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To solve the problem of the limited depth of penetration of biomolecules into silicon biosensors, which affects the performance of porous silicon devices, a new biological detection device assembled with porous silicon and Bragg structures is proposed that allows the biomolecules to directly enter the porous silicon microcavity layer, thus greatly shifting the resonance peak and improving the sensitivity of the porous silicon. The fabricated porous silicon devices with microcavities and Bragg structures are functionalized and coupled with biomolecules and then assembled with Bragg devices based on quartz glass to form the microcavity. Using the reflection spectrometer to detect the defect peak redshifts of different concentrations of target DNA molecules before and after reaction with the probe DNA molecules, obtaining the difference between the refractive indices before and after reaction. With an increase in the molecular concentration of the DNA in the target and an increase in the defect peak difference, the detection limit is 22.5 nM. The assembled microcavity has the advantages of high detection sensitivity, free labelling, low costs and so on.

Glassy carbon (GC) is a type of non-graphitizing disordered carbon material at ambient pressure and high temperatures, which has been widely used due to its excellent mechanical properties. Here we report the changes in the microstructure and mechanical properties of GC treated at high pressures (up to 5 GPa) and high temperatures. The formation of intermediate sp2–sp3 phases is identified at moderate treatment temperatures before the complete graphitization of GC, by analyzing synchrotron X-ray diffraction, Raman spectra, and transmission electron microscopy images. The intermediate metastable carbon materials exhibit superior mechanical properties with hardness reaching up to 10 GPa and compressive strength reaching as high as 2.5 GPa, nearly doubling those of raw GC, and improving elasticity and thermal stability. The synthesis pressure used in this study can be achieved in the industry on a commercial scale, enabling the scalable synthesis of this type of strong, hard, and elastic carbon materials.

In this paper, based on the gray value change of reflected light image of porous silicon (PSi) Bragg mirror, a fast and simple biological detection method is proposed. In this method, CdSe/ZnS quantum dots (QDs) are used as markers for refractive index amplification, and digital image method is used for detection. The detection light has the same wavelength as the lowest reflectivity of the edge of the Bragg mirror, and the reflected light radiated on the surface of the Bragg mirror is received by the detector. The theoretical simulation results show that the intensity of the reflected light increases with the increase of the refractive index caused by the biological reaction. According to the experimental results, the average gray value variation increases with the increase of the target DNA concentration and becomes a linear relationship in a certain range. Based on this method, the DNA detection limit is 20.74 pM. The method is low-cost, has a short detection time and can be used in the detection of biosensor microarray.

The design and synthesis of superhard carbon nitrides have always been a focus of attention. Recently, an experiment has revealed the existence of the previously predicted three-dimensional strongl...

Bismuth-Yttrium Oxide Bi3YO6 (BYO) is well-known among researchers for its potential applications in different fields but its use as an electrode for asymmetric supercapacitor (ASC) has not yet been discussed and uncovered. As high energy and power densities could be well achieved with the aid of optimum potential. In the current scenario, BYO is used as an electrode material for ASCs for the first time. The material is prepared by a solid-state reaction method and its structural, morphological, and electrochemical properties have been explored by using different characterization tools. Structural analysis declared the flourite based structure of BYO having a cubic phase without any visible impurity. In a morphological analysis, a mesoporous thin film with a high surface area (~ 36.6 m2 g−1) with a narrow pore width of (~ 5–18 nm) has been observed. The as-prepared BYO employed as an electrode material for SCs delivers a high specific capacitance of (388 F g−1 at 100 m Vs−1 in the three-electrode system) with excellent cycling stability (5% loss after 6000 cycles). Essentially, an ASC is assembled using BYO and rGO as a positive and negative electrodes operating in a stable and wide potential window up to 2.2 V. Moreover, a high energy density of 11 Wh kg−1 along with a power density of 648 W kg−1 is obtained and maintained a high power density of 888 W kg−1 with the downfall of energy density to 3.7 Wh kg−1. The results prove electrode material as an alternative promising candidate for ASCs.

In this study, a novel carboxymethyl functionalized β-cyclodextrin-modified graphene oxide (CM-β-CD-GO) adsorbent was designed and fabricated. The CM-β-CD-GO was applied to remove methylene blue (MB) from aqueous solutions. The adsorption mechanism was discussed in detail through the study of pH effect, kinetics, and isotherm models. The adsorption of CM-β-CD-GO for MB displayed high removal rates at the pH range of 6.0–10.0, and the removal efficiency is over 90% within 20 minutes. The pseudo-second-order model could well describe the kinetic process of MB adsorption, and the adsorption was determined by the multi-step process. The maximum uptake capability of CM-β-CD-GO towards MB was 245.70 mg g-1 at 25℃according to Langmuir isotherm model. A possible adsorption mechanism that electrostatic attraction, π-π interaction, and host-guest supramolecular interactions supported MB adsorption was proposed. The adsorption capacity of CM-β-CD-GO showed no significant change after five cycles. The structure and morphology of CM-β-CD-GO were characterized by XPS, FT-IR, TGA, PXRD, AFM, SEM, zeta (ζ) potential determination, and Raman spectroscopy. This work provides valuable information for the design of novel adsorbents that specifically and efficiently adsorb cationic dyes contaminants.

传统陶瓷材料的刚性结构变形能力非常有限, 通常在很小的应变下就发生断裂. 具有层状原子结构的陶瓷, 原子层间存在较弱的相互作用, 因而具有大的变形潜力. 我们以氮化硼(BN)为例, 研究了该类陶瓷的室温压缩行为. 分别以洋葱结构BN纳米颗粒和石墨状六方BN纳米片为原料, 采用放电等离子烧结(SPS)技术分别制备了BN-I和BN-II陶瓷材料. 在BN-I中, 随机取向的BN纳米薄片构成三维互锁的结构, 而在BN-II中, BN纳米薄片表现出垂直于SPS压缩方向的择优取向. BN-I的压缩强度为 343 MPa, 断裂应变为4.2%. 相比之下, BN-II的强度和应变分别为 112 MPa 和2.2%. 不同的微观组织结构导致了BN-I和BN-II压缩性能的差异. 此外, 这两种陶瓷材料均表现出1.1%的塑性变形. 该研究表明, 对于具有层状原子结构的陶瓷, 其纳米片作为结构基元构筑成无(或低)择优取向的三维互锁结构, 有望同时提高其强度和变形能力.

