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Red tides not only destroy marine ecosystems but also pose a great threat to human health. The traditional anti-red tide materials are difficult to degrade effectively in the natural environment and there may be risks of environmental leakage and secondary pollution. Furthermore, they cannot reduce the toxicity of toxins released by algae. It is very important to prepare degradable materials that can effectively control red tide and reduce their toxins in the future. Herein, degradable CDs (De-CDs) with biocompatibility and non-toxicity is successfully prepared using the one-step electrolytic method. De-CDs can effectively inhibit P. globosa (algae associated with red tide) growth. More importantly, the De-CDs not only can attenuate the toxicity of toxins released by P. globosa , but also can be degraded under visible-light irradiation in the seawater and avoids environmental leakage. The successful preparation of De-CDs provides a new idea for degradable materials with anti-red tide algae in the future. [Display omitted] • An environmentally friendly degradable De-CDs was prepared on a macroscale by a simple method. • De-CDs shows effective anti-red tide algae activity against P. globosa. • De-CDs could reduce the toxicity of hemolytic toxins released by red tide algae. • De-CDs can be degraded under visible light irradiation in seawater. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) with enzyme-like activities play crucial roles in nanobiotechnology. However, it is difficult to establish a relationship between their structure and biocatalytic properties. In this work, a series of nitrogen-doped carbon dots (TA-NCDs) were synthesized by a hydrothermal method. Their oxidase-like activity could be triggered by visible light irradiation (420 nm≤λ ≤ 700 nm). As a nanozyme, TA-NCDs show the value of maximum reaction rates (V max) is 121.95 × 10−8 M/s and the Michaelis–Menten constants (K m) is 0.61 mM. In situ transient photovoltage (TPV) tests prove that the pyrrolic nitrogen in TA-NCDs is the catalytic active sites and substrate binding sites. Under visible light irradiation, TA-NCDs, with oxidase-like activity, increased the cellular ROS level significantly, leading to their visible light induced bioactivity to kill nearly 60% of HeLa cells. Pyrrolic nitrogen dominated the mimic oxidase activity of CDs. [Display omitted] • TA-NCDs exhibit oxidase-like activity under visible light irradiation. • The maximum velocity of TA-NCDs is 121.95 × 10−8 M/s, implying TA-NCDs show higher catalytic activity than natural enzyme. • In situ TPV test was used to explore the active sites of TA-NCDs. • The application of TA-NCDs in physiological environments was confirmed. [ABSTRACT FROM AUTHOR]

Supercritical water fluidized bed is a novel gasification reactor which can achieve efficient and clean utilization of coal. The rough surface of particle produced during grinding and thermochemical conversion processing will deeply affect supercritical water-particle two-phase flow and heat transfer characteristics. In this paper, fully resolved numerical simulation of supercritical water flow past single rough sphere particle with the Reynolds number ranging from 10 to 200 was carried out to investigate the effect of surface roughness. The simulation results show that as roughness increases, the separation bubbles generated in the dimple enhance the flow separation but has no significant effect on the drag coefficient. Particle surface-average Nusselt number decreases with an increase of roughness and surface enlargement coefficient due to the isolation effect at low Re and local separation bubbles in the dimple at high Re. Furthermore, the effect of surface enlargement coefficient on heat transfer efficiency factor for supercritical water near the critical point is greater than that under constant property condition and has a higher dependence on Re. [ABSTRACT FROM AUTHOR]

Abstract Supercritical water fluidized bed (SCWFB) is a novel reactor which can achieve efficient and clean gasification of biomass. The study of supercritical water (SCW)-solid two-phase flow characteristics in SCWFB is of great significance for biomass conversion and optimization of the reactor. However, the work on the drag coefficient of single biomass particle and biomass particle cluster has limitations to describe the interactions between particles accurately. In this paper, two-particle model was used to study the drag coefficient and flow characteristics of supercritical water flow past biomass particle cluster in the range of 10 < Re < 200. The simulation results show the interactions between particles can transmit larger distances perpendicular to the flow field at low Re. Drag coefficient of particles is mainly affected by the wake zone generated behind the upstream particles and nozzle effect between particles. Nozzle effect which is significant at high Re will promote flow separation and make form drag and friction drag increase. And the wake zone generated behind the upstream particles has the opposite effect. Highlights • Momentum of SCW flow past two biomass spherical particles were studied. • Effects of Re and relative position of biomass particles were discussed. • The influence factors for C D and fluid field were discussed. [ABSTRACT FROM AUTHOR]

