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The rising global burden of cancer has driven considerable efforts into the research and development of effective anti-cancer agents. Fortunately, with impressive advances in transcriptome profiling technology, the Connectivity Map (CMap) database has emerged as a promising and powerful drug repurposing approach. It provides an important platform for systematically discovering of the associations among genes, small-molecule compounds and diseases, and elucidating the mechanism of action of drug, contributing toward efficient anti-cancer pharmacotherapy. Moreover, CMap-based computational drug repurposing is gaining attention because of its potential to overcome the bottleneck constraints faced by traditional drug discovery in terms of cost, time and risk. Herein, we provide a comprehensive review of the applications of drug repurposing for anti-cancer drug discovery and summarize approaches for computational drug repurposing. We focus on the principle of the CMap database and novel CMap-based software/algorithms as well as their progress achieved for drug repurposing in the field of oncotherapy. This article is expected to illuminate the emerging potential of CMap in discovering effective anti-cancer drugs, thereby promoting efficient healthcare for cancer patients.

Graphitic carbon nitride (g-CN) has emerged as a promising metal-free photocatalyst, while the catalytic mechanism for the photoinduced redox processes is still under investigation. Interestingly, this heptazine-based polymer optically behaves as a “quasi-monomer”. In this work, we explore upstream from melem (the heptazine monomer) to the triazine-based melamine and melam and present several lines of theoretical/experimental evidence where the catalytic activity of g-CN originates from the electronic structure evolution of the C–N heterocyclic cores. Periodic density functional theory calculations reveal the strikingly different electronic structures of melem from its triazine-based counterparts. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy also provide consistent results in the structural and chemical bonding variations of these three relevant compounds. Both melam and melem were found to show stable photocatalytic activities, while the photocatalytic activity of melem is about 5.4 times higher than that of melam during the degradation of dyes under UV–visible light irradiation. In contrast to melamine and melam, the frontier electronic orbitals of the heptazine unit in melem are uniformly distributed and well complementary to each other, which further determine the terminal amines as primary reduction sites. These appealing electronic features in both the heterocyclic skeleton and the terminated functional groups can be inherited by the polymeric but quasi-monomeric g-CN, leading to its pronounced photocatalytic activity.

It is a highly relevant topic concerning how to improve the electrochemical performance of anode materials for the next generation lithium-ion batteries (LIBs). Herein, for the first time, we report a facile and controllable approach to modify MoS2 nanosheets, a typical 2D material, as an anode material for advanced LIBs via oxygen plasma engineering. An oxygen plasma treatment not only generates vacancies/defects but also incorporates heteroatom doping to form Mo–O–C bonds. This unique hybrid specialty enables the oxygen-plasma-treated MoS2 to achieve superior electrochemical performance with high reversible capacities, a long-term cycle life, and good rate capabilities. The plasma-assisted modification is believed to be applicable for other 2D materials as an efficient anode for energy storages.

Semiconductor materials are favoured in the field of photocatalysis due to their unique optoelectronic properties. When a semiconductor is excited by external energy, electrons will transition through the band gap, providing electrons or holes for the reaction. This is similar to the chemical enhancement mode of a catalytic reaction initiated by the rough noble metal on the surface excited by plasmon resonance. In this study, different types of semiconductor silicon loaded with silver nanoparticles were used as SERS substrates. SERS detection of p-aminothiophenol (PATP) and p-nitrothiophenol (PNTP) probe molecules was performed using typical surface plasmon-driven coupling reactions, and the mechanism of optical drive charge transfer in semiconductor–metal–molecular systems was investigated. Scanning electron microscopy and plasmon luminescence spectroscopy were used to characterize the silver deposited on the substrate surface. Mapping technology and electrochemistry were used to characterize the photocatalytic reaction of the probe molecules. This study proposed a mechanism for the coupling reaction of “hot electrons” and “hot holes” on the surface of plasmon-driven molecules and provides a method for preparing a stable SERS substrate.

There is much evidence that surface plasmon photocatalytic reactions can occur on organic molecules on metal surfaces. In this paper, we focus on the photocatalytic reaction of 4-ethynylaniline (PEAN) on silver nanoparticles (Ag NPs) in a liquid environment by surface-enhanced Raman spectroscopy (SERS). Our experiments used SERS to characterize p,p′-diynylazobenzene produced from PEAN via a selective catalytic coupling reaction on Ag NPs. This discovery not only achieved the expected results but also broadens the known plasmon-driven surface catalytic reaction system. In our work, we also regulated the photocatalytic coupling reaction conditions of PEAN on Ag NPs by laser power-dependent and time-dependent SERS spectra.

