383 research outputs found

    Long-term impact of biochar on the immobilisation of nickel (II) and zinc (II) and the revegetation of a contaminated site.

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    A field remediation treatment was carried out to examine the long-term effect of biochar on the immobilisation of metals and the revegetation of a contaminated site in Castleford, UK. The extracted concentrations of nickel (Ni) (II) and zinc (Zn) (II) in the carbonic acid leaching tests were reduced by 83-98% over three years. The extracted Ni (II) and Zn (II) concentrations three years after the treatment were comparable to a cement-based treatment study carried out in a parallel manner on the same site. The sequential extraction results indicated that biochar addition (0.5-2%) increased the residue fractions of Ni (II) (from 51% to 61-66%) and Zn (II) (from 7% to 27-35%) in the soils through competitive sorption, which may have resulted in the reduction of leachabilities of Ni (II) (from 0.35% to 0.12-0.15%) and Zn (II) (from 0.12% to 0.01%) in the plots with biochar compared with that without biochar three years after the treatment. The germination of grass in the plots on site failed. Further laboratory pot study suggested that larger amounts of biochar (5% or more) and compost (5% or more) were needed for the success of revegetation on this site. This study suggests the effectiveness and potential of biochar application in immobilising heavy metals in contaminated site in the long term.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.scitotenv.2015.10.05

    Protocatechuic acid: A novel detoxication agent of fumonisin B1 for poultry industry

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    Fumonisin B1 (FB1) is a major fusarium mycotoxin that largely contaminates feedstuffs and foods, posing a health risk to both animals and humans. This mycotoxin can enter the human body directly through contaminated food consumption or indirectly by toxins and their metabolites. In a prior study, feed-borne FB1 is one of the leading mycotoxins in breeder eggs, leading to reduced hatchability and gizzard ulceration in chicken progenies. Currently, no effective way is available to remove FB1 from feeds and human-contaminated foods. We hypothesize that FB1 can be reduced to low risk by protocatechuic acid (PCA). To assess the ability of FB1 to be degraded in vivo, 1 ppm of FB1 was treated with PCA, or D-glucose, or silymarin, or anti-FB1 monoclonal antibody. Our study revealed that both D-glucose and PCA exhibited 53.4 and 71.43% degradation, respectively, at 80°C for 2 h, while 35.15% of FB1 detoxification was determined in the silymarin group at 60°C for 0.5 h. A dose-dependent manner was found after treatment with D-glucose or PCA at 80°C for 2 h. As for detoxification of anti-FB1 monoclonal antibody, the 1:3,000 dilution induced significant FB1 detoxification, accounting for 25.9% degradation at 25°C for 2 h. Furthermore, 50 SPF 11-day-old embryonated eggs were divided into 10 groups, with five eggs per group. Post treatment with PCA or D-glucose, or silymarin or anti-FB1 monoclonal antibody, the treated samples were inoculated into albumens and monitored daily until the hatching day. Consequently, 100% of the chickens survived in the D-glucose group and other control groups, except for the FB1 control group, while 80, 80, and 60% hatching rates were found in the PCA-treated group, the anti-FB1 monoclonal antibody-treated group, and the silymarin-treated group. Additionally, both the FB1 group and the silymarin-treated group yielded lower embryo growth than other groups did. Postmortem, lower gizzard ulceration index was determined in the PCA-treated group and the anti-FB1 monoclonal antibody-treated group compared to those of the silymarin-treated group and D-glucose-treated group. Based on the above evidence, PCA is a promising detoxification to reduce FB1 contamination in the poultry industry, contributing to the eradication of mycotoxin residuals in the food chain and maintaining food security for human beings

    Coupling Between Magnetic and Transport Properties in Magnetic Layered Material Mn2-xZnxSb

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    We synthesized single crystals for Mn2-xZnxSb and studied their magnetic and electronic transport properties. This material system displays rich magnetic phase tunable with temperature and Zn composition. In addition, two groups of distinct magnetic and electronic properties, separated by a critical Zn composition of x = 0.6, are discovered. The Zn-less samples are metallic and characterized by a resistivity jump at the magnetic ordering temperature, while the Zn-rich samples lose metallicity and show a metal-to-insulator transition-like feature tunable by magnetic field. Our findings establish Mn2-xZnxSb as a promising material platform that offers opportunities to study how the coupling of spin, charge, and lattice degrees of freedom governs interesting transport properties in 2D magnets, which is currently a topic of broad interest.Comment: 23 pages, 5 figures, Figures are at the end of the manuscrip

    Immobilizing lead and copper in aqueous solution using microbial- and enzyme-induced carbonate precipitation

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    Inappropriate irrigation could trigger migration of heavy metals into surrounding environments, causing their accumulation and a serious threat to human central nervous system. Traditional site remediation technologies are criticized because they are time-consuming and featured with high risk of secondary pollution. In the past few years, the microbial-induced carbonate precipitation (MICP) is considered as an alternative to traditional technologies due to its easy maneuverability. The enzyme-induced carbonate precipitate (EICP) has attracted attention because bacterial cultivation is not required prior to catalyzing urea hydrolysis. This study compared the performance of lead (Pb) and copper (Cu) remediation using MICP and EICP respectively. The effect of the degree of urea hydrolysis, mass and species of carbonate precipitation, and chemical and thermodynamic properties of carbonates on the remediation efficiency was investigated. Results indicated that ammonium ion (NH4+) concentration reduced with the increase in lead ion (Pb2+) or copper ion (Cu2+) concentration, and for a given Pb2+ or Cu2+ concentration, it was much higher under MICP than EICP. Further, the remediation efficiency against Cu2+ is approximately zero, which is way below that against Pb2+ (approximately 100%). The Cu2+ toxicity denatured and even inactivated the urease, reducing the degree of urea hydrolysis and the remediation efficiency. Moreover, the reduction in the remediation efficiency against Pb2+ and Cu2+ appeared to be due to the precipitations of cotunnite and atacamite respectively. Their chemical and thermodynamic properties were not as good as calcite, cerussite, phosgenite, and malachite. The findings shed light on the underlying mechanism affecting the remediation efficiency against Pb2+ and Cu2+

