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Organic field-effect transistors (OFETs) with polymer charge-trapping dielectric, which exhibit many advantages over Si-based memory devices such as low cost, light weight, and flexibility, still suffer challenges in practical application due to the unsatisfied endurance characteristics and even the lack of fundamental of behind mechanism. Here, we revealed that the degradation of endurance characteristics of pentacene OFET with poly(2-vinyl naphthalene) (PVN) as charge-storage layer is dominated by the deep hole-traps in PVN by using the photo-stimulated charge de-trapping technique with the fiber-coupled monochromatic-light probes. The depth distribution of hole-traps in PVN film of pentacene OFET is also provided. [ABSTRACT FROM AUTHOR]

Biological treatment is the most economical and practical wastewater treatment method; however, for highly concentrated organic wastewater, such as digested restaurant wastewater, a single biological treatment method does not meet the discharge requirements. Herein, an anaerobic/oxic-Fenton-biological aerated filter (A/O-Fenton-BAF) system was employed to treat digested restaurant wastewater with a high concentration of organic compounds in a pilot-scale experiment. The degradation process and mechanism of chemical oxygen demand (COD), total nitrogen (TN), NH4+-N, NO3−-N, and dissolved organic nitrogen (DON) in each stage of the process were analyzed. Gas chromatography–mass spectrometry and fluorescence spectrum characteristics were also studied. The average removal rate of both COD and NH4+-N in the entire process was 98%. The removal rates of COD, TN, NH4+-N, and DON reached 78.5%, 66.0%, 95.3%, and 51%, respectively, using the A/O unit. Although Fenton was ineffective in the removal of nitrogenous organic and inorganic substances, the fluorescence spectra and GC–MS showed that the nitrogen-containing organic compounds of macromolecules were transformed into small molecules after the Fenton reaction and could be removed by the BAF unit. The removal rate of DON was up to 24.3% in the Fenton + BAF process, which reduced the TN concentration in the effluent. The dominant species in all biological processes were nitrifying and organic matter-decomposing bacteria. This study provides key data for the design of a full-scale system for treating digested restaurant wastewater. [ABSTRACT FROM AUTHOR]

Detection and analysis of retinal blood vessels contribute to the clinical diagnosis of many ophthalmic diseases. In this paper, aiming on achieving more accurate segmentation of retinal vessels and enhance the ability of the algorithm to identify microvessels, we propose a U-shaped network based on adaptive aggregation of feature information. The introduced feature selection module, which could strengthen feature transmission and selectively emphasize feature information. To effectively capture the characteristics of vessels at different scales, generate richer and denser context information, and DenseASPP is embedded at the bottom of the network. Meanwhile, we propose an adaptive aggregation module to aggregate the semantic information in each layer of the encoder part and transmit it to subsequent layers, which is beneficial to the spatial reconstruction of retinal vessels. A joint loss function is also introduced to facilitate network training. The proposed network is evaluated on three public datasets. The sensitivity, accuracy, and area under curve(AUC) are 83.48%/83.16/85.86, 95.67%/96.67%/96.52%, and 98.11%/98.69%/98.60% on DRIVE, STARE and CHASE_DB1, respectively. In order to achieve more accurate retinal blood vessel segmentation and improve the ability of the algorithm to identify microvessels. We propose a U-shaped network based on adaptive aggregation of feature information. The introduction of the adaptive aggregation module aggregates the semantic information of each level of the encoder part, which improves the robustness of the model to segment blood vessels. [ABSTRACT FROM AUTHOR]

Purpose: Soil nematodes play a fundamental role in regulating ecosystem carbon and nutrient cycling. It is widely recognized that soil nematode community composition is sensitive to nutrient enrichment, but the linkage between community assembly processes and functional changes under nutrient enrichment condition remains poorly understood. Methods: We examined the compositional and functional responses and quantified the role of main community assembly processes (genus losses, genus gains, and context-dependent variations of abundance) in driving the carbon budget of soil nematode communities in response to nitrogen (N) and phosphorus (P) addition in a temperate grassland. Results: Nitrogen and P addition significantly interacted to affect nematodes abundance, biomass, and functional variables of C cycling, in that P addition increased all the variables under ambient N condition but not under N enriched condition. Soil pH, ammonium concentration, and total phosphorus concentration played important roles in driving the variations of nematode C budgets, indicating the minor role of plant community characteristics. The enhancement of all variables following P addition was caused by the increases in the abundance of common genera (e.g. Acrobeles, Scutylenchus, and Tylencholaimus). The variation of genus richness contributed to the P-induced increases of nematode abundance but not to the increases of carbon budgets. Conclusions: Our results uncover the linkages between community assembly processes and the abundance and C cycling function of soil nematode community under nutrient enrichment conditions. The significant interactive effects between N and P addition highlight the complexity in predicting the compositional and functional changes in soil nematode community under a scenario of multiple-nutrient enrichment. [ABSTRACT FROM AUTHOR]

