Search

Disentanglement tends to automatically learn and separate the interpretable factors of variation hidden in the data. Disentangled representations are more transferable and robust for the chosen model, and they are commonly used in image attack detection and anti-fraud, as well as classification and recommendation systems in special situations. As a popular method for learning unsupervised disentanglement, β-VAE re-weights the KL divergence by an adjustable hyperparameter. However, good disentangled representations always lead to blurry reconstructions and mode collapse on complex datasets. We find that the variance vector of the variational posterior is related to the nature of the dataset and representation space, limiting its value to 1 is not reasonable enough. More importantly, constraining mean variable alone can achieve better disentanglement and reconstruction performance. Therefore, we introduce mean constraint VAE, a simple and effective replacement of the β-VAE for improving the poor reconstruction and learning a higher degree of disentanglement. In addition, a classifier-free measure of disentanglement called variance proportion metric is proposed. Experiments show that our framework outperforms β-VAE on several benchmark datasets. [ABSTRACT FROM AUTHOR]

A new fractional difference equation two‐dimensional triangle function combination discrete chaotic map (2D‐TFCDM) based on Caputo derivative is proposed. Using the bifurcation diagram, the maximum Lyapunov exponent, and the phase diagram, the numerical solutions of the fractional difference equations are obtained, and the chaotic behavior is observed numerically. After encrypting the key with elliptic curve cryptosystem, the fractional map is developed as an encryption algorithm and applied to color image encryption. Finally, the proposed encryption system is systematically analyzed from five main aspects, and the results show that the proposed encryption system has a good encryption effect. [ABSTRACT FROM AUTHOR]

Learning discriminative features and mining salient visual patterns play an important role in salient object detection (SOD) task. Existing SOD methods suffer from limited receptive field and insufficient cross-level feature mining. To this end, we propose a hypergraph attentional convolutional neural network for SOD task. Specifically, our method consists of (1) an attention based feature fusion module, which efficiently fuses lower layer as well as higher layer features, (2) a hypergraph-based long-range dependency encoder, which enhances the receptive field and global context for detection model, (3) a feature refinement layer, which highlights discriminative features and fuses attentional inputs, and (4) a dual iterative feature propagation decoder, which propagates features and upscale lower level feature maps to higher resolution. Both qualitative and quantitively experiments on public datasets verify the effectiveness of our proposed method. Compared with previous works, our model plays favorably against the state-of-the-arts methods. [ABSTRACT FROM AUTHOR]

A kind of top with a fractional operator is discussed in this paper. The top has a periodic nonlinear pulse kick sequence in the magnetic field and constant precessing around the magnetic field. Then, a fractional quantum kicked top map based on the Caputo derivative is proposed. The numerical solutions of the fractional difference equation are obtained, and the chaotic behavior is observed numerically in three aspects. Fractional quantum dynamics behaviors take place in a finite dimensional Hilbert space where the squared angular momentum is free precession. Finally, the dynamic behaviors of the fractional quantum kicked top map are systematically analyzed by using the bifurcation diagram, the phase diagram, and the maximum Lyapunov exponent. [ABSTRACT FROM AUTHOR]

Few-shot semantic segmentation tackles the problem of recognizing novel class objects from images with only a few annotated exemplars. The key problem in few-shot semantic segmentation is how to effectively model the correspondences between support and query features. Previous works propose to tackle the problem by prototype matching or distance based metric learning. In this work, we introduce a kernel-based similarity matching model, enforcing robust guidance from both foreground and background semantics. In addition, guidance sorting and allocation modules are presented to better explore the guidance from support set. Specifically, guidance sorting module calibrates the most similar semantic patterns on query maps for each support pixel and produces the index vectors. While the allocation module is able to select the most representative correspondences on similarity maps based on index vectors. To integrate the insights of kernel-based similarity features we define a pyramidal paradigm, which progressively integrates guidance signal, query features and mask priors. In this way, the relationships between support and query features are dynamically explored in both foreground and background semantics. Extensive qualitative and quantitative evaluations on PASCAL-5i, COCO-20i and FSS-1000 are conducted to prove the efficiency and advantage of our proposed method. Experimental results demonstrate that our method performs favorably against state-of-the-art methods with reasonable computational cost. [ABSTRACT FROM AUTHOR]

Few-shot semantic segmentation tackles the problem of recognizing novel class objects from images with only a few annotated exemplars. In this work, a multi-scale attentional similarity guidance neural network is proposed to tackle the challenging few-shot semantic segmentation task. This work attempts to build a pyramidal paradigm, which analyzes multi-scale correspondence from diverse levels of semantic features. To achieve this goal, the attentional guided network is introduced to exploit similarity maps, attention vectors as well as query features to segment unseen class objects using only a few image samples. Specifically, the proposed network aims to extract the similarity maps with both foreground and background semantics, which enable more stable correspondences between query and support features. Meanwhile, the object-aware correlation module is introduced to construct attention vector, which is able to guide the network focusing on interested objects and suppress irrelevant background regions. The final segmentation mask is obtained by cross-scale guidance module reinforced by attention mechanism, which takes advantage of both similarity maps and attention vectors. In this way, the proposed network is capable of handling the diversity of object instances, which leads to robust segmentation results. Extensive qualitative and quantitative evaluations on PASCAL-5i, COCO-20i and FSS-1000 verify the effectiveness of the proposed method. The proposed method achieves favorable performance with much less trainable parameters (i.e., 4.2 M parameters with ResNet-50 backbone). [ABSTRACT FROM AUTHOR]

