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Microbial fuel cells (MFCs) are promising ecofriendly techniques for harvesting bioenergy from organic and inorganic matter. Currently, it is challenging to design MFC anodes with favorable microorganism attachment and fast extracellular electron transfer (EET) rate for high MFC performance. Here we prepared N-doped carbon nanotubes (NCNTs) on carbon felt (CF) and used it as a support for growing hierarchical Co

Interphase in polymer composites plays a key role in enhancing their multi-functionality. Herein, an effective strategy is designed to optimize the interphase microstructure in graphene foam/PDMS (PDMS/GrF) using polypyrrole (PPy) nanowires (denoted as PDMS/GrF@PPy). The interfacial microenvironment of graphene foam is successfully modified by anchoring polypyrrole nanowires, showing strong interfacial strength with PDMS. The tensile strength, Young’s modulus, electrical conductivity, thermal conductivity, mechanical durability and electron-photo-thermal deicing efficiency of PDMS/GrF@PPy composites are simultaneously higher than that of PDMS/GrF composites. Molecular simulations further illustrated that the interfacial interaction energy increased from 100.4 to 280.2 kcal/mol after introducing PPy nanowires between GrF and PDMS. As a proof of concept for deicing application, PDMS/GrF@PPy composites displays excellent deicing efficiencies of 82.9% and 55.7% by Joule heat and NIR irradiation after 500th stretching cycles, respectively, which is obviously outperforming PPy@GrF composites (58.3% and 44.2%). Consequently, PPy nanowires not only optimizes the interfacial strength of polymer composites, but also endows them with multi-functionalities, providing promising candidates of deicing, strain sensor, thermal interface management, etc.

It is urgent to develop non-noble metal electrocatalysts with both excellent activity and durable stability for H

Electrochemical water splitting into hydrogen is a promising strategy for hydrogen production powered by solar energy. However, the cell voltage of an electrolyzer is still too high for practical application, which is mainly limited by the sluggish oxygen evolution reaction process. To this end, hybrid water electrolyzers have drawn tremendous attention. Herein, coaxial Ni/Ni3S2@N-doped nanofibers are directly grown on nickel foam (NF), which is highly active for hydrogen evolution reaction. Meanwhile, the Ni3S2@N-doped nanofibers on NF prepared in an Ar atmosphere display superior urea oxidation reaction performance to previously reported catalysts. The cell voltage is about 1.50 V in urea electrolysis to deliver a current density of 20 mA cm-2, lower than that of a traditional water electrolyzer (1.82 V). The current density is around 77% relative to its initial value of 20 mA cm-2 after 20 h, superior to Pt/C|Ir/C-based urea electrolysis (14%). It is found that the synergistic effect between metallic Ni and Ni3S2, as well as the interfacial effect between metal centers and N-doped carbon, favors the initial dissociation of H2O and the adsorption/desorption of H* with thermal neutral Gibbs free energy. Meanwhile, the in-situ generated NiOOH on the outer surface of Ni3S2 possessed lower electrochemical activation energy for urea decomposition. Meanwhile, the abundant oxygen vacancies in electrodes could expose more active sites for the adsorption of intermediates, including H* and OOH*. It is also found that the hierarchical nanostructure of densely packed nanowires provides ideal electronic and ionic transport paths for fast electrocatalytic kinetics. The present work indicated that the modulation of compositions and hierarchical nanostructure is effective to prepare efficient catalysts for H2 production via urea electrolysis.

The simultaneous improvement of intrinsic activities and the number of active sites in electrocatalysts is the bottle-neck issue for H2 production. Herein, commercial CNTs serving as conductive kernels are in situ coupled with 3D ZIF-67 derived Co/CoP core-corona clusters. Such a hierarchical bead string nanostructure not only possesses highly exposed active sites, but also favours fast electron transfer for electrocatalytic kinetics. Our material shows excellent HER (η10 = −151 mV) and glucose oxidation reaction (GOR) performance, showing a smaller hybrid water splitting potential of 1.42 V compared to conventional water splitting (η10 = 1.74 V) for H2 production. DFT calculations indicate that the Schottky heterointerface at Co/CoP decreases the initial H2O dissociation energy barrier and possesses a thermoneutral H* adsorption free energy for the HER, as well as reducing the energy barrier for the GOR. Meanwhile, more oxidative cobalt oxyhydroxide favoured the GOR process. The present work opens a new avenue for designing Mott–Schottky multifunctional electrocatalysts for both energy-saving H2 production and value-added products.

