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Breakthroughs in the synthesis of graphyne have stimulated vast interest in the design of new unsaturated 2D materials, mainly via the elemental replacement of graphyne, for promising applications. Here, a novel group VA counterpart of graphyne, namely phosphoryne, is reported based on first-principles calculations. Computed binding energies, phonon dispersions, and elastic stiffness coefficients of phosphoryne allotropes exhibit the energetic, kinetic, and mechanical stabilities. The 2D semiconducting phosphoryne monolayers have adaptable bandgaps from 1.38 to 1.79 eV, which are tunable under biaxial strain. The sp2 phosphorus has been demonstrated, using DFT and AIMD simulations with a small overpotential, to have more useful sites for the HER. Combining the intrinsic unsaturated binding character, appropriate bandgaps, and full spectrum adsorption abilities, phosphoryne monolayers are promising candidates to act as substrates for electronic and photocatalytic nanodevices, and this may encourage future researchers to create them in the future.

The reaction of 1,3,5-triazine-2,4,6-triamine (melamine, MA) with 3-hydroxy-2-naphthoic acid (3H2NA) and 6-hydroxy-2-naphthoic acid (6H2NA) provided two ionic supramolecular salts, I and II. These supramolecular salts were constructed based on N–H⋯N, N–H⋯O and O–H⋯O hydrogen bonding interactions and confirmed by single-crystal X-ray diffraction. These structures revealed the typical monoprotonated propensity of MA when reacting with organic hydroxyl acids, and formed assembled aggregates, such as chain and reticular structures. The analysis of weak interaction networks in supramolecular salts reflected the relative approach of the –COOH group toward the N atom in the triazine ring. The assembly pattern and geometric structure were explored by density functional theory (DFT) analysis. As predicted by molecular electrostatic potential analysis (MESP), the binding mode and stable configuration were obtained. The proton-transfer phenomenon was predicted using the pKa method. The quantum theory of atoms in molecules (QTAIM) suggested that the hydrogen bonds presented in salts I and II were moderate in nature except for N5–H5A⋯O2 in salt II. Although classical hydrogen bonds dominate for the synthon formation, weak dispersive forces cannot be ignored. The dnorm-mapped Hirshfeld surface of MA established the strong characteristic features of weak interactions, which were reflected in corresponding 2D fingerprint plots (FPs). The UV-vis absorption and luminescent property were investigated, and the as-obtained salts exhibited different behaviors from that of their precursors. In addition, thermal behaviors of salts I and II were investigated by TGA analysis in detail.

By utilizing Dy(hfac)

Purpose This retrospective study aimed to investigate the clinical value of -deoxy-2-(18F)-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in detecting primary lesions of hepatic metastases. Methods A total of 124 patients with hepatic metastatic carcinoma of unknown primary underwent whole body 18F-FDG PET/CT imaging. According to the final diagnoses for both primary sites and hepatic metastases that were confirmed either histopathologically or by clinical follow up, all patients were divided into 4 groups: a true positive group (TP, 95 cases), a false positive group (FP, 9), a true negative group (TN, 8) and a false negative group (FN, 12). Results The TP rate of primary lesions, detected by 18F-FDG PET/CT, was 76.61%, the FP rate 7.26%, the TN rate 6.45% and the FN rate 9.68%. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 18F-FDG PET/CT in the detection of primary tumors were 88.78%, 52.94%, 91.35%, 40%, and 83.06%, respectively. Accurate diagnosis groups (TP, TN) showed a significantly higher SUVmax (standard uptake maximum value) level than that in error diagnosis groups (FP, FN). The SUVmax between hepatic metastases and primary lesions had a positive correlation. The primary tumor sites of hepatic metastases were mainly located in the gastrointestinal organs and the lungs. Conclusions Whole body 18F-FDG PET/CT imaging was sensitive for detecting primary sites/lesions with hepatic metastatases of unknown primary, especially when the SUVmax of hepatic metastases were greater than 4.7.

N-Doped-carbon-coated 2–4 nm SnO2 nanoparticles were synthesized via a facile metal–organic framework (MOF) coating process followed by a calcination of the SnO2@MOF composite. The as-prepared SnO2 nanoparticles are well dispersed and coated with a uniform nitrogenous carbon structure, which can effectively prevent volume expansion during discharge and charge processes. Benefiting from the advantages of a synergistic effect of SnO2 nanoparticles and carbon structure, these materials exhibit excellent electrochemical performance. For the optimized material SOC-3, a reversible specific capacity of 1032 mA h g−1 was maintained at 100 mA g−1 after 150 cycles with a coulombic efficiency of 99%. When the current was increased to 500 mA g−1, a capacity of 600 mA h g−1 was still attained.

