EN1 Regulates Cell Growth and Proliferation in Human Glioma Cells via Hedgehog Signaling.

Glioblastoma is an aggressive cancer of the nervous system that accounts for the majority of brain cancer-related deaths. Through cross-species transcriptome studies, we found that Engrailed 1 (EN1) is highly expressed in serum-free cultured glioma cells as well as glioma tissues, and increased expression level predicts a worse prognosis. EN1 controls glioma cell proliferation, colony formation, migration, and tumorigenic capacity in vivo. It also influences sensitivity of glioma cells to γ-ray irradiation by regulating intracellular ROS levels. Mechanistically, EN1 influences Hedgehog signaling by regulating the level of Gli1 as well as primary cilia length and the primary cilia transport-related protein TULP3. In conclusion, we demonstrate that EN1 acts as an oncogenic regulator that contributes to glioblastoma pathogenesis and could serve as a diagnostic/prognostic marker and therapeutic target for glioblastoma.

Phosphorous-doped 1T-MoS2 decorated nitrogen-doped g-C3N4 nanosheets for enhanced photocatalytic nitrogen fixation.

Herein, we report that the phosphorous-doped 1 T-MoS2 as co-catalyst decorated nitrogen-doped g-C3N4 nanosheets (P-1 T-MoS2@N-g-C3N4) are prepared by the hydrothermal and annealing process. The obtained P-1 T-MoS2@N-g-C3N4 composite presents an enhanced photocatalytic N2 reduction rate of 689.76 µmol L-1 g-1h-1 in deionized water without sacrificial agent under simulated sunlight irradiation, which is higher than that of pure g-C3N4 (265.62 µmol L-1 g-1h-1), 1 T-MoS2@g-C3N4 (415.57 µmol L-1 g-1h-1), 1 T-MoS2@N doped g-C3N4 (469.84 µmol L-1 g-1h-1), and P doped 1 T-MoS2@g-C3N4 (531.24 µmol L-1 g-1h-1). In addition, compared with pure g-C3N4 NSs (2.64 mmol L-1 g-1h-1), 1 T-MoS2@g-C3N4 (4.98 mmol L-1 g-1h-1), 1 T-MoS2@N doped g-C3N4 (6.21 mmol L-1 g-1h-1), and P doped 1 T-MoS2@g-C3N4 (9.78 mmol L-1 g-1h-1), P-1 T-MoS2@N-g-C3N4 (11.12 mmol L-1 g-1h-1) composite also shows a significant improvement for photocatalytic N2 fixation efficiency in the sacrificial agent (methanol). The improved photocatalytic activity of P-1 T-MoS2@N-g-C3N4 composite is ascribed to the following advantages: 1) Compared to pure g-C3N4, P-1 T-MoS2@N-g-C3N4 composite shows higher light absorption capacity, which can improve the utilization rate of the catalyst to light; 2) The P doping intercalation strategy can promote the conversion of 1 T phase MoS2, which in turn in favor of photogenerated electron transfer and reduce the recombination rate of carriers; 3) A large number of active sites on the edge of 1 T-MoS2 and the existence of N doping in g-C3N4 contribute to photocatalytic N2 fixation.

The fabrication of graphitic carbon nitride hollow nanocages with semi-metal 1T' phase molybdenum disulfide as co-catalysts for excellent photocatalytic nitrogen fixation.

Improving the efficiency of photogenerated carrier separation is essential for photocatalytic N2 fixation. Herein, the 2D semi-metal 1T'-MoS2 was uniformly distributed in g-C3N4 nanocages (CNNCs) by a hydrothermal method, and the 1T'-MoS2/CNNC composite was obtained. 1T'-MoS2 as a co-catalyst can promote the transfer of electrons, improve the separation efficiency of photogenerated carriers, and also increase the number of effective active sites. In addition, the unique nanocage morphology of CNNCs is conducive to the scattering and reflection of incident light and improves the light absorption capacity. Therefore, the optimized 1T'-MoS2/CNNC composite (5 wt%) shows a significantly improved photocatalytic N2 fixation rate (9.8 mmol L-1 h-1 g-1) and good stability, which is significantly higher than pure CNNCs (2.9 mmol L-1 h-1 g-1), Pt/CNNC (8.2 mmol L-1 h-1 g-1) and Pt/g-C3N4 nanosheet (CNNS, 6.3 mmol L-1 h-1 g-1). This work guides guidance for the design of green and efficient N2 fixation photocatalysts.