The effect of plating temperatures between 60 and 90°C on structure and corrosion resistance for electroless NiWP coatings on AZ91D magnesium alloy substrate was investigated. Results show that temperature has a significant influence on the surface morphology and corrosion resistance of the NiWP alloy coating. An increase in temperature will lead to an increase in coating thickness and form a more uniform and dense NiWP coatings. Moreover, cracks were observed by SEM in coating surface and interface at the plating temperature of 90°C. Coating corrosion resistance is highly dependent on temperature according to polarization curves. The optimum temperature is found to be 80 ∘ C and the possible reasons of corrosion resistance for NiWP coating have been discussed.

A large number of literatures have investigated the selective photocatalytic reaction of 4-aminothiophenol (PATP) to p,p'-dimercaptoazobenzene (DMAB). Most of them mainly study the contribution of substrate, excitation wavelength, exposure time, pH and added cations to plasmon-assisted surface catalytic reactions. However, we mainly study focuses on the effects of solvents on the dimerization of PATP to DMAB under the action of Ag nanoparticles (NPs). In experiments, a variety of diols was selected as solvents for the probe molecule PATP, and power-dependent SERS spectra were obtained at an excitation wavelength of 532 nm. From the laser-dependent SERS spectrum, we found that the characteristic peak enhancement effect of the product DMAB in different solvents is significantly different. That is, different solvents could regulate the rate at which DMAB is produced from PATP. Based on the experimental results, we further explored how different diol solvents regulate the response of PATP to DMAB. Our conclusion is that the solvent in the system can quickly capture the hot electrons generated by the decay of the plasmon, so that the remaining holes can oxidize PATP to form DMAB. The ability to trap hot electrons is different due to the difference in the position of the functional groups in the solvent, so that the photocatalytic reaction rate of the hole-oxidized PATP is different. The ability to capture electrons varies depending on the position of the functional groups in the solvent, so the oxidation rate of the photocatalytic reaction is also different. This work not only deepens our understanding of the mechanism of hole-driven surface catalysis oxidation reaction, but also provides a convenient method for regulating the rate of catalytic oxidation.

Although polymeric graphitic carbon nitride (g-C3N4) has been widely studied as metal-free photocatalyst, the description of its structure still remains a great challenge. Fourier transform infrared (FTIR) spectroscopy can provide complementary structural information. In this paper, we reconsider the representative crystalline melamine and develop a strategic approach to theoretically calculate the IR vibrations of this triazine-based nitrogen-rich system. IR calculations were based on three different models: a single molecule, a 4-molecule unit cell, and a 32-molecule cluster, respectively. By this comparative study the contribution of the intermolecular weak interactions were elucidated in detail. An accurate and visualized description on the experimental FTIR spectrum has been further presented by a combinatorial vibration-mode assignment based on the calculated potential energy distribution of the 32-molecule cluster. The theoretical approach reported in this study opens the way to the facile and accurate assignment for IR vibrational modes of other complex triazine-based compounds, such as g-C3N4.

Turbostratic carbon nitride was prepared by the pyrolysis of melamine and then treated with a pulse discharge for different times. It is found that after this high-temperature short-time treatment, the structures of the products have changed while the high nitrogen content has been effectively maintained. The obtained product was characterized by X-ray diffraction and infrared spectroscopy. The composition was measured by an element analyzer. An orthorhombic CN x phase has been obtained, identified by transmission electron microscopy coupled with selected area electron diffraction. High-resolution transmission electron microscopy revealed that the product has some nanocrystals having a fringe spacing of approximately 0.32 nm, which embedded in a turbostratic matrix.

