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Black N doped TiO2-x nanoparticles loaded on the carbon framework (N–TiO2-x/C, NTC) were successfully fabricated by sol-gel method. In this work, the synthesized NTC material was combined with Cd0.5Zn0.5S (ZCS) short nanorods, forming a direct Z-scheme NTC/ZCS photocatalyst without using of electron mediator. The free radicals trapping experiment was also conducted through the degradation of RhB to determine photocatalytic mechanism. As a result, the 2% NTC/ZCS exhibited an optimal photocatalytic H2 production rate which is up to 36.6 mmol/h/g and about 5.2 times higher than that of pristine ZCS nanorods. The apparent quantum efficiency (AQE) of the 2% NTC/ZCS hybrids at wavelength 420 nm was calculated to 51.2%. Moreover, long-term drying increases the close contact between NTC and ZCS, and this firm contact interface can promote charge transfer and improve photocatalytic stability of NTC/ZCS composite.

In this work, a novel direct Z-scheme g-C3N5/Zn0.5Cd0.5S (CN/ZCS) heterojunction was successfully synthesized. Furthermore, its photocatalytic activity for hydrogen production was also investigated, whose photoluminescence spectrum revealed the charge transfer procedure of g-C3N5 and ZCS. Moreover, the optimized hydrogen production rate of ZCS with 15 wt% of g-C3N5 (15% CN/ZCS) was about 142.8 mmol/h/g and quantum efficiency (Q.E.) was circa 33.7% under 420 nm monochromatic light. Compared with the pure ZCS and ZCS with 2 wt% of Pt, the 15% CN/ZCS composite exhibited considerable improved hydrogen production rate, which was about 20 times and 7 times, respectively. The formation of CN/ZCS composite resulted in faster separation of the photogenerated electron-hole pairs. Our work may supply valuable data for the application of g-C3N5 on photocatalysis.

Quantum dots (QDs) have bright luminescence and excellent photostability. New synthesis techniques and strategies also enhance QDs properties for specific applications. With the continuous expansion of the applications, QDs-mediated immunotoxicity has become a major concern. The immune system has been confirmed to be an important target organ of QDs and is sensitive to QDs. Herein, review immunotoxic effects caused by QDs and the underlying mechanisms. Firstly, QDs exposure-induced modulation in immune cell maturation and differentiation is summarized, especially pre-exposed dendritic cells (DCs) and their regulatory roles in adaptive immunity. Cytokines are usually recognized as biomarkers of immunotoxicity, therefore, variation of cytokines mediated by QDs is also highlighted. Moreover, the activation of the complement system induced by QDs is discussed. Accumulated results have suggested that QDs disrupt the immune response by regulating intracellular oxidative stress (reactive oxygen species) levels, autophagy formation, and expressions of pro-inflammatory mediators. Furthermore, several signalling pathways play a key role in the disruption. Finally, some difficulties worthy of further consideration are proposed. Because there are still challenges in biomedical and clinical applications, this review hopes to provide information that could be useful in exploring the mechanisms associated with QD-induced immunotoxicity.

Recently, the use of silica nanoparticles (SiO2-NPs) and mesoporous silica nanoparticles (mSiO2-NPs) in the biomedical field, such as biosensors, drug deliveries and bioactivator carriers, is increasing due to their special physiochemical properties. However, the biosafety assessment of them is far lagging behind their rapid application. In this study, we observed that both SiO2-NPs and mSiO2-NPs with certain exposed doses decreased the cell viability while increased the apoptosis rates in the human pulmonary alveolar epithelial cells (HPAEpiC). Generally, mSiO2-NPs presented less toxic effects than SiO2-NPs with same treated dose, which assures the positive application prospect of mSiO2-NPs in the area of biomedicine. Since both SiO2-NPs could be taken into cells and accumulated in the endoplasmic reticulum (ER), which resulted in pathologically morphological changes and subcellular organelle damages, we hypothesized that the ER stress response could be involved in the NPs-induced apoptosis. The findings suggested that SiO2-NPs and mSiO2-NPs exposure increased the expression levels of two ER stress markers, e.g. BiP and CHOP, which could be inhibited by the ER stress inhibitor 4-PBA, following with decreased apoptosis rates in HPAEpiC. Even though it is still unclear of the direct target of NPs causing ER stress response following with cell apoptosis, our findings provide a novel insight for researchers to explore the toxic mechanisms of SiO2-NPs and mSiO2-NPs in order to reduce the adverse effects of them.

