Mn2+-Triggered Swing-Arm Robot Strategy Using Anemone-Like Thi@AuPd@Cu-MOFs as Signaling Probes for the Detection of T-2 Toxin.

Herein, we synthesized anemone-like copper-based metal-organic frameworks (MOFs) loaded with gold-palladium nanoparticles (AuPd@Cu-MOFs) and polyethylenimine-reduced graphene oxide/gold-silver nanosheet composites (PEI-rGO/AuAg NSs) for the first time to construct the sensor and to detect T-2 toxin (T-2) using triple helix molecular switch (THMS) and signal amplification by swing-arm robot. The aptasensor used PEI-rGO/hexagonal AuAg NSs as the electrode modification materials and anemone-like AuPd@Cu-MOFs as the signal materials. The prepared PEI-rGO/hexagonal AuAg NSs had a large specific surface area, excellent electrical conductivity, and good stability, which successfully improved the electrochemical performance of the sensors. The AuPd@Cu-MOFs with high porosity provided a great deal of attachment sites for the signaling molecule thionine (Thi), thereby increasing the signal response. The aptasensor developed in this study demonstrated a remarkable detection limit of 0.054 fg mL-1 under optimized conditions. Furthermore, the successful detection of T-2 in real samples was achieved using the fabricated sensor. The simplicity of the THMS-based method, which entails modifying the aptamer sequence, allows for easy adaptation to different target analytes. Thus, the sensor holds immense potential for applications in quality supervision and food safety.

Maternal tobacco exposure during pregnancy and atopic dermatitis in offspring: A systematic review and meta-analysis.

The main purpose of this review was to examine the evidence of the relationship between active smoking or passive smoking during pregnancy and atopic dermatitis in offspring. The protocol was written following the PRISMA Checklist and was registered in the PROSPERO database (registration number CRD42022381136). We implemented a comprehensive search in PubMed, Embase and Web of Science databases to identify all potentially related articles from inception through 1 December 2022. We assessed cohort studies and case-control studies using the Newcastle-Ottawa Scale (NOS), and the Joanna Briggs Institute (JBI) critical appraisal tool to assess the quality of cross-sectional studies. Heterogeneity was investigated by using Cochrane Q tests and I2 statistics. In addition, according to the research design, population source and population size, the reasons for the heterogeneity were analysed. A total of 15 observational studies were included in this analysis. Our meta-analysis suggests that atopic dermatitis in offspring is not associated with active smoking during pregnancy (pooled OR, 0.96 [95% CI 0.86-1.07]); however, it is related to passive smoking (OR, 1.52 [95% CI 1.36-1.70]). Passive smoking during pregnancy is associated with an increased risk of eczema development in offspring. More research is needed to explore the risk of active smoking and eczema development in offspring, especially the association between measurements of pregnancy cotinine levels in maternal body fluids and AD in offspring.

Multi-omics analysis of bone marrow mesenchymal stem cell differentiation differences in osteoporosis.

Osteoporosis is a systemic skeletal disease characterized by low bone mass and degradation of bone tissue microarchitecture, leading to enhanced bone fragility and increased fracture risk. However, the pathogenesis of osteoporosis is unclear. Our results showed that BMSCs dervied from ovariectomized rats had a higher capacity for osteogenesis and lipogenic differentiation compared to the control group. In the meantime, we identified a total of 205 differentially expressed proteins and 2294 differentially expressed genes in BMSCs isolated from ovariectomized rats by proteomics analysis and transcriptome sequencing, respectively. These differentially expressed proteins and genes were mainly involved in ECM-receptor interaction signaling pathway. We speculate that BMSCs derived from ovariectomized rats have a higher potential for bone formation because expression of ECM collagen or genes encoding collagen in the bone ECM in BMSCs isolated from ovariectomized rats are increased compared with that from control group, which provided the prerequisite for the increased bone turnover effect. To conclusion, our results may provid new ideas for further research on the pathogenesis of osteoporosis.

Exploring bacterial community assembly in vadose and saturated zone soil for tailored bioremediation of a long-term hydrocarbon-contaminated site.

