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Metal doping for active sites exhibits remarkable potential for improving the hydrogen evolution reaction (HER). Multi-doping and the use of a conductive substrate can further modulate catalytic performance. Herein, Nb-CoSe well dispersed in N-doped carbon nanospheres (NCs, Nb-CoSe@NC) was synthesized to serve as a conductive substrate and facilitated good dispersion of active sites for the HER. Nb doping can also change the electronic structure of CoSe, which facilitates the activity for the HER. In order to further improve the conductivity and intrinsic activity of Nb-CoSe@NC, dual, nonmetal doping was realized through gas sulfurization to prepare hierarchical Nb-CoSeS@NC. The prepared Nb-CoSeS@NC, with a core-shell structure, exhibited a low overpotential of 115 mV at 10 mA cm–2, which is smaller than that of the most doped catalysts. In addition, NCs not only improved the dispersion and conductivity of the catalyst but also prevented metal corrosion in an electrolyte, thus facilitating the long-term stability of Nb-CoSeS@NC. Moreover, the synergistic effect of the multi-doping of Nb, S, and Se was explained. This work provides a promising, multi-doping strategy for the large-scale application of transition-metal-based electrocatalysts for the HER.

As the cost-effective and nontoxic alternative for hydrogen evolution reaction (HER), Co9S8 has attracted much attention. This paper explores the regulation of Zn doping impacted the unique nanostructure and electrocatalytic performance on Co9S8. Herein, utilizing copper foam (CF) as substrate, a series of different nanostructure of (Zn-)Co9S8@CF has been synthesized by accurately varying the ratio of Zn2+ to Co2+. Compared with aggregated pure Co9S8 and other different ratios contrast samples, Zn–Co9S8@CF-(1-1) with a zinc to cobalt ratio of 1 possesses highly dispersity which can be attributed to the novel nano-neuron network structure. The electrochemical measurements for HER demonstrate that Zn–Co9S8@CF-(1-1) not only reveals superior activity with small overpotentials to achieve a current density of 10 mA cm−2 in acidic (278 mV) and alkaline (273 mV) media, but also exhibits long-time durability in the solution with a wide range of pH. The excellent performance of Zn–Co9S8@CF-(1-1) can be attributed to the unique reticular structure which can facilitate exposure of numerous active sites and favorable long-term stability. The substrate of three-dimensional CF can provide the remarkable conductivity. This work provides a precise and effective approach to regulate three-dimensional nanostructure of Zn-doped electrocatalysts for HER.

This paper presents a new ship target detection algorithm to achieve efficient visual maritime surveillance from non-stationary surface platforms, e.g., buoys and ships, equipped with CCD cameras. In the proposed detector, the three main steps including horizon detection, background modeling and background subtraction, are all based on Discrete Cosine Transform (DCT). By exploiting the characteristics of DCT blocks, we simply extract the horizon line providing an important cue for sea-surface modeling. The DCT-based feature vectors are calculated as the sample input to a Gaussian mixture model which is effective in representing dynamic ocean textures, such as waves, wakes and foams. Having modeled sea regions, we perform the ship detection using background subtraction followed by foreground segmentation. Experimental results with various maritime images demonstrate that the proposed ship detection algorithm outperforms the traditional techniques in terms of both detection accuracy and real-time performance, especially for complex sea-surface background with large waves.

Temozolomide (TMZ) is the cornerstone of therapy for glioblastoma multiforme (GBM). However, its efficacy is limited due to the development of multidrug resistance (MDR). In this study, we first identified the occurrence of ER stress-tolerance (ERST) in glioma cells and confirmed that ERST was positively correlated with TMZ resistance. We further showed that the seesaw-effect of HDAC6-p97/VCP (increased HDAC6 and decreased p97/VCP) in glioma cells was crucial to ERST-associated TMZ resistance. Moreover, the combination treatment of Tubastatin A (TUB, a selective inhibitor of HDAC6) and TMZ synergistically overcame ERST, reduced cell viability and induced apoptosis in TMZ-resistant glioma cells. TUB and TMZ triggered pro-apoptotic signals of the unfolded protein response (UPR) and ER stress and reversed the ratio between HDAC6 and p97/VCP, which potentially attenuated the activation of heat shock proteins and mediated the reversal of ERST. The combination treatment also triggered the dissociation of Dynein-HDAC6 and attenuation of the Dynein-Dynactin motor complex. In addition, this treatment induced HDAC6-p97/VCP-mediated ubiquitination-autophagy turnover, which was involved in the degradation and clearance of ubiquitinated misfolded proteins. This effect could be partially reversed by HDAC6 KO and/or p97/VCP overexpression. Therefore, we proposed that glioma cells optimized the clearance of ubiquitinated misfolded proteins via the reinforcement of HDAC6-facilitated autophagy and attenuation of the p97/VCP-mediated ubiquitin-proteasome system (UPS). In conclusion, our findings showed that the balance of HDAC6-p97/VCP was crucial to ERST-associated TMZ resistance and that HDAC6 inhibition might be a synergistic target and strategy along with TMZ for the improvement of clinical glioma treatment.