A new fractional two-dimensional quadric polynomial discrete chaotic map (2D-QPDM) with the discrete fractional difference is proposed. Afterwards, the new dynamical behaviors are observed, so that the bifurcation diagrams, the largest Lyapunov exponent plot and the phase portraits of the proposed map are given, respectively. The new discrete fractional map is exploited into color image encryption algorithm and it is illustrated with several examples. The proposed image encryption algorithm is analyzed in six aspects which indicates that the proposed algorithm is superior to other known algorithms as a conclusion. [ABSTRACT FROM AUTHOR]

In this paper, a novel fractional quantum logistic map (FQLM) based on fractional difference is proposed and image encryption algorithm based on it are exploited. First, the FQLM is proposed and its dynamical behaviors are observed with bifurcation diagram, phase portraits and largest Lyapunov exponent plots. After that, the ECC is utilized to cover up the encryption keys and the FQLM is used for the permutation and diffusion process of image encryption. Finally, the cryptosystem is used in image encryption and the algorithm is analyzed in four respects, showing a distinct advantage of the proposed cryptosystem over some of existing ones. [ABSTRACT FROM AUTHOR]

A new fractional two-dimensional triangle function combination discrete chaotic map (2DTFCDM) with the discrete fractional difference is proposed in this paper. The chaos behaviors are observed through the bifurcation diagrams, the largest Lyapunov exponent plot and the phase portraits. The proposed map is applied in color image encryption with the secret keys generated by Menezes–Vanstone Elliptic Curve Cryptosystem. The image encryption system is analyzed using six aspects indicating the superiority of the proposed algorithm compared to the other algorithms. [ABSTRACT FROM AUTHOR]

The incidence rate of human hepatocellular carcinoma (HCC) is approximately three times higher in males than in females. A better understanding of the mechanisms underlying HCC development in males could lead to more effective therapies for HCC. Our previous study found that FBXW10 played a critical role in promoting HCC development in male mice and patients, but the mechanism remains unknown. Here, we found that FBXW10 promoted K63-linked ANXA2 polyubiquitination and activation in HCC tissues from males, and this process was required for S6K1-mediated phosphorylation. Activated ANXA2 further translocated from the cytoplasm to the cell membrane to bind KRAS and then activated the MEK/ERK pathway, leading to HCC proliferation and lung metastasis. Interfering with ANXA2 significantly blocked FBXW10-driven HCC growth and lung metastasis in vitro and in vivo. Notably, membrane ANXA2 was upregulated and positively correlated with FBXW10 expression in male HCC patients. These findings offer new insights into the regulation and function of FBXW10 signaling in HCC tumorigenesis and metastasis and suggest that the FBXW10-S6K1-ANXA2-KRAS-ERK axis may serve as a potential biomarker and therapeutic target in male HCC patients with high FBXW10 expression. • FBXW10 promotes ANXA2 polyubiquitination, activation, and membrane localization in male HCC tumors. • FBXW10-mediated ANXA2 ubiquitination depends on phosphorylation at S12/26 by S6K1. • Ubiquitinated ANXA2 interacts with KRAS and activates MEK/ERK signaling. • Targeting or interfering of ANXA2-KRAS-ERK axis blocks oncogenic functions of FBXW10. • A positive correlation between FBXW10 and membrane ANXA2 in male HCC patients. [ABSTRACT FROM AUTHOR]

This work clarifies the concept of cell average by pointing out the differences between cell average and cell centroid value, which are averaged cell-centered value and pointwise cell-centered value, respectively. Interpolation based on cell averages is constructed and high order QUICK-like numerical scheme is designed for such interpolation. A new approach of error analysis is introduced in this work, which is similar to Taylor's expansion. [ABSTRACT FROM AUTHOR]

Video salient object detection (VSOD), aiming to detect the most conspicuous objects or regions in a video, has become an important research topic over the past few years. Preliminary studies mainly focus on spatial–temporal architecture that heavily relies on implicit attention model to aggregate complementary information from adjacent video frames. Despite the remarkable improvements, existing approaches pay little attention to cross-video affinities, which is important to build explicit attention schema for VSOD. To this end, we propose a novel attention correctness strategy to supervise the aggregation process. Specifically, different from previous works, we employ pairwise training schema, leveraging both positive and negative aggregation supervision to explore inter-video affinities for VSOD. The proposed mechanism successfully suppresses negative correspondence for video frames and reinforces discriminative feature mining for conspicuous objects. To enhance intra-video correspondence, we propose part-aware similarity aggregation module that helps intra-video affinities to segment the salient objects with video-level context. Extensive experiments are conducted on six popular benchmarks, including FBMS, DAVIS, DAVSOD, SegTrack-V2, VOS and ViS. Experimental results on challenging scenes (i.e., for DAVSOD-T, we achieve an improvement of 0.4% for MAE, 1.1% for maximum F-measure and 0.5% for S-measure compared with other competitive models) demonstrate the effectiveness of our proposed method. • We propose an efficient training strategy leveraging both positive and negative supervision for pairwise video inputs. • We design a part-aware similarity aggregation method. • We integrate inter-video affinities and attention correctness strategy. [ABSTRACT FROM AUTHOR]

