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In this study, carbon nanofibre (CNF) and vanadium-nitride-modified CNF (VNCNF) were fabricated by the electrospinning method, followed by carbonisation. The fabricated VNCNF and CNF were sandwiched between the cathode and separator to be used as interlayers. The lithium-sulphur (Li–S) cell employing the VNCNF interlayer exhibited high initial charge and discharge capacities of 1452 and 1480 mAh g−1, corresponding a coulombic efficiency higher than 100% at a rate of 0.5 C, whereas the cell with the CNF interlayer delivered the initial charge and discharge capacities of 858 and 772 mAh g−1, respectively, corresponding to a coulombic efficiency of 89.97%. Even after 400 cycles, the cell with the VNCNF interlayer retained a remarkable high capacity of 923 mAh g−1, whereas the cell with the CNF interlayer showed only 586 mAh g−1 at a rate of 0.5 C. Furthermore, the cell with the VNCNF interlayer exhibited an excellent rate capability of up to 2 C, which was much higher than those of the cells with CNF and without an interlayer. The better performance of Li–S cell with the VNCNF interlayer is attributed to the strong adsorption ability of VNCNF for polysulphide by suppressing the shuttle effect. In addition, the catalytic effect of VN in CNF accelerated the capturing and utilisation of the dissolved active materials, thereby enhancing the Red-Ox kinetics and capacity.

Composite solid polymer electrolytes (CSPEs) are promising candidates for replacing potentially hazardous organic liquid electrolytes used in Li ion batteries (LIBs). CSPEs are easy to process, have the ability to form films, and make better interfacial contact. However, their poor mechanical strength, low ionic conductivity, and long cycling stability limit their practical applications. Here, we demonstrate the fabrication of a cost-effective, flexible, self-standing, and highly stable CSPE using poly(propylene carbonate) (PPC) as the host matrix and highly mesoporous silica nanoparticles (MSNs) as the filler. The fabricated CSPE had a high ionic conductivity of approximately 8.5 × 10−4 S cm−1 at 60°C, electrochemical potential stability up to approximately 4.8 V vs. Li/Li+, an ultra-high lithium transference number of approximately 0.86, impressive stability over 1000 h of Li stripping/plating, and an excellent electrode compatibility. With cyclability over 200 cycles and a negligible overpotential, the Li/CSPE/LFP cell delivered a reversible capacity of 171 and 103 mAh g−1 at 0.1 C and 1 C, respectively, with a good rate capability up to 5 C. The interaction of Li+ with PPC and the MSNs is demonstrated by solid-state magic angle spinning nuclear magnetic resonance (MAS-NMR) and X-ray photoelectron spectroscopy (XPS) studies. The enhanced physico-electrochemical properties of the CSPE were attributed to the large MSNs-related surface area, which enables firm interaction with the PPC matrix and provides a less-tortuous polymer-ceramic phase for fast lithium ion transportation. The proposed MSNs-reinforced CSPE thus opens new possibilities for the fabrication and engineering of solid-state batteries.

Sodium-ion batteries are being explored as an alternative to the Li-ion batteries, due to the abundance of Na and similar electrochemistry with that of Li. In this study, we report the electrochemical activity of octahedron-like antimony trioxide nanostructures for Na-ion batteries, prepared with the simple hydrothermal oxidation of antimony precursor in alkaline condition. The microstructure reveals the formation of octahedron-like microcrystals with cubic antimony trioxide phase. In Na-ion cells, the antimony trioxide electrode exhibits a reversible specific capacity of 623 mAh g−1 on the first charge and long cycle stability of 200 cycles losing only 9% capacity. The exceptional electrochemical performance achieved by antimony trioxide is owing to the conversion and alloying reactions mechanism, which accelerates the kinetics of the reactions by stabilizing the structure of anode material.

Binary Mn/Co oxide sheets with spherical flower-like hierarchical structure are grown directly on the surface of a Ni foam skeleton as a cathode for Li–O2 batteries using a hydrothermal method. This integrated cathode architecture eliminates the negative effects of a conductive carbon additive and binder on the electrochemical performance of Li–O2 batteries and minimizes the processing steps in fabrication of cathodes for Li–O2 batteries. The porous Ni foam acts as a scaffold and current collector, and the highly hierarchical porous flower-like structure of the binary Mn/Co oxide sheet acts as a highly active catalyst. Together, they facilitate effective diffusion of oxygen gas as well as rapid ion and electron conduction during electrochemical reactions. When assembled in Li–O2 cells, the prepared catalyst exhibits excellent catalytic activities, including the oxygen reduction and oxygen evolution reactions. In particular, the Li–O2 cell using the cathode delivers an extremely high specific discharge capacity of 9690 mAh g-1 under a applied specific current of 200 mA g-1 and operate successfully in a long lifespan of 66 cycles even under a high specific current of 600 mA g-1 and a limited discharge-charge capacity mode of 1000 mAh g-1. The simultaneous effect of the fast electron transport kinetics provided by the free-standing structure and the high catalytic activity of the binary Mn/Co oxide show promise for use in air electrodes for Li–O2 batteries.

Owing to its lowest standard redox potential, low density, and high theoretical specific capacity, lithium metal has been considered to be the ideal anode material for secondary lithium batteries. ...

We report the rational design and fabrication of unusual low-dimensional DNA nanostructures through programmable and sequence-specific peptide interactions. Dual-bioactive block copolymers composed of DNA and amino acid-based polymers (DNA-b-poly(amino acid)) were synthesized by coupling oligonucleotides to phenylalanine (Phe)-based polymers. Unlike prototypical DNA block copolymers, which typically form simple spherical micelles, DNA-b-poly(amino acid) assemble into various low-dimensional structures such as nanofibers, ribbons, and sheets through controllable amino acid interactions. Moreover, DNA-b-poly(amino acid) assemblies can undergo protease-induced fiber-to-sheet shape transformations, where the morphology change is dictated by the type of enzymes and amino acid sequences. The peptide-based self-assembly reported here provides a programmable approach to fabricate dynamic DNA assemblies with diverse and unusual low-dimensional structures.

Electrochemical Li-CO2 cells, which provide a sustainable and environmentally friendly pathway away from greenhouse gases, often suffer from sluggish kinetics for the growth and evolution of the ca...

The End-stage Renal Disease Registry Committee of the Korean Society of Nephrology collects data on the dialysis therapy in Korea through an internet-based registry program and reports it annually. In this article, the method and clinical implications of the mortality hazard ratio analyses of various clinical parameters in the 2017 registry report have been described, with the inclusion of data on four additional parameters. The mortality risk based on clinical parameters was analyzed only for hemodialysis patients. The number of registered patients with laboratory data was 13,943 (8,446 male and 5,497 female patients), and death was reported in 3,139 patients. Analysis of the effects of various clinical parameters on mortality was performed using non-linear Cox proportional hazard model with the R statistics program. For all clinical parameters, univariate and adjusted multivariate hazard ratio analyses were performed. Analysis of the mortality hazard ratio showed that low body mass index, low hemoglobin, low serum albumin, low serum phosphorus, and low urea reduction ratio were associated with a significantly increased mortality risk, whereas paradoxically high serum creatinine levels were associated with low mortality risk.

