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D. M. Silevitch G. Aeppli T. F. Rosenbaum 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(7):2797-2800
The intended use of a magnetic material, from information storage to power conversion, depends crucially on its domain structure, traditionally crafted during materials synthesis. By contrast, we show that an external magnetic field, applied transverse to the preferred magnetization of a model disordered uniaxial ferromagnet, is an isothermal regulator of domain pinning. At elevated temperatures, near the transition into the paramagnet, modest transverse fields increase the pinning, stabilize the domain structure, and harden the magnet, until a point where the field induces quantum tunneling of the domain walls and softens the magnet. At low temperatures, tunneling completely dominates the domain dynamics and provides an interpretation of the quantum phase transition in highly disordered magnets as a localization/delocalization transition for domain walls. While the energy scales of the rare earth ferromagnet studied here restrict the effects to cryogenic temperatures, the principles discovered are general and should be applicable to existing classes of highly anisotropic ferromagnets with ordering at room temperature or above. 相似文献
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Fernando Rivera Manuel Benavides Javier Gallego Carmen Guillen-Ponce José Lopez-Martin Marc Küng 《Pancreatology》2019,19(1):64-72
Background
Tumor Treating Fields (TTFields), low intensity alternating electric fields with antimitotic activity, have demonstrated survival benefit in patients with glioblastoma. This phase 2 PANOVA study was conducted to examine the combination of TTFields plus chemotherapy in patients with pancreatic ductal adenocarcinoma (PDAC).Methods
Forty patients with newly-diagnosed, locally advanced or metastatic PDAC received continuous TTFields (150?KHz for ≥18?h/day) plus gemcitabine (1000?mg/m2), or gemcitabine plus nab-paclitaxel (125?mg/m2). The primary endpoint was safety and secondary endpoints included compliance to TTFields, progression-free survival (PFS), and overall survival (OS).Results
Seventeen patients (85%) in each cohort reported Grade ≥3 adverse events (AEs). No increase in serious AEs (SAEs) was observed compared to that anticipated with systemic chemotherapy alone. Twenty-one patients reported TTFields-related skin toxicity, of which 7 were Grade 3; all resolved following temporary reduction of daily TTFields usage. No TTFields-related SAEs were reported. Compliance to TTFields was 68–78% of the recommended average daily use in both cohorts. Median PFS was 8.3 months (95% CI 4.3, 10.3) and median OS was 14.9 months (95% CI 6.2, NA) in the TTFields + gemcitabine cohort. In the TTFields + gemcitabine + nab-paclitaxel cohort, the median PFS was 12.7 months (95% CI 5.4, NA); median OS has not been reached.Conclusion
The PANOVA trial demonstrated that the combination of TTFields and systemic chemotherapy is safe and tolerable in patients with advanced PDAC. Based on the safety and preliminary efficacy results of this phase 2 study, a randomized phase 3 study (PANOVA-3) is underway. 相似文献84.
Nanocomposite Foams of Polypropylene and Carbon Nanotubes: Preparation,Characterization, and Evaluation of their Performance as EMI Absorbers 下载免费PDF全文
Minh‐Phuong Tran Jean‐Michel Thomassin Michaël Alexandre Christine Jerome Isabelle Huynen Christophe Detrembleur 《Macromolecular chemistry and physics.》2015,216(12):1302-1312
Highly expanded nanocomposite foams of polypropylene and carbon nanotubes (PP/CNT) are formed using supercritical carbon dioxide (scCO2) technology. The foaming parameters (temperature, pressure) are investigated to establish their influence on the morphology of the resulting foams and their impact on the electrical conductivity. As promising electromagnetic‐interference (EMI) absorbers, the EMI shielding performance of the foams is determined, and a preliminary relationship is established between foam morphology and the EMI shielding performance. The best candidates are highly expanded foams with a volume expansion of >25, containing 0.1 vol% CNTs; they are able to absorb more than 90% of the incident radiation between 25 and 40 GHz.
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A three‐dimensional point process model for the spatial distribution of disease occurrence in relation to an exposure source 下载免费PDF全文
Kathrine Grell Peter J. Diggle Kirsten Frederiksen Joachim Schüz Elisabeth Cardis Per K. Andersen 《Statistics in medicine》2015,34(23):3170-3180
We study methods for how to include the spatial distribution of tumours when investigating the relation between brain tumours and the exposure from radio frequency electromagnetic fields caused by mobile phone use. Our suggested point process model is adapted from studies investigating spatial aggregation of a disease around a source of potential hazard in environmental epidemiology, where now the source is the preferred ear of each phone user. In this context, the spatial distribution is a distribution over a sample of patients rather than over multiple disease cases within one geographical area. We show how the distance relation between tumour and phone can be modelled nonparametrically and, with various parametric functions, how covariates can be included in the model and how to test for the effect of distance. To illustrate the models, we apply them to a subset of the data from the Interphone Study, a large multinational case‐control study on the association between brain tumours and mobile phone use. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Combining electromagnetic navigation and 3‐D mapping to reduce fluoroscopy time and achieve optimal CRT response 下载免费PDF全文
Umberto Barbero MD Carlo Budano MD Pier Giorgio Golzio MD FESC FACC Davide Castagno MD PhD Fiorenzo Gaita MD 《Pacing and clinical electrophysiology : PACE》2018,41(5):557-560
Implantation of cardiac resynchronization therapy (CRT) devices can be challenging, time consuming, and associated with high‐dose x‐ray exposure. We present the technique in which an electromagnetic navigation system (MediGuideTM, St. Jude Medical) and an electroanatomical three‐dimensional mapping system (EnSite NavX, St Jude Medical) are usefully combined for implanting implantable cardioverter defibrillator CRT devices with strong reduction of x‐ray exposure, and for targeting the most delayed regions in the activation maps avoiding scars for optimal CRT response. 相似文献
89.
A case of electromagnetic interference between HeartMate 3 LVAD and implantable cardioverter defibrillator 下载免费PDF全文
Samineh Sehatbakhsh Alexander Kushnir Mohamad Kabach Matthew Kolek Robert Chait Waqas Ghumman 《Pacing and clinical electrophysiology : PACE》2018,41(2):218-220
Implantable cardioverter defibrillators (ICDs) have been shown to have a significant benefit in reducing sudden cardiac death (SCD) in patients with systolic heart failure. Additionally, cardiac devices as a bridge to transplant or destination therapy are often used in patients with end‐stage systolic heart failure. As a result, most patients with left ventricular assist devices (LVADs) also have an ICD. Here, we present an electromagnetic interference (EMI) between HeartMate 3 LVAD and ICD. This issue might be critical for both electrophysiologists and advanced heart failure cardiologists to understand prior to implantation of ICD/LVADs in these patients. 相似文献
90.
Kunal Pradip Verma MBBS David Adam MBBS FRACP 《Pacing and clinical electrophysiology : PACE》2018,41(10):1381-1383
A 62‐year‐old male presented to his treating cardiologist for routine interrogation of his implantable cardiac defibrillator on the background of severe ischemic cardiomyopathy and end‐stage kidney disease on hemodialysis. The device log revealed multiple paroxysms of atrial fibrillation; however, upon scrutinizing these episodes it was evident that they always corresponded to episodes of hemodialysis while dialyzing through a chronic dialysis catheter, but not while dialyzing via an arteriovenous fistula. We report the novel finding of inappropriate sensing of current leak from the catheter by a lead with a floating atrial dipole. 相似文献