Search

Developing hydrogel actuators with excellent driving performance and extended lifespan remains challenging. Ti3C2Tx MXene, as a two-dimensional nanomaterial with a unique layered structure, has attracted widespread attention in flexible hydrogel actuators for its excellent optical absorption properties and tunable surface functionality. However, MXene faces difficulties in dispersion and is prone to oxidation, which significantly hinders the development and use of MXene-based hydrogel actuators. In this study, we fabricated a near-infrared light-driven hydrogel actuator with rapid photo responsiveness and antioxidative properties by incorporating modified MXene with antioxidant characteristics and the pore-forming agent polyvinyl alcohol into the poly(N-isopropylacrylamide) (PNIPAM) hydrogel system. We functionalized MXene nanosheets with (3-aminopropyl)triethoxysilane (APTES), effectively enhancing antioxidative properties, preventing structural degradation caused by spontaneous oxidation, and improving surface properties. This enhanced the dispersion stability of MXene in the system and extended its lifespan from 7 days to over two weeks. The hydrophilic polyvinyl alcohol chains served as drainage channels during hydrogel contraction, imparting the hydrogel with rapid driving capabilities (127.1° s−1). Additionally, leveraging the fast response characteristics, we designed an octopus-inspired light-driven soft swimmer and gripper. This work provides novel insights into the application of intelligent responsive hydrogels in biomimetic and practical scenarios. [ABSTRACT FROM AUTHOR]

The lifetime and application of electrochemical storage devices are always threatened by thermal runaway. Intelligent self-protecting gel electrolytes can be designed using temperature-responsive polymers. However, the mechanisms and factors affecting protective behavior are unclear. Here, we fabricated supercapacitors using temperature-responsive polyacrylamide-2-hydroxyethyl acrylate (PNIPAM-co-HEA) hydrogel polyelectrolytes. It was found that the polymer changed from hydrophilic to hydrophobic with increasing temperature, and the physical cross-linking of the polymer molecular strands in the electrolyte was enhanced, thus restricting conductive ion migration and closing the ion transportation pathway. The hydrophilic–hydrophobic transition on the gel surface also contributed to the suppression of the specific capacitance of the supercapacitor. This self-protection feature is repeatable. In addition, we investigated the effect of methyl groups in the main chain structure on the electrochemical properties using poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (PNIPAM-co-HEMA). Methylene enhanced the hydrophobicity of the polymer at room temperature and reduced the thermo-protective effect. The methyl group in the main chain also reduced the thermal response temperature of the polymer. This study explores the mechanism by which temperature-responsive polymers inhibit thermal runaway in supercapacitors and provides support for the design of more rational and efficient temperature-sensitive electrolytes. [ABSTRACT FROM AUTHOR]

Black soldier fly larvae have been proven to reduce greenhouse gas emissions in the treatment of organic waste. However, the microbial mechanisms involved have not been fully understood. The current study mainly examined the dynamic changes of carbon and nitrogen, greenhouse gas emissions, the succession of microbial community structure, and changes in functional gene abundance in organic waste under larvae treatment and non-aeration composting. Thirty percent carbon and 55% nitrogen in the organic waste supplied were stored in larvae biomass. Compared to the non-aeration composting, the larvae bioreactor reduced the proportion of carbon and nitrogen converted into greenhouse gases (CO2, CH4, and N2O decreased by 62%, 87%, and 95%, respectively). 16S rRNA sequencing analysis indicated that the larvae bioreactor increased the relative abundance of Methanophaga, Marinobacter, and Campylobacter during the bioprocess, enhancing the consumption of CH4 and N2O. The metagenomic data showed that the intervention of larvae reduced the ratio of (nirK + nirS + nor)/nosZ in the residues, thereby reducing the emission of N2O. Larvae also increased the functional gene abundance of nirA, nirB, nirD, and nrfA in the residues, making nitrite more inclined to be reduced to ammonia instead of N2O. The larvae bioreactor mitigated greenhouse gas emissions by redistributing carbon and nitrogen and remodeling microbiomes during waste bioconversion, giving related enterprises a relative advantage in carbon trading. [ABSTRACT FROM AUTHOR]

Elevated Sb(V) concentration in textile wastewater is a growing environmental concern worldwide and has received wider attention in recent years. Iron oxides possess appealing characteristics as efficient and cost-effective adsorbents in large-scale applications. In the present study, Sb(V) adsorption capacity of α-Fe2O3, γ-Fe2O3, and Fe3O4 was compared under experimental conditions close to the practical textile wastewater treatment. Results demonstrated that α-Fe2O3 performed better under different pH values, reaction times, dye compounds, and co-existing ions as compared to γ-Fe2O3 and Fe3O4, and the adsorption equilibrium was achieved within 8 h. Sb(V) adsorption is found to be highly pH dependent, and higher removal was achieved in lower pH, indicating the involvement of electrostatic interactions. The pHpzc value of α-Fe2O3 was 7.15, which favored Sb(V) adsorption in practical wastewater having neutral pH value (pH ~ 7). Pseudo-first- and pseudo-second-order described the data and the simulated values of qe fitted well with the experimental values, indicating that pseudo-second-order model described the adsorption kinetics better with R2 (> 0.95) higher than of pseudo-first-order plots. The Langmuir and Freundlich models both described well the sorption data of all the adsorbents, where the R2 values were > 0.90 with a better fit in the Freundlich model for α-Fe2O3, suggesting that the adsorbent has heterogeneous surface characteristics. Similarly, characterizations revealed that the specific surface area, pore volume, and hydroxyl group content in α-Fe2O3 were higher than others, making it easier for contaminants to bind on to the active sites. Furthermore, the effect of dyes and co-existing anions on Sb(V) adsorption was negligible, except for SO42−, CO32−, and PO43− by the formation of inner-sphere complexes with iron oxides through competitive adsorption with [Sb(OH)6]−. Findings from the present study suggested that α-Fe2O3 effectively reduced Sb(V) in textile wastewater and could be a promising alternative for practical textile wastewater treatment. [ABSTRACT FROM AUTHOR]