Carbon dots, as one of carbon-based nanomaterials, with excellent fluorescent properties and low toxicity show great potential in bio-science and bio-technology. Here, we grew mung bean sprouts with different concentration of carbon dots (CDs) and studied the plant growth and photosynthesis. We found CDs show a dose-response effect on the growth of mung bean sprouts, including root elongation, stem elongation and biomass. CDs at optimal concentration also promote the root vigor and moisture level of seeds, which may have led to the promotion of plant growth and development. Moreover, mung bean sprouts treated with CDs exhibit an increase up to 21.9% in carbohydrates content compared to the control. We assumed that the increase of carbohydrates might be related to the role of CDs in photosynthesis. Further investigation revealed that CDs can enhance the photosystem activity by improving the electron transfer rate. CDs treatment also affect other critical indicators in photosynthesis, such as chlorophyll content and rubisco activity. These findings show considerable promise in biological research and agriculture production. [ABSTRACT FROM AUTHOR]

The poor cycling stability and inferior rate capability of the cathodes critically restrict the application of sodium ion batteries (SIBs). Herein, we propose a strategy to optimize the electrochemical performances of P2-Na 0.7 Mn 0.75 Fe 0.25-x-y Ni x Co y O 2 cathode materials for SIBs through modulating the crystal structure with a synergistic substitution of Fe by Ni and Co. The structure-performance relationship and the synergistic improvement mechanism have been unraveled by means of x-ray diffraction, neutron diffraction and electrochemical techniques. The synergistic substitution of Fe by Ni and Co leads to the enlargement of the interlayer spacing and the Na-O bond length, and shrinks the TM-O and O-O bonds, which enhances the sodium ion diffusion coefficient, the rate capability and the cycling stability. In addition, Jahn–Teller effect is also alleviated owing to the reduction of Mn 3+ , which can further enhance the stability of the layered structure. Ni and Co co-doped Na 0.7 Mn 0.75 Fe 0.15 Ni 0.05 Co 0.05 O 2 (FNC) cathode shows a relatively smooth charge-discharge curve in 1.5–4.2 V and demonstrates a much better rate performance in compared to Na 0.7 Mn 0.75 Fe 0.25 O 2 (MF), Na 0.7 Mn 0.75 Fe 0.15 Ni 0.1 O 2 (FN) and Na 0.7 Mn 0.75 Fe 0.15 Co 0.1 O 2 (FC). At a high current density of 1C, 2C, 5C and 10C, FNC can still deliver a reversible capacity of 127, 109, 83 and 58 mAh g −1 , respectively. FNC also provides a higher reversible capacity of 181 mAh g −1 at 0.1C with a high cycling stability. This study offers some new insights into designing high performance cathode materials for SIBs through cooperatively modulating the crystal structure with multi-elements doping. [ABSTRACT FROM AUTHOR]

• MP emulsion gel was prepared with one-step homogenization for use as lipid carriers. • MP emulsion gel had great stability and high G′ after heating and freezing. • Surimi products had great stability and low gel strength when lipid content hit 35%. • Dual emulsification of MP in emulsion gel and surimi were keys to stable lipid. In this study, surimi products rich in lipids were prepared by using myofibril protein (MP) emulsion gel as carriers. The MP emulsion gel (MP concentration, c = 1.5%, oil fraction, ø = 0.68) was prepared by one-step homogenization. The emulsion gel maintained a high elastic modulus (G′) after heating and freezing treatment. Confocal laser scanning microscopy revealed that the structure of the emulsion gel was a hybrid network consisting of polymers of cross-linked MP and aggregated protein-stabilized emulsion (W/O/W multiple structures) droplets. The double emulsification of the emulsion gel and MP stabilized the oil droplets in the surimi product, preventing water and oil from leaching out. The microstructure also showed smaller gaps between MPs with increased porosity, while oil droplets were stably embedded in the surimi gel matrix. Moreover, adding MP emulsion gel significantly reduced the surimi gel strength compared to adding oil directly (p < 0.05). [ABSTRACT FROM AUTHOR]