Wound dressings with multiple functions are required to meet the complexity of the wound healing process. The multifunctionality often leads to an increase in the complexity and difficulty in dressing preparation. To surmount this problem, we used a facile preparation and fabrication process to fabricate a multi-functional dressing by integrating four widely accessible materials: plain gauze, sodium alginate (SA), Ca2+ and Co2+. Firstly, mixed Ca2+/Co2+ ion solutions with different concentration were applied to gauzes. After drying, SA solution was added to ionized gauze and Co2+-Ca2+/Gauze/SA (Ion-GSA) composite dressings were formed easily. In vitro results showed that all Ion-GSA dressings exhibited strong mechanical properties, uniform dispersion and sustained release of Ca2+ and Co2+, and the ability to retain moisture and absorb wound exudate. Besides the above advantages, dressings prepared with 0.25 g/L Co2+ and 4 g/L Ca2+ (Co2+0.25-Ca2+4 GSA composite dressings) exhibited the best overall effect for inducing a hypoxia-like response, and favorable cytocompatibility, hemostatic property and antibacterial activity. In vivo wound healing assays revealed that Co2+0.25-Ca2+4 GSA composite dressings inhibited bacterial growth, increased local Hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), transforming growth factor-β1 (TGF-β1) protein expression, and accelerated full-thickness skin wound healing in mouse bacterial-infected wound model. The quick healing wounds had improved angiogenesis, macrophages regulation, re-epithelialization and dense collagen deposition. Collectively, our results indicated that Co2+0.25-Ca2+4 GSA composite dressings promote wound healing. Statement of Significance Wound dressings with integrated functionalities are required to meet complex clinical requirements. However, there is often a trade-off between reducing preparation complexity and increasing the multifunctionality of the dressing’s properties. In this study, we prepared multifunctional composite dressings by a facile preparation process using widely accessible materials. The composite dressings possessed the mechanical strength of gauze, had the effective wound exudate absorption, moisture maintenance and hemostatic property capacity of calcium alginate hydrogels, and had the hypoxia-like induction and the antimicrobial effects of Co2+. These functions all together promote bacteria-infected wound healing. Thus, we believed that the composite dressings can be widely applied in skin wound repair duo to their facile preparation method and good therapeutic effect.

In recent years, the cardiovascular toxicity of urban fine particulate matter (PM

Highly-efficient separation of adsorbent and pollutant from chemical sludge is urgent for the recycled materials and chemical resources and minimization of sludge production in industry. Herein, an effortless and cost-efficient salt/water system is developed for efficient zwitterionic polymer/dye separation from chemical sludge. To achieve this aim, a novel salt-tolerant zwitterionic polymer (STZP) is synthesized through etherifying 2-chloro-4,6-bis(4-carboxyphenyl amino)-1,3,5-triazine onto corn starch. It is found that "all-surface-area" adsorption of dye can be achieved by in-situ sol-gel transition of STZP. Spent polymer fluid and solid-state dye can be easily regenerated and separated from sewage sludge by a simple salt/water system. At a high NaCl concentration (225 g/L), the separation factor between zwitterionic polymer and dye is up to 50.4, which is 50 times larger than that of salt-free solution. More importantly, the regenerated polymer fluids exhibit an outstanding reusability ability and can maintain over 92.8% decoloration efficiency for dyeing effluent after multiple adsorption-desorption cycles. This study thus provides a technically feasible and economically acceptable strategy for the recycling and reuse of polymer from hazardous textile sludge waste, greatly promising to achieve zero emissions toward conventional adsorption units.

In this study, the repeated mutagenic effects of 60Co-γ irradiation combined with an optimized high-throughput screening method was applied to Chlorella pyrenoidosa to improve lipid productivity and characteristics for biodiesel. Two mutants of Chlorella pyrenoidosa, CP-232 and CP-269, were obtained. The lipid contents obtained from CP-232 and CP-269 were respectively increased by 20.8% and 20% under heterotrophic seed-photoautotrophic culture (HS-PC) model, and by 15% and 20.8% under photoautotrophic seed-photoautotrophic culture (PS-PC) model compared with the wild type strain in 1 L bubble column reactor. In addition, 60Co-γ irradiation mutagenesis increased the proportion of saturated fatty acids in lipids accumulated in CP-232 and CP-269 compared to the wild type strain. In 3 L and 15 L bioreactor scale-up, lipid productivity was equally significantly increased in both CP-232 and CP-269 mutant strains. Our findings indicated that 60Co-γ irradiation mutagenesis improves the accumulation of lipids with potential for industrial biodiesel production in mutant C. pyrenoidosa strains.

