Phase shifter (PS) is a key component of a phased array antenna (PAA) system, which controls the microwave phase and realizes the antenna beam forming and scanning. A ferrite PS (FPS) is a current-controlled PS that uses the ferrite's gyromagnetic properties to realize phase shifting. It has the advantages of short phase switching time, low microwave loss, and high reliability and, therefore, has been widely used in low-power PAA systems.
View Article and Find Full Text PDFUPLC-Q-TOF-MS combined with mass defect filtering strategies were applied for the phytochemical investigation of Harrisonia perforata, leading to the isolation of thirteen undescribed limonoids named haperforatones A-M (1-13) and seventeen known compounds (14-30). Particularly, haperforatones D-E (4-5) have an unprecedented A, B, C, D-seco-6, 7-nor-C-24-limonoid skeleton, structurally stripped of the five-membered lactone ring B and formed a double bond at the C-5 and C-10 positions. Their 2D structures and relative configurations were identified using spectroscopic data.
View Article and Find Full Text PDFEight previously undescribed sesquiterpene lactones (1-8), together with six known ones (9-14) were isolated from the aerial parts of Tithonia diversifolia (Hemsl.) A. Gray.
View Article and Find Full Text PDFPCSK9 has been recognized as an efficient target for hyperlipidemia and related cardiovascular/cerebrovascular diseases. However, PCSK9 inhibitors in the clinic are all biological products, and no small molecules are available yet. In the current work, we discovered that the crude extract of () promoted LDL uptake and then obtained 8 new and 12 known jatrophane diterpenoids by activity-guided isolation.
View Article and Find Full Text PDFFour undescribed amide alkaloids hongkongensines A-C and 1-(1-oxo-6-hydroxy-2E,4E-dodecadienyl)-piperidine, five known amide alkaloids, and three known neolignans were isolated from the aerial part of Piper hongkongense. The planar structures of these compounds were determined by detailed analyses of HR-ESI-MS and NMR data. The absolute configurations of hongkongensines A-C were elucidated by single-crystal X-ray diffraction analysis and ECD calculations.
View Article and Find Full Text PDFThe phytochemical investigation of the aerial parts of Isodon japonica var. glaucocalyx afforded four undescribed (glaucocalyxin O-R, 1-4) and six known ent-kauranoids (5-10). Their structures were established using NMR and MS measurements.
View Article and Find Full Text PDFUPLC-TOF-MS/MDF directed phytochemical research of Chloranthus japonicus led to the isolation of 46 lindenane sesquiterpenoid dimers, which included 13 new analogs. Their structures with absolute configurations were elucidated by analysis of spectroscopic data. Fourteen compounds with ester chains significantly decreased PCSK9 protein level in medium of HepG2 cells, especially for compounds 14 and 29 (5 µM) with inhibition rates of 69.
View Article and Find Full Text PDFParticle accelerators that use electromagnetic fields to increase a charged particle's energy have greatly advanced the development of science and industry since invention. However, the enormous cost and size of conventional radio-frequency accelerators have limited their accessibility. Here, we demonstrate a miniaccelerator powered by terahertz pulses with wavelengths 100 times shorter than radio-frequency pulses.
View Article and Find Full Text PDFTo achieve the application of a periodic permanent magnet in high power microwave, a compact coaxial cusped periodic permanent magnet (CPPM) focusing system is constructed. The system consists of permanent magnets with different magnetization directions and soft magnets. Taking the required magnetic field performance and the effect of demagnetization into account, NdFeB and FeCoV are selected as the permanent and soft magnet materials.
View Article and Find Full Text PDFBone tissue engineering is the most promising technology for enhancing bone regeneration. Scaffolds loaded with osteogenic factors improve the therapeutic effect. In this study, the bioactive PEI (polyethylenimine)/pBMP2- (bone morphogenetic protein-2 plasmid-) PLGA (poly(D, L-lactic-co-glycolic acid)) core-shell scaffolds were prepared using coaxial electrospinning for a controlled gene delivery to hPDLSCs (human periodontal ligament stem cells).
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