Chemically bonded CdS/Bi2MoO6 Z-scheme heterojunction synergises with strong internal electric field for photocatalytic CO2 reduction.

Constructing strong interfacial electric fields to enhance the surface charge transport kinetics is an effective strategy for promoting CO2 conversion. Herein, we present the fabrication of CdS-Bi2MoO6 Z-scheme heterojunctions with a robust internal electric field (IEF) using an in situ growth technique, establishing chemical bonding between the components. The IEF at the interface can offer an impetus for the segregation and transportation of photogenerated carriers, while the Cd-O chemical bonding mode acts as a rapid conduit for these carriers, thereby reducing the charge transfer distance. As a result, the Z-scheme charge transfer is accelerated due to the synergistic influence of these two factors. Therefore, the optimized CdS/Bi2MoO6 Z-scheme heterojunction possesses significantly enhanced dynamic carrier mobility, thus promoting the conversion of CO2 to CO without the need for additional co-catalysts or sacrificial agents. This optimization yields a remarkable CO selectivity of up to 97%. Meanwhile, the expedited Z-scheme charge transfer mechanism is validated through X-ray photoelectron spectroscopy, Kelvin probe force microscopy, and in situ diffuse reflectance infrared Fourier transform spectroscopy.

Hydrophobic TaOx Species Overlayer Tuning Light-Driven Methane Chlorination with Inorganic Chlorine.

Halogenated methane serves as a universal platform molecule for building high-value chemicals. Utilizing sodium chloride solution for photocatalytic methane chlorination presents an environmentally friendly method for methane conversion. However, competing reactions in gas-solid-liquid systems leads to low efficiency and selectivity in photocatalytic methane chlorination. Here, an in situ method is employed to fabricate a hydrophobic layer of TaOx species on the surface of NaTaO3. Through in-situ XPS and XANES spectra analysis, it is determined that TaOx is a coordination unsaturated species. The TaOx species transforms the surface properties from the inherent hydrophilicity of NaTaO3 to the hydrophobicity of TaOx/NaTaO3, which enhances the accessibility of CH4 for adsorption and activation, and thus promotes the methane chlorination reaction within the gas-liquid-solid three-phase system. The optimized TaOx/NaTaO3 photocatalyst has a good durability for multiple cycles of methane chlorination reactions, yielding CH3Cl at a rate of 233 µmol g-1 h-1 with a selectivity of 83%. In contrast, pure NaTaO3 exhibits almost no activity toward CH3Cl formation, instead catalyzing the over-oxidation of CH4 into CO2. Notably, the activity of the optimized TaOx/NaTaO3 photocatalyst surpasses that of reported noble metal photocatalysts. This research offers an effective strategy for enhancing the selectivity of photocatalytic methane chlorination using inorganic chlorine ions.

Strain-Induced Self-Assembly at Interface of Two-Dimensional Heterostructures Boosts CO2 Reduction to Methanol by H2O.

CO2 conversion with pure H2O into CH3OH and O2 driven by solar energy can supply fuels and life-essential substances for extraterrestrial exploration. However, the effective production of CH3OH is significantly challenging. Here we report an organozinc complex/MoS2 heterostructure linked by well-defined zinc-sulfur covalent bonds derived by the structural deformation and intensive coupling of dx2 - y2(Zn)-p(S) orbitals at the interface, resulting in distinctive charge transfer behaviors and excellent redox capabilities as revealed by experimental characterizations and first-principle calculations. The synthesis strategy is further generalized to more organometallic compounds, achieving various heterostructures for CO2 photoreduction. The optimal catalyst delivers a promising CH3OH yield of 2.57 mmol gcat-1 h-1 and selectivity of more than 99.5%. The reverse water gas shift mechanism is identified for methanol formation. Meanwhile, energy-unfavorable adsorption of methanol on MoS2, where the photogenerated holes accumulate, ensures the selective oxidation of water over methanol.

Unraveling Synergistic Effect of Defects and Piezoelectric Field in Breakthrough Piezo-Photocatalytic N2 Reduction.