The capsaicin in hot peppers is an important biological active substance that is widely used in food and medicine. In this work, six capsaicin derivatives such as N-(4-Hydroxy-3-acetophenone benzyl)acrylamide (A), 2-hydroxy-3-(octyloxy)phenyl-5-acrylamidemethylbenzene phenyl methanone (B), N-(2,5-dihydroxybenzene)acetamide (C), N-(5-acetamidemethyl benzene-2,4-dihydroxybenzene)acetamide (D), 4-acetamideme thylbenzene-2-benzylphenol (E), and N-(2-methyl-4-hydroxy-5-methylthiobenzene)acetamide (F) were synthesized via the Friedel-Crafts (F-C) alkylation reaction and were characterized using IR, 1 H NMR, and HRMS. The antioxidant activity of compounds was evaluated using the reducing power and DPPH radical (DPPH·) scavenging assays, and Vitamin C (Vc) was used as a control. The antibacterial activity was tested using minimum inhibition concentration (MIC) and antibacterial rate assays, and Escherichia coli and Staphylococcus aureus were used as the tested strain. The results showed that all six capsaicin derivatives had certain antioxidant and antibacterial activities, and the activities increased with increasing mass concentration. The best properties were obtained for compounds C and F; the antioxidant activity of compound C was similar to Vc and the MIC of compound F was 0.0313 mg/ml, its antibacterial rate was greater than 99% at 3 mg/ml. PRACTICAL APPLICATIONS: As a vegetable, peppers can be eaten fresh or processed to other forms such as pepper powder or pepper jam, and it is very popular because of its long history, unique flavor, and special functions. Our current study shows that capsaicin derivatives have good antioxidant and antibacterial activities, and therefore, the present study of capsaicin derivatives with good activity provides a good foundation for future applications in natural food additives and medicine.

Two novel cocrystals were successfully constructed by 1(2H)-Phthalazinone (PHT) and Tetrafluoroterephthalic acid (TETA) based on O-H⋯O, N-H⋯O, C-H⋯O, C-H⋯F, N-H⋯N and C-H⋯N hydrogen bonding networks, and were well depicted by single crystal diffraction analysis. As predicted by electrostatic potential analysis, the stoichiometry of PHT to TETA is 2:1 and stabilized by O-H⋯O and N-H⋯O hydrogen bonds. The single crystal X-ray diffraction characterized that the two cocrystals were all made up by 2PHT-TETA motif in different ways. AIM analysis and Hirshfeld surfaces indicated the adjacent 2PHT-TETA units assemble through C-H⋯O, C-H⋯F and C-H⋯N hydrogen bonds, producing a 2D plane structure in cocrystal I. Meanwhile, the C-H⋯F, N-H⋯N and C-H⋯O hydrogen bonds between 2PHT-TETA units were the stabilizing factors in cocrystal II. Topological parameters such as ∇2ρ and H revealed the strength of hydrogen bonds were moderate in nature except O31⋯H32-O34 (1.704A, -60.336kJmol-1) in compound I. The hydrogen bonding interactions, cocrystal stability and electron donor-acceptor interactions were investigated using natural bonding orbital analysis. It showed that electron transfer of n(O) σ*(O-H) and n(O) σ*(N-H) between PHT and TETA influence the packing characteristics significantly. Structural changes accompanying cocrystal process have been rationalized through the IR spectrum along with the quantum chemical calculations. The frequency downshifts of CO, N-H and O-H stretching after cocrystallization have been attributed to hydrogen bonding interactions.

A steady self-assembled protonated salt, constructed by Tetrafluoroterephthalic acid (Tera) and 5, 6-dimethyl benzimidazole (DBZ), was designed and prepared in methanol/water solution. The structure and properties were characterized by experimental tests and analyzed by theoretical calculations on molecular level. Excellent symmetry of Tera, proton transfer bridged by water molecule, intermolecular hydrogen bonding play important roles in the self-assemble process. Proton migration analysis confirms the keying action of H2O molecules on co-crystallization. AIM analyses indicate hydrogen bonds are dominant to stabilize crystal packing. In addition, vibrational analysis and luminescent property of the protonated salt were also explored in details.

We demonstrate herein the use of a one-dimensional metal-organic material as a new type of electrode material for lithium-ion batteries (LIBs) in place of the classic porous three-dimensional materials, which are subject to the size of the channel for lithium-ion diffusion and blocking of the windows of the framework by organic solvents during the charging and discharging processes. Introducing a one-dimensional coordination compound can keep organic active substances insoluble in the electrolyte during the charging and discharging processes, providing a facile and general new system for further studies. The results show that both the aromatic ligand and the metal center can participate in lithium storage simultaneously, illustrating a new energy storage mechanism that has been well-characterized by X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, and cyclic voltammetry. In addition, the fact that the one-dimensional chains are linked by weak hydrogen bonds rather than strong π-π stacking interactions or covalent bonds is beneficial for the release of capacity entirely without the negative effect of burying the active sites.

