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The sensitivity of soil organic carbon (SOC) decomposition in seasonally frozen soils, such as alpine ecosystems, to climate warming is a major uncertainty in global carbon cycling. Here we measure soil CO 2 emission during four years (2018-2021) from the whole-soil warming experiment (4 °C for the top 1 m) in an alpine grassland ecosystem. We find that whole-soil warming stimulates total and SOC-derived CO 2 efflux by 26% and 37%, respectively, but has a minor effect on root-derived CO 2 efflux. Moreover, experimental warming only promotes total soil CO 2 efflux by 7-8% on average in the meta-analysis across all grasslands or alpine grasslands globally (none of these experiments were whole-soil warming). We show that whole-soil warming has a much stronger effect on soil carbon emission in the alpine grassland ecosystem than what was reported in previous warming experiments, most of which only heat surface soils., (© 2024. The Author(s).)

In this study, a comprehensive characterization was conducted on a chiral starburst molecule (C 57 H 48 N 4 , SBM) using scanning tunneling microscopy. When adsorbed onto the hBN/Rh(111) nanomesh, these molecules demonstrate homochiral recognition, leading to a selective formation of homochiral dimers. Further tip manipulation experiments reveal that the chiral dimers are stable and primarily controlled by strong intermolecular interactions. Density functional theory (DFT) calculations supported that the chiral recognition of SBM molecules is governed by the intermolecular charge transfer mechanism, different from the common steric hindrance effect. This study emphasizes the importance of intermolecular charge transfer interactions, offering valuable insights into the chiral recognition of a simple bimolecular system. These findings hold significance for the future advancement in chirality-based electronic sensors and pharmaceuticals, where the chirality of molecules can impact their properties.

Quantum spin liquids (QSLs) are in a quantum disordered state that is highly entangled and has fractional excitations. As a highly sought-after state of matter, QSLs were predicted to host spinon excitations and to arise in frustrated spin systems with large quantum fluctuations. Here we report on the experimental observation and theoretical modeling of QSL signatures in monolayer 1T-NbSe 2 , which is a newly emerging two-dimensional material that exhibits both charge-density-wave (CDW) and correlated insulating behaviors. By using scanning tunneling microscopy and spectroscopy (STM/STS), we confirm the presence of spin fluctuations in monolayer 1T-NbSe 2 by observing the Kondo resonance as monolayer 1T-NbSe 2 interacts with metallic monolayer 1H-NbSe 2 . Subsequent STM/STS imaging of monolayer 1T-NbSe 2 at the Hubbard band energy further reveals a long-wavelength charge modulation, in agreement with the spinon modulation expected for QSLs. By depositing manganese-phthalocyanine (MnPc) molecules with spin S = 3/2 onto monolayer 1T-NbSe 2 , new STS resonance peaks emerge at the Hubbard band edges of monolayer 1T-NbSe 2 . This observation is consistent with the spinon Kondo effect induced by a S = 3/2 magnetic impurity embedded in a QSL. Taken together, these experimental observations indicate that monolayer 1T-NbSe 2 is a new promising QSL material., (© 2024. The Author(s).)

Global climate warming could affect the methane (CH 4 ) and nitrous oxide (N 2 O) fluxes between soils and the atmosphere, but how CH 4 and N 2 O fluxes respond to whole-soil warming is unclear. Here, we for the first time investigated the effects of whole-soil warming on CH 4 and N 2 O fluxes in an alpine grassland ecosystem on the Tibetan Plateau, and also studied the effects of experimental warming on CH 4 and N 2 O fluxes across terrestrial ecosystems through a global-scale meta-analysis. The whole-soil warming (0-100 cm, +4°C) significantly elevated soil N 2 O emission by 101%, but had a minor effect on soil CH 4 uptake. However, the meta-analysis revealed that experimental warming did not significantly alter CH 4 and N 2 O fluxes, and it may be that most field warming experiments could only heat the surface soils. Moreover, the warming-induced higher plant litter and available N in soils may be the main reason for the higher N 2 O emission under whole-soil warming in the alpine grassland. We need to pay more attention to the long-term response of greenhouse gases (including CH 4 and N 2 O fluxes) from different soil depths to whole-soil warming over year-round, which could help us more accurately assess and predict the ecosystem-climate feedback under realistic warming scenarios in the future., (© 2023 John Wiley & Sons Ltd.)

Cadmium (Cd) and arsenic (As) co-contamination has threatened rice production and food safety. It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors. Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils. In addition, the effect of zero-valent iron (ZVI) on grain As speciation accumulation in alkaline paddy soils was first investigated. The effect of rice straw biochar (SC), magnesium-loaded rice straw biochar (Mg/SC), and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment. Addition of SC, Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%, 90.3% and 100%, and inorganic As (iAs) by 35.4%, 33.1% and 29.1%, respectively, and reduced Cd concentrations in porewater by 74.3%, 96.5% and 96.2%, respectively. Reductions of 51.6% and 87.7% in porewater iAs concentrations were observed with Mg/SC and ZVI amendments, but not with SC. Dimethylarsinic acid (DMA) concentrations in porewater and grain increased by a factor of 4.9 and 3.3, respectively, with ZVI amendment. The three amendments affected grain concentrations of iAs, DMA and Cd mainly by modulating their translocation within plant and the levels of As(III), silicon, dissolved organic carbon, iron or Cd in porewater. All three amendments (SC, Mg/SC and ZVI) have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain, although the pathways are different., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

For covalent attachment-supported α-diimine catalysts, on the basis of ensuring the thermal stability and activity of the catalysts, the important problem is that the active group on the catalyst can quickly react with the support, anchoring it firmly on the support, shortening the loading time, reducing the negative impact of the support on the active centers, and further improving the polymer morphology, which makes them suitable for use in industrial polymerization temperatures. Herein, we synthesized a α-diimine nickel(II) catalyst bearing four hydroxyl substituents. The hydroxyl substituents enable the catalyst to be immobilized firmly on silica support by covalent linkage in 5-10 min. Compared with the toluene solvent system, the homogeneous catalysts show high activity and thermal stability in hexane solvent at the same conditions. Compared with homogeneous catalysts, heterogeneous catalysis leads to improvements in catalyst lifetime, polymer morphology control, catalytic activity, and the molecular weight of polyethylene (up to 679 kg/mol). The silica-supported catalysts resulted in higher melting temperatures as well as lower branching densities in polyethylenes. Even at 70 °C, the polyethylene prepared by S-CatA-2 still exhibits dispersed particle morphology, and there is no phenomenon of reactor fouling, which is suitable for industrial polymerization processes.