Piezo-photocatalysis is a frontier technology for converting mechanical and solar energies into crucial chemical substances and has emerged as a promising and sustainable strategy for N2 fixation. Here, for the first time, defects and piezoelectric field are synergized to achieve unprecedented piezo-photocatalytic nitrogen reduction reaction (NRR) activity and their collaborative catalytic mechanism is unraveled over BaTiO3 with tunable oxygen vacancies (OVs). The introduced OVs change the local dipole state to strengthen the piezoelectric polarization of BaTiO3 , resulting in a more efficient separation of photogenerated carrier. Ti3+ sites adjacent to OVs promote N2 chemisorption and activation through d-π back-donation with the help of the unpaired d-orbital electron. Furthermore, a piezoelectric polarization field could modulate the electronic structure of Ti3+ to facilitate the activation and dissociation of N2 , thereby substantially reducing the reaction barrier of the rate-limiting step. Benefitting from the synergistic reinforcement mechanism and optimized surface dynamics processes, an exceptional piezo-photocatalytic NH3 evolution rate of 106.7 µmol g-1  h-1 is delivered by BaTiO3 with moderate OVs, far surpassing that of previously reported piezocatalysts/piezo-photocatalysts. New perspectives are provided here for the rational design of an efficient piezo-photocatalytic system for the NRR.

Metal to non-metal sites of metallic sulfides switching products from CO to CH4 for photocatalytic CO2 reduction.

The active center for the adsorption and activation of carbon dioxide plays a vital role in the conversion and product selectivity of photocatalytic CO2 reduction. Here, we find multiple metal sulfides CuInSnS4 octahedral nanocrystal with exposed (1 1 1) plane for the selectively photocatalytic CO2 reduction to methane. Still, the product is switched to carbon monoxide on the corresponding individual metal sulfides In2S3, SnS2, and Cu2S. Unlike the common metal or defects as active sites, the non-metal sulfur atom in CuInSnS4 is revealed to be the adsorption center for responding to the selectivity of CH4 products. The carbon atom of CO2 adsorbed on the electron-poor sulfur atom of CuInSnS4 is favorable for stabilizing the intermediates and thus promotes the conversion of CO2 to CH4. Both the activity and selectivity of CH4 products over the pristine CuInSnS4 nanocrystal can be further improved by the modification of with various co-catalysts to enhance the separation of the photogenerated charge carrier. This work provides a non-metal active site to determine the conversion and selectivity of photocatalytic CO2 reduction.

The Keto-Switched Photocatalysis of Reconstructed Covalent Organic Frameworks for Efficient Hydrogen Evolution.

The keto-switched photocatalysis of covalent organic frameworks (COFs) for efficient H2 evolution was reported for the first time by engineering, at a molecular level, the local structure and component of the skeletal building blocks. A series of imine-linked BT-COFs were synthesized by the Schiff-base reaction of 1, 3, 5-benzenetrialdehyde with diamines to demonstrate the structural reconstruction of enol to keto configurations by alkaline catalysis. The keto groups of the skeletal building blocks served as active injectors, where hot π-electrons were provided to Pt nanoparticles (NPs) across a polyvinylpyrrolidone (PVP) insulting layer. The characterization results, together with density functional theory calculations, indicated clearly that the formation of keto-injectors not only made the conduction band level more negative, but also led to an inhomogeneous charge distribution in the donor-acceptor molecular building blocks to form a strong intramolecular built-in electric field. As a result, visible-light photocatalysis of TP-COFs-1 with one keto group in the skeletal building blocks was successfully enabled and achieved an impressive H2 evolution rate as high as 0.96 mmol g-1 h-1 . Also, the photocatalytic H2 evolution rates of the reconstructed BT-COFs-2 and -3 with two and three keto-injectors were significantly enhanced by alkaline post-treatment.

SARS-CoV-2 spike host cell surface exposure promoted by a COPI sorting inhibitor.