Highlights: Design and fabrication of MXene-based soft actuators with angle-independent structural color. The nanostructured MXene can not only facilitate the formation of short-range ordered 3D amorphous photonic crystals, but also help significantly improve structural color saturation. The soft actuators exhibit brilliant angle-independent structural color, ultrafast actuation and recovery speeds in response to vapor. In nature, many living organisms exhibiting unique structural coloration and soft-bodied actuation have inspired scientists to develop advanced structural colored soft actuators toward biomimetic soft robots. However, it is challenging to simultaneously biomimic the angle-independent structural color and shape-morphing capabilities found in the plum-throated cotinga flying bird. Herein, we report biomimetic MXene-based soft actuators with angle-independent structural color that are fabricated through controlled self-assembly of colloidal SiO2 nanoparticles onto highly aligned MXene films followed by vacuum-assisted infiltration of polyvinylidene fluoride into the interstices. The resulting soft actuators are found to exhibit brilliant, angle-independent structural color, as well as ultrafast actuation and recovery speeds (a maximum curvature of 0.52 mm−1 can be achieved within 1.16 s, and a recovery time of ~ 0.24 s) in response to acetone vapor. As proof-of-concept illustrations, structural colored soft actuators are applied to demonstrate a blue gripper-like bird's claw that can capture the target, artificial green tendrils that can twine around tree branches, and an artificial multicolored butterfly that can flutter its wings upon cyclic exposure to acetone vapor. The strategy is expected to offer new insights into the development of biomimetic multifunctional soft actuators for somatosensory soft robotics and next-generation intelligent machines. [ABSTRACT FROM AUTHOR]

Decoupled radiant cooling units (DRCUs) are capable of increasing the cooling capacity without increasing condensation risks even using a much lower cooling temperature than conventional radiant cooling units (CRCUs). However, it is unclear whether DRCUs using low radiant cooling temperature will increase the cooling load of the conditioned indoor spaces. In this study, the cooling load characteristics of a thermal chamber conditioned by a DRCU was investigated through developing a steady-state analysis model suitable for both DRCUs and CRCUs. The total/radiative heat flux, as well as the heat exchange with a thermal manikin and walls were analysed under different surface temperatures of DRCUs. The effect of the emissivity of the thermal chamber' external wall on the cooling load was also investigated. Results indicated that the cooling load under the DRCU was slightly smaller than that under the CRCU when the same operative environment was created. Decreasing the infrared emissivity of the exterior wall's inner surface could lead to a significant decrease in the cooling load for both the DRCU and CRCU. By decreasing the wall emissivity from 0.9 to 0.1, the total cooling load of the DRCU can be decreased by 8.4% and the heat gain of the exterior wall decreased by 21.6%. This study serves as a reference for developing the analysis model and understanding the load characteristics when DRCUs are used to create the thermal environment for indoor spaces. [ABSTRACT FROM AUTHOR]

With the significant improvement of energy density and power density of electrochemical energy storage devices, a large amount of heat will be generated during operation, and fire or explosion may occur due to high internal temperature. However, the traditional method of controlling thermal runaway is slow and irreversible. Here, we investigate a reversible electrolyte system based on thermal-responsive polymers consisting of Pluronic F127, ionic liquid (IL) [EMIM]BF4, and a lithium salt. Pluronic-IL electrolyte responds by sol–gel transformation above the lower-critical solution temperature (LCST), which inhibits electrochemical energy conversion and effectively prevents thermal runaway at 160 ℃. We investigated the effects of operating temperature, lithium-ion concentration, and Pluronic concentration on electrochemical performance and proved that by regulating the concentration of Pluronic, the loss rate of capacitance can reach nearly 70%. It can be seen that this is a green and efficient method to control thermal runaway and may be practically used in lithium-ion batteries in the future. [ABSTRACT FROM AUTHOR]

Utilization of high temperature cooling sources or natural energy sources can potentially contribute to improving energy efficiency in buildings. In this study, a dual-cavity window with gravity-driven cooling mechanism (GDC window) was proposed to integrate the low-grade cooling sources into the glazing system for improving the thermal performance of the window. The embedded pipes circulated with low-grade cooling water are the key component of GDC window, which can remove the absorbed solar heat and reduce the heat gain through the window. A numerical model based on CFD simulation was developed to analyze the flow characteristic and heat transfer within the GDC window. Model validation was conducted by comparing the simulation results with measurement data obtained from previous study. Numerical simulations were carried out to compare the thermal performance of GDC window with that of conventional blinds window. Sensitivity analysis was performed to evaluate the influence of some design parameters on the flow characteristic and thermal performance of GDC window. The simulated results show that compared with the blinds window, the GDC window reduces 57.4% and 40.4% of heat gain in summer for the low-grade cooling water of 18 °C and 25 °C, respectively. Reducing the flow resistance within the GDC window is significant for improving the heat removal performance of the embedded pipes. This study provides an alternative solution to integrate the low-grade cooling sources into the glazing system for enhancing the energy-efficiency and decreasing the building energy demand in cooling-dominated buildings. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) molecularly imprinted polymer (MIP) arrays were used for electrochemical sensor to detect sulfadimidine (SM2) residue in food. NiCo2O4 nanoneedle arrays were decorated on the free-standing and highly conductive 3D graphene by a hydrothermal process. Polypyrrole (PPy) was coated onto NiCo2O4 nanoneedle arrays via electropolymerization in the presence of template molecule SM2 to obtain MIP/NiCo2O4 nanoneedle/3D graphene electrode. The desirable detectability of the composite electrode can be ascribed to the unique structure and the synergistic effects of the components: Nanoneedle arrays on 3D graphene offered the matrix to MIP and each nanoneedle as sensing unit was accessible to analyte, resulting in high specific surface area, desirable conductivity, short ion diffusion path and excellent adsorption capacity, which could powerfully boost the electrochemical property for the detection of SM2. Under optimized conditions, a wide linear range over SM2 of 0.2-1000 ng/mL with a detection limit of 0.169 ng/mL (S/N = 3) was obtained. The developed sensor also had favorable recovery of 92.3-102.23% and the relative standard deviation of 2.27-4.10%. The MIP array sensor provided an efficient tool for the selective and rapid detection of SM2 in food. [ABSTRACT FROM AUTHOR]

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are ubiquitous and highly toxic emerging endocrine disruptors found in surface and subsurface soils and clay deposits. Seriously, they could be easily transformed to the more toxic dioxins (PBDD/Fs) in photochemical processes and incineration, but the spontaneous formation of PBDD/Fs has rarely been reported. This study focused on the formation of 1,3,8-tribromodibenzo-p-dioxin (1,3,8-TrBDD) and 2,4,6,8-tetrabromodibenzofuran (2,4,6,8-TeBDF) from 2′-OH-BDE-68 and 2,2′-diOH-BB-80 under the oxidization of iron and manganese oxides (goethite and MnOx). Approximately 0.09 μmol/kg (2.33%) and 0.17 μmol/kg (4.15%) were transformed to 1,3,8-TrBDD and 2,4,6,8-TeBDF by goethite in 8 days and a higher conversion 0.15 μmol/kg (3.77%) and 0.23 μmol/kg (5.74%) were observed for MnOx in 4 days. However, the formation of PBDD/Fs, probably proceeding via Smiles rearrangements and bromine elimination processes, was greatly inhibited by the presence of water. Transformation of OH-PBDEs by goethite and MnOx was accompanied by release of Fe and Mn ions and the possible pathways for the formation of reaction products were proposed. In view of the ubiquity of OH-PBDEs and metal oxides in the environment, oxidation of OH-PBDEs mediated by goethite and MnOx is likely an abiotic route for the formation of PBDD/Fs. [ABSTRACT FROM AUTHOR]