Background and Aims: Nitrogen enrichment affects biodiversity, plant functional traits and ecosystem functions. However, the direct and indirect effects of nitrogen addition and biodiversity on the links between plant traits and ecosystem functions have been largely overlooked, even though multidimensional characteristics of plant functional traits are probably critical predictors of ecosystem functions., Methods: To investigate the mechanism underlying the links between plant trait identity, diversity, network topology and above- and below-ground biomass along a plant species richness gradient under different nitrogen addition levels, a common garden experiment was conducted in which those driving factors were manipulated., Key Results: The study found that nitrogen addition increased above-ground biomass but not below-ground biomass, while species richness was positively associated with above- and below-ground biomass. Nitrogen addition had minor effects on plant trait identity and diversity, and on the connectivity and complexity of the trait networks. However, species richness increased above-ground biomass mainly by increasing leaf trait diversity and network modularity, and enhanced below-ground biomass through an increase in root nitrogen concentration and network modularity., Conclusions: The results demonstrate the mechanistic links between community biomass and plant trait identity, diversity and network topology, and show that the trait network architecture could be an indicator of the effects of global changes on ecosystem functions as importantly as trait identity and diversity., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Ullmann-like on-surface synthesis is one of the most appropriate approaches for the bottom-up fabrication of covalent organic nanostructures and many successes have been achieved. The Ullmann reaction requires the oxidative addition of a catalyst (a metal atom in most cases): the metal atom will insert into a carbon-halogen bond, forming organometallic intermediates, which are then reductively eliminated and form C-C covalent bonds. As a result, traditional Ullmann coupling involves reactions of multiple steps, making it difficult to control the final product. Moreover, forming the organometallic intermediates will potentially poison the metal surface catalytic reactivity. In the study, we used the 2D h BN, an atomically thin sp 2 -hybridized sheet with a large band gap, to protect the Rh(111) metal surface. It is an ideal 2D platform to decouple the molecular precursor from the Rh(111) surface while maintaining the reactivity of Rh(111). We realize an Ullmann-like coupling of a planar biphenylene-based molecule, i.e., 1,8-dibromobiphenylene (BPBr 2 ), on an h BN/Rh(111) surface with an ultrahigh selectivity of the biphenylene dimer product, containing 4-, 6-, and 8-membered rings. The reaction mechanism, including electron wave penetration and the template effect of the h BN, is elucidated by combining low-temperature scanning tunneling microscopy and density functional theory calculations. Our findings are expected to play an essential role regarding the high-yield fabrication of functional nanostructures for future information devices.

In recent years, polymorphic transformation involved in media milling has become a key factor in inducing the instability of nanosuspensions (NSs). The variation trend of microhydrodynamic parameters, including milling intensity factor (F), can be observed under different milling conditions. Therefore, this study first referenced the microhydrodynamic model to explore how formulations and process parameters affect Irbesartan (IRB) form A crystallinity during wet media milling. As a result, the crystallinity of form A was affected by the intermolecular interactions between drug particles and stabilizers. The crystallinity of form A decreased with decreasing drug loading, increasing stirrer speed and bead loading, which depended on the role of F. Milling could promote the transformation from a 1H to 2H tetrazole ring with stabilizers containing -OH, and form B was changed to form A and finally to an amorphous state. Molecular modelling shows that forms A and B are ductile and fragile materials, respectively, and both present anisotropy. When milling beads hit both polymorphs paralleling to the (010) surface, the bead-bead collisions are more helpful in fracturing IRB particles. The results of this study may provide a foundation for controlling crystal transformation and obtaining ideal crystal forms., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Agroforestry systems provide a wide range of soil multiple functions (that is, soil multi-functionality) to human society, including the regulation of nutrients and water in soils and the sequestration of atmospheric carbon dioxide, whereas how these effects varied with agroforestry practices and environmental conditions remain unclear. Here, by comparing the soil multi-functionality in agroforestry systems to forests through the field experiment and global scale meta-analysis, we tested, 1) how agroforestry affected soil multi-functionality in a single field study and at the global scale, 2) whether the effects of agroforestry on soil multi-functionality changed in different agroforestry practices, 3) whether the effects of agroforestry on soil multi-functionality varied with environmental conditions. Our study showed that most of the soil functions in agroforestry systems is higher than in forests at the global scale, but show no significant differences between agroforestry and planted forests in our field study. We also found that the effects of agroforestry on soil multi-functionality were varied with agroforestry practices, showing a greater positive in forest-herbage systems than in other practices. In addition, the positive effects of agroforestry on soil organic carbon and total phosphorus declined with the extension of experimental duration. Furthermore, our analysis found that climate conditions had a minor effect on the effects of agroforestry on soil functions. Our analysis revealing that the effects of agroforestry on soil functions depend on agroforestry practices, highlighting that the effects of agroforestry may be diminished with age, and suggesting that the evaluation of ecological impacts of agroforestry should be based on long-term experiments across multiple practices., Competing Interests: Declaration of competing interest The authors declared that they have no conflicts of interest to this work. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The structure and function of plant communities in alpine meadow ecosystems are potentially susceptible to climate warming. Here, we utilized a unique field manipulation experiment in an alpine meadow on the Qinghai-Tibetan Plateau and investigated the responses of plant species diversity, composition, biomass, and net primary productivity (NPP) at both community and functional group levels to whole-soil-profile warming (3-4 °C across 0-100 cm) during 2018-2021. Plant species diversity, biomass and NPP (both above- and belowground) at the community level showed remarkable resistance to warming. However, plant community composition gradually shifted over time. Over the whole experimental warming period, aboveground biomass of legumes significantly decreased by 45%. Conversely, warming significantly stimulated aboveground biomass of forbs by 84%, likely because of better growth and competitive advantages from the warming-induced stimulation of soil water and other variables. However, warming showed minor effects on aboveground biomass of grasses and sedges. Overall, we emphasize that experimental warming may significantly affect plant community composition in a short term by triggering adjustments in plant interspecific competition or survival strategies, which may cause potential changes in plant productivity over a more extended period and lead to changes in carbon source-sink dynamics in the alpine meadow ecosystem., Competing Interests: The authors declare that they have no conflicts of interest in this work., (© 2022 The Authors. Publishing Services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)

Four supported α-diimine nickel(II) catalysts covalently linked to silica via hydroxyl functionality on α-diimine acenaphthequinone-backbone were prepared and used in slurry polymerizations of ethylene to produce branched polyethylenes. The catalytic activities of these still reached 10 6 g/molNi·h at 70 °C. The life of the supported catalyst is prolonged, as can be seen from the kinetic profile. The molecular weight of the polyethylene obtained by the 955 silica gel supported catalyst was higher than that obtained by the 2408D silica gel supported catalyst. The melting points of polyethylene obtained by the supported catalysts S-C1-a/b are all above 110 °C. Compared with the homogeneous catalyst, the branching numbers of the polyethylenes obtained by the supported catalysts S-C1-a/b is significantly lower. The polyethylenes obtained by supported catalyst S-C1-a/b at 30-50 °C are free-flowing particles, which is obviously better than the rubber-like cluster polymer obtained from homogeneous catalyst.