Aims: Nutrient addition is a widely-used strategy to restore degraded grasslands. It remains unknown whether and how the number of added nutrients affects the soil nematode community in degraded grasslands. Methods: We examined the immediate responses of taxonomic and functional composition of the soil nematode community to different numbers of added nutrients using factorial combinations of nitrogen (N), phosphorus (P), and potassium (K + micronutrients) in a degraded grassland of northern China. Results: The taxonomic and functional composition of the soil nematode community generally formed a unimodal relationship with the number of added nutrients. Changes of soil pH after fertilization affected the structural stability and complexity of the soil nematode community. The magnitude of nematode functional responses to nutrient supply was driven by changes of plant aboveground biomass and soil pH. Conclusions: Soil nematode community showed non-linear responses to the variations of the number of added nutrients in a degraded grassland, which contrasts previous findings from plant community. The number of added nutrients should be given full consideration in formulating effective restoration strategies for degraded grasslands. [ABSTRACT FROM AUTHOR]

Aims: The stoichiometric traits of litter play an important role in driving litter decomposition and ecosystem nutrient cycling. While the impacts of nitrogen (N) deposition on the species-level litter stoichiometric traits have been well addressed, we know little about that at community-level, which is supposed to be driven by both intra-specific variation and changes in community composition. Methods: We examined the effects of N deposition on litter phosphorus (P) concentration and N:P ratio at both species- and community-level in a semi-arid grassland of northern China. We further decomposed the community-level variations of litter nutritional traits into intra- and inter-specific variation. Results: Nitrogen addition, especially at high rates, substantially changed community composition. Litter P concentrations and N:P ratios significantly varied among different species. Litter P concentrations and N:P ratios at both species- and community-level were positively correlated with N addition rates. Biomass-weighted community-level N:P ratios were more sensitive to N addition than the non-weighted ones, indicating that community composition strengthened the positive impacts of N addition on litter N:P ratios. There was positive co-variation between intra- and inter-specific variation for litter N:P ratio, indicating the consistency of community composition and intra-specific variation in their effects on litter N:P ratio. Conclusions: Our results indicated that the imbalance of N and P following N enrichment would be much larger than the expectation based on the findings from species-level, and thus highlight the importance of changes in community composition in driving the responses of community-level litter N:P stoichiometry to N deposition in the semi-arid grassland. [ABSTRACT FROM AUTHOR]

Anthropogenic nitrogen (N) deposition has affected plant community composition and nutrient cycling in terrestrial ecosystems worldwide. This includes changes to the way plants use and recycle nutrients, including effects on nutrient resorption, which is a key process through which plants recover nutrients from tissue during senescence. Nutrient resorption has considerable adaptive and functional significance for plants and helps regulate core ecosystem processes such as decomposition. However, our understanding of how N deposition affects nutrient resorption and, in particular, of how N inputs alter ecosystem resorption via changes to existing species' resorption compared with changes to community composition remains poor. To disentangle the role of species versus community composition controls driving variation in nutrient resorption responses to N inputs, we carried out an experiment with six different N addition rates in a temperate steppe. We found that species-scale nutrient resorption responses to N enrichment were variable; for example, only half of the measured species reduced both N and P resorption efficiency in response to increased N inputs. In contrast, community-scale responses consistently resulted in reduced N and P resorption. Still, N-induced changes in community composition were a weaker control on overall resorption responses than were the effects on individual species; however, it was the synergistic interaction between the two that resulted in the large total reductions of nutrient resorption in the face of increased N. Taken together, our results highlight that understanding and predicting nutrient resorption responses will be most accurately scaled by accounting not only for species' reductions in resorption but also for changes in community composition. [ABSTRACT FROM AUTHOR]

It has long been assumed that lifespan and healthspan correlate strongly, yet the two can be clearly dissociated1–6. Although there has been a global increase in human life expectancy, increasing longevity is rarely accompanied by an extended healthspan4,7. Thus, understanding the origin of healthy behaviours in old people remains an important and challenging task. Here we report a conserved epigenetic mechanism underlying healthy ageing. Through genome-wide RNA-interference-based screening of genes that regulate behavioural deterioration in ageing Caenorhabditis elegans, we identify 59 genes as potential modulators of the rate of age-related behavioural deterioration. Among these modulators, we found that a neuronal epigenetic reader, BAZ-2, and a neuronal histone 3 lysine 9 methyltransferase, SET-6, accelerate behavioural deterioration in C. elegans by reducing mitochondrial function, repressing the expression of nuclear-encoded mitochondrial proteins. This mechanism is conserved in cultured mouse neurons and human cells. Examination of human databases8,9 shows that expression of the human orthologues of these C. elegans regulators, BAZ2B and EHMT1, in the frontal cortex increases with age and correlates positively with the progression of Alzheimer's disease. Furthermore, ablation of Baz2b, the mouse orthologue of BAZ-2, attenuates age-dependent body-weight gain and prevents cognitive decline in ageing mice. Thus our genome-wide RNA-interference screen in C. elegans has unravelled conserved epigenetic negative regulators of ageing, suggesting possible ways to achieve healthy ageing. Two epigenetic regulators—identified in an RNA interference screen in Caenhorhabditis elegans, and conserved in mammals—diminish mitochondrial function and accelerate the age-related deterioration of behaviour. [ABSTRACT FROM AUTHOR]

