Corcorancooke0109

In this work, the characterization of release events from liposomes has been addressed quantitatively by an electrochemiluminescence (ECL) imaging strategy. First, ECL reagents ([Ru(bpy)3]2+ and tripropylamine) were encapsulated in sealed giant asymmetrical liposomes (100 μm in diameter) made of DOPG/DOPC phospholipids. After sedimentation on an indium tin oxide electrode material, the opening of liposomes was triggered by polarization of the surface. Under these conditions, amperometry, epifluorescence imaging, and ECL imaging were combined and synchronized to monitor and image the rupture of giant liposomes during the release and subsequent ECL emission of their redox content. Amperometry allowed the quantification of the content released from single liposomes. The location and status of liposomes (closed or opened) were assessed by epifluorescence imaging. ECL provided the image of the efflux of matter after liposome opening. This original ECL imaging approach favorably compares with strictly photoluminescent or electrochemical techniques and appears to be adapted for the investigation of membrane rupture/permeation events.In this work, peptides selected from a microarray were found to inhibit β-gal with promiscuous mechanisms. Peptides inhibited the enzyme in a noncompetitive kinetics, and the inhibition of enzyme activities was reduced under high enzyme concentrations and the addition of detergent. Dynamic light scattering and atomic force microscope revealed that peptide/enzyme aggregation was related to inhibited enzyme activities. Positively charged residues of arginine and lysine were critical for the enzyme inhibition. The preincubation of peptide inhibitors with negatively charged biopolymers of polyphosphates, ssDNA, and low pI peptides could increase the residual activity of peptide-inhibited enzyme, possibly due to the disruption of the electrostatic interaction between positively charged peptide residues and the β-gal surface. Further, negative biopolymers were able to recover the activity of the aggregated peptide/β-gal complex. Negatively charged biopolymers could be used in high-throughput screening assays to reduce peptides/protein aggregation and thereby minimize promiscuous inhibitions.Heterogeneous chemistry on the surfaces of atmospheric particles has a wide impact on the properties and composition of the Earth's atmosphere. In laboratory studies, clusters can represent proxies to atmospheric aerosols and help to discern the individual steps in reactions on or in aerosols. click here We investigate the reactivity of Cl and CCl3 radicals with methane on argon clusters using the pickup method. For radical generation, we built a new pyrolysis source partially adapting the design of radical sources that utilize the supersonic expansion into a heated silicon carbide tube. Large ArN, N̅ ≈ 110, clusters were generated in a supersonic expansion, and CH4 molecules were embedded in the clusters via a pickup process followed by the uptake of the radicals produced in the pyrolysis source. The analysis of the mass spectra recorded under different experimental conditions (i.e., with the pyrolysis ON and OFF and with only one or both reactants) allowed us to identify various products of the radical reactions on ArN. We propose a sequence of reactions based on the reaction energetics. It starts with the hydrogen abstraction from CH4 by a Cl radical resulting in HCl and CH3 followed by a halogenation step where CCl4 molecules react with the available CH3 radicals, yielding CH3Cl. By analogy, the CH3Cl enters another hydrogen abstraction by Cl, producing HCl and the CH2Cl radical, which again undergoes a halogenation step with CCl4, generating CH2Cl2. Further reaction of CH2Cl2 with Cl terminates the sequence by the production of HCl and CHCl2.Although graphene has been regarded as the most ideal anticorrosion filler, to date, some vital problems including poor dispersion, disordered arrangement, structure defects, and galvanic corrosion remain unresolved,, thus blocking its potential application in metal protection. In this work, a bio-inspried multilayered graphene-epoxy composite coating was fabricated through a scalable spraying approach with well-dispersed low-defect engineered graphene as the functional filler. Polydopamine served as an enforcer to improve the dispersity and repair the structure defects of graphene (π-π interaction) and bridged the dense graphene layers and epoxy layers (strong adhesion) for forming "interlock" structures to ensure complete coating systems. Electrochemical tests confirmed that the bio-inspired composite coating showed elevated coating resistance from 4.2 × 106 Ω cm2 for blank coating and 2.5 × 108 Ω cm2 for blending composite coating to 3.0 × 109 Ω cm2. The highly anisotropic graphene layers endowed the bio-inspried coating with highly anisotropic thermal and electrical conductivities, with the in-plane and through-plane thermal conductivities being 0.78 and 0.21 W/mK, respectively. Besides, the good anisotropic conductivities make the bio-inspired coating achieve self-monitoring of structural safety and health. This bio-inspired strategy provides a fascinating method for constructing high-performance graphene composite coatings with functional properties.Organic electrode materials have shown potential for rechargeable batteries because they are environmentally friendly, earth-abundant sources, recyclable, high sustainable, designable, flexible, and lightweight. However, low electrical conductivity and dissolution in organic liquid electrolytes hinder their further development. Herein, MXene/organics heterostructures are designed to address the problems of organic electrodes via a scalable and simple electrostatic self-assembly strategy. Under the effect of the electrostatic interaction, organic cathode material, 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), is tightly attached to MXene nanosheets. Owing to the high electronic conductivity and special two-dimensional (2D) structure of MXene nanosheets, the issues of PTCDA cathode are effectively relieved. When applied