New anode materials with large capacity and long cyclability for next-generation potassium-ion batteries (PIBs) are required. PIBs are in the initial stage of investigation and only a few anode materials have been explored. In this study, for the first time, an SnP3/C nanocomposite with superior cyclability and rate performance was evaluated as an anode for PIBs. The SnP3/C nanocomposite was synthesized by a facile and cost-effective high-energy ball-milling technique. The SnP3/C electrode delivered a first reversible capacity of 410 mAh g-1 and maintained 408 mAh g-1 after 50 cycles at a specific current of 50 mA g-1. After 80 cycles at a high specific current of 500 mA g-1, a high capacity of 225 mAh g-1 remained. From a crystallographic analysis, it was suggested that the SnP3/C nanocomposite underwent a sequential and reversible conversion and alloying reactions. The excellent cycling stability and rate capability of the SnP3/C electrode were attributed to the nanosized SnP3 particles and carbon buffer layer, which supplied channels for the migration of K-ions and mitigated the stress induced by a large volume change during potassiation/depotassiation. In addition, a full cell composed of the SnP3/C nanocomposite anode and potassium Prussian blue cathode exhibited a reversible capacity of 305 mAh g-1 at a specific current of 30 mA g-1 and retained 71.7% of the original capacity after 30 cycles. These results are important for understanding the electrochemical process of the SnP3/C nanocomposite and using the SnP3/C as an anode for PIBs.

Background Many studies have evaluated the usefulness of creatinine- (eGFRcr) and cystatin C-based estimated glomerular filtration rate (eGFRcys) at specific time points in predicting renal outcome. This study compared the performance of both eGFR changing slopes in identifying patients at high risk of end-stage renal disease (ESRD). Methods From 2012 to 2017, patients with more than three simultaneous measurements of serum creatinine and cystatin C for 1 year were identified. Rapid progression was defined as eGFR slope

Endocrine disrupting chemicals (EDCs) in the environment are considered to be a contributing factor to the decline in the sperm quality. With growing evidence of the harmful effects of EDCs on the male reproductive system, we tested the hypothesis that prenatal exposure to an environmentally relevant phthalate mixture adversely affects reproductive outcomes and androgen synthesis. In this study, an environmentally relevant composition of phthalates (15% DiNP, 21% DEHP, 36% DEP, 15% DBP, 8% DiBP, and 5% BBzP) that were detected in urine samples of pregnant women in Illinois, United States, was used. Pregnant CD-1 mice (F0) were orally dosed with a vehicle or the phthalate mixtures (20 µg/kg/day, 200 µg/kg/day, 200 mg/kg/day, or 500 mg/kg/day) from gestational day 10.5 to the day of birth. Then, the indices of the reproductive function of the F1 males born to these dams were assessed. Those male mice prenatally exposed to the phthalate mixture had smaller gonads, prostates and seminal vesicles, especially in the 20 µg/kg/day and 500 mg/kg/day phthalate mixture groups, compared to the controls. Importantly, at the age of 12 months, those prenatally exposed mice had significantly lower serum testosterone concentrations accompanied by the decreased mRNA expression of testicular steroidogenic genes (StAR, Cyp11, and Cyp17) and impaired spermatogenesis. Taken together, this study found that prenatal exposure to environmentally relevant doses of a phthalate mixture caused a life-long impact on the reproduction in male mice.

We report the first demonstration of the efficient bacteria targeting properties of DNA-based polymeric micelles with high-density DNA corona. Nanoscale polymer micelles derived from DNA-b-polystyrene (DNA-b-PS) efficiently selected most tested Gram-positive strains over Gram-negative strains; single-strand DNAs were 20-fold less selective. We demonstrate that these targeting properties were derived from the interaction between densely packed DNA strands of the micelle corona and the peptidoglycan layers of Gram-positive bacteria. DNA-b-PS micelles incorporating magnetic nanoparticles (MNPs) can efficiently capture and concentrate Gram-positive bacteria suggesting the simple applications of these DNA block copolymer micelles for concentrating bacteria. Adenine (A), thymine (T), cytosine (C), and guanine (G)-rich nanostructures were fabricated, respectively, for investigating the effect of sequence on Gram-selective bacteria targeting. T-rich micelles showed the most efficient targeting properties. The targeting properties of these DNA nanostructures toward Gram-positive bacteria may have applications as a targeted therapeutic delivery system. Agency for Science, Technology and Research (A*STAR) Ministry of Education (MOE) Nanyang Technological University Accepted version This work was funded and supported by an ASTAR RIE2020 Advanced Manufacturing and Engineering (AME) IAP-PP Specialty Chemicals Programme (SERC Grant No. A1786a0032), the Singapore MOE Tier 3 grant (MOE2018-T3-1-003) and the NTU NAFTEC funding. Zhangyong Si and Jianghua Li acknowledge the support of NTU through an NTU Research scholarship. Zhang Kaixi acknowledges the support of NTU through an Interdisciplinary Graduate School (IGS) (HealthTech) PhD scholarship.

PURPOSE To compare the effect of 3 tray designs and 3 commonly used impression materials on the displacement of flabby tissue during maxillary edentulous impression by superimposition of 3D digital models. MATERIALS AND METHODS Fifteen maxillary edentulous casts with simulated flabby tissue were fabricated by modifying a standard maxillary edentulous acrylic resin cast. Three types of impression trays were fabricated: trays with conventional relief, trays with additional relief, and trays with an open window. Three impression materials were tested: light-body polysulfide, light-body vinylpolysiloxane, and zinc oxide eugenol paste. For the analysis of tissue displacement during impression making, the test and control stone casts were scanned using a 3D laser scanner, and the 3D digital models were superimposed using metrology software. Statistical analyses were performed with an α = 0.05. RESULTS Negative deviations were recorded at the areas of the alveolar crest, posterior part of flabby tissue, and middle of the palate. On the other hand, a positive deviation was recorded at the area of the anterior part of flabby tissue. A significant difference in the displacement of flabby tissue was found when using different tray designs (p < 0.0001). The tray with the open window showed significantly low tissue displacement at the flabby tissue region. Depending on sites, the amount of flabby tissue displacement showed different significances by the different impression materials used (anterior part: p < 0.0001; alveolar crest: p = 0.097; posterior part: p < 0.0001). Conventionally relieved trays showed significantly higher values of displacement at the anterior part of flabby tissue (p < 0.0001), while trays with open windows showed similar values of displacement at all measuring points, and no significant differences among different impression materials were found (p = 0.104). CONCLUSIONS There were significant differences in the displacement of flabby tissue with different tray designs, especially with displacement occurring at the anterior and posterior parts of flabby tissue. Tray designs should be considered in order to make proper impressions when flabby tissue is present.