Via an insufficient coat protein complex I (COPI) retrieval signal, the majority of SARS-CoV-2 spike (S) is resident in host early secretory organelles and a tiny amount is leaked out in cell surface. Only surface-exposed S can be recognized by B cell receptor (BCR) or anti-S therapeutic monoclonal antibodies (mAbs) that is the trigger step for B cell activation after S mRNA vaccination or infected cell clearance by S mAbs. Now, a drug strategy to promote S host surface exposure is absent. Here, we first combined structural and biochemical analysis to characterize S COPI sorting signals. A potent S COPI sorting inhibitor was then invented, evidently capable of promoting S surface exposure and facilitating infected cell clearance by S antibody-dependent cellular cytotoxicity (ADCC). Importantly, with the inhibitor as a probe, we revealed Omicron BA.1 S is less cell surface exposed than prototypes because of a constellation of S folding mutations, possibly corresponding to its ER chaperone association. Our findings not only suggest COPI is a druggable target against COVID-19, but also highlight SARS-CoV-2 evolution mechanism driven by S folding and trafficking mutations.

Surface Ru-H Bipyridine Complexes-Grafted TiO2 Nanohybrids for Efficient Photocatalytic CO2 Methanation.

A series of novel surface Ru-H bipyridine complexes-grafted TiO2 nanohybrids were for the first time prepared by a combined procedure of surface organometallic chemistry with post-synthetic ligand exchange for photocatalytic conversion of CO2 to CH4 with H2 as electron and proton donors under visible light irradiation. The selectivity toward CH4 increased to 93.4% by the ligand exchange of 4,4'-dimethyl-2,2'-bipyridine (4,4'-bpy) with the surface cyclopentadienyl (Cp)-RuH complex and the CO2 methanation activity was enhanced by 4.4-fold. An impressive rate of 241.2 µL·g-1·h-1 for CH4 production was achieved over the optimal photocatalyst. The femtosecond transient IR absorption results demonstrated that the hot electrons were fast injected in 0.9 ps from the photoexcited surface 4,4'-bpy-RuH complex into the conduction band of TiO2 nanoparticles to form a charge-separated state with an average lifetime of ca. 50.0 ns responsible for the CO2 methanation. The spectral characterizations indicated clearly that the formation of CO2•- radicals by single electron reduction of CO2 molecules adsorbed on surface oxygen vacancies of TiO2 nanoparticles was the most critical step for the methanation. Such radical intermediates were inserted into the explored Ru-H bond to generate Ru-OOCH species and finally CH4 and H2O in the presence of H2.

Atomically Dispersed Electron Traps in Cu Doped BiOBr Boosting CO2 Reduction to Methanol by Pure H2 O.

Overall photocatalytic conversion of CO2 and pure H2 O driven by solar irradiation into methanol provides a sustainable approach for extraterrestrial synthesis. However, few photocatalysts exhibit efficient production of CH3 OH. Here, BiOBr nanosheets supporting atomic Cu catalysts for CO2 reduction are reported. The investigation of charge dynamics demonstrates a strong built-in electric field established by isolated Cu sites as electron traps to facilitate charge transfer and stabilize charge carriers. As result, the catalysts exhibit a substantially high catalytic performance with methanol productivity of 627.66 µmol gcatal -1 h-1 and selectivity of ≈90% with an apparent quantum efficiency of 12.23%. Mechanism studies reveal that the high selectivity of methanol can be ascribed to energy-favorable hydrogenation of *CO intermediate giving rise to *CHO. The unfavorable adsorption on Cu1 @BiOBr prevents methanol from being oxidized by photogenerated holes. This work highlights the great potential of single-atom photocatalysts in chemical transformation and energy storage reactions.

An innovative S-scheme AgCl/MIL-100(Fe) heterojunction for visible-light-driven degradation of sulfamethazine and mechanism insight.