Copper has long been utilized as a disinfectant for bacteria, but its impact on microbial communities attached to the steel surface in seawater remains unknown. In the present study, 3 mooring chain steels of different copper contents are subjected to a 3-month marine field exposure, and the corrosion rate increases in the order of BR5 steel (without copper) < BR5CuH steel (0.8% copper) < BR5CuL steel (0.4% copper). The microbial community results show that copper introduction does not result in an obvious change in microbial quantity, but it alters the diversity, richness, and structure of microbial communities due to the variation in copper-resistance of different species. BR5CuH steel holds microbial communities with the highest percentage of some well-known corrosive microbes including sulfate-reducing bacteria, sulfuroxidizing bacteria, and iron-oxidizing bacteria, but possesses the lowest community diversity/richness owing to the toxicity of copper. The microbial community diversity/richness is stimulated by the low-copper content of BR5CuL steel, and this steel also carries an intermediate proportion of such corrosive bacteria. Both well-known corrosive bacteria and microbial community diversity/richness seem to be involved in the corrosion acceleration of copper-bearing mooring chain steels. [ABSTRACT FROM AUTHOR]

Corrosion behavior of copper-free (BR5) and copper-bearing (BR5Cu, 0.8% Cu) bainite type grade R5 mooring chain steels is investigated in sterile and bacteria-containing seawater. Electrochemical impedance spectroscopy and weight loss results demonstrate that both steels corrode steadily with similar rates in sterile seawater, which is closely related to stable dissolved oxygen (DO) concentration and loose corrosion product layers. While in bacteria-containing seawater, corrosion is inhibited at the initial stage due to DO consumption and biofilm formation, and the inhibition efficiency declines with time because of bacteria decay, leading to a slightly smaller total weight loss than that in sterile media. Although less adhesive bacteria are observed on BR5Cu steel owing to the antimicrobial activity of copper, it does not bring a visible difference in corrosion rate. The validity of copper introduction in mooring chain steel towards seawater corrosion and MIC inhibition is expected to be checked further in different systems. [ABSTRACT FROM AUTHOR]

FeS@Fe3O4 magnetic nanoparticles were prepared by ultrasonic-assisted method and characterized by TEM, FTIR, XRD, SEM, EDS, BET and VSM. The factors affecting the adsorption properties of uranyl ions by FeS@Fe3O4 were studied. Results show that the FeS@Fe3O4 nanoparticles have core–shell structure and superparamagnetism. Under the optimized conditions, the maximum adsorption capacity can reach 229.03 mg/g. The optimum adsorption conditions were as follows: pH = 6, temperature 80 °C, C0 = 35 mg/L, contact time 2.5 h, adsorbent dosage 10 mg. Adsorption kinetics and thermodynamic studies show that the adsorption process accords with the Freundlich isotherm adsorption model and the pseudo-second-order kinetic model. [ABSTRACT FROM AUTHOR]

The thiol-functional hydrotalcite (Mg/Al-LDO-SH) composite materials were prepared and characterized by EDS, SEM, FT-IR and XRD. The variables influencing the adsorption capacity were investigated. Results show that 3-MPTMS got success in material surface modification. The best optimization condition for adsorption experiment was at time 150 min, pH 3.0, temperature 30 °C, initial uranium (VI) concentration 30 mg L−1, adsorption dosage 10 mg with 99.06% of adsorption efficiency and 1545.32 mg g−1 of adsorption capacity. Kinetics data follow the pseudo-second-order model and equilibrium data fit the Freundlich isotherm model very well. Thermodynamic studies show that adsorption process is spontaneous and exothermic. [ABSTRACT FROM AUTHOR]

Lead-free (1 − x)(0.8Bi0.5Na0.5TiO3-0.2SrTiO3)-xLiNbO3 (BNST-xLN, x = 0-0.08) piezoelectric ceramics were fabricated by a solid-state sintered technology. The effects of LN-doping on the structural and electrical properties of the BNST-xLN system were systematically investigated. The results of Raman spectroscopy revealed that the substitution of LN softens the phonon vibrations in the BNST-xLN system, in accordance with the remarkable reduction in the phase transition temperature (TF−R), remnant polarization (Pr), negative strain (Sneg) and piezoelectric coefficient (d33). However, the degradation of the long-range ferroelectric orders was accompanied by a significant increase in the electric field-induced strain response. At x = 0.04, a maximum unipolar strain of ~ 0.36% with a corresponding normalized strain (Smax/Emax) of ~ 600 pm/V was obtained at room temperature, which should be mainly ascribed to the reversibly electric field-induced phase transition between the ergodic relaxor and ferroelectric phases due to their comparable free energies in the two-phase coexistence region. Moreover, it was also found that the BNST-xLN system processes predominant electrostrictive behaviors with relatively high electrostrictive coefficient (Q33) and excellent temperature stability when the field-induced phase transition cannot be trigged by the applied electric field, as evidenced by a fact that the Q33 value of BNST-0.08LN ceramic keeps almost constant as high as ~ 0.028 m4/C2 in the temperature range from room temperature to 120 °C. [ABSTRACT FROM AUTHOR]