Coaxial fiber-shaped Zn-ion hybrid supercapacitors (CFZHSCs) with high power/energy density, long cycle life, splendid mechanical stability, and high safety are promising electrochemical energy storage devices for flexible and wearable electronics. However, the poor electrochemical performance of Zn anode severely restricts their practical application. To address this challenge, a highly reversible fiber-shaped Zn anode with controlled deposition morphology is developed based on theoretical calculation guided design of highly zincophilic 3D metal-organic-frameworks derived carbon with N- and OH-containing functional groups (N,O-MOFC) scaffold, by regulating electroplating chemistry of the initial nucleation and crystal growth time of zinc metal. Benefitting from fast ion diffusion ability of the hierarchically nanostructured 3D Zn/N,O-MOFC anode on the carbon nanotube fiber (CNTF), the assembled CFZHSCs device achieves a large volumetric specific capacitance of 128.06 F cm−3 and a high volumetric energy density of 57.63 mWh cm−3, surpassing the state-of-the-art FZHSCs device. More impressively, the efficient rechargeable capability of the fiber-shaped Zn anode also enables an adequately stable CFZHSCs device with the capacitance retention of 99.20% after 10,000 charge/discharge cycles and remarkable mechanical flexibility. As a conceptual demonstration of system integration, the as-fabricated CFZHSCs device is integrated with triboelectric nanogenerator (TENG) yarn to achieve the self-powered textile-based monitoring systems to stably detect temperature variation. The constructed coaxial fiber-shaped Zn-ion supercapacitor realize the self-powering textile-based energy-sensor to stably monitor the temperature of the human body. [Display omitted] • We construct a reversible fiber-shaped Zn anode by regulating the initial nucleation and crystal growth time of zinc metal. • The assembled CFZHSCs device achieves a large specific capacitance 128.06 F cm−3 and a high energy density 57.63 mWh cm−3. • The CFZHSCs device embraces the excellent cyclic stability and remarkable mechanical flexibility. • The CFZHSCs device is integrated with TENG yarn to achieve the self-powered textile-based monitoring systems. [ABSTRACT FROM AUTHOR]

In this work, natural convection and temperature distribution of supercritical water in a side-wall heated cavity are studied by numerical simulation. Different from ordinary single-vortex flow of perfect gas, supercritical water shows a thinner boundary layer with much higher velocity and finally forms a double-vortex natural convection pattern in the cavity. Moreover, for supercritical water, the temperature near the top wall of the cavity will exceed that of the heating wall, which is called overheating. Temperature, pressure, temperature difference between wall and fluid and aspect ratio will all affect velocity and temperature in the cavity. The mechanism analysis shows that the unique physical properties of supercritical water are vital reasons affecting the buoyancy driven flow boundary layer. The strong flow boundary layer will further lead to double-vortex flow pattern and overheating phenomenon, which will also affect natural convection pattern and temperature distribution. [Display omitted] • Unique natural convection and temperature distribution characteristics are observed. • Affecting factors of velocity and temperature are studied. • Physical properties will change flow pattern and temperature distribution. [ABSTRACT FROM AUTHOR]

Carbon dots modified WO 2 -Na x WO 3 composite was designed as UV-Vis-NIR broad spectrum-driven photocatalyst for overall water splitting. • Broad spectrum-driven WO 2 -Na x WO 3 -CDs photocatalyst can achieve overall water splitting. • The WO 2 -Na x WO 3 -CDs with 0.008 g CDs show the highest photocatalytic activity. • The H 2 /O 2 evolutions by WO 2 -Na x WO 3 -CDs show the stoichiometric ratio. • The WO 2 -Na x WO 3 -CDs shows excellent stability for about 6 cycles of repetitive experiments. • The photocataytic activity should ascribe to the synergistic effect of WO 2 -Na x WO 3 and CDs. The utilization of solar energy and valid photocatalyst is one of the most effective strategies to achieve water splitting into hydrogen (H 2) and oxygen (O 2). Although enormous effort has been devoted to photocatalysts, the sunlight still cannot be fully utilized by the developed photocatalysts. It is important but remains challenging to develop a broad spectrum-driven photocatalyst for overall water splitting. Here, we design a UV-Vis-NIR broad spectrum-driven carbon dots modified WO 2 -Na x WO 3 (WO 2 -Na x WO 3 -CDs) composite as photocatalyst for overall water splitting without requirement of any sacrificial agents or cocatalysts. When the concentration of CDs in the sample is 0.008 g CDs /g catalyst , the WO 2 -Na x WO 3 -CDs shows the highest photocatalytic activity with stoichiometric ratio of H 2 /O 2 evolutions and their rates are 0.05/0.02, 2.58/1.24, 4.74/2.28 μmol/h under UV (λ < 420 nm), visible (420 nm≤λ ≤ 760 nm) and near-infrared (λ > 760 nm) light irradiation, respectively. It is also impressive that the photocatalyst shows excellent stability for about 6 cycles of repetitive experiments. The WO 2 -Na x WO 3 -CDs composites functioned as broad spectrum-driven photocatalyst for overall water splitting should attribute to the synergistic effect of WO 2 -Na x WO 3 and CDs, in which the WO 2 -Na x WO 3 provides the suitable bandgap, while the CDs can enhance light absorption and accelerate separation efficiencies of photo-generated charge carriers. [ABSTRACT FROM AUTHOR]

