From orthogonal link to phase vortex in generalized dynamical Hopf insulators

In the creation of Hopf topological matters, the old paradigm is to conceive the Hopf invariant first, and then display its intuitive topology through links. Here we brush aside this effort and put forward a new recipe for unraveling the quenched two-dimensional (2D) two-band Chern insulators under a parallel quench protocol, which implies that the quench quantities with different momentum k are parallel or antiparallel to each other. We find that whether the dynamical Hopf invariant exists or not, the links in (2+1)D space always keep their standard shape even for topological initial states, and trace out the trajectories of phase vortices. The linking number is exactly equal to the difference between pre- and post-quench Chern numbers regardless of the construction of homotopy groups. We employ two concrete examples to illustrate these results, highlighting the polarity reversal at fixed points

Inhibition of mTORC1 signaling protects kidney from irradiation-induced toxicity via accelerating recovery of renal stem-like cells

Abstract Background Irradiation-induced kidney damage is inevitable during radiotherapeutic practice, which limits effective radiotherapy doses on tumor treatment. In the present study, the role of mTOR complex 1 (mTORC1) signaling was investigated in irradiation-induced renal injuries. Methods Mice were exposed to 8.0-Gy X-ray of total body irradiation and subsequently treated with rapamycin. Changes of renal morphology were assessed by hematoxylin and eosin staining. Expression of pS6 and CD133 was detected via immunostaining. Cellular apoptosis and proliferation were measured by TUNEL, caspase-3 and BrdU staining. Activation of mTORC1, TGF-β and NF-κB signaling pathways was determined through western blot analysis. Results Our data displayed that irradiation disrupted the structures of renal corpuscles and tubules and decreased the density of CD133+ renal stem-like cells, which were related with increasing cellular apoptosis and decreasing cell proliferation post exposure. Activation of mTORC1, TGF-β and NF-κB signaling pathways was determined in irradiated renal tissues, which were inhibited by rapamycin treatment. Application of rapamycin after irradiation decreased cellular apoptosis and increased autophagy and cell proliferation in renal tissues. The density of CD133+ renal stem-like cells was significantly increased in irradiated kidneys after rapamycin treatment. The morphology of irradiated renal corpuscles and tubules was gradually recovered upon rapamycin treatment. Conclusions These findings indicate that inhibition of mTORC1 signaling by rapamycin ameliorates irradiation-induced renal toxicity mediated by decreasing cellular apoptosis and increasing CD133+ renal stem-like cells

Recent Advances in Triboelectric Nanogenerators: From Technological Progress to Commercial Applications.

Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade

Recent advances in triboelectric nanogenerators: from technological progress to commercial applications

Serious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing. Significant experimental and theoretical efforts have been achieved toward understanding fundamental behaviors and a wide range of demonstrations since its report in 2012. As a result, considerable technological advancement has been exhibited and it advances the timeline of achievement in the proposed roadmap. Now, the technology has reached the stage of prototype development with verification of performance beyond the lab scale environment toward its commercialization. In this review, distinguished authors in the world worked together to summarize the state of the art in theory, materials, devices, systems, circuits, and applications in TENG fields. The great research achievements of researchers in this field around the world over the past decade are expected to play a major role in coming to fruition of unexpectedly accelerated technological advances over the next decade