The development of high efficient photocatalysts for antibiotics contamination in water remains a severe challenge. In this study, a novel step-scheme (S-scheme) photocatalytic heterojunction nanocomposites were fabricated from integrating AgCl nanoparticles on the MIL-100(Fe) octahedron surface through facile multi-stage stirring strategy. The S-scheme heterojunction structure in AgCl/MIL-100(Fe) (AM) nanocomposite provided a more rational utilization of electrons (e-) and holes (h+), accelerated the carrier transport at the junction interface, and enhanced the overall photocatalytic performance of nanomaterials. The visible-light-driven photocatalysts were used to degrade sulfamethazine (SMZ) which attained a high removal efficiency (99.9%). The reaction mechanisms of SMZ degradation in the AM photocatalytic system were explored by electron spin resonance (ESR) and active species capture experiments, which superoxide radical (•O2-), hydroxyl radical (•OH), and h+ performed as major roles. More importantly, the SMZ degradation pathway and toxicity assessment were proposed. There were four main pathways of SMZ degradation, including the processes of oxidation, hydroxylation, denitrification, and desulfonation. The toxicity of the final products in each pathway was lower than that of the parent according to the toxicity evaluation results. Therefore, this work might provide new insights into the environmentally-friendly photocatalytic processes of S-scheme AM nanocomposites for the efficient degradation of antibiotics pollutants.

Constructing a Channel to Regulate the Electron-Transfer Behavior of CO Adsorption and Light-Driven CO Reduction by H2 over CuO-ZnO.

Photocatalytic conversions of C1 molecules under mild conditions have been widely researched in many fields. Adsorption of reactants at a catalyst surface is an indispensable process for C1 conversion and thus it might play a key role in reaction behavior. Herein, for a ZnO sample without photocatalytic activity for CO + H2 reduction, CuO is introduced into ZnO to regulate the adsorption behavior of CO on the CuO-ZnO surface and then to drive the reduction of CO by H2 under UV irradiation. The results of gas sensitivity tests and various in situ characterization methods are as expected. Specifically, surface zinc vacancies and Cu2+ sites at the interface of ZnO and CuO cooperate to construct a special electron-transfer channel (Zn-O-Cu-O) for CO adsorption [CO (ads)]. A new linear adsorption mode of CO at Cu2+ sites occurs, and this successfully changes the electron-transfer behavior of CO (ads) from donating electrons (to ZnO) to accepting electrons (from CuO-ZnO) via electron-transfer channels and d-electrons of Cu2+ matching. Then, CO molecules are reduced by H2 under UV irradiation. The strategy here provides an insight into the design of highly effective catalysts as well as an in-depth understanding of the mechanism of C1 photocatalytic conversion.

Photocatalytic H2O2 production and removal of Cr (VI) via a novel Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure with broad spectral response.

The low-usage of solar energy and the sluggish separation efficiency of the photogenerated electrons/holes pairs are the obstacles in the practical application of photocatalysts. The integration of upconversion and Z-scheme heterojunction is expected to break the barriers to achieve the efficient charge separation and broaden near-infrared light absorption. Herein, an effective indirect Z scheme AgInS2/In2S3 heterostructure with carbon quantum dots (CQDs, as the electron conduction medium) and Lu3NbO7:Yb, Ho (as upconversion function) has been successfully synthesized. Consequently, the Lu3NbO7: Yb, Ho/CQDs/AgInS2/In2S3 heterostructure exhibited superior photocatalytic activities for Cr(VI) reduction and H2O2 production, reducing 99.9% of Cr(VI)(20 ppm, 15 min) and 78.5% of Cr(VI) (40 ppm, 30 min) with visible light irradiation as well as 94.0% of Cr(VI) (20 ppm, 39 min) under NIR light irradiation. Simultaneously, the heterostructure could generate 902.9 µM H2O2 for 5 h under visible light irradiation. The intensive photocatalytic properties could primarily be attributed to the boosted light absorption capacity, the improved solar-to-energy conversion by the remarkable upconversion capacity of Lu3NbO7: Yb, Ho/CQDs and the faster charge transfer through a Z-schematic pathway. This work is anticipated to open a novel "window" for designing the efficient photocatalysts by coupling of Lu3NbO7: Yb, Ho and CQDs.

Well-defined Co9S8 cages enable the separation of photoexcited charges to promote visible-light CO2 reduction.

