368 research outputs found
Ecological comparison of the risks of mother-to-child transmission and clinical manifestations of congenital toxoplasmosis according to prenatal treatment protocol
We compared the relative risks of mother-to-child transmission of Toxoplasma gondii and clinical manifestations due to congenital toxoplasmosis associated with intensive prenatal treatment in Lyon and Austria, short term treatment in 51% of Dutch women, and no treatment in Danish women. For each cohort, relative risks were standardized for gestation at seroconversion. In total, 856 mother–child pairs were studied: 549 in Lyon, 133 in Austria, 123 in Denmark and 51 in The Netherlands. The relative risk for mother-to-child transmission compared to Lyon was 1·24 (95% CI: 0·88, 1·59) in Austria; 0·59 (0·41, 0·81) in Denmark; and 0·65 (0·37, 1·01) in The Netherlands. Relative risks for clinical manifestations compared with Lyon (adjusted for follow-up to age 3 years) were: Austria 0·19 (0·04, 0·51); Denmark 0·60 (0·13, 1·08); and The Netherlands 1·46 (0·51, 2·72). There was no clear evidence that the risk of transmission or of clinical manifestations was lowest in centres with the most intensive prenatal treatment
Ultrasonic studies of the magnetic phase transition in MnSi
Measurements of the sound velocities in a single crystal of MnSi were
performed in the temperature range 4-150 K. Elastic constants, controlling
propagation of longitudinal waves reveal significant softening at a temperature
of about 29.6 K and small discontinuities at 28.8 K, which corresponds to
the magnetic phase transition in MnSi. In contrast the shear elastic moduli do
not show any softening at all, reacting only to the small volume deformation
caused by the magneto-volume effect. The current ultrasonic study exposes an
important fact that the magnetic phase transition in MnSi, occurring at 28.8 K,
is just a minor feature of the global transformation marked by the rounded
maxima or minima of heat capacity, thermal expansion coefficient, sound
velocities and absorption, and the temperature derivative of resistivity.Comment: 4 pages, 4 figure
Dissociative photoionization of NO across a shape resonance in the XUV range using circularly polarized synchrotron radiation.
We report benchmark results for dissociative photoionization (DPI) spectroscopy and dynamics of the NO molecule in the region of the σ* shape resonance in the ionization leading to the NO+(c3Π) ionic state. The experimental study combines well characterized extreme ultraviolet (XUV) circularly polarized synchrotron radiation, delivered at the DESIRS beamline (SOLEIL), with ion-electron coincidence 3D momentum spectroscopy. The measured (N+, e) kinetic energy correlation diagrams reported at four discrete photon energies in the extended 23-33 eV energy range allow for resolving the different active DPI reactions and underline the importance of spectrally resolved studies using synchrotron radiation in the context of time-resolved studies where photoionization is induced by broadband XUV attosecond pulses. In the dominant DPI reaction which leads to the NO+(c3Π) ionic state, photoionization dynamics across the σ* shape resonance are probed by molecular frame photoelectron angular distributions where the parallel and perpendicular transitions are highlighted, as well as the circular dichroism CDAD(θe) in the molecular frame. The latter also constitute benchmark references for molecular polarimetry. The measured dynamical parameters are well described by multichannel Schwinger configuration interaction calculations. Similar results are obtained for the DPI spectroscopy of highly excited NO+ electronic states populated in the explored XUV photon energy range
Neospora caninum infection and repeated abortions in humans.
To determine whether Neospora caninum, a parasite known to cause repeated abortions and stillbirths in cattle, also causes repeated abortions in humans, we retrospectively examined serum samples of 76 women with a history of abortions for evidence of N. caninum infection. No antibodies to the parasite were detected by enzyme-linked immunosorbent assay, immunofluorescence assay, or Western blot
Ordered Phases of Itinerant Dzyaloshinsky-Moriya Magnets and Their Electronic Properties
A field theory appropriate for magnets that display helical order due to the
Dzyaloshinsky-Moriya mechanism, a class that includes MnSi and FeGe, is used to
derive the phase diagram in a mean-field approximation. The helical phase, the
conical phase in an external magnetic field, and recent proposals for the
structure of the A-phase and the non-Fermi-liquid region in the paramagnetic
phase are discussed. It is shown that the orientation of the helical pitch
vector along an external magnetic field within the conical phase occurs via two
distinct phase transitions. The Goldstone modes that result from the long-range
order in the various phases are determined, and their consequences for
electronic properties, in particular the specific heat, the single-particle
relaxation time, and the electrical and thermal conductivities, are derived.