A tetraphenyl porphyrin tetrasulfonic acid (TPPS)-modified three-dimensional porous Mn3O4/PANi composites electrode was prepared, which has excellent electrical conductivity and rate performance. The conductivity and stability of polyaniline (PANi) gels have been improved due to the doping of TPPS and its conjugated molecular structure. Furthermore, the Mn3O4/PANi composites gel similar to reinforced concrete structure were prepared by coating PANi cross-linked by TPPS on one-dimensional Mn3O4 nanorods. On the one hand, modified PANi gel act as a functional coating of Mn3O4 nanorods, providing structural protection and providing more active sites. On the other hand, the overlapping Mn3O4 nanorods and PANi gel form a three-dimensional porous network structure, which has a high specific surface area, provides more channels for the transfer of electrons and electrolyte ions, and effectively improves the conductivity of Mn3O4. The specific capacitance of the composite electrode can reach 422 F g−1 at a current density of 0.5 A g−1, and the specific capacitance can reach 265 F g−1 at a high current density of 10 A g−1. After 2000 cycles, the capacity loss was only 11%. And the charge transfer resistance is only 1.2 Ω. These excellent electrochemical performances, as a result of the stable structure formed by TPPS modification and three-dimensional porous morphology, suggesting that these composites have an enormous potential in energy application. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel method based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change well in peak shapes caused by the expansion or compression of peaks under different gradient conditions. [ABSTRACT FROM AUTHOR]

Two biphenyl-degrading bacterial strains, SS1 and SS2, were isolated from polychlorinated biphenyl (PCB)-contaminated soil. They were identified as Rhodococcus ruber and Rhodococcus pyridinivorans based on the 16S rRNA gene sequence, as well as morphological, physiological and biochemical characteristics. SS1 and SS2 exhibited tolerance to 2000 and 3000 mg/L of biphenyl. And they could degrade 83.2 and 71.5% of 1300 mg/L biphenyl within 84 h, respectively. In the case of low-chlorinated PCB congeners, benzoate and 3-chlorobenzoate, the degradation activities of SS1 and SS2 were also significant. In addition, these two strains exhibited chemotactic response toward TCA-cycle intermediates, benzoate, biphenyl and 2-chlorobenzoate. This study indicated that, like the flagellated bacteria, non-flagellated Rhodococcus spp. might actively seek substrates through the process of chemotaxis once the substrates are depleted in their surroundings. Together, these data provide supporting evidence that SS1 and SS2 might be good candidates for restoring biphenyl/PCB-polluted environments. [ABSTRACT FROM AUTHOR]

PPy/PANI double-layer nanotubes anchored reduced graphene oxide (rGO) nanosheets with three-dimensional architecture (3DGP) have been obtained for supercapacitors applications. The freestanding electrode yields specific capacitance (542 F g at current density of 1 A/g) and excellent cycle stability (92.1% capacitance retention after 2000 cycles in a three-electrode cell configuration). The further assembled symmetric supercapacitor device exhibits a high energy density of 20.8 W h kg at a power density of 250 W kg and good cycle stability (capacitance loss of 7% up to 2000 cycles). The exceptional electrochemical performance of 3DGP can be ascribed to the unique structure and the synergistic effects of the components: (1) Integrating the highly capacitance matrix PPy/PANI coaxial nanotubes hybrid in rGO to enhance the reversible faradic reactions can boost the utilization rate of the electrode materials and circumventing the predicament of pseudo materials. (2) The desirable π- π interactions between highly conductive rGO films and polymer chains construct a high-performance network, which facilitates rapid transport of the electrolyte ions in the electrode. (3) The as-prepared electrode materials fabricated into electrodes directly decrease the 'dead weight,' for the addition of binder and conductive agents can be avoided. [ABSTRACT FROM AUTHOR]

Black carbon (BC) is considered to be a promising novel material for controlling organic contaminants due to its strong adsorption property, low production cost, and less secondary pollution. However, seldom systemic research was conducted to investigate adsorption-desorption characteristics and interaction mechanism between BC and nonylphenol (NP), one kind of endocrine-disrupting contaminants (EDCs) and persistent organic pollutants (POPs). Therefore, in the present study, adsorption characteristics of NP on two BCs (rice straw black carbon (RC) and fly ash carbon (FC)) involving adsorption isotherm, kinetics, effect of pH, as well as desorption kinetics, were investigated to explore the feasibility of BC for remediation of NP pollution in a water environment. Adsorption isotherm data showed that Q was 61,889.21 ± 2777.68 and 6538.99 ± 606.72 mg/kg and n was 0.39 ± 0.037 and 0.55 ± 0.043 for RC and FC, respectively, suggesting the sorption capacity and nonlinearity of RC to NP is far higher than FC and indicating BC was an effective sorbent for NP pollution control, especially RC. The pH affected BC sorption capacity to NP by influencing the surface properties of BC and the NP speciation together. Desorption kinetics data indicated that more than 80% NP could not be released from both BCs, suggesting that BC could reduce NP releasing risk in a water environment evidently when BC is applied for NP pollution remediation. [ABSTRACT FROM AUTHOR]

We designed the hollow ZnCoO microsphere with meshy surface by means of ormaldehyde bubble-induced method. To avoid the occurring of the side reaction on the interface caused by its high specific surface area, three-dimensional (3D) polypyrrole/sodium alginate (PPy/SA) composite via the situ polymerization of pyrrole in an aqueous solution of SA was used as the coating layer of ZnCoO to form lychee-shaped ZnCoO@PPy/SA microsphere. The PPy/SA was found to have a more favorable conductivity and mechanical strength than PPy. As anode material for lithium-ion battery, ZnCoO@PPy/SA possesses numerous merits compared with ZnCoO and ZnCoO@PPy. The more outstanding electrochemical performance of ZnCoO@PPy/SA electrode with higher reversible capacity, more excellent long-term cycling stability and better rate capability can be attributed to the porous hollow structure and PPy/SA coating, which not only reduce the path length for Li ions but also accommodate the volume expansion. Such structured composite electrode may have great potential for the application in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

In order to discuss the effect of polymer coating layer on the Sn anode, the composition and morphology of the solid electrolyte interphase (SEI) film on the surface of Sn and Sn@PEO anode materials have been investigated. Compared with the bare cycled Sn electrode, the SEI on the surface of cycled Sn@PEO electrode is thinner, smoother, and more stable. Therefore, the Sn@PEO nanoparticles can basically keep the original appearance during cycling. Based on the results obtained from X-ray photoelectron spectroscopy (XPS), the SEI formed on the Sn@PEO electrode is characterized by inorganic components (LiCO)-rich outer layer and organic components-rich inner which could make the SEI more stable and inhibit the electrolyte immerging into the active materials. In particular, the elastic ion-conductive polyethylene oxide (PEO) coating could increase the toughness of SEI and allow the SEI to endure the stress variation in repetitive lithium insertion and extraction process. As a result, the Sn@PEO electrodes show significantly better capacity retention than bare Sn electrodes. The findings can serve as the theoretical foundation for the design of lithium-ion battery electrode with high energy density and long cycle life. [ABSTRACT FROM AUTHOR]

