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Supramolecular organic frameworks (SOFs), due to the atomically precise integration of the repeated building units, exhibit intriguing properties and consequently potential applications in chemical...

Although metal silicates are considered as the promising electrode materials for lithium-ion batteries, metal silicate-based materials suffer from inadequate cycling performance and dimensional unreliability evoked by the large volume changes during cycling, which hinders their practical applications. In principle, the poor electrochemical kinetics during the redox reactions of metal silicates is originated from the instinct structure. Hence, the precise and delicate ability to construct hetero-layers to tailor intercalation reaction remains elusive. Herein, a facile strategy of designing and constructing heterostructure in a cobalt-copper silicates nano-architecture (CNT@CoCuSiOx) with synergistic interaction between cobalt silicate (Co2SiO4) with copper silicate (CuSiO3) on the surface of carbon nanotubes (CNTs). Moreover, Co2SiO4/CuSiO3 heterojunction with unbalanced charge distributions that rooted from in-situ generation on CNTs by a facile one-step hydrothermal process, can efficiently tailor the electrochemical activities of Cu3+/Cu2+ and Co3+/Co2+ redox reactions by elevating transfer of electrons and delivering the heterointerface effect. The tough and conductive nanostructure of CNTs basement facilitate the ion diffusion and improve the rate capability. The heterostructure-incorporated CNT@CoCuSiOx-(2/1) exhibits not only outstanding electrochemical capacity (545 mAh g−1 at 0.1 A g−1), superior ion/electron transmission efficiency but also robust cycling performance (516 mAh g−1 after 900 cycles at 0.5 A g−1 and an excellent capacity retention rate of 95%). Beyond energy storage, our delicate methodology in manipulating the electrochemical behavior of metal silicates opens up a critical insight into rational fabrication of next-generation anodes for lithium-ion battery.

In the satisfactory design and synthesis of high-performance nonlinear optical (NLO) materials, for meeting the rapidly expanding demands of optoelectronic devices, a deeper understanding of the relationship between the structures and NLO properties has become a key issue. Herein, five novel mislinked expanded hexaphyrins with different connections of pyrrole units are selected to study the relationship between the structures and NLO properties. These five mislinked expanded hexaphyrins are neo-fused, neo-confused hexaphyrins, singly, doubly, and triply N-confused hexaphyrins. From theoretical results, the order of the static first hyperpolarizability (β0) values is found to be: neo-fused hexaphyrin (β0 = 4163 a.u.) < neo-confused hexaphyrin (β0 = 5494 a.u.) < singly N-confused hexaphyrin (β0 = 6510 a.u.) < doubly N-confused hexaphyrin (β0 = 15 130 a.u.) < triply N-confused hexaphyrin (β0 = 26 095 a.u.). Furthermore, β0 values of the doubly and triply N-confused hexaphyrins are improved 2.1 and 3.7 times over that of their usual parent hexaphyrin (β0 = 7120 a.u.), respectively. It is worth noting that increasing mislinked connection numbers and changing mislinked connection ways of the pyrrole units in these mislinked expanded hexaphyrins plays a crucial role in the tune of their second-order NLO responses.

The mechanism of the Cu(I)-catalyzed domino reaction furnishing 1-aryl-1,2,3-triazole assisted by CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is explored with density functional theory (DFT) calculations. The overall mechanism for this domino reaction comprises four consecutive reactions: (i) deprotonation of terminal alkyne by DBU; (ii) cycloaddition of copper acetylide and N3−; (iii) C–N bond coupling of the cuprate–triazole anion and aryl bromide; and (iv) protodecupration. Our theoretical calculations indicate that the Cu-catalyzed azidation of the electron-rich aryl bromides with N3−, which would generate the aryl azide for subsequent Cu(I)-catalyzed alkyne–azide cycloaddition, is not the dominant reaction because of its high free energy barrier. In addition, the cycloaddition process can assist C(aryl)–N bond formation. Activation strain analyses suggest that oxidative addition of aryl bromide onto the cuprate–triazole anion is more facile mainly due to enhanced dCu– orbital interaction. A close attraction between copper and aryl bromide during oxidative addition is critical to the lower barrier.

The interest in new emerging pollutants (NEPs) does not only focus on the main compounds but also the degradation or intermediate products. It is important to have an effective primary treatment for the removal/degradation of NEPs from hospital and clinical wastewater to protect the environment. In this study, nifedipine degradation was performed by an electro-oxidation method using titanium-based mixed metal oxide (MMO) electrode. The determination of nifedipine was carried out by differential pulse voltammetry at hanging mercury drop electrode using Britton–Robinson buffer (BRB). The nifedipine oxidation peak was observed at + 0.7 V at a scan rate of 20 mV s−1 in BRB pH 8. Titanium-based electrodes with different metal oxide compositions were assessed as an anode material for nifedipine degradation as follows: TiO2/Ti, IrO2–TiO2/Ti, RuO2–TiO2/Ti, and IrO2–RuO2–TiO2/Ti. The electro-oxidation of nifedipine was monitored using cyclic voltammetric techniques, and the degradation intermediates were confirmed using LC–MS. Approximately 65–83% of nifedipine degradation was achieved using RuO2–TiO2/Ti and IrO2–TiO2/Ti electrodes. Interestingly, RuO2–IrO2–TiO2 electrode showed complete (100%) electro-oxidation of nifedipine at 30 min. Two nifedipine degradation intermediates were identified, namely 5-methoxycarbonyl-2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3-carboxylic acid (compound I) and 2,6-dimethyl-4-phenyl-1,4-dihydropyridine-3,5-dicarbaldehyde (compound II) during the electro-oxidation process using RuO2–IrO2–TiO2 electrode. Finally, the degradation pathway of nifedipine by MMO electrode was proposed. This is the first report on the nifedipine degradation using MMO titanium electrode by the electro-oxidation process.