A cation exchange strategy to construct Rod-shell CdS/Cu2S nanostructures for broad spectrum photocatalytic hydrogen production.

Herein, Cu2S as the outer shell is grown on CdS nanorods (NRs) to construct rod-shell nanostructures (CdS/Cu2S) by a rapid, scalable and facile cation exchange reaction. The CdS NRs are firstly synthesized by a hydrothermal route, in which thiourea as the precursor of sulfur and ethylenediamine (EDA) as the solvent. And then, the outer shells of CdS NRs are successfully exchanged by Cu2S via a cation exchange reaction. The obtained CdS/Cu2S rod-shell NRs exhibit much enhanced activity of hydrogen production (640.95 µmol h-1 g-1) in comparison with pure CdS NRs (74.1 µmol h-1 g-1) and pure Cu2S NRs (0 µmol h-1 g-1). The enhanced photocatalytic activity of CdS/Cu2S rod-shell NRs owns to the following points: i) the photogenerated electrons generated by CdS quickly migrate to Cu2S without any barrier due to rod-shell structure by the in-situ cation exchange reaction, a decreased carrier recombination is achieved; ii) Cu2S as outer shells broaden the light absorption range of CdS/Cu2S rod-shell NRs into visible or even NIR light, which can produce more electrons and holes. This work inspires people to further study the rod-shell structured photocatalyst through the cation exchange strategy to further solar energy conversion.

Facile preparation of metallic 1T phase molybdenum selenide as cocatalyst coupled with graphitic carbon nitride for enhanced photocatalytic H2 production.

Low-cost, highly active and efficient alternative co-catalysts that can replace precious metals such as Au and Pt are urgently needed for photocatalytic hydrogen evolution reaction (HER). Herein, we show that 1T phase MoSe2 can act as the co-catalyst in the 1T-MoSe2/g-C3N4 composites and we synthesize this composite by a one-step hydrothermal method to promote photocatalytic H2 generation. Our prepared 1T-MoSe2/g-C3N4 composite exhibits highly enhanced photocatalytic H2 production compared to that of g-C3N4 nanosheets (NSs) only. The 7 wt%-1T-MoSe2/g-C3N4 composite presents a considerably improved photocatalytic HER rate (6.95 mmol·h-1·g-1), approximately 90 times greater than that of pure g-C3N4 (0.07 mmol·h-1 g-1). Moreover, under illumination at λ = 370 nm, the apparent quantum efficiency (AQE) of the 7 wt%-1T-MoSe2/g-C3N4 composite reaches 14.0%. Furthermore, the 1T-MoSe2/g-C3N4 composites still maintain outstanding photocatalytic HER stability.

High-Performance Electrocatalytic Conversion of N2 to NH3 Using 1T-MoS2 Anchored on Ti3C2 MXene under Ambient Conditions.

Herein, 1T-MoS2 nanospots assembled on conductive Ti3C2 MXene (1T-MoS2@Ti3C2) are first developed to regard as efficient electrocatalytic nitrogen fixation catalysts with high selectivity. The 1T-MoS2@Ti3C2 composite exhibits outstanding NRR activity with a faradic efficiency (FE) of 10.94% and a NH3 yield rate of 30.33 µg h-1 mg-1cat. at -0.3 V versus RHE. Notably, the 1T-MoS2@Ti3C2 composite displays excellent stability and durability during the recycling test. The outstanding NRR catalytic activity is primarily attributed to the synergy effect between 1T-MoS2 and Ti3C2 MXene. In addition, the isotopic experiment confirms the synthesized NH3 deriving from the conversion of the supplied nitrogen.

Non-high temperature method to synthesize carbon coated TiO2 nano-dendrites for enhanced wide spectrum photocatalytic hydrogen evolution activity.

