Phytosterols Alleviate Hyperlipidemia by Regulating Gut Microbiota and Cholesterol Metabolism in Mice.

Phytosterols (PS) have been shown to regulate cholesterol metabolism and alleviate hyperlipidemia (HLP), but the mechanism is still unclear. In this study, we investigated the mechanism by which PS regulates cholesterol metabolism in high-fat diet (HFD) mice. The results showed that PS treatment reduced the accumulation of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) in the serum of HFD mice, while increasing the serum levels of high-density lipoprotein cholesterol (HDL-C). Compared with HFD mice, PS not only increased the antioxidant activity of the liver but also regulated the mRNA expression levels of enzymes and receptors related to cholesterol metabolism. The hypolipidemic effect of PS was abolished by antibiotic (Abx) intervention and reproduced by fecal transplantation (FMT) intervention. The results of 16S rRNA sequencing analysis showed that PS modulated the gut microbiota of mice. PS reduced the relative abundance of Lactobacillus and other bile salt hydrolase- (BSH-) producing gut microbiota in HFD mice, which are potentially related to cholesterol metabolism. These findings partially explain the mechanisms by which PS regulates cholesterol metabolism. This implies that regulation of the gut microbiota would be a potential target for the treatment of HLP.

A non-collinear autocorrelator for single-shot characterization of ultrabroadband terahertz pulses.

Conventional terahertz (THz) waveform or spectral diagnostics mainly employ the electro-optic-based techniques or the multi-shot Michelson interferometer. Simultaneously, single-shot, ultrabroadband THz spectral measurements remain challenging. In this paper, a novel probe-free scheme based on the non-collinear autocorrelation technique is proposed to characterize the ultrabroadband THz spectrum at a single-shot mode. The non-collinear autocorrelator is a modified beam-division interferometer, in which the two beams are recombined non-collinearly onto a camera. The temporal or spectral resolution and range depend on the noncollinear configuration and camera parameters. This simple approach has been applied experimentally to characterize the ultrashort THz pulse generated from ultraintense laser-solid interactions, demonstrating the capability of single-shot ultrabroadband measurements without an auxiliary ultrafast laser probe. The proposed non-collinear autocorrelator here would be much useful for characterization and applications of low-repetition-rate intense THz sources and could also be extended to other frequency bands.

Global Research Trends and Hotspots of Autophagy in Colorectal Cancer: A 20-year Bibliometric Analysis Based on Web of Science.

BACKGROUND: Autophagy plays a pivotal role in the progression and management of colorectal cancer (CRC). Recently, numerous articles focusing on the role of autophagy in CRC have emerged. The present study was conducted to provide a comprehensive analysis of the current state and changing trends in the relationship of autophagy and CRC over the past 20 years. METHODS: The Web of Science Core Collection (WOSCC) was utilized to extracted all publications with respect to autophagy and CRC during 2002-2021. The contributions of various countries/regions, institutions and journals in this field were analyzed, moreover, research hotspots and promising future trends predicted through keywords were identified by the online platform of bibliometrics, CiteSpace and VOSviewer. RESULTS: A total of 2418 related publications from 2002 to 2021 were identified and collected. China occupied first place with respect to the number of publications, followed by the USA and South Korea. Shanghai Jiao Tong University published the most papers in this field. Most publications were published in Oncotarget. Additionally, analysis of the keywords identified 4 clusters with various research focuses: "mechanism-related research", "clinical-related research", "tumorigenesis research" and "chemotherapy-related research". The three latest hot keywords in this field were epithelial-mesenchymal transition (EMT), promote and invasion. CONCLUSIONS: The number of publications and research interest on autophagy and CRC are increasing annually, and the USA had prominent academic positions in the field. Shanghai Jiao Tong University represents a high level of research and the latest progress in this field can be tracked at Oncotarget. Throughout the research history of autophagy and CRC in the past 20 years, previous studies have mainly concentrated on apoptosis and drug resistance in tumor cells, while EMT in regulating tumorigenesis and development of clinical drugs that inhibit tumor invasion through autophagy may be novel hotspots in the future.

Highly efficient generation of GV/m-level terahertz pulses from intense femtosecond laser-foil interactions.

The terahertz radiation from ultraintense laser-produced plasmas has aroused increasing attention recently as a promising approach toward strong terahertz sources. Here, we present the highly efficient production of millijoule-level terahertz pulses, from the rear side of a metal foil irradiated by a 10-TW femtosecond laser pulse. By characterizing the terahertz and electron emission in combination with particle-in-cell simulations, the physical reasons behind the efficient terahertz generation are discussed. The resulting focused terahertz electric field strength reaches over 2 GV/m, which is justified by experiments on terahertz strong-field-driven nonlinearity in semiconductors.

Two-dimensional monitoring of a laser-solid x-ray source spot via penumbral coded aperture imaging technique.

The uncertainties of spot size and position need to be clarified for x-ray sources as they can affect the detecting precision of the x-ray probe beam in applications such as radiography. In particular, for laser-driven x-ray sources, they would be more significant as they influence the inevitable fluctuation of the driving laser pulses. Here, we have employed the penumberal coded aperture imaging technique to diagnose the two-dimensional spatial distribution of an x-ray emission source spot generated from a Cu solid target irradiated by an intense laser pulse. Taking advantage of the high detection efficiency and high spatial resolution of this technique, the x-ray source spot is characterized with a relative error of ∼5% in the full width at half maximum of the intensity profile in a single-shot mode for general laser parameters, which makes it possible to reveal the information of the unfixed spot size and position precisely. Our results show the necessity and feasibility of monitoring the spot of these novel laser-driven x-ray sources via the penumbral coded aperture imaging technique.