Removal of antibiotics from aqueous solutions by photocatalysis is an advanced technology for environmental remediation. Herein, we have fabricated a series of AgX (X = I, Br)/CuBi 2 O 4 composites through an in-situ precipitation method. The photocatalytic activity of the obtained photocatalysts was measured by the degradation of tetracycline (TC) under visible light irradiation (λ > 420 nm). All the AgX (X = I, Br)/CuBi 2 O 4 composites exhibit much higher photocatalytic activity than that of pure CuBi 2 O 4 . The enhanced photocatalytic activity is mainly attributed to the efficient interfacial charge separation and migration in the AgX (X = I, Br)/CuBi 2 O 4 heterojunctions. Meanwhile, AgX (X = I, Br)/CuBi 2 O 4 heterojunctions display excellent photocatalytic stability, and the photocatalytic degradation rates were not obvious decreased even after five successive cycles. Based on the energy band structure, the radicals trapping and electronic spin resonance (ESR) experiments, the Z-scheme mechanism of AgBr/CuBi 2 O 4 and type II mechanism of AgI/CuBi 2 O 4 heterojunction photocatalysts were tentatively discussed, respectively. [ABSTRACT FROM AUTHOR]

Widely used synthetic dyes have been caused serious environmental pollution. Therefore, it is imperative to acquire highly efficient adsorbent to remove them. Here, we report the carbon dots/ZnFe 2 O 4 (CDs/ZFO) composites were prepared through a facile hydrothermal route for absorption removal of dye from aqueous solution. The characterizations reveal the CDs were uniformly deposited on the surfaces of ZFO nanoparticles in the composite. The CDs/ZFO composites as adsorbents exhibit enhanced adsorption behavior for methyl orange (MO) in comparison of pristine ZFO, in which the 5% CDs/ZFO (with the CDs mass content of 5 wt%) shows the highest absorption activity. Experimental studies on adsorption isotherms of MO over the 5% CDs/ZFO composite indicate that experimental data were found to follow Langmuir model with a monolayer adsorption capacity of 181.2 mg g −1 . The corresponding adsorption kinetics was fitted well with the pseudo-second-order kinetic model. Moreover, thermodynamics parameters including ΔG°, ΔH° and ΔS° were tested, demonstrating that the adsorption of MO over CDs/ZFO composite was spontaneous and exothermic in nature. The remarkably increased adsorption performance of CDs/ZFO composites can be attributed to abundant oxygen-containing groups on the surface of CDs. [ABSTRACT FROM AUTHOR]

• Numerical study on flow and heat transfer of SCW flow around particle pair with Stefan flow. • The fluid-particle interactions with different particle pair configurations under the Stefan flow. • The analysis of flow field, force, and heat transfer process around particles. For any flow process of mixtures containing dispersed reactive particles, especially highly concentrated particles, the particle-particle, and fluid-particle interactions are very complex and affect the overall flow. Supercritical water gasification technology is a complex multiphase-flow process that occurs in high-temperature reactors. Under these conditions, the components of the particle surface are heated and gasify to form a Stefan flow (i.e., a mass flow), which modifies fluid-particle interactions. The interaction between particles and the influence of Stefan flow cannot be ignored. In this work, we consider the simplest case of two identical spherical particles with different relative orientations and particle distances and discuss the flow and fluid-particle heat-transfer characteristics by numerical simulation of supercritical water flowing around the fixed two-particle system. We are particularly interested in the fluid-particle interactions with different particle configurations under the influence of Stefan flow. Three particle configurations are possible: tandem, cross, and parallel. The flow field, Nusselt number, drag coefficient, and temperature distribution around the particles are all analyzed. In comparison with a single particle, the two-particle configurations significantly affect the drag coefficient, Nusselt number, and vortex structure and Stefan flow strongly affects the wake vortex structure of two particles with small particle distance, reducing the drag coefficient and Nusselt number. [ABSTRACT FROM AUTHOR]