Based on metaphorical cognitive theory, this research did four experiments to examine whether and how one important feature of money, denomination, could influence prosocial behavior. Study 1 was an experiment with a sample size of 209 undergraduates ( M age  = 18.97) showed that a larger denomination enhanced the probability of participants engaging in prosocial behavior rather than with a smaller denomination. Study 2 collecting data from 269 undergraduates ( M age  = 18.50) further showed that larger denominations condition inspired more prosocial behavior than the control condition; and the small denominations condition produced similar levels of prosocial behavior to the control condition. Study 3 used single factor design with a sample size of 192 undergraduates ( M age  = 20.49) repeated the results of Study 2. Furthermore, Study 3 excluded an important alternative explanation that the value rather than the denomination influenced prosocial behavior. Last, Study 4 applied a factorial design experiment with a sample size of 132 undergraduates ( M age  = 20.92) which demonstrated that generosity mediated the effect of denomination on prosocial behavior; the effect of denomination on prosocial behavior did not depend on money priming methods. Finally, theoretical and practical implications were discussed.

Chirality is essential for various phenomena in life and matter. However, chirality and its switching in electronic superlattices, such as charge density wave (CDW) superlattices, remain elusive. In this study, we characterize the chirality switching with atom-resolution imaging in a single-layer NbSe 2 CDW superlattice by the technique of scanning tunneling microscopy. The atomic arrangement of the CDW superlattice is found continuous and intact although its chirality is switched. Several intermediate states are tracked by time-resolved imaging, revealing the fast and dynamic chirality transition. Importantly, the switching is reversibly realized with an external electric field. Our findings unveil the delicate switching process of chiral CDW superlattice in a two-dimensional (2D) crystal down to the atomic scale., (© 2022. The Author(s).)

Suppressing intramolecular vibration of non-fullerene acceptors (NFAs) by molecular rigidification has been proven to be an effective way to reduce the non-radiative recombination loss and energetic disorder of organic solar cells (OSCs). Thus far, extensive attention has been drawn on rigidifying the fused-ring backbones of NFAs, whereas the highly flexible alkyl side chains are barely concerned. Herein, an effective strategy of side chain rigidification by introducing a spiro-ring is developed for the first time and applied to construct the NFA of Spiro-F. Compared to its counterpart F-2F, the rigid spirocyclic side chain can constrain the vibrational-rotational motion and control the orientation of two highly flexible n -octyl chains effectively. As a result, an optimal molecular packing with enhanced intermolecular actions and lower energetic disorder is achieved by Spiro-F, endowing the OSC based on the as cast blend of PM6:Spiro-F with a significantly improved PCE of 13.56% and much reduced recombination loss compared to that of PM6:F-2F. This work provides a feasible strategy to achieve efficient OSCs through the rigidification of the side chain and could boost the PCEs further if applied to some other efficient systems with smaller bandgaps., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

Construction of lateral junctions is essential to generate one-dimensional (1D) confined potentials that can effectively trap quasiparticles. A series of remarkable electronic phases in one dimension, such as Wigner crystallization, are expected to be realized in such junctions. Here, we demonstrate that we can precisely tune the 1D-confined potential with an in situ manipulation technique, thus providing a dynamic way to modify the correlated electronic states at the junctions. We confirm the existence of 1D-confined potential at the homojunction of two single-layer 1T-NbSe 2 islands. Such potential is structurally sensitive and shows a nonmonotonic function of their interspacing. Moreover, there is a change of electronic properties from the correlated insulator to the generalized 1D Wigner crystallization while the confinement becomes strong. Our findings not only establish the capability to fabricate structures with dynamically tunable properties, but also pave the way toward more exotic correlated systems in low dimensions.

The alpine meadow ecosystem on the Qinghai-Tibetan Plateau (QTP) is very sensitive to warming and plays a key role in regulating global carbon (C) cycling. However, how warming affects the soil organic carbon (SOC) pool and related C inputs and outputs in alpine meadow ecosystems on the QTP remains unclear. Here, we combined two field experiments and a meta-analysis on field experiments to synthesize the responses of the SOC pool and related C cycling processes to warming in alpine meadow ecosystems on the QTP. We found that the SOC content of surface soil (0-10 cm) showed a minor response to warming, but plant respiration was accelerated by warming. In addition, the warming effect on SOC was not correlated with experimental and environmental variables, such as the method, magnitude and duration of warming, initial SOC content, mean annual temperature, and mean annual precipitation. We conclude that the surface SOC content is resistant to climate warming in alpine meadow ecosystems on the QTP., (© 2021 John Wiley & Sons Ltd.)

Nanosuspensions can effectively increase saturation solubility and improve the bioavailability of poorly water-soluble drugs attributed to high loading and surface-to-volume ratio. Wet media milling has been regarded as a scalable method to prepare nanosuspensions because of its simple operation and easy scale-up. In recent years, besides particle aggregation and Ostwald ripening, polymorphic transformation induced by processing has become a critical factor leading to the instability of nanosuspensions. Therefore, this review aims to discuss the influence factors comprehensively and put forward the corresponding improvement strategies of polymorphic transformation during the formation of nanosuspensions. In addition, this review also demonstrates the implication of molecular simulation in polymorphic transformation. The competition between shear-induced amorphization and thermally activated crystallization is the global mechanism of polymorphic transformation during media milling. The factors affecting the polymorphic transformation and corresponding improvement strategies are summarized from formulation and process parameters perspectives during the formation of nanosuspensions. The development of analytical techniques has promoted the qualitative and quantitative characterization of polymorphic transformation, and some techniques can in situ monitor dynamic transformation. The microhydrodynamic model can be referenced to study the stress intensities by analyzing formulation and process parameters during wet media milling. Molecular simulation can be used to explore the possible polymorphic transformation based on the crystal structure and energy. This review is helpful to improve the stability of nanosuspensions by regulating polymorphic transformation, providing quality assurance for nanosuspension-based products.HighlightsPolymorphic transformation depends on the intensity and temperature of milling.Stress intensities of milling can be elucidated and improved by microhydrodynamics.Higher stress intensities of milling perhaps be accompanied by higher temperatures.Molecular simulation used in polymorphs is based on crystal structure and energy.Molecular dynamics simulations can demonstrate the stability of amorphous forms.