Indigenous soil microbial communities play a pivotal role in the in situ bioremediation of contaminated sites. However, research on the distribution characteristics of microbial communities at various soil depths remains limited. In particular, there is little information on the assembly of microbial communities, especially those with degradation potential, in the vadose and saturated zones of hydrocarbon-contaminated sites. In this study, 18 soil samples were collected from the vadose zone and saturated zone at a long-term hydrocarbon-contaminated site. The diversity, composition, and driving factors of assembly of the soil bacterial community were determined by high-throughput sequencing analysis. Species richness and diversity were significantly higher in the vadose zone soils than in the saturated zone soils. Significant differences in abundance at both the phylum and genus levels were observed between the two zones. Soil bacterial community assembly was driven by the combination of pollution stress and nutrients in the vadose zone but by nutrient limitations in the saturated zone. The abundance of dechlorinating bacteria was greater in the saturated zone soils than in the vadose zone soils. Compared with contaminant concentrations, nutrient levels had a more pronounced impact on the abundance of dechlorinating bacteria. In addition, the interactions among dechlorinating bacterial populations were stronger in the saturated zone soils than in the vadose zone soils. These findings underscore the importance of comprehensively understanding indigenous microbial communities, especially those with degradation potential, across different soil layers to devise specific, effective in situ bioremediation strategies for contaminated sites.

Legacy of herbicides in water from Hailun City, Northeast China: Occurrence, source, and ecological risk assessment.

Herbicides (HBCs) are extensively used in modern agriculture. However, their potential negative impacts on environmental media have emerged as a significant environmental concern. In this study, we employed positive matrix factorization (PMF) to identify the potential sources of HBCs. Furthermore, we utilized a multi-matrix ecological risk model to assess the risks associated with HBCs in both surface water and groundwater in the black soil region of Northeast China. The findings revealed that the levels of ∑15HBCs in surface water and groundwater ranged from 585.84 to 6466.96 ng/L and 4.80 to 11,774.64 ng/L, respectively. The PMF results indicated that surface runoff and erosion accounted for 50% of the total HBCs in water, serving as the primary sources. All tested HBCs exhibited acute risk values within acceptable levels. The risk index for the ∑15HBCs was categorized as "moderate risk" in 31% of the surface waters and 13% of the groundwaters. However, 4% of the groundwater sampling sites reached the "high risk" level. The chronic risk quotient of ∑15HBCs in surface water and groundwater was 92% and 62% at the "high risk" level, respectively. Interestingly, non-carcinogenic HBCs contributed more significantly to the ecotoxicology of the aquatic system than carcinogenic HBCs. This study provides comprehensive information on the legacy of HBCs in water bodies and emphasizes the potential risks posed by HBCs to aquatic systems. The results obtained from this study could help relevant management authorities in developing and implementing effective regulations to mitigate the ecological and environmental risks associated with HBCs.

Continuous usage intention of mobile health services: model construction and validation.

BACKGROUND: Mobile health (mHealth) services can not give full play to their value if only it is used in the short term, and their continuous usage can achieve better effects in health management. This study aims to explore the factors that affect continuous usage intentions of mHealth services and their mechanism of action. METHODS: First, considering the uniqueness of health services and social environmental factors, this study constructed an extended Expectation Confirmation Model of Information System Continuance (ECM-ISC) to investigate factors that may influence the intention of continuous usage of mHealth services based on three dimensions, namely individual characteristics, technology and environment. Second, the survey method was used to validate the research model. The questionnaire items were derived from validated instruments and discussed by experts and data were collected both online and offline. The structural equation model was used for data analysis. RESULTS: There were 334 avidity questionnaires through cross-sectional data and these participants had used mHealth services ever. The reliability and validity of the test model were good, in which Cronbach's Alpha values of 9 variables exceeded 0.9, composite reliability 0.8, the average variance extracted value 0.5, and the factor loading 0.8. The modified model had a good fitting effect and strong explanatory power. It accounted for 89% of the variance in expectation confirmation, 74% of the variance in perceived usefulness, 92% of the variance in customer satisfaction, and 84% of the variance in continuous usage intention. Compared with the initial model hypotheses, perceived system quality was deleted according to the heterotrait-monotrait ratio, so paths related to it were deleted; perceived usefulness wasn't positively associated with customer satisfaction, and its path was also deleted. Other paths were consistent with the initial hypothesis. The two new added paths were that subjective norm was positively associated with perceived service quality (ß = 0.704, P < 0.001), and perceived information quality (ß = 0.606, P < 0.001). Electronic health literacy (E-health literacy) was positively associated with perceived usefulness (ß = 0.379, P < 0.001), perceived service quality (ß = 0.200, P < 0.001), and perceived information quality (ß = 0.320, P < 0.001). Continuous usage intention was influenced by perceived usefulness (ß = 0.191, P < 0.001), customer satisfaction (ß = 0.453, P < 0.001), and subjective norm (ß = 0.372, P < 0.001). CONCLUSIONS: The study constructed a new theoretical model including E-health literacy, subjective norm and technology qualities to clarify continuous usage intention of mHealth services, and empirically validated the model. Attention should be paid to E-health literacy, subjective norm, perceived information quality, and perceived service quality to improve continuous usage intention of users and self-management by mHealth Apps managers and governments. This research provides solid evidence for the validity of the expanded model of ECM-ISC in the mHealth field, which can be a theoretical and practical basis for mHealth operators' product research and development.