Photocatalytic disinfection is considered a promising method for eliminating the hazards of pathogenic bacteria. Graphitic carbon nitride (g-C 3 N 4) is an ideal photocatalytic bacterial inactivation material for its advantage of tunable band structure, good stability and easy preparation. This work has constructed a novel defective 3D porous g-C 3 N 4 by cyanamide carbonation using dendritic mesoporous silica template. The direct loading of Fe 3 O 4 nanoparticles provided an excellent pg–C 3 N 4 –Fe 3 O 4 photocatalyst suitable for water disinfection. Compared to pristine g-C 3 N 4 , the prepared 3D porous defective g–C 3 N 4 –Fe 3 O 4 exhibited the enhanced visible light absorbance as indicated by the band gap decreasing of 0.66 eV, and about 3 and 10 fold increase of photo-induced current response and O 2 adsorption respectively. The pg–C 3 N 4 –Fe 3 O 4 showed excellent visible-light-driven photocatalytic bactericidal activity. It could kill 1 × 107 cfu mL−1 Escherichia coli completely within 1 h under visible-light illumination (100 mW cm−2) with good reusability, its logarithmic bacterial inactivation efficiency was about 2.5 fold higher than pg-C 3 N 4. The enhanced bactericidal performance is mainly ascribed to the Fe 3 O 4 involved cascade photo-Fenton reaction. A novel defective 3D porous g-C 3 N 4 /Fe 3 O 4 had been prepared and exhibited high visible-light-driven bactericidal activity enhanced by the Fe 3 O 4 induced cascade photo-Fenton reaction. [Display omitted] • A novel defective 3D porous pg-C 3 N 4 /Fe 3 O 4 photocatalyst with enhanced visible light absorbance ability has been fabricated. • The pg-C 3 N 4 /Fe 3 O 4 photocatalyst exhibits superior photoinduced charge carrier separation efficiency under visible light. • The pg-C 3 N 4 /Fe 3 O 4 exhibits synergistic photodynamic bactericidal activity enhanced by the cascade photo-Fenton reaction. [ABSTRACT FROM AUTHOR]

The extensive research leveraging RGB-D information has been exploited in salient object detection. However, salient visual cues appear in various scales and resolutions of RGB images due to semantic gaps at different feature levels. Meanwhile, similar salient patterns are available in cross-modal depth images as well as multi-scale versions. Cross-modal fusion and multi-scale refinement are still an open problem in RGB-D salient object detection task. In this paper, we begin by introducing top-down and bottom-up iterative refinement architecture to leverage multi-scale features, and then devise attention based fusion module (ABF) to address on cross-modal correlation. We conduct extensive experiments on seven public datasets. The experimental results show the effectiveness of our devised method. • We define an iterative refinement schema to generate coarse-to-fine salient maps, and employ both bottom-up and top-down feature propagation pathways to improve the network model. • We propose both coarse and fine-grained refinement networks in learning process. • A novel attention mechanism is proposed to make full use of cross-modal visual cues for accurate detection results. [ABSTRACT FROM AUTHOR]

A series of norbornane-based HIV-1 protease (PR) inhibitors are designed theoretically to displace the tetrahedrally coordinated internal water molecule that bridges inhibitor to flaps via hydrogen bonds. These designed inhibitors use the norbornenone oxygen atom to mimic this structural water molecule and contain diols to interact with the carboxylate oxygens of catalytic aspartates. The binding free energies were estimated by modified linear interaction energy approach [Zoete H, Michielin O, Karplus M, J Comput Aided Mol Des17:861, 2003], in which the binding free energy is written as a linear combination of the electrostatic interaction energy between PR and the ligand, Eelec, the van der Waals interaction energy between PR and the ligand, EvdW, and the difference of the solvation free energies of the complex, the receptor, and the isolated ligand, ΔGsolv. The equation obtained in previous work [Da W. Zhang, Philip Lin Huang, Sylvia Lee-Huang, John Z. H. Zhang, J Theor Comput Chem7:485, 2008] is applied directly to calculate the binding free energy of designed norbornane-based HIV-1 PR inhibitors. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of Lu+ with CH3F, which was selected as a representative system of the activation of C–F bond in fluorohydrocarbons by late lanthanide cations, has been examined using density functional theory (DFT). The potential energy surfaces (PESs) of [Lu, C, H3, F]+ were explored in detail in both singlet and triplet electronic states. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behaviour on the transition state (TS) area was shown. The theoretical results can act as a guide to further theoretical and experimental researches. [Copyright &y& Elsevier]

Abstract: The gas-phase reaction of activation C CH3OCH3 by Ti+ has been investigated using density functional theory (DFT) at the 6-311++G(3df,3pd)//6-311+G(d) level. The structures of all reactants, intermediates, transition structures and products of this reaction have been optimized and characterized at the quartet and doublet electronic states. Crossing points (CPs) are localized, and the possible spin inversion processes are discussed by means of the intrinsic reaction coordinate (IRC) approach. Finally, two competitive reaction pathways, including the CP, are proposed from the most stable reactants to the most thermodynamically stable products. [Copyright &y& Elsevier]

Abstract: The reaction of La+ with CH3F, which was selected as a representative system of the activation of C–F bond in fluorohydrocarbons by bare lanthanide cations, has been examined using density functional theory (DFT) to explore more integrated reaction pathways and mechanisms on both singlet and triplet potential energy surfaces (PESs). A direct fluorine abstraction mechanism and an insertion–elimination mechanism were revealed, the related thermochemistry data involved in reaction of La++CH3F were determined. The crossing points (CPs) have been found by means of single-point computations as a function of the structural change along the intrinsic reaction coordinate (IRC) in this manuscript. The present results not only support the existing reaction conclusions inferred from early experimental data, but also complement the pathway and mechanism for this reaction, which can act as a guide for further experimental researches and theoretical investigations. [Copyright &y& Elsevier]

