We have experimentally studied a magnetopiezoelectric effect predicted recently for magnetic metals with low crystal symmetries. In EuMnBi2 with antiferromagnetic Mn moments at 77 K, dynamic ...displacements emerge along the a direction upon application of ac electric fields in the c direction and increase in proportion to the applied electric fields. Such displacements are not observed along the c direction of EuMnBi2 or EuZnBi2 with nonmagnetic Zn ions. As temperature increases from 77 K, the displacement signals decrease and disappear at about 200 K, above which electric conduction changes from coherent to incoherent. These results demonstrate the emergence of the magnetopiezoelectric effect in a magnetic metal lacking inversion and time-reversal symmetries.
In our studies of life‐supporting α‐1,3‐galactocyltransferase knockout (GalT‐KO) pig‐to‐baboon kidneys, we found that some recipients developed increased serum creatinine with growth of the grafts, ...without histological or immunological evidence of rejection. We hypothesized that the rapid growth of orthotopic pig grafts in smaller baboon recipients may have led to deterioration of organ function. To test this hypothesis for both kidneys and lungs, we assessed whether the growth of outbred (Yorkshire) organ transplants in miniature swine was regulated by intrinsic (graft) or extrinsic (host environment) factors. Yorkshire kidneys exhibited persistent growth in miniature swine, reaching 3.7 times their initial volume over 3 mo versus 1.2 times for miniature swine kidneys over the same time period. Similar rapid early growth of lung allografts was observed and, in this case, led to organ dysfunction. For xenograft kidneys, a review of our results suggests that there is a threshold for kidney graft volume of 25 cm3/kg of recipient body weight at which cortical ischemia is induced in transplanted GalT‐KO kidneys in baboons. These results suggest that intrinsic factors are responsible, at least in part, for growth of donor organs and that this property should be taken into consideration for growth‐curve–mismatched transplants, especially for life‐supporting organs transplanted into a limited recipient space.
Factors intrinsic to transplanted organs play a role in subsequent growth of those organs, suggesting that this property should be considered for growth‐curve mismatched transplants, especially when transplanting life‐supporting organs into limited recipient space.
It is found that, in the studies of heavy ion transport with gyrokinetic simulations, the ion parallel drift frequency can reverse sign in velocity space when the amplitude variation of the ...electrostatic potential fluctuation is strong along the magnetic field line. As a result, the particle transport related to the parallel dynamics is strongly enhanced. It is noted that, while parallel gradient of the fluctuation amplitude can be instigated by a large magnetic shear or safety factor in a tokamak, the generic mechanism is independent of its cause, which suggests broader applications to kinetic plasma problems. Some relevant topics are briefly addressed in the end.
Plasma β dependence of electromagnetic turbulent transport is investigated by means of gyrokinetic simulations with self-consistent change of the equilibrium magnetic field. It is found that energy ...transport due to ion-temperature-gradient (ITG) driven turbulence does not decrease with increasing β; that is, the ion energy diffusivity does not decrease, and the electron energy diffusivity increases with β. This is because magnetic fluctuations are significantly influenced by the background magnetic field structure change with β by the Pfirsch-Schluter current. The magnetic field change weakens the suppression effect of magnetic perturbations on the growth of the ITG mode, and it also suppresses nonlinear zonal flow production. The influence of the magnetic field change is significant as the global magnetic shear increases.
The formation of He bubbles in tungsten under exposure to a He plasma was systematically investigated using low energy (∼50eV) He+ ions with a wide fluence range (∼1023 to 1026m−2) in the linear ...divertor plasma simulator PISCES-A at several temperatures (523–973K). TEM observations after thinning exposed W samples with FIB revealed that the layer thickness (>30nm) of He bubbles largely exceeds the ion implantation range of a few nm. The size of He bubbles was found to increase with an increase in the sample temperature: it was around 10nm at 973K, while only small He bubbles of 1–2nm were observed at <773K. In addition, to obtain information on the initial formation behavior, in-situ TEM observations during He ion irradiation were also performed.
The theory of the acceleration of auroral particles is reviewed, focusing on developments in the last 15 years. We discuss elementary plasma physics processes leading to acceleration of electrons to ...energies compatible with emission observed for quiet, discrete auroral arcs, defined as arcs that have time scales of minutes or more and spatial scales ranging from less than 1 km to tens of kilometers. For context, earlier observations are first described briefly. The theoretical fundamentals of auroral particle acceleration are based on the kinetic theory of plasmas, in particular the development of parallel electric fields. These parallel electric fields can either be distributed along the magnetic field lines, often associated with the mirror geometry of the geomagnetic field, or concentrated into narrow regions of charge separation known as double layers. Observations have indicated that the acceleration process depends on whether the field-aligned currents are directed away from the Earth, toward the Earth, or in mixed regions of currents often associated with the propagation of Alfvén waves. Recent observations from the NASA Fast Auroral SnapshoT (FAST) satellite, the ESA satellite constellation Cluster, and the Japanese Reimei satellite have provided new insights into the auroral acceleration process and have led to further refinements to the theory of auroral particle acceleration.
The effect of specimen orientation, or texture on high temperature deformation behavior at a high strain rate of 10
3
s
−1 was investigated in an extruded Mg–3Al–1Zn alloy rod with
〈
1
0
1
¯
0
...〉
fiber texture. Uniaxial compression test data were obtained along two specimen directions (longitudinal and transverse directions). The temperature dependence of yield stress was small up to 673
K for both directions, indicating that a diffusion process is not rate-controlling at such a high strain rate. The alloy exhibited strong plastic anisotropy at 10
3
s
−1 from room temperature to 673
K. For the transverse specimens, the yield stress was lower than that for the longitudinal specimens. In addition, plastic deformation occurred preferentially in the radial direction of the extruded rod. These results suggest that basal slip is the dominant deformation mechanism for the transverse specimens. On the other hand, strong temperature insensitivity of flow stress as well as concave flow curves observed in the longitudinal specimens suggested the prevalence of twinning.
To compare the effectiveness and safety of antipseudomonal β-lactam empiric monotherapy for febrile neutropenia by network meta-analysis.
Searches using Pubmed, Cochrane CENTRAL, EMBASE and Web of ...Science Core Collection were carried out in June 2016. English articles, non-English articles, full-length articles, short articles and conference abstracts were allowed. Eligible trial design was a parallel-group individual randomization. We included febrile neutropenia adult and paediatric patients undergoing chemotherapy for either solid tumours or haematological malignancies and treated with intravenous antipseudomonal β-lactams for initial empiric therapy. Protocol was registered with PROSPERO ID 42016043377.
Of 1275 articles detected by the search, 50 studies with 10 872 patients were finally included. Among the guideline-recommended cefepime, meropenem, imipenem/cilastatin, piperacillin/tazobactam and ceftazidime; imipenem/cilastatin showed the highest odds of treatment success without modification, which was the primary endpoint, based on the random-effect model network analysis. Ceftazidime was related to lower treatment success rate without modification compared with imipenem/cilastatin with OR of 0.71 (95% CI 0.57–0.89, p 0.006). Imipenem/cilastatin showed the lowest odds of all-cause death. Patients treated with cefepime had higher risk for all-cause death compared with those treated with imipenem/cilastatin (OR 2.05, 95% CI 1.11–3.78, p 0.029). Any adverse event was significantly more prevalent in the imipenem/cilastatin arm; however, there was no difference concerning adverse events leading to discontinuation.
Imipenem/cilastatin, piperacillin/tazobactam and meropenem may be reasonable first-choice medications for empiric therapy of febrile neutropenia.
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