Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of dysregulated lipid and glucose metabolism, which is often associated with obesity, dyslipidemia and insulin resistance. In view of the high morbidity and health risks of NAFLD, the lack of effective cure has drawn great attention. In recent years, a line of evidence has suggested a close linkage between the intestine and liver diseases such as NAFLD. We summarized the composition and characteristics of intestinal microbes and reviewed molecular insights into the intestinal microbiome in development and progression of NAFLD. Intestinal microbes mainly include bacteria, archaea, viruses and fungi, and the crosstalk between non-bacterial intestinal microbes and human liver diseases should be paid more attention. Intestinal microbiota imbalance may not only increase the intestinal permeability to gut microbes but also lead to liver exposure to harmful substances that promote hepatic lipogenesis and fibrosis. Furthermore, we focused on reviewing the latest ''gut-liver axis''-targeting treatment, including the application of antibiotics, probiotics, prebiotics, synbiotics, farnesoid X receptor agonists, bile acid sequestrants, gut-derived hormones, adsorbents and fecal microbiota transplantation for NAFLD. In this review, we also discussed the potential mechanisms of ''gut-liver axis'' manipulation and efficacy of these therapeutic strategies for NAFLD treatment.

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Human embryogenesis is believed to involve an integrated set of complex yet coordinated development of different organs and tissues mediated by the changes in the spatiotemporal expression of many genes. Here, we report a genome-wide expression analysis during wk 4-9 of human embryogenesis, a critical period when most organs develop. About half of all human genes are expressed, and 18.6% of the expressed genes were significantly regulated during this important period. We further identified >5000 regulated genes, most of which previously were not known to be associated with animal development. Our study fills an important gap in mammalian developmental studies by identifying functional pathways involved in this critical but previously not studied period. Our study also revealed that the genes involved here are distinct from those during early embryogenesis, which include three groups of maternal genes. Furthermore, we discovered that genes in a given developmental process are regulated coordinately. This led us to develop an easily searchable database of this entire collection of gene expression profiles, allowing for the identification new genes important for a particular developmental process/pathway and deducing the potential function of a novel gene. The validity of the predictions from the database was demonstrated with two examples through spatiotemporal analyses of the two novel genes. Such a database should serve as a highly valuable resource for the molecular analysis of human development and pathogenesis.

We report on the demonstration of GaN-based ultraviolet light-emitting diodes (UV LEDs) emitting at 375 nm grown on patterned sapphire substrate (PSS) with in-situ low temperature GaN/AlGaN nucleation layers (NLs) and ex-situ sputtered AlN NL. The threading dislocation (TD) densities in GaN-based UV LEDs with GaN/AlGaN/sputtered AlN NLs were determined by high-resolution X-ray diffraction (XRD) and cross-sectional transmission electron microscopy (TEM), which revealed that the TD density in UV LED with AlGaN NL was the highest, whereas that in UV LED with sputtered AlN NL was the lowest. The light output power (LOP) of UV LED with AlGaN NL was 18.2% higher than that of UV LED with GaN NL owing to a decrease in the absorption of 375 nm UV light in the AlGaN NL with a larger bandgap. Using a sputtered AlN NL instead of the AlGaN NL, the LOP of UV LED was further enhanced by 11.3%, which is attributed to reduced TD density in InGaN/AlInGaN active region. In the sputtered AlN thickness range of 10–25 nm, the LOP of UV LED with 15-nm-thick sputtered AlN NL was the highest, revealing that optimum thickness of the sputtered AlN NL is around 15 nm.