115 research outputs found
Combined Multipoint Remote and In Situ Observations of the Asymmetric Evolution of a Fast Solar Coronal Mass Ejection
We present an analysis of the fast coronal mass ejection (CME) of 2012 March
7, which was imaged by both STEREO spacecraft and observed in situ by
MESSENGER, Venus Express, Wind and Mars Express. Based on detected arrivals at
four different positions in interplanetary space, it was possible to strongly
constrain the kinematics and the shape of the ejection. Using the white-light
heliospheric imagery from STEREO-A and B, we derived two different kinematical
profiles for the CME by applying the novel constrained self-similar expansion
method. In addition, we used a drag-based model to investigate the influence of
the ambient solar wind on the CME's propagation. We found that two preceding
CMEs heading in different directions disturbed the overall shape of the CME and
influenced its propagation behavior. While the Venus-directed segment underwent
a gradual deceleration (from ~2700 km/s at 15 R_sun to ~1500 km/s at 154
R_sun), the Earth-directed part showed an abrupt retardation below 35 R_sun
(from ~1700 to ~900 km/s). After that, it was propagating with a quasi-constant
speed in the wake of a preceding event. Our results highlight the importance of
studies concerning the unequal evolution of CMEs. Forecasting can only be
improved if conditions in the solar wind are properly taken into account and if
attention is also paid to large events preceding the one being studied
Single-Crystal Investigation of the Proposed Type-II Weyl Semimetal CeAlGe
We present details of materials synthesis, crystal structure, and anisotropic magnetic properties of single crystals of CeAlGe, a proposed type-II Weyl semimetal. Single-crystal x-ray diffraction confirms that CeAlGe forms in a noncentrosymmetric I41md space group, in line with predictions of nontrivial topology. Magnetization, specific heat, and electrical transport measurements were used to confirm antiferromagnetic order below 5 K, with an estimated magnon excitation gap of Δ = 9.11 K from heat capacity and hole-like carrier density of 1.4 x 1020 cm-3 from Hall effect measurements. The easy magnetic axis is along the [100] crystallographic direction, indicating that the moment lies in the tetragonal ab plane below 7 K. A spin-flop transition to less than 1 μB/Ce is observed to occur below 30 kOe at 1.8 K in the M(H) (H||a) data. Small magnetic fields of 3 and 30 kOe are sufficient to suppress magnetic order when applied along the a and c axes, respectively, resulting in a complex T-H phase diagram for H||a and a simpler one for H||c
Single crystal investigation of proposed type-II Weyl semimetal CeAlGe
We present details of materials synthesis, crystal structure, and anisotropic
magnetic properties of single crystals of CeAlGe, a proposed type-II Weyl
semimetal. Single-crystal x-ray diffraction confirms that CeAlGe forms in
noncentrosymmetric I4md space group, in line with predictions of
non-trivial topology. Magnetization, specific heat and electrical transport
measurements were used to confirm antiferromagnetic order below 5 K, with an
estimated magnon excitation gap of = 9.11 K from heat capacity and
hole-like carrier density of 1.44 10 cm from Hall effect
measurements. The easy magnetic axis is along the [100] crystallographic
direction, indicating that the moment lies in the tetragonal -plane
below 7 K. A spin-flop transition to less than 1 /Ce is observed to
occur below 30 kOe at 1.8 K in the () data. Small
magnetic fields of 3 kOe and 30 kOe are sufficient to suppress magnetic order
when applied along the - and -axes, respectively, resulting in
a complex phase diagram for and a simpler one for
Spin-echo and quantum versus classical critical fluctuations in TmVO
Using spin-echo Nuclear Magnetic Resonance in the model Transverse-Field
Ising system TmVO, we show that low frequency quantum fluctuations at the
quantum critical point have a very different effect on V nuclear-spins
than classical low-frequency noise or fluctuations that arise at a finite
temperature critical point. Spin-echos filter out the low frequency classical
noise but not the quantum fluctuations. This allows us to directly visualize
the quantum critical fan and demonstrate the persistence of quantum
fluctuations at the critical coupling strength in TmVO to high temperatures
in an experiment that remains transparent to finite temperature classical phase
transitions. These results show that while dynamical decoupling schemes can be
quite effective in eliminating classical noise in a qubit, a quantum critical
environment may lead to rapid entanglement and decoherence.Comment: 10 pages, 5 figure
Retreatment of Patients Nonresponsive to Pegylated Interferon and Ribavirin with Daily High-Dose Consensus Interferon