TiO2 is a popular photocatalyst due to its low cost and easy availability. Herein, we for the first time synthesized carbon coated TiO2 nano-dendrites (C-TiO2 NDs) using a simple hydrothermal method without high-temperature sintering, in which citric acid is used as an adjuvant. This unique dendritic structure consisting of a single small hexagonal piece greatly increases the BET specific area (116.386 m2 g-1) and pore size (0.418 cm3 g-1), increasing the photocatalytic active site and facilitate efficient capture of light. Besides, compared with the TiO2 nanobelts (NBs) prepared by sintering method, the surface of C-TiO2 NDs prepared by hydrothermal method with citric acid are coated with carbon layers, which make C-TiO2 NDs exhibit stronger photocatalytic hydrogen evolution performance under simulated solar light irradiation due to the presence of carbon coatings promoting electron-hole separation and absorbing NIR light.

Synthesis of salicylic acid-modified graphite carbon nitride for enhancing photocatalytic nitrogen fixation.

Finding an efficient and environment-friendly photocatalyst is significant for photocatalysis. In this research, a simple calcination with urea and salicylic acid (SA) is created for constructing a SA-modified graphite carbon nitride (g-C3N4-SA) photocatalyst. Compared to pure g-C3N4, g-C3N4-SA presents broadened light absorption, due to n â†’ π* transition at nitrogen atoms. Interestingly, SA modification can strongly affect chemical and physical properties of g-C3N4, including increasing Brunauer-Emmett-Teller (BET) specific area, forming porous structure, improving optical absorption and promoting carrier separation, thus achieving the improved photocatalytic activity of g-C3N4-SA. The optimum g-C3N4-SA with the mass of SA 0.05 g (g-C3N4-SA-0.05) presents a high ammonia evolution rate of 7.92 mmol L-1h-1 g-1, 2.5 and 1.4 times than g-C3N4 (3.2 mmol L-1h-1 g-1) and g-C3N4 loaded with Pt (5.47 mmol L-1h-1 g-1). Furthermore, the excellent photostability of g-C3N4-SA is also achieved.

Two-dimensional/one-dimensional molybdenum sulfide (MoS2) nanoflake/graphitic carbon nitride (g-C3N4) hollow nanotube photocatalyst for enhanced photocatalytic hydrogen production activity.

The graphitic carbon nitride (g-C3N4) hollow nanotubes synthesized via a simple freeze-drying method are used for constructing Two-dimensional (2D)-one-dimensional (1D) molybdenum sulfide (MoS2) nanoflake/g-C3N4 hollow nanotube (MoS2/g-C3N4 nanotube) photocatalysts. The MoS2/g-C3N4 nanotube composite with 15 wt% MoS2 shows the highest hydrogen (H2) production rate (1124 µmol·h-1·g-1), much higher than bulk g-C3N4 (64 µmol·h-1·g-1) and g-C3N4 nanotubes (189 µmol·h-1·g-1). The excellent photocatalytic activity of MoS2/g-C3N4 nanotube composites can be ascribed to more exposed active edges of 2D-1D structure, multiple light reflection/scattering channels of 2D nanoflake/1D hollow nanotube composite structure and better carrier transfer and separation by heterojunction interface.

TiO2 nanobelts with anatase/rutile heterophase junctions for highly efficient photocatalytic overall water splitting.

Herein, we report surface coarsened titanium dioxide (TiO2) nanobelts with anatase/rutile heterophase junctions via a facile hydrothermal/calcination method for simultaneous hydrogen (H2) and oxygen (O2) productions from pure water, with excellent production rates of 0.614 and 0.297 mmol h-1 g-1 with platinum (Pt)/cobalt phosphide (CoP) as cocatalysts, respectively. Besides, the TiO2 nanobelts-900 °C with anatase/rutile heterophase junctions show a notable improvement in photocatalytic H2 and O2 production than pure anatase TiO2 nanobelts (TiO2 nanobelts-600 °C, 700 °C and 800 °C) and pure rutile TiO2 nanobelts (TiO2 nanobelts-1000 °C). The anatase/rutile heterophase junctions could effectively stimulate the transfer of electrons from rutile to anatase and then to Pt, and H2 generation on the surface of Pt. In the meantime, the holes can be transferred from anatase to rutile and then to CoP, and water oxidation on CoP's surface.