AgPdNFs and AuNOs@GO nanocomposites for T-2 toxin detection by catalytic hairpin assembly.

T-2 toxin is the most potent and toxic mycotoxin, produced by various Fusarium species that can potentially affect human health, and widely exists in field crops and stored grain. In this work, an electrochemical aptasensor with nonenzymatic signal amplification strategy for the detection of T-2 toxin is presented, using noble metal nanocomposites and catalytic hairpin assembly as signal amplification strategy. Silver palladium nanoflowers and gold octahedron nanoparticles@graphene oxide nanocomposites are used for synergistic amplification of electrical signals. Simultaneously, the catalytic hairpin assembly strategy based on artificial molecular technology was introduced to further amplify the signal. Under optimal conditions, T-2 toxin was measured within a linear concentration range 1 × 10-2 ~ 1 × 104 pg·mL-1 with an extremely low detection limit of 6.71 fg·mL-1. The aptasensor exhibited high sensitivity, good selectivity, satisfactory stability, and excellent reproducibility. Moreover, this method had high accuracy in detecting T-2 toxin in beer sample. The encouraging results show the potential application in foodstuff analysis. A dual signal amplification electrochemical biosensor for the detection of T-2 toxins was constructed, through the signal amplification of noble metal nanomaterials and CHA strategy.

Molecular Recognition-Triggered Aptazyme Sensor Using a Co-MOF@MCA Hybrid Nanostructure as Signal Labels for Adenosine Triphosphate Detection in Food Samples.

Developing rapid detection technology for adenosine triphosphate (ATP) is crucial in quality supervision and food safety. Herein, an electrochemical aptasensor based on an aptazyme-catalyzed signal amplification strategy is constructed for ATP detection using polyethyleneimine-functionalized molybdenum disulfide (PEI-MoS2)/Au@PtPd nanobipyramids (MoS2/Au@PtPd NBPs) as a modification material. Additionally, a novel kind of nitrogen-rich covalent organic framework (COF) is prepared using melamine and cyanuric acid (MCA). We synthesize MCA and the Co-based metal organic framework (Co-MOF) as the signal label. Due to the fact that π-π stacking interactions of Co-MOF@MCA can expand the load efficiency and surface concentration of the signal label, the signal response is an order of magnitude higher than that of Co-MOF or MCA as the signal label. Target ATP changes the conformation of the aptazyme, and it becomes activated. With the assistance of metal ions, the signal label is circularly cleaved, causing an amplification of the signal. Among them, MoS2/Au@PtPd NBPs have a large specific surface area and good electrical conductivity and can carry substantial DNA strands and amplify the redox signal of methylene blue (MB). Under optimal conditions, the aptasensor can detect ATP from 10 pM to 100 µM with a low limit of detection of 7.37 × 10-10 µM. Therefore, the novel aptasensor has extensive application prospects in quality supervision and food safety.

Soil Type Driven Change in Microbial Community Affects Poly(butylene adipate-co-terephthalate) Degradation Potential.

Biodegradable mulch films have been developed as a suitable alternative to conventional nondegradable polyethylene films. However, the key factors controlling the degradation speed of biodegradable mulch films in soils remain unclear. Here, we linked changes in the soil microbiome with the degradation rate of a promising biodegradable material poly(butylene adipate-co-terephthalate) (PBAT) in four soil types, a lou soil (LS), a fluvo-aquic soil (CS), a black soil (BS), and a red soil (RS), equivalent to Inceptisols (the first two soils), Mollisols, and Ultisols, using soil microcosms. The PBAT degradation rate differed with the soil type, with PBAT mineralization levels of 16, 9, 0.3, and 0.9% in LS, CS, BS, and RS, respectively, after 120 days. Metagenomic analysis showed that the microbial community in LS was more responsive to PBAT than the other three soils. PBAT hydrolase genes were significantly enriched in LS but were not significantly stimulated by PBAT in CS, BS, or RS. Several members of Proteobacteria were identified as novel potential degraders, and their enrichment extent was significantly positively correlated with PBAT degradation capacity. Overall, our results suggest that soil environments harbored a range of PBAT-degrading bacteria and the enrichment of potential degraders drives the fate of PBAT in the soils.