Introduction: The preparation of nanosuspensions by wet media milling is a promising technique that increases the bioavailability of insoluble drugs. The nanosuspension is thermodynamically unstable, where its stability might be influenced by the interaction energy between the stabilizers and the drugs after milling at a specific collision energy. However, it is difficult to screen the stabilizers and the parameters of milling accurately and quickly by using traditional analysis methods. Quantum-molecular mechanics and microhydrodynamic modeling can be applied to improve screening efficiency. Areas covered: Quantum-molecular mechanics model, which includes molecular docking, molecular dynamics simulations, and data on binding energy, provides insights into screening stabilizers based on their molecular behavior at the atomic level. The microhydrodynamic model explores the mechanical processes and energy dissipation in nanomilling, and even combines information on the mechanical modulus and an energy vector diagram for the milling parameters screening of drug crystals. Expert opinion: These modeling methods improve screening efficiency and support screening theories based on thermodynamics and physical dynamics. However, how to reasonably combine different modeling methods with their theoretical characteristics and further multidimensional and cross-scale simulations of nanosuspension formation remain challenges.

Microscopically visualizing the evolution of electronic structures at the interface between two electron-correlated domains shows fundamental importance in both material science and physics. Here, we report scanning tunneling microscopy and spectroscopy studies of the interfacial electronic structures evolution in a phase-engineered monolayer NbSe 2 heterostructure. The H-NbSe 2 metallic state penetrates the Mott insulating T-NbSe 2 at the H/T phase interface, with a prominent 2D charge density wave (CDW) proximity effect. Moreover, an insulating Mott gap collapse with the disappearance of the upper Hubbard band is detected at the electronic phase transition region. Theoretical calculations reveal that such insulating Mott gap collapse can be attributed to the electron doping effect induced by the interface. Our findings promote a microscopical understanding of the interactions between different electron-correlated systems and provide an effective method for controlling the Mott insulating states with phase engineering.

The combination of chemotherapy and gene therapy has been indicated as a promising approach for cancer therapy. However, this combination strategy is still faced a challenge by the lack of suitable carriers to co-loaded chemotherapeutic drug and gene into one single nanoplatform. In this study, a tumor-targeted HC/pIL-12/polyMET micelleplexes were developed for the co-loading and co-delivery of cisplatin (CDDP) and plasmid encoding interleukin-12 gene (pIL-12), which would be utilized to generate synergistic actions through chemotherapy sensitization and microenvironment modulation. The HC/pIL-12/polyMET exhibited desirable particle size, superior serum stability, effective intracellular CDDP release and pIL-12 transfection efficiency. More important, the HC/pIL-12/polyMET generated the enhanced LLC cell proliferation inhibition and apoptosis induction efficiency. The long-circulating HC/pIL-12/polyMET micelleplexes promoted the accumulation of CDDP and pIL-12 in tumor site, which resulted in significantly inhibiting the growth of lung cancer, and prolonging the overall survival of tumor-bearing mice. The underlying immune mechanism demonstrated the combination of CDDP and pIL-12 activated immune effector cells to release IFN-γ and induced M1-type differentiation of tumor-related macrophages, thereby generating synergistic chemoimmunotherapy effect. Taken together, this study may provide an effective strategy for drug/gene co-delivery and cancer chemoimmunotherapy. STATEMENT OF SIGNIFICANCE: Chemoimmunotherapy has been indicated as an approach to improve efficacy of cancer therapy. Herein, a tumor-targeted micelleplexes (HC/pIL-12/polyMET) were developed for the co-delivery of cisplatin (CDDP) and plasmid encoding IL-12 gene (pIL-12), which can employ the synergistic effects through chemotherapy sensitization and microenvironment modulation. The HC/pIL-12/polyMET exhibited desirable particle size, superior serum stability, high gene transfection efficiency and antitumor activity on tumor cell proliferation inhibition and apoptosis induction. More importantly, the long-circulating HC/pIL-12/polyMET micelleplexes could effectively accumulate in tumor sites and then rapidly release the CDDP and pIL-12, significantly inhibit the growth of lung cancer. This strategy provides a new concept for chemo-gene combination with a strengthened overall therapeutic efficacy of chemoimmunotherapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

The low-energy excitations of graphene are relativistic massless Dirac fermions with opposite chiralities at valleys K and K^{'}. Breaking the chiral symmetry could lead to gap opening in analogy to dynamical mass generation in particle physics. Here we report direct experimental evidences of chiral symmetry breaking (CSB) from both microscopic and spectroscopic measurements in a Li-intercalated graphene. The CSB is evidenced by gap opening at the Dirac point, Kekulé-O type modulation, and chirality mixing near the gap edge. Our work opens up opportunities for investigating CSB related physics in a Kekulé-ordered graphene.

Charge density wave (CDW) in two-dimensional (2D) crystals plays a vital role in tuning the interface structures and properties. However, how the CDW tunes the self-assembled molecular superlattice still remains unclear. In this study, we investigated the self-assembled manganese phthalocyanine (MnPc) molecular superlattice on single-layered 1T- and 2H-NbSe 2 crystals under regulation by distinct CDW patterns. We observe that, in low coverage, MnPc molecules preferentially adsorb on 2H-NbSe 2 compared to 1T-NbSe 2 . With increasing coverage, MnPc can form a highly ordered superlattice on 2H-NbSe 2 ; however, it is randomly distributed on 1T-NbSe 2 . We reveal a perfect geometric commensurability between the molecular superlattice and intrinsic CDW pattern in 2H-NbSe 2 and a poor commensurability for that of 1T-NbSe 2 . We believe that the subtly different geometric commensurability dominates the different adsorption and arrangement of the molecular superlattices on 2D CDW patterns. Our study provides a pioneering approach for tuning the molecular superlattices using the CDW patterns.

Understanding Mott insulators and charge density waves (CDW) is critical for both fundamental physics and future device applications. However, the relationship between these two phenomena remains unclear, particularly in systems close to two-dimensional (2D) limit. In this study, we utilize scanning tunneling microscopy/spectroscopy to investigate monolayer 1T-NbSe 2 to elucidate the energy of the Mott upper Hubbard band (UHB), and reveal that the spin-polarized UHB is spatially distributed away from the dz 2 orbital at the center of the CDW unit. Moreover, the UHB shows a √3 × √3 R30° periodicity in addition to the typically observed CDW pattern. Furthermore, a pattern similar to the CDW order is visible deep in the Mott gap, exhibiting CDW without contribution of the Mott Hubbard band. Based on these findings in monolayer 1T-NbSe 2 , we provide novel insights into the relation between the correlated and collective electronic structures in monolayer 2D systems.