Exploring affordable cocatalysts with high performance for boosting charge separation and CO2 activation is an effective strategy to reinforce CO2 photoreduction efficiency. Herein, well-defined Co9S8 cages are exploited as a nonprecious promoter for visible-light CO2 reduction. The Co9S8 cages are prepared via a multistep strategy with ZIF-67 particles as the precursor and fully characterized by physicochemical techniques. The hollow Co9S8 cocatalyst with a high surface area and profuse catalytically active centers is discovered to accelerate separation and transfer of light-induced charges, and strengthen concentration and activation of CO2 molecules. In a hybrid photosensitized system, these Co9S8 cages efficiently promote the deoxygenative reduction of CO2 to generate CO, with a high yield rate of 35 µmol h-1 (i.e., 35 mmol h-1 g-1). Besides, this cocatalyst is also of high stability for the CO2 photoreduction reaction. Density functional theory (DFT) calculations reveal that the Ru(bpy)32+ photosensitizer is strongly absorbed on the Co9S8 (311) surface through forming four Co-C bonds, which can serve as the "bridges" to ensure quick electron transfer from the excited photosensitiser to the active Co9S8 cocatalyst, thus promoting the separation of photoexcited charges for ehannced CO2 reduction performance.

Reversal of pulmonary arterial hypertension and neointimal formation by kinin B1 receptor blockade.

BACKGROUND: This study examined whether BI113823, a novel selective kinin B1 receptor antagonist can reverse established pulmonary arterial hypertension (PAH), prevent right heart failure and death, which is critical for clinical translation. METHODS: Left pneumonectomized male Wistar rats were injected with monocrotaline to induce PAH. Three weeks later, when PAH was well established, the rats received daily treatment of BI113823 or vehicle for 3 weeks. RESULTS: Treatment with BI113823 from day 21 to day 42 after monocrotaline injection reversed established PAH as shown by normalized values of mean pulmonary arterial pressure (mPAP). BI113823 therapy reversed pulmonary vascular remodeling, pulmonary arterial neointimal formation, and heart and lung fibrosis, reduced right ventricular pressure, right heart hypertrophy, improved cardiac output, and prevented right heart failure and death. Treatment with BI113823 reduced TNF-α and IL-1ß, and macrophages recruitment in bronchoalveolar lavage, reduced CD-68 positive macrophages and expression of proliferating cell nuclear antigen (PCNA) in the perivascular areas, and reduced expression of iNOS, B1 receptors, matrix metalloproteinase (MMP)-2 and MMP-9 proteins, and the phosphorylation of ERK1/2 and AKT in lung. Treatment with BI113823 reduced mRNA expression of ANP, BNP, ßMHC, CGTF, collange-I and IV in right heart, compared to vehicle treated controls. In human monocytes cultures, BI113823 reduced LPS-induced TNF-α production, MMP-2 and MMP-9 expression, and reduced TNF-α-induced monocyte migration. CONCLUSIONS: We conclude that BI113823 reverses preexisting severe experimental pulmonary hypertension via inhibition of macrophage infiltration, cytokine production, as well as down regulation of matrix metalloproteinase proteins.

Cd0.5Zn0.5S/CoWO4 Nanohybrids with a Twinning Homojunction and an Interfacial S-Scheme Heterojunction for Efficient Visible-Light-Induced Photocatalytic CO2 Reduction.

The construction of a phase junction photocatalyst can significantly enhance the photocatalytic performance with high selectivity for CO2 reduction. In this study, an S-scheme junction Cd0.5Zn0.5S/CoWO4 semiconductor with the coupling of a twin crystal Cd0.5Zn0.5S homojunction and CoWO4 was designed through a hydrothermal method, which could convert CO2 to CO with high efficiency under visible-light illumination. Cd0.5Zn0.5S-10%CoWO4 exhibited the optimal performance and its CO yield and selectivity were up to 318.68 µmol·g-1 and 95.90%, respectively, which were 4.54 and 1.62 times higher than that of twin crystal Cd0.5Zn0.5S. Moreover, the Cd0.5Zn0.5S homojunction with a zinc-blende and wurtzite phase and the S-scheme phase junction of Cd0.5Zn0.5S/CoWO4 enhanced the property of CO2 adsorption and accelerated the detachment of photogenerated carriers. The combination of photogenerated holes in Cd0.5Zn0.5S and the electrons of CoWO4 can retain the reduction sites to improve photocatalytic performance. This study provides a neoteric concept and reference for the construction of the S-scheme phase junction.