MIL-101(Cr)/graphene oxides composites has been successfully synthesized via a facile route using a solvothermal treatment and fully characterized using powder X-ray diffraction (PXRD), scanning electron microscope (SEM), thermal gravimetric analysis (TGA) and infrared spectroscopy (IR). The specific capacity of MIL-101(Cr)/GO are almost twice larger than that of MIL-101(Cr) at the first discharge process and the multiple relationship maintained over 40 cycles, indicating that the electrochemical performance of MIL-101(Cr) as anode material has been improved through doping by GO.

Nanostructured NiP2@C was synthesized by a facile approach via calcination of a Ni-based metal–organic-framework (Ni-MOF-74) with adsorptive red phosphorus, and was tested as an anode material for lithium ion batteries. NiP2 nanoparticles are successfully embedded in situ in porous carbon matrix, constructing crosslinked channels for lithium ion diffusion. The in situ introduction of porous carbon round NiP2 nanoparticles greatly enhances the electronic conductivity. Benefiting from the advantages of porous carbon, the nanostructured NiP2@C electrode material showed excellent electrochemical performance with high reversibility, high rate capability, and long-term cycling stability.

A co-crystal of 1H-benzotriazole (HB) and tetrafluoroterephthalic acid (TETA) has been successfully prepared based on N-H⋯O, O-H⋯N, and C-H⋯F hydrogen bonding interactions and characterized using single crystal X-ray diffraction. Density functional theory (DFT) calculations and vibrational spectroscopy were performed to predict the molecular structure and electronic, chemical, and vibrational properties associated with these hydrogen bonds. Quantitative electrostatic potential analysis (ESP) explained the active hydrogen bonding sites in HB and TETA, and predicted the hydrogen bonding modes in their co-crystal structure. Quantum theory of atoms in molecules (QTAIM) and reduced density gradient (RDG) analyses suggested that the hydrogen bonds present in the HB-TETA co-crystal were moderate in nature expect O-H⋯N (1.735 A, −62.377 kJ mol−1). Meanwhile, the dnorm-mapped Hirshfeld surface of TETA can be used to understand the characteristics of the close contacts; the features were reflected in 2D fingerprint plots. Natural bond orbital (NBO) analysis of the second order perturbation theory indicated that the LP(N19)→σ∗(O5-H7) (26.76 kcal mol−1), LP(O9)→σ∗(N21-H22) (6.69 kcal mol−1), and LP(F1)→σ∗(C24-H25) (6.05 kcal mol−1) interactions were responsible for the weak interactions in the co-crystal. The structural vibrations accompanying these hydrogen bond interactions were characterized by studying the computational HB-TETA model and experimental FT-IR/FT-Raman spectra. The downward shifts observed for the C O, N-H, and O-H stretching modes after co-crystallization were attributed to the hydrogen bonds.

The corrosion inhibiting performance and mechanism of two dithioamide derivatives, N,N′-di-ethyl-dithiodipropinoamide (ED) and N,N′-di-ethyoxylpropyl-dithiodipropinoamide (EPD), for mild steel in 1.0 M HCl solution were investigated by experiments, DFT calculation and MD simulations. EPD and ED are both mixed-type inhibitors with excellent inhibition efficiency (95.2% and of 92.6%, respectively) by weight loss experiments; SEM images also demonstrate the formation of compact inhibiting monolayer. On molecular level, both molecules can be tightly parallel absorbed on Fe (110) surface through S–Fe and O–Fe coordination bounds by the overlapping of heteroatom p orbitals and Fe 3d orbitals, with binding energies of 369.56 kJ/mol and 608.55 kJ/mol. Strong multi-intermolecular H-binding network drives ED and EPD molecules orderly self-assemble on iron surface and form protective monolayer. EPD network keeps intact up to 1.0 MPa, guarantees its potential applications in deep-sea environment.