Enhanced biomass and cadmium accumulation by three cadmium-tolerant plant species following cold plasma seed treatment.

Cold plasma seed treatment can promote plant growth and enhance the resistance of agricultural crops to adverse stress. However, the effects of plasma seed treatment on the growth and phytoextraction response of plants to cadmium (Cd) remain poorly documented. Here, we have investigated the feasibility of using plasma seed treatment to enhance the biomass and Cd accumulation of three Cd-tolerant species, namely Bidens pilosa L, Solanum nigrum L. and Trifolium repens L, under different plasma treatment conditions. Possible enhancement mechanisms are also proposed according to the levels of organic acids in the roots and the Cd fractions in rhizosphere soil following different plasma treatment conditions. The optimum plasma power was 100 W (B. pilosa) or 500 W (S. nigrum and T. repens). The optimum plasma exposure time for all three species was 60 s. Plasma seed treatment under the optimum treatment conditions enhanced plant dry biomass by ~17.3-45.0% and Cd accumulation by 8.8-54.4% across all three species compared to the controls. Furthermore, the phytoremediation efficiencies, bioaccumulation factors and transfer factors of the three species also increased significantly after seed plasma treatment. The promotion of plasma treatment on the biomass and Cd accumulation of three species might be due to increased exudation of organic acids from the roots into the rhizosphere soil, thus increasing the concentrations of acid-soluble Cd to form Cd-organic acid complexes that facilitated the uptake and translocation of Cd by the plants. Results of this study revealed that cold plasma seed treatment is an environmentally friendly, economical and efficient means to develop the application of phytoremediation for Cd-contaminated soils.

Pesticide residues in soils planted with Panax notoginseng in south China, and their relationships in Panax notoginseng and soil.

In this study, 73 samples from soils planted with Panax notoginseng and six P. notoginseng samples were collected in Yunnan Province to investigate the residual levels of six pesticides and their relationships with P. notoginseng and soil. All six pesticides were detected in the soils planted with P. notoginseng located in three regions of Shilin, Kaiyuan, and Yanshan. The detection frequencies of the pesticides in the soils followed the order: quintozene (100%) > iprodione (96%) > procymidone (69%) > chlorothalonil (51%) > pyrimethanil (49%) > pyraclostrobin (29%). The median concentrations of iprodione, pyraclostrobin, pyrimethanil, quintozene, procymidone, and chlorothalonil were 46.40, 6.4, 3.1, 2.86, 2.69, and 0.24 µg/kg, respectively. The mean concentrations of pesticides in the three regions followed the order: Kaiyuan > Shilin > Yanshan, except for iprodione. Furthermore, the concentrations of pesticide residues in soils in each region followed the order: soils never planted with P. notoginseng < soils previously planted with P. notoginseng < soils currently planted with P. notoginseng. The concentration of chlorothalonil in P. notoginseng followed the order: root > stem > leaf, whereas those of the other five pesticides followed the opposite order: root < stem < leaf. There were significant positive correlations between the mean concentrations of pesticides in P. notoginseng and those in the corresponding soils. These results indicate that the rational application of pesticides in P. notoginseng cultivation would be effective for reducing the accumulation of pesticides in P. notoginseng to protect people from the harmful effects of residual pesticides.

Development and optimization of levodopa and benzylhydrazine orally disintegrating tablets by direct compression and response surface methodology.

