A DFT study of Ti3C2O2 MXenes quantum dots supported on single layer graphene: Electronic structure and hydrogen evolution performance

Heterojunction structure has been extensively employed for the design of novel catalysts. In the present study, density functional theory was utilized to investigate the electronic structure and hydrogen evolution performance of Ti₃C₂O₂ MXene quantum dots/graphene (QDs/G) heterostructure. Results show that a slight distortion can be observed in graphene after hybriding with QDs, due to which the electronic structure of QDs have been changed. Associated with such QDs-graphene interaction, the catalytic activity of Ti₃C₂O₂ QDs has been optimized, leading to excellent HER catalytic performance.     

Efficient and Robust Hydrogen Evolution: Phosphorus Nitride Imide Nanotubes as Supports for Anchoring Single Ruthenium Sites

Amorphous phosphorus nitride imide nanotubes (HPN) are reported as a novel substrate to stabilize materials containing single‐metal sites. Abundant dangling unsaturated P vacancies play a role in stabilization. Ruthenium single atoms (SAs) are successfully anchored by strong coordination interactions between the d orbitals of Ru and the lone pair electrons of N located in the HPN matrix. The atomic dispersion of Ru atoms can be distinguished by X‐ray absorption fine structure measurements and spherical aberration correction electron microscopy. Importantly, Ru SAs@PN is an excellent electrocatalyst for the hydrogen evolution reaction (HER) in 0.5 m H₂SO₄, delivering a low overpotential of 24 mV at 10 mA cm^?2 and a Tafel slope of 38 mV dec^?1. The catalyst exhibits robust stability in a constant current test at a large current density of 162 mA cm^?2 for more than 24 hours, and is operative for 5000 cycles in a cyclic voltammetry test. Additionally, Ru SAs@PN presents a turnover frequency (TOF) of 1.67 H₂ s^?1 at 25 mV, and 4.29 H₂ s^?1 at 50 mV, in 0.5 m H₂SO₄ solution, outperforming most of the reported hydrogen evolution catalysts. Density functional theory (DFT) calculations further demonstrate that the Gibbs free energy of adsorbed H* over the Ru SAs on PN is much closer to zero compared with the Ru/C and Ru SAs supported on carbon and C₃N₄, thus considerably facilitating the overall HER performance.     

Aptamer based fluorescent probe for serum HER2-ECD detection: The clinical utility in breast cancer

HB5 aptamer-based probe has been developed for serum HER2-ECD test in auxiliary clinical diagnosis and treatment for HER2-positive breast cancer patients.     

Rutin induces endoplasmic reticulum stress-associated apoptosis in human triple-negative breast carcinoma MDA-MB-231 cells – In vitro and in silico docking studies

Rutin is a bioactive compound that possesses anti-tumor activities through triggering apoptosis. Triple-negative breast cancer (TNBC) is insensitive to targeted anti-tumoral drugs, and drug resistance in TNBC poses a challenge for a successful cure. The accumulation of misfolded proteins in the lumen of the endoplasmic reticulum (ER) results in cellular stress that initiates a specialized response designated as the unfolded protein response. This study aimed to find potential ER stress targets in triple-negative breast cancer. The viability of cells was evaluated using an MTT assay. Cell migration and proliferation were done by wound scratch and colony formation assay. Cell cycle detection, measurement of ER stress, mitochondrial membrane potential disruption, and cell death identification was performed using flow cytometry. The interaction of rutin with ER stress proteins is predicted using in silico docking. The pattern of gene expression was determined by qRT-PCR. The elevated rate of cell viability, cell cycle arrest, ER stress, MMP, and apoptotic induction was observed in combination treatment. Rutin exhibited the highest glide score with ASK1 and JNK. The results of qRT-PCR showed that rutin induced apoptosis through upregulation of ASK1 and JNK. The present study provides strong evidence supporting an important role of the ER stress response in mediating rutin-induced apoptosis in triple-negative breast cancer.     

