Hortonhackett1861

Transactional relationships among maternal nervousness as well as kid anxiety threat through toddler-solicited relaxing behavior.

Data rates inside Kerr nonlinearity minimal visual dietary fiber communication systems.

The results also indicate that the extraction of strongly associated hemicelluloses would be facilitated by low temperature.Construction of strong metal-support interaction (SMSI) is of fundamental interest in the preparation of supported metal nanoparticle catalysts with enhanced catalytic activity. Herein, we report a facile in situ electrochemical redox tuning approach to build strong interactions between metals and supports. link= selleckchem As for a typical example, a composite electrocatalyst of Pd-Co hybrid nanoparticles directly developed on Ni substrate is found to follow a distinct surface self-reconstruction process in alkaline media via an in situ electrochemical redox procedure, which results in structural transition from the original nanoparticles (NPs) to nanosheets (NSs) coupled with a phase transformation of the Co component, Co → CoO/Co(OH)2. The SMSI is observed in the electrochemically tuned Pd-Co hybrid system and leads to significantly enhanced catalytic activity for methanol oxidation reaction (MOR) due to the modified atomic/electronic structure, increased surface area, and more exposed electroactive sites. Compared with commercial Pd/C catalyst, the electrochemically tuned Pd-Co hybrid catalyst with SMSI exhibits superior catalytic activity (2330 mA∙mgPd-1) and much better stability (remains 503 mA∙mgPd-1 after 1000 cycles and 172 mA∙mgPd-1 after 5000 s), and therefore has great potential in practical applications.A new type of carbon dots that emit blue emission in aqueous state while cyan emission in solid state was synthesized by a simple hydrothermal method. The photoluminescence quantum yield of the carbon dots in aqueous state and solid state is 7.6% and 29.2%, respectively. The enhanced and red-shifted emission observed in solid state carbon dots is ascribed to surface state change caused by aggregation. link2 The occurrence of surface state change in solid state carbon dots has been evidenced by concentration dependent steady-state photoluminecence spectra and time-resolved luminescence decay. Surface functionalization by Na+ is beneficial for carbon dots to resist luminescence quenching in solid state. A proof-of-concept study was performed to demonstrate the potential application of the obtained carbon dots as inks for anti-counterfeiting and printing high quality fluorescent images.Enzymes are highly significant catalysts, essential to biological systems, and a source of inspiration for the design of artificial enzymes. Although many models have been developed describing enzymatic catalysis, a deeper understanding of these biocatalysts remains a major challenge. Herein we detail the formation, characterization, performance, and catalytic mechanisms of a series of bio-inspired supramolecular polymer/surfactant complexes acting as artificial enzymes. The supramolecular complexes were characterized and exhibited exceptional catalytic efficiency for the dephosphorylation of an activated phosphate diester, the reaction rate being highly responsive to (a) pH, (b) surfactant concentration, and (c) the length of the hydrophobic chain of the surfactant. Under optimal conditions (at pH > 8 for the more hydrophobic systems and at pre-micellar concentrations), enzyme-like rate enhancements of up to 6.0 × 109-fold over the rate of the spontaneous hydrolysis reaction in water were verified. The catalytic performance is a consequence of synergy between the hydrophobicity of the aggregates and the catalytic functionalities of the polymer and the catalytic mechanism is modulated by the nature of the hydrophobic pockets of these catalysts, changing from a general base mechanism to a nucleophilic mechanism as the hydrophobicity increases. Taken as a whole, the present results provide fundamental insights, through an understandable model, which are highly relevant to the design of novel bioinspired enzyme surrogates with multifunctional potentialities for future practical applications.It has been reported that adding polyphosphoric acid (PPA) to bitumen modified with Montmorillonite clay (MMT) makes the bituminous composite less prone to swelling and more resistant to moisture damage, thus improving two major causes of pavement distress. There has been no in-depth study on the underlying mechanism for such a synergistic effect between MMT and PPA. Here, we used laboratory experiments and computational modeling to study how PPA moderates the intermolecular interactions in bitumen modified with MMT. The results showed that PPA had notable interactions with both MMT and bitumen components (BCs); however, PPA's preferential adsorption to MMT was verified by a significantly higher binding energy (-127.3 kcal/mol) for PPA-sealed MMT than for PPA-BCs (-85.9 kcal/mol). selleckchem The higher binding energy for PPA-sealed MMT caused PPA to be strongly adsorbed on the MMT surface in the first stage, causing partial intercalation into the clay gallery and blocking subsequent entry of water. PPA's affinity to interact with BCs then allowed PPA to be a bridge between MMT and BCs, leading to more intermolecular interactions and better sealing for MMT. link2 The calculated binding energies for interactions of BC with pre-adsorbed PPA on MMT were higher than those for interactions of BC with PPA alone. In both dry and wet laboratory conditions, bitumen modified with PPA-sealed MMT had higher values of shear thinning and G*/sin(δ) than bitumen modified with MMT.The reversible redox of methylene blue in organic solvents was highly attractive, yet was rarely reported. In this study, we realized the continuous filtration redox of methylene blue (MB) in dimethylsulfoxide (DMSO) through Fenton-like oxidization by using MnO2 loaded carbonaceous nanofibrous membrane (cPAN-MnO2). selleckchem The carbonaceous nanofibrous membrane (cPAN) was fabricated through electrospun of polyacrylonitrile and subsequent carbonization. The obtained cPAN nanofibrous membrane showed excellent stability in polar DMSO. MnO2 can be readily coated on cPAN nanofibers through an in situ redox reaction between cPAN and potassium permanganate. The fabricated cPAN-MnO2 membrane exhibited instantaneous reduction property towards MB in DMSO during a gravity-driven continuous filtration process. Interestingly, MB reduction was initiated by a typical Fenton-like oxidization, where hydroxyl radicals were firstly generated from hydrogen peroxide catalyzed by MnO2 in DMSO. Then hydroxyl radicals attacked DMSO to further produce methyl radicals, which resulted in the reduction of MB. In addition, MB reduction process in DMSO was reversible. Our study provides a novel strategy for continuous redox of MB in polar organic solvent and might give new ideas for MB applications.Removal of organic species from solid surfaces is a crucial process. The use of oppositely charged surfactants provides a potential method for enhanced removal. Neutron reflectometry has been used to investigate the complex behaviour of a pre-adsorbed and tenacious layer of the cationic surfactant didodecyldimethylammonium bromide (DDAB) on a mica surface, during exposure to different organic species in solution. The anionic surfactant sodium dodecylsulfate (SDS) was shown to be able to remove the cationic layer, but only if anionic micelles were present in solution. To facilitate comparison with the behaviour of a non-ionic surfactant, the direct adsorption of pentaethylene glycol monododecyl ether (C12E5) to mica was also studied; low surface coverage adsorption was seen at the critical micelle concentration and above. C12E5 was then found not to remove the cationic layer, but did include into the layer to some degree. The presence of cationic surfactant on the mica was however shown to significantly modify the adsorption behaviour of the non-ionic surfactant.