Corrosion deposits formed within drinking water distribution systems deteriorate drinking water quality and resultantly cause public health consequences. In the present study, an attempt was made to investigate the concurrent conditions of corrosion scales and the drinking water quality in selected water supply schemes (WSS) in districts Chitral, Peshawar, and Abbottabad, northern Pakistan. Characterization analyses of the corrosion by-products revealed the presence of α-FeOOH, γ-FeOOH, FeO, and SiO as major constituents with different proportions. The constituents of all the representative XRD peaks of Peshawar WSS were found insignificant as compared to other WSS, and the reason could be the variation of source water quality. Well-crystallized particles in SEM images indicated the formation of dense oxide layer on corrosion by-products. A wider asymmetric vibration peak of SiO appeared only in Chitral and Abbottabad WSS, which demonstrated higher siltation in the water source. One-way ANOVA analysis showed significant variations in pH, turbidity, TDS, K, Mg, PO, Cl, and SO values, which revealed that these parameters differently contributed to the source water quality. Findings from this study suggested the implementation of proper corrosion prevention measures and the establishment of international collaboration for best corrosion practices, expertise, and developing standards. [ABSTRACT FROM AUTHOR]

In this work, we reported the highly ordered NiCoO nanoneedle@polypyrrole arrays anchored on three-dimensional graphene (NiCoO@PPy/3D graphene) for high-sensitivity detection of trace lead ions (Pb). The 3D graphene was prepared by a hydrothermal process and then decorated with NiCoO nanoneedle arrays by another hydrothermal process. This two-step hydrothermal method is simple and mild. Furthermore, the highly conductive PPy was coated on NiCoO via a chemical vapor-phase polymerization to prepare NiCoO@PPy/3D graphene. The free-standing NiCoO@PPy/3D graphene can be directly utilized as 3D electrochemical working electrode without being decorated onto working electrode like Au and glassy carbon electrode. High conductivity, large specific surface area, short ion diffusion path and excellent adsorption capacity of NiCoO@PPy/3D graphene efficiently improved electrochemical property for the detection of Pb. Using square-wave anodic stripping voltammetry (SWASV), a linear range between the currents and the concentrations of Pb of 0.0125-0.709 μM with a high sensitivity of 115.621 μA μM was obtained. The limit of detection can reach to 0.2 nM. In addition, the fabricated sensor of Pb also had good selectivity, reproducibility and long-term stability. Finally, NiCoO@PPy/3D graphene electrode was utilized for determining Pb in tap water sample using the standard addition method, revealing a promising application for the quantitative detection of certain concentration ranges of Pb in real sample. [ABSTRACT FROM AUTHOR]

Here, a supramolecular self-assembly hydrogel was designed for SnO-based anode through electrostatic interaction and ionic bonding between poly(allylamine hydrochloride) (PAH) chain and gelator phytic acid. Microrheology measurement was employed to investigate the self-sorting mechanism of the hierarchical nanostructured PAH. Results confirmed that ionically cross-link PAH improves the structural integrity of SnO nanospheres due to the reversible ionic bonding and thus increases the lifetime of the electrodes obviously. Besides, multi-walled carbon nanotubes (MWCNTs) were applied to improve the electrochemical performance of hollow SnO nanospheres due to their high conductivity. Results confirmed that the conductive network constructed by MWCNTs reduces the polarization of the composites while increases the specific capacity of the electrodes. Attributed to the synergistic effect of PAH-60 and MWCNTs, the composite electrodes show excellent electrochemical performance with a reversible capacity of 574 mAh g after 100 cycles at 100 mA g, a discharge capacity of 321 mAh g at 2000 mA g and a spring-back capacity of 506 mAh g at 200 mA g. Additionally, the prepared composite electrodes were observed to have a complete network structure after rate capability test, demonstrating a superior structural stability. [ABSTRACT FROM AUTHOR]

A novel MWCNT/long nanotubular TiO(B) loaded with SnO nanocrystals (SnONC/TiO(B)NT/MWCNT) ternary composite has been prepared by two-step hydrothermal method and used as the anode material for the first time. In this work, the mechanical stirring improved the diffusion and surface reaction rates of reactants and promoted the appearance of longer intermediate TiO(B) nanosheets, leading to the formation of TiO(B) nanotubes with a length of ~9 μm. Among the SnONC/TiO(B)NT/MWCNT composite, the wrapping and mechanical supporting functions of TiO(B) nanotubes can effectively avoid the pulverization and aggregation of SnO nanocrystals (SnONC) in lithium-ion charging and discharging process. Moreover, the synergistic effects of nanotubular TiO(B) coating layer and three-dimensional interconnected network structure composed of TiO(B) nanotubes and MWCNT were taken to mitigate volume expansion of SnONC and improve the transport of lithium ion and electron in the network. Tested as anode materials, the SnONC/TiO(B)NT/MWCNT composite maintained 211 mAh g at 3000 mA g after three testing processes with alternative current density of 200 and 3000 mA g and could rebound to 338 mAh g at a current density of 200 mA g, indicating an effective way to optimize electrochemical properties of SnO as anode material. [ABSTRACT FROM AUTHOR]

Hollow silica spheres possessing excellent mechanical properties were successfully prepared through a layer-by-layer process using uniform polystyrene (PS) latex fabricated by dispersion polymerization as template. The formation of hollow SiO micro-spheres, structures and properties were observed in detail by zeta potential, SEM, TEM, FTIR, TGA and nitrogen sorption porosimetry. The results indicated that the hollow spheres were uniform with particle diameter of 1.6 μm and shell thickness of 150 nm. The surface area was 511 m/g and the pore diameter was 8.36 nm. A new stationary phase for HPLC was obtained by using C-derivatized hollow SiO micro-spheres as packing materials and the chromatographic properties were evaluated for the separation of some regular small molecules. The packed column showed low column pressure, high values of efficiency (up to about 43 000 plates/m) and appropriate asymmetry factors. [ABSTRACT FROM AUTHOR]