Although grafting polymers onto surfaces is widely suggested for designing smart systems, optimizing the performance of such systems is not simple. In this article, we investigate an azo-polymer-based smart surface using the single-chain-in-mean-field theory. Through the numerical simulations, we study the adhesion/erasion transition of the system and show that the performance of the smart surface can be characterized by the difference between the effective nanoparticle–surface interactions in the UV-on and UV-off states. Further exploring the optimization of the smart surface, we find that the distribution function of the receptor can have typical bimodal characteristics, which is crucial for optimizing the position of the azo-bond along the azo-polymer, f. Moreover, the presence of the homopolymer is also essential for the optimal performance of the smart surface, and we build a reference map for the good combinations of f and the homopolymer design fhomo.

The oxygen reduction reaction (ORR), which is a crucial process in fuel cells and metal-air batteries, is currently dominated by Pt-based electrocatalysts. However, these catalysts are expensive and rare on Earth; therefore, these factors are considered to impede the widespread commercialization of these technologies. As a consequence, the development of non-Pt catalysts (such as transition-metal materials) with high performance for ORR has become a main focus of research regarding these renewable energy devices. In the present work, a series of porous triazine-based frameworks (PTFs) co-decorated by iron and iodine have been successfully prepared, using different element doping sequences during the synthesis process. The PTF-Fe-I catalysts shows a high ORR activity in both alkaline and acidic media, with an onset potential of 0.95 V (in basic medium) or 0.85 V (in acidic medium) at a loading of 0.3 mg cm–2. This performance not only exceeds that of the dual-doped counterparts (PTF-I-Fe and PTF-(Fe, I)), ...

Single-atom electrocatalysts have attracted board interest in the recent years as they combine the advantages of heterogeneous and homogeneous electrocatalysts. Nevertheless, single-atom electrocatalysts with single metal component cannot further satisfy the demand of catalytic properties. This work developed atomic Co/Ni dual sites in N-doped porous carbon Janus-like frameworks through epitaxial growth of cobalt based MOFs on nickel complexes. Structural characterization and atomic-scale transmission electron microscopy revealed the homogeneously dispersed active sites of Co-Ni alloy and single Co/Ni atoms. Electrochemical data strongly demonstrated the advantages of integrating Co-MOF and Ni complex with different topological structures to form a Janus-like structure. The resultant catalysts afforded onset potential of 0.93 V and half-wave potential of 0.84 V for oxygen reduction reaction in alkaline media, and 0.86 V and 0.73 V in acid media, which is better than single noble-metal-free catalysts, even close to commercial Pt/C. Besides, the catalysts also exhibited good oxygen evolution reaction performance (a current density of 10 mA cm−2 at a potential of 1.59 V) and overvoltage between ORR and OER is 0.78 V. Density functional theory calculations indicated the high electrocatalytic activities are originated from the synergetic effect of atomic Co/Ni-N-C bonds and microstructure of the prepared materials. This work paves a new avenue for the development of multiatomic electrocatalysts for energy conversion.

In this study, ionic liquids-based salting-out extraction and sugaring-out extraction were developed to extract succinic acid. Among these five investigated ionic liquids, the ionic liquid with BF4- and OTF− anion showed the ability to form two phases not only with glucose but also with salts. However, the ionic liquid with Br− anion cannot form aqueous two-phase system with glucose, but with salts. Relatively high extractabilities were obtained by ILs–based salting-out extraction systems compared to sugaring-out systems. The extraction efficiency values ranging between 47% and 86% were obtained when succinic acid concentration increased from 5 g/L to 70 g/L in [Bmim]BF4/(NH4)2SO4 systems. It was implied that succinic acid concentration was a key factor in ILs-based salting-out extraction system. Compared to salting-out extraction, sugaring-out extraction was more suitable for succinic acid separation due to the bottom phase reutilization to achieve coupling of fermentation and separation. The distribution behavior of succinic acid in [Bmim]BF4/glucose sugaring-out extraction system depends on not only the concentrations of ionic liquid and glucose, but also the pH. The partition coefficient (2.53) and recovery (75.96%) of succinic acid were obtained by a sugaring-out system consisting of 45% (w/w) [Bmim]BF4 and 30% (w/w) glucose at pH 2.0. Moreover, to support the applicability of ILs-based sugaring-out extraction for SA separation, the most prominent systems were further tested with actual fermentation broth. The extraction efficiencies were 73.71% and 72.53% for filtered and unfiltered fermentation broth, respectively. The remarkable results obtained in this work support the establishment of IL-based sugaring-out extraction as a sound basis of greener cost-effective strategies with a substantial reduction in the environmental footprint and economical issues.

This study aimed to develop a novel sustained release system for mesalazine (MSZ) by preparing hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex loaded chitosan (CS) nanoparticles (NPs). The HP-β-CD/MSZ complex was prepared at 1:1 stoichiometry and characterized by using various analysis techniques. The HP-β-CD/MSZ/CS NPs prepared under the optimum condition had a spherical shape (90±17 nm diameter), a narrow size distribution, and a high loading efficiency. Compared with free MSZ, the HP-β-CD/MSZ/CS NPs exhibited an obvious sustained release of MSZ. The activity of the NPs against a cytokine-triggered inflammatory response was evaluated in cytokine-stimulated HT-29 cell lines by monitoring key inflammatory mediators. The results revealed that compared with free MSZ, the NPs more strongly inhibited the production of NO, PGE2, and IL-8, indicating the NPs possibly had better anti-inflammatory effects. Therefore, the established HP-β-CD/MSZ/CS NPs may be a promising delivery system of MSZ.

