Testing Electron-phonon Coupling for the Superconductivity in Kagome Metal CsV3Sb5\rm{CsV_3Sb_5}

In crystalline materials, electron-phonon coupling (EPC) is a ubiquitous many-body interaction that drives conventional Bardeen-Cooper-Schrieffer superconductivity. Recently, in a new kagome metal $\rm{CsV_3Sb_5}$, superconductivity that possibly intertwines with time-reversal and spatial symmetry-breaking orders is observed. Density functional theory calculations predicted weak EPC strength,$\lambda$, supporting an unconventional pairing mechanism in $\rm{CsV_3Sb_5}$. However, experimental determination of $\lambda$ is still missing, hindering a microscopic understanding of the intertwined ground state of $\rm{CsV_3Sb_5}$. Here, using 7-eV laser-based angle-resolved photoemission spectroscopy and Eliashberg function analysis, we determine an intermediate $\lambda$=0.45~0.6 at T=6 K for both Sb 5p and V 3d electronic bands, which can support a conventional superconducting transition temperature on the same magnitude of experimental value in $\rm{CsV_3Sb_5}$. Remarkably, the EPC on the V 3d-band enhances to $\lambda$~0.75 as the superconducting transition temperature elevated to 4.4 K in $\rm{Cs(V_{0.93}Nb_{0.07})_3Sb_5}$. Our results provide an important clue to understand the pairing mechanism in the Kagome superconductor $\rm{CsV_3Sb_5}$.Comment: To appear in Nature Communication

Conjoined Charge Density Waves in the Kagome Superconductor CsV3Sb5

The intricate interplay between novel lattice geometry and spontaneous symmetry-breaking states is at the forefront of contemporary research on quantum materials. Recently, the observation of unconventional charge and pairing density waves in a kagome metal CsV3Sb5 brings out a new showcase for intertwined orders. While electronic instabilities in CsV3Sb5 are widely believed to originate from the V 3d-electrons residing on the 2-dimensional kagome sublattice, the pivotal role of Sb 5p-electrons for 3-dimensional orders is yet to be understood. Here, using resonant tender x-ray scattering and high-pressure X-ray scattering, we report a rare realization of conjoined charge density waves (CDW) in CsV3Sb5. At ambient pressure, we discover a resonant enhancement at Sb L1-edge (2s-5p) at the 2$\times$2$\times$2 CDW wavevectors. The resonance, however, is absent at the 2$\times$2 CDW wavevectors. Applying hydrostatic pressure, we find the CDW transition temperatures to separate, where the 2$\times$2$\times$2 CDW emerges 4 K above the 2$\times$2 CDW at 1GPa. Our results establish the coexistence of the 2$\times$2 CDW and the 5p-electron assisted 2$\times$2$\times$2 CDW in CsV3Sb5. The evolution of the conjoined CDWs under pressure suggests the joint importance of electronic and phononic fluctuations for the double dome superconductivity

Spatial symmetry constraint of charge-ordered kagome superconductor CsV3_3Sb5_5

Elucidating the symmetry of intertwined orders in exotic superconductors is at the quantum frontier. Recent surface sensitive studies of the topological kagome superconductor CsV$_3$Sb$_5$ discovered a cascade 4a$_0$ superlattice below the charge density wave (CDW) ordering temperature, which can be related to the pair density modulations in the superconducting state. If the 4a$_0$ phase is a bulk and intrinsic property of the kagome lattice, this would form a striking analogy to the stripe order and pair density wave discovered in the cuprate high-temperature superconductors, and the cascade ordering found in twisted bilayer graphene. High-resolution X-ray diffraction has recently been established as an ultra-sensitive probe for bulk translational symmetry-breaking orders, even for short-range orders at the diffusive limit. Here, combining high-resolution X-ray diffraction, scanning tunneling microscopy and scanning transmission electron microscopy, we demonstrate that the 4a$_0$ superstructure emerges uniquely on the surface and hence exclude the 4a$_0$ phase as the origin of any bulk transport or spectroscopic anomaly. Crucially, we show that our detected 2$\times$2$\times$2 CDW order breaks the bulk rotational symmetry to C2, which can be the driver for the bulk nematic orders and nematic surface superlattices including the 4a$_0$ phase. Our high-resolution data impose decisive spatial symmetry constraints on emergent electronic orders in the kagome superconductor CsV$_3$Sb$_5$

