Screening and Degradation Characteristics of a Fumonisin B1-Degrading Fungal Strain

A fungal strain capable of degrading fumonisin B1 (FB1) from ground maize samples heavily contaminated with fumonisin was obtained by enrichment culture method. The strain was named as FDS-2, and was characterized for its growth and degradation characteristics, and the initial degradation pathway of FB1 by FDS-2 was investigated. The strain was identified as Exophiala spinifera according to its culture characteristics, microscopic characteristics and phylogenetic tree based on RNA-internal transcribed spacer (ITS) sequence characteristics. The optimum growth and degradation conditions were 30 ℃ and pH 5.0. Under these conditions, the strain could completely degrade 250 μg of FB1 within 48 h. Intracellular FB1-degrading enzymes were discovered in this strain. Using liquid chromatography-mass spectrometry (LC-MS) to analyze the degradation products, it was determined that the primary degradation pathway began with the degradation of FB1 into hydrolyzed FB1. This study provides a strain resource and a theoretical basis for the biodegradation of fumonisin in grain and feed

Over-Expression of PDGFR-β Promotes PDGF-Induced Proliferation, Migration, and Angiogenesis of EPCs through PI3K/Akt Signaling Pathway

The proliferation, migration, and angiogenesis of endothelial progenitor cells (EPCs) play critical roles in postnatal neovascularization and re-endothelialization following vascular injury. Here we evaluated whether the over-expression of platelet-derived growth factor receptor-β (PDGFR-β) can enhance the PDGF-BB-stimulated biological functions of EPCs through the PDGFR-β/phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. We first confirmed the expression of endogenous PDGFR-β and its plasma membrane localization in spleen-derived EPCs. We then demonstrated that the PDGFR-β over-expression in EPCs enhanced the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. Using AG1295 (a PDGFR kinase inhibitor), LY294002 (a PI3K inhibitor), and sc-221226 (an Akt inhibitor), we further showed that the PI3K/Akt signaling pathway participates in the PDGF-BB-induced proliferation, migration, and angiogenesis of EPCs. In addition, the PI3K/Akt signaling pathway is required for PDGFR-β over-expression to enhance these PDGF-BB-induced phenotypes

Recent Progress in Chemical Syntheses of Sphingosines and Phytosphingosines

International audienceSphingolipids and their derivatives such as glycosphingolipids and sphingomyelins exist ubiquitously in biomembrane of all eukaryotic cells, which play pivotal roles in cell proliferation, recognition, adhesion, and signal transduction. Sphingosine is shown to be the important lipid moiety in the large majority of glycosphingolipids and sphingomyelins, while phytosphingosine is one of the major long-chain moieties of glycosphingo-lipids. Due to the significance of the two bioactive lipids, tremendous efforts have been made to synthesize sphingosine or phytosphingosine using chiral pool approaches, chiral auxiliary and asymmetric reactions to construct the continuous stereogenic centers in them. This review covers the synthetic literatures published in the year after 2000

An Immersive Human-Robot Interactive Game Framework Based on Deep Learning for Children’s Concentration Training

In order to alleviate bottlenecks such as the lack of professional teachers, inattention during training processes, and low effectiveness in concentration training, we have proposed an immersive human–robot interactive (HRI) game framework based on deep learning for children’s concentration training and demonstrated its use through human–robot interactive games based on gesture recognition. The HRI game framework includes four functional modules: video data acquisition, image recognition modeling, a deep learning algorithm (YOLOv5), and information feedback. First, we built a gesture recognition model containing 10,000 pictures of children’s gestures, using the YOLOv5 algorithm. The average accuracy in recognition trainingwas 98.7%. Second, we recruited 120 children with attention deficits (aged from 9 to 12 years) to play the HRI games, including 60 girls and 60 boys. In the HRI game experiment, we obtained 8640 sample data, which were normalized and processed.According to the results, we found that the girls had better visual short-term memory and a shorter response time than boys. The research results showed that HRI games had a high efficacy, convenience, and full freedom, making them appropriate for children’s concentration training

Chiron Approaches to the Antitumor Natural Product Fuzanin D

International audienceFuzanin D, a pyridine-containing natural product, which exhibits cytotoxic activity against DLD-1 cells, is synthesized in a concise manner using l-arabinose or ethyl l-lactate as chiral pool substrates in nine steps (14.4% overall yield) and six steps (30.8% overall yield), respectively. The key steps involve Wittig olefination and olefin cross-­metathesis

Thieno[3,4‑<i>c</i>]pyrrole-4,6-dione Containing Copolymers for High Performance Field-Effect Transistors

Thieno­[3,4-<i>c</i>]­pyrrole-4,6-dione (TPD) containing copolymer semiconductors <b>P1–P3</b> were strategically designed and successfully synthesized. Their physicochemical properties were thoroughly investigated. All polymers exhibited good solution processability and high humidity stability in thin film transistors (TFTs). Transistor electrical characterization showed the device performance was sensitive to the alkyl chain substituent orientations of the polymers. A maximum TFT hole mobility of ∼1.29 cm²/(V s) was observed for <b>P3</b>-based devices, a recorded mobility for TPD containing polymer semiconductors reported to date. The corresponding thin-film morphologies and polymer chains packing were investigated in detail by AFM and 2D-GIXD to correlate with the alkyl orientation-dependent carrier mobility of <b>P1–P3</b>. Experimental results showed the alkyl chain orientations determined the polymer chains packing pattern in the thin films, the film morphologies, and the resulting device performances of <b>P1–P3</b>