Transition metal sulfides/selenides are promising choice for electrocatalytic water splitting. However, the relatively low conductivity and utilization of active sites severely hinder its commercial application for H2 and O2 generation. Therefore, carbon substrates have been used to construct carbon–based transition metal sulfides/selenides for improving the dispersion and charge transfer rate of active sites. Herein, the research progress and all kinds of carbon–based transition metal sulfides/selenides have been systematically summarized and discussed. Moreover, various of strategies for boosting the properties of transition metal sulfides, selenides and sulfoselenides such as carbon substrate design, nanostructure construction, ion doping and surface engineering in terms of active sites are introduced in detail. Finally, this review briefly summarizes the challenges and research direction of carbon–based transition metal sulfur selenides for electrocatalytic water splitting, providing new inspiration for the rational design of high–performance catalysts.

High levels of glucocorticoids (GCs) have been reported to damage normal hippocampal neurons, and such damage has been positively correlated with major depression (MD) and chronic stress. Our previous study showed that HDAC6 might be a potential target to regulate GC-induced glucocorticoid receptor (GR) translocation to the mitochondria and subsequent apoptosis. In the present study, we investigated the effect of HPOB, a selective HDAC6 inhibitor, on corticosterone (Cort)-induced apoptosis and explored the possible mechanism of action of HPOB in rat adrenal pheochromocytoma (PC12) cells, which possesses typical neuron features and expresses high levels of glucocorticoid receptors. We demonstrated that pre-treatment with HPOB remarkably reduced Cort-induced cytotoxicity and confirmed the anti-apoptotic effect of HPOB via the caspase-3 activity assay and H33342/PI and TUNEL double staining. Mechanistically, we demonstrated that HPOB reversed the Cort-induced elevation of GR levels in the mitochondria and blocked concomitant mitochondrial dysfunction and the intrinsic apoptosis pathway. Furthermore, HPOB was shown to attenuate expression of the multi-chaperone machinery (Hsp90-Hop-Hsp70) and cooperate with mitochondrial translocase of the outer/inner membrane (TOM/TIM) complex recruitment by triggering hyperacetylation of Hsps through HDAC6 inhibition. Considering all of these findings, the neuroprotective effect of HPOB demonstrated the crucial role of HDAC6 inhibition in reducing Cort-induced apoptosis in PC12 cells. The data further suggested that the anti-apoptotic activity of HDAC6 inhibition against the mitochondria-mediated impairment pathway might be mechanistically linked to the hyperacetylation of Hsps and consequent suppression of GR translocation to the mitochondria.

Underwater image compression has been the key technology for transmitting massive amount of image data via underwater acoustic channel with limited bandwidth. According to the characteristics of underwater color images, an efficient underwater image compression method has been developed. The new coding scheme employs a wavelet-based preprocessing method to remove the visual redundancy, and adopts a Wavelet Tree-based Wavelet Difference Reduction (WTWDR) algorithm to remove the spatial redundancy of underwater color images. Instead of scanning whole transformed image like the WDR method, the difference reduction coding is used for each significant wavelet tree in the proposed WTWDR algorithm based on the correlation between the subbands of higher levels and lower levels of a transformed image. The experimental results show that for underwater color images the proposed method outperforms both WDR and SPIHT at very low bit rates in terms of compression ratio and reconstructed quality, while for natural images it has similar performance with WDR and SPIHT. Hence, the proposed approach is especially suitable for underwater color image compression at very low bit rates.