Litter chemical traits are one of the dominant controls on litter decomposition. Increasing atmospheric nitrogen (N) deposition is expected to alter litter chemical traits at the community level in both direct (altering intraspecific chemistry) and indirect ways (changing species abundance and composition). Compared to intraspecific changes, the role of changes in species composition in driving the responses of litter chemical traits to N enrichment has been seldom quantitatively addressed. We quantified the relative contribution of intraspecific changes versus changes in community composition on litter traits and how this would be influenced by the magnitude of N deposition by taking advantage of a long-term field N addition experiment in a semi-arid grassland with a wide range of N addition rates. Nitrogen deposition altered plant species abundance by facilitating the dominance of one species with a nutrient acquisitive strategy, producing higher quality litter and being more responsive to N addition at the intraspecific level. Overall, changes in species composition, intraspecific changes and their interaction all led to higher litter quality (higher N and lower lignin, cellulose and hemicellulose concentrations) under N deposition treatments. The relative contribution of species composition on the responses of litter chemical traits to N deposition also increased with N addition rate, ranging from 5 to 40% for litter N, and from 2 to ~ 30% for the three structural carbon components. Our results demonstrate the positive impacts of increasing N deposition on litter quality through changing intraspecific C and N chemistry and species turnover, which has potential consequences for litter decomposition and nutrient cycling in ecosystems. Further, we highlight the important contribution of shifts in species abundance to the plant-mediated biogeochemical responses to N deposition. [ABSTRACT FROM AUTHOR]

The toxicity of cadmium (Cd) has posed major public health concern in crops grown in the Cd-contaminated soils. The effects of five amendments, nano-hydroxyapatite (n-HA) and it combined with lime, zeolite, bone mill and fly ash on Cd immobilization in soils and uptake in potatoes, were investigated in a contaminated soil by pot experiments. The result showed that the applications of combined amendments significantly decreased the bioavailable Cd concentrations extracted by TCLP, DTPA-TEA and MgCl2 in the contaminated soils, and changed the soluble and exchangeable and specifically sorbed fractions to oxide-bound and organic-bound fractions. Compared to the control group, the concentrations of Cd in the potato tubers grown in n-HA, n-HA + Fly ash, n-HA + Lime, n-HA + Bone mill and n-HA + Zeolite soil were reduced 17.4%, 20.7%, 15.2%, 32.6% and 39.1%, respectively. Nano-hydroxyapatite combined amendments was more effective in reducing bioavailable Cd concentrations and Cd accumulations in potatoes, especially for n-HA + Z. [ABSTRACT FROM AUTHOR]

Aims: Changes in litter chemistry and stoichiometry following N enrichment have important consequences on litter decomposition and plant-mediated nutrient cycling. Our knowledge about the responses of litter stoichiometry at different biological organization levels to N enrichment remains poorly understood. Moreover, whether the impacts of N enrichment on stoichiometric ratios in litter would depend on ecosystem management strategies remains unknown. Methods: We examined the effects of N addition and mowing on C:N:P stoichiometry in standing litter at plant organ, species, functional group, and community levels in a semi-arid grassland of northern China, taking advantage of a field experiment that has been running for seven years. Results: Nitrogen addition altered biomass allocation between different organs and among different plant functional groups, with consequences on litter stoichiometry at community level. N addition had no impacts on litter C concentration, increased litter N, and N:P ratio, and decreased litter C:N ratio from plant organ to community. The impacts of N addition on litter P and C:P depended on the identity of plant species and functional group. Mowing did not affect litter nutrient characters across all organization levels. Furthermore, no interactive effects between N addition and mowing on litter nutrient characters were observed from plant organ to community levels. Conclusions: We conclude that N deposition will enhance litter quality even in the heavily-used grasslands with shifts in biomass allocation and species composition, which may contribute to the enhancement of plant-mediating nutrient cycling. [ABSTRACT FROM AUTHOR]

The rate of behavioural decline in the ageing population is remarkably variable among individuals. Despite the considerable interest in studying natural variation in ageing rate to identify factors that control healthy ageing, no such factor has yet been found. Here we report a genetic basis for variation in ageing rates in Caenorhabditis elegans. We find that C. elegans isolates show diverse lifespan and age-related declines in virility, pharyngeal pumping, and locomotion. DNA polymorphisms in a novel peptide-coding gene, named regulatory-gene-for-behavioural-ageing-1 (rgba-1), and the neuropeptide receptor gene npr-28 influence the rate of age-related decline of worm mating behaviour; these two genes might have been subjected to recent selective sweeps. Glia-derived RGBA-1 activates NPR-28 signalling, which acts in serotonergic and dopaminergic neurons to accelerate behavioural deterioration. This signalling involves the SIR-2.1-dependent activation of the mitochondrial unfolded protein response, a pathway that modulates ageing. Thus, natural variation in neuropeptide-mediated glia-neuron signalling modulates the rate of ageing in C. elegans. [ABSTRACT FROM AUTHOR]

Disruption of FOXP2 , a gene encoding a forkhead domain transcription factor, may cause a severe developmental disorder of verbal communication, especially vocalization. In insectivorous bats, accelerated evolution of FoxP2 supports a previously proposed hypothesis that this gene plays a role in sensorimotor coordination. In order to validate this hypothesis, it is necessary to examine the expression of FoxP2 in the relevant sensorimotor structures involved in echolocation behavior. Here, we present the detailed spatial expression pattern of FoxP2 in the mature brain of Rhinolophus ferrumequinum using immunohistochemistry. FoxP2 expression was found in many regions of the bat brain. The homologous pattern of FoxP2 expression in this bat argues for the role of the gene in motor-related circuits. In addition, FoxP2 was strongly expressed in many regions related to echolocation such as the inferior colliculus, superior colliculus, periaqueductal gray, paralemniscal nucleus, nuclei of the lateral lemniscus, parabrachial nucleus and ambiguous nucleus. Overall, our findings imply that FoxP2 plays an important role in echolocation. [ABSTRACT FROM AUTHOR]