The interaction mechanism and binding mode of capecitabine with ctDNA was extensively investigated using docking and molecular dynamics simulations, fluorescence and circular dichroism (CD) spectroscopy, DNA thermal denaturation studies, and viscosity measurements. The possible binding mode and acting forces on the combination between capecitabine and DNA had been predicted through molecular simulation. Results indicated that capecitabine could relatively locate stably in the G-C base-pairs-rich DNA minor groove by hydrogen bond and several weaker nonbonding forces. Fluorescence spectroscopy and fluorescence lifetime measurements confirmed that the quenching was static caused by ground state complex formation. This phenomenon indicated the formation of a complex between capecitabine and ctDNA. Fluorescence data showed that the binding constants of the complex were approximately 2 × 10

The nitrided Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors were prepared by the conventional high temperature solid state reaction. The site occupancy of Ce 3+ ionic and its luminescent characteristics were clearly analyzed in Ba 9 Y 2 Si 6 O 24 hosts by Rietveld refinement of XRD data, PL & PLE spectra analyses, as well as the first principle calculation. Compared with Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors, p-d orbital hybridization between N 3- -p and Ce 3+ -d orbital after the nitridation leads to red shifts of Ce (Ba(1)) 3+ and Ce (Ba(2,3)) 3+ lattice ionic emission peaks. Meanwhile, the self-energy transfer was pointed from Ce (Ba) 3+ lattice sites to Ce (Y) 3+ lattice sites by the analysis of PL&PLE spectra and CIE chromaticity diagram. By optimizing the N 3- concentration, there exists abnormal outstanding thermal-stability of nitrided Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors, its emission intensities at 453 K are higher than that of room temperature (293 K). The whole photoluminescent properties of nitrided Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors were superior to that of Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors without nitridation. It hints the nitrided Ba 9 Y 2 Si 6 O 24 : Ce 3+ phosphors to be a promising candidate as a green phosphor for W-LEDs, and the nitridation technology might be an important feasible strategy to enhance and develop the luminescent properties for silicate and aluminates based phosphors.

In this work, novel cyclic-brush polymers with high grafting densities were successfully constructed via the grafting onto approach by combining a light-induced Diels–Alder ring-closure approach and activated ester chemistry as a post-modification method. The cyclic activated ester containing polymer precursor [poly(pentafluorophenyl 4-vinylbenzoate), c-PPF4VB4.0k] was synthesized by combining reversible addition–fragmentation chain transfer (RAFT) polymerization and the light-induced Diels–Alder click reaction, which was fully characterized by NMR, SEC, MALDI TOF mass and UV-Vis spectroscopy. Using activated ester chemistry, this cyclic polymer (c-PPF4VB4.0k), bearing a pentafluorophenyl group, was post-modified with PEG-NH2 to obtain a cyclic-brush polymer (c-PPF4VB4.0k-g-PEG) with hydrophilic grafting polymer chains and a hydrophobic cyclic polymer backbone. Meanwhile, c-PPF4VB4.0k was post-functionalized using propargyl amine to obtain a clickable cyclic polymer (c-P1). The cyclic polymer (c-P1) was further coupled with an azide-containing polymeric chain (l-PS-N3) to produce the cyclic-brush polymer (c-P1-g-PS). This work illustrated a concept for constructing cyclic-brush polymers by combining the ring-closure strategy and activated ester chemistry. Notably, these two cyclic-brush polymers exhibited high grafting densities (almost quantitatively) and narrow molecular weight distribution (Mw/Mn < 1.10).

Herein, a series of azobenzene (Azo)-containing side-chain cyclic polymers were successfully synthesized by combining atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed azide/alkyne cycloaddition (CuAAc) “click” reaction. The aggregates of linear and cyclic Azo polymers in a dichloroethane/limonene mixed solvent were characterized by circular dichroism (CD) and UV-visible spectroscopy, demonstrating that the topological structural constraint and molecular mass of cyclic polymers have clear effects on the supramolecular chirality driven by a chiral solvent. The difference between linear and cyclic Azo aggregates in supramolecular chirality became less distinct with increasing molecular mass of Azo polymers. The chiroptical switch of cyclic Azo polymers was firstly constructed by trans–cis photoisomerization and cis–trans heating-assisted reorganization processes. These interesting findings suggest that the cyclic topology has a clear influence on the behavior of supramolecular chirality induced by chiral limonene.

The catalytic Staudinger–Vilarrasa (S–V) reaction, a widely utilized reaction for synthesizing amide-containing compounds, has played vital roles in organic synthesis. In this work, we introduce this reaction as a highly efficient chemistry strategy for the first time in polymer chemistry. First, the polycondensation of dicarboxylic acids with organic diazides produces a series of polyamides in yields of up to 94% and high molecular weight of 28 kDa. Second, this reaction between polymer-N3 and various functional organic acids yields amide-end-functionalized polymers with near 100% efficiency. Third, amide-linked (multi)block copolymers (PEG-PEG, PS-PS, PS-b-PEG, PtBA-b-PEG) with approximate 100% efficiency, a star polymer (PEG)3 with ∼95% efficiency and side-chain amide-functionalized polymers (∼100% efficiency) are constructed via this reaction between polymers and organic acids or polymers. This highly efficient catalytic S–V reaction provides a programable platform for producing amide bond-containing polymers that compares favourably with previous reported click strategies, such as CuAAC, thiol–ene and Diels–Alder reactions in some ways.

Telaprevir (TVR) is a first-generation protein inhibitor approved in 2011 for the treatment of chronic hepatitis C, a global epidemic that threatens the human health. This study investigated the interaction between TVR and human serum albumin (HSA) by combining spectroscopic methods and molecular modeling. Fluorescence experiments indicated that TVR could bind to HSA through a static process with a moderate affinity, and the static mechanism was confirmed by time-resolved fluorescence spectroscopy. Negative free energy change obtained from thermodynamic parameters suggested a spontaneous binding reaction between TVR and HSA. Hydrogen bonds and van der Waals force were found to play major roles in the binding process, according to the negative enthalpy and entropy changes. Molecular dynamics (MD) simulation further verified the driving forces, and indicated that hydrophobic force and electrostatic interactions were also involved in the binding. The site I binding mode was demonstrated by site marker displacement experiments and MD simulations. The TVR–HSA complex was stabilized after 30 ns with a binding energy of about −298.4 KJ mol−1, and a less compacted HSA was induced by binding with TVR. Moreover, binding with TVR caused microenvironmental and conformational changes in HSA, based on their synchronous fluorescence, three-dimensional fluorescence, and circular dichroism spectra.