Cisplatin has been widely used as a conventional treatment for patients with non‑small cell lung cancer (NSCLC). However, primary and acquired cisplatin resistances are frequently developed during the treatment of patients with NSCLC, leading to an increased mortality rate. Accumulating evidence demonstrated that aberrantly expressed microRNAs (miRs) are involved in the development of chemoresistance. In the present study, sensitivity of NSCLC cells to cisplatin was identified to increase following overexpression of miR‑608. Conversely, sensitivity to cisplatin was reduced following miR‑608 knockdown. Reverse transcription‑quantitative PCR and western blotting analyses identified that TEA domain transcription factor 2 (TEAD2), a key regulator of cell stemness, was negatively regulated by miR‑608 in NSCLC cells. By repressing TEAD2, miR‑608 decreased the expression level of several target genes of the Hippo‑yes‑associated protein signaling pathway. Furthermore, TEAD2 mRNA was confirmed to be targeted by miR‑608 in NSCLC cells via a dual‑luciferase reporter assay. Importantly, the increased cisplatin sensitivity induced by miR‑608 overexpression was reversed by transfection of TEAD2 in NSCLC cells. The present data suggested that miR‑608 may represent a novel candidate biomarker for the evaluation of cisplatin sensitivity in patients with NSCLC.

The introduction of reactive groups on the surface of monodispersed highly crosslinked poly(styrene–divinylbenzene) (PSDVB) microspheres was accomplished in two steps. The first step requires immobilizing the initiating groups by a Friedel–Craft acylation between 2-chloropropionyl chlorides and the phenyl groups on the spheres. The second step requires the atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) to obtain spheres (PSDVB-g-PGMA) with epoxy groups on the surface. To demonstrate the feasibility of introducing functionality, the epoxy groups were ring-opened by ethylenediamines, resulting in spheres with amino functionality (PSDVB-g-PGMAEDA). The final spheres were found to have an adsorption capacity of 0.66 mmol/g in the Cu2+ adsorption experiments, as a preliminary application study.

The formation of host-guest inclusion complexes by Pillar [5]arene (P [5]) and cationic nitrogen heterocyclic molecules were studied by DFT calculations at B3LYP-D3/6-311 + G** level, together with their equilibrium geometries, binding energies and electronic structures. MESP, NCI-RDG and AIM topography analysis were performed to explore underlying interactions. Geometric structures of inclusion complexes were changed compared with the individual molecules; MESP analysis revealed the driving force for the binding process; QTAIM and NCI-RDG methods were utilized to reveal the underlying non-covalent interactions. The inclusion complexes in 1:1 ratio were stabilized through weak C–H⋯O hydrogen bonds, C–H···π, π+···π and van der Waals interactions. The calculated electrophilic charge transfer indicated that charge flowed from P [5] to guests. Gibbs free energy accompanying the recognition process certified that formation of complexes were spontaneous and thermodynamically favorable.

Local and global features are considerably important features in computer vision and play an important role in scene categorization task. In this paper, an integrated feature description for scene categorization is constructed. First, we extract a type of extended contextual features for scene images that contain the local gradient information and more comprehensive local structural information. Mapping the local features by using improved LLC (Local-constrained Linear Coding) scheme to form the original image representation; Secondly, a set of global features named 'gist' are extracted that provide a statistical summary of the spatial layout properties of the scene; Then, the contextual features and 'gist' features are weighted combined based on their contribution for the integrated feature description, and each image is represented by using LLC scheme. Finally, we perform the scene categorization by libSVM with the HIK (Histogram Intersection Kernel) function. The proposed method achieves a satisfactory average accuracy rate 87.60% on a set of 15-scene categories.

Natural scene classification is a challenging open problem in computer vision. We present a novel spatial pyramid representation scheme for recognizing scene category. Initially, each image is partitioned into sub-blocks, applying the technology of superpixel lattices segmentation according to a boosted edge learning boundary map, which makes the objects in each sub-block have the integrity-that is, the features in each sub-block are relatively consistent. Then, we extract the dense scale-invariant feature transform features of the images and form the contextual visual feature description. Finally, the image representations are performed by following the methodology of spatial pyramid. The feature descriptions we present include both local structural information and global spatial structural information; therefore, they are more discriminative for scene classification. Experiments demonstrate that the classification rate can achieve about 87.13% on a set of 15 categories of complex scenes.

Countercation-directed chiral resolution of (λ, δ)-[Mo2O4(H2dtpa)]− has been successfully achieved by countercation-induced supramolecular enantioselectivity (H2dtpa3− = diethylenetriamine pentaacetate). (λ)-1 and (δ)-2 crystallize in chiral space group P21 and P1 with Flack parameters of 0.00(3) and 0.02(4), respectively. (λ)-[NEt4][Mo2O4(H2dtpa)] ((λ)-1) and (δ)-Na[Mo2O4(H2dtpa] ((δ)-2) show a pair of enantiomorphic structures related by mirror symmetry. The 1D supramolecular structure of the [NEt4]+ salt (λ)-1 formed by the O⋯H+⋯O hydrogen bonds favors λ-[Mo2O4(H2dtpa)]−. However, supramolecular interactions of (δ)-2 are dominated by Na–O bonds that allow δ-[Mo2O4(H2dtpa)]− to form a 3D supramolecular porous framework.