Sulfur Vacancy-Rich O-Doped 1T-MoS2 Nanosheets for Exceptional Photocatalytic Nitrogen Fixation over CdS.

Here, we reported that sulfur vacancy-rich O-doped 1T-MoS2 nanosheets (denoted as SV-1T-MoS2) can surpass the activity of Pt as cocatalysts to assist in the photocatalytic nitrogen fixation of CdS nanorods. SV-1T-MoS2 cocatalysts exhibit sulfur vacancies, O-doping, more metallic 1T phase, and high electronic conductivity, thus leading to the exposure of more active edge sites, high Brunauer-Emmett-Teller surface area, enhanced visible light absorption, and improved electron separation and transfer, which are beneficial for photocatalytic nitrogen fixation. Consequently, the optimized 30 wt % SV-1T-MoS2-/CdS composites exhibit an outstanding nitrogen fixation rate of 8220.83 µmol L-1 h-1 g-1 and long-term stability under simulated solar light irradiation, significantly higher than pure CdS nanorods, CdS-Pt (0.1 wt %), and 30 wt % 1T-MoS2/CdS composites. The catalytic mechanism of photocatalytic nitrogen fixation on SV-1T-MoS2 is discussed by density functional theory calculations.

The Emerging Roles of Fox Family Transcription Factors in Chromosome Replication, Organization, and Genome Stability.

The forkhead box (Fox) transcription factors (TFs) are widespread from yeast to humans. Their mutations and dysregulation have been linked to a broad spectrum of malignant neoplasias. They are known as critical players in DNA repair, metabolism, cell cycle control, differentiation, and aging. Recent studies, especially those from the simple model eukaryotes, revealed unexpected contributions of Fox TFs in chromosome replication and organization. More importantly, besides functioning as a canonical TF in cell signaling cascades and gene expression, Fox TFs can directly participate in DNA replication and determine the global replication timing program in a transcription-independent mechanism. Yeast Fox TFs preferentially recruit the limiting replication factors to a subset of early origins on chromosome arms. Attributed to their dimerization capability and distinct DNA binding modes, Fkh1 and Fkh2 also promote the origin clustering and assemblage of replication elements (replication factories). They can mediate long-range intrachromosomal and interchromosomal interactions and thus regulate the four-dimensional chromosome organization. The novel aspects of Fox TFs reviewed here expand their roles in maintaining genome integrity and coordinating the multiple essential chromosome events. These will inevitably be translated to our knowledge and new treatment strategies of Fox TF-associated human diseases including cancer.

Porous graphitic carbon nitride with nitrogen defects and cobalt-nitrogen (CoN) bonds for efficient broad spectrum (visible and near-infrared) photocatalytic H2 production.

The porous graphitic carbon nitride (g-C3N4) with nitrogen defects and cobalt-nitrogen (CoN) bonds (g-C3N4-Co-K) is prepared by controllable copolymerization of melamine with KOH and Co(NO3)2·6H2O. The method not only provides g-C3N4 with porous structure and CoN bonds that accelerate photoexcited carrier transfer and endow numerous active sites, but also redshifts the g-C3N4 absorption edge into near-infrared (NIR) light region through the introduction of nitrogen defects and thus is suitable for H2 evolution. The g-C3N4-Co-K exhibits significantly superior photocatalytic hydrogen generation performance (808 µmol h-1 g-1) under simulated solar light irradiation, about 15.5 times higher than pure g-C3N4, about 5.2 times higher than g-C3N4 with CoN bonds (g-C3N4-Co), and about 2.1 times higher than g-C3N4 with nitrogen defects (g-C3N4-K). Interestingly, it is for the first time revealed that the synergistic effect of nitrogen defects and CoN bonds result in enhanced H2 generation activity (470 µmol h-1 g-1) under NIR light irradiation.

Boosting the Photocatalytic Ability of g-C3N4 for Hydrogen Production by Ti3C2 MXene Quantum Dots.