H2 production via electrocatalytic water splitting is greatly hindered by the sluggish oxygen evolution reaction (OER). The urea oxidation reaction (UOR) draws specific attention not only because of its lower theoretical voltage of 0.37 V compared with OER (1.23 V), but also for treating sewage water. Herein, Ni/NiO nanosheets with an ultrathin N-doped C layer containing a Schottky Ni and NiO heterointerface is constructed. Because of the self-driven charge redistribution at the heterointerface, janus charge domains are successfully created to drive the cleavage of urea molecules. Meanwhile, the synergistic effect between N-doped C and Ni/NiO restrains the deactivation of active sites in alkaline solution. The catalyst displays 1.35 V for UOR at 10 mA/cm2 , 0.27 V lower than that of OER. The final potential increase is only 2 mV after long-term stability test of 12 h for UOR, much smaller than the uncoated sample (38 mV). The present work shows that C-coated transition metal nanomaterials with oxygen vacancies and a Schottky heterointerface are promising candidates for simultaneously boosting UOR with both high activity and long-term stability.

In graphene-like 2D layered semiconductor-based field-effect transistors (FETs), the device performance is strongly influenced by a semiconductor–dielectric interface. In this study, it is demonstrated that a hybrid dielectric interface combines the advantages of high dielectric constant and inert polymer dielectric layer, and their synergistic effect induce the improvement of the InSe FET performance. A FET with a hybrid dielectric interface, composed of 200 nm PMMA and Hf0.5Zr0.5O2/Al2O3 (HZO/AlO), displays a mobility of 863 cm2 V−1 s−1, a relatively low sub-threshold swing of 462 mV dec−1, a diminutive hysteresis loop, an ultrahigh Ion–off ratio of ∼107, and low leakage current superior to the ones that use a conventional single dielectric layer. Experimental and theoretical results proved that the low density of charge trapping states and suppression of scattering effect at the semiconductor–dielectric interface synergistically result in enhanced device performances. The present study indicates that the smart combination of an inert polymer buffer layer and high-κ constant oxides is effective in optimizing the semiconductor–dielectric interface, and providing available interface engineering methods for other 2D materials.

Tin disulfide (SnS2) has a larger band gap (>2.0 eV) than other two-dimensional (2D) materials, which can achieve a higher on/off current ratio, a much lower off-current, and standby power dissipat...

Chemicals isolated from natural products have been broadly applied in the treatment of colorectal cancer (CRC). Bixin, an apocarotenoid from the seeds of Bixa orellana, exerts multiple pharmacological properties, including neuroprotective, anti-inflammatory, cardioprotective, and antitumor effects; yet, the therapeutic effects of Bixin on CRC are still unknown. Here, we described that Bixin treatment significantly inhibited the proliferation and motility of two CRC cell lines (CaCO2 and SW480) in vitro and in vivo. In addition, Bixin administration has sensitized CRC cells to TNF-related apoptosis-inducing ligand- (TRAIL-) induced cell apoptosis. Moreover, we showed that Bixin treatment initiated the activation of PERK/eIF-2α signal in CaCO2 and SW480 cells, leading to endoplasmic reticulum stress-associated apoptosis. Pharmacological inhibition of AMP-activated protein kinase (AMPK) abrogated the Bixin-induced activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2 alpha (eIF-2α) pathway, as well as reversed the inhibitory effects of Bixin on CRC development. In conclusion, this study indicated that Bixin treatment inhibits the progression of CRC through activating the AMPK/PERK/eIF-2α pathway, providing a novel potential strategy for clinical prevention of CRC.

The present study predicts and assesses the individual, combined, and synergistic effect of land-use change and climate change on streamflow, sediment, and total phosphorus (TP) loads under the present and future scenarios by using the Soil and Water Assessment Tool (SWAT). To predict the impacts of climate and land-use change on streamflow, sediment, and TP loads, there are 46 scenarios composed of historical climate, baseline period climate, eight climate models of Coupled Model Intercomparison Project phase 5 (CMIP5) of two representative emission pathways (RCP4.5 and RCP8.5), after downscaled and bias-corrected, two observed land-use maps (LULC 1995, LULC 2015) and the projected two future land-use maps (LU2055 and LU 2075) with the help of CA-Markov model to be fed into SWAT. The central tendency of streamflow, sediment, and TP loads under future scenarios is represented using the annual average. The intra-/inter-annual variation of streamflow, sediment, and TP loads simulated by SWAT is also analyzed using the coefficient of variation. The results show that future land-use change has a negligible impact on annual streamflow, sediment, TP loads, and intra-annual and inter-annual variation. Climate change is likely to amplify the annual streamflow and sediment and reduce the annual TP loads, which is also expected to reduce its inter-/intra-annual variation of TP loads compared with the baseline period (2000–2019). The combined impact of land-use and climate change on streamflow, sediment, and TP loads is greater than the sum of individual impacts for climate change and land-use change, especially for TP loads. Moreover, the synergistic impact caused by the interaction of climate and land use varies with variables and is more significant for TP loads. Thus, it is necessary to consider the combined climate and land-use change scenarios in future climate change studies due to the non-negligible synergistic impact, especially for TP loads. This research rare integrates the individual/combined/synergistic impact of land-use and climate change on streamflow, sediment, and TP loads and will help to understand the interaction between climate and land-use and take effective climate change mitigation policy and land-use management policy to mitigate the non-point source pollution in the future.

