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The interaction of atomically precise monolayer thiolate (SR) protected gold nanoclusters (Au NCs) with the phospholipid membranes has been studied by the all-atom molecular dynamics (AAMD) simulations. The effect of cluster size, type, and the surface charge density of protection ligand was studied. The simulation results show gold nanoclusters with different size and surface modifications have much different transmembrane behaviors. The Au

The interfacial interaction between the main oxidant filler ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) matrix in AP/HTPB propellants were studied via an all-atom molecular dynamics simulation. The results of the simulation showed the effects of the microscopic cross-linked structure of the matrix, stretching rate during uniaxial stretching, and contact area between the filler and matrix on the mechanical properties, such as the stress and strain of the composite solid propellant. Among the aforementioned factors, the stretching rate considerably affects the mechanical properties of the solid propellant, and the maximum stress of the solid propellant proportionally increases with the stretching rate. When defects were introduced on the surface of the AP filler, the contact area between the filler and matrix affected the strain type of the matrix molecules. Owing to the interaction between the molecules and atoms, the strain behaviour of the matrix molecule changed with the change in its microscopic cross-linked structure during uniaxial stretching. Molecular dynamics simulations were used to explore the characteristics at the AP–HTPB interface in AP/HTPB propellants. The aforementioned simulation results further revealed the interfacial interaction mechanism of the AP–HTPB matrix and provided a theoretical basis for the design of high-performance propellants.

Liquidity and order flows have been found to be major causes of extreme price movements (EPMs) in previous studies. However, few studies have clarified whether the impacts of these factors to EPMs are transient or permanent. In this paper, we represent the fluctuation of liquidity as a time series of price. The measurement of permanent price impact is converted to the price discovery problem solved by a quantile vector error correction model. Empirical results using the high frequency data in the Chinese stock market indicate that both liquidity and order flows contribute to the permanent component of the EPMs. However, liquidity is the dominating factor, which accounts for more than 60–80% of the information share in EPMs scenarios.

Tendon is a vital connective tissue in human skeletal muscle system, and tendon injury is very common and intractable in clinic. Tendon development and repair are two closely related but still not fully understood processes. Tendon development involves multiple germ layer, as well as the regulation of diversity transcription factors (Scx et al.), proteins (Tnmd et al.) and signaling pathways (TGFβ et al.). The nature process of tendon repair is roughly divided in three stages, which are dominated by various cells and cell factors. This review will describe the whole process of tendon development and compare it with the process of tendon repair, focusing on the understanding and recent advances in the regulation of tendon development and repair. The study and comparison of tendon development and repair process can thus provide references and guidelines for treatment of tendon injuries.

PHT1 (phosphate transporter 1) family genes play important roles in regulating plant growth and responding to stress. However, there has been little research on the role of the PHT1 family in potatoes. In this study, using molecular and bioinformatic approaches, 8 PHT1 family genes were identified from the potato genome. StPHT1;7 was highly expressed in the whole potato plants. The overexpression and silence vectors of StPHT1;7 were constructed and transformed into the potato cultivar Desiree. Consequently, StPHT1;7 overexpression (with a relative expression 2–7-fold that in the control) and silence lines (with a relative expression of 0.3%–1% that in the control) were obtained. Their growth vigor was ranked in the order overexpression line > wild type > silence line. In the absence of phosphorus, the root length of the overexpression line was approximately 2.6 times that of the wild type, while the root length of the silence line was approximately 0.6 times that of the wild type. Furthermore, their tolerance to drought stress was ranked as wild type > overexpression line > silence line. These results suggest that StPHT1;7 affects growth and stress tolerance in potato plants.

PHT1 (phosphate transporter 1) family genes play important roles in regulating plant growth and responding to stress. However, there has been little research on the role of the PHT1 family in potatoes. In this study, using molecular and bioinformatic approaches, 8 PHT1 family genes were identified from the potato genome. StPHT1;7 was highly expressed in the whole potato plants. The overexpression and silence vectors of StPHT1;7 were constructed and transformed into the potato cultivar Desiree. Consequently, StPHT1;7 overexpression (with a relative expression 2–7-fold that in the control) and silence lines (with a relative expression of 0.3%–1% that in the control) were obtained. Their growth vigor was ranked in the order overexpression line > wild type > silence line. In the absence of phosphorus, the root length of the overexpression line was approximately 2.6 times that of the wild type, while the root length of the silence line was approximately 0.6 times that of the wild type. Furthermore, their tolerance to drought stress was ranked as wild type > overexpression line > silence line. These results suggest that StPHT1;7 affects growth and stress tolerance in potato plants.