The big challenging issues in photocatalytic H2 evolution are efficient separation of the photoinduced carriers, the stability of the catalyst, enhancing quantum efficiency, and requiring photoinduced electrons to enrich on photocatalysts' surface. Herein, Ti3C2 MXene quantum dots (QDs) possess the activity of Pt as a co-catalyst in promoting the photocatalytic H2 evolution to form heterostructures with g-C3N4 nanosheets (NSs) (denoted g-C3N4@Ti3C2 QDs). The photocatalytic H2 evolution rate of g-C3N4@Ti3C2 QD composites with an optimized Ti3C2 QD loading amounts (100 mL) is nearly 26, 3 and 10 times higher than pristine g-C3N4 NSs, Pt/g-C3N4, and Ti3C2 MXene sheet/g-C3N4, respectively. The Ti3C2 QDs increase the specific surface area of g-C3N4 and boost the density of the active site. Besides, metallic Ti3C2 QDs possess excellent electronic conductivity, causing the improvement of carrier transfer efficiency.

Gold nanorods/g-C3N4 heterostructures for plasmon-enhanced photocatalytic H2 evolution in visible and near-infrared light.

Recently, broad spectrum (visible and near-infrared (NIR)) light utilization has aroused widespread attention in the research of photocatalysis. While g-C3N4, highly stable, cheap and easily synthesized, shows H2 evolution activity under visible light irradiation, it doesn't perform under NIR light irradiation. Here we report an Au nanorods (NRs)/g-C3N4 heterostructure with Au nanorods on g-C3N4's surface. The most exciting feature of designed Au NRs/g-C3N4 heterostructures is that Au nanorods themselves are excited by visible and NIR light, which produce hot electrons and inject into g-C3N4. The photocatalytic H2 evolution rate of Au NRs/g-C3N4 heterostructures (350.6 µmol g-1 h-1) is nearly 4 times higher than that of g-C3N4 with Pt as cocatalyst (68.9 µmol g-1 h-1) under visible light illumination. The improved photocatalytic activity is ascribed to the increasing visible light-absorbing capacity of transverse surface plasmon resonance (TSPR) of Au nanorods and improved charge separation of Au NRs/g-C3N4 heterostructure. Even more important, Au NRs/g-C3N4 heterostructures achieve NIR photocatalytic H2 evolution performance (63.1 µmol g-1 h-1), owing to the longitudinal SPR (LSPR) effect of Au nanorods induced NIR light harvesting ability.

Porous g-C3N4 with nitrogen defects and cyano groups for excellent photocatalytic nitrogen fixation without co-catalysts.

The porous g-C3N4 with nitrogen defects and cyano groups (NC-g-C3N4) is prepared via an alkali-assisted heat treatment of urea. Alkali can break hydrogen bonds, which accelerate thermal polymerization of urea and formation of nitrogen defects/cyano groups. The presence of nitrogen defects extends the absorption of visible light to longer wavelengths region. The cyano groups can trap g-C3N4's photoinduced electrons and therefore suppress charge recombination. The formation of porous structure increases the surface area and exposes more active sites. As a consequence, compared to pure g-C3N4, NC-g-C3N4 shows boosted visible photocatalytic nitrogen fixation activity (1.59 mmol h-1 g-1) without co-catalysts.

Metallic 1T-phase MoS2 quantum dots/g-C3N4 heterojunctions for enhanced photocatalytic hydrogen evolution.

