Assembly of Graphene Oxide at Water/Oil Interfaces: Tessellated Nanotiles

The interfacial assembly of graphene oxide (GO) at the water/oil interface and its kinetics were systematically studied. GO nanosheets were found to segregate to the water/oil interface and interact with quaternized block copolymer chains by the peripheral carboxyl groups on the GO. If the interfacial area is decreased, then GO, assembled at and confined to the interface, jams and then buckles. An analysis of the kinetics of the assembly processes leads to the conclusion that the diffusion of GO to the interface is the rate-determining step. The morphology of the jammed GO film was investigated, and TEM images show that GO sheets form a mosaic or tile across the whole oil/water interface

Assembly of Graphene Oxide at Water/Oil Interfaces: Tessellated Nanotiles

The interfacial assembly of graphene oxide (GO) at the water/oil interface and its kinetics were systematically studied. GO nanosheets were found to segregate to the water/oil interface and interact with quaternized block copolymer chains by the peripheral carboxyl groups on the GO. If the interfacial area is decreased, then GO, assembled at and confined to the interface, jams and then buckles. An analysis of the kinetics of the assembly processes leads to the conclusion that the diffusion of GO to the interface is the rate-determining step. The morphology of the jammed GO film was investigated, and TEM images show that GO sheets form a mosaic or tile across the whole oil/water interface

Supplementary document for Reflective one-to-multi-polarization conversion metasurface - 6504161.pdf

supplementary materials of (i) discussion on transmission performance, (ii) derivations of Eqs. shown in manuscrip

An Overview of Adverse Outcome Pathway Links between PM_2.5 Exposure and Cardiac Developmental Toxicity

Fine particulate matter (PM2.5) is a significant risk factor for birth defects. As the first and most important organ to develop during embryogenesis, the heart’s potential susceptibility to PM2.5 has attracted growing concern. Despite several studies supporting the cardiac developmental toxicity of PM2.5, the diverse study types, models, and end points have prevented the integration of mechanisms. In this Review, we present an adverse outcome pathway framework to elucidate the association between PM2.5-induced molecular initiating events and adverse cardiac developmental outcomes. Activation of the aryl hydrocarbon receptor (AhR) and excessive generation of reactive oxygen species (ROS) were considered as molecular initiating events. The excessive production of ROS induced oxidative stress, endoplasmic reticulum stress, DNA damage, and inflammation, resulting in apoptosis. The activation of the AhR inhibited the Wnt/β-catenin pathway and then suppressed cardiomyocyte differentiation. Impaired cardiomyocyte differentiation and persistent apoptosis resulted in abnormalities in the cardiac structure and function. All of the aforementioned events have been identified as key events (KEs). The culmination of these KEs ultimately led to the adverse outcome, an increased morbidity of congenital heart defects (CHDs). This work contributes to understanding the causes of CHDs and promotes the safety evaluation of PM2.5.</sub

Cytotoxicity Regulated by Host–Guest Interactions: A Supramolecular Strategy to Realize Controlled Disguise and Exposure

This work is aimed at providing a supramolecular strategy for tuning the cytotoxicity in chemotherapy. To this end, as a proof of concept, we employed dynamic cucurbit[7]­uril­(CB[7])-mediated host–guest interaction to control the loading and releasing of dimethyl viologen (MV) as a model antitumor agent. MV has high cytotoxicity to both normal cells and tumor cells without specificity. By encapsulating MV into the hydrophobic cavity of CB[7], the cytotoxicity of MV to normal cells can be significantly decreased. When the host–guest complex of MV-CB[7] is added into tumor cells with overexpressed spermine, the antitumor activity of MV can be recovered in tumor cell environment. There are two reasons behind this effect: on the one hand, spermine has a high affinity to CB[7], leading to releasing of MV from MV-CB[7]; on the other hand, CB[7] can soak up spermine, which is essential for tumor cell growth, therefore decreasing the cell viability furthermore. Then, it is highly anticipated that this kind of supramolecular strategy could apply to clinical antitumor agents and provide a new approach for decreasing the cytotoxicity and increasing the antitumor activity, thus opening horizons of supramolecular chemotherapy

Insight into the Structure, Dynamics and the Unfolding Property of Amylosucrases: Implications of Rational Engineering on Thermostability

<div><p>Amylosucrase (AS) is a kind of glucosyltransferases (E.C. 2.4.1.4) belonging to the Glycoside Hydrolase (GH) Family 13. In the presence of an activator polymer, in vitro, AS is able to catalyze the synthesis of an amylose-like polysaccharide composed of only α-1,4-linkages using sucrose as the only energy source. Unlike AS, other enzymes responsible for the synthesis of such amylose-like polymers require the addition of expensive nucleotide-activated sugars. These properties make AS an interesting enzyme for industrial applications. In this work, the structures and topology of the two AS were thoroughly investigated for the sake of explaining the reason why <em>Deinococcus geothermalis</em> amylosucrase (DgAS) is more stable than <em>Neisseria polysaccharea</em> amylosucrase (NpAS). Based on our results, there are two main factors that contribute to the superior thermostability of DgAS. On the one hand, DgAS holds some good structural features that may make positive contributions to the thermostability. On the other hand, the contacts among residues of DgAS are thought to be topologically more compact than those of NpAS. Furthermore, the dynamics and unfolding properties of the two AS were also explored by the gauss network model (GNM) and the anisotropic network model (ANM). According to the results of GNM and ANM, we have found that the two AS could exhibit a shear-like motion, which is probably associated with their functions. What is more, with the discovery of the unfolding pathway of the two AS, we can focus on the weak regions, and hence designing more appropriate mutations for the sake of thermostability engineering. Taking the results on structure, dynamics and unfolding properties of the two AS into consideration, we have predicted some novel mutants whose thermostability is possibly elevated, and hopefully these discoveries can be used as guides for our future work on rational design.</p> </div

The distribution of proline residues among each domain.

<p>The distribution of proline residues among each domain.</p

The unfolding curves for each domains of NpAS and DgAS.

<p>Here, the unfolding curves for the intra domain contacts of NpAS and DgAS are displayed in (A) and (B), and those for the inter domain contacts of NpAS and DgAS are shown in (C) and (D), respectively.</p

The contact maps for the native (A), LNNC = 100 (B), 200 (C) and 500 (C) states of DgAS (D).

<p>Each contact is represented by a “+” mark.</p

The contact maps for the native (A), LNNC = 100 (B), 200 (C) and 500 (C) states of NpAS (D).

<p>Each contact is represented by a “+” mark.</p