A cyclic grafted polymer, as a novel and unique kind of polymer, possesses a cyclic backbone and linear grafted side chains. Their physical properties and conformations are controlled by steric hindrance from the grafted side chains. As a cyclic derivative, cyclic grafted polymers have been successfully prepared and characterized within the past decade. To the best of our knowledge, cyclic grafted polymers have not been systematically generalized and summarized. In this review, we illustrate the considerable advances in the architectural construction of cyclic grafted polymers with three different approaches, including “grafting through”, “grafting onto” and “grafting from”. Additionally, their potential applications are also briefly discussed.

Electromicrobial conversion of carbon dioxide is a promising alternative to the direct transfer of CO2 into biomass by using bacteria that consume hydrogen and CO2 for living. The efficiency of such a hybrid system strongly depends on the electrocatalyst used for hydrogen production. Here we evidence that a mixed noble metal free Co/Cu-containing polyoxometalate/Carbon Cloth (Cu6Co7/CC) hybrid possesses excellent activity as a water splitting pre-electrocatalyst at neutral pH, with Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) overpotentials of 390 mV and 500 mV at 10 mA cm−2 and Tafel slopes of 96 mV dec−1 and 147 mV dec−1, respectively. The nature of the catalysts involved for both the oxidation and reduction processes has been investigated. The long-term activity of the electrodes is also demonstrated. A negligible amount of H2O2 is produced during the electrolysis process. CO2 fixation with wild-type R. eutropha and the biocompatible Cu6Co7/CC precatalyst as both anode and cathode materials has been tested. The hydrogen produced on the cathode is consumed by the bacteria for living and growth with more than 50% of input electrical energy transferred into biomass. The solar-to-biomass efficiency ηSCE can reach 9.9 ± 0.5% in a 6-day experiment, almost 10 times higher than those of natural plants, showing the high performance of this Cu6Co7/CC/R. eutropha system.

A series of carbonaceous-supported precious-metal-free polyoxometalate (POM)-based composites which can be easily synthesized on a large scale was shown to act as efficient cathode materials for the oxygen reduction reaction (ORR) in neutral or basic media via a four-electron mechanism with high durability. Moreover, exploiting the versatility of the considered system, its activity was optimized by the judicious choice of the 3d metals incorporated in the {(PW9)2M7} (M = Co, Ni) POM core, the POM counterions and the support (thermalized triazine-based frameworks (TTFs), fluorine-doped TTF (TTF-F), reduced graphene oxide, or carbon Vulcan XC-72. In particular, for {(PW9)2Ni7}/{Cu(ethylenediamine)2}/TTF-F, the overpotential required to drive the ORR compared well with those of Pt/C. This outstanding ORR electrocatalytic activity is linked with two synergistic effects due to the binary combination of the Cu and Ni centers and the strong interaction between the POM molecules and the porous and highly conducti...

Selective hydrogenation of amino acid methyl esters to chiral amino alcohols is an important and fascinating process. The CuZn0.3Mg0.1AlOx catalyst for the synthesis of chiral amino alcohols was prepared by the fractional co-precipitation method in the 50–100 g scale. The effect of the reduction gas on the catalytic activity, and the effects of the reaction conditions (R-p-m/Cat, temperature, reaction time, H2 pressure and solvent) on the catalytic hydrogenation of R-phenylglycine methyl ester (marked as R-p-m) were investigated. When R-p-m in the ethanol solvent was hydrogenated at 5 MPa of H2 and 80 °C for 10 h over this catalyst reduced by H2, 87.7% yield of R-phenylglycinol with ~ 100% ee value was obtained, and its reaction activation energy (Ea) was 36.7 kJ/mol. After repeated usage 16 times, its catalytic activity was hardly varied. Using this catalyst to catalyze the preparation of other amino alcohols, the high yield of product with ~100% ee value was obtained also.

Ligand-receptor molecular recognitionis the basis of biological process. The Saturation Transfer Difference-NMR (STD-NMR) technique has been recently used to gain qualitative and quantitative information about physiological interactions at atomic-resolution. The molecular recognition patterns between Vitamin B12 (VB12) and human serum albumin (HSA) were investigated by STD-NMR supplemented by other spectroscopies and molecular docking. STD-NMR delivered a complete picture that the substituent groups on the tetrapyrrole ring of VB12 interacted with site III of HSA through binding epitope mapping and competitive probe experiments. STD-NMR and fluorescence results proved the moderate binding capability of VB12 and clarified a static, spontaneous, and temperature-sensitive binding mechanism. 3D-fluorencence, FT-IR and circular dichroism spectra showed a compact protein structure by interacting with VB12. Size distribution and surface hydrophobicity showed the surface properties changes of HSA caused by the binding of VB12. Computer simulation confirmed the recognition mode in theory and was compared with experiments. This work is beneficial for understanding the safety and biological action of VB12, and will attract researchers interested in NMR technology.

The structure evolution of surface NiAl2O4 spinel phase in NixAl1O2-δ mesoporous catalysts, synthesized by the citric acid sol-gel method, was systematically investigated. Small-size Ni nanoparticles, obtained by partial reduction from NiAl2O4 spinel in NixAl1O2-δ catalysts with low Ni contents at high temperature, can effectively inhibit the carbon formation from kinetics, while the irreducible NiAl2O4 counterpart can participate in elimination of carbon deposition. The constructed structure of Ni0-NiAl2O4 interfaces, produced by exsolution of Ni from NiAl2O4 spinel, is responsible for its high long-term stability and excellent resistance to coking and sintering for dry reforming of methane (DRM) reaction. The structure sensitivity and kinetic compensation effect of CH4 dissociation on Ni0 active sites are observed. DRM reaction proceeds via a Langmuir-Hinshelwood mechanism accompanied by an additional redox mechanism. It is noteworthy that the active oxygen species generated by filling the oxygen vacancies of NiAl2O4 spinel by CO2 provide another rapid redox route to eliminate carbon species.