In order to reveal the mechanism of galvanic pitting corrosion initiation induced by typical complex inclusions in Al-Ti-Mg deoxidized high strength pipeline steel, first-principles calculations, combining with immersion tests, scanning electron microscopy was used to study the correlation between electronic work function and galvanic corrosion of Al-Ti-Mg killed steel. The results show that MnS inclusions act as anodes in the electrochemical environment, preferentially corroding and dissolving; MgAl 2 O 4 and Al 2 O 3 inclusions act as cathodes, leading to the corrosion of Fe matrix; different end planes of MgTiO 3 and MgTi 2 O 4 act as both anodes and cathodes, but they have little effect on pitting corrosion. Microcrevices on the MgTiO 3 and MgTi 2 O 4 inclusions boundary are the main cause of matrix dissolution., (Copyright © 2020. Published by Elsevier Ltd.)

The combination therapy of cisplatin (CDDP) and metformin (MET) is a clinical strategy to enhance therapeutic outcomes in lung cancer. However, the efficacy of this combination is limited due to the asynchronous pharmacokinetic behavior of CDDP and MET, used as free drugs. Therefore, in this work, hyaluronic acid-cisplatin/polystyrene-polymetformin (HA-CDDP/PMet) dual-prodrug co-assembled nanoparticles were developed, with precise ratiometric co-delivery of CDDP and MET for chemo-immunotherapy against lung cancer. The HA-CDDP/PMet NPs showed a spherical morphology with an average particle size of 166.5 nm and a zeta potential of -17.4 mV at an HA-CDDP and PMet mass ratio of 1/1. The content of CDDP and MET in HA-CDDP/PMet NPs was 3.7% and 15.2%, respectively. In vitro antitumor effects of CDDP and MET resulted in an improved synergistic action on proliferation inhibition and apoptosis induction on Lewis lung cancer cells. Moreover, in vivo by co-delivered HA-CDDP/PMet NPs into tumor cells, with an excellent intracellular CDDP and MET cleavage. These nanoparticles exhibited significantly increased tumor accumulation and tumor growth inhibition and prolonged animal overall survival in Lewis lung cancer bearing mice without nephrotoxicity, excess of free drugs and homo-prodrugs. The synergistic effect of MET and CDDP in HA-CDDP/PMet NPs resulted in up-regulation of the cleaved poly(ADP)-ribose polymerase (PARP) protein to induce tumor cell apoptosis, and down-regulation of the excision repair cross-complementation group 1 (ERCC1) protein level to decrease the resistance to CDDP. The synergistic effect of MET and CDDP in HA-CDDP/PMet NPs also resulted in induction of the adenosine monophosphate (AMP)-activated protein kinase-α (AMPK-α) pathway and inhibition of the mammalian target of rapamycin (mTOR), finally exerting a chemotherapeutic effect and modulating a potent immunotherapeutic function with an increase in CD4 + and CD8 + T cells, a concomitant decrease in regulatory T (Treg) cells, and an increased expression of the cytokines IFN-γ and TNF-α. Therefore, the immunochemotherapy using CDDP and MET mediated by this dual prodrug co-assembled nano-platform might provide a promising treatment strategy against lung cancer.

Immunization with synthetic mRNA encoding tumor-associated antigens is an emerging vaccine strategy for the treatment of cancer. In order to prevent mRNA degradation, promote antigen-presenting cells antigen presentation, and induce an anti-tumor immune response, we investigated the nasal administration of mRNA vaccines with positively charged protamine to concentrate mRNA, form a stable polycation-mRNA complex, and encapsulate the complex with DOTAP/Chol/DSPE-PEG cationic liposomes. Cationic liposome/protamine complex (LPC) showed significantly greater efficiency in uptake of vaccine particles in vitro and stronger capacities to stimulate dendritic cell maturation, which further induced a potent anti-tumor immune response. Intranasal immunization of mice with cationic LPC containing mRNA encoding cytokeratin 19 provoked a strong cellular immune response and slowed tumor growth in an aggressive Lewis lung cancer model. The results of this study provide evidence that cationic LPC can be used as a safe and effective adjuvant and this mRNA formulation provides a basis for anti-cancer vaccination of humans., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In order to solve the problem of where, why, and how to start pitting, it is necessary to study the influence of different dissolution activity of the internal heterogeneous structures of the complex inclusions. In this paper, mechanism of internal activity difference of two typical Yttrium composite inclusions on pitting corrosion is revealed from atomic scale by using immersion test, FE-SEM/EDS analysis and first-principles calculations. The results show that, for Mg-Y-S composite inclusions, pitting potential is lower than that of the matrix, therefore, The matrix around the composite inclusions dissolves preferentially; for Y-S-O composite inclusions with core-shell structure, Y-O inclusions in the shell are deformed and cracked due to the internal stress of the matrix and Y-S during the immersion process, resulting in the simultaneous dissolution of inclusions and steel matrix., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Conventional cancer therapeutics has enormous toxicity and severe side effects that generate multi-drug resistance. Therefore, an urgent need exists for new alternative therapeutic agents for cancer treatment. Cepharanthin (CEP) has anti-cancer potential but has poor aqueous solubility, which limits its clinical use. Nanosuspensions (NS) are attractive as insoluble drug delivery systems., Objectives: In this study, we used D-alpha Tocopherol acid Polyethylene Glycol Succinate (TPGS), Polyvinylpyrrolidone (PVP) VA64, and Croscamellose Sodium (CCS) as stabilizers to produce TPGS-CEP-NS, PVP VA64-CEP-NS, and CCS-CEP-NS by wet-milling technology, and then characterized the NS and evaluated their functional activities in vitro., Methods: CEP Nanosuspensions (CEP-NS) were prepared by the wet-milling method. The prepared NS were characterized by particle size distribution, zeta potential, morphology, surface properties, and molecular interactions. The NS were evaluated for their effects on HepG2 cells in vitro. The evaluations included assessment of cellular cytotoxicity, cellular apoptosis, NS uptake by cells, and mitochondrial membrane potential changes., Results: CEP-NS showed an appropriate particle size and were physically stable. All CEP-NS exhibited HepG2 enhanced anti-proliferative effects by reducing cell viability, enhanced cellular uptake, induced cellular apoptosis, and mitochondrial membrane potential loss., Conclusions: CEP-NS may be effective therapeutic agents for the treatment of hepatocellular carcinoma., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

