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Controversial results are reported whereby biodegradation of polycyclic aromatic hydrocarbons (PAHs) can be promoted or inhibited by biochar amendment of soil. Metabolomics was applied to analyze the metabolic profiles of amendment with biochar (BB) and biochar inoculated with functional bacteria (Pseudomonas putida) (BP) involved in phenanthrene (PHE) degradation. Additionally, metagenomic analysis was utilized to assess the impact of different treatments on PHE degradation by soil microorganisms. Results indicated that BB treatment decreased the PHE biodegradation of the soil indigenous bacterial consortium, but BP treatment alleviated this inhibitory effect. Metabolomics revealed the differential metabolite 9-phenanthrol was absent in the BB treatment, but was found in the control group (CK), and in the treatment inoculated with the Pseudomonas putida (Ps) and the BP treatment. Metagenomic analysis showed that biochar decreased the abundance of the cytochrome P450 monooxygenase (CYP116), which was detected in the Pseudomonas putida , thus alleviating the inhibitory effect of biochar on PHE degradation. Moreover, a noticeable delayed increase of functional gene abundance and enzymes abundance in the BB treatment was observed in the PHE degradation pathway. Our findings elucidate the mechanism of inhibition with biochar amendment and the alleviating effect of biochar inoculated with degrading bacteria. [Display omitted] • Biochar inhibited the degradation of phenanthrene. • Biochar inoculated with Pseudomonas putida alleviated its inhibitory effect. • Differential metabolite 9-phenanthrol was not observed in the treatment of biochar. • Two upstream metabolic pathways of phenanthrene were constructed. [ABSTRACT FROM AUTHOR]

Abstract: Targeted delivery strategies are becoming increasingly important. Herein, a novel hyperbranched amphiphilic poly[(amine-ester)-co-(d,l-lactide)]/1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine copolymer (HPAE-co-PLA/DPPE) with RGD peptide (cRGDfK) and transferrin (Tf) on the periphery was synthesized and used to prepare paclitaxel-loaded nanoparticles (NPs) for dual-targeting chemotherapy. These NPs show satisfactory size distribution, high encapsulated efficiency and a pH-dependent release profile. The intrinsic fluorescence of the hyperbranched copolymer renders the detection and tracking of NPs in vitro and in vivo conveniently. In vitro cytotoxicity studies proved that the presence of cRGDfK enhanced the cytotoxic efficiency by 10 folds in ανβ3 integrin over-expressed human umbilical vein endothelial cells, while Tf improved cytotoxicity by 2 folds in Tf receptor over-expressed human cervical carcinoma cells. The drug-loaded NPs can be efficiently transported into the vascular endothelial cells and the target tumor cells. These results indicate that the cRGDfK and Tf decorated HPAE-co-PLA/DPPE could deliver chemotherapies specifically inside the cell via receptor-mediated endocytosis with greater efficacy. Therefore, such a fluorescent nanocarrier prepared from non-cytotoxic and biodegradable polymers is promising for drug delivery in tumor therapy. [Copyright &y& Elsevier]

Abstract: The fate of nanomaterials with different sizes and charges in mitotic cells is of great importance but seldom explored. Herein we investigate the intracellular fate of negatively charged carboxylated polystyrene (COOH–PS) and positively charged amino-modified polystyrene (NH2–PS) nanoparticles of three different diameters (50, 100 and 500 nm) on cancer HeLa cells and normal NIH 3T3 cells during the cell cycles. The results showed that all the fluorescent PS nanoparticles differing in size and/or charge did not interact with chromosome reorganization and cytoskeleton assembly during the mitotic process in live cells. They neither disturbed chromosome reorganization nor affected the cytoskeleton reassembly in both normal and cancer cells. However, NH2–PS at the size of 50 nm caused G1 phase delay and a decrease of cyclin (D, E) expression, respectively. Moreover, NH2–PS displayed higher cellular toxicity and NH2–PS of 50 nm disturbed the integrity of cell membranes. Both cationic and anionic PS nanoparticles had a more pronounced effect on normal NIH 3T3 cells than cancer HeLa cell. Our research provides insight into the dynamic fate, intracellular behavior, and the effects of nanoparticles on spindle and chromosomes during cell division, which will enable the optimization of design and selection of much safer nanoparticles for lower risk to human health and widely medical applications. [Copyright &y& Elsevier]