    Tools for efficient epistasis detection in genome-wide association study

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    <p>Abstract</p> <p>Background</p> <p>Genome-wide association study (GWAS) aims to find genetic factors underlying complex phenotypic traits, for which epistasis or gene-gene interaction detection is often preferred over single-locus approach. However, the computational burden has been a major hurdle to apply epistasis test in the genome-wide scale due to a large number of single nucleotide polymorphism (SNP) pairs to be tested.</p> <p>Results</p> <p>We have developed a set of three efficient programs, FastANOVA, COE and TEAM, that support epistasis test in a variety of problem settings in GWAS. These programs utilize permutation test to properly control error rate such as family-wise error rate (FWER) and false discovery rate (FDR). They guarantee to find the optimal solutions, and significantly speed up the process of epistasis detection in GWAS.</p> <p>Conclusions</p> <p>A web server with user interface and source codes are available at the website <url>http://www.csbio.unc.edu/epistasis/</url>. The source codes are also available at SourceForge <url>http://sourceforge.net/projects/epistasis/</url>.</p

    Mitochondrial Uncoupling Inhibits p53 Mitochondrial Translocation in TPA-Challenged Skin Epidermal JB6 Cells

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    The tumor suppressor p53 is known to be able to trigger apoptosis in response to DNA damage, oncogene activation, and certain chemotherapeutic drugs. In addition to its transcriptional activation, a fraction of p53 translocates to mitochondria at the very early stage of apoptosis, which eventually contributes to the loss of mitochondrial membrane potential, generation of reactive oxygen species (ROS), cytochrome c release, and caspase activation. However, the mitochondrial events that affect p53 translocation are still unclear. Since mitochondrial uncoupling has been suggested to contribute to cancer development, herein, we studied whether p53 mitochondrial translocation and subsequent apoptosis were affected by mitochondrial uncoupling using chemical protonophores, and further verified the results using a siRNA approach in murine skin epidermal JB6 cells. Our results showed that mitochondrial uncoupling blocked p53 mitochondrial translocation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA), a known tumor promoter to induce p53-mediated apoptosis in skin carcinogenesis. This blocking effect, in turn, led to preservation of mitochondrial functions, and eventually suppression of caspase activity and apoptosis. Moreover, uncoupling protein 2 (UCP2), a potential suppressor of ROS in mitochondria, is important for TPA-induced cell transformation in JB6 cells. UCP2 knock down cells showed enhanced p53 mitochondrial translocation, and were less prone to form colonies in soft agar after TPA treatment. Altogether, our data suggest that mitochondrial uncoupling may serve as an important regulator of p53 mitochondrial translocation and p53-mediated apoptosis during early tumor promotion. Therefore, targeting mitochondrial uncoupling may be considered as a novel treatment strategy for cancer

    Thienoisoindigo-Based Semiconductor Nanowires Assembled with 2-Bromobenzaldehyde via Both Halogen and Chalcogen Bonding

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    We fabricated nanowires of a conjugated oligomer and applied them to organic field-effect transistors (OFETs). The supramolecular assemblies of a thienoisoindigo-based small molecular organic semiconductor (TIIG-Bz) were prepared by co-precipitation with 2-bromobenzaldehyde (2-BBA) via a combination of halogen bonding (XB) between the bromide in 2-BBA and electron-donor groups in TIIG-Bz, and chalcogen bonding (CB) between the aldehyde in 2-BBA and sulfur in TIIG-Bz. It was found that 2-BBA could be incorporated into the conjugated planes of TIIG-Bz via XB and CB pairs, thereby increasing the pi - pi stacking area between the conjugated planes. As a result, the driving force for one-dimensional growth of the supramolecular assemblies via pi - pi stacking was significantly enhanced. TIIG-Bz/2-BBA nanowires were used to fabricate OFETs, showing significantly enhanced charge transfer mobility compared to OFETs based on pure TIIG-Bz thin films and nanowires, which demonstrates the benefit of nanowire fabrication using 2-BB

    The 2023 wearable photoplethysmography roadmap

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    Photoplethysmography is a key sensing technology which is used in wearable devices such as smartwatches and fitness trackers. Currently, photoplethysmography sensors are used to monitor physiological parameters including heart rate and heart rhythm, and to track activities like sleep and exercise. Yet, wearable photoplethysmography has potential to provide much more information on health and wellbeing, which could inform clinical decision making. This Roadmap outlines directions for research and development to realise the full potential of wearable photoplethysmography. Experts discuss key topics within the areas of sensor design, signal processing, clinical applications, and research directions. Their perspectives provide valuable guidance to researchers developing wearable photoplethysmography technology
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