A novel, stable and sensitive non-enzymatic glucose biosensor based on bimetallic hollow Ag/Pt nanoparticles and the reduced graphene oxide (rGO) was obtained. The hybrid of bimetallic hollow Ag/Pt nanoparticles-reduced graphene oxide (HAg/PtNPs-rGO) was prepared by a galvanic replacement reaction and the thermal reduction of graphene oxide. Thermal reduction has been highly effective in producing graphene-like films which can render a stable substrate for hollow Ag/Pt nanoparticles. The morphology and composition of the prepared samples were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectrometry and Fourier transform infrared spectra. Cyclic voltammetry measurements demonstrated that the biosensor decorated by HAg/PtNPs-rGO can directly detect glucose and show a superior electro catalytic activity. The results of amperometric method showed a desirable amperometric response with a sensitivity of 129.32 μA mM cm, a linear range of 0.003-7.72 mM (R = 0.9943), a fast response time (less than 3 s) and a low detection limit of 1.8 μM (S/N = 3). In addition, the fabricated sensor also had good selectivity, reproducibility and long-term stability. The sensor modified by HAg/PtNPs-rGO could make a promising application in glucose determination. [ABSTRACT FROM AUTHOR]

Anaerobic oxidation of methane (AOM) coupled to nitrite reduction (AOM-NIR) is ecologically significant for mitigating the methane-induced greenhouse effect. The microbes responsible for this reaction, NC10 bacteria, have been widely detected in diverse ecosystems. However, some defects were discovered in the commonly used NC10-specific primers, 202F and qP1F. In the present work, the primers were redesigned and improved to overcome the defects found in the previous primers. A new nested PCR method was developed using the improved primers to amplify 16S ribosomal RNA (rRNA) genes from NC10 bacteria. In the new nested PCR method, the qP1mF/1492R and 1051F/qP2R primer sets were used in the first and second rounds, respectively. The PCR products were sequenced, and more operational taxonomic units (OTUs) of the NC10 phylum were obtained using the new primers compared to the previous primers. The sensitivity of the new nested PCR was tested by the serial dilution method, and the limit of detection was approximately 10 copies g dry sed. for the environmental samples compared to approximately 10 copies g dry sed. by the previous method. Finally, the improved primer, qP1mF, was used in quantitative PCR (qPCR) to determine the abundance of NC10 bacteria, and the results agreed well with the activity of AOM-NIR measured by isotope tracer experiments. The improved primers are able to amplify NC10 16S rRNA genes more efficiently than the previous primers and useful to explore the microbial community of the NC10 phylum in different systems. [ABSTRACT FROM AUTHOR]

Conducting polymer hydrogels are emerging as a promising class of materials that combine the advantageous features of conventional hydrogels and organic conductors, and would potentially be used in many applications, especially for energy storage devices. To overcome the drawbacks of conventional synthesis, this work describes the use of amino trimethylene phosphonic acid as the gelator and dopant for rapidly fabricating hierarchical nanostructured polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. Owing to 3D porous nanostructures and high surface area, the PAni hydrogel exhibits potential as high-performance supercapacitor electrodes with specific capacitance over 420 F g. Furthermore, the rapidly formed PAni hydrogel was first used for 3D multilayer printing of micro-patterns due to the unique synthesis method and desirable processability. Taken together, these results suggest that the PAni hydrogel networks exhibit highly useful for a broad range of applications. [ABSTRACT FROM AUTHOR]

Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered bioprocess that reduces nitrite to dinitrogen with methane as electron donor, which has promising potential to remove nitrogen from wastewater. In this work, a lab-scale sequencing batch reactor (SBR) was operated for 609 days with methane as the sole external electron donor. In the SBR, nitrite in synthetic wastewater was removed continuously; the final volumetric nitrogen removal rate was 12.22±0.02 mg N L day and the percentage of nitrogen removal was 98.5 ± 0.2 %. Microbial community analysis indicated that denitrifying methanotrophs dominated (60-70 %) the population of the final sludge. Notably, activity testing and microbial analysis both suggested that heterotrophic denitrifiers existed in the reactor throughout the operation period. After 609 days, the activity testing indicated the nitrogen removal percentage of heterotrophic denitrification was 17 ± 2 % and that of n-damo was 83 ± 2 %. A possible mutualism may be developed between the dominated denitrifying methanotrophs and the associated heterotrophs through cross-feed. Heterotrophs may live on the microbial products excreted by denitrifying methanotrophs and provide growth factors that are required by denitrifying methanotrophs. [ABSTRACT FROM AUTHOR]

A novel nano-Sn particle/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/poly(vinyl alcohol) core-shell hierarchical composite (nano-Sn/PEDOT:PSS/PVA CSHC) was fabricated for the first time and evaluated as a high-performance anode material in lithium ion batteries (LIBs). The core-shell hierarchical structure of the composite was revealed by field-emission scanning electron microscope and transmission electron microscope; the components of the composite were investigated by X-ray diffraction and fourier transform infrared spectroscopy; the nano-Sn particle content in the composite was obtained by thermogravimetric analysis and the electrochemical performance was studied by galvanostatic charge/discharge cycling tests and electrochemical impedance spectroscopy. When used as LIB anode material, the nano-Sn/PEDOT:PSS/PVA CSHC electrode exhibited high reversible capacity (568 mA h g after 100 charge/discharge cycles at a current density of 100 mA g), superior cycling stability (capacity retention of 66.0 % after 100 cycles), good rate performance (143 mA h g at 1500 mA g) and low charge transfer resistance compared to pristine nano-Sn particle and nano-Sn/PEDOT:PSS composite electrodes. The improved electrochemical performance can be attributed to the core-shell hierarchical structure. The results show that the nano-Sn/PEDOT:PSS/PVA CSHC is a promising anode candidate for next-generation LIBs. [ABSTRACT FROM AUTHOR]

In order to optimize the electrode system of lithium-ion batteries (LIBs) for problems like lithium-ion diffusion, electron transport, and large volume change during cycling processes, a novel three-dimensional (3D) hybrid FeO nanotube array anode coated by polypyrrole (FeO@PPy) is synthesized via a sacrificial template-accelerated hydrolysis method followed by a chemical vapor-phase polymerization process. In the hollow core-shell nanostructures, the conducting PPy layer could not only facilitate the electron transport, but also force the core to expand inward into the hollow space, which allows for free volume expansion of the FeO without mechanical breaking. Besides, the static outer surface is contributed to form a stable solid electrolyte interface film. As a result, the integration of 3D hybrid nanostructure electrode is capable of retaining a high capacity of 665 mA h g after 150 cycles with a coulombic efficiency of above 97 %, revealing better cycling properties compared with bare FeO nanotube arrays' anode. This nanoengineering strategy is proven to be an ideal candidate for the development of high-performance anode for LIBs. [ABSTRACT FROM AUTHOR]