Abstract: A Life Cycle Assessment (LCA) was performed to analyze environmental consequences of different pear production chains in terms of fossil energy use and greenhouse gas (GHG) emission in China. The assessment identified hotspots that contributed significantly to the environmental impacts of pear production from the cradle to the point of sale. The results showed that GHG emissions and fossil energy use varied in the different production chains because the environmental performance does not associate with the farming systems (i.e. organic vs. conventional), but is co-determined by farm topography and thus machinery use, by market demands to seasonality of products and thus the need for storage, and by local farming practices including manure management. The LCA could be used as a tool to guide selections of agricultural inputs with the aim of reducing environmental impacts. The results of the LCA analysis indicate that a list of choices are available to reduce energy use and GHG emission in the pear production chain, namely substitution of the traditional storage systems by an efficiently controlled atmosphere storage system, using manure for biogas production, conversion from the conventional farming to organic farming, and reduction of mechanical cultivation. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the differences in the energy consumption between the production of certified organic pear, green food certified pear, and conventional pear in two areas in China. Data were collected from interviews with farmers during 2007 and 2008. Energy inputs were significantly higher in organic systems compared with conventional and green systems. Fertilizer was the most important contributor to energy consumption in all three farming systems. Three calculation methods for energy value of manure have been found in the literature: substitution method, by-product method, and thermal method. The choice of various calculation methods for estimating the energy value of manure turns out to have great influence on the results in terms of energy inputs and energy efficiency. Additionally, energy inputs and energy efficiency were also influenced by other agricultural inputs, such as machinery and corresponding fossil fuels, human labor, etc. Possible explanations for these differences are discussed. [ABSTRACT FROM AUTHOR]

The synthesis and development of catalyst with efficient electrocatalytic activity and long-term operation stability was a critical of hydrogen production for water splitting, however it is still a challenging step. Herein, a series of different proportion bimetallic uploaded nitrogen-doped graphene materials (Fe 2 O 3 -Co NPs-N-GR) were successfully synthesized through a simple, green and cost-effective method for efficient hydrogen evolution reaction (HER). All of the materials we used were earth-abundant and inexpensive. In this work, employing the interaction between DA and metal ions, Co2+ and iron (II) phthalocyanine (FePC) were loaded on the graphene oxide (GO). Moreover, the doping of N, reduction of GO and forming of Fe 2 O 3 NPs, Co NPs were realized by one-step calcination method. Among the series of catalysts we synthesized, Fe 2 O 3(1) -Co (1) NPs-N-GR exhibits better HER performance than other catalysts that we synthesized. Fe 2 O 3(1) -Co (1) NPs-N-GR exhibits significant catalytic activity and excellent durability for HER in a wide pH range. The electrocatalytic performance of Fe 2 O 3(1) -Co (1) NPs-N-GR toward HER is better in acidic solution (0.5 M H 2 SO 4) than in alkaline solution (1.0 M NaOH), the onset overpotential is 0.36 V, Tafel slope is 66 mV dec−1 and current densities of 10 mA cm−2 at overpotential is 0.39 V. The excellent HER catalytic performance of Fe 2 O 3(1) -Co (1) NPs-N-GR stem from its unique composition and structural properties by combining Fe 2 O 3 -Co nanoparticles and N co-doped graphene. This work provides a new valuable idea for the design of highly active bimetallic N-doped graphene electrocatalyst for HER. Unlabelled Image • A series of Fe 2 O 3 and Co bimetallic N-doped graphene materials were synthesized. • Achieving the uniformity loading of Co and Fe 2 O 3 used the localization of PDA. • The doping of N, reduction of GO were realized by one-step calcination method. • Fe 2 O 3(1) -Co (1) NPs-N-GR shows high electrocatalytic activity toward HER. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multi-omics approach revealed nitrogen metabolism role in soil phenanthrene degradation. • Gene co-occurrence networks link soil nitrogen metabolism and phenanthrene degradation. • Biochar inhibited phenanthrene degradation, generating more glutathione in response to soil environmental stress. • Phenanthrene degradation could couple with nitrogen metabolism by the tricarboxylic acid cycle. The presence of polycyclic aromatic hydrocarbons (PAHs) in soil negatively affects the environment and the degradation of these contaminants is influenced by nitrogen metabolism. However, the mechanisms underlying the interrelationships between the functional genes involved in nitrogen metabolism and phenanthrene (PHE) biodegradation, as well as the effects of biochar on these mechanisms, require further study. Therefore, this study utilised metabolomic and metagenomic analysis to investigate primary nitrogen processes, associated functional soil enzymes and functional genes, and differential soil metabolites in PHE-contaminated soil with and without biochar amendment over a 45-day incubation period. Results showed that dissimilatory nitrate reduction to ammonium (DNRA) and denitrification were the dominant nitrogen metabolism processes in PHE-contaminated soil. The addition of biochar enhanced nitrogen modules, exhibiting discernible temporal fluctuations in denitrification and DNRA proportions. Co-occurrence networks and correlation heatmap analysis revealed potential interactions among functional genes and enzymes responsible for PHE biodegradation and nitrogen metabolism. Notably, enzymes associated with denitrification and DNRA displayed significant positive correlation with enzymes involved in downstream phenanthrene degradation. Of particular interest was stronger correlation observed with the addition of biochar. However, biochar amendment inhibited the 9-phenanthrol degradation pathway, resulting in elevated levels of glutathione (GSH) in response to environmental stress. These findings provide new insights into the interactions between nitrogen metabolism and PHE biodegradation in soil and highlight the dual effects of biochar on these processes. [ABSTRACT FROM AUTHOR]