Synthesizing polymers with tailor-made molecular weight distribution (MWD) is an essential step toward better control and design of functional polymer materials. We propose a novel one-pot reaction...

The stereospecific design of the interface effects can optimize the electron/Li-ion migration kinetics for energy-storage materials. In this study, an electric field was introduced to silicon-based materials (C-SiOx@Si/rGO) through the rational construction of multi-heterostructures. This was achieved by manipulating the physicochemical properties at the atomic level of advanced Li-ion batteries (LIBs). The experimental and density functional theory calculations showed that the unbalanced charge distribution generated a large potential difference, which in turn induced a large-scale electric-field response with a boosted interfacial charge transfer in the composite. The as-prepared C-SiOx@Si/rGO anode showed advanced rate capability (i.e., 1579.0 and 906.5 mAh g-1 at 1000 and 8000 mA g-1, respectively) when the migration paths of the Li-ion/electrons hierarchically optimized the large electric field. Furthermore, the C-SiOx@Si/rGO composite with a high SiOx@Si mass ratio (73.5 wt %) demonstrated a significantly enhanced structural stability with a 40% volume expansion. Additionally, when coupled with the LiNi0.8Co0.1Mn0.1O2 (NCM) cathode, the NCM//C-SiOx@Si/rGO full cell delivers superior Li-ion storage properties with high reversible capacities of 157.6 and 101.4 mAh g-1 at 500 and 4000 mA g-1, respectively. Therefore, the electric-field introduction using optimized electrochemical reaction kinetics can assist in the construction of other high-performance LIB materials.

Functional materials displaying tunable emission and long-lived luminescence have recently emerged as a powerful tool for applications in information encryption, organic electronics and bioelectronics. Herein, we present a design strategy to achieve color-tunable ultralong organic room temperature phosphorescence (UOP) in polymers through radical multicomponent cross-linked copolymerization. Our experiments reveal that by changing the excitation wavelength from 254 to 370 nm, these polymers display multicolor luminescence spanning from blue to yellow with a long-lived lifetime of 1.2 s and a maximum phosphorescence quantum yield of 37.5% under ambient conditions. Moreover, we explore the application of these polymers in multilevel information encryption based on the color-tunable UOP property. This strategy paves the way for the development of multicolor bio-labels and smart luminescent materials with long-lived emission at room temperature., Functional materials displaying tunable emission and long-lived luminescence are a powerful tool in information encryption, organic electronics and bioelectronics. Here the authors design a color-tunable ultralong organic room temperature phosphorescence polymer through radical multiple component cross-linked copolymerization.

Tantalum (Ta) is an element with high chemical stability and ductility that is used in orthopedic biomaterials. When utilized, it can produce a bioactive surface and enhance cell–material interactions, but currently, there exist scarce effective methods to introduce the Ta element onto the surface of implants. This work reported a sol–gel-assisted approach combined with micro-arc oxidation (MAO) to introduce Ta onto the surface of the titanium (TC4) substrate. Specifically, this technique produced a substrate with a hierarchically rough structured topography and introduced strontium ions into the film. The films were uniform and continuous with numerous crater-like micropores. Compared with the TC4 sample (196 ± 35 nm), the roughness of Ta (734 ± 51 nm) and Ta–Sr (728 ± 85 nm) films was significantly higher, and both films (Ta and Ta–Sr) showed increased hydrophilicity when compared with TC4, promoting cell attachment. Additionally, the in vitro experiments indicated that Ta and Ta–Sr films have the potential to enhance the recruitment of cells in the initial culture stages, and improve cell proliferation. Overall, this work demonstrated that the application of Ta and Ta–Sr films to orthopedic implants has the potential to increase the lifetime of the implants. Furthermore, this study also describes an innovative strategy to incorporate Ta into implant films.

Hypoxia of solid tumor compromises the therapeutic outcome of photodynamic therapy (PDT) that relies on localized O2 molecules to produce highly cytotoxic singlet oxygen (1O2) species. Herein, we present a safe and versatile self-assembled PDT nanoagent, i.e., OxgeMCC-r single-atom enzyme (SAE), consisting of single-atom ruthenium as the active catalytic site anchored in a metal-organic framework Mn3[Co(CN)6]2 with encapsulated chlorin e6 (Ce6), which serves as a catalase-like nanozyme for oxygen generation. Coordination-driven self-assembly of organic linkers and metal ions in the presence of a biocompatible polymer generates a nanoscale network that adaptively encapsulates Ce6. The resulted OxgeMCC-r SAE possesses well-defined morphology, uniform size distribution and high loading capacity. When conducting the in situ O2 generation through the reaction between endogenous H2O2 and single-atom Ru species of OxgeMCC-r SAE, the hypoxia in tumor microenvironment is relieved. Our study demonstrates a promising self-assembled nanozyme with highly efficient single-atom catalytic sites for cancer treatment., The hypoxic microenvironment in solid tumors limits the efficacy of photodynamic therapy (PDT) since oxygen is necessary to produce high cytotoxic singlet oxygen species. Here, the authors develop an improved self-assembled single-atom nanozyme which allows oxygen generation to enhance PDT efficacy.

