Research on the Hot Deformation Process of A100 Steel Based on High-Temperature Rheological Behavior and Microstructure.

To obtain the optimal hot deformation process, the rheological and dynamic recrystallization behaviors of A100 steel were researched through isothermal compression tests. Firstly, a Hensel-Spittel constitutive model was established based on the stress-strain curves. Secondly, dynamic recrystallization percentage and grain size models were established to identify the necessary conditions for complete dynamic recrystallization. Finally, microstructural analysis was employed to validate the accuracy of the recrystallization model. The results indicate that the flow stress is highly sensitive to both the strain rate and the temperature, and the HS model demonstrates a high predictive accuracy, with a correlation coefficient of 0.9914. There exists a contradictory relationship between decreasing the average grain size and increasing the recrystallization percentage. The higher the percentage of dynamic recrystallization, the larger the average grain size tends to be. This situation should be avoided when devising the actual processing procedures. The optimal hot working processes for achieving complete dynamic recrystallization and a smaller average grain size are as follows: a strain equal to or greater than 0.6, a temperature between 1193 and 1353 K, and a strain rate between 0.1 and 1 s-1.

High-Performance Ternary Organic Solar Cells Enabled by Introducing a New A-DA'D-A Guest Acceptor with Higher-Lying LUMO Level.

A ternary strategy is viable to minimize the trade-off between short-circuit current density (Jsc) and open-circuit voltage (Voc) in organic solar cells. Generally, the ternary OSCs can achieve a higher PCE than the binary counterparts by subtly utilizing the particular photoelectric properties of the third material. In this regard, we choose BTP-CC with a higher-lying LUMO level based on a fused TPBT (dithienothiophen[3.2-b]-pyrrolobenzothiadiazole) central framework and CC (2-(6-oxo-5,6-dihydro-4H-cyclopenta [b]thiophen-4-ylidene) malononitrile) flanking groups as the third component to broaden the light-absorption spectrum, regulate the bulk heterojunction (BHJ) morphology, improve the Voc, and reduce the charge recombination in OSCs. In addition, BTP-CC demonstrates intense intermolecular energy transfer to Y6 by fluorescence resonance energy transfer (FRET) pathway, which is due to the photoluminescence (PL) spectrum of BTP-CC covering the absorption region of Y6. The PM6:Y6:BTP-CC based ternary OSC achieves a champion PCE of 17.55%. Further investigation indicates that introduction of BTP-CC could reduce the trap states in OSCs, leading to an increased charge carrier density. Moreover, the incorporation of BTP-CC could improve the device stability. These results demonstrated that BTP-CC is important in improving the photovoltaic performance of ternary OSCs, and this work also provides a guideline for constructing ideal ternary OSCs in the future.

Asymmetric Non-Fullerene Small-Molecule Acceptors toward High-Performance Organic Solar Cells.

Applying an asymmetric strategy to construct non-fullerene small-molecule acceptors (NFSMAs) in organic solar cells (OSCs) plays a vital role in the development of organic photovoltaic materials. In the past several years, taking advantage of the larger dipole moment and stronger intermolecular interactions, asymmetric NFSMAs have witnessed tremendous progress in OSCs with a power conversion efficiency of over 18%. From a structural point of view, besides the possible changes in the conformation effect on molecular packing, asymmetric acceptors can also achieve a balance between the solubility and the crystallinity. Herein, we systematically investigate the structure-property-performance relationships of asymmetric NFSMAs that have recently emerged and try to clarify the feasibility and practicality of an asymmetric strategy for the design of higher-performance NFSMAs. Finally, we put forward our views and a concise outlook on the asymmetric strategy.

EBP50 phosphorylation by Cdc2/Cyclin B kinase affects actin cytoskeleton reorganization and regulates functions of human breast cancer cell line MDA-MB-231.

The actin cytoskeleton plays an important role in cell shape determination, adhesion and cell cycle progression. Ezrinradixin-moesin (ERM)-binding phosphoprotein 50 (EBP50), also known as Na(+)-H(+) exchanger regulatory factor 1 (NHERF1), associates with actin cytoskeleton and is related to cell cycle progression. Its Ser279 and Ser301 residues are phosphorylated by cyclin-dependent kinase 2 (cdc2)/cyclin B during the mitosis phase. However, the biological significance of EBP50 phosphorylation mediated by cdc2/cyclin B is not clear. In the present study, MDA-MB-231 cells with low levels of endogenous EBP50 protein were stably transfected with constructs of EBP50 wild type (WT), phosphodeficient (serine 279 and serine 301 mutated to alanine-S279A/S301A) or phospho-mimetic (serine 279 and serine 301 mutated to aspartic acid-S279D/S301D) mutants. Subsequently, multiple phenotypes of these cells were characterized. Failure of cdc2/cyclin B-mediated EBP50 phosphorylation in cells expressing S279A/S301A (AA cells) significantly increased F-actin content, enhanced the adherence of cells to the extracellular matrix, altered cell morphology and caused defects in cytokinesis, as reflected in the formation of giant cells with heteroploid DNA and multinucleation or giant nuclei. Furthermore, knockdown of EBP50 expression in AA cells rescued cell defects such as the cytokinesis failure and abnormal cell morphology. EBP50 S279A/ S301A had a weaker binding affinity with actin than EBP50 S279D/S301D, which might explain the increase of F-actin content in the AA cells. The present results suggest that cdc2/cyclin B-mediated EBP50 phosphorylation may play a role in the regulation of various cell functions by affecting actin cytoskeleton reorganization.

Beta-2 adrenergic receptor mediated ERK activation is regulated by interaction with MAGI-3.

The beta-2 adrenergic receptor (beta2AR) has a carboxyl terminus motif that can interact with PSD-95/discs-large/ZO1 homology (PDZ) domain-containing proteins. In this paper, we identified membrane-associated guanylate kinase inverted-3 (MAGI-3) as a novel binding partner of beta2AR. The carboxyl terminus of beta2AR binds with high affinity to the fifth PDZ domain of MAGI-3, with the last four amino acids (D-S-L-L) of the receptor being the key determinants of the interaction. In cells, the association of full-length beta2AR with MAGI-3 occurs constitutively and is enhanced by agonist stimulation of the receptor. Our data also demonstrated that beta2AR-stimulated extracellular signal-regulated kinase-1/2 (ERK1/2) activation was substantially retarded by MAGI-3 expression. These data suggest that MAGI-3 regulates beta2AR-mediated ERK activation through the physical interaction between beta2AR and MAGI-3.