Introduction of hydrophilic groups can improve the solubility of leading drugs but inevitably affect their interaction with proteins. This study selected sirtuin inhibitors Tenovin-1 (T1) and Tenovin-6 (T6) as drug models to determine differences in binding mode to human serum albumin (HSA). T1 and T6 quenched the endogenous fluorescence of HSA via static quenching mechanism. Introduction of hydrophilic groups greatly reduced the binding constant, i.e., from 1.302 × 104 L mol−1 for the HSA-T6 system to 0.128 × 104 L mol−1 for the HSA-T1 system. HSA-T1 system was mainly driven by electrostatic interactions while that of HSA-T6 system was hydrophobic interaction and both systems were spontaneous reactions. Site marker experiments and molecular docking indicated that both systems mainly bound to the hydrophobic site I of HSA. Molecular dynamics (MD) simulation analysis further revealed that Tyr148, Tyr150 and Arg257 residues played a key role in this recognition process for both systems. In particular, T6 maintained additional several hydrogen bonds with the surrounding residues. T1 had almost no effect on the esterase-like activity of HSA, but T6 inhibited the hydrolysis of p-NPA. Furthermore, differential scanning calorimetry (VP-DSC), circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy confirmed that HSA in the T6 system undergone a more significant conformational transition than that in the T1 system.

A highly efficient catalyst of graphene-supported mixed-valent Mn16-containing polyoxometalate is reported here by electrochemical strategy. The modified electrode with the catalyst exhibits an excellent electrocatalytic performance for water oxidation, which will contribute to the development of highly efficient catalysts for oxygen evolution. Keywords: Water oxidation, Polyoxometalates, Graphene, Electrocatalysis

Diamond-like B C compounds exhibit the favorable properties of high hardness and superconductivity. The explorations for novel B C phases are kept on going and it was desirable to explore whether the diamond-like structure can still exist stably or not when the content of boron increases. Herein we predicted a nondiamond-like structure t2-BC took place the lowest energy position of the diamond-like structure, which is completely different from the BCx (x ≥ 2) system. Based on elastic constants and phonon dispersion calculations, the mechanical and dynamic stability of t2-BC were confirmed. Furthermore, hardness and electron–phonon calculations reveal that t2-BC is superhard (Hv = 55.4 GPa) and superconductive with superconducting critical temperature reaching 6.4 K. These results have practical significance for the experimental synthesis of diamond and nondiamond like B C compounds.

A metal-free [2 + 2 + 2] cycloaddition of alkyne-cyanamides or ynamide-nitriles with ynamides is described for the efficient synthesis of amino-substituted α- and δ-carbolines. This novel methodology is environmentally friendly and allows for highly regioselective access to carboline derivatives in good to excellent yields with wide functional group tolerance.

The binding properties between γ-lactone essences and HSA were investigated to explore interactional mechanism and influence of ligand side chains on binding via computer simulations, microscopy, and multiple-spectroscopies. Docking and molecular dynamics presented protein recognition mode with low fluctuations. NMR analysis revealed that the lactone ring of ligands was the main group bound to HSA. UV–vis and lifetime results revealed that the combination was static quenching mechanism with binding constants of 102–103 L/mol. FTIR and CD spectra showed conformational changes in the protein secondary structure induced by ligands. Side chains affect the binding process through steric hindrance and hydrophobicity. AFM images showed the four compounds caused different effects on molecular size of HSA. In conclusion, the binding ability and the protein secondary structure changes had a positive correlation with the length of side chain. These studies are beneficial for understanding the safety and biological action of γ-lactone essences.

In order to improve the dissolution rate and oral bioavailability of lurasidone hydrochloride (LH), LH nanosuspensions (LH-NSP) were prepared by an antisolvent precipitation–ultrasonication method and characterized in this study. Three important formulation factors including the concentration of LH in the solvent, the amount of sodium dodecyl sulfonate (SDS) and poloxamer 188 (F68) in the antisolvent were optimized by the central composite design response surface methodology. Besides, the impacts of three important process parameters, namely the precipitation temperature, the power input and the duration of ultrasonication, on the particle size and polydispersity index (PDI) of LH-NSP were also investigated. The optimal values of these formulation factors were 0.21% (w/v) LH, 0.06% (w/v) SDS and 0.16% (w/v) F68, respectively, while for the process parameters, the precipitation temperature, power input and duration of ultrasonication were 5 °C, 100 W and 10 min, respectively. The particle size and PDI of the optimized LH-NSP were 124.6 ± 11.9 nm and 0.097 ± 0.0024, respectively. There was no crystalline change in the LH-NSP compared with LH raw material on the basis of powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) analysis results. With the reduced particle size, the solubility and in vitro dissolution rate of LH in the LH-NSP were significantly improved. Pharmacokinetic studies showed that the Cmax and AUC0–24 of the group with oral administration of the LH-NSP were both 1.5 times higher than that of raw LH.

Highly effective CuZn0.3MgxAlOy (x = 0–0.2) catalysts for the synthesis of chiral L-phenylalaninol derived from Cu-rich hydrotalcite-like precursors were prepared by a co-precipitation method with Na2CO3 as the precipitant, and their physicochemical and catalytic properties were characterized. The results show that the presence of Mg2+ ions can promote the formation of hydrotalcite-like (htl) precursors, and the Mg2+ content would affect the phase purity of the prepared htl precursors. The BET surface area, exposed copper surface area and amount of acid sites of the samples decreased with the increase in the molar ratio of Mg2+/Al3+. Also, the dense layered htl precursors are beneficial to the atomically uniform distribution of the corresponding metal oxides in the prepared catalysts, promoting the stronger interaction between Cu0 and Al2O3 after the catalysts were reduced (SMSI effect). The activity of the CuZn0.3MgxAlOy catalysts is greatly dependent on not only the metallic copper surface area, but also the SMSI effect and the acidity of the catalysts. When Mg2+/Al3+ = 0.1 (mol), a phase-pure htl precursor could be obtained, and after calcination, the prepared CZA-0.1 catalyst exhibited very excellent catalytic performance for the hydrogenation of L-phenylalanine methyl ester to chiral L-phenylalaninol. After 5 h of reaction at 110 °C and 4 MPa H2, 100% conversion of L-phenylalanine methyl ester and 91.1% yield of L-phenylalaninol with an ee value of ~100% were achieved. After recycling 13 times, the L-phenylalaninol selectivity of the CZA-0.1 catalyst only decreased by 7.2%.