The number of Parkinson's disease (PD) patients with the advanced phase and motor fluctuations is increasing. The objective of this study is developing levodopa/benzylhydrazine orally disintegrating tablets (L/B ODTs), which would provide greater convenience and ease of use than conventional tablets for these patients. In the present study, the L/B ODTs were developed successfully with an optimized formulation using response surface methodology (RSM). The direct compression technology was employed for the preparation of L/B ODTs. Considerably shorter disintegration time and faster dissolution profile were obtained under the optimum formulation with microcrystalline cellulose 25.7%, cross-polyvinylpyrrolidone 6.22% and Sodium carboxymethyl starch 5.36%. The content uniformity (%) of levodopa and benzylhydrazine was 50 ± 1.4% and 14.25 ± 0.6%, respectively. Thickness, friability, hardness and wetting time were 2.8 ± 0.05 mm, 0.46 ± 0.21%, 5.42 ± 1.1 kp and 31.2 ± 2.1 s, respectively, and all of data well comply with the General Principles of the Chinese Pharmacopeia. Mannitol of 22% in formulation could bring a pleasant taste: sweet, cool and refreshing. Almost all the volunteers felt that the ODTs had good taste, no roughness, and no gritty feeling, indicating that the ODTs prepared had good palatability, so patients will have good compliance when taking medicine.

Effect of Graphene Oxide on Growth of Wheat Seedlings: Insights from Oxidative Stress and Physiological Flux.

In this study, the responses of wheat seedlings to graphene oxide (GO) were investigated at a wide concentration range of 0-1000 mg L-1, including oxidative stress, real-time membrane potential as well as proton and calcium ion fluxes. The results show that GO induced a hormesis effect on root growth (low concentration (100 mg L-1) promotion and high concentration (1000 mg L-1) inhibition. Oxidative stress was responsible for the growth inhibition at GO concentration of 1000 mg L-1, as suggested from great stimulation in the activities of antioxidant enzymes and MDA content in roots or leaves. Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) activities were highly correlated with MDA levels (r2 = 0.963, 0.984, and 0.960, respectively). GO exposure caused significant concentration-dependent membrane depolarization in roots, and significantly inhibited H+ efflux and extracellular Ca2+ influx in root cap.

[Short-term effect of gas explosion in real roadway environment on rats' brain neural behavior].

OBJECTIVE: To study the effect of gas explosion on brain nerve behavior of rats in real roadway environment. METHODS: Before the gas explosion, the real gas explosion roadway environment was simulated by using the roadway and explosion test system of gas explosion test in a large coal mine in Chongqing Research Institute of China Coal Science & Technology Group, and cage fixation and explosion parameter setting were carried out. That was to use the equivalent of 9. 0% gas containing mixed air and to install special cage in roadway gas detonation distance at point 40 m, 160 m and 240 m. The SPF grade healthy adult SD male rats anesthetized with chloral hydrate were placed among them, and the rats were placed in a position that could force the head. At the same time, the trunk part below the occipital foramen and the mouth and face above the line of inner canthus were fully protected, and the gas explosion experiment was carried out. A total of 40 rats were randomly divided into four groups according to their body weight: control group, burn-blast combined injuries group(40 m), proximal group(160 m) and distance group(240 m). Ten rats in each group were placed in cages at different distance points under anesthesia except the normal control group. The general physiological behavior of the rats was observed 2 h and 7 d after the explosion, and the neurobehavioral indexes of the rats were monitored by open field behavior experiment. Gross observation and pathological examination of brain tissue were performed 7 days later. RESULTS: The spirits of the rats in the 2 h exposure group after explosion were poor, and improved slightly after 7 d. The degree of surface burn was the most serious in group 40 m. The number of urination decreased while the number of feces increased(P>0. 05). At the end of the experiment, it was found that cerebral edema and hyperemia were obvious in rats. Compared with the normal control group, the brain weight of rats in each exposure group increased, and the difference was statistically significant(P<0. 05). Pathological observation showed that the brain tissues of rats in each exposed group showed irregular and disordered arrangement of nerve cells, interstitial edema, dense and deep staining of loose nuclear chromatin, formation of dense mass and other characteristics of apoptotic cells, as well as increased glia and aggregation of inflammatory cells. At 2 d and 7 h after the explosion, compared with the control group, the resting time of the neurobehavioral indicators of rats at different distance points was significantly prolonged(P<0. 01), while the number of standing times, movement time and movement distance were significantly reduced, and the difference was statistically significant(P<0. 01). CONCLUSION: The gas explosion in real roadway environment can cause certain damage to the brain tissue of rats, and has obvious influence on its neural behavior.

TNF-α Differentially Regulates Synaptic Plasticity in the Hippocampus and Spinal Cord by Microglia-Dependent Mechanisms after Peripheral Nerve Injury.