• Effect of particle wake on heat flux ratio in supercritical water is studied. • Mechanism of effect of Reynolds number and distance on heat flux ratio is studied. • Effect of variation of physical properties on heat flux ratio is studied. • New correlation is established for heat flux ratio in supercritical water. The effect of particle wake on the heat transfer characteristics between interactive particles in supercritical water is simulated and analyzed. The main influencing factors include particle distance, Reynolds number (Re), particle temperature and pressure. It is found that the distance and Re affect the strength of wake vortex and the temperature gradient on the trailing particle surface. For the effect on the heat transfer characteristics, the temperature gradient is dominant, and the vorticity has an obvious effect within a certain Re and distance range. Temperature and pressure affect the physical properties in the particle wake. The physical property changes on the trailing particle surface are smoother affected by the leading particle. A new statistically significant heat transfer ratio correlation is established for interactive particles in supercritical water. The maximum error of this correlation is 7.3%. [ABSTRACT FROM AUTHOR]

• Heat transfer between two particles and supercritical water are studied. • Changes in physical properties have no special effect on heat transfer trend. • Heat transfer rate is affected by temperature gradient and physical properties. [Display omitted] This work takes two particles as an example to study the effect of distance and angle between two particles on the average Nusselt number Nu , average heat transfer rate η b , local Nusselt number Nu φ, and local heat transfer rate η aφ. It was found that the variation trend of Nu and Nu φ in supercritical water is the same as that in constant property flow, thus indicating that the variation trend of heat transfer between particles and fluid in supercritical water is the same as in constant property flow. The change in physical properties of supercritical water does not have any special effect on the variation trend of heat transfer. The heat transfer is mainly affected by the overlap of temperature field and the overlap of flow field. However, the results of η b and η aφ indicate that the variation trend of heat transfer rate is affected by temperature gradient changes and physical property changes. [ABSTRACT FROM AUTHOR]

Purpose Hyperglycemia is the high risk factor of vascular remodeling induced by angioplasty, and neointimal hyperplasia is strongly implicated in the pathogenesis of vascular remodeling caused by carotid artery balloon injury. Studies have shown that MicroRNA 24 (miR-24) plays an important role in angiocardiopathy, However, the role of miR-24 is far from thorough research. In this study, we investigate whether up-regulation of miR-24 by using miR-24 recombinant adenovirus (Ad-miR-24-GFP) can inhibit PDGF-BB signaling pathway and attenuate vascular remodeling in the diabetic rat model. Methods Male Sprague-Dawley rats (n = 60) were randomly divided into 5 groups and fed with high sugar and high fat diet (Sham, Saline, Scramble, Ad-miR-24 groups), or ordinary diet (Control group). The front four groups were treated with streptozotocin (STZ) four weeks later and the blood glucose level was closely monitored. After the successful establishment of diabetic rats, the external carotid artery was injured by pressuring balloon 1.5 after internal carotid artery ligation, then the blood vessels were harvested 14 days later and indexes were detected including the following: HE staining for the level of vascular intima thickness, immunohistochemical detection for PCNA and P27 to test the proliferative degree of vascular smooth muscle cells (VSMCs), qRT-PCR for the level of miR-24, RAS,PDGF-R, western blot for the protein levels of JNK1/2, p- JNK1/2, ERK1/2, p-ERK1/2, RAS, PDGF-R, AP-1,P27 and PCNA. Serological detection was conducted for TNF-α, IL-6, IL-8. Results The delivery of Ad-miR-24 into balloon injury site has significantly increased the level of miR-24. Up-regulation of miR-24 could regulate vascular remodeling effectively, lower the level of inflammatory factors, inhibit the expression of mRNA and protein levels of JNK1/2, ERK1/2, RAS, PDGF-R, AP-1, P27, PCNA. Conclusion miR-24 can inhibit the expression of AP-1 via the inhibition of PDGF-BB signaling pathway, thus inhibit VSMCs proliferation and vascular remodeling. [ABSTRACT FROM AUTHOR]