A transition metal diphosphide, WP 2 , is a candidate for type-II Weyl semimetals (WSMs) in which spatial inversion symmetry is broken and Lorentz invariance is violated. As one of the prerequisites for the presence of the WSM state in WP 2 , spatial inversion symmetry breaking in this compound has rarely been investigated. Furthermore, the anisotropy of the WP 2 electrical properties and whether its electrical anisotropy can be tuned remain elusive. Angle-resolved polarized Raman spectroscopy, electrical transport, optical spectroscopy, and first-principle studies of WP 2 are reported. The energies of the observed Raman-active phonons and the angle dependences of the detected phonon intensities are consistent with results obtained by first-principle calculations and analysis of the proposed crystal symmetry without spatial inversion, showing that spatial inversion symmetry is broken in WP 2 . Moreover, the measured ratio (R c /R a ) between the crystalline c-axis and a-axis electrical resistivities exhibits a weak dependence on temperature (T) in the temperature range from 100 to 250 K, but increases abruptly at T ≤ 100 K, and then reaches the value of ≈8.0 at T = 10 K, which is by far the strongest in-plane electrical resistivity anisotropy among the reported type-II WSM candidates with comparable carrier concentrations. Optical spectroscopy study, together with the first-principle calculations on the electronic band structure, reveals that the abrupt enhancement of the electrical resistivity anisotropy at T ≤ 100 K mainly arises from a sharp increase in the scattering rate anisotropy at low temperatures. More interestingly, the R c /R a of WP 2 at T = 10 K can be tuned from 8.0 to 10.6 as the magnetic field increases from 0 to 9 T. The so-far-strongest and magnetic-field-tunable electrical resistivity anisotropy found in WP 2 can serve as a degree of freedom for tuning the electrical properties of type-II WSMs, which paves the way for the development of novel electronic applications based on type-II WSMs., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Liposomes are versatile delivery systems and immunological adjuvants that not only can load various antigens, such as proteins, peptides, nucleic acids and carbohydrates, but also can combine them with immunostimulators. Liposomes have great potential in the development of new types of vaccines, and much effort has been devoted to enhancing vaccine efficacy in recent years. Different types of immune cells such as macrophages and dendritic cells play an important role in the immune response and in preventing or treating cancer, allergy or many other infectious diseases. Targeting liposome-based delivery systems to certain immune cells and organs is one of the most effective measures in such treatments. Extensive research has shown that liposomes combined with immunostimulators or modified with pattern recognition receptor ligands can target various immune cells and the lymphatic system, thus not only inducing and promoting the desired immune response but also decreasing adverse effects throughout the body and avoiding targeting irrelevant cell types or tissues. Therefore, in this review, we outline some targeting strategies that can be adopted in the design of liposomal vaccines to improve vaccine efficacy, and we summarise the related liposome-based vaccine applications in several diseases. These applications have great potential to treat or prevent some infectious and intractable diseases.

Objectives: Multidrug resistance (MDR) remains a primary challenge in breast cancer treatment. In the present study, D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS)-coated docetaxel-loaded liposomes were developed as a novel drug delivery system to reverse MDR and enhance breast cancer therapy compared with the traditional liposomes, DSPE-mPEG-coated liposomes (stealth liposomes) and commercial Taxotere ® ., Key Findings: Liposomes were prepared by thin - film dispersion method. Evaluations were performed using human breast cancer MCF-7 and resistant MCF-7/ADR cells. The reversal multidrug-resistant effect was assessed by P-gp inhibition assay, cytotoxicity, cellular uptake and apoptosis assay., Results: The TPGS-chol-liposomes were of an appropriate particle size (140.0 ± 6.0 nm), zeta potential (-0.196 ± 0.08 mv), high encapsulation efficiency (99.0 ± 0.9) and favourable in vitro sustained release. The TPGS-coated liposomes significantly improved cytotoxicity and increased the intracellular accumulation of docetaxel in both types of breast cancer cells. The TPGS-coated liposomes were confirmed to induce apoptosis via a synergistic effect between docetaxel and TPGS. It was demonstrated that TPGS enhanced the intracellular accumulation of drug by inhibiting overexpressed P-glycoprotein., Conclusions: The TPGS-conjugated liposomes showed significant advantages in vitro compared with the PEG-conjugated liposomes. The TPGS-conjugated liposomes could reverse the MDR and enhance breast cancer therapy., (© 2019 Royal Pharmaceutical Society.)

Multicomponent formulations have attracted increasing attention because of their favourable patient compliance and greater therapeutic effect. The aim of this study was to develop a multicomponent nanosuspension formulation of bufadienolides, the antitumor components of a traditional Chinese medicine, toad venom, using a wet-milling technique to improve its dissolution behaviour. Croscarmellose sodium (CCS) and sodium lauryl sulfate (SLS) were chosen as the combined stabilizers of the nanosuspension. A Taguchi orthogonal array design was used for this study to optimize the formulation and process parameters. The optimized nanosuspension was characterized by its particle size distribution, zeta potential, morphology, crystallinity, molecular interactions, stability and dissolution. The results showed that the nanosuspension was a homogeneous amorphous system with average particle sizes of <100 nm and significantly improved dissolution behaviour. It was also physically stable for at least 2 months; steric and kinetic stabilization were its main stability mechanisms. These findings suggested that the use of wet milling to fabricate nanosuspensions is a promising method for achieving the fast and synchronized dissolution of multicomponent formulations, presumably increasing the bioavailability of poorly water-soluble drugs.

Besides the thermoelectric properties, mechanically robust is also very important for applications in TEGs. Up to now, no studies have been reported to investigate the mechanical properties of BiCuSeO oxyselenides. In this work, the results of hardness test of pristine and Ba/Pb doped BiCuSeO are presented here. These data may help to further evaluate the mechanical properties of BiCuSeO based ceramics.