Traditional crowd counting approaches usually use Gaussian assumption to generate pseudo density ground truth, which suffers from problems like inaccurate estimation of the Gaussian kernel sizes. In this paper, we propose a new measure-based counting approach to regress the predicted density maps to the scattered point-annotated ground truth directly. First, crowd counting is formulated as a measure matching problem. Second, we derive a semi-balanced form of Sinkhorn divergence, based on which a Sinkhorn counting loss is designed for measure matching. Third, we propose a self-supervised mechanism by devising a Sinkhorn scale consistency loss to resist scale changes. Finally, an efficient optimization method is provided to minimize the overall loss function. Extensive experiments on four challenging crowd counting datasets namely ShanghaiTech, UCF-QNRF, JHU++, and NWPU have validated the proposed method., Accepted by International Joint Conference on Artificial Intelligence (IJCAI2021)

BACKGROUND: MicroRNA-495 (miR-495) is a post-translational modulator that performs several functions, and it is involved in several disease states. On the other hand, the physiological functions of miR-495 in H(2)O(2) stimulated mouse spinal cord neuronal dysfunction have not yet been fully understood. METHODS: In this study, we speculated that miR-495 may regulate the expression of STAT3 in the processes of neuronal proliferation and apoptosis following spinal cord injury (SCI). Cell viability was assessed with methyl thiazolyl tetrazolium (MTT) assay. Caspase-3 activity was assayed with ELISA. Cellular apoptotic changes were measured with TUNEL assay. Intracellular ROS production was determined by measuring uptake of dichlorodihydrofluorescein diacetate (DCFH-DA; PCR was used to assay the mRNA expression of STAT3 gene bearing predicted targeting positions for miR-495, while qRT-PCR was used to measure miR-495 mRNA. RESULTS: The results demonstrated that treatment of SCNs with H(2)O(2) led to a significant decrease in cell survival, while it enhanced apoptosis. The H(2)O(2) treatment induced cell membrane dysfunction, and increased ROS levels and DNA damage. Interestingly, the expression of miR-495 was markedly suppressed when SCNs were exposed to H(2)O(2). However, miR-495 overexpression reversed H(2)O(2)-induced cytotoxicity and apoptosis in SCNs. Moreover, H(2)O(2) exposure elevated protein and mRNA concentrations of STAT3 in SCNs. Bioinformatics analysis showed likely binding domains of miR-495 in the 3'-untranslated regions of STAT3 in SCNs. MiR-495 loss-of-function and gain-of-function significantly up-regulated and down-regulated both STAT3 mRNA and protein expressions, respectively, in SCNs. CONCLUSIONS: miR-495 overexpression inhibited H(2)O(2)-induced SCN dysfunction. This mechanism was mediated through the down-regulation of STAT3 expression.

Searching for low-cost, high-efficiency, bifunctional, non-noble-metal electrocatalysts for overall water splitting is crucial to renewable energy conversion. Herein, a series of component-controllable CC/CNTs@CoSx Se2(1-x) (CC: carbon cloth, CNT: carbon nanotube) with excellent bifunctional properties in the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were obtained by chemical vapor deposition. In this strategy, the Zif-67 precursor served as a structural inducer, which was directly grown on CC and pyrolyzed with the assistance of melamine to form multi-walled CNT-encapsulated CoSx Se2(1-x) hierarchical nanostructures. Subsequently, the electrocatalytic properties of the as-prepared materials were optimized by adjusting the S/Se molar ratio. Of note is that the lattice distortion caused by the different radii of Se and S generated a polarized electric field for easy adsorption of the intermediate products. The CoOOH generated in situ on the surface of CoSx Se2(1-x) , as well as n- and p-type domains in carbon, synergistically resulted in abundant active sites to boost the electrocatalytic activity. CC/CNTs@CoS0.74 Se0.52 exhibited overpotentials for the HER and OER of 225 and 285 mV, respectively and attained a current density of 10 mA cm-2 in alkaline solution. The as-prepared electrocatalysts could act as both cathode and anode in a water electrolyzer showing a cell voltage of 1.74 V and delivering 10 mA cm-2 , comparable to those of noble-metal-based water electrolyzers.