Recently, molybdenum disulfide (MoS2) has been regarded as an efficient non-precious-metal co-catalyst for photocatalytic hydrogen (H2) evolution, however, its inherent low-density active site and poor electron transfer efficiency have essentially limited its photocatalytic properties. Here we report that 1T-MoS2 quantum dots (QDs) can act as co-catalysts in assisting the photocatalytic H2 evolution to form heterostructures with g-C3N4 nanosheets (denoted as 1T-MoS2 QDs@g-C3N4). Benefiting from the abundance of exposed catalytic edge sites and the excellent intrinsic conductivity of 1T-MoS2 QDs, an optimized 1T-MoS2 QD@g-C3N4 composite (15 wt%) exhibits an extraordinary photocatalytic H2 evolution rate of 1857 µmol h-1 g-1 under simulated solar light irradiation, apparently 37.9 times higher than that of pure g-C3N4 NSs (49 µmol h-1 g-1). Meanwhile, the 1T-MoS2 QD@g-C3N4 composites exhibit a good stability in the cyclic runs for the photocatalytic H2 production. The high efficient photocatalytic activity and stability of the 1T-MoS2 QD@g-C3N4 composite is primarily attributed to the following reasons: (1) the introduction of 1T-MoS2 QDs results in a stronger light absorption capability in comparison with pure g-C3N4; (2) the tiny particle size of 1T-MoS2 QDs, in which edges and basal surface are catalytically active, provides a proliferated density of catalytically active sites; (3) 1T-MoS2 QD co-catalysts with metallic characteristics could act as efficient electron acceptors, which builds up a highly efficient pathway for photo-generated electrons from the CB of g-C3N4 NSs to 1T-MoS2 and thus realizes rapid spatial charge separation. The improved light harvesting ability, increased catalytically active sites, as well as increased separation of charge carriers could be responsible for the improved photocatalytic H2 evolution. This work will provide new insight for the design and fabrication of smarter, cheaper and more robust artificial photocatalysts for photocatalytic H2 evolution.

Integrating the Z-scheme heterojunction into a novel Ag2O@rGO@reduced TiO2 photocatalyst: Broadened light absorption and accelerated charge separation co-mediated highly efficient UV/visible/NIR light photocatalysis.

A photocatalyst with good electron-transfer property and wide spectrum response is of great interest. Herein, visible/NIR-light-driven Ag2O nanoparticles (NPs) and UV/visible-responsive reduced TiO2 nanosheets (TiO2-x NSs) anchored onto reduced graphene oxide (rGO) forming Ag2O@rGO@TiO2-x composites are synthesized in this study. The as-synthesized Ag2O@rGO@TiO2-x composites exhibit a superior full solar spectrum (UV, visible and NIR) response, showing their potential for effective use of solar energy. Compared to single component (TiO2 NSs and Ag2O NPs) or binary composites (Ag2O@TiO2), Ag2O@rGO@TiO2-x ternary composite has exhibited improved photocatalytic activity under UV, visible, NIR and nature sunlight irradiation and excellent photostability. The outstanding photocatalytic performance of Ag2O@rGO@TiO2-x composites depends on three sides: firstly, synergistic effect among the reduced TiO2, Ag2O, and rGO improves the wide spectrum response ability; Secondly, Ag2O@rGO@TiO2-x builds a Z-scheme structure, which promotes the separation of electron/hole pairs and retains prominent redox ability; Thirdly, the electrons of Ag2O are transferred to rGO to suppress the photo-corrosion of Ag2O during the photocatalytic process and the stability of Ag2O@rGO@TiO2-x composite has been enhanced greatly.

Photocatalytic H2 Evolution on TiO2 Assembled with Ti3C2 MXene and Metallic 1T-WS2 as Co-catalysts.

The biggest challenging issue in photocatalysis is efficient separation of the photoinduced carriers and the aggregation of photoexcited electrons on photocatalyst's surface. In this paper, we report that double metallic co-catalysts Ti3C2 MXene and metallic octahedral (1T) phase tungsten disulfide (WS2) act pathways transferring photoexcited electrons in assisting the photocatalytic H2 evolution. TiO2 nanosheets were in situ grown on highly conductive Ti3C2 MXenes and 1T-WS2 nanoparticles were then uniformly distributed on TiO2@Ti3C2 composite. Thus, a distinctive 1T-WS2@TiO2@Ti3C2 composite with double metallic co-catalysts was achieved, and the content of 1T phase reaches 73%. The photocatalytic H2 evolution performance of 1T-WS2@TiO2@Ti3C2 composite with an optimized 15 wt% WS2 ratio is nearly 50 times higher than that of TiO2 nanosheets because of conductive Ti3C2 MXene and 1T-WS2 resulting in the increase of electron transfer efficiency. Besides, the 1T-WS2 on the surface of TiO2@Ti3C2 composite enhances the Brunauer-Emmett-Teller surface area and boosts the density of active site.