All visible-light-activated Azo photoswitches have recently blossomed. Herein two kinds of photoresponsive Azo hyperbranched polymers, HPTOF and HPTNF, were efficiently synthesized from the respective trinitro-functionalized monomers via combination of the AuNP-catalyzed photocatalytic method and the A3 monomer strategy. The polymerization process showed a very high monomer conversion (>95%) and a perfect selectivity. The molecular weights of the obtained Azo hyperbranched polymers were much higher than those of linear systems as reported previously, which could be efficiently adjusted by controlling the dosages of the mononitro-compound (the end-capping reagent) employed in the polymerization system. The resulting Azo hyperbranched polymers were well characterized by using GPC, NMR, FT-IR and UV-vis spectra. From unusual to common Azo-polymers, the π–π* absorptions in the UV-vis spectra show significant red-shifts; therefore the photoisomerizations of these Azo-polymers (HPTOF and HPTNF) can be induced by visible light. Interestingly, HPTOF and HPTNF demonstrated a double-wavelength (532 nm green light and 313 nm UV light) light-responsive Z → E photoisomerization. The relatively lower photoswitching ability of HPTNF than that of HPTOF was attributed to the partial overlap of π–π* (Z-isomer) and n–π* (E-isomer) transitions resulting from its much longer extending π-conjugation structure.

A novel type of multi-stimuli responsive supramolecular polymer (MRSP) has been successfully constructed based on the self-assembly of heteroditopic macromonomers in a mixed solvent (CDCl3 : CD3CN = 2 : 1, v/v), which contain benzo-21-crown-7 (B21C7) host units and secondary ammonium salt guest moieties at each end of a poly(e-caprolactone) (PCL) chain. Owing to the reversible host–guest complexation between B21C7 and the secondary ammonium salt, the resulting MRSPs exhibit multi-stimuli responsiveness to cations, pH, anions and temperature. More interestingly, nanofibers were facilely obtained via the solution electrospinning of a MRSP, which presented enhanced degradation behaviors in the presence of K+, Cl−, Et3N, or heating, indicating a multiple stimuli-responsive nature.

The commercialization of fuel cells and metal–air batteries can only be realized if expensive and scarce platinum-based catalysts are replaced by lower cost, efficient, and durable catalysts for the oxygen reduction reaction (ORR). Along with intensive research efforts in developing low-cost, metal-free catalysts to replace platinum-based catalysts, heteroatom doped graphitic carbon materials (especially graphene and carbon nanotubes) have been demonstrated to show superior ORR performance. However, graphdiyne, another member of the carbon family, has not been completely studied as an electrocatalyst for the ORR. We demonstrate here that nitrogen and fluorine co-doped, metal-free graphdiyne exhibits comparable electrocatalytic activity to commercial Pt/C both in half-cell and full-cell (primary Zn–air battery) tests, regarding its onset potential and limiting current density. Moreover, the new catalyst has better stability, as well as a higher tolerance to methanol crossover and CO poisoning effects, than the commercial Pt/C.

Combining the ring-closure method with the “grafting from” method, a novel synthetic strategy for preparing cyclic-brush polymers with controlled grafting density was successfully demonstrated. The cyclic polystyrene (c-PS) precursor was synthesized using the general methods of activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) and Cu-catalyzed azide–alkyne cycloaddition (CuAAC), and was well characterized using NMR, GPC, MALDI-TOF mass spectroscopy and FT-IR. The benzylic hydrogen atoms of c-PS were substituted with bromine based on Wohl–Ziegler bromination to generate a tertiary bromide ATRP macroinitiator (c-PSBr), and the bromine content can be adjusted to 18.4%, 25.3%, 31.9% and 50.3% by using different reaction conditions. This ATRP macroinitiator can also be converted into a macro-RAFT agent with azole (c-PSN) or ethyoxyl (c-PSO) as the Z groups based on the styrenic polymers as the R group. Using the as-prepared ATRP macroinitiator or macro-RAFT agents, a series of cyclic-brush polymers including c-PS-g-PS, c-PS-g-PNIPAM, c-PS-g-PMMA, c-PS-g-PMA and c-PS-g-PVAc were successfully prepared. The grafting density can be facilely tuned by using variable Br content of c-PSBr or Z group content of the macro-RAFT agents. The work illustrated a first example of versatile synthesis of cyclic-brush polymers with predictable molecular weight, grafting density and different grafting polymer chains.

The entrance flow of long glass fiber reinforced polypropylene has been studied. It is demonstrated that longer glass fibers are easier to break and accumulate at the entrance. As the length of the die and shear rate increase, the fiber breakage increases for long glass fiber reinforced polypropylene. Comparison of fiber breakages of long and short glass fiber reinforced polypropylene indicates that short glass fiber mainly breaks before and at the entrance and remains almost unchanged in the die, while longer glass fibers still break after the entrance within the die. It is demonstrated that fiber accumulation increased when increasing the length of the die and shear rate. The pressure is found to oscillate at the entrance and this pressure accumulation and release should be related to the fiber interactions and fiber breakage at the entrance. It is also found that the presence of long glass fibers would lead to significantly higher viscosity which would decrease when increasing the shear rate.

Ternary Ag nanoparticles (NPs)@polyoxometalate (POM)/reduced graphene oxide (rGO) nanohybrids were prepared by a facile photoreduction method, using POM as the photocatalyst, reducing and bridging molecules. The structure of the nanohybrids was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy, etc. Most importantly, both the rotating disk electrode and rotating ring-disk electrode tests indicated that the Ag NPs@POM/rGO nanohybrids exhibited excellent electrocatalytic activity towards oxygen reduction reaction via a direct four-electron transfer pathway due to the synergistic effect of Ag NPs and rGO.

