Temperature driven spin-zero effect in TaAs2_2

The electrical and thermo-electrical transport effects of the TaAs$_2$ semimetal were measured in a magnetic field applied along [-2 0 1] direction. The resulting field dependences of the resistivity as well as the Hall, Seebeck and Nernst coefficient below T ~ 100 K can be satisfactory described within the two-band model consisting of the electron and hole pockets. At low temperature all the measured effects exhibit significant contribution from quantum oscillations. The fast Fourier transform (FFT) of the oscillatory Nernst signal shows two fundamental frequencies, Fa = 105 T and Fb = 221 T, and the second harmonic of the latter (F2b = 442 T). The ratio between FFT amplitudes of Fb and F2b changes with temperature in an unusual way, indicating that we observe the spin-zero effect caused by temperature change. This is likely related to substantial temperature dependence of the Lande g-factor, which in turn can result from non-parabolic energy dispersion or temperature evolution of the spin-orbit coupling.Comment: 30 pages, 14 figure

Real-life experiences of letermovir prophylaxis for cytomegalovirus infection in patients after hematopoietic stem cell transplantation: Polish Acute Leukemia Group (PALG) analysis

Introduction: Letermovir (LMV) is a new, cytomegalovirus (CMV)-specific, antiviral drug, approved in 2018 for CMV prophylaxis in patients after allogeneic hematopoietic transplantation. The introduction of letermovir prophylaxis has changed the management of CMV infection: it has reduced the incidence of CMV infections and CMV-related complications, and also improved the overall survival in CMV seropositive patients. However, until recently, due to its high treatment cost, prophylaxis with letermovir has not beeen a standard of care in Poland. Material and methods: To confirm the effectiveness and safety of letermovir prophylaxis, we collected real-life data from eight Polish transplant centers, in which a total of 53 patients were treated with letermovir, including off-label use. Results: LMV is characterized by low toxicity and good tolerability. There were no reports of special adverse events caused by LMV. Conclusions: Our experiences confirm the effectiveness and safety of letermovir prophylaxis, and suggest that this prophylaxis should be started as soon as possible after the infusion of stem cells, preferably no later than day 14. Moreover, our findings indicate that some patients could benefit from extended letermovir prophylaxis beyond 100 days after transplant

Age-dependent determinants of infectious complications profile in children and adults after hematopoietic cell transplantation : lesson from the nationwide study

Incidence and outcome of microbiologically documented bacterial/viral infections and invasive fungal disease (IFD) in children and adults after hematopoietic cell transplantation (HCT) were compared in 650 children and 3200 adults in multicenter cross-sectional nationwide study. Infections were diagnosed in 60.8% children and 35.0% adults, including respectively 69.1% and 63.5% allo-HCT, and 33.1% and 20.8% auto-HCT patients. The incidence of bacterial infections was higher in children (36.0% vs 27.6%; p  21 days were risk factors for death from infection. In conclusion, pediatric patients have 2.9-fold higher incidence and 2.5-fold better outcome of infections than adults after HCT

Electronic properties of TaAs2TaAs_{2} topological semimetal investigated by transport and ARPES

We have performed electron transport and ARPES measurements on single crystals of transition metal dipnictide TaAs2 cleaved along the ($\overline{2}$ 0 1) surface which has the lowest cleavage energy. A Fourier transform of the Shubnikov-de Haas oscillations shows four different peaks whose angular dependence was studied with respect to the angle between the magnetic field and the [$\overline{2}$ 0 1] direction. The results indicate the elliptical shape of the Fermi surface cross-sections. Additionally, a mobility spectrum analysis was carried out, which also reveals at least four types of carriers contributing to the conductance (two kinds of electrons and two kinds of holes). ARPES spectra were taken on freshly cleaved ($\overline{2}$ 0 1) surface and it was found that bulk states pockets at the constant energy surface are elliptical, which confirms the magnetotransport angle dependent studies. First-principles calculations support the interpretation of the experimental results. The theoretical calculations better reproduce the ARPES data if the theoretical Fermi level is increased, which is due to a small n-doping of the samples. This shifts the Fermi level closer to the Dirac point, allowing to investigate the physics of the Dirac and Weyl points, making this compound a platform for the investigation of the Dirac and Weyl points in three-dimensional materials.Comment: 12 pages, 13 figure