The drug efflux mediated by P-glycoprotein (P-gp) transporter is a major factor responsible for multidrug resistance (MDR) of paclitaxel (PTX). The efficient intracellular PTX delivery is a promising strategy for overcoming the MDR of tumor cells. A CD44 receptor targeting and endosome-pH sensitive dual functionalized hyaluronic acid-deoxycholic acid-histidine (HA-DOCA-His) micellar formulation was developed to overcome MDR, and a CD44 receptor targeting hyaluronic acid-deoxycholic acid (HA-DOCA) micelles was used as a comparison. Compared with Taxol solution and HA-DOCA micelles, the cytotoxicity of PTX loaded in HA-DOCA-His micelles against drug-resistant tumor cells was improved significantly and possessed superior MDR-overcoming performance; this phenomenon is due to the increased intracellular PTX delivery by CD44 receptor-mediated endocytosis pathway and endosome-pH sensitivity-mediated PTX triggering release. Upon pharmacokinetic study, PTX/HA-DOCA-His micelles demonstrated longer blood circulation time, larger AUC, decreased V d and CL than the Taxol solution. More importantly, PTX/HA-DOCA-His micelles were more effective in tumor growth inhibition in MCF-7/Adr tumor-bearing mice compared with PTX/HA-DOCA micelles and Taxol solution. Dual targeting strategy-functionalized HA-DOCA-His micelles demonstrated excellent MDR-reversing ability for therapeutic efficacy and improvement on MDR tumors, thereby providing an effective targeting strategy for PTX delivery of nano-drug delivery system in MDR cancer chemotherapy., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The cationic dimethyldioctadecylammonium/trehalose 6,6,9-dibehenate (DDA/TDB) liposome is as a strong adjuvant system for vaccines, with remarkable immunostimulatory activity. The mucosal administration of vaccines is a potential strategy for inducing earlier and stronger mucosal immune responses to infectious diseases. In this study, we assessed whether the intranasal administration of cationic DDA/TDB liposomes combined with influenza antigen A (H3N2) can be used as a highly efficacious vaccine to induce mucosal and systemic antibody responses. Confocal laser scanning microscopy and a flow-cytometric analysis showed that the uptake of the cationic DDA/TDB liposome carrier was significantly higher than that of neutral 1,2-distearoyl-sn-glycero-3-phosphocholine/cholesterol (DSPC/Chol) or cationic 1,2-dioleoyl-3-trimethylammonium-propane/3β-(N-[N',N'-dimethylaminoethane]-carbamoyl (DOTAP/DC-Chol) liposomes. Our results indicate that the cationic DDA/TDB liposome is more effective in facilitating its uptake by dendritic cells (DCs) in vitro than the DSPC/Chol or DOTAP/DC-Chol liposome. DCs treated with DDA/TDB liposomes strongly expressed CD80, CD86, and MHC II molecules, whereas those treated with DSPC/Chol or DOTAP/DC-Chol liposomes did not. C57BL/6 mice intranasally immunized with H3N2-encapsulating cationic DDA/TDB liposomes had significantly higher H3N2-specific s-IgA levels in their nasal wash fluid than those treated with other formulations. The DDA/TDB liposomes also simultaneously enhanced the serum IgG IgG2a, IgG1, and IgG2b antibody responses. In summary, DDA/TDB liposomes effectively facilitated their uptake by DCs and DCs maturation in vitro, and induced significantly higher mucosal IgA, systemic IgG, IgG1, and IgG2b antibody titres than other formulations after their intranasal administration in vivo. These results indicate that DDA/TDB liposomes are a promising antigen delivery carrier for clinical antiviral applications.

Luminescent semiconductor nanocrystals, also known as quantum dots (QDs), have rich surface chemistry and unique optical properties that make them useful as probes or carriers for molecular diagnostics and therapeutics. However, their potential toxicity and instability in biological environments have puzzled scientific researchers. Much research effort has been devoted to encapsulation of QDs with liposomal hybrids to make them versatile nanocarriers for simultaneous therapeutics and diagnostics (theranostics) and considerable progress has been made over recent years. We provide an overview of the use of QD-liposome complexes (QLCs) for imaging applications, in particular applications in theranostics. More specifically, the design considerations, intracellular uptake and tissue-specific targeting of QLCs are highlighted. Current findings of QLCs for theranostics are discussed. We also discuss the challenges and highlight future directions for applications of liposome-QD hybrid nanocarriers in the biomedical arena.

Hierarchical structured ZnFe 2 O 4 @SiO 2 @RGO core-shell nanocomposites were prepared via a "coating-coating" route, and its structure, composition and electromagnetic properties were characterized. Compared with the binary composites of ZnFe 2 O 4 @SiO 2 , the hierarchical ZnFe 2 O 4 @SiO 2 @RGO ternary composites exhibited enhanced electromagnetic wave (EMW) absorption properties in terms of the effective bandwidth and minimum reflection loss (RL). Furthermore, EMW absorption properties of the prepared samples can be tuned by changing RGO content and thickness of SiO 2 layer to reach the best impedance match. The minimum RL of the sample with a thickness of 2.8 mm can reach -43.9 dB at 13.9 GHz, and its effective bandwidth (RL ≤ -10 dB) was up to 6 GHz. Hence, the obtained products can be a new candidate for lightweight EMW absorbing materials.

Global warming is projected to continue, leading to intense fluctuations in precipitation and heat waves and thereby affecting the productivity and the relevant biological processes of grassland ecosystems. Here, we determined the functional responses to warming and altered precipitation in both typical and desert steppes. The results showed that watering markedly increased the aboveground net primary productivity (ANPP) in a typical steppe during a drier year and in a desert steppe over two years, whereas warming manipulation had no significant effect. The soil microbial biomass carbon (MBC) and the soil respiration (SR) were increased by watering in both steppes, but the SR was significantly decreased by warming in the desert steppe only. The inorganic nitrogen components varied irregularly, with generally lower levels in the desert steppe. The belowground traits of soil total organic carbon (TOC) and the MBC were more closely associated with the ANPP in the desert than in the typical steppes. The results showed that the desert steppe with lower productivity may respond strongly to precipitation changes, particularly with warming, highlighting the positive effect of adding water with warming. Our study implies that the habitat- and year-specific responses to warming and watering should be considered when predicting an ecosystem's functional responses under climate change scenarios.

Oxymatrine (OM) can be metabolized to matrine in gastrointestinal ileocecal valve after oral administration, which affects pharmacological activity and reduce bioavailability of OM. A type of multiple-unit alginate-chitosan (Alg-Cs) floating beads was prepared by the ionotropic gelation method for gastroretention delivery of OM. A solid dispersion technique was applied and incorporated into beads to enhance the OM encapsulation efficiency (EE) and sustain the drug release. The surface morphology and internal hollow structure of beads were evaluated using optical microscopy and scanning electron microscopy (SEM). The developed Alg-Cs beads were spherical in shape with hollow internal structure and had particle size of 3.49 ± 0.09 mm and 1.33 ± 0.09 mm for wet and dried beads. Over 84% of the optimized OM solid dispersion-loaded Alg-Cs beads were able to continuously float over the simulated gastric fluid for 12 h in vitro. The OM solid dispersion-loaded Alg-Cs beads showed drug EE of 67.07%, which was much higher than that of beads loading with pure OM. Compared with the immediate release of OM capsules and pure OM-loaded beads, the release of OM from solid dispersion-loaded Alg-Cs beads was in a sustained-release manner for 12 h. Prolonged gastric retention time of over 8.5 h was achieved for OM solid dispersion-loaded Alg-Cs floating beads in healthy rabbit in in vivo floating ability evaluated by X-ray imaging. The developed Alg-Cs beads loading with OM solid dispersion displayed excellent performance features characterized by excellent gastric floating ability, high drug EE and sustained-release pattern. The study illustrated the potential use of Alg-Cs floating beads combined with the solid dispersion technique for prolonging gastric retention and sustaining release of OM, which could provide a promising drug delivery system for gastric-specific delivery of OM for bioavailability enhancement.