Accurate and effective sensing of H2S is one of the most complex and challenging tasks. Recent studies have demonstrated that the development of an Sb-doped SnO2 nanoribbon sensor can enhance the detection limit of H2S. To clarify the enhancement mechanism, various factors that regulate the sensing processes, such as the Sb-doped sites, surface oxygen defects and possible pre-adsorbed oxygen species, are considered in this study. Theoretical calculations reveal a thorough and extensive understanding of the gas-sensing mechanisms. Once the H2S gas interacted with the Sb-doped SnO2(110) surface, the molecule released electrons back to the surface, together with a decreased resistance level and strengthened detection signal. In addition, the dissociative adsorption of the O2 molecule also plays a significant role in the sensing processes. It is expected that the present work can provide effective guidance for improving the sensitivity of metal oxide surfaces and shed new light on the development of next generation gas-sensing materials.

In this study, flavonoid myricetin-mediated gold nanoparticles (Myr-AuNPs) were synthesized and their molecular interactions were evaluated through a combined experimental and theoretical study. The physicochemical properties of the synthesized Myr-AuNPs were characterized using TEM, FT-IR, and XRD analysis. The average particle size of the Myr-AuNPs was found to be 6 nm with spherical in shape. FT-IR results indicated that the hydroxyl groups of myricetin interacts with Au 3+ ions during the nanoparticles formation. Consequently, density functional theory (DFT) was used to evaluate the possible molecular interactions of myricetin hydroxyl groups with Au 3+ ions. Interestingly, the DFT results confirmed that the 5′-hydroxyl group of ring B in myricetin was more suitable and highly stable to interact with Au 3+ ions during the nanoparticles formation in aqueous medium. Further, this study emphasized that the synthesized Myr-AuNPs exhibits excellent pH, temperature, and storage stability. In addition to this, biocompatibility study recommended that Myr-AuNPs is safe for therapeutic applications. This is the first detailed report on the molecular interaction between the hydroxyl groups of myricetin and Au 3+ ions during the nanoparticle formation.

C20H24ClNiN3O4, monoclinic, P21/c (no. 14), a = 10.3831(7) Å, b = 17.0139(12) Å, c = 12.2649(9) Å, β = 102.6230(10)°, V = 2114.3(3) Å3, Z = 4, R gt (F) = 0.0318, wR ref (F 2) = 0.1066, T = 298(2) K.

Description, Wireless and passive bioelectronic medicines mimic the biological cues of the extracellular matrix., The biophysical characteristics of the extracellular matrix (ECM), such as a three-dimensional (3D) network and bioelectricity, have a profound influence on cell development, migration, function expression, etc. Here, inspired by these biophysical cues of ECM, we develop an electromechanical coupling bio-nanogenerator (bio-NG) composed of highly discrete piezoelectric fibers. It can generate surface piezopotential up to millivolts by cell inherent force and thus provide in situ electrical stimulation for the living cells. Besides, the unique 3D space in the bio-NGs provides an ECM-like growth microenvironment for cells. As a result, our bio-NGs effectively promote cell viability and development and, more importantly, maintain its specific functional expression. These advanced in vitro bio-NGs are expected to fill the gap between the inaccurate 2D systems and the expensive and time-consuming animal models, mimicking the complexity of the ECM and the physiological relevance of an in vivo biological system.

A kind of annular uranium nitride (UN) fuel suitable for lead-cooled fast reactor applications has been designed in this study. The design is directly targeting two main issues of UN fuel: severe swelling and thermal decomposition of UN fuel at high temperatures. A performance analysis program based on FORTRAN programming language has been developed for UN fuel in fast reactors. The program contains heat transfer, fuel stress-strain analysis, cladding stress-strain analysis, fission gas release and fuel-cladding mechanical interaction (FCMI) modules, etc. Extensive code verification has been performed by comparing simulation results obtained with the code and those obtained via the COMSOL Multiphysics platform. Preliminary code validation has been conducted as well by comparing code simulation results with experimental data. The results showed that this program could predict the fuel temperature, stress-strain, and displacement of UN fuel during reactor operation with a reasonable accuracy.

Simultaneously regulating the crystallizing and combustion behaviors of poly(lactic acid) (PLA) will be conducive to its further development in the fields of electronic appliances, automotive and rail transit materials. To achieve this goal, a novel bifunctional additive triethylamine phenylphosphonate (TEAP) was synthesized through acid–base neutralization reaction between trimethylamine and phenylphosphonic acid. When TEAP was added into PLA, the crystallization behaviors of PLA/TEAP assessed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM) suggested that TEAP acted as a nucleating agent and plasticizer for PLA, which effectively increased the crystallization rate of PLA. However, PLA with 3 wt% TEAP showed a slower crystallization rate than that of PLA with 1 wt% TEAP due to the filler aggregation of TEAP. Thus, the crystallization rate increased first and then slightly decreased with increasing content of TEAP. Compared with the variation of the crystallization rate, the long period (L) and amorphous layer thickness (La) resulting from SAXS showed opposite trends, while the average crystal thickness (Lc) changed slightly; the reason may relate to the variation of the number of lamellae with increasing the content of TEAP. Meanwhile, the results of WAXD and Raman spectra showed the crystal structure of PLA was not affected by the addition of TEAP. The combustion behaviors of PLA and PLA/TEAP were evaluated by the limiting oxygen index (LOI), UL-94 test, cone calorimetry test (CCT) and thermal gravimetric analyses coupled to Fourier transform infrared spectroscopy (TGA-FTIR). According to the results, TEAP mainly promotes the removal of melt dripping, hence brings away heat and delays the combustion. Besides, the production of phosphorus-containing free radicals can quench hydrogen or oxygen free radicals in the fire. Thus, the fire safety of PLA is significantly improved by adding a very low content of TEAP (1–3 wt%). Only 1 wt% loading of TEAP can increase the LOI value of PLA from 19.5 vol% to 28.6 vol%, pass the UL-94 V-0 rating and have a low peak heat release rate of 404 kW m−2.