An intermolecular association and decarboxylation mechanism is proposed to understand the experimental evidence of the stepwise 2e

Lateral organ boundaries domain (LBD) proteins belong to a particular class of transcription factors of lateral organ boundary (LOB) specific domains that play essential roles in plant growth and development. However, a potato phylogenetic analysis of the LBD family has not been fully studied by scholars and researchers. In this research, bioinformatics methods and the growth of potatoes were used to identify 43 StLBD proteins. We separated them into seven subfamilies: Ia, Ib, Ic, Id, Ie, IIa and IIb. The number of amino acids encoded by the potato LBD family ranged from 94 to 327. The theoretical isoelectric point distribution ranged from 4.16 to 9.12 Kda, and they were distributed among 10 chromosomes. The results of qRT-PCR showed that the expression levels of StLBD2-6 and StLBD3-5 were up-regulated under drought stress in the stem. The expression levels of StLBD1-5 and StLBD2-6 were down-regulated in leaves. We hypothesized that StLBD1-5 was down-regulated under drought stress, and that StLBD2-6 and StLBD3-5 up-regulation might help to maintain the normal metabolism of potato and enhance the potatoes’ resistance to drought.

Aiming at the problem that the pedestrian navigation algorithm based on quadratic curve fitting zero-speed correction technology has low utilization rate of data samples and poor correction performance and instantaneous accuracy which cannot be optimized, an intelligent adaptive pedestrian navigation algorithm based on support vector machine is proposed, which the data of the sensors is obtained by using the optimized wavelet threshold denoising algorithm; the model trained by the SVR(support vector machine regression) is used to fit the three-dimensional velocity and the error fitting result is used as the system observations; then the intelligent estimator is formed by the SVM and the Kalman filter to estimate the system errors, thereby improving the system accuracy and reliability. The experimental verification by self-developed IMU proves that the method can accurately fit the three-dimensional velocity errors, estimate the systematic error optimally, and effectively correct the navigation data. The positioning accuracy is improved by 10.9% in complex environment. The algorithm has theoretical and engineering significance.

The paper highlights the use of the logistic regression (LR) method in the construction of acceptable statistically significant, robust and predictive models for the classification of chemicals according to their aquatic toxic modes of action. Essentials accounting for a reliable model were all considered carefully. The model predictors were selected by stepwise forward discriminant analysis (LDA) from a combined pool of experimental data and chemical structure-based descriptors calculated by the CODESSA and DRAGON software packages. Model predictive ability was validated both internally and externally. The applicability domain was checked by the leverage approach to verify prediction reliability. The obtained models are simple and easy to interpret. In general, LR performs much better than LDA and seems to be more attractive for the prediction of the more toxic compounds, i.e. compounds that exhibit excess toxicity versus non-polar narcotic compounds and more reactive compounds versus less reactive compounds. In addition, model fit and regression diagnostics was done through the influence plot which reflects the hat-values, studentized residuals, and Cook’s distance statistics of each sample. Overdispersion was also checked for the LR model. The relationships between the descriptors and the aquatic toxic behaviour of compounds are also discussed.

An intermolecular association and decarboxylation mechanism is proposed to understand the experimental evidence of the stepwise 2e- hopping in the reductant-assisted thiolate-gold cluster synthesis. Based on the newly proposed intermolecular reaction mechanism, a total of 19 molecular-like reaction equations are deduced to account for the bottom-up formation of 2e- -8e- gold nanoclusters in the CO-directed [Au25 (SR)18 ]- synthesis. With these established reaction equations, atomic pathways of three prototype cluster-size evolution reactions are comprehensively explored in the course of [Au25 (SR)18 ]- synthesis, namely, the conversion of 0e- homoleptic Au(I) -SR complexes to the 2e- intermediate Au15 (SR)13 cluster, the size-evolution of 2e- Au15 (SR)13 cluster to the 4e- -8e- cluster (stepwise 2e- -hopping), and the isoelectronic addition reaction of [Au23 (SR)16 ]- to the [Au25 (SR)18 ]- . The studies reveal that the CO can combine with the Au(I)-complex to form [Aux (SR)x -COOH]- species in the alkaline condition, which acts as the active precursors in the 2e- hopping cluster-size evolution process. Lastly, as a conceptual extension of the mechanistic studies of the CO-reduction system, a similar intermolecular reaction mechanism is proposed for the 2e- reduction in the conventional "NaBH4 reduction" system.

A new catalyst containing 1–2 nm Au nanoparticles anchored to thiophenol covalently functionalized graphene sheets (Au/TP-GS) was fabricated using a facile, synthetic approach. The details of the morphologies, size and dispersion of the Au nanoparticles (NPs) and the chemical composition of the novel catalyst were verified by systematic characterization techniques, including transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The resulting Au/TP-GS exhibited excellent catalytic activity for both the reduction of 4-nitrophenol and the photodegradation of Rhodamine B due to the synergistic effects between the TP-GS and Au NPs and the high utilization of the metal. The practical, efficient and facile in situ reduction approach to synthesize the nanocatalyst provides a more environmentally benign synthesis route to effectively produce low cost Au-based catalysts.

A high-performance palladium catalyst was developed by the covalent binding of a Schiff base ligand, N,N′-bis(3-salicylidenaminopropyl)amine (salpr), on the surface of hollow magnetic mesoporous spheres (HMMS) followed by immobilization with Pd(0). The catalyst was characterized by TEM, EDX, FT-IR, XRD, VSM, TGA and N2 adsorption–desorption. The novel catalyst exhibited high activity in hydrogenation and Suzuki coupling reaction. Furthermore, it could be recovered from the reaction mixture in a facile manner and recycled six times without any loss of activity.

