Self-Segregation Behavior of <i>N</i>-Ethyl-pentadecafluorooctanamide-Terminated Polybutylene Isophthalate and Its Effects on Film Morphology and Wettability

Polybutylene isophthalates (PBI) end-capped with N-ethyl-pentadecafluorooctanamide were synthesized from dimethyl isophthalate, 1,4-butanediol, and N-(2-hydroxyethyl)-perfluorooctanamide with fluorine monomer content from 0 to 5 mol %. The results demonstrated that there was an obvious gradient drop of fluorine concentration from the film surface down to the inner bulk, and the enriched perfluoroalkyl segments covered the rough disordered crystalline topography of PBI, leading to greatly decreased roughness values of fluorinated films. Moreover, the film with only 3 mol % fluorine monomer content exhibited the surface tension of 16.7 mN/m, even lower than that of polytetrafluoroethylene (18.5 mN/m), indicating that the fluorinated groups not only enriched on the film surface but also tended to orient the CF3 group upward. This study is of significance for further understanding the effects of polymeric structural factors on the migration ability of fluorine in the polymer film

Revealing the Evolution of Hybridized Electronic States with the Coordination Number in Surface-Supported Metal–Organic Frameworks

In metal–organic complexes, the coordination number defines the number of σ-bonds between ligands and the central metal atom and thus plays a vital role in determining the electronic, magnetic, optical, and catalytic properties of metal–organic complexes. Here, by a joint study of low-temperature scanning tunneling microscopy (STM) and density functional theory (DFT) calculations, we have investigated the coordination interaction between Fe atoms and pyridyl ligands with increasing coordination number from 2 to 4 in Fe-4,4′-di­(4-pyridyl)­biphenyl (Fe-DPBP) coordination networks on the Au(111) substrate. The hybridized electronic state located at the central Fe atom and the surrounding pyridyl ligands shifts from 1.04 eV in 2-fold to 1.24 eV in 3-fold and 1.41 eV in 4-fold coordination motifs. The shifting rate, 0.19 eV per pyridyl, gives an experimental estimation of the induced energy shift because of the repulsive potential applied by a pair of ligand electrons in the coordination interaction. Based on DFT calculations, we further reveal the Fe 3d orbitals and N 2p orbitals that participate in the coordination interaction in each motif. Our work provides insights into the correlation between the coordination geometry and electronic coupling at an atomic level

Density and Viscosity Measurements on the Ternary System of <i>exo</i>-Tetrahydrodicyclopentadiene (1) + <i>n</i>‑Decane (2) + Iso-Butanol (3) and Corresponding Binary Systems

exo-Tetrahydrodicyclopentadiene can serve as both the propellant and coolant in hypersonic vehicles. However, its applications are restricted by the poor properties of ignition and combustion to some extent. Fuel additives such as appropriate alcohols have the ability to overcome these deficits. Research on thermophysical properties of the mixtures composed of exo-tetrahydrodicyclopentadiene and fuel additives can provide important information for the research of fuel additives. In this work, densities and viscosities of the ternary system of exo-tetrahydrodicyclopentadiene (1) + n-decane (2) + iso-butanol (3) and three corresponding binary systems have been measured over the whole composition range in the temperature range from 293.15 to 333.15 K with an interval of 5 K and at pressure p = 0.1 MPa. The values of excess molar volumes (VmE) and viscosity deviations (Δη) of three binary systems and the ternary system were calculated and then fitted to the Redlich–Kister equation and four semi-empirical equations, respectively. The variations of VmE and Δη were explained from the viewpoints of intermolecular forces and structural effects. Furthermore, the Jouyban–Acree model was used to correlate the values of densities (ρ) and viscosities (η) of the studied mixtures with high accuracy

Helical Self-Assembly of Poly(para-phenylene) Chains Induced by Fullerenes

Molecular dynamics simulations show that two poly(para-phenylene) (PPP) chains can self-assemble helically to form a regular double-helix structure under the inducement of a fullerene molecule. The cross section of the PPP double helix shows a dumbbell-like shape consisting of two highly strained bulbs on two edges. The contribution of system energy and each energy component to the helical self-assembly is discussed, and the conditions and mechanism are explained. The fullerene diameter, PPP length, temperature, and relative position all have great influence on the helical self-assembly process. The thermal stability of the formed double helix is further tested. Multiple fullerenes, arranged in a string, can easily cause the helical self-assembly of two PPP chains. Three to six PPP chains have a certain probability of forming regular multiple helices under the inducement of fullerenes with an appreciate diameter. This work provides a new idea and theoretical basis for the controllable fabrication of regular helical polymers and related functional nanodevices

High-Efficiency N₂ Electroreduction Enabled by Se-Vacancy-Rich WSe_2–<i>x</i> in Water-in-Salt Electrolytes

Electrocatalytic nitrogen reduction reaction (NRR) is a promising approach for renewable NH3 production, while developing the NRR electrocatalysis systems with both high activity and selectivity remains a significant challenge. Herein, we combine catalyst and electrolyte engineering to achieve a high-efficiency NRR enabled by a Se-vacancy-rich WSe2–x catalyst in water-in-salt electrolyte (WISE). Extensive characterizations, theoretical calculations, and in situ X-ray photoelectron/Raman spectroscopy reveal that WISE ensures suppressed H2 evolution, improved N2 affinity on the catalyst surface, as well as an enhanced π-back-donation ability of active sites, thereby promoting both activity and selectivity for the NRR. As a result, an excellent faradaic efficiency of 62.5% and NH3 yield of 181.3 μg h–1 mg–1 is achieved with WSe2–x in 12 m LiClO4, which is among the highest NRR performances reported to date

Changes in gene transcription and protein expression in CCRF-CEM cells.