A series of thermoplastic poly(butylene-co-hydroquinone bis(2-hydroxyethyl)ether terephthalates) (PBHT), with different molar ratios of hydroquinone bis(2-hydroxyethyl)ether (HQEE)/1,4-butanediol 9...

Exploring a new type of nonlinear optical switch molecule with excess electron character is extremely important for promoting the application of excess electron compounds in the nonlinear optical (NLO) field. Here, we report external electric field (EEF) induced second-order NLO switch molecules of inorganic alkaline–earth alkalides, M(NH3)6Na2 (M = Mg or Ca). The centrosymmetric structure of M(NH3)6Na2 is destroyed in the presence of an EEF, and then a long-range charge transfer process occurs. It has been found that excess electrons are gradually transferred from one Na atom to the other Na atom through the inorganic metal cluster M(NH3)6. Finally, the excess electrons are completely located on one of the two Na atoms. In particular, the electronic contribution of the static first hyperpolarizability (βe0) for M(NH3)6Na2 exhibits a large significant difference when the EEF is switched on. The βe0 value of M(NH3)6Na2 is 0 when EEF = 0, while the peak βe0 values are 5.95 × 106 (a.u.) for Mg(NH3)6Na2 (EEF = 58 × 10−4 (a.u.)) and 1.83 × 107 (a.u.) for Ca(NH3)6Na2 (EEF = 53 × 10−4 (a.u.)). This work demonstrates that the compounds M(NH3)6Na2 can serve as potential candidates for NLO switches.

A pair of chiral aggregation-induced emission (AIE) enantiomers and their racemate exhibit not only distinctively different circularly polarized luminescence behaviors, but also completely opposite mechanoluminescence (ML) activities. The data from single crystal analysis identifies that the bright ML of the AIE enantiomers is probably activated by their molecular chirality, which enables unique chiral crystal structures with a polar space group and compact molecular packing. These experimental findings provide a direction for harvesting prominent ML from AIE luminogens. Concurrently, high contrast mechanochromism with larger ΔλPL,max and ΔΦF,s values by up to 140 nm and 0.61 respectively have been achieved from this AIE system, which represents the state-of-the-art mechanochromic performance for ML emitters. Moreover, force-induced white-light emission and thermally activated delayed fluorescence have also been observed. The results of theoretical calculations suggest that the destruction of intermolecular interactions and conversion of molecular conformation account for the significant multiple-variations in emission properties triggered by a single mechanical stimulus.

Understanding the atmospheric fate of hydrofluoroolefins (HFOs) is of great significance to assess their potential risk to the environment. As an important type of HFO, the comprehensive transformation mechanism and kinetics of Z(E)-CF3CH[double bond, length as m-dash]CHF initiated by OH radicals were investigated by performing quantum chemical calculations at the CCSD(T)/aug-cc-pVTZ//MP2/cc-pVDZ level. The results show that the OH-addition pathways are the most favorable for the title reaction. The rate constants are obtained by transition state theory with Wigner tunneling correction (TST/W). The calculated total rate constants are in good agreement with the experimental data. At 298 K, the computed rate constant and lifetime of Z(E)-CF3CH[double bond, length as m-dash]CHF are 9.66 × 10-13 (4.02 × 10-13) cm3 molecule-1 s-1 and 12.3 (29.7) days, respectively, which demonstrates that Z(E)-CF3CH[double bond, length as m-dash]CHF is atmospherically persistent.

In this work, we investigated the nonlinear optical (NLO) properties of excess electron electride molecules of M[Cu(Ag)@(NH3 )n ](M = Be, Mg and Ca; n = 1-3) using density functional theory (DFT). This electride molecules consist of an alkaline-earth (Be, Mg and Ca) together with transition metal (Cu and Ag) doped in NH3 cluster. The natural population analysis of charge and their highest occupied molecular orbital suggests that the M[Cu(Ag)@(NH3 )n ] compound has excess electron like alkaline-earth metal form double cage electrides molecules, which exhibit a large static first hyperpolarizability ( β0e ) (electron contribution part) and one of which owns a peak value of β0e 216,938 (a.u.) for Be[Ag@(NH3 )2 ] and vibrational harmonic first hyperpolarizability ( βzzznr ) (nuclear contribution part) values and the ratio of βzzznr / βzzze , namely, η values from 0.02 for Be[Ag@(NH3 )] to 0.757 for Mg[Ag@(NH3 )3 ]. The electron density contribution in different regions on βzzze values mainly come from alkaline-earth and transition metal atoms by first hyperpolarizability density analysis, and also explains the reason why βzzze values are positive and negative. Moreover, the frequency-dependent values β(-2ω,ω,ω) are also estimated to make a comparison with experimental measures. © 2018 Wiley Periodicals, Inc.