Urbanization has contributed to rapid development of greenhouse vegetable production in Northern China resulting in negative environmental impacts caused by the overuse of agricultural inputs. A shift towards organic consumption and production has been promoted as one of the potential solutions to this challenge. Early indications for such a shift can already be observed in many major Chinese cities. In this paper, a life cycle assessment (LCA) approach was used to examine the environmental impacts of organic and conventional production of tomatoes in greenhouses in suburban Beijing, China. Results showed clear environmental benefits associated with a 54.87% lower environmental impact index for organic tomato production compared to its conventional counterpart. For the organic system, eutrophication and soil eco-toxicity contributed the most with 56.39% and 37.87%, respectively, mainly due to manure application. For the conventional system, aquatic eco-toxicity ranked first with 59.45%, followed by eutrophication (25.70%) and soil eco-toxicity (12.12%) – mainly due to the application of chemical pesticides and fertilizers. The results of the LCA analysis suggest a positive environmental evaluation of current trends towards organic production and consumption in urban China. However, the implications of accompanying trends towards direct, cold chain delivery as well as greater land demands within the organic system should be considered. Also, more effort should be made to help organic farmers to apply organic fertilizers more efficiently in order to reduce remaining significant soil eco-toxicity impacts from manure application. [ABSTRACT FROM AUTHOR]

Contrastive learning for unpaired image-to-image translation utilizes adversarial loss to ensure the realism of generated images in the target domain and incorporates pixel-wise contrastive loss to maximize the correlation between them. However, existing methods only contrast pixel-wise features, ignoring higher-level features, and the pixel-wise contrast is imperfect, which leads to poorer perceptual and visual results. In order to alleviate these problems, we propose an effective multilevel contrast strategy for unpaired image-to-image translation (MLCUT), which contrasts features at three levels to generate more harmonious and realistic images. Specifically, we strengthen the pixel-wise level contrast and introduce the contrasts of plane and voxel-wise levels. On the one hand, MLCUT enhances training effectiveness by picking over hard negative keys for each query at the pixel-wise level. On the other hand, we strengthen the learning preferences of generators on features of objects rather than backgrounds by contrasting the plane-wise discriminative matrices in adversarial loss. Furthermore, by contrasting voxel-wise global semantic vectors, MLCUT effectively improves the realism of generated images and avoids mode collapse. Qualitative and quantitative experiments demonstrate that our method effectively improves performance in perception and vision. [ABSTRACT FROM AUTHOR]