Nano-Strategies for Enhancing the Bioavailability of Tea Polyphenols: Preparation, Applications, and Challenges

Tea polyphenols (TPs) are among the most abundant functional compounds in tea. They exhibit strong antioxidant, anti-inflammatory, and anti-cancer effects. However, their instability and low bioavailability limits their applications. Nanotechnology, which involves the use of nanoscale substances (sizes ranging from 1 to 100 nm) to improve the properties of substances, provides a solution for enhancing the stability and bioavailability of TPs. We reviewed the preparation, performance, effects, and applications of different types of TPs nanocarriers. First, we introduced the preparation of different nanocarriers, including nanoparticles, nanoemulsions, nanomicelles, and nanolipids. Then, we discussed various applications of tea polyphenol-loaded nanocarriers in functional ingredient delivery, food quality improvement, and active food packaging. Finally, the challenges and future development directions of TPs nanocarriers were elucidated. In conclusion, a nano-strategy may be the “key” to break the application barriers of TPs. Therefore, the use of nano-strategies for the safe, stable, and efficient release of TPs is the direction of future research

Maternal Body Mass Index, Gestational Weight Gain, and Risk of Cancer in Offspring: A Systematic Review and Meta-Analysis

Background: Mounting evidence suggests that maternal obesity and gestational weight gain (GWG) may increase the risk of cancer in their offspring; however, results are inconsistent. The purpose of this research is to determine the association between maternal body mass index (BMI) and GWG and the risk of cancer in offspring through a systematic and comprehensive meta-analysis. Methods: A systematic literature search of several databases was conducted on 1 October 2022 to identify relevant studies. The quality of the included studies was evaluated using the Newcastle–Ottawa scale. The overall risk estimates were pooled using a random-effects meta-analysis. Results: Twenty-two studies with more than 8 million participants were included. An increased risk of total cancer was found in offspring whose mothers had a high GWG (odds ratio [OR]: 1.10; 95% CI: 1.01–1.19; p: 0.040) but not in offspring whose mothers had a low GWG (OR: 1.06; 95% CI: 0.96–1.17; p: 0.030), when compared with offspring whose mothers had a suitable GWG. In addition, no statistically significant association was found between maternal underweight (OR: 1.05; 95% CI: 0.97–1.13; p: 0.630), overweight/obesity (OR: 1.07; 95% CI: 0.99–1.16; p: 0.020), and risk of total cancer in offspring. Conclusions: Our study proposes evidence that maternal BMI and GWG may be associated with the risk of cancer in offspring, although statistical significance was found only for high GWG. Further well-designed research is required to clarify the potential relevance of maternal BMI and GWG on offspring cancer, especially for specific cancers

Physics-Based LED Modeling and Nonlinear Distortion Mitigating With Real-Time Implementation

In this paper, a nonlinear model for Light Emitting Diodes (LEDs) inspired by semiconductor physics, and a corresponding post-compensator are implemented in a Field Programmable Gate Array (FPGA) for real-time Visible Light Communications (VLC). Our experiments demonstrate that the LED model effectively characterizes the dynamic LED nonlinearity, including the memory effects. The output signal of this nonlinear LED model shows a good resemblance with the measured LED output. In addition, a dedicated nonlinear equalizer, say, a post-compensator, inspired by this LED physical model can mitigate the nonlinear distortion substantially. Thereby it facilitates high data rate over the bandwidth-limited LED. It shows that the nonlinear compensator is attractive for practical real-time digital signal processing systems due to its high performance and low complexity

Cellulosic Biomass-Reinforced Polyvinylidene Fluoride Separators with Enhanced Dielectric Properties and Thermal Tolerance

Safety issues are critical barriers to large-scale energy storage applications of lithium-ion batteries (LIBs). Using an ameliorated, thermally stable, shutdown separator is an effective method to overcome the safety issues. Herein, we demonstrate a novel, cellulosic biomass-material-blended polyvinylidene fluoride separator that was prepared using a simple nonsolvent-induced phase separation technique. This process formed a microporous composite separator with reduced crystallinity, uniform pore size distribution, superior thermal tolerance, and enhanced electrolyte wettability and dielectric and mechanical properties. In addition, the separator has a superior capacity retention and a better rate capability compared to the commercialized microporous polypropylene membrane. This fascinating membrane was fabricated via a relatively eco-friendly and cost-effective method and is an alternative, promising separator for high-power LIBs