Background. Current treatment of chronic hepatitis C with pegylated interferon and ribavirin has the ability to eliminate viral infection in about half of the patients treated. Therapeutic options, for those with remaining chronic hepatitis, will remain limited until
novel antivirals become available in the future. Consensus interferon is currently available and has demonstrated clinical efficacy with superior invitro antiviral activity, but the maximum tolerated dose is not defined. Methods. We assessed the efficacy of daily high-dose (24 ug) consensus interferon with weight-based (1000–1200 mg daily) ribavirin in HCV genotype 1-infected non-responder patients. Results. Six adverse events were documented in five patients, and the trial was terminated with no subject achieving viral clearance. Conclusions. The occurrence of serious adverse events effectively defined the upper limit of acceptable dose, while also revealing that this dose did not offer enhanced sustained viral clearance
European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1.
Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi-disciplinary setting. It has confirmed recognition in well-known documented conditions such as graft-versus-host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.
In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.
These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T-cell lymphoma, chronic graft-versus-host disease and acute graft-versus-host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus
ESPRAS Survey on Continuing Education in Plastic, Reconstructive and Aesthetic Surgery in Europe
Background Specialty training in plastic, reconstructive and aesthetic surgery is a prerequisite for safe and effective provision of care. The aim of this study was to assess and portray similarities and differences in the continuing education and specialization in plastic surgery in Europe. Material and Methods A detailed questionnaire was designed and distributed utilizing an online survey administration software. Questions addressed core items regarding continuing education and specialization in plastic surgery in Europe. Participants were addressed directly via the European Leadership Forum (ELF) of the European Society of Plastic, Reconstructive and Aesthetic Surgery (ESPRAS). All participants had detailed knowledge of the organization and management of plastic surgical training in their respective country. Results The survey was completed by 29 participants from 23 European countries. During specialization, plastic surgeons in Europe are trained in advanced tissue transfer and repair and aesthetic principles in all parts of the human body and within several subspecialties. Moreover, rotations in intensive as well as emergency care are compulsory in most European countries. Board certification is only provided for surgeons who have had multiple years of training regulated by a national board, who provide evidence of individually performed operative procedures in several anatomical regions and subspecialties, and who pass a final oral and/or written examination. Conclusion Board certified plastic surgeons meet the highest degree of qualification, are trained in all parts of the body and in the management of complications. The standard of continuing education and qualification of European plastic surgeons is high, providing an excellent level of plastic surgical care throughout Europe
Planet Hunters Tess I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
We report on the discovery and validation of TOI 813 b (TIC55525572b), a transiting exoplanet identified by citizen scientists in data from NASA\u27s Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant (R* = 1.94 R☉, M☉ = 1.32 M☉). It was observed almost continuously by TESS during its first year of operations, during which time four individual transit events were detected. The candidate passed all the standard light curve-based vetting checks, and ground-based follow-up spectroscopy and speckle imaging enabled us to place an upper limit of 2 MJup (99 per cent confidence) on the mass of the companion, and to statistically validate its planetary nature. Detailed modelling of the transits yields a period of 83.8911+0.0027-0.0031 d, a planet radius of 6.71 ± 0.38 R⊕ and a semimajor axis of 0.423+0031-0.037 AU. The planet\u27s orbital period combined with the evolved nature of the host star places this object in a relatively underexplored region of parameter space. We estimate that TOI 813 b induces a reflex motion in its host star with a semi-amplitude of ∼6 m s−1, making this a promising system to measure the mass of a relatively long-period transiting planet
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