in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), the MXene@PTCDA heterostructure exhibits significantly enhanced rate capability and cycling performance than bare PTCDA. The heterostructures proposed here can be applied to other (K, Zn, Al, Mg, Ca, etc.) battery systems. In addition to energy storage and conversion, the heterostructures can be also extended to many fields such as catalysis, sensors, electronics, optics, membranes, semiconductors, biomedicines, etc.Thermally activated delayed fluorescence (TADF) relies on a small energy gap between the emissive singlet and the nonemissive triplet state, obtained by reducing the wave function overlap between donor and acceptor moieties. Efficient emission, however, requires maintaining a good oscillator strength, which is itself based on sufficient overlap of the wave functions between donor and acceptor moieties. We demonstrate an approach to subtly fine-tune the required wave function overlap by employing donor dendrons of changing functionality. We use a carbazolyl-phthalonitrile based donor-acceptor core (2CzPN) as a reference emitter and progressively localize the hole density through substitution at the 3,6-positions of the carbazole donors (Cz) with further carbazole, (4-tert-butylphenyl)amine (tBuDPA), and phenoxazine (PXZ). Using detailed photoluminescence studies, complemented with density functional theory (DFT) calculations, we show that this approach permits a gradual decrease of the singlet-triplet gap, ΔEST, from 300 to around 10 meV in toluene, yet we also demonstrate why a small ΔEST alone is not enough. While sufficient oscillator strength is maintained with the Cz- and tBuDPA-based donor dendrons, this is not the case for the PXZ-based donor dendron, where the wave function overlap is reduced too strongly. Overall, we find the donor dendron extension approach allows successful fine-tuning of the emitter photoluminescence properties.The application of an exogenous polymer matrix to construct aggregation-induced emission (AIE) nanoprobes promotes the utility of AIE luminogens (AIEgens) in diagnosing brain diseases. However, the limited fluorescence (FL) and low active-targeting abilities of AIE-based nanoprobes impede their imaging application. Here, we employed endogenous albumin as an effective matrix to encapsulate AIEgens to enhance FL quantum yield (QY) and active-targeting ability. The albumin-consolidated strategy effectively inhibited the intramolecular vibration of AIEgens and enhanced endocytosis mediated by the gp60 receptor. The QYs of three kinds of albumin-based AIE nanoprobes with FL emissions ranging from the visible (400-650 nm) to the second near-infrared (NIR-II, 1000-1700 nm) region was at least 10% higher, and the tumor-targeting efficiency was ∼25% higher, compared with those of nanoprobes constructed by the exogenous polymer. Albumin-based AIE nanoprobes have achieved active-targeting NIR-II imaging of brain tumors and cerebrovascular imaging with a high signal-to-background ratio (SBR, ∼90) and high resolution (∼70 μm) in mouse models. Therefore, the albumin-based AIE nanoprobes will enable FL imaging-guided surgery of brain tumors and cerebral ischemia, which will improve surgical efficacy to prevent recurrence and side effects.Sinapic acid is found in many edible plants and fruits, such as rapeseed, where it is the predominant phenolic compound. New sinapic acid phenethyl ester (SAPE) analogues were synthesized and screened as inhibitors of the biosynthesis of 5-lipoxygenase (5-LO) in stimulated HEK293 cells and polymorphonuclear leukocytes (PMNL). Inhibition of leukotriene biosynthesis catalyzed by 5-LO is a validated therapeutic strategy against certain inflammatory diseases and allergies. Unfortunately, the only inhibitor approved to date has limited clinical use because of its poor pharmacokinetic profile and liver toxicity. With the new analogues synthesized in this study, the role of the phenolic moiety, ester function, and bioisosterism was investigated. Several of the 34 compounds inhibited the biosynthesis of 5-LO products, and 20 compounds were 2-11 times more potent than zileuton in PMNL, which are important producers of 5-LO products. Compounds 5i (IC50 0.20 μM), 5l (IC50 0.20 μM), and 5o (IC50 0.21 μM) bearing 4-trifluoromethyl, methyl, or methoxy substituent at meta-position of the phenethyl moiety were 1.5 and 11.5 times more potent than SAPE (IC50 0.30 μM) and zileuton (IC50 2.31 μM), respectively. Additionally, compound 9 (IC50 0.27 μM), which was obtained after acetylation of the 4-hydroxyl of SAPE, was equivalent to SAPE and 8 times more active than zileuton. Furthermore, compound 20b (IC50 0.27 μM) obtained after the bioisosteric replacement of the ester function of SAPE by the 1,2,4-oxadiazole heterocycle was equivalent to SAPE and 8 times more active than zileuton. Thus, this study provides a basis for the rational design of new molecules that could be developed further as anti 5-LO therapeutics.Equiatomic and chemically ordered FeRh and MnRh compounds feature a first-order metamagnetic phase transition between antiferromagnetic and ferromagnetic order in the vicinity of room temperature, exhibiting interconnected structural, magnetic, and electronic order parameters. We show that these two alloys can be combined to form hybrid metamagnets in the form of sputter-deposited superlattices and alloys on single-crystalline MgO substrates. Despite being structurally different, the magnetic behavior of the alloys with substantial Mn content resembles that of the FeRh/MnRh superlattices in the ultrathin individual layer limit. For FeRh/MnRh superlattices, dissimilar lattice distortions of the constituent FeRh and MnRh layers at the antiferromagnetic-ferromagnetic transition cause double-step transitions during cooling, while the magnetization during the heating branch shows a smooth, continuous trend. For Fe50-xMnxRh50 alloy films, the substitution of Mn at the Fe sites introduces an effective tensile in-plane strain and magnetic frustration in the highly ordered epitaxial films, largely influencing the phase transition temperature TM (by more than 150 K).