Dysfunction of vascular smooth muscle cells (VSMCs) performs a key role in the pathogenesis of diabetic vascular disease. Recent studies have reported that microRNA-24 (miR-24) may be implicated in diabetes and atherosclerotic vascular diseases. This study was designed to explore the role of miR-24 on VSMC proliferation and migration under high glucose conditions mimicking diabetes, and reveal the underlying mechanism. VSMCs were isolated from rat thoracic aortas, treated with normal glucose (NG, 5.5 mM) or high glucose (HG, 30 mM) during an incubation period. Cell viability, proliferation and migration were detected by trypan blue staining, BrdU incorporation assay and transwell chamber assay. Gene and protein expression were analyzed by qRT-PCR and Western blot respectively. We also used electrophoretic mobility shift assay (EMSA) to detect nuclear factor kappaB (NF-κB) DNA binding. TNF-α and IL-6 levels were determined by enzyme-linked immunosorbent assay. The results showed that adenovirus-mediated miR-24 overexpression significantly inhibited HG-stimulated VSMC proliferation and migration. Meanwhile, high mobility group box-1 (HMGB1) as a target of miR-24, was also markedly suppressed after miR-24 transfection. Additionally, NF-κB nuclear translocation and DNA binding, TNF-α and IL-6 production were all decreased associated with the down-regulation of HMGB1. The above data indicated that miR-24 is a crucial regulator of high glucose-induced proliferation and migration in VSMCs, and suggests that elevation of miR-24 in vascular system may be a novel therapeutic strategy to prevent the development of diabetic atherosclerosis. [ABSTRACT FROM AUTHOR]

Summary The hypoxic tumor microenvironment serves as a niche for maintaining the glioma-initiating cells (GICs) that are critical for glioblastoma (GBM) occurrence and recurrence. Here, we report that hypoxia-induced miR-215 is vital for reprograming GICs to fit the hypoxic microenvironment via suppressing the expression of an epigenetic regulator KDM1B and modulating activities of multiple pathways. Interestingly, biogenesis of miR-215 and several miRNAs is accelerated post-transcriptionally by hypoxia-inducible factors (HIFs) through HIF-Drosha interaction. Moreover, miR-215 expression correlates inversely with KDM1B while correlating positively with HIF1α and GBM progression in patients. These findings reveal a direct role of HIF in regulating miRNA biogenesis and consequently activating the miR-215-KDM1B-mediated signaling required for GIC adaptation to hypoxia. [ABSTRACT FROM AUTHOR]

Abstract: Recently, a group of microRNAs (miRNAs) were shown to be dysregulated in gliomas, and involved in glioma development. However, the effect of miRNA–miRNA functional networks on gliomas is poorly understood. In this study, we identified that FBJ murine osteosarcoma viral oncogene homolog (FOS)-mediated miR-181b/miR-21 signalling was critical for glioma progression. Using microarrays and quantitative RT-PCR (qRT-PCR), we found increased FOS in high grade gliomas. FOS depletion (via FOS-shRNA), inhibited invasion and promoted apoptosis in glioma cells. Using microarrays, combined with Pearson correlation analysis, we found FOS positively correlated with miR-21 expression. Reduction of FOS inhibited miR-21 expression by binding to the miR-21 promoter using luciferase reporter assays. Introduction of miR-21 abrogated FOS knockdown-induced cell invasion and apoptosis. Moreover, bioinformatics and luciferase reporter assays showed that miR-181b modulated FOS expression by directly targeting the binding site within the 3′UTR. Expression of FOS with a FOS cDNA lacking 3′UTR overrided miR-181b-induced miR-21 expression and cell function. Finally, immunohistochemistry (IHC) and in situ hybridisation (ISH) analysis revealed a significant correlation in miR-181b, FOS and miR-21 expression in nude mouse tumour xenograft and human glioma tissues. To our knowledge, it is the first time to demonstrate that miR-181b/FOS/miR-21 signalling plays a critical role in the progression of gliomas, providing important clues for understanding the key roles of transcription factor mediated miRNA–miRNA functional network in the regulation of gliomas. [Copyright &y& Elsevier]