Oxymatrine (OM) is an alkaloid extracted from a Chinese herb that has been found to possess an anti-hepatic fibrosis effect, although its anti-fibrotic potential is limited due to a lack of targeting specificity, a short half-life and adverse effects. Polymersomes (PM) assembled from amphiphilic block copolymers represent promising vesicles for applications that include drug delivery and surface functionalization. The aim of this study was to develop a novel drug carrier based on PM modified with the peptide RGD and evaluate its therapeutic effect on liver fibrosis. A series of PM based on poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-b-PCL) were prepared and characterized. OM was loaded into PM by a pH-gradient method then the OM-loaded PM was modified with RGD peptide to obtain RGD-PM-OM. The average drug loading of RGD-PM-OM, with a size of 95 nm, was 6.8%. The targeting effects of the system were determined in cultured hepatic stellate cells (HSCs) and bile duct-ligated rats (BLD). RGD-PM-OM displayed better suppression of HSCs proliferation and significantly reduced the expression of the genes for α-SMA and collagen lα1 in cultured HSCs. Furthermore, RGD-PM-OM exhibited markedly superior anti-fibrosis activity by reducing the levels of PC-III and IV-C in serum and connective tissue deposition in BLD compared with PM-OM and OM. These results indicate that targeted RGD-PM-OM markedly attenuates the effects of hepatic fibrosis., (Copyright © 2013 Elsevier B.V. All rights reserved.)

To better understand how warming, increased precipitation and their interactions influence community structure and composition, a field experiment simulating hydrothermal interactions was conducted at an annual forb dominated desert steppe in northern China over 2 years. Increased precipitation increased species richness while warming significantly decreased species richness, and their effects were additive rather than interactive. Although interannual variations in weather conditions may have a major affect on plant community composition on short term experiments, warming and precipitation treatments affected individual species and functional group composition. Warming caused C4 grasses such as Cleistogenes squarrosa to increase while increased precipitation caused the proportions of non-perennial C3 plants like Artemisia capillaris to decrease and perennial C4 plants to increase.

Alcohol dehydrogenase (ADH) catalyzes the final step in the biosynthesis of methanol from CO2. Here, we report the steady-state kinetics for ADH, using a homogeneous enzyme preparation with formaldehyde as the substrate and nicotinamide adenine dinucleotide (NADH) as the cofactor. When changing NADH concentrations with the fixed concentrations of HCHO (more or less than NADH), kinetic studies revealed a particular zigzag phenomenon for the first time. Increasing formaldehyde concentration can weaken substrate inhibition and improve catalytic efficiency. The kinetic mechanism of ADH was analyzed using the secondary fitting method. The double reciprocal plots (1/v∼1/[HCHO] and 1/[NADH]) strongly demonstrated that the substrate inhibition by NADH was uncompetitive versus formaldehyde and partial. In the direction of formaldehyde reduction, ADH has an ordered kinetic mechanism with formaldehyde adding to enzyme first and product methanol released last. The second reactant NADH can combine with the enzyme-methanol complex and then methanol dissociates from it at a slower rate than from enzyme-methanol. The reaction velocity depends on the relative rates of the alternative pathways. The addition of NADH also accelerates the releasing of methanol. As a result, substrate inhibition and activation occurred intermittently, and the zigzag double reciprocal plot (1/v∼1/[NADH]) was obtained.

Two similar dithiafulvalene-fused conjugated polymers, with different donor-acceptor (D-A) structures, were synthesised. The polymers have different band gaps and stacking structures, as proven by the experimental results and computational studies., (This journal is © The Royal Society of Chemistry 2011)

Objective: To investigate the epileptic seizure-like effect of Sophora alkaloid sophoridine on electroencepholography (EEG) and its possible characteristic and the mechanism of the seizure-like effect., Method: Chronic electron implantation was employed for the intracranial electroencepholography (IEEG) recording in rat, and the traditional anti-seizure drugs were for the mechanism study in mice., Result: Compared with the medial perforant path (PP) area and the temporal cortex (TC), the granule cells in hippocampus dentate gyrus (DG) area is more sensitive in the kindling effect by sc sophoridine. Under-threshold hypnotic dosage of diazepam and the hypnotic dosage of pentobarbital sodium can block the sophoridine kinded seizure in mice, but the phenytoin sodium can not block the seizure, also the dosage of it can block the maximal electroconvulsive shock (MES) seizure., Conclusion: Sophoridine-induced synchronous oscillations in the hippocampus could elicit the generation and development of seizure. And the hippocampus might play the crucial role and be the original part of the seizure. Sophoridine kinded seizure might belong to clonic seizures, and the diazepam is the ideal agent for the treatment.

In the title centrosymmetric compound, C(28)H(32)N(4)O(2) (2+) 2I(-), the two midazole rings are approximately perpendicular to the central anthracene ring system [dihedral angle = 86.6 (2)°]. The ionic units are linked into a two-dimensional network parallel to (01) by C-H⋯I hydrogen bonds and π-π inter-actions involving the anthracene ring system and imidazole rings [centroid-centroid distance = 3.717 (3) Å].

With N-(5-phenyl-1,3,4-oxadiazol-2-yl)-benzamide (HL1) as the first ligand, three new luminescent europium complexes Eu2Na2(L1)6(OH)(2).2C2H5OH.2CHCl3 (1), Eu(L1)3(phen) (phen = 1,10-phenanthroline) (2) and Eu2Na2(L1)6(L2)2(OH)(2).8CHCl3 [L2 = 2,5-bis(2-pyridyl)-1,3,4-oxadiazole] (3) have been prepared and structurally characterized. Each ligand L1 coordinates with a Eu3+ ion through a carbonyl oxygen atom and oxadiazol nitrogen atom, the coordination geometry at europium is a distorted square antiprism. Complexes 1 and 3 have centrosymmetric dimeric structural features with OH- as the bridging ligand, while 2 is mononuclear with phen as the neutral ligand. All these complexes show efficient red emissions typical of Eu3+ ions at room temperature, the overall quantum yields of complexes 1, 2 and 3 were 0.15, 0.37 and 0.23, respectively. Using Eu(L1)3(phen) as the emitting material, an electroluminescent device with the structure ITO/TPD (30 nm)/Eu(L1)3(phen): TPD (1 : 3, 50 nm)/AlQ (30 nm)/Mg(0.9)Ag(0.1)/Ag was fabricated. The device emits sharp red light originating from europium complex, demonstrating that Eu(L1)3(phen) is a promising red emitter with good electron-transporting property.

In the title compound, Na(+)·4C(7)H(5)N(6) (+)·5BF(4) (-), the Na(+) ion lies on a fourfold rotation axis and one of the tetra-fluoridoborate ions lies on a site of symmetry . Each Na(+) ion is surrounded by four symmetry-related tetra-fluoridoborate ions, and is eight-coordinated by F atoms, the Na⋯F separation being 2.3956 (15) or 2.4347 (17) Å. The hexa-azaphenalenium ring system is essentially planar. In the crystal structure, the cations and anions are linked into a three-dimensional network by N-H⋯N and C-H⋯F hydrogen bonds.