In this work, we have fabricated and thoroughly characterized dielectric-stacked memory devices with AlO-CuO composites as the charge trapping layer which are prepared by using atomic layer deposition and RF-magnetron sputtering techniques. The devices exhibit a large memory window of 13.27 V and a density of the trapped charges of 9.37 × 10 cm at a working voltage of ±11 V. The microstructural observations by using high resolution transmission electron microscopy and the analysis on X-ray photoelectron spectroscopy indicate that the strong charge-trapping ability of AlO-CuO composite should be ascribed to the occurrence of Cu, resulted by the inter-diffusion at the interface of CuO/AlO. Such an interesting composite layer has very attractive application in nonvolatile memory. [ABSTRACT FROM AUTHOR]

Chemo-resistance is still a major obstacle in successful cancer treatment. Previously, we found that miR-21 (miR-21-5p) was upregulated in drug-resistant tongue cancer (TC) cell line Tca8113/PYM. However, the mechanisms for miR-21 upregulation and its role in chemo-resistance in TC remain unclear. Here, we demonstrated that functional inhibition of miR-21 sensitized TC cells to chemotherapy. In agreement, overexpressed miR-21 enhanced chemo-resistance in TC cells. We found that miR-21 directly targeted CADM1 expression, which was downregulated in drug-resistant TC cells. Restored CADM1 expression sensitized TC cells to chemotherapy, but CADM1 knockdown induced chemo-resistance. Mechanically, CADM1 interacted with BMI1 to inhibit its nuclear translocation. Moreover, MYCN which was overexpressed in drug-resistant TC cells directly bound to the miR-21 promoter to upregulated miR-21 expression in TC cells. Importantly, the expression levels of miR-21 and CADM1 negatively correlated, but MYCN and miR-21 positively correlated in TC tissues. High levels of miR-21 and MYCN and low level of CADM1 were associated with poor prognosis in TC patients. In conclusion, our study suggests an important role of the MYCN/miR-21/CADM1 axis in chemo-resistance in TC patients and may lead to promising prognostic biomarkers and novel treatment strategies to improve the chemotherapeutic efficacy for TC patients. Key messages: [ABSTRACT FROM AUTHOR]

The SrMoO phosphors activated by the Pr ions have been synthesized by precursor method conditions using PrO, NaMoO·2HO, and Sr(NO) as raw materials. The crystal structures and morphologies of the products were characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectrometry, scanning electronic microscopy, and fluorescence spectrometry. XRD indicated that the phosphors crystallized in the tetragonal system of scheelite type. The excitation spectra show intense broad bands in the 220-300 nm range, and three lines peaking at 450, 472, and 485 nm, which were assigned to the H-P, H-P, and H-P absorption transitions of Pr. The emission spectrum excited by 224, 241, and 450 nm exhibit sharp lines peaking at 485, 616, and 645 nm, which were assigned to the P-H, D-H, and P-F absorption transitions of Pr, respectively. The concentration of Pr had an obvious influence on the luminescent properties. The emission and excitation intensities reached their maxima when the concentration of Pr reached 4 %. [ABSTRACT FROM AUTHOR]

Bioconversion of dl-2-amino-Δ-thiazoline-4-carboxylic acid ( dl-ATC) catalyzed by whole cells of Pseudomonas sp. was successfully applied for the production of l-cysteine. It was found, however, like most whole-cell biocatalytic processes, the accumulated l-cysteine produced obvious inhibition to the activity of biocatalyst and reduced the yield. To improve l-cysteine productivity, an anion exchange-based in situ product removal (ISPR) approach was developed. Several anion-exchange resins were tested to select a suitable adsorbent used in the bioconversion of dl-ATC for the in situ removal of l-cysteine. The strong basic anion-exchange resin 201 × 7 exhibited the highest adsorption capacity for l-cysteine and low adsorption for dl-ATC, which is a favorable option. With in situ addition of 60 g L resin 201 × 7, the product inhibition can be reduced significantly and 200 mmol L of dl-ATC was converted to l-cysteine with 90.4 % of yield and 28.6 mmol Lh of volumetric productivity. Compared to the bioconversion without the addition of resin, the volumetric productivity of l-cysteine was improved by 2.27-fold using ISPR method. [ABSTRACT FROM AUTHOR]

The multiferroic properties of BiFeO-based ceramics were improved through optimizing their sintering method and doping with certain rare earth elements in pure BiFeO. Some methods, especially liquid-phase sintering method has largely decreased the densities of oxygen vacancies and Fe in BiFeO-based ceramics, and thus their resistivity became high enough to measure the saturated polarization and the large piezoelectric d coefficient under the high electric field of >150 kV/cm. Besides, multiferroic properties were improved through the rare earth elements' doping in pure BiFeO. Magnetization commonly increases with the proportional increase of Nd, La, Sm and Dy contents up to ~30 %, while ferroelectric phase can transform to paraelectric phase at a certain proportion. An improved magnetoelectric coupling was often observed at ferroelectric phase with a relatively large proportion. Besides, an enhanced piezoelectric coefficient is expected in BiFeO-based ceramics with morphotropic phase boundaries as they are already observed in thin epitaxial BiFeO films. [ABSTRACT FROM AUTHOR]