Abstract In the interest of developing novel electrocatalyst for high performance DNA biosensing, with distinctive chiral double helix nanostructure, nitrogen doped chiral carbonaceous nanotube (Chiral-CNT) was employed for ultrasensitive label-free DNA biosensing research. Chiral-CNT can quantitative detection of four DNA bases with high sensitivity and selectivity. Without any prehydrolysis and labeling process, direct electrochemistry of single-stranded DNA and double-stranded DNA, qualitative and quantitative detection of DNA hybridization (low detection limit: 0.0268 g L−1) were realized. Moreover, sensitive detection of DNA damage induced by fenton reagent was also realized with low detection limit of 0.0350 mg mL−1 and high sensitivity of 7.42 μA mg−1 mL. The high biosensing performance attributes to the unique chiral structure of Chiral-CNT, leads to efficient interreaction between Chiral-CNT and DNA molecule. Graphical abstract Ultrasensitive label-free DNA direct electrochemistry, DNA hybridization and damage study based on nitrogen doped chiral carbonaceous nanotube. Image 1 Highlights • Ultrasensitive DNA biosensing research based on chiral carbonaceous nanotube. • DNA direct electrochemistry without any prehydrolysis process. • Label-free DNA hybridization research. • DNA damage electrochemical detection using 8-OHdG as biomarker. [ABSTRACT FROM AUTHOR]

Abstract The development of high-performance noble metal-free electrochemical catalyst for effective water splitting is a key factor to achieve low-cost and sustainable renewable energy production. Herein, for the first time, highly dispersed cobalt nanoparticles decorated uniform nitrogen doped graphene (CoNPs-N-GR) was design synthesized. In the preparation procedure, graphene oxide (GO) was employed as supporting material, polydopamine as nitrogen source, location reagent as well as connecting agent for uploading cobalt metal ion, and then cobalt metal-organic frameworks (ZIF-67) in situ grew on GO. During the calcining process, GO reduction, nitrogen doping and cobalt nanoparticles forming were finished in one step. Scanning electron microscopy (SEM) images, transmission electron microscopy (TEM), energy-dispersive X-ray (EDS), X-ray photoelectron spectrometer (XPS) and X-ray diffraction (XRD) were applied to characterize the as-prepared CoNPs-N-GR. Moreover, owing to the presence of dopamine, high dispersed cobalt nanoparticles were obtained, leading to high electrocatalytic activity of CoNPs-N-GR for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. HER reaches 10 mA cm−2 at the over-potential of 0.453 V with a Tafel slope of 67 mV dec−1. OER reaches 10 mA cm−2 at the over-potential of 1.63 V with a Tafel slope of 65 mV dec−1. And the as-prepared CoNPs-N-GR shows excellent durability in the long-term stability for HER and OER. Graphical abstract Image 1 Highlights • Highly dispersed CoNPs decorated uniform nitrogen doped graphene was prepared. • Polydopamine as nitrogen source, location reagent as well as connecting agent. • In situ grow of cobalt metal-organic frameworks (ZIF-67) as cobalt precursor. • High electrocatalytic performance for both HER and OER in alkaline media. [ABSTRACT FROM AUTHOR]

Abstract In this work, spherical, flower and urchin–like platinum nanoparticles (PtNSs, PtNFs, PtNUs) decorated ordered mesoporous carbon (OMC) architecture were synthesized through a facile strategy without any template, surfactant and stabilizer. The different morphologies can be controlled by simple adjusting the proportion of precursor K 2 PtCl 4 , HCOOH and OMC at room temperature, this both simplifies the synthesis procedure and permits good mixing, with better interfacing between the two nanophases of K 2 PtCl 4 and OMC. The formation mechanism of PtNUs, PtNFs and PtNSs decorated OMC (OMC–PtNUs, OMC–PtNFs and OMC–PtNSs) was deeply researched. The novel structure has the potential to possess high Pt utilization, high Pt activity surface and high specific surface area of OMC, which enables the excellent electrochemical sensing performance. Paracetamol (AP), methanol and glucose were employed as redox probes to study the electrocatalytic performance, which shows favorable electron–transfer kinetics. The novel structure should be a good model for constructing a promising electrochemical sensing platform for further research in pharmaceutical preparations and in biological fluids. Graphical abstract Unlabelled Image Highlights • Spherical, flower, urchin-like platinum decorated ordered mesoporous carbon. • Without using any template, surfactant and stabilizer • Formation mechanism of different morphology PtNPs was researched. • High electrochemical sensing performance [ABSTRACT FROM AUTHOR]