Objectives To verify the anti-catabolic effects of acteoside [α-L-rhamnosyl-(1->3)-β-D-glucoside] against osteoarthritis and its anti-catabolic signaling pathway. Methods Primary rat chondrocytes were isolated enzymatically from the articular cartilage of rat knee joint. Cytotoxicity of acteoside was assessed by MTT and Cell Live/Dead assay. Proteoglycan content was measured by dimethylmethylene blue assay. The proteoglycan loss was assessed by histological analysis using safranin-O & fast green staining after ex vivo organ culture of articular cartilage. The alteration of catabolic factors such as cartilage degrading enzymes, pro-inflammation cytokines, and inflammatory mediators were assessed by qPCR, qRT-PCR, gelatin zymography, western blot, and cytokine array. Cellular signaling pathways were investigated by western blot and nucleus translocation. Acteoside was orally administrated to osteoarthritic animals generated by the destabilization of medial meniscus at the knee joint of mice for 8 weeks. Thereafter, proteoglycan loss was assessed by safranin-O & fast green staining. Results Acteoside did not decrease the viabilities of mouse fibroblast L929 cells used as a normal cells and primary rat chondrocytes. Acteoside counteracted the IL-1β-induced proteoglycan loss in the chondrocytes and articular cartilage through suppressing the expression and activation of cartilage-degrading enzyme such as matrix metalloproteinase (MMP)-13, MMP-1, and MMP-3. Furthermore, acteoside suppressed the expression of inflammatory mediators such as inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2 in the primary rat chondrocytes treated with IL-1β. Subsequently, the expression of pro-inflammatory cytokines was decreased by acteoside in the primary rat chondrocytes treated with IL-1β. Moreover, acteoside suppressed not only the phosphorylation of mitogen-activated protein kinases in primary rat chondrocytes treated with IL-1β but also the translocation of NFκB from the cytosol to the nucleus through suppression of its phosphorylation. Oral administration of 5 and 10 mg/kg acteoside attenuated the progressive degeneration of articular cartilage in the osteoarthritic mouse model generated by destabilization of the medial meniscus. Conclusion Our findings indicate that acteoside is a promising potential anti-catabolic agent or supplement to attenuate or prevent progressive degeneration of articular cartilage.

Lithium metal has attracted much attention as an anode material for high-performance batteries owing to its high specific capacity and electrode potential. However, the Li metal electrode could suffer from the dendritic growth of Li during the cell operation due to the high reactivity of Li with organic electrolytes. To address this issue, we propose the use of thiourea as an electrolyte additive for Li metal-based batteries. The thiourea additive in LiTFSI/TEGDME electrolyte allowed the formation of a stable and uniform solid electrolyte interface layer on the Li electrode, thereby aiding the suppression of dendritic growth of Li and further electrolyte decomposition. Accordingly, a Li symmetric cell containing the thiourea additive exhibited six-times longer cycle life than a cell without the additive. Further, the electrolyte additive was also successfully employed in a Li-O2 cell to improve its cyclability.

Phthalates are a family of synthetic chemicals that are used in producing a variety of consumer products. Di-(2-ethylhexyl) phthalate (DEHP) is an widely used phthalate and poses a public health concern. Prenatal exposure to DEHP has been shown to induce premature reproductive senescence in animal studies. In this study, we tested the hypothesis that prenatal exposure to DEHP impairs neurobehavior and recognition memory in her male offspring and we investigated one possible mechanism-oxidative damage in the hippocampus. Pregnant CD-1 female mice were orally administered 200 μg, 500 mg, or 750 mg/kg/day DEHP or vehicle from gestational day 11 until birth. The neurobehavioral impact of the prenatal DEHP exposure was assessed at the ages of 16-22 months. Elevated plus maze and open field tests were used to measure anxiety levels. Y-maze and novel object recognition tests were employed to measure memory function. The oxidative damage in the hippocampus was measured by the levels of oxidative DNA damage and by Spatial light interference microscopic counting of hippocampal neurons. Adult male mice that were prenatally exposed to DEHP exhibited anxious behaviors and impaired spatial and short-term recognition memory. The number of hippocampal pyramidal neurons was significantly decreased in the DEHP mice. Furthermore, DEHP mice expressed remarkably high levels of cyclooxygenase-2, 8-hydroxyguanine, and thymidine glycol in their hippocampal neurons. DEHP mice also had lower circulating testosterone concentrations and displayed a weaker immunoreactivity than the control mice to androgen receptor expression in the brain. This study found that prenatal exposure to DEHP caused elevated anxiety behavior and impaired recognition memory. These behavioral changes may originate from neurodegeneration caused by oxidative damage and inflammation in the hippocampus. Decreased circulating testosterone concentrations and decreased expression of androgen receptor in the brain also may be factors contributing to the impaired neurobehavior in the DEHP mice.

In addition to their optoelectronic applications, Zn-based oxides and sulfides have also been widely studied as electrode materials in Li-ion batteries owing to their high theoretical capacity. However, both the materials suffer from a drastic loss in capacity due to their poor conductivity and electrochemical instability. A very efficient and carefully controlled combination of these two may address these limitations. In this work, thin films of zinc oxysulfide (ZnOS) with an O/(O + S) ratio of ∼0.7 were deposited using a combination of oxide and sulfide atomic layer deposition (ALD) cycles; they were then tested as anodes in Li-ion batteries. The material was grown directly on a stainless steel substrate (SS), characterized extensively using several ex situ characterization tools, and then used as an anode with no binder or conductive additives. Cyclic voltammetry measurements were used to confirm the reversible conversion of ZnOS in addition to the well-known alloying–dealloying Li–Zn reaction. The material loading was further optimized by varying the number of ALD supercycles to attain the maximum stable cycling performance. The highest stable capacities of 632.9 and 510.3 mA h g−1 were achieved at current densities of 0.1 and 1 A g−1 (∼4 and 40 μA cm−2), respectively, for a ZnOS film with an optimum thickness of ∼75 nm. The optimized ZnOS anode exhibited superior electrochemical performance in comparison to the equivalent pristine ZnO and ZnS anodes. Finally, the post-cycling analysis of the binder-free ALD grown ZnOS anodes demonstrated excellent adhesion to the SS substrate and the high stability of these films upon cycling.