lncRNA MCM3AP-AS1 inhibits the progression of colorectal cancer via the miR-19a-3p/FOXF2 axis.

BACKGROUND: Long non-coding RNA MCM3AP antisense RNA 1 (lncRNA MCM3AP-AS1) has a regulatory role in the development of diverse malignancies, whereas its role and mechanism in colorectal cancer (CRC) is not yet clear. METHODS: The relative expression of MCM3AP-AS1, miR-19a-3p and forkhead box F2 (FOXF2) mRNA in 53 cases of CRC and its adjacent normal tissues, human normal colonic mucosal cells (FHC cells) and CRC cell lines was examined by a quantitative real-time polymerase chain reaction, and the changes of cell multiplication and migration were examined by the cell counting kit-8 method, EdU test, and scratch-healing test, respectively. Bioinformatics, dual-luciferase reporter gene assay and a RNA immunoprecipitation experiment were adopted to predict and verify the relationship between MCM3AP-AS1 and miR-19a-3p; bioinformatics and dual-luciferase reporter gene assay were adopted to predict and verify the relationship between miR-19a-3p and FOXF2. Western blotting was executed to examine the effects of MCM3AP-AS1 overexpression or knockdown on FOXF2 protein expression. RESULTS: MCM3AP-AS1 expression was down-modulated in CRC, and its dysregulation was linked to unfavorable pathological characteristics. MCM3AP-AS1 significantly impeded the multiplication and migration of CRC cells. MCM3AP-AS1 was recognized as a molecular sponge to suppress miR-19a-3p expression, and FOXF2 was a target gene of miR-19a-3p. MCM3AP-AS1 positively modulated FOXF2 expression, and its biological effect was dependent the on miR-19a-3p/FOXF2 axis. CONCLUSIONS: MCM3AP-AS1 can inhibit CRC promoting by modulating the miR-19a-3p/FOXF2 axis.

H2-oxidation driven by its behavior of losing an electron over B-doped TiO2 under UV irradiation.

In this work, TiO2 was modified by doping the electron-deficient B element, and then the gas-sensing response of B-TiO2 to H2 under UV irradiation at room temperature in a N2 atmosphere and the oxidation of H2 over B-TiO2 under corresponding conditions were tested. It was found that H2 would accept an electron when adsorbed on the TiO2 surface, while H2 would donate an electron when adsorbed on the B-TiO2 surface. Correspondingly, H2 could not be oxidized over TiO2, but could be oxidized over B-TiO2. This indicated that the oxidation of H2 was dependent on the electron-transfer behavior between H2 and the surface of TiO2 or B-TiO2. Based on the relevant characterization results, it was proposed that H2 could accept an electron from TiO2 due to the higher Fermi level of TiO2, while H2 could donate an electron to B-TiO2 due to the lower Fermi level of B-TiO2 induced by doping B. This indicated that the electron-transfer behavior between H2 and TiO2 could be changed by adjusting the Fermi level of TiO2, while the electron-transfer behavior would further affect the photocatalytic activity of oxidizing H2. This result shows that the doable H2 photocatalytic oxidation in thermodynamics can be controlled by a kinetics factor (H2 losing-an-electron behavior). This work can be applied to provide an understanding of the photocatalytic oxidation behavior of other reactants over semiconductor materials.

Visible and near-infrared driven Yb3+/Tm3+ co-doped InVO4 nanosheets for highly efficient photocatalytic applications.

