Improved in-field behaviour of uranium doped BiSCCO tapes by enhanced flux pinning

Uranium doped BiSCCO 2223 tapes were irradiated by thermal neutrons. The resulting fission-induced defects improve flux pinning and shift the irreversibility line to higher fields. Significant enhancements of the transport critical current density as well as a reduction of the Jc-anisotropy are found for the irradiated samples. Furthermore, inter- and intragranular critical current densities were determined from the remanent magnetic moments by SQUID magnetometry

A novel approach for x-ray scattering experiments in magnetic fields utilizing trapped flux in type-II superconductors

We introduce a novel approach to x-ray scattering studies in applied magnetic fields by exploiting vortices in superconductors. This method is based on trapping magnetic flux in a small disk-shaped superconductor (known as a trapped field magnet, TFM) with a single-crystal sample mounted on or at close proximity to its surface. This opens an unrestricted optical access to the sample and allows magnetic fields to be applied precisely along the x-ray momentum transfer, facilitating polarization-sensitive experiments that have been impractical or impossible to perform to date. The TFMs used in our study remain stable and provide practically uniform magnetic fields for days, which are sufficient for comprehensive x-ray diffraction experiments, specifically x-ray resonance exchange scattering (XRES) to study field-induced phenomena at a modern synchrotron source. The TFM instrument has been used in a “proof-of-principle” XRES study of a meta-magnetic phase in a rare-earth compound, TbNi2Ge2, in order to demonstrate its potential

Studies of Radiation-Induced Pinning Centers and Persistent Magnetic Field Based on Y(1)Ba(2)Cu(3)O(7) Superconductor Materials

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Long-term safety of paclitaxel drug-coated balloon-only angioplasty for de novo coronary artery disease: the SPARTAN DCB study

Objectives: We aimed to investigate long-term survival of paclitaxel DCB for percutaneous coronary intervention (PCI). Background: Safety concerns have been raised over the use of paclitaxel devices for peripheral artery disease recently, following a meta-analysis suggesting increased late mortality. With regard to drug-coated balloon (DCB) angioplasty for coronary artery intervention however, there is limited data to date regarding possible late mortality relating to paclitaxel. Methods: We compared all-cause mortality of patients treated with paclitaxel DCB to those with non-paclitaxel second-generation drug-eluting stents (DES) for stable, de novo coronary artery disease from 1st January 2011 till 31st December 2018. To have homogenous groups allowing data on safety to be interpreted accurately, we excluded patients with previous PCI and patients treated with a combination of both DCB and DES in subsequent PCIs. Data were analysed with Kaplan–Meier curves and Cox regression statistical models. Results: We present 1517 patients; 429 treated with paclitaxel DCB and 1088 treated with DES. On univariate analysis, age, hypercholesterolaemia, hypertension, peripheral vascular disease, prior myocardial infarction, heart failure, smoking, atrial fibrillation, decreasing estimated glomerular filtration rate (eGFR) [and renal failure (eGFR < 45)] were associated with worse survival. DCB intervention showed a non-significant trend towards better prognosis compared to DES (p = 0.08). On multivariable analysis age, decreasing eGFR and smoking associated with worse prognosis. Conclusion: We found no evidence of late mortality associated with DCB angioplasty compared with non-paclitaxel second-generation DES in up to 5 years follow-up. DCB is a safe option for the treatment of de novo coronary artery disease

Circulating intermediate monocytes CD14++CD16+ are increased after elective percutaneous coronary intervention