Solid electrolytes are a potential candidate for mitigating the safety issues associated with organic liquid-electrolyte-based conventional Lithium-Ion Batteries (LIBs). The film-forming ability, cost-effective fabrication, and superior interfacial contact of solid polymer electrolytes make them particularly appealing for application in all-solid-state LIBs (ASSLIBs). However, their practical applications are limited owing to their low lithium-ion conductivity and inadequate mechanical strength. In this study, we fabricated a highly flexible, soft, self-standing, and stable composite solid polymer electrolyte (CSPE) using poly(propylene carbonate) (PPC) as the main matrix and Na-superionic-conductor-type Li1.5Al0.5Ge1.5(PO4)3 (LAGP) as the active inorganic filler. The fabricated CSPE exhibited an attractive ionic conductivity of ∼0.56 mS∙cm−1, a wide electrochemical potential stability of ∼5 V vs. Li/Li+, a high lithium-ion transference number of ∼0.77, outstanding stability up to 1000 cycles of lithium plating/stripping, and better compatibility with lithium metal. In addition to these outstanding properties, the Li/CSPE/LiFePO4 (Li/CSPE/LFP) cell exhibited an impressive discharge capacity of 151 mAh∙g−1 at 0.1 C. Furthermore, at a rate of 1 C, the Li/CSPE/LFP cell delivered an initial discharge capacity of 96 mAh∙g−1, with a capacity retention of 63% over 1000 cycles. The interaction of lithium ions with the PPC was confirmed based on solid-state MAS NMR and XPS. The enhanced electrochemical performance of the CSPE is ascribed to the interaction of the LAGP filler with the PPC matrix, which forms a good polymer-inorganic interface, enabling the rapid lithium-ion transport. The proposed LAGP-reinforced CSPE presents new opportunities for the fabrication and engineering of ASSLIBs.

Europium-doped UCr4C4 cuboid phosphors with narrow and tunable emission show promise for application in designing light-emitting diodes with high color purity and thermal stability. Nevertheless, their poor chemical stability bottlenecks their use in lighting applications. Herein, a dual narrow-band blue-emitting Ce3+-doped CsNa2K(Li3SiO4)4 (CNKLSO) cuboid phosphor with a quantum yield of 80% is synthesized. The dual-band emission is attributed to the occupation of Ce3+ at two distinct sites of CNKLSO, which is consistent with the density functional theory outcomes. Ce3+ doping produces stable emission characteristics, in contrast to Eu2+ incorporation, because of the improved site stability, as realized from bond valence sum calculations. Remarkably, no drop in the emission intensity is observed even at 200 °C, making CNKLSO:Ce3+ the first Ce3+-based zero-thermal-quenching phosphor. A CNKLSO:Ce3+-based white light-emitting diode displays an excellent color rendering index (~95) at a high flux current of 1000 mA. The proposed study indicates that Ce3+ doping in other UCr4C4- type oxide phosphors may improve the site stability, which in turn the chemical stability of the phosphor materials can be boosted.

Background It is thought that hyperuricemia might lower the risk of mortality among hemodialysis patients, unlike in the general population, but the evidence is controversial. The aim of the current study was to evaluate the impact of serum uric acid level on the long-term clinical outcomes of hemodialysis patients in Korea. Methods Retrospective analysis was performed on data from the End-Stage Renal Disease Registry of the Korean Society of Nephrology. This included data for 7,333 patients (mean age, 61 ± 14 years; 61% male) who received hemodialysis from January 2001 through April 2015. Initial laboratory data were used in the analysis. Results The mean serum uric acid level in this study was 7.1 ± 1.7 mg/dL. Body mass index, normalized protein catabolic rate, albumin, and cholesterol were positively correlated with serum uric acid level after controlling for age and sex. After controlling for demographic data, comorbidities, and residual renal function, a higher uric acid level was independently associated with a significantly lower all-cause mortality (hazard ratio [HR], 0.90 per 1 mg/dL increase in uric acid level; 95% confidence interval [CI], 0.83-0.97; P = 0.008), but not cardiovascular mortality (HR, 0.90; 95% CI, 0.80-1.01; P = 0.078). Comparing uric acid levels in the highest and lowest quintiles, the HR for all-cause mortality was 0.65 (95% CI, 0.42-0.99; P = 0.046). Conclusion Hyperuricemia was strongly associated with a lower risk of all-cause mortality, but there seems to be no significant association between serum uric acid level and cardiovascular mortality among Korean hemodialysis patients with end-stage renal disease.

The need to identify lithium ion battery anodes consisting of new materials that display high energy density and good cycling stability has interested the research on reversible so-called conversion reaction between lithium and molybdenum oxides such as ternary metal oxide (Li2Mo4O13). Polycrystalline Li2Mo4O13 was synthesized by conventional solid-state reaction route and explored as new potential anode material for secondary lithium ion battery applications vs. Li+/Li in half-cell mode. The electrochemical performance of the Li2Mo4O13 electrode was studied by cyclic voltammograms and galvanostatic discharge-charge cycling under different rates. In the working voltage between 2.5 V and 0.1 V, Li2Mo4O13 shows a high first charge capacity of 1062 mAh g−1 at current rate of C/10 (24 Li react with 10 h) and a superior rate capability with capacity retention of 1008, 842, 713 and 640 mAh g−1 under current rates of C/10, C/5, C/3 and C/2 (24Li react with in 2 h), respectively. Further, the cycling performance was evaluated at C/3 rate (424 mA g−1) and after 100 cycles a reversible capacity of 550 mAh g−1 was obtained with columbic efficiency of ∼100%. Ex-situ XRD studies confirmed that the electrochemical reaction involves insertion of 5Li/f.u vs. Li+/Li during discharge to 1.3 V and the crystal structure was retained when charged to 2.5 V. Below 0.8 V, conversion reaction occurs leading to amorphization of the phase. When discharged to 0.1 V, Mo+6 is reduced to Mo0 state on the basis of the conversion reaction.

A pre-bloom application of gibberellin (GA) on grapevines (Vitis spp.) induces fruit set without fertilization (parthenocarpy) by inhibiting pollen tube growth. In the present study, we analyzed transcriptional changes in the Vitis γ-aminobutyric acid (GABA) metabolic genes and the levels of GABA in grapevines with or without GA treatment to understand how GA induces parthenocarpy in grapevines. Four Vitis glutamate decarboxylases (VvGAD), two GABA transaminases (VvGABA-T), and three succinic semialdehyde dehydrogenases (VvSSADH) were identified in grapevines, and their expression patterns were analyzed during inflorescence development from 14 days before full bloom (DBF) to 5 days after full bloom (DAF). Without GA treatment, we observed simultaneously high expression levels of VvGAD1 and VvGABA-T2, with low levels of GABA from 10 to 5 DBF. With GA application, the levels of GABA were mostly unaltered, and the expression levels of VvGAD1 and VvGABA-T2 were around 30% lower compared to the plants without GA treatment at 12 DBF. However, at near full bloom in the plants treated with GA, GABA levels increased more than two-fold and VvGAD1 was upregulated. These results indicate that GABA levels are tightly regulated by VvGAD1 and VvGABA-T2 before pollination and that application of GA alters the pattern of GABA accumulation at near full bloom. This is the first report to describe how treatment with GA disrupts the crosstalk between the pistil and pollen via changes in GABA metabolism during GA-mediated parthenocarpic fruit initiation.

