Microscopic insights to spin transport–driven ultrafast magnetization dynamics in a Gd/Fe bilayer

Laser-induced spin transport is a key ingredient in ultrafast spin dynamics. However, it remains debated to what extent ultrafast magnetization dynamics generates spin currents and vice versa. We use time- and spin-resolved photoemission spectroscopy to study an antiferromagnetically coupled Gd/Fe bilayer, a prototype system for all-optical switching. Spin transport leads to an ultrafast drop of the spin polarization at the Gd surface, demonstrating angular-momentum transfer over several nanometers. Thereby, Fe acts as spin filter, absorbing spin majority but reflecting spin minority electrons. Spin transport from Gd to Fe was corroborated by an ultrafast increase of the Fe spin polarization in a reversed Fe/Gd bilayer. In contrast, for a pure Gd film, spin transport into the tungsten substrate can be neglected, as spin polarization stays constant. Our results suggest that ultrafast spin transport drives the magnetization dynamics in Gd/Fe and reveal microscopic insights into ultrafast spin dynamics

Factors associated with fatigue in acquired immunodeficiency syndrome patients with antiretroviral drug adverse reactions: a retrospective study

AbstractObjectiveTo retrospectively study the prevalence of fatigue and factors associated with fatigue among acquired immunodeficiency syndrome (AIDS) patients with antiretroviral drug adverse reactions.MethodsData were collected from case report forms (CRFs) for a project funded by the 11th National 5-year Special Science and Technology Program on Major Infectious Diseases. Fatigue was defined by patient self-report. The outcomes were the prevalence of fatigue and the potential risk factors of fatigue. Univariate and multivariate logistic regression analyses were conducted to identify the factors associated with fatigue.ResultsAmong the 228 subjects, the prevalence of fatigue was 86.8%. In univariate analysis, the significant differences in demographic characteristics between patients with and without fatigue were: gender [OR=2.29; 95% CI (1.05-4.98)], education level [OR=0.40; 95% CI (0.18-0.85)], anemia [OR=3.80; 95% CI (1.27-11.31)], time of HIV diagnosis [OR= 0.29; 95% CI (0.13-0.65)], and route of infection [OR=0.14; 95% CI (0.06-0.32)]. Abnormal taste and rapid pulse were more commonly seen in patients with fatigue (P<0.05), while abdominal distension and lumbar soreness were encountered less often in patients with fatigue (P<0.05). Multivariate analysis showed that the four main factors associated with fatigue were anemia [OR=3.50; 95% CI (1.01-12.15)], route of infection [OR=3.40; 95% CI (1.21-9.58); P=0.02<0.05], lumbar soreness [OR=0.06; 95% CI (0.02-0.18); P=0.000<0.05], and rapid pulse [OR=10.58; 95% CI (2.16-51.75); P=0.004<0.05].ConclusionThis study demonstrated that fatigue is common (86.8% prevalence) in AIDS patients with antiretroviral drug adverse reactions, and that anemia, route of infection (i.e., non-commercial blood donation) and rapid pulse were risk factors, while lumbar soreness was a protective factor related to fatigue. More attention should be paid to fatigue and more efforts should be made to find ways to prevent, control and eliminate this symptom in AIDS patients with antiretroviral drug adverse reactions

Looking Forward to Seeing Real Experiences through Photos? It Depends on the Quality of Photos

We investigated whether the quality of photos will exert an influence on the post-evaluation of the experience? Through two experiments, we found that the effect does exist. When people reactivate memories through photos, photos can work in the following ways. First, photos can make the memory related to photo content more prominent. Secondly, photos content can replace the already obscured original memory to a certain extent. When the quality of photos is high, people tend to accept the memory being reprocessed, driven by photos, thus improving the evaluation of the original experience. When the quality of the photos is low, people subconsciously reject the information that photos convey and still insist on the judgment of the original experience. The above scenarios apply when people still have an initial impression on their experiences

Infinitely many homoclinic solutions for a class of damped vibration problems

In this paper, we consider the multiplicity of homoclinic solutions for the following damped vibration problems x¨(t) + Bx˙(t) − A(t)x(t) + Hx(t, x(t)) = 0, where A(t) ∈ (R, RN) is a symmetric matrix for all t ∈ R, B = [bij] is an antisymmetric N × N constant matrix, and H(t, x) ∈ C 1 (R × Bδ , R) is only locally defined near the origin in x for some δ > 0. With the nonlinearity H(t, x) being partially sub-quadratic at zero, we obtain infinitely many homoclinic solutions near the origin by using a Clark’s theorem

INFLUENCE OF PANEL ZONE SIZES ON ULTIMATE BEARING CAPACITY OF H-SHAPED STEEL FRAMES

In order to explore the influence of panel zone sizes on the ultimate bearing capacity of H-shaped steel frames, this study examines a steel frame structure with cross-shaped sections consisting of beams, columns and panel zones based on mechanical equilibrium principles. The area ratio of either side of the flange to the web is taken as the main parameter.The results show that the ultimate bearing capacity ratio curves can be grouped into three types. For the first type, the plastic hinge is formed in the panel zone. For the second type, when Rpcb, the strong column factor, is greater than 1.2, the plastic hinge is formed at the beam end; otherwise the plastic hinge is formed in the panel zone. For the third type, when Rpcb≤0.8, the plastic hinge is formed in the panel zone; otherwise the plastic hinge is formed at the beam end. The ultimate bearing capacity ratio curves of the local section of H-shaped steel largely fall in the first curve type, and the ultimate bearing capacity is larger when the panel zone size is excluded from the calculation than otherwise with the former being one to five times as large as the latter