Latest ArticlesSpirobisnaphthalenes comprise a relatively rare family of natural products that are normally isolated from fungi and occasionally from plants. Here we reported the discovery of seven new preussomerintype spirobisnaphthalenes, preussomerins YT1-YT7 (1-7), and seven known ones (8-14), from the endophytic fungus Edenia gomezpompae, enriching the structural diversity of this family of natural products. Their structures were established by 1D and 2D NMR spectroscopy, HRESIMS analysis and comparison with previously reported compounds, with the absolute configurations of compounds 1 and 2 being further confirmed by single-crystal X-ray diffraction using Cu Kα radiation. The antiinflammatory activities of all isolates were assessed by measuring the production of NO in LPS-induced RAW264.7 macrophage cells. Among them, compounds 8 and 13 exhibited potent inhibitory activities on the production of NO, with IC50 values of 2.61 and 1.32 μmol/L, respectively.
Transmembrane anion transporters have attracted significant attention as therapeutic agents because of their potential to disrupt cellular ion homeostasis, in which, most of the synthetic anionic transporters are organic small molecules whose synthesis routes are usually complex and tedious, and the related biological research is also only in infancy. Hence, we synthesized a kind of chloride anion (Cl-) and sodium cation (Na+) nanocarrier based on poly(D, L-lactic-co-glycolic acid) (PLGA) which was coated with polydopamine (PDA) to provide target release factor. When the nanocarrier arrives in acidic environment such as lysosomes through endocytosis, Cl- and Na+ will be released fast from the nanocarrier resulting in imbalance of cell homeostasis for inducing apoptosis. Cell experiments show that the nanocarrier promotes apoptosis and leads to an increased concentration of reactive oxygen species. By exploring the concentration of cytochrome c in mitochondria and cytoplasm and the activities of key enzymes caspase-9 and caspase-3 in apoptosis process, it is proved that the apoptotic pathway is caspase-dependent. This novel strategy allows the research of anion transporter no longer limited to artificial synthesis of small molecular and provides a novel and effective direction to investigate ion homeostasis, ion transport and cancer treatment.
Graphene is a two-dimensional nanomaterial with huge surface area, high carrier mobility and high mechanical strength. Because of its great potential in nanotechnology and environmental protection, it has attracted much attention in environmental and energy fields since its discovery in 2004. Although graphene is a star material, many reviews have introduced its use in terms of energy, the research progress in the field of environment, especially water pollution control, has been rarely reported. Here, we review exhaustively the research progress of graphene-based materials in environmental pollution remediation in the past ten years. Firstly, the advantages and classification of graphene were introduced. Secondly, the research progress and main achievements of graphene and its composites in the fields of photocatalytic degradation, pollutant adsorption and water treatment were emphatically described, and the mechanism of action in the above fields was summarized. Finally, we discuss the problems existing in the preparation and summarize the application of graphene in the environment.
Rational modification by functional groups was regarded as one of efficient methods to improve the photocatalytic performance of graphitic carbon nitride (g-C3N4). Herein, g-C3N4 with yellow (Y-GCN) and brown (C-GCN) were prepared by using the fresh urea and the urea kept for five years, respectively, for the first time. Experimental results show that the H2 production rate of the C-GCN is 39.06 μmol/h, which is about 5 times of the Y-GCN. Meantime, in terms of apparent quantum efficiency (AQE) at 420 nm, C-GCN has a value of 6.3% and nearly 7.3 times higher than that of Y-GCN (0.86%). The results of XRD, IR, DRS, and NMR show, different from Y-GCN, a new kind of functional group of —N=CH— was firstly in-situ introduced into the C-GCN, resulting in good visible light absorption, and then markedly improving the photocatalytic performance. DFT calculation also confirms the effect of the —N=CH— group band structure of g-C3N4. Furthermore, XPS results demonstrate that the existence of —N=CH— groups in C-GCN results in tight interaction between C-GCN and Pt nanoparticles, and then improves the charge separation and photocatalytic performance. The present work demonstrates a good example of "defect engineering" to modify the intrinsic molecular structure of g-C3N4 and provides a new avenue to enhance the photocatalytic activity of g-C3N4 via facile and environmental-friendly method.
Porous materials play an important role in chemical catalysis, separation and other industrial applications. High-efficiency preparation of porous materials has become an active research area. Conventional synthesis of porous materials has been dominated by one-pot solution processing conditions carried out by bulk mixing under conventional electric heating via hydrothermal, solvothermal or ionothermal reactions where high temperatures and pressures are the standard. Continuous flow synthesis has many key advantages in terms of efficient mass and heat transfer, precise control of residence times, improved opportunities for automation and feedback control of synthesis, scaling-up reactions and improved safety parameters compared to above mentioned conventional batch scale synthetic methods. In this review, continuous flow synthesis of various crystalline porous materials such as metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), porous organic cages and zeolites is discussed. Combination of microfluidic methods with other techniques are also shown including various heating ways and various methods of substrate adding.