The mixed-potential gas sensors appeared as the most promising sensing technology for the in-situ quantification of exhaust pollutants due to their simple configuration, low-cost, and thermochemical stability. Presently, high sensitivity and selectivity supplemented by long-term stability is the bottleneck challenge for these sensors to commercialize. Herein, highly sensitive and ammonia (NH3) selective mixed-potential gas sensors were developed using surface decorated CuFe2O4 (CFO)–MOX (M = Sn, Ni, Zn) composite sensing electrodes (SE). The CFO–NiO SE enriched of the surface oxygen vacancies produced a maximum response of −62 mV to 80 ppm NH3, supported by excellent sensitivity at 650 ℃. The comprehensive analysis of the response behavior and current-voltage (I–V) characteristics verified the sensing mechanism to be based upon the mixed-potential model conforming to the reaction-rate limited Butler–Volmer NH3 oxidation kinetics. Finally, the distribution of relaxation times (DRT) analysis of impedance spectra confirmed that the overall polarization resistance was invariable of the mass-transport processes and solely governed by the extent of interfacial redox reactions proceeding at the triple-phase boundaries (TPB). Moreover, the high sensitivity, selectivity, and exceptional stability over five months substantiate the suitability of the presented sensor as a potential candidate for in-situ ammonia quantifications in industrial and automotive applications.

In males, defective reproductive traits induced by an exposure to an endocrine disruptor are transmitted to future generations via epigenetic modification of the germ cells. Interestingly, the impacted future generations display a wide range of heterogeneity in their reproductive traits. In this study, the role that the Y chromosome plays in creating such heterogeneity is explored by testing the hypothesis that the Y chromosome serves as a carrier of the exposure impact to future generations. This hypothesis implies that a male who has a Y chromosome that is from a male that was exposed to an endocrine disruptor will display a more severe reproductive phenotype than a male whose Y chromosome is from an unexposed male. To test this hypothesis, we used a mouse model in which F1 generation animals were exposed prenatally to an endocrine disruptor, di-2-ethylhexyl phthalate (DEHP), and the severity of impacted reproductive traits was compared between the F3 generation males that were descendants of F1 males (paternal lineage) and those from F1 females (maternal lineage). Pregnant dams (F0 generation) were exposed to the vehicle or 20 or 200 μg/kg/day of DEHP from gestation day 11 until birth. Paternal lineage F3 DEHP males exhibited decreased fertility, testicular steroidogenic capacity, and spermatogenesis that were more severely impaired than those of maternal lineage males. Indeed, testicular transcriptome analysis found that a number of Y chromosomal genes had altered expression patterns in the paternal lineage males. This transgenerational difference in the DEHP impact can be attributed specifically to the Y chromosome.

BACKGROUND: Tacrolimus is used as a steroid-sparing immunosuppressant in adults with minimal change nephrotic syndrome. However, combined treatment with tacrolimus and low-dose steroid has not been compared with high-dose steroid for induction of clinical remission in a large-scale randomized study. METHODS: In this 24-week open-label noninferiority study, we randomized 144 adults with minimal change nephrotic syndrome to receive 0.05 mg/kg twice-daily tacrolimus plus once-daily 0.5 mg/kg prednisolone, or once-daily 1 mg/kg prednisolone alone, for up to 8 weeks or until achieving complete remission. Two weeks after complete remission, we tapered the steroid to a maintenance dose of 5–7.5 mg/d in both groups until 24 weeks after study drug initiation. The primary end point was complete remission within 8 weeks (urine protein: creatinine ratio 3.0 g/g) after complete remission to within 24 weeks of study drug initiation. RESULTS: Complete remission within 8 weeks occurred in 53 of 67 patients (79.1%) receiving tacrolimus and low-dose steroid and 53 of 69 patients (76.8%) receiving high-dose steroid; this difference demonstrated noninferiority, with an upper confidence limit below the predefined threshold (20%) in both intent-to-treat (11.6%) and per-protocol (17.0%) analyses. Groups did not significantly differ in time until remission. Significantly fewer patients relapsed on maintenance tacrolimus (3–8 ng/ml) plus tapered steroid versus tapered steroid alone (5.7% versus 22.6%, respectively; P=0.01). There were no clinically relevant safety differences. CONCLUSIONS: Combined tacrolimus and low-dose steroid was noninferior to high-dose steroid for complete remission induction in adults with minimal change nephrotic syndrome. Relapse rates were significantly lower with maintenance tacrolimus and steroid compared with steroid alone. No clinically-relevant differences in safety findings were observed.

High efficient removal and recovery of uranium and thorium from nuclear waste solution are essential for environmental preservation and fuel recycle. A new polymer fiber adsorbent (UHMEPE-g-PAO fiber), prepared by amidoximation of grafted polyacrylonitrile onto Ultra High Molecular Weight Polyethylene (UHMWPE) fiber, was used to remove the uranyl and thorium ions from acid aqueous solutions and its performance was carefully investigated. It was found that uranyl ion can penetrate the fiber through the connected pore structures, forming (UO2) (R-C(NH2)-NO)2 chelates with the amidoxime groups within the fiber. Two amidoxime groups (U-N and U-Oeq) and two water molecules (U-Oeq2) are bound to uranyl ion in the fiber. On the contrary, thorium ions are adsorbed mainly on the fiber surface in the form of Th(OH)4 precipitate that blocks the entrance of Th4+ ion into fiber pores. The maximum included other two capacities of uranyl and thorium ions were estimated to be 262.01 mg/g and 160 mg/g at room temperature with pH 3.0, respectively. The results also indicate that the UHMWPE-g-PAO fiber has higher adsorption selectivity for uranyl ion than thorium ion. Uranium and thorium oxide particles were obtained as the ultimate product after sintering of the fiber adsorbent. This novel and environmentally friendly adsorption process is feasible to extract uranium or thorium from acidic aqueous solution.

Herein, we report the self-assembly and multimodal shape transformation of dual-responsive DNA di- and triblock copolymers. Dual-responsive DNA diblock copolymer was synthesized by coupling a thermoresponsive polymer, poly(N-isopropylacrylamide (PNIPAM), and an oligonucleotide. DNA-b-PNIPAM possesses thermoresponsive properties of PNIPAM as well as molecular recognition properties of DNA. Thus, they undergo reversible temperature-triggered transition at lower critical solution temperature (LCST) between molecular DNA and polymer micelles with high density DNA corona. The hybridization of DNA-b-PNIPAM and DNA-modified nanoparticles generates functional nanoparticles showing unique temperature-dependent aggregation and disaggregation behaviors due to the dual-responsive nature of DNA-b-PNIPAM. DNA triblock copolymers of DNA-b-PNIPAM-b-PMA were synthesized by introducing a hydrophobic block, poly(methyl acrylate) (PMA), to DNA/PNIPAM block copolymers, which form spherical micelles at room temperature. They are capable of nanoscale shape transformation through the combination of thermal trigger and DNA binding. DNA-b-PNIPAM-b-PMA micelles undergo sphere-to-cylinder shape changes above LCST due to the conformational change of PNIPAM. The shape change is reversible, and fast cylinder-to-sphere transition occurs when the temperature is lowered below LCST. The low temperature spherical morphology can also be accessed while keeping the temperature above LCST by introducing complementary DNA strands with single stranded overhang regions. These results demonstrate the multidimensional shape changing capability of DNA-b-PNIPAM-b-PMA enabled by the dual-responsive property.