Airborne fine particulate matter (PM2.5) attracts more and more attention due to its environmental effects. The immune system appears to be a most sensitive target organ for the environmental pollutants. Inhaled PM2.5 can deposit in different compartments in the respiratory tract and interact with epithelial cells and resident immune cells. Exposed to PM2.5 can induce local or systematic inflammatory responses. This review focus on the effects of respiratory tract exposed to PM2.5. Firstly, we introduced the major emission sources, basic characteristics of PM2.5 and discussed its immunoadjuvant potential. Secondly, we elaborated the immune cells in the respiratory tract and the deposition of PM2.5 regarding the structural characteristics of the respiratory tract. Furthermore, we summarized the in vivo/vitro studies that revealed the immunotoxic effects of PM2.5 exposure to pulmonary cellular effectors and explored the contribution of PM2.5 exposure to the Th1/Th2 balance.

Elongated mullite was synthesized using mullite powder as a raw material and AlF3·3H2O as an additive, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The effects of AlF3·3H2O content and reaction temperature on the formation of elongated mullite were investigated, and the relevant growth mechanism was discussed based on the experimental results and density functional theory (DFT) calculations. When the optimal amount of AlF3·3H2O (4 wt% in the present work) was used, the length and diameter of elongated mullite increased with increasing the reaction temperature, and elongated mullite of 22.3 µm in average length and 4.6 µm in average diameter was formed after 5 h at 1873 K. Based on the results, elongated mullite self-reinforced porous ceramics were prepared by a combined foam-gelcasting and solid-reaction method, and their mechanical properties were examined. Elongated mullite in-situ formed in the porous samples evidently enhanced their mechanical strength. The flexural strength of the elongated mullite self-reinforced porous sample with 67.0% porosity (prepared using 6 wt% AlF3·3H2O) was as high as 13.9 MPa, which was about 26.4% higher than that of a porous sample (11.0 MPa) prepared without AlF3·3H2O.

A simple and sensitive three-dimensional voltammetric sensor was constructed for the determination of chloramphenicol (CAP). First, ordered mesoporous carbon was introduced onto a glassy carbon electrode to improve the electron transport performance, and then a polydopamine layer was formed on the surface to enhance the hydrophilicity and provide a negative charge to attract positively charged CAP. Finally, the electrode surface was modified through electrochemical polymerization with β-cyclodextrin, which contains abundant hydroxygroups to provide more hydrogen-bonding sites for CAP binding. The developed sensor was investigated with square wave voltammetry and cyclic voltammetry, and exhibited a rapid current response and high selectivity for CAP. Under optimal conditions, the method offered a wide current response for CAP from 5.0 × 10−7 to 5.0 × 10−4 mol L−1 and the limit of detection was 2.0 × 10−7 mol L−1. Milk powder and bee pollen samples spiked with CAP were extracted and then determined using the β-CD/CMK-3@PDA/GCE sensor with satisfactory recoveries of 80.0%-101.6%. The method was also used to determine CAP residues in real milk and honey samples, and the results correlated well with those obtained using high-performance liquid chromatography.

Two novel spirobifluorene derivatives containing arylamine groups, SPF-M and SPF-P were synthesized. As the protonation of the aromatic amine N atoms, SPF-M and SPF-P showed significant pH-dependent spectral properties. The pK a values are below 3.0 and they are suitable for extremely acid conditions. Under the UV light, SPF-M permit detection with the “naked eye” which makes it particularly attractive. To our knowledge, SPF-M and SPF-P represent the first examples that two-photon pH sensors were used to measure the extremely acidic pH value. When the pH is higher than 4.0, SPF-M and SPF-P exhibited strong one- and two-photon excited fluorescence and showed no dramatic spectral changes toward pH variations. Thus, the feasibility of SPF-M and SPF-P as multiphoton luminescence bioprobe under physiological conditions is demonstrated by two-photon scanning microscopy imaging experiments on 293T cells.

An environmentally friendly method of electrochemical mediated regioselective C-3 trifluoromethylation of 2H-indazole by employing CF3SO2Na as the CF3 source was described. This reaction tolerated various functional groups and provided C H trifluoromethylated products in moderate to good yields under transition metal-free and oxidant-free reaction conditions. Mechanism experiments showed that a radical process might be involved in this transformation.