Breast cancer is the most frequently diagnosed tumor type and the primary leading cause of cancer deaths in women worldwide and multidrug resistance is the major obstacle for breast cancer treatment improvement. Emerging evidence suggests that metformin, the most widely used antidiabetic drug, resensitizes and cooperates with some anticancer drugs to exert anticancer effect. However, there are no data regarding the reversal effect of metformin on chemoresistance in breast cancer. In the present study, we investigated the resistance reversal effect of metformin on acquired multidrug-resistant breast cancer cells MCF-7/5-Fu derived from MCF-7 breast cancer cells and innate multidrug-resistant MDA-MB-231 breast cancer cells, and we found that metformin resensitized MCF7/5-FU and MDA-MB-231 to 5-fluorouracil (5-FU), adriamycin, and paclitaxel. We also observed that metformin reversed epithelial-mesenchymal transition (EMT) phenotype and decreased the invasive capacity of MCF7/5-FU and MDA-MB-231 cells. However, there were no significant changes upon metformin-treated MCF7 cells. Moreover, we found metformin treatment activated AMPK signal pathway in MCF7/5-FU and MDA-MB-231 cells and compound C, the AMPK inhibitor, could partly abolish the resensitization and EMT reversal effect of metformin. To the best of our knowledge, we are the first to report that metformin can resensitize multidrug-resistant breast cancer cells due to activating AMPK signal pathway. Our study will help elucidate the mechanism of chemoresistance and establish new strategies of chemotherapy for human breast cancer. [ABSTRACT FROM AUTHOR]

The band alignments of HfO/GaN, HfO/SiO/GaN and HfO/AlO/GaN gate dielectric stacks were comparatively investigated by using X-ray photoelectron spectroscopy. It was observed that the introduction of an ultrathin buffer layer film (SiO or AlO) in HfO/GaN stack can make the band alignments more symmetrical with larger barrier height as identified by the valence band offsets and electron energy loss spectrum measurements. At room temperature, the leakage current density as function of temperature is 4.1 × 10, 3 × 10 and 9.8 × 10 A cm at the bias of 1 V for the HfO/GaN, HfO/AlO/GaN and HfO/SiO/GaN gate dielectric stacks, correspondingly. With temperature increase from room temperature to 300 °C, the HfO/SiO/GaN gate dielectric stack exhibits lowest lower leakage current density than that of others. The HfO/GaN high-k gate dielectric stack with an ultrathin SiO buffer layer appears to be a promising candidate for future GaN based high temperature metal-oxide-semiconductor (MOS) devices applications. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis type I (MPS I), caused by mutations in the gene encoding α-L-iduronidase (IDUA), is one of approximately 70 genetic disorders collectively known as the lysosomal storage diseases. To gain insight into the basis for MPS I, we crystallized human IDUA produced in an Arabidopsis thaliana cgl mutant. IDUA consists of a TIM barrel domain containing the catalytic site, a β-sandwich domain and a fibronectin-like domain. Structures of IDUA bound to iduronate analogs illustrate the Michaelis complex and reveal a 2,5B conformation in the glycosyl-enzyme intermediate, which suggest a retaining double displacement reaction involving the nucleophilic Glu299 and the general acid/base Glu182. Unexpectedly, the N-glycan attached to Asn372 interacts with iduronate analogs in the active site and is required for enzymatic activity. Finally, these IDUA structures and biochemical analysis of the disease-relevant P533R mutation have enabled us to correlate the effects of mutations in IDUA to clinical phenotypes. [ABSTRACT FROM AUTHOR]

ZrO nanocrystallites based charge trap memory cells by incorporating a (ZrO)(SiO) film as a charge trapping layer and amorphous AlO as tunneling and blocking layer were prepared and investigated. The precipitation reaction in charge trapping layer forming ZrO nanocrystallites during rapid thermal annealing was investigated by transmission electron microscopy. The density and size of ZrO nanocrystallites are the critical factors for controlling the charge storage characteristics. The ZrO nanocrystallites based memory cells after postannealing at 800 C for 60 s exhibit the best electrical characteristics and a low charge loss ∼5 % after 10 write/erase cycles operation. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) were used to modify magnesium fluoride (MgF) film via the spin coating technique. Nanoparticles of MgF were in situ synthesized on surfaces of CNTs resulted in the composites (MgF-CNTs) by means of sol-gel technique. The sizes of the MgF nanoparticles in situ synthesized on CNTs surfaces could be modulated by processing the MgF sol-gel in different ways. The MgF-CNTs as prepared was mixed with MgF sol to fabricate composite films (MgF-CNTs/MgF). Instead of adding directly CNTs, adding MgF-CNTs, into MgF sol could effectively improve the dispersion of CNTs, avoid emergence of carbon clusters in the compsite film, decrease surface roughness of the film, and enhance the interaction between the CNTs and MgF matrix. In the paper, the MgF nanoparticles were in situ synthesized on the surfaces of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) respectively to prepare MgF-SWCNTs/MgF and MgF-MWCNTs/MgF composite films. Experimental results showed that the transparency of the MgF-SWCNTs/MgF composite film was higher than that of the MgF-MWCNTs/MgF film in the range of ultraviolet, visible and near-infrared wavelengths. The results showed SWCNTS could be an ideal reinforcement of MgF films to get good toughness, and retain its optical transmittance at the same time. [ABSTRACT FROM AUTHOR]