Main purpose of present study was to enhance the therapeutic efficacy in the treatment of colon adenocarcinoma by combining the benefits of chemotherapy and gene therapy. In this study, we have successfully formulated oxaliplatin (OXL) and miRNA-204-5p loaded polyethyleneimine (PEI)/hyaluronic acid (HA)-assembled mesoporous silica nanoparticles (OXmi-HSMN). Our study, for the first time, proved that miRNA-204-5p can generate a synergistic anticancer effect with OXL with HMSN, and thus improve the effects of therapeutic efficacy in colon cancers. In vitro targeting studies showed that OXmi-HSMN exhibited higher uptake efficiency in CD44 receptor over-expressed HT-29 cells via CD44 receptor-mediated endocytosis. OXmi-HMSN exhibited a higher cell cytotoxicity compared to any other formulations indicating that internalization via CD44 receptor-mediated endocytosis increased the anticancer effect. The OXmi-HMSN showed significantly higher pre-apoptotic cells (43.9%) with significant apoptosis fractions (upper right quadrant - 20%) indicating the superior anticancer efficacy in terms of apoptosis inducing potentials. Importantly, OXmi-HMSN caused conspicuous inhibition of tumor growth and was significantly greater than that of either OXL or OXL-MSN (p 0.0001). OXmi-HMSN showed 30% of TUNEL positive cells compared to 8% TUNEL positive cells for free OXL and 6% for free miRNA-204-5p treated group indicating the wide spread apoptosis of cells throughout the tissue section. Current study provides a delivery platform for dual therapeutics for enhanced therapeutic efficacy in the management of colon cancer.

Searching for a facile and sustainable chlorination method to modify graphene has drawn tremendous attention due to the modulation of its electronic property and surface chemistry. In contrast to t...

The search for efficient overall water-splitting electrocatalysts plays an important role for low-cost hydrogen production. Metal phosphides are promising for integrating hydrogen evolution reactio...

Vertically-oriented graphene (VG) directly grown on carbon cloth serves as unique support for uniform growth of Zif-67 nanocrystals, and subsequent melamine-assisted pyrolysis results in the anchoring of multiwall carbon nanotubes (MWCNTs) encapsulated Co on VG. Systematic measurements indicate that pyridinic N and pyrrolitic N contents decreased from 600 to 900 °C, and the highest metallic Co contents, as well as well-defined MWCNTs were obtained at 800 °C. Taking advantage of the unique hierarchical nanostructures and adjusted compositions, the free-standing electrode shows excellent bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) activities. The presence of MWCNTs, metallic Co, active N species and Co-NxC sites, as well as in-situ formed Co oxides, will synergistically contribute to the electrocatalytic performance. Such free-standing film directly act as air-cathode to construct all solid-state Zn-air batteries (ZABs), showing comparable rechargeability to commercial Pt/C&Ir/C electrocatalysts, and also possessing unique flexibility. Present work opens a new avenue to improve the ORR and OER performance of Zif-67 derived nanomaterials via manipulating the hierarchical structure and chemical compositions, and sheds insights to the understanding of the electrocatalytic mechamism, also promotes the development of solid-state ZABs.

Poor crystalline MoS2/C hollow nanosphere with highly exposed active sites were rationally designed for the enhanced the hydrogen evolution reaction (HER) performance and long-term durability. Polyoxometalates were used as oxidants to spontaneously initiate the polymerization of pyrrole, and served as Mo sources for synthesizing MoS2 in the following sulfurization, as well as P sources for doping carbon. Solid, hollow, and double-shelled hollow nanoshperes were facilely controlled via improving the annealing temperature, and showing varied HER performance due to the variations in nanostructure, crystallinity, defects, mass transports, etc. It is found that hollow nanospheres annealed at 800 °C exhibited the best HER performance, showing overpotential of 207 mV at 10 mA cm−2, and Tafel slope of 73 mV dec−1, as well as long-term stability for 25 h. Poor crystalline phase with abundant defective sites and highly accessible surface area possessing highly exposed active sites, as well as the synergistic effects between MoS2 and N, P-dual doped mesoporous carbon, contributed to improving the HER performance. Present work proved that the smart manipulation of the crystallinity of MoS2 is an efficient way to prepare high performance HER catalysts, which might be further utilized in photoelectrocatalytic water splitting in comparison to complete amorphous phase.