Two-dimensional metal-semiconductor heterostructures with tunable Schottky barriers are currently attracting extensive interests, owing to their novel properties and potential applications in nanodevices. Here, heterostructures of semiconducting monolayer gold sulfides and graphene (Gr) with tunable Schottky barriers and contact types are reported based on first-principles calculations. α-, β-Au2S/Gr are n-type Schottky contacts with Φ n = 0.14 eV and 1.24 eV, respectively. They could be transformed into p-type Schottky contacts via applying vertically compressive strain. α-, β-, γ-AuS/Gr are ohmic, p-type and n-type Schottky contacts with Φ n = −0.34 eV, Φ p = 0.22 eV, Φ n = 0.22 eV, respectively. The ohmic contact of α-AuS/Gr evolves to a n-type Schottky contact with increasing vertically compressive strain, while the p-type Schottky contact of β-AuS/Gr changes to an ohmic contact. Furthermore, the mechanism of Schottky-barrier modulation via vertical strain underlies that the relative Dirac-cone position of Gr in heterostructures can be tuned by adjusting interfacial charge rearrangement. Benefitting from the tunable Schottky barriers and contact types, heterostructures of semiconducting monolayer gold sulfides and Gr are promising candidates for future-generation nano-devices.

The loess plateau of northern China has always been severely affected by drought and rainfall, impacting ecological integrity and sustainable development in particular. Super-absorbent polymers (SAPs) can relieve the pressure of water shortages and change the process of rainfall-runoff. In this study, SAPs were mixed with soil in percentages(weight ratio) of 0, 0.25%, 0.5%, 0.75%, 1% and 2%; then, these mixtures were applied in 5 cm depth layers in runoff plots of 5 m × 4 m for every treatment (T1, T2, T3, T4, T5). Artificial rainfall intensity was controlled at 40 mm/h, and the rainfall duration was 0.5 h when the soil physical and chemical properties were surveyed. With SAPs, the initial runoff time of different treatments increased by 21.5-102.7%; the amount of surface runoff decreased remarkably; the SAPs could reduce the loss of soil and water: the runoff reduction effect was 24.6% (T1), 41.5% (T2), 46.5% (T3), 50.7% (T4), and 60.6% (T5); the sediment reduction effect was very significant at 58.8% (T1), 74.1% (T2), 85.6% (T3), 80.9% (T4), and 75% (T5); and the lowest losses of total nitrogen (TN 0.09 kg), total phosphorus (TP 5.02 g) and total potassium (TK 0.08 kg) were measured in T3,with 14.9%, 14.2% and 13.1% that of the control (CK), respectively. The soil moisture content increased by 19.2%, 32.5%, 33.5% and 31.3% compared to CK in the different soil layers; SAPs could raise the soil temperature by 0.72 °C (T5) and lower the soil temperature by 0.53 °C (T5) in September and July, respectively. The aboveground biomass and underground biomass of the treatments increased by a maximum value of 84.4% in T3, which was 38% greater than CK, and the vegetation in T3 (44 kinds) was the most abundant and it was 69.2% more than CK (26 kinds). The effect was not always positively correlated with the percentage of SAPs. The application of SAPs in this study showed a comprehensive utility (soil erosion prevention, redistribution of soil water and temperature, maintenance of fertility and the synergy between SAPs and plants), which suggest that the most basic goal, to ensure socio-economic and ecological sustainability in dryland systems, is obtained.

As a fundamental study on the preparation of partially demineralized bone matrix, the demineralization of bovine bone granules was investigated. Bone granules were obtained by pulverizing with a highspeed blade mill and classified by sieving into three fractions. The lengths along major and minor axes of the individual granules were measured by image analysis to calculate the circle equivalent diameter and the aspect ratio as particulate properties. The bone granules were dissolved in nitric acid, and the calcium concentration in the solution was measured to characterize the degree of demineralization in terms of the calcium content in the demineralized granules. Some weak correlations between the degree of demineralization and the particulate properties were found. The demineralization rate was fitted to a first order rate equation, which was modified by considering the sphere equivalent diameter of individual granule, the characteristic aspect ratio of each fraction and the effective surface area of the mineral component to improve the approximation accuracy.

CrB 2 powders were successfully synthesized by the borothermal reduction of Cr 2 O 3 at 800–1000 °C under ambient pressure without B in excess. The presence of molten NaCl/KCl salts not only greatly decreased the synthesis temperature without introducing any impurities but also induced a small particle size. The CrB 2 powders synthesized at 900 °C had the largest specific surface area of 11.09 m 2 /g and the lowest equivalent average particle size of 104 nm, respectively.