Clinical studies show that chronic pain is accompanied by memory deficits and reduction in hippocampal volume. Experimental studies show that spared nerve injury (SNI) of the sciatic nerve induces long-term potentiation (LTP) at C-fiber synapses in spinal dorsal horn, but impairs LTP in the hippocampus. The opposite changes may contribute to neuropathic pain and memory deficits, respectively. However, the cellular and molecular mechanisms underlying the functional synaptic changes are unclear. Here, we show that the dendrite lengths and spine densities are reduced significantly in hippocampal CA1 pyramidal neurons, but increased in spinal neurokinin-1-positive neurons in mice after SNI, indicating that the excitatory synaptic connectivity is reduced in hippocampus but enhanced in spinal dorsal horn in this neuropathic pain model. Mechanistically, tumor necrosis factor-alpha (TNF-α) is upregulated in bilateral hippocampus and in ipsilateral spinal dorsal horn, whereas brain-derived neurotrophic factor (BDNF) is decreased in the hippocampus but increased in the ipsilateral spinal dorsal horn after SNI. Importantly, the SNI-induced opposite changes in synaptic connectivity and BDNF expression are prevented by genetic deletion of TNF receptor 1 in vivo and are mimicked by TNF-α in cultured slices. Furthermore, SNI activated microglia in both spinal dorsal horn and hippocampus; pharmacological inhibition or genetic ablation of microglia prevented the region-dependent synaptic changes, neuropathic pain, and memory deficits induced by SNI. The data suggest that neuropathic pain involves different structural synaptic alterations in spinal and hippocampal neurons that are mediated by overproduction of TNF-α and microglial activation and may underlie chronic pain and memory deficits. SIGNIFICANCE STATEMENT: Chronic pain is often accompanied by memory deficits. Previous studies have shown that peripheral nerve injury produces both neuropathic pain and memory deficits and induces long-term potentiation (LTP) at C-fiber synapses in spinal dorsal horn (SDH) but inhibits LTP in hippocampus. The opposite changes in synaptic plasticity may contribute to chronic pain and memory deficits, respectively. However, the structural and molecular bases of these alterations of synaptic plasticity are unclear. Here, we show that the complexity of excitatory synaptic connectivity and brain-derived neurotrophic factor (BDNF) expression are enhanced in SDH but reduced in the hippocampus in neuropathic pain and the opposite changes depend on tumor necrosis factor-alpha/tumor necrosis factor receptor 1 signaling and microglial activation. The region-dependent synaptic alterations may underlie chronic neuropathic pain and memory deficits induced by peripheral nerve injury.

Coupling between Nitrogen Fixation and Tetrachlorobiphenyl Dechlorination in a Rhizobium-Legume Symbiosis.

Legume-rhizobium symbioses have the potential to remediate soils contaminated with chlorinated organic compounds. Here, the model symbiosis between Medicago sativa and Sinorhizobium meliloti was used to explore the relationships between symbiotic nitrogen fixation and transformation of tetrachlorobiphenyl PCB 77 within this association. 45-day-old seedlings in vermiculite were pretreated with 5 mg L-1 PCB 77 for 5 days. In PCB-supplemented nodules, addition of the nitrogenase enhancer molybdate significantly stimulated dechlorination by 7.2-fold and reduced tissue accumulation of PCB 77 (roots by 96% and nodules by 93%). Conversely, dechlorination decreased in plants exposed to a nitrogenase inhibitor (nitrate) or harboring nitrogenase-deficient symbionts (nifA mutant) by 29% and 72%, respectively. A range of dechlorinated products (biphenyl, methylbiphenyls, hydroxylbiphenyls, and trichlorobiphenyl derivatives) were detected within nodules and roots under nitrogen-fixing conditions. Levels of nitrogenase-derived hydrogen and leghemoglobin expression correlated positively with nodular dechlorination rates, suggesting a more reducing environment promotes PCB dechlorination. Our findings demonstrate for the first time that symbiotic nitrogen fixation acts as a driving force for tetrachlorobiphenyl dechlorination. In turn, this opens new possibilities for using rhizobia to enhance phytoremediation of halogenated organic compounds.

Phytoremediation of diphenylarsinic-acid-contaminated soil by Pteris vittata associated with Phyllobacterium myrsinacearum RC6b.