Multifunctional theranostic platforms, especially single component-based platforms, enable both cancer treatment and real-time imaging as well as enhance the efficiency of treatment. In this study, 50 nm Mo2C nanospheres were explored as a “one-for-all” theranostic agent. The light-harvesting of Mo2C covered the entire near infrared region, and NIR irradiation concurrently triggered hyperthermia and reactive oxygen species (ROS) production; thus, synergistic outcomes of photothermal and photodynamic therapy could be realized. Both in vitro and in vivo experiments have confirmed the superiority of the synergistic phototherapy in killing cancer cells and removing solid tumors; moreover, Mo2C proposed herein has been proven to be applicable as a photoacoustic imaging and CT imaging contrast agent for in vivo tumor depiction; furthermore, Mo2C demonstrates excellent biocompatibility, showing minimal hematotoxicity and tissue toxicity. A theoretical simulation performed by density functional theory revealed that the metallic character and the interband/intraband transition of Mo2C accounted for its broad photoabsorption. The antitumor mechanism of Mo2C was investigated on a solid tumor by B-mode ultrasonography (US) and magnetic resonance imaging (MRI), revealing a typical liquefactive necrosis process; hence, herein, the dual-imaging guided phototherapy was efficiently mediated by Mo2C.

Bifunctional electrocatalysts for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of fundamental significance for efficient solar-water splitting devices. Herein, we report the preparation of CoP nanoparticles embedded in N-doped mesoporous carbon via a simple yet facile route involving the polymerization of dopamine, Co salts and Si precursor, as well as the subsequent phosphidation treatment. The as-prepared catalysts not only can efficiently catalyze the HER in acidic and basic media with overpotential of 139 and 203 mV to reach current density of 10 mA cm−2, but also favors the sluggish OER process due to the presence of cobalt oxy-hydroxide on the surface of CoP, showing overpotential of 345 mV to acquire the same current density. The efficient catalytic activities are, highly probably, attributed to the favorable mass-transfer in the nanoporous carbon, interfacial effects at nitrogen dopants enriched site, small charge transfer resistance, as well as synergistic effect between active species and underlying support. The catalysts are appealing to serve as the promising bifunctional electrocatalysts for overall water-splitting with overpotential of 1.72 V to reach current density of 10 mA cm−2.

Electrochemical water splitting into hydrogen is a promising strategy for hydrogen production powered by solar energy. However, the cell voltage of an electrolyzer is still too high for practical application, which is mainly limited by the sluggish oxygen evolution reaction process. To this end, hybrid water electrolyzers have drawn tremendous attention. Herein, coaxial Ni/Ni

Recent discovery of piezoelectricity that existed in two-dimensional (2D) layered materials represents a key milestone for flexible electronics and miniaturized and wearable devices. However, so far the reported piezoelectricity in these 2D layered materials is too weak to be used for any practical applications. In this work, we discovered that grain boundaries (GBs) in monolayer MoS2 can significantly enhance its piezoelectric property. The output power of piezoelectric devices made of the butterfly-shaped monolayer MoS2 was improved about 50% by the GB-induced piezoelectric effect. The enhanced piezoelectricity is attributed to the additional piezoelectric effect induced by the existence of deformable GBs which can promote polarization and generates spontaneous polarization with different piezoelectric coefficients along various directions. We further made a flexible piezoelectric device based on the 2D MoS2 with the GBs and demonstrated its potential application in self-powered precision sensors for in situ detecting pressure changes in human blood for health monitoring.

Recent discovery of piezoelectricity that existed in two-dimensional (2D) layered materials represents a key milestone for flexible electronics and miniaturized and wearable devices. However, so far the reported piezoelectricity in these 2D layered materials is too weak to be used for any practical applications. In this work, we discovered that grain boundaries (GBs) in monolayer MoS

Two-dimensional (2D) layered materials, such as MoS2, are greatly attractive for flexible devices due to their unique layered structures, novel physical and electronic properties, and high mechanical strength. However, their limited mechanical strains (

Endothermic hydrocarbon fuel has many advantages as a cooling medium in hypersonic aircraft; however substantial application has been greatly hindered due to easy coking, uncontrollable gas product...