Lateral organ boundaries domain (LBD) proteins belong to a particular class of transcription factors of lateral organ boundary (LOB) specific domains that play essential roles in plant growth and development. However, a potato phylogenetic analysis of the LBD family has not been fully studied by scholars and researchers. In this research, bioinformatics methods and the growth of potatoes were used to identify 43 StLBD proteins. We separated them into seven subfamilies: Ia, Ib, Ic, Id, Ie, IIa and IIb. The number of amino acids encoded by the potato LBD family ranged from 94 to 327. The theoretical isoelectric point distribution ranged from 4.16 to 9.12 Kda, and they were distributed among 10 chromosomes. The results of qRT-PCR showed that the expression levels of StLBD2-6 and StLBD3-5 were up-regulated under drought stress in the stem. The expression levels of StLBD1-5 and StLBD2-6 were down-regulated in leaves. We hypothesized that StLBD1-5 was down-regulated under drought stress, and that StLBD2-6 and StLBD3-5 up-regulation might help to maintain the normal metabolism of potato and enhance the potatoes&rsquo, resistance to drought.

Planar conjugated 2,7-linked carbazole blocks: Q1(2,7-dibromo-9-octyl-9H-carbazole); Q2(7,7 0 -dibromo-9,9 0 -dioctyl- 9H,9 0 H-2,2 0 -bicarbazole); Q3 (7-bromo-7 0 -(7-bromo-9-octyl-9H-carbazol-2-yl)-9,9 0 -dioctyl-9H,9 0 H-2,2 0 -bicarbazole) were coupled with same acceptor (4,7-di(2,5-thiophene)-5,6-dioctyloxy-2,1,3-Benzothiadiazole) to prepare polymers HXS-1, 2, 3 (Scheme 1). Bulk- heterojunction polymer solar cells (BHJ PSCs) with these polymers were made. Power conversion efficiency of HXS-1 was proved to be over 5.4%. It declined dramatically to 0.43% and 0.23% for HXS-2 and 3 respectively. Their absorption and X-ray diffraction pat- tern show the torsion angle in main chain increased when more carbazole units were added. More carbazoles will make polyconden- sation reaction more difficult to get high molecular weight polymers. The torsion angle was calculated using a semiempirical molecu- lar orbital method. All the results pointed out that the coplanarity in the conjugated backbone was destroyed. Electron delocalization was disturbed because p-orbital overlapping only occurs effectively in the parallel orbit so charge cannot move a longer distance. This study offers a useful and important insight to designing polymers for high performance PSCs. V C 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 129: 2671-2678, 2013

A large data set of 146 natural, synthetic and environmental chemicals belonging to a broad range of structural classes have been tested for their relative binding affinity (expressed as log (RBA)) to the androgen receptor (AR). These chemicals commonly termed endocrine disrupting compounds (EDCs) present a variety of adverse effects in humans and animals. As assays for binding affinity remains a time-consuming task, it is important to develop predictive methods. In this work, quantitative structure-activity relationships (QSARs) were determined using three methods, multiple linear regression (MLR), radical basis function neural network (RBFNN) and support vector machine (SVM). Five descriptors, accounting for hydrogen-bonding interaction, distribution of atomic charges and molecular branching degree, were selected from a heuristic method to build predictive QSAR models. Comparison of the results obtained from three models showed that the SVM method exhibited the best overall performances, with a RMS error of 0.54 log (RBA) units for the training set, 0.59 for the test set, and 0.55 for the whole set. Moreover, six linear QSAR models were constructed for some specific families based on their chemical structures. These predictive toxicology models, should be useful to rapidly identify potential androgenic endocrine disrupting compounds.

A novel Pd(0) compound immobilized on the surface of hollow magnetic mesoporous spheres, with Fe3O4 nanoparticles embedded in the mesoporous shell is prepared.

High-performance Pd(0) on the surface of hollow magnetic mesoporous spheres (HMMS), with Fe3O4 nanoparticles embedded in the mesoporous shell was prepared. The catalyst was characterized by TEM, XRD, VSM and ICP. It showed high activity for selective hydrogenation of alkynes to alkenes and the Heck coupling reaction. The catalyst could be recovered in a facile manner from the reaction mixture and recycled six times without loss in activity.

We here report the synthesis, characterization and catalytic performance of new supported Pd(0) and Pd(II) catalysts. The catalysts were characterized by TEM, XRD, FT-IR, VSM and ICP. The catalysts were found to be active in both forms, Pd(0) and Pd(II), for hydrogenation and Suzuki cross-coupling reactions. In contrast to most supported catalysts, the newly developed catalysts were prepared using nearly the same synthetic strategy, and were easily recovered and recycled from the reaction mixture by applying an external magnet and reused in 5 cycles without significant loss in activity.