Multi‐view subspace clustering always performs well in high‐dimensional data analysis, but is sensitive to the quality of data representation. To this end, a two‐stage fusion strategy is proposed to embed representation learning into the process of multi‐view subspace clustering. This article first proposes a novel matrix factorization method that can separate the coupling consistent and complementary information from observations of multiple views. Based on the obtained latent representations, we further propose two subspace clustering strategies: feature‐level fusion and subspace‐level hierarchical strategy. The feature‐level method concatenates all kinds of latent representations from multiple views, and the original problem therefore degenerates to a single‐view subspace clustering process. The subspace‐level hierarchical method performs different self‐expressive reconstruction processes on the corresponding complementary and consistent latent representations coming from each view, that is, the prior constraints imposed on different types of subspace representations are related to the relevant input factors. Finally, extensive experimental results on real‐world datasets demonstrate the superiority of our proposed methods by comparing them against some state‐of‐the‐art subspace clustering algorithms. [ABSTRACT FROM AUTHOR]

In this study, a three-dimensional porous cellulose-based microsphere material modified with ionic liquid functional groups was prepared. Seven kinds of cellulose microspheres with different ionic liquid groups were successfully produced and were used for the adsorption of Acid Orange 7 dye. Cellulose microsphere modified with 4-methylimidazole, named as CMs4, had the greatest adsorption capacity of 218.6 mg/g and the fastest adsorption rate. CMs4 reached an adsorption capacity of 100 mg/g after only 10 min. Compared with materials in other literatures, CMs4 had an excellent Acid Orange 7 dye adsorption rate. According to the zeta potential analysis, the surface potential of CMs4 depended on the pH. Exploiting this property, cationic and anionic dyes can be separated using CMs4 by changing the pH. Since cellulose materials are renewable and widely available, CMs4 is a promising environmentally friendly material for dye adsorption applications. Cellulose microspheres modified with ionic liquids for rapid removal of AO7. Image 1 • Seven different ionic liquid groups were first modified on cellulose microspheres. • CMs4 had a large adsorption capacity and a rapid adsorption rate for AO7 dye. • CMs4 can separate cationic and anionic dyes by pH control. • CMs4 can be used as a water purification filler due to its fast adsorption capacity. [ABSTRACT FROM AUTHOR]

Two-dimensional numerical simulations were performed using the FLUENT code to investigate the impacts of the shape and height of building roofs on flow and pollutant dispersion inside an isolated street canyon. The numerical model was validated against wind tunnel measured data. Five different roof shapes (vaulted, trapezoidal, slanted, upward wedge-shaped, and downward wedge-shaped roofs) and three different roof heights (= 1/6, 1/3, and 1/2, whereis the roof height andHis the building height) were considered in the simulations. The numerical results revealed that the vortical flow structure and pollutant distribution within an isolated canyon depend significantly on the shape and height of building roofs. A large unique clockwise vortex is established in the canyon, and thus the pollutants accumulate in the leeward side of the canyon for the vaulted and downward wedge-shaped roofs at= 1/6, 1/3, and 1/2, the trapezoidal roof at= 1/6 and 1/3, and the slanted and upward wedge-shaped roofs at= 1/6, while an upper clockwise vortex and a lower counterclockwise vortex are generated, and consequently the pollutants pile up in the windward side of the canyon for the trapezoidal roof at= 1/2 and the slanted and upward wedge-shaped roofs at= 1/3 and 1/2. In theone-vortexflow regimes, the vortex center moves upwards and the vortex size expands vertically as the roof height increases for the vaulted, trapezoidal, and downward wedge-shaped roofs. In thetwo-vortexflow regimes, the size and rotational speed of both the upper clockwise and lower counterclockwise vortices increase with roof height for the slanted and upward wedge-shaped roofs. At each of the three roof heights examined, the lowest pollution level occurs in the canyon with the downward wedge-shaped roof, suggesting that the downward wedged-shaped roof is more beneficial for pollutant removal from the isolated canyon than the vaulted, trapezoidal, slanted, and upward wedge-shaped roofs. Due to the establishment of two-vortex flow structures, the trapezoidal roof at= 1/2, the slanted roof at= 1/3 and 1/2, and especially the upward wedge-shaped roof at= 1/3 and 1/2 are unfavorable for pollutant dispersion and dilution in the canyon compared to the vaulted and downward wedge-shaped roofs. [ABSTRACT FROM PUBLISHER]

[Display omitted] • The FeO y @C/Fe-N x /C catalysts were prepared via a facile two step pyrolysis strategy. • The prepared FeO y @C/Fe-N x /C catalysts exhibited better oxygen reduction reaction (ORR) performance for, ethanol resistant and long-term durability than Pt/C. • The outstanding performance of ORR was attributed to FeO y @C structure, exposed abundant Fe–N x active sites and two dimensional porous carbon with a large specific surface area. Fe-based nanoparticles encapsulated in carbon can effectively promote the ORR activity of the neighboring Fe–N x and prevent the dissolution of metal nanoparticles to ensure the long-term durability of catalysts. Herein, we employed a facile two step pyrolysis strategy to construct "plane-active sites" structure, namely FeO y nanoparticles embedded in carbon were loaded on two dimensional (2D) porous carbon with exposed abundant Fe–N x active sites (FeOy@C/Fe-N x /C). The optimized FeO y @C/Fe-N x /C catalyst with low Tafel slope (48 mV dec−1) and nearly-four-electron selectivity (3.91–3.97) showed excellent performance towards ORR with a more positive shift of 15 mV of half-wave potential (E 1/2 = 0.856 V) than that of commercial Pt/C (E 1/2 = 0.841 V) in alkaline solution, and also had a superior long-term stability and methanol resistance as compared with commercial Pt/C. The excellent electrochemical performance of FeO y @C/Fe-N x /C can be attributed to FeO y @C structure, exposed abundant Fe–N x active sites and two dimensional porous carbon with a large specific surface area. [ABSTRACT FROM AUTHOR]