The development of low-cost and highly efficient hydrogen evolution reaction (HER) catalysts has driven continuous effort. Here we develop a one-step preparation method of novel two-dimensional coupled hybrid of molybdenum carbide embedded N-doped carbon nanolayer architecture (MoCx-N/CNL) using cheap cotton as carbon and nitrogen precursor and ammonium molybdate as Mo precursor. Transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), energy dispersive X-ray spectra (EDS), scanning electron microscopy (SEM), element mapping, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were utilized to characterize the as-prepared nanocomposites. The synergistic effect between dispersive Mo 2 C particles and N doping in MoCx-N/CNL leads to remarkable HER performance in acidic media. Different amount of Mo were doped in the samples by arranging the ammonium molybdate concentration. Three samples were obtained and MoCx-N/CNL-3 showed better HER electrocatalytic performance than other two samples. Moreover, the as prepared MoCx-N/CNL-3 exhibits excellent stability and durability in acidic media. A new viable route is provided to prepare molybdenum carbide embedded N-doped carbon hybrid architecture with higher HER stability and activity, it is of significance in novel HER catalyst preparation. [ABSTRACT FROM AUTHOR]

A controllable flower-like Pt-graphene oxide (PtNF-GO) architecture was synthesized through layer-by-layer electrostatic self-assembly. Hexadecyltrimethylammonium chloride (CTAC) micelles were employed as the template and Pt nanoflowers with different sizes were selectively synthesized by controlling the dissolved K2PtCl4 precursor and CTAC amounts in the reaction system. The prepared PtNF-GO was applied for DNA damage biomarker 8-hydroxy-2′-deoxyguanosine (8-OHdG) biosensing research. With the distinctive flower-like morphology of PtNFs and high electrical conductivity of GO, the PtNF-GO architecture shows excellent electrochemical biosensing performance towards the oxidation of 8-OHdG. A very low detection limit of 0.025 nM is obtained. Moreover, the fabricated PtNF-GO was used for the detection of 8-OHdG generated from the damaged DNA sample, which can be used to evaluate and confirm the mechanism of DNA damage, and it is of great importance in gene diagnosis, clinical and life sciences. [ABSTRACT FROM AUTHOR]

Abstract: The fabrication and electromechanical performance of functionalized carbon nanotube (FCNT)–Nafion composite actuators were studied. The CNTs were modified successfully with polyethylene glycol (PEG), as verified by thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy. Scanning electron microscopy (SEM) images show that the FCNTs are homogeneously dispersed in the Nafion matrix. The properties of FCNT–Nafion composites in terms of water uptake, ion exchange capacity, proton conductivity, dynamic mechanical properties, and actuation behavior were evaluated. The results show that the sample with 0.5wt% FCNT exhibits the best overall behavior. Its storage modulus is 2.4 times higher than that of Nafion. In addition, the maximum generated strain and the blocking force for the same sample are 2 and 2.4 times higher compared to the neat Nafion actuator, respectively. [Copyright &y& Elsevier]

• Risk indicators of non-compliance in organic crop production is set and weighted. • Dimension weights of production, management and environment are 0.59, 0.24 and 0.17. • Plant protection, detection, and soil fertility management are top three risk themes. • Pesticides detection rate and nutrient satisfaction rate are top two risk indicators. Farming management and certification are essential for organic agriculture development to make sure that farming practices are compliant with organic regulations. To improve the efficiency of organic certification and farm management, a risk-based indicator system of organic crop production was established according to literature review and Chinese organic regulations. Three dimensions, 11 themes, and 25 indicators were selected and the weights of which were determined through Analytic Hierarchy Process. The highest weight was assigned to the production dimension (0.59), followed by management (0.24) and environment (0.17). The three highest risk themes in the sequence were plant protection, detection and soil fertility management with a weight of 0.17, 0.15 and 0.12, respectively. At the indicator level, pesticide detection rate, nutrient satisfaction rate, the proportion of non-chemical treatment, the severity of crop diseases, pests and weeds, and the quality of soil environment ranked top five according to the weight of their risk. Chemicals application including pesticides and fertilizers was the main concern in organic production and certification. The results will provide producers, inspectors, and certifiers useful references to reduce the risk of non-compliance, and increase the integrity and credibility during organic production and certification. [ABSTRACT FROM AUTHOR]