Phonon-mediated spin dynamics in a two-electron double quantum dot under a phonon temperature gradient

We have theoretically studied phonon-mediated spin-flip processes of electrons in a GaAs double quantum dot (DQD) holding two spins, under a phonon temperature gradient over the DQD. Transition rates of inter-dot phonon-assisted tunnel processes and intra-dot spin-flip processes involving spin triplet states are formalized by the electron-phonon interaction accompanied with the spin-orbit interaction. The calculations of the spin-flip rates and the occupation probabilities of the spin-states in the two-electron DQD with respect to the phonon temperature difference between the dots are quantitatively consistent with our previous experiment. This theoretical study on the temperature gradient effect onto spins in coupled QDs would be essential for understanding spin-related thermodynamic physics

Coherent interaction of a-few-electron quantum dot with a terahertz optical resonator in the ultrastrong coupling regime

Hybrid excitations of light and matter, namely, polaritons, in the ultrastrong coupling regime have been intensively investigated to explore novel material functions and realize coherent control of material properties by optical means. However, realization of ultrastrong coupling in a-few-electron systems has been challenging, because the electronic dipole moment decreases with decreasing electron numbers in the system. Here, we fabricate a gate-defined quantum dot (QD) in the vicinity of a gap of a terahertz (THz) split-ring resonator (SRR). By illuminating the system with external THz radiation, the QD shows a current change whose spectrum exhibits anti-crossing behavior between the resonant excitation of the quantized electronic states and the resonance mode of the SRR. Our result indicates that, owing to the field enhancement by the THz SRR, the system enters the ultrastrong coupling regime even when only a few electrons reside in the QD

Histopathological diagnosis of clot tissues collected by mechanical thrombectomy provides understanding of cerebral infarction pathology in cancer associated thrombosis: A case report

Endovascular treatment has become a major tool for managing large vessel occlusion, and its applications in cancer associated thrombosis (CAT) is increasing. Histopathological diagnosis of the collected clots aids in understanding the pathology of cerebral infarction, and enables investigation of the relationship between the primary cancer and cerebral infarction if the primary cancer cells are present.We report one lung cancer patient who achieved effective recanalization by mechanical thrombectomy (MT) for acute internal carotid artery (ICA) occlusion. We diagnosed the cause of occlusion as cardiac metastasis from lung cancer based on transthoracic echocardiography and histopathological diagnosis of collected clots.In MT for large vessel occlusion induced by CAT, histopathological diagnosis of the collected clots is useful for understanding the pathology of cerebral infarction

Double deletion of tetraspanins CD9 and CD81 in mice leads to a syndrome resembling accelerated aging

Abstract Chronic obstructive pulmonary disease (COPD) has been recently characterized as a disease of accelerated lung aging, but the mechanism remains unclear. Tetraspanins have emerged as key players in malignancy and inflammatory diseases. Here, we found that CD9/CD81 double knockout (DKO) mice with a COPD-like phenotype progressively developed a syndrome resembling human aging, including cataracts, hair loss, and atrophy of various organs, including thymus, muscle, and testis, resulting in shorter survival than wild-type (WT) mice. Consistent with this, DNA microarray analysis of DKO mouse lungs revealed differential expression of genes involved in cell death, inflammation, and the sirtuin-1 (SIRT1) pathway. Accordingly, expression of SIRT1 was reduced in DKO mouse lungs. Importantly, siRNA knockdown of CD9 and CD81 in lung epithelial cells additively decreased SIRT1 and Foxo3a expression, but reciprocally upregulated the expression of p21 and p53, leading to reduced cell proliferation and elevated apoptosis. Furthermore, deletion of these tetraspanins increased the expression of pro-inflammatory genes and IL-8. Hence, CD9 and CD81 might coordinately prevent senescence and inflammation, partly by maintaining SIRT1 expression. Altogether, CD9/CD81 DKO mice represent a novel model for both COPD and accelerated senescence