In this work, seven complexes based on graphitic carbon nitride (g-C3N4) were systematically investigated. Density functional theory calculations demonstrated that the energy gap between the highes...

In this study, polyvinylidene fluoride (PVDF) nanocomposite membranes with different fillers were fabricated using electrospinning technique. The physico-chemical properties of electrospun membranes such as PVDF (NF1), PVDF-polyvinyl pyrrolidone (PVP) (NF2), PVDF-activated carbon (AC) (NF3), PVDF-MnO2 (NF4), PVDF-PVP-AC (NF5), and PVDF-PVP-MnO2 (NF6) were assessed using field emission scanning electron microscopy-energy dispersive X-ray spectroscopy (FESEM-EDX), tensile tester, contact angle measurement, zeta potential, and attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR). The Bisphenol A (BPA) removal efficacy of the membranes was assessed using flat sheet membrane filtration unit. The single layer filtration for BPA removal at 30 min was found to be 27%, 100%, 24%, 54%, 100%, and 100% for NF1, NF2, NF3, NF4, NF5, and NF6, respectively. In particular, NF2 and NF6 membranes exhibited maximum removal of BPA with good retention potential for the entire sampling time. In recyclic application, the regenerated NF6 membrane showed better reusability for BPA removal. During the removal process, BPA attached with PVP and MnO2 present in NF6 membrane through hydrogen bonding interaction. The hydrogen bonding length and energies E H were calculated by density functional theory (DFT). Finally, this study suggests that PVP and MnO2 incorporated PVDF membrane might be an effective and reusable membrane for BPA removal from drinking water sources.

Organic optoelectronic functional materials featuring circularly polarized emission and persistent luminescence represent a novel research frontier and show promising applications in data encryption, displays, biological imaging, and so on. Herein, we present a simple and universal approach to achieve circularly polarized organic phosphorescence (CPP) from amorphous copolymers by the incorporation of axial chiral chromophores into polymer chains via radical cross-linked polymerization. Our experimental data reveal that copolymers (R/S)-PBNA exhibit a maximum CPP efficiency of 30.6% and the largest dissymmetric factor of 9.4 × 10-3 and copolymers (R/S)-PNA show the longest lifetime of 0.68 s under ambient conditions. Given the CPP property of these copolymers, their potential applications in multiple information encryption and displays are demonstrated, respectively. These findings not only lay the foundation for the development of amorphous polymers with superior CPP but also expand the outlook of room-temperature phosphorescent materials. National Research Foundation (NRF) This research was supported by a Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03) and partially by the National Key Research and Development Program of China (2020YFA0709900), the National Natural Science Foundation of China (21875104), the Joint Research Funds of Department of Science & Technology of Shaanxi Province and Northwestern Polytechnical University (2020GXLH-Z-006), and the Fundamental Research Funds for the Central Universities.

Objectives In this study, we investigated the effects of intense pulsed light (IPL) combined with 30% supramolecular salicylic acid on facial seborrheic dermatitis. Methods A total of 45 patients with mild or moderate facial seborrheic dermatitis were selected from our hospital between September 2018 and September 2019. The patients were divided into three groups consisting of 15 patients each. The first group was exposed to a combination of IPL and 30% supramolecular salicylic acid treatment, the second group was exposed to the IPL treatment alone, and the third group was exposed to the 30% supramolecular salicylic acid treatment alone. They were treated once every 4 weeks in three consecutive rounds. Results Facial lesions and symptoms were observed 4 and 12 weeks after the first treatment, and adverse reactions were recorded. The combination group showed significant improvement in symptoms 4 weeks after the first treatment, while the individual treatment groups showed no significant improvement. After three rounds of treatments, seborrheic dermatitis had significantly decreased in the three groups; the efficacy of the combined treatment group was significantly higher than that of the IPL group and the 30% supramolecular salicylic acid group. Conclusion IPL combined with 30% supramolecular salicylic acid was effective in the treatment of facial seborrheic dermatitis and provided a quicker result with no adverse reactions.

Objective This study aimed to develop and validate a high-performance liquid chromatography–tandem mass spectrometry method to simultaneously determine three bioactive components of the Huangqi Chifeng decoction (HQCF) in rat plasma. Methods Taxol was used as an internal standard in the developed method. Chromatographic separation was performed on a C18 column using a gradient elution with 0.1% formic acid in acetonitrile (v/v) and 0.1% formic acid in water (v/v) as the mobile phases at a flow rate of 0.4 mL·minute−1. All compounds were monitored via selected reaction monitoring with an electrospray ionization source. Results The lower limits of quantification of paeoniflorin, calycosin, and prim- O-glucosylcimifugin were 15.0, 0.75, and 0.75 ng·mL−1, respectively. The calibration curves indicated optimal linearity ( r > 0.99) across the concentration ranges. The specificity, precision, accuracy, recovery, matrix effect, and stability of the method were validated. This method was successfully applied in a pharmacokinetics study of the three compounds in rat plasma. Conclusion The pharmacokinetics results provide insights into the mechanisms of HQCF in vivo and its future clinical application.

