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Abstract To investigate the effects of higher cellular stanniocalcin 2 (STC2) on suppressing the migration and invasion but promoting the apoptosis of triple-negative breast cancer (TNBC). STC2 in TNBC and the para-carcinoma tissues were analyzed by immunohistochemistry (IHC), while the mRNA level was measured by qPCR. Over-expressing or silencing STC2 was established in MDA-MB-231 cells. Epithelial mesenchymal transition (EMT) related proteins, cell migration, invasion, proliferation and apoptosis were detected. MDA-MB-231 with over-expressing or silencing STC2 were injected into nude mice to formatting tumors, and then EMT related proteins were measured by IHC. Lower STC2 expressed in TNBC tissues than in the para-carcinoma tissues. Silencing STC2 promoted EMT of TNBC cell MDA-MB-231, as well as cell migration, invasion and proliferation, but suppressed MDA-MB-231 apoptosis, while over-expressing STC2 had the opposite results, which might be related to PKC/PI3K/AKT/mTOR pathway. STC2 was the protective gene in TNBC, by suppressing migration and invasion to inhibit MDA-MB-231 cell EMT but promote cell apoptosis, in order to suppress TNBC progression.

Y-type zeolites are widely used in the carbon dioxide (CO2) adsorption applications due to their exceptional ion exchange performance and high stability. However, the pelletization of Y powder by adding binders such as kaolin often results in performance drops, which has limited its industrial application. This study employs a zeolite-kaolin blend to produce cylindrical pelletized Y zeolite, in which the kaolin is then transformed to zeolites via hydrothermal crystallization, resulting in binder-free Y pellets. The Design-Expert software and the response surface method (RSM) are employed to optimize the hydrothermal crystallization conditions for binder transformation, with the objective of attaining a maximized capacity for CO2 adsorption. Results demonstrate that optimized synthesis conditions yield cylindrical Y zeolite with a notable CO2 adsorption capacity of 5.52 mmol/g at 298 K and 1 bar, surpassing that of the initial Y powder. The average crushing strength is 110 N per particle (Diameter × Height = 3 mm × 3 mm). The IAST selectivity of CO2/N2 (15/85) is 824 at 298 K and 1 bar. The reaction mechanisms of the binder transformation are also investigated via experiments and DFT simulation. This study presents a simple and reliable method for manufacturing binder free Y zeolite, which is promising for carbon capture applications.

Bone marrow mesenchymal stem cells (BM-MSCs), with the properties of self-renewal and pluripotency, can migrate to the tumor sites and exert complex effects on tumor progression and communications by releasing exosomes. However, to our knowledge, only a few studies have reported the effects of BM-MSCs exosomes on breast cancer cells development. Here, utilizing exosomes isolated from in vitro BM-MSCs, we systematically investigated this issue in a breast cancer cell line. In this study, we found that BM-MSCs exosomes are actively incorporated by breast cancer cell MDA-MB-231 cells and subsequently promote MDA-MB-231 cells proliferation and migration. Mechanistically, we further found Yes-associated protein (YAP) and transcriptional coactivator with PDZ binding motif (TAZ) which are Hippo signaling components were involved in this promoting progress. Consistently, YAP and TAZ knockdown could significantly reverse breast cancer cells proliferation and migration improved by BM-MSCs exosomes. Taken together, our findings demonstrated a new mechanism through which BM-MSCs-derived exosomes may contribute to breast cancer cells proliferation and migration, which might provide an evidence for novel drug discovery based on exosomes and Hippo signaling.

Summary: Peroxymonosulfate (PMS)-based advanced oxidation process (AOP) has attracted great attention as an effective technique for oxidatively decomposing organic pollutants. The PMS activation mechanisms, nevertheless, are still ambiguous in many cases, and, thus, controlling PMS activation pathways for efficient pollutant removal remains challenging. In this work, taking defective PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) as a model system, we demonstrate that oxygen vacancies (Vo••) strongly promote PMS-based AOP, and PMS activation pathways are effectively tuned. Excessive Vo••s are found to modify the surface charge distribution, change PMS adsorption configuration, and break the S–O bond of PMS. As a result, the radical process is promoted, and the predominant nonradical activation pathway shifts from an electron transfer process to singlet oxygen formation. Our mechanistic understanding can guide the rational design of catalysts for efficient water remediation.

Polymers are found near surfaces and interfaces in a wide range of chemical and biological systems, and the structure and dynamics of adsorbed polymer chains have been the subject of intense interest for decades. While polymer structure is often inferred from dynamic measurements in bulk solution, this approach has proven difficult to implement at interfaces, and the understanding of interfacial polymer conformation remains elusive. Here we used single-molecule tracking to study the interfacial diffusion of isolated poly(ethylene glycol) molecules at oil--water interfaces. Compared to diffusion in dilute aqueous solution, which exhibited the expected dependence of the diffusion coefficient (D) upon molecular weight (M) of D ~ M-1/2 for a Gaussian chain, the behavior at the interface was approximately D ~ M-2/3, suggesting a significantly more expanded polymer conformation, despite the fact that the oil was a poor solvent for the polymer. Interestingly, this scaling remained virtually unchanged over a wide range of oil viscosity, despite the fact that at low viscosities the magnitude of the diffusion coefficient was consistent with expectations based on viscous drag (i.e., Stokes--Einstein diffusion), and for high viscosity oil, the interfacial mobility was much faster than expected and consistent with the type of intermittent hopping transport observed at the solidliquid interface. The dependence on molecular weight, in both regimes, was consistent with results from both self-consistent field theory and previous Monte Carlo simulations, suggesting that an adsorbed polymer chain adopted a partially swollen (looptrain-- tail) interfacial conformation. [ABSTRACT FROM AUTHOR]

A modified test-chain self-consistent field theory (SCFT) is presented to study the intra- and intermolecular correlations of linear and branched polymers in various solutions and melts. The key to the test-chain SCFT is to break the the translational symmetry by fixing a monomer at the origin of a coordinate. This theory successfully describes the crossover from self-avoiding walk at short distances to screened random walk at long distances in a semidilute solution or melt. The calculations indicated that branching enhances the swelling of polymers in melts and influences stretching at short distances. The test-chain SCFT calculations show good agreement with experiments and classic polymer theories. We highlight that the theory presented here provides a solution to interpret the polymer conformation and behavior under various conditions within the framework of one theory. [ABSTRACT FROM AUTHOR]

If you mix lines and circles, what happens at the edge of the mixture? The problem is simply stated, but the answer is not obvious. Twenty years ago it was proposed that a universal topological driving force would drive cyclic chains to enrich the surface of blends of linear and cyclic chains. Here such behavior is demonstrated experimentally for sufficiently long chains and the limit in molecular weight where packing effects dominate over the topological driving force is identified. [ABSTRACT FROM AUTHOR]

The contributions of chain ends and branch points to surface segregation of long-branched chains in blends with linear chains have been studied using neutron reflectometry and surface-enhanced Raman spectroscopy for a series of novel, well-defined polystyrenes. A linear response theory accounting for the number and type of branch points and chain ends is consistent with surface excesses and composition profile decay lengths, and allows the first determination of branch point potentials. Surface excess is determined primarily by chain ends with branch points playing a secondary role. [ABSTRACT FROM AUTHOR]