To effectively enhance the utilization of clean sunlight energy, harvesting a large percentage of near infrared (NIR) light is significant. One of the commonly used effective methods for modifying semiconductors is by co-doping upconversion materials on semiconductors to heighten the photocatalytic efficiency. In this work, Yb3+/Tm3+ co-doped InVO4 nanosheets were synthesized by a facile hydrothermal path, and the crystal phases, morphologies, surface chemical compositions, as well as optical properties were characterized. Yb3+/Tm3+ co-doped InVO4 revealed significantly enhanced photoactivity towards chromium(vi) reduction and methyl orange oxidation under visible or NIR light irradiation. Furthermore, 5YT-IV presented the highest electrocatalytic performance and photocatalytic production of H2O2 under visible light irradiation, requiring low overpotential and low Tafel slope (390 mV dec-1) for hydrogen evolution reaction than that of the bare InVO4 (731 mV dec-1), and as well improved the yield of photocatalytic H2O2 production by about 3.5 times. This was primarily ascribed to intensive light absorption resulting from the benign upconversion energy transfer of Yb3+/Tm3+ and the boosted charge separation caused by the intermediate energy states. Moreover, the presence of h+ and ˙O2- as the main oxidative species played a significant role during the photocatalytic oxidation process of methyl orange and electrons played a decisive role in Cr(vi) reduction. This study provides a promising platform for efficiently utilizing the visible-NIR energy of sunlight in the field of photocatalytic H2O2 production and for alleviating environmental pollution in future.

A Novel Detector Based on Convolution Neural Networks for Multiscale SAR Ship Detection in Complex Background.

Convolution neural network (CNN)-based detectors have shown great performance on ship detections of synthetic aperture radar (SAR) images. However, the performance of current models has not been satisfactory enough for detecting multiscale ships and small-size ones in front of complex backgrounds. To address the problem, we propose a novel SAR ship detector based on CNN, which consist of three subnetworks: the Fusion Feature Extractor Network (FFEN), Region Proposal Network (RPN), and Refine Detection Network (RDN). Instead of using a single feature map, we fuse feature maps in bottom-up and top-down ways and generate proposals from each fused feature map in FFEN. Furthermore, we further merge features generated by the region-of-interest (RoI) pooling layer in RDN. Based on the feature representation strategy, the CNN framework constructed can significantly enhance the location and semantics information for the multiscale ships, in particular for the small ships. On the other hand, the residual block is introduced to increase the network depth, through which the detection precision could be further improved. The public SAR ship dataset (SSDD) and China Gaofen-3 satellite SAR image are used to validate the proposed method. Our method shows excellent performance for detecting the multiscale and small-size ships with respect to some competitive models and exhibits high potential in practical application.

MCCC2 overexpression predicts poorer prognosis and promotes cell proliferation in colorectal cancer.

PURPOSES: Recently, Methylcrotonoyl-CoA carboxylase 2 (MCCC2) is reported to be involved in tumor formation and progression. However, MCCC2 has nerve been reported in colorectal cancer. In this study, we aimed to investigate the role of MCCC2 in colorectal cancer. METHODS: 118 colorectal cancer and matched adjacent normal tissues were enrolled in this study. The expression level of MCCC2 was measured by quantificational real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). The clinical significance of MCCC2 and its influence on cell proliferation was further analyzed. RESULTS: Results shown that the mRNA levels of MCCC2 in colorectal cancer tissues were significantly increased compared with those in normal tissues (P < .0001). MCCC2 high-expression was observed in 56.8% colorectal cancer tissues, which was significantly higher than those in normal controls (9.3%, P < .0001). MCCC2 high-expression correlated with tumor size, T stage, lymph node metastasis, distant metastasis, clinical stage and differentiation in colorectal cancer (P < .05). Moreover, MCCC2 high-expression predicted poorer prognosis and could be as an independent prognostic factor. In addition, MCCC2 knockdown significantly inhibited cell proliferation compared with these controls, while MCCC2 overexpression could reverse the effect. CONCLUSION: These data indicate MCCC2 overexpression promotes cell proliferation and predicts poorer prognosis in colorectal cancer.