Syntheses and Functional Studies of Self‐Adjuvanting Anti‐HER2 Cancer Vaccines

The 9‐mer peptide MFCH401 (N: 165–173: DTILWKDIF), which is located in the extracellular domain of HER2, has been predicted to be a novel epitope. Self‐adjuvanting anti‐HER2 vaccine constructs were designed and synthesized via covalently attaching MFCH401 or its linear tandem repeats (2×MFCH401, 3×MFCH401) to a lipopeptide Pam₃CSK₄ via iterative condensation reaction. The in vivo results showed the Pam₃CSK₄‐MFCH401 vaccine construct can induce higher antibody titers of IgG and IgM than those of other conjugates, and the analysis of changes in plasma cytokines level indicate the activation of Th1 cells and NK cells. In addition, the Pam₃CSK₄‐MFCH401 vaccine conjugate induced a specific immune response to HER2‐overexpressing human BT474 cells. Our data clearly indicated that MFCH401 is a promising epitope; moreover, its linear tandem repeats were unsuitable for anticancer vaccine design when conjugating with Pam₃CSK₄, which provided useful evidence for developing further anti‐HER2 cancer vaccines.     

Activating MoS2 basal planes for hydrogen evolution through the As doping and strain

As a non-precious catalyst for the electrochemical hydrogen evolution reaction (HER), the two-dimensional MoS₂ has been widely studied. To activate the MoS₂ inert basal plane to enable optimal activity, high defect concentration of sulfur vacancies is needed. Herein, based on the first-principles calculations we demonstrate that the HER of MoS₂ can be greatly enhanced by As doping and biaxial strain. We show that the As-doping sites are new catalytic sites and the bonding of H can be greatly enhanced. Moreover, the relative hydrogen adsorption free energy ($\mathrm{\Delta }\mathrm{\Delta }{\mathrm{G}}_{\mathrm{H}}$) can be further manipulated by the strain effect, which efficiently adjusts the catalytic activity. With the synergy of the biaxial strain (2%–3%) and the uniform doping of the As atoms (3.125% concentration), the $\mathrm{\Delta }\mathrm{\Delta }{\mathrm{G}}_{\mathrm{H}}$ can be modulated to zero. Our findings provide a way to achieve the high intrinsic HER activity among molybdenum-sulfide-based catalysts.     

一种水飞蓟宾恶唑衍生物的合成及体外抗肿瘤活性研究

水飞蓟宾多作为保肝药使用,近年来因其在抗肿瘤方面显示的良好潜力而备受关注。为提高水飞蓟宾的抗肿瘤活性,以天然产物水飞蓟宾为先导化合物,合成一系列水飞蓟宾衍生物,其化学结构经1H NMR、13C NMR、MS确证。采用MTT法测试目标化合物对人乳腺癌细胞(MCF-7)和人胃癌细胞(SGC-7901)的体外抗肿瘤活性;并运用分子对接的方法分析目标化合物与HER2靶点的作用方式。结果表明,目标化合物对两种癌细胞的抑制率均优于水飞蓟宾,其中衍生物Ⅱ3和Ⅱ9与阳性对照药拉帕替尼和阿法替尼抑制作用相当,衍生物Ⅱ3和Ⅱ9能与HER2靶蛋白周围的氨基酸残基通过氢键紧密结合。本研究可为新型抗肿瘤药物的研发提供参考。     

A modified damage model for advanced high strength steel sheets

More often than not, better formability in the simple tension test implies better formability performance in other stretching modes, especially in hole expansion performance since deformation in the hole expansion test is perceived to be in the same simple tension deformation mode. However, when the hole expansion formability is evaluated particularly for the twinning induced plasticity (TWIP) steel, its performance is so poor compared to other automotive steels, even though the TWIP steel has significantly superior formability in the simple tension test. Therefore, hole expansion formability was experimentally and numerically studied for advanced high-strength grade steel sheets, TWIP940 and a transformation induced plasticity (TRIP) 590 steel sheet, as well as a high-strength grade 340R steel sheet, particularly in conjunction with formability in the simple tension test and its surface condition sensitivity. In order to characterize mechanical properties, simple tension tests were performed to determine anisotropic properties and strain rate sensitivities. To account for macro-crack formation, an inverse calibration method based on a damage model utilizing a triaxiality-dependent fracture criterion and hardening behavior with stiffness deterioration was developed. In this approach, the damage model was inversely calibrated by performing numerical simulations and experiments for the simple tension test (with specimens prepared by milling and punching). Then, the damage model was applied to formability study in the hole expansion test. The damage model along with the anisotropic yield function Hill (1948) incorporated into the ABAQUS/Explicit FEM code performed well to predict hole expansion ratios (HER) and their surface condition sensitivity, elucidating the cause of the lukewarm hole expansion performance and strong surface condition sensitivity of the TWIP steel compared to the others.