Abstract: Aims: Gliomas account for 80% of malignant brain tumors. DNA damage response and subsequent checkpoint control pathways could maintain the integrity of the genome and thus defend tumorigenesis. Four kinases, ATM, ATR, ChK1 and Chk2 are the damage sensors and the early effectors in DNA damage responses. Given their importance, we investigated the transcriptional regulation of these four genes. Main methods: Tissues from ten normal brains and thirty human gliomas were utilized for mRNA analysis via real-time PCR. Another twelve normal brain tissues and forty gliomas were used for confirmation. Methylation-specific PCR (MSP) was used to determine the methylation status of the Chk2 promoter. Quantitative chromatin immunoprecipitation (ChIP) was used to measure the influence of methylation on Sp1 binding. Key findings: We found that the expression of ATR, ChK1 and Chk2 in gliomas was significantly down-regulated relative to the normal brain tissues. The most significant reduction of expression was of the Chk2 gene, whose expression was ∼10-fold decreased in gliomas (P <0.0001). Down-regulation of Chk2 was validated in the second real-time PCR analysis. This reduction in expression was partially due to promoter methylation. The Chk2 proximal promoter recruited Sp1 for transcriptional activation. We found that hypermethylation of the Chk2 promoter undermined the binding of the transcriptional factor Sp1. Significance: Our results indicate that Chk2 methylation could be involved in glioma carcinogenesis and Chk2 expression may potentially be used for the diagnosis of glioma. [Copyright &y& Elsevier]

Abstract: Glioblastoma multiform is the most common malignant primary brain tumor in adults, but there remains no effective therapeutic approach. 2-methoxyestradiol (2-ME), which is a naturally occurring metabolite of 17β-estradiol, was shown to enhance radiotherapeutic effect in certain tumors; however, whether 2-ME can also enhance the sensitivity of glioma cells to radiotherapy remains unknown. The present study, therefore, was to address this issue using two human glioma cell lines (T98G and U251MG). These cells were irradiated with and without 2-ME and then clonogenic assay, apoptosis assay, DNA damage, and cell cycle change were examined. Results showed that 2-ME significantly enhances radiation-induced cell death in both glioma cells, shown by decreasing cell viability and increasing apoptotic cell death. No such radiosensitizing effect was observed if cells pre-treated with Estrodiol, suggesting the specifically radiosensitizing effect of 2-ME rather than a general effect of estrodials. The enhanced radio-cytotoxic effect in glioma cells by 2-ME was found to be associated with its enhancement of G2/M arrest and DNA damage, and phosphorylated ATM protein kinases as well as cell cycle checkpoint protein Chk2. Furthermore, inhibition of ATM by ATM inhibitor abolished 2-ME-activated Chk2 and enhanced radio-cytotoxic effects. These results suggest that 2-ME enhancement of the sensitivity of glioma cell lines to radiotherapy is mediated by induction of G2/M cell cycle arrest and increased DNA damage via activation of ATM kinases. [Copyright &y& Elsevier]

Cobalt-doped highly mesoporous g-C 3 N 4 as efficient and stable photocatalysts for splitting water into H 2 and H 2 O 2. • A one-pot salt-assisted method is used to synthesize Co-doped mesoporous g-C 3 N 4. • The Co-mCN photocatalysts exhibit efficient and stable photocatalytic activity. • Co doping improves the charge separation efficiency and the tolerance against H 2 O 2. • The generated H 2 O 2 can be collected and directly applied in cyclohexane oxidation. Solar water splitting via graphitic carbon nitride (g-C 3 N 4) has achieved extensive attention in recent years. However, g-C 3 N 4 usually suffers from low efficiency and poor stability. Besides, the difficulty lying in the gas mixture separation remains as a big challenge. Herein, a one-pot salt-assisted method was proposed to fabricate the cobalt-doped highly mesoporous g-C 3 N 4 (Co-mCN) photocatalysts for efficient overall water splitting into H 2 and H 2 O 2. The adjustable Co doping not only improves the charge separation efficiency, but also enhances the tolerance of g-C 3 N 4 against H 2 O 2 poison. The optimal production for Co-mCN catalysts is gained to be 1.82 μmol h−1 and 1.65 μmol h−1 for H 2 and H 2 O 2 respectively, while an apparent quantum efficiency (AQE) of 2.2% at 420 nm and a working life for more than 216 h are also achieved. Moreover, it is demonstrated that the produced H 2 O 2 can be easily collected with titanium silicalite molecular sieve (TS-1) as a reusable H 2 O 2 carrier and directly applied in catalyzing cyclohexane oxidation into cyclohexanone and cyclohexanol mixture with 100% selectivity and 0.11% conversion efficiency. This work provides a new thinking and strategy for realizing overall water splitting, manipulating the products and extending the practical applications of g-C 3 N 4 materials in chemical industry. [ABSTRACT FROM AUTHOR]