Carbon nanotubes (CNTs) with different diameters were treated by plasma and acid. The CNTs were dispersed in water and the light transmittance of the CNTs dispersoid (the mixture of CNTs and water) was measured to characterize the dispersibility of CNTs. With the light transmittance of water as the baseline, relative transmittance (RT) of CNTs dispersoid was calculated and the curves of RT varying with time were fitted with a function. The effects of CNTs diameter, acid treatment and plasma treatment on the dispersion of CNTs in water were studied according to the fitting results. It could be concluded that the dispersibility of the CNTs with bigger diameters was better. Plasma treatment could improve the dispersibility of CNTs and if the CNTs were acid-treated, plasma treatment could improve their dispersibility further. [ABSTRACT FROM AUTHOR]

Due to the discharge of nutrients into the East China Sea, severe eutrophication has appeared in Hangzhou Bay. Therefore, we cultivated Gracilaria verrucosa on a large scale in the Jinshan enclosed sea with an area of 1.72 km in the northern part of Hangzhou Bay to perform bioremediation. The Fengxian enclosed sea with an area of 2.3 km and 50 km far from Jinshan was used as the control. The results showed that the Hangzhou Bay was severely eutrophicated before G. verrucosa cultivation. During the period of cultivation between August 2006 and July 2007, the annual growth rate of G. verrucosa was 9.42% day, and the sea water quality was improved from worse than grade IV to grades II-III, with the concentration of dissolved inorganic nitrogen (DIN) and PO-P significantly lower than that in the Fengxian enclosed sea ( p < 0.01). The concentration of NH-N, NO-N, NO-N, and PO-P after G. verrucosa cultivation was decreased by 54.12%, 75.54%, 49.81%, and 49.00%, respectively. The density of phytoplankton in the Jinshan enclosed sea with cultivation of G. verrucosa was 6.90 -126.53 × 10 cells m, which was significantly lower than that in the Fengxian enclosed sea. In addition, species diversity, richness, and evenness was significantly increased after cultivation of G. verrucosa in the Jinshan enclosed sea compared with that in the Fengxian enclosed sea. The density of Skeletonema costatum, Prorocentrum micans, and Prorocentrum donghaiense, which were the usual species of red tides at the coastal sea of China, in the Jinshan enclosed sea with cultivation of G. verrucosa was significantly lower. Based on these results, if the water quality in the Jinshan enclosed sea were to be maintained at grade I (DIN ≤0.20 mg L) or II (DIN ≤0.30 mg L), 21.8 t or 18.0 t fresh weight of G. verrucosa need to be cultivated, respectively. These results indicated that large-scale cultivation of G. verrucosa could play a significant role in the bioremediation of Hangzhou Bay. [ABSTRACT FROM AUTHOR]

A new coordination polymer [Ni(L)(Hbtec)] ( 1) was obtained from the reaction of NiSO·6HO, macrocyclic ligand 3,6,9,17,20,23-hexaaza-29,30-dihydroxy-13,27-di- tert-butyl-tricyclo[23,3,1,1]triaconta-1(28),11,13,15(30),25,26-hexaene (HL), and 1,2,4,5-benzenetetracarboxylic acid (Hbtec) in methanol. Its structure was determined by X-ray diffraction analysis. The crystal is monoclinic C2/ c space group with cell parameters a = 20.4923(3) Å, b = 14.2389(3) Å, c = 14.5130(2) Å, β = 97.441(2)°, V = 4199.05(12) Å, and Z = 8. The X-ray analysis shows that each Ni (II) cation is six-coordinated by an ON donor set. The macrocyclic complex [NiL] are bridged by Hbtec anions to form 1D chains, which are further joined via N-H···O hydrogen bonds to yield a 3D supramolecular structure. Thermogravimetric analysis (TGA) for the complex is discussed. Graphical Abstract: The macrocyclic complexes [NiL] are bridged by Hbtec anions to form 1D chains, which are further joined via N-H···O hydrogen bonds to yield a 3D supramolecular structure.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The structural and optical characterizations of titania incorporated with alumina nanocrystals have been presented in this paper and the films exhibit excellent properties like low current density, small hysteresis as well as high photoluminescence quantum yields of about 361 nm. These properties are promising for the applications in future electronic devices. [ABSTRACT FROM AUTHOR]

(ZrO2) x (SiO2)1− x (Zr-Si-O) films with different compositions were deposited on p-Si(100) substrates by using pulsed laser deposition technique. X-ray photoelectron spectra (XPS) showed that these films remained amorphous after annealing at 800°C with RTA process in N2 for 60 s. The XPS spectra indicated that Zr-Si-O films with x=0.5 suffered no obvious phase separation after annealing at 800°C, and no interface layer was formed between Zr-Si-O film and Si substrate. While Zr-Si-O films with x >0.5 suffered phase separation to precipitate ZrO2 after annealing under the same condition, and SiO2 was formed at the interface. To get a good interface between Zr-Si-O films and Si substrate, Zr-Si-O films with bi-layer structure (ZrO2)0.7(SiO2)0.3/(ZrO2)0.5(SiO2)0.5/Si was deposited. The electrical properties showed that the bi-layer Zr-Si-O film is of the lowest equivalent oxide thickness and good interface with Si substrate. [ABSTRACT FROM AUTHOR]