A composite gel polymer electrolyte (CGPE) based on poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) polymer that includes Al-doped Li0.33La0.56TiO3 (A-LLTO) particles covered with a modified SiO2 (m-SiO2) layer was fabricated through a simple solution-casting method followed by activation in a liquid electrolyte. The obtained CGPE possessed high ionic conductivity, a large electrochemical stability window, and interfacial stability-all superior to that of the pure gel polymer electrolyte (GPE). In addition, under a highly polarized condition, the CGPE effectively suppressed the growth of Li dendrites due to the improved hardness of the GPE by the addition of inorganic A-LLTO/m-SiO2 particles. Accordingly, the Li-ion polymer and Li-O2 cells employing the CGPE exhibited remarkably improved cyclability compared to cells without CGPE. In particular, the CGPE as a protection layer for the Li metal electrode in a Li-O2 cell was effective in blocking the contamination of the Li electrode by oxygen gas or impurities diffused from the cathode side while suppressing the Li dendrites.

Herein, we report a dynamic DNA nanostructure exhibiting switchable and size-selective molecular recognition properties. A DNA block copolymer, polystyrene-b-DNA (PS-b-DNA), and a thermo-responsive block copolymer, PS-b-poly(N-isopropylacrylamide) (PS-b-PNIPAM), were simultaneously assembled to form hybrid micelles composed of a PS core and a DNA/PNIPAM corona. PNIPAM strands did not significantly hinder the binding of molecular DNA for a broad range of PNIPAM lengths. On the other hand, they exerted significant steric hindrance for interactions with nanoscale species, which can be reversibly turned off by increasing the temperature above the lower critical solution temperature (LCST) of PNIPAM. Owing to the switchable and size-selective steric hindrance, the hybrid DNA micelles showed thermally controllable enzymatic degradation and cellular uptake. These results demonstrate that the binary self-assembly of two different responsive block copolymers is a promising approach to prepare dynamic nanostructures with controllable biological recognition properties.

Sanitary pads and diapers are made of synthetic plastic materials that can potentially be released while being used. This study measured the amounts of volatile organic compounds (VOCs) (methylene chloride, toluene, and xylene) and phthalates (DBP, DEHP, DEP, and BBP) contained in sanitary pads and diapers. In sanitary pads, 5,900- and 130-fold differences of VOC and phthalate concentrations were seen among the brands. In the diapers, 3- and 63-fold differences of VOC and phthalate concentrations were detected among the brands. VOC concentrations from the sanitary pads and diapers were similar to that of the residential air. However, phthalate concentrations of sanitary pads and diapers were significantly higher than those found in common commercial plastic products. As sanitary pads and diapers are in direct contact with external genitalia for an extended period, there is a probability that a considerable amount of VOCs or phthalates could be absorbed into the reproductive system.

Here, we report one-step DNA functionalization of hydrophobic iron oxide nanoparticles (IONPs) using DNA-grafted poly(acrylic acid) (PAA- g-DNA). PAA- g-DNA was synthesized by coupling PAA to amine-modified oligonucleotides via solid-phase amide chemistry, which yielded PAA grafted with multiple DNA strands with high graft efficiencies. Synthesized PAA- g-DNA was utilized as a phase-transfer and DNA functionalization agent for hydrophobic IONPs, taking advantage of unreacted carboxylic acid groups. The resulting DNA-modified IONPs were well dispersed in aqueous solutions and possessed DNA binding properties characteristic of polyvalent DNA nanostructures, showing that this approach provides a simple one-step method for DNA functionalization of hydrophobic IONPs.

Amidoxime-based polyethylene fiber plays an important role in sequestering uranium from seawater. Co-grafting carboxyl groups with amidoxime onto polyethylene fibers can enhance the uranium sorption efficiency. This work aims to theoretically understand the complexation of uranyl with amidoxime-, carboxyl- and mixed amidoxime/carboxyl-based host architectures within a polyethylene fiber. Using density functional theory method, we examined the geometrical structures, the electronic structures and the thermodynamic stabilities of various substitution complexes, as well as the effect of host structure on these complexes. The results showed that the affinity of amidoximate (AO−) for uranyl is similar to that of CO32−, but stronger than that of carboxyl (AA−). For the uranyl complexes with separate mixed amidoximate/carboxyl, the U–O(AO−), U–N(AO−) and U–O(AA−) bonds show the decreasing order of covalent character. However, for the uranyl complexes with mixed amidoximate/carboxyl-based host architectures, the covalent character of U–O(AO−), U–O(AA−) and U–N(AO−) bonds decrease in sequence. HAA is thermodynamically more favorable to react with UO2(CO3)34− forming a complex than HAO, which is due to the higher dissociation ability of HAA compared to HAO. The dissociated H+ from HAA is conducive for the dissociation of UO2(CO3)34−, which is possibly the origin of the synergistic effects between HAO and HAA in the uranium extraction process from seawater. The host structures have a strong impact on the interaction between uranyl and the amidoxime-, carboxyl- and mixed amidoxime/carboxyl-based host architectures. Comparing all the host architectures, those with –(CH2)4– and –(CH2)3– as linkages are more appropriate for uranyl together with one CO32− group.

Nickel-titanium oxide (NiTiO3; NTO) of an ilmenite structure that comprises a layered transition-metal octahedral structure, wherein the zigzag open tunnels are possible routes for Na intercalation, can be a potential anode material for sodium (Na) ion batteries (SIBs). In this study, nanocrystalline NTO particles that are of sizes 3 to 5 nm were prepared using a simple hydrothermal process followed by annealing, and the particles were then tested for SIB applications. The pure-NTO electrode that comprises a hexagonal crystal structure and mesoporous morphology demonstrated a reversible capacity of approximately 521 mA h g−1 that corresponds to a coulombic efficiency of 67% in the first cycle, which further improved to ∼98% in the following cycles, at an applied specific current of 50 mA g−1, and stable cycling performance for 200 cycles. Further, due to the synergetic effect of the porous network structure and high surface area, the NTO electrode exhibited an exceptional rate capability, delivering a capacity of 192 mA h g−1 at a high specific current of 4000 mA g−1. The excellent cyclability and rate capability of the NTO electrode are attributed to the improved electronic conductivity and highly porous microstructure of the NTO material, whereby fast charge transfer and facile diffusion of the Na-ions to the active sites are enabled.