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers with tailor-made structures and functionalities. To facilitate their utilization for advanced applications, it is crucial to develop a systematic approach to control the properties of COFs, including the crystallinity, stability, and functionalities. However, such an integrated design is challenging to achieve. Herein, we report supramolecular strategy-based linkage engineering to fabricate a versatile 2D hydrazone-linked COF platform for the coordination of different transition metal ions. Intra- and intermolecular hydrogen bonding as well as electrostatic interactions in the antiparallel stacking mode were first utilized to obtain two isoreticular COFs, namely COF–DB and COF–DT. On account of suitable nitrogen sites in COF–DB, the further metalation of COF–DB was accomplished upon the complexation with seven divalent transition metal ions M(II) (M = Mn, Co, Ni, Cu, Zn, Pd, and Cd) under mild conditions. The resultant M/COF–DB exhibited extended π-conjugation, improved crystallinity, enhanced stability, and additional functionalities as compared to the parent COF–DB. Furthermore, the dynamic nature of the coordination bonding in M/COF–DB allows for the easy replacement of metal ions through a postsynthetic exchange. In particular, the coordination mode in Pd/COF–DB endows it with excellent catalytic activity and cyclic stability as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction, outperforming its amorphous counterparts and Pd/COF–DT. This strategy provides an opportunity for the construction of 2D COFs with designable functions and opens an avenue to create COFs as multifunctional systems. National Research Foundation (NRF) This research is supported by the Singapore National Research Foundation Investigatorship (No. NRF-NRFI2018-03). K.P.L., S.Y.Q., and J.Q. acknowledge support from the Singapore National Research Foundation (NRF), Prime Minister’s Office, under its Medium-Sized Centre Program and Grant NRF-CRP16-2015-02. Computations were supported by the National Supercomputing Centre in Singapore, as well as the Centre for Advanced 2D Materials, funded under the NRF Medium-Sized Centre Programs. We thank Dr. Tian-Guang Zhan for helpful discussions.

Kinetic behaviors of niobium and titanium carbide precipitates in iron are simulated with cluster dynamics. The simulations, carried out in austenite and ferrite for niobium carbides, and in austenite for titanium carbide, are analyzed for dependences on temperature, solute concentration, and initial cluster distribution. The results are presented for different temperatures and solute concentrations, compared to experimental data available. They show little impact of initial cluster distribution beyond a certain relaxation time and that highly dilute alloys with monomers only present a significantly different behavior from denser alloys or ones with different initial cluster distributions.

Covalent organic frameworks (COFs) are excellent platforms with tailored functionalities in photocatalysis. There are still challenges in increasing the photochemical performance of COFs. Therefore, we designed and prepared a series of COFs for photocatalytic hydrogen generation. Varying different ratios of β-ketoenamine to imine moieties in the linkages could differ the ordered structure, visible light harvesting, and bandgap. Overall, β-ketoenamine-linked COFs exhibited much better photocatalytic activity than those COFs having both β-ketoenamine and imine moieties on account of a nonquenched excited state and more favorable HOMO level in the photoinduced oxidation reaction from the former. Specifically, after

Materials with outstanding nonlinear optical (NLO) response exhibit excellent prospects in electrooptic devices. Thus, it is essential to find a high-performance NLO material to meet the growing demand for high-speed data transmission. In this study, theoretical investigations on the second order NLO properties of the novel expanded mislinked thia-norhexaphyrin, sulfur-free pentaphyrin, and their substituted derivatives were performed using density functional theory. Theoretical calculations display that the approximate planar structures of sulfur-free pentaphyrin embedded with two five-membered rings exhibits a remarkable NLO response and holds large dipolar contribution (Φ

Heat-processed Gynostemma pentaphyllum has shown strong activity against human lung carcinoma A549 cells. In this study, two dammarane-type saponins together with two known compounds were isolated from the ethanol extract of the heat-processed leaves of G. pentaphyllum. They were identified as 2α,3β,12β-trihydroxydammar-20(22),24-diene-3-O-β-D-glucopyranoside (1, namely damulin E), 2α,3β,12β-trihydroxydammar-20,24-diene-3-O-β-D-glucopyranoside (2, namely damulin F), damulin A (3) and damulin B (4), respectively, using NMR and mass spectra. Damulin E and damulin F showed moderate activity against A549, H1299, T24, SH-SY5Y and K562 cell lines in vitro using CCK-8 assay.

Intracellular antioxidants such as glutathione (GSH) play a critical role in protecting malignant tumor cells from apoptosis induced by reactive oxygen species (ROS) and in mechanisms of multidrug and radiation resistance. Herein, we rationally design two multicomponent self-assembled photodynamic therapy (PDT) nanoagents, that is, Glup-MFi-c and Glud-MFo-c, which consist of respective GSH-passivation and GSH-depletion linkers in metal−organic frameworks encapsulated with photosensitizers for a deeply comprehensive understanding of GSH-based tumor PDT. Multicomponent coordination, π−π stacking, and electrostatic interactions among metal ions, photosensitizers, and bridging linkers under the protection of a biocompatible polymer generate homogeneous nanoparticles with satisfied size, good colloid stability, and ultrahigh loading capacity. Compared to the GSH-passivated Glup-MFi-c, the GSH-depleted Glud-MFo-c shows pH-responsive release of photosensitizer and [FeIII(CN)6] linker in tumor cells to efficiently deplete intracellular GSH, thus amplifying the cell-killing efficiency of ROS and suppressing the tumor growth in vivo. This study demonstrates that Glud-MFo-c acts as a ROS amplifier, providing a useful strategy to deeply understand the role of GSH in combating cancer. Ministry of Education (MOE) National Research Foundation (NRF) Accepted version This research is supported by the Singapore National Research Foundation Investigatorship (NRF-NRFI2018-03), the Singapore Academic Research Fund (RT12/19), the National Natural Science Foundation of China (31471268), and the National Key Research and Development Program of China (Stem Cell and Translational Research, 2016YFA0101202).