This study aims to investigate the interaction mechanism of a hypoglycemic agent, trelagliptin (TLP), and human serum albumin (HSA) through computer simulation and assisted spectroscopy methods. Computer simulation including molecular docking and molecular dynamics analysis was conducted under physiological conditions. Molecular docking results indicate that TLP bound to HSA at site I, and the binding behavior was mainly governed by hydrophobic force. Competitive experiments further verified the theoretical conclusion from molecular docking. Molecular dynamics simulation revealed that TLP indeed stably bound to site I of HSA in the hydrophobic subdomain IIA. Moreover, TLP presented a certain effect on the structural compactness of HSA. In molecular dynamics simulation, hydrogen bonds appeared, which suggested the reliability and stability of the combination. The binding energy of the stable phase is around −250 kJ/mol. Fluorescence quenching studies and time-resolved fluorescence analysis indicated that the evident fluorescence quenching phenomenon of HSA could be due to TLP binding initiated by static quenching mechanism. The binding constants (Ka) of the complex were found to be around 104 via fluorescence data, and the calculated thermodynamic parameters indicated that hydrophobic force played major role in the binding of TLP to HSA. Synchronous fluorescence and three-dimensional fluorescence results demonstrated that TLP slightly disturbed the microenvironment of amino residues. Circular dichroism spectra showed that TLP affected the secondary structure of HSA. The theoretical and experimental results showed excellent agreement.

The long-carbon-fiber-reinforced polyamide-6/nickel powder composites were designed as electromagnetic interference (EMI) shielding materials and then were prepared through the joint processing of melt blending and thermoplastic pultrusion. The obtained composites show high conductivity and permittivity as well as a high dielectric loss with co-addition of carbon fiber and nickel powders, which makes the resulting composites a higher level of shielding effectiveness due to the combination of conductive and magnetic fillers. The composites are capable of shielding mainly through absorption rather than reflection. On the other hand, the composites achieved significant improvements in tensile, flexural, and impact strength due to the superiority of the long-carbon-fiber-reinforced technique. The residual fiber length in the injectionmolded specimens is greatly superior to the critical one predicted by the Kelly–Tyson model. This takes full advantage of the strength of the reinforcing fiber itself, thus leading to a promising reinforcement effect. The enhancement of impact toughness is due to the energy dissipation by fiber fracture as a result of long fiber effect. The morphologic investigation indicated that the fiber fracture and fiber pullout concurred on the impact and tensile fracture surfaces, and the former preceded the latter. Highlighted with both good EMI shielding properties and excellent mechanical performance, the composites designed by this work exhibit potential applications for the automotive, electronic, aerospace, and military industries. POLYM. COMPOS., 00:000–000, 2015. V C 2015 Society of Plastics Engineers

International audience; The application of nanohybrids based on polyoxomolybdates, reduced graphene oxide (rGO) and/or metal nanoparticles (NPs) high-performance electrode materials in electrocatalysis and energy storage devices is promising but still limited due to the complexity and the cost of the synthesis. Here we introduce a simple polyoxomolybdate, [Mo V 4O8(OH)2(H2O)2(C4O4)2] 2-(MoS), as reducing and stabilizing agent for the facile and one-pot syntheses of large quantity of highly stable MoS/rGO and MoS/Au NPs nanohybrids in aqueous solution without any catalyst or toxic co-solvent. They were characterized by various physical techniques and electrochemistry which confirm strong interaction between MoS and rGO sheets. We also used DFT calculations to investigate the affinity between MoS or its neutral form with graphene. The adsorption energy for the most stable configuration is-1.97 eV, indicating a strong adsorption process of MoS, which can also be confirmed by the distance (3.04 Å) and the charge transfer (0.86 e) between MoS and graphene. These observations are also consistent with the electrochemical results which underscore the excellent redox properties and high stability of MoS/rGO. Importantly, the MoS/rGO nanohybrids are excellent noble metal-free electrocatalysts for hydrogen peroxide reduction with high sensitivity, large detection range and low detection limit. Finally, the preliminary tests reveal that the electrode materials based on MoS/rGO and a low-cost carbon cloth (CC) composite MoS/rGO/CC may have a potential for an application in energy storage as performant and flexible supercapacitor, showing specific capacitance as high as 870 F g-1 at 10 mV s-1 and excellent stability after 5,000 cycles.

The main bottleneck causing lags in the application of transition metal oxides as substitutes for poly (3,4-ethylenedioxythiophene):poly (styrene-sulfonate) (PEDOT:PSS) are the relatively low level efficiencies of quantum dot light-emitting diodes (QLEDs), even though they can improve a device's stability. High-performance QLEDs are fabricated with long lifetimes using low-cost, reliable and all-solution-processed hole injection materials with a double hole injection layer (HIL) structure. Vanadium oxide (V2O5)/PEDOT:PSS double HILs offer a small staircase interface barrier, which enhance the hole injection and achieve a better charge balance. By using this double HIL regular planar architecture device, the maximum external quantum efficiency (ηEQE) reaches 18.09% and over 13355 h of lifetime. The related control PEDOT:PSS-based and V2O5-based QLEDs have maximum ηEQE of 13.79% and 9.13% with 6117 and 30881 h of lifetime, respectively. Due to the enhanced hole injection with the staircase interface barrier, the double HIL architecture QLEDs also have a high ηEQE above 15.00% over a wide range of 900–26000 cd m−2 with a low efficiency roll-off. These discoveries support the use of inorganic transition metal oxides as HILs for QLEDs with high efficiency and brightness for long operational lifetimes.

Developing the high-efficient and green synthetic method for chiral amino alcohols is an intriguing target. We have developed the Mg2+-doped Cu/ZnO/Al2O3 catalyst for hydrogenation of L-phenylalanine methyl ester to chiral L-phenylalaninol without racemization. The effect of different L-phenylalanine esters on this title reaction was studied, verifying that Cu/ZnO/Al2O3 is an excellent catalyst for the hydrogenation of amino acid esters to chiral amino alcohols. DFT calculation was used to study the adsorption of substrate on the catalyst, and showed that the substrate adsorbs on the surface active sites mainly by amino group (-NH2) absorbed on Al2O3, and carbonyl (C=O) and alkoxy (RO-) group oxygen absorbed on the boundary of Cu and Al2O3. This catalytic hydrogenation undergoes the formation of a hemiacetal intermediate and the cleavage of the C–O bond (rate-determining step) by reacting with dissociated H to obtain amino aldehyde and methanol ad-species. The former is further hydrogenated to amino alcohols, and the latter desorbs from the catalyst surface.

