6,306 research outputs found
Quantum Transport and Band Structure Evolution under High Magnetic Field in Few-Layer Tellurene
Quantum Hall effect (QHE) is a macroscopic manifestation of quantized states
which only occurs in confined two-dimensional electron gas (2DEG) systems.
Experimentally, QHE is hosted in high mobility 2DEG with large external
magnetic field at low temperature. Two-dimensional van der Waals materials,
such as graphene and black phosphorus, are considered interesting material
systems to study quantum transport, because it could unveil unique host
material properties due to its easy accessibility of monolayer or few-layer
thin films at 2D quantum limit. Here for the first time, we report direct
observation of QHE in a novel low-dimensional material system:
tellurene.High-quality 2D tellurene thin films were acquired from recently
reported hydrothermal method with high hole mobility of nearly 3,000 cm2/Vs at
low temperatures, which allows the observation of well-developed
Shubnikov-de-Haas (SdH) oscillations and QHE. A four-fold degeneracy of Landau
levels in SdH oscillations and QHE was revealed. Quantum oscillations were
investigated under different gate biases, tilted magnetic fields and various
temperatures, and the results manifest the inherent information of the
electronic structure of Te. Anomalies in both temperature-dependent oscillation
amplitudes and transport characteristics were observed which are ascribed to
the interplay between Zeeman effect and spin-orbit coupling as depicted by the
density functional theory (DFT) calculations
Expression, Purification and Bioactivities Analysis of Recombinant Active Peptide from Shark Liver
The Active Peptide from Shark Liver (APSL) was expressed in E. coli BL21 cells. The cDNA encoding APSL protein was obtained from shark regenerated hepatic tissue by RT-PCR, then it was cloned in the pET-28a expression vector. The expressed fusion protein was purified by Ni-IDA affinity chromatography. SDS-PAGE and HPLC analysis showed the purity of the purified fusion protein was more than 98%. The recombinant APSL (rAPSL) was tested for its biological activity both in vitro, by its ability to improve the proliferation of SMMC7721 cells, and in vivo, by its significant protective effects against acute hepatic injury induced by CCl4 and AAP (acetaminophen) in mice. In addition, the rAPSL could decrease the blood glucose concentration of mice with diabetes mellitus induced by alloxan. Paraffin sections of mouse pancreas tissues showed that rAPSL (3 mg/kg) could effectively protect mouse islets from lesions induced by alloxan, which indicated its potential application in theoretical research and industry
Sox10+ adult stem cells contribute to biomaterial encapsulation and microvascularization.
Implanted biomaterials and biomedical devices generally induce foreign body reaction and end up with encapsulation by a dense avascular fibrous layer enriched in extracellular matrix. Fibroblasts/myofibroblasts are thought to be the major cell type involved in encapsulation, but it is unclear whether and how stem cells contribute to this process. Here we show, for the first time, that Sox10+ adult stem cells contribute to both encapsulation and microvessel formation. Sox10+ adult stem cells were found sparsely in the stroma of subcutaneous loose connective tissues. Upon subcutaneous biomaterial implantation, Sox10+ stem cells were activated and recruited to the biomaterial scaffold, and differentiated into fibroblasts and then myofibroblasts. This differentiation process from Sox10+ stem cells to myofibroblasts could be recapitulated in vitro. On the other hand, Sox10+ stem cells could differentiate into perivascular cells to stabilize newly formed microvessels. Sox10+ stem cells and endothelial cells in three-dimensional co-culture self-assembled into microvessels, and platelet-derived growth factor had chemotactic effect on Sox10+ stem cells. Transplanted Sox10+ stem cells differentiated into smooth muscle cells to stabilize functional microvessels. These findings demonstrate the critical role of adult stem cells in tissue remodeling and unravel the complexity of stem cell fate determination
(6aS,11aR,11cS)-8-Sulfanylidene-2,3,5,6,6a,7,11,11a,11b,11c-decahydro-3a,7a-diaza-1H,4H-benzo[de]anthracen-3a-ium chloride hemihydrate
The title compound, C15H23N2S+·Cl−·0.5H2O, was prepared from (6aS,11aR,11cS)-2,3,5,6,6a,7,11,11a,11b,11c-decahydro-3a,7a-diaza-1H,4H-benzo[de]anthracene-8-one (sophocarpine) and Lawesson’s reagent. The thione-substituted ring is in an envelope conformation and the three other six-membered rings are in chair conformations. In the crystal, anions and cations are linked by N—H⋯Cl and weak C—H⋯Cl hydrogen bonds. One 0.5-occupancy solvent water molecule lies on a twofold rotation axis and another 0.25-occupancy solvent water molecule is in a general position. The H atoms of these water molecules were not located or included in the refinement
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