Volatile organic compounds (VOCs) are widespread in our daily life and greatly harmful to human health, as well as to the environment. To date, it remains a formidable challenge to develop a highly sensitive visual system for selective detection of VOCs. Herein, we report on a metal-free organic molecule of 2,4-di(10 H-phenothiazin-10-yl)-1,3,5-triazine (TDP) with ultralong organic phosphorescence (UOP) feature as a visible chemical probe for chloroform detection. In the pristine solid state, this phosphor shows a green UOP with a lifetime of 56 ms after the removal of excitation light source; however, the UOP greatly diminishes when fumed with chloroform, which is ascribed to the variation in both radiative and nonradiative transitions in crystal with embedded chloroform. Remarkably, TDP materials demonstrate great potential as a visual chemical probe for chloroform, showing high sensitivity, excellent selectivity, and good repeatability. The limitation for chloroform detection is as low as 5 ppm. Combining experimental data and theoretical calculations, it is reasoned that the space confinement via intermolecular interactions between chloroform and TDP molecules play a vital role for high selectivity of chloroform detection. These results pave the way toward expanding the scope of organic luminogens with UOP as well as their applications.

Biodegradable poly(ether-imide-ester) elastomers were synthesized from succinic acid, 1,4-butanediol, polyethylene glycol 1000 and N′,N-bis(2-carboxyethyl)- pyromellitimide which was derived from pyromellitic dianhydride and glycine. The chemical structures, crystallinities, thermal stabilities, mechanical properties, hydrophilicities and biodegradabilities of these elastomers were investigated. The hard segments of the linear aliphatic poly (ether-ester) exhibited monoclinic chain packing. Increasing the amount of aromatic bisimide moieties in the poly (ether-ester) reduced the crystallinity of the material and improved the thermal stability and tensile strength of the elastomers. In addition, introducing a suitable amount of aromatic bisimide moieties into the poly(ether-ester) backbones endowed the elastomers with improved biodegradability but too many aromatic bisimide groups reduced the biodegradability of the elastomers.

A series of poly(ester-imide-ether), consisting of soft segments from poly(tetramethylene glycol) and N,N′-bis(2-carboxyethyl) pyromellitimide and hard segments based on 1,4-butanediol and N,N′-bis(2-carboxyethyl) pyromellitimide, were synthesized via the melt polycondensation. The chemical structures of the prepared elastomers were confirmed by Fourier transform infrared spectroscopy and 1HNMR, respectively. The results indicated that the introduction of aromatic bisimide groups endows the elastomers with excellent thermal stability and mechanical property, which increase with the increment of imide unit content in the prepared elastomers. Additionally, compared to the poly(ester-ether) elastomer, these poly(esterimide-ether) fibers displayed stronger tensile strength and better low-temperature elastic recovery property.

In this article, we report a benchmark experiment of the tungsten reactivity worth under a super-critical state which has been conducted at the VENUS-II facility of CIAE in Beijing. The cylindrical tungsten target reactivity worth was measured and extracted as −1.234 ± 0.114 × 10−3 Δk/k using a period method. The resultant tungsten reactivity worth was compared with those from the MCNP Monte Carlo simulations with five evaluated libraries, i.e., ENDF/B-VII.0, ENDF/B-VII.1, CENDL-3.1, JENDL-4.0 and JEFF-3.2. It is found that the results from the MCNP simulations with ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0 and JEFF-3.2 are overestimated, whereas that of CENDL-3.1 is underestimated, and those from the MCNP simulations with the ENDF/B-VII.1 and ENDF/B-VII.0 libraries show slight better agreement with the experiment data within errors. A correlation analysis was used to address these issues. We conclude that it is the discrepancy of the (n, γ) channel at the epithermal neutron region that mainly results in the difference between the measured and MCNP simulated tungsten reactivity worth values.

A series of novel polyether-based Bronsted acidic ionic liquids (ILs) have been synthesized, which contain both a polyoxyethylene (POE) chain and a sulfonic group ( SO 3 H). The prepared ILs can well dissolve trifluoromethanesulfonic acid (TfOH), and IL/TfOH mixture has good intermiscibility with the reactants of isobutane and isobutene. Then, a new IL/TfOH catalytic system for the preparation of alkylate gasoline has been developed. The advantages of the new catalytic system are high selectivity for C 8 -alkylate product and the recyclability of TfOH catalyst. Under the optimal catalytic conditions (using the IL with the polymerization degree n = 75, IL/TfOH(v/v) = 5, reaction temperature 60 °C, reaction time 30 min, and stirring rate 800 rpm), the C 8 -selectivity can reach 80%, and above 95% of C 8 -alkylate product is trimethylpentane (TMP). Therefore, the new IL/TfOH catalytic system can afford high-quality alkylate gasoline. In addition, the conversion of isobutene and C 8 -selectivity both have gradually a little drop during 6 recycles, which should attribute to a little loss of TfOH in every recycle.