Various aspects of the ferromagnetic limit, and qualitative differences between
the transport properties of helimagnets and ferromagnets, are also discussed.Comment: 22pp, 8 eps fig
Magneto-elastic interaction in cubic helimagnets with B20 structure
The magneto-elastic interaction in cubic helimagnets with B20 symmetry is
considered. It is shown that this interaction is responsible for negative
contribution to the square of the spin-wave gap which is alone has to
disrupt assumed helical structure. It is suggested that competition between
positive part of which stems from magnon-magnon interaction and
its negative magneto-elastic part leads to the quantum phase transition
observed at high pressure in and . This transition has to occur
when . For from rough estimations at ambient pressure both
parts and are comparable with the experimentally
observed gap. The magneto-elastic interaction is responsible also for 2\m k
modulation of the lattice where \m k is the helix wave-vector and
contribution to the magnetic anisotropy.
Experimental observation by -ray and neutron scattering the lattice
modulation allows determine the strength of anisotropic part of the
magneto-elastic interaction responsible for above phenomena and the lattice
helicity
The square-lattice spiral magnet Ba_2CuGe_2O_7 in an in-plane magnetic field
The magnetic structure of Ba_2CuGe_2O_7 is investigated by neutron
diffraction in magnetic fields applied along several directions in the
plane of the crystal. In relatively weak fields, ~T, the
propagation vector of the spin-spiral rotates to form a finite angle with the
field direction. This angle depends on the orientation of itself. The
rotation of the propagation vector is accompanied by a re-orientation of the
plane of spin rotation in the spiral. The observed behaviour is well described
by a continuous-limit form of a free energy functional that includes exchange
and Dzyaloshinskii-Moriya interactions, as well as the Zeeman energy and an
empirical anisotropy term.Comment: 7 pages, 6 figure
Antibiotic therapy of neuroborreliosis:A survey among infectious disease specialists and neurologists in Norway, Sweden, and Denmark
Introduction: Neuroborreliosis (NB) is a prevalent tick-borne neuroinfection in Europe. To delineate current practice in antimicrobial management of adults with NB and to prioritize future trials needed to optimize treatment recommendations, a questionnaire-based survey was performed. Methods: A self-administered Internet-based survey of NB treatment practices among specialists in infectious diseases and neurology based in Norway, Sweden, and Denmark was carried out between October 2021 and February 2022. The participants were also asked to prioritize four pre-defined research questions for randomized controlled trials (RCTs) on therapy for NB. Results: In total, 290 physicians (45% female) from Norway (30%), Sweden (40%), and Denmark (30%) participated in the survey. Of the responders, 230 (79%) were infectious disease specialists and 56 (19%) were neurologists. The preferred antibiotic treatment for patients with early NB was oral doxycycline (n = 225, 78%). Intravenous (IV) penicillin, ceftriaxone, or cefotaxime for the full treatment course was favored by 12%. A preferred treat- ment duration of 10–14 days for patients with NB was reported by 245 respondents (85%), most common among participants from Sweden (97%). A total of 170 (59%) responders reported having local hospital guidelines on the treatment of NB, most often with recommendation of oral doxycycline (92%) for 10–14 days (90%) as first line treatment. The prioritization score for future RCTs was highest for adjunctive prednisone therapy in NB patients with facial palsy (median 5; IQR 4–6) and for placebo versus repeated antibiotics in patients with persistent symptoms after completed antibiotic therapy for NB (median 5, IQR 3–6). Conclusion: In Sweden, all respondents preferred treating NB with oral doxycycline for 10–14 days, whereas 5% in Norway and 19% in Denmark still treat NB with IV antibiotics for the entire treatment course. RCTs to define the role of adjunctive prednisolone in NB patients with facial palsy and repeated antibiotics in patients with persistent symptoms are prioritized for future research.publishedVersio
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