Among the heat shock proteins (HSP), HSP27, HSP70 and HSP90 are the most studied stress-inducible HSPs, and are induced in response to a wide variety of physiological and environmental insults, thus allowing cells to survive to lethal conditions based on their powerful cytoprotective functions. Different functions of HSPs have been described to explain their cytoprotective functions, including their most basic role as molecular chaperones, that is to regulate protein folding, transport, translocation and assembly, especially helping in the refolding of misfolded proteins, as well as their anti-apoptotic properties. In cancer cells, the expression and/or activity of the three HSPs is abnormally high, and is associated with increased tumorigenicity, metastatic potential of cancer cells and resistance to chemotherapy. Associating with key apoptotic factors, they are powerful anti-apoptotic proteins, having the capacity to block the cell death process at different levels. Altogether, the properties suggest that HSP27, HSP70 and HSP90 are appropriate targets for modulating cell death pathways. In this review, we summarize the role of HSP90, HSP70 and HSP27 in apoptosis and the emerging strategies that have been developed for cancer therapy based on the inhibition of the three HSPs.

In this study, porous Bi2WO6 microsphere photocatalysts were obtained via the ultrasonic spray pyrolysis method using bismuth citrate and tungstic acid as precursors in basic aqueous solution. The characteristics of the resulting samples were investigated in detail by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption/desorption, X-ray photoelectron spectroscopy, and UV−vis diffuse reflectance spectroscopy. The resulting porous Bi2WO6 microsphere was of high crystallinity, which means fewer traps and stronger photocatalytic activity. The band-gap energy of Bi2WO6 microspheres estimated from the (αhν)2 versus photon energy (hν) plots was 2.92 eV. The formation of the porous structure in the as-prepared microspheres can be ascribed to the existence of citrate anions and in situ generated carbon residues that can serve as capping agents and templates, respectively, during the synthesis processes. It was found that the synthesis temperature was an important parameter controlling the morphology of the Bi2WO6 microspheres. As compared with the bulk Bi2WO6 sample, the resulting porous Bi2WO6 microspheres demonstrated superior photocatalytic activities on the removal of NO under either visible light or simulated solar light irradiation. The highest NO removal rates were 110 and 27 ppb/min for the porous Bi2WO6 sample under solar light and visible light (λ > 400 nm) irradiation, respectively. On the basis of the analysis of the characterization and experimental observations, a possible mechanism on the formation of porous Bi2WO6 microspheres was also proposed.

The development of catalysts that effectively activate target pollutants and promote their complete conversion is an admirable objective in the environmental photocatalysis field. In this work, graphitic carbon nitride (g-C 3 N 4 ) microtubes with tunable N-vacancy concentrations were controllably fabricated using an in situ soft-chemical method. The morphological evolution of g-C 3 N 4 , from the bulk to the porous tubular architecture, is discussed in detail with the aid of time-resolved hydrothermal experiments. We found that the NO removal ratio and apparent reaction rate constant of the g-C 3 N 4 microtubes were 1.8 and 2.6 times higher than those of pristine g-C 3 N 4 , respectively. By combining detailed experimental characterization and density functional theory calculations, the effects of N-vacancies in the g-C 3 N 4 microtubes on O 2 and NO adsorption activation, electron capture, and electronic structure were systematically investigated. These results demonstrate that surface N-vacancies act as specific sites for the adsorption activation of reactants and photoinduced electron capture, while enhancing the light-absorbing capability of g-C 3 N 4 . Moreover, the porous wall structures of the as-prepared g-C 3 N 4 microtubes facilitate the diffusion of reactants, and their tubular architectures favor the oriented transfer of charge carriers. The intermediates formed during photocatalytic NO removal processes were identified by in situ diffuse reflectance infrared Fourier transform spectroscopy, and different reaction pathways over pristine and N-deficient g-C 3 N 4 are proposed. This study provides a feasible strategy for air pollution control over g-C 3 N 4 by introducing N-vacancy and porous tubular architecture simultaneously. KEYWORDS: N-vacancy, tubular g-C 3 N 4 , porosity, photocatalytic NO x removal