Although the electronic properties of conducting films have been widely explored in optoelectronic fields, the optical absorption abilities of surface-coated films for photothermal conversion have been relatively less explored in the production of antibacterial coatings. Here, we present catechol-conjugated poly(vinylpyrrolidone) sulfobetaine (PVPS) and polyaniline (PANI) tightly linked by ionic interaction (PVPS:PANI) as a novel photothermal antibacterial agent for surface coating, which can absorb broadband near-infrared (NIR) light. Taking advantage of the NIR light absorption, this coating film can release eminent photothermal heat for the rapid killing of surface bacteria. The NIR light triggers a sharp rise in photothermal heat, providing the rapid and effective killing of 99.9% of the Gram-positive and -negative bacteria tested within 3 min of NIR light exposure when used at the concentration of 1 mg/mL. Although considerable progress has been made in the design of antibacterial coatings, the user control of NIR-irradiated rapid photothermal destruction of surface bacteria holds increasing attention beyond the traditional boundaries of typical antibacterial surfaces.

Small gold nanoparticles (∼3 nm) loaded onto various supports have been prepared by a deposition–precipitation method and studied for direct methylation of N-methylaniline with CO2/H2. Among the catalysts examined, an acid–base bifunctional support γ-alumina supported gold catalyst (Au/γ-Al2O3) exhibits the best catalytic performance. Au/γ-Al2O3 catalysts with controlled mean Au particle sizes (1.8–8.3 nm) have also been successfully prepared by regulating the concentration of HAuCl4 in solution, aging time, aging temperature and mole ratio of urea to gold in the process of deposition–precipitation with urea. The turnover frequency (TOF) values for direct methylation of N-methylaniline with CO2/H2 increase on decreasing the mean size of Au nanoparticles (from 8.3 to 1.8 nm), showing that methylation of N-methylaniline with CO2/H2 is a structure-sensitive reaction. A fast increase in TOF occurs when the mean Au particle size becomes smaller than 3 nm. Through TEM (transmission electron microscope), gold L3-edge XAFS (X-ray absorption fine structure) and CO2- and NH3-TPD (temperature programmed desorption) analysis, we can conclude the Au particle sizes, oxidation state of the gold species and acid–base properties of the supports are responsible for the high catalytic activity of direct methylation of N-methylaniline with CO2/H2.

Three dimensional (3D) hierarchical nanostructures of orthorhombic Bi2WO6 with unique morphologies were successfully synthesized by a solvothermal method. The precursor concentration plays a key role in the architecture of the hierarchical nanostructures. A peony flower-like morphology was obtained at higher precursor concentrations, and a red blood cell (RBC)-like morphology with average diameter of 1.5 μm was obtained at lower concentrations. These hierarchical nanostructures were assembled by self-alignment of 20 nm nanoplates. As their band gap is in the visible region, the photocatalytic activity of the Bi2WO6 hierarchical nanostructures for the production of hydrogen from glycerol, and the degradation of rhodamine B (RhB) and methylene blue (MB) under ambient conditions in the presence of solar light was investigated. The Bi2WO6 with peony flower morphology was observed to be the most efficient photocatalyst (H2: 7.40 mmol h−1 g−1, kRhB: 0.240 and kMB: 0.100) of the reported nanostructures. The higher activity of the peony flowers was due to their porous nature, high surface area and lower band gap. Such unique 3D nanostructures of Bi2WO6 have been fabricated for the first time, and their use as photocatalysts in the production of hydrogen from glycerol has hitherto not been attempted. These nanostructures may have potential in ferroelectric, piezoelectric, pyroelectric and nonlinear dielectric applications.

Fluorescent carbon dots have received considerable attention as a result of their accessibility and potential applications. Although several prior studies have demonstrated that nearly any organic compound can be converted into carbon dots by chemical carbonization processes, mechanisms explaining the formation of carbon dots still remain unclear. Herein, we propose a seed-growth mechanism of carbon dot formation facilitated by ferulic acid, a widespread and naturally occurring phenolic compound in the seeds of Ocimum basilicum (basil). Ferulic acid triggers the local condensation of polysaccharide chains and forms catalytic core regions resulting in nanoscale carbonization. Our study indicates that carbon dots generated from natural sources might share the similar mechanism of phenolic compound mediated nanoscale condensation followed by core carbonization.

Amidoxime-functionalized ultra-high molecular weight polyethylene fibers (UHMWPEF-AO) were used to absorb uranium U(VI) from aqueous solutions. In this paper, we study effects of pH, initial U(VI) concentration, contact time, and temperature on U(VI) adsorption by UHMWPEF-AO. The adsorption process agrees well with pseudo-second-order and Langmuir model. UHMWPEF-AO exhibits excellent adsorptive performance for U(VI) with a maximum adsorption capacity of 176.12 mg/g at pH 4 and 298 K. The structures of UHMWPEF-AO and U(VI)-loaded UHMWPEF-AO are characterized by FT-IR and nano-CT. U(VI)-loaded UHMWPEF-AO is sintered after adsorption process to recycle absorbed U(VI). Powders collected after sintering process are examined by scanning electron microscopy and X-ray diffraction. These results indicate that UHMWPEF-AO is a promising candidate to remove U(VI) from uranium aqueous solutions.

N-doped ordered mesoporous carbon (N-OMC) samples with different N contents were synthesized by infiltrating molten melamine (the N source) into the framework of mesoporous silica–sucrose. The framework was prepared using an ordered mesoporous silica hard template derived from natural kaolin clay, subsequent carbonization in an inert gas atmosphere, and etching of the silica template. In this simple methodology, N-heteroatoms were incorporated into the C framework during the carbonization. The N-doping content of the prepared N-OMC was conveniently tuned by modifying the melamine/sucrose ratio. After the N-doping, the synthesized N-OMC exhibited remarkable Li storage properties; further, it demonstrated an initial discharge capacity of 1887 mA h g−1 at a current density of 0.1 A g−1. After 100 discharge–charge cycles, the electrode retained a reversible capacity of 648.7 mA h g−1, which is significantly higher than the theoretical capacity of the commercial graphite anode. The enhanced electrochemical performance of the N-OMC was attributed to the large number of defects introduced by N-doping as well as the abundant micropores and mesopores, which provided additional Li storage sites. The N-OMC anode material, which was synthesized by the hard template method using natural kaolin clay as the raw material, exhibited remarkable electrochemical properties including a long life cycle and superior rate of performance. Thus, this study demonstrates that natural kaolin clay exhibits considerable potential for application in Li-ion batteries.