Aim Inflammation plays a central role in the pathogenesis of atherosclerosis and in the sequelae of percutaneous coronary intervention (PCI). Previous work demonstrated that intermediate monocytes (CD14++CD16+) are associated with adverse cardiovascular events, yet monocyte subset response following elective PCI has not been described. This article explores the changes in monocyte subset and humoral response after elective PCI. Methods This prospective study included 30 patients without inflammatory diseases being referred for elective PCI. We included patients treated with drug coated balloons or 2nd generation drug eluting stents. Patients underwent blood tests at baseline (prior to PCI), four hours, two weeks and two months later. Analyses were performed in terms of monocyte subsets (classical CD14++CD16-, intermediate CD14++CD16+ and non-classical CD14+CD16++), gene expression of CD14+ leucocytes and humoral biomarkers. Results Intermediate monocytes decreased significantly four hours after PCI, were recovered at two weeks, and increased significantly at two months post elective, uncomplicated PCI. They remain significantly elevated in the DES group but not in the DCB group. Gene expression analysis of CD14+ leucocytes showed IL18 had decreased expression at two weeks, CXCR4 and IL1β decreased at two months, while pentraxin 3 increased at two weeks and two months. In terms of humoral biomarkers, hsTnI remains elevated up to two weeks post PCI while IL6 and TNFα remain elevated till two months post PCI. Conclusion Intermediate monocytes increase significantly two months following elective, uncomplicated PCI. They remain significantly elevated in the DES group but not in the DCB group suggesting that the PCI strategy could be one of the ways to modulate the inflammatory response post PCI

Myocardial inflammation and energetics by cardiac MRI : a review of emerging techniques

The role of inflammation in cardiovascular pathophysiology has gained a lot of research interest in recent years. Cardiovascular Magnetic Resonance has been a powerful tool in the non-invasive assessment of inflammation in several conditions. More recently, Ultrasmall superparamagnetic particles of iron oxide have been successfully used to evaluate macrophage activity and subsequently inflammation on a cellular level. Current evidence from research studies provides encouraging data and confirms that this evolving method can potentially have a huge impact on clinical practice as it can be used in the diagnosis and management of very common conditions such as coronary artery disease, ischaemic and non-ischaemic cardiomyopathy, myocarditis and atherosclerosis. Another important emerging concept is that of myocardial energetics. With the use of phosphorus magnetic resonance spectroscopy, myocardial energetic compromise has been proved to be an important feature in the pathophysiological process of several conditions including diabetic cardiomyopathy, inherited cardiomyopathies, valvular heart disease and cardiac transplant rejection. This unique tool is therefore being utilized to assess metabolic alterations in a wide range of cardiovascular diseases. This review systematically examines these state-of-the-art methods in detail and provides an insight into the mechanisms of action and the clinical implications of their use

The Importance of mitral valve prolapse doming volume in the assessment of left ventricular stroke volume with cardiac MRI

There remains a debate whether the ventricular volume within prolapsing mitral valve (MV) leaflets should be included in the left ventricular (LV) end-systolic volume, and therefore factored in LV stroke volume (SV), in cardiac magnetic resonance (CMR) assessments. This study aims to compare LV volumes during end-systolic phases, with and without the inclusion of the volume of blood on the left atrial aspect of the atrioventricular groove but still within the MV prolapsing leaflets, against the reference LV SV by four-dimensional flow (4DF). A total of 15 patients with MV prolapse (MVP) were retrospectively enrolled in this study. We compared LV SV with (LV SVMVP) and without (LV SVstandard) MVP left ventricular doming volume, using 4D flow (LV SV4DF) as the reference value. Significant differences were observed when comparing LV SVstandard and LV SVMVP (p < 0.001), and between LV SVstandard and LV SV4DF (p = 0.02). The Intraclass Correlation Coefficient (ICC) test demonstrated good repeatability between LV SVMVP and LV SV4DF (ICC = 0.86, p < 0.001) but only moderate repeatability between LV SVstandard and LV SV4DF (ICC = 0.75, p < 0.01). Calculating LV SV by including the MVP left ventricular doming volume has a higher consistency with LV SV derived from the 4DF assessment. In conclusion, LV SV short-axis cine assessment incorporating MVP dooming volume can significantly improve the precision of LV SV assessment compared to the reference 4DF method. Hence, in cases with bi-leaflet MVP, we recommend factoring in MVP dooming into the left ventricular end-systolic volume to improve the accuracy and precision of quantifying mitral regurgitation