Cellular transition to hypoxia following tissue injury, has been shown to improve angiogenesis and regeneration in multiple tissues. To take advantage of this, many hypoxia-mimicking scaffolds have been prepared, yet the oxygen access state of implanted artificial small-diameter vascular grafts (SDVGs) has not been investigated. Therefore, the oxygen access state of electrospun PCL grafts implanted into rat abdominal arteries was assessed. The regions proximal to the lumen and abluminal surfaces of the graft walls were normoxic and only the interior of the graft walls was hypoxic. In light of this differential oxygen access state of the implanted grafts and the critical role of vascular regeneration on SDVG implantation success, we investigated whether modification of SDVGs with HIF-1α stabilizer dimethyloxalylglycine (DMOG) could achieve hypoxia-mimicking responses resulting in improving vascular regeneration throughout the entirety of the graft wall. Therefore, DMOG-loaded PCL grafts were fabricated by electrospinning, to support the sustained release of DMOG over two weeks. In vitro experiments indicated that DMOG-loaded PCL mats had significant biological advantages, including: promotion of human umbilical vein endothelial cells (HUVECs) proliferation, migration and production of pro-angiogenic factors; and the stimulation of M2 macrophage polarization, which in-turn promoted macrophage regulation of HUVECs migration and smooth muscle cells (SMCs) contractile phenotype. These beneficial effects were downstream of HIF-1α stabilization in HUVECs and macrophages in normoxic conditions. Our results indicated that DMOG-loaded PCL grafts improved endothelialization, contractile SMCs regeneration, vascularization and modulated the inflammatory reaction of grafts in abdominal artery replacement models, thus promoting vascular regeneration.

An eco-friendly and effective electrochemical process was developed for the ortho-trifluoromethylation of arylamines using CF3SO2Na as the trifluoromethyl source, affording the desired products in moderate to good yields with high regioselectivity under mild reaction conditions. Importantly, the requirement for both transition metals and oxidants utilized in previous methods were avoided. A radical mechanism was proposed on the basis of various control experiments.

The 3D characterization of particle kinematics representing the changes in fabric observed during water-driven collapse of loess is, to the best of our knowledge, performed for the first time at the micron scale. An apparatus is specially designed to perform collapse tests on loess specimens of several millimeters in size and to capture, using X-ray tomography, particle-scale microfabric features of the sample in initial, loaded and flooded (i.e. collapsed) states. Although similar approaches have been used to assess problems such as microstructural evolution in sand, the application of these methods to assess loess collapse behaviour at the micron scale constitutes the novelty of this work. Individual particles within the specimen in the initial and deformed configurations are identified and tracked through an iterative segmentation technique and the particle tracking method ‘ID-track’. This allowed determination of particle displacement and rotation. The displacement field within the collapsed sample is found to be less uniform compared to that within the unwetted sample under loading. Coefficient of heterogeneity is defined to quantify the level of non-uniformity of the particle displacements within the deformed sample, revealing higher heterogeneity in the deformation of the collapsed sample compared to that of the unwetted sample under loading. It is also found that particles tend to rotate around axes perpendicular to, rather than parallel to, the direction of major principal stress, and the rotation magnitudes appears to be controlled largely by the size of particles while their morphology plays a minor role. The influence of porosity on the collapse process is quantified significant heterogeneous volumetric strains are observed at the single particle scale. It is also shown that the evolution of particle-to-particle contacts is much more complex than previously stated. The micron-scale investigations of individual particle kinematics following loading and wetting offer exciting new avenues for visualization and an enhanced capability for quantification of loess collapse processes.

Although all-solid-state hybrid supercapacitors (HSCs) based on cobalt sulfides are revealed to procure high density of redox species, their rate performance and power are severely restricted by adverse bulk structure of the electrode materials. Here, through regulating the sulfuric agents with mutative activities to rationally vulcanize cobalt-MOF, we fabricate hierarchical CoS2 nanosheet arrays directly coated on the conductive carbon cloth (CC@CoS2). These nanosheets are featured with unique macropore-mesopore-micropore porous architecture providing multi-level channels for rapid diffusion of ions, as well as abundant periphery sites from the refined nanoparticles in favor of the pseudocapacitive reaction. Electrochemical studies indicate that the structural superiorities of the CC@CoS2 effectually accelerate ions diffusion and retard the kinetic hysteresis. Consequently, an all-solid-state HSC with the CC@CoS2 and nitrogen-doped carbon nanosheet arrays grown vertically on carbon cloth as cathode and anode, respectively, achieves synchronous high energy density of 3.16 mWh·cm−3 and power density up to 1.61 W·cm−3, as well as robust cyclic stability (86.2% retention after 16,000 cycles). Besides, the electrochemical behavior of the HSC also shows good reliability under multiple mechanical deformation conditions and thermal circumstances. This work demonstrates a universal, effective strategy to produce advanced textile electrodes for flexible all-solid-state energy storage applications.