Here, we report the fabrication of montmorillonite (MMT) to incorporate an antifouling capability using 2-chloro-3′, 4′-dihydroxyacetophenone (CCDP), and 1,3-propanesultone quaternized poly(dimethyl amino)ethyl methacrylate [(C/S)-q-PDMA]. The dispersibility of MMT was improved through an ion exchange reaction between MMT and (C/S)-q-PDMA. The developed MMT with (C/S)-q-PDMA, consisting of catechol for adhesive properties, and this combination [(C/S)-q-PDMA] worked as a zwitterionic surfactants to enhance chain mobility in an aqueous medium. The d-space interval is easy to enlarge and exfoliated the clay layers between MMT and different ratios of [(C/S)-q-PDMA] (1, 5, and 10 wt%). The degradation temperature of modified MMT composites is higher than that of the pure polymer without clay. The remaining CCDP moiety of MMT [(C/S)-q-PDMA] allowed easy access to surface coatings, which have been confirmed in terms of contact angle, XPS measurements, and antifouling effects through HeLa cell detachment. Finally, the beneficial influence of a coated polypropylene (PP) surface on the oxygen transmission rate and water vapor transmission suggest an emerging future for (C/S)-q-PDMA with an MMT hybrid coating composite. POLYM. ENG. SCI., 55:2111–2117, 2015. © 2014 Society of Plastics Engineers

In chemical growth of 1-D ZnO nanorods the selection of hydroxide anion generating agent plays a crucial role in determining the growth rate and morphological features. Due to misconception regarding the role of hexamethylenetetramine (HMTA) in the growth of ZnO nanorods, it is heavily used as hydroxide anion generating agent for ZnO nanorod growth. Though it needs repetitive renovation of growth solution and longer time deposition for the growth of high aspect ratio ZnO nanorods. Here we have carried out a comparative study on the effect of hydroxide anion generating agents (HMTA and ammonia) on growth, morphological, structural, chemical, optical, and photo-electrochemical properties of ZnO nanorods, in view to assist in the selection of the these agents in ZnO nanorod growth.

We report a potential coating material showing durable and significant antimicrobial activity for preserving the surfaces of a broad range of materials. The structure of the prepared antimicrobial adhesive material features a catechol moiety of dopamine hydrochloride conjugated to 4-bromobutanoyl chloride as an adhesive material. Antimicrobial properties against a wide range of microorganism species are achieved by quaternizing a long hydrophobic chain (N,N'-dimethyldecylamine) onto 3,4-dihydroxyphenylalanine (Dopa) to afford the prepared material (Dopa-decyl). The successful formation of Dopa-decyl is confirmed by hydrogen nuclear magnetic resonance (1H-NMR) and attenuated total reflectance-infrared (ATR-IR) measurements. The chemical composition of the quaternized adhesive material (Dopa-decyl) is characterized by X-ray photoelectron spectroscopy (XPS). Investigation of the antimicrobial activity of the Dopa-decyl-coated film against both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) stains reveals a highly efficient antimicrobial effect under both normal and extreme stress conditions due to the biocidal effect of the quaternized amine when the materials are applied on the surface of various substrates. Copyright © 2014 John Wiley & Sons, Ltd.

A universal method to modify polystyrene beads (PSBs) is proposed, using the 2-chloro-3′,4′-dihydroxyacetophenone (CCDP) quaternized to poly(ethylene glycol)-g-poly(dimethylaminethyl methacrylate) [PEG-g-PDMA, QC-PEG]. In the study, CCDP of QC-PEG is adhered onto PSBs under alkali condition, where polyvinyl pyrrolidone (PVP) has been added as stabilizer. The surface modified PSBs with QC-PEG (QC-PSBs) have been functionalized, by depositing silver nanoparticles (Ag-PSBs) as antimicrobial, iron oxide nanoparticles (Fe-PSBs) as magnet, and TiO2 nanoparticles (Ti-PSBs) as photo-catalyst. Modification and functionalization of the obtained PSBs have been rectified by microscopy and spectroscopy investigations, including scanning electron microscope, X-ray photoelectron microscope, and UV–vis spectrometer. The functionalized Ag-PSBs show outstanding antimicrobial activities against gram-positive and gram-negative bacteria, due to their containing silver nanoparticles; while significant photo-catalytic behavior was found against methylene blue, after depositing TiO2 nanoparticles. The proposed universal modified PSBs will make a strong contribution in different fields, as a functional material. Copyright © 2014 John Wiley & Sons, Ltd.

The production of methanol, an important fuel and chemical feedstock, from carbon dioxide is an important process for CO2 utilization. We describe herein a mild and efficient method for the indirect hydrogenation of carbon dioxide to methanol via a CO2-derived formate ester intermediate by using a simple heterogeneous catalyst system comprising Cu highly dispersed in an alumina matrix under solvent-free conditions. This catalyst is also effective for the hydrogenation of other formate esters, such as ethyl formate, propyl formate, and butyl formate.

Herein, Cr deposition and poisoning behavior at the commonly used (La0.6Sr0.4)(Co0.2Fe0.8) O3-delta (LSCF) electrode of solid oxide fuel cells (SOFCs) is investigated. Three-dimension (3D) microstructure evolution of the porous electrode caused by Cr deposition during the polarization test at 900 degrees C in the presence of a Fe-Cr metallic interconnect is characterized for the first time using the transmission X-ray microscopy (TXM) technique. The results indicate that a layer of solid Cr deposits similar to 1.7 mu m in thickness is formed on the electrode surface, significantly reducing the linear porosity to similar to 2% in the surface region from similar to 25% in the bulk, which explains the retarded gas diffusion process at the LSCF electrode after Cr deposition. The well-established relationship between the macroscopic performance degradation and the microstructure evolution confirms the promising application of TXM technique for in-depth study of the degradation phenomenon at the electrode of SOFCs. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

We report a stimuli-responsive fluorescent nanomaterial, based on graphene oxide coupled with a polymer conjugated with photochromic spiropyran (SP) dye and hydrophobic boron dipyrromethane (BODIPY) dye, for application in triggered target multicolor bioimaging. Graphene oxide (GO) was reduced by catechol-conjugated polymers under mildly alkaline conditions, which enabled to formation of functionalized multicolor graphene nanoparticles that can be induced by irradiation with UV light and by changing the pH from acidic to neutral. Investigation of these nanoparticles by using AFM, fluorescence emission, and in vitro cell and in vivo imaging revealed that they show different tunable colors in bioimaging applications and, more specifically, in cancer-cell detection. The stability, biocompatibility, and quenching efficacy of this nanocomposite open a different perspective for cell imaging in different independent colors, sequentially and simultaneously.

Graphene and its derivatives are increasingly applied in nanoelectronics, biosensing, drug delivery, and biomedical applications. However, the information about its cytotoxicity remains limited. Herein, the distribution and cytotoxicity of graphene oxide (GO) and TiO2-graphene oxide composite (TiO2-GO composite) were evaluated in A549 cells. Cell viability and cell ultrastructure were measured. Our results indicated that GO could enter A549 cells and located in the cytoplasm and nucleus without causing any cell damage. TiO2 nanoparticles and GO would be separated after TiO2-GO composite entered A549 cells. TiO2-GO composite could induce cytotoxicity similar to TiO2 nanoparticles, which was probably attributed to oxidative stress. These results should be considered in the development of biological applications of GO and TiO2-GO composite.