A new method based on a Direct Analysis in Real Time (DART) ionization source coupled with triple quadrupole tandem mass spectrometry has been developed for rapid qualitative and quantitative analyses of 1-deoxynojirimycin (DNJ) in mulberry leaves. Two ions produced from DNJ, [M + H] + ( m / z 164) and [M-2H + H] + ( m / z 162), are observed using DART–MS in the positive ion mode. The peak areas of the two selected ions monitoring (SIM) signals of ([M + H] + ( m / z 164) and [M-2H + H] + ( m / z 162)) are integrated to determine the peak area for quantitative analyses. A reasonable linear regression equation is obtained in the range of 1.01 to 40.50μg/mL, with a linear coefficient (R 2 ) of 0.996. The limits of detection (LOD) and quantification (LOQ) of the method are 0.25 and 0.80 μg/mL, respectively. The range of recovery is shown to be 87.73–95.61%. The results derived from the developed DART–MS method are in good agreement with those from the conventional HPLC–FLD method. By contrast, DART–MS in SIM mode is a simple, rapid and high-throughput approach for the determination of the DNJ content in mulberry leaves. The present method is advantageous for the rapid screening of mulberry leaves containing high DNJ contents. [ABSTRACT FROM AUTHOR]

Anode‐free solid‐state lithium batteries are promising for next‐generation energy storage systems, especially the mobile sectors, due to their enhanced energy density, improved safety, and extended calendar life. However, the inefficiency of lithium plating and stripping leads to rapid capacity degradation due to the absence of excess lithium inventory. Therefore, dissecting the difficulties and challenges faced by anode‐free solid‐state lithium batteries can pave the way to improving the cycle life of many lithium batteries. In this review, the key issues affecting capacity degradation are elaborated step‐by‐step based on the current understanding of anode‐free solid‐state lithium batteries. Furthermore, various strategies for optimizing performance are targeted. Finally, future opportunities and possible directions for anode‐free solid‐state lithium batteries are evaluated, aiming to stimulate the exploration of this emerging field. [ABSTRACT FROM AUTHOR]

Iron(IV)-corrolecomplexes were first investigated as catalystsfor olefination of aldehydes with ethyl diazoacetate in the presenceof triphenylphosphine. Efficient olefination of aromatic aldehydeswith high trans-selectivity was observed, showingiron corrole is a new kind of promising catalyst for olefination reaction.Transformation of the phosphazine to ylide by iron(IV) corrole wasproved to be the key step in the present system. [ABSTRACT FROM AUTHOR]

A two-dimensional numerical model for simulating airflow and pollutant dispersion inside an urban street canyon was first developed using the FLUENT code, and then it was validated against a wind tunnel experiment. Then the effects of strength and position of pollutant sources on pollutant dispersion within an urban street canyon were investigated numerically. The numerical results showed that the dimensionless pollutant concentrations within the urban street canyon were independent from the source strength. The results also revealed that the pollutant distributions inside the urban street canyon with a two-lane road were influenced significantly by the positions of the two sources: 1) the closer the two sources were to the street center of the canyon, the lower the pollutant concentrations on the leeward wall and at the human respiration level in the leeward footpath became; 2) the pollutant concentrations on the windward wall and at the human respiration level in the windward footpath were not sensitive to the locations of the two sources as long as the source on the windward lane was situated outside the small recirculation zone at the bottom corner of the canyon windward wall; 3) the pollutant concentrations on the lower parts of the windward and leeward walls as well as in the two footpaths increased greatly when the two sources were moved from outside into the small recirculation zones. [ABSTRACT FROM AUTHOR]

• Dihydroxyl A 2 B triaryl corroles and their gallium and phosphorus complexes were synthesized. • 10-(2,4-dihydroxyphenyl)-5,15-bis(pentafluorophenyl)corrole phosphorus(V) (1-P) exhibited high singlet oxygen quantum yield. • 1-P exhibited excellent photodynamic activity against MDA-MB-231 and A549 cells. • 1-P photodynamic therapy arrested MDA-MB-231 cells in the sub-G1 phase. • 1-P induced apoptosis by increasing intracellular ROS under illumination at 620–625 nm. Two new dihydroxyl A 2 B triaryl corroles 10-(2,4-dihydroxyphenyl)-5,15-bis(pentafluorophenyl)corrole (1) and 10-(3,4-dihydroxyphenyl)-5,15-bis(pentafluorophenyl)corrole (2) and their gallium(III) and phosphorus(V) complexes (1-Ga, 2-Ga, 1-P and 2-P) were synthesized and investigated as photodynamic antitumor agents. All synthesized corrole derivatives could generate singlet oxygen smoothly under illumination at 620–625 nm and showed remarkable in vitro photodynamic antitumor activity. Excited, phosphorus(V) corrole 1-P even exhibited better phototoxicity towards A549 and MDA-MB-231 tumor cell line (IC 50 , 0.08 and 0.12 µM) than clinical drug Foscan® (IC 50 , 0.27 µM). The laser confocal microscopy results showed that the cellular absorbed 1-P was located in the cytoplasm. Under illumination, intracellular reactive oxygen species (ROS) could be detected, which would triger the destruction of the mitochondrial membrane potential and finally lead to apoptosis. Furthermore, the 1-P photodynamic treatment would cause the cancer cells arrested at sub-G1 stage. 10-(2,4-dihydroxyphenyl)-5,15-bis(pentafluorophenyl)corrole phosphorus(V) (1-P) exhibited remarkable in vitro photodynamic antitumor activity under illumination of red light at 620–625 nm. [Display omitted] [ABSTRACT FROM AUTHOR]