Novel photoresponsive hybrid surfactants, in which a combination of perfluoroalkyl and alkyl chains and cationic head groups are connected via azobenzene moieties, are excellent candidates for assembling low-molecular-weight organogels (LMOGs) with reversibly switchable viscoelasticities triggered by external stimuli.

The structure-composition-property relationships of gels assembled with the hybrid surfactants were investigated by UV-vis and NMR spectroscopy, SEM, XRD, and rheology.

Hybrid surfactants containing perfluorohexyl chains with more than six carbons gelled in a variety of organic solvents at concentrations of less than a few percent. In particular, compositions with the perfluorooctyl and somewhat shorter hydrocarbon chains (C1-C4) gelled in both organic solvents and water. link3 The gellable solvent species can be well grouped according to their solubility parameters, suggesting that gelation properties can be predicted from the chemical structure of the surfactant. Mechanical and structural inveeved through the formation and deformation of lamella-like molecular aggregates. The multi-responsive gelation and facile molecular design of the present hybrid surfactants will expand the fields in which fluorinated LMOGs can be applied.Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates cholesterol metabolism by inducing the degradation of hepatic low density lipoprotein receptors (LDLRs). Plasma PCSK9 has 2 main molecular forms a 62 kDa mature form (PCSK9_62) and a 55 kDa, furin-cleaved form (PCSK9_55). PCSK9_55 is considered less active than PCSK9_62 in degrading LDLRs. link3 We aimed to identify the site of PCSK9_55 formation (intracellular vs. extracellular) and to further characterize the LDLR-degradative function of PCSK9_55 relative to PCSK9_62. Coexpressing PCSK9_62 with furin in cell culture induced formation of PCSK9_55, most of which was found in the extracellular space. Under the same conditions, we found that i) adding a cell-permeable furin inhibitor preferentially decreased the formation of PCSK9_55 extracellularly; ii) using pulse-chase analysis, we observed the formation of PCSK9_55 exclusively extracellularly in a time-dependent manner. A recombinant form of PCSK9_55 was efficiently produced but displayed impaired secretion that resulted in its intracellular trapping. However, the nonsecreted PCSK9_55 was able to induce degradation of LDLR, though with 50% lower efficiency than PCSK9_62. Collectively, our data show that 1) PCSK9_55 is formed extracellularly; 2) PCSK9_55 has a shorter half-life; 3) there is a small intracellular pool of PCSK9_55 that is not secreted; and 4) PCSK9_55 retained within the cell maintains a reduced efficiency to cause LDLR degradation.The present study investigated the effect of the enzymes papain (0.2%) and microbial transglutaminase (MTG) (1%) on the texture properties of beef and chicken burgers to develop a meat product with significant increase in softness due to the physiological limitations of the elderly. The products were characterized for pH, objective color, water activity, texture profile analysis (TPA), shear force, compression test, electrophoretic profile, cooking loss, and diameter reduction. A pronounced increase in softness was observed for both raw materials containing papain. An increase in shear force was observed for the beef burger containing only MTG, while the chicken burger showed a reduction of this parameter. The compression tests showed papain alone or combined with MTG decreased the hardness of the burgers. The results showed that the combination of the enzymes papain and MTG can be an effective strategy to develop beef and chicken burgers much softer, contributing to the future studies focused on the physiological needs of the elderly.