Gynostemma pentaphyllum, a traditional herbal tea, and its flavonoids possess antioxidant activities. This study was carried out to isolate and identify these flavonoids from G. pentaphyllu...

The fabrication of robust sensors for the monitoring of emerging contaminants in real-life water samples has received much attention. In this study, copper oxide and carbon nano-fragment modified glassy carbon electrode (CuO-CNF/GCE) based electrochemical sensor was developed for the simultaneous monitoring of dihydroxybenzene isomers such as catechol (CC) and hydroquinone (HQ). The structural and morphological characterization of CuO-CNF/GCE was done by scanning electron microscopy - energy dispersive X-ray (SEM-EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The electrochemical oxidation of HQ and CC was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The CuO-CNF/GCE exhibited high current sensitivity for CC and HQ. The oxidation peak currents of CC at the CuO-CNF/GCE were linear function of concentration 0 μM to 150 μM, with detection limit of 2 μM (at a signal-to-noise ratio of 3) (R2 = 0.997) and the oxidation peak currents of HQ were linear function of concentration 3 μM to 80 μM, with 1 μM detection limit (S/N = 3) (R2 = 0.995). The CuO-CNF/GCE was successfully used for detecting the two dihydroxybenzene isomers in real-life water samples with high selectivity.

The major aim of the present study was to explore the effects of cullin 4B (CUL4B) on the proliferation and invasion of human gastric cancer cells. Gastric tumor tissues and paired adjacent non‑tumor tissues were obtained from 21 gastric cancer patients, and gastric cancer cell lines (AGS, MGC‑803, KATO‑III, MKN‑45, SGC‑7901, BGC‑823 and MKN‑74) were cultured. BGC‑823 cells were transfected with CUL4B small interfering (si)RNA or control siRNA. Reverse transcription‑quantitative polymerase chain reaction analysis was performed to detect the mRNA expression of CUL4B. Western blot analysis was performed to measure the protein levels of Wnt, β‑catenin, glutathione synthase kinase (GSK)‑3β, caspase‑3 and cyclin E. MTT and Transwell assays were performed to examine cell proliferation and invasion following CUL4B knockdown. In addition, the effect of CUL4B knockdown on the cell cycle and apoptosis of BGC‑823 cells was evaluated by flow cytometric analysis. The results indicated that compared with the adjacent non‑tumor tissues and a normal gastric epithelial cell line, gastric cancer tissues and cell lines exhibited significantly higher expression of CUL4B. Knockdown of CUL4B in gastric cancer cells suppressed cell proliferation, caused G1 arrest and inhibited cell invasion. Silencing of CUL4B also resulted in decreased Wnt and β‑catenin expression, but increased expression of GSK‑3β, caspase‑3 and cyclin E. These results indirectly demonstrate that CUL4B enhances the proliferation and invasion abilities of gastric cancer cells by upregulating the constituent factors Wnt and β‑catenin, as well as by negatively regulating the mRNA and protein expression of GSK‑3β, caspase‑3 and cyclin E. The potential mechanism of CUL4B highlighted in the present study may be helpful for the treatment of patients with gastric cancer.

ZnO thin films were prepared by metal–organic chemical vapor deposition (MOCVD) using diethylzinc (DEZn) and N2O. The chemical reaction process of DEZn and N2O in the gas phase was studied by density functional theory and computational fluid dynamics calculation. Kinetic and thermodynamic data provide a better understanding of the ZnO deposition process. The deposition rate of ZnO in the reaction chamber was simulated by kinetic parameters, and the dependence of the film growth rate on temperature was demonstrated. The maximum ZnO film growth rate was at 973–1273 K when grown using DEZn and N2O in a high-speed rotating horizontal chamber. When the temperature exceeded 1273 K, the parasitic reaction led to a rapid decline in the ZnO deposition rate. In addition, multi-component migration and chemical reaction were analyzed, and the complete mechanism of DEZn and N2O in the reaction chamber was given.

A global switching on-the-fly trajectory surface hopping dynamics simulation at the 3SA-CASSCF(12,11)/6-31G* quantum level has been employed to probe the photo-induced Wolff rearrangement (WR) reaction of 5-diazo Meldrum's acid (DMA) within three low-lying electronic excited states. The present simulation predicted that the branching ratios for relaxing back to the ground state, isomerizing to diazirine, and reaction to ketene I via carbene I are 69% ± 0.1, 3% ± 0.4, and 28% ± 0.1, which are in excellent agreement with those obtained by the femtosecond spectroscopy experiment, 67%, 3% and 30%, respectively. In particular, the present simulation revealed that the major WR reaction to ketene I pathway is stepwise via the excited-state to carbene I (17.8% ± 0.2) and via the ground-state to carbene I (8.7% ± 0.2), and the minor pathway is concerted synchronous (1.5% ± 0.6). The photo-induced WR reaction of DMA has been quantitatively interpreted in terms of the distribution of extended seam surfaces as a function of CN dissociation bonds for two important conical intersections within three low-lying electronic excited states. Ultrafast dynamic time constants have been estimated to be about 500 fs ± 120 fs and 180 fs ± 80 fs for the stepwise and the concerted WR reaction to ketene I which are also in good agreement with those determined by the experiment. Therefore, the photo-induced excited-state WR reaction mechanism has been quantitatively revealed by the present real-time dynamics simulation.