The Archaeoglobus fulgidus gene af0721 encodes CbiXS, a small cobaltochelatase associated with the anaerobic biosynthesis of vitamin B12 (cobalamin). The protein was shown to have activity both in vivo and in vitro, catalyzing the insertion of Co2+ into sirohydrochlorin. The structure of CbiXS was determined in two different crystal forms and was shown to consist of a central mixed β-sheet flanked by four α-helices, one of which originates in the C-terminus of a neighboring molecule. CbiXS is about half the size of other Class II tetrapyrrole chelatases. The overall topography of CbiXS exhibits substantial resemblance to both the N- and C-terminal regions of several members of the Class II metal chelatases involved in tetrapyrrole biosynthesis. Two histidines (His10 and His74), are in similar positions as the catalytic histidine residues in the anaerobic cobaltochelatase CbiK (His145 and His207). In light of the hypothesis that suggests the larger chelatases evolved via gene duplication and fusion from a CbiXS-like enzyme, the structure of AF0721 may represent that of an “ancestral” precursor of class II metal chelatases. [ABSTRACT FROM AUTHOR]

The interference of Cyclosporin A (CyA) with peripheral lymphocytes DNA synthesis was investigated. The results showed that the drug could strongly inhibit T cell proliferation in response to PHA stimulation if added at the start or at the early phase of the process, and it failed to do so if added 48 h later when most cells had already started to proliferate. Without PHA, no obvious differences were detected between normal control and CyAtreated cells. A comparison was made between T cell DNA synthesis of peripheral blood lymphocytes of healthy volunteers and renal transplant patients. It was found that T-cell DNA synthesis of patients was significantly lower than that of the healthy controls. From the above it may be suggested that CyA activity on T cell proliferation is similar in vivo and in vitro. [ABSTRACT FROM AUTHOR]

This paper takes the phage of potato hospital as the research object. Firstly, the cause and infection way of the disease are analyzed in detail. Then, the viewpoint that the disease is closely related to soil ecology is put forward. Through the analysis of soil ecological environment and factors, and designed and completed the experiment of using the adaptive evolution of a high-temperature environment to screen the stable phages in the storage process. The experimental results show that the interaction of potato plant-related phage mixture in the different soil environments. [ABSTRACT FROM AUTHOR]

By first-principles calculations, the magnetism of hole doped tin dichalcogenides SnX2 (X = S, Se) monolayers is systematically studied. It is found that a phase transition from nonmagnetic to ferromagnetic ground state appears once above the critical hole density (~1014 cm−2). The spin magnetic moment can maintain a magnitude of 1.0 μB/hole with excellent stability of ferromagnetic state. Furthermore, we demonstrate that strain is very useful to modulate the DOS near the valence band, resulting in the reduction of the critical hole density to ~1013 cm−2 when the strain reaches 4% (6%) in SnS2 (SnSe2), which can be realized in common field effect transistors. Moreover, the phonon dispersion calculations for the strained SnX2 monolayers indicate that they can keep the dynamical stability under the hole doping. Therefore, the strain tunable magnetic transition in hole doped tin dichalcogenides indicates their potential promising applications in spintronic devices. [ABSTRACT FROM AUTHOR]

Metastable ω phase is common in body-centred cubic (bcc) metals and alloys, including high-alloying steels. Recent theoretical calculations also suggest that the ω structure may act as an intermediate phase for face-centred cubic (fcc)-to-bcc transformation. Thus far, the role of the ω phase played in fcc-bcc martensitic transformation in carbon steels has not been reported. In previous investigations on martensitic carbon steels, extra electron diffraction spots were frequently observed by transmission electron microscopy (TEM), and these spots were historically ascribed to the diffraction arising from either internal twins or carbides. In this paper, an intensive TEM investigation revealed that the extra spots are in fact attributed to the metastable ω phase in particle-like morphology with an overall size of several or dozens of nanometres. The strict orientation relationships between the ω phase and the ferrite matrix are in good agreement with those of the hexagonal (P6/mmm) ω phase in other bcc metals and alloys. The identification of the ω phase as well as the extra diffraction spots might provide a clue to help understand the physical mechanism of martensitic transformation in steels. [ABSTRACT FROM AUTHOR]

Phosphorene, as a novel two-dimensional material, has attracted a great interest due to its novel electronic structure. The pursuit of controlled magnetism in Phosphorene in particular has been persisting goal in this area. In this paper, an antiferromagnetic insulating state has been found in the zigzag phosphorene nanoribbons (ZPNRs) from the comprehensive density functional theory calculations. Comparing with other one-dimensional systems, the magnetism in ZPNRs display several surprising characteristics: (i) the magnetic moments are antiparallel arranged at each zigzag edge; (ii) the magnetism is quite stable in energy (about 29 meV/magnetic-ion) and the band gap is big (about 0.7 eV); (iii) the electronic and magnetic properties is almost independent on the width of nanoribbons; (iv) a moderate compressive strain will induce a magnetic to nonmagnetic as well as semiconductor to metal transition. All of these phenomena arise naturally due to one unique mechanism, namely the electronic instability induced by the half-filled one-dimensional bands which cross the Fermi level at around π/2a. The unusual electronic and magnetic properties in ZPNRs endow them possible potential for the applications in nanoelectronic devices. [ABSTRACT FROM AUTHOR]