A pot experiment was conducted to explore the phytoremediation of a diphenylarsinic acid (DPAA)-spiked soil using Pteris vittata associated with exogenous Phyllobacterium myrsinacearum RC6b. Removal of DPAA from the soil, soil enzyme activities, and the functional diversity of the soil microbial community were evaluated. DPAA concentrations in soil treated with the fern or the bacterium were 35-47% lower than that in the control and were lowest in soil treated with P. vittata and P. myrsinacearum together. The presence of the bacterium added in the soil significantly increased the plant growth and DPAA accumulation. In addition, the activities of dehydrogenase and fluorescein diacetate hydrolysis and the average well-color development values increased by 41-91%, 37-78%, and 35-73%, respectively, in the treatments with P. vittata and/or P. myrsinacearum compared with the control, with the highest increase in the presence of P. vittata and P. myrsinacearum together. Both fern and bacterium alone greatly enhanced the removal of DPAA and the recovery of soil ecological function and these effects were further enhanced by P. vittata and P. myrsinacearum together. Our findings provide a new strategy for remediation of DPAA-contaminated soil by using a hyperaccumulator/microbial inoculant alternative to traditional physicochemical method or biological degradation.

Urchin-like gold nanoparticle-based immunochromatographic strip test for rapid detection of fumonisin B1 in grains.

An immunochromatographic strip (ICS) using urchin-like gold nanoparticles (UGNs) for sensitive detection of fumonisin B1 (FB1) was developed to meet the requirement for rapidly monitoring FB1 in grain samples. The sensitivity of the ICS was 5.0 ng/mL, which represents a fourfold increase in sensitivity over conventional strip preparation using colloidal gold as the antibody-labeled probe. Analysis of FB1 in grain samples showed that data obtained from the strip tests were in a good agreement with those obtained from HPLC and enzyme-linked immunosorbent assays (ELISAs). This qualitative test did not require any specialized equipment, and the detection time was less than 5 min, which is suitable for on-site testing of FB1 in grain samples. Overall, to our knowledge, this is the first report of using a UGN as the antibody-labeled probe for sensitive detection of FB1 in grains using an ICS. Graphical Abstract Preparation of ICS using conventional colloidal gold and urchin-like gold nanoparticle, respectively.

[SERS Enhancement Factor Analysis and Experiment of Carbon Nanotube Arrays Coated by Ag Nanoparticles].

To intuitive and accurate quantitatively analyze Raman enhancement of surface enhanced Raman scattering substrate structure, three-dimensional composite structure of silver nanoparticles modified vertically aligned carbon nanotube array is produced by magnetron sputtering and thermal annealing process; Relevant experiments using Rhodamine 6G (R6G) solution as the molecular probes are conducted to analyze surface enhanced Raman enhancement factor (EF), combining with confocal Raman microscopy systems. The result of scanning electron microscopy (SEM) shows that a large number of silver nanoparticles are attached onto the tips and sidewalls of the ordered carbon nanotubes array uniformly. EF of the sample which was produced 30 min annealing time and 450 degrees C annealing temperature evaluates to 2.2 x 10(3), and the reasons for the low EF are analyzed: on the one hand, thickness of silver film sputtered on vertically aligned carbon nanotube array is non-uniform, leading to distribution of silver nanoparticles is uneven after annealing, so that the value of sample roughness is too large, EF value is low; on the other hand, the excitation light source is not the advantage wavelength of silver nanoparticles in the experiments.

Study on modification of single-walled carbon nanotubes on the surface of monocrystalline silicon solar cells.

Modification of single-walled carbon nanotubes (SWNTs) on the surface of monocrystalline silicon solar cells was investigated. The modification was realized by dropping a well-distributed mixture of SWNTs and ethanol with different dosages on the surface of monocrystalline silicon solar cells in the same effective area. The experimental results showed that the increasing rates of conversion efficiency, short-circuit current, and fill factor were 4.37%, 2.18%, and 2.11%, respectively; the open circuit voltage and series resistance decreased by 0.11% and 9.37% compared with the bare solar cell without an antireflection (AR) layer, when the modification reached the best state by dropping a 0.5 mL mixture solution with a concentration of 0.08 g/L. With the energy-band diagrams of the heterojunction and p-n junction, the principles of the modification of SWNTs on monocrystalline silicon solar cells and the reasons for the change of electrical parameters were analyzed theoretically. Through experiments and theoretical analyses, the modification of SWNTs on solar cells is a potential and effective way to improve the performance of solar cells.