Hollow Sn-Co nanospheres have been fabricated by galvanic replacement reaction. In particular, the hollow resultants with different shell thickness and void space can be obtained using sacrificial templates with different sizes. The structural evolution of Sn-Co hollow microspheres and structure changes during charge/discharge process were studied using XRD, SEM, and TEM. As an anodic material, the hollow resultants with thin shell and relatively large void space exhibited a good reversible capacity of 502 mAh g at a current density of 100 mA g and a coulomb efficiency over 99 % after 100 cycles. The contributions of the hollow structure and the inactive Co element to electrochemical performance were verified by galvanostatic charge/discharge cycling, electrochemical impedance spectroscope, and TEM measurements. A possible mechanism for hollow structure with different shell thickness to alleviate the volume change was proposed. [ABSTRACT FROM AUTHOR]

A non-enzymatic glucose sensor was successfully fabricated by immobilization of bimetallic hollow Ag/Pt nanoparticles (BH-Ag/Pt NPs) using the galvanic replacement reaction onto the surface of the pretreated pure Au electrode. The morphology and composition of the BH-Ag/Pt NPs were investigated by high-resolution transmission electron microscopy (HRTEM), scanning transmission electron microscopy (STEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD), which proved the formation of bimetallic hollow Ag/Pt nanoparticles. The electroactive surface area and interface property of the Au electrode modified by BH-Ag/Pt NPs were measured by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The associated calculated values were 0.210 cm and 11.30 Ω cm, which were distinctly higher than those of the pure Au electrode. The electrocatalytic properties of the modified electrode toward glucose oxidation were evaluated by CV and differential pulse voltammetry (DPV). The results showed that the modified electrode had a high electrocatalytic activity toward glucose oxidation, a linear response to the glucose concentrations ranging from 1 to 12 mM covering the physiological level of 3-8 mM with a current sensitivity of 7 μA mM and a low detection limit of 0.013 mM. Moreover, the modified electrode also showed ideal reproducibility, long-term stability, and high selectivity. It also showed good glucometer test values for real samples. Therefore, both of the facile preparation method and the excellent properties of the Au electrode modified by BH-Ag/Pt NPs could potentially be implemented to develop novel non-enzymatic glucose sensors. [ABSTRACT FROM AUTHOR]

This paper introduced the controllable fabrication and characterization of graded and gradient porous polypropylene (PP) via thermal treatment of PP/poly(ethylene-1-octene) copolymer (PEOc) blend with co-continuous phase morphology. The co-continuous phase structure of PP/PEOc blend would coarsen during its annealing process if the annealing temperature was higher than the melting point of the PP, while no coarsening effect would occur if the temperature was lower than the melting point. In addition, the coarsening rate of the co-continuous structure would be different making the blends annealed at different temperature. The graded or gradient phase morphology would be obtained by designing proper thermal boundary condition. The subsequent removal of PEOc phase left the graded or gradient porous PP structure. The graded and gradient porous microstructure along the sample thickness direction was studied by SEM. The SEM results indicated that by designing proper thermal boundary condition the graded PP and gradient porous PP structures along the thickness of the sample were formed, respectively. [ABSTRACT FROM AUTHOR]

Nitrite-dependent anaerobic methane oxidation (n-damo) is a newly discovered biological process that couples anaerobic oxidation of methane (AOM) to nitrite reduction. In this study, three different inocula, methanogenic sludge, paddy soil, and freshwater sediment were used to enrich n-damo bacteria in three sequencing batch reactors (SBRs), and three n-damo enrichment cultures, C1, C2 and C3, were obtained, respectively. After 500 days of incubation, Methylomirabilis oxyfera-like bacteria and n-damo activities were observed in cultures C1, C2, and C3, and the specific activities were 0.8 ± 0.1, 1.4 ± 0.1, and 1.0 ± 0.1 μmol CH h g VSS, respectively. The copy numbers of 16S rRNA genes from cultures C1, C2, and C3 were 5.0 ± 0.4 × 10, 6.1 ± 0.1 × 10, and 1.0 ± 0.2 × 10 copies g dry weight, respectively. The results indicated that paddy soil is an excellent inoculum for n-damo bacterial enrichment. This work expanded the alternative source of n-damo inoculum and benefited the further research of n-damo process. [ABSTRACT FROM AUTHOR]

Microbial-driven biogeochemical cycles in wetlands impacted by global warming pose a potential downstream eutrophication risk. However, the consequences of ongoing warming on the functional and metabolic potential of sediment microbial communities are largely unknown. We incubated sediment samples under both ambient temperature conditions (control) and simulated warming conditions of 5°C above ambient temperature (warmed) using a novel field microcosm system. In warmed samples, we observed in situ a decreased thickness of the oxidized sediment layer and associated lower sediment redox potential. GeoChip 4.0, a comprehensive functional gene microarray, demonstrated that many functional genes that are involved in oxidation-reduction reactions and in phosphorus (P) degradation were preferentially enriched under warming conditions. The enriched genes included those genes encoding carbon monoxide dehydrogenase, acetyl-CoA carboxylase biotin carboxylase ( ppc), and ribulose-1,5-bisphosphate carboxylase (Rubisco) for carbon fixation; nitrate reductases ( narG) and nitrous oxide reductases ( nosZ) for denitrification; cytochrome c for metal reduction; and exopolyphosphatase ( ppx) for polyphosphate degradation. The redox potential was one of the most significant parameters linked to microbial functional gene structure. These results demonstrate that the enhanced hypoxia and anaerobic metabolic pathways accelerated sediment P mobilization in freshwater wetland subject to warming, raising the potential of water eutrophication. [ABSTRACT FROM AUTHOR]

Nitrite-dependent anaerobic methane oxidation (n-damo) is mediated by bacteria that anaerobically oxidize methane coupled with nitrite reduction and is a potential bioprocess for wastewater treatment. In this work, the effect of reactor configuration on n-damo bacterial cultivation was investigated. A magnetically stirred gas lift reactor (MSGLR), a sequencing batch reactor (SBR), and a continuously stirred tank reactor (CSTR) were selected to cultivate the bacteria. Microbial community was monitored by using quantitative PCR, 16S rRNA gene sequencing, pmoA gene sequencing, and fluorescence in situ hybridization (FISH). The effects of substrate inhibition, methane mass transfer, and biomass washout in the three reactors were focused on. The results indicated that the MSGLR had the best performance among the three reactor systems, with the highest total and specific n-damo activities. Its maximum volumetric nitrogen removal rate was up to 76.9 mg N L day, which was higher than previously reported values (5.1-37.8 mg N L d). [ABSTRACT FROM AUTHOR]

Soil pollution by polychlorinated biphenyls (PCBs) arising from the crude disposal and recycling of electronic and electrical waste (e-waste) is a serious issue, and effective remediation technologies are urgently needed. Nanoscale zerovalent iron (nZVI) and bimetallic systems have been shown to promote successfully the destruction of halogenated organic compounds. In the present study, nZVI and Pd/Fe bimetallic nanoparticles synthesized by chemical deposition were used to remove 2,2′,4,4′,5,5′-hexachlorobiphenyl from deionized water, and then applied to PCBs contaminated soil collected from an e-waste recycling area. The results indicated that the hydrodechlorination of 2,2′,4,4′,5,5′-hexachlorobiphenyl by nZVI and Pd/Fe bimetallic nanoparticles followed pseudo-first-order kinetics and Pd loading was beneficial to the hydrodechlorination process. It was also found that the removal efficiencies of PCBs from soil achieved using Pd/Fe bimetallic nanoparticles were higher than that achieved using nZVI and that PCBs degradation might be affected by the soil properties. Finally, the potential challenges of nZVI application to in situ remediation were explored. [ABSTRACT FROM AUTHOR]