Three mono-hydroxy corroles 1 – 3 and their gallium(III) complexes Ga1 - 3 were synthesized, and their photodynamic antitumour activities towards breast cancer cells were investigated. All corroles showed excellent cytotoxicity against the MDA-MB-231 and 4T1 cell lines upon light irradiation at 625 nm. Ga3 exhibited excellent phototoxicity and selectivity against MDA-MB-231 cells, with an IC 50 of 0.06 ± 0.03 μM and a selective index value of 1338.83 (relative to human normal Huvec cells). The performance of Ga3 was even better than that of the clinical photodynamic therapy drug m -THPC. A preliminary mechanistic investigation revealed that corrole 3 and Ga3 were mainly located in the cytoplasm. Upon irradiation, they could generate intracellular reactive oxygen to destroy the mitochondrial membrane potential and arrest the cell cycle at the sub-G1 phase. Flow cytometry revealed that corrole 3 and Ga3 induced cancer cell apoptosis after photodynamic treatment. Corrole 3 and Ga3 displayed negligible cytotoxicity in the dark. These results suggest that corrole 3 and Ga3 are promising candidates for use in the photodynamic therapy of breast cancer. Hydroxy-corrole and its gallium(III) complex induced breast cancer cells apoptosis with red light irradiation. Image 1 • The photophysical and photochemical properties of hydroxy-corroles were studied. • Corrole 3 and Ga3 exhibited excellent PDT efficacy against breast cancer cells. • Corrole 3 and Ga3 induced breast cancer cells apoptosis upon 625 nm LED irradiation. [ABSTRACT FROM AUTHOR]

Mulberry ( Morus alba L.), a traditional industrial crop, has various cultivars and a large planting area in China and consequently, high exploitation potential. The aim of this study was to systematically study the mulberry resources in eastern China. Twenty-four mulberry leaf samples of eight representative cultivars from five provinces in eastern China were investigated. The alkaloid and polyphenols contents were determined by HPLC–MS/MS, and the total polyphenols and flavonoid contents were also obtained. Then, FRAP, ABTS, and DPPH tests were used to determine the antioxidant activity of mulberry leaves. The results indicated that the content of 1-deoxynojirimycin was within the range of 0.438 ± 0.010 mg/g–2.159 ± 0.016 mg/g, and the content of fagomine ranged from 0.379 ± 0.018 mg/g to 1.675 ± 0.021 mg/g. The samples from Anhui had the best antioxidant activity, of which the DPPH free radical-scavenging capacity reached 70.837 ± 1.246%, and the ferric reducing antioxidant power was 258.864 ± 22.718 mmol Fe 2+ /g. The principal component analysis results showed that there was a good correlation between the total polyphenols content, total flavonoid content, chlorogenic acid content, and antioxidant activity. Considering the active ingredient contents and antioxidant activity, we found that Yu711 was the most economically valuable variety, and Anhui is the best location to promote mulberry cultivation in eastern China, which provides a basis for the rational utilization of mulberry industrial products. [ABSTRACT FROM AUTHOR]

Exploring lanthanide complexes as luminescence sensors is an interesting topic. By utilizing 2-(4-carboxyphenyl)imidazo[4,5-f][1,10]phenanthroline (Hcpip) and 2-phenylimidazo[4,5-f][1,10]phenanthroline (pip), two series of lanthanide complexes, one-dimensional [Ln2(cpip)2(OAc)4]n (1-Ln; Ln = Sm, Eu) and zero-dimensional [Ln2(pip)2(OAc)6] (0-Ln; Ln = Sm, Eu, Tb, Dy), have been synthesized and crystallographically characterized. The in situ hydrothermal hydrolysis of acetonitrile yields the acetate anions. For both series, the main feature is the existence of [Ln2(μ-η1:η2-COO)2(μ-η1:η1-OAc)2(η2-OAc)2] subunits, in which μ-η1:η2-COO− refers to the carboxylate group when the ditopic Hcpip is used, but in the case of the monotopic pip, μ-η1:η2-COO− comes from the acetate. Insoluble polymeric 1-Eu in its water suspension exhibits specific but slow luminescence response (emission colour changes from red to bluish green). As an improvement, the dimeric 0-Eu is soluble in DMSO and shows the luminescence response immediately. [ABSTRACT FROM AUTHOR]

