Band-selective third-harmonic generation in superconducting MgB$_2$: Possible evidence for Higgs amplitude mode in the dirty limit

We report on time-resolved linear and nonlinear terahertz spectroscopy of the two-band superconductor MgB$_2$ with the superconducting transition temperature $T_c \approx 36$ K. Third-harmonic generation (THG) is observed below $T_c$ by driving the system with intense narrowband THz pulses. For the pump-pulse frequencies $f=$ 0.3, 0.4, and 0.5 THz, temperature-dependent evolution of the THG signals exhibits a resonance maximum at the temperatures with the resonance conditions $2f=2\Delta_\pi(T)$ fulfilled, for the dirty-limit superconducting gap $2\Delta_\pi$. In contrast, for $f=$ 0.6 and 0.7 THz with $2f>2\Delta_\pi(T\rightarrow0)=1.03$ THz, the THG intensity increases monotonically with …

State of the art and prospects for halide perovskite nanocrystals

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Metal-halide perovskites have rapidly emerged as one of the most promising materials of the 21st century, with many exciting properties and great potential for a broad range of applications, from photovoltaics to optoelectronics and photocatalysis. The ease with which metal-halide perovskites can be synthesized in the form of brightly luminescent colloidal nanocrystals, as well as their tunable and intriguing optical and electronic properties, has attracted researchers from different disciplines of science and technology. In the last few years, there has been a significant progress in the shape-controlled synthesis of …

Band-selective third-harmonic generation in superconducting MgB2 : Possible evidence for the Higgs amplitude mode in the dirty limit

Computing oscillatory solutions of the Euler system via 𝒦-convergence

We develop a method to compute effectively the Young measures associated to sequences of numerical solutions of the compressible Euler system. Our approach is based on the concept of [Formula: see text]-convergence adapted to sequences of parameterized measures. The convergence is strong in space and time (a.e. pointwise or in certain [Formula: see text] spaces) whereas the measures converge narrowly or in the Wasserstein distance to the corresponding limit.

Reversible neural stem cell niche dysfunction in a model of multiple sclerosis

Objective The subventricular zone (SVZ) of the brain constitutes a niche for neural stem and progenitor cells that can initiate repair after central nervous system (CNS) injury. In a relapsing-remitting model of experimental autoimmune encephalomyelitis (EAE), the neural stem cells (NSCs) become activated and initiate regeneration during acute disease, but lose this ability during the chronic phases of disease. We hypothesized that chronic microglia activation contributes to the failure of the NSC repair potential in the SVZ. Methods Using bromodeoxyuridine injections at different time points during EAE, we quantified the number of proliferating and differentiating progenitors, and evaluate…

An Ethanolic Extract of Ampelopsis Radix Exerts Anti-colorectal Cancer Effects and Potently Inhibits STAT3 Signaling In Vitro

Colorectal cancer (CRC) is a leading cause of cancer-related morbidity and mortality worldwide. Signal transducer and activator of transcription 3 (STAT3) signaling is constantly activated in CRC, and has been proposed as a pathogenic factor and a therapeutic target of CRC. Ampelopsis Radix (AR), a traditional Chinese medicinal herb, possesses low toxicity and has long been used clinically for the treatment of cancers including CRC. Some constituents of AR have been reported to exert anticancer properties by targeting STAT3. However, the anti-CRC mode and mechanism of action of AR have not been fully elucidated. Here, we investigated the involvement of STAT3 signaling in the anti-CRC effect…

Mesenchymal Stem Cells Improve Glycometabolism and Liver Regeneration in the Treatment of Post-hepatectomy Liver Failure

Background The mortality rate of post-hepatectomy liver failure (PHLF) remains very high, and liver transplantation is the only effective treatment regimen for PHLF. Cell transplantation is a potential treatment for liver diseases. Previous studies have proved that mesenchymal stem cells (MSCs) have immunomodulatory functions. In the present study, we found that MSCs promoted glycogen synthesis and liver regeneration in the treatment of PHLF. MSC transplantation also improved the survival rate of rats after 90% partial hepatectomy (PH). In our current study, we aimed to determine the efficacy and mechanism of MSC transplantation in the treatment of PHLF. Methods Mesenchymal stem cells were …