Nanostructured hollow Sn-Cu multi-phase composite nanoparticles anode that contains Sn and CuSn was synthesized via galvanic replacement reaction using Sn nanoparticles as a sacrificial template. The sacrificial oxidation of Sn and simultaneous reduction of Cu on the surface because of the redox potential difference is proposed to account for the formation of hollow Sn-Cu nanostructures. The structural evolution of the Sn-Cu hollow nanoparticle, in the process of galvanic replacement and structure, composition changes during charge/discharge processes were studied based on scanning electron microscope, X-ray powder diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy investigations. The electrochemical properties of the samples were evaluated by galvanostatic discharge-charge cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. Compared with solid Sn-Cu nanoparticles, hollow Sn-Cu nanoparticles showed better capacity retention. The improved electrochemical performance may be attributed to the stable hollow structure and the combination of CuSn. The facile solution-based process and excellent cycling stability show great potential of the multi-phase Sn-Cu hollow composite nanoparticles as an anode material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Purpose: There is a strong affinity between organic compounds and black carbon (BC) in sediments, but the release of adsorbed organic compounds from BC may vary with the duration of contaminant-sediment contact (i.e., aging). The objective of this paper was to evaluate the effect of the application of rice straw carbon (RC) on the control of hydrophobic ionizable organic compounds (HIOCs) pollution and investigate whether aging affects the release of adsorbed pentachlorophenol (PCP) in RC-amended sediment. Materials and methods: Two experiments were conducted in this study: Tenax-mediated desorption kinetics experiment and PCP's distribution experiment over aging time. The Tenax-mediated desorption kinetics data were fit with a modified two-domain model. PCP's distribution pools in sediment involves water soluble ( F), 48 h desorption ( F), 432 h desorption minus 48 h desorption ( F), strongly complexed ( F), and nonextractable fractions ( F). Results and discussion: A good fit of the desorption kinetics data was obtained with the modified two-domain model, and R ranged from 0.979 to 0.999. The presence of RC in the sediment reduced the rapid and slow desorption fractions ( F and F) as well as the rapid and slow rates of desorption of PCP ( k and k) from the sediment, and the RC also increased the desorption-resistant fraction ( F). F and F both increased, while F decreased after aging. The PCP content of F, F, and F increased but decreased in F and F with contact time. Furthermore, the segregation of PCP varied less with aging time in sediments with 2.0 % RC than in sediments with 0.5 % RC. Conclusions: RC played a dominant role in hindering PCP mass transfer and reducing PCP availability in sediments. After the RC-amended sediment was aged for 98 days, the PCP was released more easily and became more readily available, which was attributed primarily to the RC-sediment aging rather than of the PCP-sediment aging. Furthermore, 0.5 % RC is not sufficient to control PCP release from sediments, and 2.0 % RC is needed to fix PCP in sediments over long periods of time. [ABSTRACT FROM AUTHOR]

Carbon black supported ultra-high loading silver nanoparticle catalyst (Ag/CB) was prepared by a modified ethylene glycol reduction method, using ethylene glycol as the reducing agent and sodium hydroxide as the pH adjusting agent. The X-ray diffraction, thermogravimetry and scanning electron microscopy characterizations showed that the Ag nanoparticles crystallized with a face-centered cubic structure and were densely stacked on the CB surface without aggregation, despite such a small average size (ca. 10 nm) and an ultra-high loading mass (392 wt.%). The electrochemical evaluation based on cyclic voltammetry, chronoamperometry and polarization tests revealed that the ultra-high loading Ag/CB catalyst possessed a superior electrocatalytic activity for the oxidation of hydrazine, via a diffusion-limited process and a 4-electron transfer pathway. Moreover, the chronoamperometry response on an electrode modified with this ultra-high loading Ag/CB catalyst exhibited a promising application for determination of hydrazine, due to a broad linear calibration ranging from 50 to 800 μM, a high sensitivity of 0.03795 μA/μM and a low detection limit of 3.47 μM. [ABSTRACT FROM AUTHOR]

The influence of quiescent molten-state annealing process on the phase structure and morphology of poly(propylene)/poly(ethylene-co-octene) blends with co-continuous morphology was studied using scanning electron microscopy (SEM). The structure parameter called characteristic length ( L) was calculated by the pattern analysis of SEM micrographs to describe morphological variation with annealing time during molten-state annealing process under quiescent condition. Moreover, the potential fractal behavior of the phase structure and morphology of PP/PEOc = 50/50 blend during the process were discussed. The histograms of P( L/ L) obtained at various annealing time fell on a master curve, demonstrating the self-similar growth of the phase structure of the blends during quiescent molten-state annealing process. [ABSTRACT FROM AUTHOR]

This work was aimed at studying the phase structure and evolution of polypropylene (PP)/poly(ethylene-1-octene) copolymer (PEOc) blends with droplet/matrix morphology using scanning electron microscopy (SEM) during quiescent molten-state annealing process. The structure parameters, such as the area diameter, d, and number average diameters, D, of the dispersed phase in PP/PEOc blends were calculated by pattern analysis of SEM images. Moreover, the potential fractal behavior of the phase structure and morphology of PP/PEOc = 80/20 blend during the process was discussed. The histograms of $$ P\left( {{d_p \left/ {{{{\overline{d}}_p}}} \right.}} \right) $$ obtained at various annealing time fell on a master curve, demonstrating the self-similar growth of the phase structure of the blends during quiescent molten-state annealing process. [ABSTRACT FROM AUTHOR]