Since the discovery of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the process of municipal solid waste incineration (MSWI), a large number of researches have been conducted to reveal their formation mechanisms and emission characteristics. As one of national priority control pollutants, chlorinated organics are inclined to transfer into PCDD/Fs in the heterogeneously catalyzed process, which has been considered to be one of great challenges in environmental catalysis. However, so far direct evidences to support such a conversion process are insufficient, and the reaction mechanisms are lack of exploration. This study investigated the catalytic elimination of chlorobenzene (CBz) over a range of industrially applied active species including Pt, Ru, V, Ce and Mn oxides, and explored their reaction byproducts, chlorine adsorption/desorption behaviors and PCDD/F formations. We found that all of these species could generate the PCDD/Fs, amongst which, Mn species were the most active for PCDD/F formation. Approximately 140 ng I-TEQ g-1 PCDD/Fs were detected on the Mn-CNTsurface after ageing at 250 ℃ for 30 h. Even using the dichloromethane (DCM) as a precursor, significant PCDD/Fs were still detected. The Ru and V species were shown to generate much less polychlorinated byproducts and PCDD/Fs, owning to their sufficiently high abilities in Cl desorption, which were through the semi-Deacon and Brønsted H reactions, respectively.
A systematic spectral analysis was presented for bishemicyanine dyes (Hsd and D2) and monohemicyanine dyes (Hs and DSMI). The bishemicyanine dyes displayed long emission wavelengths, large Stokes shifts, low background quantum yields in aqueous solutions and high sensitivity in viscous environments. Better understanding of the structure-property relationships could benefit the design of improved dyes. Computational studies on these dyes revealed the three conjugated forms of bishemicyanines are in equilibrium due to two positive charges and a branched bulk substituent. Bishemicyanines possessed obviously lower rotating energy barrier of C-C bond rotation compared to the monohemicyanine dyes. Moreover, the synergetic effects of the rotation about the ϕ4 bond, ϕ5 bond and ϕ7 bond of the bishemicyanines (Hsd and D2) lead to lower fluorescence quantum yields in a free state and larger fluorescence quantum yield enhancements in viscous environment compared to that of monohemicyanine dyes (Hs and DSMI). The results demonstrate a foundation for interpretation of the behavior of the dyes, thus providing guidelines for future of new bishemicyanine fluorophores with specific applications.
The present review not only devotes on the environmental consequences of plastic bag wastes and other industrial wastes observable in the landfills, in the oceans or elsewhere but also gives a new insight idea on conversion of them into worth material, carbon, for the best electrochemical supercapacitor. Transformation of plastic wastes into high-value materials is the incentive for plastic recycling, end-of-life handling case for plastic bag wastes in practice quite limited. The plastic recycling waste for reuse saves energy compared with manufacturing virgin materials. Herein, we identified several synthetic methods to convert plastic waste and other industrial wastes into carbon material for supercapacitor. Different kinds of carbon materials, including nanofiber, nanotube, graphene, mesoporous carbon, etc., have been derived from plastic waste, and thus give a superior potential for transforming trash into a "gold capacitor". Finally, conclusions and future trends of high-voltage supercapacitors were made as well as the easy and mass production of high-performance electrode materials for supercapacitors. Our work offers a promising sustainable approach to handle plastic bags, waste, and other industrial wastes and provides a new avenue in supercapacitor applications and other areas.
We developed a merocyanine-based fluorescent probe, NEPB, for tracing hydrazine (N2H4) in a ratiometric manner with large Stokes shifts and long emission wavelength. The fluorescence color of probe NEPB changed from green to yellow upon addition of hydrazine. Probe NEPB displayed high selectivity and sensitivity to hydrazine in solution, and could ratiometrically monitor N2H4 in living cells and zebrafish with low cytotoxicity.
Nanocomposite hydrogels based on carbon dots (CDs) and polymers have emerged as new materials with integrated properties of individual components, leading to their important applications in the field of soft nanomaterials. This perspective highlights recent advances in the development of nanocomposite hydrogels from CDs and polymers. We review the preparation methods of nanocomposite hydrogels based on CDs and polymers, and emerging applications of these nanocomposite hydrogels such as environmental remediation, energy storage, sensing, drug delivery and bioimaging. We conclude with the discussion of new research directions in the development of new type of nanocomposite hydrogels based on CDs and polymers.