CCRF-CEM cells treated with different concentrations of 24-OH-PD (0, 60, 70, and 80 μM) and 70 μM Rh2 for 24 h. (A) The mRNA transcript levels of the Bax, Caspase-3 and Caspase-9 genes. (B) Protein expression levels of Bax, Cytc, Caspase-3 and Caspase-9 (*P < 0.05, **P < 0.01, ***P < 0.001).</p

24-OH-PD inhibits the proliferation of CCRF-CEM in vitro and in vivo.

(A) 24-OH-PD inhibited the viability of CCRF-CEM cells. Cells were treated with different concentrations of 24-OH-PD for 24 h, then measured for cell viability by the CCK-8 assay. Error bars indicate SD. (B) The survival curves of the CCRF-CEM cell-bearing NOD/SCID mouse model in the vehicle control group, 1 mg/kg 24-OH-PD group, and 10 mg/kg 24-OH-PD group (n = 8 per group). (C) HE-stained spleen and liver pathological sections of mice in different treatment groups.</p

Trinitroaromatic Salts as High-Energy-Density Organic Cathode Materials for Li-Ion Batteries

Even though organic molecules with designed structures can be assembled into high-capacity electrode materials, only limited functional groups such as −CO and −CN– could be designed as high-voltage cathode materials with enough high capacity. Here, we propose a common chemical raw material, trinitroaromatic salt, to have promising potential to develop organic cathode materials with high discharge voltage and capacity through a strong delocalization effect between −NO2 and aromatic ring. Our first-principles calculations show that electrochemical reactions of trinitroaromatic potassium salt C6H2(NO2)3OK are a 6-electron charge-transfer process, providing a high discharge capacity of 606 mAh g–1 and two voltage plateaus of 2.40 and 1.97 V. Electronic structure analysis indicates that the discharge process from C6H2(NO2)3OK to C6H2(NO2Li2)3OK stabilizes oxidized [C6]n+ to achieve a stable conjugated structure through electron delocalization from −NO2 to [C6]n+. The ordered layer structure C6H2(NO2)3OK can provide large spatial pore channels for Li-ion transport, achieving a high ion diffusion coefficient of 3.41 × 10–6 cm2 s–1

p‑Block Antimony Single-Atom Catalysts for Nitric Oxide Electroreduction to Ammonia

Electrocatalytic NO reduction to NH3 (NORR) offers a prospective approach to attain both harmful NO removal and efficient NH3 electrosynthesis. Main-group p-block metals are promising NORR candidates but still lack adequate exploration. Herein, p-block Sb single atoms confined in amorphous MoO3 (Sb1/a-MoO3) are designed as an efficient NORR catalyst, exhibiting the highest NH3 yield rate of 273.5 μmol h–1 cm–2 and a NO-to-NH3 Faradaic efficiency of 91.7% at −0.6 V vs RHE. In situ spectroscopic characterizations and theoretical computations reason that the outstanding NORR performance of Sb1/a-MoO3 arises from the isolated Sb1 sites, which can optimize the adsorption of *NO/*NHO to lower the reaction energy barriers and simultaneously exhibit a higher affinity to NO than to H2O/H species. Moreover, our strategy can be extended to prepare Bi1/a-MoO3, showing a high NORR property, demonstrating the immense potential of p-block metal single-atom catalysts toward the high-performing NORR electrocatalysis

Primer sequences used in qRT-PCR.

Ginsenoside 24-hydroxy-ginsengdiol (24-OH-PD), extracted from red ginseng, is a novel diol-type ginsenoside, strongly inhibits the growth of human T-cell acute lymphoblastic leukaemia (T-ALL) CCRF-CEM cells. Our research aimed at investigating the mechanism underlying this inhibition. Cell viability was determined using the cell counting kit-8 (CCK-8) assay, and NOD/SCID mice bearing CCRF-CEM cells were used to verify the therapeutic effect of 24-OH-PD on T-ALL in vivo. We equally analysed pathways related to 24-OH-PD in CCRF-CEM cells using RNA-Seq analysis. Cell apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), and mitochondrial permeability transition pore (mPTP) levels were detected by flow cytometry. The activity of caspase3 and caspase9 was detected by enzyme activity detection kits. The expression levels of apoptosis-related proteins and mRNA were determined through western blotting and quantitative reverse-transcription PCR assays (qRT-PCR). CCK-8 assay and animal xenograft experiments confirmed that 24-OH-PD significantly inhibited T-ALL in a dose-dependent manner, both in vivo and in vitro. RNA-Seq results suggest that mitochondria-mediated apoptosis pathway plays an important role in this process. Furthermore, intracellular ROS levels increased, mPTP opened, and ΔΨm decreased following 24-OH-PD treatment. Pretreatment with the antioxidant, NAC, reversed the effects of 24-OH-PD on apoptosis and ROS generation. Moreover, 24-OH-PD treatment increased the expression of Bax and caspase family members, thereby releasing cytochrome c (Cytc) and inducing apoptosis. Our findings showed that, 24-OH-PD induces apoptosis in CCRF-CEM cells by activating the mitochondrial-dependent apoptosis pathway through ROS accumulation. This inhibitory effect implies that 24-OH-PD could be further developed as treatment of T-ALL.</div