Since the theoretical calculations predicted that the hardness of C3N4 covalent compound might be comparable to or even higher than that of diamond [1, 2], many attempts have been made to synthesis this novel substance. Due to the great thermodynamic stability of N2, however, the ideal structural transition from precursor to crystalline carbon nitride is difficult to realize. In most cases, only amorphous products with low nitrogen content were obtained [3]. To solve this problem, it is good to prepare carbon nitride in graphitic or turbostratic form firstly, and then using it as precursor to synthesize other carbon nitride crystalline phases. Therefore, graphitic C3N4 have recently attracted more attention. Through different routes, graphitic C3N4 has been synthesized [4–6]. For previous work, the claimed graphitic-like C3N4 with unique (002) diffraction peak has the turbostratic structure actually [7–10], for the lake of other peaks in their XRD patterns. Meanwhile, the (002) spacing of those obtained turbostratic carbon nitrides are in the range of 0.32–0.33 nm. The graphitic C3N4 predicted by Teter and Hemley [11] can be described as a perfect de-ammonation polycondensate of melamine, therefore, melamine was often chosen as the carbon nitride precursor to synthesize graphitic C3N4 by electrodeposition [6] and solvothermal method [7]. Pyrolysis of melamine was investigated [12] in 1988, however, the authors focused their attention only on its thermal behavior, and they didn’t consider the possibility as potential candidate for carbon nitrides after complete polycondensate. Recently, pyrolysis of melamine under high pressure was studied at the temperatures up to 700 ◦C [13]. Obvious nitrogen loss made the attempt unsuccessful. In this letter, we report an improved pyrolysis route to prepare turbostratic carbon nitride from melamine. The pyrolysis was performed in two steps: first, the temperature was maintained at 300 ◦C in order to realize the primary condensation (melamine → melam) as complete as possible; and then it was risen to 650 ◦C to perform the advanced condensation. In the experimental, melamine was pyrolyzed in a quartz tube with a diameter of 35 mm, and an outer-thimble-shape heater was used. Melamine was placed at the middle of the quartz tube. The pyrolysis was conducted at 300 ◦C for 1 hr, then at 600◦ for 2 hr in atmosphere; after milling, the obtained powder was maintained at 300 ◦C for 0.5 hr, then at 650 ◦C for 1 hr in vacuum. Finally, a kind of brown carbon nitride powder was obtained. The chemical composition was analyzed by using elemental analyzer (LECO, CHN-1000) and EDX (EDAX INC., Phoenix). The product was characterized by X-ray diffraction (XRD) with Cu-Kα radiation (JEOL, ROTEX JRX-12), fourier transfer infrared (FTIR) spectroscopy (Bruker, EQUINOX55), scanning electron microscopy (SEM) (TOPCON, SM520), and transmission electron microscopy (TEM) coupled with selected area diffraction (SAED) (JEOL, JEM-2010) and thermogravimetry (TG) (NETZSCH, STA449C/6/G). The composition of the product characterized by elemental analysis and EDX is listed in Table I. SEM observation found that the particles dimension ranged from 5 μm to 20 μm. Most of the particles show the flake-like morphology. Fig. 1 shows a typical XRD pattern of the product. There is a single main peak at the position of 27.62 ◦, which suggests that the product was turbostratic. Its corresponding d-spacing is 0.321 nm similar to the (002) plane of the turbostratic/graphitelike carbon nitrides obtained in previous work [9, 14]. The FTIR spectrum of the prepared turbostratic carbon nitride and melamine are shown in Fig. 2. The IR spectrum of melamine presents three absorption bonds: 3000–3650 cm−1, 1100–1700 cm−1, and the last one centered at about 810 cm−1. The 3000– 3650 cm−1 band is assigned to N H stretching vibration modes, the 1100–1650 cm−1 band corresponds to the stretching vibrations related to C N, C N, and is generally associated with the skeletal stretching vibrations of these aromatic rings. The absorption at 810 cm−1 is characteristic of out-of-plane bending modes of these rings. The 460–850 cm−1 band is linked to the C NH2 group and the ring breadth or bending vibration modes [15]. Comparing the FTIR spectrum of the turbostratic carbon nitride with that of melamine, it reveals that after pyrolysis, the previous strong absorption peaks in the range of 3000–3650 cm−1 have disappeared, only a board absorption bond is left, which suggest that most of the N H bonds have been destroyed during the de-ammonation condensation. While the increased number of absorption peaks ranging from 1100 to 1700 cm−1 implies the condensation of 1,3,5-s-triazine rings making the related chemi

International audience; We successfully address the challenge of aligning single-walled carbon nanotubes (SWNTs) and conjugated polymer chains in composite nanofibers for enhancing their opto-electrical properties. A pore-filling template strategy has been developed to prepare such nanocomposites from SWNTs and poly(para-phenylene vinylene) (PPV) chains, with both species well-oriented aligned along the pore axis. Addition of the SWNTs leads to a remarkable increase in photocurrent of four orders of magnitude as compared to equivalent pristine PPV nanofibers. Further analysis indicates that the strong photocurrent enhancement is not simply an effect of alignment, but additionally benefits from alignment-enhanced interaction of polymer chains with SWNTs, as supported by density functional theory (DFT) calculations.

We report the direct synthesis of strong, highly conducting, and transparent single-walled carbon nanotube (SWNT) films. Systematically, tests reveal that the directly synthesized films have superior electrical and mechanical properties compared with the films made from a solution-based filtration process: the electrical conductivity is over 2000 S/cm and the strength can reach 360 MPa. These values are both enhanced by more than 1 order. We attribute these intriguing properties to the good and long interbundle connections. Moreover, by the help of an extrapolated Weibull theory, we verify the feasibility of reducing the interbundle slip by utilizing the long-range intertube friction and estimate the ultimate strength of macroscale SWNTs without binding agent.