Purpose: The land application or disposal of sewage sludge generally leads to phosphorus (P) loss in aquatic environments and often results in eutrophication. The nature of P fractions plays a key role in the transport of P within the environment, and alkaline phosphatase is important for the transformation of the P fractions. The objective of this study was to assess the P fractions and alkaline phosphatase activity in sewage sludge, soils, and sediments, in order to effectively evaluate their P bioavailability and mobility. Materials and methods: The Standards, Measurements and Testing (SMT) harmonized procedure was adopted for the determination of the P fractions. The alkaline phosphatase activities were determined by analyzing the production of p-nitrophenol from p-nitrophenylphosphate catalyzed by phosphatase in the various samples. Results and discussion: The results demonstrated that sewage sludge possessed larger amounts of P than soils and sediments. Inorganic phosphorus (IP) was the main P fraction of all the samples investigated and it always constituted >70% of the total P (TP). However, the distribution of IP between non-apatite inorganic P (NAIP) and apatite P (AP) varied significantly according to the type of sample. NAIP accounted for >60% of IP in sediment and sewage sludge samples obtained from domestic wastewater treatment plants. However, AP was more abundant than NAIP in soil samples. For the P fractions obtained in a closed agriculture test field, NAIP content showed an obvious increase from soil to sediment samples. This suggests that NAIP is the most easily mobilizable form of P. The average alkaline phosphatase activity in sewage sludge samples is significantly higher than that in soil and sediment samples, and it may be closely attributed to the higher biomass content in sewage samples. Conclusions: The results showed that the SMT protocol could be considered a useful tool for P monitoring of sewage sludge, soils, and sediments. The NAIP is the most easily mobilizable form of P and should receive further attention. The sewage sludge samples contain higher mobilizable forms of P and alkaline phosphatase activity than soil and sediment samples. The results are not only beneficial for analyzing P in sewage, soil, and sediment samples during their transfers to watercourses but are also beneficial for evaluating the risk of eutrophication and that associated with sewage sludge treatment and application. [ABSTRACT FROM AUTHOR]

The phase structure and evolution of polypropylene (PP)/poly(ethylene-1- octene) copolymer (PEOc) blends during heat preservation process under quiescent condition were studied using scanning electron microscopy (SEM). The structure parameters, such as the average area diameter d, characteristic length L, and average characteristic length L, of the dispersed phase in PP/ PEOc blends were calculated by pattern analysis of SEM images. Moreover, the potential fractal behavior of the phase structure and morphology of polymer blends during the process was discussed. The histograms of P( L( t)/ L) obtained at various time fell on a master curve, demonstrating the self-similar growth of the phase structure of the blends during heat preservation process. [ABSTRACT FROM AUTHOR]

Binary blends based on polypropylene and poly(ethylene- co-octene) were prepared in a co-rotating twin-screw extruder. A stretching process was carried out afterwards in the melt state at the extruder's exit to study the effect of stretching on morphological structures and mechanical properties. The morphological structures of the blends were investigated by scanning electron microscopy and small-angle X-ray scattering. The structure parameters, the correlation distance, the average chord lengths, and the Porod's index, obtained by the Debye-Bueche statistical theory of scattering were used to characterize the morphological structures. In addition, the relationship of mechanical properties with the structure parameters was also studied and some results were acquired. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "The Thermodynamic Behavior and Morphology of PP/POE Blends Prepared by Melt- and Solution-mixing Methods," by Jing Zhao, Xingming Shuai, Li Wang, Xinqiang Tang, Xinhua Xu, Jing Sheng, and Dinghai Huang published online March 11, 2009.

To observe the clinical effects of kanglaite (KLT) capsules combined with transcatheter arterial chemoembolization (TACE) in treating patients with mid or late-stage primary hepatocellular carcinoma (HCC). Sixty-five cases were randomly divided into 2 groups, 32 patients in combination group received the treatment of KLT capsules + TACE and 33 patients in control group were treated with TACE alone. The objective response rate (RR), serum alpha fetoprotein (AFP), peripheral blood T lymphocyte subgroups (T-LS), quality of life (QOL), time to progression (TTP) and adverse reaction were observed and compared between 2 groups. The objective response rate and serum alpha fetoprotein levels had no significant difference between the two groups ( P > 0.05). Combination group was superior to control group in quality of life (QOL), time to progression (TTP), peripheral blood T lymphocyte subgroups (CD3+, CD4+, CD4+∖CD8 ratio) and liver adverse reactions, with significant differences ( P < 0.05). KLT capsules combined with TACE is an effective method to treat primary hepatocellular carcinoma (HCC) patients who have lost the opportunity of surgical therapy. [ABSTRACT FROM AUTHOR]

The kinetics of Cr(VI) reduction to Cr(III) by metallic iron (Fe0) was studied in batch reactors for a range of reactant concentrations, pH and temperatures. Nearly 86.8% removal efficiency for Cr(VI) was achieved when Fe0 concentration was 6 g/L (using commercial iron powder (< 200 mesh) in 120 min). The reduction of hexavalent chromium took place on the surface of the iron particles following pseudo-first order kinetics. The rate of Cr(VI) reduction increased with increasing Fe0 addition and temperature but inversely with initial pH. The pseudo-first-order rate coefficients ( k obs) were determined as 0.0024, 0.010, 0.0268 and 0.062 8 min−1 when iron powder dosages were 2, 6, 10 and 14 g/L at 25°C and pH 5.5, respectively. According to the Arrehenius equation, the apparent activation energy of 26.5 kJ/mol and pre-exponential factor of 3 330 min−1 were obtained at the temperature range of 288–308 K. Different Fe0 types were compared in this study. The reactivity was in the order starch-stabilized Fe0 nanoparticles > Fe0 nanoparticles > Fe0 powder > Fe0 filings. Electrochemical analysis of the reaction process showed that Cr(III) and Fe(III) hydroxides should be the dominant final products. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to evaluate cyclooxygenase-2 (COX-2) expression in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, angiogenesis, and prognosis. Methods: The expressions of COX-2 and vascular endothelial growth factor (VEGF) and microvascular density (MVD) were determined with immunohistochemical methods in eighty-six NPC patients followed up over 5 years. Results: Sixty-three tumors (73.3%) were classified as COX-2 positive. COX-2 expression was positively related to VEGF expression (r=0.438, P<0.01) and correlated with the tumor pathological grade, extent of primary lesion, lymph node metastasis, distant metastasis and shorter survival. Conclusion: Our results suggest that COX-2, being highly expressed and strongly correlated with angiogenesis in nasopharyngeal carcinoma, is apt to be used as a predictor of prognosis, including local recurrence and distant metastasis. [ABSTRACT FROM AUTHOR]

Uniform dispersion of two-dimensional (2D) graphene materials in polymer matrices remains challenging. In this work, a novel layer-by-layer assembly strategy was developed to prepare a sophisticated nanostructure with highly dispersed 2D graphene oxide in a three-dimensional matrix consisting of one-dimensional bacterial cellulose (BC) nanofibers. This method is a breakthrough, with respect to the conventional static culture method for BC that involves multiple in situ layer-by-layer assembly steps at the interface between previously grown BC and the culture medium. In the as-prepared BC/GO nanocomposites, the GO nanosheets are mechanically bundled and chemically bonded with BC nanofibers via hydrogen bonding, forming an intriguing nanostructure. The sophisticated nanostructure of the BC/GO leads to greatly enhanced mechanical properties compared to those of bare BC. This strategy is versatile, facile, scalable, and can be promising for the development of high-performance BC-based nanocomposite hydrogels. [ABSTRACT FROM AUTHOR]