SrLa4-x-ySi3O13: xTb3+, yEu3+ phosphor was prepared by high temperature solid-state method. The luminescent centers of Eu3+ and Tb3+ occupying La3+ lattice sites in hosts were confirmed by Rietevld refinement method. The phenomenon of self-cross-relaxation energy transfer is observed between Tb3+ ions from 5D4-7FJ to 7F6-5D4 transition. Additionally, the direction of energy transfer (ET) was observed from Tb3+ to Eu3+ ions, and ET efficiency became more efficient as the concentration of activator increases. The type of ET between Tb3+ and Eu3+ ions was demonstrated to be the dipole-dipole mechanism. The multi-color lights were realized covering the green to red visible region by the route of energy transfer. Furthermore, the decrease of Eu3+ emission intensity resulting from thermal quenching can be effectively compensated by Tb3+→Eu3+ ET. The excellent luminescent properties and thermal stability show this phosphor to be a promising candidate for white LEDs.

A new hydrogen peroxide detection sensitive material, boron doped carbonized ZIF-67@graphene (Co-N/C@G-B) is synthesized through pyrolysis of a sandwich-like ZIF-67 coating graphene material. After doping boron atoms by using chemical vapor deposition method, new active sites such as Co2B and B-N-C bonds are created, and mesopores are significantly increased. Most importantly, this Co-N/C@G-B material is found to exhibit excellent performance as an enzyme-free biosensor for detecting hydrogen peroxide with a very wide detection range (from 0.5 x 10(-6) to 60 x 10(-3) M), a low detection limit (0.19 x 10(-6)M), and a rapid response time (approximate to 3 s). The prepared biosensor also shows strong anti-interference ability in the complex working occasions. Furthermore, for real application of the materials, an electronic device of biosensor is developed by using technologies of screen printing electrode, integrated circuit, 3D printed shell, and custom-developed program, which shows high sensitivity and portability to detect hydrogen peroxide. Such device paves a way for further practical application of advanced materials in commercial scale.

Using Brownian Dynamics, we study the dynamical behavior of a polymer grafted onto an adhesive surface close to the mechanically induced adsorption-stretching transition. Even though the transition is first order, (in the infinite chain length limit, the stretching degree of the chain jumps discontinuously), the characteristic relaxation time is found to grow according to a power law as the transition point is approached. We present a dynamic effective interface model which reproduces these observations and provides an excellent quantitaive description of the simulations data. The generic nature of the theoretical model suggests that the unconventional mixing of features that are characteristic for first-order transitions (a jump in an order parameter) and features that are characteristic of critical points (anomalous slowdown) may be a common phenomenon in force-driven phase transitions of macromolecules., 5 figures

60Co γ-ray irradiation-initiated reversible addition–fragmentation chain transfer (RAFT) polymerization at room temperature with 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) as the chain transfer agent was first applied to acrylonitrile (AN) polymerization, providing a “green” platform for preparing polyacrylonitrile (PAN)-based carbon fibers using an environment-friendly energy source. Various effects of dose rate, molar ratio of the monomer to the chain transfer agent, monomer concentration and reaction time on the AN polymerization behaviors were performed to improve the controllability of molecular the weight and molecular weight distribution of the obtained PAN. The feature of the controlled polymerization was proven by the first-order kinetics, linear increase of the molecular weight with the monomer conversion and a successful chain-extension experiment. The molecular weight and molecular weight distribution of PAN were characterized by size exclusion chromatography (SEC). 1H NMR and Matrix assisted laser desorption ionization/time of flight mass spectra (MALDI-TOF-MS) confirmed the chain-end functionality of PAN, which also was supported by the successful chain-extension experiments of original PANs with acrylonitrile and styrene as the second monomers respectively.

The development of a new generation of nanoscaled theranostics with simple compositions and versatile properties to realize enhanced diagnoses and treatment outcomes and to avoid side effects is highly desirable but remains a great challenge. Here we report a new ultrasmall theranostic based on bovine serum albumin-coated GdW10O36 nanoclusters (GdW10 NCs) as multifunctional theranostics for multifunctional bio-imaging, highly effective in vitro photothermal ablation of cancer cells and in vivo radiotherapy of tumors. The as-synthesized GdW10 NCs afford significantly enhanced computed tomography/magnetic resonance imaging signals and remarkable photothermal therapy (PTT)/radiotherapy therapy (RT) therapeutic effects for tumor treatment. Moreover, toxicity studies confirmed their low toxicity and efficient renal clearance, suggesting their potential for practical applications. These results indicated that the as-prepared GdW10 nanoclusters are promising as multifunctional nanotheranostics for multimodal imaging-guided PTT/RT of tumors. These results also encourage the further exploration of other polyoxometalate-based multifunctional nanotheranostics for cancer diagnoses and therapy. Nanostructures that can diagnose tumours and treat them with laser light and radiotherapy have been developed by researchers in China. ‘Theranostic’ nanoparticles that combine bioimaging with targeted action against cancer cells are often too large to pass safely through the kidney, leading to cytotoxicity issues. To overcome such problems, Zhanjun Gu from the Chinese Academy of Sciences and co-workers synthesized polytungstates nanoclusters containing rare-earth gadolinium ions and coated them with a biocompatible protein film. These water-soluble, sub-5-nanometre particles enhanced magnetic resonance and computed tomography imaging thanks to the gadolinium components. In vivo tests in mice revealed that the nanoclusters localized in tumour microstructures where they could be excited by laser or X-ray beams to damage and repress tumour formation. Afterwards, the nanoparticles were cleared through the kidney harmlessly. In this work, a new theranostics based on GdW10@BSA NCs with ultrasmall size, but versatile properties, were fabricated, which possesses not only significant CT/ MR imaging signal enhancement but also remarkable photothermal therapy (PTT)/radiotherapy (RT) therapeutic effects for tumor. Therefore, our work may open an avenue in developing other POM-based multifunctional nanomedicines with better therapeutic outcome and fewer side effects.