10-(3-Bromo-4-Hydroxyphenyl)-5,15-bis(pentafluorophenyl)corrole phosphorus(V) (1-P) exhibited excellent photodynamic antitumor activity in vivo and in vitro. Edible bird's nest (EBN) might have a positive effect on the elimination of tumor in mice treated with PDT by enhancing the expression of immune T cells. [Display omitted] • Several new Ga(III) and P(V) corrole complexes were synthesized. • P(V) corrole complex 1-P exhibited high singlet oxygen quantum yield and photostability. • P(V) corrole complex 1-P showed excellent photodynamic antitumor activity in vivo and vitro. • PDT treatment may enhance antitumor immune responses (eg, CD3+, CD4+ and CD8+) of tumor grafted mice. • Edible bird's nest (EBN) administration might help to eliminate tumors by enhancing T cell expression. Four new phosphorus(V) and gallium(III) corrole complexes were prepared and evaluated as antitumor agents in photodynamic therapy (PDT) in vivo and vitro. All complexes showed low dark toxicity and good photocytotoxicity under light illumination (625 ± 2 nm, 3 W/m2). Especially, phosphorus(V) corrole (1-P) exhibited quite excellent photocytotoxicity with IC 50 of 0.03 (±0.003) μM with phototoxic indices (p.i.) of >3333.33 against MDA-MB-231 tumor cells. Under light irradiation, 1-P could produce reactive oxygen species (ROS) in cells and destroy mitochondrial membrane potential, leading to apoptosis. The PDT treatment with 1-P arrested the cell at sub-G1 phase. Animal test showed 1-P could effectively inhibit the growth of MDA-MB-231 tumor cell grafted BALB/c nude mice. The PDT generated ROS might boost the anti-tumor immune response (e.g., CD3+, CD4+ and CD8+). It is well known that edible bird's nest (EBN) helps to improve the immune system and thus is beneficial to health. Photodynamic therapy combined with EBN (100 mg/kg) treatment was conducted for the first time to evaluate the possible antitumor synergistic effect in mice. It turned that EBN may do significant positive help in eliminating the tumors in PDT-treated mice by enhancing T cell expression as indicated by the detection of remarkable higher CD3+ expression in tumor and spleen tissue. [ABSTRACT FROM AUTHOR]

The Anshan region of the North China Craton hosts significant iron ore reserves in the form of Archean banded iron formations (BIF). This study focuses on NW–SE trending layered iron ore bodies identified using aeromagnetic data with a 500 m point spacing and a new method that combines structural analysis with the 3D inversion of magnetic susceptibility. This approach has identified two prominent parallel magnetic anomalies within the study area, with the bottom boundary of BIF body I estimated to be at a depth of ∼5600 m and the bottom boundary of BIF body II at ∼5200 m. The two BIF iron ore bodies are separated by granitoids associated with the Archean Anshan micro-continental nucleus. The area close to this micro-continental nucleus has undergone significant tectonic deformation, including ductile shearing. This shearing is the main control on the distribution of BIF iron ore belts in the Anshan area, in contrast to the previous view which folding was thought to control the distribution of BIF. Combining our new data with regional tectonic information yields a model where both folding and ductile shearing controlled the distribution of the main BIF ore bodies in the study area. This model provides insights into the distribution of iron ores in the Anshan area as well as a guide for future deep exploration in this region. [ABSTRACT FROM AUTHOR]

Phosphorus(V) trimethoxyl A 2 B triaryl corrole (2-P) with excellent optical characteristics induced cancer cells apoptosis upon light irradiation at 625 nm. [Display omitted] • Ga(III) and P(V) trimethoxyl A 2 B triaryl corrole were synthesized and characterized. • P(V) m , m' , p -trimethoxyl A 2 B triaryl corrole exhibited high singlet oxygen quantum yield, photostability, and excellent photodynamic activity against cancer cells. • P(V) m , mʼ , p -trimethoxyl A 2 B triaryl corrole photodynamic therapy treatment might cause tumor cells arrest at the sub-G1 phase and induced apoptosis triggered by ROS increasing upon light irradiation. Two new trimethoxyl A 2 B triaryl corroles 10-(2,4,6-trimethoxyphenyl)-5,15-bis(pentafluorophenyl)- corrole (1) and 10-(3,4,5-trimethoxyphenyl)-5,15-bis(pentafluorophenyl)-corrole (2) and their gallium(III) and phosphorus(V) (1-Ga , 1-P , 2-Ga and 2-P) complexes had been prepared and well characterized by UV–vis, NMR and HR-MS. Among all compounds, 2-Ga , 1-P and 2-P showed excellent in vivo photodynamic activity against the MDA-MB-231, A549, Hela and HepG2 cell lines upon light irradiation at 625 nm. And 2-P even exhibited higher phototoxicity than the clinical photosensitizer temoporfin. Also, 2-P exhibited the highest singlet oxygen quantum yield and photostability. The preliminary investigation revealed that 2-P could be rapidly absorbed by tumor cells and mainly located in the cytoplasm. After photodynamic therapy (PDT) treatment with 2-P , mitochondrial membrane potential destruction, intracellular ROS level increasing and nuclear fragmentation of cancer cells could be observed. Cell cycle analysis demonstrated that the 2-P PDT may cause tumor cell arrest at sub-G1 stage and induce early and late apoptosis of cells. These results suggest that 2-P is a promising candidate as a photosensitizer for photodynamic therapy. [ABSTRACT FROM AUTHOR]

Cationic meso(4- N-methylpyridyl)-based metallocorroles, μ-oxo iron corrole dimer ( 1b) and manganese corrole monomer ( 2b), were synthesized and characterized. The interactions of these two metal corrole complexes with CT-DNA were studied by UV-visible, fluorescence and circular dichroism spectroscopic methods, as well as by viscosity measurements. The results revealed that 1b interacts with CT-DNA in a difunctional binding mode, i.e. non-classical intercalation and outside groove binding with H-aggregation, while 2b can interact with CT-DNA via an outside groove binding mode only. The binding constants Kb of 1b and 2b were 4.71 × 105 m−1 and 2.17 × 105 m−1, respectively, indicating that 1b can bind more tightly to CT-DNA than 2b. Furthermore, both complexes may cleave the supercoiled plasmid DNA efficiently in the presence of or tert-butyl hydroperoxide (TBHP), albeit 1b exhibited a little higher efficiency. The inhibitor tests suggested that singlet oxygen and high-valent (oxo)iron(VI) corrole or (oxo)manganese(V) corrole might be the active intermediates responsible for the oxidative DNA scission. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The mechanism of the reaction catalyzed by Sc+ has been investigated by means of UB3LYP/6-311+G(2d) level. Our calculated results strongly indicate that both the reactions NO2(2A1)+Sc+(X3D)→NO(2∏)+ScO+(X1∑+) and are spin-forbidden reactions. The crossing points (CPs) that are involved and the possible spin inversion processes are discussed using the intrinsic reaction coordinate (IRC) approach. On the basis of Hammond postulate, they are typical ‘two-state reactivity’ (TSR) reactions. And the O-atom affinities (OA) testified that the argumentation is thermodynamically allowed. [Copyright &y& Elsevier]

Abstract: The reaction pathway and energies for the gas-phase CO2–CO conversion by W+ are discussed from density functional theory (DFT) UB3LYP calculation at the relativistic effective core potential (ECP) of Stuttgart basis sets with W+ and 6-311+G(2d) with CO2. The reaction mechanism between W+ and CO2 is an insertion–elimination mechanism. The W+ inserts with no energy barrier into a CO bond resulting in an OWCO+ insertion product. The intrinsic reaction coordinate for the insertion process has been defined and the reaction mechanism has been investigated by analyzing various structures along this path. Crossing points (CPs) are localized, and possible spin inversion processes are discussed by means of the intrinsic reaction coordinate (IRC) approach. [Copyright &y& Elsevier]

Abstract: The entire reaction mechanism for the gas-phase CO2–CO conversion by early transition metal ions, La+, Hf+, and Ta+, are studied using density functional theory (DFT). The results indicate that the lowest energy path corresponds to the η2-O coordination of CO2 followed by the insertion of M+ into the C–O bond. The reactions are all exothermic due to the participation of the metal ions, to be compared with the strong endothermic process of the unimolecular CO2 decomposition. Crossing points (CPs) are localized, and possible spin inversion processes are discussed by means of the intrinsic reaction coordinate (IRC) approach. [Copyright &y& Elsevier]

Abstract: The reactions of 4d transition metal ions (except Tc and Cd) with N2O on two potential energy surfaces, producing the metal oxide ion and N2, are studied by means of density functional theory. The results indicate that the lowest energy path corresponds to the coordination of N2O followed by the insertion of M+ into the N–O bond. The reaction mechanism between 4d transition metal ions and N2O is an insertion–elimination mechanism. All products are formed in exothermic processes. The potential energy curve crossings, which dramatically affect reaction mechanisms, are discussed in detail. [Copyright &y& Elsevier]

• PdNPs can be synthesized directly by cellulose solution. • The cellulose-Pd gel can be made into 3D porous microspheres. • The cellulose-PdNPs microspheres can degrade dyes rapidly. In this study, a simple and environmentally friendly method was developed for synthesizing 3D porous cellulose supported palladium nanoparticles (PdNPs) catalysts. PdNPs (3.1 ± 1.4 nm) can be synthesized directly by cellulose solution through microwave heating (60 °C, 4 h) and prepared into microspheres by freeze-drying to degrade methylene blue (MB) and Congo red (CR) rapidly. In addition, the reduction ability of cellulose hydroxyl group was proved by XPS and FTIR results. And the contact angle of 38.20° proves its hydrophilic ability. Cellulose-PdNPs microspheres showed high catalytic efficiency achieved 99 % and after multiple cycles it was still higher than 90 %. Therefore, the method proposed in this paper provides some new applications for cellulose, and the cellulose-Pd catalysts prepared by the research also have potential application value in the field of environment. [ABSTRACT FROM AUTHOR]

A series of transition metal corroles were synthesized and evaluated for photodynamic therapy (PDT). Complex Fe-2c exhibited significant photocytotoxicity and low dark cytotoxicity to A549 tumor cells and could induce apoptosis of A549 cells after PDT treatment. • Transition metal mono-hydroxyl corrole bind to CT-DNA via external binding mode. • Transition metal mono-hydroxyl corrole have no dark or photo- cytotoxicity to human normal cells. • Iron para -mono-hydroxyl corrole has significant photodynamic activity to A549 lung cancer cell. • Transition metal mono-hydroxyl corrole may be used as potential photodynamic anticancer drugs. A series of iron(III), manganese(III) and copper(III) mono-hydroxyl corrole complexes had been prepared and well characterized by UV–vis, 1H NMR, 19F NMR and HR-MS. These metallocorroles may bind to CT-DNA through external binding mode. Metallocorrole Fe-2c exhibited significant phototoxicity and low toxicity toward A549 tumor cells. While manganese (III) and copper (III) corroles showed hypotoxicity to A549, MCF-7 and HepG-2 tumor cells, whether under dark or illumination conditions. All tested metallocorroles exhibited non-toxicity to human normal cells (GES-1) with or without irradiation at 625 nm. Cell cycle analysis indicated that metallocorrole Fe-2c arrested the cell cycle at G2/M phase and increased the Sub-G1 phase in A549 cell lines. It was mainly localized at mitochondria and could significantly reduce mitochondrial membrane potential after photodynamic treatment, which would further induce tumor cell apoptosis. [ABSTRACT FROM AUTHOR]