterative localization algorithm that utilizes the scaling of a three-dimensional (3D) image in the axial direction and focuses on evaluating the radial symmetry center of the scaled image to achieve the desired single-particle localization. Using this approach, we analyzed simulated 3D particle images by wide-field microscopy and confocal microscopy respectively, and the 3D trajectory of quantum dots (QDs)-labeled influenza virus in live cells. Both applications indicate that the method can achieve 3D single-particle localization with a sub-pixel precision and sub-millisecond computation time. The precision is almost the same as that of the iterative nonlinear least-squares 3D Gaussian fitting method, but with two orders of magnitude higher computation speed. This approach can reduce considerably the time and costs for processing the large volume data of 3D images for 3D single-particle tracking, which is especially suited for 3D high-precision single-particle tracking, 3D single-molecule imaging and even new microscopy techniques.

Test and Analysis of Machine Center's Principal Spindle Dynamic Errors

The form of principal spindle's dynamic errors is analysed firstly. Principal spindle's radial average errors and asynchronous errors, axial average errors and asynchronous errors, minimum radial separation center of some vertical machine center are all tested with SPN-300 of API. Three vertical machine centers are tested and every machine center is tested three times at different rotating speed. The test results and the influences of all errors are analysed at last.

Characteristics of radial access site coronary procedures in patients with arteria lusoria among 5789 patients undergoing coronary angiography at a primary radial access centre

BackgroundAnatomical obstructions are the bane of radial access site for coronary procedures for inexperienced operators. The availability of better hardware in the performance of procedures by this route has mitigated...

Improved Double-Probe Technique for Spatially Resolved Diagnosis of Dual-Frequency Capacitive Plasmas

The conventional double-probe technique was improved with a combination of self-powering and radio-frequency (RF) choking. RF perturbations in dual-frequency capacitively coupled discharge were effectively eliminated, as judged by the disappearance of self-bias on the probes. The improved technique was tested by spatially resolved measurements of the electron temperature and ion density in both the axial and radial directions of a dual-frequency capacitive plasma. The measured data in the axial direction were compared with simulation results, and they were excellently consistent with each other. The measured radial distributions of the ion density and electron temperature were influenced significantly by the lower frequency (LF) power. It was shown that superposition of the lower frequency to the higher frequency (HF) power shifted the maximum ion density from the radial center to the edge region, while the trend for the electron temperature profile was the opposite. The changing feature of the ion density distribution is qualitatively consistent with that of the optical emission intensity reported.

Balloon‐assisted tracking: A must‐know technique to overcome difficult anatomy during transradial approach

To examine the use and outcomes of balloon-assisted tracking (BAT) technique for dealing with complexities of arm and chest vasculature during transradial approach (TRA) at a single high volume radial center. TRA has been used for coronary angiography and percutaneous coronary interventions (PCI) around the world. Different techniques have been described to address the anatomical issues and tortuosities for successful completion of coronary angiography and PCI. This study describes the use of BAT technique and associated outcomes during real world clinical practice. Subjects comprised 63 patients, (out of total 8,245 patients between January 2011 and December 2012) in whom we encountered significantly complex anatomical course in radial, brachial, or subclavian region, leading to difficult advancement of a diagnostic or a guide catheter despite trying all standard maneuvers. In all of them BAT technique was used and they were retrospectively analyzed for the purpose of this study. About 63 (0.76%) of 8,245 patients met the study criteria. Twenty-five (39.7%) patients had very small RA. Twenty-two (34.9%) had severe RA tortuosity. Four (6.3%) had complex RA loops. Six (9.5%) had severe RA spasm and six (9.5%) had severe subclavian tortuosity and/or stenosis. We encountered technical failure in three (4.8%) patients (two had very small RA and one had 360 degree RA loop). BAT technique was useful